Influence of biological and social-historical variables on the time taken to describe an angiosperm.

PREMISE OF THE STUDY: By convention, scientific naming of angiosperm species began in 1753; it is estimated that 10-20% of species remain undescribed. To complete this task before rare, undescribed species go extinct, a better understanding of the description process is needed. The South American Cerrado biodiversity hotspot was considered a suitable model due to a high diversity of plants, habitats, and social history of species description. METHODS: A randomized sample of 214 species (2% of the angiosperm flora) and 22 variables were analyzed using multivariate analyses and analysis of variance. KEY RESULTS: Plants with wide global distributions, recorded from many areas, and above 2.6 m were described significantly earlier than narrowly distributed, uncommon species of smaller stature. The beginning of the career of the botanist who first collected the species was highly significant, with an average delay between first collection and description of 29 yr, and between type collection and description 19 yr; standard deviations were high and rose over time. Over a third of first collections were not cited in descriptions. Trends such as scientific specialization and decline of undescribed species were highlighted. Descriptions that involved potential collaboration between collectors and authors were significantly slower than those that did not. CONCLUSIONS: Results support four recommendations to hasten discovery of new species: (1) preferential collecting of plants below 2.6 m, at least in the Cerrado; (2) access to undetermined material in herbaria; (3) fieldwork in areas where narrow-endemic species occur; (4) fieldwork by knowledgeable botanists followed by descriptive activity by the same.

MALDI-TOF MS and 16S RNA Identification of Culturable Gastric Microbiota: Variability Associated with the Presence of Helicobacter pylori.

Helicobacter pylori is the main bacteria associated with gastroduodenal diseases. Recent studies have reported that gastric microbiota might be modified by the H. pylori colonization, favoring gastric lesions' development. In Chile, the region of La Araucanía concentrates a high risk of gastric cancer associated with Helicobacter pylori colonization, rurality, poverty, and Mapuche ethnicity. Hence, we aimed to identify the culturable gastric microbiota and characterize its variability at different stages of epithelial injury, based on its H. pylori colonization in dyspeptic patients from this Chilean region. Microaerophilic bacteria strains were isolated from antrum biopsies of 155 dyspeptic patients' biopsies and identified using MALDI-TOF MS or 16sRNA gene sequencing for non-pylori species identification, and UreC gene amplification for H. pylori confirmation. We found 48 species from 18 families, mainly belonging to Neisseriaceae (21.3%), Streptococcaceae (20.0%), Actynomicetaceae (9.0%), Enterobacteriaceae, and Lactobacillaceae (4.5%); however, Streptococcaceae and Actinomycetaceae families showed a significant reduction in samples infected with H. pylori, along with a considerably lower diversity of species. Our results revealed a microbiota modification due to H. pylori colonization associated with the gastric epithelial state, suggesting a potential microbiota role for developing and progressing gastric diseases.

Evolutionary diversity in tropical tree communities peaks at intermediate precipitation.

Global patterns of species and evolutionary diversity in plants are primarily determined by a temperature gradient, but precipitation gradients may be more important within the tropics, where plant species richness is positively associated with the amount of rainfall. The impact of precipitation on the distribution of evolutionary diversity, however, is largely unexplored. Here we detail how evolutionary diversity varies along precipitation gradients by bringing together a comprehensive database on the composition of angiosperm tree communities across lowland tropical South America (2,025 inventories from wet to arid biomes), and a new, large-scale phylogenetic hypothesis for the genera that occur in these ecosystems. We find a marked reduction in the evolutionary diversity of communities at low precipitation. However, unlike species richness, evolutionary diversity does not continually increase with rainfall. Rather, our results show that the greatest evolutionary diversity is found in intermediate precipitation regimes, and that there is a decline in evolutionary diversity above 1,490 mm of mean annual rainfall. If conservation is to prioritise evolutionary diversity, areas of intermediate precipitation that are found in the South American 'arc of deforestation', but which have been neglected in the design of protected area networks in the tropics, merit increased conservation attention.

A new species of Escallonia (Escalloniaceae) from the inter-Andean tropical dry forests of Bolivia.

Over the last two decades, renewed fieldwork in poorly explored areas of the tropical Andes has dramatically increased the comparative material available to study patterns of inter- and intraspecific variation in tropical plants. In the course of a comprehensive study of the genus Escallonia, we found a group of specimens with decumbent branching, small narrowly elliptic leaves, inflorescences with up to three flowers, and flowers with red petals. This unique combination of traits was not present in any known species of the genus. To evaluate the hypothesis that these specimens belonged to a new species, we assessed whether morphological variation between the putative new species and all currently known Escallonia species was discontinuous. The lack of overlap in tolerance regions for vegetative and reproductive traits combined with differences in habit, habitat, and geographic distribution supported the hypothesis of the new species, which we named Escallonia harrisii. The new species grows in sandstone inter-Andean ridges and cliffs covered with dry forest, mostly on steep slopes between 1,300-2,200 m in southern Bolivia. It is readily distinct in overall leaf and flower morphology from other Escallonia species in the region, even though it does not grow in sympatry with other species. Because E. harrisii is locally common it may not be threated at present, but due to its restricted geographic distribution and the multiple threats of the tropical dry forests it could become potentially vulnerable.

Extrusión Apical de Barro Dentinario e Irrigante Producidos por Dos Sistemas de Instrumentación de Níquel Titanio al Utilizar Irrigación Pasiva o Activa / Apical Extrusion of Dentin and Irrigant Smear Layer Produced by Two Nickel Titanium Instrumentation Systems when Using Passive or Active Irrigation

RESUMEN: El barro dentinario producido durante tratamiento endodóntico puede ser extruido hacia el tejido periradicular junto con el irrigante, produciendo inflamación y dolor postoperatorio. Comparar la cantidad de extrusión apical de barro dentinario e irrigante, producido durante la preparación químico-mecánica, por dos sistemas de instrumentación Rotatoria (Mtwo), y Reciprocante (Reciproc), complementado con irrigación pasiva o activa (Endoactivator). Cuarenta y ocho premolares (48) inferiores, fueron aleatoriamente distribuidos en cuatro grupos de estudio (n=12 dientes), (1) Rotatorio-pasiva, (2) Reciprocante-pasiva, (3) Rotatorio-activa y (4) Reciprocante-activa. Los conductos radiculares fueron instrumentados de acuerdo a las instrucciones del fabricante, e irrigados con hipoclorito de sodio al 5 %. El barro dentinario e irrigante extruido, fueron recolectados en tubos Eppendorf previamente pesados. Se calcularon los valores de extrusión de barro dentinario e irrigante para cada grupo. Los datos fueron analizados con el análisis de varianza ANOVA. En todos los grupos se produjo extrusión apical. No se encontraron diferencias estadísticamente significativas en la extrusión apical de barro dentinario, entre los grupos estudiados (P = 0,068), sin embargo, al analizar la extrusión de irrigantes, se evidenció diferencia estadísticamente significativa entre los grupos 1 y 4 (P< 0,05), entre los demás grupos no se observaron diferencias estadísticamente significativas. (P > 0,05). Bajo las condiciones de este estudio, los sistemas rotarios y reciprocante, extruyen sólido y líquido, siendo el sistema reciprocante el que produce mayor extrusión de líquido, tanto con irrigación activa como pasiva.

ABSTRACT: The smear layer produced during endodontic treatment can be extruded into the periradicular tissue together with the irrigant, producing inflammation and postoperative pain. The purpose of this in vitro study was to compare the amount of apical extrusion, produced during the endodontic preparations with two rotary instrumentation systems using passive and active irrigation. Forty-eight (48) mandibular premolars were randomly assigned to 4 groups (n = 12 teeth), (1) Rotatory - passive, (2) Reciprocating passive, (3) Rotatory-active, (4) Reciprocating- active. The root canals were instrumented according to the manufacturer's instructions and irrigated with 5 % sodium hypochlorite. Extruded debris and irrigant were collected in previously weighed Eppendorf tubes. The extrusion values were calculated for each group. The data were analyzed with the ANOVA analysis of variance. Results: Apical extrusion was produced in all groups. No statistically significant differences were found in the apical extrusion of smear layer, between the groups studied (P = 0.068), however, when analyzing the extrusion of irrigants, a statistically significant difference was evidenced between groups 1 and 4 (P <0.05). , among the other groups no statistically significant differences were observed. (P> 0.05). Under the conditions of this study, the reciprocating and rotary systems, extrude solid and liquid, being the reciprocating system the one that produces more extrusion of liquid, with both active and passive irrigation.

Resultados visuales en cirugía del desprendimiento de retina / Visual results of the retinal detachment surgery

Se revisan las 100 últimas fichas de pacientes operados de DR por el autor en el Hospital del Salvador. Se seleccionaron aquellos DR con un seguimiento mínimo de 6 meses postoperatorio, sin PVR, no traumáticos, sin signos de antiguedad, fáquicos, sin desgarro gigante, sin diálisis, sin cirugía previa de DR y sin patología sobreagregada. La edad promedio de los operados fue de 50,8 años y en un 44% fueron altos miopes. Los días promedio de pérdida visual prequirúrgica fue de 25,7 días. Un 85% de los casos tenían visión menor de 0,1 en el preoperatorio. Al momento de consulta el DR comprometía dos o más cuadrantes en el 84% y en un 87% hubo compromiso macular. La mayoría de los desgarros fueron únicos y se ubicaron a superotemporal. En todos los casos se realizó técnica epiescleral con variaciones según el caso. El éxito anatómico fue 94,5%. Los fracasos fueron por PVR. Un 87,5% de los éxitos anatómicos tuvieron visión mayor o igual a 0,1 y en un 35% de ellos la visión fue mayor o igual a 0,5

Intoxicación mortal causada por ingestión accidental de alcohol metílico / Mortal poisoning caused by accidental consumption of methilic alcohol

El caso objeto de esta publicación se refiere al de tres hombres adultos que fallecieron tras ingerir accidentalmente una bebida alcohólica conteniendo gran cantidad de alcohol metílico. Se analizó la sangre de estos sujetos, hallándose metanol y sus metabolitos empleando la técnica de cromatografía de gases, Este es el único caso

Un caso de suicidio con fluoruro de sodio / A case of suicide with sodium fluoride

Se reporta en este trabajo el caso de un hombre que murió después de ingerir gram cantidad de tabletas de fluoruro de sodio. Utilizando la técnica de cromatografía de gases, se analizó en el plasma sanguíneo el contenido de ión fluoruro. Este es el único caso reportado hasta hoy en la literatura nacional. Ademas se hacen consideraciones al respecto y se señalan su rareza y necesidad de tener presente su ocurrencia en nuestro medio

Vitrectomía en hemorragia vítrea de causa no precisada / Vitrectomy in vitreal hemorrhage of unknown etiology

La vitrectomía en pacientes no diabéticos con hemorragia vítrea de etiología no precisada nos permitió conocer la causa en 5 de 8 casos (4 TRVST, 1 desgarro retinal) y mejorar la agudeza visual en 7 de 8 casos

Cirugía de la proliferación vitreorretinal avanzada: análisis de la técnica: casos clínicos / Surgery in vitreoretinal proliferation: technic analysis: clinical cases

Se analiza la técnica quirúrgica utilizada en casos de PVR avanzada (Grados C y D), consistente en Vitrectomía, pelamiento de membranas, retinotomías, evacuadora interna a inyección de aceite de silicona. Se presentan 5 casos clínicos operados con esta técnica en el Servicio de Oftalmología del Hospital del Salvador

Experiencia en vitrectomía convencional / Conventional vitrectomy

Se presenta la experiencia en vitrectomía convencional del Servicio de Oftalmología del Hospital Salvador, acumulada durante un año (junio 88 a junio 89). De 70 casos operados, destacan la alta frecuencia de cuadros traumáticos (54%), los pobres resultados anatómicos como visuales obtenidos en cuadros asociados a proliferación vitreorretinal, así como los buenos resultados anatómicos y funcionales en cuadros en los cuales la vitrectomía se efectuó sólo por hemorragias u opacidades del cuerpo vítreo. Destacó un 24% de iatrogenia causada principalmente por desgarros, cataratas y hemorragias