Efflux of Glutathione and Glutathione Complexes from Human Erythrocytes in Response to Inorganic Arsenic Exposure

The objective of the present study was to investigate if arsenic exposure results in glutathione efflux from human erythrocytes. Arsenite significantly depleted intracellular nonprotein thiol level in a time- and concentration-dependent manner. The intracellular nonprotein thiol level was decreased to 0.767?±?0.0017???mol/ml erythrocyte following exposure to 10?mM of arsenite for 4?h. Extracellular nonprotein thiol level was increased concomitantly with the intracellular decrease and reached to 0.481?±?0.0005???mol/ml erythrocyte in 4?h. In parallel with the change in extracellular nonprotein thiol levels, significant increases in extracellular glutathione levels were detected. Extracellular glutathione levels reached to 0.122?±?0.0013, 0.226?±?0.003, and 0.274?±?0.004???mol/ml erythrocyte with 1, 5, and 10?mM of arsenite, respectively. Dimercaptosuccinic acid treatment of supernatants significantly increased the glutathione levels measured in the extracellular media. Utilization of MK571 and verapamil, multidrug resistance-associated protein 1 and Pgp inhibitors, decreased the rate of glutathione efflux from erythrocytes suggesting a role for these membrane transporters in the process. The results of the present study indicate that human erythrocytes efflux glutathione in reduced free form and in conjugated form or forms that can be recovered with dimercaptosuccinic acid when exposed to arsenite.     

Subjective sleep quality in premenstrual syndrome

Premenstrual syndrome (PMS) is a cyclical disorder observed in late luteal phase and presenting with behavioral changes that can affect interpersonal relationships and normal daily activity. Sleep disturbances are also common. The aim of this study is to investigate the relationship between PMS and subjective sleep quality with Pitsburg Sleep Quality Index (PSQI) in the Medical Academy students, whom have considerable information about menstruation. PMS was detected with "Premenstrual Syndrome Scale", and PSQI was used to evaluate subjective sleep quality. Chi-square test and Kendall's rank correlation analysis were used in statistical analysis. p values (p < 0.05) were considered as statistical significant. Poor sleep quality was found in the 75.6% of the participants with PMS, and 58.8% of the participants without PMS (p < 0.05). Only component 5 (sleep disorder component) of the PSQI components revealed statistically significant difference (1.7 ± 0.6 in participants with PMS, and 1.5 ± 0.6 without PMS, p < 0.05). There was a positive correlation between total PSQI score and all of its' components, except component 6 (sleeping pill usage component) (p < 0.05). The strongest association was found to be in the component 5 (r = 0.528; p = 0.0001). Results of our study suggested the poor sleep quality due to sleep disorders in women with PMS.     

Hyberbaric oxygen increases atresia in normal &; steroid induced PCO rat ovaries

Background  

In this study, we investigated the effect of hyperbaric oxygen therapy (HBOT) on the morphology of estradiol valerate (EV) induced polycystic ovary (PCO) to find a new treatment modality for improvement of PCO.     

Smart Markers for Watershed-Based Cell Segmentation

Automated cell imaging systems facilitate fast and reliable analysis of biological events at the cellular level. In these systems, the first step is usually cell segmentation that greatly affects the success of the subsequent system steps. On the other hand, similar to other image segmentation problems, cell segmentation is an ill-posed problem that typically necessitates the use of domain-specific knowledge to obtain successful segmentations even by human subjects. The approaches that can incorporate this knowledge into their segmentation algorithms have potential to greatly improve segmentation results. In this work, we propose a new approach for the effective segmentation of live cells from phase contrast microscopy. This approach introduces a new set of “smart markers” for a marker-controlled watershed algorithm, for which the identification of its markers is critical. The proposed approach relies on using domain-specific knowledge, in the form of visual characteristics of the cells, to define the markers. We evaluate our approach on a total of 1,954 cells. The experimental results demonstrate that this approach, which uses the proposed definition of smart markers, is quite effective in identifying better markers compared to its counterparts. This will, in turn, be effective in improving the segmentation performance of a marker-controlled watershed algorithm.     

Chaotic gene regulatory networks can be robust against mutations and noise

Robustness to mutations and noise has been shown to evolve through stabilizing selection for optimal phenotypes in model gene regulatory networks. The ability to evolve robust mutants is known to depend on the network architecture. How do the dynamical properties and state-space structures of networks with high and low robustness differ? Does selection operate on the global dynamical behavior of the networks? What kind of state-space structures are favored by selection? We provide damage propagation analysis and an extensive statistical analysis of state spaces of these model networks to show that the change in their dynamical properties due to stabilizing selection for optimal phenotypes is minor. Most notably, the networks that are most robust to both mutations and noise are highly chaotic. Certain properties of chaotic networks, such as being able to produce large attractor basins, can be useful for maintaining a stable gene-expression pattern. Our findings indicate that conventional measures of stability, such as damage propagation, do not provide much information about robustness to mutations or noise in model gene regulatory networks.     

Obestatin is present in saliva: alterations in obestatin and ghrelin levels of saliva and serum in ischemic heart disease

Ghrelin and obestatin are a single gene products and are a multiple functional peptides that regulates energy homeostasis, and food intake. In the present work, we studied the secretion of ghrelin and its co-secreted peptide obestatin in 44 patients with ischemic heart disease with that of 27 healthy matched controls. Here we first conducted using an immunohistochemistry assay to screen whether human salivary glands have any obestatin immunoreactivity. Then, serum and saliva obestatin and acylated ghrelin levels were determined by using Radioimmunoassay. Our immunohistochemical analysis demonstrated that obestatin was localized in the striated and excretory duct of human salivary gland. We also report for the first time that obestatin, like ghrelin, is present in human salivary gland and saliva. No evidence of the role of obestatin or ghrelin saliva levels in the context of ischemic heart disease was found. Salivary ghrelin and obestatin levels are correlated in controls with the blood levels. Determination of salivary values could represent a non-invasive alternative to serum ones that can be useful in clinical practice.