DECEMBER 2015 | ISSUE 28
Vitamin D and Melatonin in Multiple Sclerosis E f f e ct s o f Se a s o n a l C h a n g e s
Hacking the Brain Ge n e T h e ra p y a s a T o o l to C o m b at E p i l e p s y
Shining Light on Biomedicine: I n t e rv i e w w i t h D r.Q i y i n F a n g, Ca n a d a Re s e a r c h C h a i r i n B i o p h o to n i c s
WWW.MEDUCATOR.ORG
Table of
Contents 02 INTRODUCTION
MEDUCATOR - ISSUE 28
03 MEDPULSE 05 MEDBULLETINS 07 PATHOPROFILE Global Perspective 09 The Implications of
table of contents
Malarial Overprescription
12 NEUROABSTRACTS Opinion 13 Autism Spectrum Disorder: It it Really on the Rise? 15 Is the Doctor in?
17 BEYOND THE HEADLINES AND INTO THE HEALTH OF SYRIAN REFUGEES Critical Review 19 Vitamin D and Melatonin in Multiple Sclerosis
Research Proposal 23 Hacking the Brain: Gene Therapy as a Tool Combat Epilepsy DR. QIYIN FANG
30 CONTRIBUTORS
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D E C E M B E R 2015
27 SHINING LIGHT ON BIOMEDICINE:
Cover Artist
MICHAEL SUN
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Welcome to Issue 28! Over the past thirteen years, the Meducator has strived to capture health sciences research in a series of pieces crafted by undergraduate students from across Ontario. The pieces we received have always been diverse in topic and perspective, reflecting the breadth and depth of the field. Health sciences research encompasses a continuous spectrum from basic science to knowledge translation. Evidence collected via systematic observations are translated into outcomes usable by society in the form of policies, therapies, and diagnostic tools. Within this issue, we aim to highlight recent advances in primary research and their applications. This past decade, we have made considerable gains in understanding the pathology of complex neurological diseases towards the development of possible treatments. We begin our journey with a new article type, the Research Review, which describes an evidence-based study design. In this issue, Maxwell Ng, Krish Bilimoria, Karanbir Brar, and Nikesh Pandey outline a series of experiments testing the use of a gene editing tool in treating epilepsy. Our editors, Ishan Aditya and Arshia Javidan, in collaboration with graphics artist Caberry Yu, walk you through the process of neoneurogenesis from stem cells to neurons and discuss its relevance to our understanding of cancer progression. Takhliq Amir and Feroze Noordin synthesize benchwork and clinical evidence to investigate the effects of vitamin D and melatonin on multiple sclerosis and their therapeutic potential. In her Opinion column, Fizza Manzoor examines the literature to present polarized explanations for the upwards trend in autism diagnosis. In our latest Forumspace, Emily Fong, Alexandra Kilian, Sara Halawa, and Annie Zhu explore policies and programs necessary to support the health of Syrian refugees in Canada and abroad. From a more evaluative standpoint, David Bobrowski approaches the challenge of identifying policy needs arising from failures in the Canadian health system in his piece, “Is the Doctor in?�. Bringing a more personal viewpoint, Jasneet Kaur questions the performance and implementation of rapid diagnostic tools for malaria based on her experiences in Ghana in her Global Perspective piece.
introduction
INTRODUCTION ISSUE 28
dear reader,
We wrap up Issue 28 with an Interview Spotlight featuring Dr. Qiyin Fang, an associate professor in the Department of Engineering Physics and Canada Research Chair in biophotonics. He describes his work with optics in the lab and shares his thoughts on how his research can influence medicine in the future.
med u c a t o r
At this point, we would like to thank our authors and incredibly talented staff for bringing our 28th issue to life. None of this would have been possible without their hard work and dedication. A special thank you is much overdue to our two Managing Editors, Avrilynn Ding and Arlinda Deng, our Creative Director, Eliya Zhao, and Managing Video Editor, Sebastian Swic for their unwavering leadership and tireless efforts. Last but not least, we would also like to thank you, the reader, for your continuous support and interest in our publication. We hope that as you browse through the pages, you will find something that piqued your curiosity, inspired you, or drove you to lengths to find your own answer. Never stop questioning. Never stop searching. Until then!
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Maylynn ding
D E C E M B E R 2015
dave nidumolu
Bachelor of Health Sciences (Hons.) Class of 2017
Bachelor of Health Sciences (Hons.) Class of 2017
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3. INDIGENOUS HEALTH CONCERNS
1. UNIVERSAL HEALTH CARE IN SOUTH AFRICA?
In light of the high rates of lung and cervical cancer amongst indigenous peoples in Canada, United States, Australia, and New Zealand, the World Health Organization has acknowledged the need for improvements in the current cancer screening and prevention program for Indigenous peoples. Across developed countries, the Indigenous population has a history of relatively poor health outcomes and shorter life expectancies.
After years of debate, South Africa could soon be implementing an overhaul of its current healthcare system, bringing universal coverage to all. This proposed scheme, 70 years in the making, would bring free primary healthcare to its citizens, 84% of whom do not have health insurance. If implemented, this plan would cost $18.3 billion over the course of 14 years.
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TAKING THE PULSE AROUND THE WORLD
MEDPULSE 2. SUNSCREEN THREATS New research attributes the degradation of coral reefs to oxybenzone, a primary component of most sunscreens. This disruption of the ecosystem has downstream effects on the human diet, posing a potential health hazard.
4. POTENTIAL EBOLA CURE
Development of the compound, GS-573, can result in the production of the first licensed drug against the Ebola virus. In a treatment administered to monkeys 3 days after being infected with the virus, a 100% survival rate was recorded. The 2014 Ebola outbreak, still ongoing in parts of West Africa, has resulted in 28,502 reported cases and 11,312 deaths.
5. HIV VACCINE ON THE HORIZON?
A potential HIV vaccine is soon entering clinical trials, projected to take one year for completion. This vaccine is unique in its ability to target the virus at the point of infection, thus allowing it to neutralize multiple strains of the virus. Previous candidate vaccines have only been effective against specific strains.
7. EL NIÑO PREDICTIONS PROMPT PREPARATION
10. VACCINE-DERIVED POLIOVIRUS
An 8-year-old boy was paralyzed and later died from oral vaccine-derived poliovirus. This type of infection occurs in areas with low vaccination coverage and poor sanitation, which allows for mutation of the polio viral genome. Subsequent infection by the mutated virus can lead to paralysis. Along with the reappearance of polio in Ukraine and Mali, this case has sparked public health concerns.
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6. NOBEL PRIZE IN MEDICINE
8. INDIA’S FROTHY TOXIC FOAM
The 2015 Nobel Prize in Physiology or Medicine was awarded to three recipients for their research involving parasitic diseases. The accolade was given to William Campbell and Satoshi Omura for their discovery of a novel therapy to combat roundworm inflections, and Tu Youyou for her discovery of a novel treatment for malaria.
The streets of Bangalore have been flooded with flammable, foam clouds that have formed as a result of sewage and chemical waste pollution in the nearby Bellandur Lake. The waste builds up under the surface of the water, and toxic clouds are formed when the lake is disrupted by rainfall. Awareness efforts have been implemented to save the integrity of the lake.
Citations can be found on www.meducator.org | events occured during Fall 2015
The Climate Prediction Centre and International Research Institute for Climate and Society have published data predicting the occurrence of an unusually strong El Niño this year. El Niño is associated with a warm band of oscillating ocean water, causing short-term weather changes including heavier rainfall in Africa. This has been linked to an increase in the incidence of Rift Valley fever, prompting a need for urgent public education and safety measures.
9. CHINA’S SMOKING “EPIDEMIC” A study conducted by researchers at Oxford University has warned that a third of Chinese men currently under the age of 20 may die prematurely from the effects of smoking. In 2010, around one million people in China died because of tobacco usage. If current trends persist, it is said that the mortality rate will double by 2030.
MEDBULLETIN analysis
Diabetes
MA XW ELL TRAN
NICOLE FALZONE
How do researchers find out what types of cells are present in a sample and which markers they express? Flow cytometry has long been the standard for single-cell analysis. 1 Fluorochromes, or fluorescent tags, are conjugated to antibodies that are specific for cell surface and intracellular antigens. 2 Single cells are interrogated by lasers in the flow cytometer, causing light scattering and fluorescence. Forward and side angle light scattering provide information on the relative size and granularity of cells, respectively, while fluorescence provides information on cell markers. However, a limitation of flow cytometry is the number of simultaneous cell measurements that can be performed, typically 6-10. Each fluorochrome has an emission spectrum that corresponds to a certain colour. The overlap between spectra means that a fluorochrome may emit fluorescent light detected as two different colours, potentially leading to false-positive results. 2
New research surrounding the use of encapsulation devices in pancreatic progenitor cell transplantation could reduce the need for exogenous insulin injections in Type 1 diabetes. The Juvenile Diabetes Research Foundation, in partnership with ViaCyte, Inc., has launched a phase 1/2 clinical trial involving the VC-01 Combination Product. 1 In this study, investigators are evaluating the device’s safety, tolerability, and efficacy in normalizing blood glucose levels in humans. 1
Mass cytometry is a new technology capable of overcoming the spectral overlap issue observed in flow cytometry. Instead of using fluorescent tags, antibodies are conjugated with heavy metal isotopes. 1 When single-cell suspensions pass through the mass cytometer, cells are vapourized, atomized, and ionized. Ionic clouds are measured one segment at a time using a technique known as time-of-flight mass spectrometry. The idea is that lighter ions will travel faster and reach the detector first. A mass spectrum for each cell-derived ionic cloud is generated. In this way, the metal tags in each cloud, and thus, the antigens of interest in each cell can be identified. Since there is no overlap between mass detection channels, up to 37 simultaneous cell measurements are possible. 1 Mass cytometry is an exciting advancement in single-cell analysis that has applications such as discovering biomarkers, elucidating intracellular signaling networks, and testing the efficacy and safety of therapeutic drugs. 3
MAcroencapsulated islet transportation
The VC-01 Combination Product uses the Encaptra drug delivery system, an encapsulation device, to protect enclosed PEC-01 (pancreatic endoderm) cells from immune cell attack. 2 A semipermeable membrane surrounds the cells, allowing input of oxygen and other nutrients and output of therapeutic products including glucose-regulating hormones. 3 Host immune cells and immunoglobulins, however, will not be able to reach the pancreatic cells housed within the device. 3 Pre-clinical studies demonstrated the ability of VC-01 implants to consistently regulate blood glucose levels in mice. 4 After being implanted with the device containing human PEC-01 cells, mice were shown to have lower blood glucose levels that were more similar to levels observed in humans. 4 Additionally, following administration of a drug that selectively destroys mice beta cells, the mature pancreatic islet cells within the device were able to maintain blood glucose levels in a normal range. 4 There are other encapsulation products currently undergoing clinical and preclinical study, including the Beta-O2 macroencapsulation device and a microencapsulation device in development at Massachusetts Institute of Technology. 5 Research into these devices is significant as it can reduce co-morbidities associated with Type 1 insulin dependent diabetes and improve quality of life for those living with the disease.
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Mass cytometry: An innovation in single-cell analysis
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1. 2. 3. 4.
Bendall SC, Nolan GP, Roederer M, Chattopadhyay PK. A deep profiler’s guide to cytometry. Trends Immunol 2012;33(7):323–32. Jaroszeski M, Radcliff G. Fundamentals of flow cytometry. Mol Biotechnol 1999;11(1):37–53. Atkuri KR, Stevens JC, Neubert H. Mass Cytometry: A highly multiplexed single cell technology for advancing drug development. Drug Metab Dispos 2014;1–33. Single Cell Advances Image [Image on the internet]. 2015 [cited 2015 October 21]. Available from:https://www.fluidigm.com/images/SingleCellMainArticle.jpg
1.
ClinicalTrials.gov [Internet]. Bethesda (MD): National Library of Medicine (US). 2000 Feb 29- Identifier: NCT02239354, ViaCyte. A Safety, Tolerability, and Efficacy Study of VC-01TM Combination Product in Subjects With Type 1 Diabetes Mellitus. 2015 Aug 24-[cited 2015 Oct 19]. Available from: https://clinicaltrials.gov/ct2/show/NCT02239354?term=VC-01&rank=1
2.
Schulz TC. Concise Review: Manufacturing of Pancreatic Endoderm Cells for Clinical Trials in Type 1 Diabetes. Stem Cells Translational Medicine [Internet]. 2015 Jun 10; Available from: http://stemcellstm.alphamedpress.org/content/early/2015/06/09/ sctm.2015-0058.abstract
3.
Cogger K, Nostro MC. Recent Advances in Cell Replacement Therapies for the Treatment of Type 1 Diabetes. Endocrinology. 2014 Nov 11;156(1):8–15.
4.
Schulz TC, Young HY, Agulnick AD, Babin MJ, Baetge EE, Bang AG, et al. A Scalable System for Production of Functional Pancreatic Progenitors from Human Embryonic Stem Cells. PLoS ONE. 2012 May 18;7(5):e37004.
5.
Dolgin E. Encapsulate this. Nat Med. 2014 Jan;20(1):9–11.
6.
Human stem cell derived beta cells [Image from the internet]. 2014 December 9 [cited 2015 October 21]. Available from: http://harvardmagazine.com/2014/10/melton-creates-beta-cells
Stem Cells
Spinal cord injury treatment with stem cells
superbugs
Killing the “superbug” via Fecal transplantation SAB RINA LIN
Spinal cord injury is the second leading cause of paralysis in the United States. 1 Once damaged, the nerves in the spinal cord are unable to repair effectively due to glial scar formation. Several methods have been explored to treat spinal cord injury, 2, 3 and researchers at Tufts University have recently engineered another one. 1
A recent study done by researchers at the Memorial SloanKettering Cancer Center has found that two of the most common intestinal “superbugs” prevalent in hospitals, vancomycinresistant Enterococcus faecium (VRE) and carbapenemresistant Klebsiella pneumoniae (CR-KP), could be eliminated by a fecal transplantation of a healthy gut microbiome. 1 These “superbugs”, named after their antibiotic-resistant properties, have become an increasing problem in healthcare settings due to their ability to spread between patients and cause bloodstream and other systemic infections. 2
In a novel study, biomedical engineers at Tufts have demonstrated that human mesenchymal stem cells (hMSCs), cells derived from bone marrow, can selectively differentiate into neuronlike cells with the treatment of exosomes. 1 Exosomes are small vesicles that act as a means of cellular communication. They are exocytosed from a diverse array of cell types, and contain genetic material and functional proteins. 4 In a report published in PLOS ONE in August 2015, researchers demonstrated how exosomes derived from PC12 cells, neuron-like progenitor cells in rats, could induce the differentiation of hMSCs into neuron-like cells. During the study, PC12 cells were placed in a growth medium. 1 Two days after, exosomes were isolated from these cells using differential centrifugation. Furthermore, hMSCs were isolated from fresh bone marrow aspirate and placed in culture medium. The hMSCs were then exposed to the exosomes over seven days. Through immunofluorescence microscopy, any morphological changes to the hMSCs were observed. It was noted that hMSCs treated with exosomes displayed growth of neurite-like extensions, while hMSCs untreated with exosomes did not display a change in morphology. Exosome inducible human stem cell differentiation had not been examined prior to these experiments. 1
1.
Takeda Y, Xu Q. Neuronal Differentiation of Human Mesenchymal Stem Cells Using Exosomes Derived from Differentiating Neuronal Cells. PLOS ONE. 2015;10(8):e0135111
2.
Straley, K., Foo C., Heilson S. Biomaterial Design Strategies for the Treatment of Spinal Cord Injuries. Journal of Neurotrauma. 2010 26 Jan;27(1):1-19
3.
Tabesh H, Amoabediny G, Nik NS, Heydari M, Yosefifard M, Siadat SO. The role of biodegradable engineered scaffolds seeded with Schwann cells for spinal cord regeneration. Neurochem International. 2009 Feb;54(2):73-83
4.
Janas, T., Janas, M., Sapoń, K., Janas, T. Mechanisms of RNA loading into exosomes. FEBS Letters. 2015 Jun 4;589(13)1391-1398
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Human Mesenchymal Stem Cells [Image on the internet]. 2015 [cited 2015 October 21]. Available from: http://www. clemson.edu/cafls/lif/gallery/images/Composite.jpg
The team found that after mice with VRE and CR-KP were colonized and treated with either fecal microbiota transplants (FMT) or a sterile control solution for three days, there was a marked difference in bacterial populations. While the mice treated with a sterile control solution saw similar or even elevated levels of both VRE and CR-KP, the FMT-treated mice saw a significant drop in bacterial density. These findings indicate a substantial difference in the mechanisms of microbiotamediated colonization resistance in VRE and CR-KP. 3 Developments in the understanding of intestinal pathogens like VRE and CR-KP are critical as they are the first steps in addressing the growing issue of antibiotic resistance in the world of health care today.
1.
Caballero S, Carter R, Ke X, Sušac B, Leiner I, Kim G, Miller L, Ling L, Manova K, Pamer E. Distinct but spatially overlapping intestinal niches for vancomycin-resistant enterococcus faecium and carbapenem-resistant klebsiella pneumoniae. PLOS Pathogens. [Online] 2015; 9. Available from: doi: 10.1371/journal.ppat.1005132. [Accessed 18th September 2015].
2.
Magill SS, Edwards JR, Bamberg W, Beldavs ZG, Dumyati G, Kainer MA. Multistate point-prevalence survey of health care-associated infections. N Engl J Med 2014, Mar 27;370(13):1198–208. doi: 10.1056/NEJMoa1306801. [Accessed 18th September 2015].
3.
van der Waaij D, Berghuis-de Vries JM, Lekkerkerk Lekkerkerk-v. Colonization resistance of the digestive tract in conventional and antibiotic-treated mice. J Hyg (Lond) 1971, Sep;69(3):405–11. doi: 10.1017/s0022172400021653. [Accessed 18th September 2015].
4.
Enterococcus Faeceum [Image on the internet]. 2015 April 22 [cited 2015 October 21]. Available from: http://superbloodbanker.tumblr.com/post/48655969120/enterococcus-faecium-is-an-important
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The researchers propose that these exosomes induced the differentiation of hMSCs by delivering miRNA, short strands of RNA that regulate cell activity, into the stem cells. 1 Ultimately, these findings have grand implications for stem cell research, and in a broader scope, injury therapy.
In the study, Dr. Eric Pamer and colleagues used a mouse model of intestinal colonization to investigate the interactions between the two pathogens, which account for around 10% of serious hospital-acquired infections in the US. 2 More specifically, tests were done to investigate whether intestinal domination by VRE or CR-KP would offer resistance against colonization by the other pathogen.
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AR S HIA J AVID AN
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PATHOPROFILE
AUTHORS ISHAN ADITYA ARSHIA JAVIDAN ARTIST CABERRY WEIYANG YU
NEO-NEUROGENESIS
INTRODUCTION
table of contents
Cancer is a disease characterized by the abnormal proliferation of cells in different parts of the body.1 Cells grow uncontrollably and form malignant masses of tissues known as tumours. Cancerous tumours are malignant, meaning that they can spread into nearby tissues. In the process of metastasis, some cancer cells may break off from the original tumour and travel through the bloodstream or the lymphatic system to form new tumours.1 These metastatic tumours develop their own vasculature via neo-angiogenesis and tumour innervation leads to heightened sensitivity and pain.
NEO-NEUROGENESIS
PERINEURAL INVASION
Neo-neurogenesis is a process resulting in tumour innervation due to factors sectreted by tumour cells that initiate stem cell differentiation into neurons.1 During neoneurogenesis, cancer cells release signaling molecules known as chemotropic cues that act on nearby neurons to direct their growth towards the tumour.
Through a process known as perineural invasion, cancer cells infiltrate neurons and migrate to distant sites.1 There is a reciprocal interaction between cancer cells and neurons, wherein cancer cells secrete signals that cause neuronal growth and neurons secrete signals that can enhance cancer cell proliferation.
General Anatomy & PhYSIOLOGY of the axon F-Actin Bundle Dynamic Microtubule Stable Microtubule
F-Actin Network
Axonal growth is necessary to form neuronal connections in order to facilitate communication in the human body.2 During axonal growth, the neuron extends its axon to reach a specific destination. Axon growth occurs through the growth cone, located at the tip of the axon, via growth cone advancement.3 Formed from actin bundles, filopodia are located at the axon terminus and are finger-like projections that detect the surrounding environment.
Microtubules comprise the main part of the axon and are mostly found as stable bundles at the core.3 Dynamic microtubules project into peripheries and their function is to detect the surrounding environment via the filopodia.
Axon Shaft
Filopodium
1. Mancino M, Ametller E, Gascón P, Almendro V. The neuronal influence on tumor progression. Biochimica et Biophysica Acta (BBA) - Reviews on Cancer. 2011;1816(2):105-118 2. Lowery LA, Van Vactor D. The trip of the tip: understanding the growth cone machinery. Nat Rev Mol Cell Biol. 2009 May;10(5):332–43. 3. Medeiros NA, Burnette DT, Forscher P. Myosin II functions in actin-bundle turnover in neuronal growth cones. Nat Cell Biol. 2006 Mar;8(3):215–26. 4. Schaefer AW, Kabir N, Forscher P. Filopodia and actin arcs guide the assembly and transport of two populations of microtubules with unique dynamic
Growth cone advancement involves a balance between actin polymerization for protrusion and retrograde flow for retraction. Polymerization involves linking actin monomers to form actin polymers. 4 Actin Retrograde flow is the movement of actin back to the core of the growth cone, mediated by actin-myosin contractions.5 Both protrusion and retraction are important for growth cone movement. parameters in neuronal growth cones. J Cell Biol. 2002 Jul 8;158(1):139–52. 5. Kalil K, Li L, Hutchins BI. Signaling mechanisms in cortical axon growth, guidance, and branching. Front Neuroanat. 2011;5:62. 6. Barberis D, Casazza A, Sordella R, Corso S, Artigiani S, Settleman J, et al. p190 Rho-GTPase activating protein associates with plexins and it is required for semaphorin signalling. J Cell Sci. 2005 Oct 15;118(Pt 20):4689–700. 7. Gallo G. RhoA-kinase coordinates F-actin organization and myosin II activity during semaphorin-3A-induced axon retraction. J Cell Sci. 2006 Aug 15;119(Pt 16):3413–23.
8. Neufeld G, Kessler O. The semaphorins: versatile regulators of tumour progression and tumour angiogenesis. Nat Rev Cancer. 2008 Aug;8(8):632–45. 9. McGough A. Cofilin Changes the Twist of F-Actin: Implications for Actin Filament Dynamics and Cellular Function. The Journal of Cell Biology. 1997;138(4):771-781. 10. Lebrand C, Dent EW, Strasser GA, Lanier LM, Krause M, Svitkina TM, et al. Critical role of Ena/VASP proteins for filopodia formation in neurons and in function downstream of netrin-1. Neuron. 2004 Apr 8;42(1):37–49. 11. Gomez T, Robles E. The Great Escape. Neuron. 2004;42(1):1-3.
Cancer-mediated Axonal Growth: Overview Tumours direct growth cone navigation by secreting chemotropic cues, which may act as attractive or repulsive signals.4 These molecules, including semaphorins and netrins, play a role in axon guidance by regulating actin dynamics. This occurs through signaling involving the Rho family of GTPases. The Rho GTPases are G-proteins that control cytoskeletal rearrangements to promote either protrusion or retraction.
ALTERNATE PATHWAY OF AXON GROWTH: RETRACTION VIA SEMAPHORINS 1. There are a variety of semaphorins. Class 3 semaphorins (Sema3A) are found in vertebrates and bind to neuropilin 1 (NP1), activating a receptor called plexA1. NP1 is part of a preformed complex with PlexA1.6 2. In absence of semaphorin, the sema domain of plexA1, which is semaphorin-specific, auto-inhibits activation of the plexA1 receptor via phosphorylation. 3. Binding of semaphorin to NP1 induces a NEURONAL MEMBRANE
Sema3A binds to NP1
conformational change in the plexin that removes this auto-inhibition, resulting in the activation of plexA1.7 4. This binding activates p190 Rho-GTPase activating protein (p190RhoGAP), which then inactivates Ras homolog gene family member A (RhoA), a Rho GTPase, via hydrolysis of GTP to GDP. 5. Normally, RhoA activates Rho-associated protein kinase (ROCK) via phosphorylation,
which in turn activates LIM domain kinase 1 (LIMK1).8 However, since RhoA has been inactivated by p190RhoGAP, ROCK and LIMK1 are also left inactivated. 6. LIMK1 is responsible for inhibiting the actin-degrading enzyme cofilin via phosphorylation.9 In the absence of active LIMK1, cofilin is activated.
CYTOPLASM
p190RhoGAP is activated
PlexA1 is activated
RhoA is inactivated
ROCK is not activated
LIMK1 is not activated
ROCK
Cofilin is not inhibited
LIMK1
Cofilin
Actin Disassembly
RETRACTION
PlexA1 p190RhoGAP
NP1
RhoA
Sema3A
Depending on which receptors they activate, netrins promote either protrusion or retraction. Netrins interact with the deleted in colorectal cancer (DCC) receptor to cause chemoattraction, and they interact with UNC-5 receptors to cause chemorepulsion.10 NEURONAL MEMBRANE
1. Netrin binds to DCC
Protrusion: Activation of DCC Receptor 1. Binding of netrins to the DCC receptor elevates cAMP levels, thus activating protein kinase A (PKA) via phosphorylation. In turn, PKA activates triple domain binding protein (Trio).11 2. Trio then activates the Rho GTPase Rac1. 3. Rac1 targets downstream effectors involved in cytoskeletal remodeling, which include ENA/VASP proteins, which promote protrusion.12 4. However, PKA itself can also activate ENA/VASP without going through the Rho GTPase pathway.
Retraction: Activation of UNC-5 Receptor 1. Binding of netrins to the UNC receptor elevates cGMP levels.13 2. This activates protein kinase G (PKA), which inactivates ENA/VASP proteins via phosphorylation. 3. This promotes capping which involves the cessation of actin polymerization, resulting in retraction.14
introduction
PATHWAY OF AXON GROWTH: NETRINS
CYTOPLASM
2. DCC is activated
3. cAMP levels increase
4. PKA is activated
5. Trio is activated
6. Rac1 is activated
7. ENA/VASP is activated
DCC
cAMP
PKA
Trio
Rac1
ENA/VASP
UNC-5
cGMP
PKG
Promotes Polymerization
PROTRUSION
Netrin
3. cGMP levels increase
4. PKG is activated
RETRACTION
5. ENA/VASP is inactivated
CONCLUSION
ing domain of Ena/VASP in actin assembly. Journal of Structural Biology. 2006;155(2):195-201. 15. Goldman J, Ashour M, Magdesian M, Tritsch N, Harris S, Christofi N. Netrin-1 Promotes Excitatory Synaptogenesis between Cortical Neurons by Initiating Synapse Assembly. Journal of Neuroscience. 2013;33(44):1727817289. 16. Stavoe A, Colon-Ramos D. Netrin instructs synaptic vesicle clustering through Rac GTPase, MIG-10, and the actin cytoskeleton. The Journal of Cell
A p r i l 2015
Understanding the dynamics of neo-neurogenesis brings us one step closer to gaining a holistic understanding of cancer physiology,. This enables us to develop treatments to mitigate the devastating effects of this condition.
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How Does Cancer Promote Synaptogenesis and Neurotransmission? Netrins increase the probability of axon and dendrite contact by increasing filopodia and promoting filopodial elongation.15 They cause recruitment of synaptic proteins synapsin and synaptophysin.16 Synapsin allows synaptic vesicles to be released from nerve terminal during action potentials while synaptophysin recruits and interacts with synaptobrevin, a SNARE protein involved in exocytosis.17 These two proteins ultimately result in increased neurotransmission via the formation of synapses. 12. O’Connor K, Mercurio A. Protein Kinase A Regulates Rac and Is Required for the Growth Factor-stimulated Migration of Carcinoma Cells. The Journal of Biological Chemistry. 2001;276(51):47895–47900. 13. Barzik M, Kotova T, Higgs H, Hazelwood L, Hanein D, Gertler F et al. Ena/ VASP Proteins Enhance Actin Polymerization in the Presence of Barbed End Capping Proteins. Journal of Biological Chemistry. 2005;280(31):2865328662. 14. Chereau D, Dominguez R. Understanding the role of the G-actin-bind-
Promotes Capping
m e d u cato r
1. Netrin binds 2. UNC-5 to UNC-5 is activated
ENA/VASP
Biology. 2012;197(1):75-88. 17. Kwon S, Chapman E. Synaptophysin Regulates the Kinetics of Synaptic Vesicle Endocytosis in Central Neurons. Neuron. 2011;70(5):847-854. 18. Luk T. An Investigation of the Role for Netrin-l and the Netrin Receptor Deleted in Colorectal Cancer in Regulating Dendritic Spine Morphology. M.Sc. Neuroscience. Department of Neurology and Neurosurgery: McGill University; 2007.
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The Implications of Antimalarial Overprescription Jasneet Kaur Dhaliwal Bachelor of Health Sciences (Honour), Class of 2015 McMaster University
meducator
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D e c e m b e r 2013
global perspective
GLOBAL PERSPECTIVE
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ARTIST David Hu
Introduction The issue of antimalarial overprescription has been a decade-long concern in Ghana.1 I was able to observe this phenomenon firsthand during a three month trip to rural Wa while pursuing a Global Health specialization in the Bachelor of Health Sciences Program. There, I volunteered with True Vision Ghana, a non-governmental organization working with youths affected by HIV/AIDS, in an administrative role in the Adolescent Health Clinic. I was responsible for completing insurance forms and documenting patient visits. After observing numerous patient visits, I soon noticed an overprescription of antimalarials after the use of Rapid Diagnostic Tests (RDTs) to diagnose malaria..
Malaria and Rapid Diagnostic Tests
Despite significant measures taken to reduce this endemic, including insecticide-treated nets and indoor residual sprays, malaria’s prevalence remains as high as ten cases in every 1000 persons in Ghana.1 Patients often visited the Adolescent Health Clinic with symptoms suggestive of malaria, such as nausea, chills, and fever. I noticed that when patients with these symptoms arrived, the nurses used RDTs as the standard diagnostic tool. This test required pricking the patient’s finger and pipetting a small amount of blood onto a glass slide.3 Two lines on a test would indicate a positive result for malaria, whereas a single line indicated a negative result.3 To my surprise, the patient would be prescribed malaria medication regardless of the RDT result. When I questioned this, the nurses attributed the practice to the test being inaccurate.
Despite the high sensitivity of RDTs, healthcare professionals frequently disregard their results. A negative RDT result has a 50% adherence rate in Ghana.4 In a qualitative study pertaining to southern Ghana, one patient said, “Even though the test result shows I had no malaria, because of the way I was feeling, the doctor said they should give me some malaria drugs.”5 One possible reason for this lack of adherence could be the fear of not detecting false negatives. However as only 7% of RDT negative results are false, healthcare adherence should be improved.4 This is feasible as studies have shown that sustained training and supervision, though potentially costly in the short-run, can increase adherence among healthcare professionals.4
Implications of Non-Adherence Lack of adherence to RDT results among healthcare professionals has its long-term ramification. By frequently disregarding RDT results, the funds used to purchase the diagnostic tests are not allocated appropriately. The World Health Organization (WHO) has reported various sources of funding in 2013 for the malaria problem in Ghana, as shown in the figure on the next page.1 In 2013, the President’s Malaria Initiative aimed to “procure approximately 4.75 million RDTs” in Ghana.6 Each RDT ranges from $0.55 to $1.50 USD, which results in a multi-million dollar expenditure (2.6 to 7.1 million USD) on inappropriately used tests.3 Moreover, patients being wrongly diagnosed for malaria must then use outof-pocket funds to buy unneeded antimalarials. From my experience in Wa, I recall the costs for antimalarials ranging from $4.00 to $8.00 USD. While this might not appear to be a high price, take into account that the Gross National Income per capita in Ghana was $1544 USD in 2011 and the price for antimalarials will no longer seem trivial.7 Thus, in addition to the ineffective utilization of third party monetary resources, poor adherence also takes an unnecessary financial toll on misdiagnosed patients.
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After further research however, I found that my assumption was incorrect. RDTs are reported to have a 93% sensitivity and a 90% specificity in malaria diagno-
healthcare personnel adherence
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Due to the nurses’ lack of confidence in the RDT, I used a microscopy test from a nearby lab in addition to an RDT to test myself regularly for malaria. During my experience in Wa, I contracted malaria twice. The second time, my RDT result indicated a false negative whereas my lab result indicated a true positive. I consequently found myself wondering if false negatives were a common occurrence when using RDTs, which would explain the nurses’ practice of invariably prescribing antimalarials.
Sensitivity = True Positives/(True Positives + False Negatives)3
global perspective
Malaria is a life-threatening infectious disease caused by Plasmodium protozoans, which are most commonly transmitted through the saliva of female Anopheles mosquitoes.2 One bite can transmit motile sporozoites of Plasmodium that navigate through the bloodstream to infect hepatocytes in the liver.2 These sporozoites subsequently multiply asexually and are released through the rupturing of their host cells to infect neighbouring erythrocytes.2 Complications from malaria such as respiratory distress and encephalopathy give rise to a morbidity rate of 10%.1
sis, meaning that 93% of diseased individuals will test positive while 90% of non-diseased individuals will test negative4. In fact, RDTs have been found to be more accurate than microscopy tests.4 The problem evidently does not lie within the testing technology. Rather than diagnostic test inaccuracy, the overprescription of antimalarials may be due to the healthcare professionals’ unwillingness to adhere by the test’s highly accurate results
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global perspective
More importantly, there are also health implications of overdiagnosing malaria. If a patient without malaria is misdiagnosed, then the true cause of their symptoms will not be identified. Interestingly, the WHO has presented limited evidence that malaria cases decreased in Ghana despite the implementation of various preventative measures.8 The lack of decrease may be attributed to an overestimation of malaria cases, leaving other diseases undiagnosed. This is especially concerning as malaria has generic symptoms that are congruent to an array of illnesses, including meningitis and pneumonia.9 In addition, given the degree of overprescribed medications, antimalarial drug resistance has become a growing concern among clinicians. For example, one study reported that increased prescription of the antimalarial sulfadoxine pyrimethamine led to more genetic mutations in the targeted strain of malaria which conferred greater resistance to this drug.10 These genetic mutations enabled the strain to be increasingly resistant to the sulphadoxine pyrimethamine treatment.10 This phenomenon has also been reported in other antimalarial drugs, such as artemisinin, indicating that the over usage of antimalarials increases risk of drug resistance in patients.1
Conclusion It is important for policymakers to review the full scope of issues related to malaria, including healthcare workers’ adherence to diagnostic tests. Policymakers should urge the government to enforce stricter adherence to tests with high sensitivities. This would increase costeffectiveness, reduce possible health complications, and slow the process of drug resistance. However, one potential downfall is that strict adherence could potentially cause the few false negative cases to remain untreated. Therefore, it remains important for additional tests, such as microscopy tests, to be used in conjunction with RDTs to ensure malaria cases are accurately diagnosed.
acknowledgements I would like to take this opportunity to thank all coordinators of the Global Health Specialization at McMaster University for allowing me to embed myself in Wa, Ghana. I would like to further extend this gratitude to the executive team of True Vision Ghana for welcoming our team to work with this non-governmental organization for three months. ■
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This Global Perspectives piece has been peer-reviewed by Dr. Lawrence Mbuagbaw, an Assistant Professor in the Department of Clinical Epidemiology & Biostatistics at McMaster. Dr. Mbuagbaw is a member of the Canadian Coalition for Global Health Research, as well as the International Epidemiology Association. His primary research interests include health systems research and using biostatistics and epidemiology to improve international health outcomes. Edited by Matthew yau 1.
World Health Organization. World malaria report: 2014. World Health Organization; 2014. 2. Gordis, L. Epidemiology. 4th ed. Philadelphia: Elsevier Saunders; 2008. 3. Wongsrichanalai C1, Barcus MJ, Muth S, Sutamihardja A, Wernsdorfer WH. A review of malaria diagnostic tools: microscopy and rapid diagnostic test (RDT). Am J Trop Med Hyg. 2007 Dec;77(6 Suppl):119-27. 4. Ansah EK1, Epokor M, Whitty CJ, Yeung S, Hansen KS. Cost-effectiveness analysis of introducing RDTs for malaria diagnosis as compared to microscopy and presumptive diagnosis in central and peripheral public health facilities in Ghana. Am J Trop Med Hyg.
2013 Oct;89(4):724-36. 5. Ansah EK1, Reynolds J, Akanpigbiam S, Whitty CJ, Chandler CI. “Even if the test result is negative, they should be able to tell us what is wrong with us”: a qualitative study of patient expectations of rapid diagnostic tests for malaria.Malar J. 2013 Jul 22;12:258. 6. USAID. President’s Malaria Initiative: 2013. Centre for Disease Control and Prevention; 2013. 7. United Nations Statistics Division. World Statistics Pocketbook: Ghana [Internet]. New York: United Nations; 2013 [updated 2015]. 8. Shillcutt S. Determining cost effectiveness of ma-
laria rapid diagnostics tests in rural areas with high prevalence. Geneva (Switzerland): World Health Organization. 9. Gwer S1, Newton CR, Berkley JA. 10. Over-diagnosis and co-morbidity of severe malaria in African children: a guide for clinicians. Am J Trop Med Hyg. 2007 Dec;77(6 Suppl):6-13. 11. Duah NO1, Quashie NB, Abuaku BK, Sebeny PJ, Kronmann KC, Koram KA. Surveillance of molecular markers of Plasmodium falciparum resistance to sulphadoxine-pyrimethamine 5 years after the change of malaria treatment policy in Ghana. Am J Trop Med Hyg. 2012 Dec;87(6):996-1003.
NEUROABSTRACTS
Award-winning abstracts and presentations from the May 2015 NeuroXchange Conference
Effect of Contrast on Perceptual and Decision-Making Processes in the Dorsal Stream
Evidence supports the integration of both dorsal and ventral stream information into motion computation processes. This gives rise to intermediate object representations in the dorsal stream which in turn facilitate object selection and decision-making mechanisms. Previous work, using superimposed moving surfaces, has found that colour (a ventral stream feature) is integrated into dorsal stream object representations only after direction computations in MT (middle temporal visual area) and allows for object selection which speeds decision-making in the dorsal stream (Perry and Fallah, 2012). However, speed (a dorsal stream feature) is integrated prior to direction computations in MT, improving direction discriminations, and also reducing processing time (Perry et al., 2014). Here we investigate at what stage of processing contrast is integrated into
dorsal stream object representations and used to facilitate perceptual and decision-making processes. Using contrast levels to which both the ventral and dorsal stream are sensitive, we determined the relative influence that varying the contrast of a second surface has on participants’ abilities to correctly determine surface direction (perceptual task) and/or the time it takes to process and decide on the directions of both surfaces. In general, as the contrast of the second surface is reduced, speed of processing increases. However, contrast levels, to which the dorsal stream is sensitive, reduces processing time but does not improve direction discrimination. This suggests that in spite of the early contribution of contrast to visual processing, integration into dorsal stream object representations occurs after direction computation in MT.
neuroabstracts
Carolyn J. Perry1,2, Prakash Amarasooriya1,2, Henna Asrar2,3, Mazyar Fallah1,2,3,4 School of Kinesiology and Health Science, York University, 2Centre for Vision Research, York University, 3Departments of Biology and Psychology, York University, 4Canadian Action and Perception Network, York University
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The Effect of Predictability of Auditory Deviants on High Beta Band Power
rarely in the sequence, or the fact that they occur unpredictably. In order to determine whether the beta band reflects truly predictive aspects of stimulus perception, we employed an isochronous auditory oddball sequence containing deviant tones that were either predictable (occurring periodically) or unpredictable (occurring pseudorandomly), and measured beta power modulation prior to deviant tone onset. Increased high beta induced power (20-30Hz) was observed 100 ms prior to deviant tones in the predictable sequence only, suggesting that high beta power reflects predictive coding mechanisms.
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Sensory prediction includes predictive timing, a prediction of when an event will occur, and predictive coding, a prediction of its content (e.g. pitch). Neural oscillatory activity in the beta band (15-30 Hz) is associated with sensory predictions. Previous studies have shown that beta band power in the auditory cortex entrains to auditory rhythms, reflecting predictive timing. In previous studies using an isochronous auditory oddball task, low-beta (15-20 Hz) power increased following occasional deviant pitches but not standard pitches, reflecting a predictive coding violation. However, the increase in beta power observed following deviant pitches in the auditory oddball task could reflect the fact that deviant tones occur
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Alexandra Rice, Andrew Chang, Laurel J. Trainor Department of Psychology, Neuroscience & Behaviour, McMaster University
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ARTIST CANDY NIU
opinion
Autism Spectrum Disorder
Is it Really on the rise? Fizza manzoor Bachelor of Health Sciences (Honours), Class of 2017 McMaster University Correspondence: manzoof@mcmaster.ca
Autism Spectrum Disorder (ASD) prevalence has increased almost fourfold from 2001 to 2010. This explosive statistic has generated controversy regarding the factors underlying this trend. One perspective is that the incidence of autism is exaggerated by factors including changing diagnostic criteria. A different viewpoint is that the trend is accurate and may be attributed to factors such as environmental toxins and increasing parental age at conception. It is imperative to educate the public on the facts, instead of focusing on constantly fluctuating statistics, in order to avoid misguided decisions fuelled by fear and misconception. Background
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ABSTRACT
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Autism spectrum disorder (ASD) is an umbrella term that encompasses restricted repetitive patterns of behaviour and social communication impairments of varying severity..1 Since the original identification of ASD by Kanner in 1943, prevalence has risen rapidly over the years. ASD prevalence increased from 1 in 250 children in 2001 to 1 in 68 children in 2010, demonstrating an almost fourfold change.2,3 Although the prevalence of ASD
has been rising, the interpretation of these numbers remains a constant challenge for the scientific community. A misinterpretation of Numbers Many believe that the rising numbers do not depict a genuine rise in prevalence of ASD and may instead be exaggerated by two main factors: (1) changing diagnostic criteria, and (2) a new classification of developmental problems, where ASD is no longer classified under mental retardation. Changes in diagnostic criteria are believed to play a critical role in increasing the perceived prevalence of ASD. ASD encompasses a broad range of symptoms and is not associated with any known biological markers.4 Diagnostic criteria are continuously changing,5 and with respect to ASD, criteria have been broadened over time.6 As a result, more people meet the defined criteria for ASD. However, a number of studies have argued that this explanation justifies only part of the trend. For example, King and Bearman estimate that only 26.4% of the increased prevalence of ASD in California, United States can be attributed
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Edited by MATTHEW YAU
Dr. Wendy Roberts is an accomplished neuroscientist at the Hospital for Sick Children. As a full-time professor at the University of Toronto and the Co-Director of the Autism Research Unit, Dr. Roberts has conducted valuable research regarding both early identification and therapeutic intervention of autism.
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American Psychiatric Association. Autism Spectrum Disorder. In: Diagnostic and statistical manual of mental disorders. 5th ed. Washington, DC: American Psychiatric Association; 2013. Wing, Lorna, and David Potter. “The Epidemiology of Autistic Spectrum Disorders: Is the Prevalence Rising?” Mental Retardation and Developmental Disabilities Research Reviews 8, no. 3 (2002): 151–61. doi:10.1002/mrdd.10029. CDC. “Autism Spectrum Disorder (ASD).” Centres for Disease Control and Prevention, March 24, 2014. http://www.cdc.gov/ ncbddd/autism/data.html Hill, Elisabeth L., and Uta Frith. “Understanding Autism: Insights from Mind and Brain.” Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 358, no. 1430 (February 28, 2003): 281–89. doi:10.1098/rstb.2002.1209. American Psychiatric Association. “DSM: History of the Manual.” American Psychiatric Association. Accessed December 22, 2014. http://www.psychiatry.org/practice/ dsm/dsm-history-of-the-manual. Gernsbacher, Morton Ann, Michelle Dawson, and H. Hill Goldsmith. “Three Reasons Not to Believe in an Autism Epidemic.” Current Directions in Psychological Science 14, no. 2 (April 2005): 55–58. doi:10.1111/j.09637214.2005.00334.x King, M., and P. Bearman. “Diagnostic Change and the Increased Prevalence of Autism.” International Journal of Epidemiology 38, no. 5 (October 1, 2009): 1224–34. doi:10.1093/ije/dyp261. Coo H, Ouellette-Kuntz H, Lloyd JEV, Kasmara L, Holden JJA, Lewis MES. Trends in Autism Prevalence: Diagnostic Substitution Revisited. Journal of Autism and Developmental Disorders. 2008 Jul;38(6):1036– 46. Weintraub, Karen. “The Prevalence Puzzle: Autism Counts.” Nature 479, no. 7371 (November 2, 2011): 22–24. doi:10.1038/479022a. Gnaulati, Enrico. Back to Normal: Why Ordinary Childhood Behavior Is Mistaken for ADHD, Bipolar Disorder, and Autism Spectrum Disorder. Boston: Beacon Press, 2013 Grether, J. K., M. C. Anderson, L. A. Croen, D. Smith, and G. C. Windham. “Risk of Autism and Increasing Maternal and Paternal Age in a Large North American Population.” American Journal of Epidemiology 170, no. 9 (November 1, 2009): 1118–26. doi:10.1093/ aje/kwp247. Bray, I., David Gunnell, and George Smith. “Advanced Paternal Age: How Old Is Too Old?” Journal of Epidemiology & Community Health 60, no. 10 (October 1, 2006): 851–53. doi:10.1136/jech.2005.045179. Landrigan, Philip J. “What Causes Autism? Exploring the Environmental Contribution:” Current Opinion in Pediatrics 22, no. 2 (April 2010): 219–25. doi:10.1097/ MOP.0b013e328336eb9a Nevison CD. A comparison of temporal trends in United States autism prevalence to trends in suspected environmental factors. Environmental Health. 2014;13(1):73. Von Ehrenstein OS, Aralis H, Cockburn M, Ritz B. In Utero Exposure to Toxic Air Pollutants and Risk of Childhood Autism: Epidemiology. 2014 Nov;25(6):851–8. Smith, M. J., S. S. Ellenberg, L. M. Bell, and D. M. Rubin. “Media Coverage of the Measles-Mumps-Rubella Vaccine and Autism Controversy and Its Relationship to MMR Immunization Rates in the United States.” Pediatrics 121, no. 4 (April 1, 2008): e836–43. doi:10.1542/peds.2007-1760. Gerber, Jeffrey S., and Paul A. Offit. “Vaccines and Autism: A Tale of Shifting Hypotheses.” Clinical Infectious Diseases 48, no. 4 (February 15, 2009): 456–61. doi:10.1086/596476. Willingham E. Presidential candidate Donald Trump on autism, vaccines and mental health. Forbes [Internet]. 2015 Aug 5; Available from: http://www.forbes.com/ sites/emilywillingham/2015/08/05/presidential-candidate-donald-trump-on-autismvaccines-and-mental-health/ World Health Organization. “WHO VaccinePreventable Disease Monitoring System 2014 Global Summary.” World Health Organization, 2014. http://www.who.int/immunization/monitoring_surveillance/data/ gs_gloprofile.pdf?ua=1.
m e d u cato r | A p r i l 2015 med u c a t o r | december 2 0 1 5
Reviewed by Dr. wendy Roberts
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opinion
to diagnostic change.7 Another study shows that possible to disregard the environmental hypothesis one third of ASD diagnoses in British Columbia, nor to accept it as the primary contributor to the Canada resulted from transferring the classification rising prevalence. Thus, it appears that the case of of a non-ASD condition to the ASD category.8 As rising prevalence of ASD, whether real or perceived, the majority of the increased prevalence remains has multiple contributing factors. unaccounted for in these studies, factors other than changing diagnostic criteria may be involved. Changing public attitudes Increased awareness of ASD may be another factor contributing to the rising numbers of ASD cases.9 Over time, more conclusive research may reveal As more parents become aware of ASD, there is which side explains the factors underlying this increased demand for specialist and testing services, increasing trend most comprehensively. It is which may make some professionals more likely to important to understand that the two perspectives make a diagnosis and parents more accepting of a are likely not mutually exclusive; a genuine rising diagnosis.2 Furthermore, as parents rush to have trend could appear inflated by some factors. In this their children tested at an earlier age, there may be scientific debate, the goal should not be to disprove a greater risk of including children who may not one side, but instead to demonstrate the extent have autism, inflating the rate at which prevalence to which each side contributes to the increasing is rising.10 prevalence. Until this has been established, the most important step is to ensure that the public is A True Trend well-informed and up-to-date on the established facts concerning this topic. This is critical, as in A contrasting view is that other factors may be some cases, public misunderstanding about ASD involved, resulting in a genuine rise in prevalence combined with knowledge of its rising prevalence of ASD such as increased parental age, and high may result in making uninformed decisions. levels of toxins in the environment.2 Societal changes in education, marriage, and employment One example is the controversial misconception have led to increasing parental age over the past regarding ASD and the measles, mumps, and few decades, which may contribute to increasing rubella (MMR) vaccine. Although this link cases of ASD.11,12 A ten-year increase in maternal has been refuted in subsequent literature,17 it is age is associated with a 38% increase in the ASD challenging to change negative public attitudes. odds ratio, a measure of the association between More than a decade later, notorious public figures exposure and outcome. Possible biological factors such as United States presidential candidate underlying this trend have been proposed, but Donald Trump continue to imply that there is a conclusive evidence outlining a causal role is lacking. causal relationship between vaccines and ASD.18 As a result of mixed perspectives presented to the Another factor linked to the rising prevalence public, parents may incorrectly associate the general of ASD is the increased levels of environmental increase in childhood vaccination rates with the toxins. While environmental toxins have not been rising prevalence of ASD.19 Parents relying on herd directly linked to ASD in a causal manner, they are immunity jeopardize both the health of their child thought to induce neurodevelopmental disorders and international vaccination efforts to eradicate that include ASD.13 These toxins affect the disease. This example of the vaccine controversy developing brain and therefore may play a critical outlines the dangers that may result when a public role in the increased prevalence of ASD. Known misconception regarding the rising prevalence of neurodevelopmental toxins are found in a large ASD can fuel misguided actions. range of consumer products, medications, motor fuels, and building materials. However, recent concluding remarks literature presents conflicting results regarding this proposed relationship. A study published in 2014 The rising prevalence of ASD is more than a shows that the levels of many suspected toxins have matter of contrasting opinions; its impact extends flat or decreasing trends over time and are poorly beyond the scientific community and shapes correlated to ASD overall.14 In contrast, in the decisions affecting individual lives. Until the debate same year, another study demonstrated that in utero is resolved, the priority should be to focus on exposure to toxic air pollutants may contribute to educating the public on established facts instead of an increase in risk for ASD in the child.15 With the making speculative decisions based on unsupported present state of research in this field, it is neither hypotheses. ■
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opinion
Is the Doctor in? DAVID BOBROWSKI ARTIST CATHY REN
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ABSTRACT
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The publicly funded Canadian health care system is at risk. The burden of chronic disease has resulted in emergency department wait times and extended hospital admissions. Insufficient community resources have led to late diagnosis and treatment, and in turn, a sicker patient population in acute care facilities. Statistics Canada has determined that Canada’s aging population will increase by about eight percent by 2030, placing an even greater demand on medical services. According to the Fraser Institute, health care costs already consume more than 50% of revenues in Ontario and other provinces. As a result, this therapeutic shortfall cannot be simply resolved through more spending. The World Health Organization has proposed a model of Collaborative Practice and suggested the establishment of a robust linkage between primary, secondary and tertiary resources. For example, health professionals who provide the first point of contact with the health care system, specialists who often provide acute care, and even more highly specialized professionals who provide care over an extended period of time. A patient-centered format comprised of increased screening and a digitally-connected, multispecialty outpatient network can expedite the shift in focus from acute to chronic universal healthcare in a cost-effective manner.
Bachelor of Health Sciences (Honours) - Biomedical Sciences Specialization, Class of 2018 McMaster University Correspondence: bobrowd@mcmaster.ca
Policymakers in Canada are confronted with the challenge of accommodating a growing number of individuals with chronic health care needs. Chronic health conditions, including diabetes mellitus, mood disorders, substance use disorders, and cancer, require continuous management of symptoms over a period of years.1 The Health Council of Canada found that chronic pathologies affect at least one in three Canadians.2 In Ontario, 43% of adults over the age of 65 suffer from two or more chronic health conditions, and the risk factors for further morbidity grow progressively with age.2,3 Chronic relapsing negatively impacts quality of life and ability to maintain employment, and increases the chance of premature death. Patients suffering from chronic disease often do not receive the right care at the right time and find themselves in hospital emergency departments. The domino effect that connects inappropriately managed hypertension to cerebrovascular disease and advanced cardiac disease is a case in point. When a health disaster strikes, it triggers an obligate chain of events that includes an ambulance ride to the emergency department,
possible hospital admission, and protracted rehabilitation. This process adds a great cost from both an economic and patient perspective.4
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REVIEWED BY Narmeen Haider Narmeen Haider is an Associate at Global Health Strategies, a project manager for the Health Impact Fund, and an instructor at McMaster University in the Department of Health Sciences. Her courses in global health cover health economics, financing health systems, behavioral policy, and social determinants of health. She holds a Master of Science in International Health Policy from the London School of Economics and Political Science and a Bachelor of Health Sciences from McMaster University. Edited by ASHLEY LAM
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Chronic Diseases and Health Promotion. [Internet]. [Place unknown]: World Health Organization; 2005 [updated 2015; cited 2015 September 5]. Available from: http:// www.who.int/chp/topics/en/ Health Council of Canada. Why Healthcare Renewal Matters: Learning from Canadians with Chronic Health Conditions. Toronto, Canada: Health Council of Canada; 2007. Canadian Institute for Health Information. Seniors and the Health Care System: What is the Impact of Multiple Chronic Conditions. Ottawa, Canada: Canadian Institute for Health Information; January 2011. Canadian Nurses Association. Chronic Disease Related to Aging. Ottawa, Canada: Canadian Nurses Association; 2011. Gutkin C. Unacceptable Emergency Wait Times. Canadian Family Physician. February 2011; 57(2):256. Canadian Institute for Health Information. Understanding Emergency Department Wait Times: Access to Inpatient Beds and Patient Flow. Ottawa, Canada: Canadian Institute for Health Information. 2007. An OHA Roundtable Discussion: Using Data to Drive Patient-Centered Care for Alternative Level of Care (ALC) Patients with Mental Health, Addiction and Behavioral Requirements in Ontario. Ontario Hospital Association. Toronto, Canada: Ontario Hospital Association; 2014. OECD etool. Canadian Institute for Health Information. [Internet]. 2013 [cited 2015 September 6]. Available from: https://www. cihi.ca/en/health-system-performance/ performance-reporting/international/oecdetool-peer-countries-on-en Canadian Medical Association. The Need for Health Infrastructure in Canada. Ottawa, Canada: Canadian Medical Association; 2013. 10. Rovere MR, Skinner BS. Why Were Paying More For Health Care and Getting Less. [Internet]. [Place unknown]: Fraser Institute; 2010 [cited 2015 September 8]. Available from: http://www.fraserinstitute.org/ article/why-we%C2%92re-paying-morehealth-care-and-getting-less Canada. Dominion Bureau of Statistics. Results At The Canada Level, 2013 to 2063. Ottawa: Statistics Canada; 2015. World Health Organization. Telemedicine: Opportunities and developments in Member States [Internet]. Switzerland: WHO Press; 2010. [cited 2015 November 4]. Available from: http://www.who.int/goe/publications/goe_telemedicine_2010.pdf Goodwin NG, Dixon AD, Anderson GA, Wodchris WW. Providing Integrated Care For Older People With Complex Needs: Lessons From Seven International Case Studies. London, England: The King’s Fund; 2013. World Health Organization. Primary Health Care: Nursing and Midwifery Perspectives. Geneva, Switzerland: WHO Document Production Services; 2013. The Conference Board of Canada. Improving Primary Health Care Through Collaboration Briefing 2 - Barriers to Successful Interprofessional Teams. Ottawa, Canada: The Conference Board of Canada; 2012. Natale-Pereira A, Enard K, Nevarez L, Jones L. The role of patient navigators in eliminating health disparities. Cancer [Internet]. 2011 [cited 5 November 2015];117(S15):35413550. Available from: http://onlinelibrary. wiley.com/doi/10.1002/cncr.26264/abstr act;jsessionid=5B6AF9854AFC04A755A EF87E941B5494.f04t02
opinion
It is from this perspective that having “multiple health workers in different professional backgrounds working together with patients, families, caregivers and communities” was formally Patients face increased wait times for emergent recognized as a strategic goal. This vision was care and then continue waiting to access hospital articulated by the Interprofessional Education beds and elective surgical procedures.5 In Canada, and Collaborative Practice in 2010 based on the one in ten patients requesting emergency care will definition of primary care set forth by the World wait eight hours or more, while the average length Health Organization in 1978.14 The push to of an emergency room visit is more than four remediate individual and system level barriers has hours.6 Policy reports by the Ontario Hospital already started in Brazil, India, South Africa, the Association have identified ongoing system United States, and in Canada, where legislation malfunctions, including the excessive number of requiring interprofessional training reinforces the alternate-level-of-care (ALC) beds in hospitals.7 goal of providing continuity in patient-centered ALC beds are defined as those a patient might care.14, 15 occupy in a hospital once acute care is no longer required. The lack of suitable community-based Therefore, the objective of Canada’s health care care facilities results in an insufficient number of evolution should be threefold: increased screening acute care beds available for patients. The problem to enable earlier diagnosis and treatment, improved is exacerbated by Canada’s already has a limited outpatient management of chronic disease, and acute care capacity, with only 1.7 acute care access to primary and secondary care resources care beds available per 1,000 residents.8 It costs with the support of tertiary care facilities.4 approximately $842 a day to care for a patient in hospital, compared to $126 a day for long-term Patients suffering from chronic diseases may benefit care (LTC) and $42 for home care.9 It is estimated from having a care coordinator so they do not fall that relocating ALC patients from hospital to between systemic cracks. Care coordinators tend LTC would save $1.4 billion annually.9 to be non-clinicians that provide a central point of contact between the various stakeholders in the Canadian health care spending in some provinces, therapeutic process.13,16 These care coordinators, including Ontario, currently amounts to more much like the conductor of an orchestra, can than 50% of total provincial revenues and these monitor compliance and improve the overall costs are set to accelerate in tandem with the aging health outcomes of the patients. population.10 The baby boomers – those born between 1945 and 1965 – will raise the population Well-targeted investment by the Canadian federal of seniors to 23.6% of the total population by the government in the integration of hospital-based year 2030, compared to 15.3% in 2013.11 To meet and outpatient services has the potential to this demand, and to bypass a stenotic health care repurpose scarce economic and human resources. system, a national strategy focused on extending If Canadians continue to put their faith and pride hospital resources into the community should in an accessible model of universal health care be considered. This concept is not foreign to and the socio-economic burdens accompanying Canadians, particularly those in communities privatization of medical services are to be avoided, with limited infrastructure who require health these changes need to be implemented. We care to be brought to them.12 An online system do not want to compromise the integrity of a facilitating cross-referral between specialized system that has been so crucial to our population’s tertiary and long-term, residential options such well-being. ■ as such as home care, hospice, and palliative care can can optimize the allocation of primary and secondary resources.13
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FORUMSPACE
Beyond the Headlines and into the Health of Syrian Refugees EMILY FONG1 , Alexandra Kilian 2 , SARA HALAWA 3 , ANNIE ZHU 4 Bachelor of Art & Science (Hons), Class of 2016, McMaster University, 2Bachelor of Health Sciences (Hons), Class of 2017, McMaster University, 3Master of Science in Global Health, McMaster University, 4 Bachelor of Health Sciences (Hons), Class of 2016, McMaster University Correspondence: zhuay@mcmaster.ca
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Introduction
The McMaster Health Forum strives to be a leading hub for improving health outcomes at the regional and provincial levels in Canada. Through problem-solving and discussion, they harness information, convene stakeholders, and prepare action-oriented leaders to meet pressing health issues creatively.
The Canadian response to the current refugee crisis has varied drastically from Canada’s response to previous In 2011, a civil war began in Syria. Protesters demanded refugee crises. Citizenship and Immigration Canada President Bashar Al-Assad’s resignation and subsequent reported that 2,374 Syrian refugees have been resettled implementation of democratic reforms.1 The Syrian in Canada between Jan 2014 and Aug 2015. Most of government responded with military action, which the refugees arriving in 2015 were privately sponsored escalated feelings of hostility and propelled anti- by families (n=1,513) and not UN-referred (n=308).8 government rebel activity. Since then, the battle against This is in stark contrast to previous Canadian responses the regime has grown into a sectarian conflict between to refugee crises where Canada accepted 5,000 refugees various ethnic and religious groups in the country.2 from Uganda in 1972 and 60,000 Vietnamese refugees in 1979-1980.9 Moreover, Syrians applying for refugee The crisis in Syria is one of the largest refugee migrations status in Canada face difficulties such as requiring in recent history, with over 9 million refugees fleeing certification from another country or a UN agency for safety. Many refugees present with pressing health before applications can be reviewed. However, the concerns such as trauma and mental health issues, newly-elected federal government has pledged to accept which are exacerbated by malnutrition and unsanitary 25,000 refugees by the end of 2015 so this process may conditions in refugee camps.3-6 Given the health impacts change significantly in the near future.8,10 of the refugee crisis and potential rise in the number of Syrian refugees admitted to Canada, t is important to Social and Economic Impacts consider whether our country’s health policies adequately meet the needs of refugees. In an increasingly interconnected world, the refugee crisis has global economic and social impacts. The International and Canadian migration process alone affects multiple countries, including the refugees’ countries of origins, their final Response to the Refugee Crisis destinations, and the countries acting as points of entry Most of the refugees escaping the conflict have fled and transit. Despite voiced concerns that the population to neighbouring countries. Turkey has accepted over increase will strain infrastructure, education, health care, 2 million refugees, Lebanon 1.1 million, and Jordan and transport systems in host countries, there is little 600,000. Many of these refugees live in refugee camps evidence to support these claims. For example, a study provided by the national governments. These camps are employing economic modeling to examine the impact of often overcrowded due to the growing refugee influx, the Syrian refugee influx in Turkey found that food and creating issues such as water and food shortages and the housing prices were not significantly affected. Moreover, spread of infections.7 the study reported that employment rates in Turkey across different sectors remained stable.11 Similarly, while
some Jordanians claim that the influx of Syrian refugees, no evidence supports this speculation.12
Health Impacts
3. Beiser M. The Health of Immigrants and Refugees in Canada. Canadian journal of public health Revue canadienne de santé publique. 2015;96(2). 4. Malnutrition a silent threat emerging among Syrian refugee children in Lebanon [Internet]. UNICEF. [cited 2015 Oct 26]. Available from: http://www.unicef.org/ emergencies/lebanon_72711.html 5. Adler D, Mgalula K, Price D, Taylor O. Introduction of a portable ultrasound unit into the health services of the Lugufu refugee camp, Kigoma District, Tanzania. Int J Emerg Med. 2008 Nov 14;1(4):261–6. 6. Toole MJ, Waldman RJ. The public health aspects of complex emergencies and refugee situations. Annu Rev Public Health. 1997;18:283–312. 7. World Vision. What You Need to Know: Conflict in Syria, children, and the refugee crisis [Internet]. 2015 [cited 21 October 2015]. Available from: http://www. worldvision.org/news-stories-videos/syria-war-refugee-crisis 8. Cic.gc.ca. How Canada is helping Syrian and Iraqi refugees [Internet]. 2015 [cited 21 October 2015]. Available from: http://www.cic.gc.ca/english/refugees/ crisis/canada-response.asp 9. Cic.gc.ca. Canada: A History of Refuge [Internet]. 2012 [cited 21 October 2015]. Available from: http:// www.cic.gc.ca/english/refugees/timeline.asp 10. Liberal.ca. Syrian refugees [Internet]. 2015 [cited 1 November 2015]. Available from: https://www.liberal. ca/realchange/syrian-refugees/ 11. Akgündüz Y, Berg V den, Marcel, Hassink WHJ. The Impact of Refugee Crises on Host Labor Markets: The Case of the Syrian Refugee Crisis in Turkey [Internet]. Rochester, NY: Social Science Research Network; 2015 Feb [cited 2015 Oct 19]. Report No.: ID 2564974. Available from: http://papers.ssrn.com/abstract=2564974 12. Balsari S, Abisaab J, Hamill K, Leaning J. Syrian refugee crisis: when aid is not enough. The Lancet. 2015 Mar;385(9972):942–3. 13. Palinkas LA, Pickwell SM, Brandstein K, Clark TJ, Hill LL, Moser RJ, et al. The journey to wellness: stages of refugee health promotion and disease prevention. J Immigr Health. 2003 Jan;5(1):19–28. 14. Hansson E, Tuck A, Lurie S, and McKenzie K, for the Task Group of the Services Systems Advisory Committee, Mental Health Commission of Canada. Improving mental health services for immigrant, refugee, ethnocultural and racialized groups: Issues and options for service improvement. 2015. Available from: http:// www.mentalhealthcommission.ca/SiteCollectionDocuments/Key_Documents/en/2010/Issues_Options_FINAL_English%2012Nov09.pdf 15. Branch LS. Consolidated federal laws of canada, Order Respecting the Interim Federal Health Program, 2012 [Internet]. 2012 [cited 2015 Oct 19]. Available from: http://laws-lois.justice.gc.ca/eng/regulations/SI2012-26/FullText.html 16. Changes to the Interim Federal Health Program: Position Statement [Internet]. Canadian Health Association; 2012. Available from: http://www.healthcarecan. ca/wp-content/uploads/2012/11/IFHP-reform-policystatement-November-2012.pdf 17. Evans A, Caudarella A, Ratnapalan S, Chan K. The Cost and Impact of the Interim Federal Health Program Cuts on Child Refugees in Canada. PLoS ONE [Internet]. 2014 May 8 [cited 2015 Oct 5];9(5). Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/ PMC4014561/ 18. Examining the impacts of recent changes to the Interim Federal Health Program | CRICH [Internet]. 2015 [cited 1 November 2015]. Available from: http://www. stmichaelshospital.com/crich/projects/refugeehealthcare/ 19. AG News. Germany Set to Accept ALL Syrian Refugees who Arrive There [Internet]. 2015 [cited 9 November 2015]. Available from: https://anongalactic. com/when-will-europe-learn-germany-set-to-acceptall-syrian-refugees-who-arrive-there/
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More details on this topic are available at http://www.mcmasterhealthforum.org/
2. BBC News. Syria: The story of the conflict - BBC News [Internet]. 2015 [cited 21 October 2015]. Available from: http://www.bbc.com/news/world-middleeast-26116868
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Refugees forcibly displaced from their home country face significant health risks. As victims of sociopolitical unrest, many are separated from loved ones or have witnessed the death of family members, contributing to the high prevalence of post-traumatic stress and depressive symptoms.13 These symptoms are often left untreated given the limited resources and health services available in refugee camps. Chronic malnutrition is another health concern in refugee camps as it increases susceptibility to many diseases and illnesses. This is especially problematic for vulnerable groups when compounded with poor hygiene practices, unsafe drinking water, lack of immunizations, and severe weather conditions.4-6 The constant turnover of staff members in refugee camps and the constant inflow and outflow of people also Conclusion present unique challenges in providing sustained care. Moreover, the locations of refugee camps Various speculations have been made regarding present even greater barriers to care as they tend the impact of the refugee influx on existing social to be remote, poorly accessible by road, and structures and health systems. While further limited in power supply.6 research is required to elucidate the exact effects of the 2012 cuts to the IFHP, available literature After settling into a host country, refugees suggests that the restricted access to health continue to face barriers to health care access. care for refugees has no clear indication of cost These include financial insecurity, language savings. Claims regarding the economic impact difficulties, cultural differences, and lack of access of refugee migration on local communities have to important programs and services. In addition, not been well-supported by evidence given the healthcare workers may lack adequate training recency and multifaceted nature of the crisis. and awareness of issues specific to refugees to be Thus, it is important to remain critical of what able to provide culturally appropriate care, which is being portrayed in the media. Finally, an is particularly important in the context of mental important point to consider is that refugees are health.14 humans deserving of our compassion, respect, and empathy. Beyond the headlines of the Syrian In Canada, the federal government is responsible refugee crisis, we should remember that this is for the delivery of healthcare to refugees. In 2012, not purely a health or economic issue, but one drastic cuts were made to the healthcare services that is founded on principles of human rights, available to refugees and refugee claimants dignity, and equality. ■
1. Morabia A, Benjamin GC. The Refugee Crisis in the Middle East and Public Health. Am J Public Health. 2015 Oct 15;e1–e2.
forumspace
through the Interim Federal Health Program (IFHP).15 While these cuts were justified by the government as a cost-saving measure, a statement by the Canadian Healthcare Association postulates that cuts to essential services may lead to increased costs due to unscreened, untreated, or poorly managed health conditions.16 Furthermore, a study conducted at The Hospital for Sick Children found that in the six months prior to the cuts, 46% of emergency room bills submitted through IFHP were paid, as opposed to 7% in the six months following the cut. This suggests that costs were simply transferred from the federal government onto hospitals.17 Given the recency of the cuts, there is limited data available on their effects. A multi-site study from 2013-2017 aims to assess the impacts of the changes to the IFHP on health status, costs, and access to healthcare for refugees in Toronto and Montreal.18
20. Gography Education. Teaching about Syrian Refugees [Internet]. 2015 [cited 9 November 2015]. Available from: http://geographyeducation.org/articles/ teaching-about-syrian-refugees/
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ARTIST MICHAEL SUN
CRITICAL REVIEW
Vitamin D and Melatonin in Multiple Sclerosis Effects of Seasonal Changes
Feroze Nooruddin1 , Takhliq Amir 2 Bachelor of Health Sciences (Honours) Program, Class of 2018, McMaster University Bachelor of Health Sciences (Honours) Program, Class of 2019, McMaster University Correspondence: noorudf@mcmaster.ca and amirt@mcmaster.ca 1
2
geographical gradient with significantly higher incidence of MS in correlation to increasing latitude.4 Previous literature has advocated varying exposure to sunlight based on seasonal patterns and the resulting alteration in vitamin D (VD) production as the explanation for this gradient. During spring and summer, the increased exposure to sunlight results in increased production of VD in our body, and this is hypothesized to allow efficient modulation of immune responses in reducing MS relapses.5 On the other hand, researchers have now discovered a seasonal paradox - MS relapses continue to increase in the spring and summer when levels of sunlight are high.2 This directed the researchers’ attention towards melatonin, a sunlight-dependent hormone that is an additional regulator of immune responses and promoter of anti-inflammatory processes. Less sunlight in the fall and winter increases melatonin, whereas more sunlight during spring and summer decreases it.6 Therefore, both melatonin and VD contribute to control MS disease activity. However, specifically with regards to seasonal changes, melatonin plays a stronger role than VD in MS.5
Multiple sclerosis (MS) is the most common inflammatory-demyelinating disease of the central nervous system (CNS) and is the most frequent cause of neurologic disability in young adults. Understanding of MS was revolutionized by recent studies on immunological pathways relevant to the disease as well as the use of high field magnetic resonance imaging (MRI). Currently, therapies for the early stages of MS have been developed, however, there is still no effective treatment for progressive MS and relapse. Recent findings suggest that MS incidence is higher in geographic regions with less sunlight exposure. Both vitamin D (VD) and melatonin influence the effect of sunlight on health and can therefore be considered to play a role in MS. Several studies indicate that high levels of both VD and melatonin may decrease the extent of disease progression. This review aims to explore various studies that elucidate the effects of VD and melatonin on the pathology, management, and treatment of MS.
m e d u cato r | A p r i l 2015 med u c a t o r | december 2 0 1 5
Multiple sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system (CNS). It involves abnormal immune responses attacking myelin, the fatty tissue that forms an insulating layer around nerve fibers and allows for efficient transmission of nerve impulses.1 The resulting degradation of the myelin sheath is a key part of MS pathogenesis since it disrupts cell-to-cell connections within Shining light on the the brain and slows signalling to the rest of the role of Vitamin D body. This clinically manifests itself through difficulties with vision, balance, and muscle VD is a nutrient that is known to help our coordination, as well as weakened cognitive bodies use calcium and phosphorus to build functions.1 The condition is known to affect and maintain strong bones and teeth. However, more than 2 million people worldwide.2 VD affects numerous aspects of health beyond Most individuals affected with MS undergo a bone strength. In fact, its anti-inflammatory, relapsing–remitting period where the symptoms immunomodulatory, and antiproliferative alternate between flaring up and disappearing. effects have recently become a research focus.6 The majority of people with relapsing–remitting VD exerts its effect on immune cells by MS (RRMS) eventually develop secondary regulating the production of cytokines, a group progressive MS, in which their symptoms of small proteins that drive inflammation by inexorably worsen.3 The cause of the disease attracting immune cells. In MS patients, the is still unknown, although researchers have pro-inflammatory action of cytokines tends to identified risk factors such as viral infections, worsen the disease by producing inflammation, specific levels of gene expression, and the tissue destruction, and in some cases, shock lack of white blood cells in the bloodstream.2 and death. In MS patients, inflammation in the brain causes loss of neurological function.7 Vitamin D or Melatonin? In 2012, a randomized, double-blind study conducted by Pennsylvania State University Recent research has shown an impressive explored the effects of 10-week high-dose
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Multiple Sclerosis
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VD supplementation on MS patients. The results demonstrated that VD lowers the production of inflammatory cytokines. This further promotes the notion that VD is a modulator of physiological immune responses.8
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melatonin production decreases in spring and summer, and increases in the fall and winter.12 Melatonin modulates immune responses by suppressing pro-inflammatory cytokine production.17 A study conducted by Farhadi et al. measured serum levels of melatonin and tumor necrosis factor alpha (TNF-α), a proinflammatory cytokine associated with most MS lesions, in both MS patients and a control group.18 Serum melatonin was lower in MS patients compared to healthy controls, while TNF-α levels were higher in MS patients.
It is interesting to note that MS prevalence increases as one approaches the geographic poles.9 Furthermore, a strong inverse relationship has been observed between amount of sun exposure and subsequent MS development within the same geographical area.4 Validating these observations, a study conducted in Norway, where the northerly latitude only allows minimal sunlight, Other studies have observed relationships demonstrated that an increase in summer between melatonin and MS through studying activities during early life significantly reduced the effects of exogenous melatonin on the the risk of MS.10 Based on the strong correlation pathogenesis of experimental autoimmune between latitude, sun exposure, and intrinsic encephalomyelitis (EAE), the most frequently VD production, VD can be interpreted to have used animal model of MS.15 These studies a substantial effect on the incidence of MS. This showed that melatonin is vital in MS disease is important from a public health perspective, progression by its effects on two cell types: as VD deficiency is common, especially in pathogenic effector and regulatory T cells. T northern countries like Canada where exposure regulatory (Treg) cells regulate the immune to sunlight is decreased during the winter. system and maintain tolerance to self-antigens. They are characterized by the production of Supplementation of VD could be beneficial interleukin-10 (IL-10), an anti-inflammatory for inhabitants of countries with cold cytokine involved in immunoregulation and climates. A large prospective cohort study antibody production. They also suppress the was conducted to evaluate the effect of VD production of autoreactive effector T cells, supplementation on MS incidence in North such as T helper (Th) cells. Conventional Th American women.11 Results showed that those cells modulate immune response by activating who took VD supplements were 45 percent other effector immune cells such as B cells and less likely to develop MS than those who did macrophages in an antigen-specific manner, but not. Relationships between the risk of MS and they have also been implicated in deleterious intake of VD only during the subject’s teenage activities.19 Two subtypes of Th cells, Th1 and years were analyzed.12 Consuming more than Th17, divide rapidly when activated and secrete 450 International Units (IU)/day of VD various cytokines to facilitate immune responses, during one’s teenage years did not significantly such as recruiting white blood cells to sites of decrease the risk of developing MS. Thus, infection or damage.20,21 Interleukin-17 (ILresearch suggests that it may be more effective 17) is a cytokine produced by Th17 cells that to consume VD supplementation throughout has been linked to pro-inflammatory responses, an entire lifetime to decrease MS incidence.12 including the production of TNF-α, and has often been implicated in diseases such as MS.
The Regulatory Role of Melatonin
While VD has been shown to play a beneficial role in lowering MS incidence, researchers recently discovered a stronger relationship between melatonin and MS symptoms.13 Melatonin is a natural hormone secreted by the pineal gland in response to sensory input from the retina.14 It is also known for having antioxidant and anti-inflammatory effects and is involved in regulating circadian and seasonal rhythms.15 There is a known correlation between melatonin levels and seasonality:
Th1 and Th17 cells are implicated as the main Th cell populations in MS. Hence, studies investigated the effects of melatonin on Th1, Th17, and Treg cells in the lymph nodes and the CNS of EAE mice.21 Evidence shows that Th17 produces pro-inflammatory IL17 in MS patients.22 Conversely, Treg cells oppose the activity of Th1 and Th17 cells, accumulating in the CNS of EAE animals and protecting the animals from EAE in an IL-10-dependent manner. Unlike IL-17, IL10 is an anti-inflammatory cytokine and is
positively correlated with serum melatonin levels.23 In particular, melatonin reduces Th1 response and instead enhances the activity of type 1 regulatory cells (Treg1), which suppress immune responses through IL-10 production.23 Results indicated that melatonin downregulates the Th1 and Th17 pro-inflammatory immune responses in MS patients and shifts the response towards immunosuppressive Treg1 cells.21,22,23 Thus, through regulating effector and regulatory T cells, seasonal changes in melatonin levels may contribute to decreased MS activity during autumn and winter.23
alleviate inflammation and attenuate neuronal damage in MS. However, future research should focus on developing a multi-center, randomized, placebo-controlled, doubleblind clinical trial to effectively evaluate the therapeutic value of VD supplementation.26 Although VD operates as a protective factor, recent research is focused on melatonin, which is considered to play a greater role in suppressing MS symptoms.15 Melatonin is a hormone involved in regulating the sleep-wake cycle and influences MS disease activity and relapse seasonality by impacting immune response and T cell activation.24,25 Research is currently exploring the molecular mechanisms that underlie melatonin’s role in MS in order to develop pharmaceuticals and identify additional mechanisms of action.14
Dr. Kenneth Rosenthal is currently Division Director of Molecular Medicine and Professor in the Department of Pathology and Molecular Medicine at McMaster University. His research focuses on the role of mucosal innate and adaptive immunity in virus infections, particularly HIV-1. As a professor, he teaches various undergraduate and graduate immunology and virology courses. Edited by avrilynn ding and arlinda deng 1.
Nylander A, Hafler DA. Multiple sclerosis. J Clin Invest [Internet]. 2012;122(4):1180–8. Available from: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3314452&tool=pmcentrez &rendertype=abstract 2. Compston A, Coles A. Multiple sclerosis. Lancet [Internet]. 2008;372(9648):1502–17. Available from: http://www.ncbi.nlm.nih.gov/ pubmed/18970977 3. Khaleeli Z, Ciccarelli O, Manfredonia F, Barkhof
F, Brochet B, Cercignani M, et al. Predicting progression in primary progressive multiple sclerosis: a 10-year multicenter study. Ann Neurol [Internet]. 2008;63(6):790–3. Available from: http://www.ncbi.nlm.nih.gov/ pubmed/18383506 4. Smolders J, Damoiseaux J, Menheere P, Hupperts R. Vitamin D as an immune modulator in multiple sclerosis, a review. J Neuroimmunol. 2008;194(1-2):7–17.
5. Mehta BK. New hypotheses on sunlight and the geographic variability of multiple sclerosis prevalence. J Neurol Sci [Internet]. 2010;292(12):5–10. Available from: http://www.ncbi.nlm. nih.gov/pubmed/20189603 6. Melamud L, Golan D, Luboshitzky R, Lavi I, Miller A. Melatonin dysregulation, sleep disturbances and fatigue in multiple sclerosis. J Neurol Sci [Internet]. 2012;314(1-2):37–40. Available from: http://www.ncbi.nlm.nih.gov/
8. Chaudhuri A. Why we should offer routine vitamin D supplementation in pregnancy and childhood to prevent multiple sclerosis. Med Hypotheses. 2010;64(3):608–18. 9. Kampman MT, Steffensen LH, Mellgren SI, Jorgensen L. Effect of vitamin D3 supplementation on cytokine production in patients with multiple sclerosis. Mult Scler J. 2012;18(1):1144–51. 10. Smolders J. Vitamin d and multiple sclerosis: correlation, causality, and controversy. Autoimmune Dis. 2011;2011:629538. 11. Van der Mei I, Ponsonby A, Dwyer T, Blizzard L, Simmons R, Taylor B et al. Past exposure to sun, skin phenotype, and risk of multiple sclerosis: case-control study. BMJ 327(7410): vitamin D and multiple sclerosis–what is clearly evident? Eur Neurol. 2013; J 2(2):113–120 316. 12. Kampman M, Wilsgaard T, Mellgren S. Outdoor activities and diet in childhood and adolescence relate to MS risk above the Arctic Circle. J Neurol. 2007; 254(4):471–477. 13. Munger K, Zhang S, O’Reilly E, Hernan M, Olek M, Willett W et al. Vitamin D intake and incidence of multiple sclerosis. Neurology. 2004; 62(1):60. 14. Munger K, Chitnis T, Frazier A, Giovannucci E, Spiegelman D, Ascherio A. Dietary intake of vitamin D during adolescence and risk of multiple sclerosis. J Neurol. 2011; 258(3):479–485. 15. Bridger H. Why MS symptoms may improve as days get shorter [Internet]. Harvard Gazette. 2015 [cited 23 October 2015]. Available from: http://news. harvard.edu/gazette/story/2015/09/ why-ms-symptoms-may-improve-asdays-get-shorter/ 16. Ghorbani A, Salari M, Shaygannejad V, Norouzi R. The Role of Melatonin in the Pathogenesis of Multiple Sclerosis: A Case-Control Study. International Journal of Preventive Medicine [Internet]. 2013 [cited 23 October 2015];4(Suppl 2):S180. Available from: http:// www.ncbi.nlm.nih.gov/pmc/articles/ PMC3678214/ 17. Lin G, Huang S, Chen S, Wang C, Chang D, Sytwu H. Modulation by Melatonin of the Pathogenesis of Inflammatory Autoimmune Diseases. IJMS. 2013;14(6):11742-11766. 18. Melamud L, Golan D, Luboshitzky R, Lavi I, Miller A. Melatonin dysregulation, sleep disturbances and fatigue in multiple sclerosis. Journal of the Neurological Sciences. 2012;314(1-2):37-40. 19. Pozo D, Delgado M, Fernandez-Santos J, Calvo J, Gomariz R, Martin-Lacave I et al. Expression of the Mel1amelatonin receptor mRNA in T and B subsets of lymphocytes from rat thymus and spleen. The FASEB Journal [Internet]. 1997 [cited 23 October 2015];11(6):466-473. Available from: http://www.fasebj.org/content/11/6/466.long 20. Farhadi N, Oryan S, Nabiuni M. Serum levels of melatonin and cytokines in multiple sclerosis. Biomed J. 2014;37(2):90. 21. Corthay A. How do Regulatory T Cells Work? Scandinavian Journal of Immunology. 2009;70(4):326-336. 22. Thomson C, Wang Y, Jackson L, Olson M, Wang W, Liavonchanka A et al. Pandemic H1N1 Influenza Infection and Vaccination in Humans Induces CrossProtective Antibodies that Target the Hemagglutinin Stem. Front Immun. 2012;3. Available from: http://brc.ubc. ca/research/cytokines-and-antibodies-j-schrader/ 23. Fletcher JM, Lalor SJ, Sweeney CM, Tubridy N, Mills KHG. T cells in multiple sclerosis and experimental autoimmune encephalomyelitis. Clin Exp Immunol. 2010;162(1):1–11. 24. Farez M, Mascanfroni I, Méndez-Huergo S, Yeste A, Murugaiyan G, Garo L et al. Melatonin Contributes to the Seasonality of Multiple Sclerosis Relapses. Cell. 2015;162(6):1338-1352. 25. Spelman T, Gray O, Trojano M, Petersen T, Izquierdo G, Lugaresi A et al. Seasonal variation of relapse rate in multiple sclerosis is latitude dependent. Annals of Neurology. 2014;76(6):880-890. 26. Kulie T, Groff A, Redmer J, Hounshell J, Schrager S. Vitamin D: an evidencebased review. J Am Board Fam Med. 2009;22(6):698–706.
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Reviewed by Dr. Kenneth Rosenthal
pubmed/22137446 Holick MF. Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease. Am J Clin Nutr. 2011; 80(6):1678S.
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Research has shown a correlation between melatonin supplementation and the quality of life of MS patients, many of whom suffer from sleep disturbances, depression, and fatigue. Studies have suggested that melatonin’s antioxidant properties can improve quality of The contrasting patterns of melatonin and VD life by reducing oxidative stress and potentially give rise to a paradox in the seasonal regulation improve sleeping patterns.24 However, a study of MS. While VD is known to increase during by Quintana et al. has warned against the use of spring and summer, melatonin levels increase melatonin supplements in MS patients, citing during winter. However, research has not yet drawbacks such as unwanted drowsiness.25 focused on establishing a connection between Thus, further research is necessary to determine the two factors that evidently attenuate the optimal dose of melatonin supplements to MS symptoms. As such, future research maintain balanced sleeping habits in MS patients. should identify mechanisms through which melatonin and VD can operate synergistically Conclusion to develop a clearer understanding of their relative effects on MS progression. ■ While previous studies focused on genetic factors involved in the development of autoimmune disorders, the rise in MS in the past 50 years and the correlation of its symptoms or incidence with seasonal changes has shifted greater attention towards environmental factors. Through epidemiological observation, a relationship between sunlight exposure and subsequent MS development was noted. Through its immunomodulatory processes, VD is able to alleviate MS symptoms during the summer. Based on experimental and clinical reports, supplementary VD can also be used to
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ARTIST Ming Bi
RESEARCH REVIEW
Hacking the Brain:
Gene Therapy as a Tool to Combat Epilepsy
MAXWELL NG, KRISH BILIMORIA, KARANBIR BRAR, NIKESH PANDEY Bachelor of Health Sciences (Honours) Program, Class of 2018 McMaster University Correspondence: ngmc2@mcmaster.ca
ABSTRACT
Since its inception in 1972, gene therapy has demonstrated remarkable progression and advancement. Initially through the use of engineered viral vectors and later through the use of complex RNA-based editing tools, the fundamental processes and techniques used in gene therapy have grounded themselves on a watershed of discovery. A potential application of gene therapy is in epilepsy, which is a prevalent set of neurological disorders characterized by epileptic seizures of numerous divergent pathologies. Though many epileptic disorders are idiopathic in nature, the genetic predisposition of generalized epilepsy with febrile seizures plus (GEFS+) has been well documented in scientific literature. GEFS+ is believed to be caused by a mutation in the SCN1A gene, coding for a subunit of a specific ion-gated sodium channel on bipolar and pyramidal neurons. In a rat model of GEFS+, we propose the use of herpes simplex virus type 1 as a vector to deliver zinc finger nucleases and a corrected SCN1A gene sequence to simultaneously knock out and replace the mutated SCN1A gene. This experimental design would demonstrate the prospects of epileptic gene therapy in the rodent brain and, by extension, validate the plausibility of genetic editing procedures in a clinical setting.
INTRODUCTION
Multiple causal factors are associated with epileptogenesis. Since the early 1990s, pharmacological approaches have had limited progress in treating epileptic symptoms, with no decrease in drug-resistant epilepsy cases.5,6 This provides the impetus for the development of new, more effective treatments, namely in the form of gene therapy.7
FIGURE 1: a) pCMV-SCN1AmKO2 transgene. The CMV enhancer and promoter pair is upstream from the corrected SCN1A gene. The mKO2 orange fluorescent protein is connected to the SCN1A by a flexible linkage to minimize interference. b) pCMV-ZFN transgene. The CMV enhancer and promoter pair is upstream from the zinc finger nuclease (ZFN) encoding gene that will remove the mutated SCN1A gene present in the host DNA. m e d u cato r | A p r i l 2015 med u c a t o r | december 2 0 1 5
Gene therapy is the process of delivering nucleic acids including adenine, thymine, guanine, and cytosine in a packaged vector to patient cells.4
Zinc finger nucleases (ZFNs) are a recent development in genetic engineering for the cleavage of DNA strands. ZFNs combine the nonspecific cleavage domain of FokI endonucleases, restriction enzymes that break phosphodiester bonds between nucleotide bases, with zinc finger proteins to achieve site specific gene targeting and editing. Subsequent nonhomologous end joining occurs after cleavage activity.12 When paired with a viral vector, ZFNs allow for a targeted combinatorial method of gene editing that has powerful potential for therapeutic applications. ZFNs have also been cleared through Phase II of clinical trials, lending towards their credibility as a safe and scalable system for genetic editing. If our proposed treatment method involving ZFNs is successful in a rat model, it can be further applied to humans and potentially serve as a therapy for this form of epilepsy.
research proposal
Epilepsy is a brain disorder predominantly characterized by recurrent and unpredictable seizures.1 Generalized epilepsy with febrile seizures plus (GEFS+) is a subtype of autosomal dominant epileptic syndromes characterized by over 90 mutations of the sodium channel voltage gated type 1 alpha subunit (SCN1A) gene.2,3 GEFS+ pathogenesis is mostly genetic. One form of GEFS+ is Dravet syndrome, a rare and lethal form of epilepsy also known as Severe Myoclonic Epilepsy of Infancy (SMEI). 80% of patients with Dravet Syndrome have mutations in the SCN1A gene.4 These mutations confer either hypoexcitability, a repressed reaction to stimuli, or hyperexcitability, an excessive reaction to stimuli, in the sodium ion channel Nav1.1. As a result, afflicted individuals have a greater susceptibility to seizures due to a widespread dysfunction of their neural network inhibition.2,3
Replication-defective recombinant herpes simplex virus type 1 (HSV-1) is an effective and unique vector for neuronal gene therapy. It is a virus that preferentially infects the brain by spreading across synapses, establishing latent infection, and evading immune responses.8,9 HSV-1 is able to disguise itself upon infection to allow the DNA vector to be conserved in neurons for extremely prolonged periods of time, thereby maintaining long-term neuronal infection. Lastly, HSV-1 has a large genome containing few spliced genes, allowing for the insertion of large foreign genes for gene therapy applications.10,11
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research proposal
RESEARCH DESIGN AND RESULTS
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FIGURE 2: Treatment concept. Cytotoxic herpes simplex virus (HSV) genes are removed from the HSV-1 KOS viral vector. The pCMV-SCN1A-mKO2 and the pCMV-ZFN transgenes are cloned into the the HSV dsDNA. The viral vector is amplified via a complementary cell line. These viral vectors are then injected into the hippocampal region of the host. The viral vector inserts its DNA, including the transgenes, into the cell’s nucleus where it circularizes and expresses the transgene proteins. The ZFN removes the mutated SCN1A host DNA and the new SCN1A channel protein with linked fluorescent protein, eventually replacing the mutated SCN1A channel proteins.
The following series of experiments outline a ‘proof-of-concept’ genetic treatment on a rat model for the specific form of epilepsy being studied. These animal subjects are characterized by GEFS+ type 2 symptoms, which are inducible via hyperthermia, due to a mutation in their Scn1a gene and are therefore known as hyperthermia-induced seizure-susceptible (Hiss) rats. The treatment is a solution of standard artificial cerebrospinal fluid (CSF) harboring HSV-1 vectors containing Scn1a-specific-ZFN DNA and the correct Scn1a gene. The expressed ZFNs will cleave the mutated Scn1a gene in the host DNA. The HSV-1 vector has a large DNA capacity of 150 kilobase pairs (kbp) that can allot for the rat Scn1a gene and the smaller ZFN.10,11 The experimental method involves an ex vivo study using rat brain slices and an in vivo study using rats. For in vivo, the treatment solution will be injected directly into the hippocampus of rats using stereotaxic surgery, a method of injection using stereotaxic coordinates that map to specific brain structures.13 Direct injection circumvents processes in the bloodstream and the blood-brain barrier that could act as confounding variables in the experiment. An overview of the treatment design is shown in Fig. 2.
wild-type F344/NSIc rats. Slices are chosen and allocated to obtain one F344/NSIc set (1) and five Hiss sets. The five Hiss brain slice sample sets are: (2) Mutant Control - Untreated cell culture; (3) Vehicle Control - “Empty” HSV-1 vector; (4) ZFN Test - HSV-1 carrying Scn1a specific ZFNs; (5) Reporter Control - HSV-1 with a gene for the mKO2 fluorescent protein; and (6) Treatment - HSV-1 carrying the ZFN, mK02 reporter, and the correct Scn1a cDNA. Wholecell patch clamp electrophysiology measurements for the F344/NSIc slices and various Hiss slices will act as controls to determine baseline electrical recordings for comparison with the test groups.15 Next, our expression measurements will measure RNA transcription. Quantitative reverse transcriptase PCR (qRT-PCR) will be utilized to determine the difference in transcription of Scn1a RNA between the control F344/NSIc and untreated Hiss slices and the four test groups, the treated Hiss slices. Western blots for the alpha subunit of Nav1.1 channels will then measure the level of the protein expression in each group. Fluorescent microscopy should detect the mKO2 reporter in cultures (5) and (6) to determine the quantity and location of successfully transfected cell populations in the brain slices. Expected results, per group, are shown in Table 1.
In Vivo Our in vivo testing will use experimentally naïve Vector Hiss rats and experimentally naïve wild-type The transgenes for the correct donor Scn1a F344/NSlc rats (line from which the mutated (pCMV-Scn1a-mKO2) (see Figure 2.a) and the Hiss line was derived), all starting at an age of four ZFN pair (pCMV-ZFN) (see Figure 2.b) will be weeks.16 Stereotaxic surgery will inject the viral enclosed in a replication defective HSV-1 vector. vector precisely into the hippocampal region.13,17 To minimize possible adverse effects, the less Weekly tests will involve inducing epileptic pathogenic KOS HSV-1 strain is chosen, seizures by situating the rats in a hot water bath while cytotoxic and replication-essential at 45°C and scoring the intensity of seizures on genes are removed.14 The expressed the 0-8 stage Moshé Racine scale.18 Unlike some ZFN will knock out mutant Scn1a in methods, hot water baths can induce seizures in targeted hippocampal cells, while the rats of up to 10 weeks of age.16 Rat behaviour new fluorescent correct sodium channel will be videotaped at all times to monitor the subunit will serve as a replacement. The presence and intensity of spontaneous seizure mKO2 fluorescent protein is used as a activity over the length of the experiment. At 10 reporter to verify the gene’s successful weeks of age, rats will be euthanized with CO2 transfection and expression. This novel and their brains will be removed and flash frozen use of HSV-1 and ZFNs offers the ability prior to sectioning. Expected results are shown to correct the Scn1a gene and alleviate in Table 1. Animals are to be housed and tested GEFS+ type 2 symptoms in Hiss rats, a in compliance with guidelines provided by the specific rat model for this epilepsy. Guide to the Care and Use of Experimental Animals.19 Ex Vivo Our ex vivo experiments are DISCUSSION divided into two broad categories: electrophysiology and expression testing. The Hiss rat model used in this experiment has The electrophysiology testing will first several limitations. Firstly, it focuses on a single use hippocampal slices in artificial CSF missense mutation - a change in one nucleotide prepared from 12 day-old Hiss rats and base resulting in a single substituted amino a in the
Group
Rat Strain
Measuring Expression (Expected to be the same ex vivo and in vivo) Scn1a RNA Levels
Nav1.1 Protein Levels
ex vivo: Electrophysiological Recordings
in vivo: Behavioural Analysis
1
F344/NSIc
Wild-type Control
Wild-type Control
Wild-type Control: Normal recordings
Wild-type Control: Relativelly low incidence and intensity of hyperthemia induced seizues (HIS)
2
Hiss
Mutant Control
Mutant Control
Mutant Control: Hyperpolarizing shift in voltage dependence of inactivation and higher persistent sodium current in bipolar neurons
Mutant Control: Relatively high incidence and intensity of HIS
3
Hiss
Equivalent to Mutant Control
Equivalent to Mutant Control
Equivalent to Mutant Control
Equivalent to Mutant Control
4
Hiss
↓Mutated
↓Mutated
Marked changes in overall electrical activity
↑Incidence and intensity of HIS ↑Incidence of spontaneous seizures
5
Hiss
Equivalent to Mutant Control
Equivalent to Mutant Control
Equivalent to Mutant Control
Equivalent to Mutant Control
6
Hiss
↑Correct ↓Mutated
Resemble Wildtype control
Resemble Wild-type Control
↓Incidence and intensity of HIS, resemble Wild-type Control
TABLE 1: Expected results
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Reviewed by Dr. eric seidlitz
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CONCLUSION Gene therapy is one of the most rapidly developing fields in science, and this proposal presents the foray of this technique into the field of epilepsy, a combination that has not been heavily explored in previous literature. Given the novelty of delivering ZFNs in conjunction with the therapeutic gene, our study would also represent a major advancement for gene therapy techniques. If successful, this therapy would have major implications in the treatment of debilitating epilepsies caused by mutations in the SCN1A gene, including Dravet Syndrome, It would set a precedent for future investigation into the use of gene therapy as a treatment for genetic brain diseases, and would be a hallmark in genetic editing science.
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ACKNOWLEDGEMENTS
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We would like to thank Dr. Margaret Fahnestock, Dr. Jack Gauldie, Dr. Deda Gillespie, Dr. Karen Mossman, Dr. Stash Nastos, Dr. P. K. Rangachari, Dr. Eric Seidlitz, and Dr. Henry Szechtman for their continued support and advice. This project would not have been possible without their tutelage and assistance. We would also like to thank the SciNapse Science Education programme, as well as the judges of the Undergraduate Science Case Competition, for the opportunity to delve into the world of epilepsy research. ■
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Edited by ELLEN HE
Dr. Eric Seidlitz is a distinguished researcher in the department of Pathology and Molecular Medicine and is a member of the Singh Lab at McMaster University. His research focuses extensively on the mechanisms surrounding pain in cancer and explores novel techniques for its management. In addition to his academic endeavours, Dr. Seidlitz is also known for teaching within the Bachelor of Health Sciences program.
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m e d u cato r | A p r i l 2015 med u c a t o r | december 2 0 1 5
Moving forward, it is important to develop a global delivery system that would enable expression of the therapeutic SCN1A gene in the entire mouse brain. To avoid activation in other cells aside from neurons, as measured using fluorescence, the currently designed CMV promoter can be replaced with a synapsin promoter.21 The experiment should also be repeated over a longer time frame using different SCN1A mutations and methods of inducing seizure to establish the long-term effects of the therapy in various scenarios. Finally, if this step is successful, we would subsequently evaluate non-invasive methods of delivery (e.g. exosomes, sonoporation) and techniques to deliver the
therapy across the blood-brain barrier, which would be required for any human applications in the future.
research proposal
protein’s peptide sequence. This is not an accurate model of human GEFS+, which is characterized by numerous mutations in the SCN1A gene. Further testing of the therapy on different mouse models would be required to improve its validity as a treatment. In addition, other species may have varied immune responses to HSV, as well as different neuronal cell populations that will have different transfection rates; thus, the treatment will need to be altered before any potential application in humans. Furthermore, the seizures in this model are only hyperthermiainduced and are therefore not representative of other causes of seizures, such as light-induced or drug-induced. Moreover, seizure activity is only tested for the first 10 weeks of life, which does not provide information about long-term efficacy of the treatment. Lastly, the vector is injected in the hippocampus in this model. Although this site has been implicated as the origin of epileptic activity GEFS+, it may not be the sole locus of seizures in the disorder.20
Fisher RS, van Emde Boas W, Blume W, Elger C, Genton P, Lee P, et al. Epileptic seizures and epilepsy: definitions proposed by the International League Against Epilepsy (ILAE) and the International Bureau for Epilepsy (IBE). Epilepsia. 2005 Apr;46(4):470–2. Löscher W, Schmidt D. Modern antiepileptic drug development has failed to deliver: Ways out of the current dilemma. 2011. 657–678 p. Löscher W, Leppik IE. Critical re-evaluation of previous preclinical strategies for the discovery and the development of new antiepileptic drugs. In: Epilepsy Research. 2002. p. 17–20. Weinberg MS, McCown TJ. Current prospects and challenges for epilepsy gene therapy. Exp Neurol. 2013 Jun;244:27– 35. Jacobs A, Breakefield XO, Fraefel C. HSV1-based vectors for gene therapy of neurological diseases and brain tumors: part II. Vector systems and applications. Neoplasia N Y N. 1999 Nov;1(5):402–16. Sasaki K, Chancellor MB, Goins WF, Phelan MW, Glorioso JC, de Groat WC, et al. Gene therapy using replication-defective herpes simplex virus vectors expressing nerve growth factor in a rat model of diabetic cystopathy. Diabetes. 2004 Oct;53(10):2723–30. Burton EA, Fink DJ, Glorioso JC. Replication-defective genomic HSV gene therapy vectors: design, production and CNS applications. Curr Opin Mol Ther. 2005 Aug;7(4):326–36. Krisky DM, Marconi PC, Oligino TJ, Rouse RJ, Fink DJ, Cohen JB, et al. Development of herpes simplex virus replication-defective multigene vectors for combination gene therapy applications. Gene Ther. 1998 Nov;5(11):1517–30. Durai S, Mani M, Kandavelou K, Wu J, Porteus MH, Chandrasegaran S. Zinc finger nucleases: custom-designed molecular scissors for genome engineering of plant and mammalian cells. Nucleic Acids Res. 2005 Jan;33(18):5978–90. Escayg A, MacDonald BT, Meisler MH, Baulac S, Huberfeld G, An-Gourfinkel I, et al. Mutations of SCN1A, encoding a neuronal sodium channel, in two families with GEFS+2. Nat Genet. 2000;24:343–5. Chopra R, Isom LL. Untangling the dravet syndrome seizure network: the changing face of a rare genetic epilepsy. Epilepsy Curr Am Epilepsy Soc. 2014 Mar;14(2):86–9. Tatum WO, Sirven JI. Epilepsy Case Studies [Internet]. Tatum WO, Sirven JI, Cascino GD, editors. Cham: Springer International Publishing; 2014. Paxinos G, Franklin KBJ. The Mouse Brain in Stereotaxic Coordinates. Gulf Professional Publishing; 2004. 140 p. Macdonald SJ, Mostafa HH, Morrison LA, Davido DJ. Genome sequence of herpes simplex virus 1 strain KOS. J Virol. 2012 Jun;86(11):6371–2. Degenetais E. Synaptic Influence of Hippocampus on Pyramidal Cells of the Rat Prefrontal Cortex: An In Vivo Intracellular Recording Study. Cereb Cortex. 2003 Jul;13(7):782–92. Mashimo T, Ohmori I, Ouchida M, Ohno Y, Tsurumi T, Miki T, et al. A missense mutation of the gene encoding voltage-dependent sodium channel (Nav1.1) confers susceptibility to febrile seizures in rats. J Neurosci Off J Soc Neurosci. 2010 Apr;30(16):5744–53. Fornari RV, Wichmann R, Atsak P, Atucha E, Barsegyan A, Beldjoud H, et al. Rodent stereotaxic surgery and animal welfare outcome improvements for behavioral neuroscience. J Vis Exp JoVE. 2012 Jan;(59):e3528. Galanopoulou. Seizures and the Developing Brain [Internet]. Morgan & Claypool Publishers; 2012. 100 p. Canadian Council on Animal Care. Guide to the Care and Use of Experimental Animals [Internet]. 1993. Gheyara AL, Ponnusamy R, Djukic B, Craft RJ, Ho K, Guo W, et al. Tau reduction prevents disease in a mouse model of Dravet syndrome. Ann Neurol. 2014 Sep;76(3):443–56. Kügler S, Kilic E, Bähr M. Human synapsin 1 gene promoter confers highly neuronspecific long-term transgene expression from an adenoviral vector in the adult rat brain depending on the transduced area. Gene Ther. 2003;10(4):337–47.
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INTERVIEW SPOTLIGHT
Dr.Qiyin Fang Shining Light on Biomedicine SABRINA LIN1, SARAH GE1, SANA GILL2
Bachelor of Health Sciences, Class of 2019 Bachelor of Health Sciences, Class of 2016 McMaster University Correspondence: sabrina.lin@learnlink.mcmaster.ca
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2
DR. QIYIN FANG IS AN ASSOCIATE PROFESSOR OF ENGINEERING
PHYSICS, MEMBER OF THE MCMASTER SCHOOL OF BIOMEDICAL ENGINEERING, AND AN ASSOCIATE MEMBER OF THE DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING AT MCMASTER UNIVERSITY. HE ALSO HOLDS THE COMMENDABLE POSITION OF CANADA RESEARCH CHAIR IN BIOPHOTONICS. HIS OTHER TITLES AND ACCOLADES INCLUDE BEING A SENIOR MEMBER OF THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING (SPIE), THE OPTICAL SOCIETY OF AMERICA (OSA), AND THE INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE). DR. FANG’S CURRENT RESEARCH INTERESTS INCLUDE STEADY-STATE AND TIME-RESOLVED FLUORESCENCE SPECTROSCOPY/IMAGING WITH BIOMEDICAL APPLICATIONS. PRIOR TO TEACHING AT MCMASTER UNIVERSITY, DR. FANG WORKED AS A PIONEERING RESEARCH SCIENTIST IN THE MINIMALLY INVASIVE SURGICAL TECHNOLOGY INSTITUTE AT THE CEDARS-SINAI MEDICAL CENTER IN LOS ANGELES. HE OBTAINED HIS UNDERGRADUATE DEGREE FROM NANKAI UNIVERISTY AND BOTH OF HIS GRADUATE DEGREES FROM EAST CAROLINA UNIVERSITY, WHERE HE STUDIED THE INTERACTION BETWEEN NANOSECOND LASER PULSE AND SOFT BIOLOGICAL TISSUE.
THANK YOU SO MUCH FOR MEETING WITH US, DR. FANG. FIRST OF ALL, CAN YOU TELL US A BIT ABOUT YOUR EDUCATIONAL BACKGROUND AND YOUR INSPIRATION FOR JOINING MCMASTER UNIVERSITY? Thank you for giving me the opportunity to talk about our research. I did my undergrad in physics and then my thesis work in optics. Around that time, I started becoming more interested in [the medical applications of ] optics because I have close family ties with medicine. As a result, I decided to pursue my graduate career in the field of biomedical optics, which, at the time, was a relatively new discipline. I did my Masters and PhD. in optics at East Carolina University and then worked at the Cedars-Sinai Medical Centre in Los Angeles for a few years. There, we focused primarily on clinical applications of optics, [specifically] on cardiovascular applications. And then about ten years ago, I decided to switch directions, so that's when I finally came to McMaster.
FIELDS INCLUDE MULTI-MODALITY OPTICAL BIOPSY TECHNIQUES. CAN YOU TELL US MORE ABOUT THIS AND WHAT IT ENTAILS FOR CLINICAL DIAGNOSIS AND GUIDED THERAPY?
YOUR RESEARCH FOCUS IS BIOPHOTONICS. CAN YOU TELL US A BIT ABOUT THIS AND WHAT INSPIRED YOU TO RESEARCH THIS FIELD?
ONE OF YOUR RECENT RESEARCH
| december 2 0 1 5
SO IS THIS APPLICABLE TO ALL TYPES OF TISSUE OR ONLY BRAIN TISSUE?
med u c a t o r
Biophotonics is a made-up word by people in our field. It is essentially the biomedical application of optics or photonics engineering. As biophotonics is an interdisciplinary research area, most of our projects are a result of a multi-disciplinary team of engineers and clinicians. In particular, our team uses a specialized technique called time-resolved fluorescence or time-resolved optical imaging to look at diagnostic applications. Recently, we have been looking at applications at the time scale of a few nanoseconds to picoseconds [and] femtoseconds. So that's quite a fast instrumentation technique.
interview spotlight
This is one of the projects I started as soon as I got here. We basically tried to look at non-invasive or minimally invasive magnets for in-vivo clinical diagnosis applications. Optical biopsy is a relatively new trend compared to traditional biopsy. In traditional biopsy, you take a piece of tissue from the patient, process it using histopathology, and look at the pathology changes in surface and subsurface features to make a diagnosis. This is a pretty standard technique for many diseases, but one of the problems with it is the associated possibility for sampling error. It is an invasive procedure so you can only take so many [samples], and as a result there are a limited number of data points or samples for analysis. Another drawback of traditional biopsy is that it is not real-time. Typically, a process called frozen biopsy is used, which allows you to analyze frozen test tissue for about fifteen to twenty minutes. Typically, it is used in skin cancer diagnosis during surgery or, in our case, in brain tumour surgery cases. This is the fastest way you can do it, but imagine the actual biopsy of a patient – you have viewpoints and you have weight, so it is not very practical. In fact, I think Hamilton Health Sciences has foregone the use of this process precisely because of this reason. Only a very few centres, such as the Cedars-Sinai Medical Centre, are still doing that. In the case of optical biopsy, we shine light on a target. In our specific case of brain tumours, we examined the cavity for residual tumours after the main bulk tumour had been removed. In those cases, we shone UV light into the cavity and based on the fluorescence light from that target [area], we were able to determine whether or not residual tumours were present. Obviously, the goal would be to remove as much of the tumour as possible. This optical fluorescence technique allowed us to sample the whole cavity without damaging it, and subsequently further probe the questionable regions with biopsy. This is what we call optical biopsy. For the multimodality part, we combined two techniques in optics – one being time-resolved fluorescence, and the other, diffuse reflectance. These two techniques are complementary so they allowed us to gain more information and cross-calibrate. This is an in-vivo technique so you see that many of the measurements are determined very quickly and so real-time calibration is very necessary.
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interview spotlight table of contents december 2 0 1 5 | med u c a t o r
“IN THE CASE OF OPTICAL BIOPSY, WE SHINE LIGHT ON A TARGET. IN OUR SPECIFIC CASE OF BRAIN TUMOURS, WE EXAMINED THE CAVITY FOR RESIDUAL TUMOURS AFTER THE MAIN BULK TUMOUR HAD BEEN REMOVED.”
Optical biopsy has broader applications that are not necessarily limited to brain tissue. We are currently focusing on the brain and also working with teams from the GI unit to look at esophageal and stomach cancer cases. For example, we are looking at lesions in the esophagus to determine whether we can distinguish malignant tissue from the normal tissue. The goal, in this case, would be early detection, instead of guided interventions.
ANOTHER RECENT
PUBLICATION OF YOUR’S IS “A 360 DEGREE SIDE VIEW ENDOSCOPE FOR LOWER GI TRACT MAPPING”. CAN YOU TELL US SOME OF THE HIGHLIGHTS AND IMPLICATIONS OF YOUR RESEARCH?
That’s a good question. For another lab, we are working with the same team in the GI division, which is led by Dr. Armstrong, chief of that division, and also Dr. Francis Xi. We are looking at the problem of colonoscopy screening in colorectal cancer. We essentially screen everyone over 50 years old. That’s a large volume of patients to try to screen. One of the problems during this process is that the cameras mounted at the tip of the endoscope are forwardlooking and they are wide-angled, quite wide-angled actually — almost 170 degrees. Nonetheless, they are still forward-looking. Now imagine that you are going through a tunnel, a narrow tunnel. Most of the interesting parts will be on the wall, right? If you actually look straight down in a forward view, the majority of what is seen will be down the tunnel, but the information we are interested in is on the sidewalls. We targeted this problem by developing a special optical system that can guide the endoscope forward by looking straight down, while creating a [lag part] of the image view, which can then be separated so that we look only at the side wall as the scope moves along. Eventually, this allows us to move the endoscope down the colon and recreate a 2-dimensional [view] of the colon [wall]. There are implications other than just improved imaging. Using this technology, we can actually skip the real-time diagnostic part because this is a very fast procedure. One of our goals is to incorporate this
technology into a pill camera so that the camera can pass through the digestive tract. Thus, medical professionals can image the whole tract and receive an “unwrapped map.” From there, we can use different methods to highlight specific regions before going back and repeating the procedure. Typically, that means that for 95% of the patients, we don’t actually have to look again. Only with patients who have potential problems will we go back and look at those regions. This technique improves the efficiency of screening procedures significantly. Currently, we are working with the GI team and the MDA** robotics team from Brampton on this technology as they have developed similar technologies for mind surface mapping.
WHERE DO YOU SEE THE FIELD OF BIOPHOTONICS GOING IN THE NEXT 20 YEARS? This is a rather new field. The term itself was conceived around the 90’s, and although the usage of optics in biomedical applications has a very long history, this field is relatively new. In the last 20 years or so, many of the techniques have become commercialized. So far, the majority of applications in Biophotonics focuses on diagnosis. Most of them, especially those from the early 90’s, are so-called laser medicine applications such as laser-based angioplasty and laser eye surgery… But I think that the direction in which we’re headed will integrate diagnostic and therapeutic applications.
DO YOU HAVE ANY SUGGESTIONS OR ADVICE FOR STUDENTS ASPIRING TO BE RESEARCH SCIENTISTS? Well, I think my advice would probably be to keep their interests broad. If they see something interesting, they should give it a try. And obviously, when they become serious about a particular topic or idea, they can start to focus… But the initial interest is most important.
ASIDE FROM YOUR ACADEMIC PURSUITS, WHAT OTHER INTERESTS OR PASSIONS DO YOU HAVE? When I have the time, I play quite a bit of sports. I mean, I may not be very good at it, but mostly it’s just interest.
WHAT TYPES OF SPORTS? I think I play soccer the most –we have a soccer team where I live, so I play pretty regularly. Over the summer, I actually participate in softball. I also swim competitively, so that keeps me busy!
**MacDonald, Dettwiler and Associates
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