Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 540
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Nature ; 614(7947): 239-243, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36755175

RESUMEN

Planetary rings are observed not only around giant planets1, but also around small bodies such as the Centaur Chariklo2 and the dwarf planet Haumea3. Up to now, all known dense rings were located close enough to their parent bodies, being inside the Roche limit, where tidal forces prevent material with reasonable densities from aggregating into a satellite. Here we report observations of an inhomogeneous ring around the trans-Neptunian body (50000) Quaoar. This trans-Neptunian object has an estimated radius4 of 555 km and possesses a roughly 80-km satellite5 (Weywot) that orbits at 24 Quaoar radii6,7. The detected ring orbits at 7.4 radii from the central body, which is well outside Quaoar's classical Roche limit, thus indicating that this limit does not always determine where ring material can survive. Our local collisional simulations show that elastic collisions, based on laboratory experiments8, can maintain a ring far away from the body. Moreover, Quaoar's ring orbits close to the 1/3 spin-orbit resonance9 with Quaoar, a property shared by Chariklo's2,10,11 and Haumea's3 rings, suggesting that this resonance plays a key role in ring confinement for small bodies.

3.
Phys Chem Chem Phys ; 24(44): 27121-27127, 2022 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-36342321

RESUMEN

During the last decade, X-ray free-electron lasers (XFELs) have enabled the study of light-matter interaction under extreme conditions. Atoms which are subject to XFEL radiation are charged by a complex interplay of (several subsequent) photoionization events and electronic decay processes within a few femtoseconds. The interaction with molecules is even more intriguing, since intricate nuclear dynamics occur as the molecules start to dissociate during the charge-up process. Here, we demonstrate that by analyzing photoelectron angular emission distributions and kinetic energy release of charge states of ionic molecular fragments, we can obtain a detailed understanding of the charge-up and fragmentation dynamics. Our novel approach allows for gathering such information without the need of complex ab initio modeling. As an example, we provide a detailed view on the processes happening on a femtosecond time scale in oxygen molecules exposed to intense XFEL pulses.

4.
Phys Rev Lett ; 126(12): 121801, 2021 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-33834796

RESUMEN

The rare decay K_{L}→π^{0}νν[over ¯] was studied with the dataset taken at the J-PARC KOTO experiment in 2016, 2017, and 2018. With a single event sensitivity of (7.20±0.05_{stat}±0.66_{syst})×10^{-10}, three candidate events were observed in the signal region. After unveiling them, contaminations from K^{±} and scattered K_{L} decays were studied, and the total number of background events was estimated to be 1.22±0.26. We conclude that the number of observed events is statistically consistent with the background expectation. For this dataset, we set an upper limit of 4.9×10^{-9} on the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level.

5.
Phys Rev Lett ; 122(2): 021802, 2019 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-30720307

RESUMEN

A search for the rare decay K_{L}→π^{0}νν[over ¯] was performed. With the data collected in 2015, corresponding to 2.2×10^{19} protons on target, a single event sensitivity of (1.30±0.01_{stat}±0.14_{syst})×10^{-9} was achieved and no candidate events were observed. We set an upper limit of 3.0×10^{-9} for the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level (C.L.), which improved the previous limit by almost an order of magnitude. An upper limit for K_{L}→π^{0}X^{0} was also set as 2.4×10^{-9} at the 90% C.L., where X^{0} is an invisible boson with a mass of 135 MeV/c^{2}.

6.
Diabet Med ; 34(12): 1788-1791, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-29044634

RESUMEN

BACKGROUND: Type B insulin resistance syndrome is a rare disease characterized by refractory transient hyperglycaemia and severe insulin resistance associated with circulating anti-insulin receptor antibodies. A standardized treatment regimen for type B insulin resistance syndrome has yet to be established. CASE REPORT: We report the case of a 64-year-old man undergoing haemodialysis for antineutrophil cytoplasmic antibody-associated vasculitis and diabetic nephropathy, who developed rapid onset of hyperglycaemia (glycated albumin 52.1%). Type B insulin resistance syndrome was diagnosed, on the basis of positivity for anti-insulin receptor antibodies and the man's autoimmune history of antineutrophil cytoplasmic antibody-associated vasculitis and idiopathic thrombocytopenic purpura. Although severe hyperglycaemia persisted in spite of corticosteroids and high-dose insulin therapy, rituximab treatment resulted in remarkable improvement of the man's severe insulin resistance and disappearance of anti-insulin receptor antibodies without any adverse effects. CONCLUSIONS: According to a literature review of 11 cases in addition to the present case, rituximab appears to be a safe and effective strategy for the treatment of corticosteroid-resistant type B insulin resistance syndrome.


Asunto(s)
Síndrome Metabólico/tratamiento farmacológico , Rituximab/uso terapéutico , Enfermedades Autoinmunes/clasificación , Enfermedades Autoinmunes/tratamiento farmacológico , Humanos , Resistencia a la Insulina , Masculino , Síndrome Metabólico/clasificación , Persona de Mediana Edad
7.
J Intensive Care Med ; 32(1): 48-58, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26168800

RESUMEN

BACKGROUND: Insulin receptors (IRs) in the brain have unique molecular features and a characteristic pattern of distribution. Their possible functions extend beyond glucose utilization. In this systematic review, we explore the interactions between insulin and the brain and its implications for anesthesiologists, critical care physicians, and other medical disciplines. METHODS: A literature search of published preclinical and clinical studies between 1978 and 2014 was conducted, yielding 5996 articles. After applying inclusion and exclusion criteria, 92 studies were selected for this systematic review. RESULTS: The IRs have unique molecular features, pattern of distribution, and mechanism of action. It has effects on neuronal function, metabolism, and neurotransmission. The IRs are involved in neuronal apoptosis and neurodegenerative processes. CONCLUSION: In this systematic review, we present a close relationship between insulin and the brain, with discernible effects on memory, learning abilities, and motor functions. The potential therapeutic effects extend from acute brain insults such as traumatic brain injury, brain ischemia, and hemorrhage, to chronic neurodegenerative diseases such as Alzheimer and Parkinson disease. An understanding of the wider effects of insulin conveyed in this review will prompt anaesthesiologists and critical care physicians to consider its therapeutic potential and guide future studies.


Asunto(s)
Encéfalo/metabolismo , Cuidados Críticos , Enfermedad Crítica/terapia , Insulina/metabolismo , Enfermedades Neurodegenerativas/fisiopatología , Receptor de Insulina/metabolismo , Encéfalo/fisiopatología , Humanos , Enfermedades Neurodegenerativas/metabolismo , Transducción de Señal
8.
Radiat Oncol ; 17(1): 39, 2022 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-35193627

RESUMEN

BACKGROUND: Some patients have noted a foul odor during radiation therapy sessions, but the cause of the odor remains unknown. Since we suspected that this phenomenon is due to ozone generated by ionizing radiation, this experimental study measured ozone concentrations in the treatment room and in a coiled polyvinyl chloride (PVC) tube placed within the radiation field. METHODS: We measured ozone concentrations using an ultraviolet absorption method and an ozone monitor. A PVC tube (inner diameter 7 mm, outer diameter 10 mm) was used to mimic the environment of the nasal cavity. The tube (790 cm) was coiled and set between two 4-cm-thick (for X-rays) or 2-cm-thick (for electron beams) water-equivalent solid phantoms. The sampling tube of the ozone monitor was inserted into the PVC tube, and the joint was sealed to prevent environmental air contamination. To measure ozone concentrations in the atmosphere, the sampling tube supplied with the unit was used. A linac was used on a full-sized treatment field (40 cm × 40 cm at a source-to-axis distance of 100 cm). The effect of an electron beam on ozone concentrations was also evaluated with a full-sized treatment field (40 cm × 40 cm at a source-to-surface distance of 100 cm). RESULTS: Ozone levels in the treatment room were undetectable before the start of daily treatment but reached 0.008 parts per million (ppm) or more at 1 h after the start of treatment. Concentrations then remained nearly constant at 0.010-0.015 ppm throughout the day. The maximum ozone concentration in the PVC tube was only 0.006 ppm, even when it was irradiated at 2400 monitor units/min. Depending on the X-ray dose rate, the concentration increased to a maximum of 0.010 ppm with oxygen flowing into the other end of the tube at 1.5 L/min. Ozone concentrations in the PVC tube did not differ significantly between X-ray and electron-beam irradiation. CONCLUSIONS: Only traces of ozone were found in the PVC tube that was used to mimic the nasal passages during radiation, these concentrations were too low for human perception. However, ozone concentrations did reach potentially detectable levels in the treatment room.


Asunto(s)
Ozono/análisis , Aceleradores de Partículas , Radioterapia , Fantasmas de Imagen
9.
J Radiat Res ; 62(4): 718-725, 2021 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-33912958

RESUMEN

During radiotherapy sessions to treat brain tumors or head-and-neck cancers, some patients experience unusual visual and/or olfactory perceptions. This prospective study sought to answer two questions: (i) what proportion of patients experience these unpleasant sensations?, and (ii) which organs are responsible? Eligible patients had brain or near-orbital tumors treated by helical tomotherapy. All were aged 10 years or older, able to communicate, and interviewed by a radiation oncologist at least once weekly during radiation therapy. If they had experienced such sensations, they were encouraged to join the second phase of the study. The patients were asked to indicate, using a button, when a sensation commenced and ended. The recorded data were collated with the treatment log. Thirty-eight consecutive patients were eligible. Twenty-six experienced visual and 13 olfactory sensations. The radiation doses to the organs related to the visual or olfactory sensations did not differ between patients who reported sensations and those who did not. Seventeen patients were enrolled in the second phase of the study. All 14 with visual sensations reported that the sensations occurred when the X-rays passed at eye level. Olfactory sensations were reported by eight out of nine patients when the X-rays passed through the olfactory epithelium and/or ethmoid sinus level. In conclusion, 68% of patients experienced visual sensations caused by X-rays passing through the level of the eyes, and 34% complained of olfactory sensations. With the exception of one patient, olfactory sensations occurred when the X-rays passed through the levels of the olfactory epithelium and/or ethmoid sinus.


Asunto(s)
Percepción Olfatoria/fisiología , Especificidad de Órganos , Radioterapia , Percepción Visual/fisiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiometría , Adulto Joven
10.
Plant Cell Environ ; 33(5): 805-15, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20040065

RESUMEN

Although reports on a gene for 1-amino-cyclopropane-1-carboxylate (ACC) oxidase (ACO1) in rice (Oryza sativa L.) suggest that high levels of its transcript are associated with internode elongation of deep-water rice during submergence, the role of ACO1 in rice development is largely unknown. The tissue-specificity of ACO1 expression indicated that its transcript significantly accumulated in lower parts of elongating internodes at the heading stage. Histochemical analysis and in situ hybridization showed that the ACO1 expression was localized in the basal parts of leaf sheaths immediately above nodes or the lower parts of elongating internodes. To further examine the role of ACO1, ACO1-deficient (aco1) and overexpressing (ACO1-OX) mutants were characterized. The total length of the elongated internodes of aco1 mutants was slightly shorter than that of wild-type plants and that of ACO1-OX mutants was longer. Interestingly, expression of the ACC synthase gene ACS1 and ethylene signalling gene OsEIN2 was up-regulated in the aco1 mutants. This study suggests that the ACO1 has a little effect on internode elongation at the heading stage, and that up-regulation of the ACS1 and OsEIN2 expression may attenuate inhibition of internode elongation.


Asunto(s)
Aminoácido Oxidorreductasas/metabolismo , Oryza/genética , Aminoácido Oxidorreductasas/genética , Regulación Enzimológica de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Técnicas de Inactivación de Genes , Genes de Plantas , Hibridación in Situ , Mutación , Oryza/enzimología , Hojas de la Planta/crecimiento & desarrollo , Regiones Promotoras Genéticas , ARN de Planta/genética
11.
Acta Psychiatr Scand ; 121(4): 301-7, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19614622

RESUMEN

OBJECTIVE: Psychotic disorders are a significant risk factor for suicide, especially among young people. Psychotic-like experiences (PLEs) in the general population may share an etiological background with psychotic disorders. Therefore, the present study examined the association between PLEs and risk of suicide in a community sample of adolescents. METHOD: Psychotic-like experiences, suicidal feelings, and self-harm behaviors were studied using a self-report questionnaire administered to 5073 Japanese adolescents. Depression and anxiety were evaluated using the 12-item General Health Questionnaire (GHQ). RESULTS: The presence of PLEs was significantly associated with suicidal feelings (OR = 3.1, 95% CI = 2.2-4.5) and deliberate self-harm behaviors (OR = 3.1, 95% CI = 2.0-4.8) after controlling for the effects of age, gender, GHQ-12 score, victimization, and substance use. Suicidal feelings and behaviors were more prevalent in subjects with a greater number of PLEs. CONCLUSION: Psychotic-like experiences may increase the risk of suicidal problems among adolescents.


Asunto(s)
Ansiedad/psicología , Depresión/psicología , Trastornos Psicóticos/psicología , Conducta Autodestructiva/psicología , Suicidio/psicología , Adolescente , Ansiedad/epidemiología , Niño , Víctimas de Crimen/psicología , Depresión/epidemiología , Femenino , Humanos , Japón , Masculino , Trastornos Psicóticos/epidemiología , Factores de Riesgo , Conducta Autodestructiva/epidemiología , Trastornos Relacionados con Sustancias/psicología
12.
J Viral Hepat ; 16(10): 716-23, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19302338

RESUMEN

Retinol-binding protein 4 (RBP4) is a recently identified adipokine that is elevated in the blood in several insulin-resistant states. We investigated the association between plasma RBP4 and histological and biochemical characteristics of chronic hepatitis C (CHC), as well as changes in RBP4 levels following interferon therapy. Eighty-one patients with CHC infected with genotype 1 received treatment with peginterferon plus ribavirin. Histological data were available for 41 out of 81 patients before treatment, and the degree of fibrosis, inflammation and steatosis was assessed. Plasma levels of RBP4 were determined in serial samples (before, at the end of treatment, and at 6 months post-treatment). RBP4 levels were lower in CHC patients than in control subjects (34.6 +/- 12.3 microg/mL vs 46.2 +/- 10.5 microg/mL; P

Asunto(s)
Antivirales/uso terapéutico , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Polietilenglicoles/uso terapéutico , Proteínas Plasmáticas de Unión al Retinol/análisis , Anciano , Hígado Graso/patología , Femenino , Genotipo , Hepacivirus/clasificación , Hepacivirus/aislamiento & purificación , Hepatitis C Crónica/patología , Humanos , Interferón alfa-2 , Hígado/patología , Cirrosis Hepática/patología , Masculino , Persona de Mediana Edad , Plasma/química , Proteínas Recombinantes , Ribavirina/uso terapéutico , Índice de Severidad de la Enfermedad , Carga Viral
13.
Injury ; 50(12): 2158-2166, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31623902

RESUMEN

BACKGROUND: Internal fixation remains the treatment of choice for non-displaced femoral neck fractures in elderly patients. Improved outcomes with arthroplasty following displaced femoral neck fractures may indicate that outcomes of non-displaced patterns should be reexamined. The aim of our study was to conduct a systematic review of the orthopaedic literature to determine the outcomes of internal fixation for the treatment of non-displaced and minimally displaced femoral neck fractures in elderly patients. METHODS: Relevant articles were identified using PubMed, Embase, and CENTRAL databases. Manuscripts were included if they contained (1) patients 60 years or older with (2) nondisplaced or minimally displaced (Garden I or II) femoral neck fractures (3) treated with internal fixation (4) separately reported outcomes in this patient population. The primary outcome was reoperation. Secondary outcomes included mortality, patient-reported outcomes, length of hospitalization, infection, and transfusions. Fixed and random effects modeling was used to determine pooled estimates of the outcomes. RESULTS: Twenty-seven studies were identified with a total of 21,155 patients, all of which were treated with internal fixation. The pooled risk of reoperation was 14.1% (95% CI: 10.6-18.2). The risk of one-year mortality was 14.6% (95% CI: 11.5-18.2) based on the reporting in 15 studies. CONCLUSIONS: The risk of reoperation and mortality following the treatment of nondisplaced femoral neck fractures in the elderly with internal fixation exceeds 14%. This complication profile may be unacceptably high. Arthroplasty may offer improved short-term functional outcomes and a reduced risk of reoperation. However, there is currently little evidence to consider this treatment to be an alternative to internal fixation.


Asunto(s)
Fracturas del Cuello Femoral/cirugía , Fijación Interna de Fracturas , Complicaciones Posoperatorias/prevención & control , Anciano , Artroplastia/efectos adversos , Artroplastia/métodos , Fijación Interna de Fracturas/efectos adversos , Fijación Interna de Fracturas/métodos , Humanos , Ajuste de Riesgo/métodos
14.
Transplant Proc ; 51(3): 774-778, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30979463

RESUMEN

BACKGROUND: Brachytherapy is one of the standard treatments for localized prostate cancer (CaP). However, the feasibility of brachytherapy for renal transplant recipients (RTRs) is still uncertain. MATERIALS AND METHODS: Between August 2007 and March 2018, all patients who had undergone low-dose-rate (LDR) brachytherapy or high-dose-rate (HDR) brachytherapy for clinically localized CaP at our institution were retrospectively identified (n = 394). Of these patients, 3 had a history of renal transplantation. We reviewed all available clinical data retrospectively. RESULTS: All of the RTRs received ABO-incompatible renal grafts from their spouses and had stable renal graft function before the diagnosis of CaP. The median age at diagnosis of CaP was 65 years (range, 60-67 years). The median time between transplantation and brachytherapy was 7 years (range, 4-10 years). In all of the patients, clinical stage was cT1cN0M0. Two patients received 125I LDR-brachytherapy (dose, 145 Gy) and 1 patient was treated by 192Ir HDR brachytherapy (dose, 19 Gy in 2 fractions) combined with external beam radiation therapy of 39 Gy in 13 fractions. The median follow-up period after brachytherapy was 44 months (range, 34-50 months). During the follow-up period, none of the patients developed disease progression including biochemical recurrence or clinically significant adverse events associated with radiation therapy. CONCLUSIONS: LDR brachytherapy and HDR brachytherapy are safe and technically feasible in RTRs with CaP, and oncological outcomes in RTRs do not appear to be inferior to those of patients who did not receive renal transplant.


Asunto(s)
Braquiterapia/métodos , Trasplante de Riñón , Neoplasias de la Próstata/radioterapia , Sistema del Grupo Sanguíneo ABO , Anciano , Histocompatibilidad , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de la Próstata/complicaciones , Dosificación Radioterapéutica , Estudios Retrospectivos , Receptores de Trasplantes , Resultado del Tratamiento
15.
J Clin Invest ; 76(2): 556-60, 1985 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-3861621

RESUMEN

To investigate purine catabolism in exercising muscles of patients with muscle glycogen storage disease, we performed ischemic forearm exercise tests and quantitated metabolites appearing in cubital venous blood. Two patients with glycogen storage disease type V and three with glycogen storage disease type VII participated in this study. Basal lactate concentrations lowered in every patient with glycogen storage disease type V or type VII. Two patients with glycogen storage disease type VII, who had markedly elevated concentrations of serum uric acid (14.3 and 11.9 mg/dl, respectively), showed high basal concentrations of ammonia (118 and 79 mumol/liter, respectively; 23 +/- 4 mumol/liter in healthy controls) and of hypoxanthine (23.4 and 20.4 mumol/liter, respectively; 2.0 +/- 0.4 mumol/liter in healthy controls). Other patients showed near normal measurements of these metabolites. After forearm exercise, ammonia, inosine, and hypoxanthine levels increased greatly in every patient studied, in contrast with the lack of increase in lactate levels. The incremental area under the concentration curves for venous ammonia was 13-fold greater in the glycogen storage disease group than in controls (1,120 +/- 182 vs. 83 +/- 26 mumol X min/liter). The incremental areas of inosine and hypoxanthine were also greater in the glycogen storage disease group (29.2 +/- 7.2 vs. 0.4 +/- 0.1 and 134.6 +/- 23.1 vs. 14.9 +/- 3.2 mumol X min/liter, respectively). The incremental areas of ammonia in controls and in glycogen storage disease patients strongly correlated with those of hypoxanthine (r = 0.984, n = 11, P less than 0.005). These findings indicated that excess purine degradation occurred in the exercising muscles of patients with glycogen storage disease types V and VII, and suggested that the ATP pool in the exercising muscles may be deranged because of defective glycogenolysis or glycolysis.


Asunto(s)
Enfermedad del Almacenamiento de Glucógeno Tipo VII/metabolismo , Enfermedad del Almacenamiento de Glucógeno Tipo V/metabolismo , Enfermedad del Almacenamiento de Glucógeno/metabolismo , Músculos/metabolismo , Esfuerzo Físico , Purinas/metabolismo , Adulto , Amoníaco/sangre , Femenino , Glucólisis , Humanos , Hipoxantina , Hipoxantinas/sangre , Inosina/sangre , Lactatos/sangre , Ácido Láctico , Masculino , Modelos Biológicos , Músculos/irrigación sanguínea , Ácido Úrico/sangre
16.
J Clin Invest ; 76(3): 1096-101, 1985 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2995446

RESUMEN

We investigated, in 36 healthy volunteers, the effects of prednisone and ketotifen on recovery of lymphocyte beta 2-adrenoceptor density (determined by (-)-125iodocyanopindolol binding) and responsiveness (assessed by lymphocyte cyclic AMP [cAMP] responses to 10 microM (-)-isoprenaline) after desensitization by the beta 2-agonist terbutaline. Terbutaline (3 X 5 mg/d) decreased lymphocyte beta 2-adrenoceptor density by approximately 40-50%; concomitantly, lymphocyte cAMP responses to 10 microM (-)-isoprenaline were significantly reduced. After withdrawal of terbutaline beta 2-adrenoceptor, density and responsiveness gradually increased, reaching predrug levels after 4 d. Prednisone (1 X 100 mg orally) accelerated beta 2-adrenoceptor recovery; only 8-10 h after administration of the steroid beta 2-adrenoceptor density and cAMP responses to (-)-isoprenaline had reached values not significantly different from pretreatment levels. Similar effects were obtained with ketotifen (2 mg; thereafter 2 X 1 mg/d for 4 d): 24 h after application of the drug beta 2-adrenoceptor density and cAMP responses to (-)-isoprenaline had reached pretreatment levels. Furthermore, ketotifen simultaneously applied with terbutaline completely prevented terbutaline-induced decrease in lymphocyte beta 2-adrenoceptor density and responsiveness. Prednisone (1 X 100 mg orally) or ketotifen (2 mg; thereafter 2 X 1 mg/d for 2 d) had no significant influence on lymphocyte beta 2-adrenoceptor density in healthy volunteers not pretreated with terbutaline, but shifted the ratio high-to-low affinity state of the lymphocyte beta 2-adrenoceptor toward high affinity state. We conclude that glucocorticoids as well as ketotifen can accelerate recovery of density and responsiveness of lymphocyte beta 2-adrenoceptors desensitized by long-term treatment with beta 2-agonists. Such an effect may have clinical implications for preventing tachyphylaxis of asthmatic patients against therapy with beta 2-agonists.


Asunto(s)
Cetotifen/administración & dosificación , Linfocitos/metabolismo , Prednisona/administración & dosificación , Receptores Adrenérgicos beta/efectos de los fármacos , Taquifilaxis , Terbutalina/administración & dosificación , Adulto , AMP Cíclico/biosíntesis , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Yodocianopindolol , Isoproterenol/farmacología , Cinética , Masculino , Pindolol/análogos & derivados , Pindolol/metabolismo , Receptores Adrenérgicos beta/análisis
17.
J Clin Invest ; 104(1): 13-9, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10393694

RESUMEN

The Fas ligand is predominantly expressed in activated T lymphocytes and is one of the major effector molecules of cytotoxic T lymphocytes and natural killer cells. Previously, we found excessive apoptosis of epithelial cells and infiltrating lymphocytes expressing Fas ligand mRNA in the lung tissue of bleomycin-induced pulmonary fibrosis in mice. Here we demonstrated that the administration of a soluble form of Fas antigen or anti-Fas ligand antibody prevented the development of this model and that lpr and gld mice were resistant against the induction of pneumopathy. These results suggest that the Fas-Fas ligand pathway plays an essential role in the development of pulmonary fibrosis and that preventing this pathway could have therapeutic value in lung injury and fibrosis.


Asunto(s)
Apoptosis , Glicoproteínas de Membrana/fisiología , Fibrosis Pulmonar/prevención & control , Receptor fas/fisiología , Animales , Bleomicina/toxicidad , Proteína Ligando Fas , Humanos , Hidroxiprolina/análisis , Fragmentos Fc de Inmunoglobulinas/genética , Fragmentos Fc de Inmunoglobulinas/inmunología , Etiquetado Corte-Fin in Situ , Células Asesinas Naturales/inmunología , Pulmón/química , Pulmón/patología , Glicoproteínas de Membrana/deficiencia , Glicoproteínas de Membrana/genética , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos ICR , Ratones Endogámicos MRL lpr , Ratones Mutantes , Fagocitosis , Fibrosis Pulmonar/inmunología , Fibrosis Pulmonar/patología , Proteínas Recombinantes de Fusión/fisiología , Linfocitos T Citotóxicos/inmunología , Receptor fas/genética
18.
Prostate Cancer Prostatic Dis ; 10(3): 301-6, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17387321

RESUMEN

The metabolic pathways of androgens and processes by which androgens induce re-growth after androgen deprivation therapy in prostate cancer have not been fully elucidated. In this study, finasteride decreased PSA secretion in medium containing testosterone, androstenedione, androstenediol and dehydroepiandrosterone, whereas dihydrotestosterone (DHT)- and hydroxy-flutamide-induced PSA production was not inhibited by finasteride in LNCaP-FGC cells. The present data show that adrenal androgen precursors do not directly interact with androgen receptors (ARs) but are converted to DHT via the intraprostatic metabolic pathways, resulting in the induction of LNCaP activity. This is the first report confirming this mechanism experimentally and also suggest the use of combined therapies that target ARs and prevent the formation of DHT within prostate cancer cells to achieve optimal therapeutic efficacy.


Asunto(s)
Glándulas Suprarrenales/metabolismo , Andrógenos/metabolismo , Neoplasias de la Próstata/metabolismo , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/metabolismo , Línea Celular Tumoral , Dihidrotestosterona/metabolismo , Inhibidores Enzimáticos/farmacología , Finasterida/farmacología , Humanos , Masculino , Neoplasias Hormono-Dependientes/metabolismo , Antígeno Prostático Específico/efectos de los fármacos , Antígeno Prostático Específico/metabolismo , Receptores Androgénicos/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
19.
Nat Prod Res ; 21(3): 260-4, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17365717

RESUMEN

Chemical investigation of polar fractions of the methanol extract of the fruits of Diploclisia glaucescens of the family Menispermaceae furnished two new phenyl glycosides, 4-(2-nitroethyl)phenyl-beta-D-xylopyranosyl-(l approximately 6)-beta-D-glucopyranoside, and 4-cyanophenyl-beta-D-xylopyranosyl-(l approximately 6)-beta-D-glucopyranoside.


Asunto(s)
Glicósidos/farmacología , Menispermaceae/química , Secuencia de Carbohidratos , Cromatografía Líquida de Alta Presión , Cromatografía en Capa Delgada , Frutas/química , Espectroscopía de Resonancia Magnética , Datos de Secuencia Molecular , Extractos Vegetales/química , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta
20.
J Natl Cancer Inst ; 78(3): 567-71, 1987 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-3469467

RESUMEN

When a 3-methylcholanthrene (CAS: 56-49-5)-induced fibrosarcoma, BMT-11, and its eight clones were transplanted sc into syngeneic C57BL/6 mice, leukemoid reaction characterized by a progressive increase in peripheral white blood cells (WBCs) and by splenomegaly was observed as the tumors grew. The WBC count reached about forty-fold of the normal level, and more than 90% of WBCs were found to be polymorphonuclear leukocytes. The increase in WBCs was correlated with tumor size, and its count decreased to normal level within 7 days after surgical excision of subcutaneous tumors. Moreover, a high level of colony-stimulating activity was detected in the supernatant of BMT-11 culture. These results suggest that the colony-stimulating factor produced by BMT-11 cells caused granulocytosis in mice. This is the first report of the marked degree of granulocytosis induced by a transplanted tumor in C57BL/6 strain mice.


Asunto(s)
Fibrosarcoma/patología , Granulocitos/patología , Animales , Médula Ósea/patología , Ensayo de Unidades Formadoras de Colonias , Femenino , Fibrosarcoma/inducido químicamente , Recuento de Leucocitos , Macrófagos/patología , Metilcolantreno , Ratones , Ratones Endogámicos C57BL , Trasplante de Neoplasias , Esplenectomía
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA