994 resultados para Polymerase1-like sequence
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The role of natural killer (NK) T cells in the development of lupus-like disease in mice is still controversial. We treated NZB/W mice with anti-NK1.1 monoclonal antibodies (mAbs) and our results revealed that administration of either an irrelevant immunoglobulin G2a (IgG2a) mAb or an IgG2a anti-NK1.1 mAb increased the production of anti-dsDNA antibodies in young NZB/W mice. However, the continuous administration of an anti-NK1.1 mAb protected aged NZB/W mice from glomerular injury, leading to prolonged survival and stabilization of the proteinuria. Conversely, the administration of the control IgG2a mAb led to an aggravation of the lupus-like disease. Augmented titres of anti-dsDNA in NZB/W mice, upon IgG2a administration, correlated with the production of BAFF/BLyS by dendritic, B and T cells. Treatment with an anti-NK1.1 mAb reduced the levels of interleukin-16, produced by T cells, in spleen cell culture supernatants from aged NZB/W. Adoptive transfer of NK T cells from aged to young NZB/W accelerated the production of anti-dsDNA in recipient NZB/W mice, suggesting that NK T cells from aged NZB/W are endowed with a B-cell helper activity. In vitro studies, using purified NK T cells from aged NZB/W, showed that these cells provided helper B-cell activity for the production of anti-dsDNA. We concluded that NK T cells are involved in the progression of lupus-like disease in mature NZB/W mice and that immunoglobulin of the IgG2a isotype has an enhancing effect on antibody synthesis due to the induction of BAFF/BLyS, and therefore have a deleterious effect in the NZB/W mouse physiology.
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Background: Adrenocortical tumors are heterogeneous neoplasms with incompletely understood pathogenesis. IGF-II overexpression has been consistently demonstrated in adult adrenocortical carcinomas. Objectives: The objective of the study was to analyze expression of IGF-II and its receptor (IGF-IR) in pediatric and adult adrenocortical tumors and the effects of a selective IGF-IR kinase inhibitor (NVP-AEW541) on adrenocortical tumor cells. Patients: Fifty-seven adrenocortical tumors (37 adenomas and 20 carcinomas) from 23 children and 34 adults were studied. Methods: Gene expression was determined by quantitative real-time PCR. Cell proliferation and apoptosis were analyzed in NCI H295 cells and a new cell line established from a pediatric adrenocortical adenoma. Results: IGF-II transcripts were overexpressed in both pediatric adrenocortical carcinomas and adenomas. Otherwise, IGF-II was mainly overexpressed in adult adrenocortical carcinomas (270.5 +/- 130.2 vs. 16.1 +/- 13.3; P = 0.0001). IGF-IR expression was significantly higher in pediatric adrenocortical carcinomas than adenomas (9.1 +/- 3.1 vs. 2.6 +/- 0.3; P = 0.0001), whereas its expression was similar in adult adrenocortical carcinomas and adenomas. IGF-IR expression was a predictor of metastases in pediatric adrenocortical tumors in univariate analysis (hazard ratio 1.84; 95% confidence interval 1.28 -2.66; P = 0.01). Furthermore, NVP-AEW541 blocked cell proliferation in a dose-and time-dependent manner in both cell lines through a significant increase of apoptosis. Conclusion: IGF-IR overexpression was a biomarker of pediatric adrenocortical carcinomas. Additionally, a selective IGF-IR kinase inhibitor had antitumor effects in adult and pediatric adrenocortical tumor cell lines, suggesting that IGF-IR inhibitors represent a promising therapy for human adrenocortical carcinoma.
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Systemic Cowdry Type A inclusions (CAs) were observed in a moribund Cherax destructor collected at an aquaculture farm in South Australia. Inclusions were most common in the gills and were associated with multifocal necrosis of the main gill axis and lamellae. The hepatopancreas was necrotic; however, only one CA was observed in the interstitial tissues. CAs were associated with necrosis in the abdominal and gut musculature. CAs were also observed in the spongy connective tissues and the epicardium. Empty capsids (17.5 +/- 0.5 nm) and microfilaments were most commonly observed within these inclusions by transmission electron microscopy. Complete icosahedral viral particles (20.8 +/- 1.2 nm) were difficult to distinguish within the viroplasm, but were visualised better in aggregates between the viroplasm and the inner nuclear membrane. The nucleolus was closely associated with the developing viroplasm, and was hypertrophied and segregated into its fibrillar and granular components. The virus was named Cherax destructor systemic parvo-like virus (CdSPV) on the basis of its histopathology, cytopathology and morphology. CdSPV is the first systemic virus described in a freshwater crayfish.
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The PKC apoptosis WTI regulator gene, also named prostate apoptosis response-4 (PAR-4), encodes a pro-apoptotic protein that sensitizes cells to numerous apoptotic stimuli. Insulin-like growth factor-1 (IGF-1) and 17 beta-estradiol (E2), two important factors for breast cancer development and progression, have been shown to down-regulate PAR-4 expression and inhibit apoptosis induced by PAR-4 in neuronal cells. In this study, we sought to investigate the mechanisms of regulation of PAR-4 gene expression in MCF-7 cells treated with E2 or IGF-1. E2 (10 nM) and IGF-1 (12.5 nM) each down-regulated PAR-4 expression in MCF-7 cells after 24 h of treatment. The effect of E2 was dependent on ER activation, as demonstrated by an increase in PAR-4 expression when cells were pretreated for 1 h with 1 mu M ICI-182,780 (ICI) before receiving E2 plus ICI. The effect of IGF-1 was abolished by pre-treatment for 1 h with 30 mu M LY294002 (a specific PI3-K inhibitor), and significantly inhibited by 30 mu M SB202190 (a specific p38MAPK inhibitor). We also demonstrated that E2 acts synergistically with IGF-1, resulting in greater down-regulation of PAR-4 mRNA expression compared with E2 or IGF-1 alone. Our results show for the first time that E2 and IGF-1 inhibit PAR-4 gene expression in MCF-7 cells, suggesting that this down-regulation may provide a selective advantage for breast cancer cell survival.
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Microsatellites or simple sequence repeats (SSRs) are ubiquitous in eukaryotic genomes. Single-locus SSR markers have been developed for a number of species, although there is a major bottleneck in developing SSR markers whereby flanking sequences must be known to design 5'-anchors for polymerase chain reaction (PCR) primers. Inter SSR (ISSR) fingerprinting was developed such that no sequence knowledge was required. Primers based on a repeat sequence, such as (CA)(n), can be made with a degenerate 3'-anchor, such as (CA)(8)RG or (AGC)(6)TY. The resultant PCR reaction amplifies the sequence between two SSRs, yielding a multilocus marker system useful for fingerprinting, diversity analysis and genome mapping. PCR products are radiolabelled with P-32 or P-33 via end-labelling or PCR incorporation, and separated on a polyacrylamide sequencing gel prior to autoradiographic visualisation. A typical reaction yields 20-100 bands per lane depending on the species and primer. We have used ISSR fingerprinting in a number of plant species, and report here some results on two important tropical species, sorghum and banana. Previous investigators have demonstrated that ISSR analysis usually detects a higher level of polymorphism than that detected with restriction fragment length polymorphism (RFLP) or random amplified polymorphic DNA (RAPD) analyses. Our data indicate that this is not a result of greater polymorphism genetically, but rather technical reasons related to the detection methodology used for ISSR analysis.
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The production of Long-R-3-IGF-1 (an IGF-1 fusion analog) by constant-rate, fed-batch fermentation of Escherichia coli yielded 2.6 g fusion protein/L, corresponding to an actual IGF-1 concentration of 2.2 g/L. A novel strategy employing three distinct feeding stages was developed which raised product concentration to 4.3 g/L (3.6 g/L of IGF-1) while minimising glucose and acetate accumulation. This improved productivity was not accompanied by an increase in inclusion body size.
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Insulin-like growth factor-I (IGF-I) is a preiotrophic polypeptide which appears to have roles both as a circulating endocrine hormone and as a locally synthesized paracrine or autocrine tissue factor. IGF-I plays a major role in regulating the growth of cells in vivo and in vitro and initiates metabolic and mitogenic processes in a wide variety of cell types by binding to specific type I receptors in the plasma membrane, In this study, we report the distribution of IGF-I receptors in odontogenic cells at the ultrastructural level using the high resolution protein A-gold technique, In the pre-secretory stage, very little gold label was visible over the ameloblasts and odontoblasts, During the secretory stage the label was mostly seen in association with the cell membranes and endoplasmic reticulum of the ameloblasts. Lysosome-like elements in the post-secretory stage were labelled as well as multivesicular dense bodies, Very little labelling was encountered in the ameloblasts in the transitional stage, where apoptotic bodies were clearly visible, The maturation stage also exhibited labelling of the secretory-like granules in the distal surface. The presence of gold particles over the plasma membrane is an indication that IGF-I receptor is a membrane-bound receptor. Furthermore, the intracellular distribution of the label over the endoplasmic reticulum supports the local synthesis of the IGF-I receptor. The absence of labelling over the transitional ameloblasts suggests that the transitional stage may require the non-expression of IGF-I as a prerequiste or even a trigger for apoptosis.
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Background: Versutoxin (delta-ACTX-Hv1) is the major component of the venom of the Australian Blue Mountains funnel web spider, Hadronyche versuta. delta-ACTX-Hv1 produces potentially fatal neurotoxic symptoms in primates by slowing the inactivation of voltage-gated sodium channels; delta-ACTX-Hv1 is therefore a useful tool for studying sodium channel function. We have determined the three-dimensional structure of delta ACTX-Hv1 as the first step towards understanding the molecular basis of its interaction with these channels. Results: The solution structure of delta-ACTX-Hv1, determined using NMR spectroscopy, comprises a core beta region containing a triple-stranded antiparallel beta sheet, a thumb-like extension protruding from the beta region and a C-terminal 3(10) helix that is appended to the beta domain by virtue of a disulphide bond. The beta region contains a cystine knot motif similar to that seen in other neurotoxic polypeptides. The structure shows homology with mu-agatoxin-l, a spider toxin that also modifies the inactivation kinetics of vertebrate voltage-gated sodium channels. More surprisingly, delta-ACTX-Hv1 shows both sequence and structural homology with gurmarin, a plant polypeptide. This similarity leads us to suggest that the sweet-taste suppression elicited by gurmarin may result from an interaction with one of the downstream ion channels involved in sweet-taste transduction. Conclusions: delta-ACTX-Hv1 shows no structural homology with either sea anemone or alpha-scorpion toxins, both of which also modify the inactivation kinetics of voltage-gated sodium channels by interacting with channel recognition site 3. However, we have shown that delta-ACTX-Hv1 contains charged residues that are topologically related to those implicated in the binding of sea anemone and alpha-scorpion toxins to mammalian voltage-gated sodium channels, suggesting similarities in their mode of interaction with these channels.
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Our data suggest that serum concentrations of insulin-like growth factor I and insulin-like growth factor binding protein 3 do not correlate with breast cancer development. (Fertil Steril (R) 2011;95:2753-5. (C)2011 by American Society for Reproductive Medicine.)
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Arginase activity has been related to leishmaniasis development, thus we studied the constitutive and insulin-like growth factor (IGF) I-induced arginase activity of Leishmania (Viannia) braziliensis isolates from patients with different clinical forms of American tegumentary leishmaniasis (ATL). Isolates from mucosal leishmaniasis presented higher basal levels of arginase activity than isolates from other clinical forms of ATL. Isolates from disseminated leishmaniasis that present mucosal lesion in some cases reached the arginase activity similar to that of isolates from mucosal leishmaniasis upon IGF-I stimulation. Differences in arginase activity may influence disease outcomes such as evolution to mucosal lesion in patients with L (V.) braziliensis infection. (C) 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.
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Background: Risperidone (RSP) is a benzisoxazole antipsychotic agent used to treat schizophrenia and other psychiatric illnesses in adults and children (including those with autism). After oral administration, RSP is completely absorbed from the gastrointestinal tract and undergoes hydroxylation to yield 9-hydroxyrisperidone (9-OH-RSP), an active metabolite that has a pharmacologic profile and potency similar to RSP. Objectives: The aims of this study were to compare the relative bioavailability of a pharmaceutical-equivalent (test) formulation with a reference formulation of oral RSP 2 mg, both available commercially on the Brazilian pharmaceutical market, and to generate data regarding the oral bioavailability of the tested drug in healthy Brazilian volunteers. Methods: This single-dose, randomized-sequence, open-label, 2-period crossover study was conducted in healthy Brazilian volunteers from August to December 2008. Subjects were randomly assigned to receive the test formulation followed by the reference formulation or vice versa, with a 30-day washout period between doses. Study drugs were administered after a 12-hour overnight fast. For pharmacokinetic analysis, blood samples were drawn at 0 (baseline), 0.25, 0.5, 1, 1.5, 3, 5, 8, 12, 24, 48, 72, 96, and 120 hours after administration. Plasma concentrations of RSP and 9-OH-RSP were determined using LC-MS/MS. The test and reference formulations were to be considered bioequivalent if the 90% CIs for the geometric mean test/reference ratios were within a predetermined range of 80% to 125%, in accordance with the policies of the Brazilian Sanitary Surveillance Agency and the US Food and Drug Administration. Tolerability was determined using clinical assessments, monitoring of vital signs, analysis of laboratory test results, and subject interviews regarding adverse events. Results: A total of 22 subjects were enrolled (11 men, 11 women; mean [SD] age, 32 [12] years [range, 18-58 years]; weight, 70.4 [11.9] kg [range, 50-103 kg]; height, 1.67 [0.08] m [range, 1.56-1.80 m]; and body mass index, 25 [4] kg/m(2) [range, 18-29 kg/m(2)]). For RSP, mean (SD) C(max) values were 12.6 (2.7) and 16.0 (2.3) ng/mL for the test and reference formulations, respectively. For 9-OH-RSP, mean C(max) values were 17.8 (1.3) and 21.0 (1.7) ng/mL for the test and reference formulations. The 90% CIs for the mean test/reference ratios for RSP C(max), AUC(0-120), and AUC(0-infinity) were 74% to 82%, 75% to 85%, and 76% to 85%, respectively, and 83% to 87%, 75% to 79%, and 75% to 78% for 9-OH-RSP. The related adverse events (headache, low back pain, drowsiness, standing hypotension, local postvenipuncture ecchymoses, insomnia, nausea, and vomiting) were transient and mild. Conclusions: This single-dose study found that the test and reference formulations of oral RSP 2 mg did not meet the Brazilian and US regulatory criteria for bioequivalence in these fasting, healthy volunteers. The study formulations appeared to be well tolerated. (Clin Ther 2010;32:2106-2115) (C) 2010 Elsevier HS Journals, Inc.
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We propose a mechanism by which single outbreaks of vector-borne infections can happen even when the value of the basic reproduction number, R(o), of the infection is below one. With this hypothesis we have shown that dynamical models simulations demonstrate that the arrival of a relatively small (with respect to the host population) number of infected vectors can trigger a short-lived epidemic but with a huge number of cases. These episodes are characterized by a sudden outbreak in a previously virgin area that last from weeks to a few months, and then disappear without leaving vestiges. The hypothesis proposed in this paper to explain those single outbreaks of vector-borne infections, even when total basic reproduction number, Ro, is less than one (which explain the fact that those infections fail to establish themselves at endemic levels), is that the vector-to-host component of Ro is greater than one and that a sufficient amount of infected vectors are imported to the vulnerable area, triggering the outbreak. We tested the hypothesis by performing numerical simulations that reproduce the observed outbreaks of chikungunya in Italy in 2007 and the plague in Florence in 1348. The theory proposed provides an explanation for isolated outbreaks of vector-borne infections, ways to calculate the size of those outbreaks from the number of infected vectors arriving in the affected areas. Given the ever-increasing worldwide transportation network, providing a high degree of mobility from endemic to virgin areas, the proposed mechanism may have important implications for public health planning. (C) 2009 Elsevier Ltd. All rights reserved.
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Human immunodeficiency virus type 1 (HIV-1) and human T-cell lymphotropic virus types 1 and 2 (HTLV-1 and -2) are retroviruses that share similar routes of transmission and some individuals may have a dual infection. These co-infected subjects may be at increased risk for tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM)-like. To study the prevalence of tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM) among coinfected HIV-1/HTLV-1 subjects. Since July 1997, our group has been following a cohort to study the interaction of HTLV with HIV and/or hepatitis C virus (HCV), as well as HTLV-1-only infected asymptomatic carriers or those already presenting with TSP/HAM. During these 9 years, 296 HTLV-1-infected individuals were identified from a total of 538 patients who were referred to our clinic at the Institute of Infectious Diseases ""Emilio Ribas,"" in Sao Paulo, Brazil. All subjects were evaluated by two neurologists, blinded to the HTLV status. TSP/HAM diagnosis was based on Kagoshima diagnostic criteria. Results: A total of 38 HIV-1/HTLV-1 co-infected subjects were identified in this cohort: Twenty-six had already been diagnosed with AIDS and 12 remained asymptomatic. Six of 38 co-infected subjects (18%) were diagnosed as having TSP/HAM and also AIDS, and for 5 of them TSP/HAM was their first illness. One additional incident case was diagnosed after 2 years of follow-up. No modifications on HIV-1 viral load was seen. In contrast, the co-infected with TSP/HAM-like group showed higher HTLV-1 proviral load (505 +/- 380 vs. 97 +/- 149 copies/10(4) PBMC, P= 0.012) than asymptomatic co-infected subjects, respectively. The incidence of myelopathy among HIV-1/HTLV-1 co-infected subjects is probably higher than among patients infected only with HTLV-1, and related to a higher HTLV-1 proviral load. Thus, HTLV-1/2 screening should be done for all HIV-1-infected patients in areas where HTLV-1 infection is endemic.
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PEComas are rare neoplasms that are sometimes associated with the tuberous sclerosis complex. They typically contain perivascular epithelioid cells that coexpress muscle and melanocytic markers. However, apart from these classical features, considerable clinical, pathologic, and immunohistochemical variation has been reported. WT1, the Wilms tumor gene product, can be expressed in various tumors from different anatomical sites, including sex-cord and other ovarian tumors with a sertoliform pattern. Neither a sex-cord like pattern nor WT1 expression has been described in PEComas. Here, we describe a case of uterine PEComa with a pattern of infiltration into the myometrium that is similar to stromal sarcomas, characterized by tongues and endovascular growing. The architecture and cellular morphology were similar to sex-cord tumors, and the PEComa was diffusely and strongly positive for WT1. We reviewed, from our files, an additional 9 cases of PEComa from different sites, and found WT1 expression in one more soft tissue tumor. We discuss the relationship between PEComas and other uterine sarcomas. (C) 2010 Elsevier Inc. All rights reserved.