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G Balazs

Publications and source records attributed to G Balazs.

9 recordsLinked to original sources
PubMed1995

Radiation-induced lung injury using a pig model. Evaluation by high-resolution computed tomography.

RATIONALE AND OBJECTIVES: To assess the early phase of radiation-induced lung injury using high-resolution computed tomography (CT) under experimental conditions and to perform precise CT-pathologic correlation. METHODS: Five Yorkshire pigs received a single dose of 12.5 Gy to the right lower lung. Computed tomographic images were obtained at 2-week intervals. The animals were killed after follow-up periods of 4-16 weeks. The lungs were removed, inflated, fixed, dried, and sliced corresponding to the CT sections. Computed tomography, specimen radiography, and histologic findings were correlated. RESULTS: Various CT findings were observed during the first 16 weeks, including ground-glass opacity, discrete consolidation, patchy consolidation, thickened interlobular septum, and bronchovascular bundle. Ground-glass opacity was associated with thickened alveolar wall and scattered tiny fibrotic foci. Thickened interlobular septum and bronchovascular bundle were the results of fibrosis adjacent to these structures. Discrete consolidation correlated with intraalveolar edema with hemorrhage and infiltration of inflammatory cells. CONCLUSIONS: High-resolution CT correlated well with pathology of the lung due to radiation injury as verified by precise radiologic-pathologic correlation.

Animals↗
PubMed1994

Bleomycin-induced fibrosis in pigs: evaluation with CT.

PURPOSE: To establish an animal model for use in evaluation of early morphologic changes of pulmonary fibrosis by means of precise correlation of findings at thin-section computed tomography (CT) and pathologic findings. MATERIALS AND METHODS: Bleomycin (1.0-2.5 U per kilogram of body weight) was delivered selectively into the left lower lobe bronchus via balloon catheter in five Yorkshire pigs. Sequential CT examinations were performed at regular intervals. The animals were killed at follow-up of 5 days to 4 weeks. At autopsy, the lungs were removed, inflated, fixed and dried, and subsequently sliced into sections that corresponded to the CT sections. The fixed lungs were examined with thin-section CT, radiography, and histologic studies. RESULTS: There was good correlation between pathologic findings at CT and specimen radiography. Histologic study revealed signs of pneumonitis and developing fibrosis. CONCLUSIONS: This disease model is suitable for radiologic and pathologic evaluation of interstitial fibrosis. CT was sensitive in detection of bleomycin-induced abnormalities.

Animals↗
PubMed1992

Lymphocytes resided in the thyroid are the main source of TSH-receptor antibodies in Basedow's-Graves' disease?

The source of TSH-receptor antibodies (TRAb) in Basedow's-Graves' disease is still under debate. Previous studies by other groups had found TRAb levels in the thyroid vein higher than or equal to that in the peripheral vein. The aim of the present work was to investigate the suspected presence of this TRAb gradient in 14 Graves' patients who underwent surgery. Interestingly, in 6 patients higher levels of TRAb were measured in the antecubital vein when compared to the thyroid vein, in another 6 there was no gradient and 2 exhibited higher TRAb levels in their thyroid veins. A clear gradient of thyroid hormones in favour of the thyroid vein was also present, while no gradient of TSH, anti-thyreoglobulin and anti-microsomal antibodies, total IgG, IgA and IgM levels and no differences of the CD4+/CD8+ cell ratios were found between the two sampling sites. We conclude that cells other than lymphocytes residing in the thyroid gland must also be involved in TRAb production.

Adult↗
PubMed1992

Experimental pulmonary infarction in a pig model.

RATIONALE AND OBJECTIVES: The authors sought to develop a reliable animal model for experimental pulmonary infarction, to evaluate it with radiologic-pathologic correlation, and to determine the use of high-resolution computed tomography (HRCT) in monitoring parenchymal lung damage due to infarction. METHODS: Selective left lower lobe pulmonary artery occlusion was performed in seven Yorkshire pigs with transcatheter silicone elastomer injection. After occlusion, 99m technetium (99mTc) macroaggregated albumin perfusion lung scans and sequential in vivo HRCT lung scans were obtained from days 0 to 46. The in vivo radiologic findings were correlated with specimen radiography, specimen HRCT, and histologic findings. RESULTS: A complete and permanent arterial occlusion was achieved, involving up to three orders of branching distal to the catheter. An anatomically defined perfusion defect was seen on 99mTc lung scans corresponding to the occluded area. HRCT changes consisted of confluent densities progressing to mixed alveolar and interstitial opacities within the first week after embolization. In the follow-up period, marked parenchymal clearing was observed. In all cases after pulmonary artery occlusion, the histologic findings were characteristic of pulmonary infarction and demonstrated alveolar edema, hemorrhage, limited alveolar wall damage, and septal thickening followed by residual fibrosis. CONCLUSION: Using this model, it is feasible to produce pulmonary infarction in the pig which may potentially be useful to study the pathophysiologic and radiologic changes of pulmonary infarction.

Animals↗
PubMed1989

Immunogenetic and immunologic studies of differentiated thyroid cancer.

The authors have studied in detail human leukocyte antigen (HLA) association in 87 Hungarian patients with thyroid epithelial carcinoma. The authors also examined in a small group of patients, five parameters of cell-mediated immunity and related them to HLA as well as to lymphocytic infiltration of the tumor/normal tissue interface. HLA-DR1 was significantly associated with thyroid carcinoma; the strongest association was in patients with follicular histologic features and DR1 homozygotes were not at greater risk for thyroid cancer. The HLA-DR3 was nonsignificantly increased in patients with papillary or mixed histologic features. The HLA-DR1, 3 heterozygotes were highly associated with follicular carcinoma, carried no risk for papillary carcinoma, and an intermediate risk for tumors with mixed histologic features. Because of the small proportion of DR1, 3 heterozygotes in the follicular and mixed histologic group, its predictive value at the population level was low. Better predictive potential was shown for the phenotype DR1 and/or DR3. Neither metastatic disease nor age at diagnosis (less than 45 years) could be related to HLA phenotypes. Patients in all histologic variants showed some measure of cell-mediated immunity compared to controls. Patients with papillary carcinoma showed an overall better response than those with tumors with follicular or mixed histology. The HLA-DR could not be related to cell-mediated immune response. Patients with papillary carcinoma with a good cell-mediated immune response occurred with much lower infiltration of the tumor boundary with lymphocyte whereas the follicular carcinoma less cell-mediated immunity was associated with dense lymphocytic infiltration, suggesting the biological relevance of lymphocytic infiltration may be different for the two histologic variants.

Adenocarcinoma↗
PubMed1986

Interaction of IgG heavy-chain allotypes (Gm) and HLA in conferring susceptibility to thyroid carcinoma.

We have recently reported an increase in HLA-DR1 in 52 patients with thyroid epithelial cancer from Eastern Hungary (Juhasz et al., 1986). We have now investigated the association of IgG heavy chain markers (Gm) in 50 patients with this disease and explored possible interaction between Gm and HLA in modifying the risk for thyroid cancer. No Gm phenotype showed significant increases in the patients compared to 168 local controls. When both Gm and HLA, however, were considered, a marked heterogeneity in risk was noted. The odds ratio for DR1+fb+ homozygotes was 37.5, for DR1+fb- individuals 6.0 and for DR1-fb+ individuals 2.6 (DR1-fb- = 1.0). Thus Gm and HLA interact to enhance greatly the risk of thyroid cancer.

Disease Susceptibility↗