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Biomedical subjects

G Pozza

Publications and source records attributed to G Pozza.

At least 199 records · Page 11Linked to original sources
PubMed1990

Pharmacological interaction between tolbutamide and acetylsalicylic acid: study on insulin secretion in man.

This study has been planned to investigate some aspects of the interaction between acetylsalicylic acid (ASA) and tolbutamide on insulin secretion. In healthy subjects, oral administration of 3.2 g daily of ASA for 3 days significantly enhanced a) basal insulin levels (p less than 0.01), b) arginine-stimulated insulin secretion (25 g i.v. over 30 min) (p less than 0.01) and c) tolbutamide-stimulated insulin secretion (1 g or 0.25 g i.v. as a bolus) (areas under curves: p less than 0.02). Corresponding decreases in glycemia were observed. Tolbutamide binding to serum proteins was significantly reduced after ASA treatment (p less than 0.02). We conclude that, in case of tolbutamide test, interferences between ASA and tolbutamide on insulin secretion might be dependent, at least in part, on enhancement of free-tolbutamide percentage in plasma and not only on a direct or synergic action of ASA on pancreatic B-cell. Therefore, acute stimulation of insulin secretion by tolbutamide appears not to be completely comparable to other traditional stimuli, when ASA effects are studied.

Adolescent↗
PubMed1989

Prevalence of retinopathy in diabetic subjects from out-patient clinics in Lombardy (Italy), and associated risk factors. A multicentre epidemiologic study.

There is little information on the prevalence of diabetic complications in Italy. For this reason, a multicentre population-based study was carried out in 1983-1985 in 12 representative out-patient clinics for the treatment of diabetes in the Lombardy region. Out of a total population of 17,704 patients 1160 diabetic subjects were randomly selected within strata based on their duration of disease (less than or equal to 5; 6-10; 11-20; greater than 20 years). Eight hundred and thirty-eight responders were examined using standardised protocols. The estimated prevalences (adjusted for duration of disease) for the total population involved in the study were 29.7% and 7.6% for background and proliferative retinopathy respectively. The overall standardised rates were higher in insulin-dependent diabetes mellitus (IDDM) (53.6%) than in non-insulin-dependent diabetes mellitus (NIDDM) (34.7%) for both background (41.1%, 28.4% respectively) and proliferative (12.5%, 6.2% respectively) retinopathy, and increased with the duration of disease. The analysis of the relationship between diabetic retinopathy and the calculated risk factors did not show any association with hypertension or metabolic control, except for post-prandial blood glucose in subjects with durations 6-10 and greater than 20 years; an association with azotaemia was found in subjects with durations less than or equal to 5 and 11-20 years. Diabetic retinopathy appeared to be independently associated with the type of treatment and not with the type of diabetes, metabolic control, or hypertension.

Diabetic Retinopathy↗
PubMed1989

Nasal administration of glucagon and human calcitonin to healthy subjects: a comparison of powders and spray solutions and of different enhancing agents.

The systemic availability of glucagon and human calcitonin given intranasally to healthy volunteers as spray solutions or powders has been examined. Glucagon was absorbed only when surfactants were used, and 9-lauryl ether (as a spray) and sodium glycocholate (as spray or powder) were equally active. Calcitonin was poorly absorbed when given alone but the surfactants dihydrofusinate (as spray or powder) and glycocholate (as a spray) were equally active in promoting absorption. Thus, enhancers are required to obtain significant nasal absorption of glucagon and calcitonin and powders and spray solutions did not differ in terms of systemic availability.

Administration, Intranasal↗
PubMed1989

Insulin requirement in elderly patients with non-insulin dependent diabetes mellitus (NIDDM).

Diabetes mellitus in the elderly is mainly of the non-insulin dependent type (NIDDM). A large proportion of such patients are treated with insulin, after many years of therapy with oral hypoglycemic agents (OHA), on the assumption that these lose their efficacy with time. Moreover, many such patients are obese and show preserved insulin release. In the present study 45 obese subjects with NIDDM (14 under good metabolic control and 31 who presented hyperglycemia for at least 3 mo prior to testing) were placed on a strictly hypocaloric diet (800 Kcal/d) for 20 to 24 d. All of these patients had preserved insulin release. At the end of the trial, all the patients presented a significant reduction in body weight and a near normalization of the blood glucose profile, as well as a significant decrease both in the serum cholesterol and triglyceride levels and in the systolic blood pressure. On the basis of these results, insulin and OHA could be reduced in all the patients and suspended in some of these. The decrease in blood glucose levels was the same in all the patients regardless of the length of time that each had suffered from NIDDM. Five non-obese patients were placed on the same regimen, but the daily insulin dose could not be reduced. These data indicate that the majority of obese elderly patients with NIDDM are unnecessarily treated with insulin or with OHA, while diet alone would be sufficient to keep them under good metabolic control.

Aged↗
PubMed1989

Platelet sensitivity in vitro to the prostacyclin analogue iloprost in diabetic patients.

Iloprost is a chemically stable analogue of prostacyclin, with similar vasodilator and anti-platelet actions. Platelet sensitivity to the inhibitory action of Iloprost has been tested in vitro. Platelet-rich plasma from six healthy subjects and from six patients with type 1 diabetes mellitus was incubated with different concentrations of Iloprost, and then stimulated with ADP (at threshold aggregating concentration) and collagen 4 micrograms/ml. The half-maximal inhibitory concentration (IC50) of Iloprost was calculated and no differences were found between patients and controls. The results of this study suggest that diabetic patients without complications do not differ from healthy subjects in their platelet sensitivity to Iloprost.

Adenosine Diphosphate↗
PubMed1989

Mental arithmetic stress as a test for evaluation of diabetic sympathetic autonomic neuropathy.

The effects of a 1-min mental arithmetic stress test on heart rate change were studied in 72 Type 1 diabetic patients, 36 without and 36 with diabetic autonomic neuropathy (mean age 33 and 44 yr, respectively), and in 80 matched normal subjects. Variation in hand skin temperature was also recorded in 25 normal subjects and 30 diabetic patients without and 32 with autonomic neuropathy. While mental arithmetic rapidly reduced skin temperature of normal volunteers and of patients without autonomic neuropathy, no effect was found in autonomic neuropath (a drop of 0.63 +/- 0.05 (+/- SE), 0.52 +/- 0.04 and 0.16 +/- 0.02 degrees C (p less than 0.001), respectively). In control subjects and in diabetic patients without and with autonomic neuropathy the heart rate increase was 22.9 +/- 6.8 (+/- SD), 21.4 +/- 8.4 and 7.0 +/- 3.7 beats min-1, respectively (p less than 0.001). The ratio between maximum mental arithmetic-induced heart rate and basal heart rate was 1.29 +/- 0.10, 1.24 +/- 0.10 and 1.07 +/- 0.05 (p less than 0.001) for healthy subjects, non-neuropathic patients, and neuropathic patients. Cut-off values (the low normal limit for these variables) are proposed: skin temperature 0.23 degrees C, heart rate increase 11.6 beats min-1 and heart rate ratio 1.12. Anxiety state, blood glucose concentration (excluding hypoglycaemia), body position, basal heart rate, and age did not interfere with responses to mental arithmetic stress.

Adult↗
PubMed1989

Effect of intranasal growth hormone-releasing hormone and corticotropin-releasing hormone administration on growth hormone and cortisol release: improved bioavailability by means of sodium-glycocholate.

Several peptide hormones are effective when administered intranasally (in); these include oxytocin, vasopressin, insulin, glucagon, and calcitonin. With regard to GHRH and CRH, previous studies demonstrated that their bioavailability following in administration was very low. In this study we evaluated the serum GH response to 50 micrograms GHRH iv and to 700 micrograms GHRH in, the latter given alone and with 5 and 15 mg sodium-glycocholate (SGC), a surfactant, in six normal men. The bioavailability of in GHRH, calculated as net GH secretory area, was very low, and increased to 7% that of iv GHRH when SGC was used. In the same men, 50 micrograms CRH was administered both iv and in, alone and with 5 and 15 mg SGC. The bioavailability of in CRH, calculated as net cortisol secretory area, was very low and increased to 100% that of iv CRH when 15 mg SGC was used. These data indicate that the efficacy of GHRH and CRH administered in is significantly augmented by SGC.

Administration, Intranasal↗
PubMed1989

Inhibition of the growth hormone (GH) response to GH-releasing hormone by constant Met-GH infusions.

GH release is controlled by hypothalamic hormones and insulin-like growth factor I, synthesized under the influence of GH, and perhaps also by GH itself. The availability of recombinant Met-GH was the basis for studies aimed at 1) obtaining constant serum GH levels by means of constant Met-GH infusions (40 and 80 ng/kg.min for 6 h), and 2) evaluating the metabolic effects of constant GH levels and, in particular, their effects on the serum GH response to GHRH. In six normal men, both Met-GH infusions increased plasma FFA levels, but did not alter the circulating levels of somatostatin, insulin-like growth factor I, insulin, glucose, cholesterol, and triglycerides. The Met-GH infusions did cause a dose-related inhibition of GHRH-induced GH release. These data indicate that it is possible to maintain constant serum GH levels by means of constant Met-GH infusions at different infusion rates, and that GH inhibits its own release.

Adult↗
PubMed1989

Islet cell autoimmunity in type I diabetic patients after HLA-mismatched pancreas transplantation.

The aim of this study was to investigate a possible reenhancement of islet cell autoimmunity in type I (insulin-dependent) diabetic patients who received HLA-mismatched pancreas transplants from cadaveric donors and who underwent generalized immunosuppression. Circulating islet cell antibodies (ICA) and complement-fixing ICAs (CF-ICAs) have been tested at 1, 2, 3, 6, and 12 mo and at least once a year posttransplantation in 23 recipients of 25 transplants (22 simultaneous with kidney, 2 retransplants, 1 isolated; 23 segmental neoprene injected, 2 whole with enteric drainage). Patients were aged 35.3 +/- 1.9 yr with a duration of diabetes of 20.6 +/- 1.1 yr. Immunosuppression consisted of double or triple association of azathioprine, cyclosporin, and prednisone with or without temporary antilymphocyte globulins. The number of HLA-A and HLA-B compatibilities was none in 8 patients, one in 12 patients, two in 4 patients, and three in 1 patient. The mean follow-up was 4.0 +/- 0.4 yr/patient (range 0.4-7.2). ICAs were positive pretransplantation in 2 of 25 patients and reappeared 1-42 mo posttransplantation in another 7. In 6 patients, CF-ICAs were also positive. In 7 of 9 ICA+ patients the pancreas transplant failed; in 1 patient this occurred 4 mo before ICA reappearance, and in 6 patients it occurred 2-35 mo after the first detection of ICAs. Pancreas-transplant failure was significantly associated with the positivity for ICAs (P less than .05) and particularly for CF-ICAs (P less than .005). ICA positivity was transitory in 4 patients (2-27 mo) and persistent in the remaining 5 (up to 61 mo).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Intranasal glucagon as remedy for hypoglycemia. Studies in healthy subjects and type I diabetic patients.

Intranasal glucagon can raise blood glucose levels in healthy subjects. The aims of this study were to 1) compare the hyperglycemic effect of intranasal and intramuscular glucagon in healthy subjects and type I (insulin-dependent) diabetes patients during euglycemic conditions and 2) test the efficacy of intranasal and intramuscular glucagon in counteracting hypoglycemic episodes in insulin-treated diabetic patients. Intranasal glucagon raised blood glucose levels in both healthy subjects and type I diabetic patients, the effect of intramuscular glucagon being similar for the first 30 min and higher thereafter. Intranasal glucagon was also quicker acting than oral glucose in healthy subjects. Intranasal glucagon raised blood glucose levels in patients with hypoglycemic episodes, although less effectively than intramuscular glucagon. These data indicate intranasal glucagon as a possible emergency remedy for self-medication in insulin-treated patients prone to hypoglycemic episodes.

Administration, Intranasal↗
PubMed1989

[MR (1.5 T) in the evaluation of pancreas transplant rejection].

Graft rejection is the major cause of graft loss following pancreatic transplantation. Early detection of the rejection process is of great importance towards planning effective treatment when transplant recipients present with aspecific clinical findings suggesting rejection. Up to date, the demonstration of pancreatic transplant rejection has been attempted with nuclear medicine and sonography (US). The authors studied high-field (1.5 T) MR potentials in pancreatic transplantation and rejection and correlated MR findings with clinical and laboratory data. Eleven MR scans were obtained from 4 patients with suspected pancreatic graft rejection, and 9 MR images from 4 patients with normal pancreatic allografts. Qualitative image evaluation showed the pancreatic tissue of the patients diagnosed with rejection to be hypointense on T1-weighted scans and highly hyperintense on T2-weighted scans, as compared to normal grafts. Quantitative data were obtained by comparing the signal intensity of pancreatic grafts to that of the nearby muscle. On both T1- and T2-weighted images, pancreatic tissue/muscle signal-intensity ratios were significantly different, in rejecting transplants, from those of normal allografts (p less than 0.001). Our qualitative and quantitative findings suggest the use of MR imaging as a reliable means of detecting pancreatic graft rejection.

Evaluation Studies as Topic↗