RESUMO
The curimbatá (Prochilodus lineatus) is one of the migratory species in the Paraná River Basin impacted by the construction of dams. Mitochondrial DNA sequences and random amplified polymorphic DNA (RAPD) fragments were used to investigate genetic variability and geographic structure of five populations of curimbatá from the Paraná River Basin. A total of 1815 bp from seven polymerase chain reaction-amplified fragments representing five protein-coding mitochondrial genes were sequenced from 12 individuals. Estimates of nucleotide sequence divergence ranged from 0.00 to 0.95%. A total of 86 RAPD markers from 58 individuals were detected. Results from the Fisher exact test indicated that P. lineatus is not genetically subdivided, although significant differences in the frequencies of a few RAPD fragments were observed. This study provides useful information for stocking and management programs for resource planning of P. lineatus.
Assuntos
Caraciformes/genética , Variação Genética , Rios , Animais , Composição de Bases/genética , Pareamento de Bases/genética , Brasil , DNA Mitocondrial/genética , Geografia , Haplótipos/genética , Filogenia , Técnica de Amplificação ao Acaso de DNA PolimórficoRESUMO
Genetic variation and divergence among samples of Chilean hake Merluccius gayi, from three localities off the coast of Chile and one locality off the coast of northern Peru, were assessed using sequences from the control region of mitochondrial DNA. Homogeneity tests revealed occurrence of at least three distinct genetic stocks of M. gayi within the region sampled. Factors potentially contributing to genetic divergence among M. gayi probably include hydrodynamics and behaviour.
Assuntos
DNA Mitocondrial/genética , Gadiformes/classificação , Gadiformes/genética , Variação Genética , Animais , Chile , Genética Populacional , Haplótipos , Dados de Sequência Molecular , Peru , Especificidade da EspécieRESUMO
BACKGROUND: The use of growth hormone (GH) in deficient adults has already been demonstrated to result in several benefits regarding metabolic parameters, body composition and quality of life. Due to the similarities between GH deficiency in adults and the aging process, the concept of somatopause has emerged. OBJECTIVES: Correlate the GH secretion profile in healthy men older than 50 years with anthropometric parameters and exercise capacity. PATIENTS AND METHODS: Twenty-nine healthy male were selected, with a mean age of 57.9+/-4.2 years (range 50-66). After hospital admission, body mass index (BMI), body composition (fat mass) and abdominal circumference, 24-h GH profile, GH peak and basal IGF-I were evaluated, and all the patients underwent a treadmill stress testing to estimate exercise capacity with the Bruce protocol, with evaluation of the maximum oxygen peak, maximum heart rate and METs. All the results are shown as mean+/-Std deviation: BMI -26.5+/-4.9kg/m2, percent fat mass -27.1+/-6.2%, abdominal circumference -92.1+/-10.1cm, 24h GH profile -0.3+/-0.2ng/dl, peak GH -2.5+/-2.0ng/dl, IGF-I -202.4+/-72.4ng/dl, maximum oxygen peak -31.9+/-6.8L, maximum heart rate - 161.4+/-7.5 bpm and METs - 9.1+/-1.9. After regression analysis using the GH secretion profile (mean GH in 24h, spontaneous peak GH and basal IGF-I) as dependent variable, no correlations were found between these and the other evaluated parameters.
Assuntos
Pesos e Medidas Corporais , Tolerância ao Exercício/fisiologia , Hormônio do Crescimento/metabolismo , Fatores Etários , Idoso , Distribuição da Gordura Corporal , Índice de Massa Corporal , Teste de Esforço , Humanos , Fator de Crescimento Insulin-Like I/análise , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Pessoa de Meia-IdadeRESUMO
Genetic studies of population or 'stock' structure in exploited marine fishes typically are designed to determine whether geographic boundaries useful for conservation and management planning are identifiable. Implicit in many such studies is the notion that subpopulations or stocks, if they exist, have fixed territories with little or no gene exchange between them. Herein, we review our long-term genetic studies of red drum (Sciaenops ocellatus), an estuarine-dependent sciaenid fish in the Gulf of Mexico and western Atlantic Ocean. Significant differences in frequencies of mitochondrial DNA haplotypes and of alleles at nuclear-encoded microsatellites occur among red drum sampled across the northern Gulf of Mexico. The spatial distribution of the genetic variation, however, follows a pattern of isolation-by-distance consistent with the hypothesis that gene flow occurs among subpopulations and is an inverse (and continuous) function of geographic distance. However, successful reproduction and recruitment of red drum depend on estuarine habitats that have geographically discrete boundaries. We hypothesize that population structure in red drum follows a modified one-dimensional, linear stepping-stone model where gene exchange occurs primarily (but not exclusively) between adjacent bays and estuaries distributed linearly along the coastline. Gene flow does occur among estuaries that are not adjacent but probabilities of gene exchange decrease as a function of geographic distance. Implications of our hypothesis are discussed in terms of inferences drawn from patterns of isolation-by-distance and relative to conservation and management of estuarine-dependent species like red drum. Based on estimates of the ratio of genetic effective population size and census size in red drum, observed patterns of gene flow in red drum may play a significant role in recruitment.
Assuntos
Peixes/crescimento & desenvolvimento , Modelos Biológicos , Animais , Peixes/genética , Genética Populacional , Estágios do Ciclo de Vida , Dinâmica PopulacionalRESUMO
Allelic variation at a total of 20 nuclear-encoded microsatellites was examined among adult red snapper (Lutjanus campechanus) sampled from 4 offshore localities in the Gulf of Mexico. The number of alleles at the 20 microsatellites ranged from 5 to 20; average (+/- SE) direct count heterozygosity values ranged from 0.148 +/- 0.025 to 0.902 +/- 0.008. No significant departures from expectations of Hardy-Weinberg equilibrium were found for any locus within samples, and genotypes at pairs of microsatellites appeared to be randomly associated, i.e., in genotypic equilibrium. Tests of homogeneity in allele distributions among the 4 localities were nonsignificant for 19 of the microsatellites. Allele distribution at microsatellite Lca 43 was heterogeneous among localities before (but not after) Bonferroni corrections for multiple tests executed simultaneously. Tests of homogeneity in the distribution of individual alleles at Lca 43 gave similar results: one low frequency allele was distributed heterogeneously among samples before, but not after, Bonferroni correction. Molecular analysis of variance indicated that more than 99% of variation at each microsatellite was distributed within sample localities. These results generally are consistent with the hypothesis of a single population (stock) of red snapper in the northern Gulf of Mexico.
RESUMO
A new method is described for the determination of Ni based on the cathodic adsorptive stripping of Ni(II) complexed with hydroxynaphthol blue (HNB) at a static mercury drop electrode. Optimal conditions were found to be: accumulation potential -0.50 V (vs. Ag/AgCl); final potential -1.10 V; accumulation time 50 sec; scan rate 200 mV/sec; linear scan mode; filter 0.1 sec; supporting electrolyte acetic acid/acetate (0.25M, pH = 6.0) and concentration of HNB 3.3 x 10(-5)M. The response of the system was found to be linear in a range of Ni concentrations from 25 ppb to the detection limit. The detection limit was found to be 1.7 nM (0.10 ppb) with 2 mins of accumulation time. The effect of various potential interferences (including a variety of cations, anions and organic surfactants) were also studied. With the exception of Co, at less than equimolar concentrations no significant interferences were observed. Al was found to interfere at high concentrations with respect to Ni, but Al concentrations up to 1000 ppb may be masked by sodium citrate or sodium fluoride. The utility of the method is demonstrated by the recovery of Ni in a doped sample of commercial mineral water.
RESUMO
Variation in mitochondrial DNA (mtDNA) was examined among 86 red snapper (Lutjanus campechanus) from three geographic localities in the northern Gulf of Mexico (Gulf). A total of 29 composite mtDNA genotypes (haplotypes) was found; one haplotype occurred in 39 of 86 (45.3%) individuals assayed, and 20 haplotypes occurred in only one individual each. Tests of heterogeneity in mtDNA haplotype frequencies among localities were not significant, and there was little evidence of phylogeographic structuring of mtDNA haplotypes. These findings are consistent with the hypothesis that red snapper in the northern Gulf comprise a single, panmictic population. The observed genetic homogeneity also indicates considerable gene flow (migration) among red snapper in the northern Gulf. Significant differences in levels of intrapopulational mtDNA variation were found among localities. Levels of intrapopulational mtDNA diversity in red snapper are low relative to other marine fish species studied to date.
Assuntos
DNA Mitocondrial/química , Peixes/genética , Variação Genética , Animais , Sequência de Bases , Análise por Conglomerados , DNA Mitocondrial/isolamento & purificação , Florida , Frequência do Gene , Haplótipos , Louisiana , Dados de Sequência Molecular , Filogenia , Polimorfismo de Fragmento de Restrição , Água do Mar , TexasAssuntos
Doença de Chagas/transmissão , Reação Transfusional , Doença Aguda , Idoso , Doadores de Sangue , Bolívia/etnologia , Doença de Chagas/tratamento farmacológico , Criança , Quimioterapia Combinada , Feminino , Doença de Hodgkin/terapia , Humanos , Interferon gama/uso terapêutico , Nifurtimox/uso terapêutico , Estados UnidosRESUMO
To evaluate the pulsed Doppler cardiac output method as a noninvasive means for determining cardiac output in critically ill children, we performed paired pulsed Doppler and thermodilution cardiac output determinations in 17 critically ill children. Commercially available equipment, specifically designed for this purpose, was employed. Forty paired thermodilution and pulsed Doppler determinations were made. There was a significant correlation between the two measurements (pulsed Doppler = 0.84 thermodilution + 0.39; r = 0.79, p less than 0.01). The ranges of thermodilution measurements (1.02 to 6.26 L/min; median 2.77 L/min) and pulsed Doppler measurements (1.13 to 6.35 L/min; median 2.57 L/min) were not different (p = 0.25). However, differences between individual paired thermodilution and pulsed Doppler measurements were large (-3.13 to 2.03 L/min; median 0.12 L/min), and the percentage difference between individual paired thermodilution and pulsed Doppler measurements ranged from 0.41% to 102.5% (median 12.7%). A discrepancy of 15% or more between thermodilution and pulsed Doppler was encountered in 18 (45%) of 40 of paired measurements (95% confidence interval: 29% to 61%), and one fourth of the paired measurements differed by more than 25%. We conclude that, as employed in this study, pulsed Doppler cardiac output determination is not sufficiently representative of the thermodilution output to be employed for hemodynamic monitoring in critically ill children.
Assuntos
Débito Cardíaco , Ecocardiografia Doppler , Termodiluição , Adolescente , Cateterismo Cardíaco , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Artéria PulmonarRESUMO
Acquired immune deficiency syndrome (AIDS) is a newly described syndrome in which patients are susceptible to certain malignancies and opportunistic infections (OI) usually found only in immunosuppressed individuals. Patients with AIDS have been found to have deficiencies of virtually all of their host defense systems. In this report, the natural resistance systems have been discussed. Although a deficiency of NK-cell function has been found in many patients with AIDS, this deficiency failed to distinguish patients susceptible to OI or malignancy from male homosexual controls. A deficiency of interferon-alpha generation by mononuclear cells upon exposure to HSV-1 infected fibroblasts was the best correlate with susceptibility to OI in AIDS patients. This deficiency failed to correlate with serum levels of acid-labile interferon-alpha in these patients. Although the interferon generating deficiency may be caused by the infections in these patients, it is more likely that the deficiency lays the groundwork for the establishment of the opportunistic infections.