Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 57
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Eurasian J Med ; 45(1): 21-33, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25610244

RESUMEN

OBJECTIVE: Betel leaf combined with areca nut is known as betel quid pan masala (PM), and tobacco with areca nut, catechu and lime is pan masala (PMT) blended with gulkhand. These narcotics are popular among young and old individuals. A prima facia chemical analysis and a toxicity assessment of PM in mice were conducted to study the relationship between longtime consumption of PM and health hazards. MATERIALS AND METHODS: Chemical analysis of different types of PM was done employing HPLC, GLC, AAS, ES, TLC, GCMS and sequential extraction for PAH, pesticides, metals and minerals, electrolytes, drugs and xenobiotics. Ethanolic PM extracts were tested by IP and PO routes in inbred Swiss mice. RESULTS: PAH, which are known xenobiotics for pre-cancerous lesions, were significantly high (p<0.01) in Rajaniganda and Pan Parag Zarda. Isomers of DDT and BHC, which principally act on nerves and muscles, were also high (p<0.01) in PM. The enhanced metal and mineral content of PM results in massive oral fibrosis. There is a high level of narcotics in PM, especially nicotine, a potentially cancerous agent in the gastrointestinal tract. CONCLUSION: Experimental studies with different extracts of plain and blended PM in mice fed for 16 and 90 days revealed no effect on blood and organ weights (kidney, heart, spleen and liver), but we did observe attenuated testis. However, in the bone marrow of the mice, chromosomes were most affected in the mice fed PM-Zarda blend for 3 months. The chromosomal abnormalities included ploidy, loss, breaks, gaps, deletions and exchanges in ring chromosomes. The PM caused sperm head anomalies (narrow, blunt, triangular and banana shapes), and the sperm were irregular, amorphous, tailless and rudimentary, with the maximum effect among the groups fed PM for 3 months. Significantly higher levels (p<0.01) of testis glycogen, cholesterol and protein were found. The group fed for 16 days showed no change in red blood corpuscles (RBC), white blood corpuscles (WBC), hemoglobin and erythrocyte sedimentation counts.

3.
Arch Med Res ; 32(2): 113-8, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11343807

RESUMEN

BACKGROUND: Immunosuppression cannot develop tumors by itself. It may induce tumors under appropriate conditions and may accelerate tumor development which may be reversed by sensitized spleen cells. This study concerns the effect of sensitized macrophages in murine-transplantable sarcomas by a combination of hyperimmune serum, sensitized spleen cells and macrophages. METHODS: The main technique adopted was intraperitoneal (ip) injection of 2 mL of 10% protease peptone broth, followed 2 days later by inoculation into the peritoneum with 10-mL Hank isotonic solution. The cells from the pooled peritoneal fluid were tested by dye exclusion test to ascertain the percentage of live cells. They were tried in whole body-irradiated mice with a combination of immune serum and sensitized spleen cells to ascertain whether a suppression of growth of solid tumors could be achieved when subcutaneously (sc) administered with the previously mentioned combinations. RESULTS: The addition of immunomacrophages from transplanted tumor-bearing mice significantly suppressed the growth of subcutaneous solid tumors when the number of tumor cells was kept constant. A change in number of immunomacrophages from hyperimmunized mice at a ratio of 4:l showed a direct relationship in suppression of tumor growth. Experiments were initiated in which tumor cells were injected sc and peritoneal macrophages were injected either intravenously (iv) or ip. Experiments were then initiated to prove that cell-to-cell contact is essential for tumor suppression. In experiments in which tumor cells were administered sc and macrophages injected either iv or ip, a significant immunosuppressive effect was not shown, thus also indicating that regardless of which, cell-to-cell contact is an absolutely essential factor involved in tumor suppression. A combination of hyperimmune serum and macrophages was found to act synergistically. Macrophages and hyperimmune serum at a lesser proportion did not suppress tumor growth. Sensitized macrophages and spleen cells together significantly suppressed tumor growth in a pure isogenic strain of irradiated mice. The sensitized macrophages injected iv prolonged the survival period and retarded tumor growth. CONCLUSIONS: Tumor suppression by macrophages was found to be due to its contact with tumor cells that enables the effective transfer of immunity. Hyperimmune serum and other cells (macrophages, spleen lymphocytes) act synergistically toward each other and prolong the survival period.


Asunto(s)
Sueros Inmunes , Macrófagos/inmunología , Sarcoma Experimental/patología , Bazo/inmunología , Animales , Femenino , Masculino , Ratones , Trasplante de Neoplasias
4.
Int J Toxicol ; 20(5): 321-7, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11766129

RESUMEN

A study was conducted on byssinotic (N = 8) and nonbyssinotic (N = 16) mill workers exposed to cotton dust and on controls (N = 15) from a cotton dust-free zone. They were examined for chest tightness and breathlessness during successive days from Mondays to Fridays. In addition to monitoring the workers only on Mondays after shift work, their blood histamine levels and pulmonary function tests such as FEV1, PEFR, and FEF25-75% (PEFR represents airflow of larger airways, FEF25-75% reflects airflow in smaller airways, and FEV1 represents airflow in both central and peripheral airways) were screened, but Monday data were only counted to appraise a contrast between these two parameters. The results showed that the histamine levels were significantly higher in the cotton dust-exposed workers in association with significantly decreased FEV1, PEFR, and FEF25-75%, indicating bronchoconstriction of the central, larger, and peripheral airways. Histamine can cause a severe constriction of the central as well as peripheral airways in cotton dust-exposed workers, enabling a paradoxical effect for a differential diagnosis of byssinosis.


Asunto(s)
Bisinosis/diagnóstico , Gossypium/efectos adversos , Histamina/sangre , Exposición Profesional/efectos adversos , Adulto , Obstrucción de las Vías Aéreas/etiología , Animales , Diagnóstico Diferencial , Humanos , Persona de Mediana Edad , Pruebas de Función Respiratoria/estadística & datos numéricos , Literatura de Revisión como Asunto , Encuestas y Cuestionarios
5.
Ann Acad Med Singap ; 28(4): 488-93, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10561758

RESUMEN

The aim of this study was to find out lead interaction on acetylcholine-induced ileal (0.8 "to 1" longitudinal total strips) contractions in varying calcium (Ca++) or magnesium (Mg++) media and the cholinergic mechanism. Potentiation of ileal strips by lead (Pb++) remained dose-dependent as elicited by acetylcholine-induced contractions (1.81 x 10(-6) M to 1.28 x 10(-4) M). These were completely antagonized by atropine (1.01 x 10(-8) M). Lead (1.2 x 10(-5) M) potentiated contractions caused by acetylcholine in normal or in excess Ca++ media, but in low Ca++ or with various Mg++ media, lead failed to potentiate such contractions. Thus Pb++ has indirect cholinomimetic effect which involved extracellular Ca++.


Asunto(s)
Acetilcolina/farmacología , Plomo/farmacología , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Animales , Atropina/farmacología , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Femenino , Íleon/efectos de los fármacos , Íleon/fisiología , Técnicas In Vitro , Magnesio/farmacología , Masculino , Antagonistas Muscarínicos/farmacología , Músculo Liso/fisiología , Ratas , Ratas Wistar
6.
Biomed Environ Sci ; 6(3): 223-30, 1993 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8292267

RESUMEN

The sensitivity of rat anococcygeus muscle to noradrenaline (NA) was reduced following carbon disulphide (CS2) pretreatment. Preparations incubated in excess Ca++ (4.2 mmol.L-1) or Zero Ca++ (0.0 mmol.L-1) media showed decrease in sensitivity to NA. Reserpinization failed to induce supersensitivity to NA in any Mg++ concentration in the media. Reserpinized tissue in Mg++ free media with EDTA showed increased sensitivity while decreased sensitivity and maximum response to NA in Mg++ (1.2 mmol.L-1) and excess Mg++ (3.6m mol.L-1) concentration of the medium. In the presence of EDTA, the inhibition observed with CS2 in excess Mg++ (3.6m mol.L-1) medium was comparatively much less in both non-reserpinized and reserpinized preparations. In normal Ca++ and its deficient medium decrease in sensitivity to CS2 and the relevant maximum response to NA were observed. In excess Ca++, the CS2 effect depressed corresponding to its maximal response to NA. Thus CS2 may be inhibiting responses to NA by interfering with Ca++ utilization.


Asunto(s)
Calcio/metabolismo , Disulfuro de Carbono/farmacología , Músculos/efectos de los fármacos , Norepinefrina/antagonistas & inhibidores , Animales , Permeabilidad de la Membrana Celular/efectos de los fármacos , Medios de Cultivo , Ácido Edético/farmacología , Técnicas In Vitro , Soluciones Isotónicas , Magnesio/farmacología , Masculino , Metisergida/farmacología , Músculos/metabolismo , Fentolamina/farmacología , Ratas , Ratas Wistar , Reserpina/farmacología , Espasmo/inducido químicamente
7.
Indian J Physiol Pharmacol ; 37(2): 109-14, 1993 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8225541

RESUMEN

Reserpine induced supersensitivity to norepinephrine (NE) in rat vas deferens was sought by alteration of Mg++ and Ca++ concentration in incubation medium in the absence and presence of EDTA. Vas deferens incubated in Mg++ free and Mg++ excess media showed supersensitivity and subsensivity to NE respectively. Alterations in the sensitivity to NE produced by varying the concentrations of Mg++ were comparatively less. In the presence of EDTA, vas deferens obtained from reserpinized animals showed subsensitivity in normal and Mg++ excess media and supersensitivity in Mg++ free medium. In the presence of EDTA, reserpinized preparations showed slight supersensitivity in normal Mg++ medium, marked supersensitivity in Mg++ free and lesser subsensitivity in Mg++ excess medium. Probably EDTA by more effectively removing Mg++ from the membrane binding sites by chelation makes the membrane permeable to Ca++ leading to supersensitivity to NE (observed only in the presence of EDTA). These results suggest that the failure of reserpine to induce supersensitivity to NE in rat vas deferens may be due to an enhanced antagonism of Mg++ on Ca++ movements in this preparations due to the poor capacity of rat tissue to retain Ca++.


Asunto(s)
Magnesio/farmacología , Norepinefrina/antagonistas & inhibidores , Reserpina/farmacología , Conducto Deferente/efectos de los fármacos , Animales , Calcio/metabolismo , Ácido Edético , Masculino , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Músculo Liso/metabolismo , Músculo Liso/fisiología , Norepinefrina/farmacología , Ratas , Ratas Wistar , Conducto Deferente/metabolismo , Conducto Deferente/fisiología
8.
Indian J Physiol Pharmacol ; 37(2): 115-20, 1993 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8225542

RESUMEN

Rats exposed to lead (lead acetate) in doses of 0.2 and 0.5 mg/ml in drinking water for a period of 90 days showed mild to moderate changes in food consumption compared to control group. Drug interactions in lead exposed rats with metoclopramide, atropine sulphate, propranolol, cyproheptadine and mepyramine maleate when administered intraperitoneally caused -30 to +30 percentage variation in food intake indicating the influence of adrenergic, serotonergic and cholinergic neurotransmitters with no change in mean body weight of lead treated rats.


Asunto(s)
Anorexia/inducido químicamente , Peso Corporal/efectos de los fármacos , Compuestos Organometálicos/farmacología , Administración Oral , Animales , Anorexia/fisiopatología , Fármacos del Sistema Nervioso Autónomo/farmacología , Encéfalo/efectos de los fármacos , Interacciones Farmacológicas , Conducta Alimentaria/efectos de los fármacos , Masculino , Compuestos Organometálicos/administración & dosificación , Ratas
9.
Indian J Exp Biol ; 30(10): 901-3, 1992 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1293016

RESUMEN

To measure cholinergic, adrenergic and tryptaminergic receptor activity of formaldehyde (HCHO) in rat uterus, albino rats were treated with 5 and 10 mg/kg, ip HCHO for 30 days. Acetylcholine (ACh) in doses 1.33, 2 and 3 micrograms/ml produced mild to moderate contraction of isolated rat uterus in control group. HCHO had no effect on isolated rat uterus per se, however it reduced ACh and carbachol induced contraction and presence of adrenaline influences in respect of ACh and carbachol activity. Adrenaline per se had no effect in control preparations, but reduced carbachol induced contraction. Propranolol had no effect on rat uterus; but its presence in the bathing medium increased activity of adrenaline. 5-Hydroxytryptamine (5-HT) had no effect of its own on isolated rat uterus but its presence in the bathing medium enhanced contractions of carbachol and oxytocin.


Asunto(s)
Formaldehído/toxicidad , Útero/efectos de los fármacos , Animales , Femenino , Técnicas In Vitro , Ratas , Ratas Endogámicas , Receptores Adrenérgicos/efectos de los fármacos , Receptores Colinérgicos/efectos de los fármacos , Receptores de Serotonina/efectos de los fármacos , Contracción Uterina/efectos de los fármacos
11.
Hum Exp Toxicol ; 11(2): 89-92, 1992 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1349225

RESUMEN

Rats were exposed to an acute dose of lead (Pb) to study the effect of Pb intoxication on different sialoglycoconjugates in serum, brain and liver. Serum levels of total sialic acid (TSA), perchloric acid (PCA)-soluble sialic acid (PSA), lipid-bound sialic acid (LBSA), free sialic acid (FSA) and alpha 1-acid glycoprotein (alpha 1-AG) were determined. They were also estimated in brain and liver tissues, except for LBSA and FSA. All these constituents were found to be significantly raised in the serum but not in the brain. In the case of the liver, only alpha 1-AG levels were found to be increased significantly, the rest were not altered. The levels of these sialoglycoconjugates in serum might be useful as biomarkers of heavy metal toxicity.


Asunto(s)
Plomo/toxicidad , Ácidos Siálicos/análisis , Animales , Química Encefálica , Plomo/administración & dosificación , Hígado/química , Masculino , Ácido N-Acetilneuramínico , Orosomucoide/análisis , Ratas , Ratas Endogámicas , Ácidos Siálicos/sangre
13.
Minerva Psichiatr ; 32(4): 237-44, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1667023

RESUMEN

Lithium affects nerve excitation, synaptic transmitter and neuronal metabolism. These effects may be produced by alteration of ions transport or distribution, by inhibition of adenyl cyclase mediated responses or by more direct interference with neuronal metabolism. Which of these effects is responsible for the therapeutic benefit in mania, if any, is still unknown. This state of ignorance is directly related to conflicting interpretations and incomplete understanding of the manic state itself.


Asunto(s)
Litio/farmacología , Corticoesteroides , Aminas Biogénicas , Corteza Cerebral/efectos de los fármacos , Humanos , Litio/metabolismo , Contracción Muscular/efectos de los fármacos , Sodio/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/efectos de los fármacos , ATPasa Intercambiadora de Sodio-Potasio/metabolismo
14.
Agents Actions ; 33(3-4): 337-42, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1950820

RESUMEN

The present study examined the effects of lead (Pb) on the 5-hydroxytryptamine (5-HT) contracture and calcium (Ca++) kinetics of ileum of rat. Isolated ileum preparations incubated in excess Ca++ (2.8 mM) or in Ca++ free Tyrode solution showed decrease in sensitivity to 5-HT. The inhibitory action of Pb reduced the sensitivity and decrease maximum responses to 5-HT in any Mg++ concentration of the medium. In the normal Ca++ and its deficient medium deterioration in sensitivity to Pb and the relevant maximum response to 5-HT were observed. In excess Ca++, the Pb effect depressed corresponding to its maximal response to 5-HT. The presence of EDTA depressed the Pb effect irrespective of the Ca++ influence on the receptors. Thus Pb may be inhibiting responses to 5-HT by interfering Ca++ utilization.


Asunto(s)
Plomo/farmacología , Músculo Liso/efectos de los fármacos , Antagonistas de la Serotonina/farmacología , Serotonina/farmacología , Animales , Calcio/metabolismo , Ácido Edético/farmacología , Íleon/efectos de los fármacos , Íleon/metabolismo , Masculino , Metisergida/farmacología , Contracción Muscular/efectos de los fármacos , Permeabilidad , Fentolamina/farmacología , Ratas , Ratas Endogámicas
16.
Pharmacol Toxicol ; 65(5): 376-80, 1989 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-2482969

RESUMEN

Effects of hexachlorocyclohexane (Technical HCH) on the contractile responses of rat isolated Vas deferens to norepinephrine (NE) were investigated by varying the Ca++ and Mg++ concentrations of the incubation medium. Preparations incubated in excess Ca++ (4.2 mM) or in Ca++-free Krebs solution showed decrease in sensitivity to NE. The inhibitory action of HCH reduced the sensitivity and decreased maximum responses to NE in any Mg++ concentration of the medium. In the normal Ca++ and its deficient medium decrease in sensitivity to HCH and the relevant maximum response to NE were observed. In excess Ca++, the HCH effect depressed corresponding to its maximal response to NE. The presence of EDTA depressed the HCH effect irrespective of the Ca++ influence on the receptors.


Asunto(s)
Hexaclorociclohexano/farmacología , Músculo Liso/efectos de los fármacos , Norepinefrina/farmacología , Animales , Calcio/farmacología , Ácido Edético/farmacología , Técnicas In Vitro , Magnesio/farmacología , Masculino , Metisergida/farmacología , Contracción Muscular/efectos de los fármacos , Fentolamina/farmacología , Ratas , Ratas Endogámicas , Conducto Deferente/efectos de los fármacos
17.
Indian J Exp Biol ; 27(6): 561-7, 1989 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2583746

RESUMEN

Water soluble dried powder of alcoholic extract of roots and rhizomes of A. calamus L. was used. The in vivo experiments involved strychnine convulsant activity in frogs, spontaneous motor activity and amphetamine hyperactivity in mice, pentobarbitone sleeping-time in rats and local anaesthetic activity in guinea pigs and rabbits. Frog skeletal muscle and heart preparations and rat phrenic nerve diaphragm constituted the in vitro experiments. Plant extracts at 10, 20 mg/kg ip did not afford protection to strychnine (1,5,2.5 mg/kg) induced convulsions and same effect was found on acetylcholine induced contractions of rectus muscle except that it inhibited caffeine citrate contractions in frog. At 1, 10 and 100 micrograms/ml doses, it caused negative iono- and chronotropic effects in frogs. Dosages of 10, 25, 50 mg/kg ip of herbal extract antagonize spontaneous motor activity and also amphetamine induced hyperactivity in mice. It was less potent than chloropromazine, though exerts sedative and tranquilizing action. Local anaesthetic activity was found to be absent at 0.5 and 1% dose levels.


Asunto(s)
Sistema Nervioso Central/efectos de los fármacos , Corazón/efectos de los fármacos , Contracción Muscular/efectos de los fármacos , Conducción Nerviosa/efectos de los fármacos , Plantas Medicinales , Animales , Cobayas , Ratones , Extractos Vegetales/análisis , Extractos Vegetales/farmacología , Conejos , Ranidae , Ratas
18.
Res Commun Chem Pathol Pharmacol ; 63(3): 463-6, 1989 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2471237

RESUMEN

The effect of hexachlorocyclohexane (HCH) treatment in male albino rats at dosages of 3 and 6 mg/kg body weight by force-feeding were studied over a period of 180 days. Histological observations revealed graded degeneration in the muscular layer of vas deferens. Moreover, the accumulation of HCH residue in serum and vas deferens is highly significant in the experimental group. The contractility of muscles showed marked inhibition by in vitro study.


Asunto(s)
Hexaclorociclohexano/toxicidad , Músculo Liso/efectos de los fármacos , Administración Oral , Animales , Hexaclorociclohexano/sangre , Técnicas In Vitro , Masculino , Contracción Muscular/efectos de los fármacos , Tamaño de los Órganos/efectos de los fármacos , Ratas , Conducto Deferente/efectos de los fármacos
19.
J Appl Toxicol ; 9(1): 67-8, 1989 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2538502

RESUMEN

Male Swiss mice were exposed to a single LD50 (75%; i.p.) of mercury, zinc, lead and manganese to determine their influence on serum sialic acid and protein levels after a refractory period of 48 h. They significantly elevated, in different proportions, the serum levels of total and perchloric acid (PCA)-soluble sialic acids (biological marker) and PCA-soluble proteins, thus indicating their toxicity.


Asunto(s)
Proteínas Sanguíneas/análisis , Ácidos Siálicos/sangre , Oligoelementos/toxicidad , Animales , Plomo/toxicidad , Dosificación Letal Mediana , Masculino , Intoxicación por Manganeso , Mercurio/toxicidad , Ratones , Ácido N-Acetilneuramínico , Percloratos , Factores de Tiempo , Zinc/toxicidad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA