Ecological aspects of Rhodnius nasutus Stål, 1859 (Hemiptera: Reduviidae: Triatominae) in palms of the Chapada do Araripe in Ceará, Brazil

The aim of this work is to present aspects related to the ecology of Rhodnius nasutus Stål, 1859 in palms from Chapada do Araripe in Ceará, Brazil. The following five species of palms were investigated: babaçu (Attalea speciosa), buriti (Mauritia flexuosa), carnaúba (Copernicia prunifera), catolé (Syagrus oleracea) and macaúba-barriguda (Acrocomia intumescens). Fifth palms were dissected (10 specimens for each species). The overall infestation index was 86%, with a total of 521 triatomines collected. The Trypanosoma cruzi Chagas, 1909 Index was 16.8% and two insects presented mixed infection with Trypanosoma rangeli Tejera, 1920. A precipitin test showed that R. nasutus from palms of Chapada do Araripe are associated with opossum and bird although other possible bloodmeals were observed. Our results showing a high index of infestation of the palms as well as T. cruzi infection, the association of R. nasutus with the most diverse species of palms and proximity of these palms to houses demonstrate the importance of this area for sylvatic T. cruzi transmission and suggest the need for epidemiological surveillance in the region of the Chapada do Araripe.

Acute acquired toxoplasmosis: clinical-laboratorial aspects and ophthalmologic evaluation in a cohort of immunocompetent patients

Most cases of acute acquired toxoplasmosis (AAT) are oligosymptomatic and self-limited. Therefore, these infections rarely indicate treatment. Prospective studies of AAT patients are rare in the medical literature. The frequency of systemic manifestations has not been sufficiently studied. In order to search for risks factors for systemic and ocular involvement, 37 patients were submitted to a diagnostic investigative protocol. The most frequent findings were lymph node enlargement (94.6%), asthenia (86.5%), headache (70.3%), fever (67.6%) and weight loss (62.2%). Hepatomegaly and/or splenomegaly were present in 21.6% of cases (8/37). Liver transaminases were elevated in 11 patients (29.7%) and lactic dehydrogenase in 17 patients (45.9%). Anaemia was found in four patients (10.8%), leucopoenia in six patients (16.2%), lymphocytosis in 14 patients (37.8%) and thrombocytopenia in one patient (2.7%). Fundoscopic examination revealed retinochoroiditis in four patients (10.8%). No statistical association was found between any one morbidity and retinochoroiditis. Nevertheless, a significant association was found between the presence of more than eight morbidity features at evaluation and long-lasting disease. An ideal diagnostic protocol for AAT would include evidence of systemic involvement. Such a protocol could be used when planning treatment.

Proven and putative vectors of American cutaneous leishmaniasis in Brazil: aspects of their biology and vectorial competence

The aim of the present review is to give relevant information on aspects of the biology and ecology, including the vectorial competence of Lutzomyia sand fly species suggested as vectors of American cutaneous leishmaniasis in Brazil. The disease, due to Leishmania (Viannia) braziliensis, has been registered in most municipalities in all the Brazilian states and its transmission is associated with more than one sand fly species in each geographical region. A variety of Leishmania species can be found in the Amazon basin, where different epidemiological chains have been detected with the participation of different phlebotomine vectors. Finally, a discussion is presented on some sand fly species found naturally infected by Leishmania, but for which there is as yet no evidence regarding their epidemiological importance.

A new approach for potential drug target discovery through in silico metabolic pathway analysis using Trypanosoma cruzi genome information

The current drug options for the treatment of chronic Chagas disease have not been sufficient and high hopes have been placed on the use of genomic data from the human parasite Trypanosoma cruzi to identify new drug targets and develop appropriate treatments for both acute and chronic Chagas disease. However, the lack of a complete assembly of the genomic sequence and the presence of many predicted proteins with unknown or unsure functions has hampered our complete view of the parasite's metabolic pathways. Moreover, pinpointing new drug targets has proven to be more complex than anticipated and has revealed large holes in our understanding of metabolic pathways and their integrated regulation, not only for this parasite, but for many other similar pathogens. Using an in silicocomparative study on pathway annotation and searching for analogous and specific enzymes, we have been able to predict a considerable number of additional enzymatic functions in T. cruzi. Here we focus on the energetic pathways, such as glycolysis, the pentose phosphate shunt, the Krebs cycle and lipid metabolism. We point out many enzymes that are analogous to those of the human host, which could be potential new therapeutic targets.

Chagas disease, adipose tissue and the metabolic syndrome

Trypanosoma cruzi infection of the adipose tissue of mice triggers the local expression of inflammatory mediators and a reduction in the expression of the adipokine adiponectin. T. cruzi can be detected in adipose tissue by PCR 300 days post-infection. Infection of cultured adipocytes results in increased expression of cytokines and chemokines and a reduction in the expression of adiponectin and the peroxisome proliferator-activated receptor ³, both of which are negative regulators of inflammation. Infection also results in the upregulation of cyclin D1, the Notch pathway, and extracellular signal-regulated kinase and a reduction in the expression of caveolin-1. Thus, T. cruzi infection of cultured adipocytes leads to an upregulation of the inflammatory process. Since adiponectin null mice have a cardiomyopathic phenotype, it is possible that the reduction in adiponectin contributes to the pathogenesis of chagasic cardiomyopathy. Adipose tissue may serve as a reservoir for T. cruzi from which parasites can become reactivated during periods of immunosuppression. T. cruzi infection of mice often results in hypoglycemia. In contrast, hyperglycemia as observed in diabetes results in increased parasitemia and mortality. Adipose tissue is an important target tissue of T. cruzi and the infection of this tissue is associated with a profound impact on systemic metabolism, increasing the risk of metabolic syndrome.

Culex quinquefasciatus vitellogenesis: morphological and biochemical aspects

The vitellogenic process in Culex quinquefasciatus, which is triggered by a blood meal, involves the synthesis, distribution and storage of the nutrients necessary for embryo development. The fat body of an adult female Cx. quinquefasciatus revealed two cell types: large trophocytes and small, eosinophilic, "oenocyte-like" cells, which show no morphological changes throughout the gonotrophic cycle. Trophocytes, which only begin to synthesise vitellogenin (Vg) 12 h post-blood meal (PBM), undergo a series of morphological changes following engorgement. These changes include the expansion of the rough endoplasmic reticulum (RER) and Golgi complex, which are later destroyed by autophagosomes. At 84 h PBM, trophocytes return to their pre-engorgement morphology. The ovarian follicles of non-blood-fed Cx. quinquefasciatus contain a cluster of eight undifferentiated cells surrounded by follicular epithelium. After engorgement, the oocyte membrane facing the perioocytic space increases its absorptive surface by microvilli development; large amounts of Vg and lipids are stored between 24 and 48 h PBM. Along with yolk storage in the oocyte, follicular cells exhibit the development of RER cisternae and electron-dense granules begin to fill the perioocytic space, possibly giving rise to endochorion. Later in the gonotrophic cycle, electron-dense vesicles, which are possible exochorion precursors, fuse at the apical membrane of follicular cells. This fusion is followed by follicular cell degeneration.

Biological and genetic aspects of crosses between species of the genus Meccus (Hemiptera: Reduviidae Triatominae)

The degree of reproductive isolation between Meccus phyllosomus and the remaining five species of the genus Meccus, as well as between Meccus bassolsae and Meccus pallidipennis, Meccus longipennis and Meccus picturatus, was examined. Fertility and the segregation of morphological characteristics were examined in two generations of hybrids from crosses between these species. The percentage of couples with offspring (fertile) was high in the vast majority of sets of crosses, with the exception of that between ♀M. phyllosomus and ♂Meccus mazzottii. In sets of crosses involving M. bassolsae specimens, no first-generation (F1) individuals were morphologically similar to M. bassolsae, but instead shared the morphology of the other parental species. A similar phenomenon was observed in most sets of crosses involving M. phyllosomus. These results indicated that different degrees of reproductive isolation exist among the species of Meccus involved in this study. The biological evidence obtained in this study does not support the proposal that M. bassolsae is a full species. It could indicate that, on the contrary, it should be considered a subspecies of a single polytypic species. The biological evidence does support the proposal that M. phyllosomus is a full species.

The classification of esterases: an important gene family involved in insecticide resistance - A review

The use of chemical insecticides continues to play a major role in the control of disease vector populations, which is leading to the global dissemination of insecticide resistance. A greater capacity to detoxify insecticides, due to an increase in the expression or activity of three major enzyme families, also known as metabolic resistance, is one major resistance mechanisms. The esterase family of enzymes hydrolyse ester bonds, which are present in a wide range of insecticides; therefore, these enzymes may be involved in resistance to the main chemicals employed in control programs. Historically, insecticide resistance has driven research on insect esterases and schemes for their classification. Currently, several different nomenclatures are used to describe the esterases of distinct species and a universal standard classification does not exist. The esterase gene family appears to be rapidly evolving and each insect species has a unique complement of detoxification genes with only a few orthologues across species. The examples listed in this review cover different aspects of their biochemical nature. However, they do not appear to contribute to reliably distinguish among the different resistance mechanisms. Presently, the phylogenetic criterion appears to be the best one for esterase classification. Joint genomic, biochemical and microarray studies will help unravel the classification of this complex gene family.

Biogeographical aspects of the occurrence of Nyssomyia neivai and Nyssomyia intermedia (Diptera: Psychodidae) in a sympatric area of the Brazilian savannah

Nyssomyia intermedia and Nyssomyia neivai constitute a species complex associated with Leishmania transmission. The aim of this study was to analyse the ecological profiles of the Ny. intermedia and Ny. neivai populations in a sympatric area in the Brazilian savannah along the banks of the Velhas River. Captures were performed from July 2003-June 2005 in two distinct environments: a gallery forest with various degrees of anthropogenic modification and animal shelters. A total of 20,508 Ny. neivai (86%) and Ny. intermedia (14%) sandflies were collected. The difference between the proportions of the sandflies that were collected (Ny. neivai/Ny. intermedia) per bank was significant. The right bank presented a greater number of sandflies (65%) and more preserved vegetation. The abundance of Ny. neivai was higher than that of Ny. intermedia on both banks. The results demonstrate that anthropic activities can affect the sandfly populations in this area, thereby leading to a reduction in species abundance. Nevertheless, the environments with higher levels of antropogenic modification displayed sandfly population numbers that favour the Leishmania transmission cycle.

Historic aspects of human susceptibility to leprosy and the risk of conjugal transmission

Estimates of genetic susceptibility to leprosy were made in the past from observational reports in familial settings using descriptive epidemiologic data. Risk of conjugal transmission of leprosy (from one spouse to another) has been estimated between 1-10% and is thought to occur in 3-5% of spouses exposed to untreated lepromatous disease in the partner. Risk of secondary transmission is presumed higher in other family members than for the conjugal partner. This belief has become dogma to many leprologists who may no longer know the basis for this estimation. This article reviews the historic epidemiologic descriptions of risk for leprosy transmission in married couples compared to other family members. Although uncommon, conjugal leprosy occurs and at higher rates in populations with traditional familial intermarriage and consanguinity.

Epidemiological aspects of influenza A related to climatic conditions during and after a pandemic period in the city of Salvador, northeastern Brazil

During the influenza pandemic of 2009, the A(H1N1)pdm09, A/H3N2 seasonal and influenza B viruses were observed to be co-circulating with other respiratory viruses. To observe the epidemiological pattern of the influenza virus between May 2009-August 2011, 467 nasopharyngeal aspirates were collected from children less than five years of age in the city of Salvador. In addition, data on weather conditions were obtained. Indirect immunofluorescence, real-time transcription reverse polymerase chain reaction (RT-PCR), and sequencing assays were performed for influenza virus detection. Of all 467 samples, 34 (7%) specimens were positive for influenza A and of these, viral characterisation identified Flu A/H3N2 in 25/34 (74%) and A(H1N1)pdm09 in 9/34 (26%). Influenza B accounted for a small proportion (0.8%) and the other respiratory viruses for 27.2% (127/467). No deaths were registered and no pattern of seasonality or expected climatic conditions could be established. These observations are important for predicting the evolution of epidemics and in implementing future anti-pandemic measures.

Evaluation of oxidative stress parameters and metabolic activities of nurses working day and night shifts

The aim of this study was to evaluate the oxidative stress and metabolic activities of nurses working day and night shifts. Intensive care unit (ICU) (n=70) and ordinary service (OS) nurses (n=70) were enrolled in the study. Just before and the end of the shifts, blood samples were obtained to measure the participants' oxidative stress parameters. Metabolic activities were analyzed using the SenseWear Armband. Oxidative stress parameters were increased at the end of the shifts for all OS and ICU nurses compared to the beginning of the shifts. Compared to the OS nurses, the ICU nurses' TAS, TOS, and OSI levels were not significantly different at the end of the day and night shifts. The metabolic activities of the OS and ICU nurses were found to be similar. As a result, the OS and ICU nurses' oxidative stress parameters and metabolic activities were not different, and all of the nurses experienced similar effects from both the day and night shifts.

The discourse of health managers on aspects related to the delay in tuberculosis diagnosis

The aim of this study was to analyze the discourse of health managers on aspects related to delay in tuberculosis diagnosis. This was a qualitative research study, conducted with 16 Family Health Unit managers. The empirical data were obtained through semi-structured interviews. The analysis was based on the theoretical framework of the French school of discourse analysis. According to the managers’ statements, the delay in tuberculosis diagnosis is related to patient and health service aspects. As for patient aspects, managers report fear, prejudice and lack of information as factors that may promote a delayed diagnosis. Regarding health service aspects, structural problems and lack of professional skills were reported. The discourse of managers should be considered to qualify tuberculosis control actions and to prevent delays in diagnosis.

Instrumental and ethical aspects of experimental research with animal models

Experimental animal models offer possibilities of physiology knowledge, pathogenesis of disease and action of drugs that are directly related to quality nursing care. This integrative review describes the current state of the instrumental and ethical aspects of experimental research with animal models, including the main recommendations of ethics committees that focus on animal welfare and raises questions about the impact of their findings in nursing care. Data show that, in Brazil, the progress in ethics for the use of animals for scientific purposes was consolidated with Law No. 11.794/2008 establishing ethical procedures, attending health, genetic and experimental parameters. The application of ethics in handling of animals for scientific and educational purposes and obtaining consistent and quality data brings unquestionable contributions to the nurse, as they offer subsidies to relate pathophysiological mechanisms and the clinical aspect on the patient.