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1.
Arch. Soc. Esp. Oftalmol ; 92(3): 120-127, mar. 2017. tab, graf
Artículo en Español | IBECS | ID: ibc-160962

RESUMEN

OBJETIVO: Conocer el porcentaje de recuperación funcional, según estrategia pro re nata (PRN) con inyecciones intravítreas con ranibizumab en pacientes con degeneración macular asociada a la edad (DMAE). MATERIAL Y MÉTODOS: Estudio observacional, retrospectivo, unicéntrico. Se incluyó a pacientes con DMAE tratados con ranibizumab según estrategia PRN y seguimiento mínimo de 18 meses. Se recogieron variables sociodemográficas y clínicas de la historia clínica. El porcentaje de recuperación de agudeza visual (AV) después de perder 5 o más letras fue calculado considerando la AV del mes anterior, así como la mejor AV previa al retratamiento. RESULTADOS: Se analizó a 128 pacientes. La media (DE) de seguimiento fue de 18,9 (2,3) meses; la media (DE) entre los primeros síntomas y el diagnóstico y entre la prescripción e inicio de tratamiento fue de 50,2 (57,4) y 10,9 (16,0) días, respectivamente. Ranibizumab solo fue prescrito en 108 pacientes tras una pérdida de 5 o más letras de AV. La media (DE) de recuperación de AV al considerar la AV de la última visita fue 70,3% (114,4). La media (DE) de recuperación de AV considerando la mejor AV antes del retratamiento fue de 43,5 (112,9), con un 59,4% de retratamientos que presentaron una recuperación de AV inferior al 75%, mientras que el 11,7% no presentaron recuperación de la AV. CONCLUSIONES: Una estrategia PRN con inyecciones intravítreas de ranibizumab podría no ser lo suficientemente efectiva en términos de mantenimiento o recuperación de AV en los casos de DMAE a largo plazo, debido a la pérdida irreversible de AV


OBJECTIVE: To analyse the functional recovery using a pro re nata (PRN) dosing strategy with intravitreal injections of ranibizumab for patients with neovascular age-related macular degeneration (AMD). MATERIAL AND METHODS: An observational, retrospective, single-centre study, was conducted on patients with neovascular AMD managed with a PRN strategy with ranibizumab, and were followed-up for a minimum of 18 months. Sociodemographic and clinical data were collected from medical records. The percentage of visual acuity (VA) recovered after losing 5 or more letters was calculated taking into account the previous visit, as well as considering the best VA recorded prior to the retreament. RESULTS: The analysis included 128 patients. The mean (SD) follow-up period was 18.9 (2.3) months. The mean (SD) elapsed days between onset of symptoms and diagnosis, and between prescription and administration of treatment was 50.2 (57.4) and 10.9 (16.0), respectively. Only 108 patients were prescribed ranibizumab after losing 5 or more letters of VA. The mean (SD) VA recovery compared to the previous VA was 70.3% (114.4). On the other hand, the mean (SD) VA recovery when considering the best VA registered before the retreatment was 43.5% (112.9), with 59.4% of re-treatments having a VA recovery below 75%, and with 11.7% not presenting any VA recovery. CONCLUSIONS: A PRN dosing strategy with intravitreal ranibizumab for neovascular AMD may not be efficient in preserving and/or recovering VA in the long-term, due to a cumulative irreversible VA loss


Asunto(s)
Humanos , Masculino , Femenino , Ranibizumab/uso terapéutico , Degeneración Macular Húmeda/complicaciones , Degeneración Macular Húmeda/diagnóstico , Degeneración Macular Húmeda/tratamiento farmacológico , Agudeza Visual , Agudeza Visual/fisiología , Retratamiento/métodos , Retratamiento/tendencias , Estudios Retrospectivos
2.
Arch Soc Esp Oftalmol ; 92(3): 120-127, 2017 Mar.
Artículo en Inglés, Español | MEDLINE | ID: mdl-27751585

RESUMEN

OBJECTIVE: To analyse the functional recovery using a pro re nata (PRN) dosing strategy with intravitreal injections of ranibizumab for patients with neovascular age-related macular degeneration (AMD). MATERIAL AND METHODS: An observational, retrospective, single-centre study, was conducted on patients with neovascular AMD managed with a PRN strategy with ranibizumab, and were followed-up for a minimum of 18 months. Sociodemographic and clinical data were collected from medical records. The percentage of visual acuity (VA) recovered after losing 5 or more letters was calculated taking into account the previous visit, as well as considering the best VA recorded prior to the retreament. RESULTS: The analysis included 128 patients. The mean (SD) follow-up period was 18.9 (2.3) months. The mean (SD) elapsed days between onset of symptoms and diagnosis, and between prescription and administration of treatment was 50.2 (57.4) and 10.9 (16.0), respectively. Only 108 patients were prescribed ranibizumab after losing 5 or more letters of VA. The mean (SD) VA recovery compared to the previous VA was 70.3% (114.4). On the other hand, the mean (SD) VA recovery when considering the best VA registered before the retreatment was 43.5% (112.9), with 59.4% of re-treatments having a VA recovery below 75%, and with 11.7% not presenting any VA recovery. CONCLUSIONS: A PRN dosing strategy with intravitreal ranibizumab for neovascular AMD may not be efficient in preserving and/or recovering VA in the long-term, due to a cumulative irreversible VA loss.


Asunto(s)
Inhibidores de la Angiogénesis/uso terapéutico , Neovascularización Coroidal/tratamiento farmacológico , Ranibizumab/uso terapéutico , Degeneración Macular Húmeda/complicaciones , Anciano , Inhibidores de la Angiogénesis/administración & dosificación , Neovascularización Coroidal/etiología , Neovascularización Coroidal/patología , Esquema de Medicación , Femenino , Estudios de Seguimiento , Humanos , Inyecciones Intravítreas , Masculino , Pacientes Desistentes del Tratamiento , Ranibizumab/administración & dosificación , Estudios Retrospectivos , Agudeza Visual
3.
Cell Death Differ ; 22(7): 1144-57, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25501596

RESUMEN

Erythropoiesis is a tightly regulated process in which multipotential hematopoietic stem cells produce mature red blood cells. Here we show that deletion of poly(ADP-ribose) polymerase-2 (PARP-2) in mice leads to chronic anemia at steady state, despite increased erythropoietin plasma levels, a phenomenon not observed in mice lacking PARP-1. Loss of PARP-2 causes shortened lifespan of erythrocytes and impaired differentiation of erythroid progenitors. In erythroblasts, PARP-2 deficiency triggers replicative stress, as indicated by the presence of micronuclei, the accumulation of γ-H2AX (phospho-histone H2AX) in S-phase cells and constitutive CHK1 and replication protein A phosphorylation. Transcriptome analyses revealed the activation of the p53-dependent DNA-damage response pathways in PARP-2-deficient cells, culminating in the upregulation of cell-cycle and cell death regulators, concomitant with G2/M arrest and apoptosis. Strikingly, while loss of the proapoptotic p53 target gene Puma restored hematocrit levels in the PARP-2-deficient mice, loss of the cell-cycle regulator and CDK inhibitor p21 leads to perinatal death by exacerbating impaired fetal liver erythropoiesis in PARP-2-deficient embryos. Although the anemia displayed by PARP-2-deficient mice is compatible with life, mice die rapidly when exposed to stress-induced enhanced hemolysis. Our results pinpoint an essential role for PARP-2 in erythropoiesis by limiting replicative stress that becomes essential in the absence of p21 and in the context of enhanced hemolysis, highlighting the potential effect that might arise from the design and use of PARP inhibitors that specifically inactivate PARP proteins.


Asunto(s)
Replicación del ADN , Células Precursoras Eritroides/metabolismo , Eritropoyesis/fisiología , Poli(ADP-Ribosa) Polimerasas/genética , Estrés Fisiológico/genética , Animales , Apoptosis , Eritropoyesis/genética , Puntos de Control de la Fase G2 del Ciclo Celular , Eliminación de Gen , Histonas/metabolismo , Ratones
4.
Rev. neurol. (Ed. impr.) ; 53(10): 577-583, 16 nov., 2011. ilus
Artículo en Español | IBECS | ID: ibc-92038

RESUMEN

Introducción. Estudios recientes han demostrado la necesidad de optimizar el manejo de los pacientes tras un primer brote sugerente de esclerosis múltiple (EM). Nuestro objetivo es comprobar si los resultados de seguimiento de estos estudios son reproducibles en un contexto multicéntrico español. Pacientes y métodos. El estudio PREM (estudio multicéntrico español prospectivo observacional a 24 meses) incluyó a pacientes en los tres primeros meses tras un primer brote sugerente de EM con al menos dos lesiones típicas en una resonancia magnética. Se obtuvo la Expanded Disability Status Scale (EDSS) y se valoró la presencia de brotes basalmente y a los 3, 6, 9, 12, 18 y 24 meses; se realizó una resonancia magnética basalmente y a los 6 y 24 meses, para el cálculo del volumen cerebral y de volúmenes lesionales (T1, T2 y T1 tras la administración de gadolinio). Se valoraron los criterios de McDonald y Poser durante el seguimiento. Un subgrupo de pacientes fue seguido hasta completar cuatro años. Resultados. Se incluyó a 110 pacientes (un 67% mujeres) de edad media de 30,2 años; 22 pacientes abandonaron prematuramente el estudio. Un 19% y un 45% de pacientes cumplían criterios de Poser a los 6 meses y 24 meses, respectivamente; un 63% y un 71% en el caso de los criterios de McDonald. La EDSS descendió signifi cativamente (–0,94; p < 0,001) y se observó desarrollo de atrofi a (–1,2%; p < 0,001) a los 24 meses. Conclusión. Los resultados de seguimiento de pacientes con primeros brotes sugerentes de EM en un contexto multicéntrico español son superponibles a los de los ensayos clínicos internacionales realizados en estos pacientes (AU)


Introduction. Recent studies have shown the need to optimise the management of patients after a fi rst attack suggestive of multiple sclerosis (MS). Our aim is to determine whether the results from follow-ups in these studies are reproducible within a Spanish multi-centre context. Patients and methods. The PREM study (observational prospective Spanish multi-centre study at 24 months) included patients in the fi rst three months following a fi rst event suggestive of MS with at least two typical lesions in a magnetic resonance scan. The Expanded Disability Status Scale (EDSS) was obtained and the presence of attacks was evaluated basally and at 3, 6, 9, 12, 18 and 24 months; a magnetic resonance scan was performed basally and at 6 and 24 months so as to be able to calculate the brain volume and the volumes of the lesions (T1, T2 and T1 after administering gadolinium). McDonald and Poser criteria were evaluated during the follow-up. A subgroup of patients was followed up for a total eriod of four years. Results. Altogether 110 patients (67% females) with a mean age of 30.2 years were included in the study; 22 patients dropped out of the study before it fi nished. Poser criteria were met by 19% and 45% of patients at 6 months and 24 months, respectively; 63% and 71% satisfi ed McDonald criteria. The EDSS decreased signifi cantly (–0.94; p < 0.001) and development of atrophy was observed (–1.2%; p < 0.001) at 24 months. Conclusions. Results of the follow-up of patients with fi rst attacks suggestive of MS within a Spanish multi-centre context are wholly comparable with those from international clinical trials performed in these patients (AU)


Asunto(s)
Humanos , Masculino , Femenino , Adulto Joven , Adulto , Esclerosis Múltiple/epidemiología , Punción Espinal , Espectroscopía de Resonancia Magnética , Líquido Cefalorraquídeo/citología , Tamizaje Masivo , Brotes de Enfermedades/estadística & datos numéricos , Interferón beta/uso terapéutico , Estudios Prospectivos
5.
Cell Mol Life Sci ; 65(24): 3936-49, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19011747

RESUMEN

Retinoic acid (RA), the most active retinoid, is synthesized in two steps from retinol. The first step, oxidation of retinol to retinaldehyde, is catalyzed by cytosolic alcohol dehydrogenases (ADHs) of the medium-chain dehydrogenase/reductase (MDR) superfamily and microsomal retinol dehydrogenases (RDHs) of the short-chain dehydrogenase/reductase (SDR) superfamily. The second step, oxidation of retinaldehyde to RA, is catalyzed by several aldehyde dehydrogenases. ADH1 and ADH2 are the major MDR enzymes in liver retinol detoxification, while ADH3 (less active) and ADH4 (most active) participate in RA generation in tissues. Several NAD(+)- and NADP(+)-dependent SDRs are retinoid active. Their in vivo contribution has been demonstrated in the visual cycle (RDH5, RDH12), adult retinoid homeostasis (RDH1) and embryogenesis (RDH10). K(m) values for most retinoid-active ADHs and RDHs are close to 1 microM or lower, suggesting that they participate physiologically in retinol/retinaldehyde interconversion. Probably none of these enzymes uses retinoids bound to cellular retinol-binding protein, but only free retinoids. The large number of enzymes involved in the two directions of this step, also including aldo-keto reductases, suggests that retinaldehyde levels are strictly regulated.


Asunto(s)
Alcohol Deshidrogenasa/metabolismo , Oxidorreductasas de Alcohol/metabolismo , Familia de Multigenes , Retinoides/metabolismo , Animales , Crecimiento y Desarrollo , Humanos , Deficiencia de Vitamina A/enzimología
6.
Cell Mol Life Sci ; 64(11): 1419-27, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17497241

RESUMEN

Zeta-crystallins constitute a family of proteins with NADPH:quinone reductase activity found initially in mammalian lenses but now known to be present in many other organisms and tissues. Few proteins from this family have been characterized, and their function remains unclear. In the present work, zeta-crystallins from human and yeast (Zta1p) were expressed, purified and characterized. Both enzymes are able to reduce ortho-quinones in the presence of NADPH but are not active with 2-alkenals. Deletion of the ZTA1 gene makes yeast more sensitive to menadione and hydrogen peroxide, suggesting a role in the oxidative stress response. The human and yeast enzymes specifically bind to adenine-uracil rich elements (ARE) in RNA, indicating that both enzymes are ARE-binding proteins and that this property has been conserved in zeta-crystallins throughout evolution. This supports a role for zeta-crystallins as trans-acting factors that could regulate the turnover of certain mRNAs.


Asunto(s)
ARN , Proteínas de Saccharomyces cerevisiae/metabolismo , zeta-Cristalinas/metabolismo , Animales , Secuencia de Bases , Humanos , Datos de Secuencia Molecular , Peso Molecular , NADP/metabolismo , Unión Proteica , ARN/genética , ARN/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , zeta-Cristalinas/química , zeta-Cristalinas/genética
7.
Cell Mol Life Sci ; 64(4): 498-505, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17279314

RESUMEN

The metabolism of all-trans- and 9-cis-retinol/ retinaldehyde has been investigated with focus on the activities of human, mouse and rat alcohol dehydrogenase 2 (ADH2), an intriguing enzyme with apparently different functions in human and rodents. Kinetic constants were determined with an HPLC method and a structural approach was implemented by in silico substrate dockings. For human ADH2, the determined K(m) values ranged from 0.05 to 0.3 microM and k(cat) values from 2.3 to 17.6 min(-1), while the catalytic efficiency for 9-cis-retinol showed the highest value for any substrate. In contrast, poor activities were detected for the rodent enzymes. A mouse ADH2 mutant (ADH2Pro47His) was studied that resembles the human ADH2 setup. This mutation increased the retinoid activity up to 100-fold. The K(m) values of human ADH2 are the lowest among all known human retinol dehydrogenases, which clearly support a role in hepatic retinol oxidation at physiological concentrations.


Asunto(s)
Alcohol Deshidrogenasa/metabolismo , Hígado/enzimología , Vitamina A/metabolismo , Alcohol Deshidrogenasa/química , Secuencia de Aminoácidos , Animales , Sitios de Unión , Humanos , Cinética , Ratones , Modelos Moleculares , Datos de Secuencia Molecular , Estructura Secundaria de Proteína , Ratas , Alineación de Secuencia
10.
Cell Mol Life Sci ; 58(9): 1323-6, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11577987

RESUMEN

A recent finding of a novel class of retinol-active alcohol dehydrogenase (ADH) in frog prompted analysis of this activity in other vertebrate forms. Surprisingly, yet another and still more unrelated ADH was identified in chicken tissues. It was found to be a member of the aldo-keto reductase (AKR) enzyme family, not previously known as an ADH in vertebrates. Its terminal blocking group and the N-terminal segment, not assigned by protein and cDNA structure analysis, were determined by electrospray tandem mass spectrometry after protein isolation by two-dimensional gel electrophoresis. The N terminus is Acetyl-Ala- and the N-terminal segment contains two consecutive Asn residues. The results establish the new ADH enzyme of the AKR family and show the usefulness of combined gel separation and mass spectrometry in enzyme-characterization.


Asunto(s)
Alcohol Deshidrogenasa/química , Oxidorreductasas de Alcohol/química , Proteoma , Acetilación , Alcohol Deshidrogenasa/genética , Oxidorreductasas de Alcohol/genética , Aldehído Reductasa , Aldo-Ceto Reductasas , Secuencia de Aminoácidos , Animales , Pollos , Fragmentos de Péptidos/química , Ranidae , Espectrometría de Masa por Ionización de Electrospray , Vertebrados
11.
Eur J Biochem ; 268(19): 5045-56, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11589695

RESUMEN

The localization of alcohol dehydrogenase (ADH) in brain regions would demonstrate active ethanol metabolism in brain during alcohol consumption, which would be a new basis to explain the effects of ethanol in the central nervous system. Tissue sections from several regions of adult rat brain were examined by in situ hybridization to detect the expression of genes encoding ADH1 and ADH4, enzymes highly active with ethanol and retinol. ADH1 mRNA was found in the granular and Purkinje cell layers of cerebellum, in the pyramidal and granule cells of the hippocampal formation and in some cell types of cerebral cortex. ADH4 expression was detected in the Purkinje cells, in the pyramidal and granule cells of the hippocampal formation and in the pyramidal cells of cerebral cortex. High levels of ADH1 and ADH4 mRNAs were detected in the CNS epithelial and vascular tissues: leptomeninges, choroid plexus, ependymocytes of ventricle walls, and endothelium of brain vessels. Histochemical methods detected ADH activity in rodent cerebellar slices, while Western-blot analysis showed ADH4 protein in homogenates from several brain regions. In consequence, small but significant levels of ethanol metabolism can take place in distinct areas of the CNS following alcohol consumption, which could be related to brain damage caused by a local accumulation of acetaldehyde. Moreover, the involvement of ADH in the synthesis of retinoic acid suggests a role for the enzyme in the regulation of adult brain functions. The impairment of retinol oxidation by competitive inhibition of ADH in the presence of ethanol may be an additional origin of CNS abnormalities caused by ethanol.


Asunto(s)
Alcohol Deshidrogenasa/genética , Encéfalo/enzimología , ARN Mensajero/metabolismo , Alcohol Deshidrogenasa/metabolismo , Animales , Western Blotting , Etanol/metabolismo , Proteína Ácida Fibrilar de la Glía/metabolismo , Inmunohistoquímica , Hibridación in Situ , ARN Mensajero/genética , Ratas , Ratas Sprague-Dawley , Fracciones Subcelulares/enzimología
12.
Gene ; 275(1): 115-24, 2001 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-11574159

RESUMEN

A synthetic gene based on the primary sequence of the mature spruce budworm antifreeze protein (sbwAFP) was constructed by primer overlap extension. The amino acid codons were chosen to mimic those of a highly expressed tobacco nuclear gene. A DNA sequence encoding the amino-terminal leader sequence from the tobacco pathogen related protein 1b (PR), which targets the protein to the apoplastic space, was fused in frame to the synthetic sbwAFP gene. This fusion was placed downstream of the cauliflower mosaic virus 35S promoter and upstream of the nopaline synthase terminator in a T-DNA binary vector. Transgenic tobacco lines transcribing PR-sbwAFP were selected by RT-PCR. The apoplastic protein fractions of sbwAFP expressing tobacco lines exhibited enhanced antifreeze activity as demonstrated by the ability to inhibit ice re-crystallization and increased thermal hysteresis.


Asunto(s)
Proteínas Anticongelantes/genética , Congelación , Genes Sintéticos/genética , Nicotiana/genética , Adaptación Fisiológica/genética , Animales , Codón/genética , Expresión Génica , Vectores Genéticos/genética , Proteínas de Insectos/genética , Hojas de la Planta/genética , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/crecimiento & desarrollo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Nicotiana/crecimiento & desarrollo , Transcripción Genética , Transformación Genética
13.
Chem Biol Interact ; 130-132(1-3): 435-44, 2001 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-11306065

RESUMEN

Class IV alcohol dehydrogenase shows a deletion at position 117 with respect to class I enzymes, which typically have a Gly residue. In class I structures, Gly117 is part of a loop (residues 114-120) that is highly variable within the alcohol dehydrogenase family. A mutant human class IV enzyme was engineered in which a Gly residue was inserted at position 117 (G117ins). Its kinetic properties, regarding ethanol and primary aliphatic alcohols, secondary alcohols and pH profiles, were determined and compared with the results obtained in previous studies in which the size of the 114-120 loop was modified. For the enzymes considered, a smaller loop was associated with a lower catalytic efficiency towards short-chain alcohols (ethanol and propanol) and secondary alcohols, as well as with a higher K(m) for ethanol at pH 7.5 than at pH 10.0. The effect can be rationalized in terms of a more open, solvent-accessible active site in class IV alcohol dehydrogenase, which disfavors productive binding of ethanol and short-chain alcohols, specially at physiological pH.


Asunto(s)
Alcohol Deshidrogenasa/genética , Alcohol Deshidrogenasa/metabolismo , Alcohol Deshidrogenasa/química , Alcoholes/química , Alcoholes/metabolismo , Animales , Dominio Catalítico , Etanol/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Técnicas In Vitro , Cinética , Modelos Moleculares , Mutagénesis Insercional , NAD/metabolismo , Conformación Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidad por Sustrato
14.
J Biol Chem ; 276(22): 19132-40, 2001 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-11278684

RESUMEN

Enzymes of the short chain and medium chain dehydrogenase/reductase families have been demonstrated to participate in the oxidoreduction of ethanol and retinoids. Mammals and amphibians contain, in the upper digestive tract mucosa, alcohol dehydrogenases of the medium chain dehydrogenase/reductase family, active with ethanol and retinol. In the present work, we searched for a similar enzyme in an avian species (Gallus domesticus). We found that chicken does not contain the homologous enzyme from the medium chain dehydrogenase/reductase family but an oxidoreductase from the aldo-keto reductase family, with retinal reductase and alcohol dehydrogenase activities. The amino acid sequence shows 66-69% residue identity with the aldose reductase and aldose reductase-like enzymes. Chicken aldo-keto reductase is a monomer of M(r) 36,000 expressed in eye, tongue, and esophagus. The enzyme can oxidize aliphatic alcohols, such as ethanol, and it is very efficient in all-trans- and 9-cis-retinal reduction (k(cat)/K(m) = 5,300 and 32,000 mm(-1).min(-1), respectively). This finding represents the inclusion of the aldo-keto reductase family, with the (alpha/beta)(8) barrel structure, into the scenario of retinoid metabolism and, therefore, of the regulation of vertebrate development and tissue differentiation.


Asunto(s)
Oxidorreductasas de Alcohol/química , Oxidorreductasas de Alcohol/metabolismo , Alcoholes/metabolismo , Retinoides/metabolismo , Oxidorreductasas de Alcohol/clasificación , Oxidorreductasas de Alcohol/genética , Aldehído Reductasa , Aldo-Ceto Reductasas , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , Pollos , Clonación Molecular , ADN Complementario/metabolismo , Electroforesis en Gel de Almidón , Concentración de Iones de Hidrógeno , Cinética , Modelos Químicos , Modelos Moleculares , Datos de Secuencia Molecular , Filogenia , Unión Proteica , Estructura Terciaria de Proteína , Análisis de Secuencia de Proteína , Homología de Secuencia de Aminoácido , Transducción de Señal , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
15.
Biotechnol Bioeng ; 70(4): 446-55, 2000 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-11005927

RESUMEN

Expression of the gene encoding bacterial hemoglobin (VHb) from Vitreoscilla has been previously used to improve recombinant cell growth and enhance product formation under microaerobic conditions. It is very likely that the properties of VHb are not optimized for foreign hosts; therefore, we used error-prone PCR to generate a number of randomly mutated vhb genes to be expressed and studied in Escherichia coli. In addition, the mutated VHb proteins also contained an extension of eight residues (MTMITPSF) at the amino terminus. VHb mutants were screened for improved growth properties under microaerobic conditions and 15 clones expressing mutated hemoglobin protein were selected for further characterization and cultivated in a microaerobic bioreactor to analyze the physiological effects of novel VHb proteins on cell growth. The expression of four VHb mutants, carried by pVM20, pVM50, pVM104, and pVM134, were able to enhance microaerobic growth of E. coli by approximately 22%, 155%, 50%, and 90%, respectively, with a concomitant decrease of acetate excretion into the culture medium. The vhb gene in pVM20 contains two mutations substituting residues Glu19(A17) and Glu137(H23) to Gly. pVM50 expresses a VHb protein carrying two mutations: His36(C1) to Arg36 and Gln66(E20) to Arg66. pVM104 and pVM134 express VHb proteins carrying the mutations Ala56(E10) to Gly and Ile24(B5) to Thr, respectively. Our experiments also indicate that the positive effects elicited by mutant VHb-expression from pVM20 and pVM50 are linked to the peptide tail. Removal of the N-terminal sequence reduced cell growth approximately 23% and 53%, respectively, relative to wild-type controls. These results clearly demonstrate that it is possible to obtain mutated VHb proteins with improved characteristics for improving microaerobic growth of E. coli by using combined mutation techniques, addition of a peptide tail, and random error-prone PCR.


Asunto(s)
Proteínas Bacterianas/genética , Escherichia coli/crecimiento & desarrollo , Escherichia coli/genética , Ingeniería Genética/métodos , Hemoglobinas/genética , Reacción en Cadena de la Polimerasa/métodos , Acetatos/metabolismo , Aerobiosis , Proteínas Bacterianas/metabolismo , Reactores Biológicos , Biotecnología/métodos , Monóxido de Carbono/metabolismo , División Celular/genética , Escherichia coli/metabolismo , Etanol/metabolismo , Hemoglobinas/metabolismo , Mutación , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Hemoglobinas Truncadas , beta-Lactamasas/genética , beta-Lactamasas/metabolismo
16.
J Biol Chem ; 275(33): 25180-7, 2000 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-10829036

RESUMEN

Mammalian class IV alcohol dehydrogenase enzymes are characteristic of epithelial tissues, exhibit moderate to high K(m) values for ethanol, and are very active in retinol oxidation. The human enzyme shows a K(m) value for ethanol which is 2 orders of magnitude lower than that of rat class IV. The uniquely significant difference in the substrate-binding pocket between the two enzymes appears to be at position 294, Val in the human enzyme and Ala in the rat enzyme. Moreover, a deletion at position 117 (Gly in class I) has been pointed out as probably responsible for class IV specificity toward retinoids. With the aim of establishing the role of these residues, we have studied the kinetics of the recombinant human and rat wild-type enzymes, the human G117ins and V294A mutants, and the rat A294V mutant toward aliphatic alcohols and retinoids. 9-cis-Retinol was the best retinoid substrate for both human and rat class IV, strongly supporting a role of class IV in the generation of 9-cis-retinoic acid. In contrast, 13-cis retinoids were not substrates. The G117ins mutant showed a decreased catalytic efficiency toward retinoids and toward three-carbon and longer primary aliphatic alcohols, a behavior that resembles that of the human class I enzyme, which has Gly(117). The K(m) values for ethanol dramatically changed in the 294 mutants, where the human V294A mutant showed a 280-fold increase, and the rat A294V mutant a 50-fold decrease, compared with those of the respective wild-type enzymes. This demonstrates that the Val/Ala exchange at position 294 is mostly responsible for the kinetic differences with ethanol between the human and rat class IV. In contrast, the kinetics toward retinoids was only slightly affected by the mutations at position 294, compatible with a more conserved function of mammalian class IV alcohol dehydrogenase in retinoid metabolism.


Asunto(s)
Alcohol Deshidrogenasa/química , Alanina/química , Alcohol Deshidrogenasa/genética , Alcohol Deshidrogenasa/metabolismo , Alitretinoína , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión , Cristalografía por Rayos X , ADN Complementario/metabolismo , Escherichia coli/metabolismo , Etanol/metabolismo , Biblioteca de Genes , Humanos , Isomerismo , Isotretinoína/metabolismo , Cinética , Pulmón/metabolismo , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Unión Proteica , Estructura Terciaria de Proteína , Ratas , Ratas Sprague-Dawley , Proteínas Recombinantes/metabolismo , Retinoides/metabolismo , Especificidad por Sustrato , Tretinoina/metabolismo , Valina/química
17.
Ann Rheum Dis ; 59(4): 263-8, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10733472

RESUMEN

OBJECTIVE: To investigate possible differences in Th1 and Th2 cytokine mRNA expression in the synovial tissue (ST) of patients with rheumatoid arthritis (RA) and seronegative spondyloarthropathies (SpA) with diagnostic and/or pathogenic interest. METHODS: Eleven RA patients and 14 SpA patients (10 with undifferentiated spondyloarthropathy (USpA), two with ankylosing spondylitis (AS) and two with psoriatic arthritis (PsA)) were included. Th1 (interferon gamma, interleukin 2) and Th2 (interleukin 4, interleukin 5 and interleukin 10) cytokine mRNA levels from arthritic knee ST were quantified by using an optimised polymerase chain reaction method with a computerised analysis system. Protein levels of proinflammatory cytokines (interleukin 1, tumour necrosis factor alpha and interleukin 6) in synovial fluid were quantified with a specific ELISA test. RESULTS: Th1 cytokines were detected in all of RA ST samples in contrast with 58% (interferon gamma) and 71% (interleukin 2) of SpA samples. Th2 cytokines were expressed in 90% of RA ST samples, but the findings in SpA were interleukin 10 in 90%, interleukin 4 in 60% and interleukin 5 in 40% of ST samples. However, when the mRNA levels of each cytokine were quantified and corrected for T cell mRNA levels, only interferon gamma levels were significantly higher in RA than in SpA (p<0.003). Thus, the Th1/Th2 cytokine ratio in RA was fivefold that of SpA. Synovial fluid interleukin 1beta concentrations were higher in RA than in SpA (p<0. 05); there were also higher synovial fluid levels of tumour necrosis factor alpha in RA than in SpA, but without statistical significance. CONCLUSION: This study has detected both Th1 and Th2 cytokine gene expression in ST from RA and SpA patients. Synovium interferon gamma mRNA levels and SF interleukin 1beta protein levels were significantly higher in RA than in SpA, so reflecting the known proinflammatory activity of interferon gamma through macrophage activation. Thus, the Th1 (interferon gamma)/Th2 (interleukin 4) ratio is significantly higher in RA than in SpA ST. These data confirm previous studies on ST Th1/Th2 balance in RA and extend previous work in comparing ST RA with subgroups of SpA distinct of ReA.


Asunto(s)
Artritis Reumatoide/inmunología , Interferón gamma/metabolismo , Espondilitis/inmunología , Líquido Sinovial/inmunología , Adulto , Anciano , Artritis Psoriásica/inmunología , Citocinas/genética , Citocinas/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prohibitinas , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Espondilitis Anquilosante/inmunología , Células TH1/inmunología , Células Th2/inmunología
18.
Hepatology ; 31(4): 984-9, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10733556

RESUMEN

Polymorphism at the ADH2 and ADH3 loci of alcohol dehydrogenase (ADH) has been shown to have an effect on the predisposition to alcoholism in Asian individuals. However, the results are not conclusive for white individuals. We have analyzed the ADH genotype of 876 white individuals from Spain (n = 251), France (n = 160), Germany (n = 184), Sweden (n = 88), and Poland (n = 193). Peripheral blood samples from healthy controls and groups of patients with viral cirrhosis and alcohol-induced cirrhosis, as well as alcoholics with no liver disease, were collected on filter paper. Genotyping of the ADH2 and ADH3 loci was performed using polymerase chain reaction-restriction fragment length polymorphism methods on white cell DNA. In healthy controls, ADH2*2 frequencies ranged from 0% (France) to 5.4% (Spain), whereas ADH3*1 frequencies ranged from 47. 6% (Germany) to 62.5% (Sweden). Statistically significant differences were not found, however, between controls from different countries, nor between patients with alcoholism and/or liver disease. When all individuals were grouped in nonalcoholics (n = 451) and alcoholics (n = 425), ADH2*2 frequency was higher in nonalcoholics (3.8%) than in alcoholics (1.3%) (P =.0016), whereas the ADH3 alleles did not show differences. Linkage disequilibrium was found between ADH2 and ADH3, resulting in an association of the alleles ADH2*2 and ADH3*1, both coding for the most active enzymatic forms. In conclusion, the ADH2*2 allele decreases the risk for alcoholism, whereas the ADH2*2 and ADH3*1 alleles are found to be associated in the European population.


Asunto(s)
Alcohol Deshidrogenasa/genética , Alcoholismo/genética , Alelos , Polimorfismo de Longitud del Fragmento de Restricción , Adulto , Anciano , Anciano de 80 o más Años , Europa (Continente) , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo
19.
Biochem Pharmacol ; 58(3): 389-95, 1999 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-10424757

RESUMEN

The alcohol dehydrogenase (ADH) gene family encodes enzymes that metabolize a wide variety of substrates, including ethanol, retinol, other aliphatic alcohols, hydroxysteroids, and lipid peroxidation products. Studies on 19 vertebrate animals have identified ADH orthologs across several species, and this has now led to questions of how best to name ADH proteins and genes. Seven distinct classes of vertebrate ADH encoded by non-orthologous genes have been defined based upon sequence homology as well as unique catalytic properties or gene expression patterns. Each class of vertebrate ADH shares <70% sequence identity with other classes of ADH in the same species. Classes may be further divided into multiple closely related isoenzymes sharing >80% sequence identity such as the case for class I ADH where humans have three class I ADH genes, horses have two, and mice have only one. Presented here is a nomenclature that uses the widely accepted vertebrate ADH class system as its basis. It follows the guidelines of human and mouse gene nomenclature committees, which recommend coordinating names across species boundaries and eliminating Roman numerals and Greek symbols. We recommend that enzyme subunits be referred to by the symbol "ADH" (alcohol dehydrogenase) followed by an Arabic number denoting the class; i.e. ADH1 for class I ADH. For genes we recommend the italicized root symbol "ADH" for human and "Adh" for mouse, followed by the appropriate Arabic number for the class; i.e. ADH1 or Adh1 for class I ADH genes. For organisms where multiple species-specific isoenzymes exist within a class, we recommend adding a capital letter after the Arabic number; i.e. ADH1A, ADH1B, and ADH1C for human alpha, beta, and gamma class I ADHs, respectively. This nomenclature will accommodate newly discovered members of the vertebrate ADH family, and will facilitate functional and evolutionary studies.


Asunto(s)
Alcohol Deshidrogenasa/clasificación , Terminología como Asunto , Alcohol Deshidrogenasa/genética , Animales , Humanos , Familia de Multigenes , Polimorfismo Genético , Especificidad de la Especie , Vertebrados
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