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Biomedical subjects

J Canivet

Publications and source records attributed to J Canivet.

At least 19 recordsLinked to original sources
PubMed1985

Influence of pregnancy on the evolution of background retinopathy. Preliminary results of a prospective fluorescein angiography study.

Previous reports have suggested that pregnancy does not influence the development of diabetic retinopathy. Since 1979 a prospective study using fluorescein angiography has been in progress. Preliminary results include 22 diabetic women with or without moderate background retinopathy studied until delivery. They were maintained under good metabolic control (mean HbA1: 7.68%). Five clinical and fluorescein angiography examinations were performed at prefixed intervals (before the 15th week, at the 28th and 35th weeks of pregnancy, and 6 and 15 months after delivery). The analysis of fluorescein angiography which did not induce any side effect showed that the mean number of microaneurysms increased from 42.7 before pregnancy to 56.7 at the 28th week and to 79.7 at the 35th week. Six months later the number was 62.7, and 15 months later 60.3, still higher than at the initial examination. This study suggests that pregnancy has an unfavourable influence on the background retinopathy in diabetic patients even when a good metabolic control is achieved and retinopathy is minimal.

Adult↗
PubMed1985

[Value of genetic studies and immunologic markers in diabetes. Prediction of insulin dependence].

A new classification based on physiopathological criteria distinguishes Type I diabetes, observed in patients with stigmata of anti-islet of Langerhans auto-immunity, from Type II diabetes without these autoimmune changes. Type I diabetes is sub-divided into Classes Ia and Ib, Class Ib comprising those cases associated with other auto-immune diseases. Serological analysis of 76 patients with clinical type Ia diabetes and 215 healthy, first degree relatives showed that the distinction between Classes Ia and Ib was not clear-cut and that patients classified clinically Ia were in fact infraclinical Ib subjects. Forty-one per cent of patients with Class Ia diabetes had anti-gastric, anti-adrenal or anti-thyroid antibodies, and 28 p. 100 of their healthy relatives also had the same types of antibodies. Several prospective studies of the families of patients with Type I diabetes have shown that anti-islet of Langerhans antibodies were associated with a high risk of diabetes. Similarly, the presence of these antibodies in patients apparently with Type II diabetes (non-insulin dependent) was associated with an increased risk of developing insulin dependence. These results illustrate the value of immunological investigations in diabetic patients. They may influence the choice of treatment in the future.

Animals↗
PubMed1984

Binding of 125I-insulin to the human histiocytic lymphoma cell line U-937: effect of differentiation with retinoic acid.

The human histiocytic lymphoma line U-937 consists of cells having characters of immature monocytes. We have demonstrated that these cells possess highly specific insulin receptors with binding properties similar to that found for mature human blood monocytes. 125I-insulin binding increased progressively with time to reach a maximum at 90 min at 22 degrees C and was proportional to the number of cells in the incubation medium. Insulin degradation as assessed by TCA precipitation was negligible. Scatchard analysis of the binding data was curvilinear and the total number of insulin binding sites was around 13,500. The average affinity profile gave an 'unoccupied site' affinity constant of 1.34 nM-1. When the U-937 cells were induced to differentiate into morphologically and functionally monocyte-like cells, after incubation with retinoic acid, the total number of binding sites decreased significantly with no change in the affinity of the hormone for its receptor.

Binding, Competitive↗
PubMed1983

[Prevalence of smoking among diabetics and influence of tobacco on diabetic retinopathy].

Among 647 patent diabetics regularly followed who attended the out-patient clinic of a hospital Diabetology Department between December 1st, 1979 and June 30th, 1980, 35% were habitual smokers, 20% ex-smokers and 45% non-smokers. Insulin-treated diabetics did not smoke more than non insulin-treated diabetics. Only one-half of the smokers declared that they had been advised by a doctor to stop smoking. This study failed to demonstrate any effect of tobacco on the prevalence or severity of diabetic retinopathy.

Diabetes Mellitus↗
PubMed1983

[Histiocytosis X with partial antehypophyseal deficiencies. 2 cases].

Diabetes insipidus is the most common endocrine disturbance associated with chronic multifocal form of histiocytosis X. Involvement of the hypothalamus can lead to growth hormone deficiency and short stature in children. Two cases with hypogonadism, growth hormone deficiency and diabetes insipidus are reported. In a 22-year-old man plasma testosterone was low and increased after administration of human chorionic gonadotrophin. Cutaneous and lytic bone lesions disappeared after treatment with Vinblastin. Partial diabetes insipidus was treated with clofibrate. A 59-year-old woman was found to have low pituitary gonadotrophins that failed to rise after administration of gonadotropin-releasing hormone and hyperprolactinemia. Fatal outcome was associated with polyuria, bone, cutaneous, gut and hypothalamic infiltration by histiocytes. There was no direct involvement of the anterior pituitary gland.

Adult↗
PubMed1982

[Mediation by opioid peptides of anterior pituitary response to insulin-induced hypoglycemia (author's transl)].

A 1.6 mg dose of the specific opiate antagonist naloxone was administered to normal volunteers, either separately or in conjunction with insulin-induce hypoglycemia, in order to study the possible mediation by opioid peptides of the release of adrenocorticotrophin (ACTH), lipotropins (LPH), human growth hormone (GH) and prolactin (PRL). Administered separately, naloxone was associated with a significant fall in PRL levels (p less than 0.01), a significant and unexpected rise in GH levels (p less than 0.02), and a suppression of the circadian decrease of ACTH and LPH levels. The association of naloxone with insulin-induced hypoglycemia significantly reduced the PRL peak (p less than 0.05), did not affect the rise of GH and lowered the ACTH peak, without altering the LPH peak. These data suggest the existence of a positive opioid tone to PRL secretion, as well as an opioid peptide role in the PRL response to hypoglycemia. They argue against the likelihood of an opioid pathway in the GH response to hypoglycemia. Furthermore, the data favor a paradoxical effect of naloxone on ACTH release during insulin-induced hypoglycemia.

Adrenocorticotropic Hormone↗
PubMed1982

[Effect of long-term administration of clonidine on growth hormone secretion in hypertensive diabetics].

The anti-hypertensive effect of clonidine is closely related to its central alpha-agonist action. In acute administration, the drug provokes a significant increase in the plasma concentrations of growth hormone (GH). In chronic administration, the effects of clonidine on GH secretion are not well documented. Clonidine was administered at a daily dose of 0,15 to 0,30 mg to 10 non-obese diabetic hypertensive male subjects for at least 3 months. Blood glucose and GH plasma concentrations were determined 15 times during the 24-hour cycle. Blood glucose and GH values recorded before the intake and after stopping the drug, in the basal state, after meals, after measured muscular exercise and during the first stage of sleep could be superimposed when on and off clonidine. The effects of prolonged administration of clonidine on GH secretion thus differ markedly from the effects of acute administration as in non diabetic subjects. The long-term use of clonidine does not induce a chronic increase of GH plasma concentrations which might worsen the evolution of the diabetic microangiopathy.

Adult↗
PubMed1981

[Long-term results of surgical hypophysectomy for diabetic retinopathy (author's transl)].

Between 1969 and 1974, ten insulin-dependent diabetic patients underwent surgical hypophysectomy for rapidly progressive proliferative retinopathy endangering sight. Six to 11 years later, the 7 patients who survived had useful visual acuity and were leading a normal life. The long-term results of hypophysectomy on the eye could be observed in this series of patients with exceptionally long follow up: oedema had subsided, haemorrhagic exsudates and newly formed retinal vessels had disappeared, and the retinal had become hypovascular. However, argon laser photocoagulation has now considerably reduced the indications of surgical hypophysectomy.

Adult↗
PubMed1981

Von Willebrand factor, diabetes mellitus and retinopathy.

Von Willebrand factor (VIII: vWf) is a glycoprotein which is essential for normal platelet adhesion to vascular subendothelium, particularly at the high shear rates encountered in small blood vessels. VIII: vWf is distributed in plasma, platelets and subendothelium, though the contributions of each pool to normal hemostasis is unknown. Raised plasma of VIII: vWf have been frequently described in association with diabetes, the highest concentrations being found in patients with retinopathy. In addition, concentrations of VIII: vWf appear to be influenced by the degree of metabolic control of the diabetics, particularly high levels being found during diabetic coma. Plasmatic concentrations of VIII: vWf greater than normal have not been shown to result in increased platelet adhesion or aggregation, so that is seems unlikely that the high levels of plasmatic VIII: vWf contribute directly to the pathogensis of retinopathy. On the other hand, increases in VIII: vWF during episodes of poor metabolic control could be evidence of reversible injury to the vascular endothelium, whereas stable, high concentrations may indicate the presence of microangiopathy.

Blood Coagulation Factors↗
PubMed1981

Rapid identification of diabetic patients with essential hypertension sensitive to acebutolol.

The antihypertensive effect of 2,000 mg of acebutolol investigated with an acute 48 hr test in 60 diabetic and 60 non-diabetic in-patients with essential hypertension. In hypertensive diabetic patients, acebutolol was induced a significant fall in blood pressure similar to that observed in non-diabetics. The acute antihypertensive effect of acebutolol was not uniform in hypertensive subjects: a significant decrease of blood pressure was observed in 34 diabetics and 31 non-diabetic patients. Fifteen out of the 34 diabetic responders to the 48 hr test were treated by acebutolol alone for six months; a highly significant correlation between the acute and the chronic antihypertensive effect of the beta-blocker was observed. As long-term results paralleled those of the short-term experiment, acute acebutolol administration appears to be a rapid means to select hypertensive diabetics sensitive or resistant to betablockers. Plasma renin activity was not found to give, in hypertensive diabetics, a reliable predictive index of the response to acute administration of acebutolol.

Acebutolol↗
PubMed1981

[A study of the knowledge of diabetics (author's transl)].

One hundred and forty five diabetics regularly attending a hospital clinic were submitted to a questionnaire assessing their knowledge of diabetes. The patients had previously been instructed in urine glucose analysis, insulin injections, diet and hypoglycaemic attacks. Despite this, they appeared to be neither better controlled nor more painstaking with their disease than before education. The replies to the questionnaire revealed that the patients had poor understanding of the symptoms and of the long-term complications of diabetes, of the criteria of good control, and of the proportion of carbohydrate in common food. Moreover, they held many fallacious ideas with regard to these concepts. The results suggest that although these diabetics had acquired sufficient knowledge to avoid the acute metabolic disturbances of diabetes and to lead a day-to-day existence with a minimum of harmful effects, they were not properly aware of the long-term consequences of diabetes and of the overall strategy for the good management of their disease. An improved educational strategy appears necessary to enable diabetics to take better care of themselves.

Adult↗
PubMed1980

Adrenocortical 11 beta-hydroxylation defect in adult women with postmenarchial onset of symptoms.

Four cases in adults of a deficiency in the 11 beta-hydroxylation of corticosteroids were investigated by both basal and dynamic biological studies. Symptoms varied from patient to patient; hirsutism, menstrual disturbance, acne, deepening of the voice, and arterial hypertension appeared post puberty. Basal testing demonstrated elevated levels of plasma androgens. These include delta 4-androstenedione (patients, 3.80-6.43 ng/ml; normal, 1.33 +/- 0.33 ng/ml), urinary 17-ketosteroids (patients, 11.8-16.7 mg/24 h; normal, 5-10 mg/24 h), and urinary dehydroepiandrosterone. The basal tests were often insufficient to show the accumulation of the precursors (especially 17-hydroxyprogesterone) which are often given as evidence for an increase in ACTH stimulation. In studying the levels of the mineralocorticoids, there was shown to be an increased basal level of tetrahydrodeoxycorticosterone (patients, 142-317 microgram/24 h; normal, 60-80 microgram/24 h) which was raised by ACTH stimulation. These results, therefore, confirm the characteristic partial enzyme defect and give evidence for the heterogeneity of this syndrome. Based on the above observations, we believe it is appropriate to rename this condition adult adrenocortical 11 beta-hydroxylation defect rather than late-onset congenital adrenal hyperplasia.

17-Ketosteroids↗
PubMed1979

[The effects of acebutolol on endocrine and metabolic reactions induced by acute hypoglycaemia. Study in normal subjects and in insulin-dependent diabetics (author's transl)].

Six normal subjects and six normotensive insulin-dependent diabetics underwent two insulin hypoglycaemia tests after administration for three days of either a placebo or of acebutolol--a cardioselective beta-blocker--at a dose of 400 mg per day. The order in which the tests were performed was decided by random selection. Acebutolol suppressed the tachycardia which occurred as a reaction to hypoglycaemia but did not interfere with other warning symptoms and signs. In both normal subjects and diabetics, acebutolol neither worsened the initial hypoglycaemia nor did it delay a return to normal values. The increase in lactate levels following hypoglycaemia was not reduced by acebutolol but free fatty acid rebound was suppressed. Hormonal responses (glucagon, cortisol, growth hormone) were unaffected by the beta-blocker. If they are confirmed by long term studies, these results would suggest that acebutolol is safer to use than non-cardioselective beta-blockers in the treatment of coronary insufficiency and of hypertension in diabetics exposed to the risk of hypoglycaemia.

Acebutolol↗
PubMed1979

[HbA1c: need of its dosage in diabetics (author's transl)].

HbA1c is the product of a slow, virtually irreversible reaction, occurring continuously throughout the 120 day life-span of the erythrocyte, between HbAo and glucose. It has been shown to represent the time-averaged blood glucose concentration of the preceeding 2 month period, and is independant of day to day fluctuations in the blood glucose concentration. HbA1c therefore acts as a biochemical marker and permits clinicans, by one test, to judge the quality of the diabetic control, in their patients.

Blood Glucose↗