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1.
Kathmandu Univ Med J (KUMJ) ; 11(41): 88-90, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23774423

RESUMEN

Lipomas are the most common benign mesenchymal tumour. Thirteen percent of lipomas are seen in head and neck region. Anterior neck lipoma is a rare one. Anterior neck lipoma with mediastinal extension is extremely rare. We are presenting a case of 52 years old male reported to Central Referral Hospital, Sikkim Manipal Institute of Medical Sciences, Gangtok, Sikkim with complains of swelling in left side of neck for last 18 months along with occasional history of dyspnoea. Physical examination, ultrasound, computed tomography and fine needle aspiration cytology are in favor of lipoma. Due to its location up to the anterior mediastinum, the surgery could not be done in this hospital and patient was referred to higher center having cardiothoracic surgical back up.


Asunto(s)
Neoplasias de Cabeza y Cuello/diagnóstico , Lipoma/diagnóstico , Tomografía Computarizada por Rayos X/métodos , Ultrasonografía Doppler en Color/métodos , Biopsia con Aguja Fina , Diagnóstico Diferencial , Humanos , Masculino , Persona de Mediana Edad
2.
Science ; 220(4604): 1345-51, 1983 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-17730635

RESUMEN

Inelastic electron tunneling spectroscopy is a useful technique for the study of vibrational modes of molecules adsorbed on the surface of oxide layers in a metal-insulator-metal tunnel junction. The technique involves studying the effects of adsorbed molecules on the tunneling spectrum of such junctions. The data give useful information about the structure, bonding, and orientation of adsorbed molecules. One of the major advantages of inelastic electron tunneling spectroscopy is its sensitivity. It is capable of detecting on the order of 10(10) molecules (a fraction of a monolayer) on a 1-square-millimeter junction. It has been successfully used in studies of catalysis, biology, trace impurity detection, and electronic excitations. Because of its high sensitivity, this technique shows great promise in the area of solid-state electronic chemical sensing.

3.
Medicine (Baltimore) ; 73(1): 21-36, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8309360

RESUMEN

Budd-Chiari syndrome (BCS) may not be as uncommon as was once believed. Our study has substantiated the existence of 2 major clinical forms. The acute syndrome is invariably associated with extensive blockage of the major hepatic veins, resulting in congestive liver cell necrosis. In a small, but significant, number of patients the inferior vena cava (IVC) is also occluded. The important etiologic factors are related to hypercoagulability of blood. Immediate placement of a shunt improves survival. The chronic syndrome is characterized by portal hypertension and is associated with a variable abnormal vascular anatomy. The causes of the chronic syndrome are not clear, but a substantial number of cases are related to the presence of an IVC membrane. Shunt surgery is effective but procedures aimed at the primary pathology are likely to be even more so. The natural history of BCS should be viewed over a long period of time. The very long survival of several patients urges a more cautious approach to surgical remedies. Budd-Chiari syndrome probably represents a spectrum of disease caused primarily by a hypercoagulable state and having a varied presentation depending on the balance between rate of formation and the extent of the thrombosis and the body's own rate of thrombolysis and recanalization. The extent and efficacy of the individual's collateral circulation and the rate of development of liver fibrosis are other determinants. It is thus possible to view BCS as a continuum of a single pathogenetic spectrum. Pregnancy-related BCS in India probably has strong social determinants, and is usually acute and fulminant. We have, however, documented a chronic form not described earlier. Children usually do not have acute BCS, but chronic BCS in children and adolescents is similar to that in adults. Membranous obstruction of the inferior vena cava (MOVC) is common and was found even at a young age. The association of MOVC with hepatocellular carcinoma, however, did not appear to be as clear as was previously believed. There has been a wide geographical variability in the causes and manifestations of BCS. Our study has clearly shown that--Kipling's categorical statement to the contrary--East and West do meet in India, in the Budd-Chiari syndrome.


Asunto(s)
Síndrome de Budd-Chiari , Enfermedad Aguda , Adolescente , Adulto , Anciano , Síndrome de Budd-Chiari/diagnóstico por imagen , Síndrome de Budd-Chiari/etiología , Síndrome de Budd-Chiari/patología , Síndrome de Budd-Chiari/cirugía , Niño , Preescolar , Enfermedad Crónica , Femenino , Humanos , India , Lactante , Hígado/irrigación sanguínea , Hígado/patología , Masculino , Persona de Mediana Edad , Embarazo , Complicaciones del Embarazo , Pronóstico , Trastornos Puerperales , Radiografía , Vena Cava Inferior/patología
4.
J Am Coll Surg ; 187(2): 142-6, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9704959

RESUMEN

BACKGROUND: In our clinical setting, patients with perforative peritonitis are frequently malnourished. Immediate postoperative enteral feeding has been shown effective in reducing septic morbidity in patients with abdominal trauma. This study was designed to investigate the feasibility and efficacy of immediate postoperative enteral feeding in patients with nontraumatic intestinal perforation and peritonitis. STUDY DESIGN: A prospective study spanning 1 year was conducted on patients with nontraumatic intestinal perforation and peritonitis. After laparotomy, patients were assigned randomly to a control or study group. The study group underwent a feeding jejunostomy and received enteral feeding from 12 hours postoperatively. A low-residue, milk-based diet was used. All patients underwent assessment for severity of sepsis and nutritional status at admission. Studies of nutritional status and nitrogen balance were repeated on days 4 and 7. RESULTS: Forty-three patients (21 in the study group; 22 in the control group) were included. The two groups were comparable except for a higher sepsis score in the study group (p < 0.05). Patients in the study group achieved a positive nitrogen balance by the third postoperative day; patients in the control group remained in negative nitrogen balance throughout the study. Abdominal distention (four patients) required temporary withdrawal of feeding. Diarrhea occurred in four patients but was controlled easily. The mortality rate was similar in the control and study groups (18.2% versus 19.1%). The control group had a total of 22 septic complications, versus eight in the study group (p < 0.05). CONCLUSIONS: Immediate postoperative feeding is feasible in patients with perforative peritonitis and reduces septic morbidity.


Asunto(s)
Nutrición Enteral , Perforación Intestinal/cirugía , Peritonitis/cirugía , Cuidados Posoperatorios , Adulto , Nutrición Enteral/efectos adversos , Humanos , Perforación Intestinal/complicaciones , Yeyunostomía , Estado Nutricional , Peritonitis/etiología , Complicaciones Posoperatorias , Estudios Prospectivos , Sepsis/complicaciones , Factores de Tiempo
5.
J Hosp Infect ; 15(4): 353-62, 1990 May.
Artículo en Inglés | MEDLINE | ID: mdl-1972951

RESUMEN

A total of 448 patients undergoing cardiovascular surgery were followed for the development of postoperative infection. Non-extracorporeal procedures were assigned to group 1 and open-heart procedures to group 2. The incidence of infection was compared in two groups who received prophylactic antibiotics. Patients (n = 253) received ampicillin alone (group 1) or in combination with gentamicin (group 2) for 7 days starting 1 day before the operation (period A). One hundred and ninety-five patients (period B) received cefazolin starting preoperatively 30 min before induction, alone (group 1) or in combination with gentamicin (Group 2) for 3 days. The percentage of patients developing infection in periods A and B for group 1 patients was 4.2% and 3.5% and for group 2 it was 25.8% and 18.7% respectively. The overall infection rate was 13%. The number of infection sites involved were 1.5 per infected patient. Urinary tract infections were the most frequent followed by endocarditis and other deep infections, wound infections and respiratory infection. Gram-negative rods were the predominant pathogens (Klebsiella spp. and Pseudomonas aeruginosa) during both periods (47 out of 70 isolates). Wound infections due to Gram-positive cocci were higher in period A (4/8) as compared to period B (1/5). During period B there were three cases of fungal endocarditis whereas no case occurred during period A. Although the incidence of infection was reduced during the period of cefazolin prophylaxis, the difference was not statistically significant.


Asunto(s)
Ampicilina/uso terapéutico , Infecciones Bacterianas/prevención & control , Procedimientos Quirúrgicos Cardíacos , Cefazolina/uso terapéutico , Gentamicinas/uso terapéutico , Complicaciones Posoperatorias/prevención & control , Adolescente , Adulto , Anciano , Infecciones Bacterianas/epidemiología , Niño , Femenino , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/aislamiento & purificación , Humanos , India , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Premedicación
6.
Toxicology ; 58(3): 285-98, 1989 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-2799830

RESUMEN

Consumption of edible oils contaminated with Argemone mexicana seed oil is known to cause various clinical manifestations. In the present study, the effect of dietary intake of argemone oil on histopathological changes, haematological indices and selected marker parameters of toxicity was investigated to observe the exact sites and mode of action of argemone oil in rats. Histopathological changes in the liver showed increased fibrosis, hyperplasia of bile ducts and congestion in a few portal tracts. Lungs of argemone oil-fed animals indicated congestion and thickening of interalveolar septa. Alveolar spaces were disorganised and irregular. Kidneys showed vascular and glomerular congestion and patchy tubular lesions. At 30 days only mild congestion was noted in the myocardium. Cardiac muscle fibres showed degenerative changes at 60 days which were more marked in the auricular wall. Haematological examination showed appearance of anaemia in experimental animals. Hepatic alkaline phosphatase, alanine transaminase and aspartate transaminase activities were inhibited by 30, 29 and 29% after 30 days of argemone intake along with concomitant enhancement in serum by 27, 29 and 66%, respectively. Liver showed decrease in glutathione (32-63%) content along with significant stimulation of lipid peroxidation (49-105%) in argemone-intoxicated animals. These results suggest that liver, lungs, heart and kidneys are the target tissues of argemone oil toxicity and that membrane destruction may be a possible mode of action.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas , Dieta , Cardiopatías/inducido químicamente , Enfermedades Renales/inducido químicamente , Enfermedades Pulmonares/inducido químicamente , Aceites de Plantas/toxicidad , Animales , Ingestión de Alimentos/efectos de los fármacos , Cardiopatías/patología , Riñón/patología , Enfermedades Renales/patología , Hígado/enzimología , Hígado/patología , Hepatopatías/patología , Pulmón/patología , Enfermedades Pulmonares/patología , Masculino , Miocardio/patología , Tamaño de los Órganos/efectos de los fármacos , Aceites de Plantas/administración & dosificación , Aceites de Plantas/farmacología , Ratas , Ratas Endogámicas , Aumento de Peso/efectos de los fármacos
7.
J Chromatogr A ; 933(1-2): 91-7, 2001 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-11758750

RESUMEN

Liquid chromatography was used for the quantification of aflatoxin B1-oxime (AFB1-oxime). The yield of AFB1-oxime in the reaction mixture was 89%, while after purification on silica gel it was 72%. LC analysis of the reaction mixture after silica gel fractionation revealed a retention time of 0.84 min for AFB1-oxime, 8.42 min for AFB1, 1.21 min for unknown 1 and 1.61 min for unknown 2. UV-visible analysis of the reaction mixture after silica gel fractionation showed a lambda(max) of 269 and 361 nm for AFB1-oxime, 263 and 360 nm for AFB1, 273 nm for unknown 1 and 275 nm for unknown 2. Excitation and emission wavelengths were found to be 269 and 368/438 nm for AFB1-oxime, 359/424 nm for AFB1, 270 and 367/450 nm for unknown 1 and 273 and 416/447 nm for unknown 2. The method may find versatile application in monitoring reactions for the preparation of oximes of various analytes for the synthesis of their immunogens.


Asunto(s)
Aflatoxina B1/análisis , Cromatografía Liquida/métodos , Oximas/análisis , Espectrometría de Fluorescencia , Espectrofotometría Ultravioleta
8.
Am J Surg ; 138(3): 453-5, 1979 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-314242

RESUMEN

A patient with hemobilia complicating an amebic liver abscess is described. The diagnosis was based on selective arteriography. The hemobilia did not stop with antiamebic treatment or ligation of the right hepatic artery. Successful results followed right hemihepatectomy.


Asunto(s)
Bilis , Hemorragia Gastrointestinal/etiología , Absceso Hepático Amebiano/complicaciones , Adulto , Femenino , Estudios de Seguimiento , Hepatectomía , Arteria Hepática/diagnóstico por imagen , Arteria Hepática/cirugía , Humanos , Ligadura , Absceso Hepático Amebiano/diagnóstico , Absceso Hepático Amebiano/cirugía , Complicaciones Posoperatorias , Radiografía
9.
Soc Sci Med ; 44(2): 171-80, 1997 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9015870

RESUMEN

This article addresses the practices of prenatal sex determination and sex-selective abortion through ethnographic research in Shahargaon, a Jat village undergoing rapid urbanization and cultural change in north India. The paper presents the sociodemographic outcomes of sex-selective abortion practiced within a system of patriarchy, manifested in terms of son preference and daughter disfavor. It argues that changes from an agriculture to an urban economy have led to a decrease in family size among Shahargaon Jats. In spite of improvements in educational and economic status, there is a reinforcement of son preference and daughter disfavor in the Jat community in Shahargaon. Jat couples are using prenatal sex determination and sex-selective abortion to achieve smaller family size and to reduce the number of daughters in a family.


Asunto(s)
Aborto Inducido/estadística & datos numéricos , Características Culturales , Composición Familiar/etnología , Preselección del Sexo/métodos , Urbanización/tendencias , Femenino , Humanos , India , Infanticidio/etnología , Masculino , Embarazo , Factores Socioeconómicos , Salud Suburbana , Encuestas y Cuestionarios
10.
Int J Cardiol ; 24(2): 228-30, 1989 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2767800

RESUMEN

We report a case of primary fibrosarcoma of the heart which presented with features of obstruction to the tricuspid valve and superior caval vein. It was correctly diagnosed by cross-sectional echocardiography.


Asunto(s)
Ecocardiografía , Fibrosarcoma/complicaciones , Neoplasias Cardíacas/complicaciones , Estenosis de la Válvula Tricúspide/etiología , Adulto , Diagnóstico Diferencial , Fibrosarcoma/diagnóstico , Fibrosarcoma/patología , Neoplasias Cardíacas/diagnóstico , Neoplasias Cardíacas/patología , Humanos , Masculino , Miocardio/patología
11.
Int J Cardiol ; 31(1): 33-7, 1991 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2071248

RESUMEN

Pseudoaneurysms of the ascending aorta is a rare postoperative complication which, once identified, needs urgent attention. This report describes 5 consecutive patients with this complication who presented 2-15 months following open heart surgery. The role of cross-sectional echocardiography in diagnosis of this condition is highlighted.


Asunto(s)
Aorta/diagnóstico por imagen , Aneurisma de la Aorta/etiología , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Ecocardiografía , Adulto , Aneurisma de la Aorta/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias
12.
Toxicol Lett ; 42(3): 301-8, 1988 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-3176059

RESUMEN

Consumption of edible oils contaminated with Argemone mexicana seed oil causes various toxic manifestations. In this investigation the in vivo effect of argemone oil on NADPH-dependent enzymatic and Fe2+-, Fe2+/ADP- or ascorbic acid-dependent non-enzymatic hepato-subcellular lipid peroxidation was studied. Parenteral administration of argemone oil (5 ml/kg body weight) daily for 3 days produced a significant increase in both non-enzymatic and NADPH-supported enzymatic lipid peroxidation in whole homogenate, mitochondria, and microsomes. Lipid peroxidation aided by various pro-oxidants, namely Fe2+, Fe2+/ADP and ascorbic acid also revealed a significant enhancement in the whole homogenate, mitochondria and microsomes of argemone oil-treated rats. Further, when compared with whole homogenate, the hepatic mitochondria and microsomes of either control or argemone oil-treated rats showed a 4- and 6-fold increase in non-enzymatic, and a 5- and 18-fold increase in NADPH-dependent enzymatic lipid peroxidation, respectively. Similarly, both mitochondrial and microsomal fractions showed a 5- and 7-fold increase in Fe2+-, and a 12- and 15-fold increase in either Fe2+/ADP- or ascorbic acid-aided lipid peroxidation, respectively. These results suggest that the hepatic microsomal as well as the mitochondrial membrane is vulnerable to the peroxidative attack of argemone oil and may be instrumental in leading to the hepatotoxicity symptoms noted in argemone poisoning victims.


Asunto(s)
Peróxidos Lipídicos/biosíntesis , Hígado/efectos de los fármacos , Aceites de Plantas/toxicidad , Fracciones Subcelulares/análisis , Animales , Ácido Ascórbico/farmacología , Grasas de la Dieta , Compuestos Férricos/farmacología , Peróxidos Lipídicos/análisis , Hígado/análisis , Hígado/metabolismo , Microsomas Hepáticos/análisis , Mitocondrias Hepáticas/análisis , Aceites de Plantas/administración & dosificación , Ratas , Ratas Endogámicas
13.
Eur J Cardiothorac Surg ; 11(3): 455-7, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9105808

RESUMEN

OBJECTIVE: To assess early and later results after surgery for sinus venous atrial septal defects (ASDs). METHODS: Forty-four patients of sinus venosus ASDs with anomalous drainage of the right superior pulmonary vein into the superior vena cava, were operated upon between January 1985 and June 1995. Defects were approached by an incision starting from the tip of the right atrial appendage then extending upward along the atrial crest to the medial wall of the superior vena cava. Atrial defects were closed by an autologous pericardial patch. Another pericardial patch was used to enlarge the superior vena cava-right atrial junction to avoid the narrowing of the superior vena cava. RESULTS: There was no operative mortality. The total duration of follow-up was 4 +/- 0.7 years. Follow-up of the echocardiographic study at 6 months and 2 years after surgery revealed a normal study. Two patients developed sinus node dysfunction of short duration in the immediate postoperative period. Follow-up of the electrocardiographic study at 6 months and 2 years revealed sinus node dysfunction in one and two patients, respectively.


Asunto(s)
Cardiopatías Congénitas/cirugía , Defectos del Tabique Interatrial/cirugía , Venas Pulmonares/anomalías , Adolescente , Adulto , Prótesis Vascular , Niño , Preescolar , Ecocardiografía , Femenino , Estudios de Seguimiento , Cardiopatías Congénitas/diagnóstico por imagen , Defectos del Tabique Interatrial/diagnóstico por imagen , Humanos , Masculino , Pericardio , Complicaciones Posoperatorias/diagnóstico por imagen , Venas Pulmonares/diagnóstico por imagen , Venas Pulmonares/cirugía , Técnicas de Sutura , Vena Cava Superior/anomalías , Vena Cava Superior/diagnóstico por imagen , Vena Cava Superior/cirugía
14.
Eur J Cardiothorac Surg ; 10(8): 666-70, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8875176

RESUMEN

OBJECTIVE: Advances in balloon catheter technology have revolutionized the management of obstructive cardiovascular diseases. For lesions like mitral stenosis, balloon commissurotomy has emerged as an alternative to surgical relief showing definite functional benefits in a few clinical trials, albeit with variable results. Such variability necessitated objective evaluation of the efficacy of balloon mitral commissurotomy. METHODS: The balloon mitral commissurotomy was carried out in 11 patients suffering from isolated mitral stenosis, under vision in a surgical setting. All patients were in NYHA class III/IV. Initially single balloon was used for mitral commissurotomy followed by double balloon, before completing the mitral valvotomy with surgical instruments whenever required. The commissural split was measured by firmly stretching the two commissures using nerve hooks and measuring the distance between the two hooks with the help of a caliper. Assessment of balloon dilation was made by calculating exact percentage of residual commissural split following balloon dilation as compared with completed mitral valvotomy. The exact percentage of commissural split was thus obtained by subtracting residual commissural split following balloon dilation from commissural split obtained after surgical open mitral valvotomy. RESULTS: Complete commissurotomy using the balloon technique was possible in two (18.2%) patients. In the remaining nine (81.8%) patients, balloon expansion provided only 50% to 80% of commissural split and required instrumental completion with good results. CONCLUSIONS: Balloon mitral commissurotomy, by virtue of its circumferential force, helps to develop a good cleavage and attains good hemodynamic improvement which may be life saving in critical mitral stenosis in selected group of patients with pliable mitral leaflets and minimal subvalvular pathology.


Asunto(s)
Cateterismo/métodos , Estenosis de la Válvula Mitral/terapia , Válvula Mitral/cirugía , Adolescente , Adulto , Ecocardiografía , Estudios de Evaluación como Asunto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estenosis de la Válvula Mitral/diagnóstico por imagen , Estenosis de la Válvula Mitral/fisiopatología , Estenosis de la Válvula Mitral/cirugía , Monitoreo Intraoperatorio , Pronóstico , Resultado del Tratamiento
15.
Toxicol In Vitro ; 3(4): 323-7, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-20702299

RESUMEN

N-Phenyl-p-phenylenediamine (N-PPDA) is known to cause strong skin irritation and a sensitization reaction in exposed persons. In a previous in vitro study with portions of skin, N-PPDA exhibited appreciable binding affinity, which suggests a likely involvement of collagen. The present study was therefore undertaken to assess the potential and kinetics of N-PPDA uptake onto collagen. A linear relationship between t-PPDA concentration and its uptake on collagen fibrils was observed. The higher the exposure or contact time the greater the uptake, until a saturation of available sites was reached. The binding was dependent on temperature, with greatest uptake noted at 35 degrees C, and a sharp decline observed at about 50 degrees C. The importance of the intact helical structure of collagen fibrils in offering optimal binding sites was evident from the diminished binding response of collagen denaturated by heat and urea and from the limited affinity towards gelatin. There appeared to be no involvement of sulphydryl groups in the N-PPDA uptake on collagen. A striking resemblance between the binding kinetics of t-PPDA onto collagen and that observed previously with skin portions in vitro, suggests that the collagen fibril model may have a use as a simple preliminary tool to screen chemicals that show binding potential towards skin, in order to make predictions about their dermal toxicity.

16.
Am Surg ; 41(3): 172-4, 1975 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1119758

RESUMEN

Two patients with acute appendicitis are discussed. On histologic examination both were found to have tuberculosis associated with pyogenic infection. Subsequent investigations failed to reveal tuberculous lesions elsewhere in the body. Both patients have responded well to appendectomy and antituberculous drug therapy.


Asunto(s)
Apendicitis/cirugía , Tuberculosis Gastrointestinal/cirugía , Adulto , Apendicitis/patología , Femenino , Humanos , Masculino , Tuberculosis Gastrointestinal/patología
17.
Food Chem Toxicol ; 32(6): 559-63, 1994 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8045463

RESUMEN

The effects of Metanil yellow, Orange II and their blend on hepatic xenobiotic metabolizing enzymes were compared. Parenteral administration of Metanil yellow and Orange II to rats at a dose of 80 mg/kg body weight for 3 days caused a significant induction of ethoxyresorufin-O-deethylase (40-190%), aniline hydroxylase (27-92%), aryl hydrocarbon hydroxylase (50-62%) and aminopyrine N-demethylase (42-49%) activities. Metanil yellow and Orange II brought about a substantial increase in cytosolic quinone reductase (34-82%) and glutathione S-transferase (23-43%) activities and significant depletion of glutathione levels with a concomitant increase in lipid peroxide formation. A blend (1:1) of Metanil yellow and Orange II showed a synergistic or additive effect on these hepatic parameters, suggesting that the addition of these two prohibited dyes together in foodstuffs may give rise to more toxic effects than are produced by each dye individually.


Asunto(s)
Compuestos Azo/toxicidad , Bencenosulfonatos/toxicidad , Hígado/enzimología , Aminopirina N-Demetilasa/metabolismo , Anilina Hidroxilasa/metabolismo , Animales , Hidrocarburo de Aril Hidroxilasas/metabolismo , Colorantes/toxicidad , Citocromo P-450 CYP1A1 , Sistema Enzimático del Citocromo P-450/metabolismo , Glutatión/metabolismo , Glutatión Transferasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Hígado/efectos de los fármacos , Masculino , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , Oxidorreductasas/metabolismo , Ratas , Ratas Wistar
18.
Food Chem Toxicol ; 36(5): 437-44, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9662419

RESUMEN

Quinalphos (QP), an organophosphate pesticide, is used in controlling the pests of a variety of crops. To understand the mechanism of the metabolic basis of the toxicity of QP it was thought pertinent to study the role of cytochrome P-450 (P450) and antioxidant enzyme systems. Albino rats treated orally with QP (0.52 and 1.04 mg/kg body weight) for 60 days showed a significant decrease in body, brain and liver weights. Hepatic P450 content and its dependent monooxygenases, namely aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin-O-deethylase (ERD), were induced to 1.8-2.5-fold, while neuronal AHH was induced to 1.8-fold following QP treatment (1.04 mg/kg) to animals. The hepatic antioxidant defence system, comprising catalase, glutathione (GSH) reductase, superoxide dismutase (SOD) and GSH peroxidase, was also significantly increased in QP-treated animals, while in the brain only catalase was increased and GSH reductase decreased. There was no significant change in hepatic GSH content and lipid peroxide levels in QP treated animals at any dose group in comparison with the control group. Pretreatment of rats with phenobarbitone (PB) or 3-methylcholanthrene (MC) (P450 inducers) prevented mortality caused by the LD50 dose of QP, whereas pretreatment with cobalt chloride (a P450 inhibitor) enhanced the mortality rate to 100% within 3 days. From the above study it can be inferred that the toxicity of QP may be due to the parent compound or its metabolite(s) produced prior to P450 oxidation and that the induction of P450 system by QP may be a defence mechanism.


Asunto(s)
Antioxidantes/metabolismo , Encéfalo/efectos de los fármacos , Sistema Enzimático del Citocromo P-450/metabolismo , Insecticidas/toxicidad , Microsomas Hepáticos/efectos de los fármacos , Compuestos Organotiofosforados/toxicidad , Acetilcolinesterasa/metabolismo , Animales , Peso Corporal/efectos de los fármacos , Encéfalo/enzimología , Encéfalo/patología , Catalasa/metabolismo , Citocromos b5/metabolismo , Femenino , Glutatión Peroxidasa/metabolismo , Glutatión Reductasa/metabolismo , Dosificación Letal Mediana , Masculino , Microsomas Hepáticos/enzimología , Microsomas Hepáticos/patología , Tamaño de los Órganos/efectos de los fármacos , Ratas , Superóxido Dismutasa/metabolismo , Tasa de Supervivencia
19.
Food Chem Toxicol ; 30(6): 517-20, 1992 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1500037

RESUMEN

The bio-elimination and organ retention of [14C]benzanthrone, an anthraquinone dye intermediate, were determined in rats, mice and guinea pigs. Urinary excretion of benzanthrone during 96 hr was higher in guinea pigs (28%) compared with rats and mice (19%). However, faecal elimination during 96 hr was higher in rats (39%) and mice (42%) than in guinea pigs (25%). Urinary elimination of benzanthrone in rats and mice was highest between 12 and 24 hr, while guinea pigs showed a peak value between 24 and 48 hr. The maximum amount of radiolabelled benzanthrone was eliminated through faeces at 24-48 hr in all the three animal species. The retention of [14C]benzanthrone in the liver was comparable in rats (11.2%) and mice (11.9%), while in guinea pigs it was substantially higher (21.9%). The testes of rats and mice were devoid of radioactivity, whereas those of guinea pigs showed a marginal retention (1.25%) of 14C. The present study suggests that guinea pigs are more prone to benzanthrone toxicity than are rats and mice since the bio-elimination of this compound is slower and its organ retention is higher in this species.


Asunto(s)
Benzo(a)Antracenos/farmacocinética , Cobayas/metabolismo , Ratones/metabolismo , Ratas/metabolismo , Animales , Sistema Digestivo/metabolismo , Heces/química , Hígado/metabolismo , Masculino , Testículo/metabolismo , Distribución Tisular
20.
Food Chem Toxicol ; 30(11): 967-71, 1992 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1473790

RESUMEN

The bio-elimination and organ retention of orally administered [14C]benzanthrone, an anthraquinone dye intermediate, were determined in control and ascorbic acid-supplemented guinea pigs. Urinary excretion of benzanthrone in control and ascorbic acid-treated animals during 96 hr was 27.9 and 30.5%, respectively, with peak elimination at 48 hr. Faecal elimination in control and supplemented animals during 96 hr was 24.5 and 38.8%, respectively, with a peak at 48 hr. The organ retention of radiolabelled benzanthrone at the end of 96 hr was of the order of 39% in control animals (gastro-intestinal tract 16%; liver 22%; testis 1.2%); ascorbic acid supplementation reduced benzanthrone retention to 19.5% (gastro-intestinal tract 12.7%; liver 6.8%). Overall, pretreatment of guinea pigs with ascorbic acid caused a 32% enhancement in the clearance of radiolabelled benzanthrone through the urine and faeces, while organ retention was reduced by about 50%. A prophylactic dose of ascorbic acid may prevent benzanthrone-induced toxic symptoms in exposed workers.


Asunto(s)
Ácido Ascórbico/farmacología , Benzo(a)Antracenos/farmacocinética , Animales , Benzo(a)Antracenos/metabolismo , Radioisótopos de Carbono , Diuresis/efectos de los fármacos , Heces/química , Cobayas , Concentración de Iones de Hidrógeno , Masculino
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