Disclosure via website corporativo: um exame de informações financeiras e de governança no mercado brasileiro

Este artigo objetiva analisar a relação entre a disseminação voluntária de informações relevantes nos websites de empresas abertas com suas características, tendo como amostra 282 empresas não financeiras listadas na Bovespa. Com base na relevância de informações corporativas (financeira e de governança) avaliadas pelos intermediários de informações, que embasaram a constituição de índices ponderados de disclosure, os resultados sugerem que há maior disclosure: i) quanto maior a firma e quanto maior o retorno das ações da empresa; ii) em empresas de governança corporativa diferenciada; iii) em categorias de informações corporativas mais requeridas pelas agências de ratinge pelas corretoras; iv) em empresas mais endividadas.

Beta-adrenergic blocking agents in heart failure

Cardiac dysfunction in heart failure is widely recognized as a progressive process, regardless of the clinical signs and symptoms. An increase in cardiac sympathetic drive is one of the earliest neurohormonal responses occurring in patients with heart failure and may be one of the major causes of the progressive remodeling leading to the decline in myocardial function, and responsible for the poor prognosis of patients with heart failure. Therefore, recent data provided by several appropriately designed clinical trials clearly indicate the benefits of beta-adrenoceptor blocking agents, combined with diuretics, ACE inhibitors, and digoxin in chronic heart failure class II to IV due to systolic ventricular dysfunction. The benefits are related to symptoms, functional capacity, remodeling, and improvement in left ventricular function, reduction in cardiovascular hospitalization, a decrease in the overall and sudden cardiac death rate, and are similar in patients with ischemic or nonischemic cardiomyopathy, independent of age, gender, or functional class. In this review we describe the cardiovascular effects of the increase in sympathetic drive, the pharmacological properties of the beta-blockers most evaluated in heart failure therapy (metoprolol, bisoprolol, and carvedilol), the major clinical trials related to these agents in heart failure, the recommendations for their appropriate use in clinical practice, the precautions to be adopted, and how to handle the more common adverse reactions.

Human antibody responses to Schistosoma mansoni: does antigen directed, isotype restriction result in the production of blocking antibodies?

After treatment young Kenyan schoolchildren are highly susceptible to reinfection with Schistosoma mansoni. Older children and adults are resistant to reinfection. There is no evidence that this age related resistance is due to a slow development of protective immunological mechanisms, rather, it appears that young children are susceptible because of the presence of blocking antibodies which decline with age, thus allowing the expression of protective responses. Correlations between antibody responses to different stages of the parasite life-cycle suggest that, in young children, antigen directed, isotype restriction of the response against cross-reactive polysaccharide egg antigens results in an ineffectual, or even blocking antibody response to the schistosomulum.

Transmission blocking immunity as observed in a feeder system and serological reactivity to Pfs 48/45 and Pfs230 in field sera

Monoclonal antibodies (mAbs) and human sera from gametocyte carriers were applied in the bio-assay to test for their transmission-blocking capacity. Competition ELISA's have been developed for the detection of natural transmission blocking antibodies. Approximately 55 of the sera blocking in the bio-assay gave positive results in these competition ELISA's.

Attempted isolation of the gene encoding the 21 Kd Plasmodium berghei ookinete transmission blocking antigen from Plasmodium yoelli and Plasmodium vivax

The 21kD ookinete antigen of Plasmodium berghei (Pbs 21) has been shown to elicit an effective and long lasting transmission blocking immune response in mice. Having cloned and sequenced this antigen (Paton et al. 1993) the sequence was compared to the genes of the same family previously identified in P. falciparum, P. gallinaceum (Kaslow et al. 1989) and P. reichenowi (Lal et al. 1990). Four conserved areas were identified in this comparison, to which degenerate oligonucleotides were designed. PCR amplification and screening of genomic libraries was then carried out using these oligonucleotides. The P. yoelii gene was successfully cloned and a number of novel P. vivax genes identified but the P. vivax homologue of Pbs21 remains elusive.

Transmission blocking vaccines to control insect-borne diseases: a review

Insect-borne diseases are responsible for severe mortality and morbidity worldwide. As control of insect vector populations relies primarily on the use of insecticides, the emergence of insecticide resistance as well to unintended consequences of insecticide use pose significant challenges to their continued application. Novel approaches to reduce pathogen transmission by disease vectors are been attempted, including transmission-blocking vaccines (TBVs) thought to be a feasible strategy to reduce pathogen burden in endemic areas. TBVs aim at preventing the transmission of pathogens from infected to uninfected vertebrate host by targeting molecule(s) expressed on the surface of pathogens during their developmental phase within the insect vector or by targeting molecules expressed by the vectors. For pathogen-based molecules, the majority of the TBV candidates selected as well as most of the data available regarding the effectiveness of this approach come from studies using malaria parasites. However, TBV candidates also have been identified from midgut tissues of mosquitoes and sand flies. In spite of the successes achieved in the potential application of TBVs against insect-borne diseases, many significant barriers remain. In this review, many of the TBV strategies against insect-borne pathogens and their respective ramification with regards to the immune response of the vertebrate host are discussed.

Malaria transmission blocking immunity and sexual stage vaccines for interrupting malaria transmission in Latin America

Malaria is a vector-borne disease that is considered to be one of the most serious public health problems due to its high global mortality and morbidity rates. Although multiple strategies for controlling malaria have been used, many have had limited impact due to the appearance and rapid dissemination of mosquito resistance to insecticides, parasite resistance to multiple antimalarial drug, and the lack of sustainability. Individuals in endemic areas that have been permanently exposed to the parasite develop specific immune responses capable of diminishing parasite burden and the clinical manifestations of the disease, including blocking of parasite transmission to the mosquito vector. This is referred to as transmission blocking (TB) immunity (TBI) and is mediated by specific antibodies and other factors ingested during the blood meal that inhibit parasite development in the mosquito. These antibodies recognize proteins expressed on either gametocytes or parasite stages that develop in the mosquito midgut and are considered to be potential malaria vaccine candidates. Although these candidates, collectively called TB vaccines (TBV), would not directly stop malaria from infecting individuals, but would stop transmission from infected person to non-infected person. Here, we review the progress that has been achieved in TBI studies and the development of TBV and we highlight their potential usefulness in areas of low endemicity such as Latin America.

Avaliação do website educacional em Primeiros Socorros

Avaliar a estrutura, a qualidade da informação e a navegabilidade do website em Primeiros Socorros. A avaliação foi realizada por profissionais de informática, da saúde e por estudantes, utilizando-se instrumentos específicos e validados. O método Kappa foi aplicado para avaliar a concordância das respostas e o coeficiente α de Cronbach , para avaliar a confiabilidade do instrumento. Nas respostas obtidas pelos profissionais, observou-se que não houve concordância das respostas dos profissionais de informática (0.047), indicando que a estrutura do website deve ser revisada. Na avaliação dos profissionais da saúde (-0.062), verificou-se que, apesar de não haver concordância, a qualidade da informação é adequada em razão dos escores positivos assinalados. Na avaliação da confiabilidade do instrumento de navegabilidade obteve-se α=0,974. Apesar de melhorias na estrutura do website serem indicadas, a qualidade da informação é boa e seu uso colaborou para o aprendizado dos estudantes.

Usando um website para explicar a espectrometria de ressonância ciclotrônica de íons por transformada de Fourier

This article shows the usefulness of a website to explain the concepts, operational events, vacuum system, applications and an experimental sequence of the Fourier Transform Ion Ciclotron Resonance Mass Spectrometry technique (http://143.107.46.113/icr/icrj.html).

A liquid phase blocking ELISA for the detection of antibodies against infectious bronchitis virus

A liquid phase blocking ELISA (LPB-ELISA) was developed for the detection and measurement of antibodies against infectious bronchitis virus (IBV). The purified and nonpurified virus used as antigen, the capture and detector antibodies, and the chicken hyperimmune sera were prepared and standardized for this purpose. A total of 156 sera from vaccinated and 100 from specific pathogen-free chickens with no recorded contact with the virus were tested. The respective serum titers obtained in the serum neutralization test (SNT) were compared with those obtained in the LPB-ELISA. There was a high correlation (r2 = 0.8926) between the two tests. The LPB-ELISA represents a single test suitable for the rapid detection of antibodies against bronchitis virus in chicken sera, with good sensitivity (88%), specificity (100%) and agreement (95.31%).

Effect of blocking Rac1 expression in cholangiocarcinoma QBC939 cells

Cholangiocarcinomas (CCs) are malignant tumors that originate from epithelial cells lining the biliary tree and gallbladder. Ras correlative C3 creotoxin substrate 1 (Rac1), a small guanosine triphosphatase, is a critical mediator of various aspects of endothelial cell functions. The objective of the present investigation was to study the effect of blocking Rac1 expression in CCs. Seventy-four extrahepatic CC (ECC) specimens and matched adjacent normal mucosa were obtained from the Department of Pathology, Inner Mongolia Medicine Hospital, between 2007 and 2009. Our results showed that the expression of Rac1 was significantly higher (53.12%) in tumor tissues than in normal tissues. Western blotting data indicated a significant reduction in Rac1-miRNA cell protein levels. Rac1-miRNA cell growth rate was significantly different at 24, 48, and 72 h after transfection. Flow cytometry analysis showed that Rac1-miRNA cells undergo apoptosis more effectively than control QBC939 cells. Blocking Rac1 expression by RNAi effectively inhibits the growth of CCs. miRNA silencing of the Rac1 gene suppresses proliferation and induces apoptosis of QBC939 cells. These results suggest that Rac1 may be a new gene therapy target for CC. Blocking Rac1 expression in CC cells induces apoptosis of these tumor cells and may thus represent a new therapeutic approach.

Cytogenetic and identification of the nucleolus organizer region in Heliconia bihai (L.) L.

The genus Heliconia is not much studied and the number of existing species in this genus is still uncertain. It is known that this number relies between 150 to 250 species. In Brazil, about 40 species are native and known by many different names. The objective of this paper was to characterize morphometrically and to identify the NOR (active nucleolus organizer regions) by Ag-NOR banding of chromosomes of Heliconia bihai (L) L. Root meristems were submitted to blocking treatment in an amiprofos-methyl (APM) solution, fixed in methanol-acetic acid solution for 24 hours, at least. The meristems were washed in distilled water and submitted to enzymatic digestion with pectinase enzyme. The slides were prepared by dissociation of the root meristem, dried in the air and also on hot plate at 50°C. Subsequently, some slides were submitted to 5% Giemsa stain for karyotype construction and to a solution of silver nitrate (AgNO3) 50% for Ag-NOR banding. The species H. bihai has 2n = 22 chromosomes, 4 pairs of submetacentric chromosomes and 7 pairs of metacentric chromosomes, and graded medium to short (3.96 to 0.67 μM), with the presence of active NOR in pairs 1 and 2 and interphase cells with 2 nucleoli. These are the features of a diploid species.