Search PubMed⌕ Search

Biomedical subjects

A Gervais

Publications and source records attributed to A Gervais.

At least 37 records · Page 2Linked to original sources
PubMed1998

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↗
PubMed1998

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↗
PubMed1998

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↗
PubMed1997

Long-term histologic improvement and loss of detectable intrahepatic HCV RNA in patients with chronic hepatitis C and sustained response to interferon-alpha therapy.

BACKGROUND: Less than 20% of patients with chronic hepatitis C have a sustained response to interferon-alpha therapy. The long-term benefit of interferon-alpha with regard to hepatic viral clearance and histologic improvement remains unknown. OBJECTIVE: To determine the long-term biochemical, virologic, and histologic outcomes in patients with chronic hepatitis C who have a sustained response to interferon-alpha therapy. DESIGN: Prospective cohort study. SETTING: University hospital. PATIENTS: 80 patients who had chronic hepatitis C, had a sustained biochemical and virologic response to interferon-alpha therapy, and were followed for at least 12-months. MEASUREMENTS: Serum hepatitis C virus (HCV) RNA detected by polymerase chain reaction (PCR); HCV genotyping determined by line probe assay; liver histologic studies; liver HCV RNA detected by PCR on frozen liver tissue samples (in 27 patients); and repeated measurements of serum alanine aminotransferase (ALT) levels. Liver biopsy was done before treatment in all 80 patients, and at least one biopsy was done in 69 patients 1 to 6 years after treatment. RESULTS: The 80 patients had follow-up 1 to 7.6 years (mean +/- SD, 4.0 +/- 2.0 years) after interferon-alpha treatment. The follow-up period was 1, 2, 3, 4, 5, 6, and more than 6 years in 11, 13, 14, 18, 10, 12, and 2 patients, respectively, after the end of therapy. During the entire follow-up period, 93% (95% CI, 84% to 97%) of patients had persistently normal serum ALT levels. Serum HCV RNA remained undetectable in 96% (CI, 89% to 99%) of patients. A comparison of liver histologic findings before and 1 to 6.2 years after interferon-alpha treatment showed a clear improvement in 94% (CI, 83% to 99%) of patients. In 62% of patients, the last biopsy done showed normal or nearly normal histologic findings. Liver HCV RNA was detectable before treatment in all 13 patients tested and was undetectable 1 to 5 years after treatment in all 27 patients tested. CONCLUSIONS: In patients with chronic hepatitis C who have persistently normal serum ALT levels and no detectable serum HCV RNA 6 months after interferon-alpha therapy, a long-term sustained biochemical and virologic response is generally seen. This response is associated with an absence of detectable intrahepatic HCV RNA and marked histologic improvement.

Alanine Transaminase↗
PubMed1997

[Systematic use of 4 French catheters for left heart catheterization and coronary angiographies].

The feasibility of left heart catheterisation and coronary angiography using small calibre 4 French catheters was assessed in a prospective register of 355 consecutive patients. The average age was 64 +/- 10 years: 21% were women. The indications were: evaluation of coronary artery disease (279 patients), control of bypass graft patency (38 patients including 34 internal mammary artery grafts), 26 valvular lesions (including 15 aortic stenoses) and 12 cardiomyopathies. In 20.5% of cases, the catheterisation was performed on an out-patient basis. The catheters used for coronary opacification were Cordis Pigtail and Amplatz; mammary, multipurpose and right Judkins were used occasionally. The operators used on average 2.14 catheters, without difficulty in 13% of cases. A larger catheter was not required in any of the cases. There were no complications. The angiograms were estimated to be of good quality in 96% of cases. With the exception of patients undergoing immediate angioplasty and 9 patients with severe hypertension or anticoagulant therapy, the patients did not require compressive dressings on the puncture site and could be mobilised early. There were no local complications at the puncture site. The results of this study suggest that 4 F catheters can be used systematically for left heart catheterisation with safety. A short period of training is required after which good quality angiograms can be obtained without technical problems. Compressive dressings are not necessary after this type of investigation.

Adult↗
PubMed1997

Do women physicians do more STD prevention than men? Quebec study of recently trained family physicians.

OBJECTIVES: To examine differences attributable to sex of family physicians in their practices and in their perceptions of sexual history taking and safer sex counseling, and to ascertain whether sex of physicians influences counseling about condoms. DESIGN: Cross-sectional survey. SETTING: Quebec family practices. PARTICIPANTS: Recently graduated (1991) Quebec family physicians: 54 men and 92 women. MAIN OUTCOME MEASURES: Frequency and content of sexual history, frequency of safer sex counseling, perceived level of comfort in taking a sexual history, perceived adequacy of medical training to take sexual histories, perceived difficulty with sexual history taking according to patients' characteristics, and perceived effectiveness of safer sex counseling. RESULTS: Response rate was 80% of 183 physicians contacted. There were few differences attributable to sex of physician in family physicians' practices and perceptions regarding sexual history taking. Men's perceptions regarding the difficulty of sexual history taking did not vary according to patient's sex, but most women reported more difficulty with male patients. Male physicians reported more difficulty with teenagers; female physicians experienced more difficulty questioning adults. More than 85% of male and female physicians reported recommending condom use to a patient in their practice at least weekly. Women physicians seemed to do more condom-related counseling than their male colleagues, even after controlling for other variables. Salaried practice in a local community health centre did not influence condom-related counseling. CONCLUSIONS: Women family physicians are more inclined than men to counsel patients about condom use. Increasing numbers of women in family practice could have a beneficial effect on prevention of STDs and undesired pregnancies.

Adolescent↗
PubMed1996

Preferential binding of the archaebacterial histone-like MC1 protein to negatively supercoiled DNA minicircles.

The interaction of the archaebacterial MC1 protein with 207 bp negatively supercoiled DNA minicircles has been examined by gel retardation assays and compared to that observed with the relaxed DNA minicircle. MC1 binding induces a drastic DNA conformational change of each minicircle, leading to an increase of the electrophoretic mobility of the DNA. A slight increase in salt concentration enhances the amount of bound MC1, and high NaCl concentrations are required to dissociate the complexes. Furthermore, the salt effect on binding depends on the supercoiling state of the DNA. The dissociation rates decrease with increasing linking difference of the minicircles relative to their relaxed configuration to reach a maximum at -2 turns. In addition, differences between the topoisomers are also observed in terms of stoichiometry of the strongest complexes. So with the -2 topoisomer the complex with two MC1 molecules is the most stable, while with the -1 and -3 topoisomers, the strongest ones are those with one MC1 molecule per DNA ring.

Archaeal Proteins↗
PubMed1996

[Serum cardiolipin antibodies in patients with alcoholic cirrhosis].

OBJECTIVE: Although portal obstruction is a complication in cirrhosis which is usually associated with hepatocellular carcinoma, its precise neoplastic or thrombotic nature is not easy to determine. Serum antiphospholipid antibodies could be involved in thrombosis-related portal obstruction. PATIENTS AND METHODS: The presence of serum anticardiolipid antibodies was investigated by an immunoenzymatic technique in 129 patients with alcoholic cirrhosis, 47 patients with hepatocellular carcinoma with (n = 18) or without (n = 29) portal obstruction, and 82 patients without hepatocellular carcinoma or portal obstruction. Five control groups were included: patients with non alcoholic cirrhosis (n = 21), non cirrhotic alcoholic liver disease (n = 21), chronic viral hepatitis (n = 14), extra-hepatic cholestasis (n = 9), and hypergammaglobulinemia associated with human immunodeficiency virus infection without liver disease (n = 28). RESULTS: The prevalence of serum anticardiolipid antibodies was 57% in patients with alcoholic cirrhosis, which was significantly different from the prevalence in the control groups which ranged from 0 to 32%. Anticardiolipid antibodies were of IgA isotypes in 90.5% of the cases, mainly related to the degree of liver failure but not to hepatocellular carcinoma or portal obstruction. CONCLUSION: In alcoholic cirrhosis, serum anticardiolipid antibodies do not seem to be related to the pathogenesis of portal obstruction in patients with hepatocellular carcinoma. They could rather reflect liver lesions and immunological dysfunctions.

Adult↗
PubMed1995

STD risk assessment and risk-reduction counseling by recently trained family physicians.

PURPOSE: To survey recently trained family physicians about their practices and perceptions regarding sexual history taking, drug-use history taking, and safe-sex counseling. METHOD: The study was conducted with all 1991 graduates from the four family practice residency programs in Quebec, Canada. Data were collected in 1992 by using a mailed questionnaire. RESULTS: A total of 148 (80%) of the 186 contacted physicians responded. The physicians reported taking a sexual history less frequently than a drug-use history when seeing patients for a general medical examination (42% versus 71%) or a first pregnancy visit (75% versus 91%). When taken, the sexual history was often too superficial to detect risk behaviors. Consequently, safe-sex counseling was infrequent. Over 20% of the physicians worried about patients' discomfort, were uneasy discussing sexual matters, and did not feel properly trained in sexual history taking. Graduates from the family practice residency at the school that offered training in human sexuality performed better sexual history taking than did graduates from the residencies at the other schools. CONCLUSIONS: Although infections from sexually transmitted diseases and the human immunodeficiency virus are important causes of morbidity and mortality, family physicians are still not actively involved in their prevention. The study suggests that medical education might be deficient in this area and that more training in human sexuality should be provided for family physicians.

Attitude of Health Personnel↗
PubMed1995

Determination of free triiodothyronine by six different methods in patients with non-thyroidal illness and in patients treated with amiodarone.

We performed a methodological comparison of free triiodothyronine (FT3) estimates in patients with liver cirrhosis and renal failure. Patients were classified in terms of severity of illness on the basis of their total triiodothyronine, total thyroxine and reverse triiodothyronine profiles. FT3 levels, measured in direct dialysis, microchromatography, labelled analogue and two-step immunoextraction assays were significantly (P < 0.01) lower than the control group in all patient categories. However, FT3 measured by a labelled antibody radioimmunoassay was significantly reduced only in the most severely ill sub-group of patients. In a further group of patients on long-term amiodarone therapy for cardiac disease all FT3 methods, with the exception of the labelled antibody radioimmunoassay and an analogue method, yielded significantly (P < 0.01) reduced levels. A significant negative association between FT3 and subject age was demonstrated for all methods except the labelled antibody radioimmunoassay, and a weak but significant negative correlation between log thyrotropin and FT3 was only seen with this assay. Three methods demonstrated a correlation (P < 0.02) with albumin levels in patients with the 'low T3 syndrome'. In this group, albumin had a predictive value (P < or = 0.02) for four out of six assays as determined by stepwise variable selection. Our findings suggest that users of FT3 assays should exercise caution in interpreting results in non-thyroidal illness and amiodarone treated patients, as there are method-related differences in the profiles obtained.

Adult↗
PubMed1995

A sensitive time-resolved immunofluorometric assay for the measurement of apolipoprotein B in cerebrospinal fluid. Application to multiple sclerosis and other neurological diseases.

Although low density lipoprotein receptors have been described on oligodendrocytes, apolipoprotein B was thought to be absent or present in only very small amounts in cerebrospinal fluid (CSF). Several immunoassays have been used for the measurement of apolipoprotein B in serum. However, the majority of methods cannot be used to measure small amounts of apolipoprotein B in CSF. In this study, we describe a highly sensitive time resolved immunofluorometric assay (TR-IFMA) using europium as label (detection limit: 0.3 microgram/l). The reliability of the TR-IFMA for the measurement of apolipoprotein B was first studied in serum. Serum and CSF apolipoprotein B concentrations were then determined in subjects free of neurological disorders and in patients with multiple sclerosis. Local intrathecal apolipoprotein B synthesis was calculated. Although the high sensitivity of the TR-IFMA allowed low amounts of apolipoprotein B in CSF to be detected (0.11 +/- 0.06; 0.12 +/- 0.06 mg/l in controls and multiple sclerosis patients, respectively), no apolipoprotein B could be detected in CSF by electroimmunodiffusion. As suggested by the blood/CSF apolipoprotein B ratio (about 6000), no apolipoprotein B synthesis was observed by both using apolipoprotein B index and formula. This indicates its probable serum origin. Moreover, there was no difference between controls and multiple sclerosis patients in CSF, serum, blood/CSF, index, and local intrathecal apoliprotein B synthesis. Finally, these results suggest that the role of apolipoprotein B in lipid transport in the central nervous system may be questionable.

Adult↗
PubMed1994

Archaebacterial histone-like protein MC1 can exhibit a sequence-specific binding to DNA.

The binding of MC1 protein, the major chromosomal protein of the archaebacterium Methanosarcina sp. CHTI 55, to the region preceding the strongly expressed genes encoding methyl coenzyme reductase in a closely related micro-organism has been investigated. By gel retardation and DNAase I footprinting assays, we identified a preferential binding sequence in an open reading frame of unknown function. The large area of DNA protected against DNAase I is interrupted by a strong cleavage enhancement site on each strand. By circular permutation assays, we showed that the DNA bends upon MC1 binding. Furthermore we observed that the presence of a sequence outside the binding site can induce an unusual electrophoretic behaviour in some complexes.

Archaeal Proteins↗
PubMed1994

Evaluation of a 99mTc-antimyosin kit for myocardial infarct imaging.

The Fab fragment of a mouse monoclonal antibody AM(3-48) that recognizes alpha and beta-heavy chains of human atrial and ventricular myosin and beta-heavy chain of human slow skeletal muscle myosin [CardioVisionTM] was labeled with 99mTc using stannous reductant in a simple, instant kit method. The infarcted heart uptake in dogs of 99mTc-AM(3-48)Fab' was compared with that of established radiopharmaceuticals routinely used for cardiac imaging in humans. The dog infarct was induced by bringing a catheter from the femoral artery to the coronary artery where an artificial blood clot was generated. The 99mTc-AM(3-48)Fab' preparation was selectively taken up by infarcted myocardium, resulting in diagnostic quality images of the infarcted area as early as 6 hour post-injection, rendering CardioVisionTM particularly useful for SPECT imaging. Good agreement was found between the images obtained with 99mTc-Pyrophosphate and those obtained with 99mTc-AM(3-48)Fab', while the infarcted area was clearly delineated as a cold spot with 99mTc-MIBI or 201 Tl-thallous chloride. The biodistribution of 99mTc-AM(3-48)Fab' was also studied in healthy and isoproterenol-infarcted rats, from which dosimetry values in man were extrapolated. The data indicate that the kidneys will receive the highest radiation dose and that they will be the main contributors to the total radiation burden, which was estimated at 0.005 rad/mCi.

Animals↗