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Biomedical subjects

C Lauzon

Publications and source records attributed to C Lauzon.

7 recordsLinked to original sources
PubMed2006

The effects of vitamin C supplementation on symptoms of delayed onset muscle soreness.

AIM: The aim of this study was to compare the effects of 8 days of vitamin C (VC) supplementation on elbow flexor delayed onset muscle soreness (DOMS) to 8 days of placebo ingestion. METHODS: For 3 days prior to an exercise bout (2 x 20 eccentric elbow extensions), and for 5 days after, a treatment group ingested 3 x 1000 mg/day of VC versus 3 x 50 mg/day of glucose ingestion for the placebo group over the same time period. All subjects were prescreened via dietary recall to exclude any subjects with habitual VC consumption greater than 400 mg/day. Subject comprised 24 subjects (male and female) randomly divided into 2 groups of 12 subjects. Treatment group comprised 5 females and placebo group comprised 8 females. RESULTS: Data from a repeated measures ANOVA indicate that DOMS was successfully induced in both groups via significant time effects for strength loss (P = 0.0001), point tenderness (P = 0.0001), elbow flexor decreased range of motion (P = 0.013), and subjective pain (P = 0.0001). However, there were no significant between group differences in response to any of the aforementioned variables: strength loss (P = 0.202), point tenderness (P = 0.824), elbow flexor range of motion (P = 0.208), subjective pain (P = 0.342). CONCLUSIONS: The results of this study suggest that a VC supplementation protocol of 3 x 1000 mg/day for 8 days is ineffective in protecting against selected markers of DOMS.

Adult↗
PubMed2001

Discharge prescriptions following admission for acute myocardial infarction at tertiary care and community hospitals in Quebec.

BACKGROUND: Many physicians are not adhering to the recommendations found in evidence-based guidelines for the treatment of acute myocardial infarction (AMI). Physicians who practise in tertiary care settings may show better adherence to guideline recommendations than physicians who practise in other settings. OBJECTIVE: To determine whether there is an association between the practice setting of admission for AMI and discharge prescriptions for cardiac drugs recommended in evidence-based guidelines. PATIENTS AND METHODS: Discharge prescription data from a prospective cohort of patients with AMI admitted at five tertiary care (n=250) and five community hospitals (n=331) in Quebec from December 1996 to November 1998 were examined. RESULTS: The proportions of patients who were prescribed recommended drugs at tertiary care hospitals compared with those at community hospitals were as follows: beta-blockers (78% versus 74%, respectively; 95% CI around the difference - 4% to 11%), lipid-lowering drugs (45% versus 39%, respectively; 95% CI - 2% to 15%) and angiotensin-converting enzyme (ACE) inhibitors (44% versus 57%, respectively; 95% CI - 22% to - 5%). In adjusted analyses, practice setting was not associated with the prescription of beta-blockers (odds ratio [OR] for tertiary care 1.36; 95% CI 0.82 to 2.24) or lipid-lowering drugs (OR for tertiary care 1.06; 95% CI 0.67 to 1.68). However, tertiary care admission reduced the likelihood of ACE inhibitor prescription (OR 0.50; 95% CI 0.32 to 0.77). This association may have been due to the increased likelihood of ACE inhibitor prescription for patients with hypertension at community hospitals (OR 2.13; 95% CI 1.23 to 3.67). The results also showed that older patients were less likely to be prescribed beta-blockers or lipid-lowering drugs, women were less likely to be prescribed beta-blockers and patients with diabetes mellitus were less likely to be prescribed lipid-lowering drugs (OR 0.45; 95% CI 0.23 to 0.89). CONCLUSION: No strong association was found between the practice setting of admission for AMI and discharge prescriptions for cardiac drugs recommended in evidence-based guidelines. Prescription rates for recommended drugs were high, yet results suggest that there is room for improvement with regard to patients with diabetes, women and older patients.

Adrenergic Antagonists↗
PubMed1997

Risk stratification after myocardial infarction using signal-averaged electrocardiographic criteria adjusted for sex, age, and myocardial infarction location.

BACKGROUND: The objectives were to investigate the factors influencing signal-averaged ECGs (SAECGs) recorded in patients after myocardial infarction (MI) and to develop criteria for predicting arrhythmic events (AEs) that account for these factors. METHODS AND RESULTS: SAECGs were recorded 5 to 15 days after MI in 2461 patients without bundle-branch block. The duration (QRSd), terminal potential (VRMS), and terminal duration (LAS) of the filtered QRS were measured. During follow-up (17 +/- 8 months), AEs (arrhythmic death; ventricular tachycardia, VT; ventricular fibrillation, VF) occurred in 80 patients (3.3%). Receiver operating characteristic curves showed that QRSd discriminated patients with all types of AEs, but VRMS and LAS discriminated only VT patients; QRSd minus LAS also discriminated AE patients. Sex, age, and MI location significantly affected the SAECG; survivors without VT or VF were divided into subgroups (2 sex x 4 age x 2 MI), and QRSd values exceeding the 70th percentile in each subgroup predicted AEs with a sensitivity of 65.4%. An unadjusted QRSd criterion showed the same overall sensitivity and specificity but with less uniform values for each subgroup. A Cox model was constructed by use of multiple prognostic indicators, and in rank order, QRSd, previous MI, and Killip class were predictive of AEs. CONCLUSIONS: SAECG adjustments for sex, age, and MI location did not improve sensitivity and specificity but produced a more uniform predictive performance. The proposed criteria are based only on QRSd, because late potentials (VRMS and LAS) did not discriminate patients with sudden death. Duration of high-level activity during QRS (QRSd-LAS) can predict AEs, suggesting that the arrhythmogenic substate involves a large mass of myocardium.

Age Factors↗
PubMed1996

Myocardial infarction patients in the 1990s--their risk factors, stratification and survival in Canada: the Canadian Assessment of Myocardial Infarction (CAMI) Study.

OBJECTIVES: This study sought to evaluate the in-hospital and postdischarge mortality of patients with an acute myocardial infarction in the 1990s. BACKGROUND: The widespread implementation of therapeutic interventions that modify the natural history of coronary artery disease has led to changes in the profile and survival of patients with an acute myocardial infarction. Although data exist for selected subsets of patients with an acute myocardial infarction, at this time there is little recent prospective information on all patients presenting with an acute myocardial infarction, particularly for survival after hospital discharge. METHODS: All patients < or = 75 years old presenting with an acute myocardial infarction between July 1, 1990 and June 30, 1992 at nine Canadian hospitals were prospectively evaluated and followed up for 1 year. From November 1991, patients of all ages were included. In two centers, recruitment continued until December 31, 1992. A total of 3,178 patients were recruited. RESULTS: The in-hospital mortality rate of patients < or = 75 years old was 8.4%, and that at 1 year after hospital discharge was 5.3%. For patients of all ages recruited after November 1, 1991, the in-hospital mortality rate was 9.9% and 7.1% for 1 year after hospital discharge. For patients < or = 75 years old, age carried an independent in-hospital but no post discharge risk. Female patients had a twofold greater risk of dying in hospital. After hospital discharge, only 1.7% of patients < or = 75 years old and 1.9% of patients of all ages died of a presumed arrhythmic death. Premature ventricular contractions had no independent prognostic value. The relatively low in-hospital (5.3%) and postdischarge (6.1%) reinfarction rate may have contributed to improved survival. A greater reinfarction rate in patients >75 years old (17.4% vs. 9.6%, p < 0.001) may have contributed to their poorer outcome. CONCLUSIONS: One-year mortality after acute myocardial infarction continues to decrease, and changes in the prognostic value of traditional methods of risk stratification have occurred.

Age Factors↗
PubMedDate not supplied

Radiopaque alginate microcapsules for X-ray visualization and immunoprotection of cellular therapeutics.

Alginate-poly-L-lysine-alginate (APA) microcapsules have been explored as vehicles for therapeutic drug and cell delivery. The permselectivity of these capsules provides a unique means of controlled drug release and immunoisolation of encapsulated cells. Immunoisolation is especially attractive as it abrogates the need for chronic immunosuppressive therapy and opens up the possibility for the delivery of numerous cell sources including xenogeneic grafts. APA microcapsules containing cellular therapeutics have proven effective in the short-term treatment of a wide range of diseases requiring enzyme or endocrine replacement therapy, including type I diabetes. If these microcapsules could be noninvasively monitored with X-ray imaging modalities (i.e., fluoroscopy, CT, and digital subtraction angiography), questions such as the ideal transplantation site, the best means of delivery, and the long-term survival of grafts could be better addressed. We have developed two novel alginate-based radiopaque microcapsule formulations containing either barium sulfate (Ba X-Caps) or bismuth sulfate (Bi X-Caps). As compared to conventional, nonradiopaque APA capsules, Ba X-Caps and Bi X-Caps containing human cadaveric islets resulted in a decrease in cellular viability of less than 5% up to 14 days after encapsulation. Both radiopaque capsules were found to be permeable to lectins < or =75 kDa, but were impermeable to lectins > or =120 kDa, thus ensuring the blockage of the penetration of antibodies while allowing free diffusion of insulin and nutrients. The glucose-responsive insulin secretion of the radiopaque encapsulated human islets was found to be unaltered compared to that of unlabeled controls, with human C-peptide levels ranging from 3.21 to 2.87 (Ba X-Caps) and 3.23 to 2.87 (Bi X-Caps) ng/islet at 7 and 14 days postencapsulation, respectively. Using fluoroscopy, both Ba X-Caps and Bi X-Caps could be readily visualized as single radiopaque entities in vitro. Furthermore, following transplantation in vivo in mice and rabbits, single capsules could be identified with no significant change in contrast for at least 2 weeks. This study represents the first attempt at making radiopaque microcapsules for X-ray guided delivery and imaging of cellular therapeutics. While human cadaveric islets were used as a proof-of-principle, these radiopaque capsules may have wide ranging therapeutic applications for a variety of cell types.

Alginates↗