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Biomedical subjects

G Szücs

Publications and source records attributed to G Szücs.

At least 19 recordsLinked to original sources

Microcirculation of the fingers in Raynaud's syndrome: (99m)Tc-DTPA imaging.

AIM: We investigated the circulatory characteristics of patients suffering of primary and secondary Raynaud's syndrome. PATIENTS, METHODS: We examined 106 patients presenting with the classical symptoms of Raynaud's syndrom (47 primary, 59 secondary) by hand perfusion scintigraphy developed by our Department of Nuclear Medicine. After visual evaluation we analyzed the images semiquantitatively, using the finger to palm ratio. We statistically compared the patients with primary and those with secondary Raynaud's syndrome. RESULTS: By visual evaluation we constated regional perfusion disturbances in 42 from 59 patients with secondary Raynaud's syndrome. However, this was observed in only 3 from 47 patients with the primary form of this disease. This difference was statistically significant (p<0.001). Semiquantitative analysis showed that the finger/palm ratios (FPR) were significantly lower (p<0.05) for the patients with primary Raynaud's syndrome. No differences in the FPR values concerning sex or right and left side. CONCLUSION: The hand perfusion scintigraphy with (99m)Tc-DTPA is a noninvasive, cost effective diagnostic tool, which objectively reflects the global and regional microcirculatory abnormalities of the hands, and provides quantitative data for follow-up.

Adolescent↗

Differential distribution of TASK-1, TASK-2 and TASK-3 immunoreactivities in the rat and human cerebellum.

In this work, the distributions of some acid-sensitive two-pore-domain K+ channels (TASK-1, TASK-2 and TASK-3) were investigated in the rat and human cerebellum. Astrocytes situated in rat cerebellar tissue sections were positive for TASK-2 channels. Purkinje cells were strongly stained and granule cells and astrocytes were moderately positive for TASK-3. Astrocytes isolated from the hippocampus, cerebellum and cochlear nucleus expressed TASK channels in a primary tissue culture. Our results suggest that TASK channel expression may be significant in the endoplasmic reticulum of the astrocytes. The human cerebellum showed weak TASK-2 immunolabelling. The pia mater, astrocytes, Purkinje and granule cells demonstrated strong TASK-1 and TASK-3 positivities. The TASK-3 labelling was stronger in general, but it was particularly intense in the Purkinje cells and pia mater.

Animals↗

The most severe forms of Perthes' disease associated with the homozygous Factor V Leiden mutation.

It has recently been postulated that thrombophilia may have a role in the aetiology of Perthes' disease. The published reports, however, remain conflicting. In this study a retrospective analysis of the coagulation parameters was made in 47 patients with Perthes' disease and the results compared with the clinical data. Five patients with Factor V Leiden mutation were found (10.6%) and surprisingly four of them had a homozygous pattern. These four patients showed the most severe form of the disease, Catterall group IV, with flattening of the entire epiphysis, involvement of the metaphysis, shortening and broadening of the femoral neck, trochanteric overgrowth and developed mushroom-shaped aspherical laterally displaced femoral heads in dysplastic acetabula. We would like to suggest that the homozygous form of Factor V Leiden mutation has some role in the clinical course of Perthes' disease and particularly its most severe form.

Activated Protein C Resistance↗

Depolarization-activated K+ currents of the bushy neurones of the rat cochlear nucleus in a thin brain slice preparation.

Depolarization-activated outward currents of bushy neurones of 6-14-day-old Wistar rats have been investigated in a brain slice preparation. Under current-clamp, the cells produced a single action potential at the beginning of suprathreshold depolarizing current steps. On voltage-clamp depolarizations, the cells produced a mixed outward K+ current that included a component with rapid activation and rapid inactivation, little TEA+ sensitivity, a half-inactivation voltage of -77 +/- 2 mV (T = 25 degrees C; n = 7; Mean +/- S.E.M.) and single-exponential recovery from inactivation (taurecovery= 12 +/- 1 ms at -100 mV; n=3). This transient component was identified as an A-type K+ current. Bushy cells developed a high-threshold TEA-sensitive K+ current that exhibited less prominent inactivation. These characteristics suggested that this current was associated with the activation of delayed rectifier K+ channels. Bushy neurones also possessed a low-threshold outward K+ current that showed partial inactivation and high 4-aminopyridine sensitivity. Part of this current component was blocked by 200 nmol/l dendrotoxin-I. Application of 100 micromol/l 4-aminopyridine changed the firing behaviour of the bushy neurones from the primary-like pattern to a much less rapidly adapting one, suggesting that the low-threshold current might have important roles in maintaining the physiological function of the cells.

Action Potentials↗

Sequence heterogeneity among human picobirnaviruses detected in a gastroenteritis outbreak.

Human picobirnaviruses characterised in this study were serendipitously detected in a non-bacterial gastroenteritis outbreak when specimens were examined for the presence of human rotaviruses using polyacrylamide gel electrophoresis. Of ten stool samples sent for virological examination, two, three, and one specimens were positive for human caliciviruses, picobirnaviruses, and both viruses, respectively. Partial sequences of the RNA-dependent RNA polymerase gene were determined for three picobirnavirus-positive samples. The sequence identity among these three strains was 60% to 65% for the nucleic acid and 64% to 70% for the deduced amino acid sequences. Phylogenetic analysis revealed that each of the three strains clustered with strains identified in geographically separate areas. In contrast, human calicivirus strains co-incidentally identified, showed complete nucleotide sequence identity. These findings demonstrate a lack of common exposure to or point of source for picobirnavirus infection, suggesting that the outbreak was caused by human caliciviruses. Further studies are needed to determine the etiologic role and to establish the taxonomic basis of picobirnaviruses.

Adult↗

Experimental examination of the healing process of telescopic esophageal anastomosis.

The basis of telescopic anastomosis is old, only the practical details of it have changed and improved. The telescopic anastomosis technique is successfully applied in our practice for reconstruction of gastrectomy and esophageal resection. The reason for this study was that data about the healing process of telescopic anastomosis had not been found in the literature. We used four groups of mongrel dogs for our experiments: Group A (n = 3) received 20 mm-long invaginations with a survival time of 7 days; Group B (n = 3) received 10 mm-long invaginations with a survival time of 21 days; Group C (n = 3) received 20 mm-long invaginations with a survival time of 21 days; Group D (n = 3) received 30 mm-long invaginations with a survival time of 21 days. At the end of the above survival times we removed the anastomosing area, measured the bursting pressures and performed morphological and histological examinations. In each case we also performed an anastomosis exactly the same as a completely healed anastomosis and its pressure tolerance was measured (0 day). The pressure tolerance within the anastomosis rises gradually and independently of the length of the invaginated esophageal part. Anastomosis leakage did not occur. The invaginated esophageal part did not suffer any damage. The muscular wall of the intragastric part of the esophagus became covered by the mucosa of the stomach during the healing process and it joined with the esophageal mucosa at the edge of the free end of the esophagus.

Anastomosis, Surgical↗

[Experiences with an Invagination Technique for Esophagogastric End-to-End Anastomoses].

80 patients with esophageal cancer underwent esophagectomy with the stomach as an esophageal substitute. For end-to-end esophagogastrostomy an invagination technique was used. We describe the technique and the results. An anastomotic leak was observed in 5 of 80 patients (6.3 %) in the total, in 5 of 64 cases with cervical anastomosis (7.8 %) and in none of the 16 patients with thoracic anastomosis. 6 of 80 patients (6.5 %) died, 5 due to nonsurgical complications and one patient due to a necrosis of the esophageal substitute. On the basis of these results we recommend the described anastomotic technique due to its simplicity and low anastomotic leakage rate.

Adult↗

Telescopic esophageal anastomosis: operative technique, clinical experiences.

The authors reconstructed the continuity of the alimentary tract by performing telescopic esophagogastrostoma in 208 patients who underwent either esophageal resection or total gastrectomy. The substance of the telescopic technique is to invaginate the distal section of any oral tubular organ to the lumen of an aboral tubular one and to fix it there. In case of telescopic esophageal anastomosis a 10-15 mm long esophageal segment is invaginated into the gastric tube or jejunum. A 3-4 mm wide serosal surface of the wall of the distal anastomosing organ straps the esophagus circularly. Ninety-six transthoracic and 12 transhiatal esophagectomies, 19 partial esophageal resections, four esophageal bypasses, and 77 total or extended total gastrectomies were reconstructed using telescopic anastomosis. Undisturbed healing could be observed in 67 patients after esophageal operations and in 46 patients of total gastrectomies. Anastomosis leakage occurred in 12 of 108 patients (11.1%) after cervical esophagogastrostomy. Leakage could be observed in 7 of 44 patients (15.9%) after end to side and in 5 of 64 patients (7.8%) in case of end to end esophago gastrostoma. There were no failures after two cases of cervical esophago-ileocolostoma and 21 of esophagogastrostomas in the thoracic position. All of the 59 intra-abdominal anastomoses healed without complication. Thirteen of 131 patients (9.9%) died after esophageal operations and four of 77 (5.2%) after gastrectomies. There were no mortal complications due to anastomotic leakage. The telescopic anastomosis is a safe alternative method in cases of total gastrectomy or esophageal operation.

Aged↗

Screening adenoviruses in stool samples: evaluation of a genus-specific monoclonal antibody based enzyme immunoassay.

To screen fecal samples for adenovirus antigens a genus-specific monoclonal antibody based enzyme immunoassay was developed. In a comparative analysis with commercial latex agglutination test, high sensitivity was demonstrated. The assay did not detect other viruses usually found in faeces suggesting its specificity. One hundred and eighty stool samples collected in Baranya County were tested and 13 (7.2%) of them showed reactivity. The application of our immunoassay combined with other, more sophisticated methods may help us to determine the serotype specificity of these adenovirus isolates and assess the importance of adenoviruses in viral gastroenteritis.

Adenovirus Infections, Human↗

Detection of antibodies to polyomavirus SV40 in two central European countries.

Simian virus 40 (SV40) is significantly associated with some human cancers. However, the frequency of tumor-associated virus detection differs by geographic regions, so it is important to understand the status of SV40 infections in different populations. Poliovaccines potentially containing live SV40 were used in well-documented nationwide vaccination programs in Hungary and the Czech Republic that are reported here. We analyzed serum samples from periodic surveillance programs in those two countries for antibodies to SV40 using a specific plaque reduction neutralization assay. The prevalence of antibodies was between 1.3 and 8.7% in Hungary and from 1.0 to 4.0% in the Czech Republic. Females had a higher rate of antibodies than males, reaching in certain age groups 15.6% in Hungary and 8.3% in the Czech Republic. Antibodies to SV40 were found in similar proportions in both countries among persons not directly exposed to poliovaccines and subjects vaccinated in the era of SV40-free vaccines. Complexities and limitations of current serological approaches to epidemiological studies of SV40 in humans are discussed. These data suggest that SV40 may be present in these populations and emphasize the importance of follow-up studies to determine the pathogenesis of infections by this emerging human agent.

Adolescent↗

[Data about the early physical reliability of hand-sewn anastomoses in esophagectomy and gastrectomy].

We examined on models the inner pressure tolerance of the most frequently performed single layer anastomoses used in esophagectomies and gastrectomies. The aim was to examine whether interrupted or continuous suture proves safer immediately after the operation. We investigated the difference between sutures involving and not involving the mucosa. The anastomosis models were of organs of hybrid pigs slaughtered in the meet-industry. Atraumatic, 3/0 Biosyn suture material was used. The bursting pressure was measured by insufflating CO2 gas. Its bursting pressure can characterize the inner pressure tolerance of an anastomosis. The circumstances of the experiment, the suture technique and the examination of the bursting pressure were standardized. Our considerations are: 1. The early inner pressure tolerance of an anastomosis does not depend on the condition of the wall. The critical factor is their ability to expand. 2. The inner pressure tolerance of continuous sutures is better than of interrupted ones if the tissues in the suture line show similar degree of dilatation. Optimal conditions are achieved with end-to-end or side-to-side anastomoses of single organs (for example between small bowel and small bowel or colon and colon). 3. Involving the mucosa in the stitches has not influenced early physical suture certainty.

Anastomosis, Surgical↗

Effects of divalent cations on voltage-gated Ca2+ channels and depolarization-induced [Ca2+], transients of freshly isolated pyramidal cells of the rat dorsal cochlear nucleus.

The effects of divalent cations on voltage-activated Ca2+ channels and depolarization-evoked cytoplasmic [Ca2+] elevations were studied in pyramidal neurones isolated from the dorsal cochlear nucleus of the rat. Ca2+ currents were recorded using the whole-cell configuration of the patch-clamp technique. 10 micromol x l(-1) Cd2+ exerted a greater blocking effect on the high-voltage activated (HVA) currents than on the low-voltage activated (LVA) ones (decrease to 26.6+/-2.5% and to 87.8+/-2.1%, respectively). The blocking effect of 200 micromol x l(-1) Cd2+ was more pronounced and the difference between the effect on the HVA and LVA currents became smaller (decrease to 11.7+/-2.1% and to 32.4+/-2.7%, respectively). 200 micromol x l(-1) Ni2+ reduced the LVA component more effectively (to 77.6+/-5.4%) than the HVA one (to 86.9+/-2.6%). Cytoplasmic [Ca2+] changes were measured applying a fluorimetric technique (Fura-2). 10 micromol x l(-1) Cd2+ decreased the peak values of 50 mmol x l(-1) K+ depolarization-induced [Ca2]+i transients to 30.4+/-1.4% while 200 micromol x l(-1) Cd2+ caused a drop to 2.5+/-0.2%. 200 micromol x l(-1) Ni2+ decreased the peak of the transients to 69.6+/-2.9%. Comparison of the blocking effects of divalent cations on Ca2+ currents and [Ca2+]i transients supports further the conclusion that the depolarization-induced [Ca2+]i changes are produced mainly by the activation of the HVA Ca2+ channels.

Animals↗

Hypercoagulability in various autoimmune diseases: no association with factor V Leiden mutation.

The coagulation factor V Leiden mutation, leading to resistance to activated protein C (APC), is the most common inherited risk factor for venous thrombosis. In various systemic autoimmune diseases the hypercoagulable state was shown to be associated with the presence of antiphospholipid antibodies (aPL). Our aim was to determine the prevalence of both, Leiden mutation and aPL in autoimmune diseases and their impact on the occurrence of venous thrombosis. The dataset consists of results from 137 patients having Sjögren's syndrome (n = 50), progressive systemic sclerosis (n = 43) (PSS), undifferentiated connective tissue disease (n = 24) (UCTD) and mixed connective tissue disease (n = 20) (MCTD) with or without venous thromboembolic complications. The Leiden mutation was detected with polymerase chain reaction (PCR), aPL, such as lupus anticoagulant (LA) with screening and confirmatory procedures and others with enzyme linked immunosorbent assay (ELISA). The prevalence of mutation ranged between 8.3% and 18.0% (13.1%). The thromboembolic risk was found to be increased in the presence of aPL. Eight patients (5.84%) (4 heterozygous) experienced thromboembolic events and 3 out of 4 heterozygous showed aPL positivity, too. There were no difference between the frequencies of Leiden mutation in examined systemic autoimmune diseases and unselected populations.

Activated Protein C Resistance↗

Studies on the toxic interaction between monensin and tiamulin in rats: effects on P450 activities.

Studies were carried out to investigate the effects of monensin and tiamulin, and the simultaneous administration of both compounds on microsomal enzymes in rats. In Phase I of the experiments the effects of monensin and tiamulin were studied separately (monensin 10, 30, and 50 mg/kg or tiamulin 40, 120, and 200 mg/kg body weight, respectively), while in Phase II the two compounds were administered simultaneously (monesin 10 mg/kg and tiamulin 40 mg/kg b.w., respectively). When monensin was administered by itself, it exerted no significant effect on microsomal liver enzymes. In a few cases, slight inhibition of certain enzyme activities was seen. Tiamulin provoked a dose-dependent hepatic enzyme induction. The combined administration of monensin and tiamulin at low doses (10 and 40 mg/kg, respectively) resulted in marked elevation of P450-related enzyme activities. The enzyme induction was more pronounced in females than in males. The results suggest that the simultaneous administration of tiamulin may influence the biotransformation of monensin, possibly increasing the amount of reactive metabolite(s) of the ionophore antibiotic.

Animals↗

Studies on the toxic interaction between monensin and tiamulin in rats: toxicity and pathology.

The characteristics of the toxic interaction between monensin and tiamulin were investigated in rats. A three-day comparative oral repeated-dose toxicity study was performed in Phase I, when the effects of monensin and tiamulin were studied separately (monensin 10, 30, and 50 mg/kg or tiamulin 40, 120, and 200 mg/kg body weight, respectively). In Phase II, the two compounds were administered simultaneously to study the toxic interaction (monensin 10 mg/kg and tiamulin 40 mg/kg b.w., respectively). Monensin proved to be toxic to rats at doses of 30 and 50 mg/kg. Tiamulin was well tolerated up to the dose of 200 mg/kg. After combined administration, signs of toxicity were seen (including lethality in females). Monensin caused a dose-dependent cardiotoxic effect and vacuolar degeneration of the skeletal muscles in the animals given 50 mg/kg. Both compounds exerted a toxic effect on the liver in high doses. After simultaneous administration of the two compounds, there was a mild effect on the liver (females only), hydropic degeneration of the myocardium and vacuolar degeneration of the skeletal muscles. The alteration seen in the skeletal muscles was more marked than that seen after the administration of 50 mg/kg monensin alone.

Administration, Oral↗

[Comments on Raynaud syndrome based on laser-Doppler studies].

The authors have in their care 286 Raynoud syndrome patients. They present their experience in the study of the microcirculation and the treatment of these patients. In 81% (232 patients, 196 women and 36 men) of the cases they did not find any underlying diseases. In the group of the patients with secondary Raynaud's syndrome (35 women and 19 men) underlying diseases, possibly leading to microcirculatory disturbances, could be identified. In the primary Raynaud's syndrome group the main capillary diameter measured by capillary microscopy was 15 +/- 4 micron. In patients with progressive systemic sclerosis the mean diameter was 43 +/- 9 micron. In the group of women with primary Raynaud's syndrome the authors performed laser Doppler measurements of the nailfold microcirculation. During the reactive hyperaemia test basal values (18.2 +/- 6.2 Perfusin Units, P. U.) and reactive hyperaemia values (a mean of 180% growth compared to the basal values) were similar to that perfusion values referred in the literature. In the progressive systemic sclerosis group the basal flow (9.3 +/- 3.3 P. U.) and the reactive hyperaemia (a mean of 20% increase compared to basal values) were significantly lower. Concerning the fact that the progression of Raynaud's syndrome into systemic autoimmune disease--mainly to progressive systemic sclerosis may be predicted, it is important to follow up carefully all patients with Raynaud's syndrome.

Adolescent↗

Investigation of the alveolar macrophages and T lymphocytes in 15 patients with systemic sclerosis.

The cell distribution and function of alveolar macrophages and T lymphocytes were investigated in the bronchoalveolar lavage (BAL) of 15 patients with systemic sclerosis (SSc). In alveolar macrophages, both spontaneous and PMA-stimulated TNF-alpha production were increased in SSc. PMA-induced IL-6 production was also elevated. Spontaneous IL-6 excretion of scleroderma alveolar macrophages was similar to the controls. Yeast and C3b-coated yeast (opsonised yeast) phagocytosis, chemotaxis and Fc receptor activity of alveolar macrophages were normal. The proportion of CD3, CD4 and CD8 T-lymphocyte subsets in the BAL was similar to the control values. The lymphocyte blast transformation index of the non-adherent cells deriving from the BAL fluid was markedly decreased.

Adult↗