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Biomedical subjects

Z Nagy

Publications and source records attributed to Z Nagy.

At least 19 recordsLinked to original sources
PubMed1992

Conformational and functional properties of peptides covering the intersubunit region of influenza virus hemagglutinin.

The functionally active part of influenza virus hemagglutinin was investigated through the synthesis of a series of peptides representing different parts of the intersubunit region. Secondary structure prediction, circular dichroism and Fourier transform infrared spectroscopic studies were undertaken to investigate the secondary structure of these peptides. The peptide fragments were found to adopt multiple conformations, depending on their concentration in solution, the presence of the non-ionic detergent octyl-beta-D-glucoside and the polarity of the solvent. The results of biological studies with these peptide fragments are discussed in relation to their conformation, as inferred from the spectroscopic analysis.

Amino Acid Sequence↗
PubMed1992

[The Budapest "stroke data bank" (goals, methods)].

The Stroke Data Bank initiated by National Institute of Neurological and Communicative Disorders and Stroke (USA) has been adapted and published here in a short form. The original questionnaire has been extended with data of patients' diets and neuropsychology. A suitable computer data basis derived from 1292 questions in 22 groups provides information about the risk factors, etiology, symptoms, signs, diagnosis, prognosis of stroke, and the easy to use follow up of patients.

Cerebrovascular Disorders↗
PubMed1992

Systemic sclerosis in the elderly.

In our study, the characteristics of 114 patients with systemic sclerosis (SSc) are discussed with emphasis on the subgroup of cases whose onset of disease occurred above the age of 60 years. Seven out of the 9 cases showed symptoms of diffuse cutaneous systemic sclerosis with an extensive skin involvement, and 5 of these cases died within 2 years following the onset of SSc. Seven of the 9 cases showed a rapid disease course with symptoms of cardiac, pulmonary and/or renal involvement, while no secondary Sjögren's syndrome, subcutaneous calcinosis and myositis were demonstrated among these patients.

Aged↗
PubMed1992

Endogenous scavenger levels (vitamin E and A) of patients with chronic alcoholic liver disease under different environmental conditions.

Serum level of endogenous scavengers (E and A vitamin) was studied in groups of patients with various chronic alcoholic liver diseases and in a healthy control group on polluted and non-polluted areas. Vitamin levels in patients with chronic liver disease are diminished in comparison to the healthy in general, but mainly in the cirrhotic group. Diminution of vitamin E levels was observed in earlier phase of liver disease than that of vitamin A levels. Patients and healthy control on polluted area showed more expressed diminution of vitamin levels than the same groups on non-polluted area. Free radical parameter (RBC diene conjugate content) and characteristic alcoholic parameters (serum GOT, gamma-GT, cholesterol level and liver GOT, gamma-GT content in biopsy specimen) were used to explain the differences between the same investigated groups on polluted and non-polluted areas. As conclusion can be supposed that industrial pollution of environment has a worsening effect in diseases with free radical mechanism.

Cholesterol↗
PubMed1991

Proteolytic enzyme activities in rat peritoneal exudate.

Proteinase activities in rat thioglycollate elicited peritoneal cells and the cell-free supernatant (lavage fluid) were measured by using the following substrates: Suc-Ala-Ala-Pro-Phe-Methyl-Coumarin-Amide (for cathepsin G or chymase), Suc-Ala-Ala-Ala-AMC (for elastase or elastase-like), Z-Arg-Arg-AMC (for cathepsin B), haemoglobin (for cathepsin D) and Ala-AMC (for alanine-aminopeptidase: AAP). The enzyme activities were correlated to the quantitative distribution of various cell types in the exudate from 0 to 192 nd h. In the supernatant all the examined activities showed a higher value at 72nd h. In the cells activity of chymase and AAP proved to be very high at 0 h but after four h the activities were dropped. From this time all enzyme activities started to elevate till the 24th h. At the 96th h only the activity of cathepsin B and AAP had a high value. We conclude that the intracellular activation and secretion of proteolytic enzymes characteristic for the various peritoneal cell types involved in the acute and chronic inflammatory reaction can be followed by activity measurements using enzyme-specific substrates and inhibitors.

Aminopeptidases↗
PubMed1991

Acute acalculous cholecystitis.

In 1884 Duncan was the first to report on acute postoperative acalculous cholecystitis (ref.: 14). Initial publications reported a small number of cases. Literary data have shown a change of the situation for the past few decades /16/. It was most frequently observed following surgical intervention, trauma, delivery or parenteral nutrition /1, 13, 16/. The number of new acalculous cholecystitis cases often requiring surgical intervention and causing death in elderly male patients has increased /5, 16/. Therefore we decided to undertake a clinical study. In Hungary the authors who deal with this theme are: Csengódy /2/, Sándor /17/, Lukács /12/ and Ezer et al. /3/.

Acute Disease↗
PubMed1990

Continuous monitoring of blood-brain barrier opening to Cr51-EDTA by microdialysis following probe injury.

Continuous detection of the permeability changes of the blood-brain (BB) interface became feasible with the recent development of the cerebral microdialysis technique. Vasogenic brain oedema was induced by the insertion of the dialysis capillary into the cerebral cortex of rats, and blood-brain transfer was measured with Cr51-EDTA as a blood-born tracer. The dialysis capillaries had an upper limit of 500 daltons (MW). Ringer solution was perfused through the dialysis tube. Samples were collected continuously. The permeability coefficient has been calculated from the radioactivity of the serum and of the washing fluid.

Animals↗
PubMed1990

Astrocytic orthogonal arrays of intramembranous particle assemblies are modulated by brain endothelial cells in vitro.

Solo astroglial cultures have randomly distributed, intramembranous, orthogonal arrays of particles (assemblies) which are only revealed by freeze-fracture electron microscopy. Co-culturing astrocytes with brain endothelial cells brought about localized, tightly packed assembly aggregates and greatly increased the overall assembly density. Cytosol homogenates of freeze-thawed brain endothelial cells caused a transient increase in astroglial assembly numbers. These results, taken together with the fact that astrocytes in vivo have the highest concentration of perivascular sites, suggest that brain endothelial cells influence the distribution and concentration of astrogial assemblies both in vivo and in vitro through cellular interactions. Meningeal cells and fibroblasts also augmented the astroglial assembly densities in co-culture, while neuronal cells (cerebellar granule cells and PC12 cells primed with nerve growth factor) and other control cell types did not affect assembly number in co-culture with astrocytes. Moreover, brain endothelial cells did not induce any formation of assemblies in the membranes of two transformed astroglial cell lines.

Animals↗
PubMed1990

Local recurrences following colorectal operations.

In about 15-20% of patients operated for colorectal tumours local recurrences develop mainly in the first postoperative year. This large number can only be reduced by adequately radical operations taking into account the patient's age, tumour site and the tumour-biological factors. Indispensable factors are the organized care and regular control of the operated patients with an emphasis, beside CEA test on US and CT studies. In local recurrences attempt should be made at removal of the tumour by an additional operation which is implementable in 20-30% of cases. For palliative treatment first of all radiotherapy can be applied for pain relief.

Adenocarcinoma↗
PubMed1979

Opening of tight junctions in cerebral endothelium. I. Effect of hyperosmolar mannitol infused through the internal carotid artery.

Infusion of 1.8 M mannitol solution into the internal carotid artery of Wistar rats allows horseradish peroxidase (HRP) to cross cerebral vascular endothelium via intercellular pathways. This was made evident by density gradients of HRP observed in consecutive tight junctional compartments following in vivo administration, and by the passage of colloidal lanthanum through junctional membrane appositions of glutaraldehyde fixed cerebral endothelium. Three hours after mannitol infusion, small non-capillary vascular segments were still focally permeable to HRP. Twenty-four hours after the osmotic insult, the tracer was absent in the affected hemisphere. Water and electrolyte assays indicated absence of brain edema during the period of observation of blood-brain barrier opening.

Animals↗
PubMed1979

Opening of tight junctions in cerebral endothelium. II. Effect of pressure-pulse induced acute arterial hypertension.

Acute arterial hypertension was produced in male Wistar rats by pressure pulse through the right internal carotid artery. The pressure pulse was induced by infusion of physiological saline as a bolus, at a rate of 0.63 ml per second by syringe pump. Evans blue (Eb) was used to visualize the areas of blood-brain barrier opening. Intravenously injected horseradish peroxidase (HRP) was used to study the ultrastructural basis of permeability changes in cerebral endothelium. Eb outlined circumscribed areas of blood-brain barrier opening. HRP extravasation was found mainly around small arteries. The capillary network was affected to a much lesser extent. Electron microscopy showed that HRP crossed the endothelial cell layer by intercellular routes. Glutaraldehyde fixed brain samples permeated with colloidal lanthanum supported these observations.

Animals↗
PubMed1979

Blood-brain barrier opening to horseradish peroxidase in acute arterial hypertension.

Acute arterial hypertension was induced in male Wistar rats using two experimental techniques: (1) i.v. injection of Aramine and (2) infusion of physiological saline as a bolus via internal carotid artery. Horseradish peroxidase (HRP) was injected i.v. prior to both experimental procedures and subsequently localized in the brain by light and electron microscopy. In the saline infusion (pressure pulse) model, colloidal lanthanum was also applied as a diffusion tracer following fixation of the cerebral endothelium. In the Aramine model, extravsation of HRP correlated with abrupt elevation of blood pressure. In the pressure pulse model HRP extravasation was consistently visualized in the affected hemisphere. Electron microscopy showed consistent labeling of plasmalemmal vesicles by HRP in segments of cerebral endothelium. However, HRP was also clearly visualized in junctional pools suggesting focal opening of endothelial tight junctions as a pathway for extravasation of this tracer in both hypertensive models. Colloidal lanthanum not transported by plasmalemmal vesicles across endothelium after fixation of the brain also bypassed consecutive membrane appositions of endothelial tight junctions indicating existance of interendothelial pathways to macromolecules in acute arterial hypertension.

Acute Disease↗
PubMed1979

Measurement of total-body 40potassium in patients with urate calculi.

Fifty-eight patients with urate calculi and 31 patients with other (non-urate) calculi were examined for total-body potassium by means of a total-body counter. The patients with urate calculosis were found to differ significantly in their total-body K from patients with other calculi as well as from normal subjects. The results indicate that total-body potassium deficiency is one of the factors causing urate calculosis.

Body Composition↗