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Biomedical subjects

L Coppola

Publications and source records attributed to L Coppola.

At least 73 records · Page 4Linked to original sources
PubMed1982

A possible role of gamma-aminobutyric acid in the control of the endocrine pancreas.

This study examines the effect of baclofen, a specific gamma-aminobutyric acid analog which crosses the blood-brain barrier freely, upon insulin, glucagon, and GH responses to iv glucose in normal man. Normal subjects received two consecutive iv glucose tolerance tests (0.33 g/kg) before and after the acute oral administration of 5, or 10 or 20 mg baclofen, respectively, (10 subjects for each group). The dose of baclofen was divided and given 8 and 1 h before the performance of the posttreatment test. A fourth group of normal subjects served as placebo group (8 subjects). The highest dose of baclofen significantly increased insulin responses to glucose and raised basal glucagon levels (P less than 0.01). No significant change occurred with the other doses. Baclofen produced a dose-related increase in basal GH levels; a 10-fold increase was observed with the 20-mg dose. However, glucose-induced glucagon and GH suppression were not affected by baclofen. Despite the increased hormonal secretions, glucose tolerance did not change after baclofen. These results seem to indicate that gamma-aminobutyric acid may play a role in the neuroendocrine control of the pancreatic islets.

Administration, Oral↗
PubMed1981

Further studies on the significance of circulating platelet aggregates induced by somatostatin in man.

The aim of the present study was to further evaluate the significance of circulating platelet aggregates induced by somatostatin in insulin-dependent diabetic subjects. Eight insulin-dependent diabetics and eight normals were infused with somatostatin at increasing doses (250, 500, and 750 microgram/h), each dose for 30 min. In diabetics, somatostatin induced the appearance in blood of platelet aggregates in a dose-dependent fashion, the highest level being observed with the highest dose (750 microgram/h), p less than 0.005). In normals, circulating platelet aggregates were detected only with the infusion of the highest rate of somatostatin (p less than 0.025). This effect of somatostatin was reversible, since it tended to disappear 30 min after the infusion was stopped. In six additional insulin-dependent diabetics, a previous infusion of phentolamine (0.5 mg/min) completely prevented the appearance of platelet aggregates by somatostatin. No significant variation of the aggregation response to both ADP and collagen and the platelet count was seen in both experiments. Somatostatin, as expected, reduced the basal concentration of plasma glucose, glucagon, and C-peptide in both diabetics and normals. On the basis of these results, we suggest that somatostatin has some proaggregating capacity in vivo, probably by interacting with adrenergic mechanisms.

Adolescent↗
PubMed1981

Impaired insulin secretion in human diabetes mellitus. II. A possible role for prostaglandins.

Human diabetes mellitus is characterized by impaired insulin response to intravenous glucose. In search of possible endogenous factors which impair insulin release, we have investigated the effect of lysine acetylsalicylate (LAS), an inhibitor of endogenous prostaglandin (PGs) synthesis, upon insulin responses to glucose and arginine in subjects with type II (adult-on-set) diabetes mellitus. Acute insulin response to glucose (20 g) was significantly increased by LAS (response before LAS=26 +/- 10%; during LAS=77+15%, mean+/-SEM, mean change 3-10 min insulin, % basal, n=8, p 0.01), as well as second phase insulin secretion (before LAS=1437+/-316%; during LAS=3960+/-550%, change 10-60 min, uU/ml-min, % basal, p less than 0.01). This effect was associated with an increase in glucose disappearance rates (p less than 0.01). Acute insulin response to arginine (5 g iv) was also increased by LAS infusion. These results suggest that endogenous PGs may be one of the factors which impair insulin secretion in human diabetes.

Adult↗
PubMed1980

[Thromboelastographic patterns in patients suffering from chronic obstructive lung disease after hyperventilation].

In an our previous study we studied the influence of O2 therapy administration on the thromboelastographic pattern of patients suffering from chronic obstructive lung disease. We showed that basal hypocoagulability of our patients became normal after O2 administration. In this study we refer the thromboelastographic pattern observed in patients suffering from the same disease before and after hyperventilation. We don't find any changes about total coagulability either in patients or in healthy subjects after hyperventilation. Therefore we suggest that the absence of any changes is due to PCO2 and pH variations that occur at the same time of PO2 modification during hyperventilation; PCO2 and pH variations may influence the haemoglobin oxygen affinity and annul the effect of the increase PO2 on the tissue oxygenation. We suppose that the increase of patients suffering from chronic obstructive lung disease, is due to decreased fibrinolysis or to increased production of prostacycline induced by hyperventilation.

Adult↗
PubMed1980

Circulating platelet aggregates induced by somatostatin in insulin-dependent diabetic subjects.

The present study was undertaken to reevaluate the influence of somatostatin on platelet function in insulin-dependent diabetics and in normal subjects. In in vivo studies, nine insulin-requiring diabetics were infused with cyclic somatostatin (250 microgram/hour) for 120 minutes or with saline, in randomized order. This dose of somatostatin, sufficient to depress the basal concentrations of plasma glucose, glucagon and C-peptide, resulted in no significant change of platelet aggregation response to either ADP or collagen. By contrast, a progressive and significant reduction of platelet aggregation response to ADP was found during saline infusion. A similar pattern of response was seen in normal subjects. In all diabetics, but not in normals, somatostatin induced the appearance of circulating platelet aggregates. In in vitro studies, somatostatin augmented the aggregation response to epinephrine in both normals and diabetics. In conclusion, somatostatin counteracts the decrease of platelet aggregation response to ADP seen in saline studies, induces the appearance of platelet aggregates in diabetics and potentiates the aggregation response to epinephrine (in vitro) in both normals and diabetics. These actions of somatostatin suggest some aggregating capacity of the peptide in man.

Adolescent↗
PubMed1977

Cyanide insensitive oxidase in platelets of newborn infant.

The authors studied the behaviour of neonate platelet O2 consumption after the addition of pyridine nucleotide compared to adult controls. O2 consumption of neonate platelets after NADH addition was 103,2 millimicronmol O2/10(9)/hr (SE = 24,74) and in adult controls 188,8 millimicronmol O2/10(9)/hr (SE = 36,46). After the addition of NADPH O2 consumption was, respectively, 233,5 millimicronmol (SE = 46,29) and 218,3 millimicronmol (SE = 30,01).

Blood Platelets↗
PubMed1977

The effect of 2,3-diphosphoglycerate on oxygen consumption burst in thrombin-stimulated platelets.

2,3-Diphosphoglycerate (2,3-DPG) modifies platelet function; it diminishes aggregation and the release reaction. The hypothesis that this occurs through a modification of the intracellular level of cyclic AMP or through an alteration in the synthesis of prostaglandins has been proposed. Since the release reaction occurs simultaneously with a burst in the consumption of oxygen, the authors have studied the effect of 2,3-DPG on oxygen consumption after the addition of thrombin with or without the addition of substances which modify platelet metabolism (aspirin, theophylline, glucagon, etc.). It was observed that 2,3-DPG diminishes oxygen consumption induced by thrombin. This mechanism alters the platelet membrane function.

Adult↗
PubMedDate not supplied

Cefoperazone therapy of bacterial meningitis: a clinical trial.

Sixteen hospitalized patients, aged between 10 and 76 years (mean: 34.3 years), with bacterial meningitis were treated i.v. with cefoperazone at daily doses of 4.5 g to 9 g. In two cases ampicillin was given in combination with cefoperazone during the last four days and the first five days of treatment, respectively. The following organisms were isolated: Neisseria meningitidis (n = 9), Haemophilus influenzae (n = 3), Escherichia coli (n = 2), Streptococcus pneumoniae (n = 2). Fourteen patients completely recovered from infection and the pathogens were eradicated; the treatment failed in only two patients and both were cured with alternative treatment. Furthermore, in 11 patients cefoperazone serum and CSF levels were determined four times during the first week of treatment (1st, 3rd, 5th and 7th days). No important side effects were recorded.

Adolescent↗
PubMedDate not supplied

Fulminant hepatic failure caused by diffuse intrasinusoidal metastatic liver disease: a case report.

A 53-year-old woman experienced rapidly progressing liver failure four years after a quadrantectomy for a breast carcinoma. She had received adjuvant chemotherapy and radiotherapy, and second-line chemotherapy for bone metastasis one year earlier. The hepatic failure manifested with ascites, jaundice, elevation of serum bilirubin and hepatic enzyme levels and hypoalbuminemia. Imaging studies showed an enlarged liver without metastatic lesions. The patient died of hepatic decompensation within two weeks. Liver examination at autopsy revealed massive neoplastic infiltration consistent with a primary breast carcinoma. It is important to realize that this unusual pattern of liver metastasis cannot be demonstrated even with the most advanced techniques of instrumental diagnosis (CT scan, ultrasonography and magnetic resonance imaging), and should be taken into account in the differential diagnosis of rapidly progressing liver failure.

Autopsy↗