54 resultados para Adenosine 5-Triphosphate, per cell
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Background Statins reduce the incidence of cardiovascular events in patients at high cardiovascular risk. However, a benefit of statins in such patients who are undergoing hemodialysis has not been proved. Methods We conducted an international, multicenter, randomized, double-blind, prospective trial involving 2776 patients, 50 to 80 years of age, who were undergoing maintenance hemodialysis. We randomly assigned patients to receive rosuvastatin, 10 mg daily, or placebo. The combined primary end point was death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. Secondary end points included death from all causes and individual cardiac and vascular events. Results After 3 months, the mean reduction in low-density lipoprotein (LDL) cholesterol levels was 43% in patients receiving rosuvastatin, from a mean baseline level of 100 mg per deciliter (2.6 mmol per liter). During a median follow-up period of 3.8 years, 396 patients in the rosuvastatin group and 408 patients in the placebo group reached the primary end point (9.2 and 9.5 events per 100 patient-years, respectively; hazard ratio for the combined end point in the rosuvastatin group vs. the placebo group, 0.96; 95% confidence interval [CI], 0.84 to 1.11; P = 0.59). Rosuvastatin had no effect on individual components of the primary end point. There was also no significant effect on all-cause mortality (13.5 vs. 14.0 events per 100 patient-years; hazard ratio, 0.96; 95% CI, 0.86 to 1.07; P = 0.51). Conclusions In patients undergoing hemodialysis, the initiation of treatment with rosuvastatin lowered the LDL cholesterol level but had no significant effect on the composite primary end point of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. (ClinicalTrials.gov number, NCT00240331.)
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In spite of considerable technical advance in MRI techniques, the optical resolution of these methods are still limited. Consequently, the delineation of cytoarchitectonic fields based on probabilistic maps and brain volume changes, as well as small-scale changes seen in MRI scans need to be verified by neuronanatomical/neuropathological diagnostic tools. To attend the current interdisciplinary needs of the scientific community, brain banks have to broaden their scope in order to provide high quality tissue suitable for neuroimaging- neuropathology/anatomy correlation studies. The Brain Bank of the Brazilian Aging Brain Research Group (BBBABSG) of the University of Sao Paulo Medical School (USPMS) collaborates with researchers interested in neuroimaging-neuropathological correlation studies providing brains submitted to postmortem MRI in-situ. In this paper we describe and discuss the parameters established by the BBBABSG to select and to handle brains for fine-scale neuroimaging-neuropathological correlation studies, and to exclude inappropriate/unsuitable autopsy brains. We tried to assess the impact of the postmortem time and storage of the corpse on the quality of the MRI scans and to establish fixation protocols that are the most appropriate to these correlation studies. After investigation of a total of 36 brains, postmortem interval and low body temperature proved to be the main factors determining the quality of routine MRI protocols. Perfusion fixation of the brains after autopsy by mannitol 20% followed by formalin 20% was the best method for preserving the original brain shape and volume, and for allowing further routine and immunohistochemical staining. Taken to together, these parameters offer a methodological progress in screening and processing of human postmortem tissue in order to guarantee high quality material for unbiased correlation studies and to avoid expenditures by post-imaging analyses and histological processing of brain tissue.
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Hepatitis B virus (HBV) infection is a significant public health concern with 350 million chronic carriers worldwide. Eight HBV genotypes (A-H) have been described so far. Genotype E (HBV/E) is widely distributed in West Africa and has rarely been found in other continents, except for a few cases in individuals with an African background. In this study, we characterized HBV genotypes in Quibdo, Colombia, by partial S/P gene sequencing, and found, for the first time, HBV/E circulating in nine Afro-Colombian patients who had no recent contact with Africa. The presence of HBV/E in this community as a monophyletic group suggests that it was a result of a recent introduction by some Afro-descendent contact or, alternatively, that the virus came with slaves brought to Colombia. By using sequences with sampling dates, we estimated the substitution rate to be about 3.2x10(-4) substitutions per site per year, which resulted in a time to the most recent common ancestor (TMRCA) of 29 years. In parallel, we also estimated the TMRCA for HBV/E by using two previously estimated substitution rates (7.7x10(-4) and 1.5x10(-5) substitutions per site per year). The TMRCA was around 35 years under the higher rate and 1500 years under the slower rate. In sum, this work reports for the first time the presence of an exclusively African HBV genotype circulating in South America. We also discuss the time of the entry of this virus into America based on different substitution rates estimated for HBV.
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We studied the results of chronic oral administration of amiodarone on in vitro lung tissue mechanics, light and electron microscopy. Fifteen Wistar male rats were divided into three groups. In control (CTRL) group animals received saline (0.5 mL/day). In amiodarone (AMIO) groups, amiodarone was administered by gavage at a dose of 175 mg/kg 5 days per week for 6 (6AMIO) or 12 weeks (12AMIO). Lung tissue strips were analyzed 24 h after the last drug administration. Tissue resistance and elastance were higher in 6AMIO and 12AMIO than in CTRL, while hysteresivity was similar in all groups. Total amount of collagen fibers in lung parenchyma increased progressively with the time course of the lesion. However, at 6 weeks there was an increase in the amount of type III collagen fibers, while in 12AMIO mainly type I collagen fibers were found. In our study amiodarone increased lung tissue impedance that was accompanied by matrix remodeling and lesion of type II pneumocytes. (C) 2008 Elsevier B.V. All rights reserved.
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Introduction. This study addressed the role of the local renin-angiotensin system (RAS) in the left ventriular hypertropy (LVH) induced by swimming training using pharmacological blockade. Materials and methods. Female Wistar rats treated with enalapril maleate (60 mg.kg(-1).d(-1), n = 38), losartan (20 mg.kg(-1).d(-1), n = 36) or high salt diet (1% NaCl, n = 38) were trained by two protocols (T1: 60-min swimming session, 5 days per week for 10 weeks and T2: the same T1 protocol until the 8(th) week, then 9(th) week they trained twice a day and 10(th) week they trained three times a day). Salt loading prevented activation of the systemic RAS. Haemodynamic parameters, soleus citrate synthase (SCS) activity and LVH (left ventricular/body weight ratio, mg/g) were evaluated. Results. Resting heart rate decreased in all trained groups. SCS activity increased 41% and 106% in T1 and T2 groups, respectively. LVH was 20% and 30% in T1 and T2 groups, respectively. Enalapril prevented 39% of the LVH in T2 group (p < 0.05). Losartan prevented 41% in T1 and 50% in T2 (P < 0.05) of the LVH in trained groups. Plasma renin activity (PRA) was inhibited in all salt groups and it was increased in T2 group. Conclusions. These data provide evidence that the physiological LVH induced by swimming training is regulated by local RAS independent from the systemic, because the hypertrophic response was maintained even when PRA was inhibited by chronic salt loading. However, other systems can contribute to this process.
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OBJECTIVE-This study sought to investigate an association of HbA1c (A1C) with incident heart failure among individuals without diabetes and compare it to fasting glucose. RESEARCH DESIGN AND METHODS-We studied 11,057 participants of the Atherosclerosis Risk in Communities (ARIC) Study without heart failure or diabetes at baseline and estimated hazard ratios of incident heart failure by categories of A1C (<5.0, 5.0-5.4 [reference], 5 5-59, and 6.0-6.4%) and fasting glucose (<90, 90-99 [reference], 100-109, and 110-125 mg/dl) using Cox proportional hazards models. RESULTS-A total of 841 cases of incident heart failure hospitalization or deaths (International Classification of Disease, 9th/10th Revision, 428/150) occurred during a median follow-up of 14.1 years (incidence rate 5.7 per 1,000 person-years). After the adjustment for covariates including fasting glucose, the hazard ratio of incident heart failure was higher in individuals with A1C 6.0-6.4% (1.40 [95% CI, 1 09-1.79]) and 5.5-6.0% (1.16 [0.98-1 37]) as compared with the reference group. Similar results were observed when adjusting for insulin level or limiting to heart failure cases without preceding coronary events or developed diabetes during follow-up. In contrast, elevated fasting glucose was not associated with heart failure after adjustment for covariates and A1C. Similar findings were observed when the top quartile (A1C, 5.7-6.4%, and fasting glucose, 108-125 mg/dl) was compared with the lowest quartile (<5 2% and <95 mg/dl, respectively). CONCLUSIONS-Elevated A1C (>= 5.5-6 0%) was associated with incident heart failure in a middle-aged population without diabetes, suggesting that chronic hyperglycemia prior to the development of diabetes contributes to development of heart failure. Diabetes 59:2020-2026, 2010
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The endocannabinoid anandamide, in addition to activating cannabinoid type 1 receptors (CB1), may act as an agonist at transient receptor potential vanilloid type 1 (TRPV1) channels. In the periaqueductal gray, CB1 activation inhibits, whereas TRPV1 increases, anxiety-like behavior. In the medial prefrontal cortex (mPFC), another brain region related to defensive responses, CB1 activation induces anxiolytic-like effects. However, a possible involvement of TRPV1 is still unclear. In the present study, we tested the hypothesis that TRPV1 channel contributes to the modulation of anxiety-like behavior in the mPFC. Male Wistar rats (n = 5-7 per group) received microinjections of the TRPV1 antagonist capsazepine (1-60 nmol) in the ventral portion of the mPFC and were exposed to the elevated plus maze (EPM) or to the Vogel conflict test. Capsazepine increased exploration of open arms in the EPM as well as the number of punished licks in the Vogel conflict test, suggesting anxiolytic-like effects. No changes in the number of entries into the enclosed arms were observed in the EPM, indicating that there were no changes in motor activity. Moreover, capsazepine did not interfere with water consumption or nociceptive threshold, discarding potential confounding factors for the Vogel conflict test. These data suggest that TRPV1 in the ventral mPFC tonically inhibits anxiety-like behavior. TRPV1 could facilitate defensive responses opposing, therefore, the anxiolytic-like effects reported after local activation of CB1 receptors.
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Leptin resistance and desensitization of hypophagia during prolonged inflammatory challenge. Am J Physiol Endocrinol Metab 300: E858-E869, 2011. First published February 22, 2011; doi: 10.1152/ajpendo.00558.2010.-Acute exposure to bacterial lipopolysaccharide (LPS) is a potent inducer of immune response as well as hypophagia. Nevertheless, desensitization of responses to LPS occurs during long-term exposure to endotoxin. We induced endotoxin tolerance, injecting repeated (6LPS) LPS doses compared with single (1LPS) treatment. 1LPS, but not 6LPS group, showed decreased food intake and body weight, which was associated with an increased plasma leptin and higher mRNA expression of OB-Rb, MC4R, and SOCS3 in the hypothalamus. Hypophagia induced by 1LPS was associated with lower levels of 2-arachidonoylglycerol (2-AG), increased number of p-STAT3 neurons, and decreased AMP-activated protein kinase (AMPK) activity. Desensitization of hypophagia in the 6LPS group was related to high 2-AG, with no changes in p-STAT3 or increased p-AMPK. Leptin decreased food intake, body weight, 2-AG levels, and AMPK activity and enhanced p-STAT3 in control rats. However, leptin had no effects on 2-AG, p-STAT3, or p-AMPK in the 1LPS and 6LPS groups. Rats treated with HFD to induce leptin resistance showed neither hypophagia nor changes in p-STAT3 after 1LPS, suggesting that leptin and LPS recruit a common signaling pathway in the hypothalamus to modulate food intake reduction. Desensitization of hypophagia in response to repeated exposure to endotoxin is related to an inability of leptin to inhibit AMPK phosphorylation and 2-AG production and activate STAT3. SOCS3 is unlikely to underlie this resistance to leptin signaling in the endotoxin tolerance. The present model of prolonged inflammatory challenge may contribute to further investigations on mechanisms of leptin resistance.
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Heat shock proteins are molecular chaperones linked to a myriad of physiological functions in both prokaryotes and eukaryotes. In this study, we show that the Aspergillus nidulans hsp30 (ANID_03555.1), hsp70 (ANID_05129.1), and hsp90 (ANID_08269.1) genes are preferentially expressed in an acidic milieu, whose expression is dependent on the palA (+) background under optimal temperature for fungal growth. Heat shock induction of these three hsp genes showed different patterns in response to extracellular pH changes in the palA(+) background. However, their accumulation upon heating for 2 h was almost unaffected by ambient pH changes in the palA (-) background. The PalA protein is a member of a conserved signaling cascade that is involved in the pH-mediated regulation of gene expression. Moreover, we identified several genes whose expression at pH 5.0 is also dependent on the palA (+) background. These results reveal novel aspects of the heat- and pH-sensing networks of A. nidulans.
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Background: Cigarette smoke exposure is considered an important negative prognostic factor for chronic rhinosinusitis (CRS) patients. However, there is no clear mechanistic evidence implicating cigarette smoke exposure in the poor clinical evolution of the disease or in the maintenance of the inflammatory state characterizing CRS. This study aimed to evaluate the effects of cigarette smoke exposure on respiratory cilia differentiation. Methods: Monse nasal septal epithelium cultures grown at an air-liquid interface were used as a model of respiratory epithelium. After 5 days of cell growth, cultures were exposed to air on the apical surface. Additionally, cigarette smoke condensate (CSC; the particulate phase of tobacco smoke) or cigarette smoke extract (CSE; the volatile phase) Were diluted in the basolateral compartment in different concentrations. After 15 days of continuous exposure, scanning electron microscopy and immunofluorescence for type IV tubulin were used to determine presence and maturation of cilia. Transepithelial resistance was also recorded to evaluate confluence and physiological barrier integrity. Results: CSC and CSE impair ciliogenesis in a dose-dependent manner with notable effects in concentrations higher than 30 mu g/mL, yielding >70% nonciliation and shorter cilia compared With control. No statistical difference on transepithelial resistance was evident. Conclusion: CSC and CSE exposure negatively impacts ciliogenesis of respiratory cells at concentrations not effecting transepithelial resistance. The impairment on ciliogenesis reduce the mucociliary clearance apparatuts after injury and/or infection and may explain the poor response to therapy for CRS patients exposed to tobacco smoke.
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Adrenocortical tumors (ACT) are rare neoplasms of the adrenal glands accounting for 0.2% of all pediatric cancers. However, the incidence of ACT in South Brazilian children is 10 to 15 times greater than the worldwide incidence. Comparative genomic hybridization studies have revealed the presence of a high degree of chromosomal instability in ACT. We evaluated 16 ACT, 8 of them carcinomas and 8 adenomas. The presence of changes in DNA copy numbers was determined by comparative genomic hybridization, and the findings were validated by real-time polymerase chain reaction on the basis of IGF-II gene expression. The adenomas showed a mean of 19.7 imbalances per case, with the most frequent gain and loss being 4p15.1-p15.3 and 20p11.2-p13.2, respectively. The carcinomas presented with a mean of 35.5 imbalances per case, with the more frequent gain being 2q14.1-q24.3 and the more frequent losses being 3q21-q26.2, 20q12-qter, and 22q11.2-q13.3. The most frequent imbalances in both adenomas and carcinomas were gains of 1p21-p31.2, 2p12-p21 and loss of 20p11.2-p12. The expression of IGF-II mRNA (11p15.5) was higher in samples that presented with a gain of this region. It has been established that great genomic instability exists in pediatric ACT.
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Introduction: The purpose of this study was to evaluate the biocompatibility of the root canal filling system Epiphany/Resilon in connective tissue of rats. Methods: Fifteen rats were used, separated into 3 groups in accordance with its period of death (7, 21, 42 days). Four filled dentin tubes were implanted with the tested materials as follows: ERSP group, Epiphany/Resilon with Self-etch Primer; ER group, Epiphany/Resilon without primer; EG group, Endofill/gutta-percha points; and ET group, empty tube. After 7, 21, and 42 days, animals were killed, obtaining 5 samples per group. A grade from I-IV was used to graduate the inflammatory reaction. Results: Results showed that Epiphany/Resilon (ERSP and ER groups) induced a slight (II) inflammatory reaction after 42 days. However, in ER group, in which the self-etch primer was not applied, severe (IV) to moderate (III) inflammatory reactions were observed between 7 and 21 days. When compared with the EG and ET groups, it was observed that these groups presented tissue reaction ranging from slight (II, 7 and 21 days) to no inflammation (I, 42 days). Conclusions: Epiphany/Resilon root canal filling system presented satisfactory tissue reaction. It was biocompatible when tested in connective tissue of rats. (J Endod 2010;36:110-114)
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The regular use of mouthrinses, particularly when combined with the use of air-powder polishing, could affect the appearance of tooth-colored restorations. The current study sought to evaluate the effect of NaHCO(3) powder on translucency of a microfilled composite resin immersed in different mouthrinses, at distinct evaluation periods. Eighty disk-shaped specimens of composite resin (Durafill VS, Heraeus Kulzer GmbH & Co. KG, Hanau, Germany) were prepared. The composite specimens were then randomly allocated into two groups according to the surface treatment: exposure to NaHCO(3) powder (10 seconds) or nonexposure, and they were randomly assigned into four subgroups, according to the mouthrinses employed (N = 10): Periogard (Colgate/Palmolive, Sao Bernardo do Campo, SP, Brazil), Cepacol (Aventis Pharma, Sao Paulo, SP, Brazil), Plax (Colgate/Palmolive), and distilled water (control group). The samples were immersed for 2 minutes daily, 5 days per week, over a 4-month test period. Translucency was measured with a transmission densitometer at seven evaluation periods. Statistical analyses (analysis of variance and Tukey`s test) revealed that: distilled water presented higher translucency values (86.72%); Periogard demonstrated the lowest translucency values (72.70%); and Plax (74.05%) and Cepacol (73.32%) showed intermediate translucency values, which were statistically similar between them (p > 0.01). NaHCO(3) air-powder polishing increased the changes in translucency associated with the mouthrinses. Air-powder polishing alone had no effect on material translucency. Translucency percent was gradually decreased from 1 week of immersion up to 4 months. It may be concluded that the NaHCO(3) powder and the tested mouthrinses have affected the translucency of microfilled composite resin, according to the tested time. CLINICAL SIGNIFICANCE During the last decade, the demand for composite resin restorations has grown considerably, however, controversy persists regarding the effect of surface roughness on color stability.
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Laurencia marilzae Gil-Rodriguez, Senties & MT Fujii is recorded for the first time for the tropical western Atlantic Ocean, occurring in Isla Mujeres, Quintana Roo, Mexican Caribbean. The specimens were collected in November 2008 and June 2009, growing epilithically in the lower intertidal zone on moderately exposed rocky shores. This species is characterized by its distinctive yellow-orange color in the natural environment, four pericentral cells per vegetative axial segment, the presence of secondary pit-connections between adjacent cortical cells, which are markedly projecting at the apices, and by the presence of one ""corp en cerise"" per cell in all cells of the thallus: cortical, medullary, including pericentral and axial cells, and trichoblasts. Morphological similarities and molecular data support the determination of this material as L. marilzae. The present study expands the geographical distribution of L. marilzae to the Caribbean Sea in the tropical Western Atlantic Ocean.
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The goal of the present study was to investigate morphological changes in the serotonergic neurons/terminals in the dorsal (DR) and median (MnR) raphe nuclei and on the hippocampal dentate gyrus (DG) in neonatal rats treated from the 1st to the 21st postnatal day with fluoxetine (10 mg/kg sc, daily) or drug vehicle (0 9% saline 1 ml/kg). The results show that postnatal chronic treatment with fluoxetine promoted. (1) a smaller body weight increase during the pre-weaning period; (2) smaller number of 5-HT neurons in the DR, (3) smaller 5-HT neuronal cell bodies (area, perimeter and diameter) in the DR and the MnR and (4) diminished serotonergic terminals in the DG. These data suggest that the development of the serotonergic system was impaired and that early exposure to fluoxetine damaged the morphology of 5-HT neurons in young adult rats While these findings are consistent with other work, more studies are needed to better clarify the effects of postnatal chronic treatment with fluoxetine on the serotonergic system and, consequently, on the functions modulated by serotonin (C) 2010 Elsevier Ireland Ltd All rights reserved