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Biomedical subjects

L Bédard

Publications and source records attributed to L Bédard.

17 recordsLinked to original sources
PubMed1998

Epidemiology of tuberculosis in Montreal.

OBJECTIVE: To identify the epidemiologic characteristics of tuberculosis (TB) in Montreal and the patterns of resistance to antituberculous drugs in order to improve TB control in the region. DESIGN: Descriptive analysis of surveillance data for TB cases reported in Montreal by physicians and laboratories between 1992 and 1995. SETTING: Region of Montreal, population 1,775,889. PARTICIPANTS: All cases of active TB among Montreal residents reported to the Department of Public Health between Jan. 1, 1992, and Dec. 31, 1995. OUTCOME MEASURES: Epidemiologic characteristics, proportion of cases resistant to antituberculous drugs and types of resistance. RESULTS: A total of 798 cases of TB (mean annual incidence 11.2 per 100,000) were reported in Montreal during the study period. Of these patients, 617 (77.3%) were born outside Canada. The annual incidence of TB in the foreign-born population (37.5 per 100,000) was 10 times the rate in the Canadian-born population, and the highest rate among foreign-born residents (62.8 per 100,000) occurred in those 15-29 years of age. In general, annual incidence in Montreal's foreign-born population reflected the reported incidence of TB in their regions of birth. In 8.7% of all cases, the disease was resistant to isoniazid, and the proportion of cases resistant to this drug was greater than 4% in almost all age groups, among both foreign-born and Canadian-born patients. CONCLUSIONS: TB remains a major problem in Montreal, as in other large cities. Surveillance data give opportunities to public health agencies to adapt their prevention and control strategies to local situations and can also help clinicians in their clinical decision-making.

Adolescent↗
PubMed1998

[Efficacy and complications associated with vasectomies in two clinics in the Quebec region].

OBJECTIVE: To compare the efficacy of, and complications associated with, vasectomies performed in two medical clinics. DESIGN: Retrospective cohort study. SETTING: A private medical clinic and a family planning clinic at a teaching hospital in the Quebec City region, where one doctor performs all surgery. PARTICIPANTS: The 1223 men who underwent a first vasectomy between January 1994 and February 1996. INTERVENTIONS: Isolations of the vas deferens through the scrotum was performed using the no-scalpel technique in both clinics. At the private clinic (n = 775), vasectomy was performed by ligature with tantalum clips. At the family planning clinic (n = 448), a combination of cauterisation of the abdominal end of the vas deferens, leaving the testicular end open, and fascial interposition with a clip was used. MAIN OUTCOME MEASURES: Rate of postoperative complications (painful granuloma; noninfectious inflammation of the vas deferens, epididymis, and testes; hematoma; infection; undiagnosed pain) and rate of recanalization (early and late). RESULTS: At the private clinic, 39 patients (5.0%) consulted for postoperative complications, compared with 55 patients (12.3%) at the family planning clinic (chi (2)1 = 21.0; P < 0.001). Of the patients who underwent semen analysis, 15 (2.8%) at the private clinic and 4 (1.2%) at the family planning clinic experienced early or late recanalization (chi (2)1 = 2.2; P < .14). CONCLUSION: The rate of consultation for postoperative complications was lower at the private clinic than at the family planning clinic, but the efficacy of the procedure appeared to be higher at the family planning clinic. The surgical techniques used at the two clinics might partially explain these differences.

Adult↗
PubMed1992

Image digitizing in conventional radiology.

Since early 1991 a new procedure has been tested at the Hôpital du St-Sacrement that uses a phosphorous plate instead of a standard x-ray cassette. The phosphorous plate is exposed to x-rays using standard equipment and is then read by a computer that transfers the resulting image onto either a plate or a cathode screen. This new technology lends importance to the radiology technician's role in image manipulation and determination of the ideal sensitometric curve for each x-ray examination. The technician can generate an image with adjustments in latitude and contrast, depending on the radiologist's needs and notwithstanding the technical parameter settings used during the x-rays.

Evaluation Studies as Topic↗
PubMed1990

An outbreak of toxic encephalopathy caused by eating mussels contaminated with domoic acid.

In Canada in late 1987 there was an outbreak of an acute illness characterized by gastrointestinal symptoms and unusual neurologic abnormalities among persons who had eaten cultivated mussels. Health departments in Canada solicited reports of this newly recognized illness. A case was defined as the occurrence of gastrointestinal symptoms within 24 hours or of neurologic symptoms within 48 hours of the ingestion of mussels. From the more than 250 reports received, 107 patients met the case definition. The most common symptoms were vomiting (in 76 percent of the patients), abdominal cramps (50 percent), diarrhea (42 percent), headache, often described as incapacitating (43 percent), and loss of short-term memory (25 percent). Nineteen patients were hospitalized, of whom 12 required intensive care because of seizures, coma, profuse respiratory secretions, or unstable blood pressure. Male sex and increasing age were associated independently with the risks of hospitalization and memory loss. Three patients died. Mussels associated with this illness were traced to cultivation beds in three river estuaries on the eastern coast of Prince Edward Island. Domoic acid, which can act as an excitatory neurotransmitter, was identified in mussels left uneaten by the patients and in mussels sampled from these estuaries. The source of the domoic acid appears to have been a form of marine vegetation, Nitzschia pungens, also identified in these waters in late 1987. The contaminated mussels from Prince Edward Island were removed from the market, and no new cases have occurred since December 1987. We conclude that the cause of this outbreak of a novel and severe intoxication was the ingestion of mussels contaminated by domoic acid, a potent excitatory neurotransmitter.

Adult↗
PubMed1989

Effects of intrahypothalamic injections of GABA, muscimol, pentobarbital, and L-glutamic acid on feed intake of satiated sheep.

Five wethers were surgically prepared with cranial implants to study the role of gabaminergic neural pathways on the hypothalamic control of feeding behaviour in ruminants. In the first experiment, the animals were injected (1 microL) with a physiological Tyrode (0.95%) solution, muscimol (0.5 and 1.0 nmol), GABA (0.5 and 1.0 nmol), and L-glutamic acid (0.5 and 1.0 nmol). Feed intake following injections of muscimol (1.0 nmol) and L-glutamic acid (0.5 and 1.0 nmol) was twice as large as that following the Tyrode solution, at 60-min postinjections. These results, however, were not statistically significant (p = 0.12-0.15). In the second experiment, the animals were injected (1 microL) with saline, muscimol (0.8 nmol), L-glutamic acid (0.8 nmol), and pentobarbital (0.26 mumol). Fifteen minutes after the injections, pentobarbital had induced a significant feeding response when compared with control values (p less than 0.01), whereas the effect of L-glutamic acid was not significant. However, 30 min after the injections, feed intake of sheep having received L-glutamic acid was higher than that obtained with the control injections (p less than 0.01). The response to pentobarbital was stronger than that to either muscimol or L-glutamic acid. Histological analyses of brain tissue indicated that injections were performed in the ventromedial hypothalamus of four sheep and in the dorsomedial hypothalamus of the other. The data indicate that L-glutamic acid stimulates feed intake by acting either as a precursor of GABA or by a direct stimulation of glutaminergic neural pathways involved in the control of feed intake.

Animals↗
PubMed1988

Comparison between pentobarbital- and muscimol-induced feeding in satiated sheep.

Twenty sheep were used to study the mechanisms by which the intracerebral administration of pentobarbital and of muscimol induces feeding in ruminants. Injections of 1 mumol calcium induced a weak feeding response at 1 h postinjection compared with control values (108 vs. 63 g, p less than 0.05). Injections of 78 mumol pentobarbital and of 100 nmol muscimol elicited strong feeding responses (p less than 0.01). A preinjection of 1 mumol calcium reduced the response to pentobarbital by about 40% but did not affect the response to muscimol. Administration of 1.1 mmol sodium chloride reduced the effect to pentobarbital by about 60% but only partially decreased the effect to muscimol. Administration of picrotoxin, a GABA antagonist, slightly decreased the feeding response to pentobarbital and to muscimol. Administration of gamma-vinyl GABA, an inhibitor of the enzyme GABA transaminase, did not affect feeding behavior of sheep at any of the doses tested (0-10 mumol). Injections of gamma-vinyl GABA followed by equimolar injections of GABA failed to provoke any feeding response. The data suggest that pentobarbital and muscimol may induce feeding by acting on a similar hypothalamic receptor complex but by different mechanisms. The lack of effect of GABA itself remains unexplained.

Aminocaproates↗
PubMed1984

Effects of intraventricular injections of gamma-aminobutyric acid and related substances on feeding behavior in satiated sheep.

Feed intake was measured following injections of gamma-aminobutyric acid (GABA), muscimol (a GABA agonist), and picrotoxin (a GABA antagonist) into the lateral ventricles of satiated sheep. Doses ranging from 0.20 to 3200 nmol of GABA did not affect feeding behavior at 15, 30, 60, and 120 min postinjection. A dose of 160 nmol of muscimol induced a marked increase in feeding, comparable to that provoked by an injection of 78 mumol of pentobarbital. Muscimol-induced feeding was blocked effectively by a preinjection of picrotoxin. These observations implicate that neurons sensitive to gamma-aminobutyric acid may be involved in the control of feeding behavior in ruminants.

Animals↗
PubMedDate not supplied

AIDS in Quebec.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Risk factors for measles and vaccine efficacy during an epidemic in Montreal.

OBJECTIVES: 1) to identify potential risk factors for measles and 2) to assess the efficacy of the measles vaccine. METHODS: Cases of measles reported from primary and secondary schools in Montreal during the 1989 epidemic were compared with classroom and sibling controls with respect to age at vaccination against measles, time since vaccination, type of vaccination, type of providers and age of the mother. RESULTS: Subjects vaccinated at 12 months had an OR of 3.9 (CI 95%: 2.1 to 7.0) of contracting measles when compared with subjects vaccinated at 15 months or later. Vaccination at age 13 or 14 months was not associated with an increased risk. Subjects vaccinated before June 1979 had an OR of 5.8 (CI 95%: 2.8 to 12.1) of developing measles compared with subjects vaccinated after June 1980. Vaccine efficacy was 96.1%. DISCUSSION: In highly vaccinated populations, vaccination at 12 months and vaccination before 1980 are probably two reasons why outbreaks still occur. The two-dose schedule could reduce the proportion of vaccinated persons who remain susceptible.

Adolescent↗
PubMedDate not supplied

Evaluation of the effectiveness of immunization delivery methods.

Scientific evidence documenting the effectiveness of immunization delivery methods was summarized using the generic approach developed by the Community Health Practice Guidelines Working Group. The delivery methods examined were those for the adult and childhood vaccines of influenza, pneumococcal infection, hepatitis B, measles-mumps-rubella and diphtheria-pertussis-tetanus-polio. Based on a critical appraisal of 54 eligible comparative studies, the effects of different interventions were obtained and pooled effects were calculated for delivery methods oriented to the client, the provider and the system. The results indicate those interventions found to be most effective for each vaccine. This review of the scientific evidence of the effectiveness of immunization delivery methods provides a base for policy development and assists in the planning of resource allocation.

Adolescent↗
PubMedDate not supplied

Practice survey of immunization in Canada.

A survey was undertaken in September 1991 to document current immunization practice across Canada. Information was obtained during interviews with provincial epidemiologists and key persons involved in immunization programs and recorded on standard data collection forms. Variations in practice are described in five areas: public/private health administration; legislation; monitoring system/coverage rates/surveillance; vaccine management and costs. As changes are being considered to immunization programs, a critical examination of issues such as standardization (in coding, in assessment of waste, in assessment of coverage), surveillance systems and the use of serosurveys would be beneficial.

Canada↗
PubMedDate not supplied

Immunization delivery methods: practice recommendations.

Immunization has unequivocally contributed to large-scale reductions in mortality and morbidity due to infectious diseases. In general, consensus on the scheduling of immunizations has been achieved at the national or international level by immunization advisory committees. However, immunization delivery methods are varied and numerous. Although specific methods have been proposed, compared and evaluated, the available evidence has not been comprehensively summarized for informed public health action. This paper integrates evidence based on scientific documentation, a Canada-wide practice survey and expert opinion to formulate practice recommendations for immunization delivery methods and to identify areas for further research.

Adult↗
PubMedDate not supplied

[The prevention of infections in child daycare centers: potential influential factors].

The Greater Montreal Public health departments have produced and distributed to daycare centres a manual on the prevention of infections in daycare personnel and trainees. In order to identify which factors can influence daycare management in applying the prevention measures suggested in the manual, a study was carried out based on the Precede/Proceed theoretical framework. A total of 134 (31.6%) daycare directors completed the questionnaire. Many were aware of the different recommendations to prevent infections. However, two of the recommendations were not followed by many: wearing gloves and verifying the vaccination status of their personnel, especially in private daycare centres. Participants had a positive attitude toward the various recommendations but mentioned several problems, specifically difficulty in obtaining the information about the vaccination status, lack of time and money, as well as having to deal with a poor physical organization of the work place. Among others things, the participants proposed that there be a greater involvement from schools, provincial daycare regulators, community clinics and public health departments.

Administrative Personnel↗