Francisco González

Phosphatase activities in the life cycle of Myxococcus coralloides D

SUMMARY: The effect of phosphate on the different stages of the life cycle of Myxococcus coralloides D has been examined. A high concentration of phosphate inhibited the process of fructification, but glycerol-induced myxospore formation and germination were independent of phosphate concentration. Acid and alkaline phosphatases were detected and both were released into liquid medium during the exponential growth phase. On solid medium, phosphatase activities showed different patterns according to the stage of the life cycle. The increase of these two activities was transient during glycerol-induced myxospore formation. Differences in phosphatase activities during germination of glycerol-induced myxospores and fruiting-body myxospores were found.

La extensión de la enfermedad coronaria determina la movilización de las células progenitoras endoteliales y las citocinas tras un primer infarto de miocardio con elevación del ST

INTRODUCTION AND OBJECTIVES Multivessel coronary disease is still a postinfarction prognostic marker despite new forms of reperfusion, such as primary angioplasty. The aim of this study was to determine the time sequence of various sets of endothelial progenitor cells and angiogenic cytokines (vascular endothelial growth factor, hepatocyte growth factor) according to the degree of extension of the postinfarction coronary disease. METHODS We studied the release kinetics in 32 patients admitted for a first myocardial infarction with ST elevation, grouped according to whether they had single or multivessel disease, and 26 controls. RESULTS The patients had a higher number of endothelial progenitor cells and angiogenic cytokines than the controls at all 3 measurements (admission, day 3, and day 7) of the following subsets: CD34, CD34+CD133+, CD34+KDR+, and CD34+CD133+KDR+CD45+(weak); this latter was higher on day 7. The levels of these cell subsets were all higher in the patients with single-vessel disease and at all 3 measurements. The vascular endothelial growth factor levels were raised during the first week and the hepatocyte growth factor showed an early peak on admission for infarction. No significant differences were seen in the cytokines according to coronary disease extension. CONCLUSIONS Although the release kinetics of different subsets of endothelial progenitor cells in patients with a first acute myocardial infarction with ST elevation was similar in those with single vessel disease to those with multivessel disease, the number of circulating endothelial progenitor cells was greater in the patients with single vessel disease. The vascular endothelial growth factor levels were raised during the first postinfarction week and the hepatocyte growth factor were higher on admission.

Influence of fibric acid derivatives on intermediate filament proteins in myocardiocyte cultures

We analyzed desmin and vimentin accumulation in chick myocardiocyte cultures treated with the fibric acid derivatives bezafibrate, fenofibrate and gemfibrozil. The most noteworthy finding was the 50% decrease in the cytoplasmic desmin fraction in cells treated with gemfibrozil in comparison to control cultures, and the 19% increase in the cytoskeletal fraction in cultures treated with gemfibrozil and with bezafibrate. Vimentin accumulation by cells treated with bezafibrate was similar to that in control cultures, however the cytoskeletal vimentin fraction rose by 26% after treatment with gemfibrozil, and fell 13% after treatment with fenofibrate. No vimentin was found in the cytoplasmic fraction of cell treated with bezafibrate. Given the role of intermediate filaments in heart muscle contraction, fibric acid derivative- induced changes in the cytoplasmic and cytoskeletal concentrations of intermediate filament proteins may be related with the secondary effects of these drugs on heart rate.

Polyphosphate glucokinase and ATP glucokinase activities in Mycococcus coralloides D

Polyphosphate glucokinase and ATP glucokinase were detected in cell-free extracts of Myxococcus coralloides strain D, but pyrophosphate glucokinase was not detected. Both glucokinase activities were separated by chromatography. The approximate molecular weight is 61 000 for polyphosphate glucokinase and 47 000 for ATP glucokinase. Substrate specificity and pH optimum was studied in the polyphosphate glucokinase. Polyphosphate and ATP glucokinase activities were verified by 13C Nuclear Magnetic Resonance.

Effect of phosphate on antibiotic and extracellular protein production by Myxococcus coralloides D

SummaryThe effect of inorganic phosphate concentrations on antibiotic and extracellular protein production by Myxococcus coralloides D have been examined. Antibiotic production by growing cells of this myxobacterium was maximal at phosphate concentrations of 10–20 mM, but was inhibited by concentrations higher than 20 mM. The total extracellular protein and the extracellular protein per cell ratio were independent of phosphate levels in the culture broth.

Factores que influyen en la liberación de células endoteliales progenitoras y citocinas angiogénicas tras un infarto de miocardio extenso

BACKGROUND AND OBJECTIVES Following an acute myocardial infarction (AMI), bone-marrow derived endothelial progenitor cells (EPC) are mobilised into the peripheral blood. Our aim was to examine the factors influencing this spontaneous cell mobilisation. PATIENTS AND METHODS In this study we analysed 47 patients with extensive AMI (left ventricular ejection fraction [LVEF] <50% by echocardiography during the first week post-AMI); we studied the peripheral blood EPC populations expressing CD133(+), CD34(+), KDR(+), CXCR4(+), as well as the cytokines VEGF (vascular endothelial growth factor), SDF-1 (stromal cell-derived factor 1) and TSP-1 (thrombospondin 1), measured on day 5±2.5 after AMI. RESULTS The extension of AMI (CPK peak) correlated with the number of CD133(+) mobilised cells: (r=0.40; P=.011). Patients who did not receive perfusion during the acute phase (34%) had more CD34(+)CXCR4(+) cells with a median (interquartile ranges) of 2,401 (498-7,004) vs. 999 (100-1,600), P=.048, and strong correlations between VEGF and CD133(+)CD34(+)KDR(+) (r=.84; P<.01) and SDF-1 and CD34(+)CXCR4(+) (r=.67; P<.01), and between these 2 cytokines (r=.57; P=.01). In the reperfused patients, the correlation between VEGF and CD133(+)CD34(+)KDR(+) was lower (r=.38; P=.03) and the correlation between SDF-1 and CD34(+)CXCR4(+) and VEGF disappeared. Multivariate analysis showed that a VEGF >7pg/mL (P<.01) predicted the mobilisation of CD133(+)CD34(+)KDR(+), whereas hypertension showed a trend (P=.055). Diabetes (P=.045) predicted the number of CD34(+)CXCR4(+), with reperfusion treatment showing a trend in this subpopulation (P=.054). CONCLUSIONS Mobilisation of progenitor cells after AMI is influenced by factors such as diabetes and the cytokine VEGF. Hypertension and reperfusion therapy during the acute phase also tend to influence the cell response.

Diverticulopexia asociada a miotomía del cricofaríngeo en el tratamiento del divertículo de Zenker. Presentación de 21 casos

Resumen Introduccion El diverticulo de Zenker consiste en la herniacion de la mucosa esofagica a traves del triangulo de Killian. En la actualidad persiste la controversia sobre que tecnica quirurgica se debe realizar en el tratamiento del diverticulo de Zenker, la diverticulopexia o la diverticulectomia y si es necesario o no asociar una miotomia del cricofaringeo. El objetivo de este trabajo es analizar de forma retrospectiva los resultados clinicos y radiologicos obtenidos en un grupo de 21 pacientes intervenidos por diverticulo de Zenker. Pacientes y metodos Entre 1985 y 2001, 21 pacientes diagnosticados de diverticulo de Zenker fueron intervenidos en nuestro servicio de cirugia, se realizo una miotomia del cricofaringeo en todos ellos, y se asocio una diverticulopexia en 19 casos y una diverticulectomia en otro paciente. Resultados El diagnostico se realizo, en todos los casos, amediante transito esofagico baritado, que mostro la presencia del diverticulo con un tamano mediano de 4 cm. El estudio manometrico se realizo en 14 pacientes, se aprecio una asinergia faringoesfinteriana en 3 casos, y el estudio cricofaringeo fue normal en el resto. Ademas, se objetivaron cuatro casos de trastorno motor esofagico primario. Tras la intervencion quirurgica, ningun paciente fallecio a consecuencia de la misma, y presentaron complicaciones 4 pacientes. Tras una mediana de seguimiento de 5,5 anos (rango, 1-16), los resultados clinicos fueron excelentes en 19 pacientes y buenos en 2. Desde el punto de vista radiologico, no se observo ningun caso de recidiva del diverticulo, ni de malignizacion del saco herniario. Conclusiones Segun nuestra experiencia, la diverticulopexia asociada a la miotomia del cricofaringeo es una buena opcion quirurgica en el tratamiento del diverticulo de Zenker.

Production of acid and alkaline phosphatases by Myxococcus coralloides.

Acid and alkaline phosphatase ofMyxococcus coralloides were examined during vegetative growth in a liquid medium. Two extracellular phosphatases and two cell-bound phosphatases, acid and alkaline in both cases, were produced. The phosphatase production was unaltered by the presence of high concentrations of inorganic phosphate. Both enzymes were produced constitutively. These two hydrolases were released into the growth medium during the exponential growth phase (approximately 10% of total activity). The production of these enzymes was modified by the presence of organic acids and metal ions in the medium.

Changes in tropomyosin during primary culture of embryonic myocardiocytes

We chose the Hamburger and Hamiltons stage 29 (HH 29) to investigate the expression of tropomyosin in chick myocardiocytes during 14 days on culture. Throughout 14 days of cell culture, changes in cell morphology were accompanied by a redistribution of tropomyosin in different cell compartments. We used FACScan, SDS-PAGE and densitometric analysis to quantify total cell tropomyosin and concentrations of this protein in different cell fractions. Tropomyosin was found mostly in the cytoskeletal fraction than in the cytoplasmic. When we compared the densitometric values from SDS-PAGE of cells in different stages of development we found that in HH 19, tropomyosin was more abundant in the cytoplasmic than in the cytoskeletal fraction. By HH 29, the two fractions had become inverted, and in HH 39, tropomyosin was clearly more abundant in the cytoskeletal than in the cytoplasmic fraction. In the IFI analysis, tropomyosin was found to label the Stress fiber-like structures (SFL) in different patterns depending on the area of the cell which expressed this protein.

Estudio clínico e inmunólogico del xenorrechazo en el xenotrasplante ortotópico de hígado de cerdo a babuino

Resumen Introduccion La experiencia de xenotrasplante hepatico (Xtoh) de cerdo a primate no humano es muy limitada. Nuestros objetivos han sido: a) comprobar si el higado de un cerdo transgenico h-DAF evita el rechazo hiperagudo; b) estudiar las funciones metabolicas del higado porcino tras el Xtoh; y c) analizar el perfil clinico, bioquimico e inmunologico del rechazo vascular agudo retardado. Animales y metodos Se realizaron 6 Xtoh de cerdo a babuino, 4 de cerdos no modificados y dos de cerdos transgenicos para h-DAF. Se llevaron a cabo determinaciones hematologicas, de coagulacion, de xenoanticuerpos y del complemento. En el babuino que sobrevivio 8 dias, se estudiaron durante los mismos las poblaciones linfocitarias y la actividad litica de los linfocitos. Resultados Los valores de xIgG e IgM descendieron drasticamente a los 3 min de la reperfusion, sobre todo del CH50, C3 y C4. En los higados no modificados geneticamente aparecio una coagulacion intravascular diseminada por rechazo hiperagudo, con una supervivencia inferior a 12 h. Con los higados h-DAF, la coagulacion se normalizo, con una supervivencia de 8 y 4 dias, falleciendo ambos por insuficiencia respiratoria, sin rechazo hiperagudo. El babuino que sobrevivio 8 dias presento a las 36 h un rechazo vascular agudo retardado, detectandose una estimulacion de las HLA clase I sobre los linfocitos CD3+ y CD19+, que respondio al tratamiento. Conclusiones El higado transgenico h-DAAF previene el rechazo hiperagudo y mantiene la coagulacion en rangos normales en el babuino. El rechazo vascular agudo provoca el cese en la produccion de bilis y un patron mixto de citolisis y colostasis. Los valores de expresion de HLA clase I en los linfocitos podrian ser utiles para diagnosticarlo.