885 resultados para Major histocompatibility complex class I
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Pós-graduação em Odontologia - FOA
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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HLA-G has a relevant role in immune response regulation. The overall structure of the HLA-G coding region has been maintained during the evolution process, in which most of its variable sites are synonymous mutations or coincide with introns, preserving major functional HLA-G properties. The HLA-G promoter region is different from the classical class I promoters, mainly because (i) it lacks regulatory responsive elements for IFN-gamma and NF-kappa B, (ii) the proximal promoter region (within 200 bases from the first translated ATG) does not mediate transactivation by the principal HLA class I transactivation mechanisms, and (iii) the presence of identified alternative regulatory elements (heat shock, progesterone and hypoxia-responsive elements) and unidentified responsive elements for IL-10, glucocorticoids, and other transcription factors is evident. At least three variable sites in the 3' untranslated region have been studied that may influence HLA-G expression by modifying mRNA stability or microRNA binding sites, including the 14-base pair insertion/deletion, +3142C/G and +3187A/G polymorphisms. Other polymorphic sites have been described, but there are no functional studies on them. The HLA-G coding region polymorphisms might influence isoform production and at least two null alleles with premature stop codons have been described. We reviewed the structure of the HLA-G promoter region and its implication in transcriptional gene control, the structure of the HLA-G 3' UTR and the major actors of the posttranscriptional gene control, and, finally, the presence of regulatory elements in the coding region.
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The Kaposi-associated Herpesvirus (KSHV) also known as Human Herpesvirus 8 (HHV-8) is associated with the development of Kaposi’s sarcoma (KS) and others limphoprolipheratives diseases such as Primary Effusion Lymphoma (PEL) and Multicentric Castleman Disease (MCD). Even though the virus is considered lymphotropic, it is able to infect others cell types such as macrophages, dendritic cells, endothelial cells, monocytes and fibroblasts. After infection, KSHV be latent expressing essential viral genes to its maintenance in a infected cell. However, in some circumstances may occur the reactivation of lytic cycle producing new viral particles. K1 protein of KSHV interferes in the cellular signaling inducing proliferation and supporting cellular transformation. K1 is encoded by viral ORF-K1, which shows high variability between different genotypes of KSHV. So far, it is not clear whether different isoforms of K1 have specific immunobiological features. The KSHV latency is maintained under strict control by the immune system supported by an adequate antigen presentation involving Human Leucocyte Antigen (HLA) class I and II. Polymorphisms of HLA class I and II genes confer an enormous variability in molecules that recognize a large amount of antigens, but also can increase the susceptibility to autoimmune diseases. Therefore, the present study aims to genotype HLA class I (A and B) and class II (DR and DQ) from volunteers to identify haplotypes that can provide better response to K1 epitopes of different KSHV genotypes. First of all, 20 volunteers were selected to genotype HLA genes. In our results we observed prevalence of certain HLA class I haplotypes as HLAA1, HLA-A2, HLA-A24, HLA-A26, HLA-B8, HLA-B18 e HLA-B44. After the in silico analysis using BIMAS and SYFPEITHI databases, we observed high scores for epitopes from the B genotype of KSHV, indicating...(Complete abstract click electronic access below)
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During the orthodontic correction planning in addition to dental-jaw correction, facial aesthetics is the orthodontist's and patient's major concern. To prevent facial aesthetics damage is really important to take into account the type of craniofacial growth: mesofacial (balanced), dolichofacial (vertical) or brachyfacial (horizontal). We evaluated 152 documentation files from the Department of Orthodontics of Dental University of Sao Jose dos Campos- UNESP in order to analyze what kind of growth occurs in most Class I malocclusions, Class II and Class III Angle of treated individuals from 6 to 12 years old. From the randomly collected samples, 15 of them belonged to Class I Angle malocclusions; 123 belonged to Angle Class II and 14 to Class III malocclusion. The results showed that in Class I, 66.67% were classified as dolicocephalic; in Class II, 64.23% were classified as dolicocephalic and in Class III, 50% were brachycephalic. We conclude that the dolichofacial was the type which ocurred the most, both in females and males and both in malocclusion Class I and Class II. The brachyfacial type most occurred in Class III malocclusion and the mesofacial type occurred in smaller numbers in the three malocclusions studied
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Objectives: The aim of this study is to report on the treatment of mandibular Class II furcation defects with enamel matrix protein derivative (EMD) combined with a beta TCP/HA (beta-tricalcium phosphate/hydroxyapatite) alloplastic material. Method and Materials: Thirteen patients were selected. All patients were nonsmokers, systemically healthy, and diagnosed with chronic periodontitis; had not taken medications known to interfere with periodontal tissue health and healing; presented one Class II mandibular furcation defect with horizontal probing equal to or greater than 4 mm at buccal site. The clinical parameters evaluated were probing depth (PD), relative gingival margin position (RGMP), relative vertical clinical attachment level (RVCAL), and relative horizontal clinical attachment level (RHCAL). A paired Student t test was used to detect differences between the baseline and 6-month measurements, with the level of significance of .05. Results: After 6 months, the treatment produced a statistically significant reduction in PD and a significant gain in RVCAL and RHCAL, but no observable change in RGMP. RVCAL ranged from 13.77 (+/- 1.31) at baseline to 12.15 (+/- 1.29) after 6 months, with a mean change of -1.62 +/- 1.00 mm (P<.05). RHCAL ranged from 5.54 (+/- 0.75) to 2.92 (+/- 0.92), with a mean change of -2.62 +/- 0.63 mm (P<.05). After 6 months, 76.92% of the patients improved their diagnosis to Class I furcation defects while 23.08% remained as Class II. Conclusion: The present study has shown that positive clinical results may be expected from the combined treatment of Class II furcation defects with EMD and beta TCP/HA, especially considering the gain of horizontal attachment level. Despite this result, controlled clinical studies are needed to confirm our outcomes.
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ln order to predict the facial growth using Jarahak's analysis, cephalometric radiographies of 120 subjects during the mixed dentition and between 6 and 10 years of age were studied. From the total, 60 subjects (30 males and 30 females) were classified as Angle's Class I and 60 subjects (30 males and 30 females) were classified as Angle's Class II, Division 1. AIl subjects did not receive any orthodontic treatment. The proportion between anterior and posterior facial heigth (SGo-NMe) was studied, which is determined by the formula PFH x 100/ AFH = %, neither being straight (> 62% < 65), clockwise ( > 58% < 62%) and anti-clockwise ( > 65% - 80%). Mean average, standard deviation and facial height proportion (SGo - NMe) were determined for males and females according to Angle's classification of malocc!usion. Sexual dimorphism was examined with regard to different types of Angle's malocclusion and the direction of the facial growth, and the correlation of four cephalometrics measurements were analvsed
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As an undergraduate sociology major, the only thing I learned about Oklahoman Laud Humphreys's classic, Tearoom Trade (1970) was how it violated standards of informed consent in social science research. As Galliher, Brekhus, and Keys recount in their biography, Laud Humphreys: Prophet of Homosexuality and Sociology, sociology graduate student Laud Humphreys needed to supplement his (quite likely, participant) observational research of men who had sex in public bathrooms (i.e., tearooms) in St. Louis in the mid-1960s with a formal questionnaire. Knowing that these men would never agree if they knew they were selected because of their participation in highly stigmatized and criminal behavior, Humphreys recorded their license plates, got their home addresses, and interviewed them as part of a "community health survey." Herein lies the deception and the major source of the controversy. What I didn't fully appreciate when I was a student, however, and what the authors so deftly illuminate is the importance of this work not only for debates around ethical issues of social science research, but more importantly, perhaps, for the study of sexuality, deviance, and urban life.
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In this action research study of my seventh grade mathematics class, I investigated whether de-emphasizing homework assignments as daily grades while stressing them as daily practice encouraged students to focus more on the learning rather than the daily grade. As part of this study, I also looked at how this change in homework expectations affected my daily teaching. I discovered that having students keep notes, examples, practice problems and homework assignments in a notebook helped them concentrate more on the process of getting answers and why they may of had an incorrect answer. Students were more likely to discuss with their peers how answers were found when comparing answers showed differences. When we reviewed the answers, they were more willing to ask questions about why their answer was wrong and then make corrections. As a result of this research, I plan to continue having seventh graders keep using notebooks to organize their notes, examples and assignments.
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In this action research study of my classroom of 10th grade geometry students, I investigated how students learn to communicate mathematics in a written form. The purpose of the study is to encourage students to express their mathematical thinking clearly by developing their communication skills. I discovered that although students struggled with the writing assignments, they were more comfortable with making comments, writing questions and offering suggestions through their journal rather than vocally in class. I have utilized teaching strategies for English Language Learners, but I had never asked the students if these strategies actually improved their learning. I have high expectations, and have not changed that, but I soon learned that I did not want to start the development of students’ written communication skills by having the students write a math solution. I began having my students write after teaching them to take notes and modeling it for them. Through entries in the journals, I learned how taking notes best helped them in their pursuit of mathematical knowledge. As a result of this research, I plan to use journals more in each of my classes, not just a select class. I also better understand the importance of stressing that students take notes, showing them how to do that, and the reasons notes best help English Language Learners.
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In this action research study of my 7th grade math class, I investigated the inclusion of homework presentations to see if they would improve students’ attitude toward mathematics, participation, and understanding. I discovered that although the implementations of presentations into our homework routine did not drastically influence grades, or even improve attitudes (according to test grades and student surveys), a multitude of other changes surfaced. These changes consisted of an increase in discussion, a team effort among students in my class, and an overall “learning community” effect. I plan to continue to pursue presentations as a major part of my homework routine, and also incorporate presentations into review sessions.
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There is a molecular crosstalk between the trophoblast and maternal immune cells of bovine endometrium. The uterine cells are able to secrete cytokine/chemokines to either induce a suppressive environment for establishment of the pregnancy or to recruit immune cells to the endometrium to fight infections. Despite morphological differences between women and cows, mechanisms for immune tolerance during pregnancy seem to be conserved. Mechanisms for uterine immunesuppression in the cow include: reduced expression of major histocompatability proteins by the trophoblast; recruitment of macrophages to the pregnant endometrium; and modulation of immune-related genes in response to the presence of the conceptus. Recently, an eGFP transgenic cloned embryo model developed by our group showed that there is modulation of foetal proteins expressed at the site of syncytium formation, suggesting that foetal cell can regulate not only by the secretion of specific factors such as interferon-tau, but also by regulating their own protein expression to avoid excessive maternal recognition by the local immune system. Furthermore, foetal DNA can be detected in the maternal circulation; this may reflect the occurrence of an invasion of trophoblast cells and/or their fragment beyond the uterine basement membrane in the cow. In fact, the newly description of exosome release by the trophoblast cell suggests that could be a new fashion of maternal-foetal communication at the placental barrier. Additionally, recent global transcriptome studies on bovine endometrium suggested that the immune system is aware, from an immunological point of view, of the presence of the foetus in the cow during early pregnancy.
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Literature data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of immediate-release (IR) solid oral dosage forms containing stavudine (d4T) are reviewed. According to Biopharmaceutics Classification System (BCS), d4T can be assigned to BCS class I. No problems with BE of IR d4T formulations containing different excipients and produced by different manufacturing methods have been reported and, hence, the risk of bioinequivalence caused by these factors appears to be low. Furthermore, d4T has a wide therapeutic index. It is concluded that a biowaiver is appropriate for IR solid oral dosage forms containing d4T as the single active pharmaceutical ingredient (API) provided that (a) the test product contains only excipients present in the IR d4T drug products that have been approved in a number of countries for the same dosage form, and (b) both test product and its comparator are either very rapidly dissolving or rapidly dissolving with similarity of dissolution profiles demonstrated at pH 1.2, 4.5, and 6.8. (c) 2011 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 101:1016, 2012
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The activity of natural killer cells depends on the balance between activating and inhibitory signals coming from their receptors. Among these are the killer cell immunoglobulin-like receptors (KIR) that recognize specific HLA class I allotypes. Here we characterized KIR genetic diversity and their HLA ligands in the population of Curitiba, Parana State (n = 164), and compared it with other worldwide populations. The distribution of 2DL4 alleles was also analyzed. The Curitiba population did not differ significantly from European and Euro-descendant populations, but as an admixed population showed higher genetic diversity. We found 27 KIR profiles, many of them uncommon in European populations, in agreement with the elevated historically recent gene flow in the study population. The frequencies of KIR genes and their respective HLA ligands were distributed independently and none of the analyzed individuals lacked functional KIR-HLA ligand combinations. KIR gene frequencies of 33 worldwide populations were consistent with geographic and ethnic distribution, in agreement with demography being the major factor shaping the observed gene content diversity of the KIR locus.
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Peptides derived from cytosolic, mitochondrial, and nuclear proteins have been detected in extracts of animal tissues and cell lines. To test whether the proteasome is involved in their formation, HEK293T cells were treated with epoxomicin (0.2 or 2 mu M) for 1 h and quantitative peptidomics analysis was performed. Altogether, 147 unique peptides were identified by mass spectrometry sequence analysis. Epoxomicin treatment decreased the levels of the majority of intracellular peptides, consistent with inhibition of the proteasome beta-2 and beta-5 subunits. Treatment with the higher concentration of epoxomicin elevated the levels of some peptides. Most of the elevated peptides resulted from cleavages at acidic residues, suggesting that epoxomicin increased the processing of proteins through the beta-1 subunit. Interestingly, some of the peptides that were elevated by the epoxomicin treatment had hydrophobic residues in P1 cleavage sites. Taken together, these findings suggest that, while the proteasome is the major source of intracellular peptides, other peptide-generating mechanisms exist. Because intracellular peptides are likely to perform intracellular functions, studies using proteasome inhibitors need to be interpreted with caution, as it is possible that the effects of these inhibitors are due to a change in the peptide levels rather than inhibition of protein degradation.