Medicine and Health Sciences Commons^™

Vitamin D Levels In Peanut Allergic Children, Adam Fowlie, Laura Kim, Trefford Simpson, Harold Kim

Department of Medicine Presentations

Background

The prevalence of peanut allergy is increasing. The reasons for this are not entirely known. A factor may be vitamin D (Vit D).

Methods

This study was performed in a referral allergist’s office in Ontario. Prospectively, all patients (<18 years old) with peanut allergy who were tested for peanut specific IgE (PN IgE) also had Vit D measured. All measurements were done between December 2010 and May 2011. The Vit D measure was 25-hydroxy vitamin D. Patients were divided into three groups: deficient (less than 25 nmol/L), insufficient (25-75 nmol/L) and sufficient (75-250 nmol/L). Vit D levels were compared to PN IgE, sex, age, body mass index (BMI) and other allergies.

Results

Fifty peanut allergic patients were included. The mean Vit D level of the patients was 73.8 nmol/L and the 95% confidence interval was 69.6 - 75.7 nmol/L. One patient (2%) had deficient and thirty-one (62%) of the patients had insufficient Vit D levels. Nineteen (38%) had Vit D levels in the sufficient range. There was no correlation between Vit …

Culture Medium, Gas Atmosphere And Mapk Inhibition Affect Regulation Of Rna-Binding Protein Targets During Mouse Preimplantation Development., Michele D Calder, Patricia H Watson, Andrew J Watson

Obstetrics & Gynaecology Publications

During oogenesis, mammalian oocytes accumulate maternal mRNAs that support the embryo until embryonic genome activation. RNA-binding proteins (RBP) may regulate the stability and turnover of maternal and embryonic mRNAs. We hypothesised that varying embryo culture conditions, such as culture medium, oxygen tension and MAPK inhibition, affects regulation of RBPs and their targets during preimplantation development. STAU1, ELAVL1, KHSRP and ZFP36 proteins and mRNAs were detected throughout mouse preimplantation development, whereas Elavl2 mRNA decreased after the two-cell stage. Potential target mRNAs of RBP regulation, Gclc, Slc2a1 and Slc7a1 were detected during mouse preimplantation development. Gclc mRNA was significantly elevated in embryos …

Master Transcription Factors Determine Cell-Type-Specific Responses To Tgf-Β Signaling, Alan C. Mullen, David A. Orlando, Jamie J. Newman, Jakob Lovén, Roshan M. Kumar, Steve Bilodeau, Jessica Reddy, Matthew G. Guenther, Rodney P. Dekoter, Richard A. Young

Paediatrics Publications

Transforming growth factor beta (TGF-β) signaling, mediated through the transcription factors Smad2 and Smad3 (Smad2/3), directs different responses in different cell types. Here we report that Smad3 co-occupies the genome with cell-type-specific master transcription factors. Thus, Smad3 occupies the genome with Oct4 in embryonic stem cells (ESCs), Myod1 in myotubes, and PU.1 in pro-B cells. We find that these master transcription factors are required for Smad3 occupancy and that TGF-β signaling largely affects the genes bound by the master transcription factors. Furthermore, we show that induction of Myod1 in nonmuscle cells is sufficient to redirect Smad3 to Myod1 sites. We …

The Effect Of Intermittent Umbilical Cord Occlusion On Elastin Composition In The Ovine Fetus., Jennifer A Thompson, Sarah A Gimbel, Bryan S Richardson, Robert Gagnon, Timothy Regnault

Paediatrics Publications

This study aimed to determine the effect of varying degrees of intermittent umbilical cord occlusion (UCO) on arterial elastin composition. Over 4 days, chronically catheterized late gestation fetal sheep received 5 total UCO per day lasting 1 min/h (mild group: n = 6), 2 min/h (moderate group: n = 4), 3 min/h (severe group; n = 6); or no occlusion (control group: n = 7). Each group was evaluated for elastin content of the carotid and superior mesenteric artery (SMA), the arterial pressure response to UCO, and plasma cortisol concentration. Elastin content of the carotid artery was significantly increased by …

Strategies For Reducing The Impact Of Tumour Motion During Helical Tomotherapy, Bryan Kim

Electronic Thesis and Dissertation Repository

Tumour motion presents a significant limitation for effective radiotherapy of lung cancer, and more specifically for helical tomotherapy. The simultaneous and continuous movements of tomotherapy subsystems (gantry, couch, and binary multi-leaf collimator) can lead to inaccurate dose delivery, when combined with tumour motion. In this thesis, we have investigated the impact of tumour motion and strategies to reduce the resulting dose discrepancies for helical tomotherapy, through computer simulations and film measurements performed in a dynamic body phantom. Three distinctively different types of dose discrepancies have been isolated: dose rounding, dose rippling, and the intensity-modulated radiation therapy (IMRT) asynchronization effect. Each …

Metastatic Disease: Interactions Between Tumor Cells And Host Environment During Cancer Cell Spread, Jennifer M. Maclean

Electronic Thesis and Dissertation Repository

Tumor and metastasis formation are not cell autonomous phenomena, but rather an evolution of disease within and responding to the host environment. Metastatic spread from a primary tumor occurs as a result of a complex interplay between tumor cells and the host, wherein tumor cells must escape the primary tumor, enter the host vasculature, travel to and arrest in a distant tissue and survive and grow in that new organ. It is known that cells that progress through these stages must both escape and exploit host systems, yet the mechanisms used are not fully understood. Therefore, the goal of this …

The Authors Reply:, Ajay P. Sharma, Guido Filler, Prabo Dwight, William F. Clark

Paediatrics Publications

No abstract provided.

A Comparison Of Two Headless Compression Screws For Operative Treatment Of Scaphoid Fractures, Ruby Grewal, Joseph Assini, David Sauder, Louis Ferreira, Jim Johnson, Kenneth Faber

Surgery Publications

PURPOSE: The purpose of this study was to compare the interfragmentary compression force across a simulated scaphoid fracture by two commonly used compression screw systems; the Acutrak 2 Standard and the 3.0 mm Synthes headless compression screw.

METHODS: Sixteen (8 pairs; 6 female, 2 male) cadaver scaphoids were randomly assigned to receive either the Acutrak 2 or Synthes screw with the contralateral scaphoid designated to receive the opposite. Guide wires were inserted under fluoroscopic control. Following transverse osteotomy, the distal and proximal fragments were placed on either side of a custom load cell, to measure interfragmentary compression. Screws were placed …

Integrin-Linked Kinase: A Scaffold Protein Unique Among Its Ilk, Lina Dagnino

Paediatrics Publications

Integrin-linked kinase (ILK) is a scaffolding protein with central roles in tissue development and homeostasis. Much debate has focused on whether ILK is a bona fide or a pseudo- kinase. This aspect of ILK function has been complicated by the large volumes of conflicting observations obtained from a wide variety of experimental approaches, from in vitro models, to analyses in invertebrates and in mammals. Key findings in support or against the notion that ILK is catalytically active are summarized. The importance of ILK as an adaptor protein is well established, and defining its role as a signaling hub will be …

Maternal Protein Restriction Elevates Cholesterol In Adult Rat Offspring Due To Repressive Changes In Histone Modifications At The Cholesterol 7Α-Hydroxylase Promoter, Gurjeev Sohi, Kelly Marchand, Andrew Revesz, Edith Arany, Daniel B. Hardy

Paediatrics Publications

Adverse events in utero, such as intrauterine growth restriction (IUGR), can permanently alter epigenetic mechanisms leading to the metabolic syndrome, which encompasses a variety of symptoms including augmented cholesterol. The major site for cholesterol homeostasis occurs via the actions of hepatic cholesterol 7α-hydroxylase (Cyp7a1), which catabolizes cholesterol to bile acids. To determine whether posttranslational histone modifications influence the long-term expression of Cyp7a1 in IUGR, we used a protein restriction model in rats. This diet during pregnancy and lactation led to IUGR offspring with decreased liver to body weight ratios, followed by increased circulating and hepatic cholesterol levels in both sexes …

Deletion Of Glycogen Synthase Kinase-3Β In Cartilage Results In Up-Regulation Of Glycogen Synthase Kinase-3Α Protein Expression, J. R. Gillespie, V. Ulici, H. Dupuis, A. Higgs, A. Dimattia, S. Patel, J. R. Woodgett, Frank Beier

Paediatrics Publications

The rate of endochondral bone growth determines final height in humans and is tightly controlled. Glycogen synthase kinase-3 (GSK-3) is a negative regulator of several signaling pathways that govern bone growth, such as insulin/IGF and Wnt/β-catenin. The two GSK-3 proteins, GSK-3 and GSK-3β, display both overlapping and distinct roles in different tissues. Here we show that pharmacological inhibition of GSK-3 signaling in a mouse tibia organ culture system results in enhanced bone growth, accompanied by increased proliferation of growth plate chondrocytes and faster turnover of hypertrophic cartilage to bone. GSK-3 inhibition rescues some, but not all, effects of phosphatidylinositide 3-kinase …

Rac1 Activation Induces Tumour Necrosis Factor-Α Expression And Cardiac Dysfunction In Endotoxemia, Ting Zhang, Xiangru Lu, Frank Beier, Qingping Feng

Paediatrics Publications

Induction of tumour necrosis factor-α (TNF-α) expression leads to myocardial depression during sepsis. However, the underlying molecular mechanisms are not fully understood. The aim of this study was to investigate the role of Rac1 in TNF-α expression and cardiac dysfunction during endotoxemia and to determine the involvement of phosphoinositide-3 kinase (PI3K) in lipopolysaccharide (LPS)-induced Rac1 activation. Our results showed that LPS-induced Rac1 activation and TNF-α expression in cultured neonatal mouse cardiomyocytes. The response was inhibited in Rac1 deficient cardiomyocytes or by a dominant-negative Rac1 (Rac1N17). To determine whether PI3K regulates Rac1 activation, cardiomyocytes were treated with LY294002, a PI3K selective …

From Isolated Tumour Cells To Overt Lymph Node Metastases: Biological And Imaging Studies On The Development Of Experimental Lymph Node Metastases, Michael M. Lizardo

Electronic Thesis and Dissertation Repository

Metastatic colonization and establishment of overt lymph node (LN) tumours indicates poor prognosis for cancer patients. However, the basic biology that influences the development of LN metastasis is poorly understood due to the lack of basic animal models. The following work provides a new lymph node experimental metastasis assay (LEMA) that permits the assessment of tumour cell fate after they arrest in draining LNs. In using this new model, we discovered that only 8% of the tumour cells that arrive in the LN are successful in forming overt tumours. This work also explored the use of imaging approaches to monitor …

Eat, Drink And Be Wary, Robert Lannigan

Pathology Presentations

The diversity of foods available and the way we produce, process and distribute them can have consequences in terms of infectious illnesses. This talk by Dr. Robert Lannigan, professor in Western’s Schulich School of Medicine & Dentistry, explores some of these concerns.

The Characteristics Of Successful Evidence Retrieval By Nephrologists And The Impact Of Pubmed Search Filters, Salimah Shariff

Electronic Thesis and Dissertation Repository

Background: Clinicians frequently search PubMed to guide patient care. This study investigated the factors that impact successful searching and the utility of PubMed search filters.

Methods: A random sample of nephrologists was surveyed between 2008 and 2010; 160 valid responses were received (72% response rate). One group of 60 respondents was presented with the same two clinical questions, while the other 100 were each presented with a unique clinical question. The clinical questions were based on recently published systematic reviews. Respondents provided the search terms they would type into PubMed to address their clinical question(s). All physician-provided searches …

Pregnant Women As Research Participants: Why Is Additional Protection Required?, Kyoko Wada

Research Day (Arts & Humanities, FIMS, and Education)

Today, blanket exclusion of pregnant women from research participation is not endorsed; however, a tendency still remains to exclude pregnant women from participating in research. This exclusion results in insufficient data to guide clinical practice for pregnant women, and hence adds risks to pregnant women and fetuses (Lyerly et al. 2007, 2008, 2009; Baylis 2010; Goldkind et al. 2010).

Human Spinal Cord Injury Causes Specific Increases In Surface Expression Of Beta Integrins On Leukocytes, Feng Bao, Christopher S. Bailey, Kevin R. Gurr, Stewart I. Bailey, M. Patricia Rosas-Arellano, Arthur Brown, Gregory A. Dekaban, Lynne C. Weaver

Paediatrics Publications

Spinal cord injury (SCI) activates circulating leukocytes that migrate into the injured cord and bystander organs using adhesion molecule-mediated mechanisms. These cells cause oxidative damage, resulting in secondary injury to the spinal cord, as well as injury to bystander organs. This study was designed to examine, over a 6-h to 2-week period, changes in adhesion molecule surface expression on human peripheral leukocytes after SCI (9 subjects), using as controls 10 uninjured subjects and 6 general trauma patients (trauma controls, TC). Both the percentage of cells expressing a given adhesion molecule and the average level of its expression was quantified for …

Hyperfiltration Affects Accuracy Of Creatinine Egfr Measurement, Shih Han S. Huang, Ajay P. Sharma, Abeer Yasin, Robert M. Lindsay, William F. Clark, Guido Filler

Paediatrics Publications

Background and objectives: Surrogate markers such as creatinine, cystatin C (CysC), and beta trace protein (BTP) have been used to estimate GFR (eGFR). The accuracy of eGFR may be altered with hyperfiltration and differences in filtration fraction (FF). It is hypothesized that the accuracy of creatinine for eGFR may be affected by hyperfiltration and different effective renal plasma flow (ERPF). Design, setting, participants, & measurements: A total of 127 pediatric patients with various renal diseases underwent simultaneous measurements of GFR using 51Cr-EDTA renal scan and ERPF ( 131I-hippurate clearance) to calculate the FF (FF = GFR/ERPF). The eGFRs were calculated …

Ouabain Stimulates A Na+/K+-Atpase-Mediated Sfk-Activated Signalling Pathway That Regulates Tight Junction Function In The Mouse Blastocyst., Holly Giannatselis, Michele Calder, Andrew J Watson

Obstetrics & Gynaecology Publications

The Na(+)/K(+)-ATPase plays a pivotal role during preimplantation development; it establishes a trans-epithelial ionic gradient that facilitates the formation of the fluid-filled blastocyst cavity, crucial for implantation and successful pregnancy. The Na(+)/K(+)-ATPase is also implicated in regulating tight junctions and cardiotonic steroid (CTS)-induced signal transduction via SRC. We investigated the expression of SRC family kinase (SFK) members, Src and Yes, during preimplantation development and determined whether SFK activity is required for blastocyst formation. Embryos were collected following super-ovulation of CD1 or MF1 female mice. RT-PCR was used to detect SFK mRNAs encoding Src and Yes throughout preimplantation development. SRC and …

Learning From Mistakes: Improving Initial Fingertip Force Scaling By Observing Lifting Errors, Gavin Buckingham, Minnie Tang, Paul Gribble, Melvyn A. Goodale

Psychology Presentations

• When lifting objects that are lighter or heaver than we expect them to be, individuals typically misapply forces in a way that reflects their prior expectations of heaviness.

• Because we lift in this predictive way, large and small cubes elicit these characteristic errors even when they are adjusted to have equal mass. Lifters will apply too much force to a large cube and substantially less force to a small cube – errors that are rapidly corrected with repeated lifts (Flanagan & Beltzner, 2000).

• When watching others lift objects, an observer’s motor system automatically reacts in a way …

Integrin-Linked Kinase Is Required For Tgf-_1 Induction Of Dermal Myofibroblast Differentiation, Linda Vi, Cristina De Lasa, Gianna M. Diguglielmo, Lina Dagnino

Paediatrics Publications

Cutaneous repair after injury requires activation of resident dermal fibroblasts and their transition to myofibroblasts. The key stimuli for myofibroblast formation are activation of transforming growth factor-b (TGF-b) receptors and mechanotransduction mediated by integrins and associated proteins. We investigated the role of integrin-linked kinase (ILK) in TGF-b1 induction of dermal fibroblast transition to myofibroblasts. ILK-deficient fibroblasts treated with TGF-b1 exhibited attenuation of Smad 2 and 3 phosphorylation, accompanied by impaired transcriptional activation of Smad targets, such as a-smooth muscle actin. These alterations were not limited to Smad-associated TGF-b1 responses, as stimulation of noncanonical mitogenactivated protein kinase pathways by this growth …

Chest Compressions And Epinephrine During Resuscitation Of Infants Born At The Border Of Viability: Yes, No Or Maybe?, Gregory P. Moore, Thierry Daboval, Kevin W. Coughlin

Paediatrics Publications

Neonatology, in large part due to its population of babies born at the edge of viability, is rife with bioethical issues. This unique population is at high risk of mortality and considerable neurodevelopmental morbidity. One contentious, ongoing debate concerns whether these extremely low birth weight infants born at the border of viability should, if required by the Neonatal Resuscitation Program guidelines, receive chest compressions and epinephrine as part of their delivery room resuscitation. The present article, through a case presentation and discussion based on the ethical framework of principlism, provides readers with a thoughtful approach to the controversial issue of …

Histamine Deficiency Promotes Inflammation-Associated Carcinogenesis Through Reduced Myeloid Maturation And Accumulation Of Cd11b +Ly6g+ Immature Myeloid Cells, Xiang Dong Yang, Walden Ai, Samuel Asfaha, Govind Bhagat, Richard A. Friedman, Guangchun Jin, Heuijoon Park, Benjamin Shykind, Thomas G. Diacovo, Andras Falus, Timothy C. Wang

Paediatrics Publications

Histidine decarboxylase (HDC), the unique enzyme responsible for histamine generation, is highly expressed in myeloid cells, but its function in these cells is poorly understood. Here we show that Hdc-knockout mice show a high rate of colon and skin carcinogenesis. Using Hdc-EGFP bacterial artificial chromosome (BAC) transgenic mice in which EGFP expression is controlled by the Hdc promoter, we show that Hdc is expressed primarily in CD11b +Ly6G+ immature myeloid cells (IMCs) that are recruited early on in chemical carcinogenesis. Transplant of Hdc-deficient bone marrow to wild-type recipients results in increased CD11b + Ly6G + cell mobilization and reproduces the …

Nitric Oxide And Osteoporosis: What A Gas!, Sophie Jamal

Canadian Centre for Activity and Aging Presentations

No abstract provided.