ABSTRACT
Objetivou-se com este trabalho estimar as herdabilidades (h²) e as correlações genéticas (r g) entre idade ao primeiro parto (IPP) e primeiro intervalo de partos (PIEP) e outras características como peso (PS) ao ano (A) e ao sobreano (S), altura do posterior (ALT) e perímetro escrotal (PE450) em animais da raça Nelore. Os parâmetros genéticos foram estimados em uma análise multicaracterística por modelo animal, utilizando-se a inferência bayesiana via algoritmo de "Gibbs Sampling". Os parâmetros genéticos estimados sugerem a existência de variabilidade genética para IPP (h² = 0,26), sendo que a seleção para a diminuição da IPP de fêmeas Nelore deve responder à seleção individual, sem causar antagonismo do valor genético dos animais para PS (r g = -0,22 (A) e -0,44 (S)) e PE450 (r g = 0,02). A seleção para a diminuição da IPP, no longo prazo, pode levar a um aumento da ALT dos animais, embora essa associação seja relativamente baixa (-0,35). A estimativa de herdabilidade a posteriori para a característica PIEP foi baixa, 0,11±0,03. As r g entre PIEP e as demais características estudadas indicam que a seleção para essas características de crescimento não afetará o PIEP.
Heritability (h²) and genetic correlations (r g) were estimated between reproductive traits such as age at first calving (AFC), first calving interval (FCI) and other economically relevant traits, i.e., weight (W) at year (Y) and at 18 months of age (S), scrotal circumference (SC), and hip height (HH) in Nelore cattle. The genetic parameters were estimated in a multiple-trait analysis, with animal models using the Bayesian inference by Gibbs Sampling algorithm. The genetic parameters estimated in this work suggest the existence of genetic variability for AFC (h² = 0.26), where the selection for the reduction of Nelore females AFC should respond to mass selection, without causing genetic antagonism in the selection of W (r g = -0,22 (Y) and -0,44 (S)), and SC (r g = 0,02). The selection for the AFC in the long term could lead to an increase in the animal's frame, although this association is relatively low (-0.35). The posteriori heritability estimate for FCI was low, 0.11±0.03. The r g between FCI and the other traits studied indicate that selection for these growth traits will not affect the FCI.
ABSTRACT
Introduction: Rotavirus is the most common cause of severe gastroenteritis in infants and young children worldwide. The aim of the study was to determine rotavirus disease burden and distribution of rotavirus genotypes in children less than five years of age. Methodology: Stool samples were collected from 1768 hospital admitted children under 5 years of age with acute watery diarrhea during November 2005 to October 2008. Rotavirus in stool samples was detected by Enzyme Immuno Assay (EIA) and positive specimens for rotavirus positive was genotyped by reverse transcription-polymerase chain reaction (RTPCR) and sequencing methods. Results: The prevalence of rotavirus was 36.59% (647/1768). Detection was higher in male (33.3%) than female (26.9%). The prevalence was higher during the month of January (2005-06) and February in other periods. During 2005-06, high prevalence of rotavirus was noted in children of age between 6-11 months while in 2006-07 and 2007-08 high prevalence was seen in age group 12-23 months. The most common genotyping of rotavirus identified 5 G types and 3 P types. Genotypes G12 and P [8] were most common during both periods studied (G12; 50%, 29% 33.7% in 2005-06, 2006-07 and 2007-08 respectively and P[8]; 47%, 35% and 43.5% in 2005-06, 2006-07 and 2007-08 respectively). Among six combined genotypes, G12P [6] was most prevalent (34%, 24% and 47.5% in 2005-06, 2006-07 and 2007-08 respectively) where as G1P [6] (4%) was seen in year 2007- 08 only. Conclusions: The study demonstrates the burden of rotavirus diarrhea in Nepal. The data on rotavirus genotypes will help inform decisions as to whether rotavirus vaccine should be considered for inclusion in to Nepal’s National Immunization Program.
ABSTRACT
Renal involvement in visceral leishmaniasis (VL) is very frequent but the pathogenesis of this nephropathy is poorly understood. In previous studies using dogs with VL we have detected new immunopathological elements in the glomeruli such as T cells and adhesion molecules. Although Leishmania (Leishmania) chagasi-infected dogs and hamsters are considered to be good models for VL, their use is limited for immunopathologic studies. The use of isogenic mouse strains susceptible to L. (L.) chagasi infection was an alternative but, on the other hand, the renal lesions of these animals have not yet been characterized. Thus, our purpose in the present study was to characterize mice infected with L. (L.) chagasi as a suitable model to study VL nephropathy. Kidney samples were obtained from control mice (N = 12) and from BALB/c mice (N = 24) injected intraperitoneally with 20 million L. (L.) chagasi amastigotes 7, 15, and 30 days after injection and processed for histopathological studies and detection of IgG deposits. Glomerular hypercellularity was clearly visible and, upon Mason's trichrome and periodic acid methenamine silver staining, a pattern suggestive of mesangial proliferative glomerulonephritis was observed in mice with VL. Time-dependent IgG deposits were also seen in infected mice. We consider L. (L.) chagasi-infected mice to be a suitable model for studies of the immunopathogenesis of glomerular lesions in VL.
Subject(s)
Animals , Male , Mice , Disease Models, Animal , Glomerular Mesangium/pathology , Glomerulonephritis/pathology , Leishmania infantum , Leishmaniasis, Visceral/pathology , Glomerulonephritis/parasitology , Leishmaniasis, Visceral/complications , Mice, Inbred BALB C , Time FactorsABSTRACT
Mice selected on the basis of an acute inflammatory response (AIR) can provide information about the immunopathological mechanisms of glomerulonephritis. We studied the differences between mice selected for a maximal AIR (AIRmax that attract more polymorphonuclear cells to the site of injury) or a minimal AIR (AIRmin that attract more mononuclear cells) in an experimental model of IgA nephropathy in order to investigate the effect of genetic background on glomerular disease progression and the participation of the monocyte chemoattractant protein-1 (MCP-1) chemokine. IgA nephropathy was induced by intraperitoneal ovalbumin injection and bile duct ligation in AIRmax and AIRmin mice. Histological changes, urinary protein/creatinine ratio, serum IgA levels, immunofluorescence for IgA, IgG and complement C3 fraction, immunohistochemistry for macrophages and MCP-1, and MCP-1 levels in macerated kidney were determined. Mesangial IgA deposition was seen only in AIRmin mice, which presented more renal lesions. Increased serum IgA levels (1.5 ± 0.4 vs 0.3 ± 0.1 mg/mL, P < 0.001), high glomerular MCP-1 expression and decreased monocyte/macrophage infiltration in the interstitial area (0.3 ± 0.3 vs 1.1 ± 0.9 macrophages/field, P < 0.05) were detected in AIRmin mice compared to AIRmax mice. No glomerular monocyte/macrophage infiltration was detected in either strain. In spite of the absence of IgA deposition, AIRmax mice presented discrete or absent mesangial proliferation. The study showed that there are differences between mice selected for AIRmax and AIRmin with respect to serum IgA levels, histological damage and MCP-1 chemokine production after ovalbumin injection in combination with bile duct ligation.