A Confidence Interval for the Wallace Coefficient of Concordance and Its Application to Microbial Typing Methods

Very diverse research fields frequently deal with the analysis of multiple clustering results, which should imply an objective detection of overlaps and divergences between the formed groupings. The congruence between these multiple results can be quantified by clustering comparison measures such as the Wallace coefficient (W). Since the measured congruence is dependent on the particular sample taken from the population, there is variability in the estimated values relatively to those of the true population. In the present work we propose the use of a confidence interval (CI) to account for this variability when W is used. The CI analytical formula is derived assuming a Gaussian sampling distribution and recurring to the algebraic relationship between W and the Simpson's index of diversity. This relationship also allows the estimation of the expected Wallace value under the assumption of independence of classifications. We evaluated the CI performance using simulated and published microbial typing data sets. The simulations showed that the CI has the desired 95% coverage when the W is greater than 0.5. This behaviour is robust to changes in cluster number, cluster size distributions and sample size. The analysis of the published data sets demonstrated the usefulness of the new CI by objectively validating some of the previous interpretations, while showing that other conclusions lacked statistical support

Synthesis of fluorescent heteroaromatic compounds using dehydroamino acids as building blocks, studies of DNA and biomembranes interactions : evaluation of antiproliferative effects on tumor cell lines

Thanks are due to the Fundação para a Ciência e Tecnologia (FCT, Portugal) and FEDER to financial support through the research centres, the research project POCI/59407/2004 and pos-Doc grants attributed to A.S.Abreu (SFRH/BPD/24548/2005) and to L.V.-S. (SFRH/BPD/29112/2006)

Planting time for maximization of yield of vinegar plant calyx (Hibiscus sabdariffa L.)

Objetivou-se avaliar a produtividade de cálices de Hibiscus sabdariffa L., planta medicinal, em quatro épocas de plantio em Lavras M.G. Os tratamentos foram quatro épocas de plantio (18 de outubro; 15 de novembro; 18 de dezembro de 2001 e 15 de janeiro de 2002) e realizada uma colheita quando praticamente não existiam cálices em desenvolvimento, quase no final do ciclo da planta. Foram considerados os números de cálices por planta, as fitomassas frescas e secas dos cálices e a qualidade. Concluiu-se que a época de plantio influenciou o rendimento por planta e as fitomassas frescas e secas dos cálices, diferindo entre si pelo teste de Tukey a 5%. No plantio de outubro, houve maior rendimento (2.522 kg/ha), com produção de 5,24 vezes a mais em relação ao plantio do mês de janeiro (481 kg/ha). Os plantios nos meses de novembro e dezembro tiveram produções de 1.695 e 1.093 kg.ha-1 de cálices secos, respectivamente, e em relação ao mês de janeiro, a produção foi 3,52 e 2,27 vezes a mais.Deve-se realizar a colheita assim que os cálices estiverem maduros, a fim de preservar a qualidade

Smoking-induced aggravation of experimental arthritis is dependent of aryl hydrocarbon receptor activation in Th17 cells.

Background: Epidemiologic studies have highlighted the association of environmental factors with the development and progression of autoimmune and chronic inflammatory diseases. Among the environmental factors, smoking has been associated with increased susceptibility and poor prognosis in rheumatoid arthritis (RA). However, the immune and molecular mechanism of smoking-induced arthritis aggravation remains unclear. The transcription factor aryl hydrocarbon receptor (AHR) regulates the generation of Th17 cells, CD4 T cells linked the development of autoimmune diseases. AHR is activated by organic compounds including polycyclic aromatic hydrocarbons (PAHs), which are environmental pollutants that are also present in cigarette smoke. In this study, we investigated the role of AHR activation in the aggravation of experiment arthritis induced by exposure to cigarette smoke. Methods: Mice were exposed to cigarette smoke during the developmental phase of antigen-induced arthritis and collagen-induced arthritis to evaluate the effects of smoking on disease development. Aggravation of articular inflammation was assessed by measuring neutrophil migration to the joints, increase in articular hyperalgesia and changes in the frequencies of Th17 cells. In vitro studies were performed to evaluate the direct effects of cigarette smoke and PAH on Th17 differentiation. We also used mice genetically deficient for AHR (Ahr KO) and IL-17Ra (Il17ra KO) to determine the in vivo mechanism of smoking-induced arthritis aggravation. Results: We found that smoking induces arthritis aggravation and increase in the frequencies of Th17 cells. The absence of IL-17 signaling (Il17ra KO) conferred protection to smoking-induced arthritis aggravation. Moreover, in vitro experiments showed that cigarette smoke can directly increase Th17 differentiation of T cells by inducing AHR activation. Indeed, Ahr KO mice were protected from cigarette smoke-induced arthritis aggravation and did not display increase in TH17 frequencies, suggesting that AHR activation is an important mechanism for cigarette smoke effects on arthritis. Finally, we demonstrate that PAHs are also able to induce arthritis aggravation. Conclusions: Our data demonstrate that the disease-exacerbating effects of cigarette smoking are AHR dependent and environmental pollutants with AHR agonist activity can induce arthritis aggravation by directly enhancing Th17 cell development

Avaliação da Vergonha em Adolescentes: ‘The Other as Shamer Scale’

Shame, as a self-conscious, multidimensional and socially focused emotion, plays a central role in the mental health of individuals. In adolescents, shame is also a frequent experience and its assessment is important for research and clinical practice. This study aims to validate a brief measure of external shame (Other as Shamer Scale – brief version for adolescents: (OASB-A). The participants were 834 adolescents with a mean age of 15 years. The final model of the OASB-A (8 items), obtained through CFA, presents a good fit to the data. The OASB-A shows a good internal consistency and an adequate temporal reliability. The OASB-A also reveals significant correlations with traumatic shame experiences (IES-R) and psychopathological symptoms (DASS-21). The OASB-A is an economic and reliable measure to assess external shame in adolescents

Fatores associados à insuficiência renal aguda pós-transplante hepático

OBJECTIVE: To evaluate the prevalence and the risk factors associated to the development of acute renal failure in patients submitted to liver transplant, at Hospitalde Clínicas de Porto Alegre from September 1996 to September 1998.PATIENTS AND METHODS: 36 patients that developed acute renal failure after liver transplant (group 1) were compared to those who did not develop acute renalfailure after liver transplant (group 2). The following factors were analyzed prior to surgery: etiology of the renal failure, classification of Child-Pugh, diabetes mellitus,and creatinine levels; during surgery: duration of warm ischemia, duration of surgery, duration of anesthesia; CHAD type of portocaval anastomosis; and after surgery: creatinine levels, infections, need for dialysis, duration of stay at the intensive care unit, cyclosporine levels, need for another intervention, and mortality. All data were evaluated during the first 7 days after surgery, with the exception of chronic renal failure and mortality, which were evaluated during a 3-month period.RESULTS: The prevalence of acute renal failure was high (approximately 49%). The presence of previous diabetes mellitus (P=0.03), the CHAD units used duringsurgery (P=0.046), the duration of stay at the intensive care unit (P=0.01), the surgical technique (P=0,04), and the need for another intervention (P=0.02), were allsignificantly associated to the development of acute renal failure after liver transplant in our sample. There was a significant level of mortality among patients that developed acute renal failure (P=0.02).CONCLUSIONS: We concluded that acute renal failure is a significant cause of mortality among patients submitted to hepatic transplant when associated to multiplerisk factors. OBJETIVO: A prevalência e os fatores de risco associados ao desenvolvimento de IRA nos pacientes submetidos a transplante no Hospital de Clínicas de Porto Älegre (HCPA) no período de setembro/96 a setembro/98.PACIENTES E MÉTODOS: Foram comparados os pacientes que desenvolveram IRA (grupo 1) com os que não desenvolveram (grupo 2). Foram analisados no préoperatório: etiologia da isuficiência hepática, classificação de Child-Pugh, diabete melito (DM) e nível de creatinina; no trans-operatório: tempo de isquemia quente, tempo cirúrgico, tempo de anestesia, unidades de concentrado de hemácias (CHAD), tipo de anastomose porto-cava; e no pós-operatório: níveis de creatinina, infecções, necessidades de diálise, permanência na unidade de tratamento intensivo (UTI), níveis de ciclosporina, reintervenções e mortalidade. Todos os dados foram avaliados nos primeiros 7 dias de pós-operatório, com exceção de insuficiência renal crônica e mortalidade avaliados por 3 meses.RESULTADOS: A prevalência de IRA foi elevada, sendo de aproximadamente 49%. Verificamos que a presença de DM prévia (P = 0,03), unidades de CHAD utilizados no trans-operatório (p = 0,046), o tempo de internação na UTI (P = 0,001), técnica cirúrgica (P = 0,04) e necessidade de reintervenção cirúrgica (P = 0,02) estiveram associados significativamente com o desenvolvimento de IRA no pós-operatório de TxH em nossa amostra. Os pacientes que desenvolveram IRA apresentaram uma significativa mortalidade (P = 0,02). Concluímos que a IRA é uma causa significativa de mortalidade nos pacientes submetidos à transplante hepático estando associada a múltiplos fatores de risco