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1.
Gen Comp Endocrinol ; 346: 114417, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38030018

RESUMEN

The egg-laying hormones (ELHs) of gastropod mollusks were characterized more than forty years ago. Yet, they have remained little explored in other mollusks. To gain insights into the functionality of the ELH signaling system in a bivalve mollusk - the oyster Crassostrea gigas, this study investigates the processing of its ELH precursor (Cragi-ELH) by mass spectrometry. Some of the ELH mature peptides identified in this study were subsequently investigated by nuclear magnetic resonance and shown to adopt an extended alpha-helix structure in a micellar medium mimicking the plasma membrane. To further characterize the ELH signaling system in C. gigas, a G protein-coupled receptor phylogenetically related to ecdysozoan diuretic hormone DH44 and corticotropin-releasing hormone (CRH) receptors named Cragi-ELHR was also characterized functionally and shown to be specifically activated by the two predicted mature ELH peptides and their N-terminal fragments. Both Cragi-ELH and Cragi-ELHR encoding genes were mostly expressed in the visceral ganglia (VG). Cragi-ELH expression was significantly increased in the VG of both fully mature male and female oysters at the spawning stage. When the oysters were submitted to a nutritional or hyposaline stress, no change in the expression of the ligand or receptor genes was recorded, except for Cragi-ELHR only during a mild acclimation episode to brackish water. These results suggest a role of Cragi-ELH signaling in the regulation of reproduction but not in mediating the stress response in our experimental conditions.


Asunto(s)
Crassostrea , Animales , Masculino , Femenino , Secuencia de Aminoácidos , Crassostrea/genética , Crassostrea/metabolismo , Transducción de Señal , Péptidos/metabolismo , Hormonas/metabolismo
2.
Mar Environ Res ; 66(2): 300-8, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18556058

RESUMEN

Like other sessile filter-feeding molluscs, oysters may be exposed in the natural environment to a variety of contaminants. Long-term exposure to pollutants may be one factor affecting prevalence of cancerous-like disorders, such as neoplasia. Environmentally induced alterations in p53 protein expression, in relation to leukemia, have been reported in various mollusc species inhabiting polluted water, suggesting that p53 proteins can also be used as a marker for environmental research. This work reports the cloning and sequencing of a p53-like cDNA in the mollusc bivalve Crassostreagigas. The deduced amino acid sequences of p53 shared a high degree of homology with the homologues from other mollusc species, including typical eukaryotic p53 signature sequences. We examined the p53 transcription expression pattern during the annual cycle in oyster gills and whole soft tissues in four locations along the French coasts. Real-time PCR analysis suggested that strong variations at p53 mRNA level are probably synchronized with the seasonal cycle at the four locations investigated.


Asunto(s)
Crassostrea/genética , Regulación de la Expresión Génica/efectos de los fármacos , Genes p53/genética , Transcripción Genética/efectos de los fármacos , Contaminantes del Agua/farmacología , Secuencia de Aminoácidos , Animales , Biomarcadores , Clonación Molecular , Crassostrea/metabolismo , ADN Complementario/genética , ADN Complementario/metabolismo , Expresión Génica , Branquias/metabolismo , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , ARN Mensajero/genética , ARN Mensajero/metabolismo , Estaciones del Año , Análisis de Secuencia de Proteína
3.
Dev Comp Immunol ; 31(1): 30-8, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-16820208

RESUMEN

Transforming growth factor-beta (TGF-beta) members represent a widespread protein superfamily in the animal kingdom, but few members have been characterised in lophotrochozoans, a major clade of invertebrates. Here, we report the identification of Crassostrea gigas-TGF-beta (Cg-TGF-beta), a homologue of vertebrate TGF-beta and activin, from the bivalve mollusc C. gigas. Phylogenetic analysis suggests an early ancestral origin of this subgroup of TGF-beta superfamily member. Investigation of the spatio-temporal expression of Cg-TGF-beta gene by real-time quantitative RT-PCR showed a ubiquitous pattern in all adult tissues. These findings imply that Cg-TGF-beta has multiple functions as described for its vertebrate counterparts. Moreover, Cg-TGF-beta was upregulated in haemocytes during infection by a Gram-negative bacterium, suggesting that it could act as a cytokine involved in immunity in molluscs.


Asunto(s)
Crassostrea/inmunología , Regulación de la Expresión Génica/inmunología , Infecciones por Bacterias Gramnegativas/inmunología , Factor de Crecimiento Transformador beta/inmunología , Activinas/genética , Activinas/inmunología , Secuencia de Aminoácidos , Animales , Crassostrea/microbiología , Citocinas/inmunología , Infecciones por Bacterias Gramnegativas/veterinaria , Datos de Secuencia Molecular , Factor de Crecimiento Transformador beta/genética
4.
Biochim Biophys Acta ; 883(3): 407-12, 1986 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-3756207

RESUMEN

Using quantitative fluorimetry with fluoresceinated wheat germ agglutinin, we have been able to investigate in vivo gamma radiation-induced damage at the outer membrane level of rat splenic lymphocytes, namely damage to the glucosidic moieties of membrane glycoproteins and glycolipids. This paper demonstrates that below an irradiation level of 1 gray (Gy), removal of sialic acid is the major feature leading to new exposed specific binding sites for wheat germ agglutinin, since this lectin is specific for sialic acid and N-acetyl-D-glucosamine. Our studies also suggest that above 1 Gy of irradiation more internal damage occurs, since we observed a striking decrease in wheat germ agglutinin binding sites.


Asunto(s)
Linfocitos/efectos de la radiación , Receptores Mitogénicos/efectos de la radiación , Aglutininas del Germen de Trigo/metabolismo , Animales , Membrana Celular/metabolismo , Membrana Celular/efectos de la radiación , Rayos gamma , Linfocitos/metabolismo , Masculino , Ratas , Ratas Endogámicas
5.
Free Radic Biol Med ; 26(11-12): 1457-66, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10401609

RESUMEN

Oxidative DNA damage and its repair in primary rat hepatocyte cultures was investigated following 4 h of incubation with the toxic iron chelate, ferric nitrilotriacetate (Fe-NTA), in the presence or absence of the potent protective flavonoid myricetin (25-50-100 microM). Seven DNA base oxidation products were quantified in DNA extracts by gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring mode. Concomitantly, DNA repair capacity of hepatocytes was estimated by the release of oxidized-base products into culture media, using the same GC-MS method. A genotoxic effect of Fe-NTA (100 microM) in hepatocytes was evidenced by a severe increase in DNA oxidation over basal levels, with accumulation in cellular DNA of five oxidation products derived from both purines and pyrimidines. This prooxidant effect of iron was also noted by an induction of lipid peroxidation, estimated by free malondialdehyde production. Addition of increasing concentrations of myricetin (25-50-100 microM) simultaneously with iron prevented both lipid peroxidation and accumulation of oxidation products in DNA. Moreover, as an activation of DNA repair pathways, myricetin stimulated the release of DNA oxidation bases into culture media, especially of purine-derived oxidation products. This removal of highly mutagenic oxidation products from DNA of hepatocytes might correspond to an activation of DNA excision-repair enzymes by myricetin. This was verified by RNA blot analysis of DNA polymerase beta gene expression which was induced by myricetin in a dose-dependent manner. This represented a novel and original mechanism of cytoprotection by myricetin against iron-induced genotoxicity via stimulation of DNA repair processes. Since iron-induced DNA damage and inefficient repair in hepatocytes could be related to genotoxicity and most probably to hepatocarcinogenesis, modulation of these processes in vitro by myricetin might be relevant in further prevention of liver cancer derived from iron overload pathologies.


Asunto(s)
Daño del ADN , Flavonoides/farmacología , Hierro/farmacología , Hígado/efectos de los fármacos , Animales , Células Cultivadas , Reparación del ADN , Cromatografía de Gases y Espectrometría de Masas , L-Lactato Deshidrogenasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Hígado/citología , Masculino , Malondialdehído/metabolismo , Pruebas de Mutagenicidad , Oxidación-Reducción , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Sprague-Dawley
6.
Appl Biochem Biotechnol ; 14(3): 241-51, 1987 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3631953

RESUMEN

Glutaraldehyde hemoglobin polymerization gives too many high polymers, resulting in a too viscous solution. We describe here an alternate method leading to superior results, as compared to the classical one. This method includes a molecular fractionation step using a tangential flow ultrafiltration that secondarily lowers the unpolymerized tetramer's content of a mildly polymerized, pyridoxylated hemoglobin solution (Pyr-Poly Hb). This leads to an adequately polymerized product with a lesser high polymer content, implying a lower viscosity. We thus obtain a pyridoxylated, polymerized molecular fractionated solution presenting suitable features as a blood substitute: A 7.5 g% hemoglobin 2 g% albumin solution had a 16% unpolymerized tetramer's ratio, a 1.8 mPas viscosity, a P50 of 2.8 kPa, a Hill coefficient of 2.1, a binding coefficient of 1.3 mL/g, a colloid osmotic pressure of 2.4 kPa, and a methemoglobin concentration of 3% Male-Sprague-Dawley rats undergoing an isovolumic blood exchange with this Pyr-Poly Hb solution, down to a 2% hematocrit, present a mean survival time of 20 h.


Asunto(s)
Sustitutos Sanguíneos , Hemoglobinas , Intercambio Plasmático , Fosfato de Piridoxal/análogos & derivados , Animales , Hematócrito , Hemoglobinas/aislamiento & purificación , Masculino , Oxihemoglobinas , Fosfato de Piridoxal/aislamiento & purificación , Ratas , Viscosidad
7.
Arch Mal Coeur Vaiss ; 69(10): 1051-7, 1976 Oct.
Artículo en Francés | MEDLINE | ID: mdl-827998

RESUMEN

A comparison of the "cumulative survival" of 1073 totally sealed cardiac pacemakers with that of 624 unsealed models showed the marked superiority of the former group. Calculation of the "cumulative survival" is not only a method which allows a comparison of technological advantages, but also one which can yield the selective replacement time". This concept has direct implications for clinical practice for, once the "elective replacement time" is known for a particular model, it becomes possible to replace the pacemaker electively without having to wait for it to break down or run out, events which are in any case unpredictable and possibly sudden. Knowledge of the "elective replacement time" will also avoid changes being made too early, which is a source of unnecessary expense for the Social Security.


Asunto(s)
Marcapaso Artificial/normas , Estudios de Evaluación como Asunto , Humanos , Marcapaso Artificial/efectos adversos
8.
Arch Mal Coeur Vaiss ; 73(1): 72-8, 1980 Jan.
Artículo en Francés | MEDLINE | ID: mdl-6770787

RESUMEN

36 cases of paroxysmal pacing failure in patients with demand pacemakers are reported. The possible causes of pacing lead problems, excluding inhibition by muscular contractions, are related to the distal extremity at the electrode itself, on the lead (rupture) or at the connection between the lead and the pulse generator. The recognition of the precise cause of the pacing failure leads to appropriate treatment. These arrrythmias are not always easy to detect and Holter monitoring is a very useful means of diagnosis.


Asunto(s)
Arritmias Cardíacas/etiología , Marcapaso Artificial/efectos adversos , Arritmias Cardíacas/diagnóstico , Humanos , Monitoreo Fisiológico/instrumentación
9.
Ann Endocrinol (Paris) ; 37(2): 123-4, 1976.
Artículo en Francés | MEDLINE | ID: mdl-188378

RESUMEN

In the irradiated dog at different doses 250-400 R., a level plasma AMPc rise has been shown since the fourth hour with a maximum at 24 hours, returning to normal values about the thirtieth day. In irradiated at 250-300 R and secondarily enterectomised animals, nucleotide level rises 24 hours later, however this phenomenon is less intensive and later irradiated at 350 and 400 R.


Asunto(s)
AMP Cíclico/efectos de la radiación , Intestinos/cirugía , Animales , AMP Cíclico/sangre , Perros , Factores de Tiempo
11.
Rev. argent. reumatol ; 24(4): 30-36, 2013. ilus
Artículo en Español | LILACS | ID: biblio-835775

RESUMEN

Introducción: La utilización de agentes biológicos para el tratamiento de la Artritis Reumatoidea (AR) es habitualmente usada en aquellos pacientes con enfermedad activa que no hayan respondido al tratamiento con drogas modificadoras de la Artritis Reumatoidea convencionales (DMARD, por sus siglas en inglés) o que hayan presentado intolerancia a las mismas. Al estado actual de la evidencia, la terapia combinada de agentes biológicos más un DMARD convencional (principalmente metotrexato) constituye el estándar de tratamiento. Sin embargo existen algunos escenarios como la intolerancia, la falta de adherencia y la aparición de eventos adversos a las DMARDs convencionales donde la monoterapia biológica emerge como una opción terapéutica válida. Según los distintos registros a nivel internacional, la frecuencia de utilización de agentes biológicos en monoterapia oscila entre 12 a 39%. Debido a la ausencia de estos datos a nivel local decidimos realizar este estudio para conocer el porcentaje de pacientes que se encuentran en monoterapia biológica y analizar las causas que llevaron a este tipo de tratamiento. Materiales y métodos: Estudio de tipo corte transversal donde se invitó a participar a diferentes centros reumatológicos distribuidos a lo largo de Argentina. Cada centro revisó las historias clínicas de los últimos 30 a 50 pacientes consecutivos vistos con AR, mayores de 18 años, que habían presentado inadecuada respuesta al tratamiento con DMARDs y que estaban bajo tratamiento biológico. Se completaba una ficha por cada paciente incluido, registrando datos demográficos, de la enfermedad y tratamientos previos. Resultados: Se incluyeron 32 centros y se evaluaron 1148 historias clínicas de pacientes con AR durante el mes de octubre y noviembre del 2012. Un 21,4% (246) de los pacientes al momento del estudio se encontraba bajo tratamiento biológico en monoterapia...


Introduction: The use of biological agents for the treatment of rheumatoid arthritis (RA) is commonly used in patients with active disease who have not responded to treatment with conventional rheumatoid arthritis-modifying drugs (DMARDs) or Who have presented intolerance to them. At the present state of evidence, combined therapy of biological agents plus conventional DMARD (mainly methotrexate) is the standard of treatment. However, there are some scenarios such as intolerance, lack of adherence and the appearance of adverse events to conventional DMARDs where biological monotherapy emerges as a valid therapeutic option. According to different international registries, the frequency of use of biological agents in monotherapy ranges from 12 to 39%. Due to the absence of these data at the local level we decided to carry out this study to know the percentage of patients who are in biological monotherapy and to analyze the causes that led to this type of treatment. Materials and methods: A cross-sectional study where different rheumatologic centers throughout Argentina were invited to participate. Each center reviewed the medical records of the last 30 to 50 consecutive patients seen with RA, older than 18 years, who had inadequate response to treatment with DMARDs and who were under biological treatment. One card was completed for each patient included, recording demographic, disease and previous treatment data. Results: Thirty-two centers were included and 1148 clinical records of patients with RA were evaluated during October and November 2012. A total of 244 patients (246) at the time of the study were under monotherapy...


Asunto(s)
Artritis Reumatoide , Tratamiento Biológico , Argentina
12.
Pacing Clin Electrophysiol ; 1(2): 222-30, 1978 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-83635

RESUMEN

This report describes some of the various techniques which may be used to demonstrate intermittent and/or incomplete fracture of a pacing lead. Eleven patients treated with an R-wave-inhibited demand pacer showed signs of paroxysmal arrhythmias. Intraoperative recordings of the ventricular electrogram showed the presence of spurious signals mimicking an R-wave. These signals varied from patient to patient but remained morphologically constant when a given technique was used in a given case. The most significant signals were picked up when pacing and recording on the same lead.


Asunto(s)
Arritmias Cardíacas/diagnóstico , Estimulación Cardíaca Artificial/métodos , Electrocardiografía/métodos , Marcapaso Artificial/efectos adversos , Arritmias Cardíacas/etiología , Humanos
13.
J Reprod Fertil ; 103(2): 293-8, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7616502

RESUMEN

The aim of the present study was to investigate the effect of size of from which goat oocytes originate on their subsequent ability to be fertilized and to undergo early embryonic development in vitro. Nonatretic follicles larger than 2 mm in diameter were dissected and distributed into three groups according to size (small: 2-3 mm; medium: 3.1-5 mm; large: > 5 mm). Cumulus-oocyte complexes were isolated from the follicles and only those with a compact multilayered cumulus were selected for in vitro maturation. After maturation, 70%, 83% and 97% of oocytes from small, medium and large follicles, respectively, were at metaphase II. After in vitro fertilization, no significant difference was observed in the cleavage rate 40 h after insemination between oocytes from small (46%) and medium (55%) follicles, and between oocytes from large follicles (69%) and ovulated oocytes (75%). After in vitro culture, significantly more embryos from small follicles arrested before or at the 8-16 cell stage (84% compared with 53%, 45% and 39% of embryos from medium and large follicles and ovulated oocytes, respectively). The proportion of morulae and blastocysts obtained was 10% and 6% from small follicles, 35% and 12% from medium follicles, 29% and 26% from large follicles and 20% and 41% from ovulated oocytes. Oocytes from small and medium follicles yielded a significantly lower proportion of hatched blastocysts (0% and 3%, respectively) than did those from large follicles and from ovulated oocytes (15% and 34%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Cabras/fisiología , Oocitos/crecimiento & desarrollo , Folículo Ovárico/fisiología , Animales , Blastocisto/fisiología , Células Cultivadas , Desarrollo Embrionario y Fetal/fisiología , Femenino , Masculino , Oogénesis , Interacciones Espermatozoide-Óvulo
14.
Carcinogenesis ; 19(6): 1053-9, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9667744

RESUMEN

Iron-overload diseases frequently develop hepatocellular carcinoma. The genotoxic mechanism whereby iron is involved in hepatocarcinogenesis might involve an oxidative process via the intermediate production of reactive oxygen species. This was presently investigated by examining kinetics of formation and repair of DNA base lesions in primary rat hepatocyte cultures supplemented with the iron chelate, ferric nitrilotriacetate Fe-NTA (10 and 100 microM). Seven DNA base oxidation products have been identified in DNA extracts by gas chromatography-mass spectrometry, which showed a predominance of oxidized-purines (8-oxo-guanine, xanthine, fapy-adenine, 2-oxo-adenine) above oxidized pyrimidines (5-OHMe-uracil, 5-OH-uracil, 5-OH-cytosine) in control cultures. All these DNA oxidation products revealed a significant dose-dependent increase at 4 to 48 h after Fe-NTA supplementation, among which fapy-adenine showed the highest increase and 5-OH-cytosine was the least prominent. Involvement of iron in this oxidative process was established by a correlation between extent in DNA oxidation and intracellular level of toxic low molecular weight iron. DNA excision-repair activity was estimated by release of DNA oxidation products in culture medium. All the seven DNA oxidation products were detected in the medium of control cultures and showed basal repair activity. This DNA repair activity was increased in a time- and dose-dependent fashion with Fe-NTA. Oxidized-pyrimidines, among which was 5-OHMe-Uracil, were preferentially repaired, which explains the low levels detected in oxidized DNA. Since oxidized bases substantially differed from one another in terms of excision rates from cellular DNA, specific excision-repair enzymes might be involved. Our findings, however, demonstrate that even though DNA repair pathways were activated in iron-loaded hepatocyte cultures, these processes were not stimulated enough to prevent an accumulation of highly mutagenic DNA oxidative products in genomic DNA. The resulting genotoxic effect of Fe-NTA might be relevant in understanding the hepatocarcinogenic evolution of iron-overload diseases.


Asunto(s)
Daño del ADN , Reparación del ADN , Hierro/farmacología , Hígado/efectos de los fármacos , Mutágenos/farmacología , Animales , Hierro/farmacocinética , Hígado/citología , Hígado/metabolismo , Masculino , Mutágenos/farmacocinética , Estrés Oxidativo , Ratas , Ratas Sprague-Dawley
15.
Hepatology ; 25(1): 122-7, 1997 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8985277

RESUMEN

An iron-mediated oxidative stress caused by an increase of the intracellular pool of low molecular weight complex of iron (LMWC) can be observed with iron overloading or ethanol metabolism. The aim of this study was to determine whether nitric oxide (NO) behaved as a pro-oxidant or an antioxidant in such an iron-mediated oxidative stress in rat hepatocytes. The cells were set up in primary cultures and incubated with lipopolysaccharide (LPS) and gamma-interferon (IFN) for 18 hours to induce NO synthase and to trigger NO production. Then 20 micromol/L iron or 50 mmol/L ethanol were added. Oxidative stress was evaluated by measuring lipoperoxidation using two markers: malondialdehyde (MDA) and conjugated dienes. Simultaneously, NO production was followed by the quantitation of nitrites in the culture medium, dinitrosyl iron complexes (DNICs) and mononitrosyl iron complexes (MNICs) in intact hepatocytes. DNIC and MNIC, evaluated by electron paramagnetic resonance (EPR), corresponded to NO bound to iron-containing molecules and to free NO, respectively. In cultures preincubated with LPS and IFN before iron or ethanol addition, a net decrease of lipid peroxidation induced by either NO, iron, or ethanol was noted. Moreover, an elevation of iron-bound NO and a decrease of free NO were observed in these cultures compared with the cultures incubated with only LPS and IFN. These data support the idea that there is a relationship between the changes of NO pool and the inhibition of oxidative stress. In addition, using N(G)-monomethyl-L-arginine (L-NMMA), a NO synthase inhibitor, NO was shown to be involved in the inhibition of oxidative stress induced by iron or ethanol. Addition of the chelator of LMWC iron, deferiprone, was followed by the inhibition of the increase of iron-bound NO and the reincrease of lipid peroxidation extent, which was as high as in cultures incubated only with LPS and IFN. Thus LMWC iron appeared to be involved also in the inhibition of oxidative stress induced by NO. All the results favor the conclusion that NO acts as an antioxidant in iron-mediated oxidative stress in rat hepatocytes. NO reacted with LMWC iron to form inactive iron complexes unable to induce oxidative stress in rat hepatocytes. Thus NO played a critical role in protecting the liver from oxidative stress.


Asunto(s)
Hierro/toxicidad , Hígado/metabolismo , Óxido Nítrico/fisiología , Estrés Oxidativo , Animales , Antioxidantes , Células Cultivadas , Deferiprona , Etanol/toxicidad , Peroxidación de Lípido , Piridonas/farmacología , Ratas , Ratas Sprague-Dawley , omega-N-Metilarginina/farmacología
16.
C R Seances Soc Biol Fil ; 189(3): 453-65, 1995.
Artículo en Francés | MEDLINE | ID: mdl-8521093

RESUMEN

Lipid peroxidation has been implicated in skin damage by ultraviolet radiation. The aim of the study was to determine the kinetic of lipid peroxidation induced by ultraviolet beta (UVB) in adult keratinocytes and fibroblasts in culture. The keratinocytes were obtained from a single primary culture and the fibroblasts were in the same subculture (4 to 10 transfers). For UVB irradiation, the cells were maintained in a small volume of Hanks balanced salt solution and were irradiated (0.75, 1.5, 3 and 4.5 Jcm-2). Then cells were cultured for 3 to 48 hours. Lipid peroxidation was estimated by free MDA determination in both extracellular medium and cells using a size exclusion chromatography coupled to an HPLC procedure. In addition, LDH release in culture media was evaluated as in indice of cytotoxicity. An increase of total free MDA was observed 3 hours after cell irradiation which was dose-dependent from 0.75 to 3 Jcm-2 for keratinocytes and fibroblasts. MDA was detected both in cells and in culture media. As soon as 3 hours after irradiation 90% in total MDA was present in the culture media. Kinetic of lipid peroxidation: for 0.75 Jcm-2, an elevation of MDA was observed 12 hours after irradiation in both cultures. A further increase in MDA was noted 24 hours after fibroblasts irradiation but not in irradiated keratinocytes. LDH release in culture media increased with post irradiation time until 48 hours. The cytotoxic effect of UVB irradiation on keratinocytes and fibroblasts cultures was shown by an enhancement of lipid peroxidation which was detectable during 48 hours after irradiation. An increase of LDH release was observed simultaneously.


Asunto(s)
Queratinocitos/metabolismo , Peroxidación de Lípido/efectos de la radiación , Rayos Ultravioleta , Adulto , Partículas beta , Células Cultivadas , Relación Dosis-Respuesta en la Radiación , Fibroblastos/metabolismo , Humanos , Cinética , L-Lactato Deshidrogenasa/farmacocinética , Malondialdehído/farmacocinética
17.
Carcinogenesis ; 18(11): 2113-7, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9395210

RESUMEN

Oltipraz (4-methyl-5-(2-pyrazinyl)-1,2-dithiole-3-thione) (OPZ) is recognized as a potent chemoprotective agent against chemical-induced carcinogenesis in several animal models and is thought to act mainly by inducing phase II conjugating together with inhibiting phase I detoxication enzymes. The present study was undertaken to determine whether oltipraz can also influence expression of genes encoding antioxidant enzymes. In rat hepatocytes in primary culture, this compound was found to selectively induce the transcription of the manganese superoxide dismutase (Mn-SOD) gene while it had no effect on copper/zinc-SOD and glutathione peroxidase genes. Oltipraz increased Mn-SOD gene expression in a time- and dose-dependent manner by 2- to 3-fold and enhanced the binding activity of the nuclear factor kappa B within 30 min. Moreover, the increase in Mn-SOD gene transcription was associated with a 2- to 3-fold increase of free malondialdehyde and conjugated dienes, two markers of lipid peroxidation, an index of oxidative stress. These results suggest that in rat hepatocytes, oltipraz induced a production of reactive oxygen species that probably acted as second messengers in order to trigger the transcription of many genes. Such a mechanism of action of OPZ and other dithiolethiones would account for the broad spectrum of action of these anticarcinogenic compounds.


Asunto(s)
Anticarcinógenos/farmacología , Hígado/enzimología , Pirazinas/farmacología , Superóxido Dismutasa/genética , Transcripción Genética/efectos de los fármacos , Animales , Peroxidación de Lípido/efectos de los fármacos , Masculino , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Tionas , Tiofenos
18.
Bull Soc Pathol Exot Filiales ; 70(1): 82-9, 1977.
Artículo en Francés | MEDLINE | ID: mdl-579334

RESUMEN

The appearance of acute eczematous dermatitis in fishermen from the estuary of the Seine, about which the responsibility of Alcyonidium gelatinosum (L.) is still under discussion, led us to estimate the ability of this Bryozoa to induce cutaneous responses of delayed hypersensitivity. Intradermal tests carried out in guinea-pigs after subcutaneous, respiratory or percutaneous sensitization, gave evidence of a clear allergenic ability of this alcyonelline. The deposit of the biological product on normal skin during four consecutive days is enough to induce strong responses of delayed hypersensitivity. This experimental study needs further investigations in which the possible existence of anaphylactic reactions should be confirmed.


Asunto(s)
Briozoos/inmunología , Hipersensibilidad Tardía/inmunología , Animales , Cobayas , Pruebas Cutáneas
19.
Ann Genet ; 35(3): 146-51, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1466563

RESUMEN

Two unrelated mentally retarded patients were found to have an interstitial deletion of 18q12. They were a 2-year-old, short, macrocephalic and autistic girl, and a 5-year-old boy. Six other liveborn patients with comparable deletion have been so far identified. The common findings are mild dysmorphic features (telecanthus, epicanthal folds, flaring eyebrows, small mouth with thin upper lip), hypotonia, behavioural disorders, mental retardation with speech delay and lack of major malformation.


Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 18 , Huesos Faciales/anomalías , Discapacidad Intelectual/genética , Cráneo/anomalías , Preescolar , Bandeo Cromosómico , Femenino , Humanos , Cariotipificación , Masculino , Linaje
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