75 resultados para Nuclear and High Energy Physics
Resumo:
The aim of this study was to develop and validate selective and sensitive methods for quantitative determination of an antibacterial agent, gemifloxacin, in tablets by high performance liquid chromatography (HPLC) and capillary zone electrophoresis (CZE). The HPLC method was carried out on a LiChrospher (R) 100 RP-8e, 5 mu m (125 x 4 mm) column with a mobile phase composed of tetrahydrofuran-water (25:75, v/v) with 0.5 % of triethylamine and pH adjusted to 3.0 with orthophosphoric acid. The CZE method was performed using 50 mM sodium tetraborate buffer (pH 8.6). Samples were injected hydrodynamicaly (0.5 psi, 5 s) and the electrophoretic system was operated under normal polarity, at +20 kV and capillary temperature of 18 degrees C. A fused-silica capillary 40.2 cm (30 cm effective length) x 75 mu m i.d. was used. Both, HPLC and CZE could be interesting and efficient techniques to be applied for quality control in pharmaceutical industries.
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A method for the simultaneous analysis of the enantiomers of mefloquine (MQ) and its main metabolite carboxymefloquine (CMQ) in plasma is described for the first time. The assay involves two-step liquid-phase micro-extraction (LPME) and enantioselective high-performance liquid chromatography. In the first LPME step, the enantiomers of MQ were extracted from an alkalinized sample through a thin layer of di-n-hexyl ether immobilized in the pores of the hollow fiber and into 0.01 M perchloric acid as acceptor solution. In the second LPME step, the same sample was acidified to enable the extraction of CMQ using the same organic solvent and 0.05 M sodium hydroxide as acceptor phase. The analytes were resolved on a Chirobiotic T column in the polar-organic mode of elution and detected at 285 nm. The recovery rates from 1 mL of plasma were in the range 35-38%. The method presented limits of quantification of 50 ng/mL for all analytes and was linear up to 1,500 and 3,000 ng/mL for the enantiomers of MQ and CMQ, respectively. The plasmatic concentrations of (+)-(RS)-MQ were higher than those of (-)-(SR)-MQ after oral administration of the racemic drug to rats.
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Background: Periodontal disease has been associated with many chronic inflammatory systemic diseases, and a common chronic inflammation pathway has been suggested for these conditions. However, few studies have evaluated whether periodontal disease, in the absence of other known inflammatory conditions and smoking, affects circulating markers of chronic inflammation. This study compared chronic inflammation markers in control individuals and patients with periodontal disease and observed whether non-surgical periodontal therapy affected inflammatory disease markers after 3 months. Methods: Plasma and serum of 20 controls and 25 patients with periodontal disease were obtained prior to and 3 months after non-surgical periodontal therapy. All patients were non-smokers, they did not use any medication, and they had no history or detectable signs and symptoms of systemic diseases. Periodontal and systemic parameters included probing depth, bleeding on probing, clinical attachment level, hematologic parameters, as well as the following inflammatory markers: interleukin (IL)-6, high-sensitivity C-reactive protein (hs-CRP), CD40 ligand, monocyte chemoattractant protein (MCP)-1, soluble P-selectin (sP-selectin), soluble vascular adhesion molecule (sVCAM)-1, and soluble intercellular adhesion molecule (sICAM)-1. Results: There were no differences in the hematologic parameters of the patients in the control and periodontal disease groups. Among the tested inflammatory markers, IL-6 concentrations were higher in the periodontal disease group at baseline compared to the controls (P=0.006). Therapy was highly effective (P<0.001 for all the analyzed clinical parameters), and a decrease in circulating IL-6 and hs-CRP concentrations was observed 3 months after therapy (P=0.001 and P=0.006, respectively). Our results also suggest that the CD40 ligand marker may have been different in the control and periodontal disease groups prior to the therapy (P=0.009). Conclusions: In apparently otherwise healthy patients, periodontal disease is associated with increased circulating concentrations of IL-6 and hs-CRP, which decreased 3 months after non-surgical periodontal therapy. With regard to the CD40 ligand, MCP-1, sP-selectin, sVCAM-1, and sICAM-1, no changes were seen in the periodontal disease group between baseline and 3 months after therapy. J Periodontol 2009;80:594-602.
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The inferior colliculus (IC) is primarily involved in the processing of acoustic stimuli, being in a position to send auditory information to motor centers that participate in behaviors such as prey catching and predators` avoidance The role of the central nucleus of the IC (CIC) on fear and anxiety has been suggested on the basis that rats are able to engage in tasks to decrease the aversiveness of CIC stimulation, increased Fos immunolabeling during diverse aversive states and increased CIC auditory evoked potentials (AEP) induced by conditioned fear stimuli Additionally it was shown that brainstem AEP, represented by wave V, for which the main generator is the IC, is increased during experimentally induced anxiety Rats segregated according to their low or high emotional reactivity have been used as an important tool in the study of fear and anxiety The IC contains a high density of GABA receptors Since the efficacy of an anxiolytic compound is a function of the animal`s anxiety level, it is possible that GABA-benzodiazepine (Bzp) agents affect LA and HA animals differently In this study we investigated the GABA-Bzp influence on the modulation of AEP in rats with low (LA) or high-anxiety (HA) levels, as assessed by the elevated plus maze test (EPM) GABA-Bzp modulation on the unconditioned AEP response was analyzed by using intra CIC injections (0 2 mu l) of the GABA-Bzp agonists muscimol (121 ng) and diazepam (30 mu g) or the GABA inhibitors bicuculline (10 ng) and semicarbazide (7 mu g) In a second experiment, we evaluate the effects of contextual aversive conditioning on AEP using foot shocks as unconditioned stimuli On the unconditioned fear paradigm GABA inhibition in creased AEP in LA rats and decreases this measure in HA counterparts Muscimol was effective in reducing AEP in both LA and HA rats Contextual fear stimuli increased the magnitude of AEP In spite of no effect obtained with diazepam in LA rats the drug inhibited AEP in HA animals The specificity of the regulatory mechanisms mediated by GABA Bzp for the ascending neurocircuits responsible for the acquisition of aversive information in LA and HA animals shed light on the processing of sensory information underlying the generation of defensive reactions (C) 2010 IBRO Published by Elsevier Ltd All rights reserved
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Ficus arpazusa Casaretto is a fig tree native to the Atlantic Rain Forest sensu lato. High levels of genetic diversity and no inbreeding were observed in Ficus arpazusa. This genetic pattern is due to the action of its pollinator, Pegoscapus sp., which disperses pollen an estimated distance of 5.6 km, and of Ficus arpazusa`s mating system which, in the study area, is allogamous. This study highlights the importance of adding both ecological and genetic data into population studies, allowing a better understanding of evolutionary processes and in turn increasing the efficacy of forest management and revegetation projects, as well as species conservation.
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Background Differences between women and men have been documented for both diagnostic testing and treatment in cardiology. This analysis evaluates whether low-density lipoprotein cholesterol (LDL-C) success rates according to current guidelines and high-density lipoprotein cholesterol (HDL-C) levels differ by gender in the L-TAP 2 population. Methods Patients aged >= 20 years with dyslipidemia on stable lipid-lowering therapy were assessed in 9 countries between September 2006 and April 2007. Low-density lipoprotein cholesterol goal attainment by cardiovascular risk level and region and determinants of low HDL-C were compared between genders. Results Of 9,955 patients (45.3% women) evaluated, women had a significantly lower overall LDL-C success rate than men (71.5% vs 73.7%, P = .014), due entirely to the difference in the high-risk/coronary heart disease (CHD) group (LDL-C goal <100 mg/dL, 62.6% vs 70.6%, P < .0001) Among CHD patients with >= 2 additional risk factors, only 26.7% of women and 31.5% of men (P = .021) attained the optional LDL-C goal of <70 mg/dL. High-density lipoprotein cholesterol was <50 mg/dL in 32.2% of women and <40 mg/dL in 26.8% of men (P < .0001), including 38.2% of women and 29.8% of men in the high risk/CHD group (P < .0001). Predictors of low HDL-C in women included diabetes, smoking, waist circumference, and hypertension. Conclusions Cholesterol treatment has, improved substantially since the original L-TAP a decade ago, when only 39% of women attained their LDL-C goal. However, high-risk women are undertreated compared to men, and a substantial opportunity remains to reduce their cardiovascular risk. (Am Heart J 2009; 158:860-6.)
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Objective: To verify an association, if it exists, between obesity and blood pressure raised beyond the 90th percentile in children and adolescents, and to determine the measure of adiposity that best correlates with blood pressure in these subjects. Design: Cross-sectional study. Setting: A school-based study in Belo Horizonte, Brazil. Participants: We selected randomly 1,403 students, aged from 6 to 18 years, from 545,046 students attending 521 public and private schools. Those selected completed the study. Main measures of outcome: We recorded the weight, height, skin fold in the triceps, subscapular, and suprailiac areas, waist and hip circumference, body-mass index, and resting systolic and diastolic blood pressures using a mercury sphygmomanometer. Results: In univariate analyses, body mass index greater or lesser than 85th percentile, measurements of skin thickness in the subscapular and suprailiac areas, and the sum of all measurements of skinfold thickness, were associated with both systolic and diastolic measurements of blood pressure. After multivariate analyses that adjusted for all measurements of adiposity except itself, and age, race, and socioeconomic state, we found that the increased body mass index was associated with a 3.6-fold increased frequency of elevated systolic measurements of blood pressure, with 9596 confidence intervals from 2.2 to 5.8, and a 2.7-fold increased frequency of elevated measurements of diastolic blood pressure, with 95% confidence intervals from 1.9 to 4.0. Conclusions: Body-mass index serves as a better predictor of elevated blood pressure among children than do local measurements of adiposity.
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PURPOSE: The purpose of this study was to analyze the agreement between anal Pap smear and high-resolution anoscopy-guided biopsy in diagnosing anal dysplasia in HIV-infected patients. METHODS: We conducted cross-sectional analysis of HIV-infected patients receiving anal dysplasia screening as part of routine care. Agreement between measures was estimated by weighted kappa statistics, using a three-tiered cytologic and histologic grading system (normal, low-grade dysplasia, and high-grade dysplasia). Estimates of sensitivity, specificity, and predictive values were calculated using a two-tiered cytologic and histologic grading system (""without dysplasia"" and ""with dysplasia of any grade""). Estimates were also calculated for the detection of high-grade dysplasia. RESULTS: During a one-year period, 222 patients underwent 330 anal Pap smears followed by high-resolution anoscopy-guided biopsies. There were 311 satisfactory Pap smears with concurrent biopsies. Considering histology the standard, the frequency of anal dysplasia was 46%. Kappa agreement between anal Pap smear and biopsy was 0.20. For detection of anal dysplasia of any grade, anal Pap smear showed sensitivity of 61%, specificity of 60%, positive predictive value of 56%, and negative predictive value of 64%. For high-grade dysplasia, anal Pap smear showed sensitivity of 16% and specificity of 97%. CONCLUSION: Anal Pap smears alone were not sensitive enough to rule out anal dysplasia. We recommend that high-resolution anoscopy-guided biopsy be incorporated as a complementary screening test for anal dysplasia in high-risk patients. Following baseline high-resolution anoscopy, these individuals could be followed with serial anal cytology to dictate the need for future high-resolution anoscopy-guided biopsies.
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Objective: To search for predictors of metformin response in women with polycystic ovary syndrome (PCOS) through a detailed analysis of clinical and laboratory parameters. Study design: We designed a prospective study to investigate clinical and laboratory parameters to search for predictors of metformin response in women with PCOS. A total of 53 PCOS patients were given metformin 850 mg twice a day for 6 months, after which patients were classified as responders or non-responders. Parameters analyzed for comparison between the two groups were: plasma fasting insulin glucose/insulin ratio; oral glucose tolerance test (OGTT) with insulin (120 min); HOMA and QUICKI tests; total cholesterol and fractions, triglycerides; LH, FSH, estradiol, progesterone, testosterone, androstenedione, 17-OH progesterone, and DHEAS. Results: From all patients, 30(56.6%) were responders and 23(43.3%) were non-responders. Multinomial analysis showed that the positive response to metformin was associated with higher levels of basal LH (p = 0.038) and lower levels of high-density lipoprotein cholesterol (HDL-C) (p = 0.015). Conclusion: In weight-matched PCOS subjects, laboratory markers might predict the metformin response. Higher levels of basal LH and lower levels of HDL-C are correlated with a positive response to metformin treatment in PCOS subjects. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
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Objective: To investigate the effects of low and high levels of positive end-expiratory pressure (PEEP), without recruitment maneuvers, during lung protective ventilation in an experimental model of acute lung injury (ALI). Design: Prospective, randomized, and controlled experimental study. Setting: University research laboratory. Subjects: Wistar rats were randomly assigned to control (C) [saline (0.1 ml), intraperitoneally] and ALI [paraquat (15 mg/kg), intra peritoneally] groups. Measurements and Main Results: After 24 hours, each group was further randomized into four groups (six rats each) at different PEEP levels = 1.5, 3, 4.5, or 6 cm H(2)O and ventilated with a constant tidal volume (6 mL/kg) and open thorax. Lung mechanics [static elastance (Est, L) and viscoelastic pressure (Delta P2, L)] and arterial blood gases were measured before (Pre) and at the end of 1-hour mechanical ventilation (Post). Pulmonary histology (light and electron microscopy) and type III procollagen (PCIII) messenger RNA (mRNA) expression were measured after 1 hour of mechanical ventilation. In ALI group, low and high PEEP levels induced a greater percentage of increase in Est, L (44% and 50%) and Delta P2, L (56% and 36%) in Post values related to Pre. Low PEEP yielded alveolar collapse whereas high PEEP caused overdistension and atelectasis, with both levels worsening oxygenation and increasing PCIII mRNA expression. Conclusions: In the present nonrecruited ALI model, protective mechanical ventilation with lower and higher PEEP levels than required for better oxygenation increased Est, L and Delta P2, L, the amount of atelectasis, and PCIII mRNA expression. PEEP selection titrated for a minimum elastance and maximum oxygenation may prevent lung injury while deviation from these settings may be harmful. (Crit Care Med 2009; 37:1011-1017)
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The human blood fluke Schistosoma mansoni is the primary cause of schistosomiasis, a debilitating disease that affects 200 million individuals in over 70 countries. The biogenic amine serotonin is essential for the survival of the parasite and serotonergic proteins are potential novel drug targets for treating schistosomiasis. Here we characterize two novel serotonin transporter gene transcripts, SmSERT-A and SmSERT-B, from S. mansoni. Southern blot analysis shows that the two mRNAs are the products of different alleles of a single SmSERT gene locus. The two SmSERT forms differ in three amino acid positions near the N-terminus of the protein. Both SmSERTs are expressed in the adult form and in the sporocyst form (infected snails) of the parasite, but are absent from all other stages of the parasite`s complex life cycle. Heterologous expression of the two cDNAs in mammalian cells resulted in saturable, sodium-dependent serotonin transport activity with an apparent affinity for serotonin comparable to that of the human serotonin transporter. Although the two SmSERTs are pharmacologically indistinguishable from each other, efflux experiments reveal notably higher substrate selectivity for serotonin compared with their mammalian counterparts. Several well-established substrates for human SERT including (+/-)MDMA, S-(+)amphetamine, RU 24969, and m-CPP are not transported by SmSERTs, underscoring the higher selectivity of the schistosomal isoforms. Voltage-clamp recordings of SmSERT substrate-elicited currents confirm the substrate selectivity observed in efflux experiments and suggest that it may be possible to exploit the electrogenic nature of SmSERT to screen for compounds that target the parasite in vivo. (C) 2009 Elsevier B.V. All rights reserved.
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Hemophilia B is a genetic disease of the coagulation system that affects one in 30,000 males worldwide. Recombinant human Factor IX (rhFIX) has been used for hemophilia B treatment, but the amount of active protein generated by these systems is inefficient, resulting in a high-cost production of rhFIX. In this study, we developed an alternative for rhFIX production. We used a retrovirus system to obtain two recombinant cell lines. We first tested rhFIX production in the human embryonic kidney 293 cells (293). Next, we tested a hepatic cell line (HepG2) because FIX is primarily expressed in the liver. Our results reveal that intracellular rhFIX expression was more efficient in HepG2/rhFIX (46%) than in 293/rhFIX (21%). The activated partial thromboplastin time test showed that HepG2/rhFIX expressed biologically active rhFIX 1.5 times higher than 293/rhFIX (P = 0.016). Recovery of rhFIX from the HepG2 by reversed-phase chromatography was straightforward. We found that rhFIX has a pharmacokinetic profile similar to that of FIX purified from human plasma when tested in hemophilic B model. HepG2/rhFIX cell line produced the highest levels of rhFIX, representing an efficient in vitro expression system. This work opens up the possibility of significantly reducing the costs of rhFIX production, with implications for expanding hemophilia B treatment in developing countries.
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In the present study, we analyzed AURKA and AURKB gene expression in 70 acute myeloid leukemia (AML) patients. There was no difference between leukemic samples and bone marrow mononuclear cells (BMMCs, n = 8) or CD34(+) progenitors (n = 10) from healthy donors. High white blood cells (WBC) counts were observed in the AURKA(+) and AURKB(+) groups, but no significant differences regarding age, gender, platelet counts or frequency of FLT3-ITD mutations. AURKA, but not AURKB, expression was independently associated with high WBC counts (OR: 3.15, 95% CI 1.07-9.24, p = 0.03). Moreover, the majority of cases that overexpressed AURKA and AURKB presented unfavorable cytogenetic abnormalities (p < 0.001). In conclusion, we described a significant association between overexpression of AURKA/B and cytogenetics findings in AML, which may be relevant to new therapeutic approaches, based on Aurora kinase inhibitors. (C) 2010 Elsevier Ltd. All rights reserved.
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Aim: The present work looked for to evaluate in rats the impact of different diets (high-lipid and high-lipid + high-protein) on liver, verifying the occurrence of oxidative stress and steatosis. Methods: The animals were treated with the respective diets (Group HLS: high-lipid diet with 50% of saturated fat; Group HPLS: high-lipid and high-protein diet with 50% of saturated fat and 40% of protein; Group Control: control diet AIN-93) for 28 days. After this period the animals were sacrificed for hepatic determinations of MDA, reduced GSH, vitamin E, steatosis and glycemia. Results: The results showed higher glycemia in the group HPLS, high concentration of MDA and GSH in the group Control and decreased hepatic vitamin E concentration in the groups that received the high-lipid diets. The hepatic fat was higher in the groups HPLS and HLS in relation to the Group Control, however HPLS presenting high level of fat concentration, showing similar results as the steatosis. Conclusion: the fat increase in the diet promoted increase of the oxidative stress, evidenced by the decrease in the hepatic concentration of vitamin E, showing its antioxidant role against the probable generated free radicals, the ones which possibly exercised a role in the steatosis occurrence.
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Background/Objectives: Reduced food intake, appetite loss and alteration of ghrelin and PYY(3-36) secretion have been suggested to have a function in the loss of body weight commonly observed after gastrectomy. The objective of this study was to investigate the circulating concentrations of ghrelin and PYY(3-36) and their relationships with food intake, appetite and resting energy expenditure (REE) after gastrectomy plus vagotomy. Subjects/Methods: Seven patients with total gastrectomy (TG), 14 with partial gastrectomy (PG) and 10 healthy controls were studied. Habitual food intake and REE was assessed; fasting and postprandial plasma total ghrelin, PYY(3-36) concentrations and appetite ratings were determined after ingestion of a liquid test meal. Results: Differently from PG and controls, fasting ghrelin correlated with REE, and a higher energy intake was observed in the TG group. Fasting plasma ghrelin concentrations were lower in TG compared with controls, and no ghrelin response to the meal was observed in either PG or TG. Fasting plasma PYY(3-36) concentrations were not different among the groups. There was an early and exaggerated postprandial rise in PYY(3-36) levels in both PG and TG groups, but not in controls. No effect of ghrelin or PYY(3-36) concentrations was observed on hunger, prospective consumption or fullness ratings. Conclusions: Total ghrelin and PYY(3-36) do not seem to be involved with appetite or energy intake regulation after gastrectomy plus vagotomy. Ghrelin secreted by sources other than stomach is likely to have a function in the long-term regulation of body weight after TG. European Journal of Clinical Nutrition (2010) 64, 845-852; doi: 10.1038/ejcn.2010.88; published online 19 May 2010