92 resultados para 153-923
Resumo:
The detection of replicative intermediate RNAs as markers of active replication of RNA viruses is an essential tool to investigate pathogenesis in acute viral infections, as well as in their long-term sequelae. In this regard, strand-specific PCR has been used widely to distinguish (-) and (+) enteroviral RNAs in pathogenesis studies of diseases such as dilated cardiomyopathy. It has been generally assumed that oligonucleotide-primed reverse transcription of a given RNA generates only the corresponding specific cDNA, thus assuring the specificity of a PCR product amplified from it. Nevertheless, such assumed strand-specificity is a fallacy, because falsely primed cDNAs can be produced by RNA reverse transcription in the absence of exogenously added primers, (cDNA(primer)(-)), and such falsely primed cDNAs are amplifiable by PCR in the same way as the correctly primed cDNAs. Using as a prototype the coxsackievirus B5 (CVB5), a (+) strand RNA virus, it was shown that cDNA(primer)(-) renders the differential detection of viral (-) and (+) RNAs by conventional PCR virtually impossible, due to gross non-specificity. Using in vitro transcribed CVB5 RNAs (+) and (-), it was shown that cDNA(primer)(-) could be removed effectively by magnetic physical separation of correctly primed biotinylated cDNA. Such strategy enabled truly strand-specific detection of RNA (-) and (+), not only for CVB5, but also for other non-polio enteroviruses. These findings indicate that previous conclusions supporting a role for the persistence of actively replicating enterovirus in the pathogenesis of chronic myocarditis should be regarded with strong skepticism and purification of correctly primed cDNA should be used for strand-specific PCR of viral RNA in order to obtain reliable information on this important subject. (C) 2009 Elsevier B.V. All rights reserved.
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Quartz Crystal Microbalance (QCM) was used to monitor the mass changes on a quartz crystal surface containing immobilized lectins that interacted with carbohydrates. The strategy for lectin immobilization was developed on the basis of a multilayer system composed of Au-cystamine-glutaraldehyde-lectin. Each step of the immobilization procedure was confirmed by FTIR analysis. The system was used to study the interactions of Concanavalin A (ConA) with maltose and Jacalin with Fetuin. The real-time binding of different concentrations of carbohydrate to the immobilized lectin was monitored by means of QCM measurements and the data obtained allowed for the construction of Langmuir isotherm curves. The association constants determined for the specific interactions analyzed here were (6.4 +/- 0.2) X 10(4) M-1 for Jacalin-Fetuin and (4.5 +/- 0.1) x 10(2) M-1 for ConA-maltose. These results indicate that the QCM constitutes a suitable method for the analysis of lectin-carbohydrate interactions, even when assaying low molecular mass ligands such as disaccharides. Published by Elsevier B.V.
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Background/Aims. Nuclear factor kappa B (NF kappa B) plays important role in the pathogenesis of skeletal muscle ischemia/reperfusion (I/R) injury. Caffeic acid phenyl ester (CAPE), a potent NF kappa B inhibitor, exhibits protective effects on I/R injury in some tissues. In this report, the effect of CAPE on skeletal muscle I/R injury in rats was studied. Methods. Wistar rats were submitted to sham operation, 120-min hindlimb ischemia, or 120-min hindlimb ischemia plus saline or CAPE treatment followed by 4-h reperfusion. Gastrocnemius muscle injury was evaluated by serum aminotransferase levels, muscle edema, tissue glutathione and malondialdehyde measurement, and scoring of histological damage. Apoptotic nuclei were determined by a terminal uridine deoxynucleotidyl transferase dUTP nick end labeling assay. Muscle neutrophil and mast cell accumulation were also assessed. Lipoperoxidation products and NF kappa B were evaluated by 4-hydroxynonenal and NF kappa B p65 immunohistochemistry, respectively. Results. Animals submitted to ischemia showed a marked increase in aminotransferases after reperfusion, but with lower levels in the CAPE group. Tissue glutathione levels declined gradually during ischemia to reperfusion, and were partially recovered with CAPE treatment. The histological damage score, muscle edema percentage, tissue malondialdehyde content, apoptosis index, and neutrophil and mast cell infiltration, as well as 4-hydroxynonenal and NF kappa B p65 labeling, were higher in animals submitted to I/R compared with the ischemia group. However, the CAPE treatment significantly reduced all of these alterations. Conclusions. CAPE was able to protect skeletal muscle against I/R, injury in rats. This effect may be associated with the inhibition of the NF kappa B signaling pathway and decrease of the tissue inflammatory response following skeletal muscle I/R. (C) 2009 Elsevier Inc. All rights reserved.
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particularly neutrophil chemoattraction. Herein, the role of C5a in the genesis of inflammatory hypernociception was investigated in rats and mice using the specific C5a receptor antagonist PMX53 (AcF-[OP(D-Cha)WR]). Experimental approach: Mechanical hypernociception was evaluated with a modification of the Randall-Selitto test in rats and electronic pressure meter paw test in mice. Cytokines were measured by ELISA and neutrophil migration was determined by myeloperoxidase activity. Key results: Local pretreatment of rats with PMX53 (60-180 mg per paw) inhibited zymosan-, carrageenan-, lipopolysaccharide (LPS)- and antigen-induced hypernociception. These effects were associated with C5a receptor blockade since PMX53 also inhibited the hypernociception induced by zymosan- activated serum and C5a but not by the direct-acting hypernociceptive mediators, prostaglandin E-2 and dopamine. Underlying the C5a hypernociceptive mechanisms, PMX53 did not alter the cytokine release induced by inflammatory stimuli. However, PMX53 inhibited cytokine-induced hypernociception. PMX53 also inhibited the recruitment of neutrophils induced by zymosan but not by carrageenan or LPS, indicating an involvement of neutrophils in the hypernociceptive effect of C5a. Furthermore, the C5a-induced hypernociception was reduced in neutrophil-depleted rats. Extending these findings in rats, blocking C5a receptors also reduced zymosan- induced joint hypernociception in mice. Conclusions and implications: These results suggest that C5a is an important inflammatory hypernociceptive mediator, acting by a mechanism independent of hypernociceptive cytokine release, but dependent on the presence of neutrophils. Therefore, we suggest that inhibiting the action of C5a has therapeutic potential in the control of inflammatory pain.
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Background and purpose: Chemokine receptors CXCR1 and CXCR2 may mediate influx of neutrophils in models of acute and chronic inflammation. The potential benefits of oral administration of a CXCR1/2 inhibitor, DF 2162, in adjuvant-induced polyarthritis (AIA) were investigated. Experimental approach: A model of AIA in rats was used to compare the therapeutic effects of the treatment with DF2162, anti-TNF or anti-CINC-1 antibodies on joint inflammation and local production of cytokines and chemokines. Key results: DF2162 prevented chemotaxis of rat and human neutrophils induced by chemokines acting on CXCR1/2. DF2162 was orally bioavailable and metabolized to two major metabolites. Only metabolite 1 retained CXCR1/2 blocking activity. Treatment with DF2162 ( 15 mg kg(-1), twice daily) or metabolite 1, but not metabolite 2, starting on day 10 after arthritis induction diminished histological score, the increase in paw volume, neutrophil influx and local production of TNF, IL-1 beta, CCL2 and CCL5. The effects of DF2162 were similar to those of anti-TNF, and more effective than those of anti-CINC-1, antibodies. DF2162 prevented disease progression even when started 13 days after arthritis induction. Conclusions and implications: DF 2162, a novel orally-active non-competitive allosteric inhibitor of CXCR1 and CXCR2, significantly ameliorates AIA in rats, an effect quantitatively and qualitatively similar to those of anti-TNF antibody treatment. These findings highlight the contribution of CXCR2 in the pathophysiology of AIA and suggest that blockade of CXCR1/2 may be a valid therapeutic target for further studies aiming at the development of new drugs for treatment of rheumatoid arthritis.
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Background and purpose: We have previously shown that noradrenaline microinjected into the bed nucleus of stria terminalis (BST) elicited pressor and bradycardiac responses in unanaesthetized rats. In the present study, we investigated the subtype of adrenoceptors that mediates the cardiovascular response to noradrenaline microinjection into the BST. Experimental approach: Cardiovascular responses following noradrenaline microinjection into the BST of male Wistar rats were studied before and after BST pretreatment with different doses of the selective alpha(1)-adrenoceptor antagonist WB4101, the alpha(2)-adrenoceptor antagonist RX821002, the combination of WB4101 and RX821002, the non-selective beta-adrenoceptor antagonist propranolol, the selective beta(1)-adrenoceptor antagonist CGP20712 or the selective beta(2)-adrenoceptor antagonist ICI118,551. Key results: Noradrenaline microinjected into the BST of unanaesthetized rats caused pressor and bradycardiac responses. Pretreatment of the BST with different doses of either WB4101 or RX821002 only partially reduced the response to noradrenaline. However, the response to noradrenaline was blocked when WB4101 and RX821002 were combined. Pretreatment with this combination also shifted the resulting dose-effect curve to the left, clearly showing a potentiating effect of this antagonist combination. Pretreatment with different doses of either propranolol or CGP20712 increased the cardiovascular responses to noradrenaline microinjected into the BST. Pretreatment with ICI118,551 did not affect cardiovascular responses to noradrenaline. Conclusion and implications: The present results indicate that alpha(1) and alpha(2)-adrenoceptors mediate the cardiovascular responses to noradrenaline microinjected into the BST. In addition, they point to an inhibitory role played by the activation of local beta(1)-adrenoceptors in the cardiovascular response to noradrenaline microinjected into the BST.
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Objectives. To compare the efficacy of three different standard chemotherapy regimens for low-risk gestational trophoblastic disease according to the FIGO staging system in a single-institute setting. Methods. From 1980 until 2002, we retrospectively reviewed 108 cases with low-risk persistent gestational trophoblastic disease who were treated with first-line chemotherapy. Patients were divided in three groups according to chemotherapy regimen: patients treated with methotrexate (MTX group; n=42), patients treated with dactinomycin (ACT group; n=42) and patients treated with methotrexate and dactinomycin in combination (MACT group; n=24). We compared the number of chemotherapy courses for achieving remission, the duration of treatment, the adverse side effects, the efficacy of the treatment and the need for performing a hysterectomy among the groups Results. The complete remission rates were 69%, 61.4% and 79.1% for methotrexate (MTX), dactinomycin (ACT) and the combination regimen (MACT) treated groups, respectively (p=0.7). The duration of the treatment and the number of chemotherapy courses were similar among the groups (p = 0.2 and p = 0.4, respectively). Adverse side effects rate was reported to be 62.5% in the MACT group, 28.6% in the MTX group and 19.1% in the ACT group (p=0.0003). Second-line chemotherapy was indicated for 30 patients. Hysterectomy was performed in 21 patients overall, and there was no difference among the groups (P=0.6). Conclusion. Our analysis indicates that single-agent chemotherapy regimens are as effective as combination chemotherapy for low-risk gestational trophoblastic disease. Dactinomycin is a less toxic drug and might offer the best cost-effective treatment option. Methotrexate must be considered as the regimen of choice for low resource areas because of the feasibility of its administration. (c) 2007 Elsevier Inc. All rights reserved.
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Background: It has been suggested that individuals with social anxiety disorder (SAD) are exaggeratedly concerned about approval and disapproval by others. Therefore, we assessed the recognition of facial expressions by individuals with SAD, in an attempt to overcome the limitations of previous studies. Methods: The sample was formed by 231 individuals (78 SAD patients and 153 healthy controls). All individuals were treatment naive, aged 18-30 years and with similar socioeconomic level. Participants judged which emotion (happiness, sadness, disgust, anger, fear, and surprise) was presented in the facial expression of stimuli displayed on a computer screen. The stimuli were manipulated in order to depict different emotional intensities, with the initial image being a neutral face (0%) and, as the individual moved on across images, the expressions increased their emotional intensity until reaching the total emotion (100%). The time, accuracy, and intensity necessary to perform judgments were evaluated. Results: The groups did not show statistically significant differences in respect to the number of correct judgments or to the time necessary to respond. However, women with SAD required less emotional intensity to recognize faces displaying fear (p = 0.002), sadness (p = 0.033) and happiness (p = 0.002), with no significant differences for the other emotions or men with SAD. Conclusions: The findings suggest that women with SAD are hypersensitive to threat-related and approval-related social cues. Future studies investigating the neural basis of the impaired processing of facial emotion in SAD using functional neuroimaging would be desirable and opportune. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
Context: Melanocortin receptor 4 (MC4R) deficiency is characterized by increased linear growth greater than expected for the degree of obesity. Objective: The objective of the investigation was to study the somatotroph axis in obese MC4R-deficient patients and equally obese controls. Patients and Methods: We obtained anthropometric measurements and insulin concentrations in 153 MC4R-deficient subjects and 1392 controls matched for age and severity of obesity. We measured fasting IGF-I, IGF-II, IGF binding protein (IGFBP)-1, IGFBP-3, and acid-labile subunit levels in a subset of 33 MC4R-deficient patients and 36 control subjects. We examined pulsatile GH secretion in six adult MC4R-deficient subjects and six obese controls. Results: Height so score was significantly greater in MC4R-deficient children under 5 yr of age compared with controls (mean +/- SEM: 2.3 +/- 0.06 vs. 1.8 +/- 0.04, P < 0.001), an effect that persisted throughout childhood. Final height (cm) was greater in MC4R-deficient men (mean +/- SEM 173 +/- 2.5 vs. 168 +/- 2.1, P < 0.001) and women (mean 165 +/- 2.1 vs. 158 +/- 1.9, P < 0.001). Fasting IGF-I, IGF-II, acid-labile subunit, and IGFBP-3 concentrations were similar in the two groups. GH levels were markedly suppressed in obese controls, but pulsatile GH secretion was retained in MC4R deficiency. The mean maximal GH secretion rate per burst (P < 0.05) and mass per burst (P < 0.05) were increased in MC4R deficiency, consistent with increased pulsatile and total GH secretion. Fasting insulin levels were markedly elevated in MC4R-deficient children. Conclusions: In MC4R deficiency, increased linear growth in childhood leads to increased adult final height, greater than predicted by obesity alone. GH pulsatility is maintained in MC4R deficiency, a finding consistent with animal studies, suggesting a role for MC4R in controlling hypothalamic somatostatinergic tone. Fasting insulin levels are significantly higher in children carrying MC4R mutations. Both of these factors may contribute to the accelerated growth phenotype characteristic of MC4R deficiency. (J Clin Endocrinol Metab 96: E181-E188, 2011)
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The successful treatment of paediatric malignancies by multimodal therapy has improved outcomes for children with cancer, especially those with acute lymphoblastic leukaemia (ALL). Second malignant neoplasms, however, represent a serious complication after treatment. Depending on dosage, 2-12% of patients treated with topoisomerase II inhibitors and/or alkylating agents develop treatment-related acute myeloid leukaemia characterized by translocations at 11q23. Our goal was to study MLL rearrangements in peripheral lymphocytes using cytogenetic and molecular methods in order to evaluate the late effects of cancer therapy in patients previously treated for childhood ALL. Chromosomal rearrangements at 11q23 were analysed in cytogenetic preparations from 49 long-term ALL survivors and 49 control individuals. Patients were subdivided depending on the inclusion or omission of topoisomerase II inhibitors (VP-16 and/or VM-26) in their treatment protocol. The statistical analysis showed significant (P = 0.007) differences between the frequency of translocations observed for the groups of patients and controls. These differences were also significant (P = 0.006) when the groups of patients (independent of the inclusion of topoisomerase II inhibitors) and controls were compared (P = 0.006). The frequencies of extra signals, however, did not differ between groups of patients and controls. Several MLL translocations were detected and identified by inverse polymerase chain reaction, followed by cloning and sequencing. Thirty-five patients (81%) presented putative translocations; among those, 91% corresponded with t(4;11) (q21;q23), while the other 9% corresponded with t(11;X), t(8;11)(q23;q23) and t(11;16). Our results indicate an increase in MLL aberrations in childhood ALL survivors years after completion of therapy. The higher frequency in this cohort might be associated with therapy using anti-tumoural drugs, independent of the inclusion of topoisomerase II inhibitors. Even though the biological significance of these rearrangements needs further investigation, they demonstrate a degree of genome instability, indicating the relevance of cytogenetic and molecular studies during the follow-up of patients in complete clinical remission.
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In an effort to develop a suitable DNA vaccine candidate for dengue, using dengue-3 virus (DENV-3) as a prototype, the genes coding for premembrane (prM) and envelope proteins (E) were inserted into an expression plasmid. After selecting recombinant clones containing prM/E genes, protein expression in the cell monolayer was detected by indirect immunofluorescence and immunoprecipitation assays. After selecting three vaccine candidates (pVAC1DEN3, pVAC2DEN3 and pVAC3DEN3), they were analyzed in vivo to determine their ability to induce a DENV-3-specific immune response. After three immunizations, the spleens of the immunized animals were isolated, and the cells were cultivated to measure cytokine levels by ELISA and used for lymphoproliferation assays. All of the animals inoculated with the recombinant clones induced neutralizing antibodies against DENV-3 and produced a T cell proliferation response after specific stimuli. Immunized and control mice were challenged with a lethal dose of DENV-3 and observed in order to assess their survival capability. The groups that presented the best survival rate after the challenge were the animals vaccinated with the pVAC3DEN3 clones, with an 80% survival rate. Thus, these data show that we have manufactured a vaccine candidate for DENV-3 that is able to induce a specific immune response and protects mice against a lethal challenge.
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As part of an epidemiological study of infectious bronchitis virus (IBV) in Brazil, 252 samples from IBV-suspect flocks were tested and the IBV-positive samples were analysed by sequencing of hypervariable regions 1 and 2 of the S1 gene. A high prevalence of IBV variants was found and the sequence analysis of 41 samples revealed a high molecular similarity among the Brazilian isolates (from 90.2 to 100% and from 85.3 to 100% nucleotide and amino acid identity, respectively). The Brazilian isolates showed low genetic relationship with Massachusetts (63.4 to 70.7%), European (45.9 to 75.6%), American (49.3 to 76.4%) and other reference serotypes (67.5 to 78.8%). The Brazilian isolates branched into one unique cluster, separate from the reference serotypes used for infectious bronchitis control in other countries. The variants analysed in this work had a high similarity with all previously published Brazilian IBV isolates, suggesting the presence and high prevalence of a unique or predominant genotype circulating in Brazil. In addition, the virus neutralization test showed that the three Brazilian isolates analysed in the present study are antigenically related to one another but are different from the Massachusetts serotype. The present study shows that IBVs of a unique genotype can be associated with different clinical diseases, and that low genetic variation was detected in this genotype over a long period of time. The molecular characterization of the Brazilian variants isolated from 2003 to 2009 from different geographic regions of the country shows that only one predominant genotype is widespread in the Brazilian territory, denominated in this study as BR-I genotype.
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The tongue of birds fills the oral cavity and has a beak-like shape. Morphological studies of birds reveal a correlation between the structure of the tongue and the mechanism of food intake and the type of food. However, several studies have shown morphological differences among the tongues of bird species. The aim of this study was to analyze ostrich tongue morphology and ultrastructural features using scanning electron microscopy. Tongues from 12 adult ostriches were examined. Six tongues were sectioned sagittally into lateral and middle portions, fixed in 10% formaldehyde solution, and examined under light microscopy. The other six samples were sectioned longitudinally, and the dorsal and ventral surfaces were separated, Immersion-fixed In modified Karnovsky solution, and examined under scanning electron microscopy. The tongue surface of the ostrich was smooth, without lingual papillae, and covered by stratified non-keratinized epithelium. In the submucosal layer, mucous salivary glands were surrounded by connective-tissue capsules, with septa dividing the glands Into lobes. Numerous salivary gland ducts of different sizes and connective-tissue laminae dividing each opening could be clearly seen in scanning electron microscope Images. The ventral surface had fewer openings than the dorsal surface. In samples treated with NaOH, connective-tissue papillae from the dorsal region were oriented posteriorly.
GP5+/6+ SYBR Green methodology for simultaneous screening and quantification of human papillomavirus
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Background: Detection and quantification of human papillomavirus (HPV) may help in predicting the evolution of HPV infection and progression of associated lesions. Objectives: We propose a novel protocol using consensus primers GP5+/6+ in a SYBR Green quantitative real-time (Q-RT) polymerase chain reaction (PCR). The strategy permits screening for HPV infection and viral load quantification simultaneously. Study design: DNA from 153 archived cervical samples, previously tested for HPV detection by GP5+/6+ PCR and typed by EIA-RLB (enzyme immunoassay-reverse line blot) or sequence analysis, was analysed using SYBR Green Q-RT PCR. Melting temperature assay (T(m)) and cycle threshold (C(t)) were used to evaluate HPV positivity and viral load. The T(m) in the range of 77-82 degrees C was considered to be positive for HPV-DNA. HPV results generated through GP5+/6+ conventional PCR were considered the gold standard against which sensitivity and specificity of our assay were measured. Results: Out of 104 HPV positive samples, 100 (96.2%) were also determined as positive by SYBR Green Q-RT PCR; of the 49 HPV-negative samples, all were determined as negative. There was an excellent positivity agreement (K = 0.94) between the SYBR Green Q-RT and the previous methods employed. The specificity and sensitivity were 100% and 96.2%, respectively. Comparison of SYBR Green Q-RT and TaqMan oligo-probe technologies gave an excellent concordance (pc = 0.95) which validated the proposed strategy. Conclusions: We propose a sensitive and easy-to-perform technique for HPV screening and viral load quantification simultaneously. (C) 2009 Elsevier B.V. All rights reserved.
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Objective: The aim of this study was to assess the effect of repeated cycles of five chemical disinfectant solutions on the roughness and hardness of three hard chairside reliners. Methods: A total of 180 circular specimens (30 mm x 6 mm) were fabricated using three hard chairside reliners (Jet; n = 60, Kooliner; n = 60, Tokuyama Rebase II Fast; n = 60), which were immersed in deionised water (control), and five disinfectant solutions (1%, 2%, 5.25% sodium hypochlorite; 2% glutaraldehyde; 4% chlorhexidine gluconate). They were tested for Knoop hardness (KHN) and surface roughness (mu m), before and after 30 simulated disinfecting cycles. Data was analysed by the factorial scheme (6 x 2), two-way analysis of variance (anova), followed by Tukey`s test. Results: For Jet (from 18.74 to 13.86 KHN), Kooliner (from 14.09 to 8.72 KHN), Tokuyama (from 12.57 to 8.28 KHN) a significant decrease in hardness was observed irrespective of the solution used on all materials. For Jet (from 0.09 to 0.11 mu m) there was a statistically significant increase in roughness. Kooliner (from 0.36 to 0.26 mu m) presented a statistically significant decrease in roughness and Tokuyama (from 0.15 to 0.11 mu m) presented no statistically significant difference after 30 days. Conclusions: This study showed that all disinfectant solutions promoted a statistically significant decrease in hardness, whereas with roughness, the materials tested showed a statistically significant increase, except for Tokuyama. Although statistically significant values were registered, these results could not be considered clinically significant.