995 resultados para Leonardo, da Vinci, 1452-1519.
Resumo:
Abad, CCC, Prado, ML, Ugrinowitsch, C, Tricoli, V, and Barroso, R. Combination of general and specific warm-ups improves leg-press one repetition maximum compared with specific warm-up in trained individuals. J Strength Cond Res 25(8): 2242-2245, 2011-Accurate assessment of muscular strength is critical for exercise prescription and functional evaluation. The warm-up protocol may affect the precision of the 1 repetition maximum (1RM) test. Testing guidelines recommend performing both general and specific warm-ups before strength tests. The general warm-up intends to raise muscle temperature, whereas the specific warm-up aims to increase neuromuscular activation. Although there is scientific evidence for performing the specific warm-up, the effects of general warm-up on strength tests are still unclear. The purpose of this study was to investigate whether the combination of a general with a specific warm-up (G + SWU) protocol would improve leg press 1RM values compared with a specific warm-up (SWU) protocol. Thirteen participants were tested for leg-press 1RM under 2 warm-up conditions. In the first condition, participants performed the SWU only, which was composed of 1 set of 8 repetitions at approximately 50% of the estimated 1RM followed by another set of 3 repetitions at 70% of the estimated 1RM. In the second condition (G + SWU), participants performed the 1RM test after a 20-minute general warm-up on a stationary bicycle at 60% of HRmax and the same specific warm-up as in the SWU. Values of 1RM in SWU and in G + SWU were compared by a paired t-test, and significance level was set at p <= 0.05. Strength values were on average 8.4% (p = 0.002) higher in the G + SWU compared with the SWU. These results suggest that the G + SWU induced temperature-dependent neuromuscular adjustments that increased muscle force production capacity. Therefore, these results support the recommendations of the testing guidelines to perform a moderate intensity general warm-up in addition to the specific warm-up before maximum strength assessments.
Resumo:
OBJECTIVE. The purpose of the study was to investigate patient characteristics associated with image quality and their impact on the diagnostic accuracy of MDCT for the detection of coronary artery stenosis. MATERIALS AND METHODS. Two hundred ninety-one patients with a coronary artery calcification (CAC) score of <= 600 Agatston units (214 men and 77 women; mean age, 59.3 +/- 10.0 years [SD]) were analyzed. An overall image quality score was derived using an ordinal scale. The accuracy of quantitative MDCT to detect significant (>= 50%) stenoses was assessed using quantitative coronary angiography (QCA) per patient and per vessel using a modified 19-segment model. The effect of CAC, obesity, heart rate, and heart rate variability on image quality and accuracy were evaluated by multiple logistic regression. Image quality and accuracy were further analyzed in subgroups of significant predictor variables. Diagnostic analysis was determined for image quality strata using receiver operating characteristic (ROC) curves. RESULTS. Increasing body mass index (BMI) (odds ratio [OR] = 0.89, p < 0.001), increasing heart rate (OR = 0.90, p < 0.001), and the presence of breathing artifact (OR = 4.97, p = 0.001) were associated with poorer image quality whereas sex, CAC score, and heart rate variability were not. Compared with examinations of white patients, studies of black patients had significantly poorer image quality (OR = 0.58, p = 0.04). At a vessel level, CAC score (10 Agatston units) (OR = 1.03, p = 0.012) and patient age (OR = 1.02, p = 0.04) were significantly associated with the diagnostic accuracy of quantitative MDCT compared with QCA. A trend was observed in differences in the areas under the ROC curves across image quality strata at the vessel level (p = 0.08). CONCLUSION. Image quality is significantly associated with patient ethnicity, BMI, mean scan heart rate, and the presence of breathing artifact but not with CAC score at a patient level. At a vessel level, CAC score and age were associated with reduced diagnostic accuracy.
Resumo:
Although major depressive disorder (MDD) has been consistently considered the most frequent complication of obsessive-compulsive disorder (OCD), little is known about the clinical characteristics of patients with both disorders. This study assessed 815 Brazilian OCD patients using a comprehensive psychiatric evaluation. Clinical and demographic variables, including OCD symptom dimensions, were compared among OCD patients with and without MDD. Our findings showed that prevalence rates of current MDD (32%) and lifetime MDD (67.5%) were similar for both sexes in this study. In addition, patients with comorbid MDD had higher severity scores of OCD symptoms. There was no preferential association of MDD with any particular OCD symptom dimension. This study supports the notion that depressed OCD patients present more severe general psychopathology. (C) 2011 Elsevier Inc. All rights reserved.
Resumo:
PURPOSE. To evaluate the relationship between pattern electroretinogram (PERG) amplitude, macular and retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT), and visual field (VF) loss on standard automated perimetry (SAP) in eyes with temporal hemianopia from chiasmal compression. METHODS. Forty-one eyes from 41 patients with permanent temporal VF defects from chiasmal compression and 41 healthy subjects underwent transient full-field and hemifield (temporal or nasal) stimulation PERG, SAP and time domain-OCT macular and RNFL thickness measurements. Comparisons were made using Student`s t-test. Deviation from normal VF sensitivity for the central 18 of VF was expressed in 1/Lambert units. Correlations between measurements were verified by linear regression analysis. RESULTS. PERG and OCT measurements were significantly lower in eyes with temporal hemianopia than in normal eyes. A significant correlation was found between VF sensitivity loss and fullfield or nasal, but not temporal, hemifield PERG amplitude. Likewise a significant correlation was found between VF sensitivity loss and most OCT parameters. No significant correlation was observed between OCT and PERG parameters, except for nasal hemifield amplitude. A significant correlation was observed between several macular and RNFL thickness parameters. CONCLUSIONS. In patients with chiasmal compression, PERG amplitude and OCT thickness measurements were significant related to VF loss, but not to each other. OCT and PERG quantify neuronal loss differently, but both technologies are useful in understanding structure-function relationship in patients with chiasmal compression. (ClinicalTrials.gov number, NCT00553761.) (Invest Ophthalmol Vis Sci. 2009; 50: 3535-3541) DOI:10.1167/iovs.08-3093
Resumo:
Objective: The study was designed to evaluate the effects of strength training (ST) on the bone mineral density (BMD) of postmenopausal women without hormone replacement therapy. Method: Subjects were randomized into untrained (UN) or trained (TR) groups. The TR group exercised three ST sessions per week for 24 weeks, and body composition, muscular strength, and BMD of the lumbar spine and femur neck were evaluated. Results: Body weight, mass index, and fat percentage were lower after 24 weeks only in the TR group (p < .05). SR also improved the one repetition maximum test in 46% and 39% of upper and lower limbs, respectively. The percentage of demineralization was higher in the UN group than in the TR group at the lumbar spine and femoral neck (p < .05). Discussion: Results indicated that 24 weeks of ST improved body composition parameters, increased muscular strength, and preserved BMD in postmenopausal women.
Resumo:
Objective: Patients undergoing amputation of the lower limb due to peripheral arterial disease (PAD) are at risk of developing deep venous thrombosis (DVT). Few studies in the research literature report the incidence of DVT during the early postoperative period or the risk factors for the development of DVT in the amputation stump. This prospective study evaluated the incidence of DVT during the first 35 postoperative days in patients who had undergone amputation of the lower extremity due to PAD and its relation to comorbidities and death. Methods: Between September 2004 and March 2006, 56 patients (29 men), with a mean age of 67.25 years, underwent 62 amputations, comprising 36 below knee amputations (BKA) and 26 above knee amputations (AKA). Echo-Doppler scanning was performed preoperatively and on postoperative days 7 and 31 (approximately). All patients received acetylsalicylic acid (100 mg daily) preoperatively and postoperatively, but none received prophylactic anticoagulation. Results: DVT occurred in 25.8% of extremities with amputations (10 ARA and 6 BKA). The cumulative incidence in the 35-day postoperative period was 28% (Kaplan-Meier). There was a significant difference (P = .04) in the incidence of DVT between AKA (37.5%) and BKA (21.2%). Age >= 70 years (48.9% vs 16.8%, P = .021) was also a risk factor for DVT in the univariate analysis. Of the 16 cases, 14 (87.5%) were diagnosed during outpatient care. The time to discharge after amputation was averaged 6.11 days in-hospital stay (range, 1-56 days). One symptomatic nonfatal pulmonary embolism occurred in a patient already diagnosed with DVT. There was no relation between other comorbidities and DVT. The multivariate analysis showed no association between risk factors and the occurrence of DVT in the amputated extremity. DVT ipsilateral to the amputation did not influence the mortality rate (9.7%). Conclusion: The incidence of DVT in the early postoperative period (<= 35 days) was elevated principally in patients aged >= 70 years and for AKA. Patients with PAD who have recently undergone major amputations should be considered at high risk for DVT, even after hospital discharge. Given the high rate of postoperative DVT observed in this study, we now recommend prophylactic anticoagulation for these patients, but further study is needed to determine the optimal duration and efficacy of this treatment. (J Vasc Surg 2008;48:1514-9.)
Penile erection induced in vivo by a purified toxin from the Brazilian spider Phoneutria nigriventer
Resumo:
OBJECTIVES To verify the effect on erectile tissue of mice of two neuropeptides extracted from the poison of a spider, Phoneutric nigriventer, (Tx2-5 and -6. termed `eretina`) after direct injection into the corpus cavernosum, to assess the minimum dosage necessary for effect. the time for initiation of action, the local duration of the erection, histological effects and the presence of local and systemic side-effects. MATERIALS AND METHODS When applied intraperitoneally, eretina promotes the relaxation of cavernous smooth muscle, thus causing penile erection. Thirty-five mice were divided in two groups; 10 control mice were injected 20 mu L of saline solution, and in the treated group, 25 mice were divided into groups of five and each subgroup received eretina in decreasing doses (0.024, 0.012, 0.006, 0.003 and 0.0015 mu g/kg) until the minimum dose that produced an erection was determined. After treatment 211 mice were monitored to determine the response and any collateral effects. RESULTS The minimum dose producing an erection was 0.006 mu g/kg, the five mice in this group having evidence of an erection at 35-45 min after injection. The histology of the cavernosum of mice treated with eretina showed dilatation and congestion of the vascular spaces with more blood than in controls. With the minimum dose there were no local or systemic collateral effects and the erection was lost after 120-140 min. CONCLUSION The minimum dose of eretina producing an erection in mice was determined. and the agent was safe for this use as it did not produce any collateral toxic effects. These studies indicate a possible means of determining the mechanism of action of eretina.
Resumo:
Background: Cadherins and integrins are important for maintenance of tissue integrity and in signal transduction during skin development. Distribution of these molecules in human skin development was investigated and associated with markers of differentiation, cytokeratins (CK) and involucrin (INV). Methods: Using immunohistochemistry expression of E- and P-cadherins, integrins beta-1 and -4, CK10, CK14 and INV was assessed in skin fragments of 10 human fetuses (gestational weeks ranged from 4 to 24, all weighing up to 500 g). Results: At initial phases of development, integrins beta-1 and -4 and E- and P-cadherins were present on epithelial cell membranes in all layers. CK14 and CK10 were expressed in all epithelial layers and INV weakly detected in the superficial layer. In more advanced stages, integrins were detected in all layers, but a marked polarized expression was seen in basal layer. E-cadherin was detected in all layers, but the cornified stratum and P-cadherin were observed in the lower layers. CK14 was expressed in basal layer, CK10 in suprabasal stratum and INV was observed in cornified layer. Conclusions: Cadherins and integrins are essential for skin development, being spatially and temporally regulated. Their expression is related with the expression of maturation markers of the epidermis.
Resumo:
The physiological effects of nitroglycerin as a potent vasodilator have long been documented. However, the molecular mechanisms by which nitroglycerin exerts its biological functions are still a matter of intense debate. Enzymatic pathways converting nitroglycerin to vasoactive compounds have been identified, but none of them seems to fully account for the reported clinical observations. Here, we demonstrate that nitroglycerin triggers constitutive nitric oxide synthase (NOS) activation, which is a major Source of NO responsible for low-dose (1-10 nM) nitroglycerin-induced vasorelaxation. Our studies in cell cultures, isolated vessels, and whole animals identified endothelial NOS activation as a fundamental requirement for nitroglycerin action at pharmacologically relevant concentrations in WT animals.
Resumo:
Background and Purpose-Plasma glutathione peroxidase (GPx-3) is a major antioxidant enzyme in plasma and the extracellular space that scavenges reactive oxygen species produced during normal metabolism or after oxidative insult. A deficiency of this enzyme increases extracellular oxidant stress, promotes platelet activation, and may promote oxidative posttranslational modification of fibrinogen. We recently identified a haplotype (H-2) in the GPx-3 gene promoter that increases the risk of arterial ischemic stroke among children and young adults. Methods-The aim of this study is to identify possible relationships between promoter haplotypes in the GPx-3 gene and cerebral venous thrombosis (CVT). We studied the GPx-3 gene promoter from 23 patients with CVT and 123 young controls (18 to 45 years) by single-stranded conformational polymorphism and sequencing analysis. Results-Over half of CVT patients (52.1%) were heterozygous (H1H2) or homozygous (H2H2) carriers of the H-2 haplotype compared with 12.2% of controls, yielding a more than 10-fold independent increase in the risk of CVT (OR=10.7; 95% CI, 2.70 to 42.36; P<0.0001). Among women, the interaction of the H2 haplotype with hormonal risk factors increased the OR of CVT to almost 70 (P<0.0001). Conclusions-These findings show that a novel GPx-3 promoter haplotype is a strong, independent risk factor for CVT. As we have previously shown that this haplotype is associated with a reduction in transcriptional activity, which compromises antioxidant activity and antithrombotic benefits of the enzyme, these results suggest that a deficiency of GPx-3 leads to a cerebral venous thrombophilic state.
Resumo:
Recent studies have investigated whether low level laser therapy (LLLT) can optimize human muscle performance in physical exercise. This study tested the effect of LLLT on muscle performance in physical strength training in humans compared with strength training only. The study involved 36 men (20.8 +/- 2.2 years old), clinically healthy, with a beginner and/or moderate physical activity training pattern. The subjects were randomly distributed into three groups: TLG (training with LLLT), TG (training only) and CG (control). The training for TG and TLG subjects involved the leg-press exercise with a load equal to 80% of one repetition maximum (1RM) in the leg-press test over 12 consecutive weeks. The LLLT was applied to the quadriceps muscle of both lower limbs of the TLG subjects immediately after the end of each training session. Using an infrared laser device (808 nm) with six diodes of 60 mW each a total energy of 50.4 J of LLLT was administered over 140 s. Muscle strength was assessed using the 1RM leg-press test and the isokinetic dynamometer test. The muscle volume of the thigh of the dominant limb was assessed by thigh perimetry. The TLG subjects showed an increase of 55% in the 1RM leg-press test, which was significantly higher than the increases in the TG subjects (26%, P = 0.033) and in the CG subjects (0.27%, P < 0.001). The TLG was the only group to show an increase in muscle performance in the isokinetic dynamometry test compared with baseline. The increases in thigh perimeter in the TLG subjects and TG subjects were not significantly different (4.52% and 2.75%, respectively; P = 0.775). Strength training associated with LLLT can increase muscle performance compared with strength training only.
Resumo:
Introduction: Mechanical properties (MP) are clinically applicable tools for healthcare professionals working on the musculoskeletal system. Objectives: The aim of this study was to evaluate two protocols of neuromuscular electric stimulation (NMES) to improve MP regeneration of the myotendinous complex after segment immobilization in female rats. Materials and Methods: Fifty animals were equally distributed into five groups: Control (CG, n=10); Immobilized (IG, n=10); Immobilized and freely remobilized (IFG, n=10); Immobilized and NMES once/day (IEG1, n=10); Immobilized and MNES twice/day (IEG2, n=10). Immobilization was kept for 14 days, and remobilization was subsequently released for 10 days. NMES was applied for 10 days, post-immobilization, every morning for 10 minutes to IEG1 animals and every morning and afternoon (total 20 minutes) to the IEG2 group. After these procedures, the gastrocnemius muscle was submitted to the mechanical traction assay to evaluate stiffness, resilience, load and stretching at maximum limit MPs. Results: Immobilization reduced the MP values concerning load and stiffness (p 0.05). Results for NMES applied twice a day were less satisfactory than the ones obtained with one application or in the remobilized group (p>0.05). Conclusion: It is concluded that the gastrocnemius muscle became structurally better organized through a single NMES application and by remobilization.
Resumo:
Imbalance and weakness of the serratus anterior and upper trapezius force couple have been described in patients with shoulder dysfunction. There is interest in identifying exercises that selectively activate these muscles and including it in rehabilitation protocols. This study aims to verify the UT/SA electromyographic (EMG) amplitude ratio, performed in different upper limb exercises and on two bases of support. Twelve healthy men were tested (average age = 22.8 +/- 3.1 years), and surface EMG was recorded from the upper trapezius and serratus anterior using single differential surface electrodes. Volunteers performed isometric contractions over a stable base of support and on a Swiss ball during the wall push-up (WP), bench press (BP), and push-up (PU) exercises. All SEMG data are reported as a percentage of root mean square or integral of linear envelope from the maximal value obtained in one of three maximal voluntary contractions for each muscle studied. A linear mixed-effect model was performed to compare UT/SA ratio values. The WP, BP, and PU exercises showed UT/SA ratio mean +/- SD values of 0.69 +/- 0.72, 0.14 +/- 0.12, and 0.39 +/- 0.37 for stable surfaces, respectively, whereas for unstable surfaces, the values were 0.73 +/- 0.67, 0.43 +/- 0.39, and 0.32 +/- 0.30. The results demonstrate that UT/SA ratio was influenced by the exercises and by the upper limb base of support. The practical application is to show that BP on a stable surface is the exercise preferred over WP and PU on either surfaces for serratus anterior muscle training in patients with imbalance between the UT/SA force couple or serratus anterior weakness.
Resumo:
This article reports the spread of bla(KPC-2) in the Sao Paulo and Rio de Janeiro states, facilitated by globally spread K. pneumoniae clonal complex 258 (CC258) clones (ST258, ST11, and ST437) and a diversity of plasmids (IncFII, IncN, and IncL/M, two untypeable plasmids carrying Tn4401a or Tn4401b) successfully disseminated among species of the Enterobacteriaceae (Enterobacter cloacae, Serratia marcescens, and Citrobacter freundii). It also constitutes the first description of sequence type 258 (ST258) in Brazil, which was associated with a nosocomial hospital outbreak in Ribeirao Preto city.
Resumo:
Chronic ethanol Consumption and hypertension are related. In the current study we investigated whether changes in reactivity of the mesenteric arterial bed could account for the increased blood pressure associated with chronic ethanol intake. Changes in reactivity to phenylephrine and acetylcholine were investigated in the perfused mesenteric bed from rats treated with ethanol for 2 or 6 weeks and their age-matched controls. Mild hypertension was observed in chronically ethanol-treated rats. Treatment of rats for 6 weeks induced an increase in the contractile response of endothelium-intact mesenteric bed to phenylephrine, but not denuded rat mesenteric bed. The phenylephrine-induced increase in perfusion pressure was not altered after 2 weeks` treatment with ethanol. Moreover, acetylcholine-induced endothelium-dependent relaxation was reduced by ethanol treatment for 6 weeks, but not 2 weeks. Pre-treatment with indometacin, a cyclooxygenase inhibitor, reduced the maximum effect induced by phenylephrine (E-max) in endothelium-intact mesenteric bed from both control and ethanol-treated rats. No differences in the E-max values for phenylephrine were observed between groups in the presence of indometacin. L-NNA, a nitric oxide (NO) synthase (NOS) inhibitor, increased the E-max for phenylephrine in endothelium-intact mesenteric bed from control rats but not from ethanol-treated rats. Levels of endothelial NOS (eNOS) mRNA were not altered by chronic ethanol consumption. However, chronic ethanol intake strongly reduced eNOS protein levels in the mesenteric bed. This study shows that chronic ethanol consumption increases blood pressure and alters the reactivity of the mesenteric bed. Moreover, the increased vascular response to phenylephrine observed in the mesenteric bed is maintained by two mechanisms: an increased release of endothelial-derived vasoconstrictor prostanoids and a reduced modulatory action of endothelial NO, which seems to be associated with reduced post-transcriptional expression of eNOS.