Comparison between one and three doses a week of recombinant erythropoietin in very low birth weight infants.

OBJECTIVE: To compare transfusion requirements and erythropoietic response in preterms between schedules of rEPO administration once or three times per week, using the same weekly dose. STUDY DESIGN: Prospective, randomized trial including infants weighing <1500 g at birth and/or were 32 weeks' gestation: Group 1 (60 infants) received subcutaneous rEPO at 250 units kg(-1) per dose, three times weekly for 6 weeks; Group 2 (59 infants), at 750 units kg(-1) per dose, once weekly for 6 weeks. Efficacy was evaluated based on the transfusion requirement, hemoglobin changes, reticulocyte counts, serum transferrin receptor (sTfR) and serum ferritin. The frequency of adverse effects was registered in both groups. RESULT: A total of 13 infants were transfused in each group (relative risk: 0.98; 95% confidence interval: 0.4 to 2.3). Phlebotomy loss and red blood cell transfusion volumes received were similar in both groups. Hemoglobin levels were lower at end of study in Group 2 (10.6±1.5 g dl(-1) versus 11.5±1.4 g dl(-1); P<0.003). At end of study, reticulocyte counts and sTfR values increased and serum ferritin values decreased, without significant differences between the two groups. Incidence of complications was similar in both groups. CONCLUSION: The once-weekly rEPO schedule for very low birth weight infants proved as effective as the three-times-weekly schedule, in relation to erythropoietic stimulus and transfusion requirement.

Microsurgical extrahepatic cholestasis in the rat: a long-term study.

An experimental model of microsurgical cholestasis is studied as an alternative to the most frequently used surgical techniques, based on the section of the common bile duct. This microsurgical technique consists of the resection of the extrahepatic biliary tract, that is, of the common bile duct in continuity with the bile ducts that drain the four lobes of the rat liver. At 30 days of evolution, rats with microsurgical cholestasis do not develop biliary pseudocysts or intraperitoneal hilar hepatopulmonary abscesses and show an increase (p < 0.001) in total bilirubin (9.50 +/- 1.50 mg/dL vs. 1.60 +/- 0.35 mg/dL), bile acids (225 +/- 87 micromol/L vs. 12.5 +/- 14.50 micromol/L), gamma-glutamyltranspeptidase (375 +/- 143 U/L vs. 8 +/- 11 U/L), and alkaline phosphatase (73 +/- 25 U/L vs. 23 +/- 4 U/L) levels. The histological study shows fibrosis with biliary proliferation. The microsurgical cholestasis technique is a valid alternative to other techniques and can be an adequate experimental model for the study of etiopathogenic mechanisms of obstructive jaundice and especially to study extrahepatic biliary atresia.

Resistencia insulínica en niños y adolescentes obesos

Objetivos. Valorar la resistencia insulínica en niños y adolescentes obesos, analizar las variables relacionadas con ella y comprobar si la acantosis nigricans es un buen marcador de la misma. Pacientes y métodos. Estudio prospectivo de los niños de 7 a 15 años que consultaron por sobrepeso y presentaban un índice de masa corporal (IMC) mayor del percentil 97 para su edad y sexo. Se excluyeron los que presentaban alguna alteración del metabolismo hidrocarbonado. Se utilizó como control un grupo de 50 niños sanos con IMC normal. Se recogieron variables clínicas (antecedentes familiares de diabetes tipo 2, edad, sexo, situación puberal, IMC, presencia de acantosis nigricans (AN), presión arterial e índice cintura-cadera). Se determinaron en ayunas glucemia, insulinemia, triglicéridos, colesterol (total, HDL y LDL) y ácido úrico. Se calculó el índice "HOMA" y se definió Resistencia Insulínica cuando su valor era superior a 3,8. Los resultados se expresan como media (desviación estándar). Resultados. Se incluyeron en el estudio 67 sujetos (32 varones) de 6,8 a 15,0 años de edad (media 11,6), 29 púberes y 38 prepúberes. Al comparar con el grupo control, los obesos presentaron niveles signicativamente más altos de glucemia (94,5 (7,7) frente a 73,8 (3,1) mg/dl), insulinemia (26,7 (15,7) frente a 12,0 (1,7) mU/l), HOMA (6,1 (3,7) frente a 2,5 (1,6)) y triglicéridos (107,9 (47,4) frente a 65,2 (27,4) mg/dl) y más bajos de HDL-colesterol (47,0 (10,0) frente a 65,1 (15,9) mg/dl). 44/67 niños (65,7 por ciento) presentaban Resistencia Insulínica, siendo más frecuente en individuos púberes (26/29 insulin resistentes, frente a 18/38 en los prepúberes) (p= 0,01). Los individuos insulin resistentes presentaban un colesterol HDL más bajo que los insulín sensibles (44 (12) frente a 53 (13) mg/dl) (p= 0,03). De los 34 pacientes que presentaban AN, 9 eran insulín sensibles y 19 que no la presentaban eran insulín resistentes. Conclusiones. En los niños y adolescentes obesos la Resistencia Insulínica es muy frecuente, incluso antes del inicio de la pubertad. Su frecuencia aumenta en individuos púberes y en aquellos con niveles bajos de colesterol HDL. La acantosis nigricans no es un buen marcador de Resistencia Insulínica (AU)

Tendinitis del supraespinoso / M. supraspinosus tendinitis

Las características peculiares de la cintura escapular hacen que la articulación del hombro muestre una tendencia aumentada a la tendinitis por roce. Presentamos un caso de tendinitis del músculo supraespinoso, con discusión del diagnóstico por imagen, del tratamiento y del curso postoperatorio (AU)

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Medicina de familia: ¿la cenicienta del pregrado? Estudio de la opinión de los estudiantes de medicina sobre la especialidad de medicina familiar y comunitaria / Family medicine: the cinderella of undergraduate studies? Study of the views of medical students about the speciality of family and community medicine

Objetivo. Conocer la opinión de los estudiantes del último curso de medicina (EM) sobre la especialidad de medicina familiar y comunitaria (MFyC).Diseño. Estudio transversal mediante cuestionario autoadministrado. Emplazamiento. Facultades de medicina de las Universidades de Oviedo y Cantabria. Participantes. EM de sexto curso y con posibilidades de finalizar su licenciatura el año 2000.Intervenciones. Cuestionario de 22 preguntas de elección múltiple, incluyendo valoración sobre formación pregrado en MFyC y opinión sobre su inclusión como asignatura, elección de la especialidad en el próximo examen MIR, prestigio de la MFyC, selección de profesional para tratar patologías comunes en atención primaria y conocimiento de una actividad (gestión de incapacidad temporal) del médico de familia (MF).Resultados principales. De los 94 EM encuestados, un 73 por ciento no había tenido formación teórica en MFyC, pero un 89 por ciento sería partidario de incluirla en el programa de la licenciatura. Un 6 por ciento desearía ejercer como MF. Un 77 por ciento creía que el prestigio de la MFyC era equiparable a otras especialidades y el resto que era inferior, aunque aumentaría para la mitad de éstos si el MIR de MFyC durara 4 años. Un 50 por ciento no elegiría al MF para tratar patologías comunes en atención primaria de salud. Un 55 por ciento identificaba al MF como el profesional capacitado para dar la baja por enfermedad común. Conclusiones. La falta de formación en MFyC en el pregrado se perfila como la causa del desinterés, desprestigio y desconocimiento de esta especialidad entre los EM (AU)

Mutations in each of the tol genes of Pseudomonas putida reveal that they are critical for maintenance of outer membrane stability.

The outer membrane of gram-negative bacteria functions as a permeability barrier that protects cells against a large number of antibacterial agents. OprL protein of Pseudomonas putida has been shown to be crucial to maintain the stability of this cell component (J. J. Rodríguez-Herva, M.-I. Ramos-González, and J. L. Ramos. J. Bacteriol. 178:1699-1706, 1996). In the present study we cloned and mutagenized the orf1, tolQ, tolR, tolA, and tolB genes from P. putida KT2440, which were located upstream of the oprL gene. Polar and nonpolar mutations of the P. putida tolQ, tolR, tolA, and tolB genes were generated in vitro by using the omega-Km(r) interposon, which carries two transcriptional stop signals, or a promoterless xylE cassette, lacking any transcriptional stop signal, respectively. The mutant constructs were used to inactivate, by reverse genetics procedures, the corresponding chromosomal copies of the genes. The phenotype of each mutant strain was analyzed and compared with those of the wild-type strain and the previously characterized P. putida oprL::xylE mutant. All mutant strains exhibited a similar phenotype: altered cell morphology, bleb formation at the cell surface, release of periplasmic and outer membrane proteins to the extracellular medium, increased sensitivity to a variety of compounds (i.e., EDTA, sodium dodecyl sulfate, deoxycholate, and some antibiotics), filament formation, and severely reduced cell motility. Altogether, these results demonstrate the importance of the Tol-OprL system for the maintenance of outer membrane integrity in P. putida and suggest a possible role of these proteins in assembling outer membrane components.

The interaction of coenzyme Q with phosphatidylethanolamine membranes.

Coenzyme Q (CoQ) is a component of the mitochondrial respiratory chain which carries out additional membrane functions, such as acting as an antioxidant. The location of CoQ in the membrane and the interaction with the phospholipid bilayer is still a subject of debate. The interaction of CoQ in the oxidized (ubiquinone-10) and reduced (ubiquinol-10) state with membrane model systems of 1,2-dielaidoyl-sn-glycero-3-phosphoethanolamine (Ela2Gro-P-Etn) has been studied by means of differential scanning calorimetry (DSC), 31P-nuclear magnetic resonance (31P-NMR) and small angle X-ray diffraction (SAXD). Ubiquinone-10 did not visibly affect the lamellar gel to lamellar liquid-crystalline phase transition of Ela2Gro-P-Etn, but it clearly perturbed the multicomponent lamellar liquid-crystalline to lamellar gel phase transition of the phospholipid. The perturbation of both transitions was more effective in the presence of ubiquinol-10. A location of CoQ forming head to head aggregates in the center of the Ela2Gro-P-Etn bilayer with the polar rings protruding toward the phospholipid acyl chains is suggested. The formation of such aggregates are compatible with the strong hexagonal HII phase promotion ability found for CoQ. This ability was evidenced by the shifting of the lamellar to hexagonal HII phase transition to lower temperatures and by the appearance of the characteristic hexagonal HII 31P-NMR resonance and SAXD pattern at temperatures at which the pure Ela2Gro-P-Etn is still organized in extended bilayer structures. The influence of CoQ on the thermotropic properties and phase behavior of Ela2Gro-P-Etn is discussed in relation to the role of CoQ in the membrane.