The Role of Reactive Oxygen Species in Inflammatory Disease: Evaluation of Methodology

The production of reactive oxidants has been implicated in the pathology of a number of inflammatory conditions, including inflamed arthritic joints. Many assays for the detection of these oxidants in diseased states have been described, but there are a number of potential pitfalls in both experimental design and the interpretation of results obtained with these techniques. Here, we describe a number of commonly used assays to detect the production of reactive oxidants and critically discuss their usefulness and limitations. We focus on the role of xanthine oxidase in reactive oxidant production in inflammatory disease.     

Heterochromatic Stellate Gene Cluster in Drosophila Melanogaster: Structure and Molecular Evolution

The 30-kb cluster comprising close to 20 copies of tandemly repeated Stellate genes was localized in the distal heterochromatin of the X chromosome. Of 10 sequenced genes, nine contain undamaged open reading frames with extensive similarity to protein kinase CK2 β-subunit; one gene is interrupted by an insertion. The heterochromatic array of Stellate repeats is divided into three regions by a 4.5-kb DNA segment of unknown origin and a retrotransposon insertion: the A region (~14 Stellate genes), the adjacent B region (approximately three Stellate genes), and the C region (about four Stellate genes). The sequencing of Stellate copies located along the discontinuous cluster revealed a complex pattern of diversification. The lowest level of divergence was detected in nearby Stellate repeats. The marginal copies of the A region, truncated or interrupted by an insertion, escaped homogenization and demonstrated high levels of divergence. Comparison of copies in the B and C regions, which are separated by a retrotransposon insertion, revealed a high level of diversification. These observations suggest that homogenization takes place in the Stellate cluster, but that inserted sequences may impede this process.     

High glucose-induced mitochondrial respiration and reactive oxygen species in mouse cerebral pericytes is reversed by pharmacological inhibition of mitochondrial carbonic anhydrases: Implications for cerebral microvascular disease in diabetes

Hyperglycemia-induced oxidative stress leads to diabetes-associated damage to the microvasculature of the brain. Pericytes in close proximity to endothelial cells in the brain microvessels are vital to the integrity of the blood–brain barrier and are especially susceptible to oxidative stress. According to our recently published results, streptozotocin-diabetic mouse brain exhibits oxidative stress and loose pericytes by twelve weeks of diabetes, and cerebral pericytes cultured in high glucose media suffer intracellular oxidative stress and apoptosis. Oxidative stress in diabetes is hypothesized to be caused by reactive oxygen species (ROS) produced during hyperglycemia-induced enhanced oxidative metabolism of glucose (respiration). To test this hypothesis, we investigated the effect of high glucose on respiration rate and ROS production in mouse cerebral pericytes. Previously, we showed that pharmacological inhibition of mitochondrial carbonic anhydrases protects the brain from oxidative stress and pericyte loss. The high glucose-induced intracellular oxidative stress and apoptosis of pericytes in culture were also reversed by inhibition of mitochondrial carbonic anhydrases. Therefore, we extended our current study to determine the effect of these inhibitors on high glucose-induced increases in pericyte respiration and ROS. We now report that both the respiration and ROS are significantly increased in pericytes challenged with high glucose. Furthermore, inhibition of mitochondrial carbonic anhydrases significantly slowed down both the rate of respiration and ROS production. These data provide new evidence that pharmacological inhibitors of mitochondrial carbonic anhydrases, already in clinical use, may prove beneficial in protecting the brain from oxidative stress caused by ROS produced as a consequence of hyperglycemia-induced enhanced respiration.     

The question of virginity testing in Turkey

Pre-marital sex for a woman is regarded as wrong in my country. As a result, it is socially forbidden for a woman to engage in this act. In order to present a woman as a virgin on her marriage day, she is subjected to pressure, and put under control both by her family and societal norms. However, a man is free and never made to suffer any of the above. A woman found to be a virgin on her first night of marriage is seen as a normal person while one suspected to have lost her virginity is made to undergo a series of medical examinations to bring clarity to her situation.     

The study of interaction between paralogous tandem repeats stellate and suppressor of stellate in the genome of Drosophila melanogaster

Testis-specific expression of tandemly repeated Stellate genes, located in eu- and heterochromatin regions of the X chromosome of Drosophila melanogaster, is suppressed by homologous Suppressor of Stellate repeats located on the Y chromosome. Using transgenic lines, we have demonstrated that three Su(Ste) copies failed to change the expression of the reporter construction carrying the bacterial beta-galactosidase gene under control of the Stellate gene regulatory sequence. Possible mechanisms of the Su(Ste) repeat suppressor activity are discussed.