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Biomedical subjects

A V Greco

Publications and source records attributed to A V Greco.

At least 181 records · Page 10Linked to original sources
PubMed1982

Lipid composition in jaundiced rat liver by radio-thin-layer chromatography and photodensitometry.

In vitro hepatic synthesis of lipids starting from (1-14C)acetate was investigated for 14 days in rats with biliary obstruction by ligation of the common bile duct using radio-thin-layer chromatography (radio-TLC). This study was correlated with a quantitative assay of the various hepatic lipids using TLC correlated with photodensitometry. Hepatic total lipid synthesis increased progressively with time. With concern to the single fractions, the major modifications were verified on the 3rd day with a decreased incorporation of the labelled acetate into the triglycerides. On the other hand, using photodensitometry, they demonstrated a percentage increase. These variations can be justified by the presence of a feedback mechanism. The syntheses of cholesterol and the other fractions were maximum during this period. Histologic examination revealed, especially on the 3rd day, a neoformation of biliary ductules and on the 14th day, a regression of these histological changes.

Acetates↗
PubMed1982

Effect of somatostatin on lower esophageal sphincter (les) pressure and serum gastrin in normal and achalasic subjects.

Serum gastrin and lower esophageal sphincter (LES) responses to somatostatin infusion were evaluated in ten normal subjects and in nine achalasic patients in order to determine evidence of hormonal (presumably gastrin)control of LES pressure. After somatostatin infusion, a significant decrease of serum gastrin was observed in normal subjects at 30 min (81.6 +/- 3.2 versus 40.0 +/- 4.7 pg/ml; p less than 0.01) and a rapid increase of LES pressure was also observed (26.0 +/- 1.3 versus 34.1 +/- 1.6 mmHg; p less than 0.01). In achalasia no change was observed in serum gastrin concentration after somatostatin infusion. LES pressure at 20 min however significantly decreased (45.8 +/- 7.6 versus 31.6 +/- 2.3 mmHg; p less than 0.05). Endogenous gastrin is not a major control factor for LES pressure in either normal or achalasic subjects.

Adult↗
PubMed1982

In vitro study of liver slices lipid 1-14C-acetate incorporation in hyperlipoproteinemic subjects.

The aim of the present study is to determine the "in vitro" rate of 1-14C-acetate incorporation into lipids in human liver slices from patients with various types of hyperlipoproteinemia. Hepatic tissue from type IIa hyperlipemic patients incorporated labelled acetate into free cholesterol at a higher rate than normolipidemic patients. In type IIb patients the incorporation was increased into hepatic free cholesterol, triglycerides and FFA. The liver of pre-beta hyperlipoproteinemic subjects incorporated 1-14C-acetate into triglycerides to a greater extent than hepatic tissue from controls. Triglyceride synthesis was highly elevated in type IV hyperlipoproteinemic patients with diabetes. In all cases, there was no significant correlation between increased hepatic triglyceride synthesis (dpm/mg of extracted lipids) and insulin response (microunits/ml) to oral glucose ingestion (75 g). The present data indicates that in the presence of disturbances in lipid and carbohydrate metabolism one observes an alteration of lipid synthesis in the liver. The in vitro incorporation of 1-14C-acetate into hepatic cholesterol and/or triglyceride in patients with primary hyperlipoproteinemia is increased. Thus the elevated serum cholesterol and triglyceride levels of these patients could be explained on the basis of an increased lipoprotein synthesis in the liver.

Acetates↗
PubMed1982

Inotropic and electrophysiological effects of tolbutamide in normal subjects.

The acute cardiac effects of tolbutamide on myocardial contractility, evaluated with systolic time intervals (ST), and on the atrio-ventricular conduction system have been studied in a group of five volunteer normal subjects. The intravenous administration of 1 g of tolbutamide showed no considerable changes of STI and of electrophysiologic parameters. Glycemia decreased whereas there was a statistically significant increase in plasmatic levels of catecholamines at the 10th and 20th min. Our findings suggest that the intravenous administration of tolbutamide has no effect either on the atrio-ventricular conduction system or on myocardial contractility in normal men.

Adult↗
PubMed1981

Bile acid content of gallbladder bile and stones in type IIb and IV hyperlipoproteinemia.

We examined the bile acid composition of gallbladder bile using reversed-phase high performance liquid chromatography (HPLC), in normolipemic and hyperlipidemic (types IIb and IV) patients with cholelithiasis and compared them with normal subjects. Similarly, bile acid composition was determined n the gallstones of these patients. No free bile acids were found in any of the samples examined. We observed that gallbladder bile and gallstones of patients with type IV hyperlipidemia showed a significant increase in the percentage of glyco-conjugated bile acids and reduction in taurine conjugates. Based on this finding we postulate that in addition to biliary lipid composition bile acid composition may also play a role in the pathogenesis of cholesterol gallstone formation.

Adult↗
PubMed1981

[Ehler-Danlos syndrome (type V) with urethra bifida and polydactyly: an unusual combination].

Ehlers-Danlos syndrome is currently regarded as a connective tissue dysplasia. Its genetic, biochemical, histological and clinical features are described, together with a personal case in a patient who presented the fundamental symptoms, plus polydactyly and bifid urethra. This association had not been hitherto reported in the literature. The case itself is classed as Ehlers-Danlos syndrome type V.

Abnormalities, Multiple↗
PubMed1981

[Lactic acidosis associated with fenformin therapy].

Irreversible lactic acidosis occurred in two phenformin-treated diabetics. In the first case, blood creatinine was 3 mg % ml, arterial blood pH was 7,12 and ketostix was negative; in the second case, blood creatinine was 1,3 mg% ml, arterial blood pH was 7,22 and ketostix was negative. Diabetic patients to be treated with phenformin must always be carefully selected and this treatment should be reserved for cases where there is a precise indication. Lactic acidosis may occur even in the presence of almost normal serum creatinine concentrations.

Acidosis↗
PubMed1981

"In vitro" study of liver slices lipid (1-14C) acetate incorporation in experimental diabetes.

The effect of insulin deficiency on lipid synthesis in the liver of normal rats, diabetic rats by alloxan and pancreatectomized rats was studied in vitro using (1-14C) acetate as lipid precursor. Insulin deficiency induces an increased incorporation of (1-14C) acetate into triglycerides in rat liver. This is particularly evident in pancreatectomized rats with respect to alloxan diabetic rats. It is concluded that in experimental diabetes an atherogenous metabolic pattern is elaborated by the liver.

Acetates↗
PubMed1981

Comparative effects of chenodeoxycholic acid and ursodeoxycholic acid on lipid synthesis in rat liver.

Chenodeoxycholic and ursodeoxycholic acids reduce significantly the hepatic synthesis of lipids in rats. The present study has been carried out using (1-14C)acetate and evaluating its incorporation into different lipidic fractions of the liver by thin-layer radiochromatography. Ursodeoxycholic acid proved to be more active than chenodeoxycholic acid: in addition to a significant decrease of the hepatic incorporation of the acetate into cholesterol and triglycerides an increase of the hepatic incorporation of the acetate into phospholipids has been observed. The exogenous administration of bile acids diminishes the hepatic synthesis of cholesterol and therefore its biliary excretion; it enriches the bile acid and phospholipid pool in the liver and bile. By this way the action of bile acids establishes in the liver a condition which induces such an increase of availability of mixed micelles in the bile as to make it unsaturated in cholesterol.

Animals↗
PubMed1981

Somatostatin and insulin infusion in the management of diabetic ketoacidosis.

The effect of low-dose insulin infusion (4.8 U/h) in diabetic ketoacidosis was compared to that of low-dose insulin infusion (4.8 U/h) plus somatostatin (500 microgram/h IV). Treatment with insulin only in 20 patients caused normalization of blood glucose levels within 6 hours and resolution of ketoacidosis within 5 hours. During insulin plus somatostatin infusion in 7 patients, blood glucose levels returned to normal within 4 hours and acidosis was reduced within 3 hours. Correction of acidosis is the most important problem in diabetic ketoacidosis: in the severest cases cardiovascular and cerebral complications may ensue. The data presented show that addition of somatostatin to treatment with low doses of insulin reduces and resolves acidosis in a shorter time while plasma levels of glucagon and GH were concomitantly reduced.

Blood Glucose↗
PubMed1981

Transient effect of glucocorticoids on red blood cell insulin receptors.

The effect of oral administration of dexamethasone or cortisone on circulating red blood cell (RBC) insulin receptors was evaluated in normal males before treatment and 24 h (day 1), 48 h (day 2) and 72 h (day 3) after the commencement of steroid administration. Dexamethasone induced a slight significant decrease of insulin binding (p less than 0.05) on days 1 and 3, whereas cortisone did not. Cortisone, on the other hand, produced transient reduction (i.e. insulin binding lower than mean -2 SD of control values) in six subjects out of eight on days 1, 2 or 3 varying from subject to subject. Binding impairment was due mainly to reduced receptor affinity, even if slight reduction of receptor concentration was detectable. Qualitatively the present data agree that impaired insulin binding is due mainly to reduced receptor affinity; however, the effect of steroids on RBC is not significant and persistent as that on monocytes. The less marked effect of dexamethasone and cortisone on RBC versus monocytes indicates that receptor modifications may be tissue specific.

Cortisone↗
PubMed1981

Changes in insulin receptors during oral contraception.

Combined estrogen/progestagen oral contraceptives (OC) have been reported to be associated with a deterioration of glucose tolerance and a decrease in insulin sensitivity; thus, since it has been suggested that steroids affect insulin receptor properties, the influence of OC on insulin receptors was investigated. The study groups were composed of nine normal menstruating women (controls), nine pill users, and two healthy women on OC for the first time. Insulin receptors on monocytes were evaluated at 7-day intervals during the 28 days between menses. Insulin receptor concentration and/or affinity did not show any variation in pill users during the test period and did not differ from values observed in controls in the luteal phase; consequently, the insulin receptor concentration in pill users is lower than that during the follicular phase or in men. The physiological variation of insulin receptor concentration and the increase of receptor affinity in the midfollicular phase, which characterize the normal menstrual cycle, are therefore abolished by OC. This effect occurs rapidly because it was also evident in the two women on OC for the first time. No difference was observed in fasting blood glucose and serum immunoreactive insulin concentrations between control subjects and pill users. The present data appear to confirm that sex steroids affect the insulin receptor and lend further support to the concept that caution must be used in clinical studies of insulin receptors when women are included. In addition, the results suggest that insulin receptors may play a role in the glucose intolerance and insulin insensitivity which have been described in pill users.

Adult↗
PubMed1981

Prolactin release in liver cirrhosis with impaired glucose tolerance (IGT).

The effects of acute TRH and cimetidine administration on the plasma prolactin (PRL) response have been studied in cirrhotic patients with impaired glucose tolerance (IGT). I v. TRH administration stimulates PRL release both in cirrhotics and controls; i.v. cimetidine did not induced a significant rise of PRL in liver cirrhosis. Present findings demonstrate that PRL is not responsible for the deterioration of glucose handling in alcoholic cirrhotic patients examined.

Adult↗