Inflammatory components in endarterectomy lesions: an immunohistological study

The aim of this study was to characterize the immunohistological components of chronic inflammation in endarterectomy lesions. Therefore, in 24 patients endarterectomy specimens were obtained from coronary arteries during CABG surgery (16 from RCA and 8 from LCA) and immunohistologically analyzed using avidin-biotin method (LSAB(R)/AP) with monoclonal antibodies. Macrophages and CD3 lymphocytes were counted under 200x magnification but MHC class II and ICAM-1 adhesion molecules were analyzed semi-quantitatively (scale from 0 to 3+). The mean macrophages density was 47.8+/-9.8 cells per mm2 and mean CD3 lymphocyte density was 1.3+/-0.6 cells per mm2. Lack or weak expression of HLA-DR (0-1+) on macrophages was found in 17 of 24 cases (70.8%). In the remaining seven cases (29.2%) there was a moderate and strong expression (2+ and 3+) of HLA-DR antigens. Similarly, no or weak ICAM-1 expression on macrophages was detected in 19 cases (79.2%). These cells were positively stained for ICAM-1 in only five cases (20.8%). Our data suggest that in advanced primary atherosclerotic lesions chronic inflammation is still present. On the other hand, the small number of activated inflammatory cells and the absence of positively stained endothelium suggests that inflammatory process tends to be burnt-out.     

The epidemiology of the morbidity of respiratory system malignant neoplasm in Poland on the background of the increasing atmospheric air pollution by dust and vehicle exhaust emission

This research work has been carried out on relationship between an increasing air pollution rate caused by dust and vehicle exhaust emissions and a rising morbidity of respiratory system malignant neoplasm in Poland in the years 1956-1982. The calculated correlation coefficients (r) are for vehicle exhausts--0.965 and for dust emissions--0.946. Those coefficients indicate the relationship between the investigated phenomena at the significance level of P less than 0.001.     

Direct vascular connection between adrenal gland and kidney may play an important role in pathogenesis of hypertension

A direct vascular connection between adrenal gland and kidney exists in various species. Thereby kidney function might be modified by the adrenal gland more precisely. In addition, the impact of adrenal hormones on the kidney function due to this circulatory 'by-pass' might be much stronger than judged from the relevant hormone concentrations in the circulating blood. Because overactivity of the sympatho-adrenal system is evident in essential hypertension we hypothesize that the adrenal-renal vascular connection plays an important role in the pathogenesis of arterial hypertension.     

Methylene ATP analogs as modulators of extracellular ATP metabolism and accumulation

1 Transient accumulation of extracellular ATP reflects both release of ATP from intracellular stores and altered rates of ATP metabolism by ecto-enzymes. Ecto-nucleoside triphosphate diphosphohydrolases (eNTPDases) and ecto-nucleotide pyrophosphatases (eNPPs) degrade ATP, while ecto-nucleotide diphosphokinases (eNDPKs) synthesize ATP from ambient ADP. 2 Although the methylene ATP analogs betagamma-meATP and alphabeta-meATP are widely used as metabolically stable tools for the analysis of purinergic signaling, their specific effects on eNTPDase, eNPP, and eNDPK activities have not been defined. This study compared the actions of these analogs on extracellular ATP metabolism by human 1321N1 astrocytes, rat PC12 pheochomocytoma cells, and rat C6 glioma cells. 3 Both analogs significantly reduced clearance of extracellular ATP by 1321N1 cells that express both eNTPDases and eNPPs, as well as by C6 cells that exclusively express eNPPs. In contrast, both analogs were much less efficacious in inhibiting ATP clearance by PC12 cells that predominantly express eNTPDases. Betagamma-meATP, but not alphabeta-meATP, was effectively hydrolyzed by the 1321N1 and C6 cells; PC12 cells did not significantly degrade this analog. 4 Alphabeta-meATP, but not betagamma-meATP, acted as a substrate for purified yeast NDPK to generate ATP via trans-phosphorylation of ADP. alphabeta-meATP also acted as substrate for the eNDPK activities expressed by 1321N1, PC12, and C6 cells and thereby induced extracellular ATP accumulation in the presence of ambient or exogenously added ADP. 5 These results indicate that methylene ATP analogs exert complex and cell-specific effects on extracellular ATP metabolism that can significantly modify interpretation of studies that use these reagents as probes of purinergic signal transduction in intact tissues.     

Medulloblastoma cell line secretes platelet-derived growth factor

Medulloblastoma is the most common malignant childhood brain tumor in which aggressive growth produces recurrence in approximately 50% of appropriately treated cases and metastases along the neuraxis in 30%. To date, no studies exist concerning the production of autocrine growth factors by this brain tumor type. Malignant brain tumors in adults often produce platelet-derived growth factor (PDGF). A medulloblastoma cell line, TE-671, has been used for many years in pediatric neuro-oncologic studies. We assayed this medulloblastoma cell line for the production of PDGF. PDGF is produced by medulloblastoma cells grown in monolayer tissue culture and stimulates PDGF-sensitive 3T3 fibroblasts to incorporate tritiated thymidine in a dose-dependent fashion. This biologic activity is blocked by PDGF antibodies in a dose-dependent relationship. We postulate that PDGF produced by medulloblastoma cells plays a role in the growth of this tumor by stimulating mitogenic activity.