Body architecture of Holstein Friesian and black frison biotypes used in south Chilean dairy farms / Arquitectura corporal de biotipos bovinos Holstein Friesian y overo negro utilizados en predios lecheros del sur de Chile

The objective of the present work was to characterize the morphostructural architecture of bovine biotypes that are mostly used in milk production in southern Chile. Measurements were carried out in 26 dairy farms located in the provinces of Osorno and Ranco, in Los Lagos and Los Ríos regions, respectively. In each farm, four animals were randomly selected from the herd; 104 four year-old cows were measured. Cows were classified into four biotypes: Holstein Friesian (HD), Overo Negro (OD), hybrid Friesian Holstein (HM) and hybrid Overo Negro (OM), according to the opinion of the owner or administrator. Nine body measurements were taken: head length (HL), head width (HW), withers height (WH), rump height (RH), bicostal diameter (BD), longitudinal diameter (LD), rump width (RW), rump length (RL) and dorso-sternal diameter (DED). Data were analyzed by principal component analysis (PCA) and the Fisher LSD test. The evaluated animals seem to converge around a basic architecture derived from cultural selection patterns regardless of the racial biotype. This architecture could be typical of grazing systems or be influenced by aspects of selection additional to those directly related to production. The data suggest that the body architecture of the dairy cattle evaluated would respond to selection patterns more than to racial biotypes. It was also seen that measures such as DED, RW and LD have a greater incidence than the other variables within the observed common selection patterns. Finally, within the evaluated animal population, two selection patterns coexist, one represented by small size body architecture and another one that, although despite its larger dimensions, also represents a small dairy animal in comparison to the sizes reported for Holstein Friesian breed in other areas.

El objetivo de este trabajo fue caracterizar la arquitectura morfoestructural de los biotipos bovinos que mayoritariamente se utilizan en la producción de leche en el sur de Chile. Para ello se realizaron evaluaciones en 26 predios lecheros ubicados en las provincias de Osorno y Ranco, en las regiones de Los Lagos y Los Ríos, respectivamente. Se midieron 104 animales clasificados en cuatro biotipos según lo declarado por los ganaderos: Holstein Friesian (HD), Overo negro (OD) y cruzamientos de Holstein Friesian (HM) y Overo Negro (OM). En cada animal se determinaron nueve medidas corporales: longitud de la cabeza (HL), ancho de la cabeza (HW), alzada a la cruz (WH), alzada a la grupa (RH), diámetro bicostal (BD), diámetro longitudinal (LD), ancho de la grupa (RW), longitud de la grupa (RL) y diámetro dorso-esternal (DED). Los datos se analizaron mediante análisis de componentes principales (PCA) y el test de Fischer LSD, usando para ello el programa XLstat pro. De acuerdo a los resultados se puede concluir que, independiente del biotipo racial, los animales evaluados parecen converger en torno a una arquitectura básica derivada de patrones de selección fenotípica con un componente cultural que pudiera ser propia de los sistemas de pastoreo, o influenciada por aspectos de selección adicionales a los relacionados directamente a la producción. En este sentido, los datos indican que la arquitectura corporal del ganado lechero respondería más a patrones de selección que a biotipos raciales. También se apreció que la profundidad (DED), el ancho de grupa (RW) y el largo (LD) presentan una mayor incidencia que las demás variables evaluadas dentro de los patrones de selección común observados. Finalmente, fue posible apreciar que al interior de la población animal evaluada coexisten dos patrones de selección. Uno representado por una arquitectura corporal de pequeño tamaño y otro que, si bien exhibe mayores dimensiones, también representa un tipo de animal lechero de menor tamaño en comparación a las dimensiones que alcanzan los biotipos relacionados a la raza Holstein Friesian en otras zonas.

Presence of organochlorine pollutants in fat and scats of pinnipeds from the Antarctic Peninsula and South Shetland Islands, and their relationship to trophic position.

Antarctica is still considered one of the few pristine areas in the globe. Despite this, several studies have shown phased out organic pollutants are present in several environmental abiotic and biological compartments. This study, based on blubber and fecal samples collected from five species of Antarctic pinnipeds, assessed the relationship between organochlorine pesticide (OCs) levels and trophic characterization using stable isotope analysis (δ13C and δ15N). The prevailing pollutants found in blubber were hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB), Heptachlor and Aldrin (0.84-564.11 ng g-1 l.w.). We also report a high presence of HCHs, Endrin, Dichlorodiphenyltrichloroethane (DDTs) and Methoxychlor (4.50-363.86 ng g-1 d.w.) in feces suggesting a detoxification mechanism. All the species tend towards high trophic positions (3.4-4.9), but with considerable variation in trophic niche and organochlorine pesticide concentrations per sampling site. This finding suggests that differences in pesticide levels in individuals are associated to foraging ecology.

Population differentiation in the body architecture of creole goats in the semi arid region of Chile / Diferenciación poblacional en la arquitectura corporal de cabras criollas en la región semiárida de Chile

The present study aimed to assess the degree of body architecture differentiation between Creole goats, two introduced breeds and their hybrids in semi arid areas of the north of Chile. The study was carried out between 2012 and 2015. One hundred and eighty five adult female goats belonging to 17 herds from the Coquimbo region were used. Ten animals of the Saanen breed and 10 animals of the Anglo nubian breed belonging to two hatcheries and 165 Creole and hybrid goats belonging to small farmers were measured. The animals were categorized into pure breed (20), hybrid (52) and creole (113). Eight body measurements were taken: head length (HL), head width (HW), longitudinal diameter (LD), bicostal diameter (BD), dorsal-sternal diameter (DSD), rump width (RW), rump length (RL) and whithers height (WH). Data were submitted to principal component analysis (PCA) and Fisher LSD test, using the XLSTAT-Pro Statistic software. The analysis indicated the existence of homogeneity subsets within the population, without a common architectural pattern for the entire population. The Creole biotype showed a smaller body architecture than the two breeds and hybrids with which it was compared, which could be an adaptative result. It is possible to assess that the Creole biotype has a differentiated body architecture with respect to the introduced goat breeds and the animals hybridized in different proportions. In addittion, it was observed that Creole goats maintain distinctive characteristics and they are differentiable even of the individuals with different degrees of hybridization.

El presente estudio tuvo por objetivo identificar si existe diferenciación en la arquitectura corporal entre caprinos Criollos, razas introducidas y rebaños hibridados con las mismas. El estudio se llevó a cabo entre 2012 y 2015 en la región de Coquimbo, Chile. Ciento ochenta y cinco cabras fueron estudiadas, pertenecientes a 17 rebaños distintos. Se midieron 10 animales de raza Saanen y 10 animales de raza Anglo nubian presentes en dos criaderos, y 165 animales Criollos e híbridos en predios de productores. Ocho medidas corporales fueron determinadas: longitud de la cabeza (HL), ancho de la cabeza (HW), diámetro longitudinal (LD), diámetro bicostal (BD), diámetro dorso-esternal (DSD), ancho de la grupa (RW), longitud de la grupa (RH) y alzada a la cruz (WH). Los datos de medidas se analizaron mediante análisis de componentes principales (PCA) y test LSD de Fischer con el programa estadístico XLSTAT Pro. Los resultados indican que las diferencias entre variables refllejan la existencia de subcojuntos de homogeneidad dentro de la población, no apreciándose un patron arquitectónico común para toda la población. De esta manera, el biotipo Criollo presenta una arquitectura corporal más reducida que las razas con las que se compara en este estudio, lo cual pudiera ser una respuesta adaptativa. En este sentido, es posible afirmar que el biotipo Criollo presenta una arquitectura corporal diferenciada respecto de las razas introducidas a la región y a los animales hibridados en distintas proporciones con dichas razas, con lo cual es posible observar que mantiene características distintivas y que es diferenciable incluso de distintos grados de hibridaje presente en dicha población.

Sublethal effects in Perinereis gualpensis (Polychaeta: Nereididae) exposed to mercury-pyrene sediment mixture observed in a multipolluted estuary.

Sediment-living organisms can be subjected to a multi-pollution condition due to an increase in the diversity of contaminants. Sediment mixtures of Mercury (Hg) and some polycyclic aromatics hydrocarbons like Pyrene (Pyr) are common in heavily industrialized coastal zones. In the present study, greater than (>) and less than (<) probable effect concentration levels (PELs) of Hg and Pyr were assessed using spiked sediments in order to determine combined (Hg + Pyr) effects in uptake, metabolization and oxidative balance in the polychaete Perinereis gualpensis at short and medium-term exposure. Hg + Pyr significantly influenced the uptake/kinetics of Hg and Pyr metabolite 1-OH-pyrene in polychaete tissues during the exposure time compared with separate treatments of each analyte (p < 0.05). Both the Hg-only and Pyr-only exposures significantly influenced both enzymatic and non-enzymatic responses respect to control groups (p < 0.05). The Hg-only treatment showed the worst scenario related to the activation and subsequent inhibition of glutathione S- transferase (GST) and peroxidase (GPx) activities, high levels of Thiol-groups (SH-groups), low antioxidant capacity (ACAP) and enhanced lipid peroxidation (TBARS) in the last days of exposure (p < 0.05). In contrast, ragworms exposed to Hg + Pyr showed a significant increase in both enzymatic and non-enzymatic activity during the first days of exposure and the absence of lipid peroxidation during the whole experiment. Our results suggest different oxidative stress scenarios in P. gualpensis when exposed to >PEL Hg concentration with

Morphostructural relationships and productive functionality of sheep breeds used for terminal crossbreeding in Chile / Relaciones morfoestructurales y funcionalidad productiva de razas ovinas usadas para cruzamiento terminal en Chile

The body shape of an animal population determines ranges of biological functionality and productive use. In sheep, meat productivity is closely related with the body size of the animal. Some sheep breeds are used in terminal crossbreeding to give the lamb favorable dimensional characteristics, but it is necessary to go deeper on the study of the relationships between morphostructure and productive aptitude of these breeds, since discrepancies could be due to the environmental effects or the degree of differentiation between the original pool of different breeds and the local populations. The study aimed to evaluate the morphostructural characters in four sheep breeds in Chile and discuss their relationship with the productive functionality of the body architecture. Two hundred and seventy-eight sheep belonging to Texel, Dorset, Coopworth and Suffolk Down breeds were used. Eleven body measurements (heart girth circumference, rump width, rump length, width of the cranium, length of the cranium, dorsal-sternal diameter, bicostal diameter, longitudinal diameter, cannon bone circumference, height at rump and height at withers) were taken. Nine zoometric indices (body index, cephalic index, thorax index, thorax depth index, pelvic index, longitudinal pelvic index, transverse pelvic index), metacarpal thorax index and metacarpal costal index) were composed from the individual measurements. The most important morphostructural relationships that contribute to explain the variability of the format of the four breeds of sheep studied were expressed by the metacarpal-thoracic index, the metacarpal-costal index, the thorax index and the bicostal index. Moreover, the breeds showed a high dispersion; the zoometric indices only partially explained the variability of the body format, expressing high format heterogeneity in influential variables as the metacarpal-thoracic index, the metacarpal-costal index and the body index. This could be because these racial populations are subjected to processes of differentiation within each breed.

La forma del cuerpo de una población animal determina rangos de funcionalidad biológica y su uso productivo. En las ovejas, la productividad de la carne está muy relacionada con el tamaño del cuerpo del animal. Algunas razas de ovejas se utilizan en cruzamientos terminales para dar al cordero características dimensionales favorables, pero es necesario profundizar en el estudio de las relaciones entre morfoestructura y aptitud productiva de estas razas, ya que las discrepancias podrían deberse a los efectos del medio ambiente o al grado de la diferenciación entre la piscina original de diferentes razas y las poblaciones locales. Este trabajo tuvo como objetivo evaluar los caracteres morfoestructurales en cuatro razas de ovinos en Chile y la relación de la funcionalidad productiva con la arquitectura del cuerpo. Se utilizaron 278 ovejas, raza Suffolk Down, pertenecientes a Texel, Dorset, Coopworth. Se tomaron 11 mediciones en el cuerpo (circunferencia del corazón, ancho del lomo, rabadilla, ancho del cráneo, longitud del cráneo, diámetro esternaldorsal, diámetro bicostal, diámetro longitudinal, circunferencia de hueso de la caña, altura de cadera y altura a la cruz). Nueve índices zoométricos (índice corporal, índice cefálico, índice de tórax, índice de profundidad del tórax, índice de la pelvis, índice pélvico longitudinal, índice transversal de la pelvis, índice metacarpiano del tórax e índice metacarpiano costal) fueron determinados a partir de mediciones individuales. Las relaciones morfoestructurales más importantes que contribuyen a explicar la variabilidad del formato de las cuatro razas de ovejas estudiadas se expresaron por el índice metacarpiano-torácico, el índice metacarpiano-costal, el índice de tórax y el índice bicostal. Por otra parte, las razas mostraron una alta dispersión de los índices zoométricos que explican sólo parcialmente la variabilidad del formato de cuerpo, la alto heterogeneidad de formato en las variables influyentes como el índice metacarpiano-torácica, el índice metacarpiano-costal y el índice del cuerpo. Esto podría ser debido a que estas poblaciones raciales son sometidos a procesos de diferenciación dentro de cada raza.

Morphostructural differentiation and variability of Merino sheep breed under sustained directional selection / Diferenciación y variabilidad morfoestructural de ovinos de raza Merino sometidos a selección direccional sostenida

In this paper, the degree of differentiation and morphostructural variability reached by the type of animal resulting from sustained directional selection, in addition to its implications for the emergence of a new sheep breed are analyzed. Twenty-five rams and 200 ewes from a sheep flock submitted to directional selection since 1987 were measured. Thirteen body measurements were taken in other to evaluate the structural morphology and sexual dimorphism. These measurements were compared with identical measures taken in Australian Merino and Marin Magellan Meat Merino sheep breeds. The intrapopulation homogeneity was assessed using the coefficients of variation of the average percentage of body measurements. It is concluded that sustained directional selection has generated the differentiation of the morphostructural format of the subject population compared to the main Merino-type breeds in the Chilean Patagonia. The population shows a similar (and in some cases lower) morphostructural variability than those found in recognized sheep breeds in Chile, so it is possible to state that this population behaves like a different animal group, with breed characteristics.

En el presente trabajo se analiza el grado de diferenciación y variabilidad morfoestructural alcanzado por el tipo de animal resultante de una selección direccional sostenida y sus implicancias en la emergencia de un nuevo grupo racial ovino. Se midieron 25 machos y 200 ovejas adultas. Se tomaron 13 medidas corporales, evaluando la diferenciación de la morfología estructural y el dimorfismo sexual. Estas mediciones se compararon con las realizadas en animales de raza Merino Australiano y Marin Magellan Meat Merino. La homogeneidad intrapoblacional se evaluó a través de los coeficientes de variación porcentual de las medias de las medidas corporales. Se concluye que la selección direccional realizada de forma sostenida ha generado una diferenciación del formato morfoestructural al comparar a la población sujeta a selección con las principales raza de tipo Merino existentes en la Patagonia Chilena. La población evaluada evidencia una variabilidad morfoestructural similar, y en muchos casos menor a la encontrada en razas ovinas reconocidas como tales en Chile, con lo cual es posible señalar que se comporta como un grupo animal distinguible con caracteres de raza.

Herbicides induce change in metabolic and genetic diversity of bacterial community from a cold oligotrophic lake.

Pristine cold oligotrophic lakes show unique physical and chemical characteristics with permanent fluctuation in temperature and carbon source availability. Incorporation of organic toxic matters to these ecosystems could alter the bacterial community composition. Our goal was to assess the effects of simazine (Sz) and 2,4 dichlorophenoxyacetic acid (2,4-D) upon the metabolic and genetic diversity of the bacterial community in sediment samples from a pristine cold oligotrophic lake. Sediment samples were collected in winter and summer season, and microcosms were prepared using a ration 1:10 (sediments:water). The microcosms were supplemented with 0.1 mM 2,4-D or 0.5 mM Sz and incubated for 20 days at 10 °C. Metabolic diversity was evaluated by using the Biolog Ecoplate™ system and genetic diversity by 16S rDNA amplification followed by denaturing gradient gel electrophoresis analysis. Total bacterial counts and live/dead ratio were determined by epifluorescence microscopy. The control microcosms showed no significant differences (P > 0.05) in both metabolic and genetic diversity between summer and winter samples. On the other hand, the addition of 2,4-D or Sz to microcosms induces statistical significant differences (P < 0.05) in metabolic and genetic diversity showing the prevalence of Actinobacteria group which are usually not detected in the sediments of these non-contaminated lacustrine systems. The obtained results suggest that contaminations of cold pristine lakes with organic toxic compounds of anthropic origin alter their homeostasis by inhibiting specific susceptible bacterial groups. The concomitant increase of usually low representative bacterial groups modifies the bacterial composition commonly found in this pristine lake.

Intergenerational morphostructural stability and harmony of marin magellan meat merino ewes / Estabilidad y armonía intergeneracional morfoestructural de ovejas marin magellan meat merino

The aim of this study was to evaluate the stability and harmony of the morphostructural format of the Marin Magellan Meat Merino breed in order to contribute to knowledge about the differentiation of sheep populations. In summer 2010, evaluation on a sheep population coming from an incomplete absorbent crossbreeding of Corriedale by Australian Merino breeds was done in Magallanes Region, Chile. All three and five year-old ewes (62 and 50, respectively) were measured. Fourteen body measurements were taken and nine body indexes were calculated. Results show that the evaluated sheep population does not show significant intergenerational differences in most of the morphostructural variables. At the same time, there is a high between-age similarity in the correlations between zoometric indexes. Therefore, it can be stated that the morphostructural model of Marin Magellan Meat Merino ewes shows a high degree of stability and harmony.

El objetivo de este estudio fue evaluar la estabilidad y la armonía del formato morfoestructural de la raza ovina Marin Magellan Meat Merino en la Región de Magallanes (Chile), con el fin de contribuir al conocimiento de la diferenciación de las poblaciones ovinas. En el verano de 2010 se evaluó esta nueva raza, que es producto de un cruzamiento absorbente incompleto de Corriedale por Merino Australiano. Se midieron todas las hembras de tres y cinco años (62 y 50, respectivamente). Se tomaron catorce mediciones corporales y se calcularon nueve índices. Los resultados indican que la población ovina evaluada no muestra diferencias intergeneracionales significativas en la mayor parte de las variables morfoestructurales estudiadas. Al mismo tiempo, hay una gran similitud entre edades respecto a las correlaciones entre índices zoométricos. Por lo tanto, se puede afirmar que el modelo morfoestructural de las ovejas Marin Magellan Meat Merino evidencia un alto grado de estabilidad y armonía.

Fuzzy model for risk assessment of persistent organic pollutants in aquatic ecosystems.

We developed a model for evaluating the environmental risk of persistent organic pollutants (POPs) to aquatic organisms. The model is based on fuzzy theory and uses information provided by international experts through a questionnaire. It has been tested in two case studies for a particular type of POPs: brominated flame retardants (BFRs). The first case study is related to the EU-funded AQUATERRA project, with sampling campaigns carried out in two Ebro tributaries in Spain (the Cinca and Vero Rivers). The second one, named the BROMACUA project, assessed different aquatic ecosystems in Chile (San Vicente Bay) and Colombia (Santa Marta Marsh). In both projects, the BFRs under study were polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). However, the model can be extrapolated to other POPs and to different aquatic ecosystems to provide useful results for decision-makers.

Autopercepción de la imagen corporal en estudiantes universitarios de Chile y Panamá / Body image perception in university students from Chile and Panama

Objetivo: Determinar la concordancia entre el estado nutricional y la percepción de la imagen corporal en universitarios chilenos y panameños. Métodos: Estudio observacional transversal en 792 estudiantes de ambos sexos, de 18 a 30 años de edad de la Universidad Santo Tomás de Vina del Mar en Chile, la Universidad Autónoma de Chile y la Universidad Latinoamericana de Ciencia y Tecnología (ULACIT) de Panamá. Se determinó el IMC real y el IMC percibido y luego éstos fueron comparados. Resultados: De 792 estudiantes evaluados, 480 eran de Chile (51,4% mujeres) y 312 de Panamá (56,7% mujeres). El IMC percibido por los chilenos fue mayor al real, en hombres y mujeres (60%); en cambio, los panameños presentan una sobreestimación menor al 50% en ambos sexos. En ambos países y para ambos sexos el porcentaje de estudiantes que se perciben igual es similar (20%). Hay concordancia diagnóstica entre el IMC y la imagen corporal en la mitad de los alumnos chilenos y en un tercio de las alumnas, pero la mejor concordancia se observó en personas con sobrepeso (69% y 90,5% respectivamente). En los panameños se observó concordancia diagnóstica de 40% en varones y 19,2% en mujeres; la mejor concordancia se observó en hombres con sobrepeso (83%). Conclusión: En los estudiantes con normopeso de ambos países existe una tendencia a sobreestimar el peso, mientras que por el contrario los obesos tienden a subestimarlo.

Objective: To determine the association between nutritional status and body image perception among university students from Chile and Panamá. Methods: An observational cross-sectional study was conducted among 792 students of both sexes, ages 18 to 30 years, from University Santo Tomás of Viña del Mar, Chile, University Autónoma of Chile and University Latinoamericana de Ciencia y Tecnología (ULACIT) of Panama. We determined the real BMI and the perceived BMI. Afterward, the two were compared to each other. Results: In a sample of 792 students, 480 from Chile (51,4% females) and 312 from Panamá (56,7% females), the perceived BMI is higher than the real one in the Chileans, men and women (60%). Instead, in Panamá the over-estimation is less than 50% in both sexes. The percentage is the same in both countries and both sexes that perceive themselves as they really are (20%). There is concordance between BMI and body image in half of Chilean men and a third of Chilean women. However, a better concordance is observed in overweight students (69% in men, 90,5% in women). In Panamanians, there is a concordance observed of40% in men and 19,9% in women. Conclusion: There is a tendency for overestimation in normal weight students of both countries. However the obese students tended to underestimate their weight.

Biochemical responses and physiological status in the crab Hemigrapsus crenulatus (Crustacea, Varunidae) from high anthropogenically-impacted estuary (Lenga, south-central Chile).

Estuarine environmental assessment by sub-individual responses is important in order to understand contaminant effects and to find suitable estuarine biomonitor species. Our study aimed to analyze oxidative stress responses, including glutathione-S-transferase (GST) activity, total antioxidant capacity (ACAP) and lipid peroxidation levels (TBARS) in estuarine crabs Hemigrapsus crenulatus from a high anthropogenically-impacted estuary (Lenga) compared to low and non-polluted estuaries (Tubul and Raqui), in a seasonal scale (winter-summer), tissue specific (hepatopancreas and gills) and sex related responses. Results showed that hepatopancreas in male crabs better reflected inter-estuary differences. Morpho-condition traits as Cephalothorax hepatopancreas index (CHI) could be used as an indicator of physiological status of estuarine crabs. Discriminant analysis also showed that GST and TBARS levels in summer are more suitable endpoints for establishing differences between polluted and non-polluted sites. These results suggest the importance of seasonality, target tissue, sex and physiological status of brachyuran crabs for estuarine biomonitoring assessment.

Development of the Morphostructure and Meat Value in Chilota Lambs / Desarrollo de la Morfoestructura y el Valor Carnicero en Corderos Chilotes

Chilota sheep are typical of the Chiloé archipelago in southern Chile. The objectives of this study were: 1) To describe the development of the morphostructure of Chilota lambs in their first months of life using some variables that determine lamb meat value (zoometric traits and body weight) and 2) To determine the optimum slaughter age. Measurements were taken from 12 male single-born lambs. Body weight, Withers height; Perimeter of thorax, Chest depth, Shoulder point width and Body length were measured in each animal. The first measurements were taken at 7 days old, and the rest at 37, 67, 97, 127, 157 and 187 days old. The body weight variables and zoometric traits developed allometrically throughout the growth phase. The correlation coefficient between all the traits was very high, varying between 0.91 and 0.98. The zoometric variable that best predicted body weight was Perimeter of thorax (r2=0.93), which was fully developed in 90% of the animals at 97 days old. Maximum growth was recorded in all the studied variables during the first control month, days 7-37, but then it decreased gradually. This decrease was moderate until day 127, becoming very low from then on until end of the study. The optimum age for slaughtering fattened lambs is approximately four months, as from day 127 the daily growth rate slows down considerably, to 61.81 g/day, in comparison with the previous stage, which is 220.00 g/day. Therefore, the maintenance of lambs after four months is not productively efficient.

La oveja Chilota es una raza típica del archipiélago de Chiloé en el sur de Chile. Se midieron 12 corderos machos nacidos de parto único. En cada animal se midieronel peso corporal, la alzada a la cruz, el perímetro del tórax, diámetro dorso esternal, diámetro bicostal y la longitud corporal. Las primeras mediciones se tomaron a los 7 días de edad, y el resto a los 37, 67, 97, 127, 157 y 187 días de edad. El peso corporal y los rasgos zoométricos se desarrollaron alométricamente a lo largo de la fase de crecimiento. El coeficiente de correlaciónentre todos los rasgos fue muy elevado, variando entre 0,91 y 0,98. La variable zoométrica mejor predicha por el peso corporal fue el perímetro torácico (r2=0,93), el cual estuvo totalmente desarrollado en el 90% de los animales a los 97 días de edad. El crecimiento máximo fue registrado durante el primer mes de control (días 7-37) para todas las variables estudiadas, pero posteriormente decreció de forma gradual. Este decrecimiento fue moderado hasta el día 127, volviéndose muy lento hacia el final del estudio. La edad óptima para el sacrificio de los corderos es aproximadamente de 4 meses, dado que a partir del día 127 la tasa diaria de crecimiento disminuye considerablemente, a 61,81 g/día, en comparación con la etapa previa, donde esta tasa es de 220,00 g/día.Por lo tanto, el sacrificio de los corderos más allá de los 4 meses de edad no resulta productivamente eficiente.

Morphology differentiation and structural functionality of ewes due to incomplete crossbreeding / Diferenciación morfológica y funcionalidad estructural de ovejas debido a cruzamiento incompleto

Most Chilean sheep stock comprises different degrees of crossbreeding over Corriedale breed. A common absorbent crossbreeding has been Australian Merino over Corriedale which, in many cases, has not been complete. The aim of this study was to evaluate the process of morphology differentiation and structural functionality of Corriedale ewes undergoing incomplete absorbent crossbreeding which was carried out in order to create an animal with a new morphology. A total of four hundred adult ewes were measured; two hundred belonging to the incomplete crossbreeding, and two hundred from the two original breeds (one hundred Corriedale and one hundred Australian Merino ewes). All measured ewes were randomly selected. Fourteen body measurements were recorded and nine body indexes were calculated for each ewe. Results show that a new biotype has been created from the absorbent crossbreeding of Corriedale by Australian Merino, which produced ewes with a clear morphological and structural functionality differentiation as compared to the two original breeds. The new body format shows morphostructural variability coefficients that are similar to those found on other formally recognized sheep breeds.

La mayor parte del stock ovino chileno comprende diferentes grados de cruzamiento con la raza Corriedale. Un cruzamiento absorbente común ha sido el de Merino Australiano sobre Corriedale, el cual, en muchos casos, no ha sido completo. En este estudio se evaluó el proceso de diferenciación morfológica y funcionalidad estructural de las ovejas Corriedale que fueron previamente sometidas a cruzamiento absorbente incompleto con el fin de crear un animal con una nueva morfología. Se midió un total de cuatrocientas ovejas adultas, doscientas provenientes del cruzamiento incompleto y doscientas de las dos razas originales (cien ejemplares de raza Corriedale y cien de Merino australiano). Todas las ovejas medidas fueron seleccionadas al azar. Para cada animal se registraron catorce mediciones corporales y se calcularon nueve índices. Los resultados de los análisis permiten concluir que el cruzamiento absorbente de Corriedale por Merino Australiano ha generado un nuevo biotipo ovino, con una diferenciación morfológica clara y diferente funcionalidad estructural al ser comparadas con las dos razas originales. Los coeficientes de variabilidad morfoestructural que presenta el nuevo formato corporal fueron similares a los de otras razas ovinas formalmente reconocidas.

Comparación de la estabilización precoz versus tardía en el trauma raquimedular / Comparison of early versus delayed stabilization in spinal cord injury

El Trauma Raquimedular (TRM) es el resultado del daño18, 19 producido por lesiones traumáticas vertebrales a cualquier nivel y que comprometen a las diferentes estructuras que componen la columna vertebral, particularmente la médula espinal o sus raíces. Su incidencia14, 16 varía entre 11.5 y 53.4 por cada millón de habitantes y la causa más frecuente en nuestro país son las caídas. La región cervical es la más afectada seguida de la unión toracolumbar. Los segmentos torácicos y lumbares se comprometen con menor frecuencia, siendo similar en ambos niveles. Es una patología catastrófica para los pacientes y sus familias, ya que habitualmente los afectados son personas jóvenes en edad productiva17. Conjuntamente con el inmenso problema social, esta patología constituye un gran problema económico15 para los sistemas de salud debido al alto costo que implica su tratamiento tanto en la fase aguda como su posterior rehabilitación. El tratamiento del TRM se debe iniciar desde el momento en que se sospecha una lesión medular. Con el fin de evitar el daño medular secundario, además de la inmovilización precoz1,2,3,4,5,6,9, 20 se han probado distintos protocolos de tratamientos farmacológicos7,8,10,12,13, sin resultados que avalen su uso. Los protocolos basados en los estudios NASCIS21,22,23,24 utilizados en la actualidad emplean metilprednisolona en dosis de 30 mg/kg en bolo infundido en 15 minutos, seguido de una infusión en dosis de 5.4 mg/kg/hora. Dependiendo si el tiempo transcurrido desde la lesión es menor a 3 horas la infusión se mantiene por 23 horas y si la lesión se encuentra entre 3 y 8 horas se mantiene por 47 horas. Del mismo modo se han utilizado TRH26, Gaciclidina, Naloxona22, Tirilizad24, Nimodipino25 y más recientemente se ha propuesto el tratamiento de células madres27,28. Por otra parte una serie de trabajos11 sugieren que la descompresión y estabilización precoz en TRM disminuye el daño medular así como las complicaciones médicas...

Spinal Cord Injury (SCI) is due to traumatic lesions involving spine, specially spinal cord and its roots. This is a catastrophic neurological disorder for the patients which are usually young people in productive age. The incidente range is from 11.5 to 53.4 per million people. Besides the great social problem it brings another important issue for health systems due to high costs involved. Different pharmacologic protocols have been proposed to avoid a possible further damage, without results supporting their use. Otherwise multiple studies suggest that early spine decompression and stabilization diminish secondary spinal cord damage as well as medical complications and period of hospitalization. Our study retrospectively evaluated a group of patients who received a late decompression and stabilization and one that received an early within the first 72 hours focusing in pre and post surgical stay and associated medical complications. The data were obtained of the Neurosurgical Department of The Rancagua Regional Hospital database and includes 233 patients with spinal cord injury between May 1997 and October 2009. Cervical Spinal Cord Injury is more prevalent and more common in middle age men. Patients who underwent early decompression were hospitalized less time and suffer less medical complications.

Alimentos: una vía de exposición a contaminantes orgánicos para la población chilena / Foodstuffs: a human exposure to organic pollutants for the Chilean population

The current state of environmental pollution by persistent bio-accumulative and toxic substances (PBTS) in the Chilean food and population is practically unknown. This short communication aims to open the discussion on the need to assess the level of contamination of PBTS derived from foods consumed by the Chilean population considering diet as one of the main route of exposure.

El estado actual de la contaminación ambiental con Sustancias Persistentes Bioacumulables y Toxicas (PBTS) en los alimentos y población Chilena es prácticamente desconocida. Por este motivo esta comunicación corta tiene como objeto abrir la discusión sobre la necesidad de evaluar el nivel de contaminación por PBTS proveniente de los alimentos que consume la población Chilena, considerando a la dieta como una principal vía de exposición.

Cold-induced glutamate release in vivo from the magnocellular region of the paraventricular nucleus is involved in ovarian sympathetic activation.

We previously reported that centrally-induced sympathetic activation in response to cold stress is associated with a polycystic ovarian condition in rats, and thyrotrophin-releasing hormone (TRH) released locally from the magnocellular region of the paraventricular nucleus (PVN) appears to be involved in this activation. Because TRH neurones express NMDA glutamate receptors, in the present study, we investigated the role of glutamate in the increased release of TRH from magnocellular neurones induced by cold stress and its relationship to ovarian neurotransmission. Animals with a push-pull cannula stereotaxically implanted into the magnocellular portion of the PVN were exposed to cold stress (4 degrees C for 64 h) and subjected to intracerebral perfusion. Perfusate fractions were obtained and analysed by high-performance liquid chromatography to measure glutamate and GABA levels. Glutamate, but not GABA, release increased significantly in animals perfused under cold exposure. In vivo administration of glutamate to the PVN increased TRH release. Injection of MK-801 into the magnocellular portion of the PVN reduced ovarian noradrenaline turnover and led to an increase in catecholamine concentration from the adrenal glands and celiac ganglia. Taken together, the results obtained in the present study strongly suggest that glutamate release from the magnocellular PVN is sensitive to cold stress and that glutamate acts through the NMDA receptor to mediate cold-induced TRH release. This in turn triggers hypothalamic-ovarian pathway activation, which might be responsible for the polycystic condition induced by cold stress and other ovarian pathologies characterised by increased sympathetic discharge.

Biomonitoring of antioxidant and oxidative stress responses in Perinereis gualpensis (Polychaeta: Nereididae) in Chilean estuarine regions under different anthropogenic pressure.

This study aimed to analyze oxidative stress parameters, including levels of the antioxidant glutathione (GSH), activity of glutamate-cysteine ligase (GCL) and glutathione-S-transferase (GST), total antioxidant capacity and protein oxidation, in the polychaete Perinereis gualpensis (Nereididae) collected from the Biobío, Itata, Valdivia and Lingue estuaries in Chile, which present different degrees of anthropogenic pressure. Sampling sites were characterized considering a geographic information system and the physicochemical characteristics of water and sediment. Significant differences (p<0.05) were observed between the sampling sites for most of the responses (GSH, GCL, GST and antioxidant capacity), mainly related to human activities such as agriculture, industry, among others. Multivariate correlation analysis indicates a certain relationship of antioxidant responses with human activities, salinity, and worm weight, this last employed to standardize GST and antioxidant capacity. These results clearly indicate biomarker responses in P. gualpensis in Biobío and Valdivia estuaries, the more affected by human activities.

Hipoglicemia como causa de hospitalización en el Hospital Dr. Gustavo Fricke en el período agosto 2001 - agosto 2006 / Hypoglycemia as admitting cause al Dr. Gustavo Fricke between august 2001 and august 2006

Introducción: La hipoglicemia es un síndrome clínico ocasionado por múltiples causas y definido por una glicemia < 60 mg/dl. Se dice que la hipoglicemia es severa cuando necesita la asistencia de terceros u hospitalización. En el paciente diabético, la hipoglicemia es la complicación aguda más frecuente y representa el factor limitante del control glicémico en estos enfermos. Objetivo: determinar la incidencia de ingresos hospitalarios por hipoglicemia, y determinar las variables biodemográficas y las causas de las hipoglicemias. Pacientes y método: Se realizó un estudio descriptivo retrospectivo de la población de pacientes ingresados con el diagnóstico de hipoglicemia al Servicio de Urgencia del Hospital Dr. Gustavo Fricke entre Agosto 2001 y Agosto 2006. Resultados: Se analizaron 93 casos. La edad promedio del grupo fue de 72,3 años y la distribución por sexo fue de 60,2 por ciento de mujeres. De ellos, 85 pacientes (91.4 por ciento) eran DM tipo 2, un paciente DM tipo 1 (1.1 por ciento) y 7 pacientes no diabéticos (7,5 por ciento). Con respecto a la causa de la hipoglicemia, 79 casos (85 por ciento) fueron secundarios a hipoglicemiantes orales, 7 casos (8 por ciento) de causa no precisada, 4 casos (4 por ciento) de intento de suicidio (3 casos con insulina y un caso con glibenclamida), 2 casos (2 por ciento) de hipoglicemia reactiva y 1 caso (1 por ciento) secundario a uso de insulina. Discusión: Es interesante destacar que dentro de los pacientes diabéticos tipo 2 usuarios de sulfonilureas que ingresaron por hipoglicemia, la mayor parte se encontraba con dosis iguales o menores a 10 mg/día (dosis bajas).

Introduction; Hypoglycemia (HG) (glycemia < 60 mg/dl) is a clinical syndrome that may be due to different causes. Severe hypoglycemia is defined by the need of help of another person or the need of hospitalization. Being a limitation of optimal therapy, is the most frequent complication in the diabetic patient. Main: determine the etiology, biodemographic features and incidence of hospital admissions due to HG. Patients and method: descriptive retrospective study of all the patients that were hospitalized due to HG in the Emergency Ward of the Gustavo Fricke Hospital between August 2001 and 2006. Results: 93 cases were included in the study. Mean age: 72,3 years, 60,2 per cent were women. One patient was diabetic type 1 and 91,4 per cent (n=85) were type 2 diabetics; 7 patients were not diabetics. Causes of HG: 79 due to oral hypoglycemiants, 7 unknown, 4 suicidal attempts, 2 reactive hypoglycemia and 1 due to insullim therapy. Discussion: the patients admitted due to hypoglycemia secundary to sulfonylurea were using a small dose of it and 23.5 per cent had impaired renal fuction. We think education about hypoclycemic events es very important to prevent and treat this frequent complication.

Nueva generación de stents, con polímero bio-compatible: resultados y seguimiento clínico / New generation of biocompatible polymer coated stents: immediate and follow-up results in 52 patients

Introducción: Una nueva generación de Stents medicados (DES) polímeros bio-compatibles no trombogénicos permitirían una rápida re-epitelización, reduciendo la inflamación y manteniendo la función endotelial de la pared vascular. Por lo tanto, no solo la droga anti-proliferativa del DES, determina la respuesta de la pared vascular sino que la biocompatibilidad del polímero también juega un rol fundamental. Objetivo: Evaluar el resultado intrahospitalario y seguimiento clínico de los pacientes sometidos a angioplastía coronaria electiva con un DES con polímero bio-compatible. Método: Se estudiaron 52 pacientes sometidos a angioplastía con DES, durante un período de seguimiento entre 3 y 15 meses (x 8.6 meses). Se evaluó, MACE definido como muerte, infarto miocárdico, cirugía urgencia, revascularización repetida de lesión objetivo (TLR), a los 30 días, 3, 6, 9 y 12 meses. Además se evaluó la trombosis del Stent, 0-30 días (precoz), 31-360 días (tardía), más de 361 días (muy tardía). Resultados: La edad promedio del grupo fue de 63.8 +/- 10.8 años, hipertensión arterial 71.15 por ciento, diabetes 17.3 por ciento, dislipidemia 50 por ciento, tabaquismo 28.8 por ciento. Un 65.3 por ciento de los pacientes tenían enfermedad de 2 o 3 vasos, con un 51.9 por ciento de compromiso de la arteria descendente anterior (ADA). El 61.2 por ciento de las lesiones eran lesiones B-2 o C (clasificación American Heart Association). Pre procedimiento el diámetro de referencia del vaso (RVD), fue de 3.0 +/- 0.6 mm, con un diámetro luminal mínimo (MLD) de 0.8 +/- 0.5 mm, un porcentaje de estenosis de 77.2 +/- 17.9 por ciento y el largo promedio de las lesiones fue de 14 +/- 8.3 mm. El éxito del dispositivo y del procedimiento fue de 98.1 por ciento. Durante el período de seguimiento el MACE fue 3.8 por ciento y no se registraron trombosis de stents. Conclusiones: Durante el período de estudio, se observó una tasa baja de MACE relacionado al procedimiento, sin trombosis...

Background: a new generation of drug-eluting stents (DES) coated with a non-thrombogenic and biocompatible polymer allows a fast re-epithelization, reducing inflammation and maintaining endothelial function of the vascular wall. Therefore, not only the anti-proliferative effect of the drug contained in DES determines the response of the vascular wall, but also the polymer biocompatibility seems to play a fundamental role. Aim: to evaluate the results and clinical follow up of patients submitted to elective coronary angioplasty using a biocompatible polymer coated DES. Method: 52 patients treated with DES were followed from 3 to 15 months (mean 8.6 months) after stent implantation. Overall MACE defined as, death, myocardial infarction, emergent cardiac surgery or repeat revascularization of the target lesion (TLR) was evaluated at 30 days, 3, 6, 9 and 12 months. Stent thrombosis was also evaluated at 0-30 days (early), 31-360 days (late), and more than 361 days (very late). Results: Mean age was 63.8 +/- 10.8 years; hypertension was present in 71.1 percent, diabetes in 17,3 percent, hyperlipidemia in 50 percent, and 28.8 percent were current smokers. Two or three vessel diseases were present in 65.3 percent of patients: lesions were present in the LAD in 51.9 percent. Lesions were classified as B-2 or C (according to American Heart Association) in 61.2 percent of cases. Pre procedure reference vessel diameter (RVD) was 3.0 +/- 0.6 mm, with a mi ni mu m luminal diameter (MLD) of 0.8 +/- 0.5 mm, percentage stenosis of 77.2 +/- 17.9 percent and lesion length averaged 14 +/- 8.3 mm. Both device and procedure success rates were 98.1 percent. During follow up MACE occurred in 3.8 percent and no stent thrombosis were registered. Conclusion: During the study period, the observed procedure related MACE rate was low, with no instances of probable, possible, or definitive stent thrombosis. The clinical results confirmed the good performance and security of...

[Coverage of preventive health activities in a Chilean region, calculated using the preventive medicine index]. / Indice de medicina preventiva: Una medida integradora de la cobertura de los programas preventivos.

BACKGROUND: Preventive activities of the public health system in Chile are not integrated and there is no parameter assessing the whole population that is benefited with these activities. AIM: To develop and implement a mathematical measure of the coverage of preventive health activities, provided to different age groups. MATERIAL AND METHODS: Data was gathered from the monthly statistical reports of the women, children, teenager, adult and elderly health programs in 30 communities of the Seventh Chilean Region. The preventive medicine index (PMI) was calculated as the ratio between the population that was ascribed to each program and the population that was a potential beneficiary of such program. RESULTS: In the studied region, the global coverage of preventive medicine, calculated using the PMI, increased from 0.229 in 1999 to 0.370 in 2003. This represents a 61% increment. However, there are important inequalities in the access to preventive health in the different communities of the region. CONCLUSIONS: The PMI revealed a substantial increment in preventive health activities in the studied region.