Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 73
Filtrar
1.
Dig Liver Dis ; 2023 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-37586908

RESUMEN

BACKGROUND: The optimal strategy for second-line (IIL) treatment in KRAS wt metastatic colorectal cancer (mCRC) is not determined yet. METHODS: A random-effect NMA of phase II/III RCTs was conducted to evaluate IIL treatment for all-RAS wt mCRC, comparing anti-EGFR or anti-VEGF, and chemotherapy (CT). RESULTS: Overall, 11 RCTs (3613 patients) were included. In KRAS wt patients, PFS was improved with anti-VEGF (HR 0.43) and anti-EGFR (HR 0.63) vs CT. However, anti-VEGF based therapy had the highest likelihood of being ranked as the best treatment in terms of PFS (SUCRA 99.3%) and OS (SUCRA 99.4%). Bevacizumab-based treatment is most likely to be the best treatment in terms of PFS (SUCRA 89.1%) and OS (SUCRA 86.7%). CONCLUSIONS: Second line treatment with anti-VEGF and anti-EGFR improved PFS in mCRC patients, however, anti-VEGF based therapy, particularly CT plus bevacizumab, is the best treatment according to SUCRA in terms of PFS and OS.

2.
Alerg. inmunol. clin ; 39(1-2): 36-40, 2020.
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1141123

RESUMEN

Se presenta un caso clínico con el objetivo de dar a conocer una genodermatosis de baja frecuencia, enfermedad de Darier, que se presentó concomitantemente a una síflis tardía, que al ser tratada con penicilina, provocó una reacción adversa a la misma.

3.
Respir Med Case Rep ; 19: 150-154, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27752465

RESUMEN

The diagnosis of sarcoidosis in a patient living with HIV infection is an uncommon event and a challenge for clinicians. Clinical manifestations are variable and fluctuating depending to adherence to ARV therapy and to the level of CD4 count. We analyze here one chronic case in which sarcoidosis appeared clinically two years after pulmonary tuberculosis. The course of the disease was influenced and prolonged by frequent interruptions of antiretroviral therapy. Moreover the diagnosis and the decision to treat have been delayed by the need of exclusion of other pathologies, principally tuberculosis reactivation/reinfection, other mycobacterial diseases, hematologic malignancies. We propose a simplified flowchart for diagnosis and follow up of sarcoidosis, which may also be applied to patients with HIV infection. Diagnosis of latent tuberculosis infection (LTBI) may be difficult in these patients, because the immunological paradox of sarcoidosis. For this reason, following exclusion of active tuberculosis, we advise to submit all sarcoidosis patients to IPT (isoniazid preventive therapy), when immunosuppressive therapy is started.

4.
J Hosp Infect ; 93(4): 355-9, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27125664

RESUMEN

Few data are available on the determinants and characteristics of post-caesarean section (CS) surgical site infections (SSIs) in resource-limited settings. We conducted a prospective observational cohort study to evaluate the rates, determinants, and microbiological characteristics of post-CS SSI at the Dodoma Regional Referral Hospital (DRRH) Gynaecology and Obstetrics Department in Tanzania. Spanning a three-month period, all pregnant women who underwent CS were enrolled and followed up for 30 days. SSI following CS occurred in 224 (48%) women. Only 10 (2.1%) women received pre-incision antibiotic prophylaxis. Urgent intervention is needed to prevent and control infections and contain the rising rate of post-CS SSI at the DRRH.


Asunto(s)
Cesárea/efectos adversos , Infección de la Herida Quirúrgica/epidemiología , Adulto , Profilaxis Antibiótica/estadística & datos numéricos , Femenino , Humanos , Embarazo , Estudios Prospectivos , Tanzanía/epidemiología , Centros de Atención Terciaria , Adulto Joven
5.
Mater Sci Eng C Mater Biol Appl ; 53: 15-22, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26042685

RESUMEN

In this work, we present new nanocomposite materials derived from segmented copolyesters, comprising ethylene terephthalate (PET) segments and dimerized linoleic acid (DLA), and nanometric cerium oxide particles (CeO2). Nanoparticles were incorporated in situ during polycondensation in various concentrations, from 0.1 up to 0.6 wt.%. It was found that preparation of nanocomposites in situ, during polycondensation, had no significant influence on changes in segmental composition as determined from (1)H and (13)C, as well as 2D NMR. Thermal analysis and calculated degree of crystallinity showed that increasing concentration of ceria nanoparticles lead to an increase in mass content of PET crystallites in hard segments. The XRD investigations also showed an increased intensity of characteristic signals with increasing ceria concentration. Simultaneously, the incorporation of CeO2 led to an increase in tensile strength and elongation at break, indicating a reinforcing and plasticizing effect of ceria nanoparticles. However, the modulus at 10% strain decreased with increasing amount of nanoparticles. The in vitro culture of human cardiac progenitor cells (hCPCs) on the new materials indicated a homogenous cell displacement across the samples after 5 days with no signs of cytotoxicity, indicating good biocompatibility in vitro of CeO2-based nanocomposites and a potential for biomedical applications.


Asunto(s)
Materiales Biocompatibles/química , Cerio/química , Nanopartículas del Metal/química , Nanocompuestos/química , Poliésteres/química , Anciano , Anciano de 80 o más Años , Materiales Biocompatibles/toxicidad , Forma de la Célula/efectos de los fármacos , Células Cultivadas , Cerio/toxicidad , Femenino , Humanos , Masculino , Nanopartículas del Metal/toxicidad , Persona de Mediana Edad , Nanocompuestos/toxicidad , Poliésteres/toxicidad , Viscosidad
6.
Infection ; 41(4): 863-5, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23553281

RESUMEN

Artemisinin and its derivatives are essential components of artemisinin-based combination therapies for treating severe falciparum malaria. In this paper, we describe the occurrence of haemolysis after oral artemether-lumefantrine treatment. To the best of our knowledge, this is the second reported case of a patient affected by severe falciparum malaria with haemolytic anaemia that is likely associated with oral artemether-lumefantrine treatment.


Asunto(s)
Anemia Hemolítica/inducido químicamente , Antimaláricos/efectos adversos , Artemisininas/efectos adversos , Etanolaminas/efectos adversos , Fluorenos/efectos adversos , Malaria Falciparum/tratamiento farmacológico , Administración Oral , Antimaláricos/administración & dosificación , Combinación Arteméter y Lumefantrina , Artemisininas/administración & dosificación , Combinación de Medicamentos , Etanolaminas/administración & dosificación , Fluorenos/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad
7.
J Biomed Biotechnol ; 2009: 910610, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19644551

RESUMEN

An immortalized murine mesenchymal stem cell line (mTERT-MSC) enriched for Lin(neg)/Sca-1(pos) fraction has been obtained through the transfection of MSC with murine TERT and single-cell isolation. Such cell line maintained the typical MSC self-renewal capacity and continuously expressed MSC phenotype. Moreover, mTERT-MSC retained the functional features of freshly isolated MSC in culture without evidence of senescence or spontaneous differentiation events. Thus, mTERT-MSC have been cultured onto PLA films, 30 and 100 microm PLA microbeads, and onto unpressed and pressed HYAFF-11 scaffolds. While the cells adhered preserving their morphology on PLA films, clusters of mTERT-MSC were detected on PLA beads and unpressed fibrous scaffolds. Finally, mTERT-MSC were not able to colonize the inner layers of pressed HYAFF-11. Nevertheless, such cell line displayed the ability to preserve Sca-1 expression and to retain multilineage potential when appropriately stimulated on all the scaffolds tested.


Asunto(s)
Antígenos Ly/metabolismo , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Proteínas de la Membrana/metabolismo , Células Madre Mesenquimatosas/metabolismo , Andamios del Tejido/química , Animales , Apoptosis/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Línea Celular Transformada , Linaje de la Célula/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Citoprotección/efectos de los fármacos , Peróxido de Hidrógeno/farmacología , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Ratones , Estrés Oxidativo/efectos de los fármacos , Fenotipo , Polímeros/química , Telomerasa/metabolismo , Transducción Genética
8.
J Fish Biol ; 75(6): 1144-57, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20738605

RESUMEN

The body shapes of both wild-caught and laboratory-reared male and female Trinidadian guppies Poecilia reticulata from two low-predation and two high-predation populations were studied, but predation regime did not seem to be the most important factor affecting body shape. Instead, complicated patterns of plasticity in body shape among populations and the sexes were found. In particular, populations differed in the depth of the caudal peduncle, which is the muscular region just anterior to the tail fin rays and from which most swimming power is generated. Strikingly, the direction of population differences in caudal peduncle depth observed in wild-caught individuals was reversed when P. reticulata were raised in a common laboratory environment.


Asunto(s)
Fenotipo , Poecilia/anatomía & histología , Poecilia/fisiología , Conducta Predatoria/fisiología , Animales , Animales Salvajes/anatomía & histología , Animales Salvajes/fisiología , Ambiente , Femenino , Variación Genética , Masculino , Poecilia/genética , Factores Sexuales , Movimientos del Agua
9.
Regul Pept ; 148(1-3): 26-32, 2008 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-18410972

RESUMEN

Brain Natriuretic Peptide (BNP), besides retaining vasodilatory, diuretic and natriuretic properties, is a vasoactive hormone that it is also involved in several cardiac diseases as well as severe sepsis and septic shock. All these conditions are characterized by an ongoing inflammatory response consisting in a complex interaction of pleiotropic mediators derived from plasma or cells, including monocytes and macrophages. However, the relationship between this hormone and inflammation remains to be elucidated. Therefore, the aim of the present study was to evaluate a possible BNP immunomodulatory activity on macrophages. Our results demonstrate that BNP regulates the production of major inflammatory molecules, such as reactive oxygen- and nitrogen species (ROS and RNS), leukotriene B(4) (LTB(4)), prostaglandin E(2) (PGE(2)); modulates the cytokines (TNF-alpha, IL-12 and IL-10) profile, and affects cell motility. These results furnish novel and brand-new proofs on BNP ability of modulating the production of inflammatory mediators in macrophages whose role has broad implications in inflammatory states where increased BNP levels have been reported.


Asunto(s)
Mediadores de Inflamación/metabolismo , Macrófagos/efectos de los fármacos , Péptido Natriurético Encefálico/farmacología , Ácido Araquidónico/metabolismo , Línea Celular , Movimiento Celular/efectos de los fármacos , Dinoprostona/metabolismo , Ensayo de Inmunoadsorción Enzimática , Humanos , Interleucina-10/metabolismo , Interleucina-12/metabolismo , Leucotrieno B4/metabolismo , Macrófagos/citología , Macrófagos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
10.
Inflammation ; 30(5): 167-77, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17594136

RESUMEN

Excessive leukocyte proliferation and proinflammatory mediators release represent common phenomena in several chronic inflammatory diseases. Multiple evidences identify lysophosphatidic acid (LPA), a small lipid endowed with pleiotropic activities, as an important modulator of both proliferation and activation of different cell types involved in several inflammation-associated pathologies. However, its possible role on monocyte proinflammatory activation is not fully understood yet. Aim of the present study was to investigate LPA effects on THP-1 cells in terms of proliferation, reactive oxygen intermediates (ROI) production and release of arachidonic acid-derived inflammatory mediators. Actually, LPA significantly increased both DNA synthesis and ROI production as well as prostaglandin E(2) release and the upregulation of LPA(3) receptor expression. These findings identified LPA as both a growth factor and a triggering mediator of proinflammatory response in THP-1 cells.


Asunto(s)
Ácido Araquidónico/metabolismo , Proliferación Celular , Mediadores de Inflamación/metabolismo , Lisofosfolípidos/metabolismo , Monocitos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Línea Celular , Proliferación Celular/efectos de los fármacos , Replicación del ADN , Dinoprostona/metabolismo , Activación Enzimática , Humanos , Inflamación/metabolismo , Isoxazoles/farmacología , Leucotrieno B4/metabolismo , Monocitos/efectos de los fármacos , NADPH Oxidasas/metabolismo , Propionatos/farmacología , ARN Mensajero/metabolismo , Receptores del Ácido Lisofosfatídico/antagonistas & inhibidores , Receptores del Ácido Lisofosfatídico/genética , Receptores del Ácido Lisofosfatídico/metabolismo , Factores de Tiempo , Regulación hacia Arriba
11.
Rev Med Suisse ; 2(78): 2024-6, 2029-34, 2006 Sep 13.
Artículo en Francés | MEDLINE | ID: mdl-17019837

RESUMEN

The management of hypertension in Switzerland follows the Guidelines of the European Society of Hypertension and Cardiology (ESH-ESC 2003). The aim of our survey was to evaluate to what extent initial check-up and determination of the absolute cardiovascular risk of hypertensive patients are performed by residents of a medical outpatient clinic. Hypertension is a very frequent condition in this kind of consultation, 1 patient in 3 being treated for a high blood pressure. Despite of this, the initial evaluation of the absolute cardiovascular risk is not performed in accordance with the guidelines. The assessment of diabetes or dyslipidemia and the search for target organ damage are not systematically done, even in case of high blood pressure values (grade I-III).


Asunto(s)
Antihipertensivos/uso terapéutico , Hipertensión/tratamiento farmacológico , Atención Primaria de Salud , Anciano , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/prevención & control , Diuréticos/uso terapéutico , Quimioterapia Combinada , Estudios de Evaluación como Asunto , Femenino , Adhesión a Directriz , Encuestas de Atención de la Salud , Humanos , Hipertensión/complicaciones , Hipertensión/dietoterapia , Hipertensión/epidemiología , Internado y Residencia , Masculino , Persona de Mediana Edad , Guías de Práctica Clínica como Asunto , Prevalencia , Medición de Riesgo , Factores de Riesgo , Sociedades Médicas , Suiza/epidemiología
12.
Mol Cell Biochem ; 272(1-2): 19-28, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16010968

RESUMEN

Lysophosphatidic acid (LPA) is a lipid mediator with multiple biological functions. In the present study we investigated the possible role of atrial natriuretic peptide (ANP), a hormone affecting cardiovascular homeostasis and inducing antimitogenic effects in different cell types, on LPA-induced cell growth and reactive oxygen species (ROS) production in rat aortic smooth muscle (RASM) cells. Both LPA effects on cell growth and levels of ROS were totally abrogated by physiological concentrations of ANP, without modifying the overexpression of LPA-receptors. These effects were also affected by cell pretreatment with wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3K). Moreover, the LPA-induced activation of Akt, a downstream target of PI3K, was completely inhibited by physiological concentrations of ANP, which were also able to inhibit p42/p44 phosphorylation. Taken together, our data suggest that PI3K may represent an important step in the LPA signal transduction pathway responsible for ROS generation and DNA synthesis in RASM cells. At same time, the enzyme could also represent an essential target for the antiproliferative effects of ANP.


Asunto(s)
Factor Natriurético Atrial/fisiología , Lisofosfolípidos/antagonistas & inhibidores , Músculo Liso Vascular/efectos de los fármacos , Androstadienos/farmacología , Animales , Aorta/citología , Factor Natriurético Atrial/farmacología , Células Cultivadas , Replicación del ADN/efectos de los fármacos , Activación Enzimática , Lisofosfolípidos/farmacología , Masculino , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Músculo Liso Vascular/citología , Músculo Liso Vascular/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Fosforilación , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/agonistas , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-akt , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Receptores del Ácido Lisofosfatídico/genética , Receptores del Ácido Lisofosfatídico/metabolismo , Transducción de Señal , Wortmanina
13.
Inflammation ; 29(4-6): 129-40, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17089191

RESUMEN

Excessive leukocyte proliferation and proinflammatory mediators release represent common phenomena in several chronic inflammatory diseases. Multiple evidences identify lysophosphatidic acid (LPA), a small lipid endowed with pleiotropic activities, as an important modulator of both proliferation and activation of different cell types involved in several inflammation-associated pathologies. However, its possible role on monocyte proinflammatory activation is not fully understood yet. Aim of the present study was to investigate LPA effects on THP-1 cells in terms of proliferation, reactive oxygen intermediates (ROI) production and release of arachidonic acid-derived inflammatory mediators. Actually, LPA significantly increased both DNA synthesis and ROI production as well as prostaglandin E(2) release and the upregulation of LPA(3) receptor expression. These findings identified LPA as both a growth factor and a triggering mediator of proinflammatory response in THP-1 cells.


Asunto(s)
Lisofosfolípidos/farmacología , Monocitos/citología , Monocitos/metabolismo , Ácido Araquidónico/metabolismo , División Celular/efectos de los fármacos , Línea Celular , Dinoprostona/metabolismo , Relación Dosis-Respuesta a Droga , Activación Enzimática/efectos de los fármacos , Humanos , Mediadores de Inflamación/metabolismo , Isoxazoles/farmacología , Leucotrieno B4/metabolismo , Lisofosfolípidos/administración & dosificación , Monocitos/efectos de los fármacos , NADPH Oxidasas/metabolismo , Propionatos/farmacología , Especies Reactivas de Oxígeno/metabolismo , Receptores de Superficie Celular/metabolismo
15.
J Lipid Res ; 45(2): 308-16, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14563831

RESUMEN

Fatty acid synthetase (FAS) is overexpressed in various tumor tissues, and its inhibition and/or malonyl-CoA accumulation have been correlated to apoptosis of tumor cells. It is widely recognized that both omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) depress FAS expression in liver, although epidemiological and experimental reports attribute antitumor properties only to omega-3 PUFA. Therefore, we investigated whether lipogenic gene expression in tumor cells is differently regulated by omega-6 and omega-3 PUFAs. Morris hepatoma 3924A cells were implanted subcutaneously in the hind legs of ACI/T rats preconditioned with high-lipid diets enriched with linoleic acid or alpha-linolenic acid. Both-high lipid diets depressed the expression of FAS and acetyl-CoA carboxylase in tumor tissue, this effect correlating with a decrease in the mRNA level of their common sterol regulatory element binding protein-1 transcription factor. Hepatoma cells grown in rats on either diet did not accumulate malonyl-CoA. Apoptosis of hepatoma cells was induced by the alpha-linolenic acid-enriched diet but not by the linoleic acid-enriched diet. Therefore, in this experimental model, apoptosis is apparently independent of the inhibition of fatty acid synthesis and of malonyl-CoA cytotoxicity. Conversely, it was observed that apoptosis induced by the alpha-linolenic acid-enriched diet correlated with a decrease in arachidonate content in hepatoma cells and decreased cyclooxygenase-2 expression.


Asunto(s)
Apoptosis/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Isoenzimas/genética , Neoplasias Hepáticas Experimentales/patología , Prostaglandina-Endoperóxido Sintasas/genética , Ácido alfa-Linolénico/administración & dosificación , Acetil-CoA Carboxilasa/genética , Acetil-CoA Carboxilasa/metabolismo , Animales , Apoptosis/genética , Proteínas Potenciadoras de Unión a CCAAT/genética , Ciclooxigenasa 2 , Dieta , Grasas Insaturadas en la Dieta , Regulación hacia Abajo/genética , Ácido Graso Sintasas/genética , Ácido Graso Sintasas/metabolismo , Ácidos Grasos Omega-6/genética , Ácidos Grasos Omega-6/metabolismo , Ácidos Grasos Insaturados/genética , Ácidos Grasos Insaturados/metabolismo , Isoenzimas/biosíntesis , Neoplasias Hepáticas Experimentales/tratamiento farmacológico , Neoplasias Hepáticas Experimentales/genética , Neoplasias Hepáticas Experimentales/metabolismo , Prostaglandina-Endoperóxido Sintasas/biosíntesis , Ratas , Ácido alfa-Linolénico/metabolismo
16.
Mol Cell Biochem ; 252(1-2): 353-62, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-14577610

RESUMEN

The aim of this study was to investigate the effects of oxidative stress on PLD activity, [Ca2+]i and pHi levels and the possible relationship among them. Moreover, since atrial natriuretic peptide (ANP) protects against oxidant-induced injury, we investigated the potential protective role of the hormone in rat aortic smooth muscle (RASM) cells exposed to oxidative stress. Water-soluble 2,2'-Azobis (2-amidinopropane) dihydrochloride (AAPH) was used as free radical generating system, since it generates peroxyl radicals with defined reaction and the half time of peroxyl radicals is longer than other ROS. A significant increase of PLD activity was related to a significant decrease in pHi, while [Ca2+]i levels showed an increase followed by a decrease after cell exposure to AAPH. [Ca2+]i changes and pHi fall induced by AAPH were prevented by cadmium which inhibits a plasma membrane Ca2+ ATPase coupled to Ca2+/H+ exchanger, that operates the efflux of Ca2+ coupled to H+ influx. The involvement of PLD in pHi and [Ca2+]i changes was confirmed by calphostin-c treatment, a potent inhibitor of PLD, which abolished all AAPH-induced effects. Pretreatment of RASM cells with pharmacological concentrations of ANP attenuated the AAPH effects on PLD activity as well as [Ca2+]i and pHi changes, while no effects were observed with physiological ANP concentrations, suggesting a possible role of the hormone as defensive effector against early events of the oxidative stress.


Asunto(s)
Aorta/metabolismo , Factor Natriurético Atrial/fisiología , Calcio/metabolismo , Concentración de Iones de Hidrógeno , Músculo Liso Vascular/metabolismo , Oxidantes/farmacología , Animales , Aorta/citología , Aorta/enzimología , Cromatografía en Capa Delgada , Masculino , Músculo Liso Vascular/citología , Músculo Liso Vascular/enzimología , Fosfolipasa D/metabolismo , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno
17.
Carcinogenesis ; 24(10): 1625-35, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12869421

RESUMEN

The expression of many cellular genes is modulated by DNA methylation and histone acetylation. These processes can influence malignant cell transformation and are also responsible for the silencing of DNA constructs introduced into mammalian cells for therapeutic or research purposes. As a better understanding of these biological processes may contribute to the development of novel cancer treatments and to study the complex mechanisms regulating gene silencing, we established a cellular system suitable to dissect the mechanisms regulating DNA methylation and histone acetylation. For this purpose, we stably transfected the neuroblastoma cell line U87 with a cytomegalovirus promoter-driven reporter gene construct whose expression was analyzed following treatment with the DNA methylation inhibitor 5'-aza-2'-deoxycytidine or histone deacetylation inhibitor trichostatin A. Both substances reactivated the silenced cytomegalovirus promoter, but with different reaction kinetics. Furthermore, whereas the kinetics of reactivation by trichostatin A did not substantially change over the time range considered (5 days), reactivation induced by 5'-aza-2'-deoxycytidine showed profound differences between day 1 and longer time points. We showed that this effect is related to the down-regulation of DNA replication by 5'-aza-2'-deoxycytidine. Finally, we have shown that the simultaneous administration of trichostatin A and 5'-aza-2'-deoxycytidine results in reactivation of the CMV promoter according to a cooperative, not synergistic or additive, mechanism. In conclusion, our cellular system should represent a powerful tool to investigate the complex mechanisms regulating gene silencing and to identify new anticancer drugs.


Asunto(s)
Metilación de ADN/efectos de los fármacos , Histonas/efectos de los fármacos , Regiones Promotoras Genéticas/efectos de los fármacos , Animales , Azacitidina/farmacología , Citomegalovirus/genética , Replicación del ADN/efectos de los fármacos , Citometría de Flujo , Regulación Neoplásica de la Expresión Génica , Silenciador del Gen , Glioblastoma , Histona Desacetilasas/farmacología , Humanos , Ácidos Hidroxámicos/farmacología , Microscopía Fluorescente , Modelos Teóricos , Plásmidos/genética , Reacción en Cadena de la Polimerasa , Inhibidores de la Síntesis de la Proteína/farmacología , Factores de Tiempo , Transfección , Células Tumorales Cultivadas
18.
J Lipid Res ; 44(4): 696-704, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12562863

RESUMEN

The hindlimb-suspended rat was used as animal model to investigate the effects induced by immobilization of the skeletal muscle in the expression of the genes encoding hepatic lipogenic enzymes. Following a 14-day period of immobilization, rats were injected intraperitoneally with radioactive acetate, and the labeling of hepatic lipids and cholesterol was evaluated 15 min after the isotope injection. The incorporation of labeled acetate in lipids and cholesterol was almost three times higher in the liver of immobilized rats than in control animals as a consequence of the enhanced transcription of the genes encoding acetyl-CoA synthase, acetyl-CoA carboxylase, fatty acid synthase, and 3-hydroxy-3-methylglutaryl-CoA reductase. The high expression of the key enzymes for fatty acid and cholesterol synthesis induced by immobilization was not paralleled by an increase of the hepatic sterol-regulatory element binding protein (SREBP)-1 and SREBP-2 mRNA content. However, the expression of the mature form of SREBP-1 and SREBP-2 was higher in the nuclear fraction of immobilized rat liver than in controls due to a significant increase of the cleavage of the native proteins. Immobilization also affected the expression of proteins involved in lipid degradation. In fact, the hepatic content of peroxisome proliferator-activated receptor-alpha (PPARalpha) mRNA and of PPARalpha target genes encoding carnitine palmitoyl transferase-1 and acyl-CoA oxidase were significantly increased upon immobilization.


Asunto(s)
Inmovilización/fisiología , Lípidos/biosíntesis , Hígado/enzimología , Acetatos/metabolismo , Animales , Proteínas Potenciadoras de Unión a CCAAT/análisis , Colesterol/biosíntesis , Proteínas de Unión al ADN/análisis , Enzimas/genética , Lípidos/análisis , Hígado/química , Masculino , Modelos Animales , ARN Mensajero/análisis , Ratas , Ratas Wistar , Proteína 1 de Unión a los Elementos Reguladores de Esteroles , Factores de Transcripción/análisis
19.
Life Sci ; 71(20): 2369-81, 2002 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-12231398

RESUMEN

UM-X7.1 hamsters (CH) are considered a representative model for human cardiomyopathy. CH display the loss of the cytoskeletal delta-sarcoglycan protein, associated with myocardium remodeling and fatal reduction of heart functional efficiency. Even though altered redox balance and calcium homeostasis have already been reported to affect cardiomyocyte function, the molecular mechanisms underlying this pathology are largely unknown. We found no significant differences in DNA binding activity of redox-related (NF-kappaB, Sp1, AP-1 and AP-2) transcription factors in heart ventricles of 90 day-old CH, compared to normal animals. On the other hand, DNA binding activity of calcium-dependent transcription factors NF-AT3 and CREB were increased and decreased respectively in CH vs. normal ventricles. Western blot experiments confirmed the down regulation of CREB levels and suggest a novel regulation mechanism for this transcription factor in the heart. Our results are consistent with recent studies on NF-AT3, GATA4 and CREB transgenic mice, and provide clues for the comprehension of pathogenetic mechanisms of hamster hereditary cardiomyopathy.


Asunto(s)
Cardiomiopatías/metabolismo , Proteínas de Unión al ADN/metabolismo , ADN/metabolismo , Factores de Transcripción/metabolismo , Animales , Secuencia de Bases , Northern Blotting , Western Blotting , Calcineurina/metabolismo , Calcio/metabolismo , Cardiomiopatías/genética , Cricetinae , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Cartilla de ADN , Glutatión Peroxidasa/metabolismo , Homeostasis , Mesocricetus , Ratones , Ratones Transgénicos , Unión Proteica , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción/genética , alfa-Tocoferol/metabolismo
20.
J Cell Physiol ; 193(1): 103-9, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12209885

RESUMEN

Atrial natriuretic factor (ANF) is a polypeptide able to affect cardiovascular homeostasis exhibiting diuretic, natriuretic, and vasorelaxant activities. ANF shows antimitogenic effects in different cell types acting through R(2) receptor. Excessive proliferation of smooth muscle cells is a common phenomenon in diseases such as atherosclerosis, but the role of growth factors in the mechanism which modulate this process has yet to be clarified. The potential antimitogenic role of ANF on the cell growth induced by growth factors appears very intriguing. Aim of the present study was to investigate the possible involvement of ANF on rat aortic smooth muscle (RASM) cells proliferation induced by known mitogens and the mechanism involved. Our data show that ANF, at physiological concentration range, inhibits RASM cell proliferation induced by known mitogens such as PDGF and insulin, and the effect seems to be elicited through the modulation of phosphatidic acid (PA) production and MAP kinases involvement.


Asunto(s)
Aorta/efectos de los fármacos , Factor Natriurético Atrial/farmacología , Mitógenos/farmacología , Músculo Liso Vascular/efectos de los fármacos , Antagonistas Adrenérgicos beta/farmacología , Animales , Aorta/citología , Aorta/metabolismo , Atenolol/farmacología , Ciclo Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Células Cultivadas , ADN/biosíntesis , Citometría de Flujo , Insulina/farmacología , Masculino , Músculo Liso Vascular/citología , Músculo Liso Vascular/metabolismo , Ácidos Fosfatidicos/metabolismo , Factor de Crecimiento Derivado de Plaquetas/farmacología , Ratas , Ratas Wistar , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA