RESUMO
We consider unsupervised classification by means of a latent multinomial variable which categorizes a scalar response into one of the L components of a mixture model which incorporates scalar and functional covariates. This process can be thought as a hierarchical model with the first level modelling a scalar response according to a mixture of parametric distributions and the second level modelling the mixture probabilities by means of a generalized linear model with functional and scalar covariates. The traditional approach of treating functional covariates as vectors not only suffers from the curse of dimensionality, since functional covariates can be measured at very small intervals leading to a highly parametrized model, but also does not take into account the nature of the data. We use basis expansions to reduce the dimensionality and a Bayesian approach for estimating the parameters while providing predictions of the latent classification vector. The method is motivated by two data examples that are not easily handled by existing methods. The first example concerns identifying placebo responders on a clinical trial (normal mixture model) and the other predicting illness for milking cows (zero-inflated mixture of the Poisson model).
RESUMO
After the emergence of the Ceratitis capitata imago, the pale and folded wings are expanded and sclerotized to acquire the definitive form and to stabilize the cuticle. The wings of this fly show a specific pattern of brownish and black spots. Black spots are pigmented by melanin, whereas there was scarce information about the development of the brownish spots. N-beta-alanydopamine (NBAD) is the main tanning precursor in C. capitata body cuticle, and we hypothesized that it may be responsible for the colouration of the brownish spots. We determined the topology and timing of NBAD synthesis and deposition to attain the species-specific colouration pattern. We demonstrated that during the first hours the colour of the brownish spots was principally determined by the tanning of the hairs. Haemolymph circulation through the veins is required to tan the wings. We confirmed that soon after wing spreading, most of the wing epidermal cells disappeared. Thus, the tanning of the brown spots was accomplished when the wing lamina was devoid of cells. NBAD synthase (NBAD-S; Ebony protein in D. melanogaster) activity in wings was detected in pharate adults and lasted several days after the emergence, even after the end of the tanning process. This observation is in contrast to epidermal NBAD-S activity in the body, where it was nearly undetectable 48â¯h post emergence. Our results indicate that NBAD-S was exported and deposited into the extracellular matrix of the brown spot areas before cell death and that tanning occurs through gradual export of NBAD precursors (dopamine and b-alanine) from veins.
Assuntos
Ceratitis capitata/fisiologia , Proteínas de Ligação a DNA/genética , Proteínas de Insetos/genética , Pigmentação/genética , Asas de Animais/fisiologia , Animais , Ceratitis capitata/genética , Cor , Proteínas de Ligação a DNA/metabolismo , Dopamina/análogos & derivados , Dopamina/química , Dopamina/metabolismo , Proteínas de Insetos/metabolismo , beta-Alanina/metabolismoRESUMO
This report shows the biochemical characterization and life cycle-dependent expression of Drosophila melanogaster N-beta-alanyldopamine synthase (NBAD-synthase or Ebony protein). This enzyme not only catalyzes the synthesis of NBAD, the main sclerotization and pigmentation precursor of insect brown cuticles, but also plays a role in brain neurotransmitter metabolism. In addition to the epidermis expression our immunodetection experiments show the novel localization of NBAD-synthase in different regions of the adult brain, in the foregut of pharate adult and, surprisingly, in the epidermis of the trachea during embryogenesis. These results demonstrate that NBAD-synthase is a versatile enzyme involved in different, previously unknown, time- and tissue-dependent processes.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/enzimologia , Animais , Drosophila melanogaster/embriologia , Epiderme/enzimologia , Feminino , Trato Gastrointestinal/enzimologia , Imuno-Histoquímica , Estágios do Ciclo de Vida , Sistema Nervoso/enzimologia , Traqueia/enzimologiaRESUMO
Insects trigger a multifaceted innate immune response to fight microbial infections. We show that in the yellow mealworm, Tenebrio molitor, septic injuries induce the synthesis of N-beta-alanyldopamine (NBAD), which is known as the main sclerotization precursor of insect brown cuticles. We demonstrate that NBAD synthase is induced in the epidermis of the mealworm and of the Medfly, Ceratitis capitata, by infection with Escherichia coli. Our results indicate that synthesis of NBAD seems to be a novel component of the overall innate immune response in insects.
Assuntos
Ceratitis capitata/enzimologia , Ceratitis capitata/imunologia , Dopamina/análogos & derivados , Imunidade Inata/imunologia , Ligases/metabolismo , Tenebrio/enzimologia , Tenebrio/imunologia , Animais , Indução Enzimática , Epiderme/enzimologia , Escherichia coli/fisiologia , Proteínas de Insetos/metabolismo , Larva/microbiologia , Ligases/imunologia , Fatores de TempoRESUMO
BACKGROUND: Cystic Fibrosis (CF) is the most prevalent Mendelian disorder in European populations. Despite the fact that many Latin American countries have a predominant population of European-descent, CF has remained an unknown entity until recently. Argentina and Brazil have detected the first patients around three decades ago, but in most countries this disease has remained poorly documented. Recently, other countries started publishing their results. METHODS: We present a compilation and statistical analysis of the data obtained in 10 countries (Argentina, Brazil, Chile, Colombia, Costa Rica, Cuba, Ecuador, Mexico, Uruguay and Venezuela), with a total of 4354 unrelated CF chromosomes studied. RESULTS: The results show a wide distribution of 89 different mutations, with a maximum coverage of 62.8% of CF chromosomes/alleles in the patient's sample. Most of these mutations are frequent in Spain, Italy, and Portugal, consistent with the origin of the European settlers. A few African mutations are also present in those countries which were part of the slave trade. New mutations were also found, possibly originating in America. CONCLUSION: The profile of mutations in the CFTR gene, which reflects the heterogeneity of its inhabitants, shows the complexity of the molecular diagnosis of CF mutations in most of the Latin American countries.
Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/genética , Mutação/genética , África/etnologia , Fibrose Cística/epidemiologia , Fibrose Cística/etnologia , Humanos , Itália/etnologia , América Latina/epidemiologia , Polimorfismo Genético/genética , Portugal/etnologia , Espanha/etnologiaRESUMO
The authors review twelve cases of chronic hepatitis seen at the IMSS hospital in Puebla in a span of three years. They analyze and compare clinical, laboratory and biopsy data with special emphasis on the microscopic evolution of the disease and the response to different therapeutic regimes. Gamma-globulins were elevated in 80% and hepatitis B antigen in 50%. RIA is more sensitive than contra-immune electrophoresis. In six cases the diagnosis was of active chronic hepatitis and two of these developed towards cirrhosis; one became chronic persistent hepatitis and the other three are stationary and well controlled with prednisone. One patient died with a clinical picture of portal-systemic encephalitis. The six cases of persistent chronic hepatitis evolved towards a spontaneous cure.