Sulforaphane Exposure Prevents Cadmium-Induced Toxicity and Mitochondrial Dysfunction in the Nematode Caenorhabditis elegans by Regulating the Insulin/Insulin-like Growth Factor Signaling (IIS) Pathway.

Cadmium (Cd) is a heavy metal that is highly toxic to humans and animals. Its adverse effects have been widely associated with mitochondrial alterations. However, there are not many treatments that target mitochondria. This study aimed to evaluate the impact of sulforaphane (SFN) pre-exposure against cadmium chloride (CdCl2)-induced toxicity and mitochondrial alterations in the nematode Caenorhabditis elegans (C. elegans), by exploring the role of the insulin/insulin-like growth factor signaling pathway (IIS). The results revealed that prior exposure to SFN protected against CdCl2-induced mortality and increased lifespan, body length, and mobility while reducing lipofuscin levels. Furthermore, SFN prevented mitochondrial alterations by increasing mitochondrial membrane potential (Δψm) and restoring mitochondrial oxygen consumption rate, thereby decreasing mitochondrial reactive oxygen species (ROS) production. The improvement in mitochondrial function was associated with increased mitochondrial mass and the involvement of the daf-16 and skn-1c genes of the IIS signaling pathway. In conclusion, exposure to SFN before exposure to CdCl2 mitigates toxic effects and mitochondrial alterations, possibly by increasing mitochondrial mass, which may be related to the regulation of the IIS pathway. These discoveries open new possibilities for developing therapies to reduce the damage caused by Cd toxicity and oxidative stress in biological systems, highlighting antioxidants with mitochondrial action as promising tools.

Ethical considerations in animal research: the principle of 3r's

In the last century, progress in the knowledge of human diseases, their diagnosis and treatment have grown exponentially, due in large part to the introduction and use of laboratory animals. Along with this important progress, the need to provide training and guidance to the scientific community in all aspects related to the proper use of experimental animals has been indispensable. Animal research committees play a primary role in evaluating experimental research protocols, from their feasibility to the rational use of animals, but above all in seeking animal welfare. The Institutional Committee for the Care and Use of Animals (IACUC) has endeavored to share several relevant aspects in conducting research with laboratory animals. Here, we present and discuss the topics that we consider of utmost importance to take in the account during the design of any experimental research protocol, so we invite researchers, technicians, and undergraduate and graduate students to dive into the fascinating subject of proper animal care and use for experimentation. The main intention of these contributions is to sensitize users of laboratory animals for the proper and rational use of them in experimental research, as well as to disseminate the permitted and unpermitted procedures in laboratory animals. In the first part, the significance of experimental research, the main functions of IACUC, and the principle of the three R's (replacement, reduction, and refinement) are addressed.

Genome-Wide Association Study Identifies a Functional SIDT2 Variant Associated With HDL-C (High-Density Lipoprotein Cholesterol) Levels and Premature Coronary Artery Disease.

Objective: Low HDL-C (high-density lipoprotein cholesterol) is the most frequent dyslipidemia in Mexicans, but few studies have examined the underlying genetic basis. Our purpose was to identify genetic variants associated with HDL-C levels and cardiovascular risk in the Mexican population. Approach and Results: A genome-wide association studies for HDL-C levels in 2335 Mexicans, identified four loci associated with genome-wide significance: CETP, ABCA1, LIPC, and SIDT2. The SIDT2 missense Val636Ile variant was associated with HDL-C levels and was replicated in 3 independent cohorts (P=5.9×10−18 in the conjoint analysis). The SIDT2/Val636Ile variant is more frequent in Native American and derived populations than in other ethnic groups. This variant was also associated with increased ApoA1 and glycerophospholipid serum levels, decreased LDL-C (low-density lipoprotein cholesterol) and ApoB levels, and a lower risk of premature CAD. Because SIDT2 was previously identified as a protein involved in sterol transport, we tested whether the SIDT2/Ile636 protein affected this function using an in vitro site-directed mutagenesis approach. The SIDT2/Ile636 protein showed increased uptake of the cholesterol analog dehydroergosterol, suggesting this variant affects function. Finally, liver transcriptome data from humans and the Hybrid Mouse Diversity Panel are consistent with the involvement of SIDT2 in lipid and lipoprotein metabolism. Conclusions: This is the first genome-wide association study for HDL-C levels seeking associations with coronary artery disease in the Mexican population. Our findings provide new insight into the genetic architecture of HDL-C and highlight SIDT2 as a new player in cholesterol and lipoprotein metabolism in humans.

Instrumento para el control y evaluación del accionar técnico-táctico de los lanzadores de béisbol / Instrumento para o controle e avaliação do desempenho técnico-táctico dos lançadores de beisebol / Instrument for the control and evaluation of the tactical technical performance in the baseball pitchers

Resumen El control y evaluación del accionar técnico-táctico en el entrenamiento, en situaciones de juego, es un aspecto que se dificulta por la no definición de indicadores a tener en cuenta en el béisbol, específicamente en el área de lanzadores. Por ello, el objetivo del presente artículo se centra en proponer un instrumento para el control y evaluación del accionar técnico-táctico de los lanzadores de béisbol, categoría 15-16 años, en situaciones de juego, durante la unidad de entrenamiento, así como en la competición deportiva. Para ello, se trabajó con una muestra primaria de 15 lanzadores de la categoría 15-16 años de la Escuela de Iniciación Deportiva "Ormani Arenado Llonch", de Pinar del Río y nueve entrenadores como muestra secundaria. Se emplearon métodos y técnicas de la investigación científica como el análisis de documentos, la observación, la entrevista estandarizada e individual. Fueron constatadas carencias en el tratamiento del control y evaluación de la preparación técnico-táctica en cuanto al accionar técnico-táctico del lanzador de béisbol en situaciones de juego, a partir de la creación de un instrumento que le aportó información al entrenador sobre el estado del accionar técnico-táctico del lanzador, al propiciar el tratamiento de debilidades que presentaron los atletas de esta área de juego.

Resumo O controle e avaliação da ação técnica tática no treinamento em situações de jogo, é um aspecto dificultado pela falta de definição de indicadores a serem levados em conta no beisebol, especificamente na área de lançamento. Portanto, o objetivo deste artigo é propor um instrumento para o controle e avaliação do desempenho técnico tático dos arremessadores de beisebol, categoria 15-16, em situações de jogo, durante a unidade de treinamento, bem como em competições esportivas. Para isso, trabalhamos com uma amostra primária de 15 arremessadores da categoria de 15-16 anos da Escola de Iniciação ao Esporte, "Ormani Arenado Llonch" de Pinar del Río e nove treinadores como amostra secundária. Foram utilizados métodos e técnicas de pesquisa científica, tais como análise documental, observação, entrevistas padronizadas e individuais. Foram encontradas deficiências no tratamento do controlo e avaliação da preparação técnica táctica em termos da ação técnica táctica do lançador de basebol em situações de jogo, com base na criação de um instrumento que forneceu ao treinador informações sobre o estado da ação técnica táctica do lançador, promovendo o tratamento das debilidades apresentadas pelos atletas nesta área de jogo.

Abstract The control and evaluation of the tactical technical action in the training in game situations, is an aspect that is made difficult by the lack of definition of indicators to be taken into account in baseball, specifically in the pitching area. Therefore, the objective of this article focuses on proposing an instrument for the control and evaluation of the tactical technical performance of baseball pitchers, category 15-16, in game situations, during the training unit, as well as in sports competition. For this purpose, we worked with a primary sample of 15 pitchers of the 15-16 years old category of the Sports Initiation School, "Ormani Arenado Llonch" of Pinar del Río and nine coaches as a secondary sample. Scientific research methods and techniques were used, such as document analysis, observation, standardized and individual interviews. Shortcomings were found in the treatment of the control and evaluation of the tactical technical preparation, in terms of the baseball pitcher's tactical technical action in game situations based on the creation of an instrument that provided the coach with information about the state of the pitcher's tactical technical action, by promoting the treatment of weaknesses presented by the athletes in this game area.

Metodología para el perfeccionamiento del accionar técnico táctico de los lanzadores de béisbol / Methodology for the improvement of the tactical technical action of baseball pitchers

Resumen El accionar técnico táctico de los lanzadores de béisbol exige la búsqueda de herramientas novedosas que se deriven en un contexto pedagógico que gestione, de manera creativa, las formas del conocimiento; a tono con esto, las metodologías actuantes en béisbol reclaman una continua actualización en el orden teórico, metodológico y práctico. De ahí que la presente investigación tuvo por objetivo elaborar una metodología para el perfeccionamiento del accionar técnico-táctico de los lanzadores de béisbol, en correspondencia con la función que desempeñan dentro del juego. Para ello se trabajó con una muestra primaria de 15 lanzadores del equipo Pinar del Río, en el último año de la categoría 17-18, así como una muestra secundaria de 12 entrenadores, 20 especialistas y 20 atletas que incursionan regular u ocasionalmente como lanzadores. Se emplearon métodos y técnicas científicas de investigación como el análisis de documentos, la observación, la entrevista estandarizada e individual y el criterio de expertos. Se constataron carencias en el tratamiento del contenido de la preparación técnico-táctica para el perfeccionamiento del accionar del lanzador de béisbol, según la función que desempeña en el juego, a partir de la cual se propone una metodología que contiene la estructura, contenido y planificación de la preparación técnica-táctica de los lanzadores de béisbol, según su función en el juego, a partir de situaciones simplificadas que didácticamente actúan sobre los componentes de esta preparación deportiva y bajo leyes y principios del entrenamiento deportivo.

Abstract The technical tactical action of baseball pitchers requires the search for new tools that are derived in a pedagogical context that creatively manages the forms of knowledge, in line with this, the methodologies used in baseball demand a continuous updating in the theoretical, methodological and practical order. Hence, the objective of the present research was to develop a methodology for improving the tactical technical action of baseball pitchers in correspondence with the function they perform within the game. In order to do this, we worked with a primary sample of 15 pitchers from the Pinar del Río team, in the last year of the 17-18 category, as well as a secondary sample of 12 coaches, 20 specialists and 20 athletes who regularly or occasionally enter as pitchers. Scientific research methods and techniques such as document analysis, observation, standardized and individual interviews and expert judgment were used. There were shortcomings in the treatment of the contents of the tactical technical preparation for improving the actions of the baseball pitcher according to the role played in the game, from which a methodology is proposed that contains the structure, content and planning of the technical-tactical preparation of baseball pitchers, according to their function in the game, from simplified situations that didactically act on the components of this sports preparation and under laws and principles of sports training.

RNA-dependent chromatin targeting of TET2 for endogenous retrovirus control in pluripotent stem cells.

Ten-eleven translocation (TET) proteins play key roles in the regulation of DNA-methylation status by oxidizing 5-methylcytosine (5mC) to generate 5-hydroxymethylcytosine (5hmC), which can both serve as a stable epigenetic mark and participate in active demethylation. Unlike the other members of the TET family, TET2 does not contain a DNA-binding domain, and it remains unclear how it is recruited to chromatin. Here we show that TET2 is recruited by the RNA-binding protein Paraspeckle component 1 (PSPC1) through transcriptionally active loci, including endogenous retroviruses (ERVs) whose long terminal repeats (LTRs) have been co-opted by mammalian genomes as stage- and tissue-specific transcriptional regulatory modules. We found that PSPC1 and TET2 contribute to ERVL and ERVL-associated gene regulation by both transcriptional repression via histone deacetylases and post-transcriptional destabilization of RNAs through 5hmC modification. Our findings provide evidence for a functional role of transcriptionally active ERVs as specific docking sites for RNA epigenetic modulation and gene regulation.

Campos problemáticos para un curso de epistemología de las ciencias de la salud / Problematic fields for a health sciences epistemology course

Analizar epistemológicamente los problemas de salud requiere incorporar la epistemología a los programas de posgrado en ciencias de la salud. Con el propósito de caracterizar los campos problemáticos que fundamenten el diseño de un programa académico para el curso de epistemología en ciencias de la salud se realizó un estudio con el enfoque de la hermenéutica gadameriana en tres etapas. El punto de partida expone la concepción de hombre, conocimiento y epistemología. El horizonte de comprensión se elaboró con tendencias epistemológicas hegemónicas. La fusión de horizontes integró las características de los siguientes campos problemáticos: epistemología de las ciencias de la salud, lógica de las ciencias de la salud, tendencias epistemológicas en ciencias de la salud, problemas epistemológicos de las ciencias de la salud. Se concluye que los campos problemáticos descritos introducen al estudiante a la reflexión de su práctica científica mediante el análisis racional, axiológico y crítico.

Analyzing health problems from an epistemological point of view requires epistemology to be included on health sciences postgraduate courses programs. Aimed at characterizing the problematic fields used as basis for the design of a health sciences epistemology academic program, a study with an approach to Gadamer hermeneutics in three stages was carried out. The starting point shows man, knowledge and epistemology conceptions. The comprehension horizon was made with epistemological-dominant trends. The horizons merge included characteristics from the following problematic fields: health sciences epistemology, health sciences logic, epistemological trends in health sciences, health sciences epistemological problems. It was reached the conclusion that the described problematic fields introduce students to their scientific practice reflection through a rational, axiological and critical analysis.

Zfp281 Coordinates Opposing Functions of Tet1 and Tet2 in Pluripotent States.

Pluripotency is increasingly recognized as a spectrum of cell states defined by their growth conditions. Although naive and primed pluripotency states have been characterized molecularly, our understanding of events regulating state acquisition is wanting. Here, we performed comparative RNA sequencing of mouse embryonic stem cells (ESCs) and defined a pluripotent cell fate (PCF) gene signature associated with acquisition of naive and primed pluripotency. We identify Zfp281 as a key transcriptional regulator for primed pluripotency that also functions as a barrier toward achieving naive pluripotency in both mouse and human ESCs. Mechanistically, Zfp281 interacts with Tet1, but not Tet2, and its direct transcriptional target, miR-302/367, to negatively regulate Tet2 expression to establish and maintain primed pluripotency. Conversely, ectopic Tet2 alone, but not Tet1, efficiently reprograms primed cells toward naive pluripotency. Our study reveals a molecular circuitry in which opposing functions of Tet1 and Tet2 control acquisition of alternative pluripotent states.

The mesenchymal transcription factor SNAI-1 instructs human liver specification.

Epithelial-mesenchymal transition (EMT) and the mesenchymal-epithelial transition (MET) are processes required for embryo organogenesis. Liver develops from the epithelial foregut endoderm from which the liver progenitors, hepatoblasts, are specified. The migrating hepatoblasts acquire a mesenchymal phenotype to form the liver bud. In mid-gestation, hepatoblasts mature into epithelial structures: the hepatocyte cords and biliary ducts. While EMT has been associated with liver bud formation, nothing is known about its contribution to hepatic specification. We previously established an efficient protocol from human embryonic stem cells (hESC) to generate hepatic cells (Hep cells) resembling the hepatoblasts expressing alpha-fetoprotein (AFP) and albumin (ALB). Here we show that Hep cells express both epithelial (EpCAM and E-cadherin) and mesenchymal (vimentin and SNAI-1) markers. Similar epithelial and mesenchymal hepatoblasts were identified in human and mouse fetal livers, suggesting a conserved interspecies phenotype. Knock-down experiments demonstrated the importance of SNAI-1 in Hep cell hepatic specification. Moreover, ChIP assays revealed direct binding of SNAI-1 in the promoters of AFP and ALB genes consistent with its transcriptional activator function in hepatic specification. Altogether, our hESC-derived Hep cell cultures reveal the dual mesenchymal and epithelial phenotype of hepatoblast-like cells and support the unexpected transcriptional activator role of SNAI-1 in hepatic specification.

Hematocolpos en la infancia. A propósito de un caso / Hematocolpos in Childhood. A case Report

El hematocolpos no es común en nuestro medio, sigue a alteraciones en la génesis del aparato genitourinario femenino; entre las cuales, el himen imperforado es la malformación congénita más frecuente. La sintomatología suele ser variable e inespecífica; el dolor abdominal y los síntomas urinarios es la forma de presentación clínica más usual. La ecografía abdominal-pélvica y la tomografía axial computarizada confirman el diagnóstico y ayudan a descartar otras malformaciones asociadas. Se presentó un caso de una adolescente afectada por esta enfermedad.

The hematocolpos is not common disease. It follow to the alterations in the genesis of female urogenital apparatus among which the imperforate hymen is the most common congenital malformation. The symptoms are variable and nonspecific. The abdominal pain and urinary symptoms is the most common clinical presentation. Abdominal-pelvic ultrasonography and computed tomography help to confirm the diagnosis as well as to find other associated malformations. This article presented a case of an adolescent affected by this disease.

Un método práctico de reducción manual sin dolor para la parafimosis de larga evolución (2009- 2011) / A practical method of painless manual reduction without pain for the long course paraphimosis (2009- 2011)

Introducción: la parafimosis es frecuente en los servicios de urgencia. Su reducción precoz resulta fácil, pero si los niños asisten tardíamente, puede constituir un problema. Debido a los intentos de reducción infructuosos y dolorosos, estos pacientes sufren gran carga de tensión emocional. Objetivos: describir y mostrar la aplicación de un método práctico de reducción manual sin dolor, en pacientes con parafimosis de largo tiempo de evolución. Métodos: se realizó un estudio longitudinal, prospectivo y descriptivo, de los pacientes tratados (n= 25), con diagnóstico de parafimosis de largo tiempo de evolución (+ 12 horas), en el periodo comprendido entre enero de 2009 y junio de 2011. Se les aplicó un método fundamentado en el bloqueo anestésico anular subcutáneo en la base del pene, derivada de la inervación pudenda. Se seleccionaron variables como edad, causa externa desencadenante, tratamiento conservador inicial, tiempo de demora en asistir para la reducción, y complicaciones. Se procesó la información en frecuencias absolutas y porcentajes, dando como resultado pruebas de significación para su análisis estadístico. Resultados: la manipulación brusca del prepucio por la propia madre, condicionó esta complicación en el 68 porciento de los menores de 5 años. Tratamientos conservadores, motivaron una demora para su reducción significativa, en el 80 porciento de los casos. Conclusiones: este método es bien aceptado por el paciente, le brinda una solución sin dolor, y es de fácil aplicación en los servicios de urgencias. Se evitan procederes más cruentos como la fimotomía

Introduction: the paraphimosis is frequent in emergence services. Its early reduction is easy, but if children come late it may to be a serious problem. Due to the unsuccessful and painful attempts of reduction, these patients suffer a significant charge of emotional tension. Objectives: to describe and to show the implementation of a practical method of painless manual reduction in patients with a prolonged paraphimosis. Methods: a descriptive, prospective and longitudinal study was conducted in patients treated (25), diagnosed with paraphimosis of long term course (+ 12 hr) from January, 2009 to June, 2011. A method based in the subcutaneous annular anesthetic block was applied in the penis base derived of the pudendal innervation. The following variables were selected: age, triggering external cause, initial conservative treatment, to until reduction and complications. Information was processed in absolute frequency and percentages where the results were significant tests for its statistic analysis. Results: the sudden manipulation of prepuce by mother leads to this complication in the 68 percent of children aged under 5. The conservative treatments caused a significant delay for its reduction in the 80 percent of cases. Conclusions: this method is well accepted by patient giving him a painless solution and it is of easy application in emergence services. Procedures more painful like the phimotomy are avoided

Structure-function relationships in fungal large-subunit catalases.

Neurospora crassa has two large-subunit catalases, CAT-1 and CAT-3. CAT-1 is associated with non-growing cells and accumulates particularly in asexual spores; CAT-3 is associated with growing cells and is induced under different stress conditions. It is our interest to elucidate the structure-function relationships in large-subunit catalases. Here we have determined the CAT-3 crystal structure and compared it with the previously determined CAT-1 structure. Similar to CAT-1, CAT-3 hydrogen peroxide (H(2)O(2)) saturation kinetics exhibited two components, consistent with the existence of two active sites: one saturated in the millimolar range and the other in the molar range. In the CAT-1 structure, we found three interesting features related to its unusual kinetics: (a) a constriction in the channel that conveys H(2)O(2) to the active site; (b) a covalent bond between the tyrosine, which forms the fifth coordination bound to the iron of the heme, and a vicinal cysteine; (c) oxidation of the pyrrole ring III to form a cis-hydroxyl group in C5 and a cis-gamma-spirolactone in C6. The site of heme oxidation marks the starts of the central channel that communicates to the central cavity and the shortest way products can exit the active site. CAT-3 has a similar constriction in its major channel, which could function as a gating system regulated by the H(2)O(2) concentration before the gate. CAT-3 functional tyrosine is not covalently bonded, but has instead the electron relay mechanism described for the human catalase to divert electrons from it. Pyrrole ring III in CAT-3 is not oxidized as it is in other large-subunit catalases whose structure has been determined. Different in CAT-3 from these enzymes is an occupied central cavity. Results presented here indicate that CAT-3 and CAT-1 enzymes represent a functional group of catalases with distinctive structural characteristics that determine similar kinetics.

Presencia de animales seropositivos al síndrome reproductivo y respiratorio porcino en Nuevo León / Presence of seropositive animals to the porcine respiratory and reproductive syndrome virus in Nuevo Leon

A preliminary study was carried out to obtain serological evidence of the presence of the porcine respiratory and reproductive syndrome (PRRS) virus and the risk of infection in different areas and phases of production in five full cycle pig farms in the state of Nuevo Leon, Mexico. Sixty blood samples of each farm were obtained (10 for each phase of production: weaning, growing, finishing, pregnancy, lactation and mating-service). The detection of antibodies against the PRRS virus was carried out using a commercial kit. All farms were positives in all phases of production. The highest seroprevalences were found in the growing and finishing phases (36% y 56%, respectively).

Se realizó un estudio preliminar para obtener evidencia serológica de la presencia del virus del síndrome respiratorio y reproductivo porcino (PRRS, por sus siglas en inglés) y del riesgo de infección en las diferentes áreas y etapas de producción en cinco granjas porcinas de ciclo completo en Nuevo León, México. Se obtuvieron 60 muestras de sangre de cada granja (diez para cada etapa de producción: destete, iniciación, finalización, cerdas gestantes, lactando o en monta-servicio). La detección de anticuerpos antivirus del PRRS se realizó utilizando un equipo comercial. Todas las granjas resultaron positivas en las diferentes etapas de producción. La seroprevalencia fue mayor en las etapas de inicio y finalización (36% y 56%, respectivamente).

The genome project of Taenia solium.

We have constituted a consortium of key laboratories at the National Autonomous University of Mexico to carry out a genomic project for Taenia solium. This project will provide powerful resources for the study of taeniasis/cysticercosis, and, in conjunction with the Echinococcus granulosus and Echinococcus multilocularis genome project of expressed sequence tags (ESTs), will mark the advent of genomics for cestode parasites. Our project is planned in two consecutive stages. The first stage is being carried out to determine some basic parameters of the T. solium genome. Afterwards, we will evaluate the best strategy for the second stage, a full blown genome project. We have estimated the T. solium genome size by two different approaches: cytofluorometry on isolated cyton nuclei, as well as a probabilistic calculation based on approximately 2000 sequenced genomic clones, approximately 3000 ESTs, resulting in size estimates of 270 and 251 Mb, respectively. In terms of sequencing, our goal for the first stage is to characterize several thousand EST's (from adult worm and cysticerci cDNA libraries) and genomic clones. Results obtained so far from about 16,000 sequenced ESTs from the adult stage, show that only about 40% of the T. solium coding sequences have a previously sequenced homologue. Many of the best hits are found with mammalian genes, especially with humans. However, 1.5% of the hits lack homologues in humans, making these genes immediate candidates for investigation on pharmaco-therapy, diagnostics and vaccination. Most T. solium ESTs are related to gene regulation, and signal transduction. Other important functions are housekeeping, metabolism, cell division, cytoskeleton, proteases, vacuolar transport, hormone response, and extracellular matrix activities. Preliminary results also suggest that the genome of T. solium is not highly repetitive.

Silencing structural and nonstructural genes in baculovirus by RNA interference.

We review several aspects of RNAi and gene silencing with baculovirus. We show that the potency of RNAi in Spodoptera frugiperda (Sf21) insect cells correlates well with the efficiency of transfection of the siRNA. Using a fluorescein-labeled siRNA we found that the siRNA localized in areas surrounding the endoplasmic reticulum (ER). Both long (700 nucleotides long) and small ( approximately 25 nucleotides long) interfering RNAs were equally effective in initiating RNA interference (RNAi), and the duration of the interfering effect was indistinguishable. Even though RNAi in Sf21 cells is very effective, in vitro experiments show that these cells fragment the long dsRNA into siRNA poorly, when compared to HEK cells. Finally, we show that in vivo inhibition of baculovirus infection with dsRNA homologous to genes that are essential for baculovirus infectivity depends strongly on the amount of dsRNA used in the assays. Five hundred nanogram of dsRNA directly injected into the haemolymph of insects prevent animal death to over 95%. In control experiments, over 96% of insects not injected with dsRNA or injected with an irrelevant dsRNA died within a week. These results demonstrate the efficiency of dsRNA for in vivo prevention of a viral infection by virus that is very cytotoxic and lytic in animals.

Using double-stranded RNA to prevent in vitro and in vivo viral infections by recombinant baculovirus.

Introduction of double-stranded RNA (dsRNA) into a wide variety of cells and organisms results in post-transcriptional depletion of the homologue endogenous mRNA. This well-preserved phenomenon known as RNA interference (RNAi) is present in evolutionarily diverse organisms such as plants, fungi, insects, metazoans, and mammals. Because the identification of the targeted mRNA by the RNAi machinery depends upon Watson-Crick base-pairing interactions, RNAi can be exquisitely specific. We took advantage of this powerful and flexible technique to demonstrate that selective silencing of genes essential for viral propagation prevents in vitro and in vivo viral infection. Using the baculovirus Autographa californica, a rapidly replicating and highly cytolytic double-stranded DNA virus that infects many different insect species, we show for the first time that introduction of dsRNA from gp64 and ie1, two genes essential for baculovirus propagation, results in prevention of viral infection in vitro and in vivo. This is the first report demonstrating the use of RNAi to inhibit a viral infection in animals. This inhibition was specific, because dsRNA from the polyhedrin promoter (used as control) or unrelated dsRNAs did not affect the time course of viral infection. The most relevant consequences from the present study are: 1) RNAi offers a rapid and efficient way to interfere with viral genes to assess the role of specific proteins in viral function and 2) using RNAi to interfere with viral genes essential for cell infection may provide a powerful therapeutic tool for the treatment of viral infections.

Riñón en herradura con doble sistema colector y compresión de la unión ureteropiélica inferior por vena renal accesoria. Caso clínico / Horseshoe kidney with dual collector system and compression of inferior ureteropyelic junction by an accesory renal vein. report of a case

Las alteraciones de la fusión renal se presentan frecuentemente asociadas a otras malformaciones renales, Se presenta en este artículo el caso de una paciente de 26 años de edad, asintomática durante la infancia, que inició su padecimiento con un cuadro de pielonefritis aguda con infección ulterior recurrente de vías urinarias; durante la protocolización del estudio se encontró un riñón en herradura con doble sistema colector completo e hidonefrosis del superior. Se sometió a lumbotomía exploradora y se realizó polectomía, y se identificó compresión extrínseca de la unión ureteropiélica izquierda por una vena renal accesoria

Estudios sobre la Biologia del ratón de las volcanes (Neotomodon alstoni alstoni): XII Parametros hematologicos comparativos de animales silvestres y nacidos en el laboratorio (F1) / Biology of the Volcano mouse (Neotomodon alstoni alstoni): XII Comparative hematological parameters of wild and laboratory-born (F1) animals

Se presenta el estudio inicial de la biometria hemática, el hierro del suero y el 2,3-difosfoglicerato sanguíneo del ratón de los volcanes (Neotomodon alstoni alstoni) silvestre y nacido en el laboratorio (F1). No se encontraron diferencias notorias en los valores de la biometria hemática entre los ratones silvestres y los F1, ni entre las hembras y los machos. Hubo diferencias pequeñas, pero significativas, entre los machos silvestres y los F1 en el hematocrito, en la concentración corpuscular media de hemoglobina (MCHC) y en la cuenta de leucocitos. La cuenta diferencial de leucocitos en los F1 mostró diferencia significativamente mayor en los porcentajes de linfocitos y monocitos y menor por ciento de los neutrófilos, tanto en las hembras como en los machos en relación con los silvestres. La comparación de los parámetros hematológicos de Neotomodon con los publicados para otros roedores de laboratorio, indica que el volumen corpuscular medio de las células rojas del ratón de los volcanes es menor, por lo que el hematocrito lo es también. La hemoglobina corpuscular media y la concentración corpuscular media de hemoglobina de neotomodon fueron semejantes a las de otros roedores de laboratorio. Los valores de hierro del suero fueron semejantes en los animales silvestres y en los F1, tanto en machos como en las hembras, a pesar de la distinta dieta. El 2,3-difosfoglicerato sanguíneo en los animales silvestres fue mayor en las hembras que en los machos,diferencia que no prevalece en los animales nacidos en el laboratorio, los que exibieron valores semejantes a los machos silvestres

Efecto de factores sociales y biológicos sobre el tamano de la familia y la proporción secundaria de sexos en dos generaciones humanas de Monterrey, Nuevo León / Effect of social and biological factors on family size and secondary sex ratio in 2 human generation of Monterrey, Nuevo León

Con el propósito de evaluar el posible efecto de factores sociales y biológicos sobre el tamaño de la familia (T de F) y la proporción secundaria de sexos (PSS) en dos generaciones, se entrevistaron a ambos miembros de 851 matrimonios, que residían en el área metropolitana de Monterrey, N.L., los que habían terminado de procrear a sus hijos, recabándose información tanto de las familias que procedían, como de las que ellos procrearon. Se encontró que el T de F disminuyó de 6.76 a 4.53 de una generación a otra, probablemente por efecto de los programas de planificación familiar. Los T de F de las que procrearon fueron inversamente afectados por el nivel socioeconómico y escolaridad de las personas y fue influenciado por la edad de la mujer y no por la edad del hombre, al momento del matrimonio. No se encontró diferencia en la PSS de una generación a otra. En las familias que procrearon, la PSS no se modificó por el nivel socioeconómico, ni por la edad de la madre, pero sí fue efectada por la escolaridad, edad y tipo de ocupación del padre. En las dos generaciones, la PSS estuvo inversamente relacionada al orden del nacimiento