Trastuzumab deruxtecan in patients with previously treated HER2-low advanced breast cancer and active brain metastases: the DEBBRAH trial.

BACKGROUND: Trastuzumab deruxtecan (T-DXd) is approved for human epidermal growth factor receptor 2 (HER2)-positive and HER2-low advanced breast cancer (ABC). T-DXd has shown encouraging intracranial activity in HER2-positive ABC patients with stable or active brain metastases (BMs); however, its efficacy in patients with HER2-low ABC with BMs is not well established yet. METHODS: DEBBRAH is a single-arm, five-cohort, phase II study evaluating T-DXd in patients with central nervous system involvement from HER2-positive and HER2-low ABC. Here, we report results from patients with heavily pretreated HER2-low ABC and active BMs, enrolled in cohorts 2 (n = 6, asymptomatic untreated BMs) and 4 (n = 6, progressing BMs after local therapy). Patients received 5.4 mg/kg T-DXd intravenously once every 21 days. The primary endpoint was intracranial objective response rate per Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM) for both cohorts. RESULTS: Intracranial objective response rate per RANO-BM was 50.0% [3/6 patients; 95% confidence interval (CI) 11.8% to 88.2%] and 33.3% [2/6 patients; 95% CI 4.3% to 77.7%; P = 0.033 (one-sided)] in cohorts 2 and 4, respectively. All responders had partial responses. Median time to intracranial response was 2.3 months (range, 1.5-4.0 months) and median duration of intracranial response was 7.2 months (range, 2.8-16.8 months). Median progression-free survival per RECIST v.1.1. was 5.4 months (95% CI 4.1-10.0 months). Treatment-emergent adverse events occurred in all patients included (16.7% grade 3). Three patients (25.0%) had grade 1 interstitial lung disease/pneumonitis. CONCLUSIONS: T-DXd demonstrated promising intracranial activity in pretreated HER2-low ABC patients with active BMs. Further studies are needed to validate these results in larger cohorts. This trial is registered with ClinicalTrials.gov, NCT04420598.

Genetic regulation of the ompX porin of Salmonella Typhimurium in response to hydrogen peroxide stress

BACKGROUND: Salmonella Typhimurium is a Gram negative pathogen that causes a systemic disease in mice resembling typhoid fever. During its infective cycle, S. Typhimurium is phagocytized by macrophages and proliferates inside a Salmonella containing vacuole where Salmonella is exposed and survives oxidative stress induced by H2O2 through modulation of gene expression. After exposure of Salmonella to H2O2, the expression of the porin encoding gene ompX increases, as previously shown by microarray analysis. Expression of ompX mRNA is regulated at a post transcriptional level by MicA and CyaR sRNAs in aerobiosis. In addition, sequence analysis predicts a site for OxyS sRNA in ompX mRNA. RESULTS: In this work we sought to evaluate the transcriptional and post transcriptional regulation of ompX under H2O2 stress. We demonstrate that ompX expression is induced at the transcriptional level in S . Typhimurium under such conditions. Unexpectedly, an increase in ompX gene transcript and promoter activity after challenges with H2O2 does not translate into increased protein levels in the wild type strain, suggesting that ompX mRNA is also regulated at a post transcriptional level, at least under oxidative stress. In silico gene sequence analysis predicted that sRNAs CyaR, MicA, and OxyS could regulate ompX mRNA levels. Using rifampicin to inhibit mRNA expression, we show that the sRNAs (MicA, CyaR and OxyS) and the sRNA:mRNA chaperone Hfq positively modulate ompX mRNA levels under H2O2 induced stress in Salmonella during the exponential growth phase in Lennox broth. CONCLUSIONS: Our results demonstrate that ompX mRNA is regulated in response to H2O2 by the sRNAs CyaR, MicA and OxyS is Salmonella Typhimurium.

Three-dimensional microscale hanging drop arrays with geometric control for drug screening and live tissue imaging.

Existing three-dimensional (3D) culture techniques are limited by trade-offs between throughput, capacity for high-resolution imaging in living state, and geometric control. Here, we introduce a modular microscale hanging drop culture where simple design elements allow high replicates for drug screening, direct on-chip real-time or high-resolution confocal microscopy, and geometric control in 3D. Thousands of spheroids can be formed on our microchip in a single step and without any selective pressure from specific matrices. Microchip cultures from human LN229 glioblastoma and patient-derived mouse xenograft cells retained genomic alterations of originating tumors based on mate pair sequencing. We measured response to drugs over time with real-time microscopy on-chip. Last, by engineering droplets to form predetermined geometric shapes, we were able to manipulate the geometry of cultured cell masses. These outcomes can enable broad applications in advancing personalized medicine for cancer and drug discovery, tissue engineering, and stem cell research.

Tuberculosis peritoneal con presentación clínica como cáncer ovárico avanzado: revisión de la literatura / Peritoneal tuberculosis with clinical presentation as advanced ovarian cancer

Se presenta el caso de paciente con ascitis, masa pelviana y CA 125 elevado, sugerentes de cáncer ovárico avanzado. Se realizó laparoscopía que demostró lesiones compatibles con tuberculosis peritoneal. La biopsia laparoscópica de las lesiones demostró granulomas, por lo que no se realizó más cirugía y se inició tratamiento antituberculoso específico con buena respuesta clínica. Se revisa en la literatura tuberculosis peritoneal y su dificultad con el diagnóstico diferencial con cáncer de ovario avanzado.

It is presented the case of a patient with ascites, pelvic mass and elevated CA 125, all suggested of advanced ovarian cancer. It was made a laparoscopy that evidenced lesions of peritoneal tuberculosis. The laparoscopic biopsy of the lesions demostrated granulomas, for that there was no more surgery made and antituberculosis specific treatment was started, with good clinical response. It is revisited in the literature peritoneal tuberculosis and its difficult differential diagnoses with advanced ovarian cancer.

Cáncer serosopélvico de alto grado: evidencia sobre su origen en la trompa de Falopio / High-grade serous pelvic cancer: evidence of its origin in the fallopian tube

Cáncer epitelial de ovario es una enfermedad altamente letal. Constituye la quinta causa de muerte por cáncer en mujeres a nivel mundial. El subtipo histológico más frecuente es el carcinoma seroso de alto grado. Este es el responsable de la alta letalidad de la enfermedad. Se presenta evidencia que respalda el origen tubario de este tipo histológico desde lesiones precursoras. A partir de estos datos se ha establecido que el cáncer tradicionalmente conocido como cáncer ovárico seroso de alto grado, el cáncer de trompa de Falopio y el carcinoma peritoneal primario, corresponden a una misma entidad nosológica: cáncer seroso pélvico de alto grado. Se revisa además la evidencia disponible para establecer que la salpingectomía podría constituir una medida de prevención para este tipo de cáncer.

Epithelial ovarian cancer is a highly lethal disease. It is the 5th cause of cancer death in women worldwide. The most common histologic subtype is the high-grade serous carcinoma. This is the responsible for the high lethality of the disease. Evidence supporting the tubal origin of this histological type from precursor lesions is presented. From these data it has been established that cancer traditionally known as serous high-grade ovarian cancer, cancer of the fallopian tube and primary peritoneal carcinoma, correspond to a single disease entity: pelvic serous high-grade cancer. We also check the available evidence to establish that the salpingectomy could be a preventive measure for this type of cancer.

Epstein-Barr virus-specific CD8(+) T lymphocytes from diffuse large B cell lymphoma patients are functionally impaired.

Epstein-Barr virus (EBV) is a persistent virus with oncogenic capacity that has been implicated in the development of aggressive B cell lymphomas, primarily in immunosuppressed individuals, although it can be present in immunocompetent individuals. Changes in the function and clonal diversity of T lymphocytes might be implied by viral persistence and lymphoma development. The aim of the present study was to evaluate the frequency, phenotype, function and clonotypical distribution of EBV-specific T cells after peripheral blood stimulation with a virus lysate in newly diagnosed patients with diffuse large B cell lymphoma (DLBCL) aged more than 50 years without prior histories of clinical immunosuppression compared with healthy controls. Our results showed impaired EBV-specific immune responses among DLBCL patients that were associated primarily with decreased numbers of central and effector memory CD8(+) T lymphocytes. In contrast to healthy controls, only a minority of the patients showed CD4(+)/tumour necrosis factor (TNF)-α(+) T cells expressing T cell receptor (TCR)-Vß17 and CD8(+)/TNF-α(+) T cells with TCR-Vß5·2, Vß9 and Vß18 in response to EBV. Notably, the production of TNF-α was undetectable among TCR-Vß5·3(+), Vß11(+), Vß12(+), Vß16(+) and Vß23(+) CD8(+) T cells. In addition, we observed decreased numbers of CD4(+)/TNF-α(+) and CD8(+)/TNF-α(+), CD8(+)/interleukin (IL)-2(+) and CD8(+)/TNF-α(+)/IL-2(+) T lymphocytes in the absence of T cells capable of producing TNF-α, IL-2 and IFN-γ after EBV stimulation simultaneously. Moreover, DLBCL patients displayed higher IL-10 levels both under baseline conditions and after EBV stimulation. These findings were also observed in patients with positive EBV viral loads. Prospective studies including a large number of patients are needed to confirm these findings.

Pseudogenization of sopA and sopE2 is functionally linked and contributes to virulence of Salmonella enterica serovar Typhi.

The difference in host range between Salmonella enterica serovar Typhimurium (S. Typhimurium) and S. enterica serovar Typhi (S. Typhi) can be partially attributed to pseudogenes. Pseudogenes are genomic segments homologous to functional genes that do not encode functional products due to the presence of genetic defects. S. Typhi lacks several protein effectors implicated in invasion or other important processes necessary for full virulence of S. Typhimurium. SopA and SopE2, effectors that have been lost by pseudogenization in S. Typhi, correspond to an ubiquitin ligase involved in cytokine production by infected cells, and to a guanine exchange factor necessary for invasion of epithelial cells, respectively. We hypothesized that sopA and/or sopE pseudogenization contributed to the virulence of S. Typhi. In this work, we found that S. Typhi expressing S. Typhimurium sopE2 exhibited a decreased invasion in different epithelial cell lines compared with S. Typhi WT. S. Typhimurium sopA completely abolished the hypo-invasive phenotype observed in S. Typhi expressing S. Typhimurium sopE2, suggesting that functional SopA and SopE2 participate concertedly in the invasion process. Finally, the expression of S. Typhimurium sopA and/or sopE2 in S. Typhi, determined changes in the secretion of IL-8 and IL-18 in infected epithelial cells.

Características polínicas y composición química del polen apícola colectado en Cayaltí (Lambayeque - Perú) / Pollinic characteristics and chemical composition of bee pollen collected in Cayalti (Lambayeque - Peru)

El objetivo del presente estudio fue determinar las características polínicas y la composición química del polen apícola, colectado en El Cafetal, Cayaltí (Lambayeque, Perú), un área rural del bosque estacionalmente seco. El polen apícola se colectó directamente de las colmenas y se clasificó en cuatro grupos de colores: amarillo, anaranjado, crema y gris. El análisis polínico reveló la presencia de polen de las especies: Acacia macracantha Humboldt & Bonpland, Encelia canescens Lamarck, Momordica charantia L. y Prosopis pallida (Humboldt & Bonpland ex Willdenow) H.B.K. El polen de P. pallida predominó en el polen apícola gris (98,1%) y amarillo (87,7%) en tanto que el polen de E. canescens predominó en el polen apícola anaranjado (72,7%) y crema (50,0%). Se observó una gran diversidad en las características morfológicas del polen, en la forma (poliada, oblado esferoidal y prolado esferoidal), elementos esculturales (liso, espinado y reticulado) y aberturas (tricolporado y estefanocolpado). Se determinó los contenidos de humedad (8,8 - 13,8%), cenizas (2,1 - 3,2%), calcio (6,4 - 12,4%), vitamina C (208 - 504 mg), azúcares totales y reductores (35 - 49,7 y 22,4 - 26%, respectivamente), grasas (0,15 - 0,18%) y proteínas (13,7 - 17,3%), observándose significativas variaciones en función del color del polen apícola. El valor nutritivo fue mayor en el polen apícola gris alcanzando el valor 3,51; en este color de polen apícola predominó P. pallida.

The aim of this study was to determine the pollen and chemical composition offour types ofbee pollen, collected in The Cafetal, Cayaltí (Lambayeque, Perú), a rural area of Perú seasonally dry forest. Bee pollen was collected directly from the hives and classified into four groups ofcolors: yellow, orange, cream and gray. Pollen analysis revealed the presence ofpollen in species: Acacia macracantha Humboldt & Bonpland, Encelia canescens Lamarck, Momordica charantia L. and Prosopis pallida (Humboldt & Bon-pland ex Willdenow) H.B.K. The pollen of P. pallida was predominant in the gray (98,1%) and yellow (87,7%) bee pollen; while pollen of E. canecens was predominant in the orange (72,7%) and cream (50,0%) bee pollen, respectively. A great diversity in the pollen morphology (polyad, oblate spheroidal and prolate spheroidal), scultural elements (psilate, echinate and reticulate) and openings (tricolporate and stephanocolpate) was observed. The moisture (8,8 - 13,8%), ash content (2,1 - 3,2%), calcium (6,4 - 12,4%), vitamin C (208 - 504 mg), total and reducing sugars (35 - 49,7y 22,4 - 26%, respectively), fat (0,15 - 0,18%) and proteins (13,7 - 17,3%) was determined, showing significant variations depending on the color of bee pollen. The nutritive value was higher in the gray bee pollen reaching the value 3.51; in this color was predominant P. pallida pollen.

Imiquimod en crema al 5% en el tratamiento de verrugas anogenitales asociadas a VPH: experiencia preliminar / Imiquimod 5% cream in the treatment of anogenital warts HPV associated

Antecedentes: La infección persistente por VPH de alto riesgo se asocia con cáncer cervicouterino, encontrándosepositividad en el 99,7% de los casos. Las verrugas anogenitales son una forma de presentación de la infección persistente. Objetivo: Investigar la eficacia y seguridad de imiquimod en crema al 5%, en el tratamiento de las verrugas anogenitales en mujeres. Método: Estudio prospectivo no randomizado, en mujeres portadoras de verrugas anogenitales asociadas a VPH. El tratamiento consiste en la autoaplicación de imiquiomod en crema al 5% tres veces a la semana por hasta un período de 16 semanas. Se define como respuesta completa al tratamiento aquella en que desaparece completamente la lesión; por respuesta parcial la disminución de al menos un 50% del volumen inicial de la lesión. Resultados: Durante un período de 8 meses fueron ingresadas y tratadas 38 pacientes La duración del tratamiento varió entre 1 y 4 meses. El número promedio de aplicaciones fue de 28,7. El 66% (25 casos) de las pacientes presentaron una respuesta completa, en tres casos no hubo respuesta, uno de ellos en una paciente inmunodeprimida, en 10 casos hubo respuestas parciales. En las pacientes con respuestas completas se necesitó un promedio de 28,7 aplicaciones hasta obtener el resultado. Conclusiones: Imiquimod es un fármaco con buena efectividad y seguridad en el tratamiento de las verrugas anogenitales asociadas a VPH, en tratamiento de tres veces por semana durante mínimo de 10 semanas.

Background: The chronic infection by high-risk HPV serotypes is strongly associated with cervical cancer, detection of HPV on tissue sample has been reported 99.7% of cases. The anal-genital warts represent the clinical manifestation of the persistent infection by this virus. Objectives: To investigate the efficacy and safety of Imiquimod cream 5% concentration, in the treatment of anal-genital warts in women. Methods: A non-randomized prospective study in women diagnosed with anal-genital warts HPV associated. The treatment consists in self-application of imiquimod cream 5%, three times a week for a period of 16 weeks or more. We define complete response to treatment in those patients where the lesion disappeared completely, and partial response to those where the lesion declined at least 50% of its initial volume. Results: Over a period of 8 months were admitted to the study and treated a total of 38 patients. Treatment duration varied between 1 and 4 months. The average number of applications was 28.7 times. 66% (25 cases) of the patients had a complete response, in three cases there was no response, one of them was an immunodepressed patients, in 10 cases there was partial response. The patients with complete response needed an average of 28.7 applications to get that result. Conclusions: Imiquimod is a drug with high effectiveness and safety in the treatment of anal-genital warts HPV associated, in a three times per week and at least 10 weeks total duration treatment.

Utilidad clínica del estudio de diseminación inicial en cáncer de mama estadios I y II / Clinical utility of initial dissemination study an patients with stage I or II breast cancer I

Se evalúa el rendimiento y utilidad clínica del estudio inicial de diseminación en nuestra serie de 616 casos de cáncer de mama, centrado especialmente en los estados I y II ( 374 casos ), buscando establecer si existe un subgrupo de mayor riesgo en el cual esté justificado el estudio inicial de diseminación. Se separaron las pacientes en 2 grupos de acuerdo a la palpación de ganglios axilares: sospechosos de metástasis (N1), no sospechosos (N0); comprobando que las pacientes N1 tenían un 5,99 por ciento de metástasis iniciales (13/217) versus un 2,3 por ciento (4/174) en las pacientes N0, (p=0,085); sin embargo durante el seguimiento de la serie (23 años) se comprobó que un porcentaje mayor de pacientes N1 desarrolló metástasis (50/ 204=24,5 por ciento) en relación a las pacientes N0 (25/170=14,7 por ciento) (p=0,0198); aunque no en todos estos casos los estudios iniciales fueron útiles para diagnosticar metástasis. En las pacientes que desarrollaron metástasis durante el seguimiento, los estudios iniciales de diseminación negativos, sirvieron de base comparativa a los estudios posteriores que mostraron metástasis, obteniéndose una utilidad clínica global para dichos estudios de un 24,4 por ciento (53/217) en las pacientes N1 versus un 14,4 por ciento (25/174) en las pacientes N0 (p=0,0154). En el 21 por ciento de las pacientes estado III, el estudio inicial de diseminación demostró metástasis. En 41 de 204 pacientes N1 (20 por ciento) la ecotomografía abdominal demostró colelitiasis, lo que se consideró un beneficio adicional del examen. Se concluye que el estudio inicial de diseminación es de utilidad clínica en pacientes con ganglios axilares palpables.

Maternal effects on encystment in crosses between two geographic strains of Artemia franciscana.

Maternal effects can have environmental or genetic causes. A method that can be used to demonstrate the genetic basis of a maternal effect is to look for grandfather effects in a backcross following reciprocal crosses. The absence of a grandfather effect would exclude a chromosomal basis for the maternal effect when the male sex is heterogametic (XX-XY sex determination system). However, in organisms in which the female is heterogametic (ZW-ZZ sex determination system), the absence of a grandfather effect does not rule out a chromosomal basis of the maternal effect, since the genes responsible for that effect can be located in the W chromosome, which is transmitted matrilineally. Conversely, the absence of a grandfather effect would point to a W-chromosome basis for the trait, provided that a maternal effect has been previously demonstrated. Distinguishing between W-located and autosome or Z-located maternal effects is important to understand the evolutionary dynamics of a trait. Here we report on a study of the chromosomal basis of maternal effects on two life-history traits related to encystment in the branchiopod crustacean Artemia franciscana, in which females are heterogametic. We performed crosses of two populations that differ in the number of cysts they produce. The proportion of encysted broods showed a maternal effect and was not affected by the grandfather's genotype, pointing to a W-chromosome basis. The average number of encysted offspring per brood showed a strong paternal effect and also a slight maternal effect. This trait also showed a grandfather effect, which suggests that the geographical variation has an autosomal or Z-chromosomal basis.

Caracterización molecular de aislamientos de enterobacter cloacae multirresistentes productores de a-lactamasas provenientes de pacientes de un hospital de tercer nivel de Bogotá / Molecular characterization of 20 isolates of resistance enterobacter cloacae from a Hospital of third level in Bogotá

Antecedentes. Las enterobacterias, antaño flora normal del tracto gastrointestinal, han cambiado su biología y emergido como agentes patógenos nosocomiales que se tornan resistentes a los antibióticos conocidos. Objetivo. Realizar la caracterización epidemiológico-molecular de 20 aislamientos de Enterobacter cloacae resistentes a cefalosporinas de tercera generación; provenientes de un hospital de tercer nivel de Bogotá-Colombia. Material y métodos. Los aislamientos fueron identificados mediante sistemas automatizados Microscan y VITEK, se utilizó el Enterobacter asbureae como control externo inter-especie. La confirmación de resistencia se hizo por técnica de difusión en agar, y una vez establecida se realizó BLEE para comprobación. La determinación de puntos isoeléctricos se hizo, mediante lisis por ultrasonido y la genotipificación mediante la metodología para bacterias Gramnegativas propuesta por Versalovic. Resultados: Los aislamientos colectados durante un año fueron causantes de 15 de infección Intrahospitalaria y dos colonizaciones. Todos los aislamientos presentaron resistencia a cefotaxima, ceftazidima, ceftriaxona, aztreonam y ciprofloxacina, 95 por ciento a amikacina, gentamicina y cloranfenicol, 75 por ciento a trimetoprim/sulfametoxazol, 20 por ciento a cefepime y todos fueron sensibles a imipenem. Dos aislamientos fueron confirmados como productores de â-lactamasas de espectro extendido (BLEE) por la técnica microbiológica de disco combinado. Por isoelectroenfoque presentaron dos â-lactamasas con puntos isoeléctricos (pI) de 5,4 y 8,2. En los 18 aislamientos no inhibidos por ácido clavulánico, se detectaron entre 2 y 4 â-lactamasas con pI de 5,4; 6,0; 7,0; 8,2 y mayor que 8,2; la resistencia a cefalosporinas de tercera generación podría ser atribuida a la hiperproducción de AmpC; los valores de pI sugieren la producción simultánea de â-lactamasas tipo SHV y TEM. La genotipificación mediante tres metodologías de rep-PCR (ERIC; REP y BOX) agrupó la población estudiada en siete clones: seis constituidos por un solo aislamiento y el clon predominante E1/B1/R1 agrupó 14 aislamientos causantes de infección en diez pacientes. Conclusión. Se identificó un clon de Enterobacter cloacae multirresistente, endémico en una institución de tercer nivel en Bogotá, causante de infección nosocomial y quirúrgica en particular

Biochemical characterization of a thermostable cysteine synthase from Geobacillus stearothermophilus V.

The cysK gene encoding a cysteine synthase of Geobacillus stearothermophilus V was overexpressed in E. coli and the recombinant protein was purified and characterized. The enzyme is a thermostable homodimer (32 kDa/monomer) belonging to the beta family of pyridoxal phosphate (PLP)-dependent enzymes. UV-visible spectra showed absorption bands at 279 and 410 nm. The band at 279 nm is due to tyrosine residues as the enzyme lacks tryptophan. The 410 nm band represents absorption of the coenzyme bound as a Schiff base to a lysine residue of the protein. Fluorescence characteristics of CysK's Schiff base were influenced by temperature changes suggesting different local structures at the cofactor binding site. The emission of the Schiff base allowed the determination of binding constants for products at both 20 degrees C and 50 degrees C. At 50 degrees C and in the absence of sulphide the enzyme catalyzes the decomposition of O-acetyl-l-serine to pyruvate and ammonia. At 20 degrees C, however, a stable alpha-aminoacrylate intermediate is formed.

The product of the cysK gene of Bacillus stearothermophilus V mediates potassium tellurite resistance in Escherichia coli.

The nucleotide sequence of a 4,539 bp fragment of Bacillus stearothermophilus V mediating tellurite resistance in Escherichia coli was determined. Four ORFs of more than 150 amino acids encoding polypeptides of 244, 258, 308, and 421 residues were found in the restriction fragment. E. coli cells harboring a recombinant plasmid containing the Ter determinant express, when challenged with tellurite, a 32 kDa protein with an amino terminal sequence identical to the ten first residues of the 308 ORF. This ORF shows great similarity with the cysteine synthase gene (cysK) of a number of organisms. Recombinant clones carrying the active cysK gene have minimal inhibitory concentrations to K2TeO3 that were tenfold higher than those determined for the host strain or that of clones carrying ORFs 244, 258, and 421. Introduction of the B. stearothermophilus V cysK gene into a cysK strain of Salmonella typhimurium LT2 resulted in complementation of the mutation as well as transfer of tellurite resistance.

Prolapso de cúpula vaginal / Prolapse of vaginal vault

El prolapso de cúpula vaginal constituye una complicación tardía de la histerectomía. Para su reparación se han descrito múltiples técnicas, tanto abdominales como vaginales. Se muestra nuestra experiencia en la reparación de este defecto utilizando la colposuspensión al promontorio con malla de Marlex. Se realizó un seguimiento de entre 1 y 2 años y se observó una tasa de curación subjetiva y objetiva de un 100 por ciento con un reinicio de la actividad sexual satisfactoria en 6/8 pacientes, y escasas complicaciones asociadas. Se concluye que esta técnica es una alternativa de elección en pacientes con prolapso de cúpula vaginal

Diagnóstico situacional de la salud mental en el distrito de Independencia / Diagnosis of the mental health in the district of Independencia

El presente estudio consiste en una evaluación de los trabajos de intervención e investigación en salud mental realizados hasta la fecha en el distrito de Independencia (Lima-Perú) y en el análisis de una nueva información de tipo cualitativo y cuantitativo sobre intervención obtenida por el proyecto

Structural studies of the BstVI restriction-modification proteins by fluorescence spectroscopy.

Structural studies of the proteins of the BstVI restriction-modification system of Bacillus stearothermophilus V were carried out using intrinsic fluorescence techniques. The exposure and environments of their tryptophanyl residues were determined using collisional quenchers. Quenching of BstVI endonuclease by iodide suggested a heterogeneous class of tryptophan residues, while the results obtained with M.BstVI methylase were consistent with a rather exposed tryptophan population. A comparison of the quenching efficiencies at 20 degrees C and 55 or 60 degrees C showed that their structures are more flexible and open at the temperature at which they exhibit maximal activity. The endonuclease reached its active conformation only after 1 h of incubation at 60 degrees C. Fluorescence changes were observed upon Mn2+ and Mg2+ binding, with Kd values in the range 3-5 microM. The binding of S-adenosyl-L-methionine to the methylase produced conformational changes, which were consistent with binding to a single site of Kd 550 and 680 microM at 20 degrees C and 55 degrees C, respectively. Quenching experiments with iodide showed that the presence of S-adenosyl-L-methionine leads to different conformational states at 20 degrees C and 55 degrees C. These results were interpreted in terms of differences in the structural characteristics of these restriction-modification proteins as well as in terms of differences in the conformational states that these enzymes exhibit at 20 degrees C and at the temperature at which they are most active.

The amino acidic substitution of cysteine 167 by serine (C167S) in BstVI restriction endonuclease of Bacillus stearothermophilus V affects its conformation and thermostability.

The restriction endonuclease BstVI from Bacillus stearothermophilus V contains three cysteine residues at positions 134, 167 and 180. Titration of Cys residues with DTNB showed that none of them are involved in disulphide bond formation. Cysteine triplets 134 and 167 were modified by recombinant PCR to introduce a serine residue in each case. The mutated genes were cloned into pGEM-T vector and transformed into E. coli JM109. Even though pGEM-T is not designed for expression, the mutant proteins were efficiently expressed in E. coli. The endonuclease carrying the mutation C134S was purified to homogeneity but appeared to be very unstable. In contrast, the C167S mutant enzyme was stable when pure and was studied biochemically. This mutant enzyme was as stable and resistant to protein-denaturing agents as the wild type enzyme. The activity of both enzymes was not affected by preincubations of 2 h at 80 degrees C. A short preincubation at 95 degrees C caused a complete inactivation of the mutant enzyme while the wild type endonuclease retained 30% of its activity. Moreover, the C167S BstVI was more susceptible to be hydrolyzed by proteinase K and trypsine compared to the wild type endonuclease. These results show that the substitution Cys --> Ser at position 167 affects the configuration and thermostability of BstVI restriction endonuclease.

Hematoma subcapsular hepático y embarazo / Hepatic subcapsular hematoma and pregnancy

Se presenta un caso de una paciente que, cursando un embarazo de 3er. trimestre, presentó un hematoma hepático subcapsular roto, manejado con técnica quirúrgica conservadora y con buen resultado materno neonatal