Altered Plasma Membrane Lipid Composition in Hypertensive Neutrophils Impacts Epithelial Sodium Channel (ENaC) Endocytosis.

Biological membranes are composed of a lipid bilayer with embedded proteins, including ion channels like the epithelial sodium channel (ENaC), which are critical for sodium homeostasis and implicated in arterial hypertension (HTN). Changes in the lipid composition of the plasma membrane can significantly impact cellular processes related to physiological functions. We hypothesized that the observed overexpression of ENaC in neutrophils from HTN patients might result from alterations in the structuring domains within the plasma membrane, disrupting the endocytic processes responsible for ENaC retrieval. This study assessed the structural lipid composition of neutrophil plasma membranes from HTN patients along with the expression patterns of key elements regulating ENaC at the plasma membrane. Our findings suggest alterations in microdomain structure and SGK1 kinase activity, which could prolong ENaC presence on the plasma membrane. Additionally, we propose that the proteasomal and lysosomal degradation pathways are insufficient to diminish ENaC presence at the plasma membrane in HTN. These results highlight the importance of understanding ENaC retrieval mechanisms and suggest that targeting these mechanisms could provide insights for developing drugs to prevent and treat HTN.

A monoclonal antibody against a Leishmania mexicana COX-like enzymatic activity also recognizes similar proteins in different protozoa of clinical importance.

In Leishmania mexicana, the protease gp63 has been documented as the protein responsible for cyclooxygenase (COX) activity. The present work aimed to obtain a monoclonal antibody capable of recognizing this protein without blocking the COX-like enzymatic activity. The antibody produced by the selected hybridoma was named D12 mAb. The antigen recognized by the D12 mAb was characterized by the determination of COX activity associated with immune complexes in the presence of exogenous arachidonic acid (AA) using the commercial Activity Assay Abcam kit. LSM-SMS analysis validated the identity of the antigen associated with the D12 mAb as the L. mexicana protease gp63. Confocal microscopy assays with the D12 mAb detected, by cross-recognition, similar proteins in other protozoan parasites. COX-like molecules are located in vesicular structures, homogeneously distributed throughout the cytoplasm in amastigotes (intracellular infectious phase) and promastigotes of L. mexicana, and trophozoites of Entamoeba histolytica, Acanthamoeba castellanii, and Naegleria fowleri. However, in Giardia duodenalis trophozoites, the distribution of the COX-like molecule was also in perinuclear areas. In comparison, in Trypanosoma cruzi trypomastigotes, the distribution was mainly observed in the plasma membrane. Structural analyses of COX-2-like antigens revealed continuous and discontinuous epitopes for B cells, which could be relevant in the cross-reaction of D12 mAb with the analyzed parasites. These results indicate that the D12 mAb against the L. mexicana gp63 also recognizes a COX-like molecule in several protozoan parasites, suggesting that this D12 mAb could potentially be used in combined therapies against infectious diseases.

Hormones and Flower Development in Arabidopsis.

Sexual reproduction requires the participation of two gametes, female and male. In angiosperms, gametes develop in specialized organs, pollen (containing the male gametes) develops in the stamens, and the ovule (containing the female gamete) develops in the gynoecium. In Arabidopsis thaliana, the female and male sexual organs are found within the same structure called flower, surrounded by the perianth, which is composed of petals and sepals. During flower development, different organs emerge in an established order and throughout their development distinct tissues within each organ are differentiated. All this requires the coordination and synchronization of several biological processes. To achieve this, hormones and genes work together. These components can interact at different levels generating hormonal interplay and both positive and negative feedback loops, which in turn, gives robustness, stability, and flexibility to flower development. Here, we summarize the progress made on elucidating the role of different hormonal pathways during flower development in Arabidopsis thaliana.

Twisting development, the birth of a potential new gene.

Evolution has long been considered to be a conservative process in which new genes arise from pre-existing genes through gene duplication, domain shuffling, horizontal transfer, overprinting, retrotransposition, etc. However, this view is changing as new genes originating from non-genic sequences are discovered in different organisms. Still, rather limited functional information is available. Here, we have identified TWISTED1 (TWT1), a possible de novo-originated protein-coding gene that modifies microtubule arrangement and causes helicoidal growth in Arabidopsis thaliana when its expression is increased. Interestingly, even though TWT1 is a likely recent gene, the lack of TWT1 function affects A. thaliana development. TWT1 seems to have originated from a non-genic sequence. If so, it would be one of the few examples to date of how during evolution de novo genes are integrated into developmental cellular and organismal processes.

Specialized metabolism and development: An unexpected friendship.

Plants produce a myriad of metabolites. Some of them have been regarded for a long time as secondary or specialized metabolites and are considered to have functions mostly in defense and the adaptation of plants to their environment. However, in the last years, new research has shown that these metabolites can also have roles in the regulation of plant growth and development, some acting as signals, through the interaction with hormonal pathways, and some independently of them. These reports provide a glimpse of the functional possibilities that specialized metabolites present in the modulation of plant development and encourage more research in this direction.

Percepciones de los estudiantes de ciencias de la salud sobre el aprendizaje cooperativo en la modalidad virtual

Objetivo: Identificar las percepciones de los estudiantes de primer año de estudios de la Facultad de Medicina de la Universidad Nacional Mayor de San Marcos (UNMSM) sobre la aplicación del aprendizaje cooperativo en la modalidad virtual durante el semestre académico 2021-II. Materiales y métodos: El diseño de investigación aplicado en este estudio fue descriptivo y transversal. La población estuvo conformada por 592 estudiantes pertenecientes a las escuelas profesionales de Medicina Humana, Enfermería, Obstetricia, Nutrición y Tecnología Médica. Se realizó un muestreo probabilístico aleatorio y se obtuvo una muestra de 429 estudiantes. Para la recolección de datos, se empleó como instrumento el Cuestionario de Aprendizaje Cooperativo, con un formato de respuesta en escala Likert, que consta de 8 indicadores y fue elaborado por McLeish. El instrumento es confiable y válido; fue aplicado a la muestra de estudiantes al finalizar la asignatura de manera virtual mediante Google Forms. Los datos cuantitativos se analizaron descriptivamente con el programa SPSS 22. La estadística descriptiva que se aplicó incluye frecuencias, promedios y desviación estándar. Resultados: De los estudiantes que conformaron la muestra, el 65,9 % fueron mujeres y el 34,1 %, hombres. La mayor parte de los participantes tuvo percepciones favorables hacia el aprendizaje cooperativo en la modalidad virtual, y se obtuvieron promedios entre 3,77 y 4,53. Se identificaron percepciones favorables hacia esta metodología, principalmente en las dimensiones calidad del proceso de interacción del grupo, enseñanza de habilidades interpersonales en grupos pequeños e interdependencia positiva. Conclusiones: Los estudiantes tuvieron percepciones favorables hacia el aprendizaje cooperativo en la modalidad virtual, ya que contribuyó a mejorar su socialización, favoreció su actitud hacia el trabajo en grupo, permitió su participación en las sesiones con agrado, ayudó a mejorar sus interacciones con sus pares, desarrolló su creatividad y habilidades interpersonales, por lo cual se recomienda su aplicación y análisis de los logros en los entornos virtuales.

Objective: To identify the perceptions of implementing online cooperative learning during the 2021 II academic semester by first-year students of Universidad Nacional Mayor de San Marcos (UNMSM) School of Medicine. Materials and methods: A descriptive and cross-sectional research design was used in this study. The population consisted of 592 students from the professional schools of Human Medicine, Nursing, Obstetrics, Nutrition and Medical Technology. A random probability sampling was carried out and a sample of 429 students was obtained. The Cooperative Learning Questionnaire with an 8-point Likert scale response format developed by McLeish was used as an instrument for data collection. It is a reliable and valid instrument that was administered online to the sample of students at the end of the course using Google Forms. The quantitative data were analyzed descriptively using IBM SPSS Statistics V22. The descriptive statistics included frequencies, averages and standard deviation. Results: Out of the students in the sample, 65.9 % were females and 34.1 % were males. Most participants had favorable perceptions of online cooperative learning, with averages between 3.77 and 4.53. Favorable perceptions of this methodology were mainly identified in the dimensions quality of the group interaction process, teaching of interpersonal skills in small groups and positive interdependence. Conclusions: The students had favorable perceptions of online cooperative learning because it helped them to improve their social skills, favored their attitude toward group work, allowed them to participate in the sessions with enthusiasm, helped them to improve peer interaction, and promoted the development of their creativity and interpersonal skills. Therefore, its implementation and analysis of achievements in online environments are recommended.

Non-destructive Plant Morphometric and Color Analyses Using an Optoelectronic 3D Color Microscope.

Gene function discovery in plants, as other plant science quests, is aided by tools that image, document, and measure plant phenotypes. Tools that acquire images of plant organs and tissues at the microscopic level have evolved from qualitative documentation tools, to advanced tools where software-assisted analysis of images extracts quantitative information that allows statistical analyses. They are useful to perform morphometric studies that describe plant physical characteristics and quantify phenotypes, aiding gene function discovery. In parallel, non-destructive, versatile, robust, and user friendly technologies have also been developed for surface topography analysis and quality control in the industrial manufacture sector, such as optoelectronic three-dimensional (3D) color microscopes. These microscopes combine optical lenses, electronic image sensors, motorized stages, graphics engines, and user friendly software to allow the visualization and inspection of objects of diverse sizes and shapes from different angles. This allow the integration of different automatically obtained images along the Z axis of an object, into a single image with a large depth-of-field, or a 3D model in color. In this work, we explored the performance of an optoelectronic microscope to study plant morphological phenotypes and plant surfaces in different model species. Furthermore, as a "proof-of-concept," we included the phenotypic characterization (morphometric analyses at the organ level, color, and cell size measurements) of Arabidopsis mutant leaves. We found that the microscope tested is a suitable, practical, and fast tool to routinely and precisely analyze different plant organs and tissues, producing both high-quality, sharp color images and morphometric and color data in real time. It is fully compatible with live plant tissues (no sample preparation is required) and does not require special conditions, high maintenance, nor complex training. Therefore, though barely reported in plant scientific studies, optoelectronic microscopes should emerge as convenient and useful tools for phenotypic characterization in plant sciences.

Cytokinins on the Move.

Cytokinins are important signals that participate in different plant processes, and are well known for their strong influence in plant development. With the years, knowledge has been built about their effects, chemical nature, metabolism, and signaling mechanisms. However, one aspect about cytokinins that has been lagging behind is cytokinin transport. Recent reports are providing more information about how cytokinins are transported and how their transport is connected to their effects in development. This review provides a general overview of what is known about cytokinin transport, with a focus on the latest reports.

The AP2/ERF Transcription Factor DRNL Modulates Gynoecium Development and Affects Its Response to Cytokinin.

The gynoecium is the female reproductive system in flowering plants. It is a complex structure formed by different tissues, some that are essential for reproduction and others that facilitate the fertilization process and nurture and protect the developing seeds. The coordinated development of these different tissues during the formation of the gynoecium is important for reproductive success. Both hormones and genetic regulators guide the development of the different tissues. Auxin and cytokinin in particular have been found to play important roles in this process. On the other hand, the AP2/ERF2 transcription factor BOL/DRNL/ESR2/SOB is expressed at very early stages of aerial organ formation and has been proposed to be a marker for organ founder cells. In this work, we found that this gene is also expressed at later stages during gynoecium development, particularly at the lateral regions (the region related to the valves of the ovary). The loss of DRNL function affects gynoecium development. Some of the mutant phenotypes present similarities to those observed in plants treated with exogenous cytokinins, and AHP6 has been previously proposed to be a target of DRNL. Therefore, we explored the response of drnl-2 developing gynoecia to cytokinins, and found that the loss of DRNL function affects the response of the gynoecium to exogenously applied cytokinins in a developmental-stage-dependent manner. In summary, this gene participates during gynoecium development, possibly through the dynamic modulation of cytokinin homeostasis and response.

Corrigendum: Anti-Lipid IgG Antibodies Are Produced via Germinal Centers in a Murine Model Resembling Human Lupus.

[This corrects the article on p. 396 in vol. 7, PMID: 27746783.].

Anti-Lipid IgG Antibodies Are Produced via Germinal Centers in a Murine Model Resembling Human Lupus.

Anti-lipid IgG antibodies are produced in some mycobacterial infections and in certain autoimmune diseases [such as anti-phospholipid syndrome, systemic lupus erythematosus (SLE)]. However, few studies have addressed the B cell responses underlying the production of these immunoglobulins. Anti-lipid IgG antibodies are consistently found in a murine model resembling human lupus induced by chlorpromazine-stabilized non-bilayer phospholipid arrangements (NPA). NPA are transitory lipid associations found in the membranes of most cells; when NPA are stabilized they can become immunogenic and induce specific IgG antibodies, which appear to be involved in the development of the mouse model of lupus. Of note, anti-NPA antibodies are also detected in patients with SLE and leprosy. We used this model of lupus to investigate in vivo the cellular mechanisms that lead to the production of anti-lipid, class-switched IgG antibodies. In this murine lupus model, we found plasma cells (Gr1-, CD19-, CD138+) producing NPA-specific IgGs in the draining lymph nodes, the spleen, and the bone marrow. We also found a significant number of germinal center B cells (IgD-, CD19+, PNA+) specific for NPA in the draining lymph nodes and the spleen, and we identified in situ the presence of NPA in these germinal centers. By contrast, very few NPA-specific, extrafollicular reaction B cells (B220+, Blimp1+) were found. Moreover, when assessing the anti-NPA IgG antibodies produced during the experimental protocol, we found that the affinity of these antibodies progressively increased over time. Altogether, our data indicate that, in this murine model resembling human lupus, B cells produce anti-NPA IgG antibodies mainly via germinal centers.

Atención prenatal en las gestantes afiliadas al régimen contributivo y vinculadas en Bogotá, 2005 / Prenatal health care to pregnant women belonging to the taxpayer health care system and to women belonging to the subsidized health care system in Bogota, in 2005

Introducción: En 2005 se encontraron diferencias en las tasas de mortalidad materna en Bogotá, según la condición de las usuarias en el sistema. Fue ostensiblemente mayor en el régimen subsidiado y, en términos generales, mayor a la observada en ciudades como Medellín y Cali. Objetivo: Describir, comparar y establecer diferencias en la integralidad y oportunidad de los servicios de salud que recibieron las gestantes antes del parto, afiliadas al régimen contributivo y las atendidas como vinculadas en Bogotá, en 2005. Método: Estudio descriptivo de corte transversal. Las categorías utilizadas para la descripción y comparación de los servicios fueron: integralidad y oportunidad (inicio de consultas antes del parto). Resultados: Hubo mayor integralidad en la atención de las gestantes afiliadas al régimen contributivo (21,5) que en las vinculadas (4,8). El 100% de las gestantes afiliadas al régimen contributivo (partos de octubre, noviembre y diciembre) empezó consultas prenatales en el primer trimestre y sólo el 50,1%, el 46,2% y el 38%, de las vinculadas, respectivamente, en cada uno de estos meses; en las consultas en el puerperio inmediato de los dos grupos (partos de octubre y noviembre) hubo diferencias significativas. Conclusiones: Existieron diferencias significativas entre los dos grupos evaluados, en integralidad y oportunidad de las atenciones de salud recibidas por las gestantes antes del parto. Palabras clave: embarazo, atención prenatal, prevención primaria.

Background: Differences were found in 2005 in the maternal mortality rates depending on the status of the users of the System in Bogota. The maternal mortality rate was higher for those inthe subsidized regime, and in general it was greater for Bogota than the rate of other cities such as Medellin and Cali. This is not an isolated case, and is possibly connected with the operation of the Colombian Social Health Care System (SGSSS) and other socioeconomic conditions which influence the health care results. Aim: To describe, compare and establish differences in the integrality and opportunity of health care services received by pregnant women before labor, for those in the contributory system and for those in the subsidized system in Bogota in 2005. Design: A cross-sectional study was conducted, based on the information of the database used by MPS to establish the sufficiency of UPC in 2005 and for women belonging to the subsidized system, as well as the RIPS for the same year. The categories used to describe and compare the services were integrality and opportunity (beginning of the consultations before labor). Results: There was greater integrality in the service rendered to pregnant women belonging to the contributory system (21.5) than the one rendered to those of the subsidized system (4.8). 100% of the pregnant women of the contributory system (labors of October, November and December) started prenatal consultations in the first quarter whereas only 50.1%, 6.2% and 38% of the women in the subsidized system did in each one of these months. Significant differences were found during the immediate puerperium in the consultations for the two groups (labors of October and November). Conclusions: There were significant differences between the two groups assessed regarding the integrality and opportunity of the health careservice received by pregnant women before labor. Keywords: Pregnancy, prenatal care, preventive care.