Restoring catalase activity in Staphylococcus aureus subsp. anaerobius leads to loss of pathogenicity for lambs

Staphylococcus aureus subsp. anaerobius, a microaerophilic and catalase-negative bacterium, is the etiological agent of abscess disease, a specific chronic condition of sheep and goats, which is characterized by formation of necrotic lesions that are located typically in superficial lymph nodes. We constructed an isogenic mutant of S. aureus subsp. anaerobius (RDKA84) that carried a repaired and functional catalase gene from S. aureus ATCC 12600, to investigate whether the lack of catalase in S. aureus subsp. anaerobius plays a role in its physiological and pathogenic characteristics. The catalase activity had no apparent influence on the in vitro growth characteristics of RDKA84, which, like the wild-type, did not grow on aerobically incubated agar plates. Restoration of catalase activity in RDKA84 substantially increased resistance to H2O2 when analyzed in a death assay. The intracellular survival rates of the catalase-positive mutant RDKA84 in polymorphonuclear neutrophils (PMN) isolated from adult sheep were significantly higher than those of the wild-type, while no differences were found with PMN isolated from lambs. RDKA84 showed significantly lower survival rates in murine macrophages (J774A.1 cells) than the wild-type strains did, whereas, in bovine mammary epithelial cells (MAC-T), no differences in intracellular survival were observed. Interestingly, the virulence for lambs, the natural host for abscess disease, of the catalase-positive mutant RDKA84 was reduced dramatically in comparison with wild-type S. aureus subsp. anaerobius in two experimental models of infection

Light-triggered carotenogenesis in myxococcus xanthus: New paradigms in photosensory signaling, transduction and gene regulation

22 pags., 6 figs. -- This article belongs to the Special Issue Myxobacteria: Physiology and RegulationMyxobacteria are Gram-negative δ-proteobacteria found predominantly in terrestrial habitats and often brightly colored due to the biosynthesis of carotenoids. Carotenoids are lipophilic isoprenoid pigments that protect cells from damage and death by quenching highly reactive and toxic oxidative species, like singlet oxygen, generated upon growth under light. The model myxobacterium Myxococcus xanthus turns from yellow in the dark to red upon exposure to light because of the photoinduction of carotenoid biosynthesis. How light is sensed and transduced to bring about regulated carotenogenesis in order to combat photooxidative stress has been extensively investigated in M. xanthus using genetic, biochemical and high-resolution structural methods. These studies have unearthed new paradigms in bacterial light sensing, signal transduction and gene regulation, and have led to the discovery of prototypical members of widely distributed protein families with novel functions. Major advances have been made over the last decade in elucidating the molecular mechanisms underlying the light-dependent signaling and regulation of the transcriptional response leading to carotenogenesis in M. xanthus. This review aims to provide an up-to-date overview of these findings and their significance.This research was funded by grants PGC2018-094635-B-C21 (to M.E.-A.) and PGC2018- 094635-B-C22 (to S.P) from the Agencia Estatal de Investigación (AEI)-Spain and European Regional Development Fund (FEDER), and by grant 20992/PI/18 (to M.E.-A.) from Fundación Séneca (Murcia)- Spain. The Ministerio de Educación y Cultura-Spain funded Ph.D. fellowships to A.J.M.-G, E.P.-M. and E.B.-M., and AEI-Spain funded that to R.P.-C

Necrotoxigenic Escherichia coli from sheep and goats produce a new type of cytotoxic necrotizing factor (CNF3) associated with the eae and ehxA genes

Fecal samples from sheep and goats were screened by tissue-culture assays and PCR for the presence of necrotoxigenic Escherichia coli (NTEC) producing cytotoxic necrotizing factors (CNFs). Of the 18 NTEC strains assayed, four were positive for the cnf1 gene while 14 strains were negative for the cnf1 and cnf2 genes. All of the NTEC strains had the eae gene and most of them also carried the ehxA gene. Moreover, all the cnf1– cnf2– NTEC strains were negative for several virulence markers associated with CNF1+ or CNF2+ strains. The cnf gene present in one of these strains was sequenced and analysis of the gene product revealed a new type of CNF, which was named CNF3 (and the coding gene cnf3). Oligonucleotide primers were designed to PCR-amplify a fragment of cnf3. The results showed that all strains examined in this study, except one cnf1+strain, were cnf3+. The association of cnf3 with eae and ehxA suggests that cnf3+ NTEC strains might be pathogenic for humans. [Int Microbiol 2007; 10(1):47-55

Propuesta de plan de negocios para la venta de Pasuchaca

El desarrollo del emprendimiento se basa en una estrategia diferenciaci?n de segmento para comercializar producto Pasuchaca a poblaci?n diab?tica de 25 a?os a m?s en Lima metropolitana, ofreciendo una propuesta de valor basada en la calidad mayores beneficios y minimiza efectos secundarios de tratamiento convencional que representar? la ventaja competitiva en el Mercado, desplegando acciones de sensibilizaci?n inicial a trav?s de campa?as de marketing para atraer al p?blico, la distribuci?n en farmacias, centros naturistas, supermercados para mantener exposici?n y disponibilidad, puntos de distribuci?n preferidos seg?n el estudio, y retenci?n a partir de actividades preventivo promocionales orientadas a mejorar la calidad de vida como charlas nutricionales, maratones, entre otros, que persigue la fidelizaci?n del segmento. El despliegue del plan de marketing, a trav?s medios de comunicaci?n masiva aprovecha las debilidades y oportunidades del entorno y desarrolla la estrategia en tres etapas: Etapa de Prelanzamiento con el objetivo es educar e informar al p?blico objetivo sobre las propiedades curativas de la Pasuchaca, en l etapa de Lanzamiento con la finalidad de concientizar al p?blico objetivo sobre las propiedades curativas de la Pasuchaca; y en la tapa de Consolidaci?n: La estrategia de lanzamiento ser? ?retener e incrementar? al p?blico objetivo

An Active Isodicentric X Chromosome in a Case of Refractory Anaemia with Ring Sideroblasts Associated with Marked Thrombocytosis

Refractory anaemia with ring sideroblasts and marked thrombocytosis (RARS-T) is a provisional entity in the World Health Organization (WHO) classification. It displays features characteristic of both myelodysplastic syndrome and myeloproliferative neoplasia plus ring sideroblasts ≥15% and marked thrombocytosis. Most patients with RARS-T show a normal karyotype. We report a 76-year-old woman diagnosed with RARS-T (76% of ring sideroblasts) with JAK2 (V617F) mutation and a load of 30–40%. Classical and molecular cytogenetic (FISH) studies of a bone marrow sample revealed the presence of isodicentric X chromosome [(idic(X)(q13)]. Moreover, HUMARA assay showed the idic(X)(q13) as the active X chromosome. This finding was correlated with the cytochemical finding of ring sideroblasts. To our knowledge, this is the first reported case of an active isodicentric X in a woman with RARS-T

Transgastric laparoscopic polypectomy in giant gastric polyps not susceptible of endoscopic management: novel surgical technique and case series

La identificación de pólipos gástricos de manera incidental en endoscopias de vías digestivas altas ha aumentado su incidencia, que varía entre el 0.5% y el 23%. El 10% de estos pólipos presentan síntomas y el 40% son hiperplásicos. Nos permitimos proponer una técnica laparoscópica para el manejo de los pólipos hiperplásicos gigantes asociados a síndrome pilórico no susceptibles de resección endoscópica. MÉTODO: Serie de pacientes llevados a polipectomía transgástrica laparoscópica por hallazgo de pólipos gástricos gigantes asociados a síndrome pilórico, en Bogotá, Colombia, de enero de 2015 a diciembre de 2018. RESULTADOS: Un total de siete pacientes, el 85% de sexo femenino, con edad promedio de 51 años, ingresaron por síndrome pilórico y fueron llevados a manejo laparoscópico, con un tiempo quirúrgico promedio de 42 minutos, sangrado intraoperatorio de 7-8 cc, tolerancia a la vía oral a las 24 horas, no conversión, sin mortalidad. CONCLUSIONES: La polipectomía transgástrica para el manejo de pólipos gástricos gigantes benignos que no pueden ser resecados por vía endoscópica resulta ser un método factible, con una baja tasa de complicaciones y sin mortalidad.The identification of gastric polyps incidentally in endoscopies of the upper digestive tract has increased its incidence, varying between 0.5% and 23%. 10% of these polyps have symptoms, 40% are hyperplastic. We allow ourselves to propose a laparoscopic technique for the management of giant hyperplastic polyps associated with a pyloric syndrome, not susceptible to endoscopic resection. METHOD: A series of patients approached by laparoscopic transgastric polypectomy due to the giant gastric polyps associated with pyloric syndrome, in Bogotá, Colombia, from January 2015 to December 2018. RESULTS: Seven patients, 85% female, with an average age of 51 years, who were admitted for pyloric syndrome and were taken to laparoscopic management, with an average surgical time of 42 min, intraoperative bleeding 7-8 cc, tolerance to the oral route 24 hours, no conversion, without mortality. CONCLUSIONS: Transgastric polypectomy for the management of benign giant gastric polyps that cannot be resected endoscopically turns out to be a feasible method, with a low rate of complications and without mortality

The origin of life: chemical evolution of a metabolic system in a mineral honeycomb?

For the RNA-world hypothesis to be ecologically feasible, selection mechanisms acting on replicator communities need to be invoked and the corresponding scenarios of molecular evolution specified. Complementing our previous models of chemical evolution on mineral surfaces, in which selection was the consequence of the limited mobility of macromolecules attached to the surface, here we offer an alternative realization of prebiotic group-level selection: the physical encapsulation of local replicator communities into the pores of the mineral substrate. Based on cellular automaton simulations we argue that the effect of group selection in a mineral honeycomb could have been efficient enough to keep prebiotic ribozymes of different specificities and replication rates coexistent, and their metabolic cooperation protected from extensive molecular parasitism. We suggest that mutants of the mild parasites persistent in the metabolic system can acquire useful functions such as replicase activity or the production of membrane components, thus opening the way for the evolution of the first autonomous protocells on Earth

Treating horse chronic laminitis with allogeneic bone marrow mesenchymal stem cells

La laminitis crónica es una condición incapacitante que afecta el corion laminar de los cascos del caballo. Por lo general, se desarrolla como una lesión colateral de numerosas enfermedades sistémicas primarias. Se cree que el evento fisiopatológico crítico que hace que un casco sea vuelva laminítico es la pérdida de células madre mesenquimales. Esta pérdida perjudica en gran medida la capacidad del corion laminar para regenerarse. Aunque el trabajo previo proporciona credibilidad a esta noción, quedan cuestiones sin resolver que deben abordarse antes de aceptarla como un hecho bien fundado. Aquí, se reexaminó el principio central del modelo fisiopatológico de la laminitis mediante la infusión de células madre mesenquimales alogénicas derivadas de la médula ósea (CMM-AMO), a través de la vena palmar digital, en los cascos de los caballos afectados por laminitis crónica. Los caballos fueron monitoreados clínicamente durante 6 meses, evaluándolos mensualmente utilizando la escala de Obel-Glasgow de cojera modificada y la termografía de cascos. Se tomaron venogramas y biopsias laminares al principio y al final del período de estudio para reunir evidencia sobre la remodelación vascular y la regeneración del corion laminar. Los resultados mostraron que la infusión de CMM-AMO promueve la remodelación vascular y la regeneración del corion laminar, lo que respalda aún más que la pérdida de células madre es el evento crítico que conduce a la laminitis crónica. Este trabajo también demostró que la infusión de CMM-AMO es segura ya que los caballos tratados no desarrollaron manifestaciones clínicas negativas locales o sistémicas en sintonía con reacciones de rechazo, al menos durante el período de 6 meses en que se les dio seguimiento y bajo el esquema terapéutico propuesto.Chronic laminitis is a disabling condition that affects the laminar corium of the horse’s hooves. Commonly, it develops as a collateral injury of numerous primary systemic diseases. It is believed that the critical physiopathological event that renders a hoof laminitic is the loss of mesenchymal stem cells. This loss greatly impairs the ability of the laminar corium to regenerate. Although previous work provides credibility to this notion, there remain unsettled issues that must be addressed before accepting it as a well-founded fact. Here, it was reexamined the central tenet of the physiopathological model of laminitis by infusing allogeneic bone marrow-derived mesenchymal stem cells (ABM-MSCs), through the digital palmar vein, into the hooves of horses afflicted by chronic laminitis. Horses were clinically monitored during 6 mo by evaluating them monthly using the lameness-modified Obel-Glasgow’s scale and hooves thermography. Venograms and lamellar biopsies were taken at the beginning and at the end of the study period to gathered evidence on vascular remodeling and laminar corium regeneration. The results showed that ABM-MSCs infusion promotes vascular remodeling and laminar corium regeneration, further supporting that the loss of stem cells is the critical event leading to chronic laminitis. This work also demonstrated that the infusion of ABM-MSCs is safe since the treated horses did not develop local or systemic, negative clinical manifestations attuned with rejection reactions, at least during the 6-mo period they were follow up and under the therapeutic scheme proposed

MYH10 activation rescues contractile defects in arrhythmogenic cardiomyopathy (ACM).

The most prevalent genetic form of inherited arrhythmogenic cardiomyopathy (ACM) is caused by mutations in desmosomal plakophilin-2 (PKP2). By studying pathogenic deletion mutations in the desmosomal protein PKP2, here we identify a general mechanism by which PKP2 delocalization restricts actomyosin network organization and cardiac sarcomeric contraction in this untreatable disease. Computational modeling of PKP2 variants reveals that the carboxy-terminal (CT) domain is required for N-terminal domain stabilization, which determines PKP2 cortical localization and function. In mutant PKP2 cells the expression of the interacting protein MYH10 rescues actomyosin disorganization. Conversely, dominant-negative MYH10 mutant expression mimics the pathogenic CT-deletion PKP2 mutant causing actin network abnormalities and right ventricle systolic dysfunction. A chemical activator of non-muscle myosins, 4-hydroxyacetophenone (4-HAP), also restores normal contractility. Our findings demonstrate that activation of MYH10 corrects the deleterious effect of PKP2 mutant over systolic cardiac contraction, with potential implications for ACM therapy.This study was supported by MCIU grant BFU2016-75144-R and PID2020- 116935RB-I00, and by a “la Caixa” Banking Foundation grant under the project code HR18-00304” to J.A.B.; The study was also supported by the “Ayudas a la Investigación Cátedra Real Madrid-Universidad Europea” (2017/RM01). C.M.-L. and S.S. hold MCIU predoctoral contracts BES-2017-079715, and BES-2017-079707 respectively. R.G. acknowledges funding from the European Research Council under grant ERCAG-340177 (3DNanoMech) and from the MCIU under grant MAT2016- 76507-R. The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación (MCIN) and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence, grant CEX2020-001041-S funded by MICIN/AEI/10.13039/501100011033. The microscopy experiments were carried out at the Dynamic Microscopy and Image Unit, CNIC, ICTS-ReDib, co-financed by MCIN/AEI /10.13039/ 501100011033 and FEDER “A way of making Europe” (#ICTS-2018-04- CNIC-16). Imaris full analysis were carried out at the Microscopy & Dynamic Imaging, CNIC, ICTS-ReDib, co-funded by MCIN/AEI /10.13039/501100011033. Biomedical Imaging has been conducted at the Advanced Imaging Unit of the CNIC (Centro Nacional de Investigaciones Cardiovasculares Carlos III), Madrid, Spain. This project used the ReDIB ICTS infrastructure TRIMA@CNIC, Ministerio de Ciencia e Innovación (MCIN).S