Population types of cataclysmic variables in the solar neighborhood

The Galactic orbital parameters of 159 cataclysmic variables in the Solar neighbourhood are calculated, for the first time, to determine their population types using published kinematical parameters. Population analysis shows that about 6 per cent of cataclysmic variables in the sample are members of the thi ck disc component of the Galaxy. This value is consistent with the fraction obt ained from star count analysis. The rest of the systems in the sample are found to be in the thin disc component of the Galaxy. Our analysis revealed no halo CVs in the Solar vicinity. About 60 per cent of the thick disc CVs have orbital periods be low the orbital period gap. This result is roughly consistent with the predictions of population synthesis models developed for cataclysmic variables. A kinematical age of 13 Gyr is obtained using total space velocity dispersion of the most probable thick disc CVs which is consistent with the age of thick disc component of the Galaxy

Susceptibility patterns and cross resistances of antibiotics against Pseudomonas aeruginosa in a teaching hospital of Turkey

BACKGROUND: Pseudomonas aeruginosa is the third most common pathogen responsible for nosocomial infections and the prevalence of multiple resistant isolates has been increasing. Ninety-nine clinical isolates were studied in order to assess the current levels of susceptibility and cross-resistances of widely used antipseudomonal antibiotics against P. aeruginosa and to determine some resistance mechanisms by phenotypic methods. METHODS: MICs of isolates for nine antipseudomonal antibiotics were determined by the E test method. RESULTS: Thirty-six percent of isolates were resistant to more than one group of antibiotics. The rates of susceptible isolates were ciprofloxacin 75%, amikacin 73%, ceftazidime 65%, meropenem 63%, imipenem 63%, piperacillin/tazobactam 60%, cefoperazone/sulbactam 59%, cefepime 54% and tobramycin 44%. The majority of carbapenem resistant isolates were susceptible to ciprofloxacin and amikacin. CONCLUSION: Ciprofloxacin seems to be the most active agent against P. aeruginosa followed by amikacin in our unit. The usefulness of combinations of these antibiotics and β-lactams should be tested in treating multi-drug resistant P. aeruginosa

Investigation of the Anti-Cancer Effects of B-asaron and Etoposide in MCF-7 Breast Cancer Cells

Currently, the options available for the treatment of various cancers including breast cancer, are associated with several limitations such as severe toxicity, drug resistance, poor prognosis, and high risk of recurrence. Therefore, there appears to be an increasing interest and necessity in investigating various phytochemicals from natural sources for a superior and safer alternative treatment strategy. The bioactive phytochemical alpha (alpha%253B) and beta (beta%253B)-asarone from Acorus calamus is a traditional medicine system that has been shown to have anti-tumor and chemo-inhibitory activities in numerous preclinical studies both in vitro and in vivo. Various experimental studies with human malignant cell lines and animal models have also confirmed the anti-tumor and anti-cancer activities of beta%253B-asarone. In this study, we aimed to investigate the anti-cancer effects of beta%253B-asarone alone or together with etoposide buy measuring cellular responses such as cell viablity, cell cycle arrest and apoptosis using breast cancer cell line MCF-7 cells. In order to get insight in to the mechanism, we also tested the expression of of NF-kappa%253BB %252F p65 activity and the expression of Bcl-2 family member pro-apoptotic Bax protein together with p53 and p21 activities in response to beta%253B-asarone alone or together with etoposide treatment. As a result, it was concluded that the use of beta%253B-asarone alone in breast cancer cells is effective in reducing cell viability, but when used together with Etoposide, it does not cause a synergistic effect. Here we suggest that that in particular activation of NF-kB%252Fp65 may be lead resistance to etoposide treatment

Ultrastructure of the Natal and Primary Teeth

Aim: The teeth present in the oral cavity at birth are known as natal teeth and their etiology is still unknown. In this study, we aimed to compare the morphologic structures of natal and primary teeth at the ultra structural level using transmission electron microscope (TEM). Material and Methods: We investigated a natal tooth of a fourteen-day-old newborn baby. It was extracted due to the hypermobility with a risk of aspiration. As a control, a healthy primary incisor tooth was extracted from another child due to the physiologic root resorption. Immediately after extraction, both teeth were fixed in 10% formalin solution and decalcified by immersion in ethylenediaminetetraacetic acid (EDTA) solution. Following routine TEM preparation process, teeth were embedded in Epon 812. Results: Histologically, structures of enamel prism and dentin tubules were different in the natal tooth compared to the primary tooth. Light microscopic (LM) and TEM investigations of the primary tooth showed prominent crystal structures in the enamel prism and regular organization in both enamel and dentin. LM and TEM investigations of the natal tooth revealed an irregular enamel prism in the hypoplastic enamel, vacuolization in the interprismatic enamel and an irregular organization in the dentin tubules. Conclusion: We conclude that the structural differences of the enamel and dentin in the natal tooth might be a result of incomplete maturation

A Quantitative Look at Fluorosis, Fluoride Exposure, and Intake in Children Using a Health Risk Assessment Approach

The prevalence of dental fluorosis in the United States has increased during the last 30 years. In this study, we used a mathematical model commonly employed by the U.S. Environmental Protection Agency to estimate average daily intake of fluoride via all applicable exposure pathways contributing to fluorosis risk for infants and children living in hypothetical fluoridated and non-fluoridated communities. We also estimated hazard quotients for each exposure pathway and hazard indices for exposure conditions representative of central tendency exposure (CTE) and reasonable maximum exposure (RME) conditions. The exposure pathways considered were uptake of fluoride via fluoridated drinking water, beverages, cow’s milk, foods, and fluoride supplements for both age groups. Additionally, consumption of infant formula for infants and inadvertent swallowing of toothpaste while brushing and incidental ingestion of soil for children were also considered. The cumulative daily fluoride intake in fluoridated areas was estimated as 0.20 and 0.11 mg/kg-day for RME and CTE scenarios, respectively, for infants. On the other hand, the RME and CTE estimates for children were 0.23 and 0.06 mg/kg-day, respectively. In areas where municipal water is not fluoridated, our RME and CTE estimates for cumulative daily average intake were, respectively, 0.11 and 0.08 mg/kg-day for infants and 0.21 and 0.06 mg/kg-day for children. Our theoretical estimates are in good agreement with measurement-based estimates reported in the literature. Although CTE estimates were within the optimum range for dental caries prevention, the RME estimates were above the upper tolerable intake limit. This suggests that some children may be at risk for fluorosis

Nuclear anomalies in the buccal cells of calcite factory workers

The micronucleus (MN) assay on exfoliated buccal cells is a useful and minimally invasive method for monitoring genetic damage in humans. To determine the genotoxic effects of calcite dust that forms during processing, MN assay was carried out in exfoliated buccal cells of 50 (25 smokers and 25 non-smokers) calcite factory workers and 50 (25 smokers and 25 non-smokers) age- and sex-matched control subjects. Frequencies of nuclear abnormalities (NA) other than micronuclei, such as binucleates, karyorrhexis, karyolysis and ‘broken eggs', were also evaluated. Micronuclei and the other aforementioned anomalies were analysed by two way analysis of covariance. The linear correlations between the types of micronucleus and nuclear abnormalities were determined by Spearman's Rho. There was a positive correlation between micronuclei and other types of nuclear abnormalities in accordance with the Spearman's Rho test. Results showed statistically significant difference between calcite fabric workers and control groups. MN and NA frequencies in calcite fabric workers were significantly higher than those in control groups (p < 0.05). The results of this study indicate that calcite fabric workers are under risk of significant cytogenetic damage

A Novel G Protein-Coupled Receptor of Schistosoma mansoni (SmGPR-3) Is Activated by Dopamine and Is Widely Expressed in the Nervous System

Schistosomes have a well developed nervous system that coordinates virtually every activity of the parasite and therefore is considered to be a promising target for chemotherapeutic intervention. Neurotransmitter receptors, in particular those involved in neuromuscular control, are proven drug targets in other helminths but very few of these receptors have been identified in schistosomes and little is known about their roles in the biology of the worm. Here we describe a novel Schistosoma mansoni G protein-coupled receptor (named SmGPR-3) that was cloned, expressed heterologously and shown to be activated by dopamine, a well established neurotransmitter of the schistosome nervous system. SmGPR-3 belongs to a new clade of “orphan” amine-like receptors that exist in schistosomes but not the mammalian host. Further analysis of the recombinant protein showed that SmGPR-3 can also be activated by other catecholamines, including the dopamine metabolite, epinine, and it has an unusual antagonist profile when compared to mammalian receptors. Confocal immunofluorescence experiments using a specific peptide antibody showed that SmGPR-3 is abundantly expressed in the nervous system of schistosomes, particularly in the main nerve cords and the peripheral innervation of the body wall muscles. In addition, we show that dopamine, epinine and other dopaminergic agents have strong effects on the motility of larval schistosomes in culture. Together, the results suggest that SmGPR-3 is an important neuronal receptor and is probably involved in the control of motor activity in schistosomes. We have conducted a first analysis of the structure of SmGPR-3 by means of homology modeling and virtual ligand-docking simulations. This investigation has identified potentially important differences between SmGPR-3 and host dopamine receptors that could be exploited to develop new, parasite-selective anti-schistosomal drugs