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1.
Epidemiol Infect ; 148: e7, 2020 01 14.
Artículo en Inglés | MEDLINE | ID: mdl-31933448

RESUMEN

In January 2012, an inpatient in a ward of a psychiatric hospital with nearly 300 beds in Kanagawa, Japan, was diagnosed with sputum smear-positive pulmonary tuberculosis (TB). Here we characterise the TB outbreak cases and identify the population at risk. TB was diagnosed when a person tested bacteriologically positive for TB or was determined to have TB by a physician. A latent TB infection (LTBI) case was defined as a person tested positive by interferon-gamma release assay (IGRA). A total of 125 contacts were screened via IGRA and chest X-ray. In all, 15 TB and 15 LTBI cases were found by the end of October 2012, and thereafter no additional TB case was found. Of the 15 TB cases, eight were culture-positive and all the isolates had identical variable number tandem repeat patterns. Twenty-four of the 56 (42.9%, 95% confidence interval (CI) 29.7-56.8) inpatients in the ward had either TB or LTBI with a relative risk of 8.6 (95% CI 1.2-59.3), compared to the staff members who did not work full-time in the ward (one of 20 (5.0%, 95% CI 0.0-24.9)). We recommend that psychiatric hospitals conduct periodic screening of staff members and inpatients for TB to prevent nosocomial TB outbreaks.


Asunto(s)
Infección Hospitalaria/epidemiología , Brotes de Enfermedades , Tuberculosis/epidemiología , Adulto , Anciano , Técnicas Bacteriológicas , Trazado de Contacto , Femenino , Hospitales Psiquiátricos , Humanos , Pacientes Internos , Ensayos de Liberación de Interferón gamma , Japón/epidemiología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
2.
J Exp Med ; 180(3): 851-60, 1994 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-7520475

RESUMEN

Normal human bone marrow cells, highly enriched for burst-forming units-erythroid (BFU-E), were cultured in serum-free medium, in the presence and absence of various factors, to investigate the mechanisms involved in regulating erythroid differentiation. In cultures containing interleukin 3 (IL-3), Steel factor (SF), and erythropoietin (Ep), benzidine-positive erythroblasts first became detectable on day 6. Their numbers then rapidly increased until, by day 16, > 99% of the cells, which were 20,000-fold amplified over input numbers, were benzidine-positive. It is interesting to note that omission of either SF or Ep from this assay markedly enhanced the rate of differentiation and reduced total cell numbers, whereas omission of IL-3 had no effect on the rate of differentiation and only slightly reduced cell numbers. Of various agents tested, the most potent erythroid differentiation inducer (and inhibitor of cell proliferation) was found to be transforming growth factor beta 1 (TGF-beta 1). This cytokine stimulated both the rapid appearance of hemoglobin-positive cells and an early cessation of cell proliferation. Using fluorescently tagged antibodies to glycophorin A and fluorescence-activated cell sorter (FACS) analysis, this phenomenon was shown to be due to an early induction of erythroid differentiation rather than an aberrant production of hemoglobin. Methylcellulose assays indicated that the well-documented reduction of BFU-E colony numbers observed with TGF-beta 1 may actually be due to a TGF-beta 1-induced "conversion" of BFU-E into colony-forming units-erythroid (CFU-E). Thus, in vivo, TGF-beta 1 might serve, in part, to decrease the number of mature erythrocytes by stimulating BFU-E to skip a number of cell divisions and differentiate early.


Asunto(s)
Células Precursoras Eritroides/efectos de los fármacos , Factor de Crecimiento Transformador beta/farmacología , Animales , Antígenos CD/análisis , Antígenos CD34 , Antígenos de Diferenciación de Linfocitos B/análisis , Diferenciación Celular/efectos de los fármacos , Dimetilsulfóxido/farmacología , Relación Dosis-Respuesta a Droga , Células Precursoras Eritroides/fisiología , Eritropoyesis/efectos de los fármacos , Eritropoyetina/farmacología , Factores de Crecimiento de Célula Hematopoyética/farmacología , Humanos , Antígenos Comunes de Leucocito/análisis , Ratones , Receptores de Transferrina , Factor de Células Madre
3.
PLoS One ; 15(4): e0231959, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32352993

RESUMEN

We measured psychophysical thresholds for discriminating the speeds of two arrays of moving dots. The arrays could be juxtaposed or could be spatially separated by up to 10 degrees of visual angle, eccentricity being held constant. We found that the precision of the judgments varied little with separation. Moreover, the function relating threshold to separation was similar whether the arrays moved in the same, in opposite or in orthogonal directions. And there was no significant difference in threshold whether the two stimuli were initially presented to the same cerebral hemisphere or to opposite ones. How are human observers able to compare stimuli that fall at well separated positions in the visual field? We consider two classes of explanation: (i) Observers' judgments might be based directly on the signals of dedicated 'comparator neurons', i.e. neurons drawing inputs of opposite sign from local regions of the visual field. (ii) Signals about local features might be transmitted to the site of comparison by a shared 'cerebral bus', where the same physical substrate carries different information from moment to moment. The minimal effects of proximity and direction (which might be expected to influence local detectors of relative motion), and the combinatorial explosion in the number of comparator neurons that would be required by (i), lead us to favor models of type (ii).


Asunto(s)
Percepción Espacial/fisiología , Percepción Visual/fisiología , Humanos , Percepción de Movimiento/fisiología , Psicofísica , Factores de Tiempo
4.
Sci Adv ; 6(1): eaay2432, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31911947

RESUMEN

The mechanism by which the cytosolic protein Zap70 physically interacts with and phosphorylates its substrate, the transmembrane protein LAT, upon T cell receptor (TCR) stimulation remains largely obscure. In this study, we found that the pharmacological inhibition of formins, a major class of actin nucleators, suppressed LAT phosphorylation by Zap70, despite TCR stimulation-dependent phosphorylation of Zap70 remaining intact. High-resolution imaging and three-dimensional image reconstruction revealed that localization of phosphorylated Zap70 to the immune synapse (IS) and subsequent LAT phosphorylation are critically dependent on formin-mediated actin polymerization. Using knockout mice, we identify mDia1 and mDia3, which are highly expressed in T cells and which localize to the IS upon TCR activation, as the critical formins mediating this process. Our findings therefore describe previously unsuspected roles for mDia1 and mDia3 in the spatiotemporal control of Zap70-dependent LAT phosphorylation at the IS through regulation of filamentous actin, and underscore their physiological importance in TCR signaling.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Forminas/inmunología , Proteínas de la Membrana/genética , Proteína Tirosina Quinasa ZAP-70/genética , Citoesqueleto de Actina/efectos de los fármacos , Citoesqueleto de Actina/inmunología , Actinas/antagonistas & inhibidores , Actinas/química , Actinas/genética , Proteínas Adaptadoras Transductoras de Señales/inmunología , Animales , Forminas/genética , Forminas/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Sistema Inmunológico/efectos de los fármacos , Sistema Inmunológico/metabolismo , Células Jurkat/inmunología , Proteínas de la Membrana/inmunología , Ratones , Ratones Noqueados , Fosforilación/efectos de los fármacos , Polimerizacion/efectos de los fármacos , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/inmunología , Transducción de Señal/efectos de los fármacos
5.
Sci Rep ; 10(1): 5, 2020 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-31913300

RESUMEN

When realising future fusion reactors, their stationary burning must be maintained and the heat flux to the divertor must be reduced. This essentially requires a stationary internal transport barrier (ITB) plasma with a fast control system. However, the time scale for determining the position of the foot point of an ITB is not clearly understood even though its understanding is indispensable for fast profile control. In this study, the foot point of the electron ITB (eITB) was observed to be reformed at the vicinity of a magnetic island when the island started to form. In addition, the enhanced confinement region was observed to expand during the eITB formation according to the radial movement of the magnetic island toward the outer region. Compared to the time scales of the local heat transport, the faster time scales of the movement of the eITB foot point immediately after island formation (~0.5 ms) suggest the importance of the magnetic island for plasma profile control to maintain stationary burning.

6.
Eur J Neurol ; 16(4): 457-60, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19187258

RESUMEN

Valacyclovir (VACV) is used increasingly to treat herpes zoster, although neuropsychiatric symptoms [VACV neurotoxicity (VAN) or acyclovir neurotoxicity], may accompany use of this drug. To promote awareness of this rare condition, we describe here two clinical cases of VAN we previously reported and review 20 cases from the literature. In all cases, chronic or acute renal failure preceded VAN. The symptoms of VAN varied, but disturbances of consciousness and hallucination occurred most commonly. When acute renal failure was due to the drug, recovery from both the disturbance of consciousness and renal failure followed within several days after discontinuation of VACV. Early recognition and diagnosis will ensure effective treatment of VAN.


Asunto(s)
Lesión Renal Aguda/inducido químicamente , Aciclovir/análogos & derivados , Antivirales/efectos adversos , Fallo Renal Crónico/inducido químicamente , Síndromes de Neurotoxicidad , Valina/análogos & derivados , Aciclovir/efectos adversos , Aciclovir/uso terapéutico , Adulto , Anciano , Antivirales/uso terapéutico , Trastornos de la Conciencia/inducido químicamente , Femenino , Alucinaciones/inducido químicamente , Herpes Zóster/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Síndromes de Neurotoxicidad/diagnóstico , Valaciclovir , Valina/efectos adversos , Valina/uso terapéutico
7.
J Phys Condens Matter ; 19(36): 365226, 2007 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-21694171

RESUMEN

The possibility of half-metallic diluted antiferromagnetic semiconductors of II-VI compounds is investigated on the basis of first-principles electronic structure calculation. The electronic structures of ZnS, ZnSe, ZnO, CdS and CdSe doped with two kinds of 3d transition metal ions are calculated using the Korringa-Kohn-Rostoker (KKR) method and their magnetic transition temperatures are determined using a cluster-type approximation. It is predicted that II-VI compound semiconductors doped with two kinds of magnetic ions might be good candidates for half-metallic antiferromagnets.

8.
J Phys Condens Matter ; 19(36): 365233, 2007 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-21694178

RESUMEN

It is well known that the magnetizations as a function of the valence electron number per atom of 3d transition metal substitutional alloys form the so-called Slater-Pauling curve. Similarly, the Curie temperatures of these alloys also show systematic behaviour against the valence electron number. Though this fact has long been known, no attempt has been made so far to explain this behaviour from first principles. In this paper we calculate T(C) of 3d transition metal alloys in the framework of first-principles electronic structure calculation based on the local density approximation.

9.
Int J Dent Hyg ; 5(3): 145-50, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17615023

RESUMEN

This paper reports an evaluation of a residential care practice, which was part of a 'Dysphagia Management' course introduced into a 3-year dental hygiene curriculum in Japan. The clinical practice was performed at a care facility for the elderly people. Dental hygiene interventions, which consisted mainly of professional oral care, were implemented on a client who was bed-bound after suffering from a stroke. As the client had severe tension in muscles around oral cavity, it was difficult for the facility care workers to provide daily oral hygiene care. The goals of the dental hygiene care plan included decreasing tension of oral muscles and reducing periodontal inflammation and halitosis. The dental hygiene interventions were given once a month for 5 months. Evaluation in the fifth month demonstrated relaxation of oral muscles, decrease in plaque accumulation, and improvements in levels of gingival inflammation, indicating the partial achievements of the initial goals. Possibilities for revision of the care plan could call for more active involvement of the facility care workers and client-centered goal setting. This learning experience provided an opportunity for continuing intervention and evaluation of dental hygiene care for the same client. The positive results of our limited interventions further confirmed the importance of professional oral care in organic and functional improvements in oral health for the elderly people.


Asunto(s)
Trastornos de Deglución/terapia , Cuidado Dental para Ancianos , Higienistas Dentales/educación , Profilaxis Dental , Hogares para Ancianos , Anciano , Anciano de 80 o más Años , Trastornos de Deglución/etiología , Placa Dental/terapia , Músculos Faciales/fisiopatología , Femenino , Gingivitis/terapia , Halitosis/terapia , Servicios de Atención de Salud a Domicilio , Humanos , Japón , Masaje , Hipertonía Muscular/terapia , Paresia/complicaciones
10.
Oncogenesis ; 6(6): e350, 2017 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-28650445

RESUMEN

Here, by combining lipidomics with transcriptome analysis, we demonstrate that Rb depletion in mouse embryonic fibroblastss induces significant alterations in their lipid composition. We discovered that Rb depletion induced increase in lysophosphatidylserine, diacylglycerol (DAG), fatty acid (FA), acylcarnitine, phosphatidylcholine (PC), arachidonoyl ethanolamine, and decrease in phosphatidylglycerol, monoacylglycerol, without change in total lipid per protein levels. Analysis of the acyl chain composition of DAG, PC and phosphatidylserine revealed increase of saturated and mono-unsaturated acyl chains with specific carbon chain length. Consistently, we observed that Rb depletion increased the levels of fatty acids with the corresponding carbon chain length and number of carbon-carbon double bondssuch as myristic acid (14:0), palmitic acid (16:0), stearic acid (18:0) and all forms of FA 18:1. Microarray analysis revealed that Rb depletion induced significant upregulation of enzymes involved in elongation and desaturation of fatty acids. Among these, we found that elongation of long chain fatty acid family member 6 (Elovl6) and stearoyl-CoA desaturase 1 (Scd1) are the most robustly controlled by Rb possibly through E2F and sterol regulatory element-binding protein transcription factors. Depletion of Elovl6 or Scd1 significantly suppressed colony formation, sphere formation and xenograft tumor growth of Rb-deficient tumor cells. Suppression of self-renewal by the SCD1 inhibitor was rescued upon supplementation of the mono-unsaturated fatty acids generated by this enzyme. This study suggests a novel role for Rb in suppressing the malignant progression of tumors by controlling the lipid composition.

11.
Oncogene ; 36(36): 5145-5157, 2017 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-28481867

RESUMEN

Retinoblastoma (RB) protein inactivation during tumor progression is often associated with acquisition of immature phenotypes and resistance to therapy. Determination of an RB inactivation signature in a context of gaining undifferentiated phenotype in a p53-null sarcoma system revealed a critical role for interleukin (IL)-6. Using a Gene Set Enrichment Analysis (GSEA), we discovered that poorly differentiated breast cancers are enriched for this RB inactivation signature. Accelerated IL-6 secretion following RB inactivation in an RB-intact luminal-type breast cancer cell line MCF-7 promoted a positive feed forward loop between IL-6 and STAT3 driving tumor growth and endocrine therapy resistance. In addition, some of RB-intact basal-like type breast cancer cell lines exhibited a similar phenotype following RB depletion. The mechanism whereby RB inactivation increases IL-6 production in MCF-7 cells appeared to involve fatty acid oxidation (FAO)-dependent mitochondrial metabolism and c-Jun NH(2)-terminal kinase (JNK). In addition, IL-6, via STAT3-mediated feedback to mitochondria, autonomously adjusts mitochondrial superoxide to levels suitable to maintain stem cell-like activity. The gene expression profile of luminal-type breast cancer patients with low RB expression revealed high enrichment of genes involved in mitochondrial respiration and downstream targets of IL-6. These findings unveiled an unexpected strategy whereby RB suppresses malignant features of cancer cells through metabolic reprogramming and cell-autonomous inflammation.


Asunto(s)
Neoplasias de la Mama/patología , Autorrenovación de las Células/efectos de los fármacos , Resistencia a Antineoplásicos , Interleucina-6/metabolismo , Mitocondrias/patología , Proteína de Retinoblastoma/metabolismo , Tamoxifeno/farmacología , Animales , Antineoplásicos Hormonales/farmacología , Apoptosis/efectos de los fármacos , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Ácidos Grasos/química , Ácidos Grasos/metabolismo , Femenino , Humanos , Interleucina-6/genética , Metaboloma , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Proteína de Retinoblastoma/genética , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/fisiología , Ensayos Antitumor por Modelo de Xenoinjerto
12.
J Neuroendocrinol ; 28(10)2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27344056

RESUMEN

Rodents show apparent sex differences in their sexual behaviours. The present study used Kiss1 knockout (KO) rats to evaluate the role of kisspeptin in the defeminisation/masculinisation of the brain mechanism that controls sexual behaviours. Castrated adult Kiss1 KO males treated with testosterone showed no male sexual behaviours but demonstrated the oestrogen-induced lordosis behaviours found in wild-type females. The sizes of some of the sexual dimorphic nuclei of Kiss1 KO male rats are similar to those of females. Plasma testosterone levels at embryonic day 18 and postnatal day 0 (PND0) in Kiss1 KO males were high, similar to wild-type males, indicating that perinatal testosterone is secreted in a kisspeptin-independent manner. Long-term exposure to testosterone from peripubertal to adult periods restored mounts and intromissions in KO males, suggesting that kisspeptin-dependent peripubertal testosterone secretion is required to masculinise the brain mechanism. This long-term testosterone treatment failed to abolish lordosis behaviours in KO males, whereas kisspeptin replacement at PND0 reduced lordosis quotients in Kiss1 KO males but not in KO females. These results suggest that kisspeptin itself is required to defeminise behaviour in the perinatal period, in cooperation with testosterone. Oestradiol benzoate treatment at PND0 suppressed lordosis quotients in Kiss1 KO rats, indicating that the mechanisms downstream of oestradiol work properly in the absence of kisspeptin. There was no significant difference in aromatase gene expression in the whole hypothalamus between Kiss1 KO and wild-type male rats at PND0. Taken together, the present study demonstrates that both perinatal kisspeptin and kisspeptin-independent testosterone are required for defeminisation of the brain, whereas kisspeptin-dependent testosterone during peripuberty to adulthood is needed for masculinisation of the brain in male rats.


Asunto(s)
Encéfalo/fisiología , Kisspeptinas/fisiología , Diferenciación Sexual , Testosterona/fisiología , Animales , Animales Recién Nacidos , Encéfalo/efectos de los fármacos , Castración , Femenino , Técnicas de Inactivación de Genes , Kisspeptinas/genética , Masculino , Caracteres Sexuales , Diferenciación Sexual/efectos de los fármacos , Conducta Sexual Animal , Testosterona/administración & dosificación , Testosterona/sangre
13.
Oncogene ; 12(10): 2137-46, 1996 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-8668339

RESUMEN

A cDNA (termed CT124) encoding a carboxyl-terminal fragment of the human homeobox protein MSX-2 was found to induce flat reversion when expressed in v-Ki-ras-transformed NIH3T3 cells. Although the expression of endogenous MSX-2 gene is low in most of the normal adult tissues examined, it is frequently activated in carcinoma-derived cell lines. Likewise, the gene is inactive in NIH3T3 cells but is transcriptionally activated after transformation by v-Ki-ras oncogene, suggesting that the intact MSX-2 may play a positive, rather than suppressive, role in cell transformation. To test this possibility, we isolated a near full-length human MSX-2 cDNA and tested its activities in two cell systems, i.e. fibroblast and myoblast. In NIH3T3 fibroblasts, although the gene by itself failed to confer a transformed phenotype, antisense MSX-2 cDNA as well as truncated CT124 cDNA interfered with the transforming activities of v-Ki-ras oncogene. In C2C12 myoblasts, MSX-2 was found to suppress MyoD gene expression, as do activated ras oncogenes, under certain culture conditions, and CT124 was found to inhibit the activities of both MSX-2 and ras in this system as well. Our findings not only suggest that CT124 may act as a dominant suppressor of MSX-2 but also raise the possibility that MSX-2 gene may be an important downstream target for the Ras signaling pathways.


Asunto(s)
Transformación Celular Neoplásica/genética , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Proteínas de Unión al ADN/genética , Genes Supresores de Tumor , Genes ras , Células 3T3/fisiología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Embrión de Pollo , Sondas de ADN , Proteínas de Unión al ADN/fisiología , Regulación Neoplásica de la Expresión Génica , Proteínas de Homeodominio , Ratones , Datos de Secuencia Molecular , Homología de Secuencia de Aminoácido , Proteínas ras/genética , Proteínas ras/fisiología
14.
Biochim Biophys Acta ; 1003(1): 9-14, 1989 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-2469475

RESUMEN

Thapsigargin, a non-TPA-type tumor promoter, releases histamine and stimulates arachidonic acid metabolism in rat peritoneal mast cells. In order to clarify the relationship between the histamine-releasing activity and the arachidonic acid metabolism-stimulating activity of thapsigargin in mast cells, the effects of cyclooxygenase inhibitors, indomethacin and ibuprofen, a lipoxygenase inhibitor, AA861, and dual inhibitors for cyclooxygenase and lipoxygenase, nordihydroguaiaretic acid and BW755C, on histamine release and arachidonic acid metabolism were examined. High-performance liquid chromatography analysis revealed that the peritoneal mast cells preferentially produce prostaglandin D2 by thapsigargin treatment. These inhibitors suppressed thapsigargin-induced prostaglandin D2 production in a dose-dependent manner, but failed to inhibit histamine release, suggesting that the mechanisms for stimulation of histamine release by thapsigargin is not dependent on increased arachidonic acid metabolism. Time-course experiments of histamine release and the release of radioactivity from [3H]arachidonic acid-labeled mast cells also provide evidence for a difference in mechanism.


Asunto(s)
Ácidos Araquidónicos/metabolismo , Liberación de Histamina/efectos de los fármacos , Mastocitos/metabolismo , Extractos Vegetales/farmacología , Animales , Araquidonato Lipooxigenasas/antagonistas & inhibidores , Ácido Araquidónico , Cromatografía Líquida de Alta Presión , Inhibidores de la Ciclooxigenasa , Técnicas In Vitro , Masculino , Mastocitos/efectos de los fármacos , Prostaglandina D2/metabolismo , Radioinmunoensayo , Ratas , Ratas Endogámicas , Tapsigargina , Factores de Tiempo
15.
Biochim Biophys Acta ; 925(2): 156-63, 1987 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-3113492

RESUMEN

Inflammatory reactions induced by TPA (12-O-tetradecanoylphorbol 13-acetate)-type tumor promoters, including TPA, teleocidin and aplysiatoxin, and chemical mediators responsible for such inflammatory reactions were analyzed. The tumor promoter dissolved in a 0.8% sodium carboxymethyl cellulose solution was injected into a subcutaneous air pouch preformed on the dorsum of rats. Within 30 min after the injection, vascular permeability as measured by the leakage of labeled albumin into the pouch fluid was increased, with a concomitant increase in histamine level. This increase in vascular permeability was inhibited by a histamine antagonist, pyrilamine, and a serotonin antagonist, methysergide. Vascular permeability at 4 h was not inhibited by pyrilamine or methysergide but was inhibited by a cyclooxygenase inhibitor, indomethacin, with a parallel decrease in the prostaglandin E2 level in the pouch fluid. These results suggest that the TPA-type tumor promoters induce inflammation by the mechanism of mast cell degranulation within a short period, this being followed by the stimulation of arachidonic acid metabolism. The mechanism of the in vivo effect of the TPA-type tumor promoters is discussed and compared with in vitro effects that we have previously reported.


Asunto(s)
Histamina/fisiología , Inflamación/inducido químicamente , Toxinas de Lyngbya/farmacología , Prostaglandinas E/fisiología , Acetato de Tetradecanoilforbol/farmacología , Animales , Permeabilidad Capilar/efectos de los fármacos , Dinoprostona , Edema/inducido químicamente , Indometacina/farmacología , Metisergida/farmacología , Neutrófilos/fisiología , Pirilamina/farmacología , Ratas
16.
Biochim Biophys Acta ; 887(1): 94-9, 1986 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-2423139

RESUMEN

Thapsigargin, a non-TPA (12-O-tetradecanoylphorbol 13-acetate)-type tumor promoter, provoked histamine release from rat peritoneal mast cells at concentrations above 30 ng/ml, but not at 10 ng/ml. TPA-type tumor promoters such as TPA, teleocidin and aplysiatoxin released very little, if any, histamine even at 100 ng/ml. When mast cells were incubated in medium containing thapsigargin at 10 ng/ml and varying concentrations of TPA-type tumor promoters, histamine release was increased synergistically. Maximum synergistic effects were observed at 10 ng/ml of each TPA-type tumor promoter. Palytoxin, another non-TPA-type tumor promoter, having no effect on histamine release at up to 10 pg/ml, also induced histamine release in the presence of 10 ng/ml of each TPA-type tumor promoter. However, no synergistic effect on histamine release was observed when mast cells were incubated in medium containing two different non-TPA-type tumor promoters, e.g., 10 ng/ml thapsigargin and 10 pg/ml palytoxin, or in medium containing two different TPA-type tumor promoters, e.g., TPA and teleocidin, TPA and aplysiatoxin, or teleocidin and aplysiatoxin (all at 10 ng/ml). These results suggest that the release of histamine from mast cells is stimulated synergistically under the mutual influence of TPA-type tumor promoters and non-TPA-type tumor promoters.


Asunto(s)
Carcinógenos/farmacología , Liberación de Histamina/efectos de los fármacos , Mastocitos/fisiología , Forboles/farmacología , Acetato de Tetradecanoilforbol/farmacología , Animales , Sinergismo Farmacológico , Técnicas In Vitro , Cinética , Masculino , Mastocitos/efectos de los fármacos , Ratas , Ratas Endogámicas
17.
Leukemia ; 11 Suppl 3: 340-3, 1997 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9209384

RESUMEN

A truncated MSX-2 homeoprotein was found to induce flat reversion when expressed in v-Ki-ras-transformed NIH3T3 cells. Although the expression of endogenous MSX-2 gene is low in most of the normal adult tissues examined, it is frequently activated in carcinoma-derived cell lines. Likewise, the gene is inactive in untransformed cells but is transcriptionally activated after transformation by v-Ki-ras oncogene, suggesting that the intact MSX-2 may play a positive, rather than suppressive, role in cell transformation. To test this possibility, we isolated a full-length human MSX-2 cDNA and tested its activities in two cell systems: fibroblast and myoblast. In NIH3T3 fibroblasts, although the gene by itself failed to confer a transformed phenotype, antisense MSX-2 cDNA as well as truncated MSX-2 cDNA interfered with the transforming activities of both v-Ki-ras and v-raf oncogene. In C2C12 myoblasts, MSX-2 was found to suppress MyoD gene expression, as do activated ras oncogenes, under certain culture conditions, and truncated MSX-2 cDNA was found to inhibit the activities of both MSX-2 and ras in this system as well. Our findings not only suggest that the truncated version MSX-2 may act as a dominant suppressor of intact MSX-2 but also raise the possibility that MSX-2 gene may be an important downstream target for the Ras signaling pathways.


Asunto(s)
Transformación Celular Neoplásica , Proteínas de Unión al ADN/metabolismo , Genes ras , Proteínas de Homeodominio/metabolismo , Células 3T3 , Animales , Línea Celular , Proteínas de Unión al ADN/biosíntesis , Humanos , Ratones , Músculo Esquelético , Proteína MioD/biosíntesis , Proteína Oncogénica p21(ras)/biosíntesis , Proteínas Oncogénicas v-raf , Oncogenes , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/metabolismo , Proteínas Oncogénicas de Retroviridae/biosíntesis , Transducción de Señal , Transcripción Genética , Transfección , Células Tumorales Cultivadas
18.
Hum Exp Toxicol ; 34(3): 300-7, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25005806

RESUMEN

Diethylpropion has been available in the market for treating obesity for over 50 years. Refined studies are lacking to fully elucidate its action spectrum. The aim of our study was to evaluate possible toxic effects of anorectic diethylpropion in Chinese hamster ovary (CHO) cells. Comet assay (detects breaks in the DNA strand), micronucleus test (detects clastogenic/aneugenic damage), and cell survival test (detects cytotoxic damage) were used to evaluate the toxic effects. In comet assay, we found that the damage scores with diethylpropion treatments at the concentrations of 20 and 40 µg/mL were more significant ( p < 0.05) than that of the negative control. When assessing the possible aneugenic and/or clastogenic damage caused by the drug in CHO cells, we found no difference ( p > 0.05) in the values of micronucleated cells when comparing different diethylpropion treatments and the negative control. Regarding the cell viability, for all the diethylpropion concentrations tested, higher values ( p < 0.05) of apoptosis were found compared with those of the negative control. In relation to the number of necrotic cells, no difference ( p > 0.05) was noted between the means of the three concentrations of diethylpropion evaluated and the negative control. In the experimental conditions, we conclude that diethylpropion has weak genotoxic and cytotoxic activities.


Asunto(s)
Depresores del Apetito/toxicidad , Citotoxinas/toxicidad , Dietilpropión/toxicidad , Mutágenos/toxicidad , Animales , Células CHO , Supervivencia Celular/efectos de los fármacos , Ensayo Cometa , Cricetinae , Cricetulus , Daño del ADN , Pruebas de Micronúcleos
19.
FEBS Lett ; 481(1): 31-6, 2000 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-10984610

RESUMEN

A human placenta cDNA expression library was screened for genes inducing flat reversion when transfected into a v-K-ras-transformed NIH3T3 cell line, DT. One such gene was found to encode a Kunitz-type serine protease inhibitor, tissue factor pathway inhibitor-2 (TFPI-2). While the TFPI-2 mRNA can be detected in normal human fibroblasts (MRC-5), it is down-regulated in MRC-5 cells expressing an activated H-ras oncogene and in the human fibrosarcoma cell line, HT1080. Restored expression of the TFPI-2 gene in HT1080 cells resulted in the suppression of matrix invasion activity in vitro with concomitant decrease in the relative amount of active matrix metalloproteinase-2 secreted from the cells. When DT cells were cultured in the presence of conditioned medium and extracellular matrix prepared from TFPI-2-transfected HT1080 cells, increased attachment and flat reversion were observed. These results suggest that TFPI-2 may be required for the maintenance of the integrity of extracellular matrix in normal tissues and its down-regulation as a result of oncogene activation may contribute to the malignant phenotypes of tumor cells.


Asunto(s)
Transformación Celular Neoplásica/genética , Regulación hacia Abajo , Genes ras/genética , Glicoproteínas/metabolismo , Metaloproteinasa 2 de la Matriz/biosíntesis , Proteínas Gestacionales/metabolismo , Animales , Adhesión Celular , División Celular , Línea Celular , Movimiento Celular , Tamaño de la Célula , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/patología , Clonación Molecular , Medios de Cultivo Condicionados , Activación Enzimática , Inducción Enzimática , Matriz Extracelular/metabolismo , Fibroblastos , Regulación Neoplásica de la Expresión Génica , Glicoproteínas/química , Glicoproteínas/genética , Humanos , Metaloproteinasa 2 de la Matriz/metabolismo , Ratones , Mutación/genética , Proteínas Gestacionales/química , Proteínas Gestacionales/genética , ARN Mensajero/análisis , ARN Mensajero/genética , Transfección , Células Tumorales Cultivadas , Proteínas ras/genética , Proteínas ras/metabolismo
20.
Transplantation ; 51(6): 1272-5, 1991 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1675504

RESUMEN

Regulation of the intercellular adhesion molecule-1 (ICAM-1) expression on human renal tubular epithelial cells in culture (hKEC-1) was investigated. A large proportion of hKEC-1 cells from the primary cultures expressed the ICAM-1 antigen. Supernatants from mixed lymphocyte reaction (MLR) of both specific and third-party combinations augmented the expression of the ICAM-1 antigen, in a dose-dependent manner. A kinetic study revealed maximal augmentation by MLR supernatant on the first day, with a gradual decrease thereafter. Among several recombinant human cytokines tested, i.e., interferon-gamma, tumor necrosis factor-alpha, interleukin 1 alpha and beta, and IL-4, IFN-gamma, TNF-alpha, and IL-1 alpha/beta were shown to augment the expression of ICAM-1. MLR supernatants and IFN-gamma were more effective in augmenting ICAM expression than TNF-alpha and IL-1 alpha/beta. IFN-gamma upregulated ICAM-1 expression in a dose-dependent manner, and maximal augmentation was achieved on the first day. The MLR supernatants were shown to contain IFN-gamma and TNF-alpha, and the activity of the MLR supernatant was partially inhibited by neutralizing antibody against IFN-gamma. These data suggest that cytokines, especially IFN-gamma, TNF-alpha, and IL-1 alpha/beta, released by T cells and antigen-presenting cells upon recognition of alloantigens upregulate ICAM-1 expression on renal tubular epithelial cells. This may result in an increase in the attachment of graft-infiltrating T cells to the renal tubular cells, by the ICAM-1-LFA-1 interaction.


Asunto(s)
Antígenos CD/metabolismo , Moléculas de Adhesión Celular/metabolismo , Citocinas/farmacología , Túbulos Renales/inmunología , Células Cultivadas , Relación Dosis-Respuesta a Droga , Epitelio/inmunología , Humanos , Técnicas In Vitro , Molécula 1 de Adhesión Intercelular , Interferón gamma/administración & dosificación , Túbulos Renales/citología , Prueba de Cultivo Mixto de Linfocitos , Proteínas Recombinantes/farmacología , Factores de Tiempo , Factor de Necrosis Tumoral alfa/administración & dosificación
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