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Biomedical subjects

A Gervais

Publications and source records attributed to A Gervais.

At least 19 recordsLinked to original sources

Physicians Taking Action Against Smoking: an intervention program to optimize smoking cessation counselling by Montreal general practitioners.

In 1997 the Direction de la santé publique de Montréal-Centre initiated "Physicians Taking Action Against Smoking," a 5-year intervention program to improve the smoking cessation counselling practices of general practitioners (GPs) in Montreal. Program development was guided by the precede-proceed model. This model advocates identifying factors influencing the outcome, in this case counselling practices. These factors are then used to determine the program objectives, to develop and tailor program activities and to design the evaluation. Program activities during the first 3 years included cessation counselling workshops and conferences for GPs, publication of articles in professional interest journals, publication of clinical guidelines for smoking cessation counselling and dissemination of educational material for both GPs and smokers. The program also supported activities encouraging smokers to ask their GPs to help them stop smoking. Results from 2 cross-sectional surveys, conducted in 1998 and 2000, of random samples of approximately 300 GPs suggest some improvements over time in several counselling practices, including offering counselling to more patients and discussing setting a quit date. More improvements were observed among female than male GPs in both psychosocial factors related to counselling and specific counselling practices. For example, improvements were noted among female GPs in self-perceived ability to provide effective counselling and in the belief that it is important to schedule specific appointments to help patients quit; in addition, the perceived importance of several barriers to counselling decreased among female GPs. A greater proportion of the female respondents to the 2000 survey offered written educational material than was the case in 1998, and a greater proportion of the male GPs devoted more time to counselling in 2000 than in 1998; however, among male GPs the proportion who discussed the pros and cons of smoking with patients in the pre-contemplation stage declined between 1998 and 2000, as did the proportion who referred patients in the preparation stage to community resources. Our experience suggests that an integrated, theory-based program to improve physicians' counselling practices could be a key component of a comprehensive strategy to reduce tobacco use.

Counseling↗

Regulation of microglial development: a novel role for thyroid hormone.

The postnatal development of rat microglia is marked by an important increase in the number of microglial cells and the growth of their ramified processes. We studied the role of thyroid hormone in microglial development. The distribution and morphology of microglial cells stained with isolectin B4 or monoclonal antibody ED1 were analyzed in cortical and subcortical forebrain regions of developing rats rendered hypothyroid by prenatal and postnatal treatment with methyl-thiouracil. Microglial processes were markedly less abundant in hypothyroid pups than in age-matched normal animals, from postnatal day 4 up to the end of the third postnatal week of life. A delay in process extension and a decrease in the density of microglial cell bodies, as shown by cell counts in the developing cingulate cortex of normal and hypothyroid animals, were responsible for these differences. Conversely, neonatal rat hyperthyroidism, induced by daily injections of 3,5,3'-triiodothyronine (T3), accelerated the extension of microglial processes and increased the density of cortical microglial cell bodies above physiological levels during the first postnatal week of life. Reverse transcription-PCR and immunological analyses indicated that cultured cortical ameboid microglial cells expressed the alpha1 and beta1 isoforms of nuclear thyroid hormone receptors. Consistent with the trophic and morphogenetic effects of thyroid hormone observed in situ, T3 favored the survival of cultured purified microglial cells and the growth of their processes. These results demonstrate that thyroid hormone promotes the growth and morphological differentiation of microglia during development.

Animals↗

Smoking cessation counseling practices of general practitioners in Montreal.

BACKGROUND: Despite the cost-effectiveness of physician smoking cessation counseling, many physicians do not adhere to current clinical practice guidelines. METHODS: A cross-sectional mail survey was conducted in a random sample of general practitioners in Montreal to document cessation-counseling practices and identify correlates of these activities. RESULTS: Of 440 eligible general practitioners, 337 (77%) completed the questionnaire. Despite favorable beliefs/attitudes about cessation counseling, only 10.5% of general practitioners provided "thorough" counseling. While high proportions of general practitioners ascertained smoking status and encouraged patients to quit, relatively few offered adjunct support (i.e., for patients preparing to quit, 49.8% offered follow-up visits; 42.5% offered educational material; 20% referred patients to community resources). Correlates of counseling completeness included high self-efficacy to provide counseling (odds ratio (OR) = 2.0, 95% confidence interval (1.1-3.6)) and favorable beliefs/attitudes about counseling (OR = 3.6 (2.0-6.4)). Correlates of ascertaining smoking status included female gender (OR = 2.3 (1.5-3.5)), high self-efficacy (OR = 3.5 (2.0-5.9)), and favorable beliefs/attitudes (OR = 2.7 (1.6-4.5)). Correlates of offering adjunct support included female gender (OR = 1.9 (1.1-3.2)), awareness of stages of change (OR = 2.4 (1.3-4.4)), and knowledge of community resources to help patients quit (OR = 2.3 (1.3-3.9)). CONCLUSION: Support, training, and intervention programs to overcome lack of awareness and knowledge, unfavorable beliefs/attitudes, and low self-efficacy could increase and enhance cessation counseling practices among general practitioners.

Adult↗

Hepatitis after intravenous buprenorphine misuse in heroin addicts.

BACKGROUND: Sublingual buprenorphine is used as a substitution drug in heroin addicts. Although buprenorphine inhibits mitochondrial function at high concentrations in experimental animals, these effects should not occur after therapeutic sublingual doses, which give very low plasma concentrations. CASE REPORTS: We report four cases of former heroin addicts infected with hepatitis C virus and placed on substitution therapy with buprenorphine. These patients exhibited a marked increase in serum alanine amino transferase (30-, 37-, 13- and 50-times the upper limit of normal, respectively) after injecting buprenorphine intravenously and three of them also became jaundiced. Interruption of buprenorphine injections was associated with prompt recovery, even though two of these patients continued buprenorphine by the sublingual route. A fifth patient carrying the hepatitis C and human immunodeficiency viruses, developed jaundice and asterixis with panlobular liver necrosis and microvesicular steatosis after using sublingual buprenorphine and small doses of paracetamol and aspirin. CONCLUSIONS: Although buprenorphine hepatitis is most uncommon even after intravenous misuse, addicts placed on buprenorphine substitution should be repeatedly warned not to use it intravenously. Higher drug concentrations could trigger hepatitis in a few intravenous users, possibly those whose mitochondrial function is already impaired by viral infections and other factors.

Administration, Sublingual↗

Quantitation of hepatic hepatitis C virus RNA in patients with chronic hepatitis C. Relationship with severity of disease, viral genotype and response to treatment.

BACKGROUND/AIMS: To determine the correlation between hepatic hepatitis C virus (HCV) RNA and histological lesions, viral genotype or response to alpha interferon therapy. METHODS: Forty-three patients with chronic hepatitis C (14 sustained responders (SR) and 29 non-sustained responders (NSR)) were studied. A liver tissue sample was obtained before and 1 year after treatment. Quantitation of hepatic HCV-RNA was performed by competitive PCR. RESULTS: Before treatment, HCV-RNA was detectable in all liver samples. There was no association between hepatic HCV-RNA and the severity of liver lesions. There was a significant association between old age and hepatic HCV-RNA (P = 0.03). There was an association, at the limit of significance, between genotype 1 and high hepatic HCV-RNA amounts (15 x 106 and 4.1 x 10(6) copies/g, P = 0.05). Pre-treatment hepatic HCV-RNA amounts were lower in SRs than in others (0.65 x 10(6) and 13.2 x 10(6) copies/g, P = 0.0002). After treatment, no liver HCV-RNA was detectable in the SRs while in the NSRs, the HCV-RNA amounts were unchanged. CONCLUSIONS: The amount of hepatic HCV-RNA is correlated to genotype and response to interferon therapy but not to histologic lesions. Hepatic HCV-RNA clearance is observed in SRs, suggesting viral eradication.

Adult↗

Prospective study on anti-hepatitis C virus-positive patients with persistently normal serum alanine transaminase with or without detectable serum hepatitis C virus RNA.

A significant proportion of patients with detectable antibodies to hepatitis C virus have normal serum alanine transaminase levels. Our aim was to study the outcome of this group. Between 1992 and 1999, 135 consecutive anti-HCV-positive patients with persistently normal ALT were followed for 3.6 +/- 2.3 years (0.5 to 8.5 years), 108 had a liver biopsy at inclusion, and 24 had a second liver biopsy 3.5 +/- 1.0 years later. Serum HCV RNA was detectable with PCR in 94 patients (69%) and not detectable in 41 patients (31%). Patients with and without detectable serum HCV RNA had similar epidemiological characteristics. Serum ALT levels and anti-HCV ratio were lower (P =.001), and histological lesions had lower grade and stage in patients without detectable serum HCV RNA (P =.001). Liver HCV RNA was not detectable with PCR in the 12-serum HCV RNA-negative patients tested. During follow-up, all patients without detectable serum HCV RNA remained HCV RNA-negative and kept normal serum ALT; all patients with detectable serum HCV RNA remained HCV RNA-positive, 20 (21%) had a slight fluctuation of serum ALT above the upper limit of normal. No significant changes were observed in the liver lesions of the 24 patients who underwent a second liver biopsy. In anti-HCV-positive patients with persistently normal serum ALT, histological lesions are significantly lower in HCV RNA-negative than in HCV RNA-positive patients. During follow-up, the HCV RNA status of patients remained unchanged; 21% of the patients with detectable serum HCV RNA had slight increase in serum ALT levels, but histological lesions remained stable.

Adult↗

Tolerability of treatments for viral hepatitis.

Interferon-alpha is the most widely used antiviral drug in chronic hepatitis B and C. Tolerability is usually good and serious adverse effects are rare. Most of the adverse effects are mild or transient and do not necessitate drug withdrawal. More than 90% of patients who are given interferon-alpha achieve 6 months to 1 year of treatment without serious adverse effects. The serious adverse effects usually occur in predisposed patients with pre-existing organ dysfunction. Nevertheless, careful selection of patients for therapy and observation during therapy are recommended. Nucleoside analogues are promising drugs in the treatment of chronic hepatitis B through inhibition of viral DNA polymerase. Lamivudine has been licensed for use in this indication. Its tolerability is excellent even when used for periods of 1 year or more. The main concern is the relatively high incidence of viral resistance resulting in breakthrough during or relapse after therapy. In the treatment of chronic hepatitis C, ribavirin, in combination with interferon-alpha is currently the reference therapy. The main adverse effect is haemolytic anaemia, which necessitates careful monitoring and adjustment of dosage in many cases. Recently, large trials showed the better efficacy of pegylated interferons as compared with standard interferon. The combination of pegylated interferon with ribavirin is under evaluation.

Antiviral Agents↗

Decrease in serum ALT and increase in serum HCV RNA during pregnancy in women with chronic hepatitis C.

BACKGROUND/AIMS: The natural history of chronic hepatitis C infection during pregnancy has not been clearly established, and thus our aim was to assess serum alanine aminotransferase levels and serum HCV RNA levels during pregnancy. METHODS: Twenty-six pregnant women with chronic hepatitis C were studied. Serum alanine aminotransferase was assessed within the 3 months before, monthly during and within the 3 months after pregnancy. In 12 women, serum HCV RNA levels were quantified by the branched DNA assay. Twenty-six age-matched non-pregnant women with chronic hepatitis C were followed up for 1 year, and used as a comparison group. RESULTS: During pregnancy, serum alanine aminotransferase levels decreased in the second and third trimesters. The third trimester levels were significantly lower than serum alanine aminotransferase levels before pregnancy (p=0.0001). Seventy-seven percent of the pregnant women with increased pre-pregnancy levels had normalization of serum alanine aminotransferase levels. In the second or third trimesters, serum HCV RNA levels increased. The third trimester serum HCV RNA levels were significantly higher than levels before pregnancy (p=0.01). No significant change in serum alanine aminotransferase or HCV RNA levels was observed in the control group. CONCLUSION: In pregnant women with chronic hepatitis C, serum alanine aminotransferase levels decrease, and serum HCV RNA levels increase during the second and third trimesters.

Adult↗

Activation of ionotropic glutamate receptors reduces the production of transforming growth factor-beta2 by developing neurons.

Neuronal cultures derived from developing rat cerebral cortex were used to investigate the influence of glutamate receptors on the neuronal production of transforming growth factor-beta2 (TGFbeta2), a multifunctional cytokine that modulates neuronal and glial growth. Long-term exposure (48 h) of cortical neurons to selective antagonists of N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptors markedly increased TGFbeta2 levels in the culture medium. Conversely, treatment with NMDA or kainate reduced TGFbeta2 to levels below those in untreated cultures. The effect of kainate did not require NMDA receptor activity. Neuronal depolarization with K+ also reduced TGFbeta2 levels by opening voltage-gated L-type Ca2+ channels. Semi-quantitative RT-PCR measurements of neuronal TGFbeta2 mRNA showed that NMDA or AMPA/kainate receptor stimulation reduced TGFbeta2 mRNA levels. These results demonstrate that tonic activation of glutamate-gated cation channels downregulates neuronal expression of the TGFbeta2 gene and provide evidence for a novel mechanism whereby excitatory amino acids could influence the development of glial and neuronal lineages.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

Lifestyle health risk assessment. Do recently trained family physicians do it better?

OBJECTIVE: To determine whether recently trained family physicians were more likely to routinely assess lifestyle health risks during general medical evaluations. To document physicians' perceptions of the difficulties of lifestyle risk assessment, of medical training in that area, and of how often they saw patients with lifestyle health risks. DESIGN: Anonymous mailed survey conducted in 1995. SETTING: Family practices in the province of Quebec. PARTICIPANTS: Stratified random sample of 805 active family physicians of 1111 surveyed; 25 were ineligible or could not be located, and 281 did not respond (74.1% response rate). MAIN OUTCOME MEASURES: Proportion of physicians graduating before and after 1989 who reported routinely (with 90% or more of their patients) assessing their adult and adolescent patients during general medical evaluations for substance use, sexual risk behaviours, and history of family violence and sexual abuse. RESULTS: Except for asking about drug use, recently trained family physicians did not report better assessment of lifestyle health risks during general medical examinations than family physicians who graduated more than 10 years ago did. In both groups, routine assessment averaged 82% for tobacco use, 68% for alcohol consumption, and 20% to 40% for sexual risk behaviours. Screening for family violence and sexual abuse was rare, but more frequently reported by older women physicians. Only 20% to 40% of recent graduates rated their medical training adequate for evaluating illicit drug use, family violence, and sexual abuse. CONCLUSION: Recently trained family physicians do not assess most lifestyle risk factors any better than their more experienced colleagues.

Adolescent↗

Do physicians assess lifestyle health risks during general medical examinations? A survey of general practitioners and obstetrician-gynecologists in Quebec.

BACKGROUND: In Canada several guidelines have been published for the screening of lifestyle health risks during general medical examinations. The authors sought to examine the extent to which such screening practices have been integrated into medical practice, to measure physicians' perceived level of difficulty in assessing these risks and to document physicians' evaluation of their formal medical training in lifestyle risk assessment. METHODS: An anonymous mail survey was conducted in 1995 in Quebec with a stratified random sample of 1086 general practitioners (GPs) and with all 241 obstetrician-gynecologists (Ob-Gyns). The authors evaluated the proportion of physicians who reported routine assessment (with 90% or more of their patients) of substance use, family violence and sexual history during general medical examinations of adult and adolescent patients; the proportion of those who find inquiring about these issues difficult; and the proportion of those who evaluated their medical training in lifestyle risk assessment as adequate or excellent. RESULTS: The overall response rate was 72.6%. Among adult patients, 82.2% of the GPs reported routinely assessing tobacco use, 67.2% alcohol consumption, 34.2% illicit drug use and 3.2% family violence; the corresponding proportions for assessment among adolescent patients were 77.1%, 61.8%, 52.9% and 5.6%. Comparatively fewer Ob-Gyns reported routinely assessing these issues (56.1%, 28.6%, 20.4% and 1.3% respectively among adults and 62.7%, 35.2%, 26.8% and 2.8% respectively among adolescents). In the area of sexual history, condom use was routinely assessed by more Ob-Gyns than GPs (47.0% v. 28.2%); however, the proportion of Ob-Gyns and GPs was equally low for assessing number of partners (24.8% and 23.1%), sexual orientation (18.8% and 16.9%) and STD risk (26.2% and 21.2%). The vast majority of GPs and Ob-Gyns reported finding it difficult to assess family violence (86.5% and 93.0%) and sexual abuse (92.7% and 92.4% respectively). Over 80% of the physicians felt that they had had adequate or excellent medical training in assessing risk behaviours for heart disease and STD risk. The proportion who felt this way about their training in screening for illicit drug use, family violence and sexual abuse ranged between 12.7% and 31.6%. INTERPRETATION: Although morbidity and mortality associated with smoking, alcohol consumption, illicit drug use, unsafe sexual practices, family violence and sexual abuse have been well documented, routine screening for these risk factors during general medical examinations has yet to be integrated into medical practice.

Adolescent↗

Sexual health risk assessment and counseling in primary care: how involved are general practitioners and obstetrician-gynecologists?

OBJECTIVES: This study examined physicians' evaluation of sexual health risks during a general medical examination and sexually transmitted disease (STD) counseling during consultations for adolescent contraception and treatment of an STD. METHODS: An anonymous mail survey was conducted in 1995 with a stratified random sample of 1086 general practitioners and all 241 obstetrician-gynecologists practicing in Quebec, Canada. RESULTS: Fewer than half of the respondents reported routinely inquiring about condom use and number of sexual partners during a general medical examination. Female general practitioners engaged in more sexual health risk assessment and counseling than male general practitioners. CONCLUSIONS: This study suggests a low level of involvement in STD prevention by generalists and obstetrician-gynecologists.

Adolescent↗

Structure-specific binding recognition of a methanogen chromosomal protein.

The archaeon Methanosarcina thermophila expresses large amounts of a small basic protein, called MC1 (methanogen chromosomal protein), which was previously identified as a DNA-binding protein possibly involved in DNA compaction in some methanogenic species. We have investigated the binding of MC1 to various kinds of branched DNA molecules whose double helix axis is severely kinked. We show that MC1 is able to distinguish and to bind preferentially to four-way junctions. This preferential binding is observed in the absence and presence of divalent cations. However, we find that MC1 has a low affinity for bulged DNA structures. These results show how MC1 is able to discriminate between different deformations of the DNA double helix.

Archaeal Proteins↗

Apolipoprotein E and multiple sclerosis: a biochemical and genetic investigation.

Apolipoprotein E (apo E) is postulated to be a major lipid carrier protein in the brain involved in brain development and repair. Multiple sclerosis (MS) is a major demyelinating disease characterized by destruction of myelin and marked alteration of myelin cholesterol and lipid metabolism. We have determined serum and cerebrospinal fluid (CSF) apo E concentrations using an original time-resolved immunofluorometric assay and calculated intrathecal apo E concentration. Apo E concentrations were determined in 13 control subjects and 129 neurological patients: 34 definite MS patients, 25 with Guillain-Barré syndrome (GBS), 32 with amyotrophic lateral sclerosis (ALS) and 38 with other neurological diseases. Seven clinical parameters (sex, age, age at MS onset, duration of the disease, course, clinical status and disability score) were considered in MS patients. Significant (P < 0.01) decrease in CSF apo E was observed in MS, linked to a decrease in intrathecal apo E. The decreased CSF apo E concentration in MS patients occur independent of the apo E genotype. Apo E is considered as a neurotrophic factor in the brain. Any decrease in intrathecal apo E synthesis would thus contribute to progression of neurological diseases, such as MS.

Adult↗

Six French sheathless coronary angioplasty using a novel technique to introduce the guiding catheter: the INTRUC, a preliminary retrospective study.

This registry describes our preliminary experience with a novel introducing-catheter allowing direct percutaneous introduction of the 6F guiding catheter (G-C), minimizing the puncture size, preventing vessel scraping, and improving the pushability and torque response of the G-C. In 1995, 203 patients had sheathless PTCA, using this device. Eighty-five percent were male. Mean age was 65+/-10 years. Thirty-nine percent had stable angina, 35% unstable angina, 7% evolving infarction, and 19% recent infarction. Two hundred fifty-six lesions were treated (1.26/patient). One hundred eight patients (52%) received one (85%) or more than one (15%) stent. The procedural success rate was 98%. Mean coronary stenosis was 82+/-10% and decreased to 20+/-15% after PTCA. No major complication occurred. The guiding catheter was immediately removed in 95% of patients, despite heparinization. No patient required surgery or blood transfusion for vascular complications, and only 7 had minor local complications (3.5%). Sheathless angioplasty provides no technical difficulties and has the same safety and quality as conventional angioplasty using a sheath. Immediate removal of the guiding catheter, without keeping vascular access, has no deleterious effect, allows early mobilization, and may limit the risk of vascular complications.

Adult↗

Novel muscle chloride channel (CLCN1) mutations in myotonia congenita with various modes of inheritance including incomplete dominance and penetrance.

Autosomal-dominant and -recessive myotonia congenita are caused by mutations in the skeletal muscle voltage-gated chloride channel gene (CLCN1). We searched for mutations in this gene in 20 unrelated families with myotonia congenita. We identified 11 different mutations in 10 families. Two of five new mutations (Ala313Thr and Ile556Asn) were both autosomal recessive and dominant with either reduced penetrance or incomplete dominance. Mutations in the CLCN1 gene do not therefore necessarily behave in a classic Mendelian manner.

Adult↗