960 resultados para Experience Effect


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Experimental and clinical evidence shows that neutrophils play an important role in the mechanism of tissue injury in immune complex diseases through the generation of reactive oxygen species. In this study, we examined the influence of academic psychological stress in post-graduate students on the capacity of their blood neutrophils to release superoxide when stimulated by immune complexes bound to nonphagocytosable surfaces and investigated the modulatory effect of cortisol on this immune function. The tests were performed on the day before the final examination. The state-trait anxiety inventory questionnaire was used to examine whether this stressful event caused emotional distress. In our study, the psychological stress not only increased plasma cortisol concentration, but it also provoked a reduction in superoxide release by neutrophils. This decrease in superoxide release was accompanied by diminished mRNA expression for subunit p47(phox) of the phagocyte superoxide-generating nicotinamide adenine dinucleotide phosphate-oxidase. These inhibitory effects were also observed by in vitro exposure of neutrophils from control volunteers to 10(-7) M hydrocortisone, and could be prevented by the glucocorticoid receptor antagonist RU-486. These results show that in a situation of psychological stress, the increased levels of cortisol could inhibit superoxide release by neutrophils stimulated by IgG immune complexes bound to nonphagocytosable surfaces, which could attenuate the inflammatory state.

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The present study has investigated in conscious rats the influence of the duration of physical training sessions on cardiac autonomic adaptations by using different approaches; 1) double blockade with methylatropine and propranolol; 2) the baroreflex sensitivity evaluated by alternating bolus injections of phenylephrine and sodium nitroprusside; and 3) the autonomic modulation of HRV in the frequency domain by means of spectral analysis. The animals were divided into four groups: one sedentary group and three training groups submitted to physical exercise (swimming) for 15, 30, and 60 min a day during 10 weeks. All training groups showed similar reduction in intrinsic heart rate (IHR) after double blockade with methylatropine and propranolol. However, only 30-min and 60-min physical training presented an increase in the vagal autonomic component for determination of basal heart rate (HR) in relation to group sedentary. Spectral analysis of HR showed that the 30-min and 60-min physical training presented the reduction in low-frequency oscillations (LF = 0.20-0.75 Hz) and the increase in high-frequency oscillations (HF = 0.75-2.5 Hz) in normalized units. These both groups only showed an increased baroreflex sensitivity to tachycardiac responses in relation to group sedentary, however when compared, the physical training of 30-min exhibited a greater gain. In conclusion, cardiac autonomic adaptations, characterised by the increased predominance of the vagal autonomic component, were not proportional to the duration of daily physical training sessions. In fact, 30-minute training sessions provided similar cardiac autonomic adaptations, or even more enhanced ones, as in the case of baroreflex sensitivity compared to 60-minute training sessions. (C) 2010 Elsevier B.V. All rights reserved.

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A new tuberculosis vaccine is urgently needed. Prime-boost strategies are considered very promising and the inclusion of BCG is highly desirable. In this investigation, we tested the protective efficacy of BCG delivered in the neonatal period followed by boosters in the adult phase with a DNA vaccine containing the hsp65 gene from Mycobacterium leprae (pVAXhsp65). Immune responses were characterized by serum anti-hsp65 antibody levels and IFN-gamma and IL-5 production by the spleen. Amounts of these cytokines were also determined in lung homogenates. Protective efficacy was established by the number of colony-forming units (CFU) and histopathological analysis of the lungs after challenge with Mycobacterium tuberculosis. Immunization with BCG alone triggered a significant reduction of CFU in the lungs and also clearly preserved the pulmonary parenchyma. BCG priming also increased the immunogenicity of pVAXhsp65. However, boosters with pVAXhsp65 or the empty vector abolished the protective efficacy of BCG. Also, higher IL-5 levels were produced by spleen and lungs after DNA boosters. These results demonstrated that neonatal BCG immunization followed by DNAhsp65 boosters is highly immunogenic but is not protective against tuberculosis.

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Obesity is considered a worldwide public health problem showing an increased prevalence in developing countries, with urgent need for new and more efficient drugs and therapies. Enalapril, an angiotensin-I converting enzyme inhibitor (ACEi), is classically used in antihypertensive therapies, however, earlier publications have shown that this drug could also have significant impact on body weight in rats as well as in humans, besides reducing blood pressure. The effect of this drug in the white adipose tissue has been neglected for long time, even considering that most components of the renin-angiotensin and kallikrein-kinin system are expressed in this tissue. Furthermore, the adipose tissue is considered today as one of the most important sites for endocrine/inflammatory regulation of appetite and energy output and AngII has been linked to the metabolism in this tissue. Therefore, we analyzed the influence of chronic enalapril treatment in normotensive rats at earlier ages, evaluating body weight, energy homeostasis, lipid profile and serum levels of the hormones leptin and insulin, in the presence of a standard or a palatable hyperlipidic diet regimen for one month. Our results show that enalapril treatment is able to reduce body fat on both diets, without alteration in serum lipid profile. Furthermore, animals receiving enalapril showed reduction in food intake, leptin level and energy intake. In summary, these findings show for the first time that the ACEi enalapril reduces body fat in young normotensive rats and highlights a novel target to treat obesity and associated diseases. (c) 2007 Elsevier B.V. All rights reserved.

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The incidence of sudden unexpected death in epilepsy (SUDEP) in Our epilepsy unit over an 8-year period was analyzed to determine a possible association between phase of the moon and SUDEP. Analysis revealed that the number of SUDEPs was highest in full moon (70%), followed by waxing moon (20%) and new moon (10%). No SUDEPs Occurred during the waning cycle. These preliminary findings suggest that the full moon appears to correlate with SUDEP. (C) 2008 Elsevier Inc. All rights reserved.

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Background/Aims. The transcription factor nuclear factor-kappa B (NF-kappa B) exerts a pivotal role in the pathogenesis of hepatic ischemia/reperfusion (I/R) injury. Caffeic acid phenyl ester (CAPE), a potent and specific NF-kappa B inhibitor, presents protective effects on I/R injury in some tissues. This study aimed to evaluate the effect of CAPE on hepatic I/R injury in rats. Materials and methods. Wistar rats were submitted to a sham operation, 60 min ischemia, or 60 min ischemia plus saline or CAPE treatment followed by 6 h reperfusion. Liver tissue injury was evaluated by alanine aminotransferase, aspartate aminotransferase, and tissue glutathione measurement, and histological damage score. Apoptotic hepatocytes were determined by the transferase-mediated dUTP-biotin nick-end labeling assay. Hepatic neutrophil accumulation was assessed by the naphthol method. Lipid peroxidation and NF-kappa B activation were evaluated by 4-hydroxynonenal and NF-kappa B p65 immunohistochemistry, respectively. Results. Animals submitted to ischemia showed a marked increase of alanine aminotransferase and aspartate aminotransferase after reperfusion, but with lower levels in CAPE group. Tissue glutathione content declined gradually during ischemia to reperfusion and was partially recovered with CAPE treatment. The histological damage score, apoptosis index, and neutrophil infiltration, as well as 4-hydroxynonenal and NF-kappa B p65 nuclear labeling, were higher in the liver of animals submitted to I/R compared to the ischemia group. However, the CAPE treatment significantly reduced all of these alterations. Conclusions. CAPE was able to protect the liver against normothermic I/R injury in rats. This effect may be associated with the inhibition of the NF-kappa B signaling pathway and decrease of the acute inflammatory response following I/R in the liver. (C) 2008 Elsevier Inc. All rights reserved.

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A single-center experience with pediatric patients who underwent surgery for intractable rolandic epilepsy was reviewed with the aim of identifying putative factors that could influence postoperative seizure outcome in this population. Clinical data of 48 patients under 18 years of age with diagnosis of intractable rolandic epilepsy who underwent surgery from January 1996 to September 2009 were reviewed. Patients` mean age at surgery was 9.9 +/- 5.3 years; mean age at epilepsy onset was 3.9 years; mean seizure duration prior to surgery was 6 years; and mean follow-up was 5.1 years. The most frequent etiologies were cortical dysplasia, astrogliosis, tumors, tuberous sclerosis complex, and Sturge-Weber syndrome, which were observed in 20/48 (41.6%), 10/48 (20.8%), 10/48 (20.8%), 5/48 (10.4%), and 3/48 (6.2%) of the patients, respectively. After surgery, 20 patients (41.6%) showed neurological deficits, which in turn recovered within no longer than 6 months after surgery. Seizure outcome was classified as Engel class I in 29 (60.4%), Engel class II in 10 (20.8%), and Engel class III in 9 (18.8%) of the patients. The factors significantly related with seizure outcome were histological features (tumor versus non-tumor cases, p = 0.04) and lesion site (focal lesions versus non-focal lesions, p = 0.04). Tailored resection of rolandic cortex for intractable epilepsy can be safely performed in children. Accurate mapping of both functional cortex and epileptogenic areas may lead to improved seizure outcome. Tumor as well as focal lesions in hand and face motor areas are associated with good seizure outcome.

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Background and Aims: Endoscopic ultrasound (EUS) is useful for the treatment of sterile pancreatic fluid collections (PFC), either by means of transmural drainage or by complete aspiration. The aim of this study was to evaluate the efficacy and safety of single-step EUS-guided endoscopic approaches for treatment of sterile PFC. Patients and Methods: During a 3-year period, 77 consecutive patients with symptomatic, persistent sterile PFC were evaluated and treated with the linear EUS. We excluded patients with grossly purulent collections, chronic pseudocyst and those whose cytology diagnostic was neoplastic cyst of pancreas. 44 patients received a single 10-Fr plastic straight stent under EUS or fluoroscopic control (group I) and 33 of these underwent a single-step complete aspiration with a 19-gauge needle (group II). Results: The mean size of the sterile PFC was 48 mm in group I and 28 mm in group II (p < 0.001). Overall, endoscopic treatment was successful in 70 (90.9%) patients. The mean volume aspirated was 25 (18-65) ml. The total number of procedures was 50 in group I and 41 punctures in group II. After a mean follow-up of 64 +/- 15.6 weeks there were 6 complications 13.6%): 2 recurrences (referred to surgery), 2 developing abscesses (submitted a new EUS-guided endoscopic drainage with success), 1 perforation that died (2.2%), and 1 case of bleeding (sent to surgery) in group I. In group II there were only 6 (18.1%) recurrences (submitted a new EUS-guided aspiration). None of the patients undergoing single-step aspiration developed infections, perforation or hemorrhage. Conclusion: The recurrence of pancreatic pseudocysts after endoscopic treatment was similar, either by means of plastic stents or by complete single-step aspiration. Copyright (C) 2009 S. Karger AG, Basel

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Methanol is an alcohol which is metabolized to folmaldehyde in humans. It is a very toxic substance, responsible for blindness in cases of methanol intoxication. This study shows the production of methanol when aspartame is used to sweeten coffee brew. The temperature versus pH binomium was also tested. When assayed at 90 degrees C coffee brew+aspartame and aspartame solution showed an increase in methanol release of 17.8 and 19.3%, respectively, as compared with coffee brew. At 180 degrees C, the increase was 32.5 and 26.3%, respectively. Our data revealed a protective effect of the pH of coffee on the degradation of aspartame and formation of methanol; an important fact, mainly for specific populations that use aspartame, like diabetics.

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Background Disease management programs (DMPs) are developed to address the high morbi-mortality and costs of congestive heart failure (CHF). Most studies have focused on intensive programs in academic centers. Washington County Hospital (WCH) in Hagerstown, MD, the primary reference to a semirural county, established a CHF DMP in 2001 with standardized documentation of screening and participation. Linkage to electronic records and state vital statistics enabled examination of the CHF population including individuals participating and those ineligible for the program. Methods All WCH inpatients with CHF International Classification of Diseases, Ninth Revision code in any position of the hospital list discharged alive. Results Of 4,545 consecutive CHF admissions, only 10% enrolled and of those only 52.2% made a call. Enrollment in the program was related to: age (OR 0.64 per decade older, 95% CI 0.58-0.70), CHF as the main reason for admission (OR 3.58, 95% CI 2.4-4.8), previous admission for CHF (OR 1.14, 95% CI 1.09-1.2), and shorter hospital stay (OR 0.94 per day longer, 95% CI 0.87-0.99). Among DMP participants mortality rates were lowest in the first month (80/1000 person-years) and increased subsequently. The opposite mortality trend occurred in nonenrolled groups with mortality in the first month of 814 per 1000 person-years in refusers and even higher in ineligible (1569/1000 person-years). This difference remained significant after adjustment. Re-admission rates were lower among participants who called consistently (adjusted incidence rate ratio 0.62, 95% CI 0.52-0.77). Conclusion Only a small and highly select group participated in a low-intensity DMP for CHF in a community-based hospital. Design of DMPs should incorporate these strong selective factors to maximize program impact. (Am Heart J 2009; 15 8:459-66.)

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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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Study Design. In vitro biomechanical investigation of the screw-holding capacity. Objective. To evaluate the effect of repetitive screw-hole use on the insertional torque and retentive strength of vertebral system screws. Summary and Background Data. Placement and removal of vertebral system screws is sometimes necessary during the surgical procedures in order to assess the walls of the pilot hole. This procedure may compromise the holding capacity of the implant. Methods. Screws with outer diameter measuring 5, 6, and 7 mm were inserted into wood, polyurethane, polyethylene, and cancellous bone cylindrical blocks. The pilot holes were made with drills of a smaller, equal, or wider diameter than the inner screw diameter. Three experimental groups were established based on the number of insertions and reinsertions of the screws and subgroups were created according to the outer diameter of the screw and the diameter of the pilot hole used. Results. A reduction of screw-holding capacity was observed between the first and the following insertions regardless the anchorage material. The pattern of reduction of retentive strength was not similar to the pattern of torque reduction. The pullout strength was more pronounced between the first and the last insertions, while the torque decreased more proportionally from the first to the last insertions. Conclusion. Insertion and reinsertion of the screws of the vertebral fixation system used in the present study reduced the insertion torque and screw purchase.