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1.
Drug Discov Ther ; 7(3): 109-15, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23917859

RESUMO

α-Santalol is active component of sandalwood oil and has been shown to have chemopreventive effects against chemically and UVB-induced skin cancer development in mice. α-Santalol is also shown to have skin permeation enhancing effects. Honokiol and magnolol isolated from Magnolia officinalis bark extract have also been shown to have chemopreventive effects against chemically and UVB-induced skin cancer in mice. This study was conducted to investigate the combination effects of α-santalol, honokiol and magnolol to study any additive/synergistic effects to lower the doses required for chemoprevention. Pretreatment of combinations of α-santalol with honokiol and magnolol significantly decreased tumor multiplicity upto 75% than control, α-santalol, honokiol and magnolol alone in SKH-1 mice. Combination of α-santalol with honokiol and magnolol also decreased cell viability, proliferation, and enhanced apotosis in comparison to α-santalol, honokiol and magnolol alone in Human epidrmoid carcinoma A431 cells. Overall, the results of present study indicated combinations of α-santalol with honokiol and magnolol could provide chemoprevention of skin cancer at lower doses than given alone.


Assuntos
Anticarcinógenos/administração & dosagem , Compostos de Bifenilo/administração & dosagem , Lignanas/administração & dosagem , Sesquiterpenos/administração & dosagem , Neoplasias Cutâneas/prevenção & controle , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Quimioterapia Combinada , Feminino , Camundongos , Neoplasias Induzidas por Radiação/prevenção & controle , Sesquiterpenos Policíclicos , Neoplasias Cutâneas/etiologia , Raios Ultravioleta
2.
Drug Discov Ther ; 4(3): 184-9, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22491182

RESUMO

Previous studies from our laboratory have shown chemopreventive effects of dietary flaxseed on azoxymethane-induced colon tumor development in male Fischer rats and Apc(Min) mice. Tumorigenesis is associated with uncontrolled cell growth and loss of apoptosis. Accordingly, the objective of this investigation was to study the effects of mammalian lignans (enterodiol and enterolactone) and ω-3 polyunsaturated fatty acid α-linolenic acid, principal active components in flaxseed on cell proliferation and apoptosis in human colon adenocarcinoma Caco-2 cells, thus elucidating possible mechanism of action. BrdU incorporation assay was used for cell proliferation and fluorescence-activated cell sorting (FACS) analysis of annexin V/propidium iodide staining was used for determining apoptotic cells. Results showed that enterodiol, enterolactone and α-linolenic acid at different concentrations caused a significant (p < 0.05) increase in apoptotic cells and decrease in cell proliferation. Therefore, dietary flaxseed containing α-linolenic acid and lignans causes a decrease in cell proliferation and an increase in apoptosis resulting in the effective chemoprevention for intestinal and colon tumor development.


Assuntos
Células CACO-2 , Linho , Adenocarcinoma , Animais , Neoplasias do Colo , Humanos
3.
J Dairy Sci ; 92(3): 847-56, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19233777

RESUMO

The objective of this research was to evaluate the rheological, sensorial, and chemopreventive properties of milk fermented with different exopolysaccharide (EPS)-producing lactic cultures. Reconstituted skim milk (11% wt/vol) was fermented with single strains of EPS-producing and non-EPS-producing cultures. Whey that collected on the surface of undisturbed fermented milks and after cutting was measured. All EPS-producing cultures reduced the amount of whey present on the surface of the undisturbed samples, whereas only 3 out of 5 strains reduced syneresis measured after cutting. All EPS-producing cultures except a strain of Lactobacillus delbrueckii ssp. bulgaricus reduced viscoelastic moduli in fermented milk. There was a linear correlation between ropiness and smoothness. In the chemoprevention study, 140 male Fisher rats were divided into 7 groups of 20 each. Rats in 6 groups were fed diets supplemented with fermented milks each made with a single strain of EPS-producing or non-producing cultures, whereas rats in group 7 (control) were fed a diet supplemented with milk acidified with glucono-delta-lactone (GDL). All rats were injected with azoxymethane (15 mg/kg, subcutaneous) at wk 7 and 8 of age to induce tumors and fed their respective diets ad libitum throughout the study. After 30 wk of initiation, all rats were anesthetized with ether, and their intestinal tissues were isolated and washed with cold normal saline. The number and size of tumors in the colon and small intestine were recorded. Rats fed diets supplemented with fermented milk made with 2 EPS-positive and 1 EPS-negative strains had significantly lowered incidence of colon tumor and colon tumor multiplicity. Cyclooxygenase-2 enzyme activity (the enzyme implicated in colon tumor development) was significantly lower in the colon tissue of rats fed diets containing milk fermented with 4 EPS-producing and 1 non-producing cultures than that in rats fed diets supplemented with GDL-acidified milk. Different EPS-positive cultures produced fermented milks with distinct rheological characteristics and levels of ropiness. No relationship was found between rheological properties or level of ropiness of fermented milk and its chemopreventive effect.


Assuntos
Produtos Fermentados do Leite/normas , Neoplasias Intestinais/prevenção & controle , Sensação , Animais , Colo/enzimologia , Neoplasias do Colo/prevenção & controle , Ciclo-Oxigenase 2/metabolismo , Dieta , Bactérias Gram-Positivas , Humanos , Masculino , Ratos , Reologia
4.
J Environ Biol ; 26(3): 495-503, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16334288

RESUMO

In the course of systematic and ecological studies on algal flora of fresh water environment of three different agroclimatic zone of Uttar Pradesh revealed one hundred eighty two species represented by fifty-two genera inhabiting fresh water bodies having different physico-chemical properties. In both the regions members of order Conjugales were dominant and represented by ninety nine species belonging to fourteen genera. This is followed by Chlorococcales having fifty two species represented by nineteen genera and Chaetophorales with nine species of four genera only. In the central Uttar Pradesh a positive correlation was found between hydrogen ions concentration with temperature and species diversity, while in western Uttar Pradesh a highly positive correlation was found in electrical conductivity and total dissolved solids.


Assuntos
Biodiversidade , Clorófitas , Água Doce/microbiologia , Condutividade Elétrica , Água Doce/química , Concentração de Íons de Hidrogênio , Índia , Dinâmica Populacional , Temperatura
5.
Eur J Cancer Prev ; 14(5): 473-6, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16175052

RESUMO

Previous studies from this laboratory have indicated that alpha-santalol (5%) provides chemopreventive effects in 7,12-dimethylbenz[a]anthracene (DMBA)-initiated and 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted skin cancer in CD-1 and SENCAR mice. Skin cancer development is associated with increased ornithine decarboxylase (ODC) activity, DNA synthesis and rapid proliferation of epidermal cells. The purpose of this investigation was to determine the effects of various concentrations (1.25% and 2.5%) of alpha-santalol on DMBA-initiated and TPA-promoted skin cancer development, TPA-induced ODC activity, and DNA synthesis in CD-1 mice. alpha-Santalol treatment at both concentrations (1.25% and 2.5%) prevented the skin cancer development. alpha-Santalol treatment (1.25% and 2.5%) resulted in a significant decrease in the TPA-induced ODC activity and incorporation of [3H]thymidine in DNA in the epidermis of CD-1 mice. There was no significant difference in the effects of 1.25% and 2.5% alpha-santalol on tumour incidence, multiplicity, epidermal TPA-induced ODC activity, or DNA synthesis in CD-1 mice.


Assuntos
Anticarcinógenos/farmacologia , Papiloma/prevenção & controle , Sesquiterpenos/farmacologia , Neoplasias Cutâneas/prevenção & controle , 9,10-Dimetil-1,2-benzantraceno , Animais , Carcinógenos , Quimioprevenção , DNA de Neoplasias/efeitos dos fármacos , DNA de Neoplasias/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Camundongos , Ornitina Descarboxilase/efeitos dos fármacos , Ornitina Descarboxilase/metabolismo , Papiloma/induzido quimicamente , Papiloma/enzimologia , Ésteres de Forbol , Sesquiterpenos Policíclicos , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/enzimologia
6.
J Environ Biol ; 26(1): 21-30, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16114457

RESUMO

The paper deals with 45 species of 21 genera of fresh water blue green algae (BGA) from three different agro-climatic zones of Uttar Pradesh. Samples were collected from different habitats varying in physico-chemical properties. Out of 45 species, 13 species belonged to order Chroococcales, 31 to order Nostocales, while only 1 species belonged to order Stigonimatales i.e. Fischerella mucicola. The physico-chemical parameters like pH, temperature, dissolved oxygen, electrical conductivity, nitrate, nitrite and rainfall play an important role in the periodicity of BGA. A positive correlation was found between dissolved oxygen (DO) of different ponds and species diversity, except in the case of western region of Uttar Pradesh (Farukhabad and Mahoba districts) where a positive correlation was found in electrical conductivity and total dissolved solids.


Assuntos
Clima , Cianobactérias/classificação , Estações do Ano , Concentração de Íons de Hidrogênio , Índia , Oxigênio , Especificidade da Espécie , Temperatura
7.
J Biomater Appl ; 15(4): 321-43, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11336386

RESUMO

Gellan gum is an anionic polysaccharide produced by the aerobic fermentation of Pseudomonas elodea in batch culture. Gellan undergoes calcium-induced cross-linking to form a three-dimensional network, and this property makes it particularly attractive for the incorporation of biological moieties such as proteins. In this study, a procedure for the preparation of gellan films was developed and optimized, and the characteristics of these films were investigated. In addition, the effects of the concentration of each ingredient in gellan films and in vitro release behavior of fluorescein isothiocyanate dextran from these films was examined. This film device was implanted for insulin delivery in diabetic rats. The blood glucose levels of the diabetic rats implanted with insulin-loaded films were about half of those implanted with blank films, and this therapeutic effect of insulin could last for one week. Both in vitro and in vivo studies indicated that the gellan film could be an ideal candidate in the development of protein delivery systems.


Assuntos
Implantes de Medicamento , Insulina/administração & dosagem , Polissacarídeos Bacterianos , Animais , Glicemia/análise , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/tratamento farmacológico , Técnicas In Vitro , Insulina/uso terapêutico , Masculino , Teste de Materiais , Microscopia Eletrônica de Varredura , Ratos , Ratos Sprague-Dawley , Estreptozocina
8.
J Gen Psychol ; 127(3): 271-7, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10975426

RESUMO

Left-, mixed-, and right-handed (each n = 10, N = 30) adolescent boys who were classified on the basis of a hand preference inventory performed a mirror-drawing task with a bilateral transfer of a skill paradigm. Participants' hand preference and the magnitude of bilateral transfer of skill were assessed in terms of errors committed and time taken to complete the mirror-drawing task. Mixed-handed participants exhibited significantly less habit interference for mirror drawing, and they performed the task significantly faster than the left-handers did; the group difference was not significant for the frequency of errors committed. These groups did not differ in terms of the magnitude of bilateral transfer of skill; the trend, however, showed that the transfer of skill was minimum in mixed-handers. These findings extend the theory that mixed-handed participants' inability to transfer motor skill from one hand to the other could be attributable to their lack of a clear pattern of lateralization. Their ability to perform well either at initial or later trials may be a function of less interference from their normal motor habits.


Assuntos
Dominância Cerebral , Lateralidade Funcional , Desempenho Psicomotor , Adolescente , Humanos , Masculino , Transferência de Experiência
9.
Eur J Cancer Prev ; 8(5): 449-55, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10548401

RESUMO

Sandalwood oil (SW oil) has been used for the treatment of inflammatory and eruptive skin diseases. In the present study, the chemopreventive effects of SW oil on 7,12-dimethylbenz(a)-anthracene (DMBA)-initiated and 12-O-tetradecanoylphorbol-13-acetate(TPA)-promoted skin tumour development and TPA-induced ornithine decarboxylase (ODC) activity in CD1 mice were investigated. Female CD1 mice (5-6 weeks old) were divided in different groups, having 30 mice in each group. One week after topical application of DMBA (200 nmole in 100 microl acetone) alone or with SW oil at different concentrations (100 microl, 1.25, 2.5, 3.75, 5% in acetone), at different times (0.5, 1, 2 h) before DMBA, the mice were treated topically with TPA (5 nmole in 100 microl acetone) alone or with SW oil at different concentrations (100 microl, 1.25, 2.5, 3.75, 5% in acetone) at different times (0.5, 1, 2 h) before TPA applications twice a week for 20 weeks. The mice were weighed and papillomas counted weekly. The results indicate that SW oil pre-treatment decreased the papilloma incidence and multiplicity in a concentration and time-dependent manner. The pre-treatment with 5% SW oil (100 microl) 1 h before DMBA and TPA treatments provided a maximum of 67% and 96% decrease in papilloma incidence and multiplicity, respectively, after 20 weeks of promotion. The mice pre-treated with SW oil at all concentrations and time period before TPA had significantly lower ODC activity than the group treated with TPA alone. The data suggest that SW oil could be an effective chemopreventive agent against chemically-induced skin cancer.


Assuntos
Antineoplásicos/administração & dosagem , Cumarínicos/administração & dosagem , Óleos de Plantas , Sesquiterpenos/administração & dosagem , Neoplasias Cutâneas/prevenção & controle , Pele/efeitos dos fármacos , 9,10-Dimetil-1,2-benzantraceno , Administração Tópica , Animais , Carcinógenos , Quimioprevenção , Distribuição de Qui-Quadrado , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Camundongos , Camundongos Endogâmicos , Valores de Referência , Pele/patologia , Neoplasias Cutâneas/induzido quimicamente , Acetato de Tetradecanoilforbol/análogos & derivados
10.
Anticancer Drugs ; 10(2): 139-46, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10211543

RESUMO

Tissue electroporation has been explored to enhance the local delivery of chemotherapueutic agents to solid tumors. The technique, known as electrochemotherapy (ECT), uses high-voltage pulses to deliver drugs across cancerous tissues. ECT has been demonstrated to be an effective treatment for cutaneous malignancies. Recent studies also indicate that the applications of ECT can be extended from the treatment of cutaneous cancers to the treatment of tumors of vital organs such as brain, liver, lungs and others. This review also discusses electrogene antitumor therapy.


Assuntos
Antineoplásicos/administração & dosagem , Sistemas de Liberação de Medicamentos , Eletroporação/métodos , Neoplasias/tratamento farmacológico , Animais , Membrana Celular , Ensaios Clínicos como Assunto , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Previsões , Humanos , Imunoterapia/métodos
11.
Anticancer Drugs ; 9(3): 291-4, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9625441

RESUMO

Clinical efficacy of doxorubicin is compromised due to free radical generation leading to cardiac toxicity. Oil-soluble organosulfur compounds, diallyl sulfide (DAS), diallyl disulfide (DADS), dipropyl sulfide (DPS) and dipropyl disulfide (DPDS), present in garlic were examined for their antiperoxidant effects. DADS inhibited liver microsomal lipid peroxidation induced by NADPH, ascorbate and doxorubicin. DAS, DPS and DPDS were ineffective inhibitors of liver microsomal lipid peroxidation. DADS could be used in combination with doxorubicin to protect oxidative injuries to improve the clinical efficacy of doxorubicin.


Assuntos
Compostos Alílicos/farmacologia , Antineoplásicos/farmacologia , Dissulfetos/farmacologia , Doxorrubicina/farmacologia , Alho , Peroxidação de Lipídeos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Plantas Medicinais , Propano/análogos & derivados , Sulfetos/farmacologia , Animais , Ácido Ascórbico/farmacologia , Masculino , Microssomos Hepáticos/efeitos dos fármacos , NADP/farmacologia , Propano/farmacologia , Ratos , Ratos Sprague-Dawley
12.
Eur J Cancer Prev ; 6(4): 399-401, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9370104

RESUMO

The essential oil, emulsion or paste of sandalwood (Santalum album L) has been used in India as an ayurvedic medicinal agent for the treatment of inflammatory and eruptive skin diseases. In this investigation, the chemopreventive effects of sandalwood oil (5% in acetone, w/v) on 7,12-dimethylbenz(a)anthracene-(DMBA)-initiated and 12-O-tetradecanoyl phorbol-13-acetate(TPA)-promoted skin papillomas, and TPA-induced ornithine decarboxylase (ODC) activity in CD1 mice were studied. Sandalwood oil treatment significantly decreased papilloma incidence by 67%, multiplicity by 96%, and TPA-induced ODC activity by 70%. This oil could be an effective chemopreventive agent against skin cancer.


Assuntos
Cumarínicos/uso terapêutico , Ornitina Descarboxilase/metabolismo , Papiloma/prevenção & controle , Óleos de Plantas/uso terapêutico , Sesquiterpenos/uso terapêutico , Neoplasias Cutâneas/prevenção & controle , 9,10-Dimetil-1,2-benzantraceno , Animais , Quimioprevenção , Distribuição de Qui-Quadrado , Modelos Animais de Doenças , Incidência , Camundongos , Camundongos Endogâmicos , Razão de Chances , Papiloma/induzido quimicamente , Papiloma/epidemiologia , Valores de Referência , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/epidemiologia , Taxa de Sobrevida
13.
Drug Chem Toxicol ; 19(4): 313-24, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8972237

RESUMO

Differences in cocaine-induced central nervous system toxicity in pregnant and postpartum rats have been observed. For example, a 20 mg/kg, intraperitoneal dosage of cocaine that was tolerated during pregnancy caused tonic-clonic convulsions and death during the postpartum period. In the present study, biodistribution of cocaine during different perinatal periods was investigated to understand the differences in toxicity. Nonpregnant, 22-day pregnant, and postpartum rats were injected with 3H cocaine (12 mg/20 mu ci/kg, i.v.). Rats were sacrificed under ether anesthesia at predetermined time intervals. Brain, serum, fetal brain and placenta (from pregnant rats) samples were isolated, solubilized, and counted in a scintillation counter for radioactivity. Peak levels of cocaine were observed at 15 and 60 minutes after injection in maternal serum and brain, respectively, in 22-day pregnant rats. However, peak levels of cocaine were observed at 30 minutes after the injection in placental and fetal brain tissues from 22-day pregnant rats. Cocaine level of brain was elevated in all postpartum rats compared to nonpregnant and pregnant rats. These results indicated that higher levels of cocaine is distributed to brain after delivery compared to the nonpregnant and pregnant rats which may explain increased CNS toxicity during postnatal period.


Assuntos
Cocaína/farmacocinética , Trabalho de Parto/metabolismo , Período Pós-Parto/metabolismo , Prenhez/metabolismo , Animais , Química Encefálica , Cocaína/toxicidade , Feminino , Feto/química , Injeções Intravenosas , Troca Materno-Fetal , Placenta/química , Gravidez , Ratos , Ratos Endogâmicos F344 , Distribuição Tecidual
14.
Anticancer Drugs ; 7(7): 792-4, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8949992

RESUMO

The effects of diallyl sulfide (DAS) and diallyl disulfide (DADS) on cisplatin-induced changes in glutathione (GSH) and glutathione-S-transferase (GST) activity in rat liver and kidney was investigated. Cisplatin treatment significantly (p < 0.05) decreased GSH and GST activity in both liver and kidney. DADS treatment significantly (p < 0.05) enhanced GSH and GST activity in rat liver and kidney. Furthermore, DADS treatment reversed the effect of cisplatin on GSH and GST activity both in liver and kidney. Administration of DADS with cisplatin could enhance GSH and GST activity and lower cisplatin-induced nephrotoxicity.


Assuntos
Compostos Alílicos , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Cisplatino/farmacologia , Dissulfetos/farmacologia , Glutationa Transferase/metabolismo , Glutationa/metabolismo , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Sulfetos/farmacologia , Animais , Rim/enzimologia , Rim/metabolismo , Fígado/enzimologia , Fígado/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley
15.
J Biomater Appl ; 11(1): 62-75, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8872600

RESUMO

The purpose of this investigation is to study the effect of long-term subcutaneous aluminum polymeric implants on aluminum release and accumulation in various tissues in rats. The implants were formulated using silicone rubber and polyurethane polymers and three different aluminum salts. The polymeric matrices were evaluated for in vitro release studies. These matrices released aluminum in vitro up to the period of four months. The aluminum matrices were implanted in rats and animals were sacrificed at various time intervals. Various tissues such as brain, kidney, liver, intestine, and heart were isolated. Aluminum in dried tissues was analyzed by Neutron Activation Analysis. Results from this investigation suggest that polymeric aluminum implants raise the aluminum concentration in the brain and liver. However, these implants did not increase aluminum levels in intestine, heart, and kidney. The polymeric aluminum implants could be used to establish an animal model for the neuropathology of dementia.


Assuntos
Alumínio , Materiais Biocompatíveis , Polímeros , Próteses e Implantes , Alumínio/química , Alumínio/farmacocinética , Compostos de Alumínio/química , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacocinética , Encéfalo/metabolismo , Demência/etiologia , Procedimentos Cirúrgicos Dermatológicos , Modelos Animais de Doenças , Técnicas In Vitro , Mucosa Intestinal/metabolismo , Rim/metabolismo , Fígado/metabolismo , Masculino , Teste de Materiais , Miocárdio/metabolismo , Análise de Ativação de Nêutrons , Polímeros/química , Polímeros/farmacocinética , Poliuretanos/química , Ratos , Ratos Sprague-Dawley , Elastômeros de Silicone/química , Fatores de Tempo , Distribuição Tecidual
16.
Res Commun Mol Pathol Pharmacol ; 90(1): 133-42, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8581338

RESUMO

The major detoxification process for selenium is methylation. The major pathway for the formation of methylated compounds in biological systems is transmethylation catalyzed by methyltransferases. In this study methyltransferase activity was assayed in the liver cytosol prepared from different strains of rats using HPLC method by measuring the formation of epinephrine from norepinephrine. The methyltransferase activity in Fischer, Wistar, and Sprague-Dawley rats were 1.65 x 10(-12), 0.74 x 10(-12), and 1.2 x 10(-12) moles epinephrine formed/mg protein/hr respectively. Volatilization of injected Se (2.5 mg/kg, i.p.) was found to be higher in Wistar rats compared to Fischer rats. LD50 for Wistar and Fischer rats were 2.58 and 3.15 mg Se/kg respectively. Our results suggest that the methylation of dimethyl selenide to trimethhyl selenide appears to be an important step in the detoxification of selenium.


Assuntos
Selênio/toxicidade , Animais , Cromatografia Líquida de Alta Pressão , Epinefrina/metabolismo , Inativação Metabólica , Dose Letal Mediana , Masculino , Metilação , Metiltransferases/metabolismo , Norepinefrina/metabolismo , Ratos , Ratos Endogâmicos F344 , Ratos Sprague-Dawley , Ratos Wistar , Selênio/metabolismo , Selênio/farmacocinética , Especificidade da Espécie
17.
Toxicol Lett ; 74(3): 235-40, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7871547

RESUMO

Organochlorine pesticides increase the incidence of liver cancer through a multistage process involving tumor promotion. Mirex, an organochlorine pesticide has been shown to be a tumor promoter in mouse skin. In the present study, the effects of methoxychlor, a commonly used organochlorine pesticide, on the development of papillomas in 7,12-dimethylbenz[a]anthracene (DMBA)-initiated mouse skin and induction of mouse epidermal ornithine decarboxylase (ODC) activity were investigated and compared with 12-O-tetradecanoylphorbol-13-acetate (TPA), a well-known tumor promoter. Methoxychlor neither caused tumor development nor induced epidermal ODC activity. However, TPA resulted in 100% tumor incidence and 8.8 tumors per mouse after 20 weeks of promotion, and induced epidermal ODC activity.


Assuntos
Metoxicloro/toxicidade , Papiloma/induzido quimicamente , Neoplasias Cutâneas/induzido quimicamente , 9,10-Dimetil-1,2-benzantraceno/administração & dosagem , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Modelos Animais de Doenças , Indução Enzimática/efeitos dos fármacos , Epiderme/efeitos dos fármacos , Epiderme/enzimologia , Feminino , Metoxicloro/administração & dosagem , Camundongos , Ornitina Descarboxilase/biossíntese , Acetato de Tetradecanoilforbol/administração & dosagem , Acetato de Tetradecanoilforbol/toxicidade
18.
Biochem Biophys Res Commun ; 199(2): 582-6, 1994 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-8135799

RESUMO

Calcium has been suggested to be an intracellular second messenger for ornithine decarboxylase (ODC) induction caused by 12-O-tetradecanoylphorbol-13-acetate (TPA). In the present study, the effects of dietary calcium supplement and calcium and verapamil injections on TPA-induced ODC activity in skin was investigated in CD-1 and SENCAR mouse. Dietary calcium supplement did not influence ODC induction caused by TPA. However, calcium injections enhanced the TPA-induced ODC activity in CD-1 and SENCAR mouse skin. Verapamil injections resulted in a significant decrease in TPA-induced ODC activity in CD-1 and SENCAR mice. These results suggest that calcium and calcium antagonists may play a role in skin tumor promotion caused by TPA.


Assuntos
Cálcio da Dieta/farmacologia , Ornitina Descarboxilase/biossíntese , Pele/enzimologia , Acetato de Tetradecanoilforbol/farmacologia , Verapamil/farmacologia , Animais , Indução Enzimática/efeitos dos fármacos , Feminino , Cinética , Camundongos , Camundongos Endogâmicos , Pele/efeitos dos fármacos , Especificidade da Espécie
19.
Anticancer Res ; 13(2): 395-9, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8517653

RESUMO

The biochemical basis for the cancer chemopreventive and anti-cancer activities of glucarate, retinoids (13-cis-retinoic acid, hydroxyphenyl retinamide) and their synergistic combination, has been evaluated. Neither alone nor in combination did these agents affect the level in the rat, of enzymes which are (a) known to correlate with reduced risk of carcinogenesis (detoxification enzyme, catalase, glutathione reductase) nor (b) enzymes which correlate with increased risk of carcinogenesis (beta-glucuronidase, xanthine oxidase, glucose-6-phosphate dehydrogenase). Retinoids, but neither glucarate nor its lactone inhibited free radical-induced lipid peroxidation. Both agents alone and synergistically in combination, raise cellular cAMP levels, repress protein kinase C and more generally inhibited DNA synthesis.


Assuntos
Anticarcinógenos/uso terapêutico , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/prevenção & controle , Ácido Glucárico/uso terapêutico , Retinoides/uso terapêutico , Animais , Neoplasias da Mama/enzimologia , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , DNA de Neoplasias/biossíntese , Sinergismo Farmacológico , Feminino , Ácido Glucárico/administração & dosagem , Humanos , Neoplasias Mamárias Animais/tratamento farmacológico , Neoplasias Mamárias Animais/enzimologia , Neoplasias Mamárias Animais/prevenção & controle , Lesões Pré-Cancerosas/tratamento farmacológico , Lesões Pré-Cancerosas/patologia , Ratos , Ratos Sprague-Dawley , Retinoides/administração & dosagem , Timidina/metabolismo , Tretinoína/uso terapêutico , Trítio , Células Tumorais Cultivadas/efeitos dos fármacos
20.
J Genet Psychol ; 154(1): 73-83, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8331333

RESUMO

Levy's (1983) familiarization and proofreading paradigm was used to examine the context-processing relationship during reading of Hindi textual materials. Sixty high- and 60 low-deprived male students in Classes 11 and 12 were asked to proofread error-filled passages of easy and difficult text. Familiarity was manipulated by presenting error-free versions of the passages to some subjects but not to others for a single reading before their actual proofreading. Familiar passages were processed faster than unfamiliar passages irrespective of students' deprivation and passage difficulty. Slow processing was recorded for highly deprived subjects and for easy passages. Faster processing was associated with higher error detection and higher short-term retention scores, whereas the opposite was true for slower processing. Familiarity enhanced short-term retention, suggesting some involvement of conceptually driven process even after familiarization. Findings are discussed in light of interactive processing models of reading.


Assuntos
Atenção , Países em Desenvolvimento , Carência Psicossocial , Leitura , Classe Social , Adolescente , Humanos , Índia , Masculino , Memória de Curto Prazo
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