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Biomedical subjects

M Demers

Publications and source records attributed to M Demers.

At least 19 recordsLinked to original sources
PubMed2006

Obesity in Canada: where and how many?

CONTEXT: Obesity rates are rising sharply among all industrialized countries; the situation seems to be worse in English speaking countries. Taking into account genetic predisposition, excess of caloric intake combined with low energy expenditure will usually result in obesity. OBJECTIVES: To describe and compare regional obesity rates across Canada and assess the ecological relationship between regional rates of obesity, low level of leisure-time physical activity, and low fruit and vegetable consumption. DESIGN: Cross-sectional population-based analysis from the 2003 Canadian Community Health Survey. MEASURES AND DATA ANALYSES: Canadian population distributions of body mass index (BMI), leisure-time physical activity and daily fruit and vegetable consumption were obtained from Statistics Canada. All these measures were based on the respondent's self-reported answers to a computer-assisted personal or telephone interview. Obesity rates (BMI> or =30), rates of low level of leisure-time physical activity (less than 1.5 kcal of energy expenditure per day), and rates of low fruit and vegetable consumption (less than five times a day) for the 106 Canadian Health regions were mapped to illustrate their geographical distribution. Cartograms were used in addition to traditional mapping to take into account the differences in population density between these small areas. RESULTS: In 2003, 15.2% of Canadian individuals aged 20 years and older were considered obese. The rates of obesity varied substantially between the 106 Canadian health regions: from 6.2% in Vancouver to 47.5% in aboriginal population area. At the health region level, low leisure-time physical activity and low fruit and vegetable consumption are both good predictors of obesity (odds ratio of 9.2 and positive predictive value of 93% when considered simultaneously). CONCLUSION: There is a strong gradient in obesity prevalence between Canadian health regions. At the regional level, high rates of low level of physical activity, and high rates of low fruit and vegetable consumption were both found good predictors of high rates of obesity.

Adult↗
PubMed2003

Upregulation of galectin-7 in murine lymphoma cells is associated with progression toward an aggressive phenotype.

We have previously shown that ICAM-1-deficient mice were resistant to lymphoma dissemination of intravenously injected 164T2 lymphoma cells. Highly aggressive variants of this cell line, however, could overcome this resistance. To discern the complex pattern of gene expression involved in the evolution of aggressiveness in lymphoma cells, we compared the transcriptome of 164T2 cells with that of their aggressive variants using cDNA arrays. We identified several genes that were differentially expressed in nonmetastatic lymphoma cells and their metastatic variants. Galectin-7, associated with the development of chemically induced mammary carcinoma, was one such gene whose expression was significantly upregulated. We showed that it was constitutively expressed in aggressive variants, at both mRNA and protein levels. Galectin-7 expression in aggressive lymphoma cells was induced upon in vivo selection in several organs, including the thymus, the spleen and kidneys. We also showed that treatment of nonaggressive lymphoma cells with 5-aza-2'-deoxycytidine was sufficient to induce galectin-7 gene expression. This report is the first to show that galectin-7 is expressed in aggressive lymphoma.

Animals↗
PubMed2002

Effect of dietary fiber on endogenous nitrogen flows in lactating dairy cows.

The effect of dietary fiber on endogenous N secretion was studied using a 15N isotope dilution technique in four fistulated Holstein cows. Two isonitrogenous diets differing only in fiber (NDF and ADF) content were used in a crossover design. One diet (HF) contained 37.4% NDF, while the other (LF) contained 23.3%. A new model was developed to estimate endogenous N secretions and losses for the preintestinal, intestinal, and the total sections of the gastrointestinal tract. Three precursor pools: TCA-soluble fraction of plasma, intestinal mucosa, and milk were compared. Although endogenous losses estimated with the model were numerically different for each precursor pool selected (TCA-soluble fraction > mucosa > milk), treatment effects were similar. As intestinal mucosa is probably closest to the precursor pool, these data are discussed. Non-urea N endogenous secretions contributed 13% of the duodenal N flow but were not affected by the fiber content of the diet. The nonurea N endogenous flow at the duodenum was comprised of approximately equal inputs from endogenous N direct, and that incorporated into the microbial biomass. Total endogenous N flows at the duodenum exceeded, by nearly twofold, estimated inputs of urea-N to microbial biomass. Metabolic fecal output averaged 17% of fecal N and was not affected by level of dietary fiber, but net losses from secretions occurring in the small intestine were higher with the low fiber diet. Overall, endogenous N secretions represented 30% of total digestive tract protein synthesis.

Animals↗
PubMed1998

Stimulus-control: nonpharmacologic treatment for insomnia.

OBJECTIVES: To evaluate the efficacy and applicability of a behavioural treatment for insomnia that can be administered by family physicians in various clinical settings. DESIGN: Efficacy of the treatment was evaluated by single-case experimental designs (multiple baseline across subjects). Applicability was assessed through semistructured interviews with physicians. SETTING: Two private offices, two offices in community health centres, and one office in a family medicine unit. PARTICIPANTS: Six general practitioners and 24 chronic insomniac patients recruited through media advertisements and from physicians' practices. Of an initial 38 subjects screened, six were excluded for sleep-onset latency less than 30 minutes, five for psychological conditions, one for physical handicaps, and two for other reasons. INTERVENTIONS: Physicians used stimulus-control treatment during individual therapeutic sessions. Patients using hypnotics were encouraged to taper off their medications after treatment was initiated. MAIN OUTCOME MEASURES: Time it took patients to get to sleep (sleep-onset latency), amount of hypnotic use, and practitioners' evaluation of the treatment. RESULTS: Fifteen patients completed the treatment; 80% of them reduced their sleep-onset latency. Six of the seven patients using hypnotics at the beginning of the study reduced or stopped their medications. All therapeutic gains were maintained at 3 and 6 months. Physicians thought stimulus-control treatment could be used in medical practice, but specified that it was most useful for highly motivated patients. CONCLUSION: Family physicians can use stimulus-control treatment effectively for patients with chronic insomnia. This nonpharmacologic approach could help motivated patients reduce their use of hypnotics.

Adult↗
PubMed1996

Factors explaining the increase in cost for physician care in Quebec's elderly population.

OBJECTIVE: To examine what role demographic factors and increases in physician fees and utilization played in the rise in costs of physician services provided for elderly people in Quebec between 1982 and 1992, and to investigate changes in patterns of care (type and amount of services) related to utilization. DESIGN: Retrospective study of population-based data. SETTING: Province of Quebec. SUBJECTS: Elderly people (65 years of age and over) in Quebec in 1982 (n = 589,800) and in 1992 (n = 803,600). OUTCOME MEASURES: Proportion of the increase in physician care costs attributable to (a) aging (defined as a shift in the age distribution) of the elderly population, (b) the increase in the size of the elderly population, (c) the increase in physician fees and (d) the increase in utilization of physician services; proportion of care provided by general practitioners (GPs) and by specialists; proportion of minor and complete examinations provided by GPs; and rates of hospital admissions and surgery. RESULTS: Aging was responsible for 0.5% of the increase in physician care costs between 1982 and 1992, population growth for 27.0% and the increase in physician fees for 25.5%. The increased utilization accounted for 47.0% of the total cost increase. Analyses of the utilization data revealed a shift toward more costly services, more visits to specialists and higher rates of hospital admissions and surgery in 1992 than in 1982. CONCLUSIONS: Aging and population growth had minor effects on the increase in physician care costs between 1982 and 1992. Increased utilization was the most important factor. The appropriateness of this trend needs to be verified.

Age Distribution↗
PubMed1996

Indicators of masticatory performance among elderly complete denture wearers.

The literature on current techniques for evaluating the masticatory capacity leads to categorizing them into two groups: objective masticatory tests and questionnaires that evaluate the subject masticatory capacity. This study examines how a simple questionnaire on the reported capacity to chew certain food can predict the masticatory performance of edentulous elderly patients. The masticatory performance of 367 completely edentulous elderly persons was measured with the Swallowing Threshold Test Index and compared with their reported masticatory capacity previously measured with a questionnaire on the capacity of the individual to chew nine food items. A total of 47.4% of the individuals had a low masticatory performance. This problem was more frequent in women (51.7%) than in men (41.8%). In measuring the reported masticatory performance with seven of the nine food items listed in the questionnaire, this indicator predicted the masticatory performance with a sensitivity of 65.5% and a specificity of 81.9%. However, even though the measure of prosthesis retention/stability is related to the masticatory performance, it was not a good predictor.

Age Factors↗
PubMed1996

Cell-specific heat-shock induction of Hsp23 in the eye of Drosophila melanogaster.

The expression of two small heat shock proteins (sHsp), Hsp23 and Hsp27, was examined by immunological approaches in the eye of Drosophila melanogaster. Neither Hsp23 nor Hsp27 is detectable in unstressed (23 degrees C) eyes but both proteins are induced by heat shock (35 degrees C). In response to heat stress, Hsp27 is expressed in all cells of the ommatidium including the cone, pigment and photoreceptor cells. However, the heat-induced expression of Hsp23 is restricted to a single cell type of the ommatidium, the cone cells, suggesting that Hsp23 is regulated by specific mechanisms acting to inhibit the expression of this polypeptide in some ommatidial cells. The cell-specific induction of Hsp23 under stress conditions does not seem to be regulated by the Drosophila melanogaster heat shock transcriptional factor (DmHSF). In both unstressed and stressed conditions, DmHSF is detected in all the different types of ommatidial cells where it is found associated with the nucleus. These observations suggest that factors, other than the heat shock transcriptional factor, are involved in regulating the expression of the hsp23 gene under stress conditions.

Animals↗
PubMed1996

[Study on insomnia treatment by family physicians].

OBJECTIVES: To describe treatment of insomnia in general practice and to identify family physicians' training needs in this area. DESIGN: Mail survey using Dillman's total design method. PARTICIPANTS: A sampling of 484 general practitioners in the Quebec City area was done to provide roughly equal representation of six practice settings. The response rate was 65%; 295 of the 315 questionnaires returned were selected for analysis. RESULTS: Most physicians reported treating insomnia with general advice and lifestyle changes; 25% reported prescribing hypnotics frequently; 56% reported they prescribed them occasionally. Although 58% often recommend relaxation techniques, only 8% taught these techniques to their patients. Other cognitive and behavioral approaches are rarely used. Most felt that training in treating insomnia should be offered. CONCLUSION: Cognitive and behavioral approaches are very effective approaches are very effective nonpharmacological treatments for insomnia. General practitioners make little use of these treatments that could be easily integrated into clinical practice. Strategies for increasing their use discussed.

Adult↗
PubMed1995

Frequent users of ambulatory health care in Quebec: the case of doctor-shoppers.

OBJECTIVE: To examine the patterns of use of ambulatory care in Quebec in 1991, with special emphasis on patients who received care from more than 20 physicians. DESIGN: Retrospective study of population-based data. SETTING: Province of Quebec. PARTICIPANTS: All 7,154,591 people eligible for coverage under the Régie de l'assurance-maladie du Québec (RAMQ) (Quebec Health Insurance Plan) in 1991, including 3639 people who received ambulatory care from more than 20 physicians. DATA EXTRACTION: The databanks of the RAMQ. OUTCOME MEASURES: Mean number (and standard deviation) of physician visits and services received, place of visit (clinic or private office), mean cost of services, patient's age, diagnosis, type of specialist visited and social assistance status of frequent users. RESULTS: The patients who obtained ambulatory care from more than 20 physicians received 10 times more medical services than the overall patient population (59.6 v. 5.8), and the mean cost per patient for ambulatory care was also 10 times higher ($1379 v. $136). Almost all of the frequent users visited at least one outpatient clinic, as compared with 37.3% of the overall population. A higher proportion of the frequent users than of the overall population obtained care from specialists (98.9% v. 54.7%), mainly general surgeons and psychiatrists. The most frequent diagnoses among the frequent users were anxiety (36.0%), abdominal pain (24.3%), drug or alcohol dependence (22.2%) and depression (16.4%). CONCLUSIONS: A small proportion of the population obtained ambulatory care from a high number of physicians during the year, leading to high expenses. Identifying and understanding this type of frequent user may be useful in developing strategies to promote more effective health-care-seeking behaviours and reduce overuse.

Adolescent↗
PubMed1995

[Preliminary validation of instruments used to measure the psychotherapeutic knowledge, skills and attitudes of family physicians].

OBJECTIVE: To examine the validity and the reliability of three measurement instruments used to evaluate mental health training offered to residents in family medicine. DESIGN: Development and submission of three French-language instruments measuring knowledge, perceived skills, and attitudes of family physicians and residents. SETTING: Weekly psychotherapy workshop. PARTICIPANTS: A group of 90 family medicine residents and practising doctors were recruited by the authors and by teaching facilities. MAIN OUTCOME MEASURE: Reliability index KR20 and an evaluation of error in the instruments were used. RESULTS: The results satisfactory in terms of the measurement of perceived skills (KR20 = 0.86) and the measurement of attitudes (KR20 = 0.96); the measurement of knowledge (KR20 = 0.70) was clearly unsatisfactory and the instrument will require upgrading. The measurement of perceived skills was the only one to reveal a distinction between the groups; practising doctors and those interested in psychotherapy believed their skills to be superior to those of residents in training (P = 0.005). CONCLUSION: Instruments measuring attitudes and perceived skills have excellent psychometric potential; however, it remains to be determined whether the measurement of perceived skills is valid and whether these instruments are useful for monitoring family medicine residents during their training or for assessing the impact of mental health training programs.

Adult↗
PubMed1994

Effectiveness of a three-month training program in psychotherapeutic intervention for family practice residents.

PURPOSE: To evaluate the influence on knowledge, perceived skills, and attitudes of a psychotherapeutic intervention program for family practice residents. METHODS: Between 1991 and 1993, a nonrandomized controlled study, using a pretest-posttest design, was used to compare a treatment group of 38 residents with a control group of 16 residents at two family medicine clinics affiliated with the Université de Montréal and Laval University Faculties of Medicine. The residents participated in a structured series of 12 seminars dedicated to psychotherapeutic interventions by family doctors. Three instruments were used to measure knowledge, perceived skills, and attitudes. Statistical analysis included two-tailed chi-square with Yates' correction and the Mann-Whitney test. RESULTS: Ten residents in the treatment group and one in the control group were excluded from analysis because they did not complete all the evaluations. Greater percentages of residents in the treatment group improved their perceived skills (89% versus 56%, p = .003), and their knowledge (82% versus 50%, p = .06). CONCLUSION: Skills of the "how-to" type improved more than relational skills. No significant effect on attitude was observed.

Clinical Competence↗
PubMed1992

Factors affecting the ingestion of fluoride dentifrice by children.

Several factors affecting the amount of fluoride ingested during toothbrushing by 2- to 7-year-old children were investigated. The specific purpose of this study was to determine the contribution of age, the amount of dentifrice used, and rinsing after brushing to the variation in the ingestion of fluoride dentifrice. Four hundred and five children brushed their teeth in front of a portable sink. The tubes of dentifrice in gel (0.24% NaF) were weighed before and after use to determine the amount of toothpaste used. The fluoride content of the collected liquids was determined with a fluoride-ion-specific electrode. The amount of fluoride ingested was derived by determining the difference between the amounts used and recovered. The amount of dentifrice used, the age, and the rinsing habits, entered in a multiple regression model, explained up to 66 percent of the total variation in the amount of fluoride ingested. The amount of dentifrice used accounted by itself for 60 percent of the total variation. Therefore, these results indicate that the quantity of dentifrice used was the most important factor affecting the ingestion of fluoride through toothbrushing by young children.

Age Factors↗
PubMed1992

A multivariate model to predict caries increment in Montreal children aged 5 years.

A study was carried out in Montreal (Canada) to predict caries development over the period of one year in primary teeth of kindergarten children (mean age 5 years 8 months +/- 4 months) living in a non-fluoridated area. The 302 children were examined at school on two occasions, one year apart. At the first examination selected predictors were collected: caries experience, salivary S. mutans and lactobacilli, buffer capacity, debris index, parents' education, fluoride consumption and family structure (one or two parents). Regression analysis was performed to select the significant factors. A total of 143 children developed new caries over the study period; the mean increment for the whole group was 2.1 dmfs. Sensitivity (Sn) and specificity (Sp) were calculated for each predictor and for the final model. The best model comprised only two factors, caries experience and lactobacillus. This could identify 81.8 per cent of children who would develop new caries during the next 12 months (Sn) and 77.4 per cent of those who would not (Sp). Among the single predictors caries experience alone reached 78.3 per cent for sensitivity and 77.4 per cent for specificity. None of the other predictors, except parents' education, was very good at predicting caries increment over one year.

Chi-Square Distribution↗
PubMed1990

Variability in the ingestion of toothpaste by preschool children.

The amount of dentifrice used and ingested on three occasions by a group of 48 children aged between 3 and 5 years was measured. The purpose of the present study was to investigate the variability in the amount of dentifrice used and ingested. The quantity of toothpaste ingested was derived from the differences between the amounts used and rejected. On average, the difference in the amount used between any two brushings was less than 0.250 g for 66% of the subjects, and the difference in the amount ingested was less than 0.100 g for 69% of the children. There were no statistically significant differences in the quantities used and ingested between the three brushings.

Analysis of Variance↗
PubMed1990

Caries predictors suitable for mass-screenings in children: a literature review.

This paper reviews the predictors used to identify children and adolescents at high risk of developing dental caries. They are presented with their degree of association with caries, their validity as screening tests and their methods of determination. The most promising predictors are identified and caries prediction models are also briefly reviewed. The article concludes with some comments about weaknesses encountered in the conduct of screening studies and makes some suggestions for improving the validity of the prediction models.

Adolescent↗
PubMed1990

[Behavior and conditions related to denture wearing in edentulous Quebecers over 60 years of age].

A study was conducted among 367 persons aged 60 and over in order to determine the type and severity of digestive and nutritional problems experienced by edentulous elderly not wearing functional dentures. This article summarizes the information collected through an interview. The data describes the prosthetic status and experience of the elderly, their use of dental services and their methods of hygiene. In addition, information is provided on the level of satisfaction relative to their dentures and the need for repair or replacement of the latter.

Aged↗