Reliability of electromyographic amplitude values of the upper limb muscles during closed kinetic chain exercises with stable and unstable surfaces

The purpose of the present study was to evaluate the intra and interday reliability of surface electromyographic amplitude values of the scapular girdle muscles and upper limbs during 3 isometric closed kinetic chain exercises, involving upper limbs with the fixed distal segment extremity on stable base of support and on a Swiss ball (relatively unstable). Twenty healthy adults performed the exercises push-up, bench-press and wall-press with different effort levels (80% and 100% maximal load). Subjects performed three maximal voluntary contractions (MVC) in muscular testing position of each muscle to obtain a reference value for root mean square (RMS) normalization. Individuals were instructed to randomly perform three isometric contraction series, in which each exercise lasted 6 s with a 2-min resting-period between series and exercises. Intra and interday reliabilities were calculated through the intraclass correlation coefficient (ICC 2.1), standard error of the measurement (SEM). Results indicated an excellent intraday reliability of electromyographic amplitude values (ICC >= 0.75). The interday reliability of normalized RMS values ranged between good and excellent (ICC 0.52-0.98). Finally, it is suggested that the reliability of normalized electromyographic amplitude values of the analyzed muscles present better values during exercises on a stable surface. However, load levels used during the exercises do not seem to have any influence on variability levels, possibly because the loads were quite similar. (C) 2007 Elsevier Ltd. All rights reserved.

Cytotoxic effects of crotamine are mediated through lysosomal membrane permeabilization

Crotamine, one of the main toxic components of Crotalus durissus terrificus venom, is a small non-enzymatic basic polypeptide, which causes hind limb paralysis and necrosis of muscle cells. it is well-known that several toxins penetrate into the cytosol through endocytosis, although in many cases the mechanism by which this occurs has not been fully investigated. Recently, using low concentrations of crotamine, we demonstrated the uptake of this toxin into actively proliferative cells via endocytosis, an event that ensues crotamine binding to cell membrane heparan sulfate proteoglycans. Thus, crotamine can be regarded as a cell-penetrating peptide that, additionally, has been shown to be able of delivering some biologically active molecules into various cells. Herein, we investigate one of the mechanisms by which crotamine exerts its cytotoxic effects by following its uptake into highly proliferative cells, as CHO-K1 cells. Crotamine accumulation in the acidic endosomal/lysosomal vesicles was observed within 5 min after treatment of these cells with a cytotoxic concentration of this toxin, a value determined here by classical MTT assay. This accumulation caused disruption of lysosomal vesicles accompanied by the leakage of these vesicles contents into the cytosol. This lysosomal lysis also promoted the release of cysteine cathepsin and an increase of caspase activity in the cytoplasm. This chain of events seems to trigger a cell death process. Overall, our data suggest that lysosomes are the primary targets for crotamine cytotoxicity, a proposal corroborated by the correlation between both the kinetics and concentration-dependence of crotamine accumulation in lysosome compartments and the cytotoxic effects of this protein in CHO-K1 cells. Although crotamine is usually regarded as a myotoxin, we observed that intraperitoneal injection of fluorescently labeled crotamine in living mice led to significant and rapid accumulation of this toxin in the cell cytoplasm of several tissues, suggesting that crotamine cytotoxicity might not be restricted to muscle cells. (C) 2008 Elsevier Ltd. All rights reserved.

Haemophilus ducreyi detection by polymerase chain reaction in oesophageal lesions of HIV patients

HIV patients frequently have opportunistic oesophageal infections. We report Haemophilus ducreyi genetic material detected by polymerase chain reaction in biopsies of oesophageal lesions in three HIV-1-infected patients. This finding may be an indication of its aetiopathological role in oesophageal lesions of HIV patients.

In vitro susceptibility to antimycotic drug undecanoic acid, a medium-chain fatty acid, is nutrient-dependent in the dermatophyte Trichophyton rubrum

The antimycotic activity of fatty acids has long been known, and their presence in human skin and sweat appears to protect the host against superficial mycoses. Undecanoic acid is a medium-chain fatty acid that has been used in the treatment of dermatophytoses in humans. In this study, we selected one Trichophyton rubrum undecanoic acid-resistant strain that showed a marked reduction in its capacity to grow on human nail fragments, which correlated with the reduced activity of secreted keratinolytic proteases. Moreover, the susceptibility of T. rubrum to undecanoic acid is also dependent on the carbon source utilized by both control and resistant strains. The growth of the control strain was strongly inhibited by undecanoic acid in Sabouraud medium or in cultures supplemented with low-fat milk, whereas it was ineffective when the cultures were supplemented with Tween 20 or keratin as the carbon source, suggesting that nutrient conditions are crucial in establishing a susceptibility to antifungal drugs, which is helpful for the isolation and characterization of resistant strains, and in the screening for new antifungal drugs.

Effects of eccentric and concentric training on capillarization and myosin heavy chain contents in rat skeletal muscles after hindlimb suspension

We studied the effects of different protocols of post-disuse rehabilitation on angiogenesis and myosin heavy chain (MHC) content in rat hindlimb muscles after caudal suspension. Thirty female Wistar rats were divided into five groups: (1) Control I, (2) Control II, (3) Suspended, (4) Suspended trained on declined treadmill, and (5) Suspended trained on flat treadmill. Fragments of the soleus and tibialis anterior (TA) muscles were frozen and processed by electrophoresis and immunohistochemistry (CD31 antibody). Hindlimb suspension caused reduction of capillary/fiber (C/F) ratios and contents of MHC type I (MHCI) in the soleus in parallel to increased capillary density. Flat treadmill protocols increased the content of the MHCI isoform. The C/F ratio was increased by concentric training after hypokinesis, but was not modified by eccentric training, which caused a greater reduction of capillary density compared to the other protocols. In the TA muscle, hindlimb suspension caused a non-significant increase in capillary density and C/F ratio with limited changes in MHC. The present data demonstrate that the different training protocols adopted and the functional performance of the muscles analyzed caused specific changes in capillarization and in the content of the various MHC types. (C) 2010 Published by Elsevier GmbH.

Organizational Learning in the Context of an Agri-Food Chain

This paper reports on the outcomes of the first stage of a longitudinal study that focused on the transformational change process being undertaken within the Supply Chain and Operations Area of a major Australian food manufacturing company. Organizational learning is an essential prerequisite for any successful change process and an organization's ability to learn is dependent on the existence of an environment within the organization that nurtures learning and the presence of key enablers that facilitate the learning process. An organization's capacity to learn can be enhanced through its ability to form and sustain collaborative relationships with its chain partners. The results show that an environment that supports organizational learning is being developed through consultative leadership and the empowerment of individuals within a culture that supports innovation and cross-functional teamwork but demands responsibility and accountability. The impact of these changes within the Supply Chain and Operations Area is evident in the significant improvement in the Area's productivity and efficiency levels over the past twelve months. The company's endeavours to engage its major supply chain partners in the learning process have been limited by the turmoil within the company. However the company has involved its supply chain partners in a series of mutually beneficial projects that have improved communication and built trust thereby laying the foundations for more collaborative chain relationships.

Advantages and Pitfalls of the Polymerase Chain Reaction in the Diagnosis of Esophageal Ulcers in AIDS Patients

HIV-1-infected patients frequently have opportunistic esophageal infections which, when associated with severe immunodeficiency, can be attributed to unusual pathogens. The clinical presentation of several esophageal diseases is similar and the best method for a specific diagnosis of these patients has not been well defined. To evaluate the role of the polymerase chain reaction (PCR) in the etiologic definition of esophageal ulcers in HIV-1-infected patients, 96 esophageal biopsies from 79 HIV-1-infected patients were processed by PCR using specific primers for cytomegalovirus (CMV), herpes virus (HSV), human papilloma virus (HPV), HIV-1, Mycobacterium tuberculosis, Mycobacterium avium, Mycobacterium intracellulare, Treponema pallidum, and Haemophilus ducreyi. The PCR results were compared to the histopathologic results. Seventy-nine patients were studied (mean age: 34 years; 62% men; median CD4 + T cell = 103.59 cells/mu l (range 1-795.2 cells/mu l). The most common endoscopic findings were as follows: esophageal candidiasis (37.1%), esophageal ulcers (24.7%), esophagitis (11.2%), and lugol-negative areas (10.1%). The histopathologic findings in the esophageal ulcers (22 biopsies) were non-specific inflammation (31.8%), HSV (36.4%), Candida (13.6%), CMV (13.6%), or HPV disease (4.5%). In the esophageal ulcer biopsies, the PCR results were negative in 27.6% of cases, and positive for HIV (65.5%), CMV (31%), HPV (20.7%), HSV (10.3%), and H. ducreyi (6.9%). The histopathologic examination did not identify a pathogen or identified only Candida in 15 biopsies of esophageal ulcers. PCR was positive in ten (66.7%) and negative in five (33.3%) of these biopsies (idiopathic ulcers). PCR detected: HIV (53.3%), CMV (20%), HPV (13.3%), and H. ducreyi (6,7%). PCR detected more etiologic agents in esophageal ulcers than histopathology and was able to detect unusual pathogens. On the other hand, sometimes more than one pathogen was detected in the esophageal ulcers, making it difficult to reach an accurate diagnosis. This finding indicates the need for more studies to evaluate the benefit of this method in the routine evaluation of esophageal ulcer biopsies in HIV-1-infected patients.

Detection of Leptospira spp. in semen and vaginal fluids of goats and sheep by polymerase chain reaction

Thirteen goat herds and seven sheep flocks in the state of Rio de Janeiro, Brazil were screened for leptospirosis. From the three herds and three flocks with greatest seroreactivity, 19 goats (16 females and three bucks) and 40 sheep (26 ewes and 14 rams) that were seropositive (specific anti-Leptospira titres >= 400, based on a microscopic agglutination test), were selected for more detailed studies. From those animals, samples of vaginal fluids or semen were collected for bacteriological and molecular assays. For both species of animals, the most prevalent reactions were to serovars Hardjo, Shermani, and Grippotyphosa. Although leptospires were detected by darkfield microscopy in three vaginal fluid samples (from two goats and one ewe), pure isolates were not obtained by bacteriological culture of vaginal fluids or semen. However, seven vaginal fluid samples (from four goats and three ewes) and six semen samples (all from rams) were positive on polymerase chain reaction (PCR). Based on these findings, in addition to analogous findings in cattle, we inferred that there is potential for venereal transmission of leptospirosis in small ruminants. (c) 2008 Elsevier Inc. All rights reserved.

Decay chain differential equations: Solution through matrix algebra

A matricial method to solve the decay chain differential equations system is presented. The quantity of each nuclide in the chain at a time t may be evaluated by analytical expressions obtained in a simple way using recurrence relations. This method may be applied to problems of radioactive buildup and decay and can be easily implemented computationally. (C) 2009 Elsevier B.V. All rights reserved.

Phosphorus kinetics in calves experimentally submitted to a trickle infection with Cooperia punctata

Ten male Holstein calves (74.3 +/- 3.2 kg LW) were used for a trial with trickle infection with Cooperia punctata to evaluate phosphorus (P) kinetics. Five calves were inoculated with 10,000 L(3) stage larvae per week during 35 days, while the other group of five calves was kept as a control. On the 29th day each calf was intravenously injected with 29.6 MBq of a (32)p solution. Blood samples were taken at 24 h periods for 7 days, after which all calves were slaughtered and worms burdens. Faeces, urine and tissue samples were taken for analysis using isotopic dilution and modeling techniques. The number of eggs per gram of faeces (EPG)was 1920 +/- 168 on 28th day and the total number of worms burdens was 11,131 +/- 1500. Infected calves showed lower feed intake and live weight gain, as well as lower P intake, absorption and retention than control calves. The P flows between body compartments were lower for blood to gastrointestinal tract (TGI), TGI to blood, blood to soft tissues, bone balance and soft tissue balance in infected calves when compared to the control. The trickle infection of C punctata affected P metabolism due to the decrease in P retained and live weight due to fall in feed intake. (C) 2009 Elsevier B.V. All rights reserved.

Insulin Affects Tissue Organization and the Kinetics of Epithelial Cell Death in the Rat Ventral Prostate After Castration

Prostate growth and physiology are regulated by steroid hormones and modulated by multiple endocrine factors We investigated the action of insulin on the tissue organization and kinetics of epithelial cells in the rat ventral prostate (VP) in response to castration up to 120 hours after surgery by using an acute protocol of alloxan induced diabetes Diabetes caused a reduction in volume density (Vv(o)/) and volume of the epithelium The effects of castration on the epithelium were accelerated in the diabetic animals as determined by changes in V(o)/, and volume The smooth muscle cells became atrophic and apparently relaxed in response to castration in contrast to the spinous aspect observed in nondiabetic castrated rats Counting of apoptotic nuclei in the epithelium showed the classical apoptosis peak at 72 hours in nondiabetic rats and an advance of the apoptosis peak to 48 hours after castration in diabetic rats Insulin restored the time of the peak to 72 hours These results were confirmed after immunostaining for cleaved caspase 3 and suggest a survival and antiapoptotic effect on VP epithelial cells in both the presence and absence of androgen stimulation This idea is supported by the observation that insulin also reduced the overall rate of apoptosis at all experimental points analyzed before and after castration

Haplotypes of the bovine IgG2 heavy gamma chain in tick-resistant and tick-susceptible breeds of cattle

Bovines present contrasting, heritable phenotypes of infestations with the cattle tick, Rhipicephalus (Boophilus) microplus. Tick salivary glands produce IgG-binding proteins (IGBPs) as a mechanism for escaping from host antibodies that these ectoparasites ingest during blood meals. Allotypes that occur in the constant region of IgG may differ in their capacity to bind with tick IGBPs; this may be reflected by the distribution of distinct allotypes according to phenotypes of tick infestations. In order to test this hypothesis, we investigated the frequency of haplotypes of bovine IgG2 among tick-resistant and tick-susceptible breeds of bovines. Sequencing of the gene coding for the heavy chain of IgG2 from 114 tick-resistant (Bos taurus indicus, Nelore breed) and tick-susceptible (B. t. taurus, Holstein breed) bovines revealed SNPs that generated 13 different haplotypes, of which 11 were novel and 5 were exclusive of Holstein and 3 of Nelore breeds. Alignment and modeling of coded haplotypes for hinge regions of the bovine IgG2 showed that they differ in the distribution of polar and hydrophobic amino acids and in shape according to the distribution of these amino acids. We also found that there was an association between genotypes of the constant region of the IgG2 heavy chain with phenotypes of tick infestations. These findings open the possibility of investigating if certain IgG allotypes hinder the function of tick IGBPs. If so, they may be markers for breeding for resistance against tick infestations.