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Metal complexes displaying antiplatelet properties is a promising research area. In our methodology, Platelet-Activating Factor (PAF), the most potent lipid pro-inflammatory mediator, serves as a biological probe. The antiplatelet activity is exerted by the inhibition of the PAF-induced aggregation in washed rabbit platelets (WRPs) and in rabbit plasma rich in platelets (rPRPs). Herein, the synthesis and biological investigation of a series of organometallic tin(II) and tin(IV) complexes, featuring the oxygen tripodal Kläui ligands [( η 5 -C 5 R 5 )Co{P(OEt) 2 O} 3 ] - , {R = H, (L OEt - ); Me (L* OEt - )}, are reported. Reaction of NaL OEt ( 1a ) and NaL* OEt ( 1b ) with SnCl 2 , yielded the rare four-coordinate L OEt SnCl ( 2a ) and L* OEt SnCl ( 2b ) complexes. Accordingly, L OEt SnPh 3 ( 3a ) and L* OEt SnPh 3 ( 3b ) were prepared, starting from Ph 3 SnCl. Characterization includes spectroscopy and X-ray diffraction studies for 2a , 2b and 3b . The antiplatelet activity of the lead complexes 2b and 3a (IC 50 = 0.5 μΜ) is superior compared to that of 1a and 1b , while both complexes display a pronounced inhibitory activity against thrombin (IC 50 = 1.8 μM and 0.6 μM). The in vitro cytotoxic activities of 3a and 2b on human Jurkat T lymphoblastic tumor cell line is higher than that of cisplatin.

Shipyards are industrial areas where workers are likely exposed to environmental pollutants such as welding fumes, fine organic solvent and dye dust, that render the occupational environment a high risk one. Assessing the risk that workers are exposed to is a high critical factor in improving their working conditions. The present study aims to investigate the potential genetic damage to workers exposed to a harsh environment in a Greek shipyard. It is focused on assessing the percentage of induced micronuclei, as well as on changes in the various cell types of shipyard workers' oral mucosa epithelium by implementing the buccal micronucleus cytome assay. Exposed workers appeared with statistically significant induced micronuclei as compared to office employees. Statistically, significant cell lesions were detected and are related to workers' exposure to environmental conditions. The workers' smoking habit contributed as well to the observed buccal epithelial cell alterations. The observed data signify the high-risk workers are exposed; resulting in the shipyard's management the need to implement measures improving the working environment conditions and to reevaluate the workers' personal protective equipment requirements.

Auger electron spectroscopy was used to detect calcium and phosphorus of cortical bone from rat femoral neck and rear tibia. Spectra were taken from bone pieces as well as from disks prepared from grinded bone material. Experimental conditions were found whereby the samples could be analyzed without conductive coatings. The results of this preliminary investigation demonstrate that Auger electron spectroscopy can be used to study bone mineral elements.

The structure of mouse skin collagen fibrils after treatment with 0.5, 1 and 2.5 Gy gamma-irradiation was studied by electron microscopy. Animals were sacrificed 1, 4 and 8 weeks after irradiation. Although there were areas where the normal parallel packing of fibrils was retained in some regions packing was interrupted by abnormal fibrils and in some cases helical twisting was apparent. Irradiated collagen fibrils had a lower mean diameter compared with normal and a large variability in width. The diameter of 0.5 Gy irradiated fibrils returned to normal by 4 or 8 weeks after irradiation. Clusters of abnormal fibrils were found when viewed in cross-sections. Their number and size was reversibly dependent on the dose level. All fibrils retained normal banding periodicity. Computer analysis of irradiated and control patterns led to the conclusion that 0.5-2.5 Gy gamma-irradiation had no considerable effect in modifying the charge distribution along the mouse skin collagen fibril.

Lithium is being used for the treatment of mental diseases and for the attenuation of muelosuppression during chemotherapy. As during long term lithium treatment kidney damage has been reported, we studied morphological alterations in cells of kidney origin after exposure to lithium chloride. Above the level of 4 mmol, lithium has fatal effects in CV1 cells while HeLa cells that are not originating from kidneys, tolerate higher lithium concentrations. Cellular morphology alters during treatment duration. At early stages, cells become flatter on their substrate and upon longer than 4 days treatment begin to detach from their substrate and eventually cell death comes in a concentration dependent manner. The only morphological alteration observed in a lymphoblastoid cell line was a statistically significant cellular swelling.

A novel approach to the identification of human chromosomes has been developed. Chromosomal in situ hybridization (or "chromosome painting") has been performed using Alu element-mediated PCR products from small quantities (250-500) of flow-sorted normal and abnormal chromosomes. Chromosome paints for various normal chromosomes, including 5, 6, 7, 14, 18, 19, 21, and 22, were generated and shown to be effective in the identification of the appropriate chromosomes. In addition, certain abnormal chromosomes, including a mental retardation-associated deletion chromosome 11 (q22-q23), the products of the constitutional translocation t(11;22), and the CML-associated t(9;22), were used to generate region-specific paints. In each case, the appropriate regions of the chromosomes were highlighted and this strategy is, therefore, well suited to the identification of previously unidentified marker chromosomes. A further direct consequence of this work is that chromosome paints specific for the common aberrant chromosomes, such as the Philadelphia chromosome, can be generated and made widely available. These may find particular use in the analysis of complex or masked chromosomal translocations.

Induction of the primitive streak is correlated with specific qualitative and quantitative changes in protein synthesis in the component areas of chick blastoderm. Blastoderm embryos at the initial to intermediate primitive streak stage were labeled with L-[ 35 S] methionine. Radioactively labeled proteins separated by two-dimensional sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis revealed differences in the number and density of spots among the component areas of the epiblast and hypoblast. Protein patterns of the area opaca, marginal zone and central area of the epiblast are very similar qualitatively but show distinct quantitative differences. A comparison between any of the component areas of the epiblast and the hypoblast in chick blastoderm embryos, however, reveals both qualitative and quantitative differences. A protein with a molecular weight of 30,000 unique to the component areas of the epiblast, and proteins with a molecular weight of 22,000 and 37,000 unique to the hypoblast are prominent and seem to be related to the initial appearance of the primitive streak.

The component areas of chick blastula show differential expression of heat shock genes. The area opaca (ao), marginal zone (mz) and central area (ca) components of the epiblast display distinct quantitative and minor qualitative differences in the heat-induced and heat-repressible proteins, but are clearly different from the primary hypoblast (endoderm) in their expression of a given stress protein (hsp) as a response to heat shock. The major proteins synthesized in the component areas of epiblast in response to heat shock include hsp 18, 24, 70 and 89 Kd. Two-dimensional electrophoresis shows that each of these proteins consists of multiple charged species. The hypoblast expresses only hsp 70 Kd at non-significant levels and shows marked inhibition in the level of synthesis of heat-shock-repressible proteins. Heat shock during the blastula stage results in an increase in the size of the blastoderm and disrupts normal embryonic development. The heat shock genes provide an important molecular marker, which attests to regional specification in the chick blastula.

Inhibition of DNA replication by aphidicolin in the chick morula interferes with its progression to a normal blastula and prevents induction of the first morphogenetic cell movements of primitive streak formation. Embryos in aphidicolin synthesize some polypeptides typical of blastula but do not display all the characteristic features of morula to blastula transition. Inhibition of DNA replication interferes with the sequential synthesis of maternally coded polypeptides and with the activation of the embryonic genome in the chick embryo.

Using immunofluorescence and immunoadsorption, CV1 cell clones MA2, V4, USA3, TR7 and P3 infected with SV40 were found to express variably SV40 large T antigen. The monoclonal antibody used was Pab 419. The results indicate that P3 cells express T antigen to a considerable level as early as 10 h post-infection, while that of TR7 and USA3 cells is minute as judged from their positive nuclei. MA2 and V4 cells did not show any positive nuclei over this period of infection. At 20 h post-infection MA2, V4 and USA3 cells developed a considerable amount of fluorescence in their nuclei while TR7 and P3 cells produced high values. By immunoadsorption of cell extracts for the same periods of infection, similar results were obtained on the electrophoretograms. We also relate these findings with those from induction of heatshock proteins by SV40 infection.

The polypeptides synthesized during the morula stage in the chick embryo are insensitive to transcriptional inhibition by α-amanitin. Protein synthesis seems to depend predominantely, if not exclusively, on the recruitment of maternal mRNA, rather than on embryonic gene expression in chick morula. The morula embryo expresses the heatshock polypeptides when stressed at 43°C. The heat-induced polypeptides are isoforms of polypeptides that are synthesized normally. These polypeptides are α-amanitin sensitive and appear to mark the first major expression of the embryonic genome in the chick embryo.

CV1 cells have been subcloned several times. Five of these clones were studied for the induction of the major heat shock proteins. These CV1 clones exhibit morphological differences as well as differences in SDS-PAGE protein profiles. These clones responded to heat shock variably as judged from the induction of the major heat shock proteins, 70, 72 and 92 kDa. Variable expression of the heat shock proteins suggests that the selective pressure for isolation of cell clones may affect gene expression differently.

Interaction between the epiblast and the primary hypoblast in chick blastula results in induction of the primitive streak (PS) in the epiblast. Alpha-amanitin, a specific inhibitor of poly A-containing RNA synthesis, inhibits formation of the definitive PS. This inhibition is associated with qualitative changes in the pattern of protein synthesis in the hypoblast but not in the epiblast. The protein pattern of the component areas of the epiblast shows increase in some polypeptides after treatment with alpha-amanitin. By contrast, alpha-amanitin resulted in a decrease in synthesis of several polypeptides, which are either undetectable or weakly present in the hypoblast. The alpha-amanitin-sensitive translational products of the embryonic genome that are observed in the hypoblast may have specific functions in the control of PS induction and stabilization.