Genetic and environmental factors affecting ultrasound measures of longissimus muscle area and backfat thickness in Nelore cattle

The aim of the present study was to evaluate the genetic and environmental factors affecting records of longissimus muscle area (LMA) and back fat thickness (BF) obtained between the 12th and 13th ribs, and rump fat thickness (RF) between the hook and pin bones, measured by real-time ultrasound in Nelore cattle. Also, weight records of 22,778 animals born from 1998 to 2003, in ten farms across six Brazilian states were used. Carcass traits as measured by ultrasound of the live animal were recorded from 2002 to 2004 in 2590 males and females with ages varying from 450 to 599 days. Fixed models including farm, year and season of birth, sex and type of feed effects, and the covariates age of dam (AOD) and age of animal at measurement were used to study the effect of environmental factors on these traits. The genetic parameters for LMA, BF and RF were estimated with two and three-trait animal models with 120-day weights using a restricted maximum likelihood method. All environmental effects significantly affected carcass traits, with the exception of year of birth for BF and RF and AOD for LMA. The heritability estimates for LMA, BF and RF were 0.35, 0.51 and 0.39, respectively. Standard errors obtained in one-trait analyses were from 0.07 to 0.09. Genetic correlation estimates between LMA and the two traits of subcutaneous fat were low (close to zero) and 0.74 between BF and RF, indicating that the selection for LMA should not cause antagonism in the genetic improvement of subcutaneous fat measured by real-time ultrasound. (C) 2007 Elsevier B.V. All fights reserved.

Genetic analysis of forest species Eugenia uniflora L. through of newly developed SSR markers

Nine microsatellite loci for genetic analysis of three populations of the tropical tree Eugenia uniflora L. (pitanga or Brazilian cherry) from fragments of semideciduous forest were developed. We used the technique of building a (GA)(n) and (CA)(n) microsatellite-enriched library by capture with streptavidin-coated magnetic beads. We assessed the polymorphism of seven microsatellites in 84 mature trees found in three areas (Ribeir (a) over tildeo Preto, Tambau and S (a) over tildeo Jose do Rio Pardo), highly impacted by the agricultural practices, in a large region among Pardo river and Mogi-Guacu river basins, in state of S (a) over tildeo Paulo, Brazil. All loci were polymorphic, and the number of alleles was high, ranging from 6 to 24, with a mean of 14.4. All stands showed the same high level of genetic diversity (mean H(E) = 0.83) and a low genetic differentiation (mean F(ST) = 0.031), indicating that genetic diversity was higher within rather than among populations. Seven of the nine loci were highly variable, and sufficiently informative for E. uniflora. It was concluded that these new SSR markers can be efficiently used for gene flow studies.

Influence of aging, tidal volume, and respiratory rate on Doppler echocardiographic indices of diastolic function in normal male subjects: A quantitative evaluation

Background: Although the influence of respiration on ventricular filling, as evaluated by Doppler technique, and the evaluation of diastolic velocities of mitral valve annulus (MVA), as measured by Doppler tissue imaging (DTI), can provide valuable information for the study of left ventricular (LV) diastolic function, the concomitant effects of aging, tidal volume (TV), and respiratory rate (RR) on these velocities have not been quantitatively investigated. Methods: We evaluated 12 normal male volunteers (Group I) aged 20-26 years (mean: 22.8) and 8 normal subjects aged 41 to 54 years old (mean: 45.9) (Group II). Using DTI we measured peak early (E-a) and late (A(a)) velocities of longitudinal axis expansion at lateral and medial MVA. Doppler mitral and tricuspid flow velocities were measured: peak early (E) and late (A) inflow velocity, early (E-i) and late (A(i)) flow integral, and deceleration time of peak early mitral flow velocity (DT). Respiratory cycles were simultaneously recorded at RR of 9, 12, 15, and 18 cycles/min and TV of 600 and 900 mL during respiration (RESP). Results and conclusions: (1) E, A, and A(i) in MV had negligible change during respiration, but E-i was significantly reduced during inspiration; (2) DT reduced slightly with inspiration, but the change was significant only with TV of 900 mL; (3) an important increase of E in right ventricular flow was observed during inspiration; (4) variations of RR and TV did not significantly influence right and left ventricular inflow in normal subjects, in the conditions of this investigation; (5) a significant increase of E-a at medial MVA was documented during inspiration only in young subjects; (6) a significant decrease of A(a) at medial MVA was observed during inspiration in both groups of volunteers; (7) RR and TV did not influence MVA velocities in young and adult subjects; (8) a consistent reduction in E-a and a significant increase in A(a) were observed with increasing age; (9) these changes were more conspicuous and consistent than those documented in ventricular filling when young and middle-age men are compared, suggesting that the DTI is more sensitive to detect changes in diastolic function; and (10) in addition, these data suggest that, for evaluation of diastolic function, in clinical context, it is not necessary to control rigorously RR or TV.

Systemic lupus erythematosus: Association with KIR and SLC11A1 polymorphisms, ethnic predisposition and influence in clinical manifestations at onset revealed by ancestry genetic markers in an urban Brazilian population

Systemic lupus erythematosus (SLE) is an autoimmune disorder of the connective tissue with a wide and heterogeneous spectrum of manifestations, with renal and neurological involvement usually related to worse prognosis. SLE more frequently affects females of reproductive age, and a high prevalence and renal manifestation seem to be associated with non-European ethnicity. The present study aims to investigate candidate loci to SLE predisposition and evaluate the influence of ethnic ancestry in the disease risk and clinical phenotypic heterogeneity of lupus at onset. Samples represented by 111 patients and 345 controls, originated from the city of Belem, located in the Northern Region of Brazil, were investigated for polymorphisms in HLA-G, HLA-C, SLC11A1, MTHFR, CASP8 and 15 KIR genes, in addition to 89 Amerindian samples genotyped for SLC11A1. We also investigated 48 insertion/deletion ancestry markers to characterize individual African, European and Amerindian ancestry proportions in the samples. Predisposition to SLE was associated with GTGT deletion at the SLC11A1 3`UTR, presence of KIR2DS2 +/KIR2DS5 +/KIR3DS1 + profile, increased number of stimulatory KIR genes, and European and Amerindian ancestries. The ancestry analysis ruled out ethnic differences between controls and patients as the source of the observed associations. Moreover, the African ancestry was associated with renal manifestations. Lupus (2011) 20, 265-273.

Analysis of five polymorphic DNA markers for indirect genetic diagnosis of haemophilia A in the Brazilian population

Hemophilia A is an X-linked, inherited, bleeding disorder caused by the partial or total inactivity of the coagulation factor VIII (FVIII). Due to difficulties in the direct recognition of the disease-associated mutation in the F8 gene, indirect diagnosis using polymorphic markers located inside or close to the gene is used as an alternative for determining the segregation of the mutant gene within families and thus for detecting carrier individuals and/or assisting in prenatal diagnosis. This study characterizes the allelic and haplotype frequencies, genetic diversity, population differentiation and linkage disequilibrium of five microsatellites (F8Int1, F8Int13, F8Int22, F8Int25.3 and IKBKG) in samples of healthy individuals from Sao Paulo, Rio Grande do Sul and Pernambuco and of patients from Sao Paulo with haemophilia A to determine the degree of informativeness of these microsatellites for diagnostic purposes. The interpopulational diversity parameters highlight the differences among the analyzed population samples. Regional differences in allelic frequencies must be taken into account when conducting indirect diagnosis of haemophilia A. With the exception of IKBKG, all of the microsatellites presented high heterozygosity levels. Using the markers described, diagnosis was possible in 10 of 11 families. The F8Int22, F8Int1, F8Int13, F8Int25.3 and IKBKG microsatellites were informative in seven, six, five and two of the cases, respectively, demonstrating the effectiveness of using these microsatellites in prenatal diagnosis and in carrier identification in the Brazilian population.

The Impact of Preexisting Myocardial Remodeling on Ventricular Function Early after Tetralogy of Fallot Repair

Background: Twenty-three patients (median age 23 months) who underwent Fallot`s tetralogy repair were investigated prospectively to detect a possible association between histopathologic myocardial remodeling and echocardiographic findings of systolic or diastolic ventricular dysfunction. Methods: Intraoperatively resected infundibular bands and subendocardial biopsy samples from the right ventricle (RV) and left ventricle were obtained for histopathologic evaluation. Tissue Doppler echocardiographic interrogation of the ventricles was performed before surgery and in the postoperative period. Results: Histopathologic data revealed hypertrophy of the RV cardiomyocytes and increased interstitial collagen in both ventricles. Mean values of RV isovolumic acceleration decreased significantly at the third evaluation compared with the preoperative values (P = .006). RV myocardial fibrosis greater than 8.3% was associated with a probability of altered E` of at least 0.7 (odds ratio = 2.31). Conclusion: Preoperative histologic myocardial remodeling influenced the postoperative RV function in this group of patients with late repair. Further studies are necessary to evaluate the myocardium in younger patients and to define its influence in the long-term follow-up. (J Am Soc Echocardiogr 2010;23:912-8.)

Chronic alcoholism associated with diabetes impairs erectile function in rats

OBJECTIVE To investigate the effects of chronic ethanol consumption and diabetes on nitric oxide (NO)-mediated relaxation of cavernosal smooth muscle (CSM). MATERIAL AND METHODS Male Wistar rats were divided into four groups: control, isocaloric, diabetic and ethanol-diabetic. The CSMs were mounted in organ chambers for measurement of isometric tension. Contraction of the strips was induced by electrical field stimulation (EFS, 1-32 Hz) and phenylephrine. We also evaluated the effect of ethanol consumption on the relaxation induced by acetylcholine (ACh; 0.01-1000 mu mol/L), sodium nitroprusside (SNP, 0.01-1000 mu mol/L) or EFS (1-32 Hz) in strips pre-contracted with phenylephrine (10 mu mol/L). Immunoexpression of endothelial NO synthase (eNOS) and inducible NOS (iNOS) was also accessed. RESULTS The endothelium-dependent relaxation induced by ACh was decreased in CSM from ethanol-diabetic rats when compared with the controls, with a mean (sem) of 21 (4) vs 37 (2)%. Similarly, the potency and maximal responses induced by SNP were reduced in the ethanol-diabetic [3.97 (0.38) and 85 (1)%, respectively] and diabetic groups [3.78 (0.56) and 81 (2)%, respectively] when compared with the controls [5.3 (0.22) and 90 (3)%, respectively] and isocaloric [5.3 (0.19) and 92 (1)%, respectively] groups. Noradrenergic nerve-mediated contractions of CSM in response to EFS were increased in rats from ethanol-diabetic and diabetic groups when compared with the control and isocaloric groups. Conversely, there were no differences in EFS-induced relaxation among the groups. The immunostaining assays showed overexpression of eNOS and iNOS in the CSM from diabetic and ethanol-diabetic rats when compared with the control and isocaloric rats. CONCLUSION There was an impairment of relaxation of CSM from ethanol-diabetic and diabetic rats that involved a decrease in the NO-cyclic guanosine monophosphate signalling pathway by endothelium-dependent mechanisms accompanied by a change in the CSM contractile sensitivity.

Effects of Nicotine Exposure on Renal Function of Normal and Hypercholesterolemic Rats

Background/Aims: Renal risks of nicotine exposure associated with hypercholesterolemia are still unknown. Methods: Thus, hypercholesterolemic rats (HC) and their control (C) were evaluated by inulin clearance (InCl) measured at baseline and during nicotine infusion (100 mu g/kg b.w.). Five groups were studied: (i) C; (ii) DEN (C submitted to a renal denervation); (iii) C + L-arginine (0.25% in drinking water); (iv) HC, and (v) HC + L-arginine (0.25% in drinking water). Furthermore, C and HC had their renal blood flow (RBF) measured and they have also been chronically treated with nicotine (12.5 mu g/ml in drinking water) to assess InCl on the 8th day. Results: Nicotine increased blood pressure in C, DEN and HC and reduced InCl only in C. L-Arginine treatment blunted nicotine effects on blood pressure and increased InCl only in C. Moreover, nicotine did not change RBF in C but elicited in HC, whereas renal vascular resistance was increased in C and unchanged in HC. Indeed, chronic nicotine exposure has also reduced InCl in C. Conclusion: Nicotine acted on the adrenergic system and nitric oxide counteracted this action in C, but the same may not be applied to HC. An impairment in renal autoregulation may explain why InCl was unchanged in HC. Copyright (C) 2009 S. Karger AG, Basel

Isolation and partial characterization of Brazilian samples of feline immunodeficiency virus

Feline immunodeficiency virus (FIV) causes a slow progressive degeneration of the immune system which eventually leads to a disease comparable to acquired immune deficiency syndrome (AIDS) in humans. FIV has extensive sequence variation, a typical feature of lentiviruses. Sequence analysis showed that diversity was not evenly distributed throughout the genome, but was greatest in the envelope gene, env. The virus enters host cells via a sequential interaction, initiated by the envelope glycoprotein (env) binding the primary receptor molecule CD134 and followed by a subsequent interaction with chemokine co-receptor CXCR4. The purpose of this study was to isolate and characterize isolates of FIV from an open shelter in Sao Paulo, Brazil. The separated PBMC from 11 positive cats were co-cultured with MYA-1 cells. Full-length viral env glycoprotein genes were amplified and determined. Chimeric feline x human CD134 receptors were used to investigate the receptor utilization of 17 clones from Brazilian isolates of Fly. Analyses of the sequence present of molecular clones showed that all clones grouped within subtype B. In contrast to the virulent primary isolate FIV-GL8, expression of the first cysteine-rich domain (CRD1) of feline CD134 in the context of human CD134 was sufficient for optimal receptor function for all Brazilian FIV isolates tested. (C) 2011 Elsevier B.V. All rights reserved.

Isolation and genetic characterisation of Toxoplasma gondii from a red-handed howler monkey (Alouatta belzebul), a jaguarundi (Puma yagouaroundi), and a black-eared opossum (Didelphis aurita) from Brazil

Toxoplasma gondii isolates are highly diverse in domestic animals from Brazil. However, little is known about the genetics of this parasite from wild mammals in the same region. Reveal genetic similarity or difference of T. gondii among different animal populations is necessary for us to understand transmission of this parasite. Here we reported isolation and genetic characterisation of three T. gondii isolates from wild animals in Brazil. The parasite was isolated by bioassay in mice from tissues of a young male red handed howler monkey (Alouatta belzebul), an adult male jaguarundi (Puma yagouaroundi), and an adult female black-eared opossum (Didelphis aurita). The monkey and the jaguarundi had inhabited the Zoo of Parque Estadual Dois Irmaos, Pernambuco State, Northeastern Brazil, for 1 year and 8 years, respectively. The wild black-eared opossum was captured in Sao Paulo State, Southeastern Brazil, and euthanised for this study because it was seropositive for T. gondii (titre 1:100 by the modified agglutination test, MAT). Ten PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism) markers, SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico, were used to genotype the isolates. T. gondii was isolated from the brain and heart homogenate of the monkey, the muscle homogenate of the jaguarundi, and the heart homogenate of the black-eared opossum. This was the first isolation of T. gondii from a neotropical fetid from Brazil. The isolate from the monkey (TgRhHmBr1) was not virulent in mice, whereas the isolates from the jaguarundi (TgJagBr1) and the black-eared opossum (TgOpBr1) were virulent in mice. The genotype of the isolate from the monkey has been identified in isolates from a goat and ten chickens in the same region of Brazil, suggesting that it may be a common lineage circulating in this region. The genotypes of the isolates from the jaguarundi and the black-eared opossum have not been previously reported. Although there are already 88 genotypes identified from a variety of animal hosts in Brazil, new genotypes are continuously being identified from different animal species, indicating an extremely high diversity of T. gondii in the population. (C) 2010 Elsevier B.V. All rights reserved.

Genetic analysis of ticks belonging to the Rhipicephalus sanguineus group in Latin America

Phylogenetic analyses based on mitochondrial 16S rDNA sequences were generated from Rhipicephalus sanguineus group specimens collected in 29 localities among 9 Latin-American countries, plus ticks collected in South Africa, Spain, and Italy. Sequences from Latin America generated six different haplotypes (A, B, C, D, E, and F). Phylogenetic analyses generated trees that segregated our tick sequences into two distinct clades: one is represented by haplotypes A-C, and South African R. sanguineus and Rhipicephalus turanicus ticks; the second clade is represented by haplotypes D-F, and European R. sanguineus and R. turanicus ticks. When haplotypes A-Fare plotted in the Latin America map according to their geographical coordinates, it is clearly seen that haplotypes D-F are restricted to the southern portion of this continent, whereas haplotypes A-C are distributed in areas between northern Mexico and Brazil (except for the extreme south of this last country, where haplotype E was present). Hence, our phylogenetic analyses separated New World specimens of R. sanguineus into two distinct clades, one represented by tropical and subtropical populations (haplotypes A-C), here designated as the `tropical` species. On the other hand, haplotypes D-F are here designated as the `temperate` species because of their distribution in the southern portion of South America. Until recently, it was assumed that the R. sanguineus group was represented by a single species in the New World, namely R. sanguineus. While the present results coupled with recent studies support the presence of at least two species under the taxon R. sanguineus in the New World, they also show that even in the Old World, the taxon R. sanguineus might be represented by more than one species, since our phylogenetic analysis segregated European and South African R. sanguineus ticks into two distinct clades. The same can be applied for Spanish and South African R. turanicus. (C) 2010 Elsevier B.V. All rights reserved.

Genetic diversity among Toxoplasma gondii isolates of small ruminants from Brazil: Novel genotypes revealed

Recent studies indicated that Toxoplasma gondii isolates of many domestic animal hosts from Brazil are genetically and biologically different from those in USA and Europe. Despite of high pathogenicity of this parasite to small ruminants, the epidemiology and genetic diversity of T. gondii in these animals are not well understood in Brazil. In this study, a total of 28 T. gondii samples (16 isolates from sheep in Sao Paulo state, and 12 isolates from goats in the states of Sao Paulo and Rio Grande do Norte) were genotyped using genetic markers SAG1, SAG2, SAG3, BTUB, CRAG, c22-8, c29-2, L358, PK1, Apico and CS3. Eleven genotypes were identified from these T. gondii isolates. Eight isolates (4 from sheep and 4 from goats) were grouped into the common clonal type Brl lineage. One sheep isolate was grouped to the type BrIII lineage. Five isolates grouped to three previously identified genotypes in Brazil, and 13 isolates grouped to six novel genotypes. Mixed genotype was found in one isolate from goat in Sao Paulo. No classical clonal Type I. II or III isolates were found, confirming previous reports that these clonal lineages are rare in Brazil. The allele types at the CS3 locus are strongly linked to mouse virulence of the parasite. The results of this study indicate that even though a large number of T. gondii genotypes have been identified from a variety of animal hosts in Brazil, high percentage of new genotypes are continuously identified from different animal species, suggesting extremely high diversity of T. gondii in the population. (C) 2010 Elsevier B.V. All rights reserved.

Genetic diversity of Brazilian isolates of feline immunodeficiency virus

FAPESP (the Sao Paulo State research funding foundation)

Low genetic diversities of rabies virus populations within different hosts in Brazil

The low rates of nonsynonymous evolution observed in natural rabies virus (RABV) isolates are suggested to have arisen in association with the structural and functional constraints operating on the virus protein and the infection strategies employed by RABV within infected hosts to avoid strong selection by the immune response. In order to investigate the relationship between the genetic characteristics of RABV populations within hosts and the virus evolution, the present study examined the genetic heterogeneities of RABV populations within naturally infected dogs and foxes in Brazil, as well as those of bat RABV populations that were passaged once in suckling mice. Sequence analyses of complete RABV glycoprotein (G) genes showed that RABV populations within infected hosts were genetically highly homogeneous whether they were infected naturally or experimentally (nucleotide diversities of 0-0.95 x 10(-3)). In addition, amino acid mutations were randomly distributed over the entire region of the G protein, and the nonsynonymous/synonymous rate ratios (d(N)/d(S)) for the G protein gene were less than 1. These findings suggest that the low genetic diversities of RABV populations within hosts reflect the stabilizing selection operating on the virus, the infection strategies of the virus, and eventually, the evolutionary patterns of the virus. (C) 2009 Elsevier B.V. All rights reserved.

Ovarian function in Nelore (Bos taurus indicus) cows after post-ovulation hormonal treatments

Maternal recognition of pregnancy in the cow requires successful signaling by the conceptus to block luteolysis. Conceptus Growth and function depend on an optimal uterine environment, regulated by luteal progesterone. The objective of this study was to test strategies to optimize luteal function, as well as prevent a dominant follicle from initiating luteolysis. Nelore (Bos taurus indicus) beef cows (n = 40) were submitted to a GnRH/PGF(2 alpha)/GnRH protocol. Cows that ovulated from a dominant ovarian follicle (ovulation = Day 0) were allocated to receive: no additional treatment (Gc; n = 7); 3000 IU of hCG on Day 5 (G(hCG); n = 5); 5 mg of estradiol-17 beta on Day 12 (G(E2); n = 6); or 3000 IU of hCG on Day 5 and 5 mg of estradiol-17 beta on Day 12 (G(hCG/E2); n = 5). Ultrasonographic imaging of the ovaries, assessment of plasma progesterone concentration, and detection of estrus were done daily from Day 5 to the day of subsequent ovulation. Treatment with hCG induced an accessory CL, increased CL volume, and plasma progesterone concentration throughout the luteal phase (P < 0.01). Estradiol-17 beta induced atresia and recruitment of a new wave of follicular growth; it eliminated a potentially estrogen-active, growing ovarian follicle within the critical period for maternal recognition of pregnancy, but it also hastened luteolysis (Days 16 or 17 vs. Days 18 or 19 in non-treated cows). In conclusion, the approaches tested enhanced luteal function (hCG) and altered ovarian follicular dynamics (estradiol-17 beta), but were unable to extend the life-span of the CL in Nelore cows. (c) 2008 Elsevier Inc. All rights reserved.