ROS-Scavenging Enzymes as an Antioxidant Response to High Concentration of Anthracene in the Liverwort Marchantia polymorpha L.

Marchantia polymorpha L. responds to environmental changes using a myriad set of physiological responses, some unique to the lineage related to the lack of a vascular- and root-system. This study investigates the physiological response of M. polymorpha to high doses of anthracene analysing the antioxidant enzymes and their relationship with the photosynthetic processes, as well as their transcriptomic response. We found an anthracene dose-dependent response reducing plant biomass and associated to an alteration of the ultrastructure of a 23.6% of chloroplasts. Despite a reduction in total thallus-chlorophyll of 31.6% of Chl a and 38.4% of Chl b, this was not accompanied by a significant change in the net photosynthesis rate and maximum quantum efficiency (Fv/Fm). However, we found an increase in the activity of main ROS-detoxifying enzymes of 34.09% of peroxidase and 692% of ascorbate peroxidase, supported at transcriptional level with the upregulation of ROS-related detoxifying responses. Finally, we found that M. polymorpha tolerated anthracene-stress under the lowest concentration used and can suffer physiological alterations under higher concentrations tested related to the accumulation of anthracene within plant tissues. Our results show that M. polymorpha under PAH stress condition activated two complementary physiological responses including the activation of antioxidant mechanisms and the accumulation of the pollutant within plant tissues to mitigate the damage to the photosynthetic apparatus.

Norbin ablation results in defective adult hippocampal neurogenesis and depressive-like behavior in mice.

Adult neurogenesis in the hippocampus subgranular zone is associated with the etiology and treatment efficiency of depression. Factors that affect adult hippocampal neurogenesis have been shown to contribute to the neuropathology of depression. Glutamate, the major excitatory neurotransmitter, plays a critical role in different aspects of neurogenesis. Of the eight metabotropic glutamate receptors (mGluRs), mGluR5 is the most highly expressed in neural stem cells. We previously identified Norbin as a positive regulator of mGluR5 and showed that its expression promotes neurite outgrowth. In this study, we investigated the role of Norbin in adult neurogenesis and depressive-like behaviors using Norbin-deficient mice. We found that Norbin deletion significantly reduced hippocampal neurogenesis; specifically, the loss of Norbin impaired the proliferation and maturation of newborn neurons without affecting cell-fate specification of neural stem cells/neural progenitor cells (NSCs/NPCs). Norbin is highly expressed in the granular neurons in the dentate gyrus of the hippocampus, but it is undetectable in NSCs/NPCs or immature neurons, suggesting that the effect of Norbin on neurogenesis is likely caused by a nonautonomous niche effect. In support of this hypothesis, we found that the expression of a cell-cell contact gene, Desmoplakin, is greatly reduced in Norbin-deletion mice. Moreover, Norbin-KO mice show an increased immobility in the forced-swim test and the tail-suspension test and reduced sucrose preference compared with wild-type controls. Taken together, these results show that Norbin is a regulator of adult hippocampal neurogenesis and that its deletion causes depressive-like behaviors.

Effect of light on the growth and photosynthesis of an invasive shrub in its native range.

Invasive species success may depend on ecophysiological attributes present in their native area or derived from changes that took place in the invaded environment. We studied the growth and photosynthetic capacity of Berberis darwinii shrubs growing under different light conditions (gap, forest edge and below the canopy) in their native area of Patagonia, Argentina. Leaf photosynthesis results determined in the native area were discussed in relation to information provided by studies carried out under the same light conditions in an invaded area in New Zealand. Shoot elongation, leaf production, stem and leaf biomass per shoot and specific leaf area (SLA, cm2 g-1) were determined in five adult plants, randomly selected in each of three light conditions in two forest sites. Net photosynthesis as a function of PPFD (Photosynthetic Photon Flux Density), stomatal conductance (gs), maximum light-saturated photosynthesis rate (Pmax), Pmass (on mass bases) and water-use efficiency (WUEi) were determined in plants of one site. We predicted that functional traits would differ between populations of native and invasive ranges. In their native area, plants growing under the canopy produced the longest shoots and had the lowest values for shoot emergence and foliar biomass per shoot, while their SLA was higher than gap and forest edge plants. Leaf number and stem biomass per shoot were independent of light differences. Leaves of gap plants showed higher Pmax, Pmass and gs but lower WUEi than plants growing at the forest edge. In its native range B. darwinii grows under different light conditions by adjusting shoot and leaf morphology and physiology. Plants of B. darwinii growing under the same light conditions show similar physiology in native and invasive ranges. This means that for B. darwinii, intra-specific variation of the functional traits studied here do not condition successful spread in new areas.

Rol de la laparoscopía en los cuadros agudos de abdomen inferior en la mujer: revisión últimos 10 años, Servicio de Ginecología del Hospital Británico / Role of laparoscopy in acute lower abdominal episodes in women: review of the last 10 years, British HospitalÆs Gynecology DepartmentABDOMEN, ACUTE - diagnosis

Introducción: los cuadros agudos de abdomen inferior (CAAI) en la mujer son una causa frecuente de consulta en puerta de emergencia. El rol de la laparoscopía como herramientadiagnóstica y terapéutica, más aun en la mujer, se encuentra bien establecido. Permite arribar a un diagnóstico de certeza en todos los casos al visualizar la totalidad de la cavidad abdominal mediante un abordaje mínimamente invasivo, evita retrasos diagnósticos y sus consiguientes complicaciones evolutivas. Objetivo: describir, analizar y comunicar la casuística de los últimos diez años de cirugías laparoscópicas por CAAI en el Servicio de Ginecología del Hospital Británico. Material y método: se realiza un estudio retrospectivo y descriptivo del rol de la laparoscopíaen los CAAI de la mujer en los últimos diez años de cirugías laparoscópicas realizadas en el Servicio de Ginecología del Hospital Británico. Se analizan las siguientes variables: edad depresentación, indicación de hallazgos nosológicos, resolución y complicaciones.Resultados: la máxima prevalencia de los cuadros agudos de abdomen se presentó entre los 30 y 35 años de edad; correspondiendo el embarazo ectópico, los quistes de ovario, seguidospor torsiones anexiales los hallazgos laparoscópicos más frecuentes. La resolución por vía laparoscópica pudo efectuarse en 93% de las pelviscopías patológicas. Solamente requirieron conversión laparotómica 7% de las pacientes, siendo la principal indicación de las mismas los abscesos tuboováricos.

Introduction: acute lower abdominal episodes in women are the most frequent cause of consultation at the emergency room. The role of laparoscopy as a diagnostic andtherapeutic tool, especially in women, has been well established. It allows for valid diagnosis in all cases since itenables the visualization of the entire abdominal cavity by means of a minimally invasive approach, it avoids diagnostic delays and its resulting complications in the evolution.Objective: to describe, analyze and communicate the casuistics of laparoscopic surgery for acute lower abdominal episodes at the British HospitalÆs Gynecology Departmentin the last ten years. We analyzed the following variables: age of consultation, nosological findings indication,resolution and complications. Results: maximum prevalence of acute abdominal episodes was between 30 and 35 years of age; the most frequentof which were cases of ectopic pregnancy, ovarian cysts, followed by adnexal torsions. Laparoscopic resolution could be performed in 93% of pathological pelvicoscopies. Only 7% of patients required laparothomic approach, the main indication of which was ovarian tube abscess.

Introdução: os quadros agudos de abdômen inferior (QAAI) na mulher são uma causa freqüente de consultano pronto-socorro. O papel da laparoscopia como ferramenta de diagnóstico e terapêutica, especialmente na mulher, já está estabelecido. Permite chegar a um diagnóstico de certeza em todos os casos por possibilitar avisualização da cavidade abdominal integralmente com uma abordagem minimamente invasiva, evita atrasos no diagnóstico e as complicações decorrentes desse atraso. Objetivo: descrever, analisar e comunicar a casuística dos últimos dez anos de cirurgias laparoscópicas por QAAI no Serviço de Ginecologia do Hospital Britânico. Material e método: faz-se um estudo retrospectivo e descritivo do papel da laparoscopia nos QAAI da mulher nos últimos dez anos de cirurgias laparoscópicas realizadas no Serviço de Ginecologia do Hospital Britânico. Foramanalisadas as seguintes variáveis: idade de apresentação, indicação de achados nosológicos, resolução e complicações.Resultados: a prevalência máxima dos quadros agudos de abdômen foi registrada no grupo entre 30 e 35 anos de idade; os achados mais freqüentes foram gravidez ectópica, cistos de ovário, seguidos por torções dos anexos.A resolução por via laparoscópica pode ser realizada em 93% das pelviscopias patológicas. Foi necessário realizarconversão laparatômica em somente 7% das pacientes, sendo os abscessos tuboováricos a principal indicação.

Are electrocyclization reactions of (3Z)-1,3,5-hexatrienone and nitrogen derivatives pseudopericyclic? A DFT study.

[reactions: see text] Electrocyclization reactions of (3Z)-1,3,5-hexatrienone and nitrogen derivatives were studied by performing density functional theory (DFT) calculations together with the 6-31+G* basis set. Reactants, products, and transition states for each reaction were localized and the IRC connecting reactants and products was also obtained. Magnetic properties were evaluated along the reaction path to elucidate the characteristics of the reactions studied. As obtained from the calculations, electrocyclization of (3Z)-1,3,5-hexatrienone is a pericyclic process, as indicated by a variety of indexes, such as Nucleus Independent Chemical Shift (NICS), anisotropy of the magnetic susceptibility, or anisotropy of the current-induced density (ACID). This reaction presents characteristics of pericyclic reactions despite the activation energy lowering relative to the electrocyclization of (4Z)-1,2,4,6-heptatetraene, and the relatively small NICS values observed in the transition state. Magnetic properties indicate that an enhancement of the aromaticity relative to reactants and products occurs revealing the absence of orbital disconnections on the cyclic loop of interacting orbitals. Only two reactions among those studied exhibit pseudopericyclic character due to the in-plane attack of the lone pair on nitrogen. In these cases, the reactions showed no barrier for the electrocyclization process, and no aromaticity enhancement was observed.