939 resultados para Nuclear Respiratory Factor 1
Resumo:
We hypothesize that, in kidney of diabetic rats, hepatocyte nuclear factors (HNF-1 alpha. and HNF-3 beta) play a critical role in the overexpression of solute carrier 2A2 (SLC2A2) gene. Diabetic rats submitted or not to rapid (up to 12 h) and short-term (1, 4 and 6 days) insulin treatment were investigated. Twofold increase in GLUT2 mRNA was observed in diabetic, accompanied by significant increases in HNF-1 alpha and HNF-3 beta expression and binding activity. Additional 2-fold increase in GLUT2 mRNA and HNF-3 beta expression/activity was observed in 12-h insulin-treated rats. Six-day insulin treatment decreased GLUT2 mRNA and HNF-1 alpha expression and activity to levels of non-diabetic rats, whereas HNF-3 beta decreased to levels of non-insulin-treated diabetic rats. Our results provide evidence for a link between the overexpression of SLC2A2 gene and the transcriptional activity of HNF-1 alpha and HNF-3 beta in kidney of diabetic rats. Furthermore, recovery of SLC2A2 gene after 6-day insulin treatment also involves HNF-1 alpha and HNF-3 beta activity. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
Resumo:
The thermo-solvatochrornic behaviors of 2,6-diphenyl-4-(2,4,6-triphenylpyridinium-1-yl) phenolate, RB; 2,6-dichloro-4-(2,4,6-triphenyloyridinium-1-yl) phenolate, WB; 2,6-dibromo-4-[(E)-2-(1-methylpyridinium-4-yl)ethenyl] phenolate, MePMBr(2); 2,6-dibromo-4-[(E)-2-(1-n-octylpyridinium-4-yl)ethenyl] phenolate, OcPMBr(2), have been investigated in binary mixtures of the ionic liquid, IL, 1-(1-butyl)-3-methylimidazolium tetrafluorborate, [BuMeIm][BF(4)], and water (W), in the temperature range from 10 to 60 degrees C. Plots of the empirical solvent polarities, ET (probe) in kcal mol(-1), versus the mole fraction of water in the binary mixture, chi(w) showed nonlinear, i.e., nonideal behavior. Solvation by these IL-W mixtures shows the following similarities to that by aqueous aliphatic alcohols: The same solvation model can be conveniently employed to treat the data obtained; it is based on the presence in the system-bulk medium and probe solvation shell of IL, W, and the ""complex"" solvent 1:1 IL-W. The origin of the nonideal solvation behavior appears to be the same, preferential solvation of the probe, in particular by the complex solvent. The strength of association of the IL-W complex, and the polarity of the IL are situated between the corresponding values of aqueous methanol and aqueous ethanol. Temperature increase causes a gradual desolvation of all probes employed. A difference between solvation by IL-W and aqueous alcohols is that probe-solvent hydrophobic interactions appear to play a minor role in case of the former mixture, probably because solvation is dominated by hydrogen-bonding and Coulombic interactions between the ions of the IL and the zwitterionic probes.
Resumo:
In this work, the use of proton nuclear magnetic resonance, (1)H NMR, was fully described as a powerful tool to follow a photoreaction and to determine accurate quantum yields, so called true quantum yields (Phi(true)), when a reactant and photoproduct absorption overlap. For this, Phi(true) for the trans-cis photoisomerization process were determined for rhenium(I) polypyridyl complexes, fac-[Re(CO)(3)(NN)(trans-L)](+) (NN = 1,10-phenanthroline, phen, or 4,7-diphenyl-1,10-phenanthroline, ph(2)phen, and L = 1,2-bis(4-pyridyl) ethylene, bpe, or 4-styrylpyridine, stpy). The true values determined at 365 nm irradiation (e. g. Phi(NMR) = 0.80 for fac-[Re(CO)(3)(phen)(trans-bpe)](+)) were much higher than those determined by absorption spectral changes (Phi(UV-Vis) = 0.39 for fac-[Re(CO)(3)(phen)(trans-bpe)](+)). Phi(NMR) are more accurate in these cases due to the distinct proton signals of trans and cis-isomers, which allow the actual determination of each component concentration under given irradiation time. Nevertheless when the photoproduct or reactant contribution at the probe wavelength is negligible, one can determine Phi(true) by regular absorption spectral changes. For instance, Phi(313) nm for free ligand photoisomerization determined both by absorption and (1)H NMR variation are equal within the experimental error (bpe: Phi(UV-Vis) = 0.27, Phi(NMR) = 0.26; stpy: Phi(UV-Vis) = 0.49, Phi(NMR) = 0.49). Moreover, (1)H NMR data combined with electronic spectra allowed molar absorptivity determination of difficult to isolate cis-complexes. (C) 2009 Elsevier B. V. All rights reserved.
Resumo:
Changes introduced by cardiopulmonar and neuromuscular training on basal serum insulin-like grow factor-1 (IGF-1) and cortisol levels, functional autonomy and quality of life in elderly women The aim of this study was to compare the effects of strength and aerobic training on basal serum IGF-1 and Cortisol levels, functional autonomy (FA) and quality of life (QoL) in elderly women after 12 weeks of training. The subjects were submitted the strength training (75-85% 1-RM) with weight exercises (SG; n=12; age=66.08 ± 3,37 years; BMI=26,77 ± 3,72 kg/m2), aerobic training with aquatic exercises (AG; n=13; age=68,69 ± 4,70 years; BMI=29,19 ± 2,96 kg/m2) and control group (CG; n=10; age=68,80 ± 5,41 years; BMI=29,70 ± 2,82 kg/m2). Fasting blood was analyzed to measure basal IGF-1 and cortisol levels by chemiluminescence method. The t-Student test showed increased IGF-1 in the SG (p<0.05) for intragroup comparison. The Repeated-measure ANOVA presented increased IGF-1 (p<0.05) in the SG compared to the other two groups. There were no differences in cortisol levels. All the FA tests (GDLAM autonomy protocol) presented decreased significant in the time marked in seconds to the SG. The same results were found in the AG, except in the rise from a sitting position test. The autonomy index presented significant improvements (p<0.05) in the SG related to the AG and CG and in the AG to the CG. The SG showed increased QoL (p<0.05) (by WHOQOL-Old questionnaire) in the facet 1 (sensorial functioning) and facet 5 (death and dying). Thus, the SG obtained positive changes on IGF-1 and FA levels when compared to the AG. This suggests that strength training can indicated to decrease the effects of ageing.
Resumo:
The correct histological diagnosis of vascular lesions in the oral mucosa is critical, especially in defining the treatment and prognosis, as some vascular lesions show spontaneous involution and others do not show such behavior. This study analyzed the expression immunohistochemistry of human glucose transporter protein (GLUT-1), in oral benign vascular tumors and to reclassify such lesions according to with his immunoexpression. In addition, we evaluated the immunohistochemical expression of hypoxia-inducible factor 1 alpha (HIF-1α), the main transcription factor involved in cellular adaptation to hypoxia. We analyzed 60 cases of benign oral vascular tumors: 30 cases with histological diagnosis of HEM and 30 cases of oral pyogenic granuloma (PG). The results of this research showed that of the 30 lesions initially classified as HEM, only 7 showed immuno-positivity for GLUT-1, remaining with the initial diagnosis. The remaining 23 were reclassified as vascular malformation (VM) (13 cases) and PG (10 cases). All cases in the sample with an initial diagnosis of PG were negative for GLUT-1, demonstrating the accuracy of histological diagnosis of these lesions. Concerning to the immunoexpression of HIF-1α, the Mann-Whitney test revealed a statistically significant difference between the cases of GP and MV (p = 0.002), where the median of GP (m=78) was higher than the MV (m=53). Based on these results, this study showed that a histological diagnosis alone is not always sufficient for the correct diagnosis of oral HEM and that HIF-1α participates in the pathogenesis of vascular lesions
Resumo:
Periodontal disease is a complex inflammatory and infectious condition that immune host, front of the microbial aggressions, can lead to disease progression, resulting in tissue destruction. The tissue damage induces the release of regulatory molecules, which protective roles and / or destructive, including proteins VEGF (vascular endothelial growth factor vascular) and HIF-1 α (hypoxia-induced factor α -1). Thus, this study investigated, quantitatively and comparatively, the immunohistochemical expression of VEGF (vascular endothelial growth factor) and HIF-1 α (hypoxia induced factor 1-α), proteins involved in inflammation, angiogenesis and hypoxia, in human gingival tissues. Therefore, 75 samples of gingival tissues were examined. Thirty samples were chronic periodontitis, 30 with chronic gingivitis and 15 healthy gingival. After sections analysis, positives and negatives inflammatory and endothelial cells in the connective tissue were counted and converted into percentage. Data were statistically analyzed using Kruskal-Wallis test and Spearman correlation. The results showed that both proteins marked. It was observed higher immunoreactivity for HIF-1 α at chronic gingivitis and periodontitis specimens compared to healthy sites, however, no statistically significant differences were observed among them (p>0.05). The VEGF immunostaining showed similarity among the cases of periodontitis, gingivitis and healthy gingiva. Moderate and positive correlation statistically significant differences were verified for the expressions of VEGF and HIF-1α in gingival health (r = 0,529, p = 0.04). Thus, it can be conclude that possibly the route of HIF-1 α, is activated in periodontal disease may have involvement of the protein in pathogenesis and progression of disease, and that activation of VEGF, can be in addition to being triggered transcription by HIF-1 α may be also influenced by other additional factors such as the action of periodontal microorganisms endotoxins
Resumo:
The Epidermoid Carcinoma (EC) is the most common lesions located in the region of the head and neck and, despite advances in treatment modalities, the prognosis is still poor. The malignant cells show an increase in glucose uptake, process mediated by glucose transporters (GLUTs). Increased expression of GLUT 1 and GLUT 3 is related to the aggressive behavior of this lesion. The aim of this study was to evaluate, through immunohistochemistry, the expression of GLUTs 1 and 3 in EC of the lower lip. The sample consisted of 40 cases of EC of the lower lip, of which 20 had regional lymph node metastasis and the remaining 20 with absence of metastasis. The percentages of immunostained cells in front of tumor invasion and in the center of tumor were evaluated. These results were related to the presence and absence of lymph node metastasis, TNM classification and histological grading. The percentage of cytoplasmic/membranous expression of GLUT 1 ranged from 77.35% to 100%, while for GLUT 3 this value ranged from 0.79% to 100%. As for nuclear staining for GLUT 1, this percentage ranged from 0 to 0.42%, however. GLUT 3 showed only one case with nuclear staining. Despite the significant expression of tumor cells related to the proteins studied, we observed no statistically significant relationship between the variables and the antibodies analyzed, regardless of the region evaluated. However, there was a moderate positive correlation between cytoplasmic/membranous immunoexpressions of GLUT 1 in invasion front and in the tumor center (r = 0.679, p <0.001). Similarly, moderate positive correlation was found between the nuclear immunoexpressions of GLUT 1 in the invasion front and in the tumor center (r = 0.547, p <0.001). For GLUT 3, was also observed a moderate statistically significant positive correlation between cytoplasmic/membranous expression in tumor invasion front and in tumor center (r = 0.589, p <0.001). We also observed that the immunoreactivity for GLUT 1 was higher than GLUT 3 expression in invasion front (p <0.001) and tumor center (p <0.001). From these results, this study suggests that tumor hypoxia is a remarkable characteristic of the EC of the lower lip and GLUT 1 may be primarily responsible for glucose uptake into the interior of the malignant cells
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
We aimed to evaluate the frequency of Kaposi sarcoma (KS)-associated herpesvirus (KSHV) infection in KS lesions in patients from Brazil. In addition, expression of human bcl-2, cleaved caspase-3, and KSHV latency-associated nuclear antigen (LANA)-1 in tumors was evaluated using inummohistochemical analysis. We studied 64 KS cases, classified as follows: classical, 20 (31 %); iatrogenic, 2 (3 %); AIDS-associated, 25 (39%); and not otherwise specified (lack of information about HIV status), 17 (27%). KSHV was detected by polymerase chain reaction (PCR) in 61 cases (95%); 40 cases (63%) were KSHV+ by PCR and immunohistochemical analysis for LANA-L Immunoexpression of bcl-2 was detected in 47 cases (73%). Only a few cells in 15 cases (23%) of KS had demonstrable immunostaining for cleaved caspase-3. These results further support the association of KSHV with all KS forms. Cleaved caspase-3 in KS tumors was infrequent, which may reflect the inhibition of apoptosis owing to bcl-2 overexpression observed in the majority of KS tumors.
Resumo:
Small blue round cell tumors (SBRCTs) are a set of malignancies that have a particular proclivity for the pediatric age group. These tumors are notoriously difficult to distinguish by histologic evaluation alone, and in recent years a number of new immunohistochemical markers have emerged that can aid in the correct categorization of these lesions. Myogenin, a muscle-restricted nuclear transcription factor, has been demonstrated to be a highly sensitive and specific marker of rhabdomyosarcoma, and is superior to previous markers such as myoglobin, muscle actins, and desmin. The FlI-1 gene product is expressed as part of the EWS/FLI-1 novel chimeric protein that results from the t(11;22)(q24;q12) translocation that occurs in approximately two-thirds of cases of PNET/Ewings sarcoma. Immunohistochemical detection of the FLI-1 gene product can thus complement detection of CD99/MIC2 for the positive identification of PNET/Ewings sarcoma. Markers of neuroblastoma include neural markers, such as chromogranin A, neurofilaments, and synaptophysin. Desmoplastic small round cell tumor (DSRCT) is a tumor with an unusual immunophenotype, including co-expression of cytokeratin, vimentin, and desmin; recent studies have also documented the use of antibodies to the WT-1 gene product as a marker of the chimeric EWS/WT-1 protein formed as a result of the t(11;22)(p13;q12) translocation that characterizes this unique tumor. In summary, there now exists a panel of antibodies defining immunohistochemical markers of individual SBRCTs that can identify rhabdomyosarcoma, PNET/Ewings sarcoma, neuroblastoma, and DSRCT with high sensitivity and specificity.
Resumo:
Preconditioning-induced ischemic tolerance has been documented in the newborn brain, however, the signaling mechanisms of this preconditioning require further elucidation. The aims of this study were to develop a hypoxic-preconditioning (PC) model of ischemic tolerance in the newborn piglet, which emulates important clinical similarities to human situation of birth asphyxia, and to characterize some of the molecular mechanisms shown to be implicated in PC-induced neuroprotection in rodent models. One day old piglets were subjected to PC (8% O(2)/92% N(2)) for 3 h and 24 h later were exposed to hypoxia-ischemia (HI) produced by a combination of hypoxia (5% FiO(2)) for a period of 30 min and ischemia induced by a period of hypotension (10 min of reduced mean arterial blood pressure; 70% of baseline). Neuropathologic analysis and unbiased stereology, conducted at 24 h, 3 and 7 days of recovery following HI, indicated a substantial reduction in the severity of brain damage in PC piglets compared to non-PC piglets (P<0.05). PC significantly increased the mRNA expression of hypoxia-inducible factor-1 alpha (HIF-1 alpha) and its target gene, vascular endothelial growth factor (VEGF) at 0 h, 6 h, 24 h, 3 and 7 days of recovery. Immunoblot analysis demonstrated that PC resulted in HIF-1 alpha protein stabilization and accumulation in nuclear extracts of cerebral cortex of newborn piglet brain compared to normoxic controls. Protein levels of VEGF increased in a time-dependent manner in both cortex and hippocampus following PC. Double-immunolabeling indicated that VEGF is mainly expressed in neurons, endothelial cells and astroglia. Our study demonstrates for the first time the protective efficacy of PC against hypoxic-ischemic injury in newborn piglet model, which recapitulates many pathophysiological features of asphyxiated human neonates. Furthermore, as has been shown in rodent models of preconditioning, our results suggest that PC-induced protection in neonatal piglets may involve upregulation of VEGF. (C) 2011 Elsevier B.V. All rights reserved.
Resumo:
The growth hormone 1 gene (GH1) is a candidate gene for body weight and weight gain in cattle since it plays a fundamental role in growth regulation. We investigated the GH1 gene AluI and DdeI restriction enzyme polymorphisms, located 149 bp apart in the cattle genome, as possible markers of the production potential of Canchim crossbreed cattle, a 5/8 Charolais (Bos taurus) and 3/8 Nelore (Bos indicus) breed developed in Brazil, by evaluating the birth weight, weaning weight, yearling weight and plasma insulin-like growth factor-1 (IGF-1) concentration of 7 month to 10 months old Canchim calves (n = 204) of known genealogy and which had been genotyped for the AluI and DdeI markers. Our results showed significant effect (p < 0.05) between the homozygous DdeI+/DdeI+ polymorphism and the estimated breeding value for weaning weight (ESB-WW), while the AluI leucine homozygous (L/L) and leucine/valine (L/V) heterozygous polymorphisms showed no significant effect on the traits studied. The restriction sites of the two enzymes led to the formation of haplotypes which also exerted a significant effect (p < 0.05) on the ESB-WW, with the largest difference being 8.5 kg in favor of the homozygous L plus DdeI+/L plus DdeI+ genotype over the heterozygous L plus DdeI-/V plus DdeI+ genotype.
Resumo:
The nuclear import of simian-virus-40 large T-antigen (tumour antigen) is enhanced via phosphorylation by the protein kinase CK2 at Ser(112) in the vicinity of the NLS (nuclear localization sequence). To determine the structural basis of the effect of the sequences flanking the basic cluster KKKRK, and the effect of phosphorylation on the recognition of the NLS by the nuclear import factor importin-alpha (Impalpha), we co-crystallized non-autoinhibited Impalpha with peptides corresponding to the phosphorylated and non-phosphorylated forms of the NLS, and determined the crystal structures of the complexes. The structures show that the amino acids N-terminally flanking the basic cluster make specific contacts with the receptor that are distinct from the interactions between bipartite NLSs and Impalpha. We confirm the important role of flanking sequences using binding assays. Unexpectedly, the regions of the peptides containing the phosphorylation site do not make specific contacts with the receptor. Binding assays confirm that phosphorylation does not increase the affinity of the T-antigen NLS to Impalpha. We conclude that the sequences flanking the basic clusters in NLSs play a crucial role in nuclear import by modulating the recognition of the NLS by Impalpha, whereas phosphorylation of the T-antigen enhances nuclear import by a mechanism that does not involve a direct interaction of the phosphorylated residue with Impalpha.
Resumo:
The influence of moderate physical training on serum growth hormone (GH), insulin-like growth factor -1 (IGF-1) and binding protein ( IGFBP-3) in experimental diabetic rats was investigated. Male Wistar rats were divided into 4 groups, sedentary control (SC), trained control (TC), sedentary diabetic (SD) and trained diabetic (TD). Experimental diabetes was induced of Alloxan (35mg/b.w.) the training program consisted by swimming 5 days/week, 1 h/day, supporting a load of 2.5% b.w., during 6 weeks. Then, the rats were sacrificed and blood was collected for determinations of serum glucose, insulin, GH, IGF-1 and IGFBP-3. Samples of liver were used to evaluate glycogen, protein and DNA contents. The results were analyzed by ANOVA, and Bonferroni test and the significance level was set at 2.5%. Diabetes decreased serum GH, IGF-1, IGFBP-3 and liver glycogen stores in SD group. Physical training promoted increase in serum IGF-1 in both TC and TD groups (SC=82 +/- 15; TC= 1 03 +/- 13; SD=77 +/- 16; TD= 112 +/- 29 ng/ml) and liver glycogen store in TD group when compared to SD (SC=5.2 +/- 1.2; TC= 6.2 +/- 1; SD=2 +/- 0.5; TD=5 +/- 1.8 mg/100mg). Therefore, physical training contributes to the increase in liver glycogen content and to rise of insulin-like growth factor level in diabetic rats. It was concluded that moderate physical training promotes important adaptations related to GH-IGF-1 axis in diabetic organisms.
Resumo:
While many members of the black yeasts genus Cladophialophora have been reported to cause diseases in humans, understanding of their natural niche is frequently lacking. Some species can be recovered from the natural environment by means of selective isolation techniques. The present study focuses on a Cladophialophora strain that caused an interdigital tinea nigra-like lesion in a HIV-positive Brazilian child. The fungal infection was successfully treated with oxiconazole. Similar strains had been recovered from the environment in Brazil, Uruguay and the Netherlands. The strains were characterized by sequencing the Internal Transcribed Spacer (ITS) regions and the small subunit (SSU) of the nuclear ribosomal RNA gene, as well as the elongation factor 1-alpha (EF1) gene. Since no match with any known species was found, it is described as the new species, Cladophialophora saturnica.