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Biomedical subjects

L Varga

Publications and source records attributed to L Varga.

At least 127 records · Page 7Linked to original sources
PubMed1984

Pancreatic glucagon secretion and exocrine function (BT-PABA test) in chronic pancreatitis.

Plasma concentrations of pancreatic glucagon, C-peptide, and pancreatic polypeptide were measured during arginine stimulation in 16 patients with chronic pancreatitis, in eight subjects with idiopathic diabetes mellitus, and in seven healthy controls. The hormone responses were compared with exocrine pancreatic function as assessed using the urinary excretion rate of p-aminobenzoic acid after oral ingestion of n-benzoyl-l-tyrosyl-p-aminobenzoic acid (BT-PABA). The increase in pancreatic glucagon levels during arginine stimulation was significantly reduced in patients with chronic pancreatitis compared to healthy controls, most markedly in those with secondary diabetes. In contrast, the glucagon response was unimpaired in patients with idiopathic diabetes. The arginine-induced increase in plasma glucagon and C-peptide concentrations correlated significantly with urinary PABA excretion in chronic pancreatitis (P less than 0.001, P less than 0.01, respectively). The responses of plasma C-peptide and pancreatic polypeptide separated pancreatitic and idiopathic diabetes less well. Thus, the glucagon response to arginine distinguished secondary diabetes due to chronic pancreatitis and idiopathic diabetes mellitus. The correlation between urinary PABA excretion and glucagon levels suggests that in chronic pancreatitis there is a parallel impairment of exocrine and endocrine function.

4-Aminobenzoic Acid↗
PubMed1984

Elemental analysis of samples of biological origin relative to their protein content by means of charged particle bombardment.

The particle-induced X-ray emission (PIXE) method and the 14N(d,p)15N nuclear reaction are combined for simultaneous trace element and nitrogen determination. Measurement of nitrogen content often allows the relating of the elemental concentrations determined by PIXE to the protein content of the sample. For the measurements only a small amount of sample material is needed; therefore, it is possible to keep track of the quantity of a certain element in the successive steps of a biomedical separation process. In about 10 min, trace element concentrations in the ppm range can be determined with a statistical accuracy of about 10%.

Cyanobacteria↗
PubMed1984

Effect of proglumide, a cholecystokinin receptor antagonist, on caerulein-stimulated pancreatic enzyme secretion and pancreatic polypeptide release in the dog.

In five conscious dogs we studied the effect of proglumide, a cholecystokinin (CCK) antagonist, on caerulein-stimulated pancreatic secretion and release of pancreatic polypeptide (PP). Graded doses of caerulein (15-240 ng/kg per h) were infused intravenously. Experiments were repeated with a fixed infusion of proglumide (40 mg/kg per h). Release of PP following increasing doses of caerulein was significantly inhibited by proglumide (P less than 0.01). However, proglumide did not significantly affect caerulein-stimulated pancreatic protein secretion. Proglumide might be useful in defining the physiological role of CCK.

Animals↗
PubMed1984

A two-center double-blind study of nomifensine, imipramine, and placebo in depressed geriatric outpatients.

Both nomifensine and imipramine were superior to placebo in a 4-week double-blind study involving 63 geriatric patients (greater than 60 years) with primary affective disorder-depression. Significant improvement in the active drug groups was demonstrated on the Hamilton Depression Rating Scale, Clinical Global Impressions, Brief Psychiatric Rating Scale, and Hopkins Symptom Check List. Analysis of laboratory and physical examination data, including ECGs, revealed no clinically significant changes associated with either drug. Compared to the imipramine group, nomifensine-treated patients showed a more rapid rate of improvement and a lower incidence of discomforting side effects.

Aged↗
PubMed1984

Sister chromatid exchange frequency in human lymphocytes exposed to ionizing radiation in vivo and in vitro.

This paper reports statistically significant elevations in peripheral blood lymphocyte sister chromatid exchange frequencies in persons occupationally exposed to low levels of ionizing radiation when compared with unexposed persons. Low doses of X or gamma rays administered in vitro also produce significant elevations in sister chromatid exchange frequencies, though the magnitude of the increases is dependent upon culture medium and other factors.

Adult↗
PubMed1983

Measurement of cholecystokinin octapeptide-induced motility of rat antrum, pylorus, and duodenum in vitro.

Motor effects of cholecystokinin octapeptide (CCK-OP) on rat antrum, pylorus, and duodenum have been studied in vitro under standard conditions. Intraluminal pressure changes were simultaneously measured at the three locations using a perfusion manometric system with a novel intraluminal pressure-sensor device. This device comprised an acrylic cast of the rat gastroduodenal tract containing the perfusion catheters that reached the surface of the cast with their outlets in the antrum, pylorus, and duodenum. A selective and sensitive intraluminal local pressure measurement was achieved with this pressure sensor due to its shape. CCK-OP increased base-line pressure in the antrum, pylorus, and duodenum; frequencies of phasic contractions in the antrum and pylorus; and amplitudes in the duodenum. The peptide also decreased contraction amplitudes in the antrum and pylorus and frequency of phasic contractions in the duodenum. It is concluded that the novel intraluminal pressure sensor is a useful tool for measuring local pressure changes in the gastroduodenal tract of the rat. In this experimental model, effects of CCK-OP on antral, pyloric, and duodenal base-line pressure are comparable with those observed in isolated muscle strips and in the intact organ of humans, dogs, and opossums. A different behavior, however, was observed in the force of antral and frequency of duodenal phasic contractions.

Animals↗
PubMed1983

Mechanism of action of cholecystokinin octapeptide on rat antrum, pylorus, and duodenum.

The mechanism of action of cholecystokinin octapeptide (CCK-OP) on tonic and phasic contraction of antral, pyloric, and duodenal smooth muscles was studied with a novel perfusion manometric system in isolated esophagogastroduodenal preparations of the rat. CCK-OP increased baseline pressure at each site, frequencies of phasic contractions in the antrum and pylorus, and amplitudes in the duodenum. It decreased antral and pyloric amplitudes and frequency of duodenal phasic contractions. CCK-OP action on tonic contraction was tetradotoxin (TTX) susceptible and its action on phasic contractions was TTX resistant. Phentolamine, phenoxybenzamine, propranolol, catecholamine depletion of preparations by reserpine-tetrabenazine, and the block of catecholamine synthesis at different levels significantly inhibited CCK-OP-induced tonic contraction, whereas atropine had no influence. Adrenergic and cholinergic neural actions on phasic contractions altered the level of amplitudes and frequencies on which CCK-OP action occurred. It is concluded that CCK-OP action on tonic contraction of the rat gastroduodenal junction is mediated by a neural noncholinergic pathway, whereas its effect on muscles responsible for phasic contractions is a direct one.

Animals↗
PubMed1983

Postnatal development of plasma prolactin level in premature infants with and without NaCl supplementation.

The role of prolactin in the adaptation of premature infants to the alterations of sodium balance was investigated by measuring plasma prolactin levels serially in 7 low birth weight, premature infants with (group I) and without (group II) NaCl supplementation. The study was performed on the 7th day and weekly thereafter until the 5th week of life. NaCl supplementation was given in a dose of 3-5 mEq/kg/day and 1.5-2.5 mEq/kg/day for 8-21 days and 22-35 days, respectively. It was demonstrated that before NaCl supplementation plasma prolactin concentration was similarly elevated in the two groups (6,490 +/- 1,291 mU/l in group I versus 7,661 +/- 1,094 mU/l in group II), and without supplementation it remained at about the same level throughout the study. When supplemental sodium was given, the plasma prolactin level declined with age at a steady rate to the mean value of 3,516 +/- 502 mU/l by the end of 5th week. In the 3rd-5th weeks it proved to be significantly higher in group II than in group I. It is concluded that physiological sodium depletion may account for the prolonged hyperprolactinemia and prolactin might have some importance in the control of sodium homeostasis in low birth weight, premature infants.

Age Factors↗
PubMed1983

Antinuclear factor, smooth and striated muscle antibodies in Duchenne-type muscular dystrophy.

Antinuclear factors and antibodies to smooth and striated muscle were studied by the indirect immune fluorescence method in the sera of 19 children suffering from progressive muscular dystrophy. In 47% of the patients antinuclear factor positivity, in 65% anti smooth muscle antibody positivity, and in 26% antistriated muscle antibody positivity was found. Antibody to striated muscle was present in patients with serious advanced dystrophy and in patients unable to walk, while anti-smooth muscle antibody occurred in less serious cases, too. On the basis of the results, it is concluded that in genetically determined progressive muscular dystrophy a secondary autoimmune process develops owing to the degeneration of muscles as the disease progresses.

Adolescent↗