RESUMEN
A cDNA clone has been obtained for a low-abundance, seed-specific mRNA that encodes a polypeptide which defines a novel family of plant proteins with some similarities to the DnaJ class of molecular chaperones. The MEM1 (Maize Endosperm Motif binding protein) protein is capable of binding to the endosperm motif and activating transcription in the yeast one-hybrid system. Recombinant MEM1 was shown to bind in vitro to nucleic acids, with a preference for RNA over DNA. MEM1 is capable of forming homodimers, a property that is dependent on a domain close to the C-terminus of the protein. The protein is expressed in mid- to late-term endosperm cells. Subcellular fractionation and size fractionation under non-denaturing conditions indicate that the protein is present in the cytosol of endosperm cells. Possible roles of MEM1 in endosperm and protein body development are discussed.
Asunto(s)
ARN Mensajero/genética , Proteínas de Unión al ARN/genética , Semillas/genética , Zea mays/genética , Secuencia de Aminoácidos , Secuencia de Bases , ADN Complementario/química , ADN Complementario/genética , Regulación de la Expresión Génica de las Plantas , Datos de Secuencia Molecular , Proteínas de Plantas/genética , Unión Proteica , ARN Mensajero/metabolismo , ARN de Planta/genética , ARN de Planta/metabolismo , Proteínas de Unión al ARN/metabolismo , Alineación de Secuencia , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Distribución Tisular , Transcripción Genética , Zeína/genéticaRESUMEN
The applicability of the laminar flamelet concept for the formation and destruction of nitric oxides in laminar and turbulent diffusion flames has been studied. In a first step, temperatures and species concentrations in an axisymmetric laminar diffusion flame have been calculated (i) by solving the detailed conservation equations and (ii) by applying the laminar flamelet concept. The main purpose of this step was the identification of differences between results from both approaches. It turned out that for highly temperature sensitive or relatively slow chemical processes, the inclusion of the full range of the prevailing scalar dissipation rates plays a major role for the calculated species concentrations. This behavior is obvious from the concept of the laminar flamelet model, where the scalar dissipation rate can be discussed in terms of the reciprocal of a residence time for attaining chemical equilibrium. In a second step, flamelet modeling of NOx formation was extended to a turbulent hydrogen diffusion flame. In both the steps, the flow fields of the flames were calculated by solving the Navier-Stokes equations in axisymmetric formulation using the SIMPLER algorithm. For the turbulent flow, Favre-averaged equations have been used and turbulence was modeled with the standard k-epsilon model including a correction term for axisymmetric systems. The averaging of the species concentrations was accomplished with presumed shape probability density functions (pdfs). The pdf of the mixture fraction was described with a beta-function whereas that of the scalar dissipation rate was assumed to be log-normal. Buoyancy effects have been taken into account. The calculated temperatures and concentrations were compared with data from different experiments.
RESUMEN
To assess whether or not liver transplantation and subsequent immunosuppression with cyclosporine and prednisone affect ulcerative colitis symptomatology, we surveyed by questionnaire all 23 surviving patients with pretransplant colonoscopy-documented ulcerative colitis who were transplanted for primary sclerosing cholangitis between June 1982 and September 1985. At follow-up [89.8 +/- 7.6 weeks (mean +/- SEM], all six patients who had had asymptomatic colonoscopy-documented ulcerative colitis reported continued ulcerative colitis quiescence. Among the 17 patients who had had symptomatic colonoscopy-documented ulcerative colitis at time of liver transplantation, 88.2% reported improvement in overall ulcerative colitis severity (P less than 0.001), with significant improvement in the frequency of bowel movements reported by 100%, in crampy abdominal pain by 87.5%, in bowel urgency by 75%, in the occurrence of pus or mucus in stool by 87.5%, in the incidence of ulcerative colitis flares by 81.8%, and in the number of days unable to function normally due to ulcerative colitis symptoms by 78.6% (all at least P less than 0.01). These data demonstrate that ulcerative colitis symptom severity significantly improves following liver transplantation with immunosuppression with cyclosporine and prednisone.
Asunto(s)
Colangitis Esclerosante/cirugía , Colitis Ulcerosa/prevención & control , Terapia de Inmunosupresión , Trasplante de Hígado , Adulto , Colitis Ulcerosa/epidemiología , Colitis Ulcerosa/psicología , Ciclosporinas/uso terapéutico , Femenino , Estudios de Seguimiento , Humanos , Masculino , Prednisona/uso terapéutico , Encuestas y CuestionariosRESUMEN
1,1,1-trichloroethane is a halogenated hydrocarbon solvent commonly used in industry because of its supposed lack of hepatotoxicity. Nonetheless, animal studies performed by several independent groups have shown the solvent to induce fat deposition, vacuolar degeneration, and centrilobular necrosis, changes similar to those seen after exposure to carbon tetrachloride, albeit of a much reduced magnitude, in animals exposed to the agent. Four patients with fatty liver disease whose work entailed substantial exposure to this agent were seen at the University of Pittsburgh (Pa). Based on this clinical experience, we believe that 1,1,1-trichloroethane should be reconsidered as an agent with potential hepatotoxicity in man.
Asunto(s)
Hígado Graso/inducido químicamente , Hidrocarburos Clorados/efectos adversos , Enfermedades Profesionales/inducido químicamente , Solventes/efectos adversos , Tricloroetanos/efectos adversos , Adulto , Exposición a Riesgos Ambientales , Humanos , Cirrosis Hepática/inducido químicamente , Masculino , Persona de Mediana EdadRESUMEN
Postoperative chylous ascites is a rare complication of aortic surgery. Two patients are presented with postoperative chylous ascites after abdominal aortic surgery. The value of either conservative management or an operative approach or peritoneo-venous shunting is discussed.
Asunto(s)
Ascitis Quilosa/terapia , Complicaciones Posoperatorias/terapia , Aorta Abdominal/cirugía , Ascitis Quilosa/etiología , Humanos , Masculino , Persona de Mediana EdadRESUMEN
The specific role of patient coordinator varies among different transplantation centers. Their role is often dependent upon the total number of patients that are being followed at a given center. With continued success of a program and continued patient survival, the functions of the patient coordinator will increase. However, the coordinator's primary mission will remain principally that of patient educator and liaison with the transplant center.
Asunto(s)
Trasplante de Hígado , Planificación de Atención al Paciente/organización & administración , Adulto , Niño , Familia , Humanos , Relaciones Interprofesionales , Grupo de Atención al Paciente , Educación del Paciente como Asunto/métodosRESUMEN
The effect of two different H2-receptor antagonists, nizatidine and cimetidine, on sperm counts and hypothalamic-pituitary-gonadal function as determined by responses to provocative gonadotropin releasing factor, GnRH, thyrotropin releasing factor, TRH, and clomiphene were compared to those of men receiving placebo medication. All subjects studied gave informed written consent and were greater than 18 but less than 55 years of age. Sperm concentrations in collected semen specimens, and GnRH and TRH responses before and after 6 weeks of drug exposure were assessed as were the gonadotropin responses to clomiphene while on the drug for an additional 3 weeks. All had normal sperm concentrations and hormone levels before drug exposure and normal responses to both GnRH and TRH. Following drug exposure, the LH response to GnRH and the growth hormone, prolactin, TSH and T4 responses to TRH were similar to those obtained prior to drug use. Sperm concentrations were unchanged in both placebo and nizatidine exposed men, but were significantly reduced (p less than 0.05) in the cimetidine exposed men. Based on these data, nizatidine does not appear to influence hormone function or fertility.
Asunto(s)
Cimetidina/farmacología , Antagonistas de los Receptores H2 de la Histamina/farmacología , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Testículo/efectos de los fármacos , Tiazoles/farmacología , Adolescente , Adulto , Humanos , Masculino , Nizatidina , Hormonas Adenohipofisarias/sangre , Recuento de Espermatozoides/efectos de los fármacos , Testosterona/sangre , Tiroxina/sangreRESUMEN
Ultrasonography and computed tomography were used to determine hepatic volume in vivo. The data obtained were compared with the weight and volume of the same livers after surgical removal at the time of orthotopic hepatic transplantation. The relationship between hepatic weight and volume was found to be linear over a 16-fold range of weights and a 19-fold range of volumes. The sonographic results more closely paralleled the results obtained directly. These data demonstrate that both methods can determine, within acceptable limits, hepatic volume or weight. The sonographic technique, however, is more accurate than the computed tomography scan method as it allows the use of sagittal scanning of the liver, which is superior to the transverse scanning technique required by the computed tomography scanner. In addition, these results demonstrate that these methods might be applied in the future for better matching of donors and recipients of orthotopic liver transplants.