998 resultados para Region competition
Resumo:
In the kallikrein-kinin and renin-angiotensin systems the main receptors, B-1 and B-2 (kinin receptors) and AT(1) and AT(2) (angiotensin receptors) respectively, are seven-transmembrane domain G-protein-coupled receptors. Considering that the B, agonists Des-Arg(9)-BK (Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe), Lys-desArg(9)-BK or Des-Arg(10)-KD (Lys-Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe) and the AT, agonist (Asp-Arg-Val-Tyr-lle-His-Pro-Phe) have the same two residues at the C-terminal region (i.e. Pro-Phe), we hypothesized that TM V and TM VI of the B-1 receptor could play an essential role in agonist binding and activity, being these regions receptor sites for binding the C-terminal sequences of Des-Arg-kinins similarly to that observed to AT, receptor. To investigate this hypothesis, we replaced Arg(212) for Ala at the top of the TM V and the sequence 274-282 (CPYHFFAFL) in TM VI of the rat kinin B, receptor by the 32 receptor homologous sequence, 289-297 (FPFQISTFL) and subsequently analyzed the consequences of these mutations by competition binding and functional assays. Despite correct expression, observed at the mRNA and protein level by RT-PCR and confocal microscopy, respectively, no agonist binding and function was verified for the mutated receptors. Therefore, our results suggest an important role for Arg(212) in the TM V and a region of TM VI of rat B, receptor in the interaction with the C-terminal residues of Des-Arg-kinins, similar to that observed with AngII. (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
It has been reported that microRNAs (miRNA) may have allele-specific targeting for the 3` untranslated region (3` UTR) of the HLA-G locus. In a previous study, we reported 11 3`UTR haplotypes encompassing the 14-bp insertion/deletion polymorphism and seven SNPs (+3003 T/C, +3010 C/G, +3027 C/A, +3035 C/T, +3142 C/G, +3187A/G,and +3196 C/G), of which only the +3142 C/G SNP has been reported to influence the binding of miRNAs. Using bioinformatics analyses, we identified putative miRNA-binding sites considering the haplotypes encompassing these eight polymorphic sites, and we ranked the lowest free energies that could potentially lead to an mRNA degradation or translational repression. When a specific haplotype or a particular SNP was associated with a miRNA-binding site, we defined a free energy difference of 4 kcal/mol between alleles to classify them energetically distant. The best results were obtained for the miR-513a-5p, miR-518c*, miR-1262 and miR-92a-1*, miR-92a-2*, miR-661, miR-1224-5p, and miR-433 miRNAs, all influencing one or more of the +3003, +3010, +3027, and +3035 SNPs. The miR-2110, miR-93, miR-508-5p, miR-331-5p, miR-616, miR-513b, and miR-589* miRNAs targeted the 14-bp fragment region, and miR-148a, miR-19a*, miR-152, mir-148b,and miR-218-2 also influenced the +3142C/G polymorphism. These results suggest that these miRNAs might play a relevant role on the HLA-G expression pattern. (C) 2009 Published by Elsevier Inc. on behalf of American Society for Histocompatibility and Immunogenetics.
Resumo:
A new polymorphic INDEL was detected at the X-STR GATA172D05 flanking region, which corresponds to an 18-bp deletion, 141 bp upstream the TAGA repeat motif. This INDEL was found to be polymorphic in different population samples from Native Americans, Africans, and Europeans as well as in an admixed population from the Amazonia (Bel,m). Gene diversities varied between 37.5% in Native Americans and 49.9% in Africans. Comparison between human and chimpanzee sequences showed that the ancestral state corresponds to the presence of two copies of 18 bp, detected in both species; and the mutated allele has lost one of these two copies. The simultaneous analysis of the short tandem repeat (STR) and INDEL variation showed an association between the INDEL ancestral allele with the shorter STR alleles. High diversities were found in all population groups when combining the information provided by the INDEL and STR variation. Gene diversities varied between 76.7% in Native Americans and 80.6% in both Portugal and Bel,m.
Resumo:
Infection by Helicobacter pylori is associated with the development of several gastroduodenal diseases, including gastritis, peptic ulcer disease (gastric ulcers and duodenal ulcers), and gastric adenocarcinoma. Although a number of putative virulence factors have been reported for H. pylori, there are conflicting results regarding their association with specific H. pylori-related diseases. In this work, we investigated the presence of virB11 and cagT, located in the left half of the cag pathogenicity island (cagPAI), and the jhp917-jhp918 sequences, components of the dupA gene located in the plasticity zone of H. pylori, in Brazilian isolates of H. pylori. We also examined the association between these genes and H. pylori-related gastritis, peptic ulcer disease, and gastric and duodenal ulcers in an attempt to identify a gene marker for clinical outcomes related to infection by H. pylori. The cagT gene was associated with peptic ulcer disease and gastric ulcers, whereas the virB11 gene was detected in nearly all of the samples. The dupA gene was not associated with duodenal ulcers or any gastroduodenal disease here analyzed. These results suggest that cagT could be a useful prognostic marker for the development of peptic ulcer disease in the state of Sao Paulo, Brazil. They also indicate that cagT is associated with greater virulence and peptic ulceration, and that this gene is an essential component of the type IV secretion system of H. pylori.
Resumo:
Activation of the immune response in hantavirus cardiopulmonary syndrome (HCPS) leads to a high TNF production, probably contributing to the disease. The polymorphic TNF2 allele (TNF -308G/A) has been associated with increased cytokine production. We investigated the association of the TNF2 allele with the outcome of hantavirus infection in Brazilian patients. A total of 122 hantavirus-exposed individuals (26 presenting HCPS and 96 only hantavirus seroconversion) were studied. The TNF2 allele was more frequently found in HCPS patients than in individuals with positive serology for hantavirus but without a history of HCPS illness, suggesting that the TNF2 allele could represent a risk factor for developing HCPS.
Resumo:
The HLA-G gene is predominantly expressed at the maternal-fetal interface and has been associated with maternal-fetal tolerance. The HLA-G*0113N is a null allele defined by the insertion of a premature stop codon at exon 2, observed in a single Ghanaian individual. Likewise the G*0105N allele, the occurrence of the HL4-G*0113N in a population from an area with high pathogen load suggests that the reduced HLA-G expression in G*0113N heterozygous placentas could improve the intrauterine defense against infections. The presence of the G*0113N allele here was investigated in 150 Amerindians from five isolated tribes that inhabit the Central Amazon and in 295 admixed individuals from the State of Sao Paulo, Southeastern Brazil, previously genotyped for HLA-G. No copy of the G*0113N null allele was found in both population samples by exon 2 sequence-based analysis, reinforcing its restricted occurrence in Africa. (C) 2010 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.
Resumo:
This study examined the effects of motor stimulation via treadmill on the behavior of male gerbils after external carotid ischemic brain lesion. The animals were assigned to five groups; ischemic with no stimulation (SIG), ischemic with stimulation (SIG 12/24/48/72 It after surgery), non-ischemic with no stimulation (CC), non-ischemic with stimulation (CE) and sham, surgery without occlusion with no stimulation (SH). All the animals were tested in the open-field (OF) and rotarod (RR), 4 days after surgery in order to evaluate exploratory behaviors and motor performance. Data were submitted to one-way variance (ANOVA) and Dunnett`s post hoc comparisons. SIG and SIG 12 groups showed a significant decrease in motor response (crossing) when compared to the control group (CC) (F = 20.65, P < 0.05) in the OF. SIG 12 group showed an increase in grooming behavior (F = 23.136, P < 0.05) and all ischemia groups (SIG, SIG 12/24/48/72) spent less time on the RR (F = 10.40, P < 0.05), when compared to the control group (CC). Histological analyses show extensive lesions in the hippocampus and neostriatum for all groups with ischemia (SIG, SIG 12/24/48/72), which are structures involved in the organization of motor behavior. Interestingly, the most pronounced damage was found in animals submitted to motor stimulation 12 h after ischemia which can be correlated to the increased number of grooming behavior showed by them in the OF. These findings suggest that motor stimulation through treadmill training improve motor behavior after ischemia, except when it starts 12h after surgery. (c) 2007 Elsevier Ireland Ltd. All rights reserved.
Resumo:
Bird sex determination using molecular methods has proved to be a valuable tool in different studies. Although it is possible to sex most birds by coupling the CHD assay with others available methods, no sex-determining gene like SRY in mammalians has been identified in birds. The male hypermethylated (MHM) region on the Z chromosome has been found to be hypermethylated in males and hypomethylated in females in birds of the order Galliformes. We analyzed the DNA from feathers of 50 adult chickens to verify the methylation pattern of the MHM region by PCR and the restriction enzyme HpaII (a method named MHM assay). The results, visualized in agarose gel, were compared with PCR amplification of the CHD-Z and CHD-W genes (polyacrylamide gel) and with the birds` phenotype. All males (25) showed hypermethylation of the MHM region, and all females (25) showed hypomethylation. The sexing by MHM assay was in according with phenotype and CHD sexing. To our knowledge, this is the first study that uses the MHM region for sexing birds. Although the real role of the MHM region in the sex determination is still unclear, this could be a universal marker for sexing birds and may be involved in sex determination by its influence on transcriptional processes. The MHM assay could be a good alternative for CHD assay in developmental studies.
Resumo:
Objectives Because of the large number of cases of visceral leishmaniasis (VL) recorded in Brazil over the last few years, this disease has been showing characteristics different from previously known ones. We report cases of pregnant women treated for VL, describing their course and outcome and the chemotherapeutic medication used according to the clinical signs and symptoms of each patient. Study design We report five cases of pregnant women treated for VL in a central-western region of Brazil. Results No case of vertical transmission was observed, even in patients who were treated after delivery. One of the patients with a late diagnosis made after the onset of symptoms died. Thus, the treatment of VL during pregnancy reduces maternal mortality and the rate of vertical transmission of the disease, being safe and effective as long as the disease is diagnosed early. Conclusion At present, amphotericin B and its derivatives appear to be the best therapeutic option for the mother-child binomial.
Resumo:
In recent years, alcohol consumption has been considered an important public health problem. Ethanol, the alcohol used in beverages, is a drug that affects the central nervous system (CNS) and impairs driving skills and co-ordination, increasing risk of deaths and injuries derived from crashes and road accidents. Consumption of alcoholic beverages is implicated with premature deaths, injuries and damages caused by motor vehicle crashes, which result in high costs to government and society. Considering that alcohol consumption is the main responsible factor for deaths and disabilities in young people, the aim of this work was to evaluate the prevalence of blood alcohol in offenders and/or fatal and non-fatal victims of traffic occurrences in the region of Ribeirao Preto, Sao Paulo State, from 2005 to 2007. The results revealed that in 2134 cases investigated, blood alcohol positivity was generally found in young adults, 25-45 years old and male. The study showed the high risk of drinking and driving and the importance in establishing actions of prevention and intervention to promote the reduction in the number of traffic occurrences related to consumption of alcoholic beverages. (C) 2010 Elsevier Ireland Ltd. All rights reserved.