Roland Dyck - Academia.edu (original) (raw)

Papers by Roland Dyck

Environmental health perspectives, Oct 20, 2014

Background: Asthma prevalence is thought to be lower in rural locations. However, among children ... more Background: Asthma prevalence is thought to be lower in rural locations. However, among children with asthma, some rural exposures thought to protect against the development of asthma could also ag...

PubMed, Jun 1, 1990

The purpose of this study was to investigate the plasma fibronectin response to complicated and u... more The purpose of this study was to investigate the plasma fibronectin response to complicated and uncomplicated acute myocardial infarction. All patients admitted to a Coronary Care Unit over a six-month period were prospectively assessed by measuring admission and daily plasma fibronectin levels using an electroimmunoassay. Of 166 patients admitted to the Unit, 66 were diagnosed as having an acute myocardial infarction. Plasma fibronectin levels were significantly lower 48 h after the onset of symptoms in 15 patients with a complicated acute myocardial infarction, compared to fibronectin levels in patients with an uncomplicated course; patients who had received intracoronary streptokinase had consistently higher plasma fibronectin levels than those seen in patients who did not receive this thrombolytic agent. This hepatocyte-derived plasma protein not only has diagnostic potential, but alterations in its levels may also provide insight into the systemic response to acute myocardial injury.

PubMed, Mar 1, 1990

Six years after the onset of polyarthritis and after several episodes of recurrent parotitis, our... more Six years after the onset of polyarthritis and after several episodes of recurrent parotitis, our patients developed the abrupt onset of renal insufficiency. Kidney histopathology showed interstitial and peritubular lymphocytic infiltration typical of Sjögren's nephropathy. Treatment with high dose intravenous methylprednisolone resulted in rapid and sustained normalization of kidney function. The favorable response of our patient to intravenous pulse corticosteroids suggests that this therapy is effective for the treatment of Sjögren's nephropathy.

Respiratory Medicine, May 1, 2018

Background: Asthma severity can be affected by microbial exposures. However, less is known about ... more Background: Asthma severity can be affected by microbial exposures. However, less is known about the specific indoor agents aggravating the disease in children. We examined the associations between indoor endotoxin and beta-(1→3)-D-glucan exposures and asthma severity in children with asthma. Methods: A clinical cross-sectional study of schoolchildren (aged 7-17 years) was conducted in the province of Saskatchewan, Canada. Children with asthma (n = 116) were identified through a combination of survey responses and objective clinical assessments. We then ascertained asthma severity based on recommended guidelines. Continuous daytime asthma symptoms, frequent nighttime asthma symptoms, and ≤60% predicted FEV 1). Levels of indoor endotoxin and beta-(1→3)-D-glucan were measured in dust samples obtained from play area floors and child's mattresses. Results: The study population of 116 children with asthma was comprised of 75.9% mild asthma and 24.1% moderate/severe asthma. Higher mattress endotoxin concentration was associated with increased odds of moderate/severe asthma [adjusted odds ratio (aOR) = 11.40, 95% confidence interval (CI): 1.45-89.43] while higher beta-(1→3)-D-glucan concentration (aOR = 0.16, 95% CI: 0.03-0.89) and load (aOR = 0.10, 95% CI: 0.02-0.72) in play areas were inversely associated with moderate/severe asthma. Furthermore, higher mattress endotoxin concentration was associated with lower FVC (p = 0.01) and FEV 1 (p = 0.03). These associations were not seen for beta-(1→3)-D-glucan. Conclusion: Our results showed differential effects of microbial exposures on childhood asthma severity and further highlight domestic endotoxin exposure effects on respiratory health outcomes in children with asthma.

PubMed, May 1, 1979

Five patients with primary idiopathic polymyositis developed proteinuria associated with urine se... more Five patients with primary idiopathic polymyositis developed proteinuria associated with urine sediment abnormalities. Renal biopsies disclosed a focal mesangial proliferative glomerulonephritis with deposits of immunoglobulin and complement. After treatment of the polymyositis with corticosteroids, proteinuria and urine sediment changes disappeared within 4 to 8 wk along with an improvement in the muscle disease. Although the pathogenesis remains to be determined, immune complexes may be implicated in the etiology of this renal lesion.

PubMed, Jan 15, 1994

Objective: To determine the rates and outcomes of diabetic end-stage renal disease (ESRD) among r... more Objective: To determine the rates and outcomes of diabetic end-stage renal disease (ESRD) among registered native people and non-native people in Saskatchewan. Design: Retrospective population-based study using data from the Canadian Organ Replacement Registry. Setting: Saskatchewan. Patients: All patients with diabetic ESRD diagnosed between Jan. 1, 1981, and Dec. 31, 1990. Main outcome measures: Incidence rates of diabetic ESRD in the general population, rates of diabetic ESRD among patients with diabetes mellitus, nature of initial dialysis treatment, length of survival from start of dialysis, cause of death and renal transplant rates. Results: The 10-year incidence rates of diabetic ESRD were higher among all age groups among registered native people than among non-native people. The overall relative risk ratio for native people was 16.2. When a higher prevalence of diabetes among native people was taken into account, native diabetic people were still seven times as likely as non-native diabetic people to manifest diabetic ESRD. The median survival from start of dialysis was under 2 years in both groups, but more native people died of stroke and more non-native people died of heart disease. Non-native diabetic people were more likely than native diabetic people to receive renal transplants. Conclusions: Although the overall incidence of diabetic ESRD in Saskatchewan is increasing, registered native people have a disproportionate risk for this serious complication.

PubMed, Nov 1, 1979

Serum amyloid P-component (protein SAP) was found to bind in vitro to isolated amyloid fibrils of... more Serum amyloid P-component (protein SAP) was found to bind in vitro to isolated amyloid fibrils of both primary and secondary types. The binding was strictly calcium-dependent, optimal uptake requiring at least 0.5 mM calcium ion. Using normal human serum as the source of protein SAP different fibril preparations became saturated with between 5--20 micrograms of SAP per mg dry weight of fibril. Isolated pure protein SAP bound in greater amounts. In control experiments SAP did not bind significantly to collagen fibrils, sheep erythrocytes, plastic shavings, or the following immobilized proteins: human kappa or lambda Bence-Jones proteins; human; rabbit or mouse IgG; human serum albumin. C-reactive protein, which resembles protein SAP structurally but has calcium-dependent specificity for different ligands, bound significantly to only one of five different amyloid fibril preparations.

Journal of the American College of Toxicology, 1985

The effects of T-2 toxin on a murine model of the acute phase response were studied. Two murine a... more The effects of T-2 toxin on a murine model of the acute phase response were studied. Two murine acute phase reactants, serum amyloid P component and plasma fibronectin, were measured after subcutaneous and intraperitoneal administration of T-2 toxin in varying doses. No acute phase response was observed. Furthermore, T-2 toxin also blocked the acute phase reaction to subcutaneous AgNO3 in a dose-dependent fashion. These observations were not explained by damage to liver, the site of synthesis of acute phase proteins. Since the acute phase response is an immediate physiological reaction to tissue injury and may be a nonspecific participant in the repair phenomenon, its abrogation by T-2 toxin may contribute to the toxicity of this trichothecene mycotoxin.

Journal of Experimental Medicine, Nov 1, 1980

PubMed, Sep 1, 1980

Amyloid P-component was sought by immunofluorescence in the tissues of CBA mice receiving repeate... more Amyloid P-component was sought by immunofluorescence in the tissues of CBA mice receiving repeated subcutaneous injections of casein. P-component appeared in a perifollicular distribution in the spleen after about twenty casein injections, and correlated precisely with amyloid deposits identified by staining with Congo red. In mice which had received at least fourteen injections of casein, P-component also became detectable within the cytoplasm of periportal hepatocytes. This is the first demonstration of P-component in murine amyloid and of a possible site for in vivo synthesis of P-component.

Clinica Chimica Acta, Jul 1, 1980

... Lond.) 273, 168170 10 Pepys, MB, Baltz, ML, Dyck, RF, de Beer, FC Evans, DJ, Feinstein, A., M... more ... Lond.) 273, 168170 10 Pepys, MB, Baltz, ML, Dyck, RF, de Beer, FC Evans, DJ, Feinstein, A., Milstein, CP, Munn, EA, Richardson, N., March, JF, Fletcher, TC, Davies, AJS, Gomer, K., Cohen ... Churchill and Livingstone, London 14 Pepys, MB, Dash, AC and Ashley, J. (1977) Clin. ...

BMJ, Feb 27, 1993

A fine needle on a syringe was introduced through the cyst wall, and air under pressure pushed th... more A fine needle on a syringe was introduced through the cyst wall, and air under pressure pushed the syringe barrel outwards. At this point the surgeon and the anaesthetist realised that this pharyngocele had resulted from the inflated cuffof the laryngeal mask used. It was more prominent through the head having been turned to the opposite side. The "diagnostic" puncture of the cuff resulted in a slow deflation, which eventually necessitated the replacement of the mask owing to the development of laryngeal spasm. The surgeon was relieved ofthe need for further investigation of the swelling.

The Lancet, Nov 1, 1979

Davies and Dr Davies (Oct. 27, p. 911) report the presence of nephrotic syndrome in two patients ... more Davies and Dr Davies (Oct. 27, p. 911) report the presence of nephrotic syndrome in two patients with dermatitis herpetiformis (DH). They point out the relation between DH (and cceliac disease) and HLA-DRw3, which is also associated with idiopathic membranous nephropathy, and suggest that evidence of nephritis be sought in patients with gluten-sensitive disease. We recently reported the case of a young woman with immune-complex glomerulonephritis and coeliac disease in whom antibodies to wheat proteins were found in serum.' Withdrawal of gluten from the diet resulted in the disappearance of immune complexes from serum and resolution of both renal and intestinal disease. Dietary antigens may be an important but unrecognised cause of immune-complex glomerulonephritis.

Arthritis & Rheumatism, Jun 1, 1980

Diabetes Research and Clinical Practice, Apr 1, 2020

Canada to develop quality improvement (QI) initiatives aimed at improving T2DM. Methods: Pre-post... more Canada to develop quality improvement (QI) initiatives aimed at improving T2DM. Methods: Pre-post mixed-methods case study design was used. The 18-month intervention included community and clinical readiness, development of a community diabetes registry and clinical system, and QI activities. Participants consisted of community members, 18 yrs and older, with diabetes. Changes in clinical outcomes and clinical practice guideline (CPG) recommendations were assessed pre and post intervention using multilevel regression (patients nested within communities) adjusted for individual and community baseline characteristics. Results: No significant change in HbA1c or sBP, but a small reduction in dBP (À0.75 mmHg, p < 0.05) and LDL (À0.09 mmol/L, p < 0.05

Journal of Investigative Dermatology, Oct 31, 1981

Canadian Journal of Diabetes, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

International Journal of Circumpolar Health, Jan 31, 2016

Background. First Nations people are experiencing increasing rates of obesity and type 2 diabetes... more Background. First Nations people are experiencing increasing rates of obesity and type 2 diabetes but no anthropometric information exists from before the 1950s to provide context to these epidemics. Objective. To compare anthropometric indices of First Nations children and youth on first entering residential schools with historical and contemporary reference groups. Methods. This observational cross-sectional study used archival records from the Department of Indian Affairs to calculate body mass index (BMI), height for age (HA) and weight for age (WA) of all known children and youth undergoing physical examinations on first entering residential schools in Saskatchewan and Manitoba from 1919 to 1953. Proportions of children and youth in each BMI category were determined by age, sex, time period and residential school. Z-scores for HA and WA were determined by age group and sex. Finally, median heights and weights were compared with a non-Indigenous cohort from the 1953 Canadian survey. Results. On admission to residential schools, 1,767 First Nations children and youth (847 boys, 920 girls) were more likely to have normal BMIs (79.8%) than Canadian children and youth today (66.5%), but lower rates of overweight/obesity (10.9% vs. 32.0%) and higher rates of underweight (9.3% vs. B2.0%). There was an overall trend of diminishing levels of underweight and increasing levels of overweight/obesity over time. Although 6.6% of boys and 7.9% of girls had HA Z-scores ! (2, age-specific median heights tended to be higher than Canadian children and youth in 1953. Under 3% of children and youth had WA Z-scores of ! (2. Conclusions. A large majority of First Nations children and youth exhibited normal anthropometric indices on first entering residential schools in Manitoba and Saskatchewan from 1919 to 1953. These historical findings provide an important context to the current epidemics of obesity and type 2 diabetes and suggest that the nutritional conditions in these First Nations children's communities were satisfactory during the residential school era.