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Biomedical subjects

A Fontbonne

Publications and source records attributed to A Fontbonne.

At least 19 recordsLinked to original sources
PubMed2006

Relationships between glycaemic abnormalities, obesity and insulin resistance in nondiabetic Polynesians of New Caledonia.

OBJECTIVE: Polynesians in New Caledonia have an increased risk for developing diabetes, compared to Melanesians or Europeans. They are also more prone to obesity. The aim of this study was to analyse differences in the pre-diabetic state that may explain the varying susceptibility to diabetes between these three ethnic groups, focusing on the balance between insulin resistance and capacity of pancreatic cells to secrete insulin. DESIGN AND SUBJECTS: The CALDIA Study is a population-based cross-sectional survey of diabetes prevalence conducted in New Caledonia. All participants who did not have diabetes, according to the results of a 0-2 h oral glucose tolerance test (n=392), were selected for analysis. RESULTS: Compared to Europeans, Polynesians and Melanesians had significantly higher body mass indices (BMI) and waist-to-hip ratios (WHRs). Polynesians had higher fasting plasma glucose values than Europeans or Melanesians (6.03 mmol/l, vs 5.78 and 5.46, respectively; P<0.0001). Fasting plasma insulin level and the estimate of insulin resistance by homeostasis model assessment were not significantly different between the three ethnic groups. Homeostasis model assessment estimate of beta-cell secretory capacity was lower in Polynesians compared to the two other ethnic groups (83.1 mU/mmol, vs 119.3 and 125.2, respectively; P<0.02). CONCLUSION: Despite a high prevalence of central obesity, as judged by high BMI and WHR, in Polynesians of New Caledonia, their high risk of diabetes may be more strongly related to a defect in insulin secretion capacity than to insulin resistance.

Blood Glucose↗
PubMed2005

Factors associated with upper respiratory tract disease caused by feline herpesvirus, feline calicivirus, Chlamydophila felis and Bordetella bronchiseptica in cats: experience from 218 European catteries.

A full history of the management practices and the prevalence of upper respiratory tract disease (URTD) at 218 rescue shelters, breeding establishments and private households with five or more cats was recorded. Oropharyngeal and conjunctival swabs and blood samples were taken from 1748 cats. The prevalences of feline herpesvirus (FHV), feline calicivirus (FCV), Chlamydophila felis and Bordetella bronchiseptica were determined by PCR on swab samples. An ELISA was applied to determine the prevalence of antibodies to B. bronchiseptica. The rates of detection by PCR of each pathogen in the cats in catteries with and without ongoing URTD were, respectively, FHV 16 per cent and 8 per cent; FCV 47 per cent and 29 per cent; C. felis 10 per cent and 3 per cent; and B. bronchiseptica 5 per cent and 1.3 per cent; the seroprevalences of B. bronchiseptica were 61 per cent and 41 per cent, respectively. There was evidence that FHV, FCV and B. bronchiseptica played a role in URTD. The risk factors associated with the disease were less than excellent hygiene, contact with dogs with URTD, and larger numbers of cats in the cattery or household.

Animals↗
PubMed2005

In vivo meiotic resumption, fertilization and early embryonic development in the bitch.

Early development in canine species follows a very specific pattern. Oocytes are ovulated at the germinal vesicle stage and meiotic resumption occurs in the oviduct. However, because of difficulties in the accurate determination of ovulation time and in the observation of oocyte nuclear stage by light microscopy, these early events have not been fully described. Moreover, the oocyte stage at which sperm penetration occurs is still uncertain since fertilization of immature oocytes has been reported in vivo and in vitro. The aim of this study was to establish the exact timing of in vivo meiotic resumption, fertilization and early embryo development in the bitch with reference to ovulation. Ovulation was first determined by ultrasonography, artificial inseminations were performed daily and oocytes/embryos were collected between 17 and 138 h after ovulation. After fixation and DNA/tubulin staining, the nuclear stage was observed by confocal microscopy. Of the 195 oocytes/embryos collected from 50 bitches, the germinal vesicle stage was the only one present until 44 h post-ovulation, and the first metaphase II stage was observed for the first time at 54 h. Sperm penetration of immature oocytes appeared to be exceptional (three out of 112 immature oocytes). In most cases, fertilization occurred from 90 h post-ovulation in metaphase II oocytes. Embryonic development was observed up to the eight-cell stage. No significant influence of bitch breed and age on ovulation rate, maturation and developmental kinetics was observed. However, some heterogeneity in the maturation/development process was observed within the cohort of oocytes/embryos collected from one bitch. In conclusion, the most peculiar aspect of the canine species remains oocyte meiotic maturation whereas fertilization follows the same pattern as in other mammals.

Animals↗
PubMed2002

[Structure and function of the arteries of very elderly people. The PROTEGER Study (Cardiovascular Prognosis and Therapeutic Optimization in Geriatrics)].

The purpose of PROTEGER, a multicenter prospective observational study, was to determine the contribution of hemodynamic, arterial, echocardiographic and biological parameters to the evaluation of individual cardiovascular risk in the elderly. The study included patients aged over 70 years hospitalized in geriatric units with overt cardiovascular disease. Cross sectional analysis of the first 194 subjects included in the study demonstrated a high rate of arterial alterations involving both structure and function. The principal alterations observed were: high pulse pressure despite normal mean systolic and diastolic pressures, frequent and diffuse arterial calcifications, reduced compliance and distensibility, increased thickness, diameter and incremental elastic modulus of the carotid and increased pulse wave velocity. Analysis of monitoring results in the PROTEGER study will demonstrate the role of hemodynamic measurements and arterial alterations in the prediction of cardiovascular risk in hospitalized elderly.

Aged↗
PubMed2001

High plasma nonesterified fatty acids are predictive of cancer mortality but not of coronary heart disease mortality: results from the Paris Prospective Study.

To assess the association of fasting plasma nonesterified fatty acid (NEFA) concentration with the risk of death from coronary heart disease and cancer, the authors computed 15-year mortality rates for the 4,589 working men aged 43-53 years who were included in the Paris Prospective Study between 1967 and 1972. A total of 251 and 126 men died from cancer and coronary heart disease, respectively. For coronary heart disease death, the age- and tobacco-adjusted relative risk for men in the highest 20% of the fasting plasma NEFA concentrations compared with those in the lowest 80% was 1.54 (95% confidence interval (CI): 1.01, 2.34). It became nonsignificant after further adjustment for blood pressure, iliac/thigh ratio, and plasma insulin and cholesterol concentrations. In contrast, a high fasting plasma NEFA concentration exhibited a strong independent relation with cancer mortality (relative risk = 1.66, 95% CI: 1.25, 2.21, after adjustment for age, cigarette consumption, heart rate, and body mass index). Despite pathophysiologic mechanisms linking NEFA metabolism with visceral fat and plasma glucose, insulin, and triglyceride concentrations, the plasma NEFA concentration does not appear to be a good marker for coronary heart disease risk. In contrast, an unexpected association with cancer mortality was found that may point to the need for further investigation.

Adult↗
PubMed2001

Changes in cognitive abilities over a 4-year period are unfavorably affected in elderly diabetic subjects: results of the Epidemiology of Vascular Aging Study.

OBJECTIVE: To compare 4-year changes in cognitive performance among elderly subjects according to category of fasting blood glucose (FBG) using American Diabetes Association criteria. RESEARCH DESIGN AND METHODS: Subjects without any detectable cognitive dysfunction were selected from the Epidemiology of Vascular Aging (EVA) Study, a cohort of community-dlwelling people aged 59-71 years at baseline. They were classified into glucose categories (normal, impaired fasting glucose [IFG], or diabetic) based on FBG values or known diabetes. Their cognitive abilities were assessed by a global test (Mini Mental Status Examination [MMSE]) and eight domain-specific tests, and they were reassessed 4 years later. Serious cognitive worsening was defined as a score evolution into the worst 15% of the sample's distribution of score differences (4-year score minus baseline score) for each test. RESULTS: At baseline, age-, sex-, and education-adjusted scores for all cognitive tests except one were similar across glucose categories. After 4 years, diabetic subjects had a lower performance on all tests except the MMSE, with differences reaching statistical significance on four tests. Adjusted odds ratios for serious worsening over 4 years in diabetic subjects, with reference to normal subjects, were >2 for four tests (P < 0.05) and bordering this value for two others (P < 0.09). Further adjustment for blood pressure or potential cognition-affecting substances (alcohol, tobacco, and medications) did not modify these results. CONCLUSIONS: Despite similar high initial cognitive function, diabetic subjects tended to have an unfavorable evolution of cognitive performance over 4 years compared with subjects who had normal glucose or IFG.

Aged↗
PubMed2001

Circulating relaxin concentrations in pregnant and nonpregnant bitches: evaluation of a new enzymeimmunoassay for determination of pregnancy.

A new kit (ReproCHEK RELAXIN) intended for the diagnosis of pregnancy in bitches is now available for veterinary use. This assay measures relaxin concentrations in plasma and whole blood samples, and the presence of significant amounts of relaxin is indicative of pregnancy. A clinical trial was carried out to evaluate the performance of the test. Serial blood samples were collected on alternate days, and relaxin concentrations were determined from day 15 to day 35 after the LH surge (estimated by progesterone concentrations). Pregnancy was confirmed using ultrasonography. At the end of pregnancy, both the day of whelping and the size of the litter were recorded. Pregnancy was established in 61 bitches. The day that pregnancy was detected using the relaxin assay ranged from day 19 to day 28 after the LH surge and had a mean (+/- SD) of 25.4 +/- 2.5 days. The day of parturition was taken as a reference point, and pregnancy was detected from -46 to -38 days (mean -40.2 +/- 2.4 days) before parturition. False positives were not observed in pseudopregnant bitches (n = 16) or in the control group (30 anoestrous and ten unmated bitches). These results demonstrate that the new assay kit is an inexpensive, user-friendly and reliable technique for determining pregnancy.

Anestrus↗
PubMed2001

Taurine and hypotaurine in spermatozoa and epididymal fluid of cats.

Taurine and hypotaurine have been found in spermatozoa and seminal plasma of numerous species and are known to have beneficial effects on sperm characteristics in mammals. Taurine is considered an essential dietary constituent in cats. Dietary deficiency has been associated with a range of serious clinical disorders. Quantification of taurine and hypotaurine in the genital tracts of male cats has not been reported. In this study, the concentrations of taurine and its precursors were measured in serum, spermatozoa, epididymal fluid and seminal plasma from cats. The concentrations of taurine measured in serum samples confirmed that the cats were not deficient in taurine. Significant amounts of taurine and hypotaurine were found in spermatozoa, seminal plasma and epididymal flushing fluid. Hypotaurine was not detected in serum samples. These results indicate that hypotaurine may be synthesized in cat testes or epididymides. Cysteamine was not detected in any of the samples.

Animals↗
PubMed1999

In vitro capacitation of dog spermatozoa as assessed by chlortetracycline staining.

We developed an assay for detecting capacitation and acrosome status in dog spermatozoa using chlortetracycline (CTC) as a fluorescent probe. Sperm cells were stained after incubation in modified canine capacitation medium (mCCM). Calcium ionophore A23187 permitted the induction of acrosomal exocytosis of capacitated sperm cells. Spermac staining and transmission electron microscopy were used as control tests to detect acrosome-reacted spermatozoa. Three different patterns of CTC distribution in the spermatozoa were found. These patterns were similar to those observed in other mammalian species. The CTC test was used to monitor the time course of the capacitation process in dogs. It was found that the kinetics of capacitation in canine sperm cells are similar to those observed in other mammals.

Acrosome Reaction↗
PubMed1996

The effect of metformin on the metabolic abnormalities associated with upper-body fat distribution. BIGPRO Study Group.

OBJECTIVE: The constellation of anomalies associated with insulin resistance is a plausible additional cause of ischemic cardiovascular disease and of NIDDM. To test this hypothesis in a primary prevention trial, the effects of metformin as a potential candidate for intervention in the insulin resistance syndrome (IRS) were evaluated in 324 middle-aged subjects with upper-body obesity. RESEARCH DESIGN AND METHODS: Trial patients were selected on the basis of a high waist-to-hip ratio. They were randomly allocated to receive either metformin or placebo, following a double-blind procedure. After 1 year of treatment, the main clinical and biological parameters of the IRS were assessed and their evolution compared between treatment groups. RESULTS: Compared with placebo, metformin induced a significant weight loss, a better maintenance of fasting blood glucose, total and LDL cholesterol levels, and a greater decrease of fasting plasma insulin concentration. Moreover, tissue-type plasminogen activator antigen, a marker of fibrinolytic impairment, showed a significant decrease under metformin. By contrast, metformin treatment had no significant effect on blood pressure or serum triglyceride and HDL cholesterol concentrations. The main side effect of metformin was diarrhea. CONCLUSIONS: The BIGuanides and Prevention of Risks in Obesity (BIGPRO1) results suggest that metformin would be a suitable candidate for long-term intervention for the prevention of diabetes but that its use in a trial of primary prevention of cardiovascular diseases requires either a reevaluation of its properties toward the most potentially atherogenic anomalies of the IRS or a better definition of the target population.

Adipose Tissue↗
PubMed1996

Insulin-resistance syndrome and cardiovascular complications of non-insulin-dependent diabetes mellitus.

Although most cohort studies have shown that diabetes is a risk factor for cardiovascular disease, the mechanisms remain unclear. Hyperglycaemia defines this disorder but does not provide the criteria for causality. However, there are new indications for the possible role of a potentially atherogenic and diabetogenic syndrome rooted in insulin resistance, which was first described by Reaven as "syndrome X". In its complete form, this syndrome includes hyperinsulinaemia, glucose intolerance, dyslipidaemia, elevated blood pressure and fibrinolytic impairment. The complex pathophysiological processes leading to the clustering of these abnormalities are still unclear but probably relate to excessive intra-abdominal fat deposits (clinically expressed by upper body fet distribution) and combined insulin resistance and hyper-insulinaemia. The presence of insulin resistance and hyperinsulinaemia in pre-diabetic individuals, and their predictive role in non-insulin dependent diabetes mellitus, has been documented in various ethnic groups, suggesting a two-step process in the natural history of the disease, i.e. "compensated" insulin resistance followed by failure of insulin secretory response leading to a hyperglycaemic (diabetic) phase. In Caucasians at least, in whom the insulin-resistance syndrome includes clear abnormalities in its most potentially atherogenic elements, this natural history suggests that the cardiovascular complications associated with non-insulin dependent diabetes mellitus originate from the initial "pre-diabetic" phase of the disease. Early prevention would theoretically require intervention before hyperglycaemia occurs (or even if it will never occur) for all upper body obese subjects who present with insulin-resistance syndrome.

Adipose Tissue↗
PubMed1995

Lower survival in AIDS patients receiving dapsone compared with aerosolized pentamidine for secondary prophylaxis of Pneumocystis carinii pneumonia. Study Group.

A randomized, unblinded study compared aerosolized pentamidine, 300 mg every month, and dapsone, 50 mg/day, for secondary prophylaxis of pneumocystosis in 196 AIDS patients. The study was prematurely discontinued due to excess mortality in the dapsone group. After a mean follow-up of 13 +/- 6.4 months, 22 (21%) of 103 patients in the pentamidine group were dead compared with 39 (42%) of 93 receiving dapsone; the estimated mortality rates at 18 months were 24.6% and 53.1%, respectively (P < .003, log-rank test). A negative interaction was observed between zidovudine and dapsone (P < .049, interaction test of Cox model), and the mean CD4 cell count during the study was lower in the dapsone (49 +/- 61/mm3) than in the pentamidine group (83 +/- 88/mm3; P < .002, t test). The lower survival might also be related to the oxidative effect of dapsone or to the addition of iron protoxalate to dapsone in this study. These results suggest caution in using dapsone as long-term therapy in advanced human immunodeficiency virus infection, especially in those receiving zidovudine.

AIDS-Related Opportunistic Infections↗
PubMed1994

The epidemiology of coronary heart disease in glucose-intolerant and diabetic subjects.

Diabetes mellitus is usually recognized as a major risk factor for coronary heart disease (CHD) morbidity and mortality. As chronic hyperglycaemia defines diabetes mellitus, it is logical to think that hyperglycaemia itself is related to these complications. But, in diabetic patients, there appears to be no relation between CHD and the specific characteristics of diabetes, namely the duration of the disease and the level of blood glucose. Moreover, in the UGDP trial, the group of patients with the best-controlled glycaemia failed to demonstrate a reduction in CHD death, in comparison with the group with poor blood-glucose control. These results are reinforced by the data from 15 prospective studies, which failed to demonstrate a homogeneous and significant increase in CHD risk with asymptomatic hyperglycaemia. Coronary heart disease mortality depends on a constellation of risk factors which are interrelated to some extent; one of the risk factors, namely blood glucose, is not an independent risk factor, nor is diabetes mellitus. In patients with abnormal glucose tolerance, the factors contributing to CHD risk are hypertriglyceridaemia and also a central fat distribution. This central fat distribution could explain the low CHD risk in nondiabetic women, which contrasts with the high risk in diabetic women, who are characterized by central adiposity, as are diabetic men. Björntorp hypothesized that intra-abdominal fat, which has an exceedingly sensitive lipid mobilization capacity, could play a key role in the development of the cluster of metabolic abnormalities that are present in the plurimetabolic syndrome. Hyperglycaemia, one of the anomalies of the syndrome, could be an 'innocent bystander' rather than a 'partner in crime', in the manifestations of CHD.

Coronary Disease↗