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Biomedical subjects

R Manna

Publications and source records attributed to R Manna.

15 recordsLinked to original sources
PubMed1992

Nicotinamide treatment in subjects at high risk of developing IDDM improves insulin secretion.

Nicotinamide (NCT) has been shown to be effective in preventing the onset of type 1 diabetes mellitus (IDDM) in mice with non-obese diabetic (NOD) and beta cell damage, mediated by the diabetogenic agents including streptozotocin. NCT therapy in man has been shown to have a beneficial effect on the remission phase of IDDM, and its use is safe. In this open pilot trial we therefore studied the effect of oral NCT administration on insulin secretion rate and islet-cell antibody (ICA) titres in IDDM high risk subjects. NCT (25 mg/10 kg bw) was administered in 6/13 high risk patients identified by a family screening programme. Those subjects tested after eight months without treatment showed a decreasing secretion in comparison to onset baseline (56,1 +/- 37.8 versus 35,5 +/- 12.2), whereas the treated subjects showed an increasing insulin secretion after treatment (26 +/- 10 versus 50.2 +/- 26.6), in spite of ICA persistence. Statistical analysis shows an increased insulin secretion in the treated group versus the untreated group (chi 2 = 3.899, P = 0.048). No side-effects were observed. We conclude that NCT may repair beta-cell function in high risk subjects too if damage is not too severe; furthermore, the effect seems not to be mediated by an immune mechanism.

Adolescent↗
PubMed1979

Glucose, insulin and somatostatin infusion for the determination of insulin resistance in liver cirrhosis.

Twelve patients with liver cirrhosis and ten normal subjects were studied. Using a constant intravneous infusion of glucose, insulin and somatostatin over 2 1/2 hours we determined the stteady state plasma glucose level (SSPG) in order to measure insulin resistance. The results demonstrated that the cirrhotic patients were insulin resistant compared to normals and that plasma glucagon does not account for the insulin resistance in these patients.

Adult↗
PubMed1979

Early insulin and glucagon response to subsequent pulses of arginine, glucose, and tolbutamide in normal man.

To determine the dynamics of insulin and of glucagon secretion in response to several sequential stimuli administered shortly after an arginine pulse (5 g), 20 nonobese, apparently healthy volunteers were given arginine (5 g), glucose (5 g), and tolbutamide (1 g) by rapid intravenous injection. The early insulin and glucagon area 0-8 min was studied. At the intervals and with the dosages used in this study, different stimuli with and without prestimulation with arginine did not lead to changes in early secretion of insulin. There was no exhaustion of the pool of insulin released after multiple sequential pulses. These results suggest a pattern in which stimulation induces a rapid release of insulin and activates the interchange between the stored and labile insulin pool; the 8-min interval is sufficient for the rapid return of the two compartments to a state of equilibrium. Also for glucagon, subsequent different stimuli did not exhaust glucagon release; nevertheless, glucagon is immediately suppressed by a submaximal glucose pulse.

Adolescent↗
PubMed1979

GH secretion in open-angle glaucoma.

Open-angle glaucoma is frequently observed in patients with acromegaly suggesting that the somatotropic hormone might facilitate a condition of glaucoma. The open-angle glaucoma patients studied, displayed higher plasma human growth hormone (HGH) levels than control subjects 60 min (30.3 +/- 1.7 against 16.8 +/- 2.7 ng/ml; p less than 0.001) and 90 min (19.0 +/- 1.9 against 9.3 +/- 1.2 ng/ml; p less than 0.001) after intravenous administration of arginine (25 g in 30 min). The authors support the hypothesis that the increased plasma HGH level may interfere with the regulation of ocular pressure by modifying the flow of aqueous humor from the eyeball via changes in the sclero-corneal trabecular meshwork; these changes are also found in diabetic subjects. The interplay between HGH and changes of carbohydrate metabolism (frequently occurring in glaucomatous patients) may be at the root of the variations of intraocular pressure in open-angle glaucoma.

Arginine↗
PubMed1979

Gastrin response to insulin in patients with cirrhosis of the liver.

Fasting gastrinemia in cirrhotics (48.35 +/- 2.77 pg/ml) was higher than in normal controls (32.93 +/- 0.75 pg/ml; P less than 0.001). After insulin-induced hypoglycemia, the mean increase of gastrin above basal level was 42.29 +/- 1.92 pg/ml in controls and 10.85 +/- 5.05 pg/ml in cirrhosis (P less than 0.001). BAO was 2.53 +/- 0.36 mEq/h in controls and 0.42 +/- 0.004 mEq/h in cirrhotics (P less than 0.001). After i.v. insulin, TAO was 8.42 +/- 0.72 mEq/h in controls and 3.06 +/- 0.26 mEq/h in cirrhotics (P less than 0.001). The authors suggest that the lack of an adequate gastrin and acid response to the hypoglycemic stimulus in cirrhotics might be accounted for by a decreased insulin sensitivity.

Adult↗
PubMed1979

Serum gastrin in portal and peripheral veins after arginine in man.

Immunoreactive serum gastrin from portal and peripheral veins was determined in five controls and in five cirrhotic patients with indwelling portal catheters in basal conditions, during and after 30 min arginine infusion, in order to assess whether the human liver is involved in gastrin metabolism. A significant difference was found between portal and peripheral gastrin concentrations in controls at 0, 60 and 90 min; no significant differences were found in cirrhotics. Our findings support the hypothesis of an at least partial breakdown of endogenous gastrin in the human liver.

Adult↗
PubMed1976

[Changes in plasma insulin and growth hormone after intravenous glucagon in hepatic cirrhosis].

Decreased increases in blood sugar by comparison with control subjects was noted in patients with cirrhosis of the liver after i.v. administration of 1 mg glucagon. Insulin secretion was similar to that observed in the controls. Basal GH values were higher in the liver patients, whereas after glucagon they displayed a gradual and progressive increase with a peak at 60'. No significant differences in GH pattern were noted in the two groups, however.

Adult↗
PubMed1976

[GH secretion after L-dopa administration in hepatic cirrhosis].

A 500 mg L-Dopa administration in normal and cirrhotic subjects does not determinate a significant varation of plasma glucose and insulin level, while a peak plasma GH level in both cirrhotic and normal subjects occurred at 90' with a significantly greates values in cirrhotics. It is doubtful to affirm that a high plasma GH level is the only one factor which responsable of glucose intolerance in cirrhotic subjects, when there are many others factors contribute to it in synergic way. In order to elucidate the hypothesis on possible pathogenetic mechanism it is discussed some of our own experience and observations.

Adult↗
PubMed1976

[Plasma insulin and GH during oral glucose load in liver cirrhosis].

Blood sugar, insulin and GH values were examined in two groups of cirrhosis of the liver patients, with and without ascites, after the administration of 100 g glucose per os. No significant differences between the two groups were observed. Insulin values were higher than those in the controls, with a pattern similar to that noted in subjects with chemical diabetes. GH values were higher than in normal subjects and secretion was not suppressed.

Adult↗
PubMedDate not supplied

Effect of somatostatin (SRIF) on plasma glucose and insulin response to glucagon in liver cirrhosis.

The present study was performed in order to evaluate the plasma glucose pattern in cirrhotic patients who, in the course of a continuous somatostatin infusion (500 microgram/h), were given pulses of glucagon (1 mg i.v.). In normal as well as in cirrhotic subjects somatostatin infusion provoked a marked reduction of the IRI plasma level and this was uninfluenced by subsequent glucagon administration. The rise in plasma glucose level in response to i.v. glucagon administration during somatostatin infusion was less marked in cirrhotics compared to normal subjects. This can be attributed to a variety of factors such as reduced number of liver cells or quantitative or qualitative changes of the liver cell glucagon receptors. Glucagon does not seem to contribute to the pathogenesis of carbohydrate intolerance in liver cirrhosis.

Adult↗
PubMedDate not supplied

[Analysis of growth, phenotype and cytotoxic activity of tumor infiltrating lymphocytes expanded in vitro with interleukin-2 and interleukin-4: preliminary results].

Tumor infiltrating lymphocytes (TIL) play an important role in the host immune response to cancer. When these cells are reinfused into cancer patients after in vitro expansion with lymphokines such as interleukin 2 (rIL-2), they often induce regression of tumor metastases. We obtained TIL of enzymatic digestion of 7 human solid tumors and then cultured them with rIL-2 and interleukin 4 (IL-4) at different concentrations for about 36 days. Immunophenotypic analysis was performed at the end of the second and fourth week; cytotoxic activity against autologous and heterologous targets was assessed on the 30th day of culture. The best lymphocytic growth was observed when we used rIL-2 and IL-4 for the first two weeks of culturing and then continued with rIL-2 alone. CD3 and CD56 cells formed the majority of TIL in all cultures. In 4 cases CD4 cells predominated at the initial stage of culturing, with CD8 cells gradually increasing and finally inverting the CD4/CD8 ratio. Autologous cytotoxicity (3/4 cases) appeared to be better in those patients in whom the CD4/CD8 ratio was inverted. These data enable identification of the combination of lymphokines that will will best provide expansion of live TIL active against tumoral cells. This procedure must be followed before in vivo reinfusion of expanded lymphocytes is carried out.

Adenocarcinoma↗