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Biomedical subjects

A Kollar

Publications and source records attributed to A Kollar.

12 recordsLinked to original sources
PubMed2001

Involvement of the hepatocyte growth factor/scatter factor receptor c-met and of Bcl-xL in the resistance of oropharyngeal cancer to ionizing radiation.

The activation of cytoplasmic signal transduction pathways by a number of growth factors and their tyrosine-kinase receptors, including hepatocyte growth factor/scatter factor (HGF/SF) and its receptor c-met, exerts an inhibitory influence on apoptosis induced by ionizing radiation in vitro. The clinical relevance of the aforementioned ligand-receptor pair, of Bcl-xL, which is targeted by HGF/SF/c-met signaling, and of Bcl-2, was assessed by evaluating their predictive and prognostic impact in a cohort of 97 patients with radically irradiated squamous cell cancers of the oropharynx. Immunohistochemical expression of c-met and Bcl-xL was correlated with decreased rates of complete remission of the primary tumor in both the univariate (c-met: P = 0.01; Bcl-xL: P = 0.001) and multivariate analyses. Expression of c-met was, moreover, a significant and independent predictor of impaired local failure-free survival (P = 0.003), disease-free survival (P = 0.003) and overall survival (p = 0.001). Bcl-2 expression was, on the other hand, associated with a favorable outcome, in terms of both local failure-free survival (P = 0.01) and overall survival (P = 0.001). In accordance with in vitro data, c-met and Bcl-xL appear to be involved in the resistance of oropharyngeal cancers to ionizing radiation, and may therefore represent attractive targets for radiosensitization.

Aged↗
PubMed2001

Mitral valve replacement and endocavitary patch repair for a giant left ventricular pseudoaneurysm.

We present a case of a giant inferior left ventricular (LV) wall pseudoaneurysm. The patient had New York Heart Association class IV heart failure due to severe mitral valve regurgitation and poor LV function. Our operative approach included right thoracotomy, excision of the mitral valve, and patch repair of the pseudoaneurysm neck from inside of the dilated LV cavity followed by mitral valve replacement. Surgery was performed without aortic cross-clamping on a normothermic perfused beating heart. The patient had an uncomplicated cardiac recovery and is doing well 15 months after surgery.

Aged↗
PubMed2001

Alternative technique to cannulate the descending aorta for abdominal organ procurement in a hemodynamically unstable patient.

During organ procurement, maintaining adequate organ perfusion is crucial. Hemodynamic instability may compromise organ viability and demand quick intervention, sometimes rapid, early cannulation of vessels, so that organs may be salvaged. In this case report of an unstable donor with large retroperitoneal hematoma, a surgical approach is presented that has previously not been described. The technique facilitated hemodynamic stability while allowing rapid cannulation of the retrocardiac descending aorta.

Adult↗
PubMed2000

Intratumoral microvessel density predicts local treatment failure of radically irradiated squamous cell cancer of the oropharynx.

PURPOSE: To determine the predictive value of intratumoral microvessel density (IMD), and of the expression of p53, vascular endothelial growth factor (VEGF) and thrombospondin-1 (TSP-1) for the radiocurability of patients with squamous cell cancer of the oropharynx. MATERIALS AND METHODS: 139 patients with squamous cell cancer of the oropharynx were radically irradiated (median dose, 74 Gy) between 1991 and 1997. Biopsies from 100 patients were processed for immunohistochemistry. IMD was determined in hot spot areas of tissue stained with anti-CD31 at a magnification of x200. Staining for p53 was considered positive if more than 10% of the cell nuclei overexpressed the protein. Immunostaining of VEGF and TSP-1 was assessed semiquantitatively. RESULTS: Increasing IMD (range, 54-282) was strongly correlated with incomplete remission of both the primary tumors (p = 0.01) and lymph node metastases (p = 0.02). Moreover, multivariate Cox regression analysis revealed local failure-free survival to decline with increasing IMD (IMD continuous: risk ratio = 1.01 per increase of 1 microvessel, p = 0. 0001; IMD categorical: </= 80: baseline, 81-110: risk ratio = 2.71, 111-130: risk ratio = 4.55, > 130: risk ratio = 13.01). Neither the expression of p53, nor that of VEGF or TSP-1 was associated with the treatment outcome or IMD, but VEGF and TSP-1 expression were positively correlated (p = 0.02). CONCLUSION: IMD represents a powerful and independent predictive factor for local treatment failure in radically irradiated patients with squamous cell cancer of the oropharynx.

Analysis of Variance↗
PubMed2000

Left internal mammary artery graft retransplantation from the recipient to the donor heart: a case report.

A case of heart transplantation with concomitant coronary artery bypass graft is reported. The patient was an alternate transplant list candidate with a history of bilateral below-knee amputation and 2 previous myocardial revascularization procedures. The previously used and patent left internal mammary artery graft was successfully removed and retransplanted from the recipient to the donor heart.

Cardiomyopathy, Dilated↗
PubMed1998

A new model of endovascularly induced renal artery stenosis in normocholesterolemic versus hypercholesterolemic rabbits.

RATIONALE AND OBJECTIVES: The authors determine the feasibility of creating renal artery stenosis by overdilatation and deendothelialization and compare the model in normocholesterolemic versus hypercholesterolemic rabbits. METHODS: Thirty male New Zealand White rabbits were randomized into two groups: group A (n = 15) was fed a normal diet and group B (n = 15) was fed a cholesterol-rich diet 4 weeks before stenosis induction. An aortogram was performed, then the right renal artery was overdilated with an angioplasty balloon-catheter, and deendothelialized. After 6 weeks, groups A and B were compared by angiographic and pathologic study. RESULTS: Comparison of group A versus group B showed that 12 arteries (80%) versus 6 (40%) were angiographically stenotic (P < 0.05); 14 (93%) versus 12 (80%) contained neointima (NS), 12 (80%) versus 3 (20%) showed medial disorganization (P < 0.01), and 9 (60%) versus 2 (13%) presented adventitial fibrosis (P < 0.01). CONCLUSIONS: A new model of endovascularly induced renal artery stenosis has been developed in rabbits. Medial proliferation and adventitial fibrosis are more frequent in normocholesterolemic rabbits.

Angiography↗
PubMed1998

Patent foramen ovale and pulmonary embolism. An underestimated co-morbidity following cardiac surgery.

When pulmonary embolism occurs in the presence of a patent foramen ovale the sudden increase in the right heart pressure can open the defect and could cause right to left atrial shunting. This may further aggravate the already existing hypoxemia, and the direct communication between the venous and the arterial circulation increases the risk of paradoxical embolization. In this paper we present a case of postoperative pulmonary embolization in a patient with patent foramen ovale, and the effects of these co-existing conditions are reviewed. In the cardiac surgical literature such a complication has not yet been described.

Aged↗
PubMed1995

Surgical management of instrumentation-induced coronary artery dissection.

The mechanism of instrument-induced coronary artery dissections (IICDs) is briefly presented. Depending on the coronary anatomy, three different situations that may occur are distinguished: (1) major coronary branches between the site of dissection and planned anastomosis; (2) no important collaterals at the same location; and (3) perforation of the coronary artery. Surgical methods applicable to each for the correction of these situations is presented.

Aortic Dissection↗
PubMed1988

[The effect of the upper cervical spine on hearing ability].

A chronic irritation in the upper cervical column of 10 rabbits by implantation of a wire string was performed. The vestibular and auditory functions were investigated by electronystagmography and by BERA before and several times after the operation. A distinct increase of the proprioceptive cervical nystagmus was found already in the first postoperative week. In contrary to the ENG findings the BERA did not show any alteration of the both threshold and latency values. These results indicate that the existence of the proprioceptive cervical hearing loss is very doubtful.

Animals↗