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2.
Pediatr Surg Int ; 30(8): 815-22, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25052255

RESUMEN

PURPOSE: Intestinal neuronal dysplasia Type B (IND-B) has been proposed to be an allied disorder of Hirschsprung's disease (ADHD). The original histological criteria included hyperganglionosis, giant ganglia, ectopic ganglion cells and an increased AChE activity in the lamina propria. The criteria for IND-B have been gradually revised. The present diagnostic criteria are [1] more than 20 % of the submucosal ganglia contain nine or more ganglion cells and [2] the patient is older than 1 year. To clarify the current status of IND-B in Japan, a nationwide retrospective cohort study was performed. METHODS: Questionnaires were sent to 161 major institutes of pediatric surgery and gastroenterology in Japan. RESULTS: A total of 355 cases of ADHD were collected, including 18 cases of IND-B (5 %). Based on original criteria, 13 out of 18 cases were diagnosed as IND-B. However, only four cases met the current criteria. Three of the four patients (75 %) required pull-through operation. All of the patients exhibited giant ganglia and ganglioneuromatosis-like hyperplasia of the myenteric plexus. CONCLUSIONS: IND-B cases matching the current criteria are thought to be quite rare and they are associated with marked hyperplasia of the myenteric plexus. "True" IND-B is a rare and intractable disease.


Asunto(s)
Sistema Nervioso Entérico/patología , Enfermedad de Hirschsprung/patología , Mucosa Intestinal/inervación , Plexo Submucoso/patología , Adolescente , Niño , Preescolar , Femenino , Enfermedad de Hirschsprung/epidemiología , Humanos , Incidencia , Mucosa Intestinal/patología , Japón/epidemiología , Masculino , Estudios Retrospectivos , Encuestas y Cuestionarios
3.
Science ; 382(6673): 903-907, 2023 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-37995237

RESUMEN

Cosmic rays are energetic charged particles from extraterrestrial sources, with the highest-energy events thought to come from extragalactic sources. Their arrival is infrequent, so detection requires instruments with large collecting areas. In this work, we report the detection of an extremely energetic particle recorded by the surface detector array of the Telescope Array experiment. We calculate the particle's energy as [Formula: see text] (~40 joules). Its arrival direction points back to a void in the large-scale structure of the Universe. Possible explanations include a large deflection by the foreground magnetic field, an unidentified source in the local extragalactic neighborhood, or an incomplete knowledge of particle physics.

4.
Cryo Letters ; 33(3): 202-13, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22825787

RESUMEN

A number of volvocalean green algae species were subjected to a two-step cryopreservation protocol with various cryoprotectants. Potential cryoprotectants were methanol (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide, N-methylformamide, and hydroxyacetone (HA). We confirmed prior reports that MeOH was effective for cryopreserving Chlamydomonas, but did not work well for larger volvocaleans such as Volvox. In contrast, DMF and HA were effective for both unicellular and multicellular representatives. When we used a cold-inducible transposon to probe Southern blots of Volvox DNA samples taken before and after storage for one month in LN, we could detect no differences, indicating that the genome had remained relatively stable and that the transposon had not been induced by the cryopreservation procedure. We believe these methods will facilitate long-term storage of several volvocine algal species, including Volvox strains harboring transposon-induced mutations of developmental interest.


Asunto(s)
Acetona/análogos & derivados , Chlorophyta/citología , Criopreservación/métodos , Crioprotectores , Formamidas , Acetona/química , Chlamydomonas/citología , Crioprotectores/química , Formamidas/química , Volvox/citología
5.
Am J Transplant ; 11(2): 394-8, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21219577

RESUMEN

Progressive familial intrahepatic cholestasis is a syndrome of severe cholestasis progressing to biliary cirrhosis and liver failure that develops in childhood. This report describes two siblings with PFIC-2 who underwent living-related liver transplantation from their genetically proven heterozygous parents. Both patients had normal gamma-glutamyl transpeptidase levels, but showed severe pruritus with sleep disturbance, cholestasis, jaundice and growth failure. Genetic testing of each patient revealed two missense mutations of the bile salt export pump, S901R and C1083Y, which have not previously been associated with PFIC-2. Usual medical treatment failed to improve their clinical symptoms, and the two siblings underwent living-related liver transplantation from their heterozygous parents. The transplants improved their clinical symptoms significantly, and the patients have since shown age-appropriate growth. Electron microscopic findings of the explanted liver of the younger sister revealed dense and amorphous bile, which is characteristic of PFIC-2. In the cases presented here, living-related liver transplantation from a heterozygous donor was associated with better quality of life and improvement of growth, and thus appears to be a feasible option for PFIC-2 patients. Mutation analysis is a useful tool to help decide the course of treatment of PFIC.


Asunto(s)
Trasplante de Hígado/métodos , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP , Transportadoras de Casetes de Unión a ATP/genética , Adulto , Niño , Desarrollo Infantil , Preescolar , Colestasis Intrahepática/genética , Colestasis Intrahepática/patología , Colestasis Intrahepática/cirugía , Femenino , Heterocigoto , Humanos , Donadores Vivos , Masculino , Mutación Missense , Padres , Calidad de Vida , Hermanos
6.
Gut ; 57(12): 1682-9, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18653729

RESUMEN

BACKGROUND: A novel T helper (Th) cell lineage, Th17, that exclusively produces the proinflammatory cytokine interleukin 17 (IL17) has been reported to play important roles in various inflammatory diseases. IL23 is also focused upon for its potential to promote Th17. Here, the roles of the IL23/IL17 axis in inflammatory bowel diseases such as ulcerative colitis (UC) and Crohn's disease (CD) were investigated. METHODS: Mucosal samples were obtained from surgically resected specimens (controls, n = 12; UC, n = 17; CD, n = 22). IL17 production by isolated peripheral blood (PB) and lamina propria (LP) CD4(+) cells was examined. Quantitative PCR amplification was performed to determine the mRNA expression levels of IL17, interferon gamma (IFNgamma), IL23 receptor (IL23R) and retinoic acid-related orphan receptor gamma (RORC) in LP CD4(+) cells, and IL12 family members, such as IL12p40, IL12p35 and IL23p19, in whole mucosal specimens. The effects of exogenous IL23 on IL17 production by LP CD4(+) cells were also examined. RESULTS: IL17 production was higher in LP CD4(+) cells than in PB. Significant IL17 mRNA upregulation in LP CD4(+) cells was found in UC, while IFNgamma was increased in CD. IL23R and RORC were upregulated in LP CD4(+) cells isolated from both UC and CD. IL17 production was significantly increased by IL23 in LP CD4(+) cells from UC but not CD. Upregulated IL23p19 mRNA expression was correlated with IL17 in UC and IFNgamma in CD. CONCLUSIONS: IL23 may play important roles in controlling the differential Th1/Th17 balance in both UC and CD, although Th17 cells may exist in both diseases.


Asunto(s)
Colitis Ulcerosa/metabolismo , Enfermedad de Crohn/metabolismo , Interleucina-17/biosíntesis , Interleucina-23/fisiología , Linfocitos T Colaboradores-Inductores/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Colitis Ulcerosa/inmunología , Enfermedad de Crohn/inmunología , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Inmunohistoquímica , Interleucina-23/farmacología , Mucosa Intestinal/metabolismo , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Subgrupos de Linfocitos T/metabolismo , Regulación hacia Arriba , Adulto Joven
7.
Br Poult Sci ; 49(3): 273-81, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18568751

RESUMEN

1. Inter-breed morphological comparisons were made among 11 breeds of Japanese native chickens (Gifujidori, Hinaidori, Shokoku, Totenko, Tomaru, Satsumadori, Shamo, Koshamo, Koeyoshi, Chabo and Nagoya), White Leghorn, broiler chickens (Chunky) and red junglefowl collected in the Philippines, based on results of direct measurements and analysis by computer vision techniques of the skull. 2. Analysis of direct measurements identified two groups of chicken: a small type that included the Chabo, Koshamo, red junglefowl, Gifujidori and Shokoku and a large type that included the remaining breeds studied. These groupings were made based on size determined both in the first (PC1) and second principal component (PC2). The greatest length of the cranium and condylobasal length greatly contributed to the morphological differences between these two groups. 3. Analysis by computer vision techniques, however, identified three groups: the Bantam group (which includes red junglefowl), Shokoku group and Shamo group. White Leghorn clustered within the Shokoku group while the broiler chicken belonged to the Shamo group. The region around the junction of the neural cranium and the visceral cranium contributed greatly to the morphological differences among breeds, both in the PC1 and PC2.


Asunto(s)
Pollos/anatomía & histología , Pollos/genética , Cráneo/anatomía & histología , Animales , Pollos/clasificación , Gráficos por Computador , Simulación por Computador , Femenino , Variación Genética , Japón , Masculino , Filogenia , Especificidad de la Especie
8.
Cancer Res ; 55(3): 652-7, 1995 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-7530600

RESUMEN

nm23 was originally identified as an antimetastatic gene, the expression of which was inversely correlated with tumor metastatic potential in rodent model systems. Subsequently, two related human nm23 genes, nm23-H1 and nm23-H2, were identified. The relationship between expression of nm23-H1 and nm23-H2 in hepatocellular carcinoma specimens from 30 patients and metastatic potential was investigated with the use of a quantitative reverse transcription-PCR procedure. The abundance of nm23-H1 and nm23-H2 mRNA was compared with serum alpha-fetoprotein concentration, tumor size (maximum diameter), and histopathological parameters such as portal vein tumor thrombus, intrahepatic metastasis, capsular formation, capsular infiltration, differentiation of tumor cells, and TNM stage. The abundance of nm23-H1 mRNA showed a significant inverse correlation with intrahepatic metastasis and TNM stage. Furthermore, we confirmed that reduced expression of nm23-H1 mRNA was in accordance with a reduced amount of NM23-H1 protein using Western blot analysis. No correlation was apparent between nm23-H2 mRNA abundance and intrahepatic metastasis. These data support the conclusion that nm23-H1 may play a more important role than nm23-H2 in intrahepatic metastasis in hepatocellular carcinoma. Furthermore, nm23-H1 mRNA abundance may be a predictor of intrahepatic metastasis, the most important factor correlated with the metastatic potential of hepatocellular carcinoma.


Asunto(s)
Carcinoma Hepatocelular/genética , Expresión Génica , Neoplasias Hepáticas/genética , Proteínas de Unión al GTP Monoméricas , ARN Mensajero/biosíntesis , Factores de Transcripción/biosíntesis , Factores de Edad , Secuencia de Bases , Western Blotting , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/cirugía , Diferenciación Celular , Cartilla de ADN , Humanos , Cinética , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/cirugía , Persona de Mediana Edad , Datos de Secuencia Molecular , Análisis Multivariante , Nucleósido Difosfato Quinasas NM23 , Metástasis de la Neoplasia , Estadificación de Neoplasias , Nucleósido-Difosfato Quinasa/biosíntesis , Reacción en Cadena de la Polimerasa , ARN Mensajero/análisis , Factores de Transcripción/genética , alfa-Fetoproteínas/análisis
9.
Oncogene ; 19(34): 3941-7, 2000 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-10951587

RESUMEN

Human myeloid leukemia cells respond to 12-tetradecanoylphorbol-13-acetate (TPA) and other activators of protein kinase C (PKC) with the induction of terminal monocytic differentiation. The present studies demonstrate that TPA treatment of U-937 leukemia cells is associated with release of mitochondrial cytochrome c, activation of caspase-3 and induction of internucleosomal DNA fragmentation. By contrast, the TUR cell variant, which is deficient in PKCbeta, failed to respond to TPA with release of cytochrome c and induction of the caspase-3 cascade. Moreover, stable overexpression of PKCbeta in TUR cells reconstituted sensitivity to TPA-induced cytochrome c release and activation of caspase-3. The results also demonstrate that treatment of cells with the caspase inhibitor Z-VAD-fmk blocks both TPA-induced apoptosis and monocytic differentiation. Similar results were obtained in U-937 cells stably expressing the CrmA caspase inhibitor. These findings demonstrate that TPA induces cytochrome c release by a PKCbeta-dependent mechanism and that activation of caspase-mediated signaling is required for induction of the differentiated monocytic phenotype.


Asunto(s)
Caspasas/metabolismo , Leucemia Mieloide/metabolismo , Leucemia Mieloide/patología , Proteínas Virales , Clorometilcetonas de Aminoácidos/farmacología , Caspasa 1/metabolismo , Caspasa 3 , Inhibidores de Caspasas , Diferenciación Celular/efectos de los fármacos , Inhibidores de Cisteína Proteinasa/farmacología , Grupo Citocromo c/efectos de los fármacos , Grupo Citocromo c/metabolismo , Activación Enzimática , Humanos , Isoenzimas/metabolismo , Leucemia Mieloide/tratamiento farmacológico , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Proteína Quinasa C/metabolismo , Proteína Quinasa C beta , Serpinas/genética , Serpinas/metabolismo , Transducción de Señal , Acetato de Tetradecanoilforbol/farmacología , Células Tumorales Cultivadas
10.
Oncogene ; 19(16): 1975-81, 2000 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-10803458

RESUMEN

The release of mitochondrial cytochrome c by genotoxic stress induces the formation of a cytosolic complex with Apaf-1 (mammalian CED4 homolog) and thereby the activation of procaspase-3 (cas-3) and procaspase-9 (cas-9). Here we demonstrate that heat-shock protein 27 (Hsp27) inhibits cytochrome c (cyt c)-dependent activation of cas-3. Hsp27 had no effect on cyt c release, Apaf-1 and cas-9 activation. By contrast, our results show that Hsp27 associates with cas-3, but not Apaf-1 or cas-9, and inhibits activation of cas-3 by cas-9-mediated proteolysis. Furthermore, the present results demonstrate that immunodepletion of Hsp27 depletes cas-3. Importantly, treatment of cells with DNA damaging agents dissociates the Hsp27/cas-3 complex and relieves inhibition of cas-3 activation. These findings define a novel function for Hsp27 and provide the first evidence that a heat shock protein represses cas-3 activation.


Asunto(s)
Caspasas/metabolismo , Grupo Citocromo c/metabolismo , Precursores Enzimáticos/metabolismo , Proteínas de Choque Térmico/metabolismo , Actinas/metabolismo , Factor Apoptótico 1 Activador de Proteasas , Caspasa 3 , Caspasa 9 , Caspasas/efectos de los fármacos , Caspasas/inmunología , Línea Celular/efectos de los fármacos , Línea Celular/efectos de la radiación , Sistema Libre de Células , Citarabina/farmacología , Grupo Citocromo c/efectos de los fármacos , Grupo Citocromo c/efectos de la radiación , Citosol/metabolismo , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Precursores Enzimáticos/efectos de los fármacos , Precursores Enzimáticos/inmunología , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/inmunología , Proteínas de Choque Térmico/efectos de la radiación , Humanos , Immunoblotting , Isoenzimas/metabolismo , Metilmetanosulfonato/farmacología , Oligopéptidos/metabolismo , Proteína Quinasa C/metabolismo , Proteína Quinasa C-delta , Proteínas/metabolismo , Estaurosporina/farmacología
11.
Biochim Biophys Acta ; 477(1): 1-9, 1977 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-195612

RESUMEN

Escherichia coli K-12 nadC13 (ColE1) was starved for nicotinic acid and cellular NAD levels decreased to less than 10% of the normal. Under these conditions, induction of colicin E1 synthesis decreased to about 1% of the normal value, while 30% of the total protein synthesis remained intact. Addition of nicotinic acid reversed both the ability of the colicin induction and cellular NAD level. Induced replication of colicin E1 DNA was greatly reduced in the NAD-deprived cells.


Asunto(s)
Colicinas/biosíntesis , Escherichia coli/metabolismo , NAD/metabolismo , Ácidos Nicotínicos/farmacología , Adenosina Trifosfato/biosíntesis , Proteínas Bacterianas/biosíntesis , Replicación del ADN/efectos de los fármacos , ADN Bacteriano/metabolismo , Escherichia coli/efectos de los fármacos , Mitomicinas/farmacología , Ácidos Nicotínicos/deficiencia , ARN Bacteriano/biosíntesis , Timina/metabolismo , Uridina/metabolismo
12.
Biochim Biophys Acta ; 1489(2-3): 383-8, 1999 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-10673039

RESUMEN

We have characterized the 5'-flanking region of the gene encoding bovine adenylate kinase isozyme 3 (AK3). S1 mapping analysis revealed multiple transcription start points in the bovine AK3 gene. The promoter activities were tested in HeLa cells using the chloramphenicol acetyltransferase (CAT) gene as a reporter. The CAT analysis showed that the basal promoter sequence was located within the region from -189 to +228. In the presence of short DNA fragments of the 5'-flanking region as competitors, the transcriptional activity of the bovine AK3 promoter changed depending on the fragments used. The results identified the basal regulatory elements in the proximal promoter region.


Asunto(s)
Adenilato Quinasa/genética , Isoenzimas/genética , Regiones Promotoras Genéticas , Animales , Secuencia de Bases , Bovinos , Cloranfenicol O-Acetiltransferasa/genética , ADN , Datos de Secuencia Molecular
13.
Biochim Biophys Acta ; 1115(1): 36-41, 1991 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-1958703

RESUMEN

To examine whether cytosolic adenylate kinase (AK1, EC 2.7.4.3) catalyzes synthesis of thiamin triphosphate (TTP) in vivo, chicken AK1 was expressed in Escherichia coli, and cellular AK1 activity and TTP content were determined. E. coli harboring the vector plasmid was used as a control. Chicken AK1 was expressed in the producer strain at a high level (83 U/mg protein) even without inducers, and this expression was doubled (153 U/mg protein) by beta-D-isopropylthiogalactopyranoside (IPTG). TTP was accumulated in the producer cells at a high level (5.7 nmol/g dry weight) without IPTG and this was also doubled (10.2 nmol/g dry weight) by IPTG. TTP content in the control strain was very low (0.2-0.9 nmol/g dry weight) and was unaffected by IPTG. Neither bacterial growth curve nor cellular content of AMP, ADP, ATP, thiamin diphosphate or total thiamin (sum of thiamin and its phosphate esters) was different between the producer and the control strains. These results indicate that chicken AK1 expressed in E. coli catalyzed the synthesis and accumulation of TTP within the bacterial cells.


Asunto(s)
Adenilato Quinasa/metabolismo , Citosol/enzimología , Escherichia coli/enzimología , Tiamina Trifosfato/biosíntesis , Adenosina Difosfato/metabolismo , Adenosina Monofosfato/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Catálisis , Sistema Libre de Células , Pollos , Escherichia coli/genética , Escherichia coli/metabolismo , Vectores Genéticos , Isopropil Tiogalactósido/metabolismo , Tiamina Trifosfato/metabolismo
14.
Biochim Biophys Acta ; 1161(2-3): 230-4, 1993 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-8431472

RESUMEN

The thiamin triphosphate (TTP)-synthesizing activity and the ATP-synthesizing activity of two mutant enzymes of chicken cytosolic adenylate kinase whose Arg-128 was substituted by Trp (cAK1(Trp)) or Ala (cAK1(Ala)) were compared to those of the wild-type enzyme. The TTP-synthesizing activity of both the mutant enzymes was higher due to higher affinity to thiamin diphosphate (cAK1(Trp)) or a larger Vmax (cAK1(Ala)). The optimal pH shifted to pH 9.0 from pH 10.5. The ATP-synthesizing activity of both the mutant enzymes was, on the other hand, markedly decreased with lower affinity for ADP and lower Vmax. These results suggest that Arg-128 plays an important role in the substrate specificity of the cytosolic adenylate kinase.


Asunto(s)
Adenilato Quinasa/metabolismo , Arginina/metabolismo , Tiamina Trifosfato/metabolismo , Adenilato Quinasa/genética , Adenilato Quinasa/aislamiento & purificación , Animales , Pollos , Citosol/enzimología , Electroforesis en Gel de Poliacrilamida , Concentración de Iones de Hidrógeno , Cinética , Mutación , Especificidad por Sustrato , Temperatura
15.
Biochim Biophys Acta ; 1490(1-2): 109-14, 2000 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-10786623

RESUMEN

As a step toward understanding of the role of adenylate kinase (AK) in energy metabolism, we analyzed this enzyme in Drosophila melanogaster. The enzyme activities of all three AK isozymes were determined in cell-free extracts of flies, and their proteins were detected by Western blot analysis using polyclonal antibodies against the mammalian isozymes. A cDNA encoding adenylate kinase was isolated from D. melanogaster cDNA library. The cDNA encodes a 240-amino acid protein, which shows high similarity to bovine, human and rat AK2, and hence was named DAK2. Preliminary subcellular fractionation analysis indicated that DAK2 is localized in both cytoplasm and mitochondria. In situ hybridization to salivary gland polytene chromosomes revealed that the Dak2 gene is located at 60B on the right arm of the second chromosome.


Asunto(s)
Adenilato Quinasa/genética , Drosophila melanogaster/genética , Isoenzimas/genética , Adenilato Quinasa/química , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sistema Libre de Células , Mapeo Cromosómico , Clonación Molecular , Citosol/enzimología , Drosophila melanogaster/enzimología , Metabolismo Energético , Isoenzimas/química , Mitocondrias/enzimología , Datos de Secuencia Molecular
16.
Biochim Biophys Acta ; 1395(1): 34-9, 1998 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-9434148

RESUMEN

We isolated two kinds of cDNAs encoding human adenylate kinase (AK) isozyme 2 from a HeLa cell cDNA library using bovine AK2 cDNA as a probe. Nucleotide sequencing revealed that the cDNAs encoded 239- and 232-amino acid proteins with deduced molecular mass of 26.5 (AK2A) and 25.6kDa (AK2B), respectively. Northern blot analysis demonstrated that AK2 mRNA is strongly expressed in liver, heart, skeletal muscle and pancreas, and moderately in kidney, placenta and brain, and weakly in lung. However, Western blot analysis showed that AK2 protein was present in large amounts in liver, heart, kidney, and in a small amount in lung, and undetectable in brain and skeletal muscle. These results suggested the presence of the tissue-specific gene-expression including post-transcriptional regulation in expression of the AK2 gene.


Asunto(s)
Adenilato Quinasa/genética , ADN Complementario/genética , Regulación Enzimológica de la Expresión Génica/fisiología , Isoenzimas/genética , Adenilato Quinasa/análisis , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Biblioteca de Genes , Células HeLa , Humanos , Isoenzimas/análisis , Datos de Secuencia Molecular , Especificidad de Órganos , ARN Mensajero/análisis , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido
17.
J Mol Biol ; 280(3): 551-8, 1998 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-9665856

RESUMEN

GTP:AMP phosphotransferase (adenylate kinase isozyme 3, AK3) mutants were obtained by using the ability of AK3 to complement a temperature-sensitive mutation of Escherichia coli adenylate kinase (AKe). Five mutants, P16L, G19S, G91D, G91S, and P93L, had mutation sites located at two loops that are involved in substrate binding of the enzyme. P16L and G19S bearing changes at the first loop showed reduced affinity for both GTP and AMP, the extent of reduction being slightly higher for GTP than AMP. In contrast, G91S and P93L having alterations at the second loop had lower affinities for AMP. Only the alterations at the second loop strongly influenced the Vmax value of the enzyme. Another mutant, D163N, had a substitution at the site forming a salt bridge in adenylate kinase isozyme 1 (AK1), which influenced the Vmax as well as the Km values for both substrates. The kinetic characteristics of these mutants were comparable to those of the corresponding AK1 or AKe mutants. Furthermore, from the results of mutations T201P and T201A that had alterations in all the kinetic parameters of AK3 and from a comparison with the structure and the kinetic parameters of AKe, we expect that a residue(s) around Thr201 is involved in recognition of the base of nucleoside triphosphate.


Asunto(s)
Mitocondrias/enzimología , Nucleósido-Fosfato Quinasa , Adenilato Quinasa/metabolismo , Sitios de Unión , Escherichia coli/genética , Guanosina Trifosfato/metabolismo , Isoenzimas/metabolismo , Mutación/genética , Nucleósido-Fosfato Quinasa/genética , Nucleósido-Fosfato Quinasa/aislamiento & purificación , Nucleósido-Fosfato Quinasa/metabolismo
18.
J Mol Biol ; 216(2): 251-60, 1990 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-2174974

RESUMEN

Transcription of the first operon coding for m-xylene-degrading enzymes on the TOL plasmid of Pseudomonas putida is activated by the xylR gene product in the presence of m-xylene. The operon has the consensus sequence of the ntr/nif promoters at -24 and -12 regions, and the transcription is dependent on an RNA polymerase containing a sigma factor NtrA (RpoN or sigma 54). Deletion derivatives of the upstream sequence of the operon promoter were made in vitro and connected with the xylE gene on a plasmid. Their promoter activities were analyzed in Escherichia coli by monitoring catechol 2,3-dioxygenase activity, the xylE gene product. A cis-acting DNA element was identified, which is required for activation of the operon promoter by XylR protein in the presence of the inducer. This regulatory sequence of about 40 base-pairs in length was located 150 base-pairs upstream from the transcription start site. Analysis of the mutants containing insertions between the upstream regulatory sequence and the promoter sequence demonstrated strong dependence of the activation upon helical periodicity of DNA. The regulatory sequence functioned in the inverse orientation or at a distance of more than 1 x 10(3) base-pairs upstream from the promoter though less efficient. These results indicated that this upstream regulatory sequence might be the binding site for XylR protein. DNA-loop formation through protein-protein interaction between XylR protein attached to the upstream sequence and the NtrA-containing RNA polymerase bound by the promoter sequence was suggested for activation of the operon transcription. A sequence similar to the regulatory sequence of the first operon of xylene metabolism was found in the upstream region of the xylS gene, which is also activated by XylR protein in the presence of m-xylene.


Asunto(s)
Operón , Plásmidos , Pseudomonas/genética , Transcripción Genética , Xilenos/metabolismo , Secuencia de Bases , Elementos Transponibles de ADN , Regulación Bacteriana de la Expresión Génica , Genes Bacterianos , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , Mapeo Restrictivo , Homología de Secuencia de Ácido Nucleico
19.
Placenta ; 36(5): 531-7, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25725937

RESUMEN

INTRODUCTION: Villitis of unknown etiology (VUE) is associated with fetal growth restriction. However, the underlying mechanisms of villous injury in placentas with VUE are still largely unknown. We aimed to verify whether apoptosis-related factors are increased in VUE placentas. Furthermore, we determined apoptosis of villous cells. METHODS: Six placentas with VUE and 3 control placentas were stained using immunohistochemistry with antibodies for CD3, CD4, CD8, CD68, CD163, perforin, granzyme B, granzyme K, and C5b-9. TUNEL assay analysis was also performed with these placentas. The percentage of cells that stained positive, CD163/CD68 ratio, percentage of C5b-9 positive area, and apoptosis index were quantified and compared between the inflammatory lesions of the VUE placentas, non-VUE inflammatory lesions of the VUE placentas, and control placentas. RESULTS: The percentages of CD3, CD4, CD8 CD68, CD163, perforin, and granzyme B positive cells were significantly higher in the inflammatory lesions of the VUE placentas (p < 0.05). The intravillous CD163/CD68 ratio was higher in the inflammatory lesions compared with the non-inflammatory lesion of the VUE placentas (p < 0.05). The percentage of granzyme K-positive cells was not significantly different between the groups. C5b-9 deposition was higher in the inflammatory lesions of the VUE placentas (p < 0.05). TUNEL-positive cells were significantly higher in the inflammatory lesions of the VUE placentas (p < 0.05). DISCUSSION: To the best of our knowledge, this is the first report to assess villous injury, especially from a viewpoint of villous apoptosis in VUE placentas. An activated perforin/granzyme pathway and C5b-9 are suggested as possible mechanisms of apoptosis.


Asunto(s)
Complejo de Ataque a Membrana del Sistema Complemento/metabolismo , Granzimas/metabolismo , Perforina/metabolismo , Enfermedades Placentarias/metabolismo , Placenta/metabolismo , Adulto , Apoptosis , Estudios de Casos y Controles , Femenino , Humanos , Etiquetado Corte-Fin in Situ , Placenta/patología , Enfermedades Placentarias/patología , Embarazo
20.
Gene ; 66(2): 301-6, 1988 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-3169574

RESUMEN

We have determined the nucleotide sequence of the xylR gene for a transcriptional activator for the degradative pathway of aromatic hydrocarbons on the TOL plasmid from Pseudomonas putida. The 1698-bp sequence for a 566-amino acid (aa) protein (Mr 63741) was identified as the XylR-encoding sequence. Three regions in XylR show homology to Klebsiella pneumoniae NtrC and NifA, both of which are transcriptional activators for the ntr and nif genes involved in the nitrogen metabolism. The central region of XylR (aa 234-473) corresponds to the region that was proposed to interact with RNA polymerase having a sigma factor, NtrA [Drummond et al., EMBO J. 5 (1986) 441-447]. The C-terminal region (aa 515-558) has a putative DNA-binding structure. A short segment proximal to the central region (aa 211-229) is thought to be an interdomain linker. No amino acid homology was found in the N-terminal regions among these proteins. These findings suggest the interaction of XylR with an NtrA in the transcriptional activation of the degradative pathway.


Asunto(s)
Secuencia de Bases , Genes Reguladores , Plásmidos , Homología de Secuencia de Ácido Nucleico , Datos de Secuencia Molecular , Pseudomonas/genética
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