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Biomedical subjects

G Chiumello

Publications and source records attributed to G Chiumello.

At least 163 records · Page 9Linked to original sources
PubMed1978

Hemoglobin A1C separation by isoelectric focusing.

A modified type of isolectric focusing has been applied successfully to the separation of hemoglobin A1C (HbA1C) from HbA in normal and diabetic cell lysates. It consists of transforming a linear pH gradient into a nonlinear one, by the addition of an amphoteric substance ("separator" or "pH gradient modifier") with an isoelectric point (pI) close to the pI's of the two hemoglobins. Among the "modifiers" tested, histidine, proline, threonine, beta-alanine, 6-amino caproic acid, and 5-amino valeric acid are not useful in the hemoglobin pI range (pH 6.9--7.0). The dipeptide histidyl-glycine (pI = 6.8; pI-pK1 = 1) is very efficient in flattening the pH gradient, in the hemoglobin region. even when added in low concentrations (10--100 mM), thus affording full resolution of the two hemoglobin species.

Alanine↗
PubMed1977

Glucagon response to arginine stimulation in obese and diabetic children.

The effect of arginine infusion on blood sugar and plasma levels of growth hormone and glucagon has been studied in children with clinical diabetes mellitus and in obese children with normal carbohydrate tolerance. Basal levels of plasma GH are significantly lower in obese children than in diabetics and controls; in obese subjects the increment of GH is significantly lower than in diabetics and controls. Basal plasma glucagon levels are comparable in all three groups despite the high sugar levels in diabetic patients. After arginine infusion there is a significant rise in glucagon levels without significant differences between the three groups.

Adolescent↗
PubMed1976

Effect of somatostatin on blood sugar, plasma growth hormone, and glucagon levels in diabetic children.

In nine children with clinically overt insulin-dependent diabetes mellitus the authors injected cyclic somatostatin (3 mug./kg. bolus, followed by infusion of 13 mug./kg. in 60 minutes) and measured blood glucose, plasma growth hormone, and glucagon concentrations throughout the infusion. The rapid administration produced no significant changes of these parameters. With the prolonged infusion there was a significant reduction of blood glucose from a mean of 148 +/- 19.7 to a mean of 88.5 +/- 18.1 mg./100 ml. (P less than 0.005) and of plasma glucagon from a basal mean of 33.3 +/- 2.4 to a minimum mean of 22.1 +/- 1.7 pg./ml. (P less than 0.01). There was a statistically significant correlation between the two parameters (0.01 less than P less than 0.05). Plasma GH values also diminished during the infusion, but the reduction was not statistically significant. These results show that somatostatin lowers blood glucose concentrations as a secondary effect of inhibition of glucagon secretion. Somatostatin is not suitable for therapy in diabetes. We speculate that a similar substance with a more prolonged and specific action on glucagon might prove of practical value in the treatment of diabetes mellitus.

Blood Glucose↗
PubMed1975

Muscular exertion: a test of pituitary function in children.

The elevated level of growth hormone after moderate standardized physical exercise was compared with that induced by intravenous arginine infusion and by insulin induced hypoglycemia in children with normal pituitary function. Tests were performed on 49 prepubertal children (34 boys and 15 girls); in 42 cases the increase was significant for all three tests, in 5 cases the response was minimal after insulin stimulation but normal after arginine and physical exertion; in 1 case arginine produced no response but the other tests were positive; in 1 case there was a response to arginine but none to insulin or physical exertion. The results indicate that frequently more than one test is necessary for the diagnosis of normal pituitary function; physical exertion being a physiologic test, is simple to perform, acceptable to the children and without side effects. It appears the test of first choice because it can be used in patients seen ambulatorily, other tests being performed in case of doubt or negative response.

Arginine↗
PubMed1975

Effect of physical exercise on secretion of growth hormone, glucagon, and cortisol in obese and diabetic children.

The effect of muscular exertion of moderate intensity on blood sugar (BS), plasma levels of growth hormone (GH), glucagon, and cortisol (F) has been studied in endocrinologically normal children with short stature and compared with children with clinical diabetes mellitus and obese children with normal and diminished carbohydrate tolerance. In diabetic children, physical exertion induces a rise in plasma GH levels comparable to that in controls; in obese children with normal or with diminished glucose tolerance, the rise is considerably smaller. Physical exertion caused no change in F levels in the groups tested, although basal level in the obese children was significantly higher than in the controls. Basal glucagon levels were similar in all groups and showed no change on physical exertion. The behavior of GH and glucagon in diabetic children was comparable to that in the controls even where blood sugar level was high.

Adolescent↗
PubMed1975

The effect of alpha1-24-corticotropin on growth hormone release in prepubertal children.

The effect of alpha1-24-corticotropin-Zn on the results of pituitary stimulation tests (moderate standardized physical exercise, arginine infusion, insulin-induced hypoglycemia) was studied in 27 prepubertal children with non-endocrine retardation of growth and development. After administration of 1 mg alpha1-24-corticotropin, the basal blood glucose and plasma cortisol levels rose significantly. However, the growth hormone increase after the three stimulation tests was significantly lower than without the corticotropin injection. The results demonstrate the inhibiting effect of alpha1-24-corticotropin on growth hormone secretion.

Adolescent↗