Effect of ractopamine on the chemical and physical characteristics of pacu(Piaractus mesopotamicus) steaks / Efeito da ractopamina sobre as características físicas e químicas de filés de pacu (Piaractus mesopotamicus)

The objective was to evaluate the use of ractopamine (RAC) in the diet for pacu (Piaractus mesopotaminus) in the finishing phase on some quality parameters of the fillets. Thirty-five animals weighing 0.868±0.168kg were distributed in a completely randomised design with five treatments (0.0 - control; 11.25, 22.50, 33.75 and 45 ppm of RAC) and seven replicates with two fillets obtained from the same animal. The diets were isocaloric and isoprotein and experimental time was 90 days. RAC did not affect (P>0.05) the initial pH or ph after 24 hours of the fillets. Compared to the control, RAC increased (P<0.05) the moisture content of the fillets in natura and lipid oxidation of samples stored for 12 days in the refrigerator or freezer for 60 days. The RAC in 11.25 ppm reduced (P<0.05) the lipid content, while 45 ppm reduced (P<0.05) the crude protein in the fillets. Considering only RAC, there was a linear increase (P<0.05) in the lipid content (P<0.05) and a linear reduction in crude protein and weight loss after cooking the fillets. There was a quadratic effect (P<0.05) on the ash content, weight loss and lipid oxidation in fillets stored in the refrigerator or freezer. A RAC dose of 33.75 ppm resulted in a lower lipid oxidation index. In conclusion, ractopamine at 11.25 ppm is effective for reducing the fat content in fillets of pacu, although it increases the formation of peroxides in samples kept in the freezer for longer than 60 days. At 33.75 ppm, ractopamine is effective in reducing the effect of oxidation during storage in the refrigerator or freezer.

O objetivo foi avaliar a influência do uso de ractopamina na alimentação de pacus (Piaractus mesopotaminus) na fase de terminação sobre alguns parâmetros de qualidade dos filés. Trinta e cinco animais com peso de 0,868±0,168kg foram distribuídos em delineamento inteiramente ao acaso com cinco tratamentos (0,0 - controle; 11,25; 22,50; 33,75 e 45ppm de ractopamina) e sete repetições, sendo a parcela representada por dois filés provenientes de um animal. As rações foram isoenergéticas e isoproteicas, e o tempo experimental foi de 90 dias. A ractopamina não influenciou (P>0,05) o pH inicial dos filés e nem após 24 horas. Comparado ao controle, a RAC aumentou (P<0,05) a umidade dos filés in natura e a oxidação lipídica dos mesmos quando armazenados por 12 dias em geladeira ou 60 dias em freezer. Na dose de 11,25 reduziu (P<0,05) o teor de extrato etéreo e, na dose de 45 ppm, reduziu (P<0,05) o de proteína bruta dos filés. Considerando somente a RAC, houve aumento linear (P<0,05) do teor de gordura e redução linear (P<0,05) da proteína bruta e perda de peso por cocção. Houve efeito quadrático (P<0,05) sobre o teor de cinzas, perda de peso por descongelamento e oxidação lipídica para os filés armazenados em geladeira ou em freezer, sendo 33,75 ppm o nível de RAC que resultou em menor índice de oxidação lipídica. Conclui-se que a ractopamina a 11,5 ppm é efetiva em reduzir o teor de lipídeos em filés de pacu, embora aumente a formação de peróxidos em amostras mantidas em freezer após 60 dias. A 33,75 ppm a ractopamina é efetiva em reduzir os efeitos da oxidação durante o armazenamento em geladeira ou freezer.

Prevención de enfermedades podales mediante el recorte funcional de la pezuña al momento del secado en vacas lecheras confinadas en el trópico / Functional trimming at the dry off period to prevent foot diseases in confined dairy cows at the tropical area

Con el objetivo de evaluar el efecto del recorte funcional al momento del secado, para la prevención de enfermedades podales en vacas lecheras confinadas se utilizaron 47 vacas Pardo Suizo con más de dos partos al inicio del periodo seco. Se dividieron en dos grupos en forma aleatoria; a uno de ellos se le aplicó recorte funcional como grupo tratamiento y el otro, como grupo control. Se procedió a observar el comportamiento de las vacas en cuanto a la aparición de enfermedades podales durante los 5 primeros meses de su lactancia. Los resultados muestran que el 39 por ciento de las pezuñas presentó algún tipo de lesión podal, y en el 61 por ciento había ausencia de lesiones, así mismo se observó que de los animales que recibieron tratamiento, solo enfermaron el 4 por ciento de ellos y de los animales del grupo control enfermaron el 45,4 por ciento. El estudio comparativo de ambos grupos muestra diferencias estadísticas significativas (P<0,05). La mayor cantidad de lesiones que causaron claudicaciones en los animales que enfermaron en el transcurso del ensayo se observaron en los miembros posteriores en sus pezuñas laterales o externas y el promedio de días postparto para la aparición de claudicaciones fue de 72,6 días. Según los resultados se puede concluir que la quiropodia funcional al momento del secado, ayuda a prevenir la aparición de enfermedades podales en vacas lecheras confinadas en sus primeros meses de lactancia.

The aim of the present research was to evaluate the functional trimming effect at the dry off period to prevent the hoof diseases in confined milking cows. To do that 47 Brown Swiss cows with two or more parturition were studed at the beginning of the dry off period. The cows were divided in two groups in a random way. One group received the functional trimming as treatment and the other one serve as a control. The cows were monitor to look into the appearance of hoof diseases within the first 5 months of the milk yield period. The results show that 39 percent of the hoof had any kind of lesions and 61 percent of the hoof were without lesions, in the same way the treated animal group show only 4 percent of sick animals whereas in the control group were 45.4 percent. A comparison study of both groups show a significant statistically differences (P<0.05). The highest amount of lesions that causes lameness in the animals during the trial occur at the rear limb at the lateral claw and the average of days for the appearance of lameness was 72.6 days. From the results it was concluded that functional trimming at the dry off period help to prevent hoof diseases in confined cows at the beginning of the milk yield period.

Detección y tipificación de virus papiloma humano en adenocarcinoma de cuello uterino mediante reverse line blot, Región de La Araucanía, Chile / Detection and genotyping of human papillomavirus in biopsies of uterine cervical adenocarcinoma

Background: The genotyping of Human Papillomavirus (HPV) will improve knowledge about the local epidemiological association of this virus with adenocarcinoma. Aim: To determine the frequency of HPV genotypes in biopsies of women with uterine cervical adenocarcinoma in a geographic region of Chile. Materials and Methods: Forty-one cervical biopsies with a pathological diagnosis of adenocarcinoma, corresponding to all women diagnosed with this cancer between 2002 and 2004, were analyzed. Viral gene Ll was amplified by PCRfor viral detection. HPV genotyping was carried out by a Reverse Line Blot technique. Results: Seventy one percent of biopsies were positive for HPV. The most common genotypes found were HPV 16 (61 percent), followed by HPV 18 (19.5 percent). Eighty seven percent of biopsies had a single HPV infection. Three patients had a multiple HPV infection. All of the latter were infected by HPV 16, associated with other three viral genotypes (45, 52 and 66). No low-risk HPV genotypes were found. Conclusions: In this sample of biopsies, there was a high prevelence of HPV 16 and a low prevalence of HPV 18, which historically has been related to adenocarcinoma. The genotypes found correspond to those described in South America.

Lesiones podales encontradas al realizar la quiropodia funcional al momento del secado en vacas lecheras en estabulación / Foot lesions findings during the functional claw trimming at the dry off period in confinement dairy cows

El objetivo de la presente investigación fue describir las lesiones podales observadas al realizar la Quiropodia Funcional al momento del secado de vacas lecheras en estabulación, para lo cual se tomaron 25 vacas de la raza Pardo Suizo, a las cuales se realizó un examen clínico de las pezuñas y se les aplicó la quiropodia funcional al inicio del periodo seco. Las lesiones podales encontradas se asentaron en fichas diseñadas para tal fin. Los resultados muestran que el 39% de las pezuñas presentaron lesiones al realizar la quiropodia, así mismo se observó que las lesiones más frecuentes fueron: hemorragias (39,8%), enfermedad de la línea blanca (23,7%) y sobre crecimiento del tejido córneo (20,4%). El 78,4% de las lesiones se presentaron en los miembros posteriores y el 21,6% en los miembros anteriores, para estos resultados se observaron diferencias estadísticamente significativas (P < 0,05). La distribución de las lesiones en los dedos fue la siguiente: en los miembros posteriores el 68,1% de las patologías se observaron en los dedos laterales y el 31,9% en los dedos mediales, contrario a esto, en los miembros anteriores el 58,4% de las lesiones se presentaron en los dedos mediales y el 41,6% en los laterales, en estos resultados no se observaron diferencias estadísticamente significativas (P > 0,05). Se puede concluir que la mayor cantidad de lesiones se encontraron en las pezuñas laterales de los miembros posteriores, igualmente se observó que los miembros llegan al periodo de secado en muy mal estado, lo cual refleja las condiciones de las pezuñas al momento del parto y primeros meses de lactancia, esta condición podría ocasionar enfermedades podales en este periodo, en el cual se encuentra la mayor productividad de las vacas lecheras.

The objective of this research was to describe the foot lesions found during the functional trimming at the dry off period of confinement dairy cows. Twenty five Brown Swiss cows were submitted to a hooves examination during the functional trimming at the dry off period. All the foot lesions were recorded on cards designed for this purpose. The results reported that 39% of the claws showed lesions during the functional trimming and also it was determined that the most frequent foot lesion were hemorrhage (39.8%), white line disease (23.7%) and horn overgrowth (20.4%). Also it was determined that 78.4% of the injuries were in the hind limbs and 21.6% were in the forelimb. Based upon these results it was determined that they were statistically significantly differences (P < 0.05). The foot lesions distribution was as follow: in the hind limb 68.1% of the pathologies were at the lateral digit, while 31.9% of the lesions were located at the medial digit. On the contrary, in the forelimbs 58.4% of lesions were in the medial claw and 41.6% were in the lateral claw. Statistically significantly differences were not observed (P > 0.05) in these results. It may be concluded that the majority of lesions were found in the lateral claw of the hind limbs. Also it was observed that the limbs reach the dry off period in very bad conditions reflecting feet conditions at the delivery time and during the first month of lactation. This condition could cause foot diseases within this period in which dairy cows are highly productive.

Control of the phosphorylation of the astrocyte marker glial fibrillary acidic protein (GFP) in the immature rat hippocampus by glutamate and calcium ions: possible key factor in astrocytic plasticity

The present review describes recent research on the regulation by glutamate and Ca2+ of the phosphorylation state of the intermediate filament protein of the astrocytic cytoskeleton, glial fibrillary acidic protein (GFAP), in immature hippocampal slices. The results of this research are discussed against a background of modern knowledge of the functional importance of astrocytes in the brain and of the structure and dynamic properties of intermediate filament proteins. Astrocytes are now recognized as partners with neurons in many aspects of brain function with important roles in neural plasticity. Site-specific phosphorylation of intermediate filament proteins, including GFAP, has been shown to regulate the dynamic equilibrium between the polymerized and depolymerized state of the filaments and to play a fundamental role in mitosis. Glutamate was found to increase the phosphorylation state of GFAP in hippocampal slices from rats in the post-natal age range of 12-16 days in a reaction that was dependent on external Ca2+. The lack of external Ca2+ in the absence of glutamate also increased GFAP phosphorylation to the same extent. These effects of glutamate and Ca2+ were absent in adult hippocampal slices, where the phosphorylation of GFAP was completely Ca2+ -dependent. Studies using specific agonists of glutamate receptors showed that the glutamate response was mediated by a G protein-linked group II metabotropic glutamate receptor (mGluR). Since group II mGluRs do not act by liberating Ca2+ from internal stores, it is proposed that activation of thereceptor by glutamate inhibits Ca2+ entry into the astrocytes andconsequently down-regulates a Ca2+-dependent dephosphorylationcascade regulating the phosphorylation state of GFAP. The functional significance of these results may be related to the narrow developmental window when the glutamate response is present. In the rat brain this window corresponds to the period of massive synaptogenesis during which astrocytes are known to proliferate. Possibly, glutamate liberated from developing synapses during this period may signal an increase in the phosphorylation state of GFAP and a consequent increase in the number of mitotic astrocytes.