Functional dissection of the Drosophila Kallmann's syndrome protein DmKal-1

BACKGROUND: Anosmin-1, the protein implicated in the X-linked Kallmann's syndrome, plays a role in axon outgrowth and branching but also in epithelial morphogenesis. The molecular mechanism of its action is, however, widely unknown. Anosmin-1 is an extracellular protein which contains a cysteine-rich region, a whey acidic protein (WAP) domain homologous to some serine protease inhibitors, and four fibronectin-like type III (FnIII) repeats. Drosophila melanogaster Kal-1 (DmKal-1) has the same protein structure with minor differences, the most important of which is the presence of only two FnIII repeats and a C-terminal region showing a low similarity with the third and the fourth human FnIII repeats. We present a structure-function analysis of the different DmKal-1 domains, including a predicted heparan-sulfate binding site. RESULTS: This study was performed overexpressing wild type DmKal-1 and a series of deletion and point mutation proteins in two different tissues: the cephalopharyngeal skeleton of the embryo and the wing disc. The overexpression of DmKal-1 in the cephalopharyngeal skeleton induced dosage-sensitive structural defects, and we used these phenotypes to perform a structure-function dissection of the protein domains. The reproduction of two deletions found in Kallmann's Syndrome patients determined a complete loss of function, whereas point mutations induced only minor alterations in the activity of the protein. Overexpression of the mutant proteins in the wing disc reveals that the functional relevance of the different DmKal-1 domains is dependent on the extracellular context. CONCLUSION: We suggest that the role played by the various protein domains differs in different extracellular contexts. This might explain why the same mutation analyzed in different tissues or in different cell culture lines often gives opposite phenotypes. These analyses also suggest that the FnIII repeats have a main and specific role, while the WAP domain might have only a modulator role, strictly connected to that of the fibronectins

Assembly of Inflammation-Related Genes for Pathway-Focused Genetic Analysis

Recent identifications of associations between novel variants in inflammation-related genes and several common diseases emphasize the need for systematic evaluations of these genes in disease susceptibility. Considering that many genes are involved in the complex inflammation responses and many genetic variants in these genes have the potential to alter the functions and expression of these genes, we assembled a list of key inflammation-related genes to facilitate the identification of genetic associations of diseases with an inflammation-related etiology. We first reviewed various phases of inflammation responses, including the development of immune cells, sensing of danger, influx of cells to sites of insult, activation and functional responses of immune and non-immune cells, and resolution of the immune response. Assisted by the Ingenuity Pathway Analysis, we then identified 17 functional sub-pathways that are involved in one or multiple phases. This organization would greatly increase the chance of detecting gene-gene interactions by hierarchical clustering of genes with their functional closeness in a pathway. Finally, as an example application, we have developed tagging single nucleotide polymorphism (tSNP) arrays for populations of European and African descent to capture all the common variants of these key inflammation-related genes. Assays of these tSNPs have been designed and assembled into two Affymetrix ParAllele customized chips, one each for European (12,011 SNPs) and African (21,542 SNPs) populations. These tSNPs have greater coverage for these inflammation-related genes compared to the existing genome-wide arrays, particularly in the African population. These tSNP arrays can facilitate systematic evaluation of inflammation pathways in disease susceptibility. For additional applications, other genotyping platforms could also be employed. For existing genome-wide association data, this list of key inflammation-related genes and associated subpathways can facilitate comprehensive inflammation pathway- focused association analyses

Cobertura, foco, fatores associados à participação e vinculação à Campanha Nacional de Detecção de Diabetes em uma cidade no Sul do Brasil Coverage, focus, risk factors associated with participation, and linkage to the National Campaign for Diabetes Detection in a city in Southern Brazil

Medir cobertura, foco, fatores associados à participação e vinculação à Campanha Nacional de Detecção de Diabetes Mellitus em Pelotas, sul do Brasil. Foram entrevistadas 3.100 pessoas na zona urbana de Pelotas, em estudo transversal de base populacional. Utilizaram-se diferentes critérios para cobertura: utilização, cobertura entre usuários estimados, cobertura entre usuários declarados. O foco foi a proporção dos testes realizados em pessoas que atendiam a critérios de inclusão. As coberturas encontradas foram: utilização 45,8% (IC95%: 43,0-48,5), cobertura entre usuários estimados 37,7% (IC95%: 35,1-40,5), cobertura entre usuários declarados 38,5% (IC95%: 35,2-41,9). O foco foi de 46,5% (IC95%: 42,8-50,2). Sexo feminino, maior idade e menor escolaridade foram associados com aderência à campanha. Dentre aqueles com rastreamento positivo e sem diagnóstico prévio, 42,4% foram mais tarde vistos por médico e metade confirmou diagnóstico. A campanha teve baixa cobertura e foi pouco focalizada. Esforços devem ser concentrados em melhor atendimento aos já diagnosticados, vinculando-os aos serviços através de oferta regular de medicações e estratégias educativas.<br>The objective of this study was to measure coverage, focus, factors associated with participation, and linkage to the National Campaign for the Detection of Diabetes Mellitus in Pelotas, Southern Brazil. 3,100 individuals living within the city limits of Pelotas were interviewed in a cross-sectional study. Coverage was calculated based on different criteria: utilization, coverage among estimated users, and coverage among self-declared users. The focus was the proportion of tests performed in individuals who had met the inclusion criteria. Coverage rates were: utilization, 45.8% (95%CI: 43.0-48.5), among estimated users, 37.7% (95%CI: 35.1-40.5), and among self-declared users, 38.5% (95%CI: 35.2-41.9). Focus was 46.5% (95%CI: 42.8-50.2). Female gender, older age, and lower schooling were associated with adherence to the campaign. A total of 42.4% of individuals with positive screening tests but without prior diagnoses were subsequently examined by physicians, and half of the diagnoses were confirmed. The campaign showed a low coverage and poor focus. Efforts should be concentrated on improving care for individuals who have already been diagnosed, linking them to services by offering regular medication and educational strategies

Hospitalizations during infancy in three population-based studies in Southern Brazil: trends and differentials

Three cohort studies of children born in the urban area of Pelotas, Southern Brazil, were carried out in 1982, 1993, and 2004. The aim of these studies was to measure the occurrence of hospitalization in the first year of life and to examine the association between hospitalization and the cause of admission and sex, birth weight, and family income. Cause of admission was categorized as “diarrhea” and “all other causes”. The frequency of children hospitalized at least once during their first year of life was 19.6% in 1982, 18.1% in 1993, and 19.2% in 2004. There was a marked reduction in hospitalizations due to diarrhea, but the frequency of hospitalization for all causes remained constant. In all three cohorts, infants from poorer families and those born weighing under 2,000g showed the highest frequencies of hospitalization due to diarrhea and all other causes, and the latter also showed a marked increase in hospitalizations due to all causes. These findings could be explained by an epidemic of preterm births in the study population.Foram organizadas três coortes de crianças nascidas na área urbana de Pelotas, Rio Grande do Sul, em 1982, 1993 e 2004. O presente estudo teve como objetivos medir a ocorrência de hospitalização no primeiro ano de vida e estudar a associação entre hospitalização e causa de internação e sexo, peso ao nascer e renda familiar. As causas de internação eram categorizadas como “diarréia” e “todas as outras causas”. As proporções de crianças hospitalizadas pelo menos uma vez durante o primeiro de ano de vida foram 19,6% em 1982, 18,1% em 1993 e 19,2% em 2004. Houve uma redução marcante nas internações por diarréia, enquanto permanecia constante a freqüência de internações por todas as causas. Nas três coortes, as crianças de famílias mais pobres e aquelas que nasceram com peso abaixo de 2000g mostraram as freqüências mais elevadas de internações por diarréia e por todas as outras causas, e a coorte de 2004 também mostrou um aumento marcante nas internações por todas as causas. Os achados podem ser explicados por uma epidemia de nascimentos prematuros na população estudada