Divalent ion-dependent swelling of tomato bushy stunt virus: a multi-approach study.

Time-resolved small-angle X-ray and neutron scattering (SAXS and SANS) in solution were used to study the swelling reaction of TBSV upon chelation of its constituent calcium at mildly basic pH. SAXS intensities comprise contribution from the protein capsid and the RNA moiety, while neutron scattering, recorded in 72% D2O, is essentially due to the protein capsid. Cryo-electron micrographs of compact and swollen virus were used to produce 3D reconstructions of the initial and final conformations of the virus at a resolution of 13 A and 19 A, respectively. While compact particles appear to be very homogeneous in size, solutions of swollen particles exhibit some size heterogeneity. A procedure has been developed to compute the SAXS pattern from the 3D reconstruction for comparison with experimental data. Cryo-electron microscopy thereby provides an invaluable starting (and ending) point for the analysis of the time-resolved swelling process using the scattering data.

A large cluster of highly expressed genes is dispensable for growth and development in Aspergillus nidulans.

We investigated the functions of the highly expressed, sporulation-specific SpoC1 genes of Aspergillus nidulans by deleting the entire 38-kb SpoC1 gene cluster. The resultant mutant strain did not differ from the wild type in (1) growth rate, (2) morphology of specialized reproductive structures formed during completion of the asexual or sexual life cycles, (3) sporulation efficiency, (4) spore viability or (5) spore resistance to environmental stress. Thus, deletion of the SpoC1 gene cluster, representing 0.15% of the A. nidulans genome, had no readily detectable phenotypic effects. Implications of this result are discussed in the context of major alterations in gene expression that occur during A. nidulans development.

Asm-1+, a Neurospora crassa gene related to transcriptional regulators of fungal development.

This report describes the identification, cloning, and molecular analysis of Asm-1+ (Ascospore maturation 1), the Neurospora crassa homologue of the Aspergillus nidulans stuA (stunted A) gene. The Asm-1+ gene is constitutively transcribed and encodes an abundant, nucleus-localized 68.5-kD protein. The protein product of Asm-1+ (ASM-1), contains a potential DNA-binding motif present in related proteins from A. nidulans (StuA), Candida albicans (EFGTF-1), and Saccharomyces cerevisiae (Phd1 and Sok2). This motif is related to the DNA binding motif of the Swi4/Mbp1/Res family of transcription factors that control the cell cycle. Deletion of Asm-1+ destroys the ability to make protoperithecia (female organs), but does not affect male-specific functions. We propose that the APSES domain (ASM-1, Phd1, StuA, EFGTF-1, and Sok2) defines a group of proteins that constitute a family of related transcription factors involved in the control of fungal development.

Colpoperineocleisis de Labhardt: una alternativa segura y eficaz para el tratamiento del prolapso genital en pacientes sin actividad sexual / Labhardt colpocleisis in the treatment of pelvic organ prolapse

Introducción: El prolapso genital impacta negativamente la calidad de vida y autoimagen de la mujer. Rutinariamente indicamos la colpoperineocleisis de Labhardt a pacientes de edad avanzada y sin actividad sexual. Objetivo: Evaluar los resultados con esta técnica e identificar posibles factores de riesgo que predigan la falla. Métodos: Análisis retrospectivo de pacientes tratadas con la técnica entre los años 2008-2010. Se realizó análisis univariado y multivariado para identificar factores de riesgo asociados a la falla y se construyeron curvas libre de falla anatómica a fin de evaluar la durabilidad. Resultados: 68 pacientes cumplieron los criterios de inclusión. La edad promedio fue 71,9 +/- 5,7 años; 95,6 por ciento fueron clasificadas en etapa III o IV según POP-Q. El tiempo operatorio fue de 54 +/- 20 minutos. Seguimiento promedio de 21 meses; la tasa de recidiva anatómica fue de 14,7 por ciento. La tasa de incontinencia de orina de esfuerzo (IOE) de novo fue de 5,9 por ciento. El análisis univariado identificó como factor predictor de recidiva el flujo vaginal posoperatorio; en análisis multivariado de Cox, esa condición mantuvo significancia estadística (OR 6,3). Se identificó como factor de riesgo el no acatamiento de la técnica quirúrgica (OR 7,2). Conclusión: La colpoperineocleisis de Labhardt es una técnica segura, con baja tasa de complicaciones, una tasa de recurrencia aceptable y baja tasa de IOE de novo. Pilar del éxito es evitar la infección y respetar la técnica quirúrgica. Es necesario estudios comparativos con otras técnicas oclusivas, como también evaluar el rol de la infección como causa de falla de la técnica.

Introduction: Genital prolapse affects up to 50 percent of multiparous women, impacting their quality of life and self-image. At our Institution Labhardt's colpoperineocleisis is usually proposed to older patients, without sexual activity, regardless the type or grade of prolapse. Objective: To evaluate the results with this technique and identify potential risk factors predicting the failure. Methods: Analysis of a retrospective cohort of patients treated with this technique between 2008 and 2010. Univariate and multivariate analysis were carried out to identify risk factors and failure-free curves were built to estimate durability. Results: 68 patients met the inclusion criteria. Average age was 71.9 +/- 5.7 years; 95.6 percent of patients were classified as stage III or IV based on POP-Q system. Operative time was 54 +/- 20 min. At 21 months of follow-up, recurrence rate was 14.7 percent. De novo stress urine incontinence (SUI) was diagnosed in 5.9 percent of patients. In univariate analysis, post operative vaginal discharge was identified as predicting factor for defect recurrence. In Cox analysis, this condition remained significant (OR 6.3), In addition, failure to observe the surgical technique was also identified as risk factor for defect recurrence (OR 7.2). Conclusion: Labhardt 's colpoperineocleisis is a safe technique, with low complication rate, acceptable recurrence rate, and low de novo SUI rate. Mainstay for success is to avoid infection and observe the surgical technique. Comparative studies with other occlusive techniques might be carried out, as well as exploring the role of infection as predisposing condition for failure.

The Aspergillus nidulans yA gene is regulated by abaA.

The developmentally regulated Aspergillus nidulans yA gene encodes a p-diphenol oxidase that is needed for synthesis of green conidial pigment. We subjected the yA 5' flanking region to mutational analysis in A. nidulans and Saccharomyces cerevisiae to identify DNA sequence elements involved in its transcriptional control, and identified two functionally distinct elements. Element I contained potential BrlA binding sites and was required for full level yA transcription, but not for developmental regulation in the presence of element II. Element II contained putative TEF-1 binding sites flanking a CCAAT element and was sufficient for developmental regulation of transcription. Mutation of the TEF-1 binding sites eliminated developmental regulation, whereas mutation of the CCAAT element led to elevated levels of transcription. Element II was also sufficient to induce transcription in S. cerevisiae when the A.nidulans developmental regulatory gene abaA was expressed from the GAL1 promoter. As AbaA and TEF-1 possess similar DNA binding domains, the abaA-yA interaction in yeast is probably direct. Thus, abaA appears to be a direct activator of yA, but yA regulation may also involve interactions with BrlA and a member of the CCAAT class of DNA binding proteins.

Meiotic transvection in fungi.

The Neurospora crassa Asm-1+ (ascospore maturation 1) gene encodes an abundant nucleus-localized protein required for formation of female structures and for ascospore maturation. Deletion mutants of Asm-1+ are "ascus-dominant," i.e., when crossed to wild type, neither Asm-1+ nor Asm-1 delta spores mature. To explain this behavior, we considered three models: an effect of reduced dosage of the gene product, failure of internuclear communication, and failure of transvection (regulation dependent on pairing of alleles). We found that for proper regulation of subsequent sexual sporulation, Asm-1+ must be in proximity, probably paired, to its allelic counterpart in the zygote: i.e., transvection must occur. Disruption of pairing causes failure of ascospore progeny to mature. Transvection in Neurospora, unlike in Drosophila, occurs immediately before meiosis, and can be demonstrated between wild-type alleles.

Translocation of Neurospora crassa transcription factor NUC-1 into the nucleus is induced by phosphorus limitation.

NUC-1, a basic helix-loop-helix zipper protein, activates the expression of several genes involved in phosphorus acquisition in Neurospora crassa. In the present study we investigated whether posttranscriptional mechanisms control the activity of NUC-1. The NUC-1 level was higher (up to fivefold) in wild-type cells grown at low external phosphate concentration and in mutant strains expressing the phosphorus acquisition genes constitutively than in a wild-type strain grown at high external phosphate concentration. Using indirect immunofluorescence we demonstrated that NUC-1 is localized at least predominantly in the cytosol when wild-type N. crassa is grown with an adequate supply of phosphate, whereas NUC-1 is largely concentrated in the nucleus upon limitation of external phosphate. In mutant strains expressing the phosphorus acquisition genes constitutively, NUC-1 localization was also primarily in the nucleus. Thus, subcellular compartmentation of regulatory proteins is an important mechanism in regulating gene expression in filamentous fungi.

NUC-2, a component of the phosphate-regulated signal transduction pathway in Neurospora crassa, is an ankyrin repeat protein.

In response to phosphorus limitation, the fungus Neurospora crassa synthesizes a number of enzymes that function to bring more phosphate into the cell. The NUC-2 protein appears to sense the availability of phosphate and transmits the signal downstream to the regulatory pathway. The nuc-2+ gene has been cloned by its ability to restore growth of a nuc-2 mutant under restrictive conditions of high pH and low phosphate concentration. We mapped the cloned gene to the right arm of linkage group II, consistent with the chromosomal position of the nuc-2 mutation as determined by classical genetic mapping. The nuc-2' open reading frame is interrupted by five introns and codes for a protein of 1066 amino acid residues. Its predicted amino acid sequence has high similarity to that of its homolog in Saccharomyces cerevisiae, PHO81. Both proteins contain six ankyrin repeats, which have been implicated in the cyclin-dependent kinase inhibitory activity of PHO81. The phenotypes of a nuc-2 mutant generated by repeat-induced point mutation and of a strain harboring a UV-induced nuc-2 allele are indistinguishable. Both are unable to grow under the restrictive conditions, a phenotype which is to some degree temperature dependent. The nuc-2+ gene is transcriptionally regulated. A 15-fold increase in the level of the nuc-2+ transcript occurs in response to a decrease in exogenous phosphate concentration.

Loss of growth polarity and mislocalization of septa in a Neurospora mutant altered in the regulatory subunit of cAMP-dependent protein kinase.

In filamentous fungi, growth polarity (i.e. hyphal extension) and formation of septa require polarized deposition of new cell wall material. To explore this process, we analyzed a conditional Neurospora crassa mutant, mcb, which showed a complete loss of growth polarity when incubated at the restrictive temperature. Cloning and DNA sequence analysis of the mcb gene revealed that it encodes a regulatory subunit of cAMP-dependent protein kinase (PKA). Unexpectedly, the mcb mutant still formed septa when grown at the restrictive temperature, indicating that polarized deposition of wall material during septation is a process that is, at least in part, independent of polarized deposition during hyphal tip extension. However, septa formed in the mcb mutant growing at the restrictive temperature are mislocalized. Both polarized growth and septation are actin-dependent processes, and a concentration of actin patches is observed at growing hyphal tips and sites where septa are being formed. In the mcb mutant growing at the restrictive temperature, actin patches are uniformly distributed over the cell cortex; however, actin patches are still concentrated at sites of septation. Our results suggest that the PKA pathway regulates hyphal growth polarity, possibly through organizing actin patches at the cell cortex.

Una experiencia de acompañamiento con doula a adolescentes en trabajo de parto / Doula support during labor: experience in a sample of pregnant teenagers

Objetivo: Comparar la percepción del dolor-temor durante el trabajo de parto y parto, y el grado de dificultad-satisfacción con la experiencia de parto, en un grupo de adolescentes acompañadas por doula y otro con atención habitual. Método: El grupo estudio comprendió 80 adolescentes del "Programa Emprende Mamá" que controlaron sus embarazos en centros de salud de la comuna de La Florida y con parto en el hospital Dr. Sótero del Río, acompañadas por una mujer familiar o amiga, elegida por la joven, con capacitación previa de 2 horas. El grupo control estuvo formado por 80 adolescentes no participantes del programa, que controlaron sus embarazos en los mismos centros de salud, con parto en el mismo período. Resultados: El grupo estudio refirió menor percepción de dolor durante el trabajo de parto y parto, menor temor durante el parto y lo percibió como más fácil. No se encontraron diferencias significativas en el nivel de satisfacción respecto de la experiencia total. Sin embargo, las adolescentes con doula señalaron estar satisfechas por aspectos positivos de la vivencia, mientras que el grupo control centra su satisfacción en la ausencia de expectativas negativas temidas. Conclusión: El acompañamiento por doula en el parto de la embarazada adolescente, es una intervención de bajo costo que permite mejorar cualitativamente su vivencia de parto.

Objective: To compare the effects of continuous doula support and standard hospital care on pain and fear perception, during labor and delivery, as well as perception of difficulty and satisfaction with the birth experience, in a sample of pregnant teenagers. Method: The study group was conformed by eighty pregnant teenagers participants in "Emprende Mama Program" attended in the outpatient clinics of La Florida county for their prenatal care and delivery at a public hospital. They received emotional support during labor by a 2 hour trained female relative or friend, previously chosen by them. The control group was conformed by eighty non participants teenagers attended at the same outpatient clinics and delivery in the same period. Results: Teenagers with doula support reported less pain and fear during labor and delivery and perceived their birth experience as less difficult. No significant differences were reported in relation to satisfaction with birth experience. Although teenagers with doula support reported satisfaction due to positive aspects with birth experience, meanwhile the control group felt mostly satisfied due the absence of negative feared expectations. Conclusion: Labor support given by doula, is a low cost intervention which improves quality perception of birth experience in the adolescent pregnant.

Problemática anticonceptiva en la mujer que se embaraza / Contraception methods in pregnancy women

Se encuestan 1000 pacientes puérperas de aborto o parto en las cuales se analizan las causas por las cuales se embarazaron, enfocada al uso o no de métodos anticonceptivos. La mayoría son mujeres muy jóvenes, de 18 a 19 años. Se encontró una relación importante entre la baja paridad y edad entre 13 y 20 años con mayor número de embarazadas asociados a no uso de métodos anticonceptivos, considerándose que las fallas de la educación o en el manejo a nivel de consultorio en este grupo de personas puede ser la causa fundamental de un embarazo que generalmente no es deseado. El uso de anticonceptivos orales tiene una fuerte asociación con aborto provocado y menor edad de las pacientes, el uso de DIU se asocia a una menor probabilidad de aborto provocado y mayor edad

Factores de riesgo en infección de herida operatoria: cesárea de urgencia / Risk factor in surgical wound infection: emergency cesarean

Se analizan los factores de riesgo presentes en infecciones de heridas operatorias en cesárea de urgencia en un hospital público docente asistencial de Santiago. Se diseñó un estudio de casos y controles prospectivos que incluyó 90 casos y 171 controles. Los resultados obtenidos fueron analizados según tipo de incisión, presencia de obesidad, número de tactos vaginales, número de horas de rotura ovular, tipo de cirujano, uso de irrigación del tejido celular subcutáneo y hora del día en que se realizó la intervención. Los resultados obtenidos indican que no hay diferencia entre los tipos de incisión media infraumbilical o pfannenstiel, la presencia de obesidad o el tipo de cirujano. Existe mayor riesgo de infección de herida operatoria con más de 5 tactos vaginales en el trabajo de parto, más de 13 horas de trabajo de parto, uso de cierre del tejido celular subcutáneo y no irrigación de éste y cuando la intervención se realiza en la madrugada en nuestro hospital