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Biomedical subjects

J Nagy

Publications and source records attributed to J Nagy.

At least 109 records · Page 6Linked to original sources

HPLC-purified bovine satietin suppresses food intake and weight without causing conditioned taste aversion.

Satietin (SAT) is a putative satiety agent found in a variety of species including man and the rat. In the present study, satietin was extracted from bovine plasma (b-SAT) and further high-pressure liquid chromatography (HPLC)-purified. Rats were given chronic third ventricle cannulas and patency was verified. In experiment 1, rats were divided into three groups and ICV infused with artificial cerebrospinal fluid (a-CSF) or b-SAT: group 1, a-CSF (n = 11); group 2, 20 micrograms/rat, b-SAT (n = 11); and group 3, 40 micrograms/rat, b-SAT (n = 9). Infusions were repeated thrice three days apart. Compared to a-CSF, the high b-SAT dose suppressed food intake for 24-h after each successive infusion. The low dose significantly decreased food intake only after the first infusion. Water intake was suppressed only after the first injection of the high dose. Body weight was decreased after the first and second infusions of both doses and following the third infusion of the high dose. In experiment 2, rats were trained to drink fluid for 1 h/day while food was ad lib. On day 1, both groups received no infusions and were given tap water. On day 2, the groups were ICV infused with a-CSF, but group 1 (n = 12) was given banana-flavored fluid (BFF) and group 2 (n = 12) almond-flavored fluid (AFF). On day 3, group 1 was again a-CSF-infused but given AFF, whereas group 2 received 40 micrograms/rat b-SAT and was given BFF.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗

Purification of the anorectic agent satietin from bovine serum.

Purification and properties of an endogenous anorexigenic substance extracted from the bovine serum has recently been reported. The semipurified and HPLC-purified substances have shown similar biological effect in ad lib-fed or fasted rats, as was found in the case of human satietin. This substance purified from bovine serum or plasma suppressed food intake following intracerebroventricular (ICV) or peripheral administration in rats. A similar purification procedure as was used for the preparation of human serum satietin resulted in semipurified bovine material. This preparation was further purified by HPLC reversed-phase column and yielded two peaks (peak 1 and peak 2). The retention time of peak 2 revealed by HPLC (peak addition method) and the molecular weight measurements carried out by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE) and high performance size-exclusion chromatography (SE-HPLC) proved that peak 2 contains bovine serum albumin mostly. Rats were injected with 20 micrograms/rat of peak 1 and peak 2. Peak 1 can be considered as a putative satiety agent. Preliminary chemical and biochemical studies showed that the semipurified active agent contained 20-22% protein, 28-30% lipids, and an undetermined amount of carbohydrate. The molecular size of anorectic bovine serum preparation was 38-40 kDa, determined by means of SE-HPLC and SDS-PAGE. Based upon the similarity of chemical and biological nature to human serum satietin we named this new material bovine serum satietin (BS-SAT).

Amino Acids↗

Ethanol-induced signal transducing mechanism associated with a transient antiviral state in human amniotic cells.

Short-term effects of ethanol on human amnion cells were investigated by studying the cellular signaling processes and the replication of vesicular stomatitis virus. Treatment of human amniotic cells with ethanol transiently triggers the breakdown of inositol phospholipids, stimulates intracellular [Ca2+]i mobilization and activates the translocation of protein kinase C. Activation of this signal transduction mechanism is associated with the development of an antiviral state, as proven by studying 3H-uridine incorporation into the RNA of vesicular stomatitis virus. Induction of the antiviral state in human amniotic cells correlates with the solubility of the alcohols in the lipid membrane of the cells.

Amnion↗

[Experience with routine use of combined inhalation-perfusion lung scintigraphy. The most reliable diagnosis of pulmonary embolism].

The authors performed combined inhalation/perfusion scintigraphy in 217 patients with suspected pulmonary embolism in order to improve the diagnostic accuracy. Before the conventional perfusion study they also visualized the distribution of ventilation with a Venticis-II inhalator equipment. Regarding pulmonary embolism 10 (5%), 96 (44%), 39 (18%) investigations were "very low", "low", and "high probability", respectively. The inhalation study was successful in 93 percent of patients. These results were necessary in 141 patients. However, it was uncertain in 26% of cases (57 patients) concerning the diagnosis of pulmonary embolism. As the inhalation scintigraphy was applied without preselection, this study was unnecessary in 30%. On the other hand, if the combined studies had been performed only in the cases of previously proved segmental perfusion defects, the number of perfusion scintigraphies would have increased by 65%. The authors recommend the routine use of the inhalation lung scintigraphy.

Bronchial Provocation Tests↗

Increased intracellular calcium level in peripheral blood mononuclear cells of alcoholic patients under withdrawal.

Cytosolic free Ca2+ functions as a main regulator of numerous cellular processes, including those implicated in synthesis, release and responsiveness of hormones and neurotransmitters are discussed. To examine whether a change in the intracellular free calcium ion concentration [Ca2+]i occurs associated with delirium tremens and related states we compared [Ca2+]i in peripheral blood mononuclear cells (PBMC) of alcoholic patients under withdrawal with that of non-alcoholic patients and of healthy controls. [Ca2+]i in PBMC of alcoholic patients was significantly higher (P < 0.001) compared to both control groups, suggesting that changes in [Ca2+]i may be relevant to increased excitability of the central nervous system. Increased [Ca2+]i in PBMC might be diagnostically valuable as a biological marker of alcohol dependency.

Adult↗

Hypercholesterolemia promotes endothelial dysfunction in vitamin E- and selenium-deficient rats.

Abnormal regulation of local vascular tone occurs early in human and experimental atherosclerosis. Impaired endothelium-dependent vascular relaxations mediated by endothelium-derived relaxing factor are an important contributor to these abnormalities. Endothelium-derived relaxing factor is nitric oxide released as such or attached to a carrier molecule. Oxidized lipoproteins impede endothelium-derived relaxing factor-mediated responses in vitro. We designed in vivo experiments to determine whether hypercholesterolemia with and without deficiency of two endogenous lipid antioxidants, vitamin E and selenium, would result in endothelial dysfunction. Vitamin E and selenium deficiencies were induced in a group of hypertension-prone Dahl salt-sensitive rats fed a diet high in cholesterol (4%) but low in NaCl (0.5%) for 18 weeks. Two other groups of Dahl salt-sensitive rats received diets sufficient in vitamin E and selenium but containing either high or normal cholesterol levels (control group). Serum cholesterol levels increased approximately 10-fold in the two groups of rats fed high-cholesterol diets. Systolic blood pressure was 143 +/- 3 mm Hg in high-cholesterol/vitamin E- and selenium-sufficient rats and 142 +/- 5 mm Hg in high-cholesterol/vitamin E- and selenium-deficient rats (P = NS). Mild intimal thickening and occasional mononuclear cell infiltration were observed in both of these groups. Serum vitamin E levels were decreased, whereas serum thiobarbituric acid-reactive substances and exhaled pentane (two indicators of endogenous lipid oxidation) were significantly increased in high-cholesterol/vitamin E- and selenium-deficient rats compared with high-cholesterol/vitamin E- and selenium-sufficient rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

[The thinning of the glomerular basal membrane in IgA glomerulonephritis].

Ultrastructural changes of the glomerular basement membrane (GBM) in 34 patients with IgA nephritis and their possible correlation with the main clinical symptoms were examined. In 23 patients thinner than normal GBM segments were found with a mean thickness of 116-120 nm (measured by the method of Osawa). Often foot process fusion but neither disruption nor deposition of immune complexes was seen in the affected capillaries. All patients had hematuria, while those with thin GBM segments had more severe hematuria and more episodes of macrohematuria. Other clinical features were unrelated to ultrastructural changes. It is suggested that the thin GBM may be a predisposing factor to hematuria.

Adult↗

[Surgical cerclage in the treatment of cervical incompetence during pregnancy (determining the legitimacy of the procedure)].

The authors studied the effectiveness of the cervical cerclage operation in the therapy of cervical insufficiency during the pregnancy. Two Hundred sixteen pregnant women took part in this trial in whose pregnancy the necessity of cerclage operation was not unequivocal. It means, that the therapeutical cerclage operation was not necessary, but the necessity of prophylactic cerclage operation was doubtful as well. From the randomized 216 cases they performed cerclage operation in 108 pregnancies and in 108 cases they did not perform it. In the respect of pregnancy care they did not make any difference between the two groups. The authors from their trial draw the conclusion, that in doubtful cases where the necessity of cervical cerclage operation is not unequivocal--e.g. at serious gestational case history--it is advisable to perform the operation. The danger of premature birth can be diminished in this way.

Female↗

[Long-term phenytoin (Diphedan) therapy leading to IgA nephropathy].

A single case of IgA nephropathy with a concomitant tubulointerstitial nephritis, developing during a long-term phenytoin therapy is reported. The prolonged phenytoin therapy did neither prevent the transitional increases of serum IgA level nor ward off deterioration of the histological alterations. This case suggests that acute tubulointerstitial nephritis may have played a role in the mesangial trapping of IgA immunocomplexes.

Adult↗

[Questions concerning transhepatic gallbladder puncture].

Development and spread of several diagnostic and therapeutic procedures focuses the radiologists' attention on the percutaneous gall-bladder puncture. Percutaneous rapid gall-stone dissolution is one of these important questions. Authors studied the anatomical situation of the liver and gall-bladder regarding the possibilities of the percutaneous gall-bladder puncture. Authors have concluded that the transhepatic approach is possible in every case. The extra-peritoneal approach cannot be avoided. On the basis of the results lateral direction of puncture on the so-called one-stick-introduces system is recommended by the authors.

Cholangiography↗

[Antinuclear antibodies in IgA nephropathy, as well as mesangiocapillary and membranous glomerulonephritis].

IgA nephropathy, assumed to be a form of chronic immune complex glomerulonephritis, has sometimes been associated with various autoimmune diseases and autoimmune phenomena including autoantibody production. The present study was aimed at thoroughly investigating the frequency of autoantibodies against five common nuclear autoantigens in 59 patients with IgA nephropathy and in 48 patients with other immune complex glomerulonephritides (24 patients with membranous and 24 with mesangio-capillary glomerulonephritis) and in 30 healthy controls. The incidence of raised autoantibody titres (greater than or equal to 2 SD of the average of controls) in IgA NP was not found to be significantly different from the incidence of other immune complex glomerulonephritis groups. In none of the subjects was a titer above 3 SD of the average of controls found. Although IgA NP is thought to be an immune mediated disease, on the basis of our study it is not associated with a statistically significant incidence of raised antinuclear antibodies.

Antibodies, Antinuclear↗

Evidence that the interaction between circulating IgA and fibronectin is a normal process enhanced in primary IgA nephropathy.

A solid-phase ELISA was set up to measure the direct binding capacity (BC) of different, commercially available, purified human IgA preparations to plates coated with human fibronectin (FN). It was found that secretory, polymeric, and, to a much lesser extent, monomeric IgA exhibited elevated FN-BC as compared to their BC to plates coated with bovine serum albumin. This binding was specific since not observed with human IgG or IgM antibodies. In addition, we noted that this interaction was dose dependent, Ca2+ dependent, saturable, and not covalent, was inhibited by soluble FN, but not by a prior incubation of FN-coated plates with anti-human fibronectin antibodies, and appeared to involve on the dimeric FN other structures than its heparin-binding, collagen-binding, or C1q-binding domains. Similar experiments conducted with normal plasma indicated that plasma IgA, but not plasma IgG or IgM, was also capable of significant binding to FN-coated plates. In contrast, serum IgA did not significantly bind to those plates under otherwise identical experimental conditions. Thus, the coagulation process induces a strong decrease in the FN-BC of circulating IgA, which implies the necessity of using plasma rather than serum to study such interactions. The apparent molecular weight of plasma IgA interacting with FN-coated plates ranged between 450 and 900 kd, and its major binding characteristics were quite similar to those observed with purified polymeric IgA. The FN-BC of plasma IgA was then measured by the same ELISA in 30 patients with primary IgA nephropathy (IgAN) and in 23 healthy controls. The mean FN-BC of plasma IgA was significantly higher in patients than in normal controls. This enhancement was due mainly to the augmentation in the concentration of circulating "macromolecular" IgA and was significantly correlated with the plasma levels of IgA-FN complexes. However, the pathogenetic role of these findings was probably not determinant since similar observations were made in alcoholic liver cirrhosis without urinary abnormalities and since the FN-BC of plasma IgA or the plasma levels of IgA-FN complexes were not correlated with the various biological parameters of evolutivity of primary IgAN. In conclusion, these studies suggest that the ability of polymeric IgA to directly bind to FN is involved in the formation of circulating IgA-FN complexes and that this normal binding process, although enhanced in IgAN, is probably not responsible for kidney injury, at least in the patients studied.

Adolescent↗