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.     

New species and records of Heteroconium (anamorphic fungi) from southern China

Four anamorphic fungal species of Heteroconium were collected from tropical and subtropical forests in southern China. Among them, Heteroconium tsoongiodendronis sp. nov. and Heteroconium fici sp. nov. are described from specimens collected on dead branches of Tsoongiodendron odorum and Ficus gibbosa, respectively. Two species of Heteroconium, H. decorosum and H. ponapense, are recorded for the first time in China. A key to Heteroconium and related genera is also provided.     

Reperfusion Promotes Mitochondrial Dysfunction following Focal Cerebral Ischemia in Rats

Background and Purpose

Mitochondrial dysfunction has been implicated in the cell death observed after cerebral ischemia, and several mechanisms for this dysfunction have been proposed. Reperfusion after transient cerebral ischemia may cause continued and even more severe damage to the brain. Many lines of evidence have shown that mitochondria suffer severe damage in response to ischemic injury. The purpose of this study was to observe the features of mitochondrial dysfunction in isolated mitochondria during the reperfusion period following focal cerebral ischemia.

Methods

Male Wistar rats were subjected to focal cerebral ischemia. Mitochondria were isolated using Percoll density gradient centrifugation. The isolated mitochondria were fixed for electron microscopic examination; calcium-induced mitochondrial swelling was quantified using spectrophotometry. Cyclophilin D was detected by Western blotting. Fluorescent probes were used to selectively stain mitochondria to measure their membrane potential and to measure reactive oxidative species production using flow cytometric analysis.

Results

Signs of damage were observed in the mitochondrial morphology after exposure to reperfusion. The mitochondrial swelling induced by Ca²⁺ increased gradually with the increasing calcium concentration, and this tendency was exacerbated as the reperfusion time was extended. Cyclophilin D protein expression peaked after 24 hours of reperfusion. The mitochondrial membrane potential was decreased significantly during the reperfusion period, with the greatest decrease observed after 24 hours of reperfusion. The surge in mitochondrial reactive oxidative species occurred after 2 hours of reperfusion and was maintained at a high level during the reperfusion period.

Conclusions

Reperfusion following focal cerebral ischemia induced significant mitochondrial morphological damage and Ca²⁺-induced mitochondrial swelling. The mechanism of this swelling may be mediated by the upregulation of the Cyclophilin D protein, the destruction of the mitochondrial membrane potential and the generation of excessive reactive oxidative species.     

Genes Encoding Cher-TPR Fusion Proteins Are Predominantly Found in Gene Clusters Encoding Chemosensory Pathways with Alternative Cellular Functions

Chemosensory pathways correspond to major signal transduction mechanisms and can be classified into the functional families flagellum-mediated taxis, type four pili-mediated taxis or pathways with alternative cellular functions (ACF). CheR methyltransferases are core enzymes in all of these families. CheR proteins fused to tetratricopeptide repeat (TPR) domains have been reported and we present an analysis of this uncharacterized family. We show that CheR-TPRs are widely distributed in GRAM-negative but almost absent from GRAM-positive bacteria. Most strains contain a single CheR-TPR and its abundance does not correlate with the number of chemoreceptors. The TPR domain fused to CheR is comparatively short and frequently composed of 2 repeats. The majority of CheR-TPR genes were found in gene clusters that harbor multidomain response regulators in which the REC domain is fused to different output domains like HK, GGDEF, EAL, HPT, AAA, PAS, GAF, additional REC, HTH, phosphatase or combinations thereof. The response regulator architectures coincide with those reported for the ACF family of pathways. Since the presence of multidomain response regulators is a distinctive feature of this pathway family, we conclude that CheR-TPR proteins form part of ACF type pathways. The diversity of response regulator output domains suggests that the ACF pathways form a superfamily which regroups many different regulatory mechanisms, in which all CheR-TPR proteins appear to participate. In the second part we characterize WspC of Pseudomonas putida, a representative example of CheR-TPR. The affinities of WspC-Pp for S-adenosylmethionine and S-adenosylhomocysteine were comparable to those of prototypal CheR, indicating that WspC-Pp activity is in analogy to prototypal CheRs controlled by product feed-back inhibition. The removal of the TPR domain did not impact significantly on the binding constants and consequently not on the product feed-back inhibition. WspC-Pp was found to be monomeric, which rules out a role of the TPR domain in self-association.     

Airway delivery of soluble mycobacterial antigens restores protective mucosal immunity by single intramuscular plasmid DNA tuberculosis vaccination: role of proinflammatory signals in the lung

Protection by parenteral immunization with plasmid DNA vaccines against pulmonary tuberculosis (TB) is very modest. In this study, we have investigated the underlying mechanisms for the poor mucosal protective efficacy and the avenues and mechanisms to improve the efficacy of a single i.m. immunization with a monogenic plasmid DNA TB vaccine in a murine model. We show that i.m. DNA immunization fails to elicit accumulation of Ag-specific T cells in the airway lumen despite robust T cell responses in the spleen. Such systemically activated T cells cannot be rapidly mobilized into the airway lumen upon Mycobacterium tuberculosis exposure. However, airway deposition of low doses of soluble mycobacterial Ags in previously immunized mice effectively mobilizes the systemically activated T cells into the airway lumen. A fraction of such airway luminal T cells can persist in the airway lumen, undergo quick, robust expansion and activation and provide marked immune protection upon airway M. tuberculosis exposure. Airway mucosal deposition of soluble mycobacterial Ags was found to create a tissue microenvironment rich in proinflammatory molecules including chemokines and hence conducive to T cell recruitment. Thus, in vivo neutralization of MIP-1alpha or IFN-inducible protein-10 markedly inhibited the accumulation of Ag-specific T cells in the airway lumen. Our data suggest that immunoprotective efficacy on the mucosal surface by i.m. plasmid DNA immunization could be substantially improved by simple mucosal soluble Ag inoculation and restoration of mucosal luminal T cells. Our study holds implication for the future design of DNA vaccination strategies against intracellular infections.     

Regulation of cAMP on the first mitotic cell cycle of mouse embryos

Mitosis promoting factor (MPF) plays a central role during the first mitosis of mouse embryo. We demonstrated that MPF activity increased when one-cell stage mouse embryo initiated G2/M transition following the decrease of cyclic adenosine 3', 5'-monophosphate (cAMP) and cAMP-dependent protein kinase (PKA) activity. When cAMP and PKA activity increases again, MPF activity decreases and mouse embryo starts metaphase-anaphase transition. In the downstream of cAMP/PKA, there are some effectors such as polo-like kinase 1 (Plk1), Cdc25, Mos (mitogen-activated protein kinase kinase kinase), MEK (mitogen-activated protein kinase kinase), mitogen-activated protein kinase (MAPK), Wee1, anaphase-promoting complex (APC), and phosphoprotein phosphatase that are involved in the regulation of MPF activity. Here, we demonstrated that following activation of MPF, MAPK activity was steady, whereas Plk1 activity fluctuated during the first cell cycle. Plk1 activity was the highest at metaphase and decreased at metaphase-anaphase transition. Further, we established a mathematical model using Gepasi algorithm and the simulation was in agreement with the experimental data. Above all the evidences, we suggested that cAMP and PKA might be the upstream factors which were included in the regulation of the first cell cycle development of mouse embryo.     

Synergie between molecular imprinted polymer based on solid-phase extraction and quartz crystal microbalance technique for 8-OHdG sensing

Recently, the 8-hydroxy-2'-deoxyguanosine (8-OHdG) has been used as a marker to determine the oxidative stress. There is no any cheap and easy determination method based on chips and sensor systems for the determination of 8-OHdG. In this study, we have proposed imprinting methods for 8-OHdG recognition and determination using methacryloylamidohistidine-platinum(II) [MAH-Pt(II)] as a new metal-chelating monomer. The study includes the solid-phase extraction (SPE) of blood sample by a new 8-OHdG imprinted sorbent and the measurement of binding interaction of 8-OHdG imprinted quartz crystal microbalance (QCM) sensor via ligand interaction. 8-OHdG imprinted sorbent has prepared by bulk polymerization of MAH-Pt(II) and N-N'-methylenebisacrylamide. 8-OHdG imprinted sensor has prepared on a QCM chip coating the thiol pretreated Au electrode. At the end of these steps, a thin molecular imprinted polymer (MIP) film for the detection of 8-OHdG has developed and analytical performance of QCM sensor which has prepared using MIP was investigated. The affinity constant (K(a)) for 8-OHdG using MAH-Pt-based thin film has determined by using the Scatchard method. The average percentage recovery of 8-OHdG from plasma samples was found as 80% by using of 8-OHdG imprinted SPE material. At the last step, 8-OHdG level in several blood plasma has been determined by this improved QCM sensor. The obtained results confirmed that the 8-OHdG level in cancer patient's blood was significantly higher than in general subjects.