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Biomedical subjects

J Mirouze

Publications and source records attributed to J Mirouze.

At least 109 records · Page 6Linked to original sources
PubMed1980

[Stereotaxic pituitary implantation of radio-gold in the treatment of severe diabetic retinopathy. Long term results (author's transl)].

The ophtalmic, diabetic and hormonal outcome in 16 patients treated identically for diabetic ophtalmopathy with pituitary radio-gold implants were assessed 1, 2, 5 and 10 years afterwards. Four patients (25%) died in the first 6 years, 3 of them of severe renal insufficiency which developed after pituitary implantation. Of these remaining alive at each assessment visual acuity was either stable or improved in 78%, 58%, 64% and 42% respectively, but at very low levels since at 10 years acuity was 1/10 or less in half the population. Four patients became blind, the remaining eight had a severe proliferative retinopathy with exsudates and haemorrhages but retained useful vision. Haemorrhage and new vessel formation continued to develop with the years following implantation in all patients who at the time had one on either lesion. Cataracts were removed in 6 patients, 3 and 7 years after implantation. The mean insulin requirements of the group fall from 55 to 31 units daily. The fall in growth hormone concentration, occuring in only 45% of cases, does not account for all the improvements observed. Several hormonal deficiencies developed: 2 cases of adrenal insufficiency, 3 of hypothyroïdism and 6 of hypogonadal impotence.

Adult↗
PubMed1980

Effects of somatostatin on intestinal calcium absorption in man with primary hyperparathyroidism.

Eight patients suffering from primary hyperparathyroidism were studied in basal conditions, i.e. during a saline infusion and under somatostatin administration (a 250 micrograms bolus injection followed by continuous infusion of 500 micrograms per hour over 240 min). The calcium metabolism was estimated from (i) concentrations of plasma calcium, phosphorus, 25-hydroxyvitamin D (25-OH-D), iPTH and (ii) intestinal calcium absorption determined by a double radiotracer technique using oral 47Ca and IV 45Ca. The results show that somatostatin produced no significant change in calcium, phosphorus, 25-OH-D or iPTH levels. On the contrary, the fractional absorption of calcium (FA Ca), expressed as a percentage of the total oral dose and measured at 30 minute intervals over 240 min, was significantly depressed with somatostatin during the first 2 hours. Beyond the second hour FA Ca remained slightly depressed with somatostatin, but was not significantly different from the basal conditions. From the present results, we conclude that somatostatin slows down calcium absorption, while the total amount of calcium absorbed at the completion of the absorption process is not significantly diminished. Furthermore, as 25-OH-D and iPTH remained unchanged, somatostatin seems to have no effect on the hormonal control of calcium absorption. Therefore, we suggest that somatostatin has only a mechanical effect on calcium absorption, slowing down the intestinal transit.

Calcifediol↗
PubMed1980

Evidence and mechanism for pectin-reduced intestinal inorganic iron absorption in idiopathic hemochromatosis.

The intestinal absorption of iron was measured in 13 patients suffering from idiopathic hemochromatosis by using a double radiotracer technique. For each patient, iron absorption was determined in the fasting state, i.e., under basal conditions, and after an oral indigestible fiber load (9 g/m2 of body surface) with either pectin (group I: eight patients) or cellulose (group II: five patients). The results were compared with those from a group of seven normal control subjects investigated under basal conditions. The patients with haemochromatosis (groups I and II) had a significant increase in the basal value of fractional iron absorption as compared with controls. In the patients of group I, the pectin induced a significant fall in fractional iron absorption (P less than 0.02). In group II, iron absorption rates remained unchanged whether or not cellulose was given. Furthermore, we found in vitro that pectin had a high iron binding activity, while cellulose bound none. From the present study, we conclude that pectin but not cellulose reduces iron absorption by forming unabsorbable complexes with dietary iron. Thus, enrichment of the diet with foods providing significant amounts of noncellulosic dietary fibers, such as pectin, may be useful in the management of hemochromatosis patients.

Adult↗
PubMed1980

Evidence for 25-hydroxyvitamin D deficiency as a factor contributing to osteopenia in diabetic patients with idiopathic haemochromatosis.

Osteopenia is frequently encountered in the course of idiopathic haemochromatosis. In order to establish the mechanism of this bone disorder, the following parameters were studied in nine diabetic patients wih idiopathic haemochromatosis: (i) the intestinal calcium absorption measured by using a double radiotracer technique; (ii) the bone mineral content (BMC, mg/cm2) determined on the forearm by the Cameron's absorptiometric technique, (iii) the plasma 25 hydroxyvitamin D (25-OH-D ng/ml) by a competitive protein-binding radioassay. The results were compared to those obtained in ten controls and in eight diabetics without haemochromatosis. The patients suffering from haemochromatosis had a significant fall in total fractional absorption of calcium and BMC as compared with controls and diabetics without haemochromatosis. Furthermore plasma 25-OH-D was significantly lower in haemochromatosis patients (5.1 +/- 0.6 ng/ml) than in controls (16.4 +/- 1.3 ng/ml, P less than 0.01) and in diabetics without haemochromatosis (14.2 +/- 1.4 ng/ml, P less than 0.02). These results indicate that haemochromatosis patients exhibit important disturbances in calcium homeostasis, i.e. low concentration of plasma 25-OH-D and reduced intestinal absorption of calcium. The latter abnormalities may well be related to the bone rarefaction observed in these patients.

Adult↗
PubMed1980

[Mechanical effects of obesity on lung function (author's transl)].

Spirometry, blood gases, steady state diffusing lung capacity for carbon monoxyde, ductance for carbon monoxyde were determined in 27 obeses. In 13 of them we also measured closing volume. In 80 per cent of these patients we observed a decrease in expiratory reserve volume certainly due to a shift on the right of the chest wall volume-pressure curve. In 50% of the obeses we found an arterial hypoxia, usually observed when the expiratory level was lower than closing volume. Finally in 20% of the subjects we observed a decrease in diffusing lung capacity and/or ductances probably due to an important fall in and expiratory level at the closing volume level with impairment of the distribution of ventilation.

Adolescent↗
PubMed1980

[Recent advances on vitamin D (author's transl)].

Our knowledge of vitamin D metabolism has undergone major advances within the last few years. The vitamin D3 produced by the skin or absorbed across the intestine is converted successively to 25-hydroxyvitamin D3 by the liver and to 1,25-hydroxyvitamin D3 (1,25-(OH)2D3) by the kidney. The latter metabolite is also the most active on three types of target tissue: gut, bone and kidney. The mechanism of action of 1,25-(OH2D3 has been investigated mostly in the intestinal tract, where it increased calcium absorption by stimulating the synthesis of such transfer proteins as the calcium binding protein (Ca BP). Although the level of 1,25 (OH)2D3 is regulated by vitamin D intake, it depends mainly on renal hydroxylation, the limiting step which controls 1,25-(OH)2D3 production. Both parathyroid hormone and calcium or phosphorus depletion stimulate renal 1-alpha-hydroxylase; 1,25-(OH)2D3 is also regulated directly or indirectly (through its action on the parathyroid glands) by a feedback system. In some diseases such as hepatic insufficiency and chronic renal failure, a profound impairment in endogenous synthesis of the biologically active metabolites of vitamin D results in sever calcium and skeletal disese. During the last decade, the therapeutic possibilities in vitamin D deficiency have been greatly improved by the synthesis of new derivatives of vitamin D and by a better knowledge of their bioavailability

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed1979

[Major metabolic disturbances occur in diabetic patients whether they are obese or not (author's transl)].

The authors analyzed the effects of obesity/non-obesity in 162 epidoses of severe metabolic disturbances. Ketoacidosis and hypoglycaemics comas were more frequent in the non-obese group of diabetics, who were often insulin treated; whereas hyperosmolar coma and lactic acidosis were frequent in the obese group of diabetics, usually not treated with insulin. In the obese group both advanced age as well as a higher frequency of degenerative complications impaired the prognosis of these metabolic accidents. However the mortality rate was not significantly different in the two groups of patients. Despite the importance of the weight balance in the natural history of diabetes mellitus, it did not seem to influence the clinical aspects nor did it modify the therapeutic management of the major metabolic disturbances which occur in diabetes.

Adult↗
PubMed1979

Circulating lymphocyte subpopulations in juvenile insulin-dependent diabetes. Correction of abnormalities by adequate blood glucose control.

Circulating lymphocytes from 39 juvenile insulin dependent diabetics of recent onset were studied by six membrane marker techniques and mitogen stimulation. Well controlled (n = 14) were grouped separately from poorly controlled (n = 25) patients. The total lymphocyte counts were not different from 50 control subjects. The percentage of T-cells detected by erythrocyte rosettes and B-cells detected by erythrocytes--antibody--complement rosettes was significantly decreased only in poorly-controlled diabetics (64.1 +/- 1.3 and 9.7 +/- 1.8, vs 71.0 +/- 1.0 and 15.3 +/- 0.6 in controls). Cells bearing receptors for the Fc fragment of IgG immunoglobulins were decreased in both groups. Mitogen stimulation was not different from controls but was significantly lower in poorly controlled than in well controlled diabetics. Optimal blood glucose control for 5 +/- 2 days using an external artificial pancreas led to a rapid normalisation of membrane marker values and mitogen responsiveness of lymphocytes from previously poorly controlled diabetics. Separate in vitro experiments showed that glucose had an inhibitory effect on mitogen stimulation at concentrations greater than or equal to 8.3 mmol/l and on T- and B-lymphocyte numbers at concentrations greater than or equal to 55.6 mmol/l. DL 3-hydroxybutyrate tested at 17.1 and 34.2 mmol/l only depressed mitogen responsiveness. Such results suggest a rapidly reversible T-cell defect closely linked to the existing metabolic disturbances.

Adolescent↗
PubMed1979

The external artificial pancreas: an instrument to induce remissions in severe recent juvenile diabetes. Comparison with a preprogrammed insulin infusion system.

Remission of juvenile insulin-dependent diabetes is a rare, temporary, and partial phenomenon which seems to be related to an improvement of the residual insulin secretion supported by prompt and rigorous insulin therapy. Thus, remissions allowing the replacement of insulin by oral drugs were attempted in 23 insulin dependent ketotic juvenile diabetics (age 10 +/- 2 years) of recent onset (apparent duration of diabetes 71 +/- 5 days) treated by an external artificial pancreas during 5 +/- 1 days and compared with 10 control diabetics treated by a less effective technique (preprogrammed insulin pump without feedback control) during 6 +/- 1 days. 18 (78%) remissions of long duration (1-26 months) occurred after artificial pancreas compared with 3 (30%) in the control group. Measurement of daily urinary C-peptide excretion confirmed the improvement of the residual insulin secretion in patients with insulin-induced remissions. Thus, the excellent blood glucose control given by an artificial pancreas seems necessary to lead to much more frequent remissions of diabetes than usually reported.

Acute Disease↗
PubMed1979

[Late hypoglycaemia in chemical diabetes. Abnormalities of pancreatic glucagon secretion and effect of pectine (author's transl)].

Nineteen patients suffering from chemical diabetes either with (group A, ten cases) or without (group B, nine cases) reactive hypoglycaemia were included in the study and compared with seven control (group C). The following variables were measured over a 5 hour period during a standard oral glucose tolerance test (OGTT): (i) blood glucose by continuous monitoring; (ii) plasma insulin and glucagon levels by radioimmunoassay. Furthermore, in five diabetics of group A, the data from the standard OGTT were compared with those from a pectin-supplemented OGTT (9 g per square meter of body surface). Although the insulin response was similar glucagon levels were significantly higher (45.1 +/- 11.8 pmol/l) (p less than 0.01) in group B than in group A (9.6 +/- 1.3) and C (8.1 +/- 1.4 at 30 minutes). The high glucagon levels noted in group B may explain the absence of reactive hypoglycaemia. The pectin supplementation improved the OGTT pattern by blunting the blood glucose peak (p less than 0.05), and avoiding the reactive hypoglycaemia (p less than 0.01). The addition of pectin did not produce any significant effect on the insulin response while a significant increase in glucagon concentrations (p less than 0.05) was observed beyond the 150th minute. Therefore, the data suggest that pectin may improve the OGTT pattern by increasing the glucagon response in the late period of the test. The development of postprandial reactive hypoglycaemia seldom coincides with a plasma glucagon peak, while the absence of reactive hypoglycaemia tends to be associated with high levels of glucagon, as is the case in overt diabetes mellitus.

Adult↗