Is acute static stretching able to reduce the time to exhaustion at power output corresponding to maximal oxygen uptake?

Samogin Lopes, FA, Menegon, EM, Franchini, E, Tricoli, V, and de M. Bertuzzi, RC. Is acute static stretching able to reduce the time to exhaustion at power output corresponding to maximal oxygen uptake? J Strength Cond Res 24(6): 1650-1656, 2010-This study analyzed the effect of an acute static stretching bout on the time to exhaustion (T(lim)) at power output corresponding to (V) over dotO(2)max. Eleven physically active male subjects (age 22.3 +/- 2.8 years, (V) over dotO(2)max 2.7 +/- 0.5 L . min(-1)) completed an incremental cycle ergometer test, 2 muscle strength tests, and 2 maximal tests to exhaustion at power output corresponding to (V) over dotO(2)max with and without a previous static stretching bout. The T(lim) was not significantly affected by the static stretching (164 +/- 28 vs. 150 +/- 26 seconds with and without stretching, respectively, p = 0.09), but the time to reach (V) over dotO(2)max (118 +/- 22 vs. 102 +/- 25 seconds), blood-lactate accumulation immediately after exercise (10.7 +/- 2.9 vs. 8.0 +/- 1.7 mmol . L(-1)), and oxygen deficit (2.4 +/- 0.9 vs. 2.1 +/- 0.7 L) were significantly reduced (p <= 0.02). Thus, an acute static stretching bout did not reduce T(lim) at power output corresponding to (V) over dotO(2)max possibly by accelerating aerobic metabolism activation at the beginning of exercise. These results suggest that coaches and practitioners involved with aerobic dependent activities may use static stretching as part of their warm-up routines without fear of diminishing high-intensity aerobic exercise performance.

On the finite element modeling of fatigue crack growth in pressurized cylindrical shells

A methodology for the computational modeling of the fatigue crack growth in pressurized shell structures, based on the finite element method and concepts of Linear Elastic Fracture Mechanics, is presented. This methodology is based on that developed by Potyondy [Potyondy D, Wawrzynek PA, Ingraffea, AR. Discrete crack growth analysis methodology for through crack in pressurized fuselage structures. Int J Numer Methods Eng 1995;38:1633-1644], which consists of using four stress intensity factors, computed from the modified crack integral method, to predict the fatigue propagation life as well as the crack trajectory, which is computed as part of the numerical simulation. Some issues not presented in the study of Potyondy are investigated herein such as the influence of the crack increment size and the number of nodes per element (4 or 9 nodes) on the simulation results by means of a fatigue crack propagation simulation of a Boeing 737 airplane fuselage. The results of this simulation are compared with experimental results and those obtained by Potyondy [1]. (C) 2008 Elsevier Ltd. All rights reserved.

Soil Organic Carbon Stocks of Rio Grande do Sul, Brazil

Robust and accurate regional estimates of C storage in soils are currently an important research topic because of ongoing debate about human-induced changes in the terrestrial C cycle. Widely available geoprocessing tools were applied to estimate native soil organic C (SOC) stocks of Rio Grande do Sul state in southern Brazil to a depth of 30 cm from previously sampled soil pedons under undisturbed vegetation. The study used a statewide comprehensive soil survey comprising a small-scale soil map, a climate map, and a soil pedon database. Soil organic C stocks under native vegetation were calculated with two different approaches: the Tier 1 method of the Intergovernmental Panel on Climate Change (IPCC) and a refined method based on actual field measurements derived from soil profile data. Highest SOC stocks occurred in Neossolos Quartzarenico hidromorfico (Aquents), Organossolos Tiomorficos (Hemists), Latossolos Brunos (Udox), and Vertissolos Ebanicos (Uderts) soil classes. Before human use of soils, most C was stored in the Latossolos Vermelhos (Udox) and Neossolos Regoliticos (Orthents), which occupy a large area of Rio Grande do Sul. Generally, IPCC default reference SOC stocks compared well with SOC stocks calculated from soil pedons. The total SOC stock of Rio Grande do Sul was estimated at 1510.3 Tg C (5.8 kg C m(-2)) by the IPPC method and 1597.5 +/- 363.9 Tg C (7.4 +/- 1.9 kg C m(-2)) calculated from soil pedons. The SOC digital map and SOC database developed in this study provide crucial background information for state-level contemporary assessment of C stocks and soil C sequestration programs and initiatives.

Effect of Brazil nut supplementation on the blood levels of selenium and glutathione peroxidase in hemodialysis patients

Objective: In patients who have undergone hemodialysis, large amounts of reactive oxygen species (ROS) are produced and, at higher concentrations, ROS are thought to be involved in the pathogenesis of cardiovascular disease. It has been proposed that selenium (Se) may exert an anti-atherogenic influence by reducing oxidative stress. The richest known food source of selenium is the Brazil nut (Bertholletia excelsa, family Lecythidaceae), found in the Amazon region. We evaluated the effect of Brazil nut supplementation on blood levels of Se and glutathione peroxidase (GSH-Px) activity in patients on hemodialysis. Methods: A total of 81 patients on hemodialysis (52.0 +/- 15.2 y old, average time on dialysis 82.3 +/- 91.4 mo, body mass index 24.9 +/- 4.4 kg/m(2)) from the RenalCor and RenalVida Clinics in Rio de Janeiro, Brazil, were studied. All patients received one nut (around 5 g, averaging 58.1 mu g Se/g) a day for 3 mo. The Se concentrations in the nuts and in plasma and erythrocytes were determined by atomic absorption spectrophotometry with hydride generation (Hitachi, Z-500). GSH-Px levels were measured using Randox commercial kits. Results: Plasma Se (18.8 +/- 17.4 mu g/L) and erythrocyte (72.4 +/- 37.9 mg/L) levels were below the normal, range before nut supplementation. After supplementation, the plasma level increased to 104.0 +/- 65.0 mu g/L and erythrocytes to 244.1 +/- 119.5 mg/L (P<0.0001). The activity of GSH-Px also increased after supplementation, from 46.6 +/- 14.9 to 55.9 +/- 23.6 U/g of hemoglobin (P<0.0001). Before supplementation, 11% of patients had GSH-Px activity below the normal range (27.5-73.6 U/g of hemoglobin). After supplementation, all patients showed GSH-Px activity within the normal range. Conclusion: The data revealed that the investigated patients presented Se deficiency and that the consumption of only one Brazil nut a day (5 g) during 3 mo was effective to increase the Se concentration and GSH-Px activity in these patients, thus improving their antioxidant status. (C) 2010 Elsevier Inc. All rights reserved.

Determination of chlorpheniramine in human plasma by HPLC-ESI-MS/MS: application to a dexchlorpheniramine comparative bioavailability study

In the present study a fast, sensitive and robust validated method to quantify chlorpheniramine in human plasma using brompheniramine as internal standard (IS) is described. The analyte and the IS were extracted from plasma by LLE (diethyl ether-dichloromethane, 80:20, v/v) and analyzed by HPLC-ESI-MS/MS. Chromatographic separation was performed using a gradient of methanol from 35 to 90% with 2.5 mm NH(4)OH on a Gemini Phenomenex C(8) 5 mu m column (50 x 4.6 mm i.d.) in 5.0 min/run. The method fitted to a linear calibration curve (0.05-10 ng/mL, R > 0.9991). The precision (%CV) and accuracy ranged, respectively: intra-batch from 1.5 to 6.8% and 99.1 to 106.6%, and inter-batch from 2.4 to 9.0%, and 99.9 to 103.1%. The validated bioanalytical procedure was used to assess the comparative bioavailability in healthy volunteers of two dexchlorpheniramine 2.0 mg tablet formulations (test dexchlorpheniramine, Eurofarma, and reference Celestamine (R), Schering-Plough). The study was conducted using an open, randomized, two-period crossover design with a 2 week washout interval. Since the 90% confidence interval for C(max) and AUC ratios were all within the 80-125% interval proposed by ANVISA and FDA, it was concluded that test and reference formulations are bioequivalent concerning the rate and the extent of absorption. Copyright (C) 2009 John Wiley & Sons, Ltd.

Deconstructing Tick Saliva NON-PROTEIN MOLECULES WITH POTENT IMMUNOMODULATORY PROPERTIES

Dendritic cells (DCs) are powerful initiators of innate and adaptive immune responses. Ticks are blood-sucking ectoparasite arthropods that suppress host immunity by secreting immunomodulatory molecules in their saliva. Here, compounds present in Rhipicephalus sanguineus tick saliva with immunomodulatory effects on DC differentiation, cytokine production, and costimulatory molecule expression were identified. R. sanguineus tick saliva inhibited IL-12p40 and TNF-alpha while potentiating IL-10 cytokine production by bone marrow-derived DCs stimulated by Toll-like receptor-2, -4, and -9 agonists. To identify the molecules responsible for these effects, we fractionated the saliva through microcon filtration and reversed-phase HPLC and tested each fraction for DC maturation. Fractions with proven effects were analyzed by micro-HPLC tandem mass spectrometry or competition ELISA. Thus, we identified for the first time in tick saliva the purine nucleoside adenosine (concentration of similar to 110pmol/mu l) as a potent anti-inflammatory salivary inhibitor of DC cytokine production. We also found prostaglandin E(2) (PGE(2) similar to 100 nM) with comparable effects in modulating cytokine production by DCs. Both Ado and PGE(2) inhibited cytokine production by inducing cAMP-PKA signaling in DCs. Additionally, both Ado and PGE(2) were able to inhibit expression of CD40 in mature DCs. Finally, flow cytometry analysis revealed that PGE(2), but not Ado, is the differentiation inhibitor of bone marrow-derived DCs. The presence of non-protein molecules adenosine and PGE(2) in tick saliva indicates an important evolutionary mechanism used by ticks to subvert host immune cells and allow them to successfully complete their blood meal and life cycle.

Morphology of the thyroid in coastal and noncoastal populations of the koala (Phascolarctos cinereus) in Queensland

The gross morphology, histology, and ultrastructure of the thyroid gland of the koala, Phascolarctos cinereus, is described. Generally, the glands were found to contain large-diameter follicles in association with an epithelium of low height. Morphometric analysis demonstrated a high relative thyroid weight (0.3 +/- 0.2 g/kg) for koalas compared with the 0.07-0.24 g/kg typical of eutherian mammals and 0.03-0.1 g/kg found in other marsupials. The relative thyroid weight of glands (0.33 +/- 0.21 g/kg) from the coastal population (less than 28 km from the coastline) was found to be significantly higher (ANOVA: P = 0.007, significant at the 1% level) than that for glands (0.21 +/- 0.11 g/kg) of noncoastal koalas (greater than 28 km from the coastline). Follicle size was positively correlated (at the 0.1% level) with relative thyroid weight in the overall koala sample. The presence of C cells, occurring singly in the epithelial layer, was demonstrated in electron micrographs. Structural features such as low epithelial height, large follicle length and width, and large intercellular spaces in association with low concentrations of free TS (3.3 +/- 2.1 pM) and free T-3 (1.4 +/- 0.9 pM) as reported previously (Lawson et al., 1996) are consistent with an unusually low level of glandular activity in the koala thyroid even though iodine concentrations in the thyroid gland [4.7 +/- 1.6 mg/g (dry weight)] as well as leaf [0.8 +/- 0.3 mu g (dry weight)] and soil samples [3.8 mu g/g (dry weight)] from the koalas' habitat appear unremarkable. (C) 1998 Academic Press.

Friedmanniella spumicola sp nov and Friedmanniella capsulata sp nov from activated sludge foam: Gram-positive cocci that grow in aggregates of repeating groups of cocci

Two Gram-positive, non-motile, non-spore-forming, strictly aerobic, pigmented cocci, strains Ben 107(T) and Ben 108(T), growing in aggregates were isolated from activated sludge samples by micromanipulation. Both possessed the rare type A3 gamma' peptidoglycan. Major menaquinones of strain Ben 107(T) were MK-9(H-4) and MK-7(H-2), and the main cellular fatty acid was 12-methyltetradecanoic acid (ai-C-15:0). In strain Ben 108(T), MK-9(H-4), MK-9(H-2) and MK-7(H-4) were the menaquinones and again the main fatty acid was 12-methyltetradecanoic acid (ai-C-15:0). Polar lipids in both strains consisted of phosphatidyl inositol, phosphatidyl glycerol and diphosphatidyl glycerol with two other unidentified glycolipids and phospholipids also present in both. These data, together with the 16S rDNA sequence data, suggest that strain Ben 107(T) belongs to the genus Friedmanniella which presently includes a single recently described species, Friedmanniella antarctica. Although the taxonomic status of strain Ben 108(T) is far less certain, on the basis of its 16S rRNA sequence it is also adjudged to be best placed in the genus Friedmanniella, The chemotaxonomic characteristics and DNA-DNA hybridization data support the view that Ben 107(T) and Ben 108(T) are novel species of the genus Friedmanniella. Hence, it is proposed that strain Ben 107(T) (=ACM 5121(T)) is named as Friedmanniella spumicola sp. nov. and strain Ben 108(T) (=ACM 5120(T)) as Friedmanniella capsulata sp. nov.

Do simple prudent health behaviours protect men from myocardial infarction?

Background We tested whether behaviours such as discarding obvious fat on meat, cessation of smoking, avoidance of passive smoking, habitual use of reduced fat milk, prudent consumption of alcohol and regular but moderate physical exercise are associated with a reduction of cardiovascular risk. Methods This was a population-based case-control study done in Perth, Western Australia. The cases (n = 336) were men aged 27-64 years with a first-ever acute myocardial infarction (AMI) during the period 1992-1993, and who survived at least 28 days. The controls (n = 735) were participants in a population-based survey of cardiovascular risk factors conducted during May-November 1994. Both groups completed the same questionnaire and the data were analysed with multiple logistic regression using backward elimination technique. Results Among men aged 27-64 years simple measures such as participation in non-vigorous exercise (odds ratio [OR] = 0.5, 95% CI : 0.4-0.7), and avoidance of added salt (OR = 0.6, 95% CI : 0.4-0.9) are associated with significant and Important protection from AMI. Conclusion After 25 years of falling mortality in Australia, lifestyles can still be significantly improved to reduce heart disease even further.

Exposure of rats to a high but not low dose of ethanol during early postnatal life increases the rate of loss of optic nerve axons and decreases the rate of myelination

Visual system abnormalities are commonly encountered in the fetal alcohol syndrome although the level of exposure at which they become manifest is uncertain. In this study we have examined the effects of either low (ETLD) or high dose (ETHD) ethanol, given between postnatal days 4-9, on the axons of the rat optic nerve. Rats were exposed to ethanol vapour in a special chamber for a period of 3 h per day during the treatment period. The blood alcohol concentration in the ETLD animals averaged similar to 171 mg/dl and in the ETHD animals similar to 430 mg/dl at the end of the treatment on any given day. Groups of 10 and 30-d-old mother-reared control (MRC), separation control (SC), ETLD and ETHD rats were anaesthetised with an intraperitoneal injection or ketamine and xylazine, and killed by intracardiac perfusion with phosphate-buffered glutaraldehyde. In the 10-d-old rat optic nerves there was a total of similar to 145000-165000 axons in MRC, SC and ETLD animals. About 4 % of these fibres were myelinated. The differences between these groups were not statistically significant. However, the 10-d-old ETHD animals had only about 75000 optic nerve axone (P < 0.05) of which about 2.8 % were myelinated. By 30 d of age there was a total of between 75000 90000 optic nerve axons, irrespective of the group examined. The proportion of axons which were myelinated at this age was still significantly lower (P < 0.001) in the ETHD animals (similar to 77 %) than in the other groups (about 98 %). It is concluded that the normal stages of development and maturation of the rat optic nerve axons, as assessed in this study, can be severely compromised by exposure to a relatively high (but not low) dose of ethanol between postnatal d 4 and 9.

Factors associated with rural practice among Australian-trained general practitioners

Objective: To determine the factors associated with general practitioners' current practice location, with particular emphasis on rural location. Design: Observational, retrospective, case-control study using a self-administered questionnaire. Setting: Australian general practices in December 2000. Participants: 2414 Australian-trained rural and urban GPs. Main outcome measure: Current urban or rural practice location. Results: For Australia as a whole, rural GPs were more likely to be male (odds ratio [OR], 1.42; 95% CI, 1.17-1.73), Australian-born (OR, 1.95; 95% CI, 1.55-2.45), and to report attending a rural primary school for some (OR, 2.21; 95% CI, 1.69-2.89) or all (OR, 2.79; 95% CI, 1.94-4.00) of their primary schooling. Rural GPs' partners or spouses were also more likely to report some (OR, 2.75; 95% CI, 2.07-3.66) or all (OR, 2.86; 95% CI, 2.02-4.05) rural primary schooling. A rural background in both GP and partner produced the highest likelihood of rural practice (OR, 6.28; 95% CI, 4.26-9.25). For individual jurisdictions, a trend towards more rural GPs being men was only significant in Tasmania. In all jurisdictions except Tasmania and the Northern Territory, rural GPs were more likely to be Australian-born. Conclusions: GPs' and their partners' rural background (residence and primary and secondary schooling) influences choice of practice location, with partners' background appearing to exert more influence.

Properties of a purified thermostable glucoamylase from Aspergillus niveus

A glucoamylase from Aspergillus niveus was produced by submerged fermentation in Khanna medium, initial pH 6.5 for 72 h, at 40A degrees C. The enzyme was purified by DEAE-Fractogel and Concanavalin A-Sepharose chromatography. The enzyme showed 11% carbohydrate content, an isoelectric point of 3.8 and a molecular mass of 77 and 76 kDa estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis or Bio-Sil-Sec-400 gel filtration, respectively. The pH optimum was 5.0-5.5, and the enzyme remained stable for at least 2 h in the pH range of 4.0-9.5. The temperature optimum was 65A degrees C and retained 100% activity after 240 min at 60A degrees C. The glucoamylase remained completely active in the presence of 10% methanol and acetone. After 120 min hydrolysis of starch, glucose was the unique product formed, confirming that the enzyme was a glucoamylase (1,4-alpha-d-glucan glucohydrolase). The K (m) was calculated as 0.32 mg ml(-1). Circular dichroism spectroscopy estimated a secondary structure content of 33% alpha-helix, 17% beta-sheet and 50% random structure, which is similar to that observed in the crystal structures of glucoamylases from other Aspergillus species. The tryptic peptide sequence analysis showed similarity with glucoamylases from A. niger, A. kawachi, A. ficcum, A. terreus, A. awamori and A. shirousami. We conclude that the reported properties, such as solvent, pH and temperature stabilities, make A. niveus glucoamylase a potentially attractive enzyme for biotechnological applications.

Laparoscopic treatment of type 2 diabetes mellitus for patients with a body mass index less than 35

Background Type 2 diabetes mellitus (T2DM) is a common disease with numerous complications. Bariatric surgery is an efficient procedure for controlling T2DM in morbidly obese patients. In T2DM, the incretin effect is either greatly impaired or absent. This study aimed to evaluate the preliminary results from interposing a segment of ileum into the proximal jejunum associated with a sleeve or diverted sleeve gastrectomy to control T2DM in patients with a body mass index (BMI) less than 35 kg/m(2). Methods For this study, 39 patients (16 women and 23 men) underwent two laparoscopic procedures comprising different combinations of ileal interposition into the proximal jejunum via a sleeve or diverted sleeve gastrectomy. The mean age of these patients was 50.3 years (range, 36-66 years). The mean BMI was 30.1 kg/m(2) (range, 23.4-34.9 kg/m(2)). All the patients had a diagnosis of T2DM that had persisted for at least 3 years and evidence of stable treatment with oral hypoglycemic agents or insulin for at least 12 months. The mean duration of T2DM was 9.3 years (range, 3-22 years). Results The mean operative time was 185 min, and the median hospital stay was 4.3 days. Four major complications occurred in the short term (30-days), and the mortality rate was 2.6%. The mean postoperative follow-up period was 7 months (range, 4-16 months), and the mean percentage of weight loss was 22%. The mean postoperative BMI was 24.9 kg/m(2) (range, 18.9-31.7 kg/m2). An adequate glycemic control was achieved for 86.9% of the patients, and 13.1% had important improvement. The patients whose glycemia was not normalized were using a single oral hypoglycemic agent. No patient needed insulin therapy postoperatively. All the patients except experienced normalization of their cholesterol levels. Targeted triglycerides levels were achieved by 71% of the patients, and hypertension was controlled for 95.8%. Conclusions The laparoscopic ileal interposition via either a sleeve gastrectomy or diverted sleeve gastrectomy seems to be a promising procedure for the control of T2DM and the metabolic syndrome. A longer follow-up period is needed.

Hemodynamic Changes during Myocardial Revascularization without Extracorporeal Circulation

Background and objectives: Cardiac positioning and stabilization during myocardial revascularization without extracorporeal circulation (ECC) may cause hemodynamic changes dependent to the surgical site. The objective of this study was to evaluate these changes during distal coronary anastomosis. Methods: Twenty adult patients undergoing myocardial revascularization without ECC were monitored by pulmonary artery catheter and transesophageal Echo Doppler. Hemodynamic data were collected at the following times before removing the stabilizer wall: (1) after volume adjustments, (2) at the beginning of distal anastomosis, and (3) after 5 minutes. Treated coronary arteries were grouped according to their location in the lateral, anterior, or posterior wall. Two-way ANOVA with repetition and Newman-Keuls post-test were used in the analysis. A p value < 0.05 was considered statically significant. Results: During myocardial revascularization without ECC, pulmonary artery wedge pressure showed elevation from 17.7 +/- 6.1 to 19.2 +/- 6.5 (p < 0.001) and 19.4 +/- 5.9 mmHg (p < 0.001), while the central venous pressure went from 13.9 +/- 5.4 to 14.9 +/- 5.9 mmHg (p = 0.007) and 15.1 +/- 6.0 mmHg (p = 0.006). Intermittent cardiac output was reduced from 4.70 +/- 1.43 to 4.23 +/- 1.22 (p < 0.001) and 4.26 +/- 1.25 L.min(-1) (p < 0.001). According to transesophageal Doppler, a significant group-time interaction was observed in cardiac output, which was reduced in the lateral group from 4.08 +/- 1.99 to 2.84 +/- 1.82 (p = 0.02) and 2.86 +/- 1.73 L.min(-1) (p = 0.02), and aortic blood flow, which went from 2.85 +/- 1.39 to 1.99 +/- 1.26 (p = 0.02) and 2.00 +/- 1.21 L.min(-1) (p = 0.02). Other hemodynamic changes were not observed during anastomoses. Conclusions: A significant hemodynamic deterioration was observed during myocardial revascularization without ECC. Transesophageal Doppler detected a decrease in cardiac output only in the lateral group.

Penetration of cefuroxime in subcutaneous tissue during coronary artery bypass grafting surgery

A sensitive and rapid HPLC assay for determining cefuroxime penetration in the subcutaneous tissue near to surgical incision of patients submitted to coronary artery bypass grafting (CABC) with or without cardiopulmonary bypass (CPB) was performed. Blood and subcutaneous tissue samples were collected from 14 patients. in four periods during surgery. The analytical method presented linearity from 0.5 to 100 mu g/g. LOQ = 0.50 mu g/g, LOD = 0.25 mu g/g. intra- and interday precision (%CV) ranged from 4.9 to 8.9% and 6.4 to 9.9%, respectively, and intra-and interday accuracy expressed as % of the nominal concentration ranged from 87.1 to 104.6% and 94.8 to 103.8%, respectively (mean of three concentrations). Relative recovery was 98.4%. Tissue/plasma ratios obtained for CPB and non-CPB were, respectively: 14.6% vs 19.0% (0.6 h); 15.7% vs 15.7% (2.1 h); 22.5% vs 19.9% (3.6 h); 15.7% vs 18.8% (4.5 h). Data obtained indicate that tissue/plasma ratio remains unchanged in CPB and non-CPB patients during all period of surgery and the CPB does not affect the penetration of cefuroxime in tissues close to the surgical wound. (C) 2009 Elsevier B.V. All rights reserved.