BackgroundKnowledge of the linkage disequilibrium (LD) between markers is important to establish the number of markers necessary for association studies and genomic selection. The objective of this study was to evaluate the extent of LD in Nellore cattle using a high density SNP panel and 795 genotyped steers.ResultsAfter data editing, 446,986 SNPs were used for the estimation of LD, comprising 2508.4 Mb of the genome. The mean distance between adjacent markers was 4.90 ± 2.89 kb. The minor allele frequency (MAF) was less than 0.20 in a considerable proportion of SNPs. The overall mean LD between marker pairs measured by r2 and |D'| was 0.17 and 0.52, respectively. The LD (r2) decreased with increasing physical distance between markers from 0.34 (1 kb) to 0.11 (100 kb). In contrast to this clear decrease of LD measured by r2, the changes in |D'| indicated a less pronounced decline of LD. Chromosomes BTA1, BTA27, BTA28 and BTA29 showed lower levels of LD at any distance between markers. Except for these four chromosomes, the level of LD (r2) was higher than 0.20 for markers separated by less than 20 kb. At distances < 3 kb, the level of LD was higher than 0.30. The LD (r2) between markers was higher when the MAF threshold was high (0.15), especially when the distance between markers was short.ConclusionsThe level of LD estimated for markers separated by less than 30 kb indicates that the High Density Bovine SNP BeadChip will likely be a suitable tool for prediction of genomic breeding values in Nellore cattle.

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Purpose:The aim of this study was to analyse the changes in transfusion requirements, in patients submitted to orthotopic liver transpantation from cadaveric donors, with the use of intraoperative red blood cell salvage (Cell Saver). Methods: Data from 41 transplants were analysed. Intraoperative blood loss was calculated from the cell salvage, suction and the swabs. The autologous and heterologous transfusions were recorded The red blood salvage was performed using the Cell Saver 5 System (Haemonetics).. For analysis the patients were divided in two groups: one that used the Cell Saver and another that didn´t. Results: The median age of the patients was 50 years and the main indication for liver transplantation was cirrhosis (35 cases -85.3%). The median blood loss was 8362 + 3994 ml (with the Cell Saver) and 10824 + 7002 ml (without the Cell Saver) and the median transfusion of heterologous packed red blood cells was 9,6 + 8 units (with the Cell Saver) compared to 22,3 + 21 units (without the Cell Saver). Conclusions: The Cells Saver has the potential to reduce the need for heterologous blood transfusion reducing the risks of transmissible diseases. Key words: Liver Transplantation. Cell Saver. Blood Transfusion. Liver Surgery. RESUMO Objetivo: O objetivo desse estudo foi analisar as mundanças na quantidade de transfusão necessária com uso doIntraoperative red blood cell salvage (Cell saver), em pacientes submetidos a transplante ortotópico de fígado, doador cadáver. Métodos: Foram avaliados dados de 41 pacientes submetidos a transplante de fígado. O sangramento foi calculado de acordo com débito do aspirador, compressas e captação do Cell saver. A reposição necessária foi avaliada de acordo com a quantidade de transfusão heteróloga e autóloga. Para análise dos dados os pacientes foram dividos em dois grupos: com e sem uso de Cell saver. Resultados: A mediana de idade foi 50 anos e principal indicação de transplante foi cirrose hepática com 35 casos (85,3%). A mediana de sangramento durante o procedimento cirúrgico 8362 + 3994 ml (com cell saver) e 10824 + 7002 ml (sem cell saver) e a mediana de transfusão de concentrado de hemácias heterólogo, durante o período de internação hospitalar 9,6 + 8 unidades (com cell saver) compar 22,3 + 21 unidades (sem cell saver). Conclusão: Uso de Cell Saver tem um potential para reduzir a quantidade de transfusão heteróloga, dimuindo o risco de transmissão de doenças.

High proportions of HBV-infected subjects with an HBeAg-negative pattern were observed, with a higher risk of vertical/intrafamily transmission. Alcohol abuse was associated with male subjects and with cirrhosis of the liver in this group. A tendency toward an increase in the number of HBeAg-negative cases was observed over time.

The aim of this study was to analyze LEP and DGAT1 gene polymorphisms in 3 Nelore lines selected for growth and to evaluate their effects on growth and carcass traits. Traits analyzed were birth, weaning, and yearling weight, rump height, LM area, backfat thickness, and rump fat thickness obtained by ultrasound. Two SNP in the LEP gene [LEP 1620(A/G) and LEP 305(T/C)] and the K232A mutation in the DGAT1 gene were analyzed. The sample consisted of 357 Nelore heifers from 2 lines selected for yearling weight and a control line, established in 1980, at the Estação Experimental de Zootecnia de Sertãozinho (Sertãozinho, Brazil). Three genotypes were obtained for each marker. Differences in allele frequencies among the 3 lines were only observed for the DGAT1 K232A polymorphism, with the frequency of the A allele being greater in the control line than in the selected lines. The DGAT1 K232A mutation was associated only with rump height, whereas LEP 1620(A/G) was associated with weaning weight and LEP 305(T/C) with birth weight and backfat thickness. However, more studies, with larger data sets, are necessary before these makers can be used for marker-assisted selection.

ABSTRACT. The objective of this study was to identify associations between known polymorphisms in genes related to adipose tissue and sexual precocity in Nellore cattle. A total of 1689 precocious and nonprecocious heifers belonging to farms participating in Conexão Delta G breeding program were studied. SNPs from the Illumina High-Density Bovine SNP BeadChip were used. This chip contains 777,000 SNPs located within the region of the candidate genes at a distance of up to 5 kb, considering that linkage disequilibrium (LD) exists at this distance. Linear models were used for statistical analysis. The fastPHASE and GenomeStudio programs were used for haplotype reconstruction and LD analysis based on r 2 statistics. Fifty-seven candidate genes and 443 SNPs were analyzed: among the latter, 370 SNPs formed 83 haplotypes, while the remaining SNPs were studied separately. Statistical analysis showed that only three haplotypes, one haplotype consisting of two SNPs located in the FABP4 gene and two haplotypes consisting of four and Lipid metabolism-related genes as candidates of precocity two SNPs located in the PPP3CA gene, had a significant effect on sexual precocity at P < 0.05. It can be concluded that the FABP4 and PPP3CA genes influence sexual precocity and may therefore be used in selection programs designed to improve sexual precocity in Nellore cattle.

Hepatitis B virus (HBV) is distributed worldwide, with geographical variations regarding prevalence of the different genotypes. The aim of this study was to determine the HBV genotypes and subgenotypes circulating in Southeast Brazil and compare the genetic sequences found with HBV sequences previously described in the world. Sequences from 166 chronic HBV carriers were analyzed using the fragment constituted by 1306 base pairs comprising surface and polymerase regions of the HBV genome. The sequences obtained were submitted to phylogenetic analysis. HBV subgenotypes A1, A2, D1-D4, F2a, and F4 were found. HBV genotype D was the most frequent, found in 99 patients (58.4%). Within this group, subgenotype D3 was the most prevalent, in 73 patients (42.9%). HBV genotype A was identified in 58 (36%) patients, subgenotype A1, in 48 (29.8%) subjects. Genotype F was identified in 9 (5.4%). According to the phylogenetic analysis, the sequences found were grouped with sequences from Europe, Asia and Middle East (subgenotypes D1, D2, D3) and sequences from Latin America and Africa (subgenotype A1). HBV D3 grouped in different clusters inside D3 clade, several of them with sequences isolated in Italy. We also identified eight families whose relatives were infected with the same HBV subgenotype, most with high similarity between sequences. In conclusion, the distribution of the HBV sequences obtained interweaved with sequences from other continents, corresponding to regions from where many immigrants came to this region, in accordance to the hypothesis that the HBV detected over there were brought during the colonization times.

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