The journey of a generation: advances and promises in the study of primordial germ cell migration.

The germline provides the genetic and non-genetic information that passes from one generation to the next. Given this important role in species propagation, egg and sperm precursors, called primordial germ cells (PGCs), are one of the first cell types specified during embryogenesis. In fact, PGCs form well before the bipotential somatic gonad is specified. This common feature of germline development necessitates that PGCs migrate through many tissues to reach the somatic gonad. During their journey, PGCs must respond to select environmental cues while ignoring others in a dynamically developing embryo. The complex multi-tissue, combinatorial nature of PGC migration is an excellent model for understanding how cells navigate complex environments in vivo. Here, we discuss recent findings on the migratory path, the somatic cells that shepherd PGCs, the guidance cues somatic cells provide, and the PGC response to these cues to reach the gonad and establish the germline pool for future generations. We end by discussing the fate of wayward PGCs that fail to reach the gonad in diverse species. Collectively, this field is poised to yield important insights into emerging reproductive technologies.

Metabolic Profiling of Vasorelaxant Extract from Malvaviscus arboreus by LC/QTOF-MS.

We aimed to develop a standardized methodology to determine the metabolic profile of organic extracts from Malvaviscus arboreus Cav. (Malvaceae), a Mexican plant used in traditional medicine for the treatment of hypertension and other illnesses. Also, we determined the vasorelaxant activity of these extracts by ex vivo rat thoracic aorta assay. Organic extracts of stems and leaves were prepared by a comprehensive maceration process. The vasorelaxant activity was determined by measuring the relaxant capability of the extract to decrease a contraction induced by noradrenaline (0.1 µM). The hexane extract induced a significant vasorelaxant effect in a concentration- and endothelium-dependent manner. Secondary metabolites, such as polyunsaturated fatty acids, terpenes and one flavonoid, were annotated by liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/QTOF-MS) in positive ion mode. This exploratory study allowed us to identify bioactive secondary metabolites from Malvaviscus arboreus, as well as identify potentially-new vasorelaxant molecules and scaffolds for drug discovery.

Synthesis and anti-inflammatory activity of three nitro chalcones.

The aim of this study was to synthesize three nitro substituted chalcones and to evaluate their anti-inflammatory activity in the model of carrageenan induced edema in rats. The nitro chalcone were prepared by aldol condensation using of mechanical agitation and environmentally friendly solvents with 72-73% yields in approximately 2h. The three structures were evaluated on biological activity at dose of 200mg/kg and they showed anti-inflammatory protective effect by both oral and intraperitoneal administration, this effect was time dependent.

Isolation of Undifferentiated Spermatogonia from Adult and Developing Mouse Testes.

In the mammalian testis, the mitotic complements of spermatogenic cells are spermatogonia, including spermatogonial stem cells (SSCs) which form the basis of life-long spermatogenesis and male fertility. Thus, investigating spermatogonia and subdivisions thereof is essential to increase our understanding of male germline development and infertility. This protocol describes the isolation of spermatogonia from both adult and developing [postnatal day 6 (P6)] mouse testes. Cell suspensions of the adult mouse testis from the Id4-Egfp transgenic mouse line are obtained through a two-step enzymatic digestion and are subjected to Percoll pre-enrichment before spermatogonia are isolated by selecting testis cells that are CD9bright and ID4-EGFP+ through FACS. For P6 mice, the testis is digested using trypsin-DNase, and spermatogonia are isolated by FACS selection of ID4-EGFP+ testis cells. In both cases, nearly pure populations of undifferentiated spermatogonia are obtained that can be further subdivided using additional parameters (e.g., EGFP intensity, cell surface protein immunostaining), and recovered for use in various downstream applications, such as biochemical analyses (e.g., transcriptome/epigenome), functional analyses by SSC transplantation or propagation in vitro.

Hallmarks of glycogene expression and glycosylation pathways in squamous and adenocarcinoma cervical cancer.

BACKGROUND: Dysregulation of glycogene expression in cancer can lead to aberrant glycan expression, which can promote tumorigenesis. Cervical cancer (CC) displays an increased expression of glycogenes involved in sialylation and sialylated glycans. Here, we show a comprehensive analysis of glycogene expression in CC to identify glycogene expression signatures and the possible glycosylation pathways altered. METHODS: First, we performed a microarray expression assay to compare glycogene expression changes between normal and cervical cancer tissues. Second, we used 401 glycogenes to analyze glycogene expression in adenocarcinoma and squamous carcinoma from RNA-seq data at the cBioPortal for Cancer Genomics. RESULTS: The analysis of the microarray expression assay indicated that CC displayed an increase in glycogenes related to GPI-anchored biosynthesis and a decrease in genes associated with chondroitin and dermatan sulfate with respect to normal tissue. Also, the glycogene analysis of CC samples by the RNA-seq showed that the glycogenes involved in the chondroitin and dermatan sulfate pathway were downregulated. Interestingly the adenocarcinoma tumors displayed a unique glycogene expression signature compared to squamous cancer that shows heterogeneous glycogene expression divided into six types. Squamous carcinoma type 5 (SCC-5) showed increased expression of genes implicated in keratan and heparan sulfate synthesis, glycosaminoglycan degradation, ganglio, and globo glycosphingolipid synthesis was related to poorly differentiated tumors and poor survival. Squamous carcinoma type 6 (SCC-6) displayed an increased expression of genes involved in chondroitin/dermatan sulfate synthesis and lacto and neolacto glycosphingolipid synthesis and was associated with nonkeratinizing squamous cancer and good survival. In summary, our study showed that CC tumors are not a uniform entity, and their glycome signatures could be related to different clinicopathological characteristics.

Metagenomic analysis and antimicrobial activity of two fermented milk kefir samples.

In recent years, the fermented milk product kefir has been intensively studied because of its health benefits. Here, we evaluated the microbial consortia of two kefir samples, from Escarcega, Campeche, and Campeche (México). We considered a functional comparison between both samples, including fungal and bacterial inhibition; second, we applied shotgun metagenomics to assess the structure and functional diversity of the communities of microorganisms. These two samples exhibited antagonisms against bacterial and fungal pathogens. Bioactive polyketides and nonribosomal peptides were identified by LC-HRMS analysis. We also observed a high bacterial diversity and an abundance of Actinobacteria in both kefir samples, and a greater abundance of Saccharomyces species in kefir of Escarcega than in the Campeche kefir. When the prophage compositions were evaluated, the Campeche sample showed a higher diversity of prophage sequences. In Escarcega, we observed a prevalence of prophage families that infect Enterobacteria and Lactobacillus. The sequences associated with secondary metabolites, such as plipastatin, fengycin, and bacillaene, and also bacteriocins like helveticin and zoocin, were also found in different proportions, with greater diversity in the Escarcega sample. The analyses described in this work open the opportunity to understand the microbial diversity in kefir samples from two distant localities.

Expression analysis of ST3GAL4 transcripts in cervical cancer cells.

ST3GAL4 gene expression is altered in different cancer types, including cervical cancer. Several mRNA transcripts have been reported for this gene; however, their expression levels in cervical cancer have not been analyzed. ST3GAL4 encodes for ß­galactosidase α­2,3­sialyltransferase 4, involved in the biosynthesis of the tumour antigens sLe(x) and sulfo­sLe(x). The present study evaluated the presence of three mRNA variants (V1, V2 and V3) in cervical cancer cell lines, detecting the three variants. Additionally, the expression level of the V1 transcript of the ST3GAL4 gene was determined by reverse transcription­quantitative polymerase chain reaction in cervical cell lines and in normal, premalignant and cervical cancer tissue. The V1 transcript of the ST3GAL4 demonstrated significant decreased expression in premalignant and malignant cervical tissues. The results suggested that deregulation of this gene could occur prior to the presence of cancer and demonstrated the importance of evaluating the expression level of V1, and its association with disease progression.

The Mammalian Spermatogenesis Single-Cell Transcriptome, from Spermatogonial Stem Cells to Spermatids.

Spermatogenesis is a complex and dynamic cellular differentiation process critical to male reproduction and sustained by spermatogonial stem cells (SSCs). Although patterns of gene expression have been described for aggregates of certain spermatogenic cell types, the full continuum of gene expression patterns underlying ongoing spermatogenesis in steady state was previously unclear. Here, we catalog single-cell transcriptomes for >62,000 individual spermatogenic cells from immature (postnatal day 6) and adult male mice and adult men. This allowed us to resolve SSC and progenitor spermatogonia, elucidate the full range of gene expression changes during male meiosis and spermiogenesis, and derive unique gene expression signatures for multiple mouse and human spermatogenic cell types and/or subtypes. These transcriptome datasets provide an information-rich resource for studies of SSCs, male meiosis, testicular cancer, male infertility, or contraceptive development, as well as a gene expression roadmap to be emulated in efforts to achieve spermatogenesis in vitro.

Phytochemical screening and hypoglycemic activity of Carica papaya leaf in streptozotocin-induced diabetic rats

The extraction of plant constituents is essential to isolate biologically active compounds, aimed to understand their role on the treatment of diabetes. This study was designed to explore the preliminary phytochemical and physicochemical analysis of Carica papaya L., Caricaceae, leaf, and further evaluation of its hypoglycemic effect on diabetic rats. C. papaya leaves were extracted using chloroform, n-hexane or ethanol. For each extract a phytochemical screening was performed. The tests were conducted in triplicate and the qualitative and quantitative determination of the various metabolites was done using analytical standards proposed by Mexican Herbal Pharmacopoeia. The chloroform extract, containing steroids and quinones as major components, was chosen to study C. papaya biological effects. The chloroform extract was evaporated to dryness, and doses 0, 31, 62, 125 mg/kg were orally administered in 300 µl polyethylene glycol to diabetic rats; and 0 and 62 mg/kg to non-diabetic rats. After a 20-day treatment with the chloroform extract, the animals were sacrificed and blood was obtained for biochemical studies. The main effect observed was a decrease in serum glucose, triglycerides and transaminases in diabetic rats after the administration of C. papaya chloroform extract. These results confirm the potential beneficial action of C. papaya to treat the symptoms of diabetic patients.

Desarrollo de la competencia médica para el ejercicio profesional en centros ambulatorios / Development of competence for the professional practice in ambulatory centres

El desarrollo de competencias, es una característica profesional que trasciende las aulas, y cuyo progreso se describe como un proceso continuo. En un grupo de médicos se planeó analizar el grado de identificación con aspectos de la competencia presentados "Modelo de tres circulos" y la opinión de los mismos sobre el contexto laboral donde se inician como profesionales, siguiendo un diseño cuantitativo-cualitativo. Participaron 296 médicos egresados de 8 universidades venezolanas (promedio de egreso: 9 meses desviación estándar: 5,41 meses). Laborando en abulatorios rurales. Se utilizó un modelo descriptivo de la competencia que agrupa las actitudes, habilidades y conocimientos en 12 dominios, para elaborar dos cuestionarios validados llamados "dominios clínicos" de 95 ítems, y "dominios no clínicos" de 75 ítems, con un escalamiento tipo Likert de cinco puntos, con una confiabilidad aceptable (Alfa>0,75). Con el objeto de explorar las posibles variaciones entre diferentes subgrupos de la muestra de médicos, se consideraron las variables procedencia y universidad de origen. Para este fin se compararon los promedios de cada subgrupo en los puntajes totales de cada cuestionario mediante análisis de varianza o Kruskal Wallis, usando el programa SPSS versión 12.0 y Excel 2003. Los datos cualitativos relativos a opiniones sobre su experiencia laboral, se recogieron en 146 médicos mediante un cuestionario de preguntas abiertas, y un diario de campo, triangulando con tres informantes claves. Esta información fue procesada usando el programa Atlas/ti versión 4.2. Se encontró que los médicos se identifican con los aspectos de la competencia explorados en un 79% y se observaron diferencias significativas en los puntajes promedio de los instrumentos según la universidad de origen. La exploración cualitativa mostró una opinión desfavorable, en los médicos participantes en el estudio, hacia el ejercicio en centros ambulatorios, relacionada con factores económicos...

The development of competition is a profesional characteristic which go beyond the lecture room and its progress is described as a continual process. In a medical group it was decided to analyze the identification level with competition included in the model of the three circles and their opinions on the labour context where they begin as professionals, following a qualitative-qualitative design. In the study participate 296 medical doctors from 8 venezuelan universities (avaerage time of graduation: 9 ± 5,4 months) and working in rural health clinics. A descriptive competition model was used which includes evaluation of attitudes, skills and knowledge on 12 scopes, in order to elaborate two validated questionnaires: clinical (95 items) and non clinical (75 items), in a Lickert scale of five points with acceptable confidence (Cronbach alpha > 0.75. In order to explore possible vartation among the different sub-group of the sample of medical doctors, origin and university were considered. Mean scores from each type of questionnaire were compared by analysis of variance or Kruskall Walls test using the Statistical Package for the Social Sciences, 12th version and Excel 2003. Opinions on labour experience were collected from 146 medical doctors by means of a set of open ended questions and a field work diary and triangulation with three key informants. This qualitative data was processed by means of the Atlas/ti program, version 4.2. According to the results the medical doctors identified themselves in a 79% with the competition explored aspects. The qualitative inquire show unfavourable opinions from the participants medical doctors on their practice in the raraul clinics in relation to economic factors, labour contest and few opportunities to professional bring up. to date

Despitaje masivo del cancer gastrico en el Edo. Tachira. / Massive screening of gastric cancer in the State of Tachira

Con el fin de diagnosticar cancer gastrico en su fase precoz, se realiza en el Estado Tachira un programa de despistaje masivo, el cual se lleva a cabo con unidades moviles dotadas de aparato de rayos X apropiado y donde se practican estudios radiologicos con tecnica de doble contraste a la poblacion rural comprendida por encima de los 35 anos que previamente ha sido motivada y educada por los Trabajadores Sociales. Las personas con lesiones o con sospecha de ello son sometidos a endoscopia y biopsiados. Los que resultan con cancer son sometidos a tratamiento quirurgico.Desde octubre 80 a julio 81 se han examinado 4.407 personas, diagnosticandose 58 casos de cancer gastrico de los cuales 7 han sido precoces. Tambien ha permitido diagnosticar otra patologia gastrica como: polipos, ulceras, hernias hiatales etc.suceptibles de tratamiento. Concluimos que con este metodo, el pronostico de esta enfermedad cambiara en forma muy favorable para estos pacientes y se lograra en porcentaje de sobrevida muy altos

Estudio del financiamiento del PAI en Colombia: impacto de la reforma y la descentralización / Colombia EPI financing study: reform and decentralization impact

Desde 1990, el sector salud en Colombia ha venido en un proceso de reforma en el cual el nuevo Sistema General de Seguridad Social en Salud se organiza de manera descentralizada pretendiendo garantizar condiciones de acceso equitativo y oligatorio a toda la población mediante los regímenes contributivo y subsidiado, integrándose para el efecto nuevos actores como las autoridades políticas y administrativas territoriales, EPS, ARS, ESE'S e IPS. Bajo este contexto de ajuste del sistema se ha presentado disminución en las coberturas de vacunación y deterioro de la vigilancia epidemiológica por lo que se requiere conocer y analizar los factores que están incidiendo en esta situación con énfasis en los efectos de la reforma y la descentralización en el financiamiento del Programa Ampliado de Inmunizaciones -PAI-. Dado lo anterior, el Ministerio de Salud, con la asesoría de la OPS/OMS y el apoyo de la AID adelantó el presente estudio que aborda los componentes técnico-administrativo y financiero del programa a nivel departamental profundizando, a manera de estudio de casos, en los Departamentos de Antioquia, Chocó, Nariño y Guajira y los municipios de Medellín, Quibdó, Túquerres, Ipiales, Maicao y Riohacha. Con base en el estudio se identificaron algunos logros susceptibles de potencializar y diversas limitaciones que afectan el desarrollo del programa. En relación con coberturas y vigilancia epidemiológica se ha logrado ampliar y mantener esquema vacunación...(TRUNCADO A 1500 K)