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Biomedical subjects

G Varga

Publications and source records attributed to G Varga.

At least 127 records · Page 7Linked to original sources
PubMed1987

Bombesin promotes pancreatic growth in suckling rats.

UNLABELLED: The pancreatic growth promoting effect of long term administration of bombesin was investigated in suckling rats. The authors showed that bombesin given in 10 micrograms/kg b.wt doses s.c. every 8 h for 10 days from the day of parturition stimulated pancreatic growth: it increased pancreatic weight, protein and DNA content, trypsin and amylase activity and trypsin/DNA ratio. CONCLUSION: Bombesin is an effective stimulator of pancreatic growth in suckling rats.

Aging↗
PubMed1987

Caerulein stimulates pancreatic growth and somatic growth in suckling rats.

This study deals with the stimulatory effect of caerulein on pancreatic and somatic growth in CFY suckling rats before weaning. After birth, caerulein (0.25, 0.5, 1, 3, 10 and 30 micrograms/kg) was given subcutaneously (s.c.) 3 times daily for 10 days. Saline-treated newborn rats were used as control. Caerulein increased pancreatic weight and total pancreatic trypsin activity reaching the maximum at 1 microgram/kg dose; higher doses did not cause higher values. On this basis 1 microgram/kg caerulein was applied s.c. 3 times daily for 3, 5, 10 and 20 days. At the end of the treatment pancreatic weight, total pancreatic protein, DNA content, trypsin and amylase activity was measured. Increases in body weight due to caerulein treatment were found from 6 days of treatment. Caerulein treatment increased pancreatic weight, total pancreatic DNA and protein content, and trypsin and amylase activity when applied for 5, 10 and 20 days. Treatment for 3, 5, 10 and 20 days with caerulein preferentially increased pancreatic trypsin activity compared to amylase activity. Trypsin activity per mg DNA increased with time in each caerulein-treated group demonstrating that the effect of caerulein increases with duration of treatment. In the saline-treated control group, however, pronounced increase in pancreatic amylase activity compared to that of trypsin activity was found in the age between days 11 and 21. This may be explained by the observation that the plasma corticosterone level increased during this period of postnatal life. The effect of caerulein in promoting pancreatic and somatic growth of suckling rats before weaning may be attributed to a specific enhancing effect of the peptide on proteolytic (e.g. trypsin) enzyme production of the pancreas.

Amylases↗
PubMed1987

Different types of nerve profile in the wall of the canine hepatic artery: an electron microscopic study.

The fine structure of the hepatic artery of dogs was studied at electron microscopic level. The majority of nerve fibres innervating the artery was found at the adventitial-medial border of the vessel, but some of them entered the middle part of the media. The average distance of nerve to muscle fibre was found to measure 450 nm. Three types of nerve profile could be observed, viz. adrenergic, cholinergic and cholinergic-peptidergic as suggested by the morphology of their vesicles. It is suggested that the cholinergic and cholinergic-peptidergic nerve endings probably modulate the release and the constrictor effect of the main neurotransmitter noradrenaline in the hepatic artery.

Adrenergic Fibers↗
PubMed1987

PGI2 and PGE1 induce morphological alterations in human platelets similar to those of the initial phase of activation.

The effects of PGI2 and PGE1 on the ultrastructure of human platelets were studied by scanning (SEM) and transmission (TEM) electron microscopy in relation to the record of an optical aggregometer. Addition of PGI2 or PGE1 to citrated platelet-rich plasma (C-PRP) resulted in a permanent slight decrease in percent light transmission (%T) recorded by the aggregometer. SEM investigation of the platelets showed marginal pseudopods and occasional large stomata after application of prostaglandins. These alterations occurred within the initial 30 s and remained constant during the subsequent 20 min of incubation. TEM studies revealed morphological changes of alpha granules and moderately electron-dense material in the dilated profiles of the surface-connected canalicular system (SCCS). Addition of 10 microM ADP to C-PRP preincubated for 30 s with either 2 ng/ml (5 nmol/liter) PGI2 or 30 ng/ml (85 nmol/liter) PGE1 resulted in a further decrease of %T followed by a slight increase. The alterations of the aggregometer tracing were characterized in SEM by platelet shape change and the generation of primary aggregates. C-PRP samples preincubated with 3 and 9 ng/ml (8 nmol/liter and 24 nmol/liter) PGI2 or 40 and 120 ng/ml (113 nmol/liter and 338 nmol/liter) PGE1 did not produce additional changes in the aggregometer curves or in the ultrastructure of platelets in response to ADP. Our morphological study indicates that antiaggregatory prostaglandins induce an early phase of platelet activation but inhibit "shape change" and the formation of aggregates.

Adenosine Diphosphate↗
PubMed1987

Pancreatic and intestinal growth-promoting effect of truncal vagotomy in the rat.

The effect of chronic subdiaphragmatic truncal vagotomy was investigated on body weight gain, food intake pattern, and also on intestinal and pancreatic growth, in adult rats. Two sham-operated groups, the one fed ad libitum, the other pair-fed with the vagotomized rats, served as controls. Body weight of vagotomized rats decreased in the first 5 postoperative days, due to hypophagia. Then, body weight increased as food intake reached the presurgery level. The rats were killed after 34 days of vagotomy. A moderate pancreatic and intestinal hypertrophy was observed in the vagotomized rats, while the tissue weight of and the DNA and protein contents in the colon and the oxyntic and antral areas of the stomach did not change compared to controls. The mechanism of the intestinal and pancreatic hypertrophy is unknown; several humoral and nervous factors may be involved in it.

Animals↗
PubMed1986

Vasoactive intestinal peptide may participate in the vasodilation of the dog hepatic artery.

The possible direct action of vasoactive intestinal peptide (VIP) on dog hepatic arterial wall or on the noradrenergic innervation of the artery was investigated in vitro. In addition, VIP-containing nerve fibers and terminals were located in the wall of the artery with immunochemical staining. Direct evidence showed that VIP did not affect the release of [3H]norepinephrine but reduced the response of the isolated hepatic artery to electrical field stimulation and exogenous norepinephrine. This suggests that the effect of VIP is postjunctional on the smooth muscle of the artery. VIP-containing nerve fibers and varicosities were observed in the adventitial and medial layer of the arterial wall. These findings strongly support the hypothesis that vasoactive intestinal peptide is a physiological mediator of vasodilation in the hepatic artery.

Animals↗
PubMed1986

Prognostic factors in dysmyelopoietic syndromes.

Dysmyelopoietic syndromes are characterized by cytopenia in peripheral blood and marrow maturation abnormalities. The condition has been studied in 33 patients with regard to the initial haematologic picture. A certain number of variables of prognostic value was observed: excess of marrow blasts, pancytopenia, and decreased growth of bone marrow cells in agar culture. The length of survival and the percentage of leukaemic transformation were different in patients with refractory anaemia and refractory anaemia with an excess of blasts.

Granulocytes↗
PubMed1985

[The role of splenectomy in the treatment of lymphomas of low malignancy].

The effect of splenectomy was studied in 30 patients with non-Hodgkin lymphoma of low malignancy. Severe bacterial infections occurred in 9 patients. Follow-up of the total group of 72 patients-years revealed one infection requiring hospitalization per eight patient-years. With chronic lymphatic leukaemia there was no difference in the incidence of severe infection between splenectomized and non-splenectomized patients. In 12 patients the splenectomy produced favourable results in that in some (8) cytostatic treatment was no longer required, while in others (4) the dose of cytostatic drugs could be reduced after several months without any medication. Survival rate was not influenced by splenectomy.

Adult↗
PubMed1985

Inhibition of pancreatic secretory and trophic response to caerulein by the H2-receptor antagonist ranitidine in the rat.

The effect of ranitidine (20 mg . kg-1) and cimetidine (50 mg . kg-1) on pancreatic secretory and trophic responses to caerulein (1 microgram . kg-1) was studied in the rat. Ranitidine or cimetidine were administered alone or combined with caerulein twice a day for 7 days. Saline-treated rats were used as controls. At the end of treatment animals were anesthetized and pancreatic juice was collected for 1 h after intravenous secretin plus CCK-PZ (8 U . kg-1). Afterwards rats were sacrificed and growth and composition of pancreatic tissue were determined. Compared with control (saline) values, volume of pancreatic juice and output of trypsin and amylase were increased by treatment with caerulein. Ranitidine, when given combined with caerulein, completely abolished the secretory response induced by the peptide, whereas it was totally ineffective when given alone. Cimetidine (alone or combined with caerulein) was always ineffective. Caerulein increased pancreatic weight, total pancreatic trypsin, amylase and RNA content. Here again ranitidine, combined with caerulein, abolished almost completely the trophic effect of caerulein on the pancreas, but when given alone it did not influence pancreatic growth and composition. Also in this case, cimetidine was completely inactive. These results suggest that ranitidine affects exocrine pancreas with an action independent of the H2-receptor blockade.

Amylases↗
PubMed1985

[In vitro study of bone marrow from leukemia patients and patients without hematologic disease].

The bone-marrow of 26 patients not affected with hematological diseases and 10 patients with untreated leukemia was investigated according to Dexter in long-term cultures. Survival time and cell content of those long-term cultures started with normal bone marrow were not influenced significantly, if reinoculation was made with autologeneic or allogeneic bone marrow. Even without repeated inoculation, leukemic cells grew for a longer time in long-term cultures than normal bone marrow cells. As far as the outcome of the disease is concerned, no conclusion can be drawn from the duration of cultivating leukemic cells growth.

Adult↗
PubMed1984

Ranitidine inhibits the trophic effect of caerulein on the pancreas in rats (preliminary data).

The aim of this study was to establish whether ranitidine treatment influences the trophic effect of caerulein on the pancreas of rats. Ranitidine (20 mg/kg b.w.), caerulein (1 microgram/kg b.w.) were applied for 7 days alone, or combined with caerulein, given intraperitoneally twice a day. Saline treated rats served as control. Caerulein increased pancreatic weight, total pancreatic protein, trypsin, amylase and RNA contents. Ranitidine when given alone did not influence pancreatic growth and composition. When ranitidine, however, was combined with caerulein, it abolished the trophic effect of caerulein on the pancreas. The trophic effect of caerulein on rat pancreas could be abolished by H2-receptor antagonist (ranitidine) treatment. The authors suggest that the drug exerts its inhibitory effect on the acinar cells directly.

Amylases↗