Mateja Legan

Expression of cyclooxygenase-2, glucose transporter-1 and angiogenesis in gallbladder carcinomas and their impact on prognosis.

Objective. To investigate the angiogenic and prognostic role of cyclooxygenase-2 (COX-2) in gallbladder carcinomas. We assume COX-2 overexpression, neoangiogenesis and glucose transporter-1 (GLUT-1) to be involved in disease progression. Material andmethods. The carcinoma tissues of 56 patients with gallbladder carcinomas were studied immunohistochemically for the expression of COX-2, GLUT-1 and micro-vessel density. The results were correlated with clinico-pathological features and survival/prognosis. Results. The overexpression of COX-2 in gallbladder carcinomas was significantly associated with increased angiogenesis and GLUT-1 expression. Neither angiogenesis nor the grade of the tumour correlate significantly with poor survival. Age, gender and a strong GLUT-1 expression were significant factors of adverse prognosis. Conclusions. Next to age and gender of patients, hypoxia of gallbladder tumours is a factor influencing survival. Among hypoxic factors, GLUT-1 expression is an important (significant) denominator of poor prognosis in gallbladder carcinomas, but not COX-2 nor angiogenesis.

Glucose Transporter-1 (GLUT-1) Immunoreactivity in Benign, Premalignant and Malignant Lesions of the Gallbladder

GLUT-1 is a transmembrane glucose transport protein that allows the facilitated transport of glucose into cells, normally expressed in tissues which depend mainly on glucose metabolism. Enhanced expression of GLUT-1 can also be found in a large spectrum of carcinomas. This study aimed to investigate GLUT-1 expression in gallbladder tissue: from normal tissue samples, hyperplasias, low-grade and high-grade dysplasias to gallbladder carcinomas. In all, 115 archived samples of gallbladder tissue from 68 patients, presented after cholecystectomy, were immunohistochemically stained for GLUT-1. According to the intensity of GLUT-1 immunoreactivity, samples were divided into negative (stained 0–10% of cells stained), positive with weak to moderate (10–50%) and positive with strong (>50%) GLUT-1 expression. The GLUT-1 immunoreactivity of the samples showed a characteristic increase from premalignant lesions to carcinomas. Normal gallbladder tissue samples did not express GLUT-1 (100%). Weak expression was shown only focally in hyperplasias, but to a greater extent with low-grade dysplasias (20%), high-grade dysplasias (40%) and carcinomas (51.8%). Normal gallbladder tissue is GLUT-1 negative. GLUT-1 expression in carcinoma tissue is significantly higher than in dysplastic lesions. Strong GLUT-1 expression indicates 100% specificity for detecting gallbladder carcinomas. Therefore, GLUT-1 is a candidate as a diagnostic as well as a tissue prognostic marker in gallbladder carcinoma patients.

Histopathologic signs for the inflammatory role of Chlamydia pneumoniae in the high-grade atherosclerotic coronary artery wall.

The aim of the study was to prove the long-lasting and continuously harmful effect of chronic Chlamydia pneumoniae (CPn) infection on vessel walls in patients with diffuse coronary artery disease (CAD). In surgically obtained endarterectomized atherosclerotic plaques grade VI-VIII (Stary classification) from 10 patients with diffuse coronary artery disease and chronic (7) or past (3) CPninfection, signs of inflammatory response of the vessel wall on infectious agents were studied. In all 10 endarterectomized plaque step serial sections, immunologic signs of vessel wall response were present (positive T- and B-lymphocytes, macrophages, and capillarogenesis). In 8 of 10 patients’ atherosclerotic plaque, unique features of active vasculitis in the neoarteriolar wall as well as arteriologenesis, were found. Seven of these 8 patients had serologically proven chronic CPninfection, and 1 had past infection. Features of vasculitis as well as arteriologenesis were absent in 2 patients who recovered from CPninfection at the time of surgery. In the endarterectomized segments of 3 randomly chosen patients in this study, the polymerase chain reaction method revealed positive DNA of CPn.Two of these patients had chronic infection, but the third had only a past CPninfection. This study provides evidence that CPninfection has continuous and a long-lasting inflammatory response in the high-grade atherosclerotic coronary artery vessel wall.

Detection of Chlamydia pneumoniae DNA in the coronary arteries and bypass in three patients with diffuse coronary artery disease

Accessible online at: www.karger.com/crd There is growing evidence of the possible pathogenetic mechanism through which Chlamydia pneumoniae (CP) could affect the atherosclerotic process [1, 2]. CP is commonly found in atherosclerotically changed human vessels, but only rarely in the nonatherosclerotic part of the vessel [3]. The reported detection rate was about 60% in atheromatous lesions versus 3% in nonatherosclerotic arterial specimens. So far, there have been no reports on the presence of CP in diffuse coronary atherosclerosis. This letter reports on the association of CP-DNA and diffuse coronary atherosclerosis in 3 patients with chronic/past infection with CP. Patient M.R., born in 1939, was reoperated in May 2000. The revascularization procedure was done in the coronary and carotid vessels. The bypass (arteria mammaria) performed in 1992 on the left circumflex coronary artery was occluded and the endarterectomy procedure was used. The patient had elevated CP antibodies that indicated chronic CP infection according to serological criteria [4]. Patient T.T., born in 1942, who had diffuse coronary artery disease for 15 years and who had an antibody response indicating chronic CP infection, had a third bypass operation on coronary arteries in January 2001 (the first operation was in 1989 and the second in 1994). Patient I.K., born in 1956, who had diffuse coronary artery disease and chronic persistent infection with CP, was surgically treated in June 1999. A coronary artery bypass graft operation with endarterectomy was performed. The tissue samples of the left anterior descending artery and their diagonal branches were examined for the presence of CP-DNA by the PCR method. Preoperatively, serum antibody levels to CP were determined from a peripheral blood sample with the standard microimmunofluorescence method utilizing CP, Chlamydia psittaci and Chlamydia trachomatis elementary bodies (MRL Diagnostics, USA) as antigens to detect specific IgG, IgM and IgA antibodies. Serological evidence of CP infection was based on the criteria published by Grayston et al. [4]. A 4-fold rise in IgG/IgA titer in paired sera or an IgM titer of 61:20 in any serum was considered as presumptive evidence of acute or recent infection with CP. Titers of IgG 61:32 and !1:512 were assumed to be due to past infection with CP. Titers with stable IgG and IgA titers 61:32 were assumed to represent chronic infection with CP. A negative result was defined as an IgG/IgA titer !1:32 and IgM titer !1:20. Serum samples were taken twice in a 4-week period and occasionally during the following months, to detect the stable titer of antibodies (the diapason of variability is shown in table 1). Table 1. Consecutive titers of CP antibodies in our patients’ sera

Apoptosis and Histopathologic Changes in Diffuse Coronary Atherosclerosis

The aims of the study were to investigate the histopathologic characteristics of atherosclerotic lesions and to evaluate the role of apoptosis or programmed cell death in diffuse coronary atherosclerosis. The study included 59 patients who underwent coronary artery bypass grafting coupled with coronary endarterectomy because of diffuse coronary atherosclerosis. Histopathologic analysis of endarterectomy sequesters showed atheroma with confluent extracellular lipid core—type IV lesions in 13 cases (22%); atheroma with lipid core and a cap of fibromuscular layers—type V lesions in 9 cases (15.3%); predominantly calcified fibrous tissue—type VII lesions in 13 cases (22%); and predominantly fibrous tissue—type VIII lesions in 24 cases (40.7%). TUNEL-positive cells were observed in 4 endarterectomy sequesters (6.8%) of subjects with diffuse coronary atherosclerosis. TUNEL-positive cells were demon strated in the area of mononuclear infiltrates as well as in the vessel wall. The percentage of TUNEL-positive cells in mononuclear infiltrates was 0.5%. Intense mononuclear infiltrates in tunica intima were found in 50% of sequesters, and they consisted of macrophages (40%), T-lymphocytes (17%), and B-lymphocytes (14%). In the area of infiltrates the proportion of MIB-1-positive cells was 2.7%, which was higher than in the intima outside the area of infil trates (0.5%). In conclusion, apoptosis, which is confined to mononuclear infiltrates, is most likely involved in the development of diffuse coronary atherosclerosis; however, the percentage of apoptotic cells was low (0.5%). A higher proportion of apoptotic cells in the area of infiltrates compared to the rest of the intima was associated with a higher proportion of MIB-1-positive cells. Atherosclerotic lesions in diffuse coronary atherosclerosis were advanced, with a predom inance of type VII to VIII lesions.