Season of birth as a risk factor for multiple sclerosis in Brazil

Risk factors for development of multiple sclerosis (MS) are still a matter of debate. Latitude gradient, vitamin D deficiency and season of birth are among the most investigated environmental factors associated with the disease. Several international studies suggest that birth in spring is a substantial risk factor for MS. We investigated the season of birth as a potential risk for MS in different geographical regions of Brazil. We conducted a cross-sectional retrospective study with 2257 clinically definite MS patients enrolled in 13 Brazilian MS clinics in the south, southeast, and northeast regions of Brazil. Demographic and clinical data relating to date of birth and clinical features of the disease were collected and analysed, and subsequently compared with birth date among the general Brazilian population. The distribution of date of birth of MS patients showed an increase in spring and a decrease in autumn, with no difference being observed in the other seasons. In conclusion, season of birth is a probable risk factor for MS in most parts of Brazil. These findings may be related to the role that vitamin D plays in MS pathogenesis. © 2013 Elsevier B.V. All rights reserved.

Effects of sire breed-grazing system and environmental parameters on the behaviour of beef calves just after birth

Effects of sire breed-grazing system and environmental factors on the first activities of high grade Nellore and crossbred Canchim x Nellore, Angus x Nellore, and Simmental x Nellore calves raised in intensive production systems and high grade Nellore calves raised in an extensive production system, after birth, were studied. During 2 years, 185 calves were observed from birth until the end of first suckling, and the following variables were estimated: duration of maternal attention (cow to calf) during the first 15 min after calving, latency to first attempt to stand up, latency to stand up, latency to first suckling, duration of first suckling and the interval from standing to suckling. Data were analyzed by least squares methods, with models that included fixed effects of year and time of the year of birth (March-April (early autumn) and May-June (late autumn)), sire breed-grazing system (Sy), sex of calf (Se), category of cow (primiparous and pluriparous), time of birth, Sy x Se, year x Sy and year x time of the year interactions and the covariates weight of calf, rainfall, air temperature and relative humidity in the day of birth. Calves born from 6:00 to 8:00 h presented the longest latencies to first stand up (40.3 +/- 5.1 min) and the shortest occur from 14:00 to 16:00 h (15.8 +/- 2.7 min) (P < 0.01). Primiparous cows provided longer attention toward the calf in the first 15 min after birth than pluriparous cows (13.0 +/- 0.7 min versus 11.1 +/- 0.5 min; P < 0.05). This attention was also shorter in earlier autumn (11.0 +/- 0.5 min) and longer in late autumn (13.1 +/- 0.8 min) (P < 0.05). Relative to sire breed-grazing system, Nellore calves raised intensively did take longer to stand and to suckle after birth as compared to crossbred calves also raised intensively (P < 0.01). However, grazing system did not affect (P > 0.05) any behaviour variable studied. As regard to sex differences, female calves did take less (P < 0.01) time to suckle after standing than male calves. Results showed that even purebred or crossbred Bos indicus calves in subtropical environmental need extra care when born on rainy days, especially during the first hours of the day. (C) 2006 Elsevier B.V. All rights reserved.

Birth defects in newborns and stillborns: An example of the Brazilian reality

Background: This study constitutes a clinical and genetic study of all newborn and stillborn infants with birth defects seen in a period of one year in a medical school hospital located in Brazil. The aims of this study were to estimate the incidence, causes and consequences of the defects. Methods. For all infants we carried out physical assessment, photographic records, analysis of medical records and collection of additional information with the family, besides the karyotypic analysis or molecular tests in indicated cases. Result: The incidence of birth defects was 2.8%. Among them, the etiology was identified in 73.6% (ci95%: 64.4-81.6%). Etiology involving the participation of genetic factors single or associated with environmental factors) was more frequent 94.5%, ci95%: 88.5-98.0%) than those caused exclusively by environmental factors (alcohol in and gestational diabetes mellitus). The conclusive or presumed diagnosis was possible in 85% of the cases. Among them, the isolated congenital heart disease (9.5%) and Down syndrome (9.5%) were the most common, followed by gastroschisis (8.4%), neural tube defects (7.4%) and clubfoot (5.3%). Maternal age, parental consanguinity, exposure to teratogenic agents and family susceptibility were some of the identified risk factors. The most common observed consequences were prolonged hospital stays and death. Conclusions: The current incidence of birth defects among newborns and stillbirths of in our population is similar to those obtained by other studies performed in Brazil and in other underdeveloped countries. Birth defects are one of the major causes leading to lost years of potential life. The study of birth defects in underdeveloped countries should continue. The identification of incidence, risk factors and consequences are essential for planning preventive measures and effective treatments. © 2011 Fett-Conte et al; licensee BioMed Central Ltd.

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

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Genetic analysis of visual scores and their relationships to mature female weight in Nellore breed

Dados de 79.884 animais da raça Nelore foram utilizados para estimar parâmetros genéticos e avaliar as relações entre os escores de conformação, precocidade e musculatura obtidos à desmama e ao sobreano e o peso das fêmeas à idade adulta. Utilizou-se o método da máxima verossimilhança restrita, em análise multicaracterísticas, com modelo que incluiu os efeitos genéticos aditivos direto e residual, como aleatórios, e os efeitos fixos de grupo de contemporâneos e, como covariáveis, a idade do animal à pesagem e a idade da mãe ao parto (exceto para o peso das fêmeas à idade adulta). Os grupos contemporâneos à desmama foram definidos pelas variáveis: sexo, rebanho, ano e mês de nascimento, grupo de manejo ao nascimento e à desmama. Na definição de grupo contemporâneo ao sobreano também foi incluída a variável grupo de manejo ao sobreano. Para o peso das fêmeas à idade adulta, o grupo de contemporâneos foi composto por rebanho, ano de nascimento, grupo de manejo ao sobreano, ano e estação da pesagem. Os efeitos genético materno e de ambiente permanente materno também foram incluídos no modelo para análise dos escores de conformação, precocidade e musculatura à desmama. As estimativas de herdabilidade direta obtidas foram 0,18 ± 0,02 para o escore de conformação; 0,21 ± 0,01 para o escore de precocidade; 0,22 ± 0,01 para o escore de musculatura à desmama e 0,24 ± 0,01 para o escore de conformação; 0,27 ± 0,01 para o escore de precocidade; e 0,26 ± 0,01 para o escore de musculatura ao sobreano e 0,42 ± 0,02 para o peso das fêmeas à idade adulta. As correlações genéticas estimadas entre os escores visuais medidos à desmama e ao sobreano foram positivas, variando de média a alta magnitude (0,56 ± 0,03 a 0,85 ± 0,01). Por outro lado, as correlações genéticas estimadas entre os escores visuais e o peso das fêmeas à idade adulta foram positivas e moderadas, variando de 0,21 ± 0,03 a 0,35 ± 0,03. Os resultados obtidos indicam que a seleção de animais com maiores escores visuais, principalmente ao sobreano, deve promover aumento do peso das fêmeas à idade adulta.

Comparison of non-linear growth models to describe the growth curve in West African Dwarf sheep

The objectives of this study were to compare the goodness of fit of four non-linear growth models, i.e. Brody, Gompertz, Logistic and Von Bertalanffy, in West African Dwarf (WAD) sheep. A total of 5274 monthly weight records from birth up to 180 days of age from 889 lambs, collected during 2001 to 2004 in Betecoucou breeding farm in Benin were used. In the preliminary analysis, the General Linear Model Procedure of the Statistical Analysis Systems Institute was applied to the dataset to identify the significant effects of the sex of lamb (male and female), type of birth (single and twin), season of birth (rainy season and dry season), parity of dam (1, 2 and 3) and year of birth (2001, 2002, 2003 and 2004) on the observed birth weight and monthly weight up to 6 months of age. The models parameters (A, B and k), coefficient of determination (112), mean square error (MSE) were calculated using language of technical computing package Matlab(R), 2006. The mean values of A, B and k were substituted into each model to calculate the corresponding Akaike's Information Criterion (AIC). Among the four growth functions, the Brody model has been selected for its accuracy of fit according to the higher R(2), lower MSE and A/C Finally, the parameters A, B and k were adjusted in Matlab(R) 2006 for the sex of lamb, year of birth, season of birth, birth type and the parity of ewe, providing a specific slope of the Brody growth curve. The results of this study suggest that Brody model can be useful for WAD sheep breeding in Betecoucou farm conditions through growth monitoring.

Evaluation of neonatally-induced mild diabetes in rats: Maternal and fetal repercussions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Perinatal factors associated with early deaths of preterm infants born in Brazilian Network on Neonatal Research centers

Objective: To evaluate perinatal factors associated with early neonatal death in preterm infants with birth weights (BW) of 400-1,500 g.Methods: A multicenter prospective cohort study of all infants with BW of 400-1,500 g and 23-33 weeks of gestational age (GA), without malformations, who were born alive at eight public university tertiary hospitals in Brazil between June of 2004 and May of 2005. Infants who died within their first 6 days of life were compared with those who did not regarding maternal and neonatal characteristics and morbidity during the first 72 hours of life. Variables associated with the early deaths were identified by stepwise logistic regression.Results: A total of 579 live births met the inclusion criteria. Early deaths occurred in 92 (16%) cases, varying between centers from 5 to 31%, and these differences persisted after controlling for newborn illness severity and mortality risk score (SNAPPE-II). According to the multivariate analysis, the following factors were associated with early intrahospital neonatal deaths: gestational age of 23-27 weeks (odds ratio - OR = 5.0; 95%CI 2.7-9.4), absence of maternal hypertension (OR = 1.9; 95%CI 1.0-3.7), 5th minute Apgar 0-6 (OR = 2.8; 95%CI 1.4-5.4), presence of respiratory distress syndrome (OR = 3.1; 95%CI 1.4-6.6), and network center of birth.Conclusion: Important perinatal factors that are associated with early neonatal deaths in very low birth weight preterm infants can be modified by interventions such as improving fetal vitality at birth and reducing the incidence and severity of respiratory distress syndrome. The heterogeneity of early neonatal rates across the different centers studied indicates that best clinical practices should be identified and disseminated throughout the country.

Growth curve of Nellore calves reared on natural pasture in the Pantanal

Weight-age and hip height-age relations of Nellore calves, from birth to 10 months old were fitted using a logistic model including sex and year of birth as fixed effects. Calves and their dams were reared on natural pasture using continuous grazing system. The crude protein content and total digestible nutrients were analyzed for pasture selected by the animals. The weights of the calves were adjusted to 205 days and 365 days. There were no significant effects of sex and birth year on the growth curve parameters, but there were significant effects of sex on hip height. The average weight (a parameter) at 10 months of age was 170 kg and the inflection point was observed at 93.5 days old. When weight-age and hip height-age curves were combined in the same graph, the intersection occurred at 142 days. The number of days to gain 160 kg from birth to 205 days of age (adjusted) and number of days to gain 240 kg from 205 days to slaughter was different between the birth years, which were probably due to the quality of the natural pastures. It is necessary to implement nutritional management strategies such as high quality pasture and/or feeding supplementation for calves once they reach three months of age.

Genetic trends in the expected progeny difference of the asymptotic weight of Nelore females

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genetic and phenotypic trends for growth traits of buffaloes in Brazil

The objectives this paper were to estimate genetic parameters and genetic and phenotypic trends of birth weight (BWT) and weights adjusted to 205 (WT205), 365 (WT365) and 550 (P550) days of age of beef buffaloes born from 1985 to 2003 in Brazil. For BWT and WT205 the model included direct and maternal genetic and maternal environment as random effects and contemporary and genetic groups as fixed effects. For WT365 and WT550 the same model was used except without direct maternal and maternal environmental effects. The genetic and phenotypic trends were estimated by regression of means of dependent variables on birth year of animals Regressions were obtained by using two methodologies: 1) linear regression; and 2) non-parametric splined regression. The direct heritability estimates were 0.09, 0.45, 0.46 and 0.58 for BWT, WT205, WT365 and WT550, respectively. The direct genetic trends from linear regression were 0.01, 0.23, 0.58 and 1.40 kg per year for PN, WT205, VVT365 and WT550, respectively (P<0.001 for all). Phenotypic trends were strongly positive while genetic trends were consistently positive but small. Genetic parameters indicate potential for increased rate of genetic change with full implementation of genetic improvement programs.

Treatment of developmental defect of upper lip with carbon dioxide laser radiation (CO2): First surgical time

With the exception of the cleft lip, developmental defects (DD) of the lip are rare. The upper lip originates from the ectomesenchyme and is formed by the merging of the nasal medial and lateral processes with the maxillary process. Disturbances during this formation period can cause DD with functional and/or esthetic repercussions. We present a case of DD of the upper lip in a patient with a history of progressive growth of the left lateral portion of the upper lip that occurred from the time of birth until the age of 22 years. Clinical examination revealed hypertrophy of the area from the left philtral columns to the left commissure of the lip, extending the portion of the surface mucosa creating a flaccid and asymptomatic tissue mass. All other buccal structures appeared to be within normal limits and without any evidence of defects or deformities. In the surgical planning we decided to carry out corrective surgery in two phases. The first phase accomplished a conservative excision of the total abnormal labial tissue mass with a CO2 laser radiation (5 W in continuous mode, bunch diameter φ = 0.6 mm with a power density of 768 W/cm2 and fluency of 0.231 J/cm2) being careful to preserve the vermilion portion of the lip. Postsurgical clinical evaluations were done every three days until the skin sutures were removed and then every seven days until two months post surgery. While the entire mass of excessive tissue could not be completely removed, the removal of the excessive mucosal tissue produced a very good outcome relative to lip function, with a good esthetic result without scarring, and good tissue mobility. The results showed that the CO2 laser is an extremely useful instrument that can provide excellent control of the surgical field and allow for healing that produces excellent functional and esthetic results. © 2005 Taylor & Francis.

Analysis of culling probability in dairy buffalo using survival models

In order to contribute to the genetic breeding programs of buffaloes, this study aimed to determine the influence of environmental effects on the stayability (ST) of dairy female Murrah buffalo in the herd. Data from 1016 buffaloes were used. ST was defined as the ability of the female to remain in the herd for 1, 2, 3, 4, 5 or 6 years after the first calving. Environmental effects were studied by survival analysis, adjusted to the fixed effects of farm, year and season of birth, class of first-lactation milk yield and age at first calving. The data were analyzed using the LIFEREG procedure of the SAS program that fits parametric models to failure time data (culling or ST = 0), and estimates parameters by maximum likelihood estimation. Breeding farm, year of birth and first-lactation milk yield significantly influenced (P < 0.0001) the ST to the specific ages (1 to 6 years after the first calving). Buffaloes that were older at first calving presented higher probabilities of being culled 1 year after the first calving, without any effect on culling at older ages. Buffaloes with a higher milk yield at first calving presented a lower culling probability and remained for a longer period of time in the herd. The effects of breeding farm, year of birth and first-lactation milk yield should be included in models used for the analysis of ST in buffaloes. Copyright © The Animal Consortium 2010.

Genotype×production environment interaction for weaning weight in Angus populations of Brazil and Uruguay

The objective of this study was to define production environments by grouping different environmental factors and, consequently, to assess genotype by production environment interactions on weaning weight (WW) in the Angus populations of Brazil and Uruguay. Climatic conditions were represented by monthly temperature means (°C), minimum and maximum temperatures in winter and summer respectively and accumulated rainfall (mm/year). Mode in month of birth and weaning, and calf weight (kg) and age (days) at weaning were used as indicators of management conditions of 33 and 161 herds in 13 and 34 regions in Uruguay and Brazil, respectively. Two approaches were developed: (a) a bi-character analysis of extreme sub-datasets within each environmental factor (bottom and top 33% of regions), (b) three different production environments (including farms from both countries) were defined in a cluster analysis using standardized environmental factors. To identify the variables that influenced the cluster formation, a discriminant analysis was previously carried out. Management (month, age and weight at weaning) and climatic factors (accumulated rainfalls and winter and summer temperatures) were the most important factors in the clustering of farms. Bi or trivariate analyses were performed to estimate heritability and genetic correlations for WW in extreme sub-datasets within environmental factor or between clusters, using MTDFREML software. Heritability estimates of WW in the first approach ranged from 0.27 to 0.54, and genetic correlations between top and bottom sub-datasets within environmental factors, from -0.29 to 0.70. In the cluster approach, heritabilities were 0.58±0.04 for cluster 1, 0.31±0.01 for Cluster 2 and 0.40±0.02 for Cluster 3. Genetic correlations were 0.27±0.08, 0.32±0.09 and 0.33±0.09, between clusters 1 and 2, 1 and 3, and 2 and 3, respectively. Both approaches suggest the existence of genotype x environment interaction for weaning weight in Angus breed of Brazil and Uruguay. © 2012 Elsevier B.V.