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1.
Transplant Proc ; 47(3): 809-14, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25891736

RESUMEN

We previously reported our data on telaprevir (TVR) used in combination with pegylated-interferon and ribavirin (PEG-IFN/RBV) for the treatment of recurrent hepatitis C virus (HCV) genotype 1 infection after liver transplantation (LT). TVR substantially increases the blood levels of immunosuppressive agents such as cyclosporine and tacrolimus for drug-drug interactions. On the other hand, the effect of simeprevir (SMV) on the blood levels of these immunosuppressive agents is unclear. We report 2 patients who achieved viral responses with little effect on the blood levels of cyclosporine and tacrolimus using SMV plus PEG-IFN/RBV treatment. The first was a 71-year-old woman with HCV-related liver cirrhosis and hepatocellular carcinoma who failed to respond to PEG-IFN/RBV after living donor LT. She was treated with 40 mg/d of cyclosporine, and received SMV plus PEG-IFN/RBV treatment. The second was a 65-year-old man with HCV-related liver cirrhosis who failed to respond to PEG-IFN/RBV after living donor LT. He was treated with 3 mg/d of tacrolimus, and received SMV plus PEG-IFN/RBV treatment. Serum HCV RNA became undetectable using TaqMan polymerase chain reaction (PCR) test after 4 weeks of treatment in both patients, and no remarkable fluctuation in blood concentration was observed either in cyclosporine or tacrolimus during the 12 weeks of SMV treatment. Completion of 12-week SMV triple therapy was followed by PEG-IFNα2b plus RBV, and both patients achieved sustained virological response 12 weeks after the end of treatment. SMV plus PEG-IFNRBV treatment showed a remarkable viral response with little effect on blood levels of immunosuppressive agents for recurrent HCV genotype 1 infection after LT.


Asunto(s)
Hepatitis C/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Polietilenglicoles/uso terapéutico , Inhibidores de Proteasas/uso terapéutico , Ribavirina/uso terapéutico , Simeprevir/uso terapéutico , Anciano , Antivirales/uso terapéutico , Ciclosporina/sangre , Quimioterapia Combinada , Femenino , Humanos , Inmunosupresores/uso terapéutico , Interferón alfa-2 , Cirrosis Hepática/virología , Trasplante de Hígado , Donadores Vivos , Masculino , Proteínas Recombinantes/uso terapéutico , Tacrolimus/sangre , Resultado del Tratamiento
2.
J Viral Hepat ; 18(10): e550-60, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21914076

RESUMEN

The present study was designed to determine the predictive factors for the viral response to pegylated interferon-alpha plus ribavirin combination therapy (PEGIFN/RBV) administered after curative treatment for hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). The study group was 78 patients treated between January 2005 and January 2009. The sustained viral response (SVR) rate was 25.8% (15/58) in patients infected with HCV-genotype 1 and 55.0% (11/20) in those with genotype 2. Among the 78 patients, 32 (41.0%) could not complete the treatment protocol, and this was because of HCC recurrence in 17 (53%) of them. Multivariate analysis identified partial early viral response (pEVR) as the only independent determinant of SVR [odds ratio (OR) 14.73, P = 0.013] for patients with genotype 1. Multivariate analysis identified male gender (OR 8.72, P = 0.001) and interleukin-28B (IL-28B) genotype (rs8099917) TT (OR 7.93, P = 0.007) as independent predictors of pEVR. Multivariate analysis also identified IL-28B genotype GG+TG (OR 14.1, P = 0.021) and α-fetoprotein >30 (OR 5.4, P = 0.031) as independent predictors of null response. Patients with SVR showed a better survival rate than those without SVR (P = 0.034). The second HCC recurrence rate tended to be lower in patients with SVR than in those without SVR (P = 0.054). With regard to the prognosis of patients with SVR, it is desirable to achieve SVR with interferon therapy even when administered after HCC treatment. IL-28B genotype is a potentially useful marker for the response to PEGIFN/RBV therapy administered after curative treatment of HCV-related HCC.


Asunto(s)
Antivirales/administración & dosificación , Carcinoma Hepatocelular/tratamiento farmacológico , Hepatitis C/tratamiento farmacológico , Interferones/administración & dosificación , Interleucinas/genética , Polimorfismo Genético , Ribavirina/administración & dosificación , Anciano , Anciano de 80 o más Años , Femenino , Genotipo , Hepacivirus/clasificación , Hepacivirus/genética , Hepatitis C/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Recurrencia , Análisis de Supervivencia , Resultado del Tratamiento
3.
Water Sci Technol ; 61(4): 1073-80, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20182088

RESUMEN

Change of nutrients load and flow according to land-use change induced by housing development was investigated in Bang Yai, Nonthaburi, Thailand, which located in the peri-urban area of Bangkok. Each house in the newly developed residential community was regulated to be equipped with a septic tank to collect night soil. However, greywater and leachate from the septic tank was collected by a community sewage system and discharged into the canals with insufficient treatment, while the canals still function as infrastructure for irrigation and transportation. In the study area, built-up area became 1.4 times and agricultural fields decreased by 13% from 2003 until 2007. Total nutrients load to the canals was increased by 25% as nitrogen and 14% as phosphorus according to the increase of built-up area. Net nutrients load from agricultural fields was largely set off when we evaluated nutrients inflow from the canals to the agricultural field through irrigation. Consequently, nutrients load from domestic wastewater accounted most of net nutrients load into the canal.


Asunto(s)
Eliminación de Residuos Líquidos/métodos , Agricultura , Ciudades , Conservación de los Recursos Naturales , Ambiente , Monitoreo del Ambiente , Geografía , Vivienda , Nitrógeno/aislamiento & purificación , Fósforo/aislamiento & purificación , Tailandia , Movimientos del Agua , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos
4.
Eye (Lond) ; 24(4): 535-9, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19590526

RESUMEN

PURPOSE: To determine the vision-related quality of life (VRQOL) with the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) in patients with retinitis pigmentosa (RP), and to examine the relationship between VRQOL and peripheral visual field defects. DESIGN: Prospective study. METHODS: The Japanese version of the NEI VFQ-25 was used to study 40 patients with typical RP whose visual acuity was >/=0.7 (better than 0.15 in log MAR). For control, 40 volunteers with normal vision were studied in the same way. The peripheral visual field was evaluated by Goldmann's perimetry, and the degree of field loss was classified into seven grades. The correlation between the mean of the total composite score of the NEI VFQ-25 and the degree of the visual field loss was determined. RESULTS: The mean NEI VFQ-25 score was 68.4 in RP patients and 90.1 in normal controls. This difference was highly significant (P=0.00004). Among RP patients, there was a significant negative correlation between the mean NEI VFQ-25 score and the degree of visual field loss (r=-0.519, P=0.0006). CONCLUSION: The significant correlation between the peripheral visual field loss and VRQOL score obtained with the NEI VFQ-25, indicates that a good estimate of the QOL can be determined by the degree of visual field loss in RP patients.


Asunto(s)
Calidad de Vida , Retinitis Pigmentosa/fisiopatología , Baja Visión/fisiopatología , Campos Visuales , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Encuestas y Cuestionarios , Baja Visión/diagnóstico , Adulto Joven
5.
Leuk Lymphoma ; 47(1): 89-95, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16465716

RESUMEN

Various angiogenic factors, such as vascular endothelial growth factor (VEGF) and an associated molecule, placenta growth factor (PlGF), are thought to be important for normal and malignant hematopoiesis. This study examined mRNA expression of VEGF, PlGF and receptors for these molecules in AML cells and identified the disease-specific patterns of expression. AML M3 having t(15;17) abnormality showed highest expression of VEGF and VEGF receptor type 1 (VEGFR1), suggesting the autocrine pathway of VEGF-VEGFR1. Then, t(8;21) AML demonstrated augmented expression of VEGF and VEGF receptor type 2 (VEGFR2), suggesting VEGF-VEGFR2 autocrine pathway. Then, addition of VEGFR2 kinase inhibitor in Kasumi-1, a t(8;21) AML cell line, resulted in marked inhibition of cell growth, although growth inhibitory effect of R2 kinase inhibitor to HL-60 was marginal. In addition, cell cycle analysis study showed S-phase cell population reduction by R2 kinase inhibitor in Kasumi-1, but not in HL-60. This observation is thought to be the rationale for novel molecular target therapy directed to angiogenic molecules.


Asunto(s)
Comunicación Autocrina/genética , Leucemia Mieloide Aguda/genética , Translocación Genética/genética , Factor A de Crecimiento Endotelial Vascular/genética , Receptor 1 de Factores de Crecimiento Endotelial Vascular/genética , Receptor 2 de Factores de Crecimiento Endotelial Vascular/genética , Adulto , Anciano , Ciclo Celular/efectos de los fármacos , Ciclo Celular/fisiología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Aberraciones Cromosómicas , Cromosomas Humanos Par 15/genética , Cromosomas Humanos Par 17/genética , Cromosomas Humanos Par 21/genética , Cromosomas Humanos Par 8/genética , Enfermedad , Inhibidores Enzimáticos/farmacología , Regulación Leucémica de la Expresión Génica/genética , Células HL-60 , Humanos , Leucemia Mieloide Aguda/metabolismo , Persona de Mediana Edad , Factor de Crecimiento Placentario , Proteínas Gestacionales/biosíntesis , Proteínas Gestacionales/genética , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas , Factor A de Crecimiento Endotelial Vascular/biosíntesis , Receptor 1 de Factores de Crecimiento Endotelial Vascular/biosíntesis , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Receptor 2 de Factores de Crecimiento Endotelial Vascular/biosíntesis
6.
J Dairy Sci ; 86(7): 2452-61, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12906063

RESUMEN

The effects of milk products fermented by Bifidobacterium longum strain BL1, a probiotic strain, on blood lipids in rats and humans were studied. Rats were fed a cholesterol-enriched experimental diet, supplemented with lyophilized powders of 1) acid milk (control), 2) milk fermented with a mixed culture of ordinary yogurt starters composed of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (SL), and 3) bifidobacterium milk fermented with the probiotic B. longum strain BL1, respectively. The bifidobacterium milk feeding brought about significant lowering of the serum concentrations of total cholesterol, low-density lipoprotein cholesterol, and triglycerides, in comparison with the control, while no change in high-density lipoprotein cholesterol concentration was observed. On the other hand, supplementation with SL milk resulted in only slight, nonsignificant decreases in serum lipid concentrations in comparison with the control. In the human study, 32 subjects with serum total cholesterol ranging from 220 to 280 mg/dl were randomly assigned to two treatments: 1) intake of a low-fat drinking yogurt prepared with ordinary yogurt starters composed of S. thermophilus and L. delbrueckii subsp. bulgaricus (P-group) and 2) intake of a low-fat drinking yogurt prepared with the two ordinary yogurt starters plus B. longum strain BL1 (B-group). After intake for 4 wk at 3 x 100 ml/day, reduction of serum total cholesterol was observed in approximately half of the B-group subjects; a particularly significant decrease in serum total cholesterol was found among subjects with moderate hypercholesterolemia (serum total cholesterol > 240 mg/dl). However, the serum lipid concentrations in the P-group subjects were almost stable during the experimental periods. The present results indicate the potential of the probiotic B. longum strain BL1 in serum lipid improvement.


Asunto(s)
Bifidobacterium/fisiología , Productos Lácteos , Fermentación , Lípidos/sangre , Probióticos , Adulto , Animales , Bilis , Colesterol/sangre , LDL-Colesterol/sangre , Jugo Gástrico , Humanos , Hipercolesterolemia/sangre , Hipercolesterolemia/terapia , Masculino , Persona de Mediana Edad , Leche/microbiología , Placebos , Ratas , Ratas Sprague-Dawley , Triglicéridos/sangre , Yogur/microbiología
7.
Biochem J ; 322 ( Pt 3): 809-14, 1997 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-9148753

RESUMEN

Decorin (DCN) is a ubiquitous proteoglycan comprised of a core protein attached to a single dermatan/chondroitin sulphate glycosaminoglycan chain. It may play a role in regulation of collagen fibrillogenesis and function as a reservoir of transforming growth factor beta (TGF-beta) in the extracellular milieu. We have examined the susceptibility of DCN to five different matrix metalloproteinases (MMPs): MMP-1 (tissue collagenase), MMP-2 (gelatinase A), MMP-3 (stromelysin 1), MMP-7 (matrilysin) and MMP-9 (gelatinase B). MMP-2 and MMP-3 digest DCN into seven major fragments in a similar pattern. The N-terminal sequence of the two fragments generated by MMP-2 and MMP-3 is Leu211-Lys-Gly-Leu-Asn, but that of the others is Asp1-Glu-Ala-Ser-Gly. MMP-7 cleaves DCN into three major fragments which have the N-termini Asp1-Glu-Ala-Ser-Gly, Glu2-Ala-Ser-Gly-Ile and Leu244-His-Leu-Asp-Asn. Activities of MMP-1 and MMP-9 against DCN are negligible. The values of Km for the MMPs capable of degrading DCN are very similar (10-12 microM), but the kcat/Km value for MMP-7 (30.5 microM-1.h-1) is 4.5-fold higher than those for MMP-2 and MMP-3. Incubation of a DCN-TGF-beta1 complex with MMP-2, -3 or -7 results in release of TGF-beta1 from the complex. These data indicate proteolytic degradation of DCN by MMP-2, MMP-3 and MMP-7, and suggest the possibility that, under pathophysiological conditions, the digestion by the MMPs may induce tissue reactions mediated by TGF-beta1 released from DCN in the connective tissues.


Asunto(s)
Metaloendopeptidasas/metabolismo , Proteoglicanos/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Secuencia de Aminoácidos , Animales , Sitios de Unión , Células CHO , Cricetinae , Decorina , Proteínas de la Matriz Extracelular , Humanos , Datos de Secuencia Molecular , Proteínas Recombinantes/metabolismo , Especificidad por Sustrato
8.
J Clin Gastroenterol ; 17 Suppl 1: S116-20, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-7904283

RESUMEN

A monoclonal antibody to proliferating cell nuclear antigen (PCNA) has been previously shown to be capable of identifying proliferating cells. We investigated proliferative activity in the healing process of acetic acid-induced gastric ulcer by immunohistochemical staining of PCNA and 5-bromo-2-deoxyuridine (BrdU), and the two methods were compared. Cell proliferative activity of regenerated mucosa around ulcers showed continuous acceleration for 42 days, and PCNA-labeled cells had stained nuclei as clearly discernible as those of BrdU-labeled cells. In addition, immunohistochemical staining of PCNA provided reproducible and quantifiable results without the requirement of pretreatment. We conclude that immunohistochemical staining of PCNA may represent a useful technique for analysis of proliferative activity during healing of gastric ulcers.


Asunto(s)
Acetatos/farmacología , División Celular/efectos de los fármacos , Mucosa Gástrica/efectos de los fármacos , Proteínas Nucleares/análisis , Úlcera Gástrica/inducido químicamente , Ácido Acético , Animales , Mucosa Gástrica/patología , Técnicas para Inmunoenzimas , Masculino , Antígeno Nuclear de Célula en Proliferación , Ratas , Ratas Sprague-Dawley , Úlcera Gástrica/patología
9.
Antiviral Res ; 17(4): 323-33, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1322646

RESUMEN

Yucca leaf protein (YLP), an inhibitor of tobacco mosaic virus isolated from the leaves of Yucca recurvifolia Salisb., exhibited potent activity against herpes simplex virus type 1 (HSV-1) with no cytotoxicity below 300 micrograms/ml. The inhibitory dose was varied with the time of addition; 50% effective concentrations (ED50) of YLP were 3, 19 and 95 micrograms/ml when YLP exposure was begun 3 h before virus infection, 0 h and 3 h after infection, respectively. This protein also inhibited the multiplication of herpes simplex virus type 2 and human cytomegalovirus. YLP has been shown to have a weak virucidal activity at higher concentrations. Analysis of early events following infection showed that YLP affected viral penetration in HeLa cells but did not interfere with adsorption to the cells. YLP was found to exert strong inhibition of protein synthesis in virus-infected cells but not in uninfected cells. This selective effect can be considered to attribute mainly to the antiviral activity of YLP.


Asunto(s)
Antivirales/farmacología , Proteínas de Plantas/farmacología , Simplexvirus/efectos de los fármacos , Animales , Antivirales/toxicidad , Células Cultivadas , Humanos , Proteínas de Plantas/toxicidad , Biosíntesis de Proteínas , Replicación Viral/efectos de los fármacos
10.
Digestion ; 48(4): 185-91, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1724763

RESUMEN

We studied the proliferative ability of the marginal mucosal cells surrounding the ulcer in the healing processes of gastric ulcers. We obtained a labeling index (LI) at the neck and generative zone of gastric pit using a monoclonal antibody against DNA polymerase alpha for tractable and intractable gastric ulcers located at the fundic mucosa during each endoscopic stage. The LI during the healing stage was higher than that during the active stage in both the tractable and intractable cases. However, in each stage, the LI of the tractable gastric ulcers was higher than that of their intractable counterparts. Finally, we analyzed the LI in tractable gastric ulcers after setting two groups: one treated with anti-ulcer drugs and the other untreated. There were no significant differences between these two groups. We believe that investigation of proliferative abilities in the marginal mucosa of gastric ulcers is important to understand the nature of gastric ulcers and to assess therapeutic efficacy.


Asunto(s)
ADN Polimerasa II/análisis , Mucosa Gástrica/patología , Úlcera Gástrica/patología , Adulto , Anciano , Anticuerpos Monoclonales , División Celular/efectos de los fármacos , Cimetidina/farmacología , Cimetidina/uso terapéutico , ADN Polimerasa II/inmunología , Famotidina/farmacología , Famotidina/uso terapéutico , Femenino , Mucosa Gástrica/enzimología , Humanos , Cinética , Masculino , Persona de Mediana Edad , Ranitidina/farmacología , Ranitidina/uso terapéutico , Coloración y Etiquetado , Úlcera Gástrica/tratamiento farmacológico
11.
J Int Med Res ; 18(6): 506-14, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2127258

RESUMEN

The progressive expansion of calcification into the wall of the stomach and peritoneal metastatic foci was observed in a 31-year-old female with Borrmann type 4 calcified advanced gastric cancer. Despite treatment with systemic lentinan, uracil tegaful and mitomycin C, together with intraperitoneal injections of mitomycin C, OK-432 and prednisolone, the patient died 27 months after first presentation. The case provided a useful means of studying the mechanism of calcification.


Asunto(s)
Adenocarcinoma/diagnóstico , Calcinosis/diagnóstico , Neoplasias Gástricas/diagnóstico , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/patología , Adulto , Calcinosis/patología , Femenino , Humanos , Lentinano/uso terapéutico , Mitomicina , Mitomicinas/uso terapéutico , Estadificación de Neoplasias , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/patología , Tomografía Computarizada por Rayos X
13.
IEEE Trans Neural Netw ; 1(1): 122-30, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-18282829

RESUMEN

A learning method that uses neural networks for service quality control in the asynchronous transfer mode (ATM) communications network is described. Because the precise characteristics of the source traffic are not known and the service quality requirements change over time, building an efficient network controller which can control the network traffic is a difficult task. The proposed ATM network controller uses backpropagation neural networks for learning the relations between the offered traffic and service quality. The neural network is adaptive and easy to implement. A training data selection method called the leaky pattern table method is proposed to learn precise relations. The performance of the proposed controller is evaluated by simulation of basic call admission models.

15.
Scand J Gastroenterol Suppl ; 162: 67-70, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2595311

RESUMEN

We examined the time courses for gastric mucosal hemodynamics and lipid peroxides after intravenous infusion of PAF (platelet-activating factor). The gastric mucosal hemodynamics were continuously monitored by laser-Doppler flowmetry and reflectance spectrophotometry during 20 min infusion of PAF and the subsequent 60 min. Gastric mucosal damage was assessed by microscopical scoring and measurement of thiobarbituric acid (TBA) reactants. Intravenous infusion of PAF caused macroscopical gastric mucosal damage, hemodynamic disturbance, a reduction in blood pressure and elevation of TBA reactants. These changes did not recover to control levels, even at 60 min after PAF infusion. The mucosal injury caused by the hemodynamic disturbance (congestion) was related to the elevation of TBA reactants, that reflect lipid peroxidation and oxygen-derived free radicals.


Asunto(s)
Mucosa Gástrica/efectos de los fármacos , Factor de Activación Plaquetaria/farmacología , Animales , Mucosa Gástrica/irrigación sanguínea , Mucosa Gástrica/patología , Hemodinámica , Inyecciones Intravenosas , Masculino , Ratas , Ratas Endogámicas , Tiobarbitúricos , Factores de Tiempo
17.
Gastroenterol Jpn ; 19(3): 216-20, 1984 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-6745599

RESUMEN

A crossed thermocouple method in combination with endoscopy was applied to determine the blood flow rate of the human gastric mucosa. Determination was carried out with 11 healthy control subjects at 8 sites of the stomach. The blood flow rates at all sites in the corpus were found to be higher than those at the antrum. In subjects less than 50 years old the blood flow rate in the corpus was higher than in older subjects. These results were in agreed well with those obtained by the hydrogen gas clearance method, which is widely adopted clinically. The crossed thermocouple method is easily applicable to all sites in the gastric mucosa and the time required for the assay is very short. This method dose not require the inhalation of hydrogen gas which is necessary for the hydrogen gas clearance method and which is possibly harmful to humans. Although the values obtained by the crossed thermocouple method are relative to the value at a certain fixed site, this method will holds great potential for the determination of gastric mucosal blood flow rate.


Asunto(s)
Mucosa Gástrica/irrigación sanguínea , Reología/métodos , Temperatura , Adulto , Anciano , Velocidad del Flujo Sanguíneo , Gastroscopios , Humanos , Hidrógeno , Masculino , Persona de Mediana Edad
18.
Eur J Biochem ; 57(2): 587-93, 1975 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-1175659

RESUMEN

Ethoxyformic acid anhydride, amino-1H-tetrazole, and photooxidation in the presence of rose bengal, which are reagents known to react with histidine residues of proteins, were shown to inactivate monoamine oxidase. Ethoxyformic acid anhydride reacted with about 6 histidine residues per 100 000 g of protein under the experimental conditions adopted and completely inactivated the enzyme. However, NH2OH reactivated the ethaxyformic acid derivative t only. Since NH2OH specifically deacylates N-ethoxyformylimidazole, it was shown that at least some of the histidine residues are essential for activity. In addition, photooxidation experiments in the presence of 0.01% rose bengal confirmed that only histidine residues of bovine hepatic monoamine oxidase are destroyed under the designated experimental conditions. About 9 histidine residues per 100 000 g of protein were destroyed during the photooxidation experiments. In the presence of substrate, kynuramine or benzylamine, only 7 histidine residues were destroyed, which indicates that 2 histidine residues per 100 000 g of protein are essential for activity.


Asunto(s)
Mitocondrias Hepáticas/enzimología , Monoaminooxidasa/análisis , Aminoácidos/análisis , Animales , Sitios de Unión , Bovinos , Éteres de Etila/farmacología , Flavina-Adenina Dinucleótido/análisis , Formiatos/farmacología , Histidina/análisis , Yodoacetatos/farmacología , Cinética , Oxidación-Reducción , Fotoquímica , Unión Proteica , Rosa Bengala/farmacología , Tetrazoles/farmacología
19.
Biochim Biophys Acta ; 400(2): 451-60, 1975 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-1164517

RESUMEN

Ethoxyformic acid anhydride and photooxidation have been used to study the function of histidine residues in bovine plasma amine oxidase. Ethoxyformic acid anhydride at pH 6.1 reacted with nearly all of the histidine residues in the enzyme in 15 min but complete enzyme inactivation occurred in several minutes. The concentration of the reagent which caused 50% inhibition was 2.2-10(-5) M under the conditions of the experiment. The diamine oxidases, Aspergillus niger and pea seedling amine oxidases were also inhibited by ethoxyformic acid anhydride. The concentrations of reagent required for 50% inhibition were 6.6-10(-5) and 3.3-10(-4) M, respectively, for the two enzymes. NH2OH could not be used to regenerate the reacted histidine residues since NH2OH itself inhibited the enzyme. Photooxidation in the presence of 0.001% Rose Bengal at pH 7.0 also inactivated bovine plasma amine oxidase. Histidine was the only amino acid destroyed by photooxidation. About six histidine residues were destroyed but in the presence of the substrate kynuramine, two less histidine residues were destroyed. Since lysine which is neither a substrate nor inhibitor of the enzyme did not protect the enzyme from photooxidation, it was concluded that two histidine residues, one in each sub-unit of the enzyme are essential for activity.


Asunto(s)
Histidina/análisis , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/sangre , Aminoácidos/análisis , Anhídridos/farmacología , Animales , Sitios de Unión , Bovinos , Formiatos/farmacología , Cinética , Oxidación-Reducción , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/análisis , Fotoquímica , Unión Proteica , Rosa Bengala/farmacología
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