A rapid preparative-TLC/GC-MS methodology for discriminating between two filmy ferns (Hymenophyllaceae) native from the temperate rain forest of Southern Chile based on their soluble carbohydrates / Una metodología de CCF-preparativa/CG-EM rápida para discriminar entre dos helechos película(Hymenophyllaceae) nativos del bosque templado del sur de Chile basada en sus hidratos de carbono

Filmy ferns are a conspicuous epiphytic component of the temperate rain forest of southern Chile and the more abundant genus is Hymenophyllum represented by 19 species, they are a primitive fern family sharing their limited water lost control (poikilohydricity) with lower non-vascular plants, such as bryophytes and lichens. Because, carbohydrate accumulation is a desiccation tolerance mechanism proposed for desiccation-tolerant vascularized plants, the aim of this investigation was to propose a methodology for soluble carbohydrate analysis in native ferns. Preparative- TLC showed to be a simple and rapid technique for separating Hymenophyllum sugars. GC-MS analysis allowed identifying glucitol (2.0 percent), sucrose (2.0 percent), alpha or beta-melibiose (5.0 percent) and salidroside (4.4 percent) in H. cruentum carbohydrate profile from H. dentatum showed significant differences presenting only two sugars sucrose (1.4 percent) and alpha or beta-melibiose (3.2 percent). Furthermore, salidroside, an antioxidant compound, was identified only in H. cruentum. Our results suggest that H. cruentum, has higher preventive mechanisms than H. dentatum; that would allow delay the effects of desiccation (prevent a rapid dehydration) and thus survive to short periods of drought present in the study area. Due to the presence of salidroside in H. cruentum this species should be more resistant to oxidative stress that H. dentatum.

Los helechos película se pueden encontrar en el bosque templado lluvioso del sur de Chile, siendo el género más abundante Hymenophyllum representado con 19 especies. Son una familia de helechos primitivos que comparten la limitación de control de pérdida de agua (poiquilohidrícos) con plantas no vasculares, tales como briófitas y líquenes. Como el contenido de hidratos de carbono ha sido asociado a la protección de la planta durante la desecación, su análisis es una herramienta importante para dilucidar el mecanismo asociado a este fenómeno. El objetivo de esta investigación fue proponer una metodología fácil y rápida para el análisis de hidratos de carbono en helechos nativos. La CCF-preparativa permitió la separación de hidratos de carbono presentes en plantas del género Hymenophyllum. El análisis por GC-MS logró identificar glucitol (2,0 por ciento), sacarosa (2,0 por ciento), alfa o Beta-melibiosa (5.0 por ciento) y salidrosido (4,4 por ciento) en H. cruentum. El perfil de hidratos de carbono de H. dentatum mostró diferencias significativas, mostrando sólo dos compuestos sacarosa (1,4 por ciento) y alfa o beta- melibiosa (3.2 por ciento). Además, salidrosido, un compuesto antioxidante, sólo fue identificado en H. cruentum. Nuestros resultados sugieren que ante la menor tolerancia a la desecación observada previamente en H. cruentum, esta especie presenta mecanismos que le permitirían retardar los efectos de la desecación (prevención de una rápida pérdida de agua) y así sobrevivir a los periodos cortos de sequía presentes en la zona de estudio. Debido a La presencia de salidrosido en H. cruentum, esta especie debería ser más resistente al estrés oxidativo que H. dentatum.

Caries risk assessment in chilean adolescents and adults and its association with caries experience

Cariogram is a computer program that uses an algorithm to assess caries risk. Although the use of Cariogram has recently increased, little information is available regarding its effectiveness in adults. This study aimed to determine whether caries risk from Cariogram relates to caries experience in adults. One hundred and eighty Cariogram files were completed from patients aged ten to fifty-six years (mean: 23.28 years). Seven factors from the software were included from patient records to complete the Cariogram: caries experience, diet (content and frequency), stimulated salivary flow, hygiene index, related diseases and fluoride usage. The percentages of "chances of avoiding new lesions" (caries risk) were obtained from Cariogram, and the subjects were classified into five risk groups. Results were compared for each variable with ANOVA, and a correlation between caries and Cariogram variables was calculated by Pearson's correlation coefficient. A multivariate regression model was also used. Only three patients were classified as low risk, and none were classified as very low risk. Thus, only the four upper quintiles were considered for the analysis, and the lower quintile was not considered in the study. Neither DMFT nor the number of lesions were significantly different among the Cariogram's risk categories (p > 0.05). Only diet content was significantly correlated with caries experience (p = 0.006). Caries lesions failed to correlate with any Cariogram variable (p > 0.05). Age, not sex or caries risk scores, showed a strong and positive association with DMFT (p < 0.01). Caries risk from Cariogram appears to be unrelated with caries experience or caries lesions in a high-caries adult population.

Genotypic variation in morphology and freezing resistance of Eucalyptus globulus seedlings subjected to drought hardening in nursery / Variación genotípica en la morfología y resistencia a la congelación del Eucalyptus globulus a la sequía sometido al endurecimiento en vivero

Eucalyptus globulus Labill is one of the most planted species in Chile, because of its fast growth and superior pulp qualities. Nevertheless, the incidence of drought and frost damage immediately after planting is frequent. The purpose of this work was to study the effect of drought hardening on frost resistance and on variations in morphological traits that may increase drought resistance at nursery phase in four genotypes of E. globulus Labill. Drought hardening treatments consisted in induced water stress by watering restriction, until pre-dawn stem xylem water potentials (Psi pd) reached -0.2, -1.8 and -2.6 MPa. Two water stress-rewatering cycles were applied during 54 days of hardening. Plant and root biomasses were affected by the interaction of drought hardening and genotypes. The rest of morphological and alometrical traits were affected independently by drought or genotype. Plant height, leaf area, specific leaf area (SLA), stem, and leaf biomasses decreased with drought hardening, while collar diameter was not affected. Genotypes responded differentially to drought hardening in plant height, leaf area, SLA, and stem, and leaf biomasses. Ice nucleation temperature (INT), and freezing temperatures (FRT), and 50 percent freezing damage index of leaves (LT50) were affected by the interaction between drought hardening and genotypes. EG-13, EG-23 and EG-22 genotypes became freezing tolerant with drought hardening (-2.6 MPa). Additionally, EG-14 genotype increased its freezing resistance at -1.8 MPa. Therefore, freezing resistance levels and mechanism depend on genotype and drought hardening treatment. The success in tree breeding by genetic selection should be facilitated by improved understanding of the physiology of stress resistance development and survival during water supply limitations. The knowledge of morphological and freezing resistance dependency on the interaction between genotype and drought hardening may be useful...

Changes in morpho-physiological attributes of Eucalyptus globulus plants in response to different drought hardening treatments

Morpho-physiological attributes exhibited in response to drought hardening at the end of the growing season of Eucalyptus globulus Labill under nursery conditions were studied to evaluate the effect of three drought hardening treatments in morpho-physiological traits used as suitable indicators of drought hardiness, such as, plant growth, root growth potential, plant water relationships and survival. Freezing resistance of drought hardened plants was also studied in order to evaluate cross hardening effects in cuttings of Eucalyptus globulus Labill. Drought hardening consisted in induced water stress by watering restriction, until plant stem xylem water potentials (psipd) reached to-0.2, -1.3 and -2.4 MPa. Two water stress-rewatering cycles were applied during 54 days of treatment. The hardening treatments caused a significant reduction in plant height, leaf area, specific leaf area, plant, leaf, stem and root biomass. However, stem diameter was not affected. Root growth potential increased with the exposure to moderate water stress (-1.3 MPa). Drought hardening treatments have not effect on water relationship parameters such as saturation osmotic potential (psipisat), volumetric module of elasticity (e), relative water content (RWCtlp) and osmotic potential (psitlp) at the turgor loss point. Only 1.7 percent and 6 percent of dehydrated dead plants were observed on treatments at -1.3 and -2.4 MPa respectively. Finally, the freezing damage index of leaves (LT50) was not significantly affected by drought hardening treatments. Furthermore, a reduction of 1.1ºC of supercooling capacity was observed at -2.4 MPa. As a conclusion, drought hardening is an important step of plants production programs during the final phase of nursery, because changes in morphological attributes caused by exposure to moderate drought, enable the plants to maintain the balance between transpiration and absorption areas and increase the capacity of plants to generate n...

Enfrentamiento quirúrgico de la litiasis biliar / Surgical confront of the biliary litiasis

Se presenta un casuística personal de 222 pacientes biliares sintomáticos. Se comunica su estudio preoperatorio, los procedimientos quirúrgicos y sus resultados. Se concluye que la patología biliar es un problema real, que hay un importante grupo de pacientes en los que debe resolverse complicaciones serias. Un buen método de estudio preoperatorio es el criterio clínico radiológico. La colangiografía intraoperatoria de rutina no influye en la prevención de daño de la vía biliar, siempre que se mantengan los principios básicos de la cirugía y, se reconfirman los buenos resultados de la colecistectomía laparoscópica

Cirugía de la enfermedad hemorroidal / Surgery of hemorrhoidal disease

Se presenta la casuística de 173 pacientes operados de enfermedad hemorroidal mediante técnica tipo Milligan y Morgan en nuestro Servicio. La mitad de los pacientes tenía historia de 5 a 10 años de evolución y la mayoría presentaba hemorroides de grados III y IV. En el 75% se practicaron tres colgajos cutáneos - mucosos y en 23%, dos, adicionando fisurectomía, esfinterotomía, criptectomía y ligaduras cuando fue necesario. El promedio de hospitalización fue de 5,8 días y de cicatrización de 39 días. Se presentaron escasas complicaciones precoces y un 4,04% de complicaciones tardías. El 90% de pacientes controlados están asintomáticos. Recomendamos la técnica de Milligan y Morgan por ser sencilla y de baja morbilidad