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Biomedical subjects

A Chevalier

Publications and source records attributed to A Chevalier.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Prescription of beta-lactams for community-acquired broncho-pulmonary infections in adults. Observations in the hospital environment].

OBJECTIVE: Analyze beta-lactam prescription patterns used in hospitals for the treatment of community-acquired lower respiratory tract infections in adults. PATIENTS AND METHODS: A prospective study was carried out over 4 months (October 1997 to January 1998) in 54 medical units caring for lung disease, internal medicine/infectious disease, geriatric and general medicine patients in 27 hospitals representative of the public facilities in France. Data were collected on the medical unit, the patients, and the antibiotic prescriptions, including discharge prescriptions. The cost analysis of antibiotic therapy took into account all antibiotics given to the patients during their hospital stay. RESULTS: One thousand eighteen patients were included in the study: 266 were treated for acute bronchitis, 405 for bronchitis infection with underlying chronic respiratory disease, and 347 for pneumonia. Noteworthy findings included: low percentage of protocols within the medical units (25.3%), an unexpected frequency of hospitalization for acute bronchitis generally among elderly women, and prolonged intravenous antibiotic therapy and hospitalization (5 to 6 days and 9 to 12.5 days respectively). CONCLUSION: This study confirms the need to reinforce measures aimed at optimizing antibiotic prescriptions in hospitals.

Adult↗
PubMed2000

Occupational risk factors for lung cancer in the French electricity and gas industry: a case-control survey nested in a cohort of active employees.

The main aim of this study was the analysis of occupational lung cancer risk factors in the French national electricity and gas company (Electricité de France-Gaz de France (EDF-GDF)). A case-control survey nested in a cohort of male employees was undertaken. The study population consisted of all male staff who were active at EDF-GDF between January 1, 1978, and December 31, 1989. During this period, 310 cases of lung cancer were identified in the cancer register set up by the medical department of the company. For each case, four age-matched controls who were free of cancer at the time of occurrence of the case's lung cancer were randomly selected. Occupational exposures to 21 chemical agents were assessed for each subject using a job exposure matrix. The associations between lung cancer and the different agents were estimated using conditional logistic regression analysis. After adjustment for various occupational confounding factors, the analysis showed increased lung cancer risks linked to exposure to crystalline silica (highest exposure class: odds ratio = 2.27; 95% confidence interval: 1.10, 4.68) and creosotes (highest exposure level: odds ratio = 2.14; 95% confidence interval: 1.06, 4.31), with significant dose-response relationships for both exposures.

Adult↗
PubMed2000

Chronic consumption of fresh but not heated yogurt improves breath-hydrogen status and short-chain fatty acid profiles: a controlled study in healthy men with or without lactose maldigestion.

BACKGROUND: Ingestion of fermented dairy products induces changes in the equilibrium and metabolism of the intestinal microflora and may thus have beneficial effects on the host. OBJECTIVE: We compared the effects of chronic consumption of yogurt with (fresh) or without (heated) live bacterial cultures (Lactobacillus bulgaricus and Streptococcus thermophilus) on plasma glucose, insulin, triacylglycerols, cholesterol, fatty acids, and short-chain fatty acids. DESIGN: Two groups of 12 healthy men with or without lactose malabsorption were selected with use of a breath-hydrogen test after a 30-g lactose load. Subjects were randomly assigned in a crossover design to 500 g/d of either fresh or heated yogurt for 2 periods of 15 d each, separated by a 15-d washout interval. RESULTS: Chronic consumption of fresh or heated yogurt had no detrimental effects on plasma glucose, insulin, or fatty acid areas under the curve in response to acute ingestion of 500 g yogurt in healthy men with or without lactose malabsorption. There were also no detectable changes in fasting plasma glucose, insulin, fatty acid, triacylglycerol, or cholesterol concentrations. In contrast, plasma butyrate was higher (P: < 0.03) and plasma propionate tended to be higher (P: = 0.059) in subjects without lactose malabsorption after fresh yogurt consumption than after heated yogurt consumption. There were no significant changes in plasma acetate. In subjects with lactose malabsorption, 15 d of fresh yogurt consumption also increased propionate production compared with values at baseline (P: < 0.04). In the same group, the production of breath hydrogen was lower after fresh yogurt consumption than after heated yogurt consumption (P: < 0.01). CONCLUSIONS: In men with lactose malabsorption, chronic consumption of yogurt containing live bacterial cultures ameliorated the malabsorption, as evidenced by lower breath-hydrogen excretion, but increased propionate concentrations. In subjects without lactose malabsorption, such yogurt tended to increase propionate and increased butyrate.

Adult↗
PubMed2000

Insufficient adaptation of hypoglycaemic threshold for cognitive impairment in tightly controlled type 1 diabetes.

UNLABELLED: It is well known that hypoglycaemic thresholds for hormones and symptoms occur at lower plasma glucose levels in patients with strict glycaemic control. However, whether the threshold for cognitive impairment also shifts is still an unresolved question. We studied 19 type 1 diabetic patients, including 8 with hypoglycaemia unawareness, aged 37.0 +/- 7.4 y.r., with diabetes duration 15.2 +/- 10.7 yr, and HbA1c 7.6 +/- 1.1%. Hypoglycaemic thresholds for hormones, symptoms, awareness and cognitive function using the 4-choice reaction time test (4RT), were measured every 30 min during a 150 min stepped 4.4 to 2.2 mM hypoglycaemic hyperinsulinemic clamp. We found that 4RT- accuracy deteriorated earlier than 4RT-time (3.2 and 2.7 mM, respectively, p<0.01), and that both correlated poorly with HbA1C before and after adjustment for age and diabetes duration (r=0.11, and 0.18, respectively). On the opposite, adrenaline, autonomic and neuroglycopenic symptoms, and awareness significantly correlated with HbA1c values (r=0.56, 0.70, 0.61, and 0.63, after adjustment, respectively). Furthermore, after allocating the patients into two subgroups according to HbA1c values (<8% n=12, and >=8% n=7), we found that, as opposed to other thresholds, accuracy and 4RT-time were minimally and not significantly influenced by glycaemic control, therefore exhibiting the smaller glucose thresholds shifts (- 0.2 and - 0.5 mM for accuracy and time, respectively, vs. 0.6 -0.8 for other thresholds). IN CONCLUSION: 1) the hypoglycaemic thresholds for cognitive dysfunction shift with strict glycaemic control, but not significantly and less than other thresholds, 2) as opposed to other reports, accuracy deteriorates earlier than speed during the 4RT test, and 3) these "maladapted" reactions may contribute to the higher risk for severe hypoglycaemia in subjects with tight glycaemic control.

Adult↗
PubMed1999

Socioeconomic status, social mobility and cancer occurrence during working life: a case-control study among French electricity and gas workers.

OBJECTIVES: A case-control study within a cohort of the workers employed by Electricité de France and Gaz de France between 1988 and 1992 was carried out to investigate relationships between cancers and socioeconomic status, including the effects of social mobility, by studying three professional career points. METHODS: All the incident cases of breast cancer in women and all the incident cases of upper respiratory and digestive tract cancer (comprising cancers of the larynx, pharynx, buccal cavity and esophagus), lung cancer, hematopoietic system cancers and colon cancer in men were extracted from the Cancer Register of the Social Security Department. The controls were matched for age (men) and for age and length of employment in the company (women). Socioeconomic status was measured at three professional career points (beginning, midpoint (about 35), and time of diagnosis (about 48)) by two types of socio-professional variables: employee category (low, medium, high) and a variable based on the French socioeconomic status classification system. An estimation of social mobility was done between career beginning and midpoint. Cases and controls were compared for socioeconomic status at the three career points. They were also compared for social mobility. RESULTS: The differences between the social categories were larger at the start than later in the career for breast cancer in women. The category of operations staff was used as a reference, and this analysis shows a difference between the risks associated with supervisors (OR = 2.0) and managers and specialist professions (OR = 1.5). There were large differences according to the type of cancer in men. A socioeconomic gradient in the incidence of cancers of the upper respiratory and digestive tract was observed at every career stage. The gradient was largest at the moment of diagnosis. The odds ratio was 3.4 for supervisors, 7.8 for operations staff and 14.8 for production staff. There was a socioeconomic gradient in lung cancer at all points in the career and in the incidence of the hematopoietic system cancers at mid-career and at diagnosis. No association between socioeconomic status and colon cancer was found. Social mobility accentuated all these results. CONCLUSION: Socioeconomic status is involved in the development of cancers. Our study suggests that the transition from social to biological processes could act via specific lifestyle and/or work-related risk factors. When there is a social gradient in the incidence of a cancer, an individual's social change is at least as important as his/her original social status in the relationship between cancer and social class.

Adult↗
PubMed1999

Absenteeism and mortality of workers exposed to electromagnetic fields in the French Electricity Company.

The objective of this study was to describe the health status of electricity workers exposed to electromagnetic fields during their job. Two groups of exposed workers were studied from 1978 to 1993: the live line workers (n = 121) and the substation workers (n = 232.7) of the French Electricity Company (EDF). A control group was randomly selected from all the company non-management male employees; one control for each exposed subject was matched for the first year of employment. Absenteeism indices and mortality rates were computed and compared in the exposed and control groups. The absence rates were 1.98% in the substation workers and 2.5% in the control group (p < 0.001) and 2.7% in the live-line workers and 2.8% in the control group (NS). No effect of the length of exposure was found. However the medical causes of sickness absence were different: exposed employees had less psychiatric and respiratory diseases but more accidents at work than their control group. Relative risks of accidents at work were 1.2 95% confidence interval (CI) = 1.08-1.33[ for substation workers and 3.22 (CI = 1.78-5.88) for live line workers. EDF electromagnetic field exposed workers seemed not to be affected by any specific health problems except for an excess of accidents at work.

Absenteeism↗
PubMed1998

Symptom distress and frequency of life events.

A study of the frequency of life events was conducted in a group of subjects selected from the general population over a period of 9 months. Four assessments were made, using an events questionnaire and the Psychiatric Symptom Index (PSI), at 3-monthly intervals. The results show a significant relationship (maintained over time) between PSI score and the number of upsetting events, but no significant relationship between PSI score and non-upsetting events. These observations are interpreted as follows: the higher frequency of upsetting life events is secondary to the previous psychological pattern of subjects.

Adult↗
PubMed1998

Decreased uptake of therapeutic doses of iodine-131 after 185-MBq iodine-131 diagnostic imaging for thyroid remnants in differentiated thyroid carcinoma.

We performed a prospective random study to assess possible thyroid stunning by a 185-MBq iodine-131 dose used to diagnose thyroid remnants. Patients with differentiated thyroid carcinoma were included after total or near-total thyroidectomy. They were randomly assigned to two groups. In group 0 (G0, 32 patients), iodine-123 administration only was used to diagnose thyroid remnants and/or metastasis, so that no thyroid stunning by 131I would occur. In group 1 (G1, 19 patients), diagnostic imaging was performed with 123I and 185 MBq 131I. 123I imaging was less sensitive than 131I imaging in identifying thyroid remnants in both groups (94%). Thyroid uptake of 123I was measured in both groups (at 2 h) and was not significantly different between the groups. Patients with thyroid remnants who remained in the study (28/32 in G0, 17/19 in G1) were treated with 370 MBq 131I, 5 weeks after treatment (mean time, range 12-84 days). In 12/17 G1 patients thyroid uptake measurement was repeated immediately before treatment. Uptake was equal to 1.97% +/- 0.71% and significantly lower (P < 0.05) than the previous measurement (3.76% +/- 1.50%). Patients were imaged 7 days after administration of the therapeutic dose and the images were compared with the diagnostic images. In 28/28 G0 patients thyroid remnants were unchanged and clearly seen. In 5/17 G1 patients, however the remnants were hardly identified, although they had been clearly seen at the time of diagnosis. We conclude the following: (1) a diagnostic dose of 185 MBq 131I decreases thyroid uptake for several weeks after administration and can impair immediate subsequent 131I therapy; (2) 123I is slightly less sensitive than 131I in identifying thyroid remnants; and (3) the need to scan for thyroid remnants remains to be confirmed, since only 2/51 patients enrolled in this study were not treated with 131I.

Carcinoma, Papillary↗
PubMed1998

Carotid atherosclerosis in renal transplant recipients.

BACKGROUND: Cardiovascular accidents are the major cause of morbidity and mortality in renal transplant recipients. However, there is little information concerning carotid atherosclerotic wall changes in renal transplant recipients, their relationship with cardiovascular accidents and their possible association with cardiovascular risk factors in such patients. METHODS: Between April 1991 and December 1997, we prospectively assessed cardiovascular accidents in 79 renal transplant recipients who had received a transplant at our institution before January 1, 1986. Carotid morphology by B-mode ultrasonography, relevant clinical and laboratory cardiovascular risk factors, including lipid abnormalities and total homocyst(e)ine, were determined at the start of the follow-up period. Seventeen healthy subjects matched for age and sex with renal transplant recipients served as controls who volunteered for ultrasonographic examination of carotid arteries. RESULTS: Nine patients experienced cardiovascular events during the period of follow-up. Compared with healthy, age- and sex-matched control subjects (n = 17), the frequency of carotid plaques was higher in renal transplant recipients with cardiovascular events (n = 9), but not in those without such events (n = 70). The frequency of cardiovascular accidents was related to the number of carotid plaques (4, 17 and 24% for no plaque, one plaque and > 1 plaque respectively, P < 0.04). However, by multivariate analysis, serum total cholesterol [odds ratio (OR) of 1.8 for each 1.0 mM, P < 0.07) and the presence of diabetes mellitus (OR of 28.4 for presence, P < 0.01) were the only predictors of cardiovascular events in such patients, whereas the presence of carotid plaques was not. Moreover, neither serum lipoprotein (a) nor total homocyst(e)ine concentrations could be identified as risk factors. CONCLUSIONS: This prospective study shows that although a close association exists between asymptomatic carotid atherosclerosis and cardiovascular accidents in renal transplant recipients with long-term follow-up and relatively good renal function, other potentially modifiable risk factors appear to be better predictors of cardiovascular events. Consequently, the assessment of carotid atherosclerosis may not be clinically useful for the systematic identification of renal transplant recipients with an increased risk of developing cardiovascular events.

Adult↗
PubMed1998

Moderate intake of n-3 fatty acids for 2 months has no detrimental effect on glucose metabolism and could ameliorate the lipid profile in type 2 diabetic men. Results of a controlled study.

OBJECTIVE: To evaluate the effect of a moderate dose of fish oil on glycemic control and in vivo insulin action in type 2 diabetic men with elevated plasma triacylglycerols and to determine the effect of the same treatment on gene expression of GLUT4, lipoprotein lipase (LPL), and hormone-sensitive lipase (HSL) in the abdominal adipose tissue. RESEARCH DESIGN AND METHODS: A total of 12 type 2 diabetic men were randomly allocated to 2 months of 6 g daily of either fish oil or sunflower oil, separated by a 2-month washout interval, in a double-blind crossover design. RESULTS: For glucose metabolism, 2 months of fish oil supplementation compared with sunflower oil led to similar fasting plasma insulin, glucose, and HbA1c. Basal hepatic glucose production did not increase after fish oil. There was no difference in insulin suppression of hepatic glucose production nor in insulin stimulation of whole-body glucose disposal measured by the euglycemic-hyperinsulinemic clamp. Fish oil did not ameliorate the low mRNA level of GLUT4 in adipose tissue of these patients. For lipid profile, fish oil lowered plasma triacylglycerol more than sunflower oil (P < 0.05) and tended to increase the amount of mRNA of both LPL and HSL in adipose tissue. CONCLUSIONS: A moderate dose of fish oil did not lead to deleterious effects on glycemic control or whole-body insulin sensitivity in type 2 diabetic men, with preserved triacylglycerol-lowering capacities.

Basal Metabolism↗
PubMed1998

[Helminth diagnosis in pathologic anatomy].

Most publications devoted to diagnosis of helminths emphasize characteristic parasitological features. Histological feature are seldom described in detail. The purpose of this study was to propose a diagnostic method suitable for use by histologists who, unlike parasitologists, do not visualize the whole worm but rather pieces randomly scattered over a slide. It is relatively easy to distinguish helminths which have smooth muscle, no respiratory or circulatory system, and no coelom from arthropods which have striated muscle, both respiratory and circulatory systems, and coelom. At the adult stage, roundworms or nemathelminths present an external cuticle that may have patterned markings. The visceral cavity is empty. Adults can dwell either in the intestine in which case they are oviparous (oxyuris, ascaris, Ancylostoma, Strongyloides stercoralis, Trichuris...) or in tissue in which case they are viviparous (filaria). Larva of some species can be found in tissues. Adult tape-worms are devoid of cuticle and have a mesenchymatous visceral cavity. Cestodes which are segmented and have no digestive tract (taenias) are readily distinguishable from trematodes which are not segmented and have a digestive tract (faciolasis) Some cestodes unable thrive in man can cause cyst formation (hydatidosis, sparganosis, cysticercosis, coenurosis). On the basis of symptoms and histological features, it is usually possible to diagnose the genus and even the species of the offending helminth provided that the parasite has not been excessively damaged and that a sufficient number of sections are available.

Animals↗
PubMed1997

Comparison of amitriptyline metabolism in hepatocytes from streptozocin-induced diabetic rats and from non-diabetic rats.

Biotransformation of amitriptyline (AMI) was studied at different intervals in freshly isolated hepatocytes from healthy or streptozocin-induced diabetic rats in order to investigate the influence of the diabetic state. Levels of free and conjugated AMI, demethylated and hydroxylated metabolites, were assessed by HPLC analysis. In hepatocytes isolated from diabetic rats, AMI was less completely metabolized and the demethylation reaction became more important than in non-diabetic rat hepatocytes. Although the proportions of hydroxylated metabolites decreased in diabetic rats, it always remained predominant. Furthermore, glucuronidation of metabolites was greater, especially for (Z)-10-hydroxynortriptyline in diabetic animals.

Amitriptyline↗
PubMed1997

In vitro calcium antagonistic and antioxidant effects of Org 13061 and its enantiomers, new potential antiatherosclerotic compounds.

The calcium antagonistic and antioxidant properties of a new potential antiatherosclerotic agent, Org 13061 were compared with those of its (-) and (+) enantiomers (Org 13471 and Org 13581) In vitro and with appropriate reference drugs. Org 13061 antagonized contractions induced by potassium in rabbit aortic rings with an IC50 value of 0.50 microM and reduced the maximum rate of phase 0 depolarization (Vmax) of the 'slow' calcium-mediated transmembrane action potentials in cardiac tissue (IC25 = 0.82 microM). Similarly to reference drugs, Org 13061 was more selective in reducing vascular compared to cardiac contraction. In concentrations overlapping those exerting vasorelaxant actions, Org 13061 inhibited copper ion-induced human low density lipoprotein (LDL) peroxidation (0.1-1 microM) and inhibited lipid accumulation by rat aortic smooth muscle cells in culture (1-3 microM). Higher concentrations (3 microM) modestly inhibited proliferation of these cells. The (-) enantiomer was ten times more potent than the (+) enantiomer as a vasorelaxant but was equipotent in inhibiting lipid accumulation and LDL peroxidation (eg, lag phase of conjugated dienes formation increased by 29 and 61 min and by 22 and 56 min in response to 0.3 and 1 microM (-) and (+) enantiomers, respectively). The antioxidant probucol was approximately three times more potent than Org 13061 in inhibiting lipid accumulation but was 30 times less potent in antagonizing LDL peroxidation. The classical calcium channel blocking agents were totally ineffective on lipid accumulation (1-10 microM), whereas human LDL peroxidation was slightly reduced by nifedipine (0.1-3 microM) but unaltered by diltiazem (0.1-30 microM) and verapamil (0.1-3 microM). In conclusion, the racemic Org 13061 selectively blocks voltage-operated calcium channels (VOCs) in concentrations that also exert marked antioxidant activity. The (-) enantiomer is largely responsible for calcium channel block but as antioxidants, the enantiomers are equipotent. This mixed pharmacological profile of Org 13061, not shared by known calcium channel blocking agents, may be potentially useful in the treatment of atherosclerosis.

Animals↗
PubMed1997

[Cancer incidence among active female workers at Electricité de France-Gaz de France].

Our aim was to draw up a first general view of cancer pathology among the EDF-GDF women thanks to the cancer register among active employees created by the social security department of the French national electric and gas company EDF-GDF. Between 1978 and 1992, 764 cases of cancer were diagnosed. Breast cancer was the most common (52.4%), followed by gynaecological cancers: uterus (8.6%) and ovary (6.2%), and colon and rectum cancers (5.4%). The age-standardized breast cancer incidence using the 1978-1982 period as a basis increased over time. A higher incidence for breast cancer and a lower incidence for uterus cancer were observed among the EDF-GDF women during the 1978-1982 and 1983-1987 periods, compared to French women of same age. The study of the relationship between breast cancer risk and socioeconomic status, by means of indirect standardization, showed that the breast cancer risk increased with increasing socioeconomic status. Thus manual workers had a lower breast cancer risk than the EDF-GDF woman cohort (SIR = 0.72), foremen had the same risk (SIR = 1.05) and managers had a significantly higher risk (SIR = 1.64). Moreover a case-control study showed that the change in socioeconomic status between the beginning (20 years old) and the middle of a career (35 years old) was important but it was essentially the socioeconomic status at the beginning which determined the breast cancer risk. The results support the hypothesis of a "social class" effect through risk factors during the first part of the life.

Adult↗
PubMed1996

Exposure to 50-Hz electric field and incidence of leukemia, brain tumors, and other cancers among French electric utility workers.

Recent studies on the association between exposure to 50- to 60-Hz fields and cancer carried out among electric utility workers have focused mainly on the magnetic field component of exposure. The authors have investigated tumor risks specifically associated with electric fields, as this exposure is distinct from magnetic fields. The study design is a case-control study nested within a cohort of 170,000 workers employed at Electricité de France-Gaz de France (EDF) between 1978 and 1989. All incident cases of cancer and benign tumor of the brain diagnosed in 1978-1989 among workers before the age of retirement were included. Four randomly selected controls were individually matched to each case by year of birth. The exposure to electric fields was assessed from measurements collected in 850 EDF workers for a full work week. Arithmetic and geometric mean exposures were included in a job-exposure matrix to determine the cumulative exposure of the cases and the controls. Exposures to potentially carcinogenic chemicals found at the workplace were also evaluated through expert judgment. The analysis by site of tumor did not show any increased risk for leukemia (72 cases). An odds ratio of 3.08 (95% confidence interval 1.08-8.74) was observed for all brain tumors (69 cases) for exposure above the 90th percentile (> or = 387 V/m-year), and there was some indication of a dose-response relation, although the risk did not increase monotonically with exposure. No confounding from magnetic fields or from other potentially carcinogenic hazards was apparent. The observed association was somewhat stronger after allowing a 5-year latency period before diagnosis (odds ratio = 3.69, 95% confidence interval 1.10-12.43) for exposure above the 90th percentile. However, the risk of brain tumor could not be linked to a specific type of tumor. An unexpected association was also observed for colon cancer, using geometric indexes of exposure, but no other association was seen for any other type of cancer. Our study indicates that electric fields may have a specific effect on the risk of brain tumor, and that this should be taken into account in future analyses on the carcinogenic effects of 50- to 60-Hz fields.

Brain Neoplasms↗