259 resultados para Resistance parameters
Resumo:
Background. Heart transplantation (OHT) has traditionally been contraindicated in the presence of severe pulmonary hypertension (PH), as detected by right heart catheterization. Noninvasive methods are still not reliably accurate to make this evaluation. Objectives. Determine the efficacy of echo Doppler analysis for the diagnosis of severe PH. Methods. One hundred thirty patients (mean age = 42 +/- 15 years, 82 men) showed severe left ventricular dysfunction (mean ejection fraction = 29 +/- 12%; functional class III-IV). We excluded patients with atrial fibrillation, heart failure secondary to congenital disease, and valvulopathy. The pulmonary parameters defined as severe PH were: systolic pulmonary artery pressure (sPAP) >= 60 mm Hg; a mean transpulmonary gradient >= 15; or pulmonary vascular resistance >= 5 Wood units. Patients underwent a right heart catheterization using a Swan-Ganz catheter to measure hemodynamic parameters and to noninvasively estimate right-sided pressures from spectral Doppler recordings of tricuspid regurgitation velocity (right ventricular systolic pressure [RVsP]). A Pearson correlation of sPAP was obtained with RVsP by; the sensitivity of RVsP for the diagnosis of PH was determined by a receiver operating characteristic (ROC) curve. Results. A good correlation between sPAP and RVsP was obtained by Pearson correlation analysis (r = 0.64; 95% confidence interval [CI] 0.50-0.75; P < .001). The ROC curve analysis showed a sensitivity of 100%, a specificity of 37.2%, (95% CI 0.69-0.83, P < .0001) of a RVsP < 45 mm Hg (cutoff) on the exclusion of severe PH. Conclusions. The cutoff of RVsP < 45 mm Hg, on noninvasive echo Doppler evaluation of PH is an efficient method to replace invasive heart catheterization in OHT candidates.
Resumo:
BACKGROUND: The most common laparoscopic complications are associated with trocar insertion. The purpose of this study was to develop an objective method of evaluating the safety profile of various access devices used in laparoscopic surgery. STUDY DESIGN: In 20 swine, 6 bladed and 2 needle access devices were evaluated. A force profile was determined by measuring the force required to drive the trocar or needle through the fascia and into the peritoneum, at 0 and 10 mmHg. The amount Of tissue deformation, the length of blade exposed, and the duration of exposure were measured using a high-speed digital imaging system. RESULTS: The needle system without the sheath required the least driving force and had the most favorable force profile. In contrast, the bladed, nonretractable trocar system required a higher driving force and a rapid loss of resistance. Insertion under a pneumoperitoneum did not significantly alter the force profile of the various access devices except for the amount of tissue deformation. With the bladed system, the blade itself was exposed for an average of 0.5 to 1.0 seconds for a distance of 4.5 to 5.0 cm. In comparison, the needle system was exposed for 0.2 seconds for a distance of 1.8 cm. CONCLUSIONS: We developed a reproducible method of measuring the forces required to place the access systems, their pattern of resistance loss, and the characteristics of the blade exposure. These parameters may provide an adjunctive and objective measurement of safety, allowing for more direct comparison between various trocar designs. (J Am Coll Surg 2009;209:222-232. (C) 2009 by the American College of Surgeons)
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:
Background and objective The influence of ventilatory settings on static and functional haemodynamic parameters during mechanical ventilation is not completely known. The purpose of this study was to evaluate the effect of positive end-expiratory pressure, tidal volume and inspiratory to expiratory time ratio variations on haemodynamic parameters during haemorrhage and after transfusion of shed blood. Methods Ten anaesthetized pigs were instrumented and mechanically ventilated with a tidal volume of 8 ml kg(-1), a positive end-expiratory pressure of 5 cmH(2)O and an inspiratory to expiratory ratio of 1 : 2. Then, they were submitted in a random order to different ventilatory settings (tidal volume 16 ml kg(-1), positive end-expiratory pressure 15 cmH(2)O or inspiratory to expiratory time ratio 2: 1). Functional and static haemodynamic parameters (central venous pressure, pulmonary artery occlusion pressure, right ventricular end-diastolic volume and pulse pressure variation) were evaluated at baseline, during hypovolaemia (withdrawal of 20% of estimated blood volume) and after an infusion of withdrawn blood (posttransfusion). Results During baseline, a positive end-expiratory pressure of 15cmH(2)O significantly increased pulmonary artery occlusion pressure from 14.6 +/- 1.6 mmHg to 17.4 +/- 1.7 mmHg (P<0.001) and pulse pressure variation from 15.8 +/- 8.5% to 25.3 +/- 9.5% (P<0.001). High tidal volume increased pulse pressure variation from 15.8 8.5% to 31.6 +/- 10.4% (P<0.001), and an inspiratory to expiratory time ratio of 2: 1 significantly increased only central venous pressure. During hypovolaemia, high positive end-expiratory pressure influenced all studied variables, and high tidal volume strongly increased pulse pressure variation (40.5 +/- 12.4% pre vs. 84.2 +/- 19.1 % post, P<0.001). The inversion of the inspiratory to expiratory time ratio only slightly increased filling pressures during hypovolaemia, without without affecting pulse pressure variation or right ventricle end-diastolic volume. Conclusion We concluded that pulse pressure variation measurement is influenced by cyclic variations in intrathoracic pressure, such as those caused by augmentations in tidal volume. The increase in mean airway pressure caused by positive end-expiratory pressure affects cardiac filling pressures and also pulse pressure variation, although to a lesser extent. Inversion of the inspiratory to expiratory time ratio does not induce significant changes in static and functional haemodynamic parameters. Eur J Anaesthesiol 26:66-72 (c) 2009 European Society of Anaesthesiology.
Resumo:
Purpose: In this study we analyzed the role played by aerobic exercise training in the plasma lipoprotein profile, prebeta 1-HDL concentration, and in the in vitro HDL3 ability to remove cholesterol from macrophages and inhibit LDL oxidation in type 2 diabetes mellitus (DM) patients and control subjects, in the fasting and postprandial states. Methods: Healthy controls (HTC, N = 11; 1 M/10 F) and subjects with type 2 diabetes mellitus (DMT, N = 11; 3M/ 8F) were engaged in a 4-month aerobic training program, and compared with a group of sedentary subjects with type 2 diabetes mellitus (DMS, N = 10; 4 M/6 F). All groups were submitted to an oral fat load test to analyze all parameters, both at the beginning of the investigation protocol (basal) and at the end of the study period (final). Results: Exercising did not modify body weight, BMI, plasma concentrations of total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides (TG), glucose, insulin, or HOMA-IR, but it reduced the waist circumference. The HDL3 Composition did not change, and its ability to remove cell cholesterol was unaltered by aerobic training. In DMT but not in HTC, aerobic training improved 15% the HDL3 protective effect against LDL maximal oxidation rate in the fasting state, and reduced 24% the plasma prebeta 1-HDL concentration in the postprandial state, suggesting an enhanced prebeta 1-HDL conversion into larger, more mature HDL particles. In this regard, regular aerobic exercise enriched HDL2 with TG in the fasting and postprandial states in HTC and in the fasting phase in DMT. Conclusion: Our results show that aerobic exercise training in diabetes mellitus improves the HDL efficiency against LDL oxidation and favors HDL maturation. These findings were independent of changes in insulin resistance and of the rise of plasma HDL cholesterol concentration.
Resumo:
Background Facial motor evoked potential (FMEP) amplitude ratio reduction at the end of the surgery has been identified as a good predictor for postoperative facial nerve outcome. We sought to investigate variations in FMEP amplitude and waveform morphology during vestibular schwannoma (VS) resection and to correlate these measures with postoperative facial function immediately after surgery and at the last follow-up. Methods Intraoperative orbicularis oculi and oris muscles FMEP data from 35 patients undergoing surgery for VS resection were collected, then analysed by surgical stage: initial, dural opening, tumour dissection (TuDis), tumour resection (TuRes) and final. Findings Immediately after surgery, postoperative facial function correlated significantly with the FMEP amplitude ratio during TuDis, TuRes and final stages in both the orbicularis oculi (p = 0.003, 0.055 and 0.028, respectively) and oris muscles (p = 0.002, 0.104 and 0.014, respectively). At the last follow-up, however, facial function correlated significantly with the FMEP amplitude ratio only during the TuDis (p = 0.005) and final (p = 0.102) stages for the orbicularis oris muscle. At both time points, postoperative facial paresis correlated significantly with FMEP waveform deterioration in orbicularis oculi during the final stage (immediate, p = 0.023; follow-up, p = 0.116) and in orbicularis oris during the TuDis, TuRes and final stages (immediate, p = 0.071, 0.000 and 0.001, respectively; follow-up, p = 0.015, 0.001 and 0.01, respectively). Conclusions FMEP amplitude ratio and waveform morphology during VS resection seem to represent independent quantitative parameters that can be used to predict postoperative facial function. Event-to-baseline FMEP monitoring is quite useful to dictate when intraoperative changes in surgical strategy are warranted to reduce the chances of facial nerve injury.
Resumo:
Ambient particles have been consistently associated with adverse health effects, yielding mainly high cardiorespiratory morbidity and mortality. Diesel engines represent a major source of particles in the urban scenario. We aimed to modify the composition of diesel particles, by means of different extraction procedures, to relate changes in chemical profile to corresponding indicators of respiratory toxicity. Male BALB/c mice were nasally instilled with saline, or with diesel particles, treated or not, and assigned to five groups: saline ( SHAM), intact diesel particles (DEP), and diesel particles previously treated with methanol ( METH), hexane ( HEX), or nitric acid (NA). Elemental composition and organic compounds were analyzed. Twenty-four hours after nasal instillation, respiratory parameters were measured and lung tissue was collected for histological analysis. Static elastance was significantly increased in groups DEP and MET in relation to the other groups. HEX and NA were different from DEP but not significantly different from SHAM and METH groups. The difference between dynamic and static elastance was increased in DEP, METH, and NA treatments; HEX was not statistically different from SHAM. DEP and METH groups presented significantly increased upper airways resistance, while DEP, METH, and NA showed higher peripheral airways resistance values. All groups had a higher total resistance than SHAM. DEP, METH, and NA showed significant increased infiltration of polymorphonuclear cells. In conclusion, diesel particles treated with hexane ( HEX) resulted in a respiratory-system profile very similar to that in SHAM group, indicating that hexane treatment attenuates pulmonary inflammation elicited by diesel particles.
Resumo:
Objective: To introduce a new coupling system between screw driver and interference screw, and biomechanical tests that validate the safety of its application. Methods: The new system was submitted to biomechanical torsion assays. Two types of analysis were performed: maximum torque of manual insertion of the screws into bovine bone; destructive assays of torsion of the system using an INSTRON 55MT machine. The same tests were also performed on a control group, using a commercially available interference screw coupling system (Acufex (R)). Results: In the tests on manual insertion of screws in bovine femurs, the average values found with a digital torque meter were 1.958 N/m for Acufex (R) and 2.563 N/m for FMRP. Considering p>0.05, there were no statistical differences between the two groups (p=0.02) in the values for maximum torque of insertion, in the two systems studied. The average values for maximum torque of torsion resisted by the screw were 15N/m for the Acufex (R) screw and 13N/m for the FMRP screw, again with no statistical differences between the two groups (p>0.05). In the evaluation of angular deformation, there was also no significant difference between the two screw types (p=0.15). Conclusion: The new coupling system for interference screws developed at FMRP-USP revealed a torsion resistance that is comparable with the system already available on the market and regulated for international use.
Resumo:
Background: The goal of this study was to determine if increasing strength in primary knee extensors and flexors would directly affect net knee joint moments during a common functional task in persons with knee osteoarthritis. Methods: An exploratory single sample clinical trial with pre-post treatment measures was used to study volunteers with clinical diagnosis of mild knee osteoarthritis (OA) in one knee. Subjects participated in an individually supervised training program 3 times a week for eight weeks consisting of progressive resistive exercises for knee extensors and knee flexors. Pre and post training outcome assessments included: 1. Net internal knee joint moments, 2. Electromyography of primary knee extensors and flexors, and 3. Self-report measures of knee pain and function. The distribution of lower extremity joint moments as a percent of the total support moment was also investigated. Findings: Pain, symptoms, activities of daily life, quality of life, stiffness, and function scores showed significant improvement following strength training. Knee internal valgus and hip internal rotation moments showed increasing but non-statistically significant changes post-training. There were no significant differences in muscle co-contraction activation of the Quadriceps and Hamstrings. Interpretation: While exercise continues to be an important element of OA management, the results of this study suggest improvements in function, pain, and other symptoms, as a result of strength training may not be causally related to specific biomechanical changes in net joint moments. (C) 2011 Elsevier Ltd. All rights reserved.
Resumo:
In adolescent idiopathic scoliosis (AIS) there has been a shift towards increasing the number of implants and pedicle screws, which has not been proven to improve cosmetic correction. To evaluate if increasing cost of instrumentation correlates with cosmetic correction using clinical photographs. 58 Lenke 1A and B cases from a multicenter AIS database with at least 3 months follow-up of clinical photographs were used for analysis. Cosmetic parameters on PA and forward bending photographs included angular measurements of trunk shift, shoulder balance, rib hump, and ratio measurements of waist line asymmetry. Pre-op and follow-up X-rays were measured for coronal and sagittal deformity parameters. Cost density was calculated by dividing the total cost of instrumentation by the number of vertebrae being fused. Linear regression and spearman`s correlation were used to correlate cost density to X-ray and photo outcomes. Three independent observers verified radiographic and cosmetic parameters for inter/interobserver variability analysis. Average pre-op Cobb angle and instrumented correction were 54A degrees (SD 12.5) and 59% (SD 25) respectively. The average number of vertebrae fused was 10 (SD 1.9). The total cost of spinal instrumentation ranged from $6,769 to $21,274 (Mean $12,662, SD $3,858). There was a weak positive and statistically significant correlation between Cobb angle correction and cost density (r = 0.33, p = 0.01), and no correlation between Cobb angle correction of the uninstrumented lumbar spine and cost density (r = 0.15, p = 0.26). There was no significant correlation between all sagittal X-ray measurements or any of the photo parameters and cost density. There was good to excellent inter/intraobserver variability of all photographic parameters based on the intraclass correlation coefficient (ICC 0.74-0.98). Our method used to measure cosmesis had good to excellent inter/intraobserver variability, and may be an effective tool to objectively assess cosmesis from photographs. Since increasing cost density only improves mildly the Cobb angle correction of the main thoracic curve and not the correction of the uninstrumented spine or any of the cosmetic parameters, one should consider the cost of increasing implant density in Lenke 1A and B curves. In the area of rationalization of health care expenses, this study demonstrates that increasing the number of implants does not improve any relevant cosmetic or radiographic outcomes.
Resumo:
Objective: The aim of this study was to assess the effects of protein restriction in growing rats. Methods: Rats (approximate weight, 100 g) were maintained with low-protein (LP; 6%) or normo-proteic (control; 17%) diets, and at the end of the 15th day, hormonal and biochemistry parameters and energetic balance were evaluated. Data were analyzed using Student`s t test (with statistical significance set at P <= .05). Results: LP animals were hyperphagic and showed increased energetic gain (24%) and energy expenditure (EE) compared with controls. The increase in EE was followed by increased sympathetic activity in brown adipose tissue, evidenced by increased norepinephrine turnover, suggesting increased thermogenesis. In spite of hyperphagia, protein ingestion in LP animals was lower than that of controls (P < 0.01). The LP diet impaired body growth and caused deep alterations in body chemical composition, with an increase in carcass lipid content (64%) and reductions of protein and water. In LP animals, postprandial glycemia was unchanged, and insulinemia was lower than in controls (P <= .01). Reduction in fasting glycemia without changes in insulinemia also was detected (P < .01), suggesting increased insulin sensitivity. The LP diet caused a 100% increase in serum leptin (P < .01). Conclusions: Protein restriction led to an increase in EE, with probable activation of thermogenesis in brown adipose tissue, evidenced by an increase in catecholamines levels. Despite the higher EE, energetic gain and lipids increased. The high level of leptin associated with hyperphagia led to the supposition that these animals are leptin resistant, and the increase in insulin sensitivity, suggested by the relation between insulin and glycemia in fasting and fed animals, might contribute to lipid accumulation. (C) 2009 Elsevier Inc. All rights reserved.
Resumo:
BACKGROUND There is evidence that the subgroup of patients with essential hypertension who are also insulin resistant is at increased risk of cardiovascular disease (CVD). We are unaware of the frequency of insulin resistance in patients with essential hypertension as well as the CVD risk in this subgroup of patients. This analysis was aimed at providing the prevalence of insulin resistance and associated CVD risk factors in treated and untreated patients with essential hypertension. METHODS The study population consisted of 126 patients with hypertension: 56 untreated and 70 in a stable treatment program. Body mass index (BMI), blood pressure, plasma glucose and insulin responses to an oral glucose challenge, lipid and lipoprotein concentrations, and steady-state plasma glucose (SSPG) concentration during the insulin suppression test were measured. Insulin resistance was defined operationally as a SSPG concentration >180 mg/dl. RESULTS Demographic characteristics and metabolic CVD risk factors were comparable in both groups, with 30-50% of both treated and untreated patients having abnormalities of all risk factors measured. Approximately 50% of patients met the criteria for insulin resistance in both groups, and the prevalence of abnormal CVD risk factors in this group was increased two to threefold as compared to the other half of the subjects. CONCLUSIONS Approximately 50% of patients with essential hypertension, both treated and untreated, appear to be insulin resistant, and CVD risk factors are greatly accentuated in this subset of patients.
Resumo:
Few studies are available about the evaluation of resistance training in patients with protein-energy malnutrition. To assess the effects of resistance training on the recovery of nutritional status of patients with short bowel syndrome, with a small bowel remnant of less than 100 cm, 9 patients of both sexes with protein-energy malnutrition after extensive resection of the small bowel were submitted to resistance training of progressive intensity consisting of concentric and eccentric work exercises for the upper limbs, trunk, and lower limbs, with the individuality and limitations of each patients being respected. Food consumption was monitored by 24-hour food recall performed during the initial phase of the study, before and 7 and 14 weeks after physical training, and by a dietary record for a period of 3 days of oral feeding. The nutrients administered by the enteral and parenteral route were recorded. A significant increase in total arm area (P <= .01) and fat-free mass (P <= .01) was observed as determined by computed tomography. An increase in total energy ingestion and carbohydrate consumption (P <= .01) was also observed. In addition, the activity of the enzyme carnosinase was increased after resistance training (P <= .01). The present results show that resistance training in patients with short bowel syndrome and protein-energy malnutrition can be considered to be a part of the nonmedicamentous treatment of these patients, leading to better nutrient use and to a gain of lean mass. (c) 2008 Elsevier Inc. All rights reserved.
Resumo:
Scher, LML, Ferriolli, E, Moriguti, JC, Scher, R, and Lima, NKC. The effect of different volumes of acute resistance exercise on elderly individuals with treated hypertension. J Strength Cond Res 25(4): 1016-1023, 2011-Acute resistance exercise can reduce the blood pressure (BP) of hypertensive subjects. The aim of this study was to evaluate the effect of different volumes of acute low-intensity resistance exercise over the magnitude and the extent of BP changes in treated hypertensive elderly individuals. Sixteen participants (7 men, 9 women), with mean age of 68 6 5 years, performed 3 independent randomized sessions: Control (C: 40 minutes of rest), Exercise 1 (E1: 20 minutes, 1 lap in the circuit), and Exercise 2 (E2: 40 minutes, 2 laps in the circuit) with the intensity of 40% of 1 repetition maximum. Blood pressure was measured before (during 20 minutes) and after each session (every 5 minutes during 60 minutes) using both a mercury sphygmomanometer and a semiautomatic device (Omrom-HEM-431). After that, 24-hour ambulatory blood pressure monitoring was performed (Dyna-MAPA). Blood pressure decreased during the first 60 minutes (systolic: p < 0.01, diastolic: p < 0.05) after all exercise sessions. Only the highest volume session promoted a reduction of mean systolic 24-hour BP and awake BP (p, 0.05) after exercise, with higher diastolic BP during sleep (p, 0.05). Diastolic 24-hour BP and both systolic and diastolic BP during sleep were higher after E1 (p, 0.05). Concluding, acute resistive exercise sessions in a circuit with different volumes reduced BP during the first 60 minutes after exercise in elderly individuals with treated hypertension. However, only the highest volume promoted a reduction of mean 24-hour and awake systolic BP.
Resumo:
Deminice, R, Sicchieri, T, Mialich, MS, Milani, F, Ovidio, PP, and Jordao, AA. Oxidative stress biomarker responses to an acute session of hypertrophy-resistance traditional interval training and circuit training. J Strength Cond Res 25(3): 798-804, 2011-We have studied circuit resistance schemes with high loads as a time-effective alternative to hypertrophy-traditional resistance training. However, the oxidative stress biomarker responses to high-load circuit training are unknown. The aim of the present study was to compare oxidative stress biomarker response with an acute session of hypertrophy-resistance circuit training and traditional interval training. A week after the 1 repetition maximum (1RM) test, 11 healthy and well-trained male participants completed hypertrophy-resistance acute sessions of traditional interval training (3 x 10 repetitions at 75% of the 1RM, with 90-second passive rest) and circuit training (3 x 10 repetitions at 75% of the 1RM, in alternating performance of 2 exercises with different muscle groups) in a randomized and cross-over design. Venous blood samples were collected before (pre) and 10 minutes after (post) the resistance training sessions for oxidative stress biomarker assays. As expected, the time used to complete the circuit training (20.2 +/- 1.6) was half of that needed to complete the traditional interval training (40.3 +/- 1.8). Significant increases (p < 0.05) in thiobarbituric acid reactive substances (40%), creatine kinase (CK) (67%), glutathione (14%), and uric acid (25%) were detected posttraditional interval training session in relation to pre. In relation to circuit training, a significant increase in CK (33%) activity postsession in relation to pre was observed. Statistical analysis did not reveal any other change in the oxidative stress biomarker after circuit training. In conclusion, circuit resistance-hypertrophy training scheme proposed in the current study promoted lower oxidative stress biomarkers and antioxidant modulations compared with resistance traditional interval training.