Characterisation and preliminary lipid-lowering evaluation of Lactobacillus isolated from a traditional Serbian dairy product.

We investigated the potential probiotic properties of indigenous lactic acid bacteria (LAB) isolated from Serbian homemade cheese. Seventeen LAB strains were isolated and characterised using standard protocols. One of the strains showed several probiotic properties: survival at low pH and in bile salts solution, antimicrobial activity, susceptibility to antibiotics and adhesion to hexodecane. DNA analysis identified the isolate as Lactobacillus casei, hereafter named L. casei 5s. The lipid lowering effect of L. casei 5s was evaluated in vivo using a hyperlipidemic rat model. Orally administered L. casei 5s significantly decreased the elevated total serum cholesterol and triglycerides, and attenuated macro vesicular steatosis in the liver. Moreover, L. casei 5s improved the intestinal microbial balance in favour of lactobacilli, while decreasing the number of Escherichia coli cells. The bacteria were re-isolated and identified from the surface of the intestinal mucosa and from the faecal samples of treated animals, indicating adhesiveness and colonisation ability. The results of an acute oral toxicity study in mice and the absence of translocation to other organs demonstrated the safety of the strain. In conclusion, L. casei 5s demonstrated promising probiotic potential and might be a good candidate for more detailed investigations.

p16INK4a as an adjunct test in cervical cytology.

BACKGROUND: This study investigated the correlation between cervical cytology, the expression of P16INK4a, and human papilloma virus (HPV) infection. MATERIALS AND METHODS: The study included 100 subjects with suspected pathological cervical lesions. Cervical smears were analyzed for malignancy and p16INK4a. Histological finding represented "the golden standard". RESULTS: Immunocytochemical analysis of protein p16INK4a expression on epithelial cells of cervical smear demonstrated increased p16lNK4a expression in 36.0% of subjects. There was statistically significant positive correlation (Spearman r = 0.70; p < 0.001) between the pathological findings and the intensity of p16INK4a protein expression inside the epithelial cells, as well as with the histological finding (Spearman r = 0.71; p < 0.001). The intensity of p16INK4a protein expression in cytology finding was significantly higher in HPV16 positive patients (Mann- Whitney test, p = 0.0065). CONCLUSION: Good correlation between the expression rate and the severity of lesions indicates that this test might improve the results of cytology and HPV screening, as well as the results of predicting the prognosis of the disorder of the cervix.

Transport of endogenous nucleosides in guinea pig heart.

The purpose of this study was to investigate the characteristics of transport of endogenous nucleosides into cardiac tissue from coronary circulation. The study was performed on the isolated perfused guinea pig heart, using the rapid paired tracers single-pass technique. The maximal cellular uptake (U(max)) and total cellular uptake (U(tot)) of adenosine, deoxyadenosine, thymidine, uridine, and cytidine were determined. The cellular uptake of adenosine was significantly higher than the cellular uptake of other studied nucleosides. To elucidate the mechanisms of nucleoside transport, competition studies were performed and the influence of S-(p-nitrobenzyl)-6-thioinosine (NBTI) and sodium ion absence on U(max) and U(tot) was investigated. Self- and cross-inhibition studies indicated the saturable mechanism of nucleosides transport into cardiac tissue and the involvement of different transport mechanisms for purine and pyrimidine nucleosides. The study also showed that both equilibrative-sensitive (es) and sodium-dependent transport were responsible for adenosine and thymidine cellular uptake.

Effects of atropine, trimedoxime and methylprednisolone on the development of organophosphate-induced delayed polyneuropathy in the hen.

In this study we have examined the effects of atropine, trimedoxime (TMB-4) and methylprednisolone (MP) on the development of organophosphate-induced delayed polyneuropathy (OPIDP) in the hen. The birds were treated with standard neuropathic dose of diisopropylfluorophosphate (DFP) (1.1 mg/kg, sc), which produced OPIDP that could be graded as 5 on the 8-point scale, and the development of OPIDP was observed for the next 22 days. The results obtained have shown that atropine (20 mg/kg, ip), TMB-4 (15 mg/kg, im) and MP (2 or 10 mg/kg, ip) either alone or in different combinations are able to improve the condition of the birds. The most potent effect was obtained with atropine, TMB-4 (given 20 min before DFP) and MP (2 mg/kg, sc, given 20 min before and at 48 hour intrevals after poisoning) since the signs of OPIDP could hardly be seen (grade 1 at the 8-point scale). When TMB-4 and MP were given 15 or 40 min after DFP the protective/therapeutic effects of these drugs appeared to be diminished since walking disorders were more serious and graded as 2 or 4, respectively. The possible mechanisms of the action of the drugs in respect to OPIDP are discussed. In conclusion, the results of this study have shown that it is possible to prevent the development of DFP-induced OPIDP in the hen by treatment with atropine, trimedoxime and methylprednisolone when they were given before or soon after DFP.

8-Cl-cAMP and tiazofurin affect vascular endothelial growth factor production and glial fibrillary acidic protein expression in human glioblastoma cells.

Compounds that could block tumor angiogenesis and induce tumor cell differentiation in malignant gliomas represent a very valuable tool in anticancer treatments. In this paper, we demonstrate that more selective drugs, which interfere with specific cellular targets, could treat glioma more effectively. 8-Cl-cAMP and tiazofurin (TR) are site-specific analogs that selectively inhibit PKAI and IMP dehydrogenase, are directly involved in cell proliferation and apoptosis, and mediate the mitogenic effects of different oncogenes and growth factors. In this study, we have examined influence of 8-Cl-cAMP and TR on the production of an angiogenic factor [vascular endothelial growth factor (VEGF)] by human glioblastoma U251 MG cells, as well as their influence on the expression of a differentiating marker [glial fibrillary acidic protein (GFAP)]. Using a cell proliferation assay, VEGF enzyme-linked immunoassay and GFAP immunocytochemistry we demonstrated the effects of these compounds. Our results demonstrate that 8-Cl-cAMP and TR decrease VEGF production by U251 MG cells, and that under the influence of both agents these cells increase GFAP expression and change their morphology, becoming more differentiated. These findings also suggest that 8-Cl-cAMP and TR may have potential for further investigation of their antiangiogenic and differentiational role in malignant disease such as human gliomas.

Detection of apoptosis and phagocytosis in vitro in C6 rat glioma cells treated with tiazofurin.

Tiazofurin, an anticancer drug which inhibits IMP dehydrogenase activity and decreases GTP concentration in various malignant cells, induced inhibition of growth and apoptosis in C6 rat glioma in vitro. The effects of tiazofurin were significantly blocked by addition of exogenous guanosine, suggesting the role of decreased GTP in triggering specific signal transduction pathways involved in apoptosis of C6 cells. The most interesting result of this study was the evidence of phagocytosis of apoptotic cells in vitro by neighbouring cells, a phenomenon considered to occur only in apoptosis in vivo. The possibility of observing phagocytosis in C6 glioma cells suggests that this cell system could be a good model for studying mechanisms of phagocytosis in vitro.