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Biomedical subjects

J Nagy

Publications and source records attributed to J Nagy.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Thin glomerular membrane nephropathy. Clinico-pathological observations].

In two nephrology centres between 1983 and 1993 among 1545 kidney biopsies 34 cases of thin basement membrane nephropathy have been diagnosed. All patients had a varying degree of microscopic dysmorph haematuria, occasional slight proteinuria--except two nephrotic children; and normal blood pressure with one exception. 5 children and 7 adults experienced repeated bouts of macroscopic haematuria mainly after exercise or upper respiratory tract infection, one child after tonsillectomy. All patients had normal renal function and retained it during the follow-up period (mean 61 months, 3 months to 22 years), except a 46 year old patient, who was found to have the joint occurrence of light chain gammopathy and hypertension. Seven patients had positive family history for microscopic haematuria, in four family members of three patients renal biopsy disclosed mesangioproliferative glomerulonephritis with thin GBM segments. As a cut off value for thin basement membrane nephropathy we considered 264 nm. The morphometric analysis of the electron micrographs revealed a mean thickness of 210 nm. No differences in basement membrane thickness were measured regarding gender, age or the presence of macroscopic haematuria. The thin basement membrane is considered to be the pathological basis and predisposing alteration leading to haematuria.

Adolescent↗
PubMed1997

Interaction of Silane Coupling Agents with CaCO3

A study of eight silane coupling agents showed very different effect of these compounds on the mechanical properties of PP/CaCO3 composites. The application of aminofunctional silane coupling agents resulted in the reactive coupling of the two inactive components leading to increased strength and decreased deformability. A detailed study of the interaction between CaCO3 and the various coupling agents was carried out in order to find an explanation for the strong coupling effect. The amount of coupling agent creating a monolayer coverage was determined by a dissolution method for each coupling agent. The obtained values changed between 0.3 and 1.0 wt% calculated for the CaCO3 . An attempt was made to determine the orientation of the adsorbed molecules to the filler surface. Most of the coupling agents are oriented perpendicularly to the surface with the exception of a methacryl functional silane compound. Possible interactions between hydrolyzed or condensed silane coupling agents and the filler were studied by Fourier transform infrared spectroscopy using transmitting (FTIR-TS) and diffuse reflectance (DRIFT) modes, as well as gel permeation chromatography (GPC). The results showed that bulky organofunctional groups form a caged, polycyclic, low-molecular-weight structure on the surface, while silanes with smaller groups tend to condense into open, ladder type, high-molecular-weight polysiloxane chains. Polymer/filler adhesion, however, depends primarily on the chemical character of the organofunctional group. Aminofunctional silane coupling agents adhere well to the filler surface and react also with the polymer. In the case of similar functionality the size of the organofunctional group determines the strength of the adhesion.

Journal Article↗
PubMed1997

Possible role of free radicals generated by pseudohypoxia in the regulation of hepatic glucose output. An in vitro model using rat liver microsomal glucose 6-phosphatase.

Hepatic glucose output is decreased by hyperglycaemia through an unknown mechanism. We hypothesize that free radicals generated by hyperglycaemic pseudohypoxia might cause glucose output to decrease by inhibiting glucose 6-phosphatase - a key enzyme of gluconeogenesis. To prove this a model experiment was performed on a microsome fraction of rat liver. One of the characteristic features of pseudohypoxia due to hyperglycaemia is an increase in the ratio of NADH/NAD+, so in the present study the changes in NADH - induced glucose 6-phosphatase activity were investigated as related to the release of inorganic phosphate (Pi) derived from glucose 6-phosphate. After incubation for 50 min, Pi release was significantly reduced by NADH (4.026 +/- 0.189 vs 2.696 +/- 0.429 micromol x l(-1) x mg protein(-1), control vs NADH samples, p < 0.01). The decrease in the activity of glucose 6-phosphatase generated by NADH was prevented by using desferrioxamine, an irreversible ferric chelator, butylated hydroxytoluene and Trolox, two agents which inhibit lipid peroxidation, and reduced glutathione, a non-specific radical scavenger. Superoxide dismutase, catalase and the hydroxyl radical scavenger dimethyl sulphoxide proved to be ineffective. When the above investigations were carried out in the presence of a ferric-EDTA complex the inhibition of glucose 6-phosphatase was found to be inducible by hydrogen peroxide and/or hydroxyl free radicals. These investigations seem to indicate that pseudohypoxia due to hyperglycaemia can inhibit the activity of glucose 6-phosphatase both by lipid peroxidation and by inducing hydrogen peroxide and/or hydroxyl free radicals and thus it may play a part in the glucose-induced decrease of hepatic glucose output.

Adenosine Triphosphate↗
PubMed1997

Oxidative stress and antioxidant defense mechanism in glomerular diseases.

The changes in red blood cell (RBC) lipid peroxidation [measured via the malonyl dialdehyde (MDA) concentration], reduced (GSH), and oxidized glutathione (GSSG) levels, hemoglobin (Hb) oxidation and antioxidant enzyme [catalase (Cat), glutathione peroxidase, and superoxide dismutase (SOD)] activities were studied in 45 pediatric patients with various glomerular diseases [minimal change nephrotic syndrome (MCNS) in relapse or in remission, lupus nephropathy (SLE), poststreptococcal glomerulonephritis (APSGN), IgA nephropathy (IGA gn)], and in 20 adult patients with IGA gn and also in 15 pediatric and 14 adult controls. The in vitro effects of hydrogen peroxide [acetyl phenylhydrazine (APH) test] on the GSH and Hb metabolisms were likewise investigated. There was an increased oxidative stress in MCNS with relapse, IGA gn, SLE gn, and APSGN, which could be detected in the GSH and Hb oxidation and in the lipid peroxidation on the peripheral RBC-s. The RBC SOD and Cat activities were significantly lower in all patients than in the controls. The RBC GSSG level was significantly elevated in all patients, with the exception of MCNS in remission. This stimulated a compensatory GSH production in MCNS with relapse and in IGA gn, but not in SLE or APSGN. The regeneration of GSH from GSSG was reduced in MCNS with relapse, SLE, and IGA gn, but not in APSGN. In remission, the GSH-GSSG redox system normalizes, but in vitro the APH test stimulates an intensive Hb oxidation. In conclusion, there is a correlation between the presence of active glomerular disease and the evidence of oxidative changes in the various parameters measured in peripheral RBCs.

Adolescent↗
PubMed1997

Richard Bright in Hungary: a reevaluation.

Richard Bright, the highly respected physician and nephrologist at Guy's Hospital, had a strong liking for travel. In 1815 he traveled in Hungary and made very important observations about the country. His 762-page book, entitled Travels from Vienna through Lower Hungary has detailed, sometimes appreciative, sometimes very critical remarks and comments on Hungarian history, art, archeology, religion, the situation of nationalities, education, social conditions, law, farming, and mining. The Hungarians cherished the memory of Bright's travel in their country as reflected in several papers and on two commemorative tablets recognizing him as a true and sincere friend of Hungary.

England↗
PubMed1997

Membrane attack complex and membrane cofactor protein are related to tubulointerstitial inflammation in various human glomerulopathies.

Immunohistochemical analysis of the membrane attack complex (MAC) and the membrane cofactor protein (MCP) was performed on the tubuli and cortical vessels of 46 kidney biopsies with various types of human glomerulopathies. Irrespective of the type of glomerulopathy, significant correlations between tubular MAC and interstitial lymphomonocyte infiltration (p < 0.001) and interstitial volume (p < 0.02) were found. Tubular MCP was significantly overexpressed at the site of MAC deposition (p < 0.002). There was no correlation between the vascular MAC and MCP and tubulointerstitial lesions. Since tubular MAC is deposited in inflamed areas of tubulointerstitium, we propose that MAC might contribute to the development of tubulointerstitial inflammatory processes in human glomerulopathies. MCP as a regulatory factor in the tubulointerstitium might abrogate further tissue damage and cell-stimulatory effects of the MAC.

Adolescent↗
PubMed1997

Induction of endothelial cell injury by cigarette smoke.

Cigarette smoke contains different populations of free radicals which may be responsible for endothelial cell (EC) injury of smokers. The purpose of this study was to examine the effects of gas-phase cigarette smoke on EC endothelium-derived relaxing factor (EDRF)/NO-guanylate cyclase (GC)-cGMP pathway and on EC detachment-type injury after incubation with smoke. Furthermore, we examined whether different kind of antioxidants can prevent smoke-caused EC injury. We measured cGMP pathway using direct (sodium nitroprusside, SNP) and indirect (A23187, the calcium ionophore and bradykinin, BK) activators of GC. Directly and indirectly stimulated EC cGMP production dose-dependently decreased and EC detachment increased after incubation with smoke. Externally added thiols (glutathione, GSH; D-Penicillamine, DP; N-acetylcysteine, NAC) protected EC from damage of cGMP production and cell detachment. Other antioxidants (catalase, deferoxamine and superoxide dismutase) were ineffective. These results suggest that the thiol containing GC in EC is destroyed or inactivated or thiol like species responsible for activation of GC is incomplete in EC after incubation with smoke. It is also possible that externally added thiols bind an unknown component of smoke and this way, EC is protected. EC injury may contribute to vascular diseases associated with cigarette smoking.

Animals↗
PubMed1997

Predictive morphological findings in "zero-hour" biopsies of renal allografts.

"Zero-hour" biopsies of 65 donors have been performed since 1994. Donor kidneys were categorized into five groups based on the morphological findings in "zero-hour" biopsies. No morphological abnormalities were found in 38% of the cases (group 1). Arteriosclerosis was present in 31% of donor kidneys (group 2). Specific morphological alterations, i.e. acute tubular necrosis [21.5%], tubulointerstitial nephritis [6.2%] or glomerulonephritis [3.1%] were detectable in the cases remained (group 3-5). During an average of 336 posttransplant days clinical and histological follow up was performed (50 rebiopsies). Statistical data of mismatch (1.4-2.0), average of donor/recipient age (35-42 years), cold and warm ischaemic time (1290 and 66 min) were comparable in all groups. According to our observations: 1. higher creatinin was found in grafts with arteriosclerosis (group 2) (p < 0.05), 2. there were more non-viable grafts and longer period of delayed graft function in acute tubular necrosis (group 3), 3 higher creatinin, rejections with the need of rehemodialysis were observed in four cases of tubulointerstitial nephritis (TIN-group 4). Glomerulonephritis (GN-group 5) grafts had only delayed graft function, however these groups were few for statistical evaluation. Biopsy complication in 1/115 cases was found (rebiopsy induced kidney haemorrhage). In conclusion, "zero-hour" biopsies can be useful and safe tools to predict early graft function. Besides "zero-hour" biopsies help the histological interpretation of consecutive graft rebiopsies.

Adult↗
PubMed1997

[The effect of spasmolytics on dilatation of the uterine cervix].

UNLABELLED: Spasmolytics and spasmoanalgetic mixtures are administered to facilitate dilatation of the cervix during delivery and to shorten the first stage of labour. This medication is used in 70% deliveries at the 1st Dept. of Obstetrics and Gynaecology Masaryk University in Brno. The aim of the study was to analyze the spasmolytic effect on the process of cervix dilatation. The study comprises 108 uncomplicated deliveries (52 deliveries with spasmolytics and 56 deliveries without). We analyzed the effect of spasmolytics on the cervix, process of labour and outcome of delivery. Six kinds of spasmolytics were used, administered from once to four times during labour and most of them (85%) in the latent phase of the first stage of labour. In the group with spasmolytics there was statistically insignificant by prolonged active phase of the first stage of labour (126 vs 104 minutes) and more frequent administration of Oxytocin. Others parameters such as length of the second stage of labour, rate of birth injuries, the 1st minute Apgar score less than 7 and the necessity of neonatal resuscitation did not differ in the two groups. CONCLUSIONS: The application of spasmolytics did not significantly affect the process of delivery.

Adult↗
PubMed1996

[Does tonsillectomy cause any change in long-term course of IgA nephropathy?].

Tonsillectomy seems to be a logical step in IgA nephropathy owing to the frequent tonsillitis before the beginning and the acute exacerbations of the disease. The usefulness of tonsillectomy is questionable because there are only few and short-term follow-up data after it. We followed up 35 kidney biopsy proven IgA nephropathy patients (25 men and 10 women) for an average of 12.2 yrs (range 7-32) after tonsillectomy. The values of endogenous creatinine clearance, serum creatinine, hematuria and proteinuria were compared at regular intervals during a follow-up with those obtained before tonsillectomy. We considered more than 12,000 data using 2 tailed t test. We found that proteinuria started to decrease significantly already 6 months after tonsillectomy (1.40 +/- 0.27 g/day before tonsillectomy vs 0.92 +/- 0.25 g/day after it, p < 0.05) and was significantly lower under follow-up. The tendency in microhematuria was similar (70.5 +/- 35.0 million RBC/12 hours before and 14.0 +/- 6.5 million RBC/12 hours 6 months after tonsillectomy, p < 0.0001). Furthermore, tonsillectomy stopped gross hematuria appearing in the acute exacerbation of the disease in more than two-thirds of patients. Creatinine clearance did not change in the first 2 years after tonsillectomy, however, from 2.5 years after it is significant slow and continual decrease started (117.0 +/- 9.8 ml/min before and 106.2 +/- 10.8 mil/min 2.5 yrs after tonsillectomy, p < 0.05). End-stage renal failure was detected only in 4 patients out of 35 after 10 years after tonsillectomy, in our non-tonsillectomised control group in 8 patients out of 40.

Adolescent↗
PubMed1996

[Nail-patella syndrome: clinico-pathologic characteristics].

The nail-patella syndrome is a hereditary disorder showing an autosomal dominant trait. It is characterized by a series of skeletal disorders and nephropathy. The skeletal defects and the renal involvement might occur separately. The usual clinical presenting syndromes of the nephropathy are asymptomatic proteinuria, microscopic haematuria and sometimes nephrotic syndrome. In a considerable proportion of patients renal failure develops. We summarise the clinico-pathological features of the disease presenting in two children and in a young man. The two children showed heavy microscopic occasionally, macroscopic haematuria, asymptomatic proteinuria and the adult patient had nephrotic syndrome. Nail-patella abnormalities were observed in one child without the involvement of family members. Except for the mother of the other child no urine abnormalities could be demonstrated in the patient's families. The kidney biopsy revealed the characteristic signs of the nail-patella syndrome in different extent: bundles of collagen fibrils in the glomerular basement membrane (GBM). Segmental and thinning of the GBM also occurred in the two children. This defect predisposes to the clinically dominant micro- and macroscopic haematuria. These children's reual function remained stable during the follow-up period of 4-7 years. In the GBM of the third patient small subepithelial electron dense deposits-corresponding to stage I. membranous glomerulonephritis- and extensive collagen deposition was found. After two years follow-up persistent nephrotic syndrome and gradual decline in renal function could be observed.

Adolescent↗
PubMed1996

[Mesangiocapillary glomerulonephritis].

Mesangiocapillary glomerulonephritis (MCGN) accounting for 15 percent of adult glomerulopathy has not received proper attention in the Hungarian medical literature. The present study offers a detailed description of the procedures to be used for distinguishing its three types, which is only possible by histological, mainly electron microscopic examination of kidney biopsy samples. Type I represents subendothelial deposits; Type II is the "sausage-like" dense deposits localised on the lamina densa of the glomerular basal basement membrane; Type III is the mixed type. There is no significant difference in their clinical appearance. They occur most frequently as "coloured nephrosis" (the syndrome of nephrosis is associated with haematuria and/or hypertension). The course of the disease is characterised by periodicity, and in 50 percent of the cases kidney failure may develop. The therapy for MCGN has not been established. The administration of steroid, cyclophosphamide and anticoagulant can have a favourable effect.

Adult↗
PubMed1996

[HIV infection es IgA nephropathy].

Similar immunological abnormalities exist in IgA nephropathy and HIV infection and several IgA nephropathy cases were reported in HIV-infected patients. To estimate the number of HIV-infected patients in IgA nephropathy, 80 patients with IgA nephropathy were studied for HIV-1 and HIV-2 antibody seropositivity. Although they failed to detect HIV positivity among their IgA nephropathy patients, because of the increasing number of people are being infected with HIV, the screening of IgA nephropathy patients for HIV infection would warrant.

AIDS-Associated Nephropathy↗