Genome-enabled prediction of reproductive traits in Nellore cattle using parametric models and machine learning methods.

This study aimed to assess the predictive ability of different machine learning (ML) methods for genomic prediction of reproductive traits in Nellore cattle. The studied traits were age at first calving (AFC), scrotal circumference (SC), early pregnancy (EP) and stayability (STAY). The numbers of genotyped animals and SNP markers available were 2342 and 321 419 (AFC), 4671 and 309 486 (SC), 2681 and 319 619 (STAY) and 3356 and 319 108 (EP). Predictive ability of support vector regression (SVR), Bayesian regularized artificial neural network (BRANN) and random forest (RF) were compared with results obtained using parametric models (genomic best linear unbiased predictor, GBLUP, and Bayesian least absolute shrinkage and selection operator, BLASSO). A 5-fold cross-validation strategy was performed and the average prediction accuracy (ACC) and mean squared errors (MSE) were computed. The ACC was defined as the linear correlation between predicted and observed breeding values for categorical traits (EP and STAY) and as the correlation between predicted and observed adjusted phenotypes divided by the square root of the estimated heritability for continuous traits (AFC and SC). The average ACC varied from low to moderate depending on the trait and model under consideration, ranging between 0.56 and 0.63 (AFC), 0.27 and 0.36 (SC), 0.57 and 0.67 (EP), and 0.52 and 0.62 (STAY). SVR provided slightly better accuracies than the parametric models for all traits, increasing the prediction accuracy for AFC to around 6.3 and 4.8% compared with GBLUP and BLASSO respectively. Likewise, there was an increase of 8.3% for SC, 4.5% for EP and 4.8% for STAY, comparing SVR with both GBLUP and BLASSO. In contrast, the RF and BRANN did not present competitive predictive ability compared with the parametric models. The results indicate that SVR is a suitable method for genome-enabled prediction of reproductive traits in Nellore cattle. Further, the optimal kernel bandwidth parameter in the SVR model was trait-dependent, thus, a fine-tuning for this hyper-parameter in the training phase is crucial.

Idade à puberdade e características reprodutivas de novilhas mestiças F1 Holandês x Gir com fenótipos divergentes para consumo alimentar residual / [Age at puberty and reproductive characteristics of F1 Holstein x Gyr crossbred heifers with divergent phenotypes for residual feed intake]

A relação da eficiência nutricional com a idade e o peso à puberdade e as características reprodutivas foram estudadas em 35 novilhas F1 Holandês x Gir, em ensaios usando o consumo alimentar residual (CAR) nos períodos pós-desaleitamento (PD) e pós-puberdade (PP). Novilhas PD (P<0,0001) e PP (P<0,001) foram ranqueadas como de alta, intermediária e baixa eficiências e apresentaram CAR de -0,259 -0,014 e 0,346kg/dia e -0,848 -0,096 e 0,842kg/dia, respectivamente. Novilhas PD diferiram (P<0,05) na idade à puberdade entre ranques de alta, intermediária e baixa eficiências, em média, aos 339,7; 346,4; 315,3 dias, respectivamente. Os pesos à puberdade de novilhas PD com alta, intermediária e baixa eficiências foram, em média, de 321±28,1kg e não diferiram (P>0,05) entre CAR. Não foi verificada correlação entre diâmetro folicular, taxa de crescimento do folículo, número de ondas foliculares no ciclo estral e taxa de gestação à primeira IA com o CARPD ou CARPP. Novilhas F1HG selecionadas para CAR com baixa eficiência podem ter idade à puberdade 10 dias a mais, quando comparadas às novilhas de alta eficiência para CAR. Não foi verificado que novilhas selecionadas para alta ou baixa eficiências alimentares, usando CAR, tivessem algum impacto negativo sobre características reprodutivas avaliadas.(AU)

The relationship between nutritional efficiency and age and weight at puberty and reproductive traits was studied in 35 F1 Holstein x Gyr heifers, in trials using residual food consumption (CAR) in the post-weaning (PW) and post-pubertal (PP) periods. PD heifers (P<0.0001) and PP (P<0.001) were classified as high, intermediate and low efficiencies and presented CAR of -0.259 -0.014 and 0.346kg/day and -0.848 -0.096 and 0.842kg/day, respectively. PD heifers differed (P<0.05) in age at puberty between high, intermediate and low efficiencies, on average, at 339.7, 346.4 and 315.3 days, respectively. The weight at puberty of PD heifers with high, intermediate and low efficiencies were, on average, 321±28.1kg and did not differ (P>0.05) between CAR. No correlation was found between follicular diameter, follicle growth rate, number of follicular waves in the estrous cycle and pregnancy rate at 1st AI with the CARPD or CARPP. F1HG heifers selected for CAR with low efficiency can be aged at puberty 10 days longer when compared to high-efficiency heifers for CAR. These results did not show that heifers selected for high or low food efficiency, using CAR, had negative impact on the reproductive characteristics evaluated.(AU)

Idade à puberdade e características reprodutivas de novilhas mestiças F1 Holandês x Gir com fenótipos divergentes para consumo alimentar residual / [Age at puberty and reproductive characteristics of F1 Holstein x Gyr crossbred heifers with divergent phenotypes for residual feed intake]

A relação da eficiência nutricional com a idade e o peso à puberdade e as características reprodutivas foram estudadas em 35 novilhas F1 Holandês x Gir, em ensaios usando o consumo alimentar residual (CAR) nos períodos pós-desaleitamento (PD) e pós-puberdade (PP). Novilhas PD (P<0,0001) e PP (P<0,001) foram ranqueadas como de alta, intermediária e baixa eficiências e apresentaram CAR de -0,259 -0,014 e 0,346kg/dia e -0,848 -0,096 e 0,842kg/dia, respectivamente. Novilhas PD diferiram (P<0,05) na idade à puberdade entre ranques de alta, intermediária e baixa eficiências, em média, aos 339,7; 346,4; 315,3 dias, respectivamente. Os pesos à puberdade de novilhas PD com alta, intermediária e baixa eficiências foram, em média, de 321±28,1kg e não diferiram (P>0,05) entre CAR. Não foi verificada correlação entre diâmetro folicular, taxa de crescimento do folículo, número de ondas foliculares no ciclo estral e taxa de gestação à primeira IA com o CARPD ou CARPP. Novilhas F1HG selecionadas para CAR com baixa eficiência podem ter idade à puberdade 10 dias a mais, quando comparadas às novilhas de alta eficiência para CAR. Não foi verificado que novilhas selecionadas para alta ou baixa eficiências alimentares, usando CAR, tivessem algum impacto negativo sobre características reprodutivas avaliadas.(AU)

The relationship between nutritional efficiency and age and weight at puberty and reproductive traits was studied in 35 F1 Holstein x Gyr heifers, in trials using residual food consumption (CAR) in the post-weaning (PW) and post-pubertal (PP) periods. PD heifers (P<0.0001) and PP (P<0.001) were classified as high, intermediate and low efficiencies and presented CAR of -0.259 -0.014 and 0.346kg/day and -0.848 -0.096 and 0.842kg/day, respectively. PD heifers differed (P<0.05) in age at puberty between high, intermediate and low efficiencies, on average, at 339.7, 346.4 and 315.3 days, respectively. The weight at puberty of PD heifers with high, intermediate and low efficiencies were, on average, 321±28.1kg and did not differ (P>0.05) between CAR. No correlation was found between follicular diameter, follicle growth rate, number of follicular waves in the estrous cycle and pregnancy rate at 1st AI with the CARPD or CARPP. F1HG heifers selected for CAR with low efficiency can be aged at puberty 10 days longer when compared to high-efficiency heifers for CAR. These results did not show that heifers selected for high or low food efficiency, using CAR, had negative impact on the reproductive characteristics evaluated.(AU)

HPV infection as a risk factor for atherosclerosis: A connecting hypothesis.

Atheromatous plaques occurring in large arteries are common and life-threatening lesions. Multiple factors are involved in the pathogenesis of atheromatous plaques, such as hyperlipidaemia and hypercholesterolaemia, high blood pressure and chronic systemic inflammation. Recent findings have suggested that infection with high-risk human papillomavirus (HPV) may increase the risk of developing atheromatous plaques. However, HPV is considered a tissue-specific virus with a strong tropism towards squamous epithelial cells, and the mechanisms whereby it may promote the development of atheromas remain unclear. Here, we propose a connecting hypothesis to explain the possible causative role of HPV on atheroma development. We hypothesize that HPV infection may promote atheroma formation in infected patients by enhancing systemic inflammation or by directly targeting blood vessels via nucleic acids carried by extracellular vesicles such as exosomes. The pro-inflammatory effects of HPV and the release of extracellular vesicles by HPV-transformed cells are well documented in scientific literature. Possible experimental approaches to test this hypothesis are also discussed, especially experiments employing transgenic mice bearing HPV16 transgenes. If correct, this hypothesis would have major implications for the prevention of cardiovascular diseases, especially due to the preventable nature of HPV infection through vaccination.

Mortality risk among women exposed to violence in Brazil: a population-based exploratory analysis.

OBJECTIVES: The objective of this study was to estimate mortality risk among women exposed to violence in Brazil using population-based data. STUDY DESIGN: This study used a linked database containing nearly 800,000 violence (against women) notifications and 16,500 associated deaths over the period 2011-2016. METHODS: Aggregate age-standardized population-based rates of mortality were built to estimate risk ratios (RRs) at the national and state level, and for different forms of violence and causes of death, as well as type of offender involved, and across various characteristics of the women. RRs compared the rate of mortality among women exposed to violence with that in the general population of women - excess mortality due to violence was also derived from this comparison. The analysis was divided into two time periods (2011-13 and 2014-16). RESULTS: During 2014-16, women exposed to violence had an estimated mortality risk that was 8.3 [95% confidence interval (CI): 8.2-8.5] times higher than that of the general woman population, and an estimated 100 women died on a weekly basis as a direct or indirect consequence of exposure to violence. Higher (all-cause) mortality risk was associated with physical violence and violence that involved repetition and that was self-inflicted. The risk of mortality increased when the cause of death involved external causes (RR: 51.2, 95% CI: 49.6-52.8). When death was attributable to (i) non-communicable diseases and (ii) communicable, maternal, neonatal, and nutritional diseases, the risk was 5.4 [95% CI: 5.3-5.6] and 6.7 [95% CI: 6.1-7.2] times, respectively. Women at greatest (all-cause) mortality risk include white and multiracial (parda) and single women in the age group 10-29 years, who live in the northeast part of the country. When the offender was a partner/ex., women aged 10-19 years showed the greatest (all-cause) mortality risk at 16.9 [95% CI: 13.9-19.8] times. Higher risk was also observed within the age group 30-59 years when death was attributable to external causes (RR: 74.6, 95% CI: 71.3-77.9). For younger women and girls, there was a clear gradient in (all-cause) mortality risk, with those living in the poorest municipalities at greater risk. Age-specific mortality risk also showed significant variation within and across states. CONCLUSIONS: This analysis suggests that most women exposed to violence will likely experience an increased risk of mortality, regardless of her place of residence, age group, racial/ethnic background, marital status situation, and socio-economic status. The estimated RRs are only an approximation given the design of this analysis and should be interpreted with caution.

Hepatic injury induced by thioacetamide causes aortic endothelial dysfunction by a cyclooxygenase-dependent mechanism.

Liver cirrhosis is associated with a wide range of cardiovascular abnormalities including hyperdynamic circulation and cirrhotic cardiomyopathy. The pathogenic mechanisms of these cardiovascular changes are multifactorial and include vascular dysregulations. AIM: The present study tested the hypothesis that the systemic vascular hyporesponsiveness in thioacetamide (TAA)-induced liver injury model is dependent on nitric oxide (NO) and cyclooxygenase (COX) derivatives. MAIN METHODS: Wistar rats were treated with TAA for eight weeks to induce liver injury. KEY FINDINGS: The maximal contractile response in concentration-effect curves to phenylephrine was decreased in aorta from TAA-treated rats, but no differences were found in aorta without endothelium, suggesting an endothelium-dependent mechanism in decreased contractile response. There was no difference in the contractile response with and without L-NAME (N(ω)-nitro-l-arginine methyl ester) in rats with liver injury, showing that the TAA treatment impairs NO synthesis. Pre-incubation of the aorta with indomethacin, a COX-inhibitor, normalized the reduced contractile response to phenylephrine in arteries from TAA group. Also, COX-2 and iNOS (inducible nitric oxide syntase) protein expression was increased in aorta from TAA group compared to control group. Animals submitted to TAA treatment had a reduction in systolic blood pressure. Our findings demonstrated that liver injury induced by TAA caused a decrease in aortic contractile response by a COX-dependent mechanism but not by NO release. Also, it was demonstrated an inflammatory process in the aorta of TAA-treated rats by increased expression of COX-2 and iNOS. SIGNIFICANCE: Therefore, there is an essential contribution of COX-2 activation in extra-hepatic vascular dysfunction and inflammation present in cirrhosis induced by TAA.

Resistance of mice to Leptospira infection and correlation with chemokine response.

Leptospirosis is globally widespread neglected disease, affecting most mammalian species. Clinical signs can be confused with other diseases which make the diagnosis and treatment difficult. Chemokines and cytokines are known for their role in the inflammatory and immune response to infections. The profile determination of chemokines' expressions in the course of infection may elucidate the defense mechanisms of the host and support the search for effective treatment strategies. We investigated the mechanisms of innate immunity through the comparison of chemokines induced during infection with L. interrogans in mice with different levels of susceptibility. We used lung and spleen tissues samples of mice from C3H/HeJ, C3H/HePas and Balb/c, respectively sensitive, intermediate susceptibility and resistant to the pathogen. The inoculation of L. interrogans in C3H/HeJ mice led a comparatively smaller change in chemokines expression in both spleen and lung tissues. In samples from spleens and lungs of C3H/HePas and Balb/c the higher increases occurred on CXCL9, CXCL16, CXCL5, CCL8 and CCL5 in Balb/c. Given the same genetic background, the differences in the responses of C3H/HePas compared to C3H/HeJ mice strongly suggest the role of chemokines for the survival of parental strain. Therefore, the greatest increase in CXC chemokines appears to be efficient to induce migration of cells to the secondary lymphoid organs and affected tissues, which is important to control infection. Overall, CXC chemokines are important for the activation and attraction of T cell and may influence the course and control of the infection in resistant Balb/c mice.

Comparison of body adiposity index (BAI) and air displacement plethysmograph with estimations of % body fat in adults with Down's syndrome.

BACKGROUND/OBJECTIVES: The aim of this study was to verify the agreement between body fat percentage (%BF) values evaluated by air displacement plethysmograph (ADP) and body adiposity index (BAI) in adults with Down's syndrome (DS). SUBJECTS/METHODS: Forty-five adults with DS volunteered to participate in this study (19 women; age 28.7±8.5 years and 26 men; age 29.1±8.8 years). The %BF was measured by ADP (%BFADP) and estimated by anthropometric measures [%BF=(hip circumference/height)1.5-18] (%BFBAI). Agreement between methods was evaluated by paired t-test, Pearson's correlation coefficient and Bland-Altman analysis. RESULTS: Although high correlation coefficients were found between %BFADP and %BFBAI for women (r=0.78, P<0.05) and men (r=0.87, P<0.05), significant differences were observed between methods for both sexes (38.9±8.9 vs 42.5±8.5% for women, and 25.8±11.3 vs 32.6±5.4% for men in %BFADP and %BFBAI, respectively). Moreover, Bland-Altman analysis showed that the mean error estimate was +3.6 (95%CI, -7.59 to 14.79) in women and +6.74 (95%CI, -7.25 to 20.72) in men. CONCLUSIONS: The results indicate that BAI seems to be a limited method to evaluate %BF in women and in men with DS.

An electronic device to record consensual reflex in human pupil.

Examination of the pupil offers an objective evaluation of visual function as well as the vegetative pathways to the eye. This work proposes the development of an effective method and a portable device to test the consensual pupillary reflex. The first results demonstrate the success of a new device construction and methodology to record the consensual reflex with different stimulus, in a situation of complete blockage of light.

Spatial and temporal distribution in density and biomass of two Pseudodiaptomus species (Copepoda: Calanoida) in the Caeté river estuary (Amazon region--North of Brazil).

Spatial and temporal density and biomass distribution of the planktonic copepods Pseudodiaptomus richardi and P. acutus along a salinity gradient were investigated in the Caeté River Estuary (North-Brazil) in June and December, 1998 (dry season) and in February and May, 1999 (rainy season). Copepod biomass was estimated using regression parameters based on the relation of dry weight and body length (prosome) of adult organisms. The Caeté River Estuary was characterized by high spatial and temporal variations in salinity (0.8-37.2). Exponential length-weight relationships were observed for both Pseudodiaptomus species. Density and biomass values oscillated between 0.28-46.18 ind. m-3 and 0.0022-0.3507 mg DW. m-3 for P. richardi; and between 0.01-17.02 ind. m-3 and 0.0005-0.7181 mg DW. m-3 for P. acutus. The results showed that the contribution of P. richardi for the secondary production in the Caeté River Estuary is more important in the limnetic zone than in other zones where euhaline-polyhaline regimes were predominant. However, it was not possible to observe a clear pattern of spatial and temporal distribution for P. acutus.

Spatial and temporal distribution in density and biomass of two Pseudodiaptomus species (Copepoda: Calanoida) in the Caeté river estuary (Amazon region - North of Brazil)

A distribuição espacial e temporal da densidade e biomassa dos copépodos planctônicos Pseudodiaptomus richardi e P. acutus, ao longo de um gradiente de salinidade, foi estudada no Estuário do Rio Caeté (Norte do Brasil) durante os meses de junho e dezembro de 1998 (estação seca) e fevereiro e maio de 1999 (estação chuvosa). A biomassa dos copépodos foi estimada a partir de parâmetros da regressão baseada na relação entre o peso seco e o comprimento do corpo (prossoma) de organismos adultos. O Estuário do Rio Caeté caracterizou-se por uma grande variação espacial e sazonal na salinidade (0,8-37,2‰). A relação peso-comprimento para ambas as espécies de Pseudodiaptomus foi do tipo exponencial. Os valores de densidade e biomassa oscilaram entre 0,28-46,18 ind. m-3 e 0,0022-0,3507 mg DW. m-3 para P. richardi; e entre 0,01-17,02 ind. m-3 e 0,0005-0,7181 mg DW. m-3 para P. acutus. Os resultados revelaram que a contribuição de P. richardi para a produção secundária no Estuário do Rio Caeté é mais importante na zona liminética que em outras zonas onde foram dominantes os regimes eurihalino-polihalino. Contudo, para P. acutus não foi possível observar de forma clara um padrão de distribuição espacial e temporal para a área estudada.

In vitro and in vivo properties of usnic acid encapsulated into PLGA-microspheres.

Microparticles will probably play a promising role in the future of chemotherapy. These polymeric delivery systems are capable of maximizing the therapeutic activity while reducing side effects of anti-cancer agents. Usnic acid (UA) is a secondary metabolite produced by lichens, which exhibits an anti-tumour activity. In this study, PLGA-microspheres containing usnic acid from Cladonia substellata were prepared by the double emulsion method, with or without PEG as stabilizer. The morphology of the microspheres was examined by optical and scanning electron microscopy. The in vitro kinetic profile of usnic acid loaded-microspheres was carried out by dissolution testing. The usnic acid content was analysed by HPLC. The cytotoxicity of free and encapsulated usnic acid was evaluated against HEp-2 cells using the MTT method. The anti-tumour assay was performed in mice against Sarcoma-180 tumour (UA 15 mg kg(-1) weight body/day) during 7 days. Animals were then sacrificed and tumour and organs were excised for histopathological analysis. Microspheres presented a smooth spherical surface with a mean diameter of 7.02 +/- 2.72 microm. The usnic acid encapsulation efficiency was approximately 100% (UA 10 mg 460 mg(-1) microspheres). A maximum release of 92% was achieved at the fifth day. The IC50 values for free and encapsulated usnic acid were 12 and 14 microg ml(-1), respectively. The encapsulation of usnic acid into microspheres promoted an increase of 21% in the tumour inhibition as compared with the free usnic acid treatment. In summary, usnic acid was efficiently encapsulated into PLGA-microspheres and the microencapsulation improved its anti-tumour activity.

The participation of AtXPB1, the XPB/RAD25 homologue gene from Arabidopsis thaliana, in DNA repair and plant development.

Nucleotide excision repair in Arabidopsis thaliana differs from other eukaryotes as it contains two paralogous copies of the corresponding XPB/RAD25 gene. In this work, the functional characterization of one copy, AtXPB1, is presented. The plant gene was able to partially complement the UV sensitivity of a yeast rad25 mutant strain, thus confirming its involvement in nucleotide excision repair. The biological role of AtXPB1 protein in A. thaliana was further ascertained by obtaining a homozygous mutant plant containing the AtXPB1 genomic sequence interrupted by a T-DNA insertion. The 3' end of the mutant gene is disrupted, generating the expression of a truncated mRNA molecule. Despite the normal morphology, the mutant plants presented developmental delay, lower seed viability and a loss of germination synchrony. These plants also manifested increased sensitivity to continuous exposure to the alkylating agent MMS, thus suggesting inefficient DNA damage removal. These results indicate that, although the duplication seems to be recent, the features described for the mutant plant imply some functional or timing expression divergence between the paralogous AtXPB genes. The AtXPB1 protein function in nucleotide excision repair is probably required for the removal of lesions during seed storage, germination and early plant development.

Bioequivalence of two lamivudine tablet formulations.

The present study describes the determination of the bioavailability of a new commercial tablet formulation of lamivudine (CAS 134678-17-4) compared with a reference formulation. The comparative bioequivalence of the test and a reference formulation (each 3 x 150 mg) was assessed in 24 healthy volunteers by means of a randomized two-way crossover design. Prior to the study both the test and reference formulations were examined for conformation to chromatographic purity and drug content. Each volunteer received the test (T) and the reference formulation (R) with a one-week drug-free interval between administrations. The plasma concentrations of T were monitored over a period of 12 h after drug administration using a sensitive HPLC method. Pharmacokinetic parameters for T were determined from plasma concentration-time data. Statistical tests were carried out at 90% confidence intervals using a parametric method (three-way ANOVA) for AUC and Cmax, and non-parametric method for Tmax. The present study showed that both formulations were bioequivalent for the geometric mean of AUC(0-12), AUC0-infinity), Cmax, and Tmax at the 90% confidence interval. The bioavailability of the test (%) was 96.7, 93.3, 99.7, 100.3, respectively. The T:R ratio was, in each case, well within the acceptable range of 100 +/- 20%.

DNA repair-related genes in sugarcane expressed sequence tags (ESTs)

A identificaçäo e caracterizaçäo de genes envolvidos com reparo de DNA säo de grande interesse, dada a sua importância na manutençäo da integridade genômica. Além disso, a alta conservaçäo dos genes de reparo de DNA faz com que possam ser utilizados como fonte de informaçäo no que diz respeito à origem e evoluçäo das espécies. Os mecanismos relacionados à remoçäo de danos pelo reparo de DNA, bem como suas conseqüências biológicas, já säo bem conhecidas em bactérias, leveduras e animais. Entretanto, no que diz respeito a organismos vegetais, ainda há muito a ser investigado. No presente trabalho, apresentamos a identificaçäo dos genes envolvidos nas principais vias de reparo de DNA em cana-de-açúcar, através de uma análise de similaridade do banco de dados do projeto brasileiro Sugarcane Expressed Sequence Tag (SUCEST) com seqüências protéicas conhecidas disponíveis em outros bancos de dados públicos (National Center of Biotechnology Information (NCBI) e Munich Information Center for Protein Sequences (MIPS) Arabidopsis thaliana). Esta busca revelou que a gama de proteínas envolvidas no reparo de DNA em cana-de-açúcar é similar a de outros eucariotos. Mesmo assim, foi possível identificar algumas características interessantes encontradas apenas em vegetais, provavelmente em funçäo do seu processo evolutivo independente. As vias de reparo do DNA aqui representadas incluem fotorreativaçäo, reparo excisäo de bases, reparo excisäo de nucleotídeos, reparo mismatch, end-joinning näo homólogo, reparo por recombinaçäo homóloga e tolerância a lesões. Este trabalho descreve as principais diferenças encontradas na maquinaria de reparo de DNA de células vegetais em relaçäo àquela de organismos nos quais encontra-se bem descrita. Tais diferenças chamam a atençäo para um potencial de mecanismos distintos em vegetais, que merecem futuras investigações.

Cloning of a cDNA from Arabidopsis thaliana homologous to the human XPB gene.

The human gene XPB, defective in xeroderma pigmentosum patients complementation group B, encodes a DNA helicase involved in several DNA metabolic pathways, including DNA repair and transcription. The high conservation of this gene has allowed the cloning of homologs in various species, such as mouse, yeast and Drosophila. Not much information on the molecular basis of nucleotide excision repair in plants is available, but these organisms may have similar mechanisms to other eukaryotes. A homolog of XPB was isolated in Arabidopsis thaliana by using polymerase chain reaction (PCR) with degenerate oligonucleotides based on protein domains which are conserved among several species. Screening of an Arabidopsis cDNA library led to the identification and isolation of a cDNA clone with 2670 bp encoding a predicted protein of 767 amino acids, denoted araXPB. Genomic analysis indicated that this is a nuclear single copy gene in plant cells. Northern blot with the cDNA probe revealed a major transcript which migrated at approx. 2,800 b, in agreement with the size of the cDNA isolated. The araXPB protein shares approximately 50% identical and 70% conserved amino acids with the yeast and human homologs. The plant protein maintains all the functional domains found in the other proteins, including nuclear localization signal, DNA-binding domain and helicase motifs, suggesting that it might also act as part of the RNA transcription apparatus, as well as nucleotide excision repair in plant cells.

Avaliaçäo da fauna e degradabilidade no rúmen de búfalos sob dietas exclusivas de silagem de sorgo e de feno de alfafa / Evaluation of fauna and degradability in the rumen of buffalo on exclusive diets of sorghum silage and alfafa hay

A populaçäo de protozoários ciliados no rúmen e a degradabilidade in situ da matéria seca e proteína bruta foram estudadas em dois búfalos com cânulas ruminais alimentados com dieta exclusiva de silagem de sorgo e dois com feno de alfafa. Os animais foram alimentados ad libitum por cinco semanas e 68 amostras de líquido ruminal (LR) foram colhidas para contagens de ciliados e determinaçäo do pH. Na última semana, sacos de náilon com feno de alfafa foram incubados no rúmen em seis tempos. Os búfalos alimentados com feno de alfafa apresentaram maior concentraçäo de Epidinium spp e menor de holotricos (P<0,05). A concentraçäo média (x 10 elevado a quarta potência/ml LR) e a composiçäo da fauna, entre parênteses, foram: Entodinium spp, 1,59 (25,2 por cento); Diplodiniinae, 3,92 (62,1 por cento); Epidinium spp, 0,54 (8,4 por cento); holotricos, 0,25 (3,9 por cento) e total, 6,31. Näo houve diferenças no pH ruminal (média 6,86). Dieta com silagem de sorgo resultou em menor solubilidade e maior taxa de degradaçäo in situ da MS e PB do feno de alfafa. A ingestäo média de MS da silagem (95,4g/kg0,75) foi maior (P<0,05) que do feno (82,2g/kg 0,75sobrescrito)

An urban outbreak of visceral leishmaniasis in Natal, Brazil.

The epidemiological pattern of visceral leishmaniasis in north-eastern Brazil is changing. The disease was typically seen in rural, endemic areas, but is now occurring as an epidemic in the city of Natal where 316 cases have been reported since 1989; 49% were in children less than 5 years of age. The principle clinical and laboratory findings were weight loss, fever, hepato-splenomegaly, anaemia, leucopenia and hypergammaglobulinaemia. Elevated transaminases and hyperbilirubinaemia were also observed. The diagnosis was confirmed in 87% of cases by identifying amastigotes in aspirates from bone marrow or spleen. Five isolates were identified as Leishmania (L.) chagasi by isoenzyme analysis. The mortality rate was 9%; all deaths occurred during the first week in hospital. One person had concurrent human immunodeficiency virus infection. Among 210 household contacts and neighbours of patients from the endemic area examined for evidence of L. (L.) chagasi infection, 6 additional cases of visceral leishmaniasis were diagnosed. Thirty-eight percent of house-mates and neighbours gave a positive Montenegro skin test reaction, indicating prior subclinical infection.

"Pararamose": an occupational arthritis caused by lepidoptera (Premolis semirufa). An epidemiological study.

The frequency of "pararama" occupational accidents between 1988 and 1990 as well as some associated clinical manifestations are herein reported. Data were collected at an industrial rubber tree plantation, in the northern part of Brazil and compared with data similarly collected from 1971 to 1974 on the same plantation, before starting protective measures. "Pararama" is the popular name of the larval form of a native insect of the Amazonian region, Premolis semirufa. During the study period, the annual average number of latex extractors was 337 and 60 accidents caused by "pararama" were registered. The annual average number of accidents per worker from 1971 to 1974 was 0.117 and in the period of this study, 0.063 (p = 0.061). Nineteen injured subjects were clinically evaluated and 13 of them were symptomatic. There was a statistically significant association between multiple accidents and the presence of symptoms (p = 0.001). "Pararamose", an occupational arthropathy, which may evolve with functional impairment of the affected joint, can be prevented with the latex extractors education and the institution of prophylactic measures, such as the use of gloves, boots and protective glasses.