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1.
Psychiatry Res ; 336: 115910, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38608539

RESUMEN

Approximately half of generalised anxiety disorder (GAD) patients do not recover from first-line treatments, and no validated prediction models exist to inform individuals or clinicians of potential treatment benefits. This study aimed to develop and validate an accurate and explainable prediction model of post-treatment GAD symptom severity. Data from adults receiving treatment for GAD in eight Improving Access to Psychological Therapies (IAPT) services (n=15,859) were separated into training, validation and holdout datasets. Thirteen machine learning algorithms were compared using 10-fold cross-validation, against two simple clinically relevant comparison models. The best-performing model was tested on the holdout dataset and model-specific explainability measures identified the most important predictors. A Bayesian Additive Regression Trees model out-performed all comparison models (MSE=16.54 [95 % CI=15.58; 17.51]; MAE=3.19; R²=0.33, including a single predictor linear regression model: MSE=20.70 [95 % CI=19.58; 21.82]; MAE=3.94; R²=0.14). The five most important predictors were: PHQ-9 anhedonia, GAD-7 annoyance/irritability, restlessness and fear items, then the referral-assessment waiting time. The best-performing model accurately predicted post-treatment GAD symptom severity using only pre-treatment data, outperforming comparison models that approximated clinical judgement and remaining within the GAD-7 error of measurement and minimal clinically important differences. This model could inform treatment decision-making and provide desired information to clinicians and patients receiving treatment for GAD.


Asunto(s)
Trastornos de Ansiedad , Aprendizaje Automático , Índice de Severidad de la Enfermedad , Humanos , Trastornos de Ansiedad/terapia , Adulto , Masculino , Femenino , Persona de Mediana Edad , Psicoterapia/métodos , Teorema de Bayes , Adulto Joven
2.
Food Chem ; 192: 107-13, 2016 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-26304326

RESUMEN

Ovomucin was hydrolyzed using enzymes or by heating under alkaline conditions (pH 12.0), and the functional, structural and compositional characteristics of the peptides in the hydrolysates were determined. Among the treatments, heating at 100 °C for 15 min under alkaline conditions (OM) produced peptides with the highest iron-binding and antioxidant capacities. Ovomucin hydrolyzed with papain (OMPa) or alcalase (OMAl) produced peptides with high ACE-inhibitory activity. The mass spectrometry analysis indicated that most of the peptides from OMPa were <2 kDa, but peptides from OMTr and OM were >2 kDa. OMAl hydrolyzed ovomucin almost completely and no peptides within 700-5000 Da were found in the hydrolasate. The results indicated that the number and size of peptides were closely related to the functionality of the hydrolysates. Considering the time, cost and activities of the hydrolysates, OM was the best treatment for hydrolyzing ovomucin to produce functional peptides.


Asunto(s)
Espectrometría de Masas/métodos , Ovomucina/química , Péptidos/química , Antioxidantes , Hidrólisis
3.
J Appl Microbiol ; 120(4): 975-85, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26678243

RESUMEN

AIM: To identify the active compounds from the Streptomyces sp. MJM4426 that can protect rice from bacterial blight disease (BB), and to evaluate the potential of this Streptomyces strains and the compound for biocontrol of rice bacterial blight disease. METHODS AND RESULTS: The ethyl acetate extract of Streptomyces sp. MJM4426 can significantly protect rice leaf explants from the infection of Xanthomonas oryzae pv. oryzaeKACC 10331 (Xoo), the pathogen which cause BB. To identify the active compounds, the ethyl acetate extract of Streptomyces sp. MJM4426 was fractionated through a Sephadex LH-20 column chromatography, and further purified by preparative HPLC guided by the inhibitory activity against BB in rice leaf explants. UPLC-Q-TOF/MS analysis showed the active compound displayed its m/z values at [M+H](+) 467·2086 and [M+FA-H](-) 511·1963, and the molecular formula was estimated as C28 H26 N4 O3 which is identical to commercial standard staurosporine. In this study, the isolated staurosporine dramatically suppressed bacterial blight in rice leaf explants with the lowest concentration at 12·5 µmol l(-1) , however, it exhibited low inhibitory activity against Xoo with the MIC value at 256 µg ml(-1) . In addition, greenhouse study showed both crude extract and purified staurosporine can suppress the bacterial blight at the concentration of 5000 and 200 µg ml(-1) respectively. CONCLUSION: Streptomyces sp. MJM4426 can protect rice leaf explants from the infection of Xoo by producing staurosporine, but not by direct inhibitory activity against Xoo. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report that staurosporine can protect rice leaf against bacterial blight disease and showed the potential of Streptomyces sp. MJM4426 as an alternative to chemical bactericide for bacterial blight disease in rice.


Asunto(s)
Antibacterianos/farmacología , Inhibidores Enzimáticos/farmacología , Oryza/efectos de los fármacos , Enfermedades de las Plantas/microbiología , Estaurosporina/farmacología , Antibacterianos/aislamiento & purificación , Resistencia a la Enfermedad/efectos de los fármacos , Inhibidores Enzimáticos/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Oryza/microbiología , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/microbiología , Estaurosporina/aislamiento & purificación , Streptomyces/metabolismo , Xanthomonas/efectos de los fármacos
4.
Poult Sci ; 94(9): 2280-7, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26195809

RESUMEN

Ovomucoid is well known as a "trypsin inhibitor" and is considered to be the main food allergen in egg. However, the negative functions of ovomucoid can be eliminated if the protein is cut into small peptides. The objectives of this study were to hydrolyze ovomucoid using various enzyme combinations, and compare the functional properties of the hydrolysates. Purified ovomucoid was dissolved in distilled water (20 mg/mL) and treated with 1% of pepsin, α-chymotrypsin, papain, and alcalase, singly or in combinations. Sodium sodium dodecyl sulfate-polyacrylamide (SDS-PAGE) results of the hydrolysates indicated that pepsin (OMP), alcalase (OMAl), alcalase+trypsin (OMAlTr), and alcalase+papain (OMAlPa) treatments best hydrolyzed the ovomucoid, and the 4 treatments were selected to determine their functional characteristics. Among the 4 enzyme treatments, hydrolysate from OMAlTr showed the highest iron-chelating and antioxidant activities, while OMP showed higher ACE-inhibitory activity, but lower Fe-chelating activity than the other treatments. However, no difference in the copper-chelating activity among the treatments was found. MS/MS analysis identified numerous peptides from the hydrolysates of OMAlPa and OMAlTr, and majority of the peptides produced were <2 kDa. Pepsin treatment (OMP), however, hydrolyzed ovomucoid almost completely and produced only amino acid monomers, di- and tri-peptides. The ACE-inhibitory, antioxidant and iron-chelating activities of the enzyme hydrolysates were not consistent with the number and size of peptides in the hydrolysates, but we do not have information about the quantity of each peptide present in the hydrolysates at this point.


Asunto(s)
Proteínas Aviares/química , Proteínas Aviares/metabolismo , Pollos/metabolismo , Ovomucina/química , Ovomucina/metabolismo , Óvulo/química , Inhibidores de la Enzima Convertidora de Angiotensina/análisis , Animales , Antioxidantes/análisis , Quelantes/análisis , Electroforesis en Gel de Poliacrilamida , Endopeptidasas/química , Endopeptidasas/metabolismo , Hidrólisis , Metales/química , Péptidos/química , Péptidos/metabolismo , Espectrometría de Masas en Tándem
5.
J Appl Microbiol ; 117(3): 766-73, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24909841

RESUMEN

AIMS: To identify an actinobacterial strain that can promote growth and alleviate salinity stress in tomato plants. METHODS AND RESULTS: Actinobacteria were isolated from agricultural soil and screened for ACC deaminase activity, production of indole acetic acid (IAA), solubilization of tricalcium phosphate and sodium chloride (NaCl) salinity tolerance. Among the several strains tested, one strain designated PGPA39 exhibited higher IAA production, and phosphate solubilization in addition to ACC deaminase activity, and tolerance to 1 mol l(-1) NaCl. Strain PGPA39 was identified as a Streptomyces strain based on 16S rDNA sequence and designated Streptomyces sp. strain PGPA39. It promoted the growth of Arabidopsis seedlings in vitro as evidenced by a significant increase in plant biomass and number of lateral roots. Salinity stress-alleviating activity of PGPA39 was evaluated using 'Micro Tom' tomato plants with 180 mmol l(-1) NaCl stress under gnotobiotic condition. A significant increase in plant biomass and chlorophyll content and a reduction in leaf proline content were observed in PGPA39-inoculated tomato plants under salt stress compared with control and salt-stressed noninoculated plants. CONCLUSIONS: Streptomyces sp. strain PGPA39 alleviated salt stress and promoted the growth of tomato plants. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows the potential of Streptomyces sp. strain PGPA39 in alleviating salinity stress in tomato plants and could be utilized for stress alleviation in crop plants under field conditions.


Asunto(s)
Salinidad , Solanum lycopersicum/crecimiento & desarrollo , Streptomyces/metabolismo , Estrés Fisiológico , Biomasa , Liasas de Carbono-Carbono/metabolismo , Ácidos Indolacéticos/metabolismo , Solanum lycopersicum/efectos de los fármacos , Solanum lycopersicum/microbiología , Hojas de la Planta/microbiología , Plantones/crecimiento & desarrollo , Cloruro de Sodio/farmacología , Streptomyces/enzimología , Streptomyces/aislamiento & purificación
6.
Pol J Vet Sci ; 17(1): 99-103, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24724476

RESUMEN

The association between physiologically dependent pharmacokinetic parameters (CL(B), T1/2beta, Vd(ss)) of marbofloxacin and body weight was studied in eight animal species based on allometric equation Y = aWb, where 'Y' is the pharmacokinetic parameter, 'W' is body weight, 'a' is allometric coefficient (intercept) and 'b' is the exponent that describes relation between pharmacokinetic parameter and body weight. The body clearance of marbofloxacin has shown significant (P < 0.0001) relation with size (Bwt) in various animal species. However, half-life and volume of distribution were not in association with body weight. Although half-life and volume of distribution were not in a good correlation with body weight, statistically significant association between the body clearance and body weight suggests validity of allometric scaling for predicting pharmacokinetic parameters of marbofloxacin in animal species that have not been studied yet. However further study considering large sample size and other parameters influencing pharmacokinetics of marbofloxacin is recommended.


Asunto(s)
Antibacterianos/farmacocinética , Peso Corporal , Fluoroquinolonas/farmacocinética , Animales , Semivida , Estudios Retrospectivos , Especificidad de la Especie , Distribución Tisular
7.
J Appl Microbiol ; 115(1): 207-17, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23560777

RESUMEN

AIM: To study the antifungal mechanism of proteases from Streptomyces phaeopurpureus strain ExPro138 towards Colletotrichum coccodes and to evaluate its utilization as biofungicide. METHODS AND RESULTS: We screened proteolytic Streptomyces strains from the yam rhizosphere with antifungal activity. Forty proteolytic Streptomyces were isolated, among which eleven isolates showed gelatinolytic activity and antagonistic activity on C. coccodes. Of the 11 isolates, protease preparation from an isolate designated ExPro138 showed antifungal activity. 16S rDNA sequence analysis of the strain showed 99% similarity with Streptomyces phaeopurepureus (EU841588.1). Zymography analysis of the ExPro138 culture filtrate revealed that the strain produced several extracellular proteases. The protease preparation inhibited spore germination, spore adhesion to polystyrene surface and appressorium formation. Microscopic study of the interaction between ExPro138 and C. coccodes revealed that ExPro138 was mycoparasitic on C. coccodes. The protease preparation also reduced anthracnose incidence on tomato fruits compared with untreated control. CONCLUSION: This study demonstrates possibility of utilizing antifungal proteases derived from antagonistic microbes as biofungicide. SIGNIFICANCE AND IMPACT OF THE STUDY: Microbial proteases having the ability to inhibit spore adhesion and appressorium formation could be used to suppress infection establishment by foliar fungal pathogens at the initial stages of the infection process.


Asunto(s)
Antifúngicos/farmacología , Colletotrichum/efectos de los fármacos , Péptido Hidrolasas/farmacología , Streptomyces/enzimología , Antibiosis , Adhesión Celular/efectos de los fármacos , Colletotrichum/citología , Colletotrichum/crecimiento & desarrollo , Dioscorea/microbiología , Solanum lycopersicum/microbiología , Péptido Hidrolasas/metabolismo , Enfermedades de las Plantas/terapia , Proteolisis , Esporas Fúngicas/citología , Esporas Fúngicas/efectos de los fármacos , Streptomyces/clasificación
8.
J Appl Microbiol ; 111(2): 443-55, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21714834

RESUMEN

AIM: To find a suitable biocontrol agent for yam anthracnose caused by Colletotrichum gloeosporioides. METHODS AND RESULTS: An actinobacterial strain, MJM5763, showing strong antifungal activity, multiple biocontrol and plant growth-promoting traits was isolated from a yam cultivation field in Yeoju, South Korea. Based on morphological and physiological characteristics and analysis of the 16S rDNA sequence, strain MJM5763 was identified as a novel strain of Streptomyces and was designated as Streptomyces sp. MJM5763. Treatment with MJM5763 and the crude culture filtrate extract (CCFE) was effective in suppressing anthracnose in detached yam leaves in vitro and reduced incidence and severity of anthracnose in yam plants under greenhouse conditions. The CCFE treatment was the most effective of all the treatments and reduced the anthracnose severity by 85-88% and the incidence by 79-81%, 90 days after inoculation with the pathogen. CCFE treatment was also effective under field conditions and showed a reduction of 86 and 75% of anthracnose severity and incidence, respectively. CONCLUSION: Streptomyces sp. strain MJM5763 was effective in biocontrolling anthracnose in yam caused by C. gloeosporioides. SIGNIFICANCE AND IMPACT OF THE STUDY: Streptomyces sp. MJM5763 is a potential alternative to chemical fungicides for reducing yield losses to anthracnose in yam.


Asunto(s)
Antibiosis , Colletotrichum/crecimiento & desarrollo , Dioscorea/microbiología , Enfermedades de las Plantas/prevención & control , Streptomyces/fisiología , Colletotrichum/aislamiento & purificación , Colletotrichum/patogenicidad , ADN Bacteriano/genética , Filogenia , Enfermedades de las Plantas/microbiología , Hojas de la Planta/microbiología , ARN Ribosómico 16S/genética , República de Corea , Esporas Fúngicas/crecimiento & desarrollo , Streptomyces/clasificación , Streptomyces/genética
9.
Proc IEEE Int Symp Biomed Imaging ; : 1223-1226, 2011 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-23377533

RESUMEN

We present a new registration method for whole-body rat computed tomography (CT) image and positron emission tomography (PET) images using a weighted demons algorithm. The CT and PET images are acquired in separate scanners at different times and the inherent differences in the imaging protocols produced significant nonrigid changes between the two acquisitions in addition to heterogeneous image characteristics. In this situation, we utilized both the transmission-PET and the emission-PET images in the deformable registration process emphasizing particular regions of the moving transmission-PET image using the emission-PET image. We validated our results with nine rat image sets using M-Hausdorff distance similarity measure. We demonstrate improved performance compared to standard methods such as Demons and normalized mutual information-based non-rigid FFD registration.

10.
Proc IEEE Int Symp Biomed Imaging ; 2010: 25, 2010 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-21479163

RESUMEN

Vascular registration is a challenging problem with many potential applications. However, registering vessels accurately is difficult as they often occupy a small portion of the image and their relative motion/deformation is swamped by the displacements seen in large organs such as the heart and the liver. Our registration method uses a vessel detection algorithm to generate a vesselness image (probability of having a vessel at any given voxel) which is used to construct a weighting factor that is used to modify the intensity metric to give preference to vascular structures while maintaining the larger context. Therefore, our proposing method uses fully data-driven calculated weights and needs no prior knowledge for the weight calculation. We applied our method to the registration of serial MRI lamb images obtained from studies on tissue engineered vascular grafts and demonstrate encouraging performance as compared to non-weighted registration methods.

11.
Curr Microbiol ; 53(3): 204-8, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16874544

RESUMEN

Genetic characterization of afsK-av (SAV3816) in Streptomyces avermitilis ATCC 31272 was performed to evaluate the role(s) of this eukaryotic-type serine-threonine protein kinase (STPK) in the regulation of morphologic differentiation and secondary metabolism. The afsK-av::neo mutant (SJW4001) was defective in sporulation, melanogenesis, and avermectin production. These phenotypic defects were complemented by introduction of either the intact afsK-av or the 900-nt catalytic domain region. The catalytic domain restored sporulation and melanogenesis to SJW4001 whereas it partially recovered avermectin production. This study reveals that AfsKav is a pleiotropic regulator and demonstrates in vivo that the C-region of AfsKav is not essential for its regulatory role in S. avermitilis differentiations.


Asunto(s)
Dominio Catalítico/genética , Proteínas Serina-Treonina Quinasas/genética , Streptomyces/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Prueba de Complementación Genética/métodos , Ivermectina/análogos & derivados , Ivermectina/metabolismo , Melaninas/metabolismo , Mutación/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Esporas Bacterianas/genética , Esporas Bacterianas/metabolismo , Streptomyces/enzimología , Streptomyces/fisiología
12.
J Appl Microbiol ; 99(1): 213-21, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15960681

RESUMEN

AIMS: To identify an antagonistic strain against Streptomyces scabiei and to characterize the antibiotic agent. The efficacy of the isolated strain in controlling common scab disease was also evaluated. METHODS AND RESULTS: A bacterial strain antagonistic against S. scabiei was isolated from the soil of a potato-cultivating area. This bacterium was identified as a Bacillus species by 16S rRNA gene sequence analysis and was designated Bacillus sp. sunhua. Antibiotics produced by this strain were proven to be stable within a broad pH range and at high temperatures. The culture broth was extracted with ethyl acetate, and then the crude extract was applied to HPLC. Two compounds were isolated and identified as iturin A and macrolactin A by 1H-NMR, 13C-NMR, HMBC, HMQC and mass spectrometer. The culture broth of Bacillus sp. sunhua had a suppressive effect on common scab disease in a pot assay, decreasing the infection rate from 75 to 35%. This strain also suppressed Fusarium oxysporum, the pathogen of potato dry rot disease. CONCLUSIONS: Bacillus sp. sunhua was shown to inhibit S. scabiei effectively. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report demonstrating that macrolactin A and iturin A inhibit S. scabiei. This study demonstrated the possibility of controlling potato scab disease using Bacillus sp. sunhua.


Asunto(s)
Antibacterianos/análisis , Bacillus/fisiología , Enfermedades de las Plantas/microbiología , Microbiología del Suelo , Streptomyces/efectos de los fármacos , Antifúngicos/análisis , Secuencia de Bases , Bioensayo/métodos , Sistema Libre de Células , Concentración de Iones de Hidrógeno , Macrólidos/análisis , Microscopía Electrónica de Rastreo/métodos , Péptidos/análisis , Péptidos Cíclicos , Control Biológico de Vectores/métodos , ARN Ribosómico 16S/análisis , Solanum tuberosum , Esporas Bacterianas/efectos de los fármacos , Esporas Bacterianas/crecimiento & desarrollo , Streptomyces/crecimiento & desarrollo , Streptomyces/ultraestructura , Temperatura
13.
FEMS Microbiol Lett ; 202(1): 97-102, 2001 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-11506914

RESUMEN

Forty one strains isolated from 21 samples of various mushroom composts in Korea were analyzed by 16S rRNA gene sequencing to investigate the phylogenetic diversity of thermophilic actinomycetes. The 25 strains of thermophilic actinomycete isolates were related to the five genera, Pseudonocardia, Saccharomonospora, Saccharopolyspora, Streptomyces, and Thermobifida, within the order Actinomycetales, and 16 strains were classified into the genus Thermoactinomyces within the family Bacillaceae. Most of 41 isolates were encompassed by two genera, Streptomyces and Thermoactinomyces, that were isolated mainly in composts prepared from waste cotton and hay, respectively. Among them, M104 and M109 were placed in distinct taxonomic positions although these strains formed phylogenetic lineages related to the genus Streptomyces and to the family Streptosporangiaceae, respectively. Therefore, a phenetic and genetic characterization of these strains will be needed to pinpoint their taxonomic position.


Asunto(s)
Agaricales , ADN Ribosómico/genética , Genes Bacterianos/genética , Micromonosporaceae/clasificación , Micromonosporaceae/genética , Filogenia , ARN Ribosómico 16S/genética , Variación Genética/genética , Corea (Geográfico) , Mutación/genética , Análisis de Secuencia de ADN , Residuos
14.
Antonie Van Leeuwenhoek ; 78(3-4): 237-42, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11386345

RESUMEN

The catabolism of branched chain amino acids, especially valine, appears to play an important role in furnishing building blocks for macrolide and polyether antibiotic biosyntheses. To determine the active site residues of ValDH, we previously cloned, partially characterized, and identified the active site (lysine) of Streptomyces albus ValDH. Here we report further characterization of S. albus ValDH. The molecular weight of S. albus ValDH was determined to be 38 kDa by SDS-PAGE and 67 kDa by gel filtration chromatography indicating that the enzyme is composed of two identical subunits. Optimal pHs were 10.5 and 8.0 for dehydrogenase activity with valine and for reductive amination activity with alpha-ketoisovaleric acid, respectively. Several chemical reagents, which modify amino-acid side chains, inhibited the enzyme activity. To examine the role played by the residue for enzyme specificity, we constructed mutant ValDH by substituting alanine for glycine at position 124 by site-directed mutagenesis. This residue was chosen because it has been considered to be important for substrate discrimination by phenylalanine dehydrogenase (PheDH) and leucine dehydrogenase (LeuDH). The Ala-124-Gly mutant enzyme displayed lower activities toward aliphatic amino acids, but higher activities toward L-phenylalanine, L-tyrosine, and L-methionine compared to the wild type enzyme suggesting that Ala-124 is involved in substrate binding in S. albus ValDH.


Asunto(s)
Aminoácido Oxidorreductasas/metabolismo , Streptomyces/enzimología , Aminoácido Oxidorreductasas/química , Aminoácido Oxidorreductasas/genética , Secuencia de Aminoácidos , Bacterias/enzimología , Sitios de Unión , Cromatografía en Gel , Clonación Molecular , Electroforesis en Gel de Poliacrilamida , Escherichia coli , Cinética , Lisina , Datos de Secuencia Molecular , Peso Molecular , Subunidades de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Streptomyces/genética , Especificidad por Sustrato , Valina Deshidrogenasa (NADP+)
15.
FEMS Microbiol Lett ; 182(1): 29-34, 2000 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-10612726

RESUMEN

A gene encoding valine dehydrogenase (Vdh) has been cloned from Streptomyces albus, a salinomycin producer, and expressed in Escherichia coli. The S. albus Vdh is composed of 364 amino acids that showed high homology with several other amino acid dehydrogenases as well as Vdhs from Streptomyces spp. and leucine and phenylalanine dehydrogenases (Ldh and Pdh) from Bacillus spp. A protein of 38 kDa, corresponding to the approximate mass of the predicted S. albus Vdh product (38.4 kDa) exhibiting specific Vdh activity, was observed when the S. albus vdh gene was overexpressed in E. coli under the controlled T7 promoter and was subsequently purified to homogeneity. Among branched- and straight-chain amino acids, L-valine and L-alpha-aminobutyrate were the preferred substrates for the enzyme. Lys-79 and Lys-91 of S. albus Vdh were highly conserved in the corresponding region of NAD(P)(+)-dependent amino acid dehydrogenase sequences. To elucidate the functional roles of the lysyl residues, the Lys residues have individually been replaced with Ala by site-directed mutagenesis. Kinetic analyses of the Lys-79 and Lys-91-mutated enzymes revealed that they are involved in the substrate binding site and catalysis, respectively, analogous to the corresponding residues in the homologous Ldh and Pdh.


Asunto(s)
Aminoácido Oxidorreductasas/genética , Aminoácido Oxidorreductasas/metabolismo , Streptomyces/enzimología , Valina/metabolismo , Aminoácido Oxidorreductasas/química , Aminoácido Oxidorreductasas/aislamiento & purificación , Secuencia de Aminoácidos , Sitios de Unión , Clonación Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Cinética , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Análisis de Secuencia de ADN , Streptomyces/genética , Especificidad por Sustrato , Valina Deshidrogenasa (NADP+)
16.
J Pediatr Surg ; 34(12): 1782-6, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10626854

RESUMEN

BACKGROUND: Nitrofen (2,4-dichloro-4'-nitrodiphenyl ether), a diapheny ether herbicide, is known to induce in rat fetuses a variety of congenital cardiovascular anomalies, together with diaphragmatic hernia and hydronephrosis. The purpose of the current study was to produce congenital cardiovascular anomalies in rat fetuses by oral nitrofen administration at the indicated doses and days of gestation, and to determine the characteristics of resulting nitrofen-induced cardiovascular anomalies. METHODS: All the observed fetuses were removed from pregnant Sprague-Dawley rats killed on the 21st day of gestation. They were preserved in 10% formalin, and dissection for examination was carried out under a dissecting microscope. RESULTS: The following results were based on dissecting microscopic findings of 482 offspring: (1) The 11th day of gestation was the most sensitive for nitrofen induction of congenital cardiovascular anomalies. The incidence of these was dose related. (2) Ventricular septal defect was the most common single cardiovascular anomaly, representing more than half of all such irregularities. The next most common were aortic arch anomalies and tetralogy of Fallot. (3) Cardiac anomalies derived from infundibular maldevelopment such as tetralogy of Fallot and pulmonary atresia with ventricular septal defect were observed only in the group treated with nitrofen on the 11th gestational day. (4) Aortic arch anomalies were very frequent; the great majority were anomalous right subclavian artery with left aortic arch. CONCLUSION: This animal model is suitable for further embryological investigation of the development of congenital cardiovascular anomalies.


Asunto(s)
Cardiopatías Congénitas/inducido químicamente , Herbicidas/toxicidad , Éteres Fenílicos/toxicidad , Animales , Anomalías de los Vasos Coronarios , Modelos Animales de Enfermedad , Femenino , Edad Gestacional , Defectos del Tabique Interventricular/inducido químicamente , Embarazo , Ratas , Ratas Sprague-Dawley
17.
J Dermatol ; 25(5): 322-8, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9640886

RESUMEN

Merkel cell carcinoma (MCC) is an unusual malignant tumor that arises from neuroendocrine cells with features of epithelial differentiation. We describe a MCC patient with unusual clinical, histopathological, and immunohistochemical features. Although the microscopic, immunohistochemical, and ultrastructural characteristics of MCC have been well defined, diagnostic difficulties remain, particularly in distinguishing it from lymphoma involving the skin, as suggested by our case. This is an unusual case in which dense lymphoid infiltration masked the true tumor. All the immunohistochemical markers of MCC except neuron-specific enolase (NSE) were negative. The dramatic response to primary chemotherapy was also very noteworthy.


Asunto(s)
Carcinoma de Células de Merkel/diagnóstico , Neoplasias Cutáneas/diagnóstico , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células de Merkel/tratamiento farmacológico , Ciclofosfamida/administración & dosificación , Diagnóstico Diferencial , Doxorrubicina/administración & dosificación , Humanos , Linfoma/diagnóstico , Masculino , Prednisolona/administración & dosificación , Neoplasias Cutáneas/tratamiento farmacológico , Vincristina/administración & dosificación
18.
Cancer Lett ; 122(1-2): 1-8, 1998 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-9464484

RESUMEN

Eleven urinary polyamine levels were determined in controls (32 cases) and 43 patients with varying stages of leukemia including initial, relapse and complete remission, using gas chromatography nitrogen-phosphorus detection. Also, to indirectly evaluate the possible involvement of enzymes, precursor to product concentration ratios were compared between controls and patients with each stage of leukemia. As a result, it is confirmed that the ratio of N1-acSpd/N8-acSpd could be used as a diagnostic marker and the level of N1,N12-diacetylspermine could be used for determining disease stage and as a malignancy marker for leukemia. An altered metabolic pathway related to leukemia is also proposed in which N1,N12-diacetylspermine can be produced directly from spermine and N1,N12-diacetylspermine is a major source of N1-acetylspermidine.


Asunto(s)
Poliaminas Biogénicas/orina , Leucemia/orina , Adolescente , Adulto , Biomarcadores de Tumor/orina , Femenino , Humanos , Masculino , Persona de Mediana Edad
19.
Artif Organs ; 21(2): 154-9, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9028499

RESUMEN

Although the use of sheep in total artificial heart (TAH) implantation has many advantages, they are known to show a significant morbidity rate on cardiopulmonary bypass (CPB); this has been considered to be a major limiting factor in using them for TAH experiments. We conducted a series of ovine CPB experiments to evaluate the sheep's pathophysiological response to CPB. CPB-related hemolysis, bleeding, and lung dysfunction were analyzed in 5 sheep, which had undergone CPB, used at our hospital for TAH implantation. Four of the 5 sheep survived the experimental procedures, and 3 of them survived on a long-term basis. Unacceptable degrees of hemolysis related to CPB were not observed. Postoperative bleeding was not remarkable, and coagulation test results did not show significant abnormal findings. Acute lung injuries of a mild to moderate degree were found mainly at the microscopic level, but rarely had clinical significance. In conclusion, this experiment suggests that sheep can be used for the animal model for TAH implantation with acceptable risk on CPB circuits and techniques are used.


Asunto(s)
Puente Cardiopulmonar/veterinaria , Corazón Artificial , Ovinos/cirugía , 3,4-Metilenodioxianfetamina/sangre , Animales , Puente Cardiopulmonar/efectos adversos , Femenino , Hemólisis , Hemorragia/etiología , Hemorragia/veterinaria , Pulmón/patología , Pulmón/ultraestructura , Masculino , Microscopía Electrónica , Complicaciones Posoperatorias/veterinaria , Medición de Riesgo , Ovinos/fisiología , Enfermedades de las Ovejas/etiología , Trombosis/etiología , Trombosis/veterinaria , beta-Tromboglobulina/análisis
20.
J Chromatogr B Biomed Sci Appl ; 688(2): 179-86, 1997 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-9061454

RESUMEN

With a newly modified analytical method, the concentrations of free and acetylated urinary polyamines were simultaneously determined in a control group (32 cases) and patients with various types of cancers (104 cases, 20 males and 84 females) by gas chromatography-nitrogen-phosphorus detection. Significant concentration differences between normal subjects and various cancer patients were found. The various types of cancers (advanced gastric carcinoma, ovarian cancer, acute myelocyte leukemia, non-Hodgkin's lymphoma) gave unique patterns of urinary polyamine profile as well as significant differences of concentration. To indirectly evaluate the possible involvement of enzymes, precursor-to-product concentration ratios were compared between controls and patients with various types of cancers.


Asunto(s)
Neoplasias/orina , Poliaminas/orina , Adulto , Carcinoma/diagnóstico , Carcinoma/orina , Cromatografía de Gases/métodos , Femenino , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/orina , Linfoma no Hodgkin/diagnóstico , Linfoma no Hodgkin/orina , Masculino , Persona de Mediana Edad , Neoplasias/diagnóstico , Neoplasias Ováricas/diagnóstico , Neoplasias Ováricas/orina , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/orina
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