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I Testa

Publications and source records attributed to I Testa.

At least 73 records · Page 4Linked to original sources
PubMed1980

Effect of dexamethasone and cortisone on insulin receptors in normal human male.

Results of a recent study suggested that depending upon the glucocorticoid or the model used, opposite changes occur in insulin binding; in fact, the increase in insulin receptor number on monocytes after prednisone ingestion in man appears to contrast with previous reports in animals in which a decrease was shown after dexamethasone. To establish whether this apparent discrepancy depends upon the model used in human studies (i.e. monocytes), the effect of dexamethasone and corticone intake on normal men was evaluated. A significant decrease was observed in insulin binding on circulating monocytes 24, 48, and 72 h after both steroids, mainly due to reduced receptor affinity. Furthermore, steroid treatment increased insulinemia which did not appear to be related to insulin binding. These data are in agreement with results in animal studies and appear to suggest that previous data on prednisone do not depend upon the model used (i.e. monocytes) but upon the hormone itself, thus indicating that glucocorticoids, depending upon their chemical structure, may produce opposite changes in membrane insulin binding sites. Furthermore, since dexamethasone and cortisone affect plasma insulin levels in the same fashion as previously reported with prednisone, it is suggested that the variation in insulin binding observed after glucocorticoid treatment is not due to variations in insulinemia.

Cortisone↗
PubMed1980

Insulin receptors on monocytes and erythrocytes from obese patients.

Insulin receptors were studied in monocytes and erythrocytes [red blood cells (RBC)] isolated from 15 normal and 15 nondiabetic obese outpatients on an unrestricted diet. Insulin binding on both monocytes (P < 0.001) and RBC (P < 0.01) was higher in normal than in obese subjects due to different receptor concentrations. In some obese patients, binding to monocytes was decreased, while binding to RBC was normal. These data demonstrate that obese out-patients on an unrestricted diet have a reduced number of insulin receptors. It is suggested that interpretation of insulin binding based upon RBC should be used with caution, since a discrepancy exists in some subjects in the results obtained with these cells and monocytes.

Adult↗
PubMed1980

Erythrocyte insulin receptors in non-insulin-dependent diabetes mellitus.

Insulin binding was studied on circulating erythrocytes isolated from 12 normal and 12 untreated, adult, nonobese, nonketotic, non-insulin-dependent diabetic subjects. Insulin binding in normal subjects was higher than in diabetics (P less than 0.01); binding variation was caused mainly by a reduction in insulin receptor concentration. Insulin binding was inversely correlated with fasting serum insulin levels (R = 0.49; P less than 0.01). The close agreement between the present data and previous data on other cell populations suggests that isolated erythrocytes may be a useful tool in clinical investigations on the human insulin receptor.

Diabetes Mellitus↗
PubMed1979

[Role of 17-beta-estradiol in the synthesis and secretion of prolactin].

In 5 post-menopausal women TSH and prolactin secretions, induced by TRH, were studied before and after treatment with mg 20 of polyestradiol valerate. After this drug, plasma prolactin concentration increased, but no difference was observed in TSH secretion. The data suggest that 17-beta-estradiol doesn't increase the number of TRH receptors on pituitary cell surface, but stimulates prolactin synthesis.

Age Factors↗
PubMed1979

[Influence of cimetidine on hypoglycemia-induced GH secretion].

Dopaminergic drugs inhibit prolactin and stimulate GH secretion. On the contrary antidopaminergic drugs stimulate prolactin and decrease hypoglycemia-induced GH secretion. According to the hypothesis that Cimetidine, an H2-receptor antagonist, decreases hypothalamic dopamine secretion, it was evaluated GH response to hypoglycemia after this drug. It was demonstrated that Cimetidine decreases hypoglycemia-induced GH secretion.

Adult↗
PubMed1979

[Cimetidine and hyperprolactinemia].

Plasma TSH was determined in 12 normal subjects before and after administration of mg 400 of cimetidine i.v., an H2-receptor antagonist. TSH concentration remained unchanged. In 7 normal subjects, pretreated with bromocriptine; variation of plasma prolactin were studied before and after administration of mg 400 and 800 of cimetidine. Bromocriptine inhibited the increase of prolactin secretion, induced by cimetidine. It can be assumed that: a) cimetidine doesn't release hypothalamic TRH in portal vessels; b) that drug has no direct effect on pituitary cells; c) hypothalamic H2-receptor blockade by cimetidine decreases dopamine release from hypothalamus to pituitary gland.

Adult↗
PubMedDate not supplied

Age-dependent changes of serum oxygen radical scavenger capacity and haemoglobin glycosylation in non-insulin-dependent diabetic patients.

BACKGROUND: Contradictory results have been reported in the literature concerning the correlation between glycosylated haemoglobin (HbA1c) and peroxidation level in serum of diabetic patients. OBJECTIVE: To evaluate this correlation in type 2 diabetic patients by comparing the level of HbA1c with the oxygen radical absorbance capacity (ORAC(OH)) of serum. METHODS: One hundred and five type 2 diabetic patients were enrolled for the study. After having obtained informed consent, venous blood samples were drawn after overnight fast at the time of routine diabetic check-ups. The blood was collected in plain and EDTA (1 mg/ml) tubes. Glycosylated haemoglobin (HbA1c) was determined by cation-exchange chromatography (HPLC), and spectrophotometric detection (Diamat Analyzer, BioRad). Serum was used for biochemical determinations performed by standard laboratory procedures and for ORAC(OH) analysis. This last parameter was determined measuring the loss of beta-phycoerytrin fluorescence due to oxidation by hydroxyl radicals generated by Cu(2+) and H(2)O(2), in the presence and absence of serum. Seventy-eight control age-matched subjects were obtained from the personnel staff of our Research Department and old healthy subjects, selected on the basis of Senieur Protocol, were relatives of the above mentioned personnel. RESULTS: When the population of diabetic patients was taken as a whole, a decrease of ORAC(OH) has been observed compared to the controls. Moreover, negative correlations were found comparing ORAC(OH) either with HbA1c (r = -0.213; p = 0.029) and with the age of patients (r = -0.27; p = 0.005). To better understand the effect of age, the data were re-examined dividing the diabetics into two populations, i.e. under and over 65 years of age. An age-dependent decrease of ORAC(OH) and an increase in HbA1c levels has been observed comparing these two populations; however, the correlation between the two parameters remained statistically significant only in the oldest group (r = -0.31; p = 0.026). CONCLUSIONS: Present data point to an involvement of oxidative stress in the glycation of haemoglobin especially in old diabetic patients, and provide support for the potential use of an antioxidant therapy in these patients, irrespective of their glycaemic control.

Adult↗
PubMedDate not supplied

Autonomic diabetic neuropathy: skin sympathetic response and neurovegetative cardiovascular functionality tests.

One hundred and twelve diabetic patients were submitted to several tests for evaluation of autonomic cardiovascular and sudomotor function. It was found that a patient could be positive to one test and negative to others, thus confirming the presence of sectorial lesions which do not affect the autonomic nervous system uniformly. The parasympathetic system is more frequently and precociously affected than the sympathetic system. The tests used for investigating the sympathetic component, the sympathetic skin response (SSR) gives results which are more frequently and precociously altered.

Adolescent↗
PubMedDate not supplied

[Intracellular potassium in normal and pathological pregnancy. II. Experimental results].

Intraerythrocyte potassium was determined on samples from 198 physiologic, 88 hypertensive and 92 diabetic pregnant women. An increasing trend was observed during puerperium after the day 3, but a significant difference among the groups was not detected. These results may be due to a wider involvement of other cations (sodium, calcium) in the pathophysiology of pregnancy.

Erythrocytes↗
PubMedDate not supplied

[Prognostic evaluation of the cardiopathy in Duchenne's muscular dystrophy].

As it has now been ascertained that there is cardiac damage during the course of Duchenne muscular dystrophy (DMD), the authors have aimed at evaluating the relationship existing between the development of heart damage with respect to the advancement of age, and, at finding a sure prognostic index of the illness, easily acquired by using non-invasive techniques. Whilst the parameters which show the behaviour of the pumping function of the left ventricle (EF, Delta D%) did not demonstrate a clear correlation regarding their alteration in relation to age, the relationship PEP/LVET showed an accuracy of 92% predicting the terms of survival of patients suffering from DMD.

Adolescent↗