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Biomedical subjects

A Orsetti

Publications and source records attributed to A Orsetti.

At least 55 records · Page 3Linked to original sources
PubMed1985

[Glycoregulation disorders in giant-cell arteritis].

Eight patients with giant cell arteritis (6 with Horton's disease and 2 with polymyalgia rheumatica) were investigated for abnormalities in glycoregulation, previously reported in Horton's disease, using oral glucose tolerance tests with measurement of insulinaemia and C-peptide response to glucagon to evaluate pancreatic function. The results were compared with those obtained in an age and weight matched population of patients with inflammatory syndromes of other origins. All patients with giant cell arteritis had abnormal glucose tolerance tests, with diabetes mellitus in 6 and impaired glucose tolerance in 2. Insulinaemias at all stages of the test, insulin response areas and basal C-peptide values were elevated; C-peptide response to glucagon was normal. Similar results were observed in patients with other inflammatory syndromes. It is concluded that glycoregulation disorders are not incidental in giant cell arteritis, that the normal pancreatic function seems to exclude immune pancreatic vasculitis, and that the abnormal glycoregulation is probably due to insulin-resistance. Since these abnormalities cannot be explained by the patients' advanced age alone, the part played by the inflammatory syndrome, which was common to both groups, is discussed. Its responsibility for inducing insulin-resistance may account for the fact that corticosteroids, which are rapidly effective against giant cell arteritis, normalise oral glucose tolerance tests.

Aged↗
PubMed1985

Influence of the frequency of gonadotropin-releasing hormone (GnRH) administration on ovulatory responses in women with anovulation.

In attempt to optimize gonadotropin-releasing hormone (GnRH) treatment of anovulation, we compared the effect of intravenous GnRH administration at three pulse intervals (PI) during 63 cycles in 30 anovulatory patients who had: (1) amenorrhea secondary to anorexia nervosa (group I: 10 patients, 21 cycles); (2) unexplained anovulation with normal to high luteinizing hormone plasma levels (group II: 12 patients, 24 cycles); and (3) polycystic ovarian disease (PCOD) (group III: 8 patients, 18 cycles). Ovulation was achieved more frequently in group I (85%) than in group II (41%) or in group III (50%). In both groups I and II, the frequency of ovulatory responses was not different with the PI used, and 6 of the 17 women treated for infertility conceived; 3 with 90-minute PIs, 2 with 64-minute PIs, and 1 with 128-minute PIs. In women with PCOD, seven of the nine ovulatory responses and three pregnancies were obtained with 128-minute PIs. The overweight women with PCOD did not respond reliably to GnRH at the doses used, i.e., 4 to 15 micrograms per pulse. In all groups, the urinary estrone and estradiol preovulatory peak, duration of luteal phase, progesterone levels, and preovulatory follicle diameter were unrelated to the frequency of GnRH administration.

Anovulation↗
PubMed1985

[Functional study of rat islands of Langerhans cultured in agarose gel].

We have studied the viability of rat's pancreatic islets included in agarose and cultured in RPMI 1640 Medium in basal conditions (glucose: 11 mM) and during periods of stimulation (glucose: 22 mM + theophylline 5 mM). In our experiments, the capacity of the islets to release insulin in response to glucose variation has been conserved during ten days. In view of these encouraging results, we hope to use islets-agarose systems in bio-artificial pancreas.

Animals↗
PubMed1985

Pharmacokinetics of insulin infused intra-peritoneally via portable pumps.

Plasma free insulin was measured repeatedly for 4 hours following a standardized breakfast in 20 C-peptide negative chronically pumped type I diabetic patients and 5 normal subjects. In the former group, insulin was given as a 1 u/h basal infusion and a 1h superimposed meal-dose of 6 u via a peritoneal (IP) catheter lying in the low (n = 10), or in the mid-abdomen (n = 10). The results of the IP patients were correlated with glycosylated haemoglobin and home capillary blood glucose. Fasting free insulin of IP patients was lower than those of normals (14.7 +/- 0.5 vs 21.0 +/- 1.3 mU/l, p less than 0.01). Dose-induced peak occurred similarly in IP patients and normals (70 +/- 6 vs 70 +/- 12 min.). Values tended to baseline after 165 +/- 15 and 185 +/- 22 min. in IP patients and normals (NS). Results of the mid--and low peritoneum subgroups differed only for peak values (31.5 +/- 2.9 vs 25.0 +/- 1.6 mU/l respectively) and did not correlate with diabetic control.

Adult↗
PubMed1984

Effects of dietary fiber on postprandial glycemic profiles in diabetic patients submitted to continuous programmed insulin infusion.

Conventional (C) or fiber supplemented (F) test breakfast and lunch were given on 3 successive randomized days to six insulin-dependent diabetic patients treated with continuous programmed insulin infusion. Meal distribution was as follows: day 1 (C breakfast and C lunch), day 2 (F breakfast and C lunch), day 3 (F breakfast and F lunch). No rise in blood glucose (BG) was observed after F breakfast (days 2 and 3) while a small rise in BG occurred after the C breakfast (day 1). Significant differences were observed between day 1 and days 2 and 3 for absolute BG values as well as for BG changes (delta BG) from base-line. At lunch slight differences in delta BG were only noted at 45 min (p less than 0.05) between days 2 and 3, while there was no difference between days 1 and 2. Our results indicate that fiber supplementation is useful even in pump-treated insulin-dependent diabetics but that F breakfasts have no influence on the carbohydrate tolerance to the subsequent lunch.

Adult↗
PubMed1984

Plasma beta-thromboglobulin response to insulin-induced hypoglycemia in type I diabetic patients.

The effect of an insulin-induced hypoglycemia was examined in 14 type I diabetic patients. After an overnight blood glucose normalization, each patient received an additional intravenous bolus of 3 U regular insulin at 0900 h (time 0). Blood glucose was continuously recorded up to 180 min. Plasma samples were assayed for beta-thromboglobulin (beta TG, ng/ml), pancreatic glucagon (pg/ml), cortisol (microgram/dl), and growth hormone (ng/ml) 30 min before the insulin stress, at time 0, at blood glucose nadir, and at 180 min. The blood glucose fell from a baseline level of 85.0 +/- 3.2 mg/dl to a nadir value of 39.2 +/- 1.9 mg/dl (P less than 0.001) reached at an average time of 41.4 +/- 4.9 min. Plasma beta TG increased significantly (P less than 0.05) during the insulin stress: 93.4 +/- 23.7 ng/ml at nadir versus 42.5 +/- 5.9 at time 0. Plasma cortisol and growth hormone were significantly increased (P less than 0.02 and P less than 0.01) at nadir compared with time 0 values. Plasma pancreatic glucagon was higher at nadir than at time 0, but the difference was not significant. The present results indicate that in vivo platelet activation can be triggered by hypoglycemic episodes in insulin-treated diabetic patients.

Adolescent↗
PubMed1984

Effects of dietary gamma-linolenate supplementation on serum lipids and platelet function in insulin-dependent diabetic patients.

In order to gain insight into the mechanism of platelet dysfunction in insulin-dependent diabetics we studied in 17 patients the influence of a 6-week period with a dietary supplement of gamma-linolenate: 2 g/d (group I, n = 8) or 500 mg/d (group II, n = 9). Serum lipids, plasma beta-thromboglobulin (beta TG), platelet aggregation in vitro, and TxB2 and PGE1 released from platelets during the aggregation process were measured. In group I, serum triglycerides fell from 1.57 +/- 0.28 mmol/l to 0.99 +/- 0.17 mmol/l (P less than 0.01) and cholesterol fell from 5.85 +/- 0.55 mmol/l to 5.08 +/- 0.52 mmol/l (P less than 0.01). In group I plasma beta TG fell from 100.0 +/- 15.7 ng/ml to 73.7 +/- 12.1 ng/ml (P less than 0.025), while the sum of the percentages of the C18:3 omega 6 and its chain elongated (C20:3 omega 6) and desaturated (C20:4 omega 6) metabolites increased in serum triglycerides (P less than 0.05), cholesterol esters (P less than 0.02) and phospholipids (P less than 0.02). No changes were observed on the other parameters in either group. The results show that the lowering effects of gamma-linolenate on serum triglycerides, cholesterol and plasma beta TG occur only with daily intakes of 2 g. The changes in fatty acid composition of serum lipids suggest that the gamma-linolenate intake of 2 g may exert its beneficial effect through an increased incorporation of long-chain polyunsaturated fatty acids, but no firm conclusion can be drawn as membrane platelet fatty acid composition was not evaluated.

Adult↗
PubMed1983

[Value of continuous registration of blood D-beta-hydroxybutyrate and glucose. Application in a case of acromegaly].

We describe the use of an autoanalyzer II for continuous whole blood D-beta-hydroxybutyrate and glucose monitoring. The former is analyzed by an enzymatic-fluorimetric determination. This method is simple, reliable and sensitive at low cost. It permits to record dynamic patterns of the two major energetic substrates in response to various stimuli, as shown in an acromegalic patient following a glucose load.

3-Hydroxybutyric Acid↗
PubMed1983

Plasma lipid fatty acids and platelet function in insulin-dependent diabetic patients.

Platelet function, estimated from plasma beta-thromboglobulin (beta-TG, ng/ml), is frequently altered in insulin-dependent diabetics (IDDs). As several factors may affect beta-TG, we studied respectively in 15 IDDs, the roles played by: (i) diabetic control evaluated from glycosylated haemoglobin (HbA1); (ii) plasma C-peptide and pancreatic glucagon; (iii) plasma lipids and the relative percentages of fatty acids in total plasma lipids. Plasma beta-TG did not correlate significantly with the first 3 parameters. However, beta-TG was correlated: (i) positively with plasma triglycerides (P less than 0.01), cholesterol (P less than 0.02), phospholipids (P less than 0.05) and total plasma lipids (P less than 0.01) and the percentage of oleic acid (C18 : 1 omega 9) in plasma lipids (P less than 0.01); (ii) negatively with the percentage of linoleic acid (C18 : 2 omega 6) in plasma lipids (P less than 0.02). No correlation was found between beta-TG and the percentages of the other saturated (C16 : 0, C18 : 0), monounsaturated (C16 : 1 omega 7) and polyunsaturated fatty acids (C18 : 3 omega 6, C20 : 3 omega 6 and C20 : 4 omega 6). The present results indicate that beta-TG in IDDs can be markedly improved by all dietary and therapeutic measures which lower plasma lipids and increase the percentage of the linoleic acid in the body.

Adult↗
PubMed1982

[Chronic insulin urticaria. Therapeutic efficacy and good tolerability of human insulins].

A case of type III (Arthus') hypersensitivity to insulin which occurred several years after insulin treatment was instituted is described. Its persistence even with highly purified insulins of bovine or porcine origin was suggestive of a direct reaction against insulin itself. The patient had no history of allergy and, contrary to most similar cases published, had not received intermittent insulin therapy. Using stimulation of lymphocyte blastogenesis, the authors were able to demonstrate the presence of specific antigen-mediated hypersensitivity to all insulins tested, including human insulins. The circulating immune complexes did not appear to be pathogenic, since the patient only had minimal retinopathy after 22 years of insulin-dependent diabetes. Human insulin was tolerated and proved effective in controlling both blood glucose levels and skin rashes in response to conventional insulins.

Adult↗
PubMed1982

Restored synergistic entero-hormonal response after addition of dietary fibre to patients with impaired glucose tolerance and reactive hypoglycaemia.

Although some dietary fibres (DF) improve glucose tolerance by slowing carbohydrate absorption, other mechanisms are certainly involved. Some of the entero-hormonal responses after DF were investigated in six patients with impaired glucose tolerance and reactive hypoglycaemia. All patients received two different breakfasts, each containing 25 g of starch supplied either as white bread (WB) or a fibre-enriched bread preparation (FB): 4 g hemicellulose and 4 g guar. Metabolic and hormonal responses were evaluated over 5 hours. Compared to WB, the FB had a blunting effect on the resulting blood glucose peak (116 +/- 9 mg/100 ml with FB vs. 148 +/- 15 with WB P less than 0.025) or trough (88 +/- 3 mg/100 ml with FB vs. 79 +/- 5 with WB), and upon the insulin response at 60 min (20 +/- 4 micro U/ml with FB vs. 70 +/- 20 with WB). Gut glucagon immunoreactivity was diminished with FB at 90 min (185 +/- 39 vs. 242 +/- 42 P less than 0.05) and 150 min (180 +/- 39 vs. 242 +/- 40). Pancreatic glucagon was initially similar after FB and WB, but a significant rise was observed with FB at 180 min (116 +/- 17 pg/ml vs. 67 +/- 18 P less than 0.05). The improvement of the blood glucose pattern with DF, especially the suppression of reactive hypoglycaemia, seems to depend partly on reduced and delayed response of the entero-hormonal axis. This in turn results in a better synergistic secretion of insulin and glucagon in the late post-prandial period.

Adult↗
PubMed1981

Effects of somatostatin added to insulin in a glucose-controlled insulin infusion system.

Five insulin treated diabetics were studied on three consecutive days. Overnight variable intravenous insulin infusions were used before each study to maintain normoglycaemia and to calculate the optimal basal insulin infusion rate (1.1 +/- 0.1 U/h) which ws then kept constant throughout the study day. A standard 400 kCal breakfast with 25 g xylose was given at 0800 h. When the blood glucose rose above 4.1 mmol/l, an external artificial pancreas was used to infuse either extra insulin (day INS) or somatostatin for either 3h (day som) or the entire 8h experimental period (day SOM). Peak post-prandial blood glucose values were similar on all three days. The blood glucose rebounded after the cessation of the somatostatin infusion on day som. Post-prandial blood xylose peaks were lowered by somatostatin on both days but rebounded after the cessation of the somatostatin infusion on day som. The area under the plasma and urinary xylose curves was lowered by somatostatin only on day SOM. Growth hormone and glucagon levels were not statistically different on all 3 days. Thus somatostatin, when added to an optimal insulin infusion, minimised the insulin requirements by slowing intestinal absorption, but led to rebound hyperglycaemia if not feed-back controlled.

Adult↗
PubMed1981

Glucagon immunoreactivity and antidiabetic action of somatostatin in the totally duodeno-pancreatectomized and gastrectomized human.

Ten patients who had been totally duodeno-pancreatectomized and totally (N = 1) or partially gastrectomized (N = 9) for chronic pancreatitis (N = 9) or pancreatic carcinoma (N = 1) were investigated. None had a measurable basal level of either plasma C-peptide or a C-peptide response to i.v. glucagon. Immunoreactive glucagon (IRG) was present in all patients, and the mean level (69 +/- 8 pg/ml) was not significantly different from the mean observed in normal subjects (81 +/- 16 pg/ml). Plasma IRG was unequivocally stimulated by arginine in 2 of the 10 subjects. The effect of somatostatin on plasma glucose and IRG during an oral glucose tolerance test was studied in 5 of the 10 patients. The effects of somatostatin on spontaneous hyperglycemia, plasma growth hormone, and IRG after withdrawal of insulin treatment was studied in 4 patients. Somatostatin blunted both the hyperglycemic and paradoxical IRG responses to the glucose challenge, and reduced the spontaneous rise of blood glucose that occurred after insulin withdrawal. This latter effect was not related to clear-cut changes in plasma growth hormone or in IRG. These data confirm the existence of circulating IRG in pancreatectomized patients and demonstrate the presence of circulating IRG in a completely gastrectomized and pancreatectomized patient. The somatostatin-induced improvement in glucose tolerance in the oral glucose tolerance test seems to be related to a reduction of the paradoxical IRG response. In contrast, the inhibition by somatostatin of the rise in blood glucose which occurs after insulin withdrawal does not seem to be mediated through IRG or growth hormone.

Adult↗
PubMed1981

[Autotransplantation of islands of Langerhans in dogs].

Six dogs received intraportally an autograft of isolated non purified pancreatic islets after total pancreatectomy. The isolation was made by collagenase technique, using a quarter to a half of the total pancreatic mass. The results of different transplantation technics are discussed. We conclude the necessity of: 1) a good venous distension of the pancreas, 2) the use of at least a third of the pancreatic gland to prepare the islets, 3) a tissue reinjection the closest as possible of the portal vein.

Animals↗
PubMed1981

[Critical analysis of the fractional value of a bio-artificial pancreas (hollow-fiber model)].

The implantation of a bio-artificial pancreas, in a totally depancreated dog, allowed to underline the functional limits of this system. This study would want to explain in vitro a defect of the bio-distributor artificial picked out in vivo. Double stimulation by glucose have been realised composing the conventional system of perifusion (Millipore) to the artificial bio-distributor. While the insulin secretion increases directly at every raise of the glucose concentration in the conventional systems, it seems to hot move during the first test with the artificial biodistributor of insulin. It increases during the second phase of rest and reaches its maximum during the second phase of raise. The insulin concentration represents at the end of the test approximatively 1/5 of this obtained by the conventional system (the experimental conditions and the islets number are the same in the two cases).

Animals↗