974 resultados para AMPA RECEPTOR SUBUNITS


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BACKGROUND: Diabetics have a significantly higher percentage of sperm with nuclear DNA (nDNA) fragmentation and increased levels of advanced glycation end products (AGEs), in their testis, epididymis and sperm. As the receptor for AGEs (RAGE) is important to oxidative stress and cell dysfunction, we hypothesise, that it may be involved in sperm nDNA damage. METHODS: Immunohistochemistry was performed to determine the presence of RAGE in the human testis and epididymis. A comparison of the receptor's incidence and localisation on sperm from 10 diabetic and 11 non-diabetic men was conducted by blind semi-quantitative assessment of the immunostaining. ELISA analysis ascertained RAGE levels in seminal plasma and sperm from 21 diabetic and 31 non-diabetic subjects. Dual labelling immunolocalisation was employed to evaluate RAGE's precise location on the sperm head. RESULTS: RAGE was found throughout the testis, caput epididymis, particularly the principle cells apical region, and on sperm acrosomes. The number of sperm displaying RAGE and the overall protein amount found in sperm and seminal plasma were significantly higher in samples from diabetic men (p

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Rheumatoid and juvenile idiopathic arthritis (RA, JIA) are chronic inflammatory arthropathies with polygenic autoimmune background. We analysed the IL-4 +33 C/T and IL-4R Q551R single nucleotide polymorphisms (SNPs) in 294 RA, 72 JIA and 165 controls from Northern Ireland. Analysis of the individual phenotypes (RA or JIA) showed that both the IL-4 +33 TT (P = 0.02; OR: 0.25, 95% CI: 0.07-0.87) and the IL-4R Q551R CC genotypes (P = 0.001; OR: 0.19, 95% CI: 0.06-0.56) were exclusively decreased in female RA patients compared to female controls. Similar non-significant trends were observed in female JIA patients (OR: 0.25, 95% CI: 0.03-2.11 and OR: 0.31, 95% CI: 0.07-1.47, respectively). Analysis of the common phenotype (inflammatory arthropathy; i.e. JIA and RA combined) corroborated the unique association of these polymorphisms with female inflammatory arthropathy (P = 0.013 and 0.002, respectively). This is the first demonstration of sex-specific association of the two foremost genes of the IL-4 signalling cascade with chronic inflammatory arthropathies.

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Glucose-dependent insulinotropic polypeptide (gastric inhibitory polypeptide [GIP]) is an important incretin hormone secreted by endocrine K-cells in response to nutrient ingestion. In this study, we investigated the effects of chemical ablation of GIP receptor (GIP-R) action on aspects of obesity-related diabetes using a stable and specific GIP-R antagonist, (Pro3)GIP. Young adult ob/ob mice received once-daily intraperitoneal injections of saline vehicle or (Pro3)GIP over an 11-day period. Nonfasting plasma glucose levels and the overall glycemic excursion (area under the curve) to a glucose load were significantly reduced (1.6-fold; P <0.05) in (Pro3)GIP-treated mice compared with controls. GIP-R ablation also significantly lowered overall plasma glucose (1.4-fold; P <0.05) and insulin (1.5-fold; P <0.05) responses to feeding. These changes were associated with significantly enhanced (1.6-fold; P <0.05) insulin sensitivity in the (Pro3)GIP-treated group. Daily injection of (Pro3)GIP reduced pancreatic insulin content (1.3-fold; P <0.05) and partially corrected the obesity-related islet hypertrophy and ß-cell hyperplasia of ob/ob mice. These comprehensive beneficial effects of (Pro3)GIP were reversed 9 days after cessation of treatment and were independent of food intake and body weight, which were unchanged. These studies highlight a role for GIP in obesity-related glucose intolerance and emphasize the potential of specific GIP-R antagonists as a new class of drugs for the alleviation of insulin resistance and treatment of type 2 diabetes.

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Purpose: Up to now, there have been no established predictive markers for response to epidermal growth factor receptor (EGFR/HER1/erbB1) inhibitors alone and in combination with chemotherapy in colorectal cancer. To identify markers that predict response to EGFR-based chemotherapy regimens, we analyzed the response of human colorectal cancer cell lines to the EGFR-tyrosine kinase inhibitor, gefitinib (Iressa, AstraZeneca, Wilmington, DE), as a single agent and in combination with oxaliplatin and 5-fluorouracil (5-FU). Experimental Design: Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and crystal violet cell viability assays and analyzed by ANOVA. Apoptosis was measured by flow cytometry, poly(ADP-ribose) polymerase, and caspase 3 cleavage. EGFR protein phosphorylation was detected by Western blotting. Results: Cell lines displaying high constitutive EGFR phosphorylation (a surrogate marker for EGFR activity) were more sensitive to gefitinib. Furthermore, in cell lines exhibiting low constitutive EGFR phosphorylation, an antagonistic interaction between gefitinib and oxaliplatin was observed, whereas in cell lines with high basal EGFR phosphorylation, the interaction was synergistic. In addition, oxaliplatin treatment increased EGFR phosphorylation in those cell lines in which oxaliplatin and gefitinib were synergistic but down-regulated EGFR phosphorylation in those lines in which oxaliplatin and gefitinib were antagonistic. In contrast to oxaliplatin, 5-FU treatment increased EGFR phosphorylation in all cell lines and this correlated with synergistic decreases in cell viability when 5-FU was combined with gefitinib. Conclusions: These results suggest that phospho-EGFR levels determine the sensitivity of colorectal cancer cells to gefitinib alone and that chemotherapy-mediated changes in phospho-EGFR levels determine the nature of interaction between gefitinib and chemotherapy.

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Background Interferon ? receptor 1 (IFN? R1) deficiency is a primary immunodeficiency with allelic dominant and recessive mutations characterised clinically by severe infections with mycobacteria. We aimed to compare the clinical features of recessive and dominant IFN?R1 deficiencies. Methods We obtained data from a large cohort of patients worldwide. We assessed these people by medical histories, records, and genetic and immunological studies. Data were abstracted onto a standard form. Findings We identified 22 patients with recessive complete IFN?R1 deficiency and 38 with dominant partial deficiency. BCG and environmental mycobacteria were the most frequent pathogens. In recessive patients, 17 (77%) had environmental mycobacterial disease and all nine BCG-vaccinated patients had BCG disease. In dominant patients, 30 (79%) had environmental mycobacterial disease and 11 (73%) of 15 BCG-vaccinated patients had BCG disease. Compared with dominant patients, those with recessive deficiency were younger at onset of first environmental mycobacterial disease (mean 3·1 years [SD 2·5] vs 13·4 years [14·3], p=0·001), had more mycobacterial disease episodes (19 vs 8 per 100 person-years of observation, p=0·0001), had more severe mycobacterial disease (mean number of organs infected by Mycobacterium avium complex 4·1 [SD 0·8] vs 2·0 [1·1], p=0·004), had shorter mean disease-free intervals (1·6 years [SD 1·4] vs 7·2 years [7·6], p