Influence of exercise order on the number of repetitions performed and perceived exertion during resistance exercises

This study examined the performance effects of exercise order during a resistance-training session composed of only upper-body exercises. The 10 repetition maximum of 14 men and 4 women with at least 6 months of previous weight-training experience was determined for 5 upper-body exercises. Each subject then completed 2 training sessions separated by 48 hours in a counterbalanced crossover design. One session began with exercises of the large-muscle group and progressed to exercises of the small-muscle group (sequence A), whereas the other session was performed with the opposite exercise sequence (sequence B). The exercise order for sequence A was free-weight bench press (BP), machine lat pull-down (LPD), seated machine shoulder press (SP), standing free-weight biceps curl (BC) with a straight bar, and seated machine triceps extension (TE). The exercise order for sequence B was TE, BC, SP, LPD, and BP. During both sequences, 3 sets of each exercise were performed to concentric failure, with 2-minute recovery intervals between sets and exercises. Performing exercises of both the large- and the small-muscle groups at the end of an exercise sequence resulted in significantly fewer repetitions in the 3 sets of an exercise. This decrease in the number of repetitions performed was especially apparent in the third set when an exercise was performed last in an exercise sequence.     

Heritability of hemostasis phenotypes and their correlation with type 2 diabetes status in Mexican Americans

Hypercoagulation often occurs in type 2 diabetes, suggesting pleiotropy of the genes that influence disease liability and hemostasis-related phenotypes. To better understand the relationship between hemostasis and diabetes, we first used maximum-likelihood methods to estimate the relative contribution of additive genetic, measured environmental, and shared household effects to the normal variance of 16 hemostasis-related traits in 813 individuals participating in the San Antonio Family Heart Study. We estimated moderate to high heritabilities (0.20-0.60) for each phenotype. Von Willebrand factor (VWF), thrombin activatable fibrinolysis inhibitor, activated protein C (APC) ratio, factor V, and prothrombin time had heritabilities greater than 0.50. The correlation between type 2 diabetes status and the hemostasis-related traits was then partitioned into genetic and environmental components using bivariate variance-components methods. Significant (p < or = 0.05) positive genetic correlations (0.37-0.51) occurred with factors II and VIII, VWF, total protein S (tPS), and tissue factor pathway inhibitor. Significant negative genetic correlations were estimated for activated partial thromboplastin time (-0.49) and APC ratio (-0.38). By contrast, significant environmental correlations occurred only with factor II (-0.40) and tPS (-0.31). Our results suggest that genes are important contributors to the normal variation in hemostasis-related traits and that genes influencing hemostasis-related traits pleiotropically influence diabetes risk.     

Effects of hyperbaric oxygen on Leishmania amazonensis promastigotes and amastigotes

In the present study, we evaluated the effects of hyperbaric oxygen (HBO) exposure in both Leishmania amazonensis life stages (promastigotes and amastigotes) and on macrophage cultures infected with the parasite. HBO treatment protocols, which can be tolerated by humans and animals, induced irreversible metabolic damage and affected parasite morphology, growth and ability to transform. The observation that the antioxidant N-acetylcysteine (NAC) prevents some of these deleterious effects indicated an involvement of oxidative stress during parasite HBO exposure. In addition, HBO exposed L. amazonensis-infected macrophage cultures showed reduction of the percentage of infected cells and of the number of intracellular parasites per cell. Thus, the demonstration that HBO, a therapy used in the management of different diseases, is toxic for both L. amazonensis life stages and can alter macrophage susceptibility to the infection encourages further studies of this therapy in animal models of Leishmania infection.     

Macromolecular accessibility of fluorescent taxoids bound at a paclitaxel binding site in the microtubule surface

The macromolecular accessibility of the paclitaxel binding site in microtubules has been investigated using a fluorescent taxoid and antibodies against fluorescein, which cannot diffuse into the microtubule lumen. The formation of a specific ternary complex of microtubules, Hexaflutax (7-O-{N-[6-(fluorescein-4'-carboxamido)-n-hexanoyl]-l-alanyl}paclitaxel) and 4-4-20 IgG (a monoclonal antibody against fluorescein) has been observed by means of sedimentation and electron microscopy methods. The kinetics of binding of the antibody to microtubule-bound Hexaflutax has been measured. The quenching of the observed fluorescence is fast (k+ 2.26 +/- 0.25 x 10(6) m(-1) s(-1) at 37 degrees C), indicating that the fluorescein groups of Hexaflutax are exposed to the outer solvent. The velocity of the reaction is linearly dependent on the antibody concentration, indicating that a bimolecular reaction is being observed. Another fluorescent taxoid (Flutax-2) bound to microtubules has also been shown to be rapidly accessible to polyclonal antibodies directed against fluorescein. A reduced rate of Hexaflutax quenching by the antibody is observed in microtubule-associated proteins containing microtubules or in native cellular cytoskeletons. It can be concluded that the fluorescent taxoids bind to an outer site on the microtubules that is shared with paclitaxel. Paclitaxel would be internalized in a further step of binding to reach the known luminal site, this step being blocked in the case of the fluorescent taxoids. Because the fluorescent ligands are able to induce microtubule assembly, binding to the outer site should be enough to induce assembly by a preferential binding mechanism.     

Phylogenetic relationships of Deschampsia antarctica (Poaceae): Insights from nuclear ribosomal ITS

Deschampsia antarctica E. Desv. is the only monocot in the Antarctic floristic zone. We evaluated the phylogenetic relationships of Deschampsia antarctica to other grasses using parsimony as the optimality criterion. Five different sets of gap, transversion and transitions costs were explored to analyze the effect of parameter choice on the phylogenetic results. Both internal transcribed spacers (ITS1 and ITS2) and the 5.8S subunit of nuclear ribosomal DNA were included in the analysis. A total of 43 species were analyzed including seven species of Deschampsia. Deschampsia antarctica forms a well supported group with five species of Deschampsia. Deschampsia does not appear monophyletic as D. flexuosa (L.) Trin. is not included in this clade. The clade to which D. antarctica belongs is sister to some Aveneae in all analyses. This study is the first contribution that evaluates the phylogenetic position of D. antarctica in relation to other species of Deschampsia.     

Expression levels and subcellular localization of Bcy1p in Candida albicans mutant strains devoid of one BCY1 allele results in a defective morphogenetic behavior

We investigated expression, functionality and subcellular localization of C. albicans Bcy1p, the PKA regulatory subunit, in mutant strains having one BCY1 allele fused to a green fluorescent protein (GFP). DE-52 column chromatography of soluble extracts of yeast cells from strains bearing one BCY1 allele (fused or not to GFP) showed co-elution of Bcy1p and Bcy1p-GFP with phosphotransferase activity, suggesting that interaction between regulatory and catalytic subunits was not impaired by the GFP tag. Subcellular localization of Bcy1p-GFP supports our previous hypothesis on the nuclear localization of the regulatory subunit, which can thus tether the PKA catalytic subunit to the nucleus. Protein modeling of CaBcy1p, showed that the fusion of the GFP tag to Bcy1p C-terminus did not significantly disturb its proper folding. Bcy1p levels in mutant strains having one or both BCY1 alleles, led us to establish a direct correlation between the amount of protein and the number of alleles, indicating that deletion of one BCY1 allele is not fully compensated by overexpression of the other. The morphogenetic behavior of several C. albicans mutant strains bearing one or both BCY1 alleles, in a wild-type and in a TPK2 null genetic background, was assessed in N-acetylglucosamine (GlcNAc) liquid medium at 37 degrees C. Strains with one BCY1 allele tagged or not, behaved similarly, displaying pseudohyphae and true hyphae. In contrast, hyphal morphology was almost exclusive in strains having both BCY1 alleles, irrespective of the GFP insertion. It can be inferred that a tight regulation of PKA activity is needed for hyphal growth.     

Bacteriocin-like substance inhibits potato soft rot caused by Erwinia carotovora

Soft rot is a major problem encountered in potatoes during postharvest storage. The soft rot bacterium Erwinia carotovora was inhibited by a novel bacteriocin-like substance (BLS) produced by Bacillus licheniformis P40. The BLS caused a bactericidal effect on E. carotovora cells at 30 microg mL(-1). Transmission electron microscopy showed that BLS-treated cells presented wrinkled bacterial surfaces and shrinkage of the whole cell, indicating plasmolysis. Erwinia carotovora cells treated with BLS were analyzed by FTIR showing differences in the 1390 cm(-1) and 1250-1220 cm(-1) bands, corresponding to assignments of membrane lipids. BLS was effective in preventing E. carotovora spoilage on potato tubers, reducing the symptoms of soft rot at 240 microg mL(-1) and higher concentrations. Soft rot development was completely blocked at 3.7 mg mL(-1). This BLS showed potential to protect potato tubers during storage.     

Comparative study with two different enrichments in the culture media used in the disinfectant efficacy assay

Recent changes in Brazilian legislation for commercial disinfectants have been published due to the recent epidemic of nosocomial infections caused by rapidly growing mycobacteria (RGM) in many states of Brazil over the last 8 years. One of these documents requires that all the manufacturers provide evidence of efficacy of sterilizing and disinfectant products, used for semi critical medical devices, against the Mycobacterium bovis BCG Moreau and Mycobacterium abscessus subsp. bolletii INCQS 00594 strains by using the Confirmative in vitro Test for Determining Tuberculocidal Activity of Disinfectants recommended by the Association of Official Analytical Chemists. These changes have caused additional costs and increased problems for importation of enrichment products at national laboratories where disinfectant efficacy assay service is performed. Middlebrook ADC Enrichment (ADC) is provided by a unique manufacturer and used in the official protocol. The aim of the present study was to evaluate an alternative in house low-cost enrichment composed of fetal bovine serum and glucose (FBSG) with ADC for performance of disinfectant efficacy assay against mycobacteria. After obtaining the growth curves for M. abscessus ATCC 19977, M. abscessus subsp. bolletii INCQS 00594, Mycobacterium chelonae ATCC 35752, and Mycobacterium fortuitum ATCC 6841 by using ADC enrichment and FBSG in Kirchners and 7H9 culture media. Through statistical analysis via the Kruskal-Wallis test on the evaluation of microorganism growth rate, it was observed that there was no inhibition of RGM growth by any of the enrichments used. These results suggest that low-cost enrichment FBSG may be used as a potential substitute of ADC for composition of media for mycobacterial growth, including in disinfectant tests.     

Insecticidal Activity of Piper Essential Oils from the Amazon Against the Fire Ant Solenopsis saevissima (Smith) (Hymenoptera: Formicidae)

Pepper plants in the genus Piper (Piperales: Piperaceae) are common in the Brazilian Amazon and many produce compounds with biological activity against insect pests. We evaluated the insecticidal effect of essential oils from Piper aduncum, Piper marginatum (chemotypes A and B), Piper divaricatum and Piper callosum against workers of the fire ant Solenopsis saevissima (Smith) (Hymenoptera: Formicidae), as well as their chemical composition by gas chromatography and gas chromatography?Cmass spectrometry. The lowest median lethal concentration (LC₅₀) in 48?h was obtained with the oil of P. aduncum (58.4?mg/L), followed by the oils of P. marginatum types A (122.4?mg/L) and B (167.0?mg/L), P. divaricatum (301.7?mg/L), and P. callosum (312.6?mg/L). The major chemical constituents were dillapiole (64.4%) in the oil of P. aduncum; p-mentha-1(7),8-diene (39.0%), 3,4-methylenedioxypropiophenone (19.0%), and (E)-??-ocimene (9.8%) in P. marginatum chemotype A and (E)-isoosmorhizole (32.2%), (E)-anethole (26.4%), isoosmorhizole (11.2%), and (Z)-anethole (6.0%) in P. marginatum chemotype B; methyleugenol (69.2%) and eugenol (16.2%) in P. divaricatum; and safrole (69.2%), methyleugenol (8.6%), and ??-pinene (6.2%) in P. callosum. These chemical constituents have been previously known to possess insecticidal properties.