CtpB is a plasma membrane copper (I) transporting P-type ATPase of Mycobacterium tuberculosis

BACKGROUND: The intracellular concentration of heavy-metal cations, such as copper, nickel, and zinc is pivotal for the mycobacterial response to the hostile environment inside macrophages. To date, copper transport mediated by P-type ATPases across the mycobacterial plasma membrane has not been sufficiently explored. RESULTS: In this work, the ATPase activity of the putative Mycobacterium tuberculosis P1B-type ATPase CtpB was associated with copper (I) transport from mycobacterial cells. Although CtpB heterologously expressed in M. smegmatis induced tolerance to toxic concentrations of Cu2+ and a metal preference for Cu+, the disruption of ctpB in M. tuberculosis cells did not promote impaired cell growth or heavy-metal accumulation in whole mutant cells in cultures under high doses of copper. In addition, the Cu+ ATPase activity of CtpB embedded in the plasma mem-brane showed features of high affinity/slow turnover ATPases, with enzymatic parametersKM 0.19 ± 0.04 µM and Vmax 2.29 ± 0.10 nmol/mg min. In contrast, the ctpB gene transcription was activated in cells under culture conditions that mimicked the hostile intraphagosomal environment, such as hypoxia, nitrosative and oxidative stress, but not under high doses of copper. CONCLUSIONS: The overall results suggest that M. tuberculosis CtpB is associated with Cu+ transport from mycobacterial cells possibly playing a role different from copper detoxification.

The aminoglycoside antibiotic gentamicin is able to alter metabolic activity and morphology of MDCK-C11 cells: a cell model of intercalated cells

It is well known that the aminoglycoside antibiotic gentamicin is capable of causing damage to kidney cells. Given the known involvement of Ca2+ in the nephrotoxic action of gentamicin, the purpose of this study was to establish a relationship between the concentration of intracellular Ca2+ ([Ca2+]i) and cellular cytotoxicity using MDCK-C11 cells, a clone that has several properties that resemble those of intercalated cells of the distal nephron. Changes in [Ca2+]i was determined using fluorescence microscopy. Cell viability was evaluated by the neutral red method, and cell cytotoxicity by the MTT method. The [Ca2+]i gradually increased when cells were exposed to 0.1 mM gentamicin for 10, 20, and 30 min. The presence of extracellular Ca2+ was found to be necessary to stimulate the increase in [Ca2+]i induced by gentamicin, since this stimulus disappeared by using 1.8 mM EGTA (a Ca2+ chelator). Morphological changes were observed with scanning electron microscopy in epithelial cells exposed to the antibiotic. Furthermore, with the MTT method, a decrease in metabolic activity induced by gentamicin was observed, which indicates a cytotoxic effect. In conclusion, gentamicin was able to alter [Ca2+]i, change the morphology of MDCK-C11 cells, and promote cytotoxicity.

Membrane permeabilization of colistin toward pan-drug resistant Gram-negative isolates

Abstract Pan-drug resistant Gram-negative bacteria, being resistant to most available antibiotics, represent a huge threat to the medical community. Colistin is considered the last therapeutic option for patients in hospital settings. Thus, we were concerned in this study to demonstrate the membrane permeabilizing activity of colistin focusing on investigating its efficiency toward those pan-drug resistant isolates which represent a critical situation. We determined the killing dynamics of colistin against pan-drug resistant isolates. The permeability alteration was confirmed by different techniques as: leakage, electron microscopy and construction of an artificial membrane model; liposomes. Moreover, selectivity of colistin against microbial cells was also elucidated. Colistin was proved to be rapid bactericidal against pan-drug resistant isolates. It interacts with the outer bacterial membrane leading to deformation of its outline, pore formation, leakage of internal contents, cell lysis and finally death. Furthermore, variations in membrane composition of eukaryotic and microbial cells provide a key for colistin selectivity toward bacterial cells. Colistin selectively alters membrane permeability of pan-drug resistant isolates which leads to cell lysis. Colistin was proved to be an efficient last line treatment for pan-drug resistant infections which are hard to treat.

Efeito da Laserfototerapia associada ou não à Vitamina C na indução de membranas celulares (cell sheets) de células-tronco da polpa dentária humana / Effect of laserphototherapy associated or not to Vitamin C in the induction of cell sheets of human dental pulp stem cells

Membranas celulares (MCs; Cell Sheets), constituídas por células-tronco (CTs), são autodestacáveis da placa de cultivo, e sem subcultivos geram grande quantidade de células que podem ser transplantadas de maneira mais próxima da fisiologia celular, mantendo-se as ligaçُões celulares e a matriz extracelular produzidas em cultura. O Ácido ascórbico ou vitamina C (VC) tem efeito indutor da formação destas MCs, aumentando a longevidade e tempo de indiferenciação das CTs. A similaridade observada entre respostas biológicas da VC em MCs e aquelas da Laserfototerapia (LFT) sobre células e tecidos, nos levou à hipótese de que estas terapias poderiam se complementar melhorando o prognóstico de futura aplicação clínica dessas MCs em regenerações tecidos de interesse odontológico. Para testar essa hipótese, LFT e VC foram aplicadas associadas ou não na indução de MCs de células-tronco da polpa dentária humana (hDPSCs). Para tanto, hDPSCs descongeladas, que expressaram níveis típicos de marcadores de superfície de células-tronco mesenquimais, foram plaqueadas em placas de 6 poços (5x104 células por poço). Vinte e quatro horas depois do plaqueamento as culturas foram submetidas aos tratamentos dos grupos experimentais: Controle: hDPSCs em P3 cultivadas com meio clonogênico; Senescente: hDPSCs em P27 cultivadas com meio clonogênico; VC: P3 cultivadas com meio clonogênico acrescido de VC (20µg/ml); Laser: P3 cultivadas com meio clonogênico e submetido à LFT (contato e pontual - 5 pontos / poço, 660 nm, 20 mW, 0,028 cm², 0,71 W/cm², 7 segundos, 5 J/cm², 0,14 J por ponto, 48 horas de intervalo) e Laser+VC: P3 cultivadas com meio clonogênico acrescido de VC e submetido

à LFT. Em 24 horas, 7 e 13 dias as hDPSCs dos diferentes grupos experimentais foram observadas macro e microscopicamente, e atividade da enzima telomerase foi avaliada por PCR-TRAP, complementado por ELISA. Para a avaliação da expressão de genes relacionados à natureza e indiferenciação (Mitofilina e Oct 4) e à longevidade (fase catalíca da enzima telomerase - hTERT); bem como à senescência das células do grupo senescente (­­ß-galactosidase), as hDPSCs de todos os grupos experimentais foram submetidas ao RT-qPCR As hDPSCs foram capazes de formar MCs somente nos grupos VC e Laser+VC (100%), entre 10 e 13 dias. As MCs do grupo Laser+VC apresentaram maior facilidade na manipulação. Atividade de Telomerase nas hDPSCs foi observada somente em 24 horas (Controle e LFT) e em 7 dias (VC e Laser+VC). Os marcadores de indiferenciação (Oct 4) e mesenquimal (mitofilina), bem como a hTERT foram expressos nas hDPSCs de todos os grupos experimentais. O Oct4 e o hTERT, em 7 dias, apresentaram expressões significativamente maiores nos grupos VC e Laser+VC em comparação com os demais (p < 0,0001, p = 0,0009, respectivamente). A expressão da mitofilina foi significativamente maior no grupo Laser+VC, em 7 dias (p =0,033). A técnica de obtenção de MCs de hDPSCs por essa metodologia foi considerada adequada para ser testada em procedimentos regenerativos. A LFT quando associada à VC não interferiu na formação das MCs, nem na manutenção da longevidade e indiferenciação das hDPSCs. Adicionalmente, a LFT melhorou a manipulação das MCs. Assim sendo, a associação de VC e LFT na indução de MCs parece promissora para futura utilização de MCs na odontologia regenerativa.

Cell Sheets, consisting of stem cells (SCs) are self detachable from the cultivation plate, and with no subcultivation can generate large amount of cells. The cell sheets can be transplanted closer to cell physiology environment by keeping the cell connections and the extracellular matrix produced in culture. Ascorbic acid or Vitamin C (VC) has inductive effect on cell sheet formation, increasing the longevity and the stemness of the cell for long period of time. The similarity between biological responses of VC in cell sheets and those of Laserphototherapy (LPT, Laser) on cells and tissues led us to hypothesize that these therapies could improve the prognosis of future clinical application of these cell sheets in regeneration of dental tissues. To test this hypothesis, LPT and VC were applied, associated or not, to induce human dental pulp stem cells (hDPSCs). Therefore, hDPSCs, which expressed typical levels of mesenchymal stem cell surface markers, were plated in 6-well plates (5x104 cells per well). Twenty-four hours later they were subjected to the treatment of experimental groups: Control: hDPSCs in P3 cultured with regular medium; Senescent: hDPSCs in P27 cultured with regular medium; VC: P3 cultured with regular medium supplemented with VC (20 ?g/ml); Laser: P3 cultures with regular medium and submitted to LPT (punctual and contact mode-5 points / well, 660 nm, 20 mW, 0.028 cm², 0.71 W/cm²,

7 sec, 5 J/cm², 0.14 J per point, 48 hours-intervals) and Laser+VC: P3 cultured with regular medium supplemented with VC and submitted to LPT Within 24 hours, 7 and 13 days the hDPSCs of the different experimental groups were observed macroscopically and microscopically, and the telomerase enzyme activity was assessed by PCR-TRAP, complemented by ELISA. To evaluate the expression of genes related to the nature and differentiation (Mitofilina and Oct 4), longevity (catalytic phase of telomerase-hTERT enzyme), and the senescence of the senescent group cells (?-galactosidase), the hDPSCs of all experimental groups were subjected to RT-qPCR. The RT-qPCR data were compared by ANOVA complemented by the Tukey's test (p <= 0.05). The hDPSCs were able to form cell sheets only in the VC and Laser+VC groups (100%). Additionally, the cell sheets of the Laser+VC group presented easier handling...

Evolution of mammographic image quality in the state of Rio de Janeiro / A evolução da qualidade da imagem em mamografia no Estado do Rio de Janeiro

Objective: To evaluate the evolution of mammographic image quality in the state of Rio de Janeiro on the basis of parameters measured and analyzed during health surveillance inspections in the period from 2006 to 2011. Materials and Methods: Descriptive study analyzing parameters connected with imaging quality of 52 mammography apparatuses inspected at least twice with a one-year interval. Results: Amongst the 16 analyzed parameters, 7 presented more than 70% of conformity, namely: compression paddle pressure intensity (85.1%), films development (72.7%), film response (72.7%), low contrast fine detail (92.2%), tumor mass visualization (76.5%), absence of image artifacts (94.1%), mammography-specific developers availability (88.2%). On the other hand, relevant parameters were below 50% conformity, namely: monthly image quality control testing (28.8%) and high contrast details with respect to microcalcifications visualization (47.1%). Conclusion: The analysis revealed critical situations in terms of compliance with the health surveillance standards. Priority should be given to those mammography apparatuses that remained non-compliant at the second inspection performed within the one-year interval. .

Objetivo: Avaliar a evolução da qualidade da imagem de mamógrafos localizados no Estado do Rio de Janeiro, de 2006 a 2011, com base em parâmetros medidos e observados durante inspeções sanitárias. Materiais e Métodos: Estudo descritivo sobre a evolução de parâmetros que condicionam a qualidade da imagem focalizou 52 mamógrafos, inspecionados no mínimo duas vezes, com intervalo de um ano. Resultados: Dos 16 parâmetros avaliados, 7 apresentaram mais de 70% de conformidade: força do dispositivo de compressão (85,1%), processamento dos filmes (72,7%), resposta do filme do serviço (72,7%), detalhes lineares de baixo contraste (92,2%), visualização de massas tumorais (76,5%), ausência de artefatos de imagem (94,1%), existência de processadoras específicas para mamografia (88,2%). Importantes parâmetros apresentaram-se abaixo de 50% de conformidade: realização de testes mensais da qualidade de imagem pelo estabelecimento (28,8%) e detalhes de alto contraste, que dizem respeito à visualização de microcalcificações (47,1%). Conclusão: A análise revelou situações críticas da atuação da vigilância sanitária, cuja prioridade deveria ser dirigida aos estacionários, ou seja, os mamógrafos que permaneceram na situação de não conformidade nas inspeções realizadas com intervalo de um ano. .

Different Extracts of Zingiber officinale Decrease Enterococcus faecalis Infection in Galleria mellonella

Dried, fresh and glycolic extracts of Zingiber officinale were obtained to evaluate the action against G. mellonella survival assay against Enterococcus faecalis infection. Eighty larvae were divided into: 1) E. faecalis suspension (control); 2) E. faecalis + fresh extract of Z. officinale (FEO); 3) E. faecalis + dried extract of Z. officinale (DEO); 4) E. faecalis + glycolic extract of Z. officinale (GEO); 5) Phosphate buffered saline (PBS). For control group, a 5 μL inoculum of standardized suspension (107 cells/mL) of E. faecalis (ATCC 29212) was injected into the last left proleg of each larva. For the treatment groups, after E. faecalis inoculation, the extracts were also injected, but into the last right proleg. The larvae were stored at 37 °C and the number of dead larvae was recorded daily for 168 h (7 days) to analyze the survival curve. The larvae were considered dead when they did not show any movement after touching. E. faecalis infection led to the death of 85% of the larvae after 168 h. Notwithstanding, in treatment groups with association of extracts, there was an increase in the survival rates of 50% (GEO), 61% (FEO) and 66% (DEO) of the larvae. In all treatment groups, the larvae exhibited a survival increase with statistically significant difference in relation to control group (p=0.0029). There were no statistically significant differences among treatment groups with different extracts (p=0.3859). It may be concluded that the tested extracts showed antimicrobial activity against E. faecalis infection by increasing the survival of Galleria mellonella larvae.

Extratos seco, fresco e glicólico de Zingiber officinale foram obtidos para avaliar suas ações por meio de ensaio de sobrevivência em G. mellonella contra infecção por Enterococcus faecalis. Oitenta larvas foram divididas em: 1) Suspensão de E. faecalis (controle); 2) E. faecalis + extrato fresco de Z. officinale (FEO); 3) E. faecalis + extrato seco de Z. officinale (DEO); 4) E. faecalis + extrato glicólico de Z. officinale (GEO); 5) Solução tampão fosfato salina (PBS). Para o grupo de controle, 5 µL de inóculo de suspensão padronizada (107 células/mL) de E. faecalis (ATCC 29212) foi injetado na última proleg esquerda de cada lagarta. Para os grupos com tratamento, após a injeção de E. faecalis, os extratos foram injetados na última proleg direita. Após as injeções, as lagartas foram armazenadas a 37 °C e o número de animais mortos foi registrado diariamente em 168 h (7 dias) para analisar a curva de sobrevivência. As lagartas foram consideradas mortas quando elas não mostraram qualquer movimento após o toque. A infecção por E. faecalis levou à morte de 85% das lagartas após 168 h. Não obstante, nos grupos de tratamento com associação dos extratos, houve um aumento nas taxas de sobrevivência de 50% (GEO), 61% (FEO) e 66% (DEO) das lagartas. Em todos os grupos com tratamento, as lagartas apresentaram um aumento na sobrevivência, com diferença estatisticamente significativa em relação ao grupo controle (p=0,0029). Não houve diferença estatisticamente significativa entre os tratamentos com os diferentes extratos (p=0,3859). Pode concluir-se que os extratos testados mostraram atividade antimicrobiana contra a infecção por E. faecalis, aumentando a sobrevivência das lagartas de G. mellonella.

Cardiac misconceptions among healthy adults: implications for the promotion of health in the community / Crenças erróneas sobre as doenças cardíacas em adultos saudáveis: implicações para a promoção da saúde na comunidade

This study sought to confirm the structure and to investigate the psychometric properties of an experimental Portuguese version of the York Cardiac Beliefs Questionnaire (YCBQ) in a general population sample. It also set out to identify the prevalent misconceptions in the community and to assess the differences according to socio-demographic characteristics. It involved a cross-sectional survey in which both test and validation samples were collected (n = 476), including participants aged between 18 and 40, recruited via e-mail and social networks. The Confirmatory Factor Analysis on both samples suggested a shorter, three factor version of the YCBQ. Also, misconceptions differed significantly according to sociodemographic variables. The validation of the YCBQ for samples in the community constitutes an important starting point to promote research on misconceptions held in the community by specific groups, as well as to provide key points for health promotion.

Este estudo teve como objetivo confirmar a estrutura e investigar as propriedades psicométricas de uma versão experimental portuguesa do York Cardiac Beliefs Questionnaire numa amostra da população geral; identificar as crenças erróneas mais fortes na comunidade; e avaliar as diferenças de acordo com características sociodemográficas. Trata-se de um estudo transversal com uma amostra de teste e outra de validação, incluindo um total de 476 participantes, com idade entre 18 e 40 anos, recrutados via e-mail e nas redes sociais. A Análise Fatorial Confirmatória em ambas as amostras indicou uma versão reduzida do YCBQ de três factores. As crenças erróneas diferiram significativamente de acordo com as variáveis sociodemográficas. A validação do YCBQ para amostras da comunidade constitui um importante ponto de partida para promover a investigação sobre crenças erróneas em grupos específicos da comunidade, assim como fornecer indicadores relevantes para a promoção da saúde.

Incorporación de paciente virtual en portafolio de estudiantes de medicina de pregrado / Introduction of virtual patients to clinical case portfolios for undergraduate medical students

Background: In 2007, a Clinical-Case-Portfolio (CCP) was introduced as a new assessment instrument for fourth grade undergraduate medical students. Since then, several changes have been implemented such as reduction on the number of clinical cases, peer review and the introduction of virtual patient to the portfolio. Aim: To describe the virtual patient model incorporated to the CCP and assess the perception of this change and its effects on the performance of undergraduate students. Material and Methods: Virtual patients were implemented based on prototype clinical cases with specific syndromes. Students’ perceptions about CCP before and after the introduction of virtual patients were evaluated using a validated questionnaire that was answered voluntarily and anonymously. Results: Overall perception of CCP significantly improved after the incorporation of virtual patients (97.1 ± 24.9 and 111.3 ± 25.7 points; 57.8 and 66.2% respectively). The same improvements were observed for the domains “Student Learning”, “Organization and Evaluation”, “Teaching Methodology” and “Integration”. In both years, students obtained high grades in CCP evaluations. However CCP grades were not significantly correlated with integrated final grades. Conclusions: The incorporation of virtual patients improved undergraduate students’ perception of CCP.

Epilepsy-induced electrocardiographic alterations following cardiac ischemia and reperfusion in rats

The present study evaluated electrocardiographic alterations in rats with epilepsy submitted to an acute myocardial infarction (AMI) model induced by cardiac ischemia and reperfusion. Rats were randomly divided into two groups: control (n=12) and epilepsy (n=14). It was found that rats with epilepsy presented a significant reduction in atrioventricular block incidence following the ischemia and reperfusion procedure. In addition, significant alterations were observed in electrocardiogram intervals during the stabilization, ischemia, and reperfusion periods of rats with epilepsy compared to control rats. It was noted that rats with epilepsy presented a significant increase in the QRS interval during the stabilization period in relation to control rats (P<0.01). During the ischemia period, there was an increase in the QRS interval (P<0.05) and a reduction in the P wave and QT intervals (P<0.05 for both) in rats with epilepsy compared to control rats. During the reperfusion period, a significant reduction in the QT interval (P<0.01) was verified in the epilepsy group in relation to the control group. Our results indicate that rats submitted to an epilepsy model induced by pilocarpine presented electrical conductivity alterations of cardiac tissue, mainly during an AMI episode.

Total clipless cholecystectomy by means of harmonic sealing / Colecistectomia laparoscópica totalmente ultrassônica sem uso de clipe metálico

BACKGROUND: In traditional laparoscopic cholecistectomy, the cystic duct and artery are commonly closed by metallic clips just before their division. Although the placement of these clips for occluding cystic artery and duct can be considered safe, biliary leaks and bleeding may occur especially by its dislodgement. AIM: To report a prospective case-series in total clipless cholecystectomy by means of harmonic shears for closure and division of the artery and cystic duct as well removal of the gallbladder from the liver. METHODS: Was evaluate a series of 125 patients who underwent laparoscopic cholecystectomy where the sealing and division of cystic artery and duct was carried out only by harmonic shears. The intact extracted gallbladder was submitted to a reverse pressure test for assessment of the technique safety by means of CO2 insuflation. RESULTS: The most common indication for surgery was gallstones. The mean operative time was 26 min and all gallbladders were dissected intact from the liver bed. There was no mortality and the overall morbidity rate was 0.8% with no hemorrhage or leaks. The reverse pressure test showed that all specimens support at least 36-mmHg of pressure without leaking. CONCLUSION: The harmonic shears is effective and safe in laparoscopic cholecystectomy as a sole instrument for sealing and division of the artery and cystic duct. The main advantages could be related to the safety and decreased operative time. .

RACIONAL: A colecistectomia laparoscópica na técnica tradicional oclui o ducto cístico e a artéria cística por clipes cirúrgicos, que podem se deslocar ou desprender no pós-operatório, possibilitando a ocorrência de fístula biliar ou hemorragia. OBJETIVO: Relato prospectivo de série de casos de colecistectomias laparoscópicas sem uso de clipe cirúrgico, sendo que a ligadura e secção da artéria cística e do ducto cístico foram realizadas por meio de bisturi ultrassônico. MÉTODO: Foram incluídos 125 pacientes submetidos à colecistectomia laparoscópica sem utilização de clipe cirúrgico metálico, onde a ligadura da artéria e do ducto cístico e também a remoção da vesícula biliar de seu leito hepático foram realizadas por meio de tesoura ultrassônica. Realizou-se teste de pressão reversa na vesícula biliar removida intacta do leito hepático para verificar a segurança da técnica. RESULTADOS: A principal indicação cirúrgica foi a colelitíase. O tempo cirúrgico médio foi de 26 min e todas as vesículas biliares foram retiradas intactas do leito hepático. Não houve mortalidade e a taxa global de morbidade foi de 0,8%, sem hemorragias ou fístulas. O teste de pressão reversa mostrou que o ducto cístico ocluído pelo bisturi harmônico suportou ao pelo menos 36 mmHg de pressão sem que ocorresse nenhum vazamento. CONCLUSÃO: O bisturi harmônico é eficaz e seguro em colecistectomias laparoscópicas eletivas como um instrumento único para ocluir e seccionar tanto a artéria cística quanto o ducto cístico. Vantagens podem ser apontadas ao método com relação a sua segurança e diminuição do tempo cirúrgico. .

Knockdown of interleukin-10 induces the redistribution of sigma1-receptor and increases the glutamate-dependent NADPH-oxidase activity in mouse brain neurons

BACKGROUND: In the central nervous system, interleukin-10 (IL-10) provides trophic and survival effects directly on neurons, modulates neurite plasticity, and has a pivotal importance in the neuronal regeneration in neurodegenerative and neuroinflammatory conditions. This cytokine is primarily produced by glial cells and has beneficial effects on the neuronal viability. However, the mechanisms of IL-10-elicited neuroprotection are not clear. RESULTS: Membrane preparations, isolated from wild-type (Wt) and IL-10 knockout (KO) mice brain were used in this study. It has been shown that compared to wild-type mice, in IL-10 KO mice brain, the amount of immunoglobulin binding protein (BiP) is greatly increased, whereas the content of sigma receptor-1 (SigR1) is not changed significantly. Co-immunoprecipitation experiments have shown that the association of SigR1 with small GTPase Rac1 (Ras-related C3 botulinum toxin substrate 1), NR2B subunit of NMDA-receptor (NMDAR) and inositol-3-phosphate receptor (IP3R) is higher in the IL-10 KO mice brain than in the Wt mice brain. Besides, we have found that either glutamate or sigma ligands, separately or together, do not change glutamate-induced NADPH-oxidase (NOX) activity in Wt-type mice brain membrane preparations, whereas in IL-10 KO mice high concentration of glutamate markedly increases the NOX-dependent production of reactive oxygen species (ROS). Glutamate-dependent ROS production was decreased to the normal levels by the action of sigma-agonists. CONCLUSIONS: It has been concluded that IL-10 deprivation, at least in part, can lead to the induction of ER-stress, which causes BiP expression and SigR1 redistribution between components of endoplasmic reticulum (ER) and plasma membrane. Moreover, IL-10 deficiency can change the specific organization of NMDAR, increasing the surface expression of SigR1-sensitive NR2B-containing NMDAR. In these conditions, glutamate-dependent ROS production is greatly increased leading to the initiation of apoptosis. In this circumstances, sigma-ligands could play a preventive role against NMDA receptor-mediated excitotoxicity.

Mechanisms for the Defects in Phospholipid Signal Transduction in Diabetic Cardiomyopathy.

Although diabetic cardiomyopathy is associated with heart dysfunction and disturbance in cardiac sarcolemmal membrane phospholipid composition, the role of the different phospholipases and their related signaling mechanisms to altered function of the heart in diabetes is not completely understood. Thus, understanding the pathophysiology of cardiovascular abnormalities in diabetes, as well as identifying defects in various components of the phospholipid signaling pathways, that could serve as therapeutic targets, is warranted. Accordingly, this review provides an outline of the role of and the mechanisms for the defects in phospholipase A2, C and D-mediated signal transduction in the diabetic heart. In addition, the potential of different phospholipases as targets for drug development for the prevention/treatment of heart disease in diabetes is discussed.

Autonomia do graduando em enfermagem na (re)construção do conhecimento mediado pela aprendizagem baseada em problemas / Autonomy of nursing undergraduate student in the (re)construction of knowledge mediated by problem-based learning / La autonomía del estudiante de enfermería en la (re)construcción del conocimiento mediada por el aprendizaje basado en problemas

Estudo qualitativo, método Bricolagem, que objetivou analisar como a Aprendizagem Baseada em Problemas (ABP) promove o desenvolvimento da autonomia do aluno no processo de aprender a aprender. Os sujeitos foram 16 alunos e dois tutores envolvidos na disciplina. A coleta dos dados combinou entrevista semiestruturada, observação participante, registro em portfólios, fichas de avaliação, e gravação em áudio das tutorias. A análise dos dados seguiu estratégias de interpretação definidas pelas autoras: leituras iniciais e aprofundada; construção e reunião de mapas de significados; elaboração, descrição e análise de categorias empíricas, à luz do referencial teórico. A ABP favorece a (re)construção de conhecimentos pela utilização de saberes e experiências prévias, que são compartilhados no pequeno grupo; pelo processo de teorização; e pela via do conhecimento pertinente - aquele passível de aplicação à prática. Concluímos que a ABP estimula o aprendizado contínuo, desenvolvendo no aluno autonomia no processo de aprender a aprender.

This is a qualitative study, using the ‘Do it yourself’ method, which aimed to analyze how Problem-Based Learning (PBL) promotes the development of learner’s autonomy in the process of learning to learn. The subjects were 16 students and two tutors involved in the discipline. Data collection techniques combined semi-structured interviews, participant observation, log in portfolios, evaluation forms, and audio recording of the tutorials. Data analysis followed interpretation strategies defined by the authors: initial and in depth readings; construction and assembly of meanings’ maps; development, description and analysis of empirical categories, in the light of the theoretical framework. The PBL favors the (re)construction of knowledge by the use of prior knowledge and experiences that are shared in small group; through the process of theorization; and by means of relevant knowledge - one that can be applied to practice. We conclude that PBL encourages continuous learning, developing in the student the autonomy in the process of learning to learn.

Estudio cualitativo, con método Bricolage, que tuvo como objetivo analizar cómo el Aprendizaje Basado en Problemas (ABP) promueve el desarrollo de la autonomía del alumno en el proceso de aprender a aprender. Los sujetos fueron 16 alumnos y dos tutores que participan en la disciplina. Para recolección de datos se combinaran entrevistas estructuradas, observación participante, registro en portfolios, formularios de evaluación y grabación de audio de los tutoriales. El análisis de los datos siguió las estrategias de interpretación definidos por los autores: lecturas iniciales y profundadas; construcción y montaje de mapas de significados; el desarrollo, descripción y análisis de categorías empíricas, a la luz de lo referencial teórico. El ABP favorece la construcción de conocimientos mediante el uso de saberes y experiencias que se comparten en grupos pequeños, a través del proceso de teorización, y por medio de los conocimientos pertinentes - uno que se puede aplicar a la práctica. Llegamos a la conclusión que el ABP promueve el aprendizaje continuo, el desarrollo de los estudiantes, la autonomía en el proceso de aprender a aprender.

Limits and possibilities experienced by nurses in the treatment of women with chronic venous ulcers / Límites y posibilidades vividas por enfermeras en el tratamiento de mujeres con úlcera venosa crónica / Limites e possibilidades vivenciados por enfermeiras no tratamento de mulheres com úlcera venosa crônica

Objective To understand the experiences and expectations of nurses in the treatment of women with chronic venous ulcers. Method Phenomenological research was based on Alfred Schütz, whose statements were obtained in January, 2012, through semi-structured interviews with seven nurses. Results The nurse reveals the difficulties presented by the woman in performing self-care, the perceived limitations in the treatment anchored in motivation, and the values and beliefs of women. It showed professional frustration because venous leg ulcer recurrence, lack of inputs, interdisciplinary work and training of nursing staff. There was an expected adherence to the treatment of women, and it emphasized the need for ongoing care, supported self-care and standard practices in treatment. Conclusion That treatment of chronic venous leg ulcers constitutes a challenge that requires collective investment, involving women, professionals, managers and health institutions. .

Objetivo Comprender las experiencias y expectativas de enfermeras en el tratamiento de mujeres con úlcera venosa crónica. Método Investigación fenomenológica fundamentada en Alfred Schutz, que buscó Se realizó entrevista semiestructurada con siete enfermeras, en enero del 2012. Resultados La enfermera revela dificultades presentadas por la mujer para realizar el autocuidado, percibe limitaciones en el tratamiento relacionadas con la desmotivación, los valores y las creencias de las mujeres. Refiere frustración profesional debido a la recidiva de la lesión, a la falta de insumos, al deficiente trabajo interdisciplinar y a la limitada capacitación del equipo de enfermeras. Espera la adhesión de la mujer al tratamiento y resalta la necesidad del cuidado continuo, del autocuidado apoyado y de estandarizar conductas de tratamiento. Conclusión El tratamiento de la úlcera venosa crónica es un desafío que requiere contribución colectiva, involucrando a las mujeres, a los profesionales, a los gestores y a las instituciones de salud. .

Objetivo Compreender as experiências e expectativas de enfermeiras no tratamento de mulheres com úlcera venosa crônica na Atenção Primária à Saúde. Método Pesquisa fundamentada na fenomenologia social de Alfred Schütz, com depoimentos obtidos em janeiro de 2012, por meio de entrevista semiestruturada com sete enfermeiras. Resultados As enfermeiras revelam dificuldades apresentadas pelas mulheres com úlcera venosa crônica para realizar o autocuidado, percebem limitações na terapêutica ancoradas na desmotivação e nos valores e crenças das mulheres. Referem frustração profissional em razão da recidiva da lesão, falta de insumos e tecnologia, de trabalho interdisciplinar e da capacitação da equipe de enfermagem. Esperam a adesão das mulheres ao tratamento e ressaltam a necessidade do cuidado contínuo, do autocuidado apoiado e da padronização de condutas no tratamento. Conclusão O tratamento da úlcera venosa crônica constitui-se em um desafio que requer investimento coletivo, envolvendo a mulher, os profissionais, os gestores e as instituições de saúde. .

Kinetic modelling of coupled transport across biological membranes.

In this report, we have modelled a secondary active co-transporter (symport and antiport), based on the classical kinetics model. Michaelis-Menten model of enzyme kinetics for a single substrate, single intermediate enzyme catalyzed reaction was proposed more than a hundred years ago. However, no single model for the kinetics of co-transport of molecules across a membrane is available in the literature. We have made several simplifying assumptions and have followed the basic Michaelis-Menten approach. The results have been simulated using GNU Octave. The results will be useful in general kinetic simulations and modelling.

Binding chemistry and molecular heterogeneity of neurotensin binding protein(s)/receptor in adult chicken tissues.

The study focuses on the importance of Tyr11 amino acid (AA) and subsequent stereochemistry involved in the binding process of neurotensin (NT) with its receptor (NTR)/binding protein(s) as well as the size heterogeneity. Using the binding of 125I-NT with several chicken tissues, it is identified that one of the crucial factors behind all high affinity (Kd ~10 pM) interactions is due to phenolic-OH (Φ-OH) at the para (p) position of Tyr11 within RRPYIL-CO2H (NT8-13) sequence. Replacing the p-OH only in Tyr11 by substituting with p-Cl, p-F and p-NH2 results in significant change of the binding affinity (Kd); p-OH ≈ p-NH2 (~10 pM), p-Cl (~100 pM), p-F (~120 pM). Interestingly, p-NH2 equals to p-OH displaying the highest affinity. Experiments conducted by binding several of the 125I-azido–NT analogs having azido group attached at different positions within the NT molecule have further confirmed the necessity of RRPYIL sequence for high affinity ligand-receptor interaction. The role of Tryp11 in place of Tyr11 in addition to the results above establishes a significant possibility of H–bonding occurring between p-OH of NT and NTR inside the docking space. Photo labeling of the liver tissue by substituted 125I-Y3-azido-NT analogs shows several specifically labeled bands with considerable range of molecular weight (Mr ~90-30 kDa) variations. These results indicate the existence of molecular heterogeneity concerning the sizes of NTR or else any NT binding proteins in the avian tissues. Further, the study has revealed that besides liver, several other chicken tissues also express similar specific high affinity binding (Kd ~20 pM) with varying capacities (Bmax). The order for Bmax is: liver (1.2 pMol/mg) gall bladder (1.03 pMol/mg) > spleen (0.43 pMol/mg) > brain (0.3 pMol/mg) > colon lung (0.15 pMol/mg). In all cases, the binding was reduced by GTPgS (ED50 ~ 0.05 nM), NEM (ED50 ~ 0.50 mM) and NaCl (ED50 ~30 mM), indicating the existence of NTR identical to the mammalian type-1.

Interações medicamentaosas: definições e mecanismos / Drug interactions: definitions and mechanisms

Com mudanças na expectativa de vida, comorbidades edisponibilidade de novos fármacos, aumentou a ocorrênciade interações medicamentosas por mecanismos farmacocinéticose farmacodinâmicos. Para a biotransformação dosmedicamentos, os organismos desenvolveram sistemas enzimáticoscapazes de metabolizar e excretar esses produtos.Os polimorfismos genéticos dessas enzimas condicionamsua eficiência em metabolizar determinados medicamentos.A conjugação com moléculas solúveis em água, adicionadasao medicamento, facilitam sua excreção. Os transportadoresdesempenham importante papel no influxo, efluxo e na excreçãode medicamentos através dos sistemas biliar e urinário.O tratamento de doenças cardiovasculares frequentementeenvolve uso de múltiplos fármacos, principalmente nos pacientesidosos e portadores de comorbidades. Nesse sentido, éimportante o conhecimento dessas interações medicamentosas,frequentemente responsáveis pelos insucessos terapêuticos epela ocorrência de efeitos adversos...

With changes in life expectancy, co-morbidities and theavailability of new drugs, the occurrence of drug interactionsby pharmacokinetic and pharmacodynamic mechanisms hasincreased. For the bio-transformations of medications theorganisms have developed enzymatic systems able to metabolizeand excrete these products. The genetic polymorphisms ofthese enzymes affect their efficiency in metabolizing certaindrugs. The combination with water-soluble molecules addedto the medication facilitates the excretion. Transporters playan important role in the inflow, outflow and the excretion ofmedications through the biliary and urinary systems. Thetreatment of cardiovascular diseases often involves the useof multiple drugs especially in elderly patients and patientswith co-morbidities. In this sense, it is very important theknowledge about these drugs interactions which are oftenresponsible for the therapeutic failure and for the occurrenceof adverse effects...

Characterization of differentially expressed stress-associated proteins in starch granule development under heat stress in wheat (Triticum aestivum L.).

Abiotic stress causes abrupt increase in the expression of stress-associated proteins, which provide tolerance by modulating the defense mechanism of plants. Small heat shock proteins (sHSPs) and anti-oxidant enzymes are important for environmental stress tolerance of the plants. In this study, two full-length cDNAs encoding small heat shock protein (sHSP) and superoxide dismutase (SOD), designated as TasHSP and SODI were identified and characterized from C-306 (thermotolerant) and PBW343 (thermosusceptible) cultivars of wheat (Triticum aestivum L.). An alpha crystalline domain was observed in TasHSP and manganese/iron binding domain in case of SODI. Quantitative real-time PCR showed very high transcript level of TasHSP and SOD in C-306 compared to PBW343 at different stages of growth and against differential heat stress (HS). Under differential HS at milky-dough stage, the fold change in transcript of both TasHSP and SOD was observed maximum in C-306, compared to PBW343. Protein profiling and isoenzymes analysis showed the expression of several heat-stable proteins and prominent isoenzymes of SOD in C-306, compared to PBW343. Scanning electron microscopy (SEM) of starch granules showed globular, well-shaped and more numbers of endospermic cells in C-306, compared to defragmented, irregular shaped and shrunken granules in case of PBW343 under HS treatment (42°C for 2 h). Diurnal change in soluble starch synthase (SSS) activity showed an increase in the activity during afternoon (35°C), compared to morning (29°C) and evening (32°C) in both the cultivars. Under heat stress (42°C for 2 h), a drastic decrease in the SSS activity was observed, due to the thermal denaturation of the enzyme. Thermotolerance capacity analyzed using cell membrane stability (CMS) showed significantly higher CMS in case of C-306, compared to PBW343 at different stages of growth. Findings suggest that abundance of TasHSP and SODI during milky-dough stage plays a very important role in starch granule biosynthesis. The mechanism may be further exploited to develop tolerant wheat cultivar with high quality seeds.

VP22 herpes simplex virus protein can transduce proteins into stem cells

The type I herpes simplex virus VP22 tegument protein is abundant and well known for its ability to translocate proteins from one cell to the other. In spite of some reports questioning its ability to translocate proteins by attributing the results observed to fixation artifacts or simple attachment to the cell membrane, VP22 has been used to deliver several proteins into different cell types, triggering the expected cell response. However, the question of the ability of VP22 to enter stem cells has not been addressed. We investigated whether VP22 could be used as a tool to be applied in stem cell research and differentiation due to its capacity to internalize other proteins without altering the cell genome. We generated a VP22.eGFP construct to evaluate whether VP22 could be internalized and carry another protein with it into two different types of stem cells, namely adult human dental pulp stem cells and mouse embryonic stem cells. We generated a VP22.eGFP fusion protein and demonstrated that, in fact, it enters stem cells. Therefore, this system may be used as a tool to deliver various proteins into stem cells, allowing stem cell research, differentiation and the generation of induced pluripotent stem cells in the absence of genome alterations.

The signal sequence of type II porcine reproductive and respiratory syndrome virus glycoprotein 3 is sufficient for endoplasmic reticulum retention

The glycoprotein 3 (GP3) of type II porcine reproductive and respiratory syndrome virus has the characteristic domains of a membrane protein. However, this protein has been reported to be retained in the endoplasmic reticulum (ER) rather than transported to the plasma membrane of the cell. In this study, we performed confocal laser scanning microscopy analysis of variants of GP3 and foundthat the signal sequence of the GP3 led to confinement of GP3 in the ER, while the functional ortransmembrane domain did not affect its localization. Based on these results, we concludedthat the signal sequence of GP3 contains the ER retention signal, which might play an important role in assembly of viral proteins.