Chronic administration of the angiotensin-converting enzyme inhibitor, ramipril, prevents fractionated whole-brain irradiation-induced perirhinal cortex-dependent cognitive impairment

We hypothesized that chronic administration of the angiotensin-converting enzyme inhibitor, ramipril, to young adult male rats would prevent/ameliorate fractionated whole-brain irradiation-induced perirhinal cortex-dependent cognitive impairment. Eighty 12-14-week-old young adult male Fischer 344 rats received either: (1) sham irradiation, (2) 40 Gy of fractionated whole-brain irradiation delivered as two 5 Gy fractions/week for 4 weeks, (3) sham irradiation plus continuous administration of 15 mg/L of ramipril in the drinking water starting 3 days before irradiation, or (4) fractionated whole-brain irradiation plus ramipril. Cognitive function was assessed using a perirhinal cortex-dependent version of the novel object recognition task 26 weeks after irradiation. Microglial activation was determined in the perirhinal cortex and the dentate gyrus of the hippocampus 28 weeks after irradiation using the ED1 antibody. Neurogenesis was assessed in the granular cell layer and subgranular zones of the dentate gyrus using a doublecortin antibody. Fractionated whole-brain irradiation led to: (1) a significant impairment in perirhinal cortex-dependent cognitive function, (2) a significant increase in activated microglia in the dentate gyrus but not in the perirhinal cortex, and (3) a significant decrease in neurogenesis. Continuous administration of ramipril before, during, and after irradiation prevented the fractionated whole-brain irradiation-induced changes in perirhinal cortex-dependent cognitive function, as well as in microglial activation in the dentate gyrus. Thus, as hypothesized, continuous administration of the angiotensin-converting enzyme inhibitor, ramipril, can prevent the fractionated whole-brain irradiation-induced impairment in perirhinal cortex-dependent cognitive function.     

Seed Priming with Sodium Nitroprusside and H2O2 Confers Better Yield in Wheat Under Salinity: Water Relations,Antioxidative Defense Mechanism and Ion Homeostasis

Journal of Plant Growth Regulation - To mitigate the deleterious effects of abiotic stresses signaling molecules play a significant role. The present study was aimed to assess the responses of two...     

A survey for phosphoglucose isomerase with lysyl aminopeptidase activity in Vibrionaceae and non-Vibrio pathogens

Phosphoglucose isomerase (PGI) with a novel lysyl aminopeptidase (LysAP) activity was recently purified and characterized from Vibrio vulnificus. We showed that it cleaves the amino-terminal lysyl residue from des-Arg(10)-kallidin to produce des-Arg(9)-bradykinin, suggesting that it plays a role in virulence. A survey was conducted to determine the presence of this potential virulence-enhancing enzyme among twenty-three halotolerant human and fish pathogens from eleven species within the Vibrionaceae family, including V. vulnificus, V. parahaemolyticus, V. cholerae, Aeromonas hydrophila, and Plesiomonas shigelloides. In addition, fourteen species of non-Vibrionaceae pathogens were screened for LysAP activity. Cell lysates were partially purified by anion exchange chromatography and fractions were screened for LysAP and isomerase activities. PGI-LysAP activity was detected in chromatographic fractions from all the Vibrio species tested, but was not detected in any of the non-Vibrionaceae pathogens. Levels of isomerase and LysAP activity correlated (R(2)=0.92) for nine strains of V. vulnificus. Since the Vibrionaceae represent an important family of human and fish pathogens, our identification of PGI-LysAP activity in a broad array of vibrios may lead to the development of improved analytical methods for their identification as well as interventions to reduce the high morbidity and mortality associated with some Vibrionaceae infections in clinical, veterinary, and aquaculture settings.     

Diversity and dynamics of free-living and particle-associated Betaproteobacteria and Actinobacteria in relation to phytoplankton and zooplankton communities

The diversity of attached and free-living Actinobacteria and Betaproteobacteria, based on 16S rRNA gene sequences, was investigated in a mesotrophic lake during two periods of contrasting phytoplankton dominance. Comparison analyses showed a phylogenetic difference between attached and free-living communities for the two bacterial groups. For Betaproteobacteria, the betaI clade was detected at all sampling dates in free-living and attached bacterial communities and was the dominant clade contributing to 57.8% of the total retrieved operational taxonomic units (OTUs). For Actinobacteria, the acIV cluster was found to be dominant, followed by acI contributing to 45% and 25% of the total retrieved OTUs, respectively. This study allows the determination of eight new putative clades among the Betaproteobacteria termed lbI-lbVIII and a new putative clade named acLBI belonging to the Actinobacteria. The seasonal dynamics of phytoplankton and zooplankton communities have been reflected as changes in distinct bacterial phylotypes for both attached and free-living communities. For attached communities, relationships were observed between Actinobacteria and Chrysophyceae, and between Betaproteobacteria and Dinophyceae and Chlorophyceae biomass. On the other hand, within free-living communities, few actinobacterial clades were found to be dependent on either nutrients or phytoplankton communities, whereas Betaproteobacteria were mainly associated with biological parameters (i.e. phytoplankton and copepod communities).     

Modulatory effects of Pycnogenol® in a rat model of insulin-dependent diabetes mellitus: biochemical, histological, and immunohistochemical evidences

A number of experimental and clinical findings have consistently demonstrated the protective effects of Pycnogenol® (PYC) in the management of diabetes. However, the protective mechanism by which PYC provides protection in a model type I diabetes has not been studied. This study examines the beneficial effect of PYC on hyperglycemia, inflammatory markers, and oxidative damage in diabetic rats. We also evaluated the possible mechanism of action of PYC which might be that it stimulates beta islet expression, which has been implicated in the process of insulin secretion and diabetes management. Diabetes was induced in rats by an intraperitoneal injection of streptozotocin (STZ; 60 mg/kg body weight) followed by free access to 5 % glucose for the next 24 h. Four days after STZ injection, rats were supplemented with PYC (10 mg/kg body weight) for 4 weeks. At the end of the experiment, blood was drawn, and rats were then sacrificed, and their livers and pancreases were dissected for biochemical and histological assays. The level of fasting blood glucose and glycosylated hemoglobin significantly increased but amylase, insulin, and hepatic glycogen level decreased in the STZ group. PYC significantly augmented these effects in STZ?+?PYC group. The STZ group showed elevated level of nitric oxide, tumor necrosis factor-α, and interleukin-1beta in serum which were decreased by PYC treatment. Moreover, PYC significantly ameliorated increased thiobarbituric reactive substances, protein carbonyl, and decreased levels of glutathione, glutathione-s-transferase, and catalase activity in the liver and pancreas of the STZ rats. Histopathological and immunohistochemical examination also revealed a remarkable protective effect of PYC. The study suggests that PYC is effective in reducing diabetic-related complications in a type I model of diabetes and might be beneficial for the treatment of diabetic patients.     

PLAC1 expression increases during trophoblast differentiation: evidence for regulatory interactions with the fibroblast growth factor-7 (FGF-7) axis

PLAC1 is a recently described, trophoblast-specific gene that localizes to a region of the X-chromosome important in placental development. Immunohistochemical analysis demonstrated that PLAC1 polypeptide localizes to the differentiated syncytiotrophoblast throughout gestation (8-41 weeks) as well as a small population of villous cytotrophoblasts. Consistent with these observations, quantitative RT-PCR demonstrated that PLAC1 mRNA increases more than 300-fold during cytotrophoblast differentiation in culture to form syncytiotrophoblasts. Agents known to be relevant to trophoblast differentiation were then tested for the ability to influence PLAC1 expression. Fibroblast growth factor-7 (FGF-7), also known as keratinocyte growth factor (KGF), stimulated PLAC1 mRNA expression approximately two-fold in the BeWo(b30) trophoblast cell line. FGF-7 stimulation was significantly inhibited by PD-98059 and wortmannin suggesting mediation via MAP kinase and PI-3 kinase-dependent signaling pathways. Interestingly, epidermal growth factor (EGF) treatment of trophoblasts had no effect on PLAC1 expression alone, but potentiated the effect of FGF-7, suggesting the presence of a regulatory interaction of the two growth factors. FGF-7 and its receptor, FGFR-2b, exhibited spatial overlap with PLAC1 suggesting these regulatory interactions are physiologically relevant during gestation. These data demonstrate PLAC1 expression is upregulated during trophoblast differentiation, localizing primarily to the differentiated syncytiotrophoblast. Furthermore PLAC1 expression is specifically regulated by peptide growth factors relevant to trophoblast differentiation.     

Cytochemical localization of phosphatase in differentiating secondary vascular cells

Summary Phosphatase activity was studied in the cambium and differentiating vascular cells of beech by using a modified Washstein and Meisel method. After fixation in glutaraldehyde or crotonaldehyde and incubation in a medium containing ATP and lead nitrate at pH 7.2, a deposit of electron-opaque granules was found in the nucleoli, nucleoplasm, nuclear envelope, endoplasmic reticulum, plastids, mitochondria, and at the plasmalemma. Although located at these different sites, the distribution varied both inter- and intra-cellularly. This is thought to be a true reflection of the variation in activity between closely adjacent cells in this part of the stem.Some reaction was obtained when ADP replaced ATP in the reaction mixture, but there was no reaction at all when both ATP and ADP were omitted. Fixation in hydroxyadipaldehyde, or incubation at pH 6.4 both produced very little reaction.     

Characterization of a clinical Vibrio cholerae O139 isolate from Mexico

Pathogenic strains of Vibrio cholerae O139 possess the cholera toxin A subunit (ctxA) gene as well as the gene for toxin co-regulated pili (tcpA). We report the isolation of a ctxA-negative, tcpA-negative V. cholerae O139 strain (INDREI) from a patient in Mexico diagnosed with gastrointestinal illness. Certain phenotypic characteristics of this strain were identical to those of V. cholerae O1 biotype El Tor. Unlike ctxA-positive V. cholerae O139 strains, this strain was sensitive to a wide panel of antibiotics, including ampicillin, chloramphenicol, ciprofloxacin, gentamicin, furazolidone, nalidixic acid, nitrofurantoin, tetracycline, trimethoprim-sulfamethoxazole, and streptomycin, but was resistant to polymyxin B. Ribotype and pulsed-field gel electrophoresis profiles of INDRE1 differed from those of ctxA-positive V. cholerae O139 and other V. cholerae strains. Phenotypic characteristics of the Mexico strain were similar to those reported for V. cholerae O139 isolates from Argentina and Sri Lanka.