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1.
Am J Transplant ; 16(7): 2016-29, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26749114

RESUMEN

Neural transplantation is a promising therapeutic approach for neurodegenerative diseases; however, many patients receiving intracerebral fetal allografts exhibit signs of immunization to donor antigens that could compromise the graft. In this context, we intracerebrally transplanted mesencephalic pig xenografts into primates to identify a suitable strategy to enable long-term cell survival, maturation, and differentiation. Parkinsonian primates received WT or CTLA4-Ig transgenic porcine xenografts and different durations of peripheral immunosuppression to test whether systemic plus graft-mediated local immunosuppression might avoid rejection. A striking recovery of spontaneous locomotion was observed in primates receiving systemic plus local immunosuppression for 6 mo. Recovery was associated with restoration of dopaminergic activity detected both by positron emission tomography imaging and histological examination. Local infiltration by T cells and CD80/86+ microglial cells expressing indoleamine 2,3-dioxigenase were observed only in CTLA4-Ig recipients. Results suggest that in this primate neurotransplantation model, peripheral immunosuppression is indispensable to achieve the long-term survival of porcine neuronal xenografts that is required to study the beneficial immunomodulatory effect of local blockade of T cell costimulation.


Asunto(s)
Antígeno CTLA-4/inmunología , Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Terapia de Inmunosupresión/métodos , Neuronas/citología , Enfermedad de Parkinson/terapia , Linfocitos T/inmunología , Animales , Animales Modificados Genéticamente , Células Cultivadas , Femenino , Rechazo de Injerto/tratamiento farmacológico , Rechazo de Injerto/inmunología , Supervivencia de Injerto/efectos de los fármacos , Supervivencia de Injerto/inmunología , Xenoinjertos , Inmunosupresores/uso terapéutico , Activación de Linfocitos , Macaca fascicularis , Masculino , Neuronas/inmunología , Enfermedad de Parkinson/inmunología , Sus scrofa , Trasplante Heterólogo
2.
Rev Stomatol Chir Maxillofac ; 112(3): 180-2, 2011 Jun.
Artículo en Francés | MEDLINE | ID: mdl-21481900

RESUMEN

INTRODUCTION: Non-Hodgkin lymphomas are common cancers that can develop in the upper aero-digestive tract. We describe a case of a large B-cell palatine lymphoma with spontaneous clinical regression. CASE: A 58-year-old female patient presented with a sub-mucosal lesion of the hard palate. CT scan and magnetic resonance imaging revealed a lesion invading the right posterior palatine canal. At the second consultation, 15 days after performing the biopsy, the lesion had disappeared. PET scan proved the absence of lesion. Lymph node biopsy supported the diagnosis of large B-cell lymphoma. DISCUSSION: Large B-cell lymphoma of the hard palate is a rare disease. Only 27 cases have been described in the international literature. The anatomopathological analysis is often difficult to perform. The final diagnosis is often made by immunochemistry. The usual treatment is R-CHOP chemotherapy (cyclophosphamide, adriamycin, vincristine, prednisone combined to rituximab) with a 5-year survival rate at 55%.


Asunto(s)
Linfoma de Células B Grandes Difuso/patología , Regresión Neoplásica Espontánea/patología , Neoplasias Palatinas/patología , Paladar Duro/patología , Biopsia , Femenino , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Tomografía de Emisión de Positrones , Neoplasias de la Glándula Submandibular/patología , Tomografía Computarizada por Rayos X
3.
J Eur Acad Dermatol Venereol ; 22(1): 94-100, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18181979

RESUMEN

BACKGROUND: In the last two decades, there has been an increasing use of isotretinoin (13-cis-retinoic acid or 13-CRA) for treatment of severe, and recently mild and moderate, acne in Westernized populations. Recent human and animal studies emphasized alterations caused by 13-CRA administration on folate-dependent, one-carbon metabolism. Folate deficiency and subsequent hyperhomocysteinemia increase the risk of degenerative diseases. OBJECTIVES: We determine whether a short-term supplementation with 13-CRA alters folate status and homocysteinemia in young and elderly healthy human subjects. METHODS: Twenty young and 20 elderly (age mean, 26.1 and 65.4 years, respectively) healthy male volunteers were supplemented with approximately 0.5 mg/kg/day of 13-CRA for 28 days. Fasting plasma concentrations of 13-CRA, 5-methyltetrahydrofolate (5-mTHF) as the main circulating form of folate, and homocysteine (Hcy), as well as haematologic parameters and biochemical markers of liver and renal function, were measured at baseline and at the end of supplementation. Statistical analyses were carried out using two-way anova and standard tests. RESULTS: In both groups, isotretinoin supplementation caused a dramatic increase in the circulating concentration of 13-CRA and its derivatives. It also led to significant increases in serum triglyceride (P < 0.0001) and creatinine (P = 0.002) concentrations and gamma-glutamyltranspeptidase activity (P = 0.0001) and decrease in serum level of urea (P = 0.027). However, the latter four parameters remained within normal ranges. These changes were accompanied by a 17.7% and 13.5% decrease in the plasma level of 5-mTHF (P = 0.001) in the young and elderly volunteers, respectively. Supplementation with 13-CRA did not cause significant variations in their plasma Hcy concentration. However, the latter parameter seemed to respond differently in each group of age (P = 0.046). CONCLUSIONS: Our data indicate that a 28-day supplementation with isotretinoin alters the plasma folate in young and old healthy individuals. This stresses the necessity of studying the long-term effects of retinoid therapy on folate status and homocysteinemia in acne patients, given that alteration in the latter parameters is known to increase the risk of degenerative diseases.


Asunto(s)
Envejecimiento/sangre , Fármacos Dermatológicos/farmacología , Ácido Fólico/sangre , Isotretinoína/farmacología , Acné Vulgar/tratamiento farmacológico , Adulto , Anciano , Fármacos Dermatológicos/administración & dosificación , Fármacos Dermatológicos/sangre , Suplementos Dietéticos , Homocisteína/sangre , Humanos , Isotretinoína/administración & dosificación , Isotretinoína/sangre , Masculino , Tetrahidrofolatos/sangre
4.
Waste Manag ; 28(12): 2456-64, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18248976

RESUMEN

This study is conducted to look at the modification of mechanical properties of recycled polypropylene (PP) from post-consumer containers with the addition of stabilizers, elastomer (ethylene-octene rubber, EOR) and calcium carbonate (CaCO(3)). The mechanical and thermal properties of the blends were evaluated. The results showed limited changes with the addition of elastomer and calcium carbonate on the mechanical properties of the recycled polypropylene. Some differences were observed, but the trends were not reproducible over the different compositions. DSC analysis confirmed the presence of polyethylene (PE) in the recycled polypropylene. The polyethylene impurity and the presence of many different qualities of polypropylene in the recycled material may have prevented any possible improvement in the mechanical properties by the addition of EOR and CaCO(3), improvements seen in previous studies on virgin polypropylene. The compatibility of the different homopolymers and copolymers of PP used in consumer packaging is not known, while polyethylene and polypropylene are known not to be miscible with each other. The mixture of qualities and materials may explain such a poor blending. Reusing and upgrading of recycled PP from post-consumer containers would therefore first require a better sorting of the post-consumer waste. The use of an adequate compatibilizer that would allow a uniform and homogeneous blending of the raw material mixture might enhance the mechanical properties.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Polipropilenos/química , Embalaje de Productos , Residuos
5.
Cancer Treat Rev ; 53: 53-60, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28073101

RESUMEN

BACKGROUND: Molecular targeted therapies have improved progression-free survival (PFS) without translating systematically into overall survival (OS) for patients with metastatic renal cell carcinoma (mRCC). In this population, patient-reported outcomes (PROs) have become a significant outcome. We evaluated the methodological quality of the assessment of PROs in randomized controlled trials (RCTs) and the clinical benefit of the different treatments including survival and quality of life (QoL). METHODS: A systematic review identified RCTs published between January 2005 and July 2014. They were evaluated according to 11 items derived from the 2013 CONSORT PROs reporting guidelines. Survival outcomes and PROs main results were analyzed and the magnitude of clinical benefit was assessed with the European Society for Medical Oncology Magnitude of Clinical Benefit Scale (ESMO-MCBS). RESULTS: 12 RCTs were included with a total of 22 publications. The mean CONSORT score for all items was 4.5 on an 11-point scale. No publication reported the power of the PROs analysis and only one reported a PRO hypothesis. 50% of studies did not interpret PROs in relation to clinical outcomes and only 18% discussed specific limitations of PROs and their implications for generalizability. By adding the QoL criterion to PFS, 4 trials (36.4%) obtained a high level of proven clinical benefit according to the ESMO-MCBS. CONCLUSION: The methodology for assessing PROs in mRCC is not optimal. Efforts should focus on defining PROs endpoint and increasing the quality of reporting of QoL. New-generation therapies in mRCC should demonstrate a gain not only in survival but also in QoL to be included in the therapeutic arsenal.


Asunto(s)
Carcinoma de Células Renales/tratamiento farmacológico , Neoplasias Renales/tratamiento farmacológico , Terapia Molecular Dirigida/métodos , Antineoplásicos/uso terapéutico , Bevacizumab/uso terapéutico , Carcinoma de Células Renales/mortalidad , Carcinoma de Células Renales/patología , Humanos , Neoplasias Renales/mortalidad , Neoplasias Renales/patología , Niacinamida/análogos & derivados , Niacinamida/uso terapéutico , Compuestos de Fenilurea/uso terapéutico , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto , Sirolimus/análogos & derivados , Sirolimus/uso terapéutico , Sorafenib , Resultado del Tratamiento
6.
Biochim Biophys Acta ; 578(1): 232-42, 1979 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-222338

RESUMEN

The extracellular cyclic-AMP phosphodiesterase of a mutant of Dictyostelium discoideum which accumulates this enzyme was found to exist in multiple forms. Using the isoelectric focusing technique the phosphodiesterase activity was distributed into three peaks with isoelectric points of 4.6, 6.5 and 8.3, designated as p4, p6 and p8. Gel filtration and sucrose gradient analysis showed that the p4 activity consisted of two forms of different sedimentation coefficients. At high enzyme concentrations, the heavy form was favored. Dilution of enzyme activity shifted the equilibrium toward the light form. Direct analysis by sucrose gradient sedimentation of all isoelectric forms demonstrated that besides p4, p6 activity also existed as a mixture of the heavy (9.7 S) and the light (5.4 S) components. In contrast, the p8 activity displayed only the light form. The heterogeneity of the p4 and p6 isoelectric forms was also observed by polyacrylamide gel electrophoresis. A procedure for a partial purification of the extracellular enzyme to about 70-fold is presented.


Asunto(s)
3',5'-AMP Cíclico Fosfodiesterasas/metabolismo , Dictyostelium/enzimología , Centrifugación por Gradiente de Densidad , Cromatografía en Gel , Espacio Extracelular/enzimología , Punto Isoeléctrico , Sustancias Macromoleculares , Peso Molecular
7.
Biochim Biophys Acta ; 640(2): 572-82, 1981 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-6260258

RESUMEN

A phosphodiesterase activity is shown to copurify with the plasma membrane fraction prepared by the two-phase partition method. The enrichment in phosphodiesterase parallels that of alkaline phosphatase, which is thought to be a typical membranous enzyme. Up to 66% of the phosphodiesterase activity can be solubilized by a treatment with 0.2% Triton X-100. Higher doses were ineffective in solubilizing more activity. Analysis by native gel electrophoresis showed that an activity extracted by 2 M NaCl migrated at the same position as 'soluble' phosphodiesterase of cytosolic or extracellular origin. In contrast, the Triton-solubilized enzyme had an apparently higher molecular weight. When subjected to charge shift electrophoresis on agarose gels in the presence of an ionic detergent, the Triton-solubilized phosphodiesterase displayed a hydrophobic character. This behaviour contrasts with that of 'soluble' phosphodiesterases, the electrophoretic mobility of which is unaffected by the presence of an anionic detergent. The hydrophobic character of the membranous enzyme was lost after gentle hydrolysis by papain.


Asunto(s)
Dictyostelium/enzimología , Hidrolasas Diéster Fosfóricas/metabolismo , Membrana Celular/enzimología , Ácido Desoxicólico , Electroforesis en Gel de Agar , Electroforesis en Gel de Poliacrilamida , Octoxinol , Papaína , Polietilenglicoles , Solubilidad
8.
Biochim Biophys Acta ; 1227(3): 161-70, 1994 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-7986823

RESUMEN

Intestinal absorption of putrescine and tissue metabolism of polyamines were investigated in rats grafted with the rapidly growing Mat-Lylu prostatic tumor. These animals exhibited a dramatic 21% decrease in weight and protein, but not DNA, content of their intestinal mucosa, relative to healthy rats reared under similarly controlled nutritional conditions. No significant variation in the specific activities of intestinal brush-border membrane enzymes was observed, however, suggesting a comparable differentiation state of intestinal cells exists in both groups. Putrescine uptake by brush-border membrane vesicles prepared from cancerous or healthy rat intestine was a time dependent process at 25 degrees C. Equilibrium uptake was much greater than could be explained by equilibration of the vesicle space with putrescine, indicating that the diamine was bound to membrane sites. Kinetics of putrescine uptake at 2 min revealed that the process involves two components, a saturable Michaelis-Menten carrier and passive diffusion. With respect to the kinetic parameters of putrescine transport, no significant changes were observed between the tumor-bearing and the control rats. After correction for nonspecific binding to the membranes, putrescine accumulation at equilibrium (75 min) was concentration-dependent and fit a single-site saturable model. Maximum accumulation of the diamine at equilibrium (Bmax) was increased by more than 46% in the cancerous rats relative to the controls, but the dissociation constant (Kd) was unchanged. Efflux of putrescine from the vesicles was slightly slower in the tumor-bearing group, but the differences were generally not significant. No change was observed with respect to the specific activity of ornithine decarboxylase and the concentration of polyamines in the intestinal mucosa. In Mat-Lylu grafted rats fed a standard diet supplemented with [14C]putrescine, about 19% of body radioactivity was recovered in the tumor within 24 h. This was concomitant with a decrease in the percentage of radioactivity retained in the intestinal, renal and hepatic tissues, relative to that retained in the same tissues of healthy rats. Our findings indicate that the presence of the tumor evolves an adaptive response in the small intestine of the rat, involving an increased capacity of the brush-border membrane to accumulate putrescine.


Asunto(s)
Adenocarcinoma/metabolismo , Mucosa Intestinal/metabolismo , Neoplasias de la Próstata/metabolismo , Putrescina/metabolismo , Adenocarcinoma/patología , Animales , Peso Corporal , Relación Dosis-Respuesta a Droga , Ingestión de Alimentos , Femenino , Absorción Intestinal , Mucosa Intestinal/ultraestructura , Intestino Delgado/metabolismo , Intestino Delgado/ultraestructura , Cinética , Masculino , Microvellosidades/metabolismo , Neoplasias de la Próstata/patología , Putrescina/farmacocinética , Putrescina/farmacología , Ratas , Distribución Tisular
9.
Cell Death Differ ; 5(1): 116-25, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10200452

RESUMEN

C6.9 rat glioma cells undergo a cell death program when exposed to 1, 25-dihydroxyvitamin D3 (1,25-D3). As a global analytical approach, we have investigated gene expression in C6.9 engaged in this cell death program using differential screening of a rat brain cDNA library with probes derived from control and 1,25-D3-treated cells. Using this methodology we report the isolation of 61 differentially expressed cDNAs. Forty-seven cDNAs correspond to genes already characterized in rat cells or tissues. Seven cDNAs are homologous to yeast, mouse or human genes and seven are not related to known genes. Some of the characterized genes have been reported to be differentially expressed following induction of programmed cell death. These include PMP22/gas3, MGP and beta-tubulin. For the first time, we also show a cell death program induced up-regulation of the c-myc associated primary response gene CRP, and of the proteasome RN3 subunit and TCTP/mortalin genes. Another interesting feature of this 1,25-D3 induced-cell death program is the down-regulated expression of transcripts for the microtubule motor dynein heavy chain/MAP 1C and of the calcium-binding S100beta protein. Finally 15 upregulated cDNAs encode ribosomal proteins suggesting a possible involvement of the translational apparatus in this cell program. Alternatively, these ribosomal protein genes could be up-regulated in response to altered rates of cellular metabolism, as has been demonstrated for most of the other isolated genes which encode proteins involved in metabolic pathways. Thus, this study presents to our knowledge the first characterization of genes which are differentially expressed during a cell death program induced by 1, 25-D3. Therefore, this data provides new information on the fundamental mechanisms which participate in the antineoplastic effects of 1,25-D3 and on the machinery of a cell death program in a glioma cell line.


Asunto(s)
Apoptosis/efectos de los fármacos , Biomarcadores de Tumor , Calcitriol/farmacología , Agonistas de los Canales de Calcio/farmacología , Proteínas de la Matriz Extracelular , Glioma , Vitamina D/farmacología , Animales , Apoptosis/fisiología , Huesos/fisiología , Proteínas de Unión al Calcio/genética , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/fisiología , Cisteína , Cisteína Endopeptidasas/genética , ADN/análisis , ADN Complementario , Dineínas/genética , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Biblioteca de Genes , Proteínas HSP70 de Choque Térmico/genética , Complejos Multienzimáticos/genética , Proteínas de la Mielina/genética , Proteínas de Neoplasias/genética , Osteonectina/genética , Complejo de la Endopetidasa Proteasomal , Biosíntesis de Proteínas/fisiología , ARN Mensajero/análisis , Ratas , Proteínas Ribosómicas/genética , Tubulina (Proteína)/genética , Células Tumorales Cultivadas/química , Células Tumorales Cultivadas/citología , Células Tumorales Cultivadas/fisiología , Proteína Tumoral Controlada Traslacionalmente 1 , Proteína Gla de la Matriz
10.
Cell Signal ; 13(6): 417-23, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11384840

RESUMEN

Long-term amino acid starvation represents a form of metabolic stress which stimulates gene expression. Here we report that depriving HeLa cells for any one of a series of amino acids activates c-Jun N-terminal kinase-1 (JNK-1). In contrast, the other mitogen-activated protein kinases (MAPKs) ERK-1 and, to a lesser extent, p38 activities decreased under such conditions. In methionine- or leucine-deprived cells, JNK-1 activation occurred after 4 or 6 h, respectively, and reached a steady maximum of 5- to 7-fold over control cells afterwards. This activation was dependent on the amino acid concentration and it could be reversed by resupplying the complete medium. Limitation for all amino acids also augmented JNK-1 activity, whereas increased amino acid concentrations had an opposite effect. The free radical scavenging thiol antioxidant N-acetylcysteine (NAC) alleviated partially JNK-1 activation in amino acid-deprived cells. The data indicate that activation of JNK-1 by long-term amino acid deprivation may be mediated in part by oxidative stress.


Asunto(s)
Aminoácidos/deficiencia , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Acetilcisteína/farmacología , Activación Enzimática , Depuradores de Radicales Libres/farmacología , Células HeLa , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos , Estrés Oxidativo , Pruebas de Precipitina , Especificidad por Sustrato , Factores de Tiempo , Proteínas Quinasas p38 Activadas por Mitógenos
11.
J Neuropathol Exp Neurol ; 55(8): 904-14, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8759780

RESUMEN

1,25-dihydroxyvitamin D3 (1,25-D3) is already known to prevent clinical signs of experimental allergic encephalomyelitis when animals are treated during the immunization phase. In the present work we have evaluated the ability of 1,25-D3 to inhibit chronic relapsing experimental allergic encephalomylitis (EAE) of the Lewis rat, when administered after the beginning of clinical signs. We observed a significant clinical improvement in 1,25-D3-treated rats. This effect was accompanied by a profound inhibition of CD4 antigen expression by central nervous system (CNS) infiltrating monocytes/macrophages and parenchymal microglia. In addition, immunohistochemical analysis performed at the time of the second attack evidenced a region-specific distribution of inflammatory cells. In the same way, some aspects of the effects exerted by 1,25-D3 appeared to vary depending on the region considered, namely spinal cord, brainstem, cerebellum, midbrain or anterior brain. Thus, in 1,25-D3-treated rats, we observed an almost complete inhibition of CD4 antigen expression in the granule cell layer and the adjacent white matter of the cerebellum as well as a marked decrease in the number of OX42-positive cells (macrophages and activated microglia) in anterior brain sections. We conclude that 1,25-D3 can exert immunomodulatory effects inside the CNS during an ongoing immune process and may thus represent a promising therapy for multiple sclerosis.


Asunto(s)
Calcitriol/farmacología , Sistema Nervioso Central/efectos de los fármacos , Encefalomielitis Autoinmune Experimental/fisiopatología , Animales , Calcifediol/farmacología , Sistema Nervioso Central/metabolismo , Encefalomielitis Autoinmune Experimental/metabolismo , Femenino , Inmunohistoquímica/métodos , Ratas , Ratas Endogámicas Lew , Coloración y Etiquetado
12.
FEBS Lett ; 166(1): 104-8, 1984 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-6363124

RESUMEN

Sera raised against the alpha-, beta- and gamma-subunits of the mouse 7 S NGF were used to characterize translation products coded by submaxillary gland mRNAs microinjected into Xenopus oocytes. Anti-beta NGF sera did not cross-react with any material. In contrast, the precursors of the alpha- and gamma-subunits, as well as that of renin were identified. Use of tunicamycin, and a comparison of the translation products obtained in oocytes or in the reticulocyte lysate indicated that oocytes achieved the cleavage of signal sequences, the glycosylation of the alpha- and gamma-precursors, and the subsequent secretion of the 3 proteins. In the submaxillary gland, however, the mature forms of alpha NGF, gamma NGF and renin are composed of peptides of smaller size than those produced by the oocytes. These latter appear to lack specific proteases involved in the terminal processing of the submaxillary gland proteins.


Asunto(s)
Factores de Crecimiento Nervioso/biosíntesis , Renina/biosíntesis , Animales , Femenino , Sustancias Macromoleculares , Ratones , Peso Molecular , Factores de Crecimiento Nervioso/genética , Oocitos , Precursores de Proteínas/metabolismo , Procesamiento Proteico-Postraduccional , Reticulocitos , Glándula Submandibular/fisiología , Xenopus laevis
13.
FEBS Lett ; 189(1): 37-41, 1985 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-3839757

RESUMEN

Mouse L cells synthesize and secrete a neurotrophic factor related to the beta subunit of the submaxillary gland nerve growth factor (NGF) of male mice. Use of a cDNA probe which encodes the beta-NGF mRNA demonstrated that L cells produce a transcript identical in size to that of the submaxillary gland. Moreover, target sites of restriction enzymes EcoRI, PstI and BamHI were not significantly rearranged in the beta-NGF gene locus of these cells. The abundance of the beta-NGF transcript was found to depend on culture conditions. Removal of serum depressed the cellular content of polyadenylated RNA by a factor of 1.7, and decreased specifically the pool of beta-NGF transcript by an additional factor of 4. The presence of 10(-7) M testosterone in the serum-free medium did not modify the level of beta-NGF mRNA, while addition of 10(-7) M T3 (or T4) increased this level by a factor of 1.5. These data provide the first evidence that the beta-NGF mRNA of L cells is subjected to regulation, but in a way apparently different from that described for the submaxillary gland.


Asunto(s)
Sangre , Factores de Crecimiento Nervioso/genética , ARN Mensajero/metabolismo , Tiroxina/farmacología , Triyodotironina/farmacología , Animales , ADN/análisis , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Masculino , Ratones , Testosterona/farmacología , Transcripción Genética
14.
FEBS Lett ; 262(1): 42-4, 1990 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-2318311

RESUMEN

The rise of the NGF mRNA pool which takes place following exposure of L-929 fibroblasts to serum was prevented in the presence of 5 microM K-252a, a compound which inhibits several species of protein kinase activities. To characterize further this phenomenon, L-929 cells growing in a serum-free medium were exposed to cyclic nucleotide analogs, to a divalent cation ionophore or to the phorbol ester PMA. Only this latter compound induced an enhancement of the NGF mRNA pool, suggesting an involvement of protein kinase C in the upregulation of the NGF transcripts. The effects of PMA or serum also require a synthesis of protein since the level of NGF transcripts remained stable in the presence of cycloheximide.


Asunto(s)
Expresión Génica/efectos de los fármacos , Factores de Crecimiento Nervioso/genética , Acetato de Tetradecanoilforbol/farmacología , Animales , Fenómenos Fisiológicos Sanguíneos , Carbazoles/farmacología , Fibroblastos/metabolismo , Alcaloides Indólicos , Ratones , Biosíntesis de Proteínas , Proteína Quinasa C/fisiología , ARN Mensajero/análisis
15.
FEBS Lett ; 266(1-2): 183-6, 1990 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-2194838

RESUMEN

The isozyme A of L-2-hydroxyacid oxidase is a peroxisomal flavoenzyme that catalyzes the oxidation of short-chain aliphatic L-2-hydroxyacids in many tissues of higher organisms. A new purification procedure allowed us to obtain a 1400-fold purified enzyme from chicken liver. The N-terminal amino acid of the polypeptide chain was found to be blocked as that of spinach glycolate oxidase, contrastingly with that of rat kidney isozyme B. Its amino acid composition was comparable to that of other known L-2-hydroxyacid oxidases. Despite different substrate specificity, some immunological identity was observed between chicken liver L-2-hydroxyacid isozyme A and rat kidney isozyme B.


Asunto(s)
Oxidorreductasas de Alcohol/aislamiento & purificación , Hígado/enzimología , Oxidorreductasas de Alcohol/inmunología , Oxidorreductasas de Alcohol/metabolismo , Aminoácidos/análisis , Animales , Western Blotting , Pollos , Cinética , Metionina/análogos & derivados , Metionina/metabolismo , Microcuerpos/enzimología , Peso Molecular
16.
FEBS Lett ; 436(1): 6-10, 1998 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-9771884

RESUMEN

delta9-Tetrahydrocannabinol (THC), the major active component of marijuana, induced apoptosis in C6.9 glioma cells, as determined by DNA fragmentation and loss of plasma membrane asymmetry. THC stimulated sphingomyelin hydrolysis in C6.9 glioma cells. THC and N-acetylsphingosine, a cell-permeable ceramide analog, induced apoptosis in several transformed neural cells but not in primary astrocytes or neurons. Although glioma C6.9 cells expressed the CBI cannabinoid receptor, neither THC-induced apoptosis nor THC-induced sphingomyelin breakdown were prevented by SR141716, a specific antagonist of that receptor. Results thus show that THC-induced apoptosis in glioma C6.9 cells may rely on a CBI receptor-independent stimulation of sphingomyelin breakdown.


Asunto(s)
Apoptosis/efectos de los fármacos , Dronabinol/farmacología , Glioma/tratamiento farmacológico , Receptores de Droga/efectos de los fármacos , Esfingomielinas/metabolismo , Animales , Astrocitos/efectos de los fármacos , Línea Celular Transformada , Glioma/patología , Hidrólisis , Neuronas/efectos de los fármacos , Piperidinas/farmacología , Pirazoles/farmacología , Ratas , Receptores de Cannabinoides , Receptores de Droga/antagonistas & inhibidores , Receptores de Droga/metabolismo , Rimonabant , Células Tumorales Cultivadas
17.
FEBS Lett ; 364(3): 301-4, 1995 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-7758586

RESUMEN

Addition of phosphatidylcholine-hydrolyzing phospholipase C (PC-PLC) to cultured glial cells increased the levels of nerve growth factor (NGF) mRNA and the amount of cell-secreted NGF. The effect of PC-PLC was 2.5 times higher than that elicited by 4 beta-phorbol 12 beta-myristate 13 alpha-acetate. In cells in which protein kinase C (PKC) was fully inhibited or downregulated, the effect of PC-PLC was reduced-though still evident-and similar to that exerted by sphingosine. Results thus indicate that PC-PLC induces the synthesis of NGF by glial cells by a PKC-dependent and PKC-independent mechanisms.


Asunto(s)
Factores de Crecimiento Nervioso/biosíntesis , Neuroglía/metabolismo , Fosfatidilcolinas/metabolismo , Fosfolipasas de Tipo C/farmacología , Animales , Northern Blotting , Encéfalo/citología , Células Cultivadas , Activación Enzimática/efectos de los fármacos , Hidrólisis , Factores de Crecimiento Nervioso/genética , Proteína Quinasa C/metabolismo , ARN Mensajero/biosíntesis , Ratas , Esfingosina/farmacología , Acetato de Tetradecanoilforbol/farmacología , Fosfolipasas de Tipo C/metabolismo
18.
FEBS Lett ; 203(1): 82-6, 1986 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-3720959

RESUMEN

A chicken gene cross-hybridizing with a murine beta-nerve growth factor (beta NGF) cDNA probe was identified by Southern blot analysis and isolated from a genomic DNA library. The DNA sequence coding for the putative mature beta NGF protein was determined, providing direct evidence for the existence in birds of a neurotrophic factor sharing a high degree of sequence homology with mammalian beta NGF. In addition this gene is shown to be transcriptionally active in adult avian brain as demonstrated by Northern blot analysis.


Asunto(s)
Encéfalo/fisiología , Factores de Crecimiento Nervioso/genética , Animales , Secuencia de Bases , Pollos/genética , Clonación Molecular , Coturnix/genética , Genes , Homología de Secuencia de Ácido Nucleico , Transcripción Genética
19.
Mech Ageing Dev ; 101(1-2): 153-66, 1998 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-9593321

RESUMEN

In mammalian DNA cytosine methylation occurs specifically at CpG dinucleotide. Although the full array of function of DNA methylation is yet to be elucidated, it is well established that DNA methylation is an important mechanism involved in gene expression, DNA replication and cancer. Rat glioma C6.9 cells undergo programmed cell death (PCD) after treatment with 1,25-dihydroxyvitamin D3 (1,25-D3). Hence, these cells were used to study whether DNA methylation was involved in the control of PCD. We found that 1,25-D3-mediated PCD of C6.9 cells was suppressed by exposure of the cells to the DNA demethylating agents 5-azacytidine (5-AzaC) and 5-aza-2'-deoxycytidine. This effect remains detectable several cell divisions following removal of 5-AzaC and, therefore, involves DNA methylation as an epigenetic regulatory mechanism of PCD. Accordingly, internucleosomal fragmentation, a feature of apoptosis that is detected in 1,25-D3-treated cells, is no longer observable after treatment of these cells with 5-AzaC. However, 5-AzaC does not totally suppress the responsiveness of C6.9 cells to 1,25-D3 since the induction of the c-myc gene remains unaffected. These results suggest that a change in DNA methylation pattern could suppress 1,25-D3-mediated PCD through the expression of previously hypermethylated genes such as proto-oncogenes with death-repressor activity, endogenous virus sequences or even genes inducing change in the differentiated state of these cells.


Asunto(s)
Apoptosis , Azacitidina/farmacología , Calcitriol/farmacología , Metilasas de Modificación del ADN/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Animales , Azacitidina/análogos & derivados , Fragmentación del ADN , Decitabina , Genes myc , Glioma , Ratas , Esfingosina/análogos & derivados , Esfingosina/farmacología , Células Tumorales Cultivadas
20.
Cancer Lett ; 100(1-2): 3-10, 1996 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-8620449

RESUMEN

1 alpha,25-Dihydroxyvitamin D3 (1 alpha,25(OH)2D3) has recently been reported to exert a toxic effect on both rat and human glioma cell lines. However the potential clinical use of 1 alpha,25(OH)2D3 in the treatment of glioma is impaired by its potent hypercalcemic effects. We have therefore investigated the effects on glioma cell growth of several vitamin D3 analogues which have previously been shown to be less calcemic in vivo than 1 alpha,25(OH)2D3. The present study shows that several analogues are able to induce, in vitro, the death of rat glioma cells (C6.9). The compound KH 1060 appears to be the most effective in the induction of cell death, while MC 1288 and CB 1093 are as potent as 1 alpha,25(OH)2D3. EB 1089 was somewhat less effective than 1 alpha,25(OH)2D3 and MC 903, which is currently used in the treatment of psoriasis, has only a weak activity on C6.9 cells. The effective doses used are around 10(-9) M for 1 alpha,25(OH)2D3 and 10(-10) M for KH 1060. Interestingly, the toxic effect exerted by 1 alpha,25(OH)2D3 and its analogues is accompanied by several of the biochemical features of apoptosis, such as DNA fragmentation and induction of the c-myc protooncogene. These findings, together with the fact that the therapies currently available for glioma are only palliative, suggest that 1 alpha,25(OH)2D3 analogues such as KH 1060, EB 1089 or CB 1093, alone or in combination with other therapeutic approaches, could be of potential interest in the treatment of brain glial tumors.


Asunto(s)
Calcitriol/farmacología , Colecalciferol/análogos & derivados , Glioma/tratamiento farmacológico , Animales , Calcitriol/toxicidad , Calcio/metabolismo , Muerte Celular/efectos de los fármacos , Colecalciferol/farmacología , Daño del ADN , ADN de Neoplasias/efectos de los fármacos , ADN de Neoplasias/genética , Ensayos de Selección de Medicamentos Antitumorales , Expresión Génica , Genes myc , Glioma/metabolismo , Homeostasis/efectos de los fármacos , Hipercalcemia/inducido químicamente , Ratas , Sales de Tetrazolio , Tiazoles , Células Tumorales Cultivadas
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