Ograniczanie wyników

Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 17

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Peroxisome proliferators-activated receptor-g (PPAR-g) is a ligand-activated transcription factor. 15 deoxy-12,14 prostaglandin J2 (15d-PGJ2) is a potent PPAR- ligand and acts as an anti-inflammatory agent via PPAR--dependent and independent mechanisms. Helicobacter pylori (H. pylori) induces gastric inflammation by inducing the activation of oxidant-sensitive transcription factor NF-B and cytokine expression in gastric epithelial cells. Since 15d-PGJ2 inhibits NF-B activation in various cells, it may suppress H. pylori-induced inflammatory signaling and cytokine expression in gastric epithelial cells. The present study aims to determined the effect of 15d-PGJ2 on the activation of inflammatory mediators Jak/Stat (Janus kinase/signal transducers and activators of transcription) and induction of cytokine RANTES in H. pylori-infected gastric epithelial AGS cells. Since NADPH oxidase is a candidate for the production of reactive oxygen species in H. pylori-infected gastric epithelial cells, we determined the effect of 15d-PGJ2 on the activation of NADPH oxdase. AGS cells were cultured in the presence of H. pylori treated with or without 15d-PGJ2. The activations of NADPH oxidase and Jak1/Stat3, the levels of H2O2 and RANTES in the medium, and DNA binding activity of Stat3 were assessed. A Jak/Stat3 specific inhibitor AG490 and an inhibitor of NADPH oxidase diphenyleneiodonium (DPI) were treated to determine the direct involvement of Jak/Stat and NADPH oxidase on the production of H2O2 and RANTES in H. pylori-infected cells. H. pylori induced the production of H2O2 and RANTES as well as the activations of NADPH oxidase and Jak1/Stat3, which were inhibited by the treatment of 15d-PGJ2. DPI suppressed H. pylori-induced alterations similar to 15d-PGJ2. However, AG490 had no effect on NADPH oxidase activation, but reduced the level of RANTES in the medium released from H. pylori-infected cells. Conclusion: NADPH oxidase activation is an upstream signaling of Jak1/Stat3 activation and induction of RANTES in H. pylori-infected AGS cells. 15d-PGJ2, inhibits the activations of NADPH oxidase and Jak1/Stat3 and RANTES expression, suggesting that 15d-PGJ2 may be beneficial for the treatment of H. pylori-induced gastric inflammation.
The aim of this study was to develop a method for efficiently extracting eight N-nitrosamines (NAs) from chlorinated drinking water using a solid-phase extraction sorbent. This was achieved by completely drying the sorbent using dry air after passing the water through it and before eluting NAs from it. A 500 mL water sample containing NAs was passed through 2.0 g of Carboxen 572. The sorbent was dried by applying a vacuum (-34 kPa) to the sorbent cartridge for 1 h with a silica gel trap connected to the other end of the cartridge. The NAs were then eluted by passing 15 mL of dichloromethane through the cartridge. The dansyl derivatives of the NAs were analyzed by high-performance liquid chromatography with fluorescence detection using a Microsorb-MV Si column and a mixture of water (40%) and acetonitrile (60%) as stationary and mobile phases, respectively. The coefficients of determination (R2) for five-point linear calibration curves (2-80 ng/L) were 0.9968-0.9997. The relative standard deviations of repeated measurements were mostly less than 5.1%, but were higher for two NAs. The recoveries of all of the NAs when spiked samples were analyzed were > 95.1%, and the estimated method detection limits were 0.5-1.4 ng/L. The method showed much better performance than when the moisture trap was not applied to the cartridge, particularly when the laboratory air had a high level of humidity.
Taking advantage of recent developments in molecular biology and imaging, we have developed a system for monitoring status of transplanted cells non-invasively. We use high-resolution MRI to acquire information about the position of grafted cells and reporter gene-based bioluminescent imaging (BLI) to monitor their survival and differentiation. Here, we report on two different approaches for the in vivo imaging of glial precursors cells (GRPs). Approach I: Monitoring of the targeted, intravascular cerebral delivery of GRPs. Cells were engineered to express VLA-4 integrin (to enhance vascular adhesion) and were labeled with the MR contrast agent Feridex. Recipient rats were injected i.p. with lipopolysaccharide, a known inducer of endothelial VCAM-1 expression, and the cells were infused into the carotid artery. MRI demonstrated extensive hypointense regions, indicating successful targeting. Approach II: Monitoring of the survival and differentiation of intracerebrally injected GRPs. Cells were engineered to express luciferase under the control of a constitutive or the cell-type-specifi c promoters and were injected into the brain of immunodefi cient or immunocompetent mice. BLI demonstrated that transplanted GRPs survived for extended periods of time in immunodefi cient animals, while, in immunocompetent animals, rejection was initiated two weeks after grafting. With cell type-specifi c promoters, we were able to visualize the process of glial differentiation in vivo.
The ovine skeletal-muscle-specific calpain gene (p94), which is known also as the n-calpain or calpain 3 gene (CAPN3), was screened with primers. Selection of the PCR primers was based on the ovine cDNA sequence (GenBank accession No. AF087570). After sequence alignment between the ovine and human (AY902237) genes, exon and intron boundaries were determined. Polymorphisms were observed in the intron region for the CAPN31112 and CAPN31213 segments, and the sequences for these segments were submitted to the GenBank (AF309635 and AY102617, respectively). Body weight was recorded at birth, weaning and post-weaning. Calpain 3 genotypes of the CAPN31112 segment were associated with birth weight (P < 0.01), and a dominant gene effect was observed. Breeding group, birth type, and rearing type were significantly associated with weight traits. Allele frequencies were similar in purebred and crossbred animals.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.