Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 93
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Assist Reprod Genet ; 37(7): 1567-1577, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32594284

RESUMEN

PURPOSE: The state of limited resource settings that Coronavirus (COVID-19) pandemic has created globally should be taken seriously into account especially in healthcare sector. In oncofertility, patients should receive their fertility preservation treatments urgently even in limited resource settings before initiation of anticancer therapy. Therefore, it is very crucial to learn more about oncofertility practice in limited resource settings such as in developing countries that suffer often from shortage of healthcare services provided to young patients with cancer. METHODS: As an extrapolation during the global crisis of COVID-19 pandemic, we surveyed oncofertility centers from 14 developing countries (Egypt, Tunisia, Brazil, Peru, Panama, Mexico, Colombia, Guatemala, Argentina, Chile, Nigeria, South Africa, Saudi Arabia, and India). Survey questionnaire included questions on the availability and degree of utilization of fertility preservation options in case of childhood cancer, breast cancer, and blood cancer. RESULTS: All surveyed centers responded to all questions. Responses and their calculated oncofertility scores showed different domestic standards for oncofertility practice in case of childhood cancer, breast cancer, and blood cancer in the developing countries under limited resource settings. CONCLUSIONS: Medical practice in limited resource settings has become a critical topic especially after the global crisis of COVID-19 pandemic. Understanding the resources necessary to provide oncofertility treatments is important until the current COVID-19 pandemic resolves. Lessons learned will be valuable to future potential worldwide disruptions due to infectious diseases or other global crises.


Asunto(s)
Betacoronavirus/patogenicidad , Infecciones por Coronavirus/prevención & control , Atención a la Salud/normas , Preservación de la Fertilidad/métodos , Neoplasias/terapia , Pandemias/prevención & control , Neumonía Viral/prevención & control , Betacoronavirus/aislamiento & purificación , COVID-19 , Infecciones por Coronavirus/transmisión , Infecciones por Coronavirus/virología , Atención a la Salud/economía , Países en Desarrollo , Femenino , Preservación de la Fertilidad/economía , Preservación de la Fertilidad/estadística & datos numéricos , Humanos , Neoplasias/virología , Neumonía Viral/transmisión , Neumonía Viral/virología , SARS-CoV-2 , Encuestas y Cuestionarios
2.
Fish Physiol Biochem ; 38(2): 341-53, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21611720

RESUMEN

A 2 × 2 × 2 factorial experiment was conducted to delineate the main effect of water soaking of plant ingredients, phytase, cellulase, and their interactions on the growth and digestive enzyme activities of Labeo rohita fingerlings. Two basal diets were prepared using water-soaked (S) or unsoaked (US) plant-based ingredients. Feed of US ingredients was supplemented with phytase (U kg(-1)) and cellulase (%) at the level of 0, 0 (C(us)); 500, 0 (T(1)); 0, 0.2 (T(2)); 500, 0.2 (T(3)), and feed of S ingredients at 0, 0 (C(s)); 500, 0 (T(4)); 0, 0.2 (T(5)), and 500, 0.2 (T(6)), respectively. Three hundred and sixty fingerlings were randomly distributed into eight treatments, each with three replicates. Soaking of the ingredients for 24 h significantly reduced the tannin content. However, feeding of S diets did not improve the fish growth. Highest performance was recorded in the T(3) group. A significant interaction between dietary phytase and cellulase was observed for apparent net protein utilization. Tissue crude protein, ether extract, and ash content of the fingerlings were observed highest in the T(3) group. Activities of amylase, protease, and lipase were recorded highest in the T(3) group. Results suggested that soaking of plant-based ingredients reduces tannin content; however, growth and digestive enzyme activities of group fed soaked diet were not improved, possibly due to leaching of soluble nutrients. Probably, a shorter duration soaking may be effective in reducing tannin content and avoiding nutrients leaching.


Asunto(s)
Acuicultura , Composición Corporal , Cipriniformes/fisiología , Dieta , 6-Fitasa/metabolismo , Amilasas/metabolismo , Animales , Celulasa/metabolismo , Digestión , Proteínas de Peces/metabolismo , Lipasa/metabolismo , Péptido Hidrolasas/metabolismo , Ácido Fítico/química , Taninos/química
3.
Fish Physiol Biochem ; 38(2): 499-509, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21681415

RESUMEN

Two experiments, one short-term and one long-term, were conducted to elucidate the acute and chronic effects, respectively, of endosulfan exposure on the haemato-immunological and histopathological responses of Channa puncatatus. In the short-term study, fish were exposed to sublethal endosulfan (8.1 µg l(-1)) for 12, 24, 36, 48, 72 and 96 h. In the long-term study, fish were fed with normal diet and simultaneously either exposed to endosulfan (1.2 µg l(-1)) for 90 days or not. Results showed that the ascorbic acid levels in both the liver and the muscle decreased significantly (P < 0.05) by acute and chronic endosulfan exposure. The haemoglobin (Hb) level reduced significantly (P < 0.05) by 15.5% within 12 h of acute endosulfan exposure, further decreased by 25.8% after 24 h of exposure, however, thereafter the values increased and at the end of 72 h returned to normal levels. Almost similar trend was observed for the erythrocyte (RBC) count. The WBC count and the nitroblue tetrazolium (NBT) value showed a general increasing trend with increase in the duration of acute endosulfan exposure. The chronic exposure of C. punctatus to endosulfan significantly (P < 0.05) lowered the Hb level, RBC and WBC counts, NBT reduction value and the plasma parameters such as plasma protein, albumin (A) and globulin (G) compared with that of the control (except for A/G ratio). Endosulfan exposure also severely altered the liver histological structure. Overall results indicated that both short-term acute and long-term chronic endosulfan exposure had a significant impact on the haemato-immunological parameters and tissue histopathology of C. punctatus.


Asunto(s)
Endosulfano/toxicidad , Insecticidas/toxicidad , Hígado/efectos de los fármacos , Perciformes , Animales , Recuento de Células Sanguíneas , Hígado/patología , Perciformes/sangre , Perciformes/inmunología , Pruebas de Toxicidad Aguda , Pruebas de Toxicidad Crónica
4.
J Fish Biol ; 74(7): 1487-98, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-20735648

RESUMEN

The biochemical and stress responses of two Indian major carps, rohu Labeo rohita and mrigal Cirrhinus mrigala were studied after acclimating them to four preset temperatures (26, 31, 33 and 36 degrees C) for 30 days. The blood glucose and liver glycogen levels showed an inverse trend in both the species and were significantly different in L. rohita at higher temperatures. The decrease in the liver glycogen level of C. mrigala, however, was not significant. Plasma cortisol levels increased significantly whereas the ascorbic acid content in the brain and kidney of both the species decreased significantly with increasing temperatures. Total lipid content in the liver of both the species decreased significantly with increasing acclimation temperatures. The phospholipid concentration decreased in L. rohita with increasing acclimation temperatures, and in C. mrigala the values decreased up to 33 degrees C and increased at 36 degrees C. In C. mrigala, the cholesterol level decreased up to 33 degrees C and then increased at 36 degrees C, but the absolute value was lower in comparison to L. rohita. The cholesterol levels, however, were not significantly different in L. rohita. Triglycerides and free fatty acids concentrations decreased significantly with increasing acclimation temperatures in both the species. The present study indicates species-specific metabolic responses of L. rohita and C. mrigala to thermal acclimation.


Asunto(s)
Aclimatación , Cyprinidae/fisiología , Estrés Fisiológico , Temperatura , Animales , Glucemia/análisis , Cyprinidae/metabolismo , Glucógeno Hepático/análisis
5.
J Fish Dis ; 31(9): 649-57, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18786027

RESUMEN

A 60-day feeding trial was conducted to study the immuno-protective effect of microbial levan on Labeo rohita juveniles challenged with Aeromonas hydrophila. Six purified diets were prepared with different levels of microbial levan: control (no levan), T1 (Basal + 0.25%), T2 (Basal + 0.50%), T3 (Basal + 0.75%), T4 (Basal + 1%) and T5 (Basal + 1.25%), fed to six groups of fish in triplicate. Among the treatment groups the haemoglobin content and total leucocyte count were increased with a dietary supplementation of levan at 1% or more. An increasing trend for total erythrocyte count was observed with increasing level of dietary levan. Lower levan-supplemented groups showed a higher albumin/globulin ratio. As the levan supplementation was increased, there was a gradual increase in serum lysozyme activity and respiratory burst activity [nitroblue tetrazolium (NBT) assay] reduction values. The highest lysozyme activity and NBT were observed in the T5 group although this was similar to the T4 group (P > 0.05). No significant histo-architectural changes were associated with dietary levan levels. After challenge with A. hydrophila, moderately degenerated hepatocytes, oedema and leucocytic infiltration in parenchymatous tissues, and extensive haemorrhage and haemosiderosis in the kidney were observed in the control group. However, the T5 group supplemented with 1.25% levan showed infiltrating leucocytes in the liver while the kidney showed only moderate degeneration of renal tubules. The relative survival per cent of juveniles after challenge with A. hydrophila was the highest in the T5 group followed by T4. This suggests that microbial levan at 1.25% can be used as dietary immunostimulant for L. rohita juveniles.


Asunto(s)
Aeromonas hydrophila/fisiología , Cyprinidae/inmunología , Enfermedades de los Peces/dietoterapia , Fructanos/farmacología , Infecciones por Bacterias Gramnegativas/veterinaria , Inmunidad Innata/efectos de los fármacos , Probióticos/farmacología , Animales , Dieta , Enfermedades de los Peces/inmunología , Enfermedades de los Peces/mortalidad , Enfermedades de los Peces/patología , Infecciones por Bacterias Gramnegativas/dietoterapia , Infecciones por Bacterias Gramnegativas/inmunología , Infecciones por Bacterias Gramnegativas/patología , Hepatocitos/efectos de los fármacos , Hepatocitos/patología , Riñón/efectos de los fármacos , Riñón/patología , Hígado/efectos de los fármacos , Hígado/patología , Muramidasa/sangre , Estallido Respiratorio/efectos de los fármacos , Análisis de Supervivencia
6.
Fish Physiol Biochem ; 34(4): 299-306, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18958586

RESUMEN

A feeding trial of 120 days was conducted to study the effect of graded levels of dietary phosphorus on haematology, serum protein concentrations and HSP70 expression in fingerlings of the Indian major carp, Catla (Catla catla). Eight isonitrogenous and isoenergetic purified diets were formulated to contain graded levels of dietary phosphorus (dP), i.e., T(1), 0.1%; T(2), 0.3%; T(3), 0.5%; T(4), 0.7%; T(5), 0.9%; T(6), 1.1%; T(7), 1.3%; or T(8), 1.5%. Four hundred and eighty fish (average weight 4.23 +/- 0.016 g) were equally distributed into 24 tanks forming eight treatments with three replicates each. The fish were fed daily at the rate of 3.5% body weight in two instalments. At the end of feeding trial fish were sampled to study total RBC and WBC count, haemoglobin, serum lysozyme activity, serum total protein, albumin (A), globulin (G) concentration and HSP70 expression. Total RBC count, haemoglobin concentration and serum lysozyme activity did not vary significantly in response to different dietary phosphorus concentrations. Total WBC count was found to be significantly (P < 0.05) higher in T(1 )relative to all other treatments. Serum albumin and A/G ratio was found to be significantly lower in fish of T(1) and T(2) in relation to T(7) group (P < 0.05). Serum globulin and total protein levels remained unaffected by variations in dietary phosphorus. HSP70 expression was observed in T(1) group (0.1% dP) in gills and brain tissue, but not in liver and muscle tissues. No HSP70 expression was observed in fish of T(4) (0.7% dP) and T(8) (1.5% dP) treatments. These prima facie results suggest that dietary phosphorus had only minor influence on the haemato-biochemical parameters studied; however dietary phosphorus deficiency caused organ specific induction of HSP70 in catla fingerlings.


Asunto(s)
Carpas/fisiología , Regulación de la Expresión Génica/efectos de los fármacos , Proteínas HSP70 de Choque Térmico/metabolismo , Fósforo Dietético/farmacología , Animales , Análisis Químico de la Sangre , Proteínas Sanguíneas/metabolismo , Western Blotting , Carpas/sangre , Carpas/metabolismo , Recuento de Eritrocitos , Hemoglobinas/metabolismo , Recuento de Leucocitos , Muramidasa/sangre
7.
J Med Microbiol ; 8(2): 319-24, 1975 May.
Artículo en Inglés | MEDLINE | ID: mdl-1095749

RESUMEN

Chromatographically separated antigens of Mycobacterium leprae were tested for their ability to elicit skin reactions in guinea-pigs sensitised with homologous and heterologous mycobacteria. Of the three antigen-positive fractions obtained, one showed specific activity and the other two cross-reactivity, as indicated by studies of hypersensitivity and passive cutaneous anaphylaxis. The fraction exhibiting specificity contained only one antigen, which was protein in nature, whereas the other two fractions contained more than one antigen and possessed both protein and polysaccharide constituents. Because the single-antigen-containing fraction showed both positive skin and PCA reactivity, the suggestion is made that this fraction may contain either an antigen with two determinants or may contain two antigens that are not easily distinguishable by immunodiffusion methods.


Asunto(s)
Antígenos Bacterianos/análisis , Lepra/inmunología , Mycobacterium leprae/inmunología , Animales , Proteínas Bacterianas/análisis , Reacciones Cruzadas , Cobayas , Hipersensibilidad Tardía , Lepromina , Anafilaxis Cutánea Pasiva , Polisacáridos Bacterianos/análisis , Pruebas Cutáneas
8.
J Med Microbiol ; 8(1): 177-81, 1975 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-805240

RESUMEN

Immunodiffusion analysis of Mycobacterium lepraemurium indicated the presence of at lease six antigens. Comparative analysis of the M. lepraemurium antigen-antibody system with similar systems established for other mycobacterial species, showed that M. lepraemurium shared up to two antigens with other species. Although our observations are in accord with some of the studies on the antigenic mosaic of M. lepraemurium, they are in disagreement with the observations of Stanford (1973) concerning a close serological relationship of this organism to M.avium. This incompatiblity cannot be explained satifactorily at present.


Asunto(s)
Antígenos Bacterianos/análisis , Mycobacterium lepraemurium/inmunología , Reacciones Cruzadas , Inmunodifusión , Mycobacterium/inmunología , Mycobacterium leprae/inmunología , Mycobacterium tuberculosis/inmunología , Especificidad de la Especie
9.
Toxicology ; 71(1-2): 63-8, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1729768

RESUMEN

The effect of benomyl administered orally (p.o.) and intraperitoneally (i.p.) on the activity of hepatic microsomal mixed-function oxidases (MFOs) was studied in rats. A dose of 100 mg/kg given i.p. reduced the activities of several hepatic drug-metabolizing enzymes 24 h following the treatment. A similar reduction in the activities of the MFOs was also noted 24 h following oral benomyl administration at a dose of 500 mg/kg. Furthermore, in vivo inhibition of drug metabolism by benomyl was demonstrated by increased pentobarbital sleeping-time 24 h after p.o. as well as i.p. dosing. No alterations were found in the serum sorbitol dehydrogenase (SDH) at 24 h after i.p. or oral benomyl indicating a lack of hepatotoxic effect. These results indicate that benomyl shows a route-independent effect on MFOs and is not toxic to the liver.


Asunto(s)
Benomilo/toxicidad , Microsomas Hepáticos/efectos de los fármacos , Administración Oral , Animales , Benomilo/administración & dosificación , Inyecciones Intraperitoneales , L-Iditol 2-Deshidrogenasa/sangre , L-Iditol 2-Deshidrogenasa/metabolismo , Masculino , Microsomas Hepáticos/enzimología , Oxigenasas de Función Mixta/metabolismo , Tamaño de los Órganos/efectos de los fármacos , Ratas , Ratas Endogámicas , Sueño/efectos de los fármacos
10.
Toxicology ; 9(4): 341-51, 1978 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-663942

RESUMEN

The degree of toxicity caused in rats by captan (N-trichloromethylthio-4-cyclohexene-1,2-dicarboximide) administered intraperitoneally is greater than that induced by orally administered captan. With regard to its effect on the drug-metabolizing enzymes of rat liver, the activity of aniline hydroxylase and the level of cytochrome P-450 were found to decrease in the treated rats 24 h after a single oral dose (650 mg/kg). The loss was even greater in the animals receiving diethyl maleate 1 h prior to captan. Furthermore, usual increase in the activity of drug biotransformation enzymes seen after phenobarbital treatment appears to decrease in rats dosed with this funaicide. In vitro incubations of rat liver microsomes with captan resulted in a profound loss of cytochrome P-450 and the acitivty of benzphetamine N-demethylase as well as aniline hydroxylase. Although the inhibition of drug-metabolizing enzyme activity by captan was observed in microsomal incubations with or without NADPH, a detectable amount of carbonyl sulfide (COS) was found only in the incubations that contained captan plus NADPH. Carbonyl sulfide appears to arise from a captan-derived metabolite, thiophosgene (CSCl2), which decomposes to COS in aqueous solutions and in the presence of NADPH inhibits the activity of drug biotransformation enzymes.


Asunto(s)
Biotransformación/efectos de los fármacos , Captano/toxicidad , Microsomas Hepáticos/efectos de los fármacos , Anilina Hidroxilasa/metabolismo , Animales , Benzfetamina , Sistema Enzimático del Citocromo P-450/metabolismo , Masculino , Maleatos/farmacología , Microsomas Hepáticos/enzimología , Fenobarbital/metabolismo , Proadifeno/farmacología , Ratas
11.
Toxicology ; 3(3): 269-85, 1975.
Artículo en Inglés | MEDLINE | ID: mdl-47657

RESUMEN

Pesticides are widely used for the protection of economic crops from a variety of noxious pests. The repeated and indiscriminate uses and the extreme stability of certain pesticides have led to their accumulation in plants, animals, soils and sediments, thus effecting widespread contamination of the environment. Soil contaminants are especially serious because they can inhibit or impair the seed germination of our food and feed crops. Seeds can come in close contact with pesticides through processes such as prematurity application, fumigation, seed dressings, and seed treatments. Several reports have indicated the toxic effects of pesticides on seed germination. Possible mechanisms of the toxic action on pesticides during the germination of seeds have been discussed with emphasis on biochemical, histological, and cytological alterations. Bioassay procedures employing seed germination as a smiple, feasible, economical, time-saving indicator of toxicity have been described briefly. Attention is then drawn to the possible potential health hazards arising from the presence of pesticidal chemicals in food plants since the toxicological implications of long term exposure to pesticides are often more far-reaching.


Asunto(s)
Plaguicidas/toxicidad , Plantas Comestibles/efectos de los fármacos , Semillas/efectos de los fármacos , Animales , Carcinógenos/farmacología , Fumigación , Herbicidas/análisis , Hexaclorociclohexano/toxicidad , Insecticidas/análisis , Insecticidas/toxicidad , Residuos de Plaguicidas/análisis , Plaguicidas/metabolismo , Proteínas de Plantas/metabolismo , Plantas Comestibles/enzimología , Semillas/crecimiento & desarrollo , Semillas/ultraestructura , Suelo/análisis , Microbiología del Suelo , Contaminantes del Suelo , Teratógenos/farmacología , Factores de Tiempo , Triazinas/toxicidad
12.
Chem Biol Interact ; 10(5): 347-61, 1975 May.
Artículo en Inglés | MEDLINE | ID: mdl-237636

RESUMEN

The results of these studies have indicated that the decrease in the activity of the hepatic mixed-function oxidase enzyme system and the concentration of cytochrome P-450 seen on incubation of carbon disulfide (CS2) with rat liver microsomes in the presence of NADPH is the result of the binding of the sulfur atom released in the mixed-function oxidase catalyzed metabolism of CS2 to carbonyl sulfide (COS). Moreover, it appears that COS is further metabolized by the mixed-function oxidase enzyme system to CO2 and that, analogous to the metabolism of CS2 to COS, the sulfur atom released in this reaction also binds to the microsomes and inhibits benzphetamine metabolism and decreases the concentration of cytochrome P-450 detectable as its carbon monoxide complex. The results of these studies also suggest that the decrease in the concentration of cytochrome P-450 and the liver damage seen on in vivo administration of CS2 to phenobarbital pretreated rats, is due to the mixed-function oxidase catalyzed release and binding of the sulfur atoms of CS2. The decrease in the concentration of cytochrome P-450 seen on incubation of CS2 with rat liver microsomes in the presence of NADPH does not appear to be the result of destruction of the heme group or its dissociation from the apoenzyme since the total amount of protoheme is unchanged in microsomes which have been incubated with CS2 and NADPH as compared to those not incubated with these compounds.


Asunto(s)
Disulfuro de Carbono/metabolismo , Microsomas Hepáticos/enzimología , Oxigenasas de Función Mixta , Oxidorreductasas , Animales , Benzfetamina , Disulfuro de Carbono/farmacología , Sistema Enzimático del Citocromo P-450/metabolismo , Hemo/metabolismo , Cinética , Masculino , Malondialdehído/metabolismo , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Oxigenasas de Función Mixta/antagonistas & inhibidores , NADP/farmacología , Proadifeno/farmacología , Unión Proteica , Ratas , Óxidos de Azufre/metabolismo , Óxidos de Azufre/farmacología , Radioisótopos de Azufre
13.
Toxicol Lett ; 60(3): 299-305, 1992 May.
Artículo en Inglés | MEDLINE | ID: mdl-1595088

RESUMEN

Studies were conducted to examine the effect of a single and repeated administrations of garlic oil (diallyl sulfide) on Phase I and Phase II biotransformation enzymes in rats. Adult, male Sprague-Dawley rats treated with a single dose of garlic oil (500 mg/kg i.p.) showed a significant depression of hepatic cytochrome P-450, aminopyrine N-demethylase and aniline hydroxylase while microsomal protein content, cytochrome b5, NADPH-cytochrome c reductase, benzphetamine N-demethylase and cytosolic glutathione, S-transferase remained unaffected 24 h following the treatment. Although certain microsomal enzymes were depressed, there was no liver damage caused by garlic oil as judged by the putative serum enzyme test. On the other hand, daily administration of garlic oil (50 mg/kg i.p. for 5 days) produced a significant increase in hepatic cytochrome P-450, aminopyrine N-demethylase and benzphetamine N-demethylase activities, but not in the rest of the aforementioned parameters of biotransformation reactions. These data indicate that the effect of garlic oil on the hepatic drug-metabolizing enzyme system is dose-dependent.


Asunto(s)
Compuestos Alílicos , Hígado/enzimología , Sulfuros/farmacología , Animales , Sistema Enzimático del Citocromo P-450/efectos de los fármacos , Sistema Enzimático del Citocromo P-450/metabolismo , Grupo Citocromo b/efectos de los fármacos , Grupo Citocromo b/metabolismo , Ajo , Inactivación Metabólica , Hígado/anatomía & histología , Masculino , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/enzimología , NADPH-Ferrihemoproteína Reductasa/efectos de los fármacos , NADPH-Ferrihemoproteína Reductasa/metabolismo , Tamaño de los Órganos/efectos de los fármacos , Plantas Medicinales , Ratas , Ratas Endogámicas
14.
Toxicol Lett ; 16(1-2): 153-7, 1983 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-6404013

RESUMEN

Liver injury caused by a toxic dose of aflatoxin B1 (AFB1) (6 mg/kg, p.o.) in experimental chickens was measured by observing changes in hepatic microsomal cytochrome P-450 and the activity of microsomal benzphetamine N-demethylase and serum glutamic oxaloacetic transaminase (SGOT). However, simultaneous administration of activated charcoal, reduced glutathione (GSH), cysteine, selenium, beta-carotene or fisetin with aflatoxin B1 considerably reduced the toxic injury to liver as measured by the above parameters.


Asunto(s)
Aflatoxinas/antagonistas & inhibidores , Carbón Orgánico/uso terapéutico , Hepatopatías/prevención & control , Aflatoxina B1 , Animales , Aspartato Aminotransferasas/sangre , Benzfetamina/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas , Pollos , Sistema Enzimático del Citocromo P-450/metabolismo , Femenino , Masculino , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/enzimología
15.
Toxicol Lett ; 55(3): 317-23, 1991 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1900643

RESUMEN

Dimethyl sulfoxide (DMSO) at a single dose of 3 ml/kg body wt, administered i.p. to male rats, caused a significant increase in the hepatic microsomal aniline hydroxylase activity. However, the level of cytochrome P-450, the activities of NADPH-cytochrome c reductase, benzphetamine N-demethylase and aminopyrine N-demethylase were unchanged at 24 h post-treatment. DMSO interacted with control rat liver microsomes in vitro and produced a type II spectral change (peak at 420 nm and trough at 392 nm). On the other hand, liver microsomes from DMSO-treated rats gave qualitatively similar spectra, but with a higher magnitude of binding. Liver microsomes from DMSO-treated rats showed a 3.4-fold increase in Vmax for aniline hydroxylase, while Km was found to be the same when compared with control rat liver microsomes. In vitro addition of 6 mM DMSO to microsomal incubations from control and DMSO-treated rats caused a 9-fold and a 25-fold increase in Km, respectively, while Vmax values for aniline hydroxylase were unchanged. When DMSO (6 mM) was incubated with rat liver microsomes in the presence of NADPH, there was formation of formaldehyde. The results suggest an interaction of DMSO with microsomal cytochrome P-450.


Asunto(s)
Anilina Hidroxilasa/metabolismo , Dimetilsulfóxido/toxicidad , Microsomas Hepáticos/efectos de los fármacos , Aminopirina N-Demetilasa/antagonistas & inhibidores , Aminopirina N-Demetilasa/metabolismo , Anilina Hidroxilasa/antagonistas & inhibidores , Animales , Inhibidores Enzimáticos del Citocromo P-450 , Sistema Enzimático del Citocromo P-450/metabolismo , Técnicas In Vitro , Masculino , Microsomas Hepáticos/enzimología , NADPH-Ferrihemoproteína Reductasa/antagonistas & inhibidores , NADPH-Ferrihemoproteína Reductasa/metabolismo , Oxidorreductasas N-Desmetilantes/antagonistas & inhibidores , Oxidorreductasas N-Desmetilantes/metabolismo , Ratas , Ratas Endogámicas
16.
Toxicol Lett ; 6(1): 25-8, 1980 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-7423540

RESUMEN

Rats given calcium disodium ethylenediaminetetraacetic acid (CaNa2EDTA), diethylenetriaminepentaacetic acid (DTPA), dimercaprol, p-aminosalicylic acid (PAS), or d-penicillamine (penicillamine) i.p. for 7 successive days showed a significant decrease in the activity of hepatic microsomal benzphetamine N-demethylase. There was no appreciable change in the microsomal cytochrome P-450 concentration. In vitro incubation of the chelating drugs with liver microsomes isolated from rats pre-treated with phenobarbital caused no significant loss of the hemoprotein. The decreased rate of benzphetamine metabolism in microsomal preparations from rats, pretreated with the chelating drugs, may be attributed partly to hepatic depletion of essential trace elements by the chelating drugs.


Asunto(s)
Ácido Aminosalicílico/metabolismo , Ácidos Aminosalicílicos/metabolismo , Benzfetamina/metabolismo , Dimercaprol/metabolismo , Microsomas Hepáticos/efectos de los fármacos , Penicilamina/metabolismo , Ácido Pentético/metabolismo , Fenetilaminas/metabolismo , Animales , Sistema Enzimático del Citocromo P-450/metabolismo , Masculino , Microsomas Hepáticos/enzimología , Ratas
17.
J Pharm Pharmacol ; 39(5): 386-8, 1987 May.
Artículo en Inglés | MEDLINE | ID: mdl-2886588

RESUMEN

Adult, male Sprague-Dawley rats were given 0, 10, 20, 40 or 80 mg kg-1 of monocrotaline intraperitoneally and the following toxicity parameters determined 24 h post treatment. Compared with the control none of the doses caused significant change in either the relative liver weight or the hepatic microsomal protein concentration. Microsomal cytochrome P450 content and activities of benzphetamine N-demethylase and aniline hydroxylase did not differ from the control at 10 or 20 mg kg-1 dosage. But, there was a significant loss of cytochrome P450 at 40 and 80 mg kg-1 dosages and decrease in the activity of the two enzymes only at the highest dose. Similarly, the highest dose caused a marked elevation of serum sorbitol dehydrogenase and glutamic pyruvic transaminase activity suggestive of severe liver damage.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas , Microsomas Hepáticos/enzimología , Alcaloides de Pirrolicidina/toxicidad , Animales , Relación Dosis-Respuesta a Droga , Hepatopatías/enzimología , Masculino , Monocrotalina , Oxidorreductasas/metabolismo , Ratas , Ratas Endogámicas , Transaminasas/metabolismo
18.
J Pharm Pharmacol ; 42(1): 58-9, 1990 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1969953

RESUMEN

To examine the effect of levamisole on the hepatic drug metabolizing enzyme system of mice, levamisole at a dose of 20 mg kg-1 day-1 was administered i.p. for 5 days. Compared with the control values, the levamisole treatment significantly increased the amount of cytochrome P450 and cytochrome b5 and the in-vitro activities of aminopyrine N-demethylase, benzphetamine N-demethylase and aniline hydroxylase. In contrast, there was no change in microsomal NADPH-cytochrome c reductase activity in-vitro or in the relative liver weight and microsomal protein content compared with the corresponding values for control mice. Furthermore, in-vivo induction of drug metabolism was demonstrated by decreased pentobarbitone sleeping times after levamisole pretreatment. These results indicate that certain hepatic microsomal mixed function oxidases of mice are induced by levamisole, the drug that is frequently used as an anthelmintic in veterinary medicine and as an immunostimulant drug in human medicine.


Asunto(s)
Levamisol/farmacología , Microsomas Hepáticos/enzimología , Oxigenasas de Función Mixta/biosíntesis , Animales , Sistema Enzimático del Citocromo P-450/biosíntesis , Citocromos b5/biosíntesis , Inducción Enzimática/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos ICR , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , NADPH-Ferrihemoproteína Reductasa/biosíntesis , Tamaño de los Órganos/efectos de los fármacos , Pentobarbital/farmacología , Biosíntesis de Proteínas , Sueño/efectos de los fármacos
19.
Avian Dis ; 28(1): 61-9, 1984.
Artículo en Inglés | MEDLINE | ID: mdl-6426455

RESUMEN

Aspergillus flavus NRRL 3357 was grown on enriched long-grain rice for 7-10 days to produce aflatoxin B1 (AFB1). The quantity of AFB1 in moldy rice was determined by thin-layer chromatography using ultraviolet light. When the dried moldy rice powder was fed to day-old Hubbard X Hubbard broiler chicks in unmedicated feed (AFB1 level 10 ppm) for 8 weeks, there was a profound reduction in weight gain and feed consumption. Chickens fed AFB1 developed severe liver damage, as determined by the concentration of hepatic microsomal cytochrome P-450 and by the activities of microsomal benzphetamine N-demethylase and serum glutamic oxalacetic transaminase. However, activated charcoal, reduced glutathione, cysteine, selenium (as sodium selenite), beta-carotene, and fisetin administered orally considerably reduced the toxicity of AFB1 in the experimental chickens.


Asunto(s)
Aflatoxinas/toxicidad , Alimentación Animal/toxicidad , Pollos/metabolismo , Enfermedades de las Aves de Corral/etiología , Aflatoxina B1 , Aflatoxinas/antagonistas & inhibidores , Aflatoxinas/metabolismo , Animales , Carbón Orgánico/uso terapéutico , Cisteína/uso terapéutico , Femenino , Flavonoides/uso terapéutico , Flavonoles , Cobayas , Hepatopatías/etiología , Hepatopatías/metabolismo , Hepatopatías/veterinaria , Masculino , Enfermedades de las Aves de Corral/metabolismo , Conejos , Ratas
20.
Avian Dis ; 34(3): 571-4, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2241682

RESUMEN

Quail were fed monensin to determine liver damage, as measured by changes in activities of serum enzymes and liver microsomal enzymes. Monensin fed at a therapeutic level of 110 ppm for 2 weeks produced an increase in cytochrome P-450 and cytochrome b5 and induction of the activities of benzphetamine N-demethylase, aminopyrine N-demethylase, and aniline hydroxylase, with no changes in the activities of serum sorbitol dehydrogenase (SDH), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). On the other hand, quail fed 110 ppm, 220 ppm, and 330 ppm monensin in feed for 6 weeks showed a significant rise in SDH and AST activities at 330 ppm but not at 110 ppm and 220 ppm. The manifestations of liver toxicity observed at 330 ppm were accompanied by a significant decrease in all the aforementioned hepatic microsomal mixed-function oxidases. In contrast, quail fed monensin at 110 ppm and 220 ppm for 6 weeks produced no change in these parameters except for benzphetamine N-demethylase, aminopyrine N-demethylase, and aniline hydroxylase, which were significantly increased in birds fed 220 ppm of monensin.


Asunto(s)
Colinus/metabolismo , Hígado/efectos de los fármacos , Monensina/toxicidad , Administración Oral , Aminopirina N-Demetilasa/análisis , Anilina Hidroxilasa/análisis , Animales , Sistema Enzimático del Citocromo P-450/análisis , Citocromos b5/análisis , Relación Dosis-Respuesta a Droga , Hígado/enzimología , Masculino , Microsomas Hepáticos/química , Monensina/administración & dosificación , Oxidorreductasas N-Desmetilantes/análisis
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA