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1.
Phys Rev Lett ; 131(25): 253003, 2023 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-38181354

RESUMEN

Muonic helium atom hyperfine structure (HFS) measurements are a sensitive tool to test the three-body atomic system and bound-state quantum electrodynamics theory, and determine fundamental constants of the negative muon magnetic moment and mass. The world's most intense pulsed negative muon beam at the Muon Science Facility of the Japan Proton Accelerator Research Complex allows improvement of previous measurements and testing further CPT invariance by comparing the magnetic moments and masses of positive and negative muons (second-generation leptons). We report new ground-state HFS measurements of muonic helium-4 atoms at a near-zero magnetic field, performed for the first time using a small admixture of CH_{4} as an electron donor to form neutral muonic helium atoms efficiently. Our analysis gives Δν=4464.980(20) MHz (4.5 ppm), which is more precise than both previous measurements at weak and high fields. The muonium ground-state HFS was also measured under the same conditions to investigate the isotopic effect on the frequency shift due to the gas density dependence in He with CH_{4} admixture and compared with previous studies. Muonium and muonic helium can be regarded as light and heavy hydrogen isotopes with an isotopic mass ratio of 36. No isotopic effect was observed within the current experimental precision.

2.
Phys Rev Lett ; 130(17): 173001, 2023 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-37172243

RESUMEN

To test bound-state quantum electrodynamics (BSQED) in the strong-field regime, we have performed high precision x-ray spectroscopy of the 5g-4f and 5f- 4d transitions (BSQED contribution of 2.4 and 5.2 eV, respectively) of muonic neon atoms in the low-pressure gas phase without bound electrons. Muonic atoms have been recently proposed as an alternative to few-electron high-Z ions for BSQED tests by focusing on circular Rydberg states where nuclear contributions are negligibly small. We determined the 5g_{9/2}- 4f_{7/2} transition energy to be 6297.08±0.04(stat)±0.13(syst) eV using superconducting transition-edge sensor microcalorimeters (5.2-5.5 eV FWHM resolution), which agrees well with the most advanced BSQED theoretical prediction of 6297.26 eV.

3.
Phys Rev Lett ; 127(5): 053001, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-34397250

RESUMEN

We observed electronic K x rays emitted from muonic iron atoms using superconducting transition-edge sensor microcalorimeters. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic Kα and Kß x rays together with the hypersatellite K^{h}α x rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the L-shell electrons, accompanied by electron side feeding. Assisted by a simulation, these data clearly reveal the electronic K- and L-shell hole production and their temporal evolution on the 10-20 fs scale during the muon cascade process.

4.
Ann Oncol ; 27(12): 2242-2250, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27765756

RESUMEN

BACKGROUND: The human IgG4 monoclonal antibody nivolumab targets programmed cell death-1 (PD-1) and promotes antitumor response by blocking the interaction of PD-1 with its ligands. This single-center phase Ib study investigated the tolerability, safety, and pharmacokinetics of nivolumab combined with standard chemotherapy in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Patients who had stage IIIB without indication for definitive radiotherapy, stage IV, or recurrent NSCLC were eligible. Regimens were nivolumab 10 mg/kg + gemcitabine/cisplatin (arm A), pemetrexed/cisplatin (arm B), paclitaxel/carboplatin/bevacizumab (arm C), or docetaxel (arm D). Regimens A, B, and D were repeated every 3 weeks for up to four cycles and regimen C was repeated for up to six cycles; nivolumab alone (arm A), with pemetrexed (arm B), bevacizumab (arm C), or docetaxel (arm D) was continued every 3 weeks as maintenance therapy until disease progression or unacceptable toxicity. Dose-limiting toxicity (DLT) was evaluated during the first treatment cycle. RESULTS: As of March 2014, six patients were enrolled in each arm. The combination of nivolumab 10 mg/kg and chemotherapy was well tolerated. DLT was observed in only one patient in arm A (alanine aminotransferase increased). Select adverse events (those with a potential immunologic cause) of any grade were observed in six, four, six, and five patients in arms A, B, C, and D, respectively. Three, three, six, and one patient achieved partial response while median progression-free survival was 6.28, 9.63 months, not reached, and 3.15 months in arms A, B, C, and D, respectively. CONCLUSIONS: Combination of nivolumab 10 mg/kg and chemotherapy showed an acceptable toxicity profile and encouraging antitumor activity in patients with advanced NSCLC. CLINICAL TRIALS NUMBER: Japanese Pharmaceutical Information Center Clinical Trials Information (JapicCTI)-132071.


Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Adulto , Anciano , Anticuerpos Monoclonales/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Bevacizumab , Carboplatino/administración & dosificación , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Cisplatino/administración & dosificación , Desoxicitidina/administración & dosificación , Desoxicitidina/análogos & derivados , Supervivencia sin Enfermedad , Docetaxel , Femenino , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/radioterapia , Estadificación de Neoplasias , Nivolumab , Paclitaxel/administración & dosificación , Pemetrexed/administración & dosificación , Taxoides/administración & dosificación , Gemcitabina
5.
ESMO Open ; 8(6): 102030, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37852033

RESUMEN

BACKGROUND: Immune checkpoint inhibitors (ICIs) are indicated for various cancers and are the mainstay of cancer immunotherapy. They are often associated with ICI-related pneumonitis (CIP), however, hindering a favorable clinical course. Recently, non-oncology concomitant drugs have been reported to affect the efficacy and toxicity of ICIs; however, the association between these drugs and the risk for CIP is uncertain. The aim of this study was to assess the impact of baseline concomitant drugs on CIP incidence in ICI-treated advanced cancer patients. PATIENTS AND METHODS: This was a single-center retrospective study that included a cohort of 511 patients with advanced cancer (melanoma and non-small-cell lung, head and neck, genitourinary, and other types of cancer) treated with ICIs. Univariable analysis was conducted to identify baseline co-medications associated with CIP incidence. A propensity score matching analysis was used to adjust for potential CIP risk factors, and multivariable analysis was carried out to assess the impact of the identified co-medications on CIP risk. RESULTS: Forty-seven (9.2%) patients developed CIP. In these patients, the organizing pneumonia pattern was the dominant radiological phenotype, and 42.6% had grade ≥3 CIP, including one patient with grade 5. Of the investigated baseline co-medications, the proportion of antiplatelet drugs (n = 50, 9.8%) was higher in patients with CIP (23.4% versus 8.4%). After propensity score matching, the CIP incidence was higher in patients with baseline antiplatelet drugs (22% versus 6%). Finally, baseline antiplatelet drug use was demonstrated to increase the risk for CIP incidence regardless of cancer type (hazard ratio, 3.46; 95% confidence interval 1.21-9.86). CONCLUSIONS: An association between concomitant antiplatelet drug use at baseline and an increased risk for CIP was seen in our database. This implies the importance of assessing concomitant medications for CIP risk management.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Neumonía , Humanos , Inhibidores de Agregación Plaquetaria/efectos adversos , Estudios Retrospectivos , Neumonía/inducido químicamente , Neumonía/epidemiología
6.
J Dairy Sci ; 93(9): 4189-95, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20723693

RESUMEN

The objective of this study was to investigate the effect of dietary supplementation with the disaccharides trehalose and cellobiose on antioxidant activity in rumen fluid, blood, and milk of dairy cows. Nine Holstein dairy cows housed in a free-stall barn were divided into 3 groups, with each group receiving a different dietary treatment (a control diet, a 1% trehalose-supplemented diet, or a 1% cellobiose-supplemented diet) following a 3x3 Latin square design. Feed intake and milk production increased in cows receiving the trehalose-supplemented diet compared with those receiving the control and cellobiose-supplemented diets. The total protozoa numbers in the rumen fluid of cows fed trehalose- or cellobiose-supplemented diets were greater than those of the control group. The C18:0 and C18:1 fatty acid content was increased in the milk of cows fed the trehalose-supplemented diet compared with that of the control group, and the C18:3n-3 fatty acid content in the milk of cows fed the cellobiose-supplemented diet was less than that of the control group. Plasma biochemical parameters were unchanged among the different treatments. In rumen fluid, 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and superoxide dismutase activity were increased 2h after feeding in cows receiving the cellobiose-supplemented diet compared with the control group, and the concentration of thiobarbituric acid reactive substances in the rumen fluid of cows fed the cellobiose-supplemented diet was decreased. In contrast, the values of these parameters measured in the milk of cows fed the cellobiose-supplemented diet were no different from those of control cows. Dietary supplementation with trehalose did, however, bring about an improvement of the oxidative status of milk and blood in these animals compared with controls. These results provide the first evidence supporting the use of dietary disaccharides to decrease lipid peroxide levels and increase the antioxidant content of dairy cow milk. The findings suggest that disaccharides, particularly trehalose, might be useful as supplements for reducing oxidative stress and improving the quality of milk for human consumption, as well as possibly impairing the processes that give rise to lipid oxidation odor in dairy cow milk.


Asunto(s)
Antioxidantes/análisis , Suplementos Dietéticos , Peróxidos Lipídicos/análisis , Leche/química , Trehalosa/farmacología , Animales , Bovinos , Celobiosa/farmacología , Dieta/veterinaria , Ingestión de Alimentos/efectos de los fármacos , Eucariontes/efectos de los fármacos , Ácidos Grasos/análisis , Femenino , Depuradores de Radicales Libres/análisis , Jugo Gástrico/química , Lactancia/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Leche/efectos de los fármacos , Leche/metabolismo , Rumen/efectos de los fármacos , Rumen/parasitología , Superóxido Dismutasa/análisis
7.
J Fish Biol ; 76(1): 161-82, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20738704

RESUMEN

The kiss1 gene product kisspeptin is now considered to be an essential regulator of the hypothalamic-pituitary-gonadal (HPG) axis in most vertebrate species. Recent findings in fishes are beginning to set a new stage for the kisspeptin study; the existence of paralogous kisspeptin genes as well as kisspeptin receptor (formerly called GPR54) genes has quite recently been reported in several fish and amphibian species. The fishes may provide excellent animal models for the study of general principles underlying the kisspeptin and kisspeptin receptor systems of vertebrates from the evolutionary viewpoint. Unlike placental and marsupial mammalian species mainly studied so far, many teleost species have two paralogous genes of kisspeptin, kiss1 and kiss2. Medaka, Oryzias latipes, in which kiss1 and kiss2 are expressed in distinctive hypothalamic neuron populations, is a good model system for the study of central regulation of reproduction. Here, the kiss1 system but not the kiss2 system shows expression dynamics strongly indicative of its direct involvement in the HPG axis regulation via its actions on GnRH1 neurons. On the other hand, the kiss1 gene is missing, and only kiss2 is expressed in some fish species. Also, there are some recent reports that Kiss2 peptide may be a potent regulator of reproduction in some fish species. The ancestral vertebrate probably already had two paralogous kiss genes, and their main function was the HPG axis regulation. In the species that retained both paralogues during evolution, either Kiss1 or Kiss2 predominantly retains its ability for the HPG axis regulation, while the other may assume new non-reproductive functions (neofunctionalization). Alternatively, both the paralogues may assume complementary functions in the HPG axis regulation (subfunctionalization). After the divergence of teleost and tetrapod lineages, either one of the two paralogues, or even both in birds, have been lost (degradation) or became a pseudogene (non-functionalization), but the remaining paralogue retained its original function of HPG axis regulation. The identification of multiple forms of kisspeptin receptors and the rather promiscuous ligand-receptor relationships has led to the further proposal that such promiscuousness may be the basis for the functional robustness of kisspeptin and kisspeptin receptor systems in the HPG axis regulation, when one or both paralogous genes are lost or functionally partitioned during evolution.


Asunto(s)
Evolución Biológica , Encéfalo/metabolismo , Peces/fisiología , Proteínas Supresoras de Tumor/metabolismo , Animales , Peces/clasificación , Regulación de la Expresión Génica , Ligandos , Proteínas Supresoras de Tumor/genética
8.
Cancer Res ; 52(7): 1681-6, 1992 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-1348012
9.
J Nutr Health Aging ; 20(4): 453-7, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26999247

RESUMEN

OBJECTIVES: Older patients receiving home medical care often have declining functional status and multiple disease conditions. It is important to identify the risk factors for care transition events in this population in order to avoid preventable transitions. In the present study, therefore, we investigated the factors associated with discontinuation of home medical care as a potentially preventable care transition event in older patients. METHODS: Baseline data for participants in the Observational study of Nagoya Elderly with HOme MEdical (ONEHOME) study and data on the mortality, institutionalization, or hospitalisation of the study participants during a 2-year follow-up period were used. Discontinuation of home care was defined as admission to a hospital for any reason, institutionalization, or death. Univariate and multivariate Cox hazard models were used to assess the association of each of the factors with the discontinuation of home care during the observational period. The covariates included in the multivariate analysis were those significantly associated with the discontinuation of home care at the level of P<0.05 in the univariate analysis. RESULTS: The univariate Cox hazard model revealed that a low hemoglobin level (< 11g/dL), low serum albumin level (< 3g/dL), higher Charlson Comorbidity Index score, and low Mini Nutritional Assessment Short Form score (< 7) were significantly associated with the discontinuation of home care. A multivariate Cox hazard model including these four factors demonstrated that all four were independently associated with home-care discontinuation. CONCLUSIONS: The present results demonstrated that anemia, hypoalbuminemia, malnourishment, and the presence of serious comorbidities were associated with the discontinuation of home medical care among low-functioning older patients.


Asunto(s)
Evaluación Geriátrica , Servicios de Atención de Salud a Domicilio/estadística & datos numéricos , Hospitalización/estadística & datos numéricos , Anciano , Anciano de 80 o más Años , Comorbilidad , Femenino , Estudios de Seguimiento , Hemoglobinas/análisis , Humanos , Masculino , Evaluación Nutricional , Modelos de Riesgos Proporcionales , Factores de Riesgo , Albúmina Sérica/análisis
10.
Oncogene ; 18(22): 3354-64, 1999 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-10362356

RESUMEN

We have examined fibroblast growth factor (FGF) receptor-1 mediated signal transduction in differentiation of endothelial cells (EC). The activated FGFR-1 couples to Ras through two adaptor proteins, FRS2 and Shc. In FGF-2 treated proliferating EC, FRS2 as well as Shc are tyrosine phosphorylated and interact with Grb2. In contrast, in FGF-2 treated differentiating cells, Shc, but not FRS2, is engaged in Grb2-interactions. Sustained MAP kinase activity has previously been implicated in differentiation. In FGF stimulated proliferating and differentiating endothelial cells, the MAP kinase Erk2 is activated in a sustained manner. Inhibition of MEK and MAP kinase activity by PD98059 treatment of cells, still allows EC tube formation. The FGFR-1 mediates activation of protein kinase C (PKC) through direct binding and activation of phospholipase C-gamma (PLC-gamma), and has also been shown to activate the cytoplasmic tyrosine kinase Src. Treatment of the cells with the PKC inhibitor bisindolylmaleimide does not prevent tube formation. In contrast, Src kinase activity is a prerequisite for EC differentiation, since treatment of the cells with PP1, a Src family specific inhibitor, abrogates tube formation. In differentiating EC, FGF-2 induces complex formation between Src and focal adhesion kinase (FAK). These data indicate that the Ras pathway is initiated via Shc or FRS2, dependent on the cellular program. Blocking the function of Src family kinases, attenuates differentiation.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Endotelio Vascular/metabolismo , Factor 2 de Crecimiento de Fibroblastos/metabolismo , Genes ras , Dominios Homologos src , Animales , Becaplermina , Proteínas Quinasas Dependientes de Calcio-Calmodulina/efectos de los fármacos , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Moléculas de Adhesión Celular/efectos de los fármacos , Moléculas de Adhesión Celular/metabolismo , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/fisiología , División Celular/fisiología , Línea Celular , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Factor 2 de Crecimiento de Fibroblastos/farmacología , Flavonoides/farmacología , Quinasa 1 de Adhesión Focal , Proteína-Tirosina Quinasas de Adhesión Focal , Proteína Adaptadora GRB2 , Indoles/farmacología , Isoenzimas/efectos de los fármacos , Isoenzimas/metabolismo , Maleimidas/farmacología , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Transgénicos , Fosfolipasa C gamma , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Factor de Crecimiento Derivado de Plaquetas/metabolismo , Factor de Crecimiento Derivado de Plaquetas/farmacología , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C/efectos de los fármacos , Proteína Quinasa C/metabolismo , Proteínas Tirosina Quinasas/efectos de los fármacos , Proteínas Tirosina Quinasas/metabolismo , Proteínas/genética , Proteínas/metabolismo , Proteínas Proto-Oncogénicas c-sis , Proteínas Tirosina Quinasas Receptoras/genética , Proteínas Tirosina Quinasas Receptoras/metabolismo , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos , Receptores de Factores de Crecimiento de Fibroblastos/genética , Receptores de Factores de Crecimiento de Fibroblastos/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transducción de Señal , Fosfolipasas de Tipo C/efectos de los fármacos , Fosfolipasas de Tipo C/metabolismo , Proteínas ras/genética
11.
Oncogene ; 20(52): 7610-23, 2001 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-11753639

RESUMEN

Dysregulated cell motility is one of the major characteristics of invasion and metastatic potentials of malignant tumor cells. Here, we examined the hepatocyte growth factor (HGF)-induced cell motility of two human renal carcinoma cell lines, ACHN and VMRC-RCW. Scattering and migration was induced in ACHN in an HGF-dependent manner, whereas they were maintained in VMRC-RCW even in the absence of HGF. In VMRC-RCW, HGF receptor (HGFR) tyrosine kinase was constitutively active, and sequence analysis showed N375S, A1209G and V1290L mutations. However, transfection experiments using porcine aortic endothelial (PAE) cells demonstrated that no single mutation or combination of two or three mutations caused HGF-independent constitutive activation. Conversely, the expressed amount of receptor protein had a pivotal role in the basal kinase activity. With respect to downstream signaling molecules of HGFR in ACHN or VMRC-RCW, the Ras-MAPK pathway was downregulated, whereas phosphoinositide 3-kinase (PI3-kinase) was not further activated by HGF-treatment in VMRC-RCW cells. The PI3-kinase inhibitors, wortmannin and LY294002 strongly inhibited spontaneous migration of VMRC-RCW. One transfected PAE cell line with massive overexpression of HGFR demonstrated scattered morphology and increased PI3-kinase activity in association with increased motility, which was partially inhibited by LY294002. Taken together, our results indicate that the overexpression of HGFR causes increase in cellular motility and PI3-kinase shows the important contribution on the increased motility of renal carcinoma cells.


Asunto(s)
Carcinoma de Células Renales/enzimología , Neoplasias Renales/enzimología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-met/metabolismo , Transducción de Señal , Animales , Comunicación Autocrina , Movimiento Celular , Células Cultivadas , Endotelio Vascular/citología , Activación Enzimática , Factor de Crecimiento de Hepatocito/metabolismo , Factor de Crecimiento de Hepatocito/farmacología , Humanos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Metástasis de la Neoplasia , Inhibidores de las Quinasa Fosfoinosítidos-3 , Proteínas Proto-Oncogénicas c-met/genética , Porcinos , Transfección , Células Tumorales Cultivadas , Proteínas ras/metabolismo
12.
Arterioscler Thromb Vasc Biol ; 21(5): 765-70, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11348872

RESUMEN

Although the accumulation of vascular endothelial growth factor (VEGF) has been observed in human atherosclerotic lesions, the exact role of this growth factor in atherogenesis remains unknown. We hypothesized that VEGF in the vascular wall might have a preventive effect on endothelial cell damage during atherosclerosis. To test our hypothesis, we examined whether VEGF protects against the toxicity of oxidized low density lipoprotein (Ox-LDL) in cultured endothelial cells derived from bovine aortas (BAECs). Preincubation of BAECs with VEGF prevented Ox-LDL-induced toxicity in a preincubation time- and VEGF concentration-dependent manner. Addition of N(omega)-nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor, did not reverse the protective effect of VEGF on Ox-LDL toxicity. Incubation of BAECs with VEGF increased intracellular glutathione (GSH) content in a time-dependent manner. Combined addition of VEGF and L-buthionine sulfoximine, a GSH synthesis inhibitor, reversed both GSH levels and the protective effect of VEGF on Ox-LDL-induced cytotoxicity. Placenta growth factor, which ligates to the VEGF Flt-1 receptor but not KDR/Flk-1, failed to prevent Ox-LDL toxicity and had no effect on intracellular GSH levels. An anti-KDR antibody completely blocked these beneficial activities of VEGF. These results suggest that VEGF prevents Ox-LDL-induced endothelial cell damage via an intracellular GSH-dependent mechanism through the KDR/Flk-1 receptor.


Asunto(s)
Factores de Crecimiento Endotelial/farmacología , Endotelio Vascular/efectos de los fármacos , Glutatión/metabolismo , Lipoproteínas LDL/toxicidad , Linfocinas/farmacología , Proteínas Tirosina Quinasas Receptoras/metabolismo , Receptores de Factores de Crecimiento/metabolismo , Animales , Anticuerpos/inmunología , Arteriosclerosis/metabolismo , Bovinos , Células Cultivadas , Endotelio Vascular/metabolismo , Inhibidores Enzimáticos/farmacología , L-Lactato Deshidrogenasa/metabolismo , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico/antagonistas & inhibidores , Oxidación-Reducción , Proteínas Tirosina Quinasas Receptoras/inmunología , Receptores de Factores de Crecimiento/inmunología , Receptores de Factores de Crecimiento Endotelial Vascular , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial Vascular
13.
Nucleosides Nucleotides Nucleic Acids ; 24(10-12): 1947-70, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16438059

RESUMEN

The synthesis of pyrazolo[4,3-d]pyrimidine nucleoside library using solid-phase parallel synthesis methodology is described. Glycosylation of the trimethylsilyl (TMS) derivative of 1- and 2-(methyl)-1H and 2H-pyrazolo[4,3-d]pyrimidine-5,7-(4H, 6H)-dione (5) with 1-O-acetyl-2,3,5-tri-O-benzoyl-D-ribofuranose in the presence of TMS triflate provided two novel protected nucleosides 6 and 7. The structures of 6 and 7 were assigned by 1H and 2D NMR experiments. Nucleosides 6 and 7 were then transformed to the key intermediates 12 and 15 respectively. Reaction of 12 and 15 with MMTCl resin in the presence of 2,6-lutidine afforded the necessary scaffolds B and C. Different amines (96) were introduced selectively by nucleophilic substitution on scaffolds B and C using solid-phase parallel semi-automated synthesizer. Cleavage of the products from the solid support with 30% HFIP in a parallel fashion yielded nucleoside libraries simultaneously, and they were analyzed and characterized by high-throughput LC-MS.


Asunto(s)
Alopurinol/análogos & derivados , Ribonucleósidos/síntesis química , Alopurinol/síntesis química , Alopurinol/química , Estructura Molecular , Ribonucleósidos/química
14.
Neurology ; 35(7): 998-1002, 1985 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-4010967

RESUMEN

In six patients with CT evidence of posterior thalamic hemorrhage, we found the following signs: saccadic hypometria away from the lesion; defective pursuit toward the lesion with corresponding opticokinetic abnormalities; mild ipsilateral ptosis; ipsilateral miosis; unilateral sensory neglect; and sensorimotor hemiparesis. This distinct syndrome has a benign course and satisfactory recovery. It differs from the classic picture of thalamic hemorrhage, and can be called "the syndrome of posterior thalamic hemorrhage."


Asunto(s)
Hemorragia Cerebral/diagnóstico por imagen , Enfermedades Talámicas/diagnóstico por imagen , Anciano , Hemorragia Cerebral/patología , Movimientos Oculares , Femenino , Fijación Ocular , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Síndrome , Enfermedades Talámicas/patología , Vías Visuales/patología
15.
Eur J Cancer ; 35(6): 1003-8, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10533485

RESUMEN

Epidemiological and clinical studies imply that retinoids have a chemopreventative action against cancer and can suppress the growth of cancer cells. The regulation of connexin (Cx) expression by retinoids varies among tissues and organs. In this study, we investigated whether all-trans retinoic acid (ATRA) upregulates gap junctional intercellular communication (GJIC) in renal epithelial cells exposed to renal carcinogens. Madin Darby canine kidney (MDCK) cells were incubated with ATRA for 3 days, then briefly exposed to 12-O-tetradecanoyl-phorbol-13-acetate (TPA) or renal carcinogens potassium bromate (KBrO3) and dimethylnitrosamine (DMN). ATRA increased the expression of connexin 43 mRNA and protein without affecting Cx 43 phosphorylation and prevented inadequate Cx 43 localisation caused by TPA/KBrO3 or DMN. Consequently, ATRA prevented the disruption of GJIC in MDCK cells. These data suggest that ATRA enhanced GJIC by upregulating Cx 43 expression and that ATRA might be useful for prevention of renal cell carcinoma.


Asunto(s)
Carcinógenos/farmacología , Comunicación Celular/efectos de los fármacos , Uniones Comunicantes/efectos de los fármacos , Tretinoina/farmacología , Western Blotting , Comunicación Celular/fisiología , División Celular , Células Cultivadas , Células Epiteliales/citología , Técnica del Anticuerpo Fluorescente , Uniones Comunicantes/fisiología , Humanos
16.
Atherosclerosis ; 155(2): 321-7, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11254902

RESUMEN

Although Rho, a small GTPase, has been demonstrated to play an important role in the smooth muscle contraction and relaxation, little is known about the involvement of Rho protein in smooth muscle cell (SMC) migration. In this study the role of Rho-Rho kinase pathway was examined in SMC migration induced by platelet-derived growth factor (PDGF) and lysophosphatidic acid (LPA). C3 transferase, a specific inhibitor of Rho, blocked SMC migration induced by PDGF and LPA. Y-27632, a specific inhibitor of Rho kinase, a direct target molecule of Rho, inhibited PDGF and LPA-induced SMC migration in a concentration dependent manner. Although rapid increase in myosin light chain (MLC) phosphorylation in SMC treated with LPA was observed, no enhanced MLC phosphorylation was detected in response to PDGF. Y-27632 suppressed LPA-induced as well as basal level of MLC phosphorylation. ML-9, a specific inhibitor of myosin light chain kinase (MLCK), inhibited PDGF and LPA-induced SMC migration without the suppression of MLC phosphorylation at 5 min incubation, suggesting that MLCK may contribute to SMC migration via mechanism other than MLC phosphorylation. These results suggest that Rho-Rho kinase pathway is implicated in SMC migration and that different signaling pathways downstream of Rho-Rho kinase may be involved in LPA and PDGF-induced SMC migration. MLC phosphorylation via Rho-Rho kinase pathway appears to be implicated in LPA-dependent SMC migration. Whereas PDGF-mediated SMC migration is independent of increased MLC phosphorylation and other target molecules downstream of Rho-Rho kinase seem to be involved.


Asunto(s)
Músculo Liso Vascular/citología , Quinasa de Cadena Ligera de Miosina/fisiología , Procesamiento Proteico-Postraduccional , Proteínas Serina-Treonina Quinasas/fisiología , Transducción de Señal/efectos de los fármacos , Túnica Media/citología , Proteínas de Unión al GTP rho/fisiología , Amidas/farmacología , Animales , Aorta/citología , Azepinas/farmacología , Bovinos , Adhesión Celular , Movimiento Celular/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Péptidos y Proteínas de Señalización Intracelular , Lisofosfolípidos/farmacología , Músculo Liso Vascular/efectos de los fármacos , Fosforilación/efectos de los fármacos , Factor de Crecimiento Derivado de Plaquetas/farmacología , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Piridinas/farmacología , Quinasas Asociadas a rho
17.
Neuroscience ; 97(2): 279-84, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10799759

RESUMEN

alpha-Synuclein is a key component of Lewy bodies found in the brains of patients with Parkinson's disease and two point mutations in this protein, Ala53Thr and Ala30Pro, are associated with rare familial forms of the disease. Several lines of evidence suggest the involvement of oxidative stress in the pathogenesis of nigral neuronal death in Parkinson's disease. In the present work we studied the effects of changes in the alpha-synuclein sequence on the susceptibility of cells to reactive oxygen species. Human dopaminergic neuroblastoma SH-SY5Y cells were stably transduced with various isoforms of alpha-synuclein and their survival following exposure to hydrogen peroxide or to the dopaminergic neurotoxin MPP(+) was assessed. Cells expressing the two point mutant isoforms of alpha-synuclein were significantly more vulnerable to oxidative stress, with the Ala53Thr engineered cells faring the worst. In addition, cells expressing C-terminally truncated alpha-synuclein, particularly the 1-120 residue protein, were more susceptible than control beta-galactosidase engineered cells. The present experiments indicate that point mutations and C-terminal truncation of alpha-synuclein exaggerate the susceptibility of dopaminergic cells to oxidative damage. Thus, these observations provide a pathogenetic link between alpha-synuclein aberrations and a putative cell death mechanism in Parkinson's disease.


Asunto(s)
Encéfalo/metabolismo , Proteínas del Tejido Nervioso/fisiología , Estrés Oxidativo , 1-Metil-4-fenilpiridinio/toxicidad , Sustitución de Aminoácidos , Supervivencia Celular/efectos de los fármacos , Humanos , Peróxido de Hidrógeno/farmacología , Mutagénesis Sitio-Dirigida , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/genética , Neuroblastoma , Estrés Oxidativo/efectos de los fármacos , Fosfoproteínas/fisiología , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Eliminación de Secuencia , Sinucleínas , Transfección , Células Tumorales Cultivadas , alfa-Sinucleína
18.
Cancer Lett ; 69(2): 85-91, 1993 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-7684317

RESUMEN

A study was conducted on the effect of vinblastine (VBL), an anti-mitotic drug that is commonly employed in the treatment of human renal cell carcinoma. When VBL was added to serum-free cultures of the ACHN and NT cell lines (both lines are of human renal carcinoma origin), a concentration of 1 microgram/ml resulted in death of most of the cells of both cell types. However, at a concentration of 10 ng/ml or less, although the cells detached from the culture dish, many viable cells were observed. In addition, in an in vitro invasion assay, the invasiveness of these detached cells was demonstrated to be accelerated in comparison with the parent monolayed cells. This increase of invasion was observed in the treatment of TN-16 which is known to have a metaphase-arresting effect, not to have an anti-cancer effect. When detached cells by VBL were inoculated into soft agar, their colony-forming ability was clearly increased in comparison with the parent cells or TN-16 treated cells. These results indicate that low concentration of VBL appears to increase the malignant potential of human renal carcinoma cells in culture.


Asunto(s)
Carcinoma de Células Renales/patología , Adhesión Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Invasividad Neoplásica , Vinblastina/administración & dosificación , Aprotinina/farmacología , Relación Dosis-Respuesta a Droga , Fibronectinas/metabolismo , Humanos , Técnicas In Vitro , Metafase/efectos de los fármacos , Pirrolidinonas/farmacología , Células Tumorales Cultivadas/efectos de los fármacos
19.
J Endocrinol ; 166(3): 545-51, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10974649

RESUMEN

Oscillation of insulin release by the pancreatic islets was evaluated under stringent Ca(2+)-free conditions for the first time. Isolated single rat islets were exposed to 16.7 mM glucose in the presence of 1.9 mM Ca(2+), or under the stringent Ca(2+)-free conditions (Ca(2+) omission with 1 mM EGTA, 6 microM forskolin and 100 nM phorbol 12-myristate 13-acetate). Fifteen minutes after the initiation of glucose stimulation, effluent was collected at a 6-s interval, insulin was determined in duplicate by a highly sensitive insulin radioimmunoassay, and oscillation and pulsatility of release statistically analyzed. Significant oscillation of insulin release was observed in all islets irrespective of presence and absence of Ca(2+). Significant pulsatility of release was detected in 7 of 11 islets in the presence of Ca(2+) and three of six isl! ets in the absence of Ca(2+). In conclusion, high glucose elicits oscillatory insulin release both in the presence and absence of extracellular Ca(2+).


Asunto(s)
Calcio/metabolismo , Glucosa/farmacología , Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Animales , Células Cultivadas , Secreción de Insulina , Masculino , Ratas , Ratas Wistar , Tasa de Secreción
20.
Hum Pathol ; 25(2): 198-202, 1994 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7907076

RESUMEN

The proliferative activity of dysplasia and carcinoma in situ (CIS) in the uterine cervix was examined using proliferating cell nuclear antigen (PCNA) immunostaining and silver-binding argyrophilic nucleolar organizer region (AgNOR) staining. A significant difference in the labeling index of PCNA immunostaining obtained from dysplastic cells in each histopathologic category was demonstrated between severe dysplasia and CIS. There was no significant difference among each category of dysplasia. The frequency of mitotic figures was highest in CIS, followed in decreasing order by severe, moderate, and mild dysplasia, and was closely correlated with the histopathologic classification. There was an intimate correlation between the PCNA and mitotic indexes in severe dysplasia and CIS. However, the mean numbers of AgNORs in each category of dysplasia and CIS were not significantly different, and there was no apparent relationship with the histologic classification. The PCNA index seemed to be a useful means of evaluating proliferative activity in dysplasia and CIS, and especially in distinguishing CIS from severe dysplasia. In addition, the present PCNA index suggests that a considerable alteration of the biologic behavior involving genetic changes occurs during the progression of carcinogenesis from severe dysplasia to CIS. However, AgNOR staining did not appear to reliably represent the proliferative activity in these lesions.


Asunto(s)
Carcinoma in Situ/patología , Proteínas Nucleares/análisis , Región Organizadora del Nucléolo/patología , Displasia del Cuello del Útero/patología , Neoplasias del Cuello Uterino/patología , Antígenos de Neoplasias/análisis , Carcinoma in Situ/inmunología , División Celular , Femenino , Humanos , Inmunohistoquímica , Índice Mitótico , Antígeno Nuclear de Célula en Proliferación , Tinción con Nitrato de Plata , Displasia del Cuello del Útero/inmunología , Neoplasias del Cuello Uterino/inmunología
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