Seleção e classificação multivariada de modelos não lineares para frangos de corte / Selection and classification of multivariate nonlinear models for broilers

Objetivou-se com este estudo utilizar a técnica de análise de agrupamento para classificar modelos de regressão não lineares usados para descrever a curva de crescimento de frangos de corte, levando em consideração os resultados de diferentes avaliadores de qualidade de ajuste. Para tanto, utilizaram-se dados de peso corporal e idade dos seguintes grupos genéticos de frangos de corte: Cobb500, Hubbard Flex e Ross308, de ambos os sexos, constituindo, assim, seis classes. Foram ajustados 10 modelos não lineares, cuja qualidade de ajuste foi medida pelo coeficiente de determinação ajustado, pelos critérios de informação de Akaike e bayesiano, pelo quadrado médio do erro e pelo índice assintótico. A análise de agrupamento indicou os modelos logístico, Michaelis-Menten, Michaelis-Menten modificado e von Bertalanffy como os mais adequados à descrição das curvas de crescimento das seis classes estudadas.

The aim of this study was to classify non-linear models used to describe the growth curve of broilers using the cluster analysis technique, taking into account the results of different measures of quality adjustment regression. For this purpose, we used data of body weight and age the following genetic groups of broilers: Cobb500, Hubbard Flex and Ross308, of both sexes, thus constituting six classes. Ten non-linear models were fitted, the quality of fit was measured by the adjusted coefficient of determination, Akaike information criteria and Bayesian, mean square error and index asymptotic. Cluster analysis indicated the Logistico, Michaelis Menten, Michaelis Menten Modificado and von Bertalanffy models as the most appropriate description of the growth curves for the six classes studied.

Crescimento de genótipos de frangos tipo caipira / Growth of genotypes of an alternative strain of broiler chickens

Objetivou-se com este trabalho comparar o padrão de crescimento, mediante ajustes das respectivas curvas de crescimento por modelos não lineares, bem como estudar o desenvolvimento de cortes de carcaça em relação ao peso da carcaça em diferentes genótipos de frangos tipo caipira. Foram utilizados 840 pintos de um dia, machos, distribuídos em delineamento inteiramente ao acaso, dos seguintes genótipos da linhagem Redbro: Caboclo, Carijó, Colorpak, Gigante Negro, Pesadão Vermelho, Pescoço Pelado e Tricolor. As aves foram alojadas em 28 boxes, sendo 30 aves/boxe, em galpão de alvenaria com acesso a um piquete de 45m², com quatro repetições. O peso corporal individual dos frangos foi medido ao nascer, aos 14, 28, 42, 56, 70 e 84 dias de idade. Para a determinação das curvas de crescimento do peso corporal das aves, os dados coletados foram avaliados por meio dos modelos não lineares: Brody, Gompertz, Logístico, Richards e von Bertalanffy. Foi empregado o PROC NLIN do SAS, utilizando-se o método interativo de Gauss-Newton. Os critérios usados para escolha do modelo de melhor ajuste da curva de crescimento foram o coeficiente de determinação, o desvio padrão assintótico, o desvio médio absoluto dos resíduos e o índice assintótico. As análises para obtenção dos coeficientes alométricos foram realizadas por meio do PROC GLM do SAS para os genótipos Carijó, Colorpak, Pesadão Vermelho, Pescoço Pelado e Tricolor. Foram avaliados os pesos da carcaça, do peito, das coxas, das sobrecoxas, das pernas e das asas das aves abatidas aos 85 dias de idade. Apenas as equações propostas por Gompertz, von Bertalanffy e Logístico atingiram a convergência, e o modelo proposto por von Bertalanffy foi o mais adequado para descrever o crescimento dos genótipos de frangos caipiras. Todos os cortes avaliados apresentaram crescimento tardio em relação ao peso da carcaça em genótipos de frangos tipo caipira.

The aim of this work was to compare the growth pattern, adjusting the growth curves by nonlinear models and studying the development of housing sections in relation to the weight of the chicken carcass in different genotypes of an alternative strain of broiler chickens. We used 840 one day old male chicks distributed in a completely randomized design, with the following genotype strains: Redbro: Caboclo, Carijó, Colorpak, Gigante Negro, Pesadão Vermelho, Pescoço Pelado and Tricolor. The birds were housed in 28 boxes, 30 birds / box in a masonry shed with access to a 45 square meter paddock, with four replications. Body weight was measured in chickens up to 84 days of age. To determine the growth curves of the body weight of birds, collected data were evaluated from the nonlinear models: Brody, Gompertz, Logistic, Richards and von Bertalanffy. Was used "proc nlin" of SAS, using the iterative method of Gauss-Newton. The criteria used to choose the best model for the growth curve were the coefficient of determination, the asymptotic standard deviation, the mean absolute deviation of the waste and the asymptotic index. The analysis to obtain the allometric coefficients were performed using the "proc glm" SAS for genotypes Carijó, Colorpak, Pesadão Vermelho, Pescoço Pelado and Tricolor. We assessed the weights of carcass, breast, thighs, drumsticks, legs and wings. Only the equations proposed by Gompertz, Logistic and von Bertalanfy reached convergence, and the model proposed by von Bertalanffy was the most appropriate. All sections were evaluated in relation to the late growth of carcass weight in alternative lines of broiler chickens.

Egg laying and egg quality in meat type quails in diallel crosses.

This study aimed to assess egg laying and egg quality in quail lines in diallel crosses. We evaluated 16 genetic groups obtained from crosses of four strains of meat quails (L1, L2, L3, and L4) in a complete diallel. We assessed weekly egg number (WEN), egg yield (EY), egg weight (EW), and Haugh unit (HU) for: 51-80, 81-110, 111-140, and 51-140 days (whole period) old. The general combining capacity (GCC) showed significance for WEN and EY, with the exception of the period of 111-140 days. In general, L3 had the highest positive GCC estimates. The additive genetic variability was significant for EW in all periods, as was HU, with the exception of the first period. The specific combining capacity was significant for HU, except in the second period. The largest estimates for GCC were submitted by L1 for EW, followed by L4, considering the whole period. For HU, L2 had the highest estimates for GCC. The more favorable cross for HU was L2xL3, in the whole period. In the third period, there was a significant reciprocal effect, where there was a positive estimate for the cross L2xL3.

Th1 and th2 cytokine expression in nasopharyngeal secretions during acute bronchiolitis in children younger than two years old.

OBJECTIVES: We characterised the T helper cytokine profiles on the surface of nasal mucosa of children with acute bronchiolitis caused by Respiratory Syncytial Virus, Parainfluenza Virus, Influenza Virus, Adenovirus, or without any viral identification, in order to examine whether these viral types modified cytokine responses. As an additional objective we sought to determine if T helper polarisation was associated with other demographic and environmental factors. METHODS: A prospective study of children with acute bronchiolitis was performed. Patients were recruited from the emergency department of a central hospital in Lisbon, Portugal. Demographical, epidemiological and clinical data were gathered from a questionnaire. Nasal swabs were collected for viral studies (immunofluorescence) and T cell cytokine responses (detection of expression of interleukins 4, 13, 12 and interferon-γ by real-time polymerase chain reaction assays). RESULTS: Respiratory Syncytial Virus elicited lower levels of interleukin 4, when compared with samples without virus identification. A similar tendency to Th1 polarisation was found in older children, in those who attended day-care centres, and in breastfed individuals. Exposure to tobacco smoke was associated with a Th2 bias in this population. CONCLUSIONS: These findings show that Respiratory Syncytial Virus infection contributes to Th1 polarisation in immune response of respiratory mucosa, an effect that is similar to other environmental factors. Further studies are needed to assess immune response to other infectious causes of acute bronchiolitis.

Upper arm anthropometry is not a valid predictor of regional body composition in preterm infants.

BACKGROUND: Upper arm anthropometry has been used in the nutritional assessment of small infants, but it has not yet been validated as a predictor of regional body composition in this population. OBJECTIVE: Validation of measured and derived upper arm anthropometry as a predictor of arm fat and fat-free compartments in preterm infants. METHODS: Upper arm anthropometry, including the upper arm cross-sectional areas, was compared individually or in combination with other anthropometric measurements, with the cross-sectional arm areas measured by magnetic resonance imaging, in a cohort of consecutive preterm appropriate-for-gestational-age neonates, just before discharge. RESULTS: Thirty infants born with (mean +/- SD) a gestational age of 30.7 +/- 1.9 weeks and birth weight of 1,380 +/- 325 g, were assessed at 35.4 +/- 1.1 weeks of corrected gestational age, weighing 1,785 +/- 93 g. None of the anthropometric measurements are reliable predictors (r(2) < 0.56) of the measurements obtained by magnetic resonance imaging, individually or in combination with other anthropometric measurements. CONCLUSION: Both measured anthropometry and derived upper arm anthropometry are inaccurate predictors of regional body composition in preterm appropriate-for-gestational-age infants.

Allele frequencies and genetic diversity in two groups of wild tufted capuchin monkeys (Cebus apella nigritus) living in an urban forest fragment

There have been numerous studies genetically characterizing Old World Primates using microsatellites. However, few studies have been made of New World species and none on free-ranging Cebus apella, even though it is probably the most widely distributed species of monkey in the New World. The paucity of studies is due, in part, to the lack of polymorphisms described for this species. We studied two groups of wild tufted capuchins, Cebus apella nigritus, which inhabit Mata Santa Teresa, the Ecological Reserve of Ribeirão Preto, a 158-ha forest fragment in a semi-urban zone of Ribeirão Preto, SP, Brazil. Group 1 had about 60 animals, 35 of which were sampled, and group 2 had about 40 animals, 20 of which were sampled. These group sizes are much larger than the published reports of 6-30 for this species, despite, or perhaps due to the isolation and the size of the forest fragment. Allele PEPC59*1 was the most frequent of all alleles at all loci in both groups (55.7 and 55%), allele PEPC8*1 was the most common allele in group 2 (46.9%) and PEPC8*4 in group 1 (41.1%), allele PEPC3*2 was the most common in group 1 (35.7%) and allele PEPC3*4 in group 2 (31.6%). The genetic diversity, considering each locus in each group, varied from 61.9% at locus PEPC59 to 78.6% at locus PEPC3, both in group 1. The mean genetic diversity (H(S)), considering both groups for all of the loci, was 71.1%. The inter-group diversity (F(ST)) was 1.9%, indicating that these groups belong to the same population. These groups apparently have a high genetic diversity, despite their isolation in a limited forest fragment, although more data are needed to adequately characterize this population.

A simple equation to estimate the osmolarity of neonatal parenteral nutrition solutions.

UNLABELLED: A predictive equation of osmolarity that correlates closely with the measured osmolality was determined. Taking into account that an osmometer is not available in most clinical settings, the proposed equation appears to provide a quick and simple osmolarity calculation of neonatal parenteral nutrition solutions. OBJECTIVE: We measured the osmolalities of neonatal parenteral nutrition (PN) solutions to determine if these values may be predicted by a simple equation for calculation of their osmolarity values. METHODS: The osmolalities of 101 consecutive different final PN admixtures, prepared for 36 neonates, were measured by the freezing point depression method. The respective intra-assay and interassay coefficients of variation were always <2.1%. Linear multivariate regression analysis was used to determine a predictive equation of osmolarity that correlates closely with the value of measured osmolality. RESULTS: The mean (SD) osmolality of the final PN admixtures was 749.7 (165.4) mOsm/kg. The best-fitted equation, with a coefficient of discrimination R2 = .95 (R2 = .90 for samples between 500 and 1000 mOsm/L) is osmolarity (mOsm/L) = (nitrogen x 0.8) + (glucose x 1.235) + (sodium x 2.25) + (phosphorus x 5.43)-50, with the concentration of components in mmol/L. Adapting the equation in our daily practice, using g/L for glucose and amino acids, mg/L for phosphorus, and mEq/L for sodium, the equation is osmolarity (mOsm/L) = (amino acid x 8) + (glucose x 7) + (sodium x 2) + (phosphorus x 0.2) - 50, with a similar R2. CONCLUSIONS: Taking into account that an osmometer is not available in most clinical settings, the proposed equation appears to provide a quick and simple osmolarity calculation of neonatal PN solutions, thus allowing more accurate decisions to be taken regarding the choice of route and rate of administration of PN solutions.

Osmolality of solutions, emulsions and drugs that may have a high osmolality: aspects of their use in neonatal care.

OBJECTIVE: Administration of some hypertonic substances to neonates has been associated with a variety of adverse effects. This study was conducted to determine the osmolality of intravenous drugs and solutions used in neonates receiving intensive care. METHODS: Osmolality was measured by freezing point depression. Vasoactive drugs, diuretics, anticonvulsants, antimicrobials, and glucose and electrolyte solutions were some of the substances analyzed. RESULTS: The osmolalities of 90 substances were measured; the respective intra-assay and interassay coefficients of variation were always less than 5%. A few drugs were found to be extremely hypertonic (> 8000 mOsm/kg), and most of them contain propylene glycol as vehicle (e.g. digoxin, phenytoin, diazepam and phenobarbital). Other drugs, at the same concentration, evidenced a significant discrepancy of osmolality depending on the trademark. CONCLUSIONS: The finding of some extremely hypertonic drugs highlights the need for further investigation in order to study their potential adverse effects in neonates, as well as to evaluate any advantage in diluting, infusing slowly or even avoiding such substances. Given the fact that there exists a discrepancy in osmolalities in some drugs at the same concentration depending on the trademark, the more isotonic solutions should be the preferred choice for intravenous administration.

Upper arm measurements of healthy neonates comparing ultrasonography and anthropometric methods.

OBJECTIVE: To compare measurements of the upper arm cross-sectional areas (total arm area, arm muscle area, and arm fat area of healthy neonates) as calculated using anthropometry with the values obtained by ultrasonography. MATERIALS AND METHODS: This study was performed on 60 consecutively born healthy neonates: gestational age (mean+/-SD) 39.6+/-1.2 weeks, birth weight 3287.1+/-307.7 g, 27 males (45%) and 33 females (55%). Mid-arm circumference and tricipital skinfold thickness measurements were taken on the left upper mid-arm according to the conventional anthropometric method to calculate total arm area, arm muscle area and arm fat area. The ultrasound evaluation was performed at the same arm location using a Toshiba sonolayer SSA-250A, which allows the calculation of the total arm area, arm muscle area and arm fat area by the number of pixels enclosed in the plotted areas. STATISTICAL ANALYSIS: whenever appropriate, parametric and non-parametric tests were used in order to compare measurements of paired samples and of groups of samples. RESULTS: No significant differences between males and females were found in any evaluated measurements, estimated either by anthropometry or by ultrasound. Also the median of total arm area did not differ significantly with either method (P = 0.337). Although there is evidence of concordance of the total arm area measurements (r = 0.68, 95% CI: 0.55-0.77) the two methods of measurement differed for arm muscle area and arm fat area. The estimated median of measurements by ultrasound for arm muscle area were significantly lower than those estimated by the anthropometric method, which differed by as much as 111% (P < 0.001). The estimated median ultrasound measurement of the arm fat was higher than the anthropometric arm fat area by as much as 31% (P < 0.001). CONCLUSION: Compared with ultrasound measurements using skinfold measurements and mid-arm circumference without further correction may lead to overestimation of the cross-sectional area of muscle and underestimation of the cross-sectional fat area. The correlation between the two methods could be interpreted as an indication for further search of correction factors in the equations.

[Mucoviscidosis with respiratory symptomatology in the neonatal period]. / Mucoviscidose com sintomatologia respiratória no período neonatal.

A case of cystic fibrosis presented in the neonatal period with respiratory symptomatology associated with early pancreatic insufficiency is reported. The CFTR gene molecular analysis was found to be a compound heterozygotes for delta F508 and G542X. The rarity of this mode of presentation and the inclusion of this entity in the differential diagnosis for neonatal respiratory distress syndrome is emphasised. The pathogenesis and some therapeutic aspects carried out in our patient, which might have improved the life expectancy of patients with this disease, are discussed.

[Acute myocardial infarct in infants]. / Enfarte agudo do miocárdio na criança.

A retrospective study was made of 6 children, with nonsurgical-related acute myocardial infarction (AMI), between January 1987 and December 1994. The ratio for gender was 1 and mean age at AMI was 49 days, 4 cases being associated with congenital heart disease (Fallot's tetralogy, truncus arteriosus and DiGeorge syndrome, one case each, and anomalous origin of left coronary artery, 2 cases). Kawasaki disease and coronary embolisation from thrombosis of the renal vein occurred in the other 2 cases respectively. All developed congestive cardiac failure and cardiomegaly. In the ECG pathologic q waves with more than 35 msec occurred in all, and QT prolongation occurred in 3. Five children (83%) all with AMI in the anterior and lateral wall of the left ventricle died, death being related with cardiac mechanical failure and not with arrhythmias.