PubMed Health⌕ Search

Biomedical subjects

J Bringer

Publications and source records attributed to J Bringer.

At least 55 records · Page 3Linked to original sources
PubMed1997

Obesity and breast cancer risk.

Being overweight appears to be associated with a higher risk of post-menopausal breast cancer in most studies. Although the relative risk of breast cancer related to Quetelet's index is generally weak (range 1.1-1.9 in the major cohort studies), some studies have found that timing of weight gain and body fat distribution could be more significant factors of an increased risk. Conversely, obesity appears to be slightly correlated with a decreased risk of breast cancer in pre-menopausal women. These contrasting effects of excess weight on breast cancer incidence according to menopausal status, and the lack of a strong association between obesity and breast cancer in some studies, could be due to a number of confounding factors. Among these factors, age, country of origin, family history, alcohol consumption, nutrition, and hormonal treatment could account for the differences observed, and are reviewed in the present study. Obesity and central fat distribution are believed to act through endocrine intermediates such as hyperinsulinaemia and steroid hormones. Since obesity is one of the few breast cancer risk factors that can be modified, the influence of weight loss, particularly in women at high risk, deserves to be further investigated.

Body Constitution↗
PubMed1997

Influences of weight, body fat patterning and nutrition on the management of PCOS.

Polycystic ovary syndrome (PCOS) is a heterogeneous clinical entity that is defined as the association of hyperandrogenism with chronic anovulation in women without specific underlying diseases of the adrenal or pituitary glands. PCOS is also associated with a metabolic disturbance (insulin resistance). The nature of the complex interrelation of obesity, insulin resistance and endocrine abnormalities in PCOS remains unresolved. However, several studies link obesity, body fat distribution and nutritional habitus with the hormonal and metabolic profiles of PCOS. Moreover, intervention studies have suggested that reducing weight and/or hyperinsulinaemia either by diet alone or by a combination of diet and drugs improves hirsutism, fertility and the hormonal and metabolic profiles of PCOS. In fact, the evaluation of nutritional factors in PCOS is helpful for the screening of metabolic abnormalities and the management of women with PCOS. A point of particular interest in the management of PCOS is that the choice of contraception remains difficult in these high cardiovascular risk women. The impact of pills with ethinyl oestradiol on weight, body fat distribution and carbohydrate metabolism in women with PCOS has not been thoroughly evaluated. The lack of prospective studies to evaluate long-term metabolic and cardiovascular tolerance necessitates care and the assessment of other hormonal possibilities.

Body Constitution↗
PubMed1997

Choice of stimulation in polycystic ovarian syndrome: the influence of obesity.

Obesity modifies insulin sensitivity and gonadotrophins dynamics, and is associated with disorders of spontaneous ovulation. High concentrations of leptin are possibly a link between weight and spontaneous ovulation. Weight excess in polycystic ovary syndrome (PCOS) patients increases hyperinsulinaemia, which may result in altered follicular maturation. Obese PCOS women are characterized by a decreased efficiency of the different stimulation treatments. Although clomiphene resistance is not associated with obesity, the dose of clomiphene required to achieve ovulation is positively correlated with body weight. Obese PCOS women also require higher doses of gonadotrophins than their lean counterparts, with ultimately poorer results in pulsatile gonadotrophin releasing hormone-stimulated cycles. The first stage in the optimal management of obese PCOS anovulatory women is a weight loss programme, which helps to correct the clinical and endocrine abnormalities.

Clomiphene↗
PubMed1997

[Interrelation of visceral fat and muscle mass in non insulin-dependent diabetes (type II): practical implications].

Insulin resistance, which is found in 85-95% of non-insulin-dependent diabetes mellitus (NIDDM) patients, results from three factors: genetic background (which has been widely investigated), nutritional status (mostly obesity and fat distribution) and exercise. Upper body obesity, which can be found in 85% of these subjects, can increase muscular insulin resistance through several mechanisms, the best known being a free fatty acid-induced decrease in intracellular free CoA/acylCoA that inhibits the stimulatory effect of insulin on glycolysis, glucose transport across cell membrane, and glycogen storage. However, muscle insulin resistance in NIDDM exists before adiposity and is likely to induce it. Actually, muscles of subjects at risk for NIDDM exhibit a very early defect in both glycogen storage ability and free fatty acid oxidation capacity that can impair fuel utilization and increase fat storage. Regular exercise induces muscular metabolic changes which can compensate for those diabetogenic defects and thus prove useful in the management of NIDDM. Moreover, exercise has been shown to prevent subjects at risk for NIDDM from developing overt diabetes.

Abdomen↗
PubMed1996

Ovarian reserve test with the gonadotrophin-releasing hormone agonist buserelin: correlation with in-vitro fertilization outcome.

A gonadotrophin-releasing hormone agonist stimulation test determination of follicle stimulating hormone (FSH) concentrations before and 2 h after buserelin injection was carried out in 78 in-vitro fertilization cycles, and compared with basal FSH concentrations to predict ovarian response. Ovarian response was quantified by the ratio of peak oestradiol concentration divided by the total dose of human menopausal gonadotrophin (HMG) administered, the most reproducible parameter in 11 patients who underwent two treatment cycles. Stimulation outcome was highly related to the buserelin test, the best prognostic indicator being the sum of FSH concentrations. However, basal FSH concentration achieved similar correlations, even in those patients aged > 35 years. Sensitivity, specificity, positive and negative predictive values of basal FSH concentration and sum of FSH concentrations were similar. Low basal concentration and sum of FSH concentrations were both associated with a better ovarian response. Construction of receiver operator characteristic curves demonstrated that basal FSH concentration was more informative than the sum of FSH concentrations. Finally, the sum of FSH concentrations did not increase the prediction of ovarian response variability. We conclude that the buserelin test is strongly predictive of stimulation outcome, but is no more informative than the usual screening. We suggest that the performance of other stimulation tests should be clearly compared with that of basal FSH concentration.

Adult↗
PubMed1996

Degree of thyrotropin suppression as a prognostic determinant in differentiated thyroid cancer.

We investigate whether the prognosis of patients with differentiated thyroid cancer is improved by maintaining a greater level of TSH suppression. One hundred and forty-one patients who underwent hormone therapy after thyroidectomy were followed up from 1970 to 1993 (mean, 95 months). Patients received levothyroxine (L-T4; mean dose, 2.6 micrograms/kg-day). TSH suppression was evaluated by TRH stimulation test until 1986 and thereafter by a second generation immunoradiometric assay. As TSH underwent fluctuation over time in most patients, we focused on subgroups of patients with relatively constant TSH levels during the follow-up. The relapse-free survival (RFS) was longer in the group with constantly suppressed TSH (all TSH values, < or = 0.05 mU/L; n = 18) than in the group with nonsuppressed TSH (all TSH values, > or = 1 mU/L; n = 15; P < 0.01). Age, sex, tumor node metastasis stage, and initial therapy were not different between the suppressed and nonsuppressed TSH groups. In the overall population, we analyzed the level of TSH suppression by studying the percentage of undetectable TSH values (< or = 0.05 mU/L) during the follow-up. The patients with a greater degree of TSH suppression (> 90% of undetectable TSH values; n = 19) had a trend toward a longer RFS than the remaining population (n = 102; P = 0.14). The patients with a lesser degree of TSH suppression (< 10% of undetectable TSH values; n = 27) had a shorter RFS than the remaining patients (n = 94; P < 0.01). In multivariate analysis that included TSH suppression, age, sex, histology, and tumor node metastasis stage, the degree of TSH suppression predicted RFS independently of other factors (P = 0.02). This study shows that a lesser degree of TSH suppression is associated with an increased incidence of relapse, supporting the hypothesis that a high level of TSH suppression is required for the endocrine management of thyroid cancer.

Adolescent↗
PubMed1996

Insulin underdelivery from implanted pumps using peritoneal route. Determinant role of insulin pump compatibility.

OBJECTIVE: To evaluate the incidence and investigate determinants of insulin underdelivery events occurring with implanted pumps using peritoneal route from a 103 patient-year experiment. RESEARCH DESIGN AND METHODS: Of the MiniMed (MIP 2001) pumps implanted in 47 type I diabetic patients, 70 were refilled quarterly with four successive batches (A, B, C, D) of U400 Hoechst 21 PH neutral insulin during a 3-year study period. Any reduction of insulin flow rate > 15% was considered as abnormal insulin delivery. Diagnosis of the cause of underdelivery was established according to the response to the following steps: 1) 0.01 mol/l NaOH rinse of pump circuits to solubilize insulin aggregates, 2) surgical examination and replacement of blocked catheters, and 3) postsurgical 0.01 mol/l NaOH rinse of pump. Step 2 was selected first if the increase of insulin requirements or reduction of flow rate were > 50%. Relative contributions of insulin and the implanted system to underdelivery events were analyzed. RESULTS: There were 76 episodes of insulin underdelivery that occurred during the study, resulting in an incidence of 74 events per 100 patient-years. Of 52 NaOH pump rinses, 30 restored normal flow rate. Surgery, performed after rinse failure (n = 22) or as the first step (n = 24), disclosed catheter blockages due to tip obstructions in 28 cases and omental encapsulations in 18 other cases. Five combined severe reductions of pump flow rate requiring pump replacements were diagnosed during surgery, and additional NaOH rinses had to be performed after catheter change in 12 other cases. Analysis of the incidence of underdelivery events indicated that both pump- and catheter-related problems were significantly increased while implanted systems infused batches B, C, and D versus batch A (P < 0.01), whereas the duration of pump implantation had no significant influence. CONCLUSIONS: Underdelivery events constitute serious limiting obstacles to prolonged peritoneal insulin infusion from implanted pumps. Progress in insulin pump compatibility is expected to reduce their occurrence and, thus, to improve the feasibility of this treatment.

Adult↗
PubMed1996

[Evolution of blood glucose control and retinopathy during long-term treatment of insulin-dependent diabetes mellitus with intraperitoneal infusion of insulin].

To evaluate the efficacy on blood glucose control of long-term peritoneal insulin infusion and its consequences on the evolution of diabetic retinopathy, we analyzed retrospectively the values of glycosylated haemoglobin measured quarterly and the retinal angiograms obtained after 1, 5 and 9 years from seventeen insulin-dependent diabetic patients treated by this technique during 9.0 +/- 2.2 years. Blood glucose control was significantly improved from the first year of treatment (p < 0.01). Seventy-one per cent of patients had a level of glycosylated hemoglobin below one standard deviation of normal values after five years and ninety-two per cent of 12 patients treated up to nine years remained in the same near-normal range. Glycaemic excursions below 0.5 g/l and over 2 g/l were limited to 5-7% and 15-17% of four times-daily capillary glucose measurements respectively, along the whole IP insulin infusion period. Among 7 patients with no retinopathy (n = 1) or with mild to moderate nonproliferative retinopathy, requiring no specific ophthalmological treatment, (levels 20 to 40 on worse eye according to a simplified version of ETDRS classification, n = 6), 3 remained stable, 2 improved and 2 impaired although remaining under level 50 of the classification, after 5 to 9 years. Nine patients with severe nonproliferative (level 50, n = 1) or proliferative (level 65, n = 8) retinopathy, all treated by panretinal photocoagulation before initiation of IP treatment, improved and one patient with severe nonproliferative retinopathy, incompletely treated by laser photocoagulation, remained stable, after 5 to 9 years. No macular edematous reaction or impairment of existing macular edema occurred after panretinal photocoagulation under IP treatment. These data indicate that a sustained near-normal blood glucose control can be achieved under long-term peritoneal insulin infusion, without significant impairment of diabetic retinopathy when an initial ophthalmological evaluation, and a specific treatment if necessary, are performed.

Adolescent↗
PubMed1996

[Prognostic value of high FSH concentrations].

Ovarian age is a major determinant of success in assisted reproductive technologies. The number and quality of oocytes retrieved directly depend upon the ovarian reserve. The evaluation of FSH concentration during the first days of the menstrual cycle provides a simple and accurate means of assessing ovarian reserve. Plasma FSH value is correlated with cancellation rate, peak estradiol, number of oocytes retrieved and of the resulting embryos, pregnancy rate, outcome of cryopreservation. However, a poor response to the stimulation treatment is unpredictable in a subgroup of women whose FSH concentration remain within the normal range. Ovarian aging begins several years before any clinical or endocrinological modification. Recurrent FSH determinations may help in predicting a poor response, as a large intercycle FSH variability is correlated with ovarian failure. The value of ovarian reserve tests is presently not fully established.

Age Factors↗
PubMed1995

Metastatic phaeochromocytoma with a long-term response after iodine-131 metaiodobenzylguanidine therapy.

Iodine-131 metaiodobenzylguanidine ([131I]MIBG), a radiopharmaceutical agent, is used for treating malignant phaeochromocytoma. [131I]MIBG therapy results in a hormone response rate of approximately 50%, but generally it yields only a partial or no tumour response. We present a case of a 46-year-old woman with a familial history of von Hippel-Lindau disease, who was treated with [131I]MIBG for a metastatic phaeochromocytoma involving the lungs, liver and bones. The patient received a cumulative dose of 33.3 GBq (900 mCi) and a complete hormone response was observed, as evaluated on the basis of catecholamine and metanephrine levels. Conventional radiography, computerized tomography and [131I]MIBG scintigraphy indicated that a near-complete tumour regression was achieved, with no evidence of relapse during a 4-year follow-up period. This case thus demonstrates that treatment with [131I]MIBG may lead to a dramatic tumour response in malignant phaeochromocytoma presenting both soft tissue and bone metastases.

3-Iodobenzylguanidine↗
PubMed1995

Effect of topical basic fibroblast growth factor on the healing of chronic diabetic neuropathic ulcer of the foot. A pilot, randomized, double-blind, placebo-controlled study.

OBJECTIVE: To assess the efficacy and safety of topical human recombinant basic fibroblast growth factor (bFGF) on the healing of diabetic neurotrophic foot ulcers. RESEARCH DESIGN AND METHODS: Seventeen diabetic patients suffering from chronic neuropathic ulcer of the plantar surface of the foot entered a pilot, randomized, double-blind study comparing local application of bFGF with placebo. Main inclusion criteria were a typical neuropathic ulcer of Wagner grade I-III, more than 0.5 cm in the largest diameter, with an abnormally high vibration perception threshold in the absence of significant peripheral vascular disease or wound infection. bFGF or placebo was applied daily during the 6 weeks as inpatients then twice a week for 12 weeks. Evolution of ulcer size was assessed through weekly clinical examination and computerized photographs. RESULTS: In the bFGF group, three of nine ulcers healed compared with five of eight in the placebo group (NS). The weekly reduction in ulcer perimeter and area was identical in both groups, as was the rate of linear advance from entry to the 6th week of treatment (bFGF: 0.053 +/- 0.048 mm vs. placebo: 0.116 +/- 1.129 mm): the same result was obtained at the 11th week. Moreover, percent healed area at the end of the study did not differ significantly. No side effects were observed during bFGF application. CONCLUSIONS: Topical application of bFGF has no advantage over placebo for healing chronic neuropathic diabetic ulcer of the foot. Because diabetes causes significant wound-healing defects, we hypothesized that using a single growth factor might be insufficient to accelerate wound closure of diabetic ulcers.

Administration, Cutaneous↗
PubMed1995

Catheter complications associated with implantable systems for peritoneal insulin delivery. An analysis of frequency, predisposing factors, and obstructing materials.

OBJECTIVE: To evaluate catheter survival and identify mechanisms involved in catheter obstructions during a 109.8 patient-year experience with implanted pumps for peritoneal insulin delivery. RESEARCH DESIGN AND METHODS: Fifty-one type I diabetic patients were recruited in feasibility studies of two models of implanted systems for peritoneal insulin delivery. Both systems had a silicone-coated polyethylene catheter and infused Hoechst 21 PH neutral insulin (U400 or U100). Catheter obstruction was suspected each time the increase of insulin flow rate over 50% of usual need was insufficient to correct an impairment of glycemic control in the absence of of intercurrent factors. A laparoscopic examination was then systematically performed under general anesthesia. The disclosed material occluding the catheter was submitted to a pathological analysis. By actuarial analysis, we examined the estimated effects of the potential determinants of the catheters' duration of proper operation on catheter survival. RESULTS: Over an implantation duration of 25.8 +/- 14.0 months (mean +/- SD), 34 catheter obstructions were diagnosed in 24 patients, resulting in an incidence of 31 events per 100 patient-years. Fifty percent survival rate of the first implanted catheter was 27 months (95% confidence interval [CI]: 19-32) on actuarial analysis. Six catheters were cleared under laparoscopy and 24 were replaced, while 2 systems were definitively explanted and 2 combined replacements of pump and catheter were performed because of an associated pump slowdown. In five cases, an alkaline rinse procedure of the pump was necessary after catheter replacement to restore usual insulin needs, suggesting an associated insulin aggregation in the pump. Twenty obstructions were due to a fibrin clot at the catheter tip, and 14 obstructions were created by a tissue encapsulation around the catheter. A previous experience of peritoneal insulin infusion from portable pumps or a longer duration of diabetes ( > 21 years) both appeared as conditions significantly reducing the time of a catheter's proper operation (P < 0.01 and P < 0.05, respectively) either by tip obstructions or by encapsulations. Pathological analysis of catheter encapsulations showed a collagen fibrosis in all studied patients (n = 11), which was associated with a lymphocytic infiltrate in five patients and also with anti-insulin immunoreactive amyloid deposits in four patients. Catheter tip clots were composed of fibrinlike material, nonreactive to anti-insulin antibodies. CONCLUSIONS: Catheter obstruction is a frequent adverse technical event occurring with implanted insulin pumps. Progress is expected in the biocompatibility of catheter material and more specifically in the stability of insulin preparations to prevent immuno-inflammatory reactions and insulin amyloid deposits that appear to be involved in catheter failures.

Actuarial Analysis↗