Infection with Trypanosoma spp. in Platydoras armatulus (Siluriformes, Doradidae), in southwestern Amazon, Brazil.

Trypanosoma is a hemoflagellate capable of infecting a wide variety of invertebrates and vertebrates, such as Neotropical freshwater fish. The present study described and morphologically compared Trypanosoma spp., found in Platydoras armatulus, Valenciennes, 1840, in southwestern Amazon. Fish specimens were sampled in Ipixuna and Juruá rivers located in the states of Amazonas and Acre, Brazil. Fish blood samples were taken by cardiac puncture, and smears were prepared for quantification, morphometric measurements, and morphotyping (characterization of the trypanosomes according to their morphological variations) of trypanosomes found. Prevalence, mean abundance, and intensity of parasitism were estimated in the parasitized fish specimens. Five fish specimens were collected, showing a 100% prevalence of parasites in the host. We found two Trypanosoma morphotypes, A and B, in which A had the highest infection intensity in host specimens. Thus, the present study presented the first report of Trypanosoma parasitizing P. armatulus, with different morphological variations.

Lattice model for self-folding at the microscale.

Three-dimensional shell-like structures can be obtained spontaneously at the microscale from the self-folding of 2D templates of rigid panels. At least for simple structures, the motion of each panel is consistent with a Brownian process and folding occurs through a sequence of binding events, where pairs of panels meet at a specific closing angle. Here, we propose a lattice model to describe the dynamics of self-folding. As an example, we study the folding of a pyramid of N lateral faces. We combine analytical and numerical Monte Carlo simulations to find how the folding time depends on the number of faces, closing angle, and initial configuration. Implications for the study of more complex structures are discussed.

Exploring Ubiquinone Biosynthesis Inhibition as a Strategy for Improving Atovaquone Efficacy in Malaria.

Atovaquone (AV) acts on the malaria parasite by competing with ubiquinol (UQH2) for its union to the mitochondrial bc1 complex, preventing the ubiquinone-8 and ubiquinone-9 (UQ-8 and UQ-9) redox recycling, which is a necessary step in pyrimidine biosynthesis. This study focused on UQ biosynthesis in Plasmodium falciparum and adopted proof-of-concept research to better elucidate the mechanism of action of AV and improve its efficacy. Initially, UQ biosynthesis was evaluated using several radioactive precursors and chromatographic techniques. This methodology was suitable for studying the biosynthesis of both UQ homologs and its redox state. Additionally, the composition of UQ was investigated in parasites cultivated at different oxygen saturations or in the presence of AV. AV affected the redox states of both UQ-8 and UQ-9 homologs by increasing the levels of the respective reduced forms. Conversely, low-oxygen environments specifically inhibited UQ-9 biosynthesis and increased the antimalarial efficacy of AV. These findings encouraged us to investigate the biological importance and the potential of UQ biosynthesis as a drug target based on its inhibition by 4-nitrobenzoate (4-NB), a 4-hydroxybenzoate (4-HB) analog. 4-NB effectively inhibits UQ biosynthesis and enhances the effects of AV on parasitic growth and respiration rate. Although 4-NB itself exhibits poor antimalarial activity, its 50% inhibitory concentration (IC50) value increased significantly in the presence of a soluble UQ analog, p-aminobenzoic acid (pABA), or 4-HB. These results indicate the potential of AV combined with 4-NB as a novel therapy for malaria and other diseases caused by AV-sensitive pathogens.

Cost-effectiveness of bariatric surgery in adolescents with severe obesity in the UK.

Evidence shows that surgery for severe obesity in adults improves health and psychological functioning, and is cost-effective. Data on bariatric surgery for adolescents with severe obesity are extremely limited, with no evidence on cost-effectiveness. We evaluated the lifetime cost-effectiveness of bariatric surgery compared with no surgery in adolescents with severe obesity from the UK's National Health Service perspective. Eighteen adolescents with body mass index ≥40 kg m-2 who underwent bariatric surgery (laparoscopic Roux en Y Gastric Bypass [RYGB] [N = 9], and laparoscopic Sleeve Gastrectomy [SG] [N = 9]) at University College London Hospitals between January 2008 and December 2013 were included. We used a Markov cohort model to compare the lifetime expected costs and quality-adjusted life years (QALYs) between bariatric surgery and no surgery. Mean cost of RYGB and SG procedures were £7100 and £7312, respectively. For RYGB vs. no surgery, the incremental cost/QALY was £2018 (95% CI £1942 - £2042) for males and £2005 (95% CI £1974 - £2031) for females. For SG vs. no surgery, the incremental cost/QALY was £1978 (95% CI £1954 - £2002) for males and £1941 (95% CI £1915 - £1969) for females. Bariatric surgery in adolescents with severe obesity is cost-effective; it is more costly than no surgery however it markedly improved quality of life.

Phase III study of the European Organisation for Research and Treatment of Cancer satisfaction with cancer care core questionnaire (EORTC PATSAT-C33) and specific complementary outpatient module (EORTC OUT-PATSAT7).

Advances in cancer care delivery require revision and further development of questionnaires assessing patients' perceived quality of care. This study pre-tested the revised EORTC satisfaction with cancer care core questionnaire applicable in both the cancer inpatient and outpatient settings, and its new, outpatient-specific complementary module. The process of revision, development of the extended application, and pre-testing of these questionnaires was based on phases I to III of the "EORTC Quality of Life Group Module Development Guidelines." In phase III, patients in 11 countries in four European regions, South America and Asia completed provisional versions of the questionnaires. Fifty-seven relevant issues selected from literature reviews and input from experts were operationalized into provisional items, and subsequently translated into ten languages. Assessment of understanding, acceptability, redundancy and relevance by patients (n = 151) from oncology inpatient wards, and outpatient chemotherapy, radiotherapy and consultation settings, led to retention of, deletion of and merging of 40, 14 and 6 items respectively. Cronbach's alpha coefficients for hypothesized questionnaire scales were above 0.80. Our results provide preliminary support for the 33-item EORTC Satisfaction with cancer care core questionnaire and the 7-item complementary module specific for the outpatient care setting. A large scale phase IV cross-cultural psychometric study is now underway.

Predictors of immunodeficiency-related death in a cohort of low-income people living with HIV: a competing risks survival analysis.

We conducted a survival analysis with competing risks to estimate the mortality rate and predictive factors for immunodeficiency-related death in people living with HIV/AIDS (PLWH) in northeast Brazil. A cohort with 2372 PLWH was enrolled between July 2007 and June 2010 and monitored until 31 December 2012 at two healthcare centres. The event of interest was immunodeficiency-related death, which was defined based on the Coding Causes of Death in HIV Protocol (CoDe). The predictor variables were: sociodemographic characteristics, illicit drugs, tobacco, alcohol, nutritional status, antiretroviral therapy, anaemia and CD4 cell count at baseline; and treatment or chemoprophylaxis for tuberculosis (TB) during follow-up. We used Fine & Gray's model for the survival analyses with competing risks, since we had regarded immunodeficiency-unrelated deaths as a competing event, and we estimated the adjusted sub-distribution hazard ratios (SHRs). In 10 012·6 person-years of observation there were 3·1 deaths/100 person-years (2·3 immunodeficiency-related and 0·8 immunodeficiency-unrelated). TB (SHR 4·01), anaemia (SHR 3·58), CD4 <200 cells/mm3 (SHR 3·33) and being unemployed (SHR 1·56) were risk factors for immunodeficiency-related death. This study discloses a 13% coverage by highly active antiretroviral therapy (HAART) in our state and adds that anaemia at baseline or the incidence of TB may increase the specific risk of dying from HIV-immunodeficiency, regardless of HAART and CD4.

Body composition in male rats subjected to early weaning and treated with diet containing flour or flaxseed oil after 21 days until 60 days.

The aim of this study was analyzed if the flour or flaxseed oil treatment contributes to body composition in male rats subjected to early weaning. Pups were weaned for separation from mother at 14 (early weaning, EW) and 21 days (control, C). At 21 days, part of the pups was evaluated (C21 v. EW21). After 21 days, control (C60) was fed with control diet. EW was divided in control (EWC60); flaxseed flour (EWFF60); flaxseed oil (EWFO60) diets until 60 days. Body mass, length and body composition by dual-energy X-ray absorptiometry were determined. EW21 (v. C21) and EWC60 (v. C60 and EWFF60) showed lower (P<0.05) mass, length and body composition. EWFO60 (v. C60 and EWFF60) showed lower (P<0.05) body mass and length, body and trunk lean mass, bone mineral density and content and bone area. Flaxseed flour, in comparison with flaxseed oil, contributes to recovery of body composition after early weaning.

Brain development in male rats subjected to early weaning and treated with diet containing flour or flaxseed oil after 21 days until 60 days.

The precocious interruption of lactation is a prime factor for developmental plasticity. Here we analyzed whether flour or flaxseed oil treatment contributes to body and brain mass in male rats subjected to early weaning. Pups were weaned for separation from their mother at 14 (early weaning, EW) and 21 days (control, C). At 21 days, some of the pups were evaluated (C21 v. EW21). After 21 days, control pups (C60) were fed a control diet. EW pups were divided into those fed a control diet (EWC60), those given flaxseed flour (EWFF60), and those given flaxseed oil (EWFO60) until 60 days. EW21 showed lower body and absolute brain mass and higher relative brain mass. At 60 days, EWC60 and EWFO60 had lower body mass. With regard to relative brain mass, EWC60 was heavier; EWFO60 had lower values compared with EWC60 and higher values compared with C60 and EWFF60. These results indicated that flaxseed flour, in comparison with flaxseed oil, contributes to brain development after EW.

Evaluation of multiplex PCR in first episodes of febrile neutropenia as a tool to improve early yeast diagnosis in leukemic/preleukemic patients.

In febrile neutropenic onco-hematological patients, delayed microbiological diagnosis leads to an increase in morbidity and mortality. Identification of the microorganism changes antibiotic therapy in more than half of cases; however, in only 20-30 % of such cases pathogen isolation is achieved. This study evaluates the frequency of fungus infection and its etiology in onco-hematological patients with febrile neutropenia utilizing blood cultures and non-commercial multiplex polymerase chain reaction (MT-PCR) primers. Fifty-three febrile neutropenia episodes in 35 onco-hematological patients were observed, and the results for the first unique 30 episodes are presented. Blood cultures were positive for Candida tropicalis (one case), gram-positive bacteria (two cases), and gram-negative bacteria (four cases), showing a 23.3 % microbiological isolation rate. Multiplex-PCR pan-fungal sequence was positive in 18 cases (60 %), and further sequencing identified fugal pathogens in 11 cases (Candida glabrata and Candida parapsilosis being the most common). MT-PCR pan-fungal sequence amplification was detected in 13 of 16 patients that later received antifungal treatment for clinical reasons only, while positivity was found in 5 out of 14 patients that did not receive antifungal treatment (p = 0.02). These results show that performing in-house non-commercial MT-PCR is feasible and may provide additional information about fungal infection without the need to wait for culture results. Further research is necessary to incorporate this technology into the decision-making process.

The removal of thermo-tolerant coliform bacteria by immobilized waste stabilization pond algae.

This study investigated the potential of laboratory- scale columns of immobilized micro-algae to disinfect effluents using thermo-tolerant coliforms (TTC) as a model system. Cells of a Chlorella species isolated from a waste stabilization pond complex in Northeast Brazil were immobilized in calcium alginate, packed into glass columns and incubated in contact with TTC suspensions for up to 24 hours. Five to six log removals of TTC were achieved in 6 hours and 11 log removals in 12 hours contact time. The results were similar under artificial light and shaded sunlight. However little or no TTC removal occurred in the light in columns of alginate beads without immobilized algae present or when the immobilized algae were incubated in the dark suggesting that the presence of both algae and light were necessary for TTC decay. There was a positive correlation between K(b) values for TTC and increasing pH in the effluent from the immobilized algal columns within the range pH 7.2 and 8.9. The potential of immobilized algal technology for wastewater disinfection may warrant further investigation.

Mitogenic response and cytokine production induced by cramoll 1,4 lectin in splenocytes of inoculated mice.

Cramoll 1,4 is a lectin with specific glucose/mannose binding, which is extracted from seeds of Cratylia mollis Mart. Many assays have shown the cytokine expression activity and anti-inflammatory profile of this lectin. The aim of this study was to evaluate the immunostimulatory response, in vitro, of splenocytes in mice previously inoculated, in vivo, with C. mollis (Cramoll 1,4) and Canavalia ensiformis (Con A) lectins. Results demonstrated higher proliferation indexes induced by Cramoll 1,4 than Con A lectin in relation to all experimental groups. Cramoll 1,4 and Con A also induced high levels of IL-2, IL-6, IFN-γ and nitric oxide production. Moreover, Cramoll 1,4 did not induce apoptosis and stimulated a significant number of cells in the S phase of the cell cycle. Results showed that Cramoll 1,4 lectin induces proliferative response and suggested that this lectin can be used as a mitogenic agent in immunostimulatory assays.

Physiological and molecular analysis of the stress response of Saccharomyces cerevisiae imposed by strong inorganic acid with implication to industrial fermentations.

AIMS: This work aimed to identify the molecular mechanism that allows yeast cells to survive at low pH environments such as those of bioethanol fermentation. METHODS AND RESULTS: The industrial strain JP1 cells grown at pH 2 was evaluated by microarray analysis showing that most of the genes induced at low pH were part of the general stress response (GSR). Further, an acid-tolerant yeast mutant was isolated by adaptive selection that was prone to grow at low pH in inorganic but weak organic acid. It showed higher viability under acid-temperature synergistic treatment. However, it was deficient in some physiological aspects that are associated with defects in protein kinase A (PKA) pathway. Microarray analysis showed the induction of genes involved in inhibition of RNA and protein synthesis. CONCLUSIONS: The results point out that low pH activates GSR, mainly heat shock response, that is important for long-term cell survival and suggest that a fine regulatory PKA-dependent mechanism that might affect cell cycle in order to acquire tolerance to acid environment. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings might guide the construction of a high-fermentative stress-tolerant industrial yeast strain that can be used in complex industrial fermentation processes.

B2 receptor-mediated dual effect of bradykinin on proximal tubule Na+ -ATPase: sequential activation of the phosphoinositide-specific phospholipase Cbeta/protein kinase C and Ca2+ -independent phospholipase A2 pathways.

In a previous paper we showed that bradykinin (BK), interacting with its B2 receptor, inhibits proximal tubule Na+ -ATPase activity but does not change (Na+ +K+)ATPase activity. The aim of this paper was to investigate the molecular mechanisms involved in B2-mediated modulation of proximal tubule Na+ -ATPase by BK. To abolish B1 receptor-mediated effects, all experiments were carried out in the presence of (Arg-Pro-Pro-Gly-Phe-Ser-Pro-Leu), des-Arg9-[Leu8]-BK (DALBK), a specific antagonist of B1 receptor. A dual effect on the Na+ -ATPase activity through the B2 receptor was found: short incubation times (1-10 min) stimulate the enzyme activity; long incubation times (10-60 min) inhibit it. The stimulatory effect of BK is mediated by activation of phosphoinositide-specific phospholipase C beta (PI-PLCbeta)/protein kinase C (PKC); its inhibitory action is mediated by Ca2+ -independent phospholipase A2 (iPLA2). Prior activation of the PI-PLCbeta/PKC pathway is required to activate the iPLA2-mediated inhibitory phase. These results reveal a new mechanism by which BK can modulate renal sodium excretion: coupling between B2 receptor and activation of membrane-associated iPLA2.

Variations in BOD, algal biomass and organic matter biodegradation constants in a wind-mixed tropical facultative waste stabilization pond.

This study considered the impact of wind mixing on the efficiency of BOD removal and the first order biodegradation constant for organic matter in a primary facultative pond. Wind speeds of 1-4 m/s blowing from the effluent end of the pond towards the influent created surface-water flows of up to 0.94 m/s as determined by orange and coconut drogues moving in the opposite direction to the bulk hydraulic flow of 0.217 m/s. This was sufficient to cause mixing of the water column resulting in loss of stratification in terms of chlorophyll a, temperature and dissolved oxygen. BOD and chlorophyll a concentrations were spatially and temporally homogeneous throughout this large pond. BOD removal efficiency was only 50.30% as opposed to a projected value of 79% despite an acceptable surface organic loading of 350 kgBOD5/ha/d and an actual k value for BOD removal using influent sewage samples of 0.29 d-1 close to the projected value of 0.30 d-1. It would seem that wind mixing reduced pond efficiency by destroying stratification and thus reducing the microbial activity necessary to consume organic material. Mixing also increased the mean chlorophyll a concentration compared to stratified facultative ponds receiving similar loads and non-motile algae dominated the water column.

Determination of the sedimentation constants for total suspended solids and the algal component in a full-scale primary facultative pond operating at high wind velocities under tropical conditions.

This study evaluated the amount, distribution and sedimentation constant of solids in a full-scale primary facultative pond operating mostly under high wind conditions and the contribution made by the algal biomass. Solids deposition rates were measured using sedimentation traps placed in the inlet and outlet zones of the pond. Most sludge accumulation occurred, not surprisingly, in the inlet zone A1 with a sludge volume of 9072.m3 accumulating over an operating time of approximately 3 years. However, sludge deposition within this zone was uneven and affected by wind action. Mean proportionality constant (K) values for solids sedimentation were 3.02 and 5.70 for depths of 50 cm and 100 cm respectively for A1. In contrast in zone A3, (the outlet zone), reduced K values of 1.38 and 3.22 were obtained for depths of 50 cm and 100 cm respectively. The algal sedimentation constant varied from 0.8 d(-1) in zone A1 to 0.02 d(-1) in A3. These data suggest that in this large facultative pond the wind, blowing predominantly from the direction of the outlets towards the pond inlets, had a greater influence on solids deposition than the bulk hydraulic flow and also kept the pond completely mixed for most of the time.

Anaerobic-aerobic sewage treatment using the combination UASB-SBR activated sludge.

The performance of a pilot scale sewage treatment system composed of an upflow anaerobic sludge blanket (UASB) digester and a sequencing batch activated sludge reactor (SBR) is described. The system constitutes a simple, economic, and compact treatment option and is able to produce consistently a final effluent quality that is equal or better than that of a conventional activated sludge plant. The entire treatment system had a retention time of only 9h and an average operational temperature of 25 degrees C. Due to the efficient anaerobic pre treatment the aerobic sludge production was low and could easily be accommodated for stabilisation in the UASB reactor. The system exhibited excellent operational stability with full nitrification for aerobic sludge ages longer than 9 days. At shorter sludge ages there was excessive wash out of sludge particles and the sludge mass could not be maintained in the SBR reactor. Sludge settleability was good throughout the experimental investigation period of one year. The reduction of the reactor volume and oxygen consumption was more than 50% compared to conventional activated sludge. The anaerobic excess sludge had a high concentration and good stability so that its dewatering and final disposal was a relatively minor problem.

Ethical and legal issues in xenotransplantation.

In most western countries, there is a 'human organ shortage' with waiting lists for the performance of transplantation. In a recent report of the UNOS Ethics Committee it is stated that there are approximately 31,000 potential recipients on waiting lists, but only one fourth of potential donors give their specific consent. Xenotransplantation--defined as the transplantation of animal cells, tissues or organs into human beings--is associated with particular ethical dilemmas, namely the problems of efficiency and safety of this medical procedure. The objective of this study is to analyse the ethical dilemmas in xenotransplantation with the background of a personal view of moral life. Also, xenotransplantation will be evaluated as far as the legal regulation of transplantation is concerned. In particular, we will consider patients rights in accordance with existing laws on organ and tissue transplantation, animal research and clinical trials.

[HTLV-I-associated myelopathy, tropical spastic paraparesis: report of the first cases in Sergipe, Brazil]. / Mielopatia associada ao HTLV-I/paraparesia espástica tropical. Relato dos primeiros casos em sergipe.

HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) has been described in practically all regions of Brazil. The authors present eight clinically defined cases of HAM/TSP, as being the first reported in Sergipe (Northeastern Brazil). All of them were confirmed through ELISA in two examinations, although only two were confirmed by Western Blot. According to clinical/laboratorial investigation protocol, all patients presented involvement of the pyramidal tract with minimal sensory loss and sphincter alteration. The authors call the attention for the endemicity of HTLV-I in the region, whose prevalence amongst blood donors is significant (0.43%).