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1.
Phys Rev Lett ; 129(25): 255001, 2022 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-36608252

RESUMEN

The ablation and assimilation of cryogenic pure H_{2} and mixed H_{2}+Ne pellets, which are foreseen to be used by the ITER tokamak for mitigating thermal and electromagnetic loads of major disruptions, are observed by spatially and temporally resolved measurements. It is experimentally demonstrated that a small fraction (here ≈5%) of neon added to hydrogenic pellets enhances the core density assimilation with reduced outward transport for the low magnetic-field side injection. This is consistent with theoretical expectations that line radiation increased by doped neon in dense plasmoids suppresses the plasmoid pressure and reduces the E[over →]×B[over →] transport of the ablated material.

2.
N Z Vet J ; 65(5): 227-231, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28441916

RESUMEN

AIMS: To compare the survival of dogs with completely resected massive hepatocellular carcinoma (HCC) with that of dogs in which HCC were incompletely excised. METHODS: A retrospective cohort study was conducted. Dogs that underwent surgical excision of massive HCC between November 2006 and April 2015 were included. Dogs that died in the perioperative period or were lost to follow-up within 2 months after surgery were excluded. Data were collected from the medical records and a single pathologist examined all available histology slides to confirm the diagnosis of HCC. Surgical margins were defined as complete if no neoplastic cells were seen at the edge of excised tissues, based on original histopathology reports. Progression-free survival (PFS) and overall survival (OS) were compared between dogs with complete surgical margins (CM) and those with incomplete margins (IM) using a log-rank test. RESULTS: Of the 37 dogs included in the study, 25 were allocated to the CM group and 12 to the IM group. Progressive local disease developed after surgery in three dogs in the CM group and seven dogs in the IM group. Three dogs in the CM group and five dogs in the IM group died due to tumour progression. Median PFS was longer for dogs in the CM group (1,000 (95% CI=562-1,438) days) compared to dogs in the IM group (521 (95% CI=243-799) days; p=0.007). OS was also longer for dogs in the CM group (>1,836 days) compared to those in the IM group (median 765 (95% CI=474-1,056) days; p=0.02). CONCLUSIONS AND CLINICAL RELEVANCE: Compared with complete resection, incomplete resection decreased PFS and OS in dogs with massive HCC. Dogs with incompletely excised HCC should be closely monitored for local recurrence, although median OS was >2 years following incomplete excision. Further prospective studies are warranted to confirm these findings.


Asunto(s)
Carcinoma Hepatocelular/veterinaria , Enfermedades de los Perros/cirugía , Neoplasias Hepáticas/veterinaria , Recurrencia Local de Neoplasia/veterinaria , Animales , Carcinoma Hepatocelular/mortalidad , Carcinoma Hepatocelular/cirugía , Enfermedades de los Perros/mortalidad , Perros , Femenino , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/cirugía , Masculino , Márgenes de Escisión , Estudios Retrospectivos , Resultado del Tratamiento
3.
Dis Esophagus ; 28(1): 78-83, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24224952

RESUMEN

Esophagectomy, one of the most invasive of all gastrointestinal operations, is associated with a high frequency of postoperative complications and in-hospital mortality. The purpose of the present study was to determine whether exposure to the atomic bomb explosion at Hiroshima in 1945 might be a preoperative risk factor for in-hospital mortality after esophagectomy in esophageal cancer patients. We thus reviewed the outcomes of esophagectomy in 31 atomic bomb survivors with esophageal cancer and 96 controls (also with cancer but without atomic bomb exposure). We compared the incidences of postoperative complications and in-hospital mortality. Of the clinicopathological features studied, mean patient age was significantly higher in atomic bomb survivors than in controls. Of the postoperative complications noted, atomic bomb survivors experienced a longer mean period of endotracheal intubation and higher incidences of severe pulmonary complications, severe anastomotic leakage, and surgical site infection. The factors associated with in-hospital mortality were exposure to the atomic bomb explosion, pulmonary comorbidities, and electrocardiographic abnormalities. Multivariate analysis revealed that exposure to the atomic bomb explosion was an independent significant preoperative risk factor for in-hospital mortality. Exposure to the atomic bomb explosion is thus a preoperative risk factor for in-hospital death after esophagectomy to treat esophageal cancer.


Asunto(s)
Neoplasias Esofágicas/mortalidad , Esofagectomía/mortalidad , Mortalidad Hospitalaria , Enfermedades Pulmonares/epidemiología , Complicaciones Posoperatorias/epidemiología , Ceniza Radiactiva/efectos adversos , Infección de la Herida Quirúrgica/epidemiología , Anciano , Fuga Anastomótica/epidemiología , Estudios de Casos y Controles , Neoplasias Esofágicas/cirugía , Femenino , Humanos , Japón , Masculino , Persona de Mediana Edad , Análisis Multivariante , Armas Nucleares , Factores de Riesgo , Sobrevivientes
4.
Sci Rep ; 12(1): 7282, 2022 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-35508614

RESUMEN

As photoreceptor cells die during retinal degeneration, the surrounding microenvironment undergoes significant changes that are increasingly recognized to play a prominent role in determining the efficacy of therapeutic interventions. Chondroitin Sulphate Proteoglycans (CSPGs) are a major component of the extracellular matrix that have been shown to inhibit neuronal regrowth and regeneration in the brain and spinal cord, but comparatively little is known about their expression in retinal degeneration. Here we provide a comprehensive atlas of the expression patterns of four individual CSPGs in three models of inherited retinal degeneration and wildtype mice. In wildtype mice, Aggrecan presented a biphasic expression, while Neurocan and Phosphacan expression declined dramatically with time and Versican expression remained broadly constant. In degeneration, Aggrecan expression increased markedly in Aipl1-/- and Pde6brd1/rd1, while Versican showed regional increases in the periphery of Rho-/- mice. Conversely, Neurocan and Phosphacan broadly decrease with time in all models. Our data reveal significant heterogeneity in the expression of individual CSPGs. Moreover, there are striking differences in the expression patterns of specific CSPGs in the diseased retina, compared with those reported following injury elsewhere in the CNS. Better understanding of the distinct distributions of individual CSPGs will contribute to creating more permissive microenvironments for neuro-regeneration and repair.


Asunto(s)
Neurocano , Degeneración Retiniana , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Agrecanos/genética , Agrecanos/metabolismo , Animales , Proteoglicanos Tipo Condroitín Sulfato/genética , Proteoglicanos Tipo Condroitín Sulfato/metabolismo , Lectinas Tipo C/metabolismo , Ratones , Proteínas del Tejido Nervioso/metabolismo , Neurocano/metabolismo , Proteínas Tirosina Fosfatasas Clase 5 Similares a Receptores/metabolismo , Retina/metabolismo , Degeneración Retiniana/genética , Versicanos/genética , Versicanos/metabolismo
5.
Phys Rev Lett ; 104(4): 042302, 2010 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-20366701

RESUMEN

We show that two almost degenerate poles near the piDelta threshold and the next higher mass pole in the P11 partial wave of piN scattering evolve from a single bare state through its coupling with piN, etaN, and pipiN reaction channels. This finding provides new information on understanding the dynamical origins of the Roper N{*}(1440) and N{*}(1710) resonances listed by Particle Data Group. Our results for the resonance poles in other piN partial waves are also presented.

6.
Bull Environ Contam Toxicol ; 82(3): 363-6, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19050818

RESUMEN

To determine the relationship between soluble methylmercury and soil characteristics which was contaminated by mercury, several experiments were conducted. As a result, a good correlation was founding between the leached methylmercury level from soil and the EC (electronic conductivity) level of soil. Moreover, to grasp the relationship between soluble methylmercury and soluble anions from soil, several anions (Cl(-), NO(3-), SO(4) (2-)) were measured using the ion chromatography method. Although the correlation coefficient was small (r = 0.40), only a correlation between the level of SO(4) (2-) and leached methylmercury was recognized.


Asunto(s)
Mercurio/análisis , Compuestos de Metilmercurio/aislamiento & purificación , Contaminantes del Suelo/análisis , Suelo/análisis , Álcalis , China , Compuestos de Metilmercurio/análisis
7.
Methods Inf Med ; 46(2): 227-30, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17347761

RESUMEN

OBJECTIVES: Automatic detection of arrhythmias is important for diagnosis of heart problems. However, in ECG signals, there is significant variation of waveforms in both normal and abnormal beats. It is this phenomenon, which makes it difficult to analyse ECG signals. The aim of developing methodology is to distinguish between normal beats and abnormal beats in an ECG signal. METHODS: ECG signals were first decomposed using wavelet transform. The feature vectors were then extracted from these decomposed signals as normalised energy and entropy. To improve the classification of the feature vectors of normal and abnormal beats, the normal beats which occur before and after the abnormal beats were eliminated from the group of normal beats. RESULTS: With our proposed methods, the normal beats and abnormal beats formed different clusters of vector points. By eliminating normal beats which occur before and after the abnormal beats, the clusters of different types of beats showed more apparent separation. CONCLUSIONS: The combination of wavelet decomposition and the classification using feature vectors of the beats in ECG signals separate abnormal beats from normal beats. The elimination of the normal beats which occur before and after the abnormal beats succeeded in minimising the size of normal beats cluster.


Asunto(s)
Arritmias Cardíacas/diagnóstico , Electrocardiografía/instrumentación , Fractales , Procesamiento de Señales Asistido por Computador , Entropía , Humanos
8.
J Endocrinol ; 188(2): 333-44, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16461559

RESUMEN

Aging is associated with a decrease in growth hormone (GH) secretion, appetite and energy intake. As ghrelin stimulates both GH secretion and appetite, reductions in ghrelin levels may be involved in the reductions in GH secretion and appetite observed in the elderly. However, only preliminary studies have been performed on the role of ghrelin in elderly subjects. In this study, we sought to clarify the physiologic implications of the age-related alterations in ghrelin secretion by determining plasma ghrelin levels and other clinical parameters in healthy elderly subjects. Subjects were > or = 65 years old, corresponding to the SENIEUR protocol, had not had a resection of the upper gastrointestinal tract and had not been treated with hormones. One hundred and five volunteers (49 men and 56 women) were admitted to this study (73.4 +/- 6.3 years old). Plasma levels of acylated ghrelin in elderly female subjects positively correlated with serum IGF-I levels and bowel movement frequency and negatively with systolic blood pressure. In elderly men, desacyl ghrelin levels correlated only weakly with bowel movement frequency. These findings suggest that the plasma levels of the acylated form of ghrelin may influence the age-related alterations in GH/IGF-I regulation, blood pressure and bowel motility. These observational associations warrant further experimental studies to clarify the physiologic significance of these effects.


Asunto(s)
Defecación/fisiología , Factor I del Crecimiento Similar a la Insulina/análisis , Hormonas Peptídicas/sangre , Acilación , Anciano , Anciano de 80 o más Años , Envejecimiento/fisiología , Glucemia/análisis , Presión Sanguínea/fisiología , Índice de Masa Corporal , Femenino , Ghrelina , Hormona de Crecimiento Humana/sangre , Humanos , Insulina/sangre , Leptina/sangre , Masculino
9.
J Clin Pathol ; 59(9): 978-83, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16751306

RESUMEN

AIM: To investigate overall chromosomal alterations using array-based comparative genomic hybridisation (CGH) of myxoid liposarcomas (MLSs) and myxofibrosarcomas (MFSs). MATERIALS AND METHODS: Genomic DNA extracted from fresh-frozen tumour tissues was labelled with fluorochromes and then hybridised on to an array consisting of 1440 bacterial artificial chromosome clones representing regions throughout the entire human genome important in cytogenetics and oncology. RESULTS: DNA copy number aberrations (CNAs) were found in all the 8 MFSs, but no alterations were found in 7 (70%) of 10 MLSs. In MFSs, the most frequent CNAs were gains at 7p21.1-p22.1 and 12q15-q21.1 and a loss at 13q14.3-q34. The second most frequent CNAs were gains at 7q33-q35, 9q22.31-q22.33, 12p13.32-pter, 17q22-q23, Xp11.2 and Xq12 and losses at 10p13-p14, 10q25, 11p11-p14, 11q23.3-q25, 20p11-p12 and 21q22.13-q22.2, which were detected in 38% of the MFSs examined. In MLSs, only a few CNAs were found in two sarcomas with gains at 8p21.2-p23.3, 8q11.22-q12.2 and 8q23.1-q24.3, and in one with gains at 5p13.2-p14.3 and 5q11.2-5q35.2 and a loss at 21q22.2-qter. CONCLUSIONS: MFS has more frequent and diverse CNAs than MLS, which reinforces the hypothesis that MFS is genetically different from MLS. Out-array CGH analysis may also provide several entry points for the identification of candidate genes associated with oncogenesis and progression in MFS.


Asunto(s)
Fibrosarcoma/genética , Liposarcoma Mixoide/genética , Neoplasias de los Tejidos Blandos/genética , Adulto , Anciano , Aberraciones Cromosómicas , Cromosomas Humanos Par 8/genética , ADN de Neoplasias/genética , Femenino , Fibrosarcoma/patología , Genes Relacionados con las Neoplasias , Humanos , Liposarcoma Mixoide/patología , Masculino , Persona de Mediana Edad , Hibridación de Ácido Nucleico/métodos , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Neoplasias de los Tejidos Blandos/patología
10.
Circ Res ; 85(1): 108-16, 1999 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-10400916

RESUMEN

The scavenger receptor class B type I (SR-BI) and its human homologue CLA-1 (CD36 and LIMPII Analogous-1) have recently been identified to bind HDL and mediate the selective uptake of HDL lipids. Tissue distribution of both murine and human receptors is quite similar, in that they are expressed abundantly in liver and steroidogenic tissues. However, expression and function of the human SR-BI (hSR-BI), in the periphery of reverse cholesterol transport such as macrophages, are still unclear. In the present study, we have raised two different kinds of anti-hSR-BI polypeptide antibodies (Abs): one against the extracellular domain and the other against the intracellular domain. We have investigated the expression of hSR-BI mRNA and immunoreactive mass in freshly isolated cultured human monocyte-derived macrophages (hMphi) and in atherosclerotic lesions. Contrary to the earlier report, hSR-BI mRNA was expressed in cultured hMphi and markedly upregulated with differentiation, determined by Northern blot and reverse transcriptase-based polymerase chain reaction analyses. The mRNA expression pattern during differentiation of hMphi was very similar to those of SR class A and another member of SR class B, CD36. Protein expression was confirmed by Western blot analyses with the above Abs to show a major 83-kDa band. Modified lipoproteins such as oxidized LDL and acetylated LDL induced a 5-fold increase in mRNA and protein expression of hSR-BI. Confocal immunofluorescence microscopy demonstrated that hSR-BI immunoreactive mass was detectable as a heterogeneous, punctate staining pattern. Furthermore, immunohistochemical analysis showed that immunoreactive mass of hSR-BI was detected in foam cells in human aortic atherosclerotic lesions and that there was no significant difference of staining patterns between the two Abs. This study clearly demonstrates that hSR-BI is expressed in the lipid-laden macrophages in human atherosclerotic lesions, suggesting that it is very important to know its function and regulation in hMphi to understand the biological utility of this molecule.


Asunto(s)
Arteriosclerosis/metabolismo , Macrófagos/metabolismo , Proteínas de la Membrana , Monocitos/citología , Receptores Inmunológicos/metabolismo , Receptores de Lipoproteína , Animales , Aorta/metabolismo , Aorta/patología , Arteriosclerosis/patología , Antígenos CD36 , Células CHO , Diferenciación Celular/fisiología , Línea Celular , Cricetinae , Técnica del Anticuerpo Fluorescente , Humanos , Inmunohistoquímica , Técnicas Inmunológicas , Lipoproteínas/farmacología , Macrófagos/efectos de los fármacos , Microscopía Fluorescente , Isoformas de Proteínas/metabolismo , ARN Mensajero/metabolismo , Receptores Inmunológicos/genética , Receptores Depuradores , Valores de Referencia , Receptores Depuradores de Clase A , Receptores Depuradores de Clase B
11.
Australas Phys Eng Sci Med ; 29(1): 13-7, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16623217

RESUMEN

The Electrocardiogram (ECG) is one of the most commonly known biological signals. Traditionally ECG recordings are analysed in the time-domain by skilled physicians. However, pathological conditions may not always be obvious in the original time-domain signal. Fourier analysis provides frequency information but has the disadvantage that time characteristics will be lost. Wavelet analysis, which provides both time and frequency information, can overcome this limitation. Here a new method, the combination of wavelet analysis and feature vectors, is applied with the intent to investigate its suitability as a diagnostic tool. ECG signals with normal and abnormal beats were examined. There were two stages in analysing ECG signals: feature extraction and feature classification. To extract features from ECG signals, wavelet decomposition was first applied and feature vectors of normalised energy and entropy were constructed. These feature vectors were used to classify signals. The results showed that normal beats and abnormal beats composed different clusters in most cases. In conclusion, the combination of wavelet transform and feature vectors has shown potential in detecting abnormalities in an ECG recording. It was also found that normalised energy and entropy are features, which are suitable for classification of ECG signals.


Asunto(s)
Algoritmos , Arritmias Cardíacas/diagnóstico , Inteligencia Artificial , Diagnóstico por Computador/métodos , Electrocardiografía/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Procesamiento de Señales Asistido por Computador , Análisis por Conglomerados , Humanos , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad
12.
Cancer Res ; 61(15): 5714-7, 2001 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-11479204

RESUMEN

Radiotherapy is a useful component of treatment for esophageal cancer. Identification of the genes that are differentially expressed between radiosensitive and radioresistant cancer cells is important for predicting clinical effectiveness of radiotherapy. We established human esophageal cancer cell lines resistant to X-ray. Using differential display, we obtained one gene that was expressed in radiosensitive cells but was rarely expressed in radioresistant cells, and that gene was identical with hepatoma-derived growth factor (HDGF), an acidic polypeptide with mitogenic activity for fibroblasts. The semiquantitative reverse transcription-PCR assay confirmed that HDGF mRNA expression was reduced in established radioresistant cells, and its reduction was associated with reduced sensitivity to irradiation. Radiotherapy was more effective in clinical cases with high HDGF mRNA expression compared with cases with low expression (P < 0.05). The findings demonstrate that HDGF may play an important role in radiosensitivity, and it could be a novel marker predicting effectiveness of radiotherapy in clinical cases.


Asunto(s)
Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/radioterapia , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/radioterapia , Sustancias de Crecimiento/genética , Péptidos y Proteínas de Señalización Intercelular , Tolerancia a Radiación/genética , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/metabolismo , Neoplasias Esofágicas/metabolismo , Femenino , Factor 2 de Crecimiento de Fibroblastos/biosíntesis , Factor 2 de Crecimiento de Fibroblastos/genética , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Sustancias de Crecimiento/biosíntesis , Humanos , Masculino , Persona de Mediana Edad , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Células Tumorales Cultivadas/efectos de la radiación
13.
Cancer Res ; 61(20): 7379-82, 2001 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-11606365

RESUMEN

Frequent loss of Fhit expression has been reported in human gastrointestinal tract carcinomas; opinions remain divergent regarding Fhit expression in colorectal carcinoma (CRC) cases. Recent studies have suggested that Fhit inactivation can be a consequence of defects in mismatch repair proteins, particularly Msh2. Immunohistochemical analysis of Msh2 and Fhit protein expression in 62 CRC cases was performed. The same CRCs were examined for allelic loss at three loci within or near FHIT and for FHIT mRNA expression by reverse transcription-PCR amplification. Half of the 62 CRC cases were positive for Fhit protein. Fhit protein loss correlated significantly with the progression of carcinoma (P < 0.01) as well as lymph node metastasis (P < 0.05). Loss of Msh2 protein correlated significantly with loss of Fhit protein (P < 0.05) and FHIT locus alteration (P < 0.05). Loss of Fhit protein expression was observed in 50% of sporadic CRCs and was significantly more frequent in more advanced cancers. Interestingly, alteration of the fragile FHIT locus and loss of Fhit protein expression were significantly more frequent in sporadic CRCs lacking Msh2 protein, suggesting that this mismatch repair protein may be important in maintaining the integrity of the common fragile locus within the FHIT gene.


Asunto(s)
Ácido Anhídrido Hidrolasas , Neoplasias Colorrectales/metabolismo , Proteínas de Unión al ADN , Proteínas de Neoplasias/biosíntesis , Proteínas Proto-Oncogénicas/biosíntesis , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Femenino , Regulación Neoplásica de la Expresión Génica , Silenciador del Gen , Humanos , Inmunohistoquímica , Masculino , Repeticiones de Microsatélite , Persona de Mediana Edad , Análisis Multivariante , Proteína 2 Homóloga a MutS , Proteínas de Neoplasias/genética
14.
Biochim Biophys Acta ; 418(3): 321-9, 1976 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-1247548

RESUMEN

Cells permeable to deoxyribonucleoside triphosphate were prepared from Micrococcus radiodurans, and DNA synthesis and rejoining of strand scissions induced by gamma-rays were investigated. DNA synthesis was stimulated by ATP at an optimal concentration of 1mM. This reaction requires four deoxyribonucleoside triphosphates and MgCl2. NAD inhibited the reaction, but no rejoining of primer DNA was observed. Even in the presence of NAD, DNA which was synthesized in the unirradiated permeable cells had a peak molecular weight of only 1.3 - 10(6). DNA synthesis was stimulated by irradiation of the permeable cells with gamma-rays, but this stimulatory effect was eliminated by the addition of NAD. Both primer and synthesized DNA in the irradiated permeable cells were rejoined in vitro in the presence of NAD and deoxyribonucleoside triphosphates, while those in the unirradiated permeable cells were not rejoined.


Asunto(s)
Reparación del ADN , Replicación del ADN/efectos de la radiación , Micrococcus/metabolismo , Efectos de la Radiación , Transporte Biológico , Reparación del ADN/efectos de los fármacos , Replicación del ADN/efectos de los fármacos , Desoxirribonucleótidos/metabolismo , Micrococcus/efectos de los fármacos , Micrococcus/efectos de la radiación , Permeabilidad , Polietilenglicoles/farmacología
15.
Biochim Biophys Acta ; 475(1): 23-31, 1977 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-14686

RESUMEN

DNA polymerase activities in Micrococcus radiodurans were separated into two fractions after purification more than 2000 fold. They differ in pH optimum and residual activities in the absence of a full deoxyribonucleoside triphosphates complement. NAD partly inhibited one of the activities. Both activities were eluted as a single peak on gel filtration and sedimented at the same rate on glycerol gradient centrifugation. Molecular weight 140000 was calculated from Stokes radius and sedimentation constant. Deoxyribonuclease activity was detected on one of the polymerase activities which preferentially degraded double-stranded DNA. Priming activity of nicked DNA was reduced by gamma-irradiation. These results have been related to the possible rolls in repair synthesis in vivo or DNA synthesis in permeable cells of M. radiodurans.


Asunto(s)
ADN Polimerasa Dirigida por ADN , Micrococcus/enzimología , ADN/efectos de la radiación , ADN Polimerasa Dirigida por ADN/aislamiento & purificación , ADN Polimerasa Dirigida por ADN/metabolismo , Desoxirribonucleasas/aislamiento & purificación , Desoxirribonucleasas/metabolismo , Relación Dosis-Respuesta en la Radiación , Concentración de Iones de Hidrógeno , Cinética , Peso Molecular , NAD/farmacología , Moldes Genéticos
16.
Biochim Biophys Acta ; 520(1): 122-30, 1978 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-698224

RESUMEN

An exonuclease activity is associated with one of three DNA polymerase in Micrococcus radiodurans. The nuclease activity co-sedimented with its DNA polymerase I of this bacterium on glycerol gradient centrifugation. Both activities show the same optimum pH and heat-inactivation kinetics. This nuclease hydrolyzes preferentially double-stranded DNA in an exonucleolytic manner from both ends of the duplex DNA. The products of hydrolysis are mostly deoxyribonucleoside 5'-monophosphate and no nucleosides are released into the acid-soluble fraction. Di- or other oligonucleotides are also produced but their relative amounts are constant during the time of incubation. The exonuclease activity requires Mg2+ and is inhibited by high concentrations of KCl as is DNA polymerase I of M. radiodurans.


Asunto(s)
ADN Polimerasa I/metabolismo , ADN Polimerasa Dirigida por ADN/metabolismo , Exonucleasas/metabolismo , Micrococcus/enzimología , ADN Polimerasa I/aislamiento & purificación , ADN Bacteriano/metabolismo , Desoxirribonucleasas/metabolismo , Exonucleasas/aislamiento & purificación , Calor , Magnesio/farmacología , Manganeso/farmacología , Poli dA-dT/metabolismo , Cloruro de Potasio/farmacología , Nucleótidos de Timina/metabolismo
17.
Biochim Biophys Acta ; 1219(2): 559-62, 1994 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-7918659

RESUMEN

The phosphotransacetylase gene (pta) from Escherichia coli strain K-12 1100 was identified in a cloned fragment of chromosomal DNA (Yamamoto-Otake, H., Matsuyama, A. and Nakano, A. (1990) Appl. Microbiol. Biotechnol. 33, 680-682). Overexpression in E. coli confirmed the presence of the pta gene within the cloned fragment. DNA sequence analysis of the cloned pta gene indicates that the predicted phosphotransacetylase polypeptide chain is 713 amino acids in length. The carboxyterminal region of the E. coli phosphotransacetylase shows 42.6% sequence identity with the corresponding enzyme from Methanosarcina thermophila (142 out of 333 residues in corresponding positions are identical). Several short regions of high sequence identity may be structurally or functionally important for enzymic activity.


Asunto(s)
Escherichia coli/genética , Genes Bacterianos , Fosfato Acetiltransferasa/genética , Secuencia de Aminoácidos , Secuencia de Bases , Escherichia coli/enzimología , Methanosarcina/genética , Datos de Secuencia Molecular , Alineación de Secuencia , Homología de Secuencia de Aminoácido
18.
Circulation ; 103(8): 1057-63, 2001 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-11222466

RESUMEN

BACKGROUND: Excessive lipid accumulation in macrophages plays an important role in the development of atherosclerosis. Recently, we discovered an adipocyte-specific plasma protein, adiponectin, that is decreased in patients with coronary artery disease. We previously demonstrated that adiponectin acts as a modulator for proinflammatory stimuli and inhibits monocyte adhesion to endothelial cells. The present study investigated the effects of adiponectin on lipid accumulation in human monocyte-derived macrophages. METHODS AND RESULTS: Human monocytes were differentiated into macrophages by incubation in human type AB serum for 7 days, and the effects of adiponectin were investigated at different time intervals. Treatment with physiological concentrations of adiponectin reduced intracellular cholesteryl ester content, as determined using the enzymatic, fluorometric method. The adiponectin-treated macrophages contained fewer lipid droplets stained by oil red O. Adiponectin suppressed the expression of the class A macrophage scavenger receptor (MSR) at both mRNA and protein levels by Northern and immunoblot analyses, respectively, without affecting the expression of CD36, which was quantified by flow cytometry. Adiponectin reduced the class A MSR promoter activity, as measured by luciferase reporter assay. Adiponectin treatment dose-dependently decreased class A MSR ligand binding and uptake activities. The mRNA level of lipoprotein lipase as a marker of macrophage differentiation was decreased by adiponectin treatment, but that of apolipoprotein E was not altered. Adiponectin was detected around macrophages in the human injured aorta by immunohistochemistry. CONCLUSIONS: The adipocyte-derived plasma protein adiponectin suppressed macrophage-to-foam cell transformation, suggesting that adiponectin may act as a modulator for macrophage-to-foam cell transformation.


Asunto(s)
Adipocitos/química , Péptidos y Proteínas de Señalización Intercelular , Metabolismo de los Lípidos , Macrófagos/efectos de los fármacos , Proteínas/farmacología , Receptores Inmunológicos/biosíntesis , Adiponectina , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Proteínas Sanguíneas/farmacología , Antígenos CD36/metabolismo , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Ésteres del Colesterol/metabolismo , Células Espumosas/citología , Células Espumosas/efectos de los fármacos , Humanos , Lipoproteína Lipasa/genética , Lipoproteína Lipasa/metabolismo , Lipoproteínas LDL/metabolismo , Macrófagos/metabolismo , Monocitos/citología , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/metabolismo , ARN Mensajero/efectos de los fármacos , ARN Mensajero/metabolismo , Receptores Depuradores , Receptores Depuradores de Clase A
19.
Genetics ; 155(2): 539-49, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10835379

RESUMEN

The fission yeast ste7 mutant cannot mate and undergo meiosis, but shows no defect in vegetative growth. We cloned and characterized the ste7 gene. The deduced ste7 gene product (Ste7p) was a protein of 569 amino acids with no significant similarity to other proteins. Transcription of ste7 was induced by nutrient starvation via the function of the transcription factor Ste11p. Disruption of the ste7 gene blocked both conjugation and meiosis, showing that Ste7p plays a positive role in these two processes, probably activating the pheromone signal pathway. Unexpectedly, overexpression of ste7(+) promoted conjugation but inhibited meiosis in wild-type cells. The temperature-sensitive pat1-114 mutant underwent ectopic conjugation at the semirestrictive temperature when its genetic background was ste7(+), whereas the same mutant initiated haploid meiosis when its genetic background was ste7Delta. Two-hybrid analysis suggested that Ste7p interacts physically with both Pat1p and Mei2p, which together constitute the major switch to initiate meiosis. Ste7p tagged with green fluorescent protein accumulated in haploid cells under nutrient starvation until they completed conjugation, but this protein disappeared when they were to enter meiosis. These observations suggest that Ste7p may have a function to suppress the onset of meiosis until the conjugation process has been duly completed.


Asunto(s)
Meiosis/genética , Proteínas Quinasas/genética , Proteínas de Saccharomyces cerevisiae , Schizosaccharomyces/citología , Schizosaccharomyces/genética , Secuencia de Aminoácidos , Secuencia de Bases , Cartilla de ADN , Quinasas de Proteína Quinasa Activadas por Mitógenos , Datos de Secuencia Molecular , Técnicas del Sistema de Dos Híbridos
20.
FEBS Lett ; 484(3): 275-9, 2000 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-11078892

RESUMEN

Cholesterol efflux (CE) is the initial and important step of reverse cholesterol transport (RCT), a major protective system against atherosclerosis. However, most of the molecular mechanism for CE still remains to be clarified. In the present study, cDNA subtraction revealed that the expression of a member of the Rho GTPase family, Cdc42Hs, was markedly decreased in both passaged fibroblasts and macrophages (Mφ) from patients with Tangier disease (TD), a rare lipoprotein disorder with reduced CE. This small G protein is known to have many cell biological activities such as rearrangement of actin cytoskeleton and vesicular transport, however the association between this molecule and lipid transport has never been reported. We demonstrate that MDCK cells expressing the dominant negative form of Cdc42Hs had reduced CE, inversely ones expressing the dominant active form had increased CE. From these observations, we would like to raise a novel hypothesis that this type of small G protein may play a role in some steps of CE. To our knowledge, the present study is the first demonstration that the expression of this molecule is altered in cells from human disease.


Asunto(s)
Proteínas Tirosina Quinasas/metabolismo , Enfermedad de Tangier/enzimología , Proteína de Unión al GTP cdc42/metabolismo , Animales , Línea Celular , Células Cultivadas , Perros , Fibroblastos/enzimología , Biblioteca de Genes , Humanos , Macrófagos/enzimología , Masculino , Persona de Mediana Edad , Proteínas Tirosina Quinasas/genética , Piel/enzimología , Enfermedad de Tangier/genética , Transfección , Proteína de Unión al GTP cdc42/genética
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