Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Cancer Sci ; 111(10): 3726-3738, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32681682

RESUMEN

Lorlatinib is a potent, brain-penetrant, third-generation anaplastic lymphoma kinase (ALK)/ROS proto-oncogene 1 (ROS1) tyrosine kinase inhibitor (TKI) that is active against most known resistance mutations. This is an ongoing phase 1/2, multinational study (NCT01970865) investigating the efficacy, safety and pharmacokinetics of lorlatinib in ALK-rearranged/ROS1-rearranged advanced non-small cell lung cancer (NSCLC) with or without intracranial (IC) metastases. Because patterns of ALK TKI use in Japan differ from other regions, we present a subgroup analysis of Japanese patients. Patients were enrolled into six expansion (EXP) cohorts based on ALK/ROS1 mutation status and treatment history. The primary endpoint was the objective response rate (ORR) and the IC-ORR based on independent central review. Secondary endpoints included pharmacokinetic evaluations. At data cutoff, 39 ALK-rearranged/ROS1-rearranged Japanese patients were enrolled across the six expansion cohorts; all received lorlatinib 100 mg once daily. Thirty-one ALK-rearranged patients previously treated with ≥1 ALK TKI (EXP2 to EXP5) were evaluable for ORR and 15 were evaluable for IC-ORR. The ORR and the IC-ORR for Japanese patients in EXP2-5 were 54.8% (95% confidence interval [CI]: 36.0-72.7) and 46.7% (95% CI: 21.3-73.4), respectively. Among patients who had received prior alectinib only (EXP3B), the ORR was 42.9%; 95% CI: 9.9-81.6). The most common treatment-related adverse event (TRAE) was hypercholesterolemia (79.5%). Hypertriglyceridemia was the most common grade 3/4 TRAE (25.6%). Single-dose and multiple-dose pharmacokinetic profiles among Japanese patients were similar to those in non-Japanese patients. Lorlatinib showed clinically meaningful responses and IC responses among ALK-rearranged Japanese patients with NSCLC who received ≥1 prior ALK TKI, including meaningful responses among those receiving prior alectinib only. Lorlatinib was generally well tolerated.


Asunto(s)
Neoplasias Encefálicas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Lactamas Macrocíclicas/administración & dosificación , Proteínas Tirosina Quinasas/genética , Proteínas Proto-Oncogénicas/genética , Anciano , Anciano de 80 o más Años , Aminopiridinas , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/secundario , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Resistencia a Antineoplásicos/efectos de los fármacos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Humanos , Hipercolesterolemia/inducido químicamente , Hipercolesterolemia/epidemiología , Lactamas , Lactamas Macrocíclicas/efectos adversos , Persona de Mediana Edad , Mutación/efectos de los fármacos , Metástasis de la Neoplasia , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/efectos adversos , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Pirazoles
2.
Gan To Kagaku Ryoho ; 46(Suppl 1): 81-83, 2019 May.
Artículo en Japonés | MEDLINE | ID: mdl-31189863

RESUMEN

The home care support system, newly established in 2014, is a system that always secures the hospitalization of pre-registered home care patients who need to be hospitalized. Ashigarakami Hospital has operated this system since April 2014. As of May 2018, a total of 215 people registered, and 156 people have died. Among the deceased patients, 77(49.4%)died at home, which was higher than the proportion of home deaths(13.0%)in the Japanese population dynamics survey in 2016. In patients who had malignant diseases, they could spend more than half of the period from their introduction to the system up to death being treated at home. Even in the case of death at a hospital, the duration of the last hospitalization was 18 days on average(median of 12 days). In most cases, patients were treated at home until shortly before death.


Asunto(s)
Servicios de Atención de Salud a Domicilio , Neoplasias , Cuidado Terminal , Hospitalización , Hospitales , Humanos
3.
Gynecol Oncol ; 142(1): 62-69, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27103175

RESUMEN

OBJECTIVE: PF-04691502 and gedatolisib (PF-05212384) are potent, dual PI3K/mTOR inhibitors. This phase II study (B1271004) was conducted in patients with recurrent endometrial cancer following platinum-containing chemotherapy. The primary endpoint was to assess clinical benefit response (complete or partial response, or stable disease for ≥16weeks) following treatment with PF-04691502 or gedatolisib. METHODS: The main study consisted of four independent arms based on a Simon two-stage design. Patients were assigned to putative PI3K-basal (PF-04691502 or gedatolisib) or PI3K-activated (PF-04691502 or gedatolisib) arms based on stathmin-low or stathmin-high tumor expression, respectively. Japanese patients were also enrolled in a separate lead-in cohort. RESULTS: In stage 1 (main study), eighteen patients were randomized to PF-04691502 and 40 to gedatolisib. The two PF-04691502 arms were discontinued early due to unacceptable toxicity, including pneumonia and pneumonitis. The most common treatment-related adverse events associated with gedatolisib were nausea (53%), mucosal inflammation (50%), decreased appetite (40%), diarrhea (38%), fatigue (35%), and dysgeusia and vomiting (each 30%). Clinical benefit response rate was 53% (10/19) in the gedatolisib/stathmin-low arm and 26% (5/19) in the gedatolisib/stathmin-high arm. Safety profile and pharmacokinetic characteristics of both drugs in the Japanese lead-in cohort were comparable to the Western population. CONCLUSIONS: Gedatolisib administered by weekly intravenous infusion demonstrated acceptable tolerability and moderate activity in patients with recurrent endometrial cancer. PF-04691502 daily oral dosing was not well tolerated. Clinical benefit response criteria for proceeding to stage 2 were only met in the gedatolisib/stathmin-low arm. Stathmin-high expression did not correlate with greater treatment efficacy. ClinicalTrials.gov registration ID: NCT01420081.


Asunto(s)
Neoplasias Endometriales/tratamiento farmacológico , Morfolinas/uso terapéutico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Piridonas/uso terapéutico , Pirimidinas/uso terapéutico , Triazinas/uso terapéutico , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/metabolismo , Neoplasias Endometriales/enzimología , Femenino , Humanos , Persona de Mediana Edad , Morfolinas/efectos adversos , Recurrencia Local de Neoplasia/enzimología , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Inhibidores de Proteínas Quinasas/efectos adversos , Piridonas/efectos adversos , Pirimidinas/efectos adversos , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Serina-Treonina Quinasas TOR/metabolismo , Triazinas/efectos adversos
4.
Invest New Drugs ; 32(2): 261-70, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23665950

RESUMEN

BACKGROUND: This phase I, dose-finding study evaluated the maximum tolerated dose (MTD), safety, pharmacokinetics, and antitumor activity of sunitinib plus S-1/cisplatin in Japanese patients with advanced/metastatic gastric cancer. PATIENTS AND METHODS: Patients received oral sunitinib on a continuous daily dosing (CDD) or 2-weeks-on/2-weeks-off schedule (Schedule 2/2; 25 mg/day or 37.5 mg/day), plus S-1 (80-120 mg/day)/cisplatin 60 mg/m(2). RESULTS: Twenty-seven patients received treatment, including 26 patients treated per protocol (sunitinib 25 mg/day CDD schedule, n = 4; sunitinib 25 mg/day Schedule 2/2, n = 16 [dose-limiting toxicity (DLT) cohort, n = 6 plus expansion cohort, n = 10]; sunitinib 37.5 mg/day Schedule 2/2, n = 6). One patient erroneously self-administered sunitinib 12.5 mg/day and was excluded from the analyses. The MTD was sunitinib 25 mg/day on Schedule 2/2. DLTs were reported for: 2/4 patients given sunitinib 25 mg/day on the CDD schedule; 1/6 patients administered sunitinib 25 mg/day on Schedule 2/2 (grade [G] 3 neutropenic infection, G4 thrombocytopenia, and S-1 dose interruption ≥5 days), and 3/6 patients given sunitinib 37.5 mg/day on Schedule 2/2. Results below are for the overall MTD cohort (n = 16). The most frequently reported G3/4 adverse events were neutropenia (93.8 %) and leukopenia (75.0 %). The objective response rate was 37.5 %; six additional patients experienced no disease progression for ≥24 weeks. Median progression-free survival was 12.5 months. No pharmacokinetic drug-drug interactions were observed between sunitinib/S-1/cisplatin and S-1/cisplatin. CONCLUSIONS: The MTD of sunitinib was 25 mg/day on Schedule 2/2 combined with cisplatin/S-1 in patients with advanced/metastatic gastric cancer. This regimen had a manageable safety profile and preliminary antitumor activity.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias Gástricas/tratamiento farmacológico , Adulto , Anciano , Inhibidores de la Angiogénesis/administración & dosificación , Inhibidores de la Angiogénesis/efectos adversos , Inhibidores de la Angiogénesis/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Pueblo Asiatico , Cisplatino/administración & dosificación , Cisplatino/efectos adversos , Cisplatino/farmacocinética , Combinación de Medicamentos , Femenino , Humanos , Indoles/administración & dosificación , Indoles/efectos adversos , Indoles/farmacocinética , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Ácido Oxónico/administración & dosificación , Ácido Oxónico/efectos adversos , Ácido Oxónico/farmacocinética , Pirroles/administración & dosificación , Pirroles/efectos adversos , Pirroles/farmacocinética , Neoplasias Gástricas/metabolismo , Sunitinib , Tegafur/administración & dosificación , Tegafur/efectos adversos , Tegafur/farmacocinética , Resultado del Tratamiento
5.
J Cell Biol ; 172(4): 565-75, 2006 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-16461360

RESUMEN

Upon the accumulation of unfolded proteins in the mammalian endoplasmic reticulum (ER), X-box binding protein 1 (XBP1) premessenger RNA (premRNA) is converted to mature mRNA by unconventional splicing that is mediated by the endonuclease inositol-requiring enzyme 1. The transcription factor protein (p) XBP1 spliced (S), which is translated from mature XBP1 mRNA, contains the nuclear localization signal and the transcriptional activation domain and activates the transcription of target genes, including those encoding ER chaperones in the nucleus. We show that pXBP1 unspliced (U) encoded in XBP1 pre-mRNA was constitutively expressed and markedly accumulated at the recovery phase of ER stress. pXBP1(U) contained the nuclear exclusion signal instead of the transcriptional activation domain and shuttled between the nucleus and the cytoplasm. Interestingly, pXBP1(U) formed a complex with pXBP1(S), and the pXBP1(U)-pXBP1(S) complex was sequestered from the nucleus. Moreover, the complex was rapidly degraded by proteasomes because of the degradation motif contained in pXBP1(U). Thus, pXBP1(U) is a negative feedback regulator of pXBP1(S), which shuts off the transcription of target genes during the recovery phase of ER stress.


Asunto(s)
Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Retículo Endoplásmico/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Pliegue de Proteína , Empalme de Proteína/fisiología , Precursores del ARN/metabolismo , Animales , Núcleo Celular/metabolismo , Células Cultivadas , Cicloheximida/farmacología , Citoplasma/metabolismo , Ditiotreitol/farmacología , Retículo Endoplásmico/efectos de los fármacos , Retroalimentación Fisiológica/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Células HeLa , Humanos , Transporte de Proteínas/efectos de los fármacos , Precursores del ARN/genética , ARN Mensajero/biosíntesis , Factores de Transcripción del Factor Regulador X , Factores de Transcripción , Proteína 1 de Unión a la X-Box
6.
Toxicol In Vitro ; 23(4): 687-96, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19490838

RESUMEN

In order to find a novel biomarker for a simple assay to predict skin sensitization, we evaluated cell-surface thiols as a biomarker reflecting intracellular signaling in THP-1 cells (human monocytic cell line). First, we found that a decrease of cell-surface thiols on hapten-treated THP-1 cells was induced in parallel with phosphorylation of p38 MAPK. Next, we confirmed that 2-mercaptoethanol in the culture medium and the differentiation state of THP-1 cells did not affect the changes of cell-surface thiols by hapten. Changes of cell-surface thiols on THP-1 cells were detected after 2h treatment with most allergens (e.g., DNCB, NiSO(4)), as well as some non-allergens (e.g., Tween80, benzalkonium chloride), though other non-allergens (e.g., SDS, glycerol) had no effect. When either a significant decrease or increase of cell-surface thiols (more than 15% in each case) was used as a criterion, the results using 36 allergens and 16 non-allergens were in good accordance with those of in vivo assays. Finally, we confirmed that ATP, which is released as a consequence of cytotoxicity, did not affect the changes of cell-surface thiols. Our results suggest that changes of cell-surface thiols may be useful for an in vitro sensitization assay, which we designate as the SH test.


Asunto(s)
Piel/efectos de los fármacos , Compuestos de Sulfhidrilo/análisis , Adenosina Trifosfato/farmacología , Biomarcadores , Diferenciación Celular , Células Cultivadas , Humanos , Mercaptoetanol/farmacología , Fosforilación , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
7.
Mol Biol Cell ; 14(1): 262-73, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12529442

RESUMEN

VCP/p97 is involved in a variety of cellular processes, including membrane fusion and ubiquitin-dependent protein degradation. It has been suggested that adaptor proteins such as p47 and Ufd1p confer functional versatility to VCP/p97. To identify novel adaptors, we searched for proteins that interact specifically with VCP/p97 by using the yeast two-hybrid system, and discovered a novel VCP/p97-interacting protein named small VCP/p97-interacting protein (SVIP). Rat SVIP is a 76-amino acid protein that contains two putative coiled-coil regions, and potential myristoylation and palmitoylation sites at the N terminus. Binding experiments revealed that the N-terminal coiled-coil region of SVIP, and the N-terminal and subsequent ATP-binding regions (ND1 domain) of VCP/p97, interact with each other. SVIP and previously identified adaptors p47 and ufd1p interact with VCP/p97 in a mutually exclusive manner. Overexpression of full-length SVIP or a truncated mutant did not markedly affect the structure of the Golgi apparatus, but caused extensive cell vacuolation reminiscent of that seen upon the expression of VCP/p97 mutants or polyglutamine proteins in neuronal cells. The vacuoles seemed to be derived from endoplasmic reticulum membranes. These results together suggest that SVIP is a novel VCP/p97 adaptor whose function is related to the integrity of the endoplasmic reticulum.


Asunto(s)
Proteínas Nucleares/metabolismo , Proteínas Protozoarias/metabolismo , Vacuolas/metabolismo , Animales , Retículo Endoplásmico/metabolismo , Unión Proteica , Ratas , Técnicas del Sistema de Dos Híbridos
8.
J Invest Dermatol ; 130(1): 175-83, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19641517

RESUMEN

p38 mitogen-activated protein kinase (MAPK) has a crucial role in the maturation of dendritic cells (DCs) by sensitizers. Recently, it has been reported that the oxidation of cell surface thiols by an exogenous impermeant thiol oxidizer can phosphorylate p38 MAPK. In this study, we examined whether sensitizers oxidize cell surface thiols of monocyte-derived DCs (MoDCs). When cell surface thiols were quantified by flow cytometry using Alexa fluor maleimide, all the sensitizers that we examined decreased cell surface thiols on MoDCs. To examine the effects of decreased cell surface thiols by sensitizers on DC maturation, we analyzed the effects of an impermeant thiol oxidizer, o-phenanthroline copper complex (CuPhen). The treatment of MoDCs with CuPhen decreased cell surface thiols, phosphorylated p38 MAPK, and induced MoDC maturation, that is, the augmentation of CD83, CD86, HLA-DR, and IL-8 mRNA, as well as the downregulation of aquaporin-3 mRNA. The augmentation of CD86 was significantly suppressed when MoDCs were pretreated with N-acetyl-L-cystein or treated with SB203580. Finally, we showed that epicutaneous application of 2,4-dinitrochlorobenzene on mouse skin significantly decreased cell surface thiols of Langerhans cells in vivo. These data suggest that the oxidation of cell surface thiols has some role in triggering DC maturation by sensitizers.


Asunto(s)
Células Dendríticas , Oxidantes/farmacología , Fenantrolinas/farmacología , Compuestos de Sulfhidrilo/metabolismo , Acetilcisteína/farmacología , Animales , Células Cultivadas , Células Dendríticas/citología , Células Dendríticas/efectos de los fármacos , Células Dendríticas/metabolismo , Interacciones Farmacológicas , Inhibidores Enzimáticos/farmacología , Células Epidérmicas , Epidermis/inmunología , Femenino , Citometría de Flujo , Depuradores de Radicales Libres/farmacología , Haptenos/farmacología , Humanos , Imidazoles/farmacología , Ratones , Ratones Endogámicos BALB C , Monocitos/citología , Oxidación-Reducción , Fosforilación/efectos de los fármacos , Piridinas/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
9.
Toxicol In Vitro ; 24(3): 1009-18, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20006982

RESUMEN

The aim of this study is to characterize the dispersion characteristics of various metal oxide nanoparticles and secondary nanoparticle formation in culture medium. Many studies have already investigated the in vitro toxicities of various metal oxide nanoparticles; however, there have been few discussions about the particle transport mode to cells during a period of toxicity assessment. The particle transport mode would strongly affect the amount of uptake by cells; therefore, estimation of the transport mode for various metal oxide particles is important. Fourteen different metal oxide nanoparticle dispersions in a culture medium were examined. The sizes of the secondary nanoparticles were observed to be larger than 100 nm by dynamic light scattering (DLS). According to Stokes law and the Stokes-Einstein assumption, pure metal oxide particles with such sizes should gravitationally settle faster than diffusion processes; however, the secondary metal oxide particles examined in this study exhibited unexpectedly slower gravitational settling rates. The slow gravitational settling kinetics of particles was estimated to be caused by the inclusion of protein into the secondary nanoparticles, which resulted in lower densities than the pure metal oxide particles. The ratios of metal oxide to protein in secondary particles could be affected by the protein adsorption ability of the corresponding metal oxide primary particles. To the best of our knowledge, it was clarified for the first time that stably dispersed secondary metal oxide nanoparticles with slow gravitational settling kinetics are induced by secondary nanoparticles consisting of small amounts of metal oxide particles and large amounts of protein, which results in lower particle densities than the pure metal oxide particles. The estimation of particle dynamics in culture medium using this method would be significant to recognize the inherent toxicity of nanoparticles.


Asunto(s)
Medios de Cultivo/química , Metales/química , Metales/toxicidad , Nanopartículas/toxicidad , Algoritmos , Luz , Nanopartículas/química , Óxidos/química , Óxidos/toxicidad , Tamaño de la Partícula , Dispersión de Radiación , Suspensiones , Viscosidad
10.
J Toxicol Sci ; 35(6): 871-9, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21139337

RESUMEN

Changes of cell-surface thiols induced by chemical treatment may affect the conformations of membrane proteins and intracellular signaling mechanisms. In our previous study, we found that a non-toxic dose of diphenylcyclopropene (DPCP), which is a potent skin sensitizer, induced an increase of cell-surface thiols in cells of a human monocytic cell line, THP-1. Here, we examined the influence of DPCP on intracellular signaling. First, we confirmed that DPCP induced an increase of cell-surface thiols not only in THP-1 cells, but also in primary monocytes. The intracellular reduced-form glutathione/oxidized-form glutathione ratio (GSH/GSSG ratio) was not affected by DPCP treatment. By means of labeling with a membrane-impermeable thiol-reactive compound, Alexa Fluor 488 C5 maleimide (AFM), followed by two-dimensional gel electrophoresis and analysis by liquid chromatography coupled with electrospray tandem mass spectrometry (LC/MS/MS), we identified several proteins whose thiol contents were modified in response to DPCP. These proteins included cell membrane components, such as actin and ß-tubulin, molecular chaperones, such as heat shock protein 27A and 70, and endoplasmic reticulum (ER) stress-inducible proteins. Next, we confirmed the expression in DPCP-treated cells of spliced XBP1, a known marker of ER stress. We also detected the phosphorylation of SAPK/JNK and p38 MAPK, which are downstream signaling molecules in the IRE1α-ASK1 pathway, which is activated by ER stress. These data suggested that increase of cell-surface thiols might be associated with activation of ER stress-mediated signaling.


Asunto(s)
Ciclopropanos/toxicidad , Haptenos/toxicidad , Leucocitos Mononucleares/efectos de los fármacos , Proteínas de la Membrana/metabolismo , Transducción de Señal/efectos de los fármacos , Compuestos de Sulfhidrilo/metabolismo , Técnicas de Cultivo de Célula , Línea Celular , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Cromatografía Líquida de Alta Presión , Dermatitis Alérgica por Contacto/metabolismo , Electroforesis en Gel Bidimensional , Citometría de Flujo , Humanos , Leucocitos Mononucleares/enzimología , Leucocitos Mononucleares/metabolismo , Oxidación-Reducción , Fosforilación , Conformación Proteica , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masas en Tándem
11.
Toxicol In Vitro ; 24(6): 1629-38, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20541599

RESUMEN

Even though there have been some investigations into cellular responses induced by ultrafine titanium dioxide (TiO(2)) in vitro, the relationship between cellular responses and secondary particle size is still not clear. In this study, a stable and uniform TiO(2)-cell culture-medium dispersion was prepared, and cellular responses prompted by "ultrafine secondary particles" were examined. The TiO(2)-DMEM-FBS dispersion included secondary particles in which the secondary particle size was 100 nm or less. In the present study, a "secondary particle" was defined as a complex aggregate of TiO(2) primary particles, proteins from FBS and other medium components. Secondary particle size did not influence the cell viability. The TiO(2)-DMEM-FBS dispersion introduced to the human keratinocyte HaCaT cells caused weak intracellular oxidative stress and apoptosis. The cellular influence of ultrafine TiO(2)in vitro is caused by the following mechanisms: (1) Secondary particles are formed. Ultrafine TiO(2) particles dispersed in medium immediately form secondary particles with proteins and salts. (2) "Ultrafine" secondary particles are taken up by the cells. The secondary particles reach the cells by diffusion and/or sedimentation and are taken up by the cells, through endocytosis. (3) Intracellular reactive oxygen species (ROS) level increases. Internalized secondary particles induce an increase in intracellular reactive oxygen species levels, although the secondary particles do not break up in the cell. In the case of ultrafine TiO(2), the increase of the intracellular ROS level was minimal. Moreover, the antioxidation system of cells such as glutathione was working. (4) Apoptotic cell death is induced. An accumulation of oxidative stress activates the apoptotic pathway (such as the caspase-3) and subsequently induces apoptotic cell death. After 24h of exposure to TiO(2), the percentage of apoptotic cells was only 6-7%. As a result, although the ultrafine TiO(2) particles induce some cellular responses, these cellular responses to ultrafine TiO(2) are weaker than those of other cytotoxic ultrafine metal oxide particles, such as nickel oxide.


Asunto(s)
Queratinocitos/efectos de los fármacos , Nanopartículas del Metal/toxicidad , Titanio/toxicidad , Apoptosis/efectos de los fármacos , Caspasas/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Glutatión/metabolismo , Humanos , Peróxido de Hidrógeno/metabolismo , Queratinocitos/metabolismo , Queratinocitos/ultraestructura , Microscopía Electrónica de Transmisión , Tamaño de la Partícula , Especies Reactivas de Oxígeno
12.
Toxicol In Vitro ; 23(5): 911-8, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19358883

RESUMEN

In this study, with the aim of developing a cell-based in vitro photosensitization assay, we examined whether changes of CD86 and CD54 expression on cells of a human monocytic cell line, THP-1, could be used to assess the photosensitizing potential of chemicals. First, we identified suitable conditions of UV-irradiation (irradiation dose; 5.0 J/cm(2), irradiation intensity; 1.7 mW/cm(2)) by investigating the effect of UV-irradiation on CD86 and CD54 expression on untreated or 6-methylcoumarin (a representative photoallergen)-treated THP-1 cells (irradiation method). However, acridine, a representative photo-irritant, augmented CD86 and CD54 expression on THP-1 cells, apparently via induction of reactive oxygen species (ROS). In order to abolish the effect of ROS, we examined CD86 and CD54 expression on THP-1 cells treated with pre-irradiated chemicals (pre-irradiation method). We found that UV-irradiated photoallergens, but not photo-irritants, enhanced CD86 and/or CD54 expression on the THP-1 cells. Finally, based on the results of irradiation, non-irradiation, and pre-irradiation with 18 test chemicals, we built a decision tree, which allows us to distinguish between photoallergens and photo-irritants. We suggest that this system may be useful for in vitro evaluation of the photoallergic potential of chemicals.


Asunto(s)
Monocitos/efectos de los fármacos , Fármacos Fotosensibilizantes/toxicidad , Pruebas de Toxicidad/métodos , Rayos Ultravioleta , Acridinas/toxicidad , Alérgenos/toxicidad , Antígeno B7-2/genética , Antígeno B7-2/efectos de la radiación , Línea Celular , Cumarinas/toxicidad , Árboles de Decisión , Relación Dosis-Respuesta en la Radiación , Humanos , Molécula 1 de Adhesión Intercelular/genética , Molécula 1 de Adhesión Intercelular/efectos de la radiación , Irritantes/toxicidad , Monocitos/efectos de la radiación , Especies Reactivas de Oxígeno/metabolismo
13.
J Toxicol Sci ; 34(2): 139-50, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19336971

RESUMEN

Human monocytic cell line THP-1 cells are used as an indicator for in vitro skin sensitization testing. Although p38 mitogen-activated protein kinases (MAPKs) and intracellular redox imbalance play crucial roles in the activation of THP-1 by skin sensitizers, the trigger of cell activation has not been identified. Therefore, we examined whether haptens induce THP-1 maturation directly or indirectly. 2,4-Dinitrochlorobenzene (DNCB), but not dinitrophenol (DNP)-conjugated bovine serum albumin or DNP-conjugated fetal bovine serum, induced CD86 expression. DNCB and nickel sulfate (NiSO4) also induced related changes of cell-surface thiols and phosphorylation of p38 MAPK. However, DNCB is membrane-permeable, and so its direct effect may not be confined to cell membrane proteins. Next, we found that CD86 expression and macrophage inflammatory protein-1beta (MIP-1beta) production were augmented by the membrane-impermeable thiol blocker 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), and these changes were suppressed by an inhibitor of the p38 MAPK pathway, SB203580. Finally, we confirmed that endocytotic activity for bovine serum albumin (BSA) Alexa Fluor 488 conjugate did not affect cell-surface thiols on THP-1 cells. Thus, our data indicate that the changes of cell-surface thiols are one of the triggers of maturation, and play a key role in activation of THP-1 cells by haptens.


Asunto(s)
Membrana Celular/efectos de los fármacos , Dinitroclorobenceno/toxicidad , Haptenos/toxicidad , Irritantes/toxicidad , Monocitos/efectos de los fármacos , Níquel/toxicidad , Animales , Antígeno B7-2/metabolismo , Bovinos , Línea Celular Tumoral , Membrana Celular/metabolismo , Quimiocina CCL4/metabolismo , Dinitroclorobenceno/química , Endocitosis/efectos de los fármacos , Endocitosis/inmunología , Inhibidores Enzimáticos/farmacología , Citometría de Flujo , Haptenos/química , Humanos , Imidazoles/farmacología , Irritantes/química , Monocitos/metabolismo , Níquel/química , Fosforilación/efectos de los fármacos , Piridinas/farmacología , Albúmina Sérica Bovina/química , Compuestos de Sulfhidrilo/análisis , Compuestos de Sulfhidrilo/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
14.
Toxicol In Vitro ; 23(5): 927-34, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19397995

RESUMEN

Dynamic light scattering (DLS) is widely used for the evaluation of the particle size in the toxicity assessment of nanoparticles. However, the many types of DLS instruments and analytical procedures sometimes give different apparent sizes of particles and make it complicated to understand the size dependence on particles for the toxicity assay. In this study, we established an evaluation method of secondary nanoparticle sizes using a DLS analysis. First, we established a practical method for determining size with an appropriate evaluation of uncertainties. This proposed method could be a universal protocol for toxicity assessment that would allow researchers to achieve some degree of concordance on the size of nanoparticles for an assessment. Second, we investigated the processes associated with particles in suspension by examining the changes in the size and the light scattering intensity of secondary nanoparticles during an in vitro toxicity assessment, since the transport mode of particles to cells is significant in understanding in vitro nano-toxicity. In this study, these two points were investigated on TiO(2) nanoparticles suspension as an example. The secondary particles of TiO(2) with a light scattering intensity-averaged diameter (d(l)) of 150-250 nm were characterized with appropriate uncertainties. The sizes were found to be comparable with values determined using other analytical procedures and other instruments. It is suggested that d(l) could be an effective size parameter for toxicity assessments. Furthermore, TiO(2) secondary nanoparticle suspensions are well dispersed with slow gravity settling, no agglomeration, with the diffusion process as the primary transport mode of particles to cells.


Asunto(s)
Nanopartículas , Dispersión de Radiación , Pruebas de Toxicidad/métodos , Difusión , Luz , Tamaño de la Partícula , Reproducibilidad de los Resultados , Suspensiones , Titanio/toxicidad
15.
Toxicol Lett ; 191(2-3): 109-17, 2009 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-19695317

RESUMEN

Assessing in vitro cellular responses to molecular events is an effective mean to elucidate the toxicological behavior of the ultrafine nanoparticles. In this study, we utilized the DNA microarray analysis technique to determine the gene expression profiles of the human keratinocyte HaCaT cells exposed to anatase titanium dioxide (TiO(2)) particles of different (7 nm, 20 nm and 200 nm) average diameters without illumination. Cells were incubated for 24 h with TiO(2) particles, which were dispersed in the culture medium and size-fractionated such that the concentration of titanium in all the fractionated samples was nearly equivalent. According to the cluster analysis, only genes involved in the 'inflammatory response' and 'cell adhesion', but not the genes involved in 'oxidative stress' and 'apoptosis', were over-represented among the genes that were up-regulated in HaCaT cells. After 24 h exposure to ultrafine 7 nm TiO(2) particles, we observed altered expression levels of genes involved in matrix metalloproteinase activity (MMP-9 and MMP-10) and cell adhesion (fibronectin FN-1, integrin ITGB-6, and mucin MUC-4). These results suggest that the ultrafine TiO(2) particles without illumination have no significant impact on ROS-associated oxidative damage, but affect the cell-matrix adhesion in keratinocytes for extracellular matrix remodeling.


Asunto(s)
Adhesión Celular/efectos de los fármacos , Matriz Extracelular/metabolismo , Expresión Génica/efectos de los fármacos , Queratinocitos/metabolismo , Nanopartículas/toxicidad , Titanio/toxicidad , Apoptosis/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Análisis por Conglomerados , Colorantes , ADN/biosíntesis , ADN/genética , Matriz Extracelular/efectos de los fármacos , Perfilación de la Expresión Génica , Humanos , Queratinocitos/efectos de los fármacos , Metaloproteinasas de la Matriz/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , Estrés Oxidativo/efectos de los fármacos , Tamaño de la Partícula , Sales de Tetrazolio , Tiazoles
16.
Psychiatry Clin Neurosci ; 61(6): 651-7, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18081627

RESUMEN

A number of studies have reported that parents of autistic children face higher levels of stress, but few studies examined the stress associated with the home care of children with pervasive developmental disorders (PDD) other than autistic disorder. The aims of the present study were therefore to (i) evaluate the emotional stress level of parents caring for their children with PDD; and (ii) explore the correlates of their emotional stress. Participants were 147 families (147 mothers and 122 fathers) of 158 children with PDD (42 with autistic disorder, 35 with Asperger's disorder and 81 with PDD not otherwise specified). K6 was used to measure the stress level of the parents. Marital relationships and personality were assessed with the Intimate Bond Measure and the NEO Five-Factor Inventory, respectively. The parents also rated the characteristics of their children with PDD through the Pervasive Developmental Disorder-Autism Society Japan Rating Scale (PARS). The mean K6 score of the mothers was significantly higher than that of the women in the general population in Japan. Stepwise multiple regression indicated that the emotional stress of the mothers was correlated with the personality traits of Neuroticism and Agreeableness, perceived Control by the husband, and the children's PARS score. Clinicians can deliver better service by paying appropriate attention to the emotional distress of mothers of children with not only autistic disorder but also other PDD.


Asunto(s)
Trastornos Generalizados del Desarrollo Infantil/psicología , Padres/psicología , Estrés Psicológico/psicología , Adulto , Edad de Inicio , Atención Ambulatoria , Síndrome de Asperger/psicología , Trastorno Autístico/psicología , Niño , Conducta Infantil , Interpretación Estadística de Datos , Femenino , Humanos , Inteligencia , Masculino , Matrimonio , Apego a Objetos , Personalidad , Escalas de Valoración Psiquiátrica , Análisis de Regresión , Instituciones Académicas , Factores Socioeconómicos , Encuestas y Cuestionarios
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA