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1.
Insect Mol Biol ; 29(5): 490-497, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32681683

RESUMEN

We describe a new member of the aldo-keto reductase (AKR) superfamily in the silkworm Bombyx mori. On the basis of its amino acid sequence and phylogenetic tree, this AKR belongs to the AKR1B family and has been designated as bmALD1. In the current study, recombinant bmALD1 was overexpressed, purified to homogeneity and kinetically characterized. We discovered that bmALD1 uses NADPH as a coenzyme to reduce carbonyl compounds such as DL-glyceraldehyde, glucose and 2-nonenal. No NADH-dependent activity was detected. To the best of our knowledge, bmALD1 is only the third AKR characterized in silkworm which, given its substrate specificity, could play a major role in glucose metabolism and antioxidant reactions. Our data provide an increased understanding of insect AKR function.


Asunto(s)
Aldehído Reductasa/genética , Bombyx/genética , Proteínas de Insectos/genética , Aldehído Reductasa/química , Aldehído Reductasa/metabolismo , Secuencia de Aminoácidos , Animales , Bombyx/crecimiento & desarrollo , Bombyx/metabolismo , Proteínas de Insectos/química , Proteínas de Insectos/metabolismo , Cinética , Larva/crecimiento & desarrollo , Larva/metabolismo , Filogenia , Alineación de Secuencia , Especificidad por Sustrato
3.
Dis Esophagus ; 27(8): 737-43, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24917486

RESUMEN

The survival benefit of second-line chemotherapy with docetaxel in platinum-refractory patients with advanced esophageal cancer (AEC) remains unclear. A retrospective analysis of AEC patients with Eastern Cooperative Oncology Group performance status (PS)≤2 was performed, and major organ functions were preserved, who determined to receive docetaxel or best supportive care (BSC) alone after failure of platinum-based chemotherapy. The post-progression survival (PPS), defined as survival time after disease progression following platinum-based chemotherapy, was analyzed by multivariate Cox regression analysis using factors identified as significant in univariate analysis of various 20 characteristics (age, sex, PS, primary tumor location, etc) including Glasgow prognostic score (GPS), which is a well-known prognostic factor in many malignant tumors. Sixty-six and 45 patients were determined to receive docetaxel and BSC between January 2007 and December 2011, respectively. The median PPS was 5.4 months (95% confidence interval [CI] 4.8-6.0) in the docetaxel group and 3.3 months (95% CI 2.5-4.0) in the BSC group (hazard ratio [HR] 0.56, 95% CI 0.38-0.84, P=0.005). Univariate analysis revealed six significant factors: treatment, PS, GPS, number of metastatic organs, liver metastasis, and bone metastasis. Multivariate analysis including these significant factors revealed three independent prognostic factors: docetaxel treatment (HR 0.62, 95% CI 0.39-0.99, P=0.043), better GPS (HR 0.61, 95% CI 0.46-0.81, P=0.001), and no bone metastasis (HR 0.31, 95% CI 0.15-0.68, P=0.003). There was a trend for PPS in favor of the docetaxel group compared with patients who refused docetaxel treatment in the BSC group (adjusted HR 0.61, 95% CI 0.29-1.29, P=0.20). Docetaxel treatment may have prolonged survival in platinum-refractory patients with AEC.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/mortalidad , Platino (Metal)/uso terapéutico , Taxoides/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Progresión de la Enfermedad , Docetaxel , Femenino , Humanos , Masculino , Persona de Mediana Edad , Platino (Metal)/administración & dosificación , Pronóstico , Estudios Retrospectivos , Análisis de Supervivencia , Taxoides/administración & dosificación
4.
Horm Metab Res ; 45(1): 69-73, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22893261

RESUMEN

Although nonvasodilating ß1 blockers increase the levels of uric acid in serum, it is not known whether vasodilating ß1 blockers have a similar effect. In the present study, we evaluated the effect of celiprolol on the release of hypoxanthine, a uric acid precursor, from muscles after an exercise. We used the semi-ischemic forearm test to examine the release of lactate (ΔLAC), ammonia (ΔAmm), and hypoxanthine (ΔHX) before and 4, 10, and 60 min after an exercise in 18 hypertensive patients as well as 4 normotensive subjects. Before celiprolol treatment, all the levels of ΔHX and ΔAmm, and ΔLAC were increased by semi-ischemic exercise in hypertensive patients, and the increases were remarkably larger than those in normotensive subjects. Celiprolol decreased both systolic and diastolic pressure. It also decreased the levels of ΔHX and ΔAmm without changes in ΔLAC after an exercise. These findings also were confirmed by summation of each metabolite (ΣΔMetabolites). Celiprolol caused a marginal decrease of serum uric acid, but the difference was not statistically significant. On the other hand, nonvasodilating ß1 blockers did not suppress the levels of ΔHX and ΔAmm, whereas they significantly increased ΔLAC after an exercise. Celiprolol improved energy metabolism in skeletal muscles. It suppressed HX production and consequently did not adversely affect serum uric acid levels.


Asunto(s)
Antagonistas de Receptores Adrenérgicos beta 1/uso terapéutico , Celiprolol/uso terapéutico , Hipertensión/tratamiento farmacológico , Hipoxantina/metabolismo , Músculos/metabolismo , Ácido Úrico/sangre , Vasodilatadores/uso terapéutico , Antagonistas de Receptores Adrenérgicos beta 1/farmacología , Anciano , Presión Sanguínea/efectos de los fármacos , Celiprolol/farmacología , Prueba de Esfuerzo , Femenino , Antebrazo/irrigación sanguínea , Antebrazo/patología , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Hipertensión/sangre , Hipertensión/fisiopatología , Isquemia/patología , Masculino , Persona de Mediana Edad , Músculos/efectos de los fármacos , Vasodilatadores/farmacología
5.
Colorectal Dis ; 15(8): 982-6, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23560619

RESUMEN

AIM: The annual incidence of colonic diverticular bleeding is increasing, but treatments are not yet well established. Here we aimed to identify the risk factors for early re-bleeding and to determine the associated duration of hospitalization. METHOD: Records of 90 emergent patients with colonic diverticular bleeding between 1999 and May 2012 were retrospectively reviewed. They were divided into an early re-bleeding within 1 month group (n = 24) and a no re-bleeding group (n = 66) and we investigated the risk factors for early re-bleeding. In the former group, we calculated the time from the first haemostasis to early re-bleeding and the associated duration of hospitalization. RESULTS: Univariate analysis showed that there were significantly more patients with signs of shock (P = 0.00055) and active bleeding on the first colonoscopy after admission (P = 0.020) in the early re-bleeding group. Multivariate conditional logistic regression analysis using stepwise variable selection showed that signs of shock on admission (odds ratio, 5.23; 95% confidence interval, 1.84-14.90; P = 0.0019) remained statistically significant. All patients who re-bled without signs of shock (n = 7) and 16 of 17 with signs of shock re-bled within 126 h (5.25 days) of initial hospitalization. CONCLUSION: Shock was an independent risk factor for early re-bleeding. The associated duration of hospitalization was 6 days.


Asunto(s)
Divertículo del Colon/complicaciones , Hemorragia Gastrointestinal/etiología , Hemostasis/fisiología , Choque/diagnóstico , Anciano , Divertículo del Colon/sangre , Divertículo del Colon/terapia , Femenino , Hemorragia Gastrointestinal/epidemiología , Humanos , Incidencia , Tiempo de Internación/estadística & datos numéricos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Recurrencia , Estudios Retrospectivos , Factores de Riesgo
6.
Nat Genet ; 19(2): 179-81, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9620777

RESUMEN

Nijmegen breakage syndrome (NBS), also known as ataxia-telangiectasia (AT) variant, is an autosomal recessive disorder characterized by microcephaly, growth retardation, severe combined immunodeficiency and a high incidence of lymphoid cancers. Cells from NBS patients display chromosome instability, hypersensitivity to ionizing radiation and abnormal cell-cycle regulation after irradiation, all of which are characteristics shared with AT. Recently, the NBS locus was mapped at 8q21 by two independent approaches, complementation studies and linkage analysis. Here, we report the positional cloning of the NBS gene, NBS1, from an 800-kb candidate region. The gene comprises 50 kb and encodes a protein of 754 amino acids. The amino-terminal region of the protein shows weak homology to the yeast XRS2, MEK1, CDS1 and SPK1 proteins. The gene is expressed at high levels in the testes, suggesting that it might be involved in meiotic recombination. We detected the same 5-bp deletion in 13 individuals, and conclude that it is likely to be a founder mutation.


Asunto(s)
Ataxia Telangiectasia/genética , Proteínas de Ciclo Celular/genética , Rotura Cromosómica/genética , Cromosomas Humanos Par 8 , Proteínas Nucleares , Secuencia de Aminoácidos , Mapeo Cromosómico , Clonación Molecular , Bases de Datos Factuales , Trastornos del Crecimiento/genética , Humanos , Microcefalia/genética , Datos de Secuencia Molecular , Linaje , Inmunodeficiencia Combinada Grave/genética , Síndrome
7.
Clin Exp Nephrol ; 16(2): 269-78, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22127399

RESUMEN

BACKGROUND: Achieving adequate blood pressure (BP) control often requires more than one antihypertensive agent. The purpose of this study was to determine whether a fixed-dose formulation of losartan (LOS) plus hydrochlorothiazide (HCTZ) (LOS/HCTZ) is effective in achieving a greater BP lowering in patients with uncontrolled hypertension. METHODS: The study was a prospective, multicenter, observational trial exploring the antihypertensive effect of a single tablet of LOS 50 mg/HCTZ 12.5 mg. A total of 228 patients whose BP had previously been treated with more than one antihypertensive agents without having achieved BP goal below 130/80 mmHg enrolled in the study. RESULTS: A significant decrease in systolic and diastolic BP was observed in both clinic and home measurement after switching from the previous treatment to LOS/HCTZ. There was a significant decrease in both B-type natriuretic peptide (BNP) and urinary albumin creatinine (Cr) excretion ratio (ACR), especially in patients with elevated values. In contrast, there was a significant increase in serum Cr concentration in conjunction with a decrease in estimated glomerular filtration rate (eGFR). Overall serum uric acid (UA) concentration increased, whereas in patients with hyperuricemia there was a significant reduction in this value. CONCLUSION: Switching to LOS/HCTZ provides a greater reduction in clinic and home BP in patients with uncontrolled hypertension. This combination therapy may lead to cardio-, reno protection and improve UA metabolism.


Asunto(s)
Antihipertensivos/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Hidroclorotiazida/uso terapéutico , Hipertensión/tratamiento farmacológico , Losartán/uso terapéutico , Adulto , Anciano , Determinación de la Presión Sanguínea , Creatinina/orina , Combinación de Medicamentos , Femenino , Tasa de Filtración Glomerular , Humanos , Hipertensión/metabolismo , Hipertensión/fisiopatología , Hiperuricemia , Japón , Masculino , Persona de Mediana Edad , Péptido Natriurético Encefálico/sangre , Estudios Prospectivos , Resultado del Tratamiento , Ácido Úrico/sangre , Adulto Joven
8.
Clin Exp Immunol ; 165(1): 85-93, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21501152

RESUMEN

Intestinal epithelial cells (IECs) play an important role in protecting the intestinal surface from invading pathogens by producing effector molecules. IECs are one of the major sources of human beta-defensin 2 (hBD-2), and can produce it in response to a variety of stimuli. Although IECs express Toll-like receptor 3 (TLR-3) and can respond to its ligand, double-stranded RNA (dsRNA), hBD-2 expression in response to dsRNA has not been elucidated. In the present study, using an artificial analogue of dsRNA, polyinosinic-polycytidylic acid (poly I:C), we investigated whether the human IEC line, HT-29, can produce hBD-2 in response to poly I:C. HT-29 cells can express hBD-2 mRNA only when stimulated with poly I:C. The induction of hBD-2 mRNA expression was observed at 3 h after stimulation and peaked at 12 h of post-stimulation. Pre-incubation of the cells with nuclear factor kappa B (NF-κB)-specific inhibitor, l-1-4'-tosylamino-phenylethyl-chloromethyl ketone (TPCK) and isohelenine abolished the expression of hBD-2. Detection of the poly I:C signal by TLR-3 on the surface of HT-29 cells was revealed by pre-incubating the cells with anti-TLR-3 antibody. The 5'-regulatory region of the hBD-2 gene contains two NF-κB binding sites. A luciferase assay revealed the importance of the proximal NF-κB binding site for poly I:C-induced expression of hBD-2. Among NF-κB subunits, p65 and p50 were activated by poly I:C stimulation and accumulated in the nucleus. Activation of the p65 subunit was investigated further by determining its phosphorylation status, which revealed that poly I:C stimulation resulted in prolonged phosphorylation of p65. These results indicate clearly that NF-κB plays an indispensable role in poly I:C induced hBD-2 expression in HT-29 cells.


Asunto(s)
Células Caliciformes/metabolismo , FN-kappa B/metabolismo , Poli I-C/inmunología , Virosis/inmunología , beta-Defensinas/metabolismo , Regiones no Traducidas 5'/genética , Anticuerpos Monoclonales/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Células Caliciformes/inmunología , Células Caliciformes/patología , Células HT29 , Humanos , Inmunidad Mucosa , Mucosa Intestinal/patología , FN-kappa B/antagonistas & inhibidores , FN-kappa B/genética , FN-kappa B/inmunología , Fosforilación , Unión Proteica/genética , ARN Viral/inmunología , Receptor Toll-Like 3/genética , Receptor Toll-Like 3/inmunología , Receptor Toll-Like 3/metabolismo , Clorometilcetona de Tosilfenilalanila/farmacología , beta-Defensinas/genética , beta-Defensinas/inmunología
10.
Eur Surg Res ; 47(3): 135-40, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21921634

RESUMEN

BACKGROUND: Endotoxin (Et) adsorption therapy with a column of polymyxin B-immobilized fibers (PMX) is effective in improving the partial pressure of arterial oxygen/fraction of inspired oxygen ratio (PaO(2)/FiO(2) ratio) and increasing mean arterial blood pressure (MAP) in sepsis. S100A12 and soluble receptor for advanced glycation end product (sRAGE) are useful as early markers of acute lung injury. PURPOSE: To investigate the effect of improving the PaO(2)/FiO(2) ratio by PMX-direct hemoperfusion (PMX-DHP) on production of S100A12 and sRAGE. SUBJECTS AND METHODS: Sepsis patients after surgery for perforation of the lower gastrointestinal tract were adopted as the subjects. We retrospectively reviewed the cases of 20 patients on mechanical ventilation and continuous administration of norepinephrine. We recorded PaO(2)/FiO(2) ratio, MAP, and norepinephrine doses. S100A12, sRAGE, and Et levels were measured before and after PMX-DHP. RESULTS: The PaO(2)/FiO(2) ratio and MAP improved significantly after PMX-DHP (p < 0.05). S100A12 and Et decreased significantly after PMX-DHP (p < 0.05). No differences were observed in sRAGE. CONCLUSION: S100A12 is useful as a marker that reflected improvement in the PaO(2)/FiO(2) ratio after PMX-DHP. We consider PMX-DHP to be useful as adjunctive therapy for sepsis that reduces the Et and corrects the pathology in the early stage.


Asunto(s)
Hemoperfusión/métodos , Complicaciones Posoperatorias/terapia , Receptores Inmunológicos/sangre , Proteínas S100/sangre , Choque Séptico/terapia , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Endotoxinas/sangre , Endotoxinas/aislamiento & purificación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Polimixina B , Complicaciones Posoperatorias/sangre , Receptor para Productos Finales de Glicación Avanzada , Estudios Retrospectivos , Proteína S100A12 , Choque Séptico/sangre
11.
Eur Surg Res ; 47(1): 32-8, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21576972

RESUMEN

BACKGROUND: Glucose control is essential to avoid hypoglycemia in postoperative patients. AIM: To conduct a preliminary examination to evaluate the feasibility of the use of an artificial pancreas for glucose control as well as the accuracy of assessment by the artificial pancreas of the insulin dose required. SUBJECTS AND METHODS: Glucose control using an artificial pancreas was undertaken in 8 postoperative sepsis patients. The blood glucose level was set at 80-150 mg/dl. Blood glucose levels over time, insulin dose requirements, and occurrence of hypoglycemia (≤40 mg/dl) were recorded for each patient. The patients were divided into 2 groups based on the total insulin dose they received over the 7 days (HG, n = 4: consisting of patients who required a higher insulin dose; LG, n = 4: patients who required a lower insulin dose). The data of the 2 groups were analyzed retrospectively. RESULTS: The blood glucose level before glucose control was 203.3 ± 9.9 mg/dl and could be controlled in all patients to within the target range. No hypoglycemia events were recorded for any of the patients. The insulin dose in the HG and LG groups was 21,824.8 ± 6,030.4 and 6,254.5 ± 3,402.3 mU/kg (p < 0.05). CONCLUSIONS: Accurate glucose control could be achieved with the artificial pancreas.


Asunto(s)
Glucemia/metabolismo , Hipoglucemia/prevención & control , Páncreas Artificial , Complicaciones Posoperatorias/prevención & control , Sepsis/sangre , Sepsis/cirugía , Anciano , Femenino , Glucosa/administración & dosificación , Humanos , Insulina/administración & dosificación , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Estudios Retrospectivos
12.
Kyobu Geka ; 64(4): 271-4, 2011 Apr.
Artículo en Japonés | MEDLINE | ID: mdl-21491719

RESUMEN

We hypothesized that apical bullae recurred due to the dead space problem after apical bullectomy and caused recurrent pneumothorax. Apical tenting with a large polyglycolic acid (PGA) [15 x 15 cm] sheet was performed to attenuate over-expansion of the apical lung after bullectomy in the 43 patients (37 men and 6 women) with primary spontaneous pneumothorax. Shrinkage of the apical lung was estimated by measurement of the distance between the lower edge of the 1st rib and the apex on the chest radiography and computed tomography. Shrinkage was 9.22 (0-24) mm on the 10th postoperative day and 7.76 (2-17) mm at 3 months after surgery. Bullous formation recurred in 7 apical lungs of 6 patients. Minimal pneumothorax, which resolved with no treatment recurred in 3 patients. Thoracic drainage for recurrent pneumothorax was required in 1 patient. The degree of shrinkage at 3 months after bullectomy was not correlated to recurrent bullous formation, but correlated to recurrent pneumothorax. These data suggested that apical tenting method with a PGA sheet can reduce the recurrence rate of the pneumothorax after bullectomy, while it can not inhibit recurrent bullous formation.


Asunto(s)
Neumotórax/cirugía , Adolescente , Adulto , Vesícula/cirugía , Femenino , Humanos , Masculino , Ácido Poliglicólico , Estudios Prospectivos , Prevención Secundaria , Toracoscopía
13.
Kyobu Geka ; 64(4): 266-70, 2011 Apr.
Artículo en Japonés | MEDLINE | ID: mdl-21491718

RESUMEN

We evaluated the validity of the SOFT COAG electrosurgical output system for the treatment of spontaneous pneumothorax. From April 2008 to May 2010, we compared 64 patients who had undergone bullae resection using endoscopic linear staplers, to 20 patients subjected to electroablation of the bullae using the SOFT COAG output system. There was no significant difference between the 2 groups in terms of operation time, bleeding, and mean duration of postoperative chest tube drainage. Postoperative recurrence was apparent in 3 cases for the linear stapler, and in 2 cases for SOFT COAG. Electroablation using the SOFT COAG output system was suggested to be valid for treatment of spontaneous pneumothorax.


Asunto(s)
Electrocirugia/instrumentación , Neumotórax/cirugía , Adulto , Femenino , Humanos , Masculino , Estudios Retrospectivos
14.
Colorectal Dis ; 12(10 Online): e320-5, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19863598

RESUMEN

AIM: Acute haemorrhagic rectal ulcer (AHRU) is characterized by sudden onset of painless and massive rectal bleeding in elderly bedridden patients who have serious illness. Endoscopic diagnosis and management of AHRU is, however, still controversial. We retrospectively investigated 95 AHRU patients to elucidate the clinical characteristics, endoscopic findings and haemostatic strategies. METHOD: Between January 1999 and March 2007, 95 patients were diagnosed with AHRU in our hospital. Medical records and colonoscopy files were reviewed. Clinical features, colonoscopic findings, haemostatic treatment and outcome of the patients were evaluated. RESULTS: Eighty per cent of the patients were bedridden at the onset. The most frequent underlying disorder was cerebrovascular disease (36.8%). Hypoalbuminaemia (< 3.5 g/dl) was seen in 92.6% of the patients. Endoscopic findings of AHRU were classified as circumferential ulcer (41.1%), linear or nearly round small ulcer(s) (44.2%), circumferential and small ulcer(s) (7.4%) and Dieulafoy-like ulcer (7.4%). Primary endoscopic haemostatic treatment was performed in 45.3% of cases. Recurrent bleeding occurred in 24.2% of patients. Permanent haemostasis was achieved by secondary endoscopic treatment in 82.6% of re-bleeding patients. CONCLUSION: Understanding the typical clinical and endoscopic findings and careful endoscopic examination are important for the accurate diagnosis of AHRU, and endoscopic haemostatic therapy may be effective for bleeding patients.


Asunto(s)
Hemorragia Gastrointestinal/patología , Hemorragia Gastrointestinal/terapia , Hemostasis Endoscópica/métodos , Enfermedades del Recto/patología , Enfermedades del Recto/terapia , Úlcera/patología , Úlcera/terapia , Anciano , Colonoscopía , Femenino , Hemorragia Gastrointestinal/etiología , Humanos , Hipoalbuminemia/complicaciones , Masculino , Enfermedades del Recto/complicaciones , Recurrencia , Estudios Retrospectivos , Úlcera/complicaciones
15.
Cell Mol Life Sci ; 66(9): 1570-9, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19337691

RESUMEN

L-xylulose reductase (XR) is involved in water re-absorption and cellular osmoregulation. The crystal structure of human XR complemented with site-directed mutagenesis (Cys138Ala) indicated that the disulfide bond in the active site between Cys138 and Cys150 is unstable and may affect the reactivity of the enzyme. The effects of reducing agents on the activities of the wild-type and mutant enzymes indicated the reversibility of disulfide-bond formation, which resulted in three-fold decrease in catalytic efficiency. Furthermore, the addition of cysteine (>2 mM) inactivated human XR and was accompanied by a 10-fold decrease in catalytic efficiency. TOF-MS analysis of the inactivated enzyme showed the S-cysteinylation of Cys138 in the wild-type and Cys150 in the mutant enzymes. Thus, the action of human XR may be regulated by cellular redox conditions through reversible disulfide-bond formation and by S-cysteinylation.


Asunto(s)
Deshidrogenasas del Alcohol de Azúcar/química , Sitios de Unión , Cristalografía por Rayos X , Cisteína/química , Humanos , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Mutación , Oxidación-Reducción , Estructura Terciaria de Proteína , Relación Estructura-Actividad , Deshidrogenasas del Alcohol de Azúcar/genética , Deshidrogenasas del Alcohol de Azúcar/fisiología
16.
Appl Radiat Isot ; 161: 109148, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32250844

RESUMEN

The aim of this paper is to validate the microdosimetric functionality of the Monte Carlo code, PHITS, and verify its use for estimating dose and RBE for radiobiological studies performed at Kyoto University Institute for Integrated Radiation and Nuclear Science (KURNS). Lineal energy spectra produced by the KUR mixed irradiation mode were measured with a tissue equivalent proportional counter (TEPC) place in free air. The Monte Carlo calculation showed a good agreement with the measured data. In the second part of the study, a realistic set-up of a typical in-vivo radiobiological experiment was simulated with PHITS and the simulation results were compared against TLD and gold foil activation measurements. The Monte Carlo simulation results and the measured data showed an agreement within 3%. The calculated RBE also showed a close value to clinically utilised values. This study shows that PHITS can be utilised to evaluate thermal neutron fluxes and gamma ray absorbed dose rates inside a tumour like medium.


Asunto(s)
Terapia por Captura de Neutrón de Boro/métodos , Radiometría/métodos , Dosificación Radioterapéutica , Animales , Humanos , Ratones , Método de Montecarlo , Neoplasias/radioterapia , Oryzias , Radiobiología , Efectividad Biológica Relativa
17.
Radiat Res ; 171(1): 118-22, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19138052

RESUMEN

The first measurements of (63)Ni produced by A-bomb fast neutrons (above approximately 1 MeV) in copper samples from Hiroshima encompassed distances from approximately 380 to 5062 m from the hypocenter (the point on the ground directly under the bomb). They included the region of interest to survivor studies (approximately 900 to 1500 m) and provided the first direct validation of fast neutrons in that range. However, a significant measurement gap remained between the hypocenter and 380 m. Measurements close to the hypocenter are important as a high-value anchor for the slope of the curve for neutron activation as a function of distance. Here we report measurements of (63)Ni in copper samples from the historic Hiroshima Atomic Bomb Dome, which is located approximately 150 m from the hypocenter. These measurements extend the range of our previously published data for (63)Ni providing a more comprehensive and consistent A-bomb activation curve. The results are also in good agreement with calculations based on the current dosimetry system (DS02) and give further experimental support to the accuracy of this system that forms the basis for radiation risk estimates worldwide.


Asunto(s)
Cobre/química , Neutrones Rápidos , Armas Nucleares , Japón , Espectrometría de Masas , Níquel/análisis , Radioisótopos/análisis
18.
J Cell Biol ; 148(1): 101-14, 2000 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-10629221

RESUMEN

Kettin is a giant muscle protein originally identified in insect flight muscle Z-discs. Here, we determined the entire nucleotide sequence of Drosophila melanogaster kettin, deduced the amino acid sequence of its protein product (540 kD) along with that of the Caenorhabditis elegans counterpart, and found that the overall primary structure of Kettin has been highly conserved in evolution. The main body of Drosophila Kettin consists of 35 immunoglobulin C2 domains separated by spacers. The central two thirds of spacers are constant in length and share in common two conserved motifs, putative actin binding sites. Neither fibronectin type III nor kinase domains were found. Kettin is present at the Z-disc in several muscle types. Genetic analysis showed that kettin is essential for the formation and maintenance of normal sarcomere structure of muscles and muscle tendons. Accordingly, embryos lacking kettin activity cannot hatch nor can adult flies heterozygous for the kettin mutation fly.


Asunto(s)
Proteínas de Drosophila , Drosophila melanogaster/fisiología , Evolución Molecular , Vuelo Animal/fisiología , Proteínas de Insectos/fisiología , Proteínas Musculares/fisiología , Músculos/fisiología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Caenorhabditis elegans , Conectina , ADN Complementario , Drosophila melanogaster/embriología , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Genes de Insecto , Proteínas de Insectos/biosíntesis , Proteínas de Insectos/genética , Operón Lac , Larva , Datos de Secuencia Molecular , Proteínas Musculares/biosíntesis , Proteínas Musculares/genética , Músculos/embriología , Músculos/metabolismo , Mutación , Proteínas Quinasas/genética , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Secuencias Repetitivas de Aminoácido , Sarcómeros/ultraestructura , Homología de Secuencia de Aminoácido
19.
Science ; 251(4995): 786-8, 1991 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-17775458

RESUMEN

A high-pressure phase of TiO(2), which had been observed by shock-wave experiments and remained unresolved, has been studied by in situ x-ray diffraction. The single phase was formed at 20 gigapascals and 770 degrees C with the use of sintered-diamond multianvils; it has the same structure as baddeleyite, the stable phase of ZrO(2) at ambient conditions. The coordination number of Ti increases from six to seven across the rutile to baddeleyite transition, and the volume is reduced by approximately 9 percent.

20.
Science ; 275(5304): 1318-20, 1997 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-9036859

RESUMEN

The role of transforming growth factor-beta (TGF-beta) in long-term synaptic facilitation was examined in isolated Aplysia ganglia. Treatment with TGF-beta1 induced long-term facilitation (24 and 48 hours), but not short-term (5 to 15 minutes) or intermediate-term (2 to 4 hours) facilitation. The long-term effects of TGF-beta1 were not additive with those of serotonin. Moreover, serotonin-induced facilitation was blocked by an inhibitor of TGF-beta. Thus, activation of TGF-beta may be part of the cascade of events underlying long-term sensitization, consistent with the hypothesis that signaling molecules that participate in development also have roles in adult neuronal plasticity.


Asunto(s)
Aplysia/fisiología , Plasticidad Neuronal , Sinapsis/fisiología , Transmisión Sináptica , Factor de Crecimiento Transformador beta/farmacología , Factor de Crecimiento Transformador beta/fisiología , Animales , Estimulación Eléctrica , Neuronas Motoras/fisiología , Neuronas Aferentes/fisiología , Proteínas Serina-Treonina Quinasas , Receptor Tipo II de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/fisiología , Serotonina/farmacología , Transducción de Señal , Sinapsis/efectos de los fármacos , Transmisión Sináptica/efectos de los fármacos
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