Decoding the genetic and functional diversity of the DSF Quorum-Sensing system in Stenotrophomonas maltophilia

Stenotrophomonas maltophilia uses the Diffusible Signal Factor (DSF) quorum sensing (QS) system to mediate intra- and inter-specific signaling and regulate virulence-related processes. The components of this system are encoded by the rpf cluster, with genes rpfF and rpfC encoding for the DSF synthase RpfF and sensor RpfC, respectively. Recently, we have shown that there exist two variants of the rpf cluster (rpf-1 and rpf-2), distinguishing two groups of S. maltophilia strains. Surprisingly, only rpf-1 strains produce detectable DSF, correlating with their ability to control biofilm formation, swarming motility and virulence. The evolutive advantage of acquiring two different rpf clusters, the phylogenetic time point and mechanism of this acquisition and the conditions that activate DSF production in rpf-2 strains, are however not known. Examination of this cluster in various species suggests that its variability originated most probably by genetic exchange between rhizosphere bacteria. We propose that rpf-2 variant strains make use of a strategy recently termed as "social cheating." Analysis of cellular and extracellular fatty acids (FAs) of strains E77 (rpf-1) and M30 (rpf-2) suggests that their RpfFs have also a thioesterase activity that facilitates the release of unspecific FAs to the medium in addition to DSF. Production of DSF in rpf-1 strains appears in fact to be modulated by some of these extracellular FAs in addition to other factors such as temperature and nutrients, while in rpf-2 strains DSF biosynthesis is derepressed only upon detection of DSF itself, suggesting that they require cohabitation with DSF-producer bacteria to activate their DSF regulatory machinery. Finally, we show that the mixed rpf-1/rpf-2 population presents synergism in DSF production and virulence capacity in an in vivo infection model. Recovery and quantification of DSF from co-infected animals correlates with the observed mortality rate

First-in-man Safety and Efficacy of the Adipose Graft Transposition Procedure (AGTP) in Patients With a Myocardial Scar

The present study evaluates the safety and efficacy of the Adipose Graft Transposition Procedure (AGTP) as a biological regenerative innovation for patients with a chronic myocardial scar. This prospective, randomized single-center controlled study included 10 patients with established chronic transmural myocardial scars. Candidates for myocardial revascularization were randomly allocated into two treatment groups. In the control arm (n = 5), the revascularizable area was treated with CABG and the non-revascularizable area was left untouched. Patients in the AGTP-treated arm (n = 5) were treated with CABG and the non-revascularizable area was covered by a biological adipose graft. The primary endpoint was the appearance of adverse effects derived from the procedure including hospital admissions and death, and 24-hour Holter monitoring arrhythmias at baseline, 1 week, and 3 and 12 months. Secondary endpoints of efficacy were assessed by cardiac MRI. No differences in safety were observed between groups in terms of clinical or arrhythmic events. On follow-up MRI testing, participants in the AGTP-treated arm showed a borderline smaller left ventricular end systolic volume (LVESV; p = 0.09) and necrosis ratio (p = 0.06) at 3 months but not at 12 months. The AGTP-treated patient with the largest necrotic area and most dilated chambers experienced a noted improvement in necrotic mass size (− 10.8%), and ventricular volumes (LVEDV: − 55.2 mL and LVESV: − 37.8 mL at one year follow-up) after inferior AGTP. Our results indicate that AGTP is safe and may be efficacious in selected patients. Further studies are needed to assess its clinical value. (ClinicalTrials.org , AdiFlap Trial). The Adipose Graft Transposition Procedure (AGTP) is a new surgical technique for reducing the scar after a heart attack. It has been evaluated in 10 patients for the first time and has been proved to be safe. This technique consists on the use of the existing fat surrounding the heart that has beneficial properties. The procedure is easy for the surgeons to perform. The next step will be to test the efficacy in a larger population

Ruptura traumática de la válvula mitral

Presentamos dos pacientes que sufrieron un accidente de tráfico con resultado de traumatismo de la válvula mitral. En el primer caso, al cuarto día del accidente, se diagnosticó insuficiencia mitral masiva por ruptura de la cabeza del músculo papilar anterolateral, con versión completa de los segmentos A1 y P1, procediéndose a reparación quirúrgica al mes del accidente, siendo la válvula mitral estructuralmente normal. En el segundo caso, el diagnóstico se hizo a los 10 días del accidente. Se trataba de una insuficiencia mitral grave por ruptura de cuerdas del velo posterior. La reparación quirúrgica se llevó a cabo a los 2 meses y medio del accidente. En este caso la válvula mitral era, además, degenerativa. En ambos casos la cirugía consistió en reparación valvular mitral. Se revisa la ruptura traumática de la válvula mitral

III Registro Nacional del Procedimiento de Ross en España (2004)

Tras más de 10 años desde las primeras aplicaciones de la operación de Ross en España describimos el grado de implantación y sus resultados. Métodos: Anualmente los centros nacionales que realizan esta intervención envían sus datos al coordinador. Analizamos morbimortalidad, disfunción de auto y homoinjerto, y necesidad de reintervención. Resultados: Desde febrero de 1991 hasta mayo de 2004 se han incluido 281 pacientes. La etiología más frecuente fue la congénita (166, 59,4%). La insuficiencia aórtica fue el tipo de lesión predominante (126, 44,83%). Nueve (3,2%) pacientes requirieron balón de contrapulsación intraaórtico. La mortalidad a 30 días fue del 3,2% (n = 7). El seguimiento está completo en el 98,2%, con una media de 46,08 ± 33,09 meses (rango 1–159), estando el 28,89% (n = 84) de los pacientes seguidos más de 4 años. Respecto al estatus del autoinjerto, el 82,91% (233) se encuentra sin insuficiencia, presentando 12 (4,27%) insuficiencia moderada y cuatro (1,42%) insuficiencia grave (96,73 ± 1,2% libres de reintervención). El homoinjerto se encuentra normofuncionante o con disfunción leve en 255 pacientes (90,74%), presentando siete (2,49%) estenosis grave. Cuatro (1,42%) pacientes han requerido alguna reintervención sobre el tracto de salida del ventrículo derecho. La supervivencia a 48 meses es de 96,3 ± 1,05%. Conclusiones: 1. El número de pacientes incluidos de forma anual tiende a mantenerse y crecer. 2. El número de centros implicados continúa en aumento pero la mayor actividad se concentra en un grupo reducido de centros. 3. La morbimortalidad inicial es baja. 4. El índice de disfunción del homo y/o autoinjerto es aceptable

Revascularización miocárdica con uso de doble arteria mamaria interna y morbilidad esternal. Experiencia de un centro

Introducción y objetivos: El empleo de doble mamaria se ha asociado con un aumento de complicaciones esternales, especialmente en pacientes diabéticos y obesos. El objetivo de este trabajo es revisar los factores de riesgo de aquellos pacientes en los que se ha usado doble mamaria y la tasa de complicación esternal en este grupo. Métodos: De nuestra base de datos se ha seleccionado a 526 pacientes revascularizados quirúrgicamente con uso de doble arteria mamaria. La edad media de los pacientes fue de 59 años, con un EuroScore logístico-1 medio de 2,7%. Resultados: Presentaron dehiscencia esternal 3 pacientes (0,57%), no se correlacionó con ningún factor de riesgo. Problemas de herida tanto superficial como profunda 31 pacientes (5.9%), (2 mediastinitis-0.38%). Con respecto a los pacientes que presentaron infección superficial de la herida quirúrgica (29 pacientes, 5,513%), se obtuvo mayor incidencia en mujeres, pacientes con insuficiencia renal y aquellos a los que se les realizó transfusión de concentrado de hematíes en quirófano, Siendo estas diferencias estadísticamente significativas (p < 0,05). También hubo mayor incidencia de infección superficial en pacientes diabéticos, enfermedad pulmonar obstructiva crónica, obesos, fumadores y a aquellos a los que se les realizó revascularización miocárdica incompleta, siendo estas diferencias no significativas. Conclusiones: En nuestra experiencia, la utilización de doble mamaria no se acompañó de mayor incidencia de dehiscencia esternal, pero si con problemas de infección superficial de la herida, sobre todo en el grupo de pacientes mujeres, con insuficiencia renal y transfundidos en quirófano. Para mantener el beneficio de la doble mamaria en estos pacientes, deberíamos ser especialmente cuidadosos e implementar nuevas estrategias de cierre esternal

Decoding the genetic and functional diversity of the DSF Quorum-Sensing system in Stenotrophomonas maltophilia

Stenotrophomonas maltophilia uses the Diffusible Signal Factor (DSF) quorum sensing (QS) system to mediate intra- and inter-specific signaling and regulate virulence-related processes. The components of this system are encoded by the rpf cluster, with genes rpfF and rpfC encoding for the DSF synthase RpfF and sensor RpfC, respectively. Recently, we have shown that there exist two variants of the rpf cluster (rpf-1 and rpf-2), distinguishing two groups of S. maltophilia strains. Surprisingly, only rpf-1 strains produce detectable DSF, correlating with their ability to control biofilm formation, swarming motility and virulence. The evolutive advantage of acquiring two different rpf clusters, the phylogenetic time point and mechanism of this acquisition and the conditions that activate DSF production in rpf-2 strains, are however not known. Examination of this cluster in various species suggests that its variability originated most probably by genetic exchange between rhizosphere bacteria. We propose that rpf-2 variant strains make use of a strategy recently termed as "social cheating." Analysis of cellular and extracellular fatty acids (FAs) of strains E77 (rpf-1) and M30 (rpf-2) suggests that their RpfFs have also a thioesterase activity that facilitates the release of unspecific FAs to the medium in addition to DSF. Production of DSF in rpf-1 strains appears in fact to be modulated by some of these extracellular FAs in addition to other factors such as temperature and nutrients, while in rpf-2 strains DSF biosynthesis is derepressed only upon detection of DSF itself, suggesting that they require cohabitation with DSF-producer bacteria to activate their DSF regulatory machinery. Finally, we show that the mixed rpf-1/rpf-2 population presents synergism in DSF production and virulence capacity in an in vivo infection model. Recovery and quantification of DSF from co-infected animals correlates with the observed mortality rate

Reparación valvular de la insuficiencia mitral degenerativa. Evolución clínica y ecocardiográfica según el grado de regurgitación residual intraoperatoria

Introduction and objectives: A successful mitral valve repair is considered when no or mild residual regurgitation is determined in the echocardiography after weaning from cardiopulmonary bypass. Little is known about the clinical and echocardiographic outcome, in the medium term, of the patients with mild residual regurgitation post‑repair. The aim of this study was to evaluate the clinical and echocardiographic outcome depending on the presence or absence of mild residual regurgitation after weaning from cardiopulmonary bypass Methods: A prospective study was conducted on patients with severe degenerative mitral regurgitation, who underwent mitral valve repair in our hospital during the period 2002‑2010