Enabling International Communication among Brazilian Occupational Therapists: Seeking Consensus on Occupational Terminology

The purpose of this study was to examine how key occupational therapy terminologies are used by Brazilian occupational therapists. A nominal group approach combined with a Delphi technique involving 31 Brazilian occupational therapists was applied. A sociolinguistic approach was adopted since it broadens our understanding of the social and cultural determinants of terminology consolidation. Brazilian occupational therapists were found to adopt the term activity more often than human action or doing. Even less often were praxis and occupation applied. No consensus was reached regarding which of the terms is most preferred. While Brazilian occupational therapists have been developing their profession from international standards, it is still embedded in local demands and policies. Additionally, the political context must be considered when building an international dialogue between members of a professional body. Such a dialogue could engage professionals from different countries in meaningful exchanges about their practices. These exchanges may lead to the development of solid professional communities that can contribute meaningfully to social change. Copyright (C) 2010 John Wiley & Sons, Ltd.

The role of predator overlap in the robustness and extinction of a four species predator-prey network

Predators and preys often form species networks with asymmetric patterns of interaction. We study the dynamics of a four species network consisting of two weakly connected predator-prey pairs. We focus our analysis on the effects of the cross interaction between the predator of the first pair and the prey of the second pair. This is an example where the predator overlap, which is the proportion of predators that a given prey shares with other preys, is not uniform across the network due to asymmetries in patterns of interaction. We explore the behavior of the system under different interaction strengths and study the dynamics of survival and extinction. In particular, we consider situations in which the four species have initial populations lower than their long-term equilibrium, simulating catastrophic situations in which their abundances are reduced due to human action or environmental change. We show that, under these reduced initial conditions, and depending on the strength of the cross interaction, the populations tend to oscillate before re-equilibrating, disturbing the community equilibrium and sometimes reaching values that are only a small fraction of the equilibrium population, potentially leading to their extinction. We predict that, contrary to one`s intuition, the most likely scenario is the extinction of the less predated preys. (C) 2010 Elsevier B.V. All rights reserved.

A possible mechanism of low molecular weight protein tyrosine phosphatase (LMW-PTP) activity modulation by glutathione action during human osteoblast differentiation

Objective: Low molecular weight protein tyrosine phosphatases (LMW-PTPs) are a family of enzymes strongly involved in the regulation of cell growth and differentiation. Since there is no information concerning the relationship between osteoblastic differentiation and LMW-PTP expression/activity, we investigated its involvement during human osteoblast-like cells (hFOB 1.19) differentiation. It is known that LMW-PTP is regulated by an elegant redox mechanism, so we also observed how the osteoblastic differentiation affected the reduced glutathione levels. Design: hFOB 1.19 cells were cultured in DMEM/F12 up to 35 days. The osteoblast phenotype acquisition was monitored by measuring alkaline phosphatase activity and mineralized nodule formation by Von Kossa staining. LMW-PTP activity and expression were measured using the p-nitrophenylphosphate as substrate and Western blotting respectively. Crystal violet assay determined the cell number in each experimental point. Glutathione level was determined by both HPLC and DNTB assays. Results: LMW-PTP modulation was coincident with the osteoblastic differentiation biomarkers, such as alkaline phosphatase activity and presence of nodules of mineralization in Vitro. Likewise LMW-PTP, the reduced glutathione-dependent microenvironment was modulated during osteoblastic differentiation. During this process, LMW-PTP expression/activity, as well as alkaline phosphatase and glutathione increased progressively up to the 21st day (p < 0.001) of culturing, decreasing thereafter. Conclusions: Our results clearly suggest that LMW-PTP expression/activity was rigorously modulated during osteoblastic differentiation, possibly in response to the redox status of the cells, since it seems to depend on suitable levels of reduced glutathione. in this way, we pointed out LMW-PTP as an important signaling molecule in osteoblast biology and bone formation. (C) 2009 Elsevier Ltd. All rights reserved.

Visual Feedforward Control in Human Locomotion During Avoidance of Obstacles that Change Size

The purpose of the current study was to understand how visual information about an ongoing change in obstacle size is used during obstacle avoidance for both lead and trail limbs. Participants were required to walk in a dark room and to step over an obstacle edged with a special tape visible in the dark. The obstacle's dimensions were manipulated one step before obstacle clearance by increasing or decreasing its size. Two increasing and two decreasing obstacle conditions were combined with seven control static conditions. Results showed that information about the obstacle's size was acquired and used to modulate trail limb trajectory, but had no effect on lead limb trajectory. The adaptive step was influenced by the time available to acquire and process visual information. In conclusion, visual information about obstacle size acquired during lead limb crossing was used in a feedforward manner to modulate trail limb trajectory.

Bothrops jararaca Peptide with Anti-Hypertensive Action Normalizes Endothelium Dysfunction Involved in Physiopathology of Preeclampsia

Preeclampsia, a pregnancy-specific syndrome characterized by hypertension, proteinuria and edema, is a major cause of fetal and maternal morbidity and mortality especially in developing countries. Bj-PRO-10c, a proline-rich peptide isolated from Bothrops jararaca venom, has been attributed with potent anti-hypertensive effects. Recently, we have shown that Bj-PRO-10c-induced anti-hypertensive actions involved NO production in spontaneous hypertensive rats. Using in vitro studies we now show that Bj-PRO-10c was able to increase NO production in human umbilical vein endothelial cells from hypertensive pregnant women (HUVEC-PE) to levels observed in HUVEC of normotensive women. Moreover, in the presence of the peptide, eNOS expression as well as argininosuccinate synthase activity, the key rate-limiting enzyme of the citrulline-NO cycle, were enhanced. In addition, excessive superoxide production due to NO deficiency, one of the major deleterious effects of the disease, was inhibited by Bj-PRO-10c. Bj-PRO-10c induced intracellular calcium fluxes in both, HUVEC-PE and HUVEC, which, however, led to activation of eNOS expression only in HUVEC-PE. Since Bj-PRO-10c promoted biological effects in HUVEC from patients suffering from the disorder and not in normotensive pregnant women, we hypothesize that Bj-PRO-10c induces its anti-hypertensive effect in mothers with preeclampsia. Such properties may initiate the development of novel therapeutics for treating preeclampsia.

Interference with Hemozoin Formation Represents an Important Mechanism of Schistosomicidal Action of Antimalarial Quinoline Methanols

Background: The parasitic trematode Schistosoma mansoni is one of the major causative agents of human schistosomiasis, which afflicts 200 million people worldwide. Praziquantel remains the main drug used for schistosomiasis treatment, and reliance on the single therapy has been prompting the search for new therapeutic compounds against this disease. Our group has demonstrated that heme crystallization into hemozoin (Hz) within the S. mansoni gut is a major heme detoxification route with lipid droplets involved in this process and acting as a potential chemotherapeutical target. In the present work, we investigated the effects of three antimalarial compounds, quinine (QN), quinidine (QND) and quinacrine (QCR) in a murine schistosomiasis model by using a combination of biochemical, cell biology and molecular biology approaches. Methodology/Principal Findings: Treatment of S. mansoni-infected female Swiss mice with daily intraperitoneal injections of QN, and QND (75 mg/kg/day) from the 11(th) to 17(th) day after infection caused significant decreases in worm burden (39%-61%) and egg production (42%-98%). Hz formation was significantly inhibited (40%-65%) in female worms recovered from QN- and QND-treated mice and correlated with reduction in the female worm burden. We also observed that QN treatment promoted remarkable ultrastructural changes in male and female worms, particularly in the gut epithelium and reduced the granulomatous reaction to parasite eggs trapped in the liver. Microarray gene expression analysis indicated that QN treatment increased the expression of transcripts related to musculature, protein synthesis and repair mechanisms. Conclusions: The overall significant reduction in several disease burden parameters by the antimalarial quinoline methanols indicates that interference with Hz formation in S. mansoni represents an important mechanism of schistosomicidal action of these compounds and points out the heme crystallization process as a valid chemotherapeutic target to treat schistosomiasis.

Recombinant human prolactin promotes human beta cell survival via inhibition of extrinsic and intrinsic apoptosis pathways

Transplantation of pancreatic islets constitutes a promising alternative treatment for type 1 diabetes. However, it is limited by the shortage of organ donors. Previous results from our laboratory have demonstrated beneficial effects of recombinant human prolactin (rhPRL) treatment on beta cell cultures. We therefore investigated the role of rhPRL action in human beta cell survival, focusing on the molecular mechanisms involved in this process. Human pancreatic islets were isolated using an automated method. Islet cultures were pre-treated in the absence or presence of rhPRL and then subjected to serum starvation or cytokine treatment. Beta cells were labelled with Newport green and apoptosis was evaluated using flow cytometry analysis. Levels of BCL2 gene family members were studied by quantitative RT-PCR and western blot. Caspase-8, -9 and -3 activity, as well as nitric oxide production, were evaluated by fluorimetric assays. The proportion of apoptotic beta cells was significantly lowered in the presence of rhPRL under both cell death-induced conditions. We also demonstrated that cytoprotection may involve an increase of BCL2/BAX ratio, as well as inhibition of caspase-8, -9 and -3. Our study provides relevant evidence for a protective effect of lactogens on human beta cell apoptosis. The results also suggest that the improvement of cell survival may involve, at least in part, inhibition of cell death pathways controlled by the BCL2 gene family members. These findings are highly relevant for improvement of the islet isolation procedure and for clinical islet transplantation.

Evaluation of the role of environmental factors in the human gastrointestinal tract on the behaviour of probiotic cultures of Lactobacillus casei Shirota and Lactobacillus casei LC01 by the use of a semi-dynamic in vitro model

This study evaluated the influence of gastrointestinal environmental factors (pH, digestive enzymes, food components, medicaments) on the survival of Lactobacillus casei Shirota and Lactobacillus casei LC01, using a semi-dynamic in vitro model that simulates the transit of microorganisms through the human GIT. The strains were first exposed to different simulated gastric juices for different periods of time (0, 30, 60 and 120 min), and then to simulated intestinal fluids for zero, 120, 180 and 240 min, in a step-wise format. The number of viable cells was determined after each step. The influence of food residues (skim milk) in the fluids and resistance to medicaments commonly used for varied therapeutic purposes (analgesics, antiarrhythmics, antibiotics, antihistaminics, proton pump inhibitors, etc.) were also evaluated. Results indicated that survival of both cultures was pH and time dependent, and digestive enzymes had little influence. Milk components presented a protective effect, and medicaments, especially anti-inflammatory drugs, influenced markedly the viability of the probiotic cultures, indicating that the beneficial effects of the two probiotic cultures to health are dependent of environmental factors encountered in the human gastrointestinal tract.

Prospective ultramorphological characterization of human hair by optical coherence tomography

Background/purpose The continuous advancement in cosmetic science has led to an increasing demand for the development of non-invasive, reliable scientific techniques directed toward claim substantiation, which is of utmost relevance, to obtain data regarding the efficacy and safety of cosmetic products. Methods In this work, we used the optical coherence tomography (OCT) technique to produce in vitro transversal section-images of human hair. We also compared the OCT signal before and after chemical treatment with an 18% w/w ammonium thioglycolate solution. Results The mean diameter of the medulla was 29 +/- 7 mu m and the hair diameter was 122 +/- 16 mu m in our samples of standard Afro-ethnic hair. A three-dimensional (3D) image was constructed starting from 601 cross-sectional images (slices). Each slice was taken in steps of 6.0 mu m at eight frames per second, and the entire 3D image was constructed in 60 s. Conclusion It was possible to identify, using the A-scan protocol, the principal structures: the cuticle, cortex and medulla. After chemical treatment, it was not possible to identify the main structures of hair fiber due to index matching promoted by deleterious action of the chemical agent.

Micromethod for Quantification of Carbamazepine, Phenobartital and Phenytoin in Human Plasma by HPLC-UV Detection for Therapeutic Drug Monitoring Application

A simple, rapid, selective and sensitive analytical method by HPLC with UV detection was developed for the quantification of carbamazepine, phenobarbital and phenytoin in only 0.2 mL of plasma. A C18 column (150 x 3.9 mm, 4 micra) using a binary mobile phase consisting of water and acetonitrile (70:30, v/v) at a flow rate of 0.5 mL/min were proposed. Validation of the analytical method showed a good linearity (0.3 to 20.0 mg/L for CBZ, 0.9 to 60.0 mg/L for PB and 0.6 to 40.0 mg/L for PHT), high sensitivity (LOQ: 0.3, 0.9 and 0.6 mg/L respectively). The method was applied for drug monitoring of antiepileptic drugs (AED) in 27 patients with epilepsy under polytherapy.

In vitro safety assessment of papain on human skin: A qualitative Light and Transmission Electron Microscopy (TEM) study

Papain is a thiol proteolytic enzyme widely used in dermatology that found applications in wound treatment. Recently, papain was also used as absorption enhancer which can modify the peptide/ protein material in the bilayer domain. We investigated papain safety using human skin that was exposed to papain in vitro at different times: 4, 24 and 48 hours. The samples were examined using Light and Transmission Electron Microscopy (TEM) to study of the mechanisms involved in enhancer-skin interaction. After 24 hours, changes occurred in corneosomes. However, samples of 48 hours did not show major changes in agreement with the control. These findings indicated that papain could be used safely onto the skin.

Further sesquiterpene lactones from viguiera robusta and the potential anti-inflammatory activity of a heliangolide: Inhibition of human neutrophil elastase release

In addition to known heliangolides, a new eudesmanolide was isolated from the leaf rinse extract of Viguiera robusta (Asteraceae). Structural elucidation was based oil spectral analysis. It is the first report on eudesmanolides in members of the subgenus Calanticaria of Viguiera. In this work, the main isolated compound, the furanoheliangolide budlein A, besides its previously, reported in vitro and in vivo anti-inflammatory activities, inhibited human neutrophil elastase release. The inhibition was at the concentration of (16.83 +/- 1.96) mu M for formylated bacterial tripeptide (fMLP) stimulation and (11.84 +/- 1.62) mu M for platelet aggregation factor (PAF) stimulation, being slightly less active than the reference drug parthenolide. The results are important to demonstrate the potential anti-inflammatory activities of sesquiterpene lactones and corroborate the previous studies using other targets.

Structural complexes of human adenine phosphoribosyltransferase reveal novel features of the APRT catalytic mechanism

Adenine phosphoribosyltransferase (APRT) is an important enzyme component of the purine recycling pathway. Parasitic protozoa of the order Kinetoplastida are unable to synthesize purines de novo and use the salvage pathway for the synthesis of purine bases rendering this biosynthetic pathway an attractive target for antiparasitic drug design. The recombinant human adenine phosphoribosyltransferase (hAPRT) structure was resolved in the presence of AMP in the active site to 1.76 angstrom resolution and with the substrates PRPP and adenine simultaneously bound to the catalytic site to 1.83 angstrom resolution. An additional structure was solved containing one subunit of the dimer in the apo-form to 2.10 angstrom resolution. Comparisons of these three hAPRT structures with other `type I` PRTases revealed several important features of this class of enzymes. Our data indicate that the flexible loop structure adopts an open conformation before and after binding of both substrates adenine and PRPR Comparative analyses presented here provide structural evidence to propose the role of Glu 104 as the residue that abstracts the proton of adenine N9 atom before its nucleophilic attack on the PRPP anomeric carbon. This work leads to new insights to the understanding of the APRT catalytic mechanism.

Evaluation of the genotoxicity of Crotalus durissus terrificus snake venom and its isolated toxins on human lymphocytes

In the present study, experiments were carried out to evaluate the mutagenic potential and genotoxic effects of Crotalus durissus terrificus snake venom and its isolated toxins on human lymphocytes, using the micronucleus and comet assays. Significant damage to DNA was observed for crotoxin and crotapotin (CA). Basic phospholipase A(2) (CB) and crotamine did not present any mutagenic potential when evaluated by the micronucleus test. C. d. terrificus crude venom was able to induce the formation of micronuclei, similarly to the mutagenic drug used as a positive control. In the comet assay, all the toxins tested (crotamine, crotoxin, CB and CA) and C. d. terrificus venom presented genotoxic activity. Studies on the cytogenetic toxicology of animal venoms and their isolated proteins are still very scarce in the literature, which emphasizes the importance of the present work for the identification and characterization of potential therapeutic agents, as well as for the better understanding of the mechanisms of action of toxins on the human body. (C) 2011 Elsevier B.V. All rights reserved.