Genotypic and allelic frequencies of gene polymorphisms associated with meat tenderness in Nellore beef cattle.

The objectives of this study were to characterize the allelic and genotypic frequencies of polymorphisms in the µ-calpain and calpastatin genes, and to assess their association with meat tenderness and animal growth in Nellore cattle. We evaluated 605 Nellore animals at 24 months of age, on average, at slaughter. The polymorphisms were determined for the molecular markers CAPN316, CAPN530, CAPN4751, CAPN4753, and UOGACAST1. Analyses of meat tenderness at 7, 14, and 21 days of maturation were performed in samples of longissimus thoracis obtained between the 12th and 13th rib and sheared using a Warner Bratzler Shear Force. Significant effects were observed for meat tenderness at days 7, 14, and 21 of maturation for the marker CAPN4751, at day 21 for the marker CAPN4753, and at days 14 and 21 for the marker UOGCAST1. For genotypic combinations of markers, the results were significant for the combination CAPN4751/UOGCAST1 in the three maturation periods and CAPN4753/UOGCAST1 at days 14 and 21 of maturation.

Sire effects on carcass and meat quality traits of young Nellore bulls.

Meat quality is being increasingly demanded by consumers in recent years. Several factors can affect meat quality, ranging from animal traits such as breed and genetic heritage to pre- and post-slaughter processes. This study investigated the influence of Nellore bulls on carcass and meat quality traits. We used 475 young uncastrated males, the progeny of 54 bulls, to evaluate characteristics of the following carcass traits: hot carcass weight, rib-eye area, and fat thickness. We also evaluated the following beef quality traits: marbling, color, drip loss, cooking loss, and shear force at 0, 7, and 14 days of aging. Bulls had a significant influence (P≤0.05) on rib-eye area, fat thickness, marbling, drip loss at 14 days of aging and color at all aging periods. Based on these results, the use of bulls with high breeding values for these traits can provide important advances in carcass traits and meat quality in breeding programs of Nellore cattle that are raised in tropical conditions.

Protein synthesis and degradation gene SNPs related to feed intake, feed efficiency, growth, and ultrasound carcass traits in Nellore cattle.

We looked for possible associations of SNPs in genes related to protein turnover, with growth, feed efficiency and carcass traits in feedlot Nellore cattle. Purebred Nellore bulls and steers (N = 290; 378 ± 42 kg body weight, 23 months ± 42 days old) were evaluated for daily feed intake, body weight gain (BWG), gross feed efficiency, feed conversion ratio, partial efficiency of growth, residual feed intake (RFI), ultrasound backfat, rump fat, and ribeye area. Genotypes were obtained for SNPs in the growth hormone receptor (GHR-1 and GHR-2); calpain (CAPN4751); calpastatin (UoGCAST); ubiquitin-conjugating enzyme 2I (UBE2I-1 and UBE2I-2); R3H domain containing 1 (R3HDM1-1, -2, -3, and -4), ring finger protein 19 (RNF19); proteasome 26S subunit, non-ATPase, 13 (PSMD13); ribosomal protein, large, P2 (RPLP2); and isoleucine-tRNA synthetase 2, mitochondrial (IARS2) genes. Allelic substitution, additive and dominant effects were tested and molecular breeding values were computed. CAPN4751, GHR-1 and -2, IARS2, R3HDM1-4, and UoGCAST were found to be normally segregating polymorphisms. Additive and dominance effects were observed on BWG, feed efficiency and carcass traits, although dominant effects predominated. Significant allelic substitution effects were observed for CAPN4751, GHR-1 and -2, and UoGCAST on BWG, gross feed efficiency, RFI, and carcass traits, under single- or multiple-marker analyses. Correlations between molecular breeding values and phenotypes were low, excepted for RFI, based on allelic substitution estimates obtained by stepwise linear regression. We conclude that SNPs in genes related to protein turnover are related to economically important traits in Nellore cattle.

Single nucleotide polymorphisms in CAPN and leptin genes associated with meat color and tenderness in Nellore cattle.

We analyzed single nucleotide polymorphisms in calpain, leptin, leptin receptor, and growth hormone receptor genes and their association with color, drip and cooking losses of longissimus muscle at 7, 14 and 21 days postmortem in 638 purebred Nellore bulls slaughtered between 22 and 26 months of age. Meat samples were vacuum-packed and aged at 4°C. The single nucleotide polymorphisms T945M, GHR2, E2FB, and CAPN4751 were evaluated. All genotypic classes were observed; however, the T/T genotype of T945M and E2FB was found at a low frequency. A significant association of E2FB with drip loss (a measure of water-holding capacity) was detected at seven days of meat aging. CAPN4751 had an additive effect on red and yellow color intensities. The T allele of CAPN4751 was found to be positively associated with improved meat color, but not with meat tenderness, differing from a previous report indicating that it is associated with meat tenderness. We conclude that the potential for use of CAPN4751 as a marker for these meat quality traits requires further research.

Association of SNPs on CAPN1 and CAST genes with tenderness in Nellore cattle.

We examined whether single-nucleotide polymorphisms (SNPs) in the calpain (CAPN) and calpastatin (CAST) genes, described from Bos primigenius taurus, are polymorphic in Nellore cattle. We also looked for a possible association of linkage disequilibrium of this polymorphism with tenderness of the longissimus dorsi muscle after 7, 14 and 21 days of postmortem aging in 638 purebred Nellore bulls. Meat tenderness was measured as Warner-Bratzler shear force. Additive and dominance effects were tested for SNPs of the three genotypic classes; the substitution effect was tested for SNPs with missing genotypic classes. Genotypic and gene frequencies were also calculated for the different SNPs. An increase in tenderness was observed from 7 to 21 days; the average values for shear force at 7, 14 and 21 days of aging were 5.92 +/- 0.06, 4.92 +/- 0.05, and 4.38 +/- 0.04 kg, respectively. All markers showed polymorphism, but there was no CC genotype for CAPN316, and few animals showed the AA genotype for CAPN530. The alleles CAPN4751, UOGCAST1, and WSUCAST were found to have additive and dominance effects for shear force at 7, 14 and 21 days, while CAPN316 showed a substitution effect for shear force at 7 and 21 days. An additive-by-additive epistatic interaction was observed between CAPN4751 and markers on the CAST gene. In conclusion, these markers should be considered for use in breeding programs.

Pulp bleaching using laccase from Trametes versicolor under high temperature and alkaline conditions.

Kraft pulp was delignified using laccase produced by the white rot fungus Trametes versicolor immobilized in solid support under specific conditions. The stability tests showed that this enzyme was stable for 6 h at 55 degrees C and pH 8.0, allowing its use under pH and temperature conditions very close to those used in industrial bleaching. In this work, unbleached hardwood Kraft pulp was submitted to prebleaching using 2 U laccase/g pulp basis. Reaction time, temperature, and pH of the enzymatic treatment were investigated. Good results regarding Kappa number reduction, selectivities, and high viscosities were obtained when prebleaching was performed for 1 h at temperature of 55 degrees C and pH 8.0 followed by alkaline extraction and ECF bleaching sequences.

Laccase from Trametes versicolor: stability at temperature and alkaline conditions and its effect on biobleaching of hardwood kraft pulp.

The enzyme laccase was produced by the white-rot fungus Trametes versicolor in repeated batches cultures with immobilized mycelium. Two different culture conditions were used. Enzymes produced were evaluated regarding their stability at high temperatures (55 degrees C and 65 degrees C) and at alkaline conditions (pH 7.0 and pH 8.0) having in view the application of these enzymes in biobleaching of hardwood Kraft pulp. Biobleaching experiments were divided in two parts, enzymatic prebleaching followed by chemical bleaching. In the enzymatic prebleaching the enzyme laccase was used at two conditions of pH and temperature, whereas the reaction time was fixed at 1 h in all pretreatments. In the chemical bleaching the DEDED and DEpDED sequences were used. The enzyme action was evaluated by Kappa number, viscosity, and brightness at the end of bleaching sequences. There were obtained values of Kappa numbers lower than control assays, viscosities compatible with industrial pulps, and brightness higher than controls, when pulps were pretreated for 1 h with laccase at pH 8.0 and 55 degrees C.

Production and characterization of Phanerochaete chrysosporium lignin peroxidases for pulp bleaching.

The production of lignin peroxidase from Phanerochaete chrysosporium was studied using immobilized mycelia in nylon-web cubes in semicontinuous fermentation using glucose pulses or ammonium tartrate pulses. Consistent enzyme production was achieved when glucose pulses were used, leading to an average activity of 253 U/L. The crude enzyme was added to eucalyptus kraft pulp before conventional and ECF bleaching sequences. Optimization of the enzymatic pretreatment led to the following operational conditions: enzyme load of 2 U/g of pulp, hydrogen peroxide addition rate of 10 ppm/h, and reaction time of 60 min. Pulp final characteristics were dependent on the chemical treatment sequence that followed enzymatic pretreatment. The chief advantage of enzymatic pretreatment was pulp viscosity preservation, which was observed in most of the experiments carried out with seven different chemical treatment sequences.

Human infection with Trypanosoma cruzi in Nasca, Peru: a seroepidemiological survey.

We estimated the proportion of seropositivity for infection with Trypanosoma cruzi (Chagas' disease) in a sample of the rural population of the Province of Nasca, Department of Ica, southwestern Peru. Although Triatoma infestans, the only vector species identified in the Department of Ica, is often found in domestic environments, data of the extent of human infection with T. cruzi are scant. This study comprised 446 houses, known to be infested with triatomines, distributed in 19 rural localities. While visiting those houses we collected filter paper bloodspots from 864 occupants (of both sexes, aged one year or over). By means of the indirect fluorescent antibody test (IFAT), we detected anti-T. cruzi IgG antibodies in samples from 178 individuals (20.6%). Seropositivity was significantly more frequent in females (23.8%) than in males (17.5%). Among the 410 individuals in the 1- to 10-year-old age group (47.5% of the population sample), 85 (20.7%) were found seropositive, which is indicative of an early acquisition of the infection. Within this group no significant differences in seropositivity were associated with sex.

[Triatoma infestans in area under entomological surveillance for Chagas' disease in São Paulo State, Brazil]. / Triatoma infestans em área sob vigilância entomológica para doença de Chagas, Estado de São Paulo, Brasil.

In response to notification of the capture of a winged triatomine bug by local inhabitants, an epidemiological investigation was investigated in the rural area of the Municipality of Paulínia, São Paulo State (Brazil). This led to the collection of 109 specimens of Triatoma infestans from peridomiciliary breeding sites. Local conditions favored colonization by triatomine bugs: many abandoned outbuildings were inhabited by pigeons and sparrows, which meant abundant feed for these bugs. Thus, surveillance is mandatory as long as conditions for triatomine breeding persist. Nevertheless, entomological and serological indicators ruled out immediate concern over vectorial transmission of Chagas' disease in this municipality. All domiciliary units of the region were sprayed with residual-effect insecticides and the triatomine breeding sites were destroyed by the use of mechanical control of bird nests. The importance of reporting the occurrence of triatomine bugs, particularly Triatoma infestans, in this region, is emphasized.

Flotation technique with coagulant and polymer application applied to the post-treatment of effluents from anaerobic reactor treating sewage.

This paper presents the results of a study performed with a lab-scale batch DAF unit fed with previously coagulated (with FeCl3 and/or cationic polymer) effluent from a pilot-scale expanded bed anaerobic reactor treating domestic sewage. The association between ferric chloride and polymers was studied, aimed at sludge reduction. Ferric chloride dosages ranging from 15 to 65 mg.l-1, and polymer dosages from 0.25 to 7.0 mg.l-1 were investigated. Flocculation conditions were kept constant: 20 min of time (Tf) and 80 s-1 of mean velocity gradient (Gf). Air requirement was kept to 19.0 g of air.m-3 wastewater, using 20% recycle ratio and saturation pressure at 450 kPa. When the anaerobic reactor was operating at steady state conditions, it was possible to reduce the FeCl3 dosage from 65 to 30 mg.l-1 after applying 0.4 mg.l-1 of non-ionic polymer, before the DAF process. For these dosages, 79% COD removal (residual of 23 mg.l-1), 86% total phosphate removal (residual of 0.9 mg.l-1) and 98% turbidity removal (residual of 2.6 NTU) were observed. Furthermore, the use of adequate polymer together with 30 mgFeCl3.l-1 leads to the production of high rising rate flocs.

[Seroprevalence of Triatoma infestans Chagas disease after vector control measures]. / Soroprevalência de infecção chagásica de Triatoma infestans após medidas de controle.

INTRODUCTION: The study is part of a project intended to retrieve information about the serology of the American trypanosomiasis in the state of São Paulo, Brazil, during the period when there was a state effort to control the vector. Data from the municipality of Taquarituba, administrative region of Sorocaba, which was then important in the epidemiology of Chagas disease in that region, were analyzed. Despite the government efforts started in the 1950s, domiciliary triatomines were still being captured in that region during the 1970s. METHODS: Population samples were selected from five localities of Taquarituba. Age, sex, birthplace, and time of residence in the house being occupied at the time of the interview, were recorded. It is used Probit analysis to assess a possible relationship between age and seropositivity, the latter taken as indicative of the risk of transmission. RESULTS: Blood from Taquarituba native people represented 62.9% of the samples examined (n = 2.784) and 62.4% of all seropositives (n = 380). Overall proportion of seropositives was 13.6% with no significant difference between genders (p = 0.538). Children under 6 years of age were not seropovitive, Seropositivity increased from 2.7% in the age group 6-9 years to 30.6% in the age group 30-39 years. By using probit analysis, an age-seropositivity relationship was found within these groups. CONCLUSIONS: The results of serological tests pointed to an association between the actions taken against Triatoma infestans and the decline and eventual control of the transmission of Chagas disease in the late 1960s.

[Transfusional Chagas infection detected in the program for the control of Chagas disease in the state of São Paulo (Brazil)]. / Infecção chagásica transfusional detectada no programa de controle da doença de Chagas no Estado de São Paulo (Brasil).

A system of surveillance for Chagas' disease aiming at a systematic investigation of the occurrence of triatominae in human dwellings in S. Paulo, Brazil was proposed. It included a serological survey of residents in house considered to be potential breeding places for blood-sucking triatomines. Serologically positive cases were observed to be distributed in age groups from 19 years of age upwards. Case-investigation revealed that the infection had been acquired either in S. Paulo in the past or recently in other States. A serologically positive (titre = 128 - IgG) case of an 8-year-old male child, was detected by the In direct Fluorescent Antibody Technique (IFAT). In S. Paulo State natural transmission is now of low probability. An epidemiological investigation disclosed the fact that this was a case of blood transfusion infection. The donor was found to be serologically positive (IFAT, titre = 1024 - IgG). His case-history was typical of vector transmitted infection. It is worthy of note that blood had been donated by this patient in four instances, without his condition having been diagnosed. The necessity of organizing an integrated Public Health Service to take more efficient care of such cases is stressed.

Chagas disease in an area of recent occupation in Cochabamba, Bolivia.

INTRODUCTION: A descriptive, entomological and seroepidemiological study on Chagas disease was conducted in a place of recent occupation on the outskirts of Cochabamba, Bolivia: Avaroa/Primer de Mayo (population:3,000), where the socio-economic level is low and no control measures have been made available. METHODS: The immunofluorescent antibody test (IFAT) was used for IgG and IgM anti-Trypanosoma cruzi antibodies in filter paper bloodspot eluates from 128 subjects (73 females, 55 males) selected by systematic sampling. Concerning each subject age, gender, birthplace, occupation, duration of residence and building materials used in their houses were recorded. Vectors were captured both in domestic and peridomestic environments. RESULTS: Seropositive, 12.5% (16/128): females, 15.1% (11/73); males, 9.1% (5/55). Average time of residence: 6.1 years for the whole population sample and 7.4 years for the seropositive subjects. Most houses had adobe walls (76. 7%, n= 30), galvanized iron rooves (86.7%) and earthen floors (53. 4%) 80% of the walls had crevices. One hundred forty seven specimens of Triatoma infestans were captured, of which 104 (70.7%) were domestic, and 1 peridomestic Triatoma sordida. Precipitin host identification: birds, 67.5%; humans, 27.8%; rodents, 11.9%; dogs, 8. 7%; cats, 1.6%. House infestation and density indices were 53.3 and 493.0 respectively. We found 21 (14.3%) specimens of T. infestans infected with trypanosomes, 18 (85.7%) of which in domestic environments. DISCUSSION: The elements for the vector transmission of Chagas disease are present in Avaroa/Primer de Mayo and the ancient custom of keeping guinea pigs indoors adds to the risk of human infection. In neighboring Cochabamba, due to substandard quality control, contaminated blood transfusions are not infrequent, which further aggravates the spread of Chagas disease. Prompt action to check the transmission of this infection, involving additionally the congenital and transfusional modes of acquisition, is required.

[Incidence of dyslipidemia and its relation to coronary artery disease in Brazilian populations]. / Incidência de dislipidemia e sua relação com doença arterial coronária em populações brasileiras.

PURPOSE: To describe the incidence of dyslipidemia and its relation to coronary artery disease (CAD) in two brazilian populations. PATIENTS AND METHODS: 1.261 subjects were analyzed; 674, whose mean age was 53 years, came from a cardiology private office (population A) and 587, whose mean age was 37 years, were employees of an engineering company (population B). Cholesterol was determined by the enzymatic method Chod-pap and LDL calculated by the Friedwald's formula. RESULTS: CAD was present in 35.1% of population A and in 1.4% of population B. In population A total cholesterol and LDL were above the expected, in all age groups. About 70% of these patients had cholesterol greater than 200 mg% and LDL greater than 130 mg%, which are considered desirable levels; 28% of women and 44% of men had HDL less than 35 mg%. Conversely, in population B total cholesterol and LDL were slightly above normal only in patients greater than 45 years old. In addition, about 65% of population had cholesterol less than 200 mg% and LDL less than 130 mg%; even so, 28% of women and 48% of men had HDL less than 35 mg%. In population A, there were no significant differences between the percentages of patients with and without CAD, over a wide range of cholesterol values. Similarly, levels of LDL, HDL and triglycerides as well as the incidence of hypertension, smoking and diabetes did not differ between patients with and without CAD. CONCLUSION: There is a high incidence of dyslipidemia in these brazilian populations, especially among patients from private office. Further, the isolated measurement of lipid fractions does not discriminate between patients with and without DAC, suggesting that other factors are involved in the genesis of the disease.

Hormonal and cardiovascular reflex assessment in a female patient with pure autonomic failure.

We report the case of a 72-year-old female with pure autonomic failure, a rare entity, whose diagnosis of autonomic dysfunction was determined with a series of complementary tests. For approximately 2 years, the patient has been experiencing dizziness and a tendency to fall, a significant weight loss, generalized weakness, dysphagia, intestinal constipation, blurred vision, dry mouth, and changes in her voice. She underwent clinical assessment and laboratory tests (biochemical tests, chest X-ray, digestive endoscopy, colonoscopy, chest computed tomography, abdomen and pelvis computed tomography, abdominal ultrasound, and ambulatory blood pressure monitoring). Measurements of catecholamine and plasmatic renin activity were performed at rest and after physical exercise. Finally the patient underwent physiological and pharmacological autonomic tests that better diagnosed dysautonomia.

Induction of autolysis in Streptococcus faecium.

Autolysis of exponential-phase Streptococcus faecium cells was promoted by pretreating the bacteria (freezing-thawing; -70 degrees C) in Tris buffer, followed by incubation at 37 degrees C in the same buffer. The effect was dependent on Tris concentration. The pretreatment provoked ultrastructurally visible damage with extensive loss of K+ and leakage of UV-absorbing components. No autolysis was observed when the bacteria frozen-thawed in Tris were incubated in the presence of the autolysin inhibitor N-bromosuccinimide nor when they had been grown in the presence of chloramphenicol or tetracycline. Furthermore, two autolytic-defective mutants, EC31 and EC78, isolated from S. faecium, did not autolyse when frozen-thawed and incubated in Tris. Freezing-thawing in Tris, however, imparted extensive cell damage to the mutants and to the antibiotic-treated bacteria as well as considerable leakage of K+ and UV-absorbing materials. These observations indicate that the lysis of S. faecium reported above is due to the activity of the endogenous bacterial autolysin. Induction of autolysis of S. faecium by freezing-thawing was also observed, although to a lesser extent, when Tris was replaced by imidazole.