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1.
Ann Oncol ; 32(3): 368-374, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33278599

RESUMO

BACKGROUND: Adjuvant chemotherapy and chemoradiotherapy are some of the standards of care for gastric cancer (GC). The Adjuvant chemoRadioTherapy In Stomach Tumors (ARTIST) 2 trial compares two adjuvant chemotherapy regimens and chemoradiotherapy in patients with D2-resected, stage II or III, node-positive GC. PATIENTS AND METHODS: The ARTIST 2 compared, in a 1:1:1 ratio, three adjuvant regimens: oral S-1 (40-60 mg twice daily 4 weeks on/2 weeks off) for 1 year, S-1 (2 weeks on/1 week off) plus oxaliplatin 130 mg/m2 every 3 weeks (SOX) for 6 months, and SOX plus chemoradiotherapy 45 Gy (SOXRT). Randomization was stratified according to surgery type (total or subtotal gastrectomy), pathologic stage (II or III), and Lauren histologic classification (diffuse or intestinal/mixed). The primary endpoint was disease-free survival (DFS) at 3 years; a reduction of 33% in the hazard ratio (HR) for DFS with SOX or SOXRT, when compared with S-1, was considered clinically meaningful. The trial is registered at clinicaltrials.gov (NCT0176146). RESULTS: A total of 546 patients were recruited between February 2013 and January 2018 with 182, 181, and 183 patients in the S-1, SOX, and SOXRT arms, respectively. Median follow-up period was 47 months, with 178 DFS events observed. Estimated 3-year DFS rates were 64.8%, 74.3%, and 72.8% in the S-1, SOX, and SOXRT arms, respectively. HR for DFS in the control arm (S-1) was shorter than that in the SOX and SOXRT arms: S-1 versus SOX, 0.692 (P = 0.042) and S-1 versus SOXRT, 0.724 (P = 0.074). No difference in DFS was found between SOX and SOXRT (HR 0.971; P = 0.879). Adverse events were as anticipated in each arm, and were generally well-tolerated and manageable. CONCLUSIONS: In patients with curatively D2-resected, stage II/III, node-positive GC, adjuvant SOX or SOXRT was effective in prolonging DFS, when compared with S-1 monotherapy. The addition of radiotherapy to SOX did not significantly reduce the rate of recurrence after D2 gastrectomy.


Assuntos
Neoplasias Gástricas , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Capecitabina/uso terapêutico , Quimioterapia Adjuvante , Intervalo Livre de Doença , Fluoruracila/uso terapêutico , Humanos , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Oxaliplatina/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia
2.
Neurogastroenterol Motil ; 28(1): 127-38, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26526698

RESUMO

BACKGROUND: A majority of the subjects with irritable bowel syndrome (IBS) show increased behavioral and brain responses to expected and delivered aversive visceral stimuli during controlled rectal balloon distension, and during palpation of the sigmoid colon. We aimed to determine if altered brain responses to cued and uncued pain expectation are also seen in the context of a noxious somatic pain stimulus applied to the same dermatome as the sigmoid colon. METHODS: A task-dependent functional magnetic resonance imaging technique was used to investigate the brain activity of 37 healthy controls (18 females) and 37 IBS subjects (21 females) during: (i) a cued expectation of an electric shock to the abdomen vs a cued safe condition; and (ii) an uncued cross-hair condition in which the threat is primarily based on context vs a cued safe condition. KEY RESULTS: Regions within the salience, attention, default mode, and emotional arousal networks were more activated by the cued abdominal threat condition and the uncued condition than in the cued safe condition. During the uncued condition contrasted to the cued safe condition, IBS subjects (compared to healthy control subjects) showed greater brain activations in the affective (amygdala, anterior insula) and attentional (middle frontal gyrus) regions, and in the thalamus and precuneus. These disease-related differences were primarily seen in female subjects. CONCLUSIONS & INFERENCES: The observed greater engagement of cognitive and emotional brain networks in IBS subjects during contextual threat may reflect the propensity of IBS subjects to overestimate the likelihood and severity of future abdominal pain.


Assuntos
Dor Abdominal/fisiopatologia , Antecipação Psicológica , Encéfalo/fisiopatologia , Sinais (Psicologia) , Síndrome do Intestino Irritável/fisiopatologia , Adulto , Tonsila do Cerebelo/fisiopatologia , Estudos de Casos e Controles , Córtex Cerebral/fisiopatologia , Colo Sigmoide , Estimulação Elétrica , Feminino , Neuroimagem Funcional , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Dor/fisiopatologia , Limiar da Dor , Lobo Parietal/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Pressão , Reto , Fatores Sexuais , Tálamo/fisiopatologia , Adulto Jovem
3.
Acta Anaesthesiol Scand ; 56(3): 376-81, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22260199

RESUMO

BACKGROUND: Spinal block induces hyperkinetic change in lower extremity blood flow. We compared the venous flow dynamic responses to spinal block in normotensive and hypertensive elderly patients. METHODS: Following spinal block using 10 mg 0.5% (w/v) bupivacaine, we measured changes in blood pressure, heart rate, and venous flow dynamics of the popliteal vein by duplex ultrasonography in 20 normotensive (NBP group) and 18 hypertensive (HIBP group) patients. RESULTS: Spinal block caused significant decreases in blood pressure in both groups; similar rates of hypotension were observed. At baseline, peak velocity, time-averaged maximum velocity, and time-averaged mean velocity were higher in the HIBP than in the NBP group. During spinal block, peak velocity increased in both groups, and the between-group differences were no longer significant. At baseline, volume flow in the two groups was similar and increased by 141.5% in the NBP and 131.7% in the HIBP group during spinal block. CONCLUSIONS: Blood pressure and flow dynamics in the popliteal vein showed similar changes during spinal anaesthesia in elderly patients taking antihypertensive medication and normotensive patients, despite differences in baseline values.


Assuntos
Raquianestesia , Hipertensão/diagnóstico por imagem , Hipertensão/fisiopatologia , Veia Poplítea/diagnóstico por imagem , Veia Poplítea/fisiologia , Idoso , Pressão Sanguínea/fisiologia , Interpretação Estatística de Dados , Frequência Cardíaca/fisiologia , Humanos , Masculino , Fluxo Sanguíneo Regional/fisiologia , Reprodutibilidade dos Testes , Tamanho da Amostra , Ressecção Transuretral da Próstata , Ultrassonografia
4.
Acta Anaesthesiol Scand ; 56(3): 382-7, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22220945

RESUMO

BACKGROUND: Dexmedetomidine (DMT) has been shown to prolong spinal anaesthesia. We evaluated the effects of intravenous DMT on low-dose bupivacaine spinal anaesthesia in elderly patients. METHODS: Fifty-one elderly patients undergoing transurethral resection of the prostate were randomized into two groups receiving either 1.0 µg/kg DMT (DMT group, n = 26) or normal saline (control group n = 25) intravenously prior to spinal anaesthesia with 1.2 ml of bupivacaine, 5 mg/ml. RESULTS: The mean time to two-segment regression (39 min vs. 78 min for cold, 41 min vs. 61 min for pinprick) and that to motor regression (23 min vs. 46 min) were longer in the DMT group than in the control group. The atropine-requiring bradycardia was more frequent in the DMT group than in the control group (24.0% vs. 3.8%). The median sedation scores (ranges) during surgery were 4 (2-6) in the DMT group and 2 (1-3) in the control group (P < 0.001). Two patients in the DMT group showed oxygen desaturation (peripheral oxygen saturation < 90%) during surgery. The duration of post-operative care unit stay was longer in the DMT group than in the control group (58 min vs. 96 min). Post-operative pain intensity was lower and the mean time to first request for post-operative analgesia was longer in the DMT group compared to the control group (6.6 h vs. 2.1 h). CONCLUSION: Intravenous DMT prolonged the duration of spinal anaesthesia and improved post-operative analgesia. However, more profound sedation with desaturation was observed with more frequent bradycardia, and delayed recovery should be considered in elderly patients.


Assuntos
Raquianestesia , Anestésicos Locais , Bupivacaína , Dexmedetomidina , Hipnóticos e Sedativos , Idoso , Raquianestesia/efeitos adversos , Anestésicos Locais/administração & dosagem , Anestésicos Locais/efeitos adversos , Bupivacaína/administração & dosagem , Bupivacaína/efeitos adversos , Dexmedetomidina/administração & dosagem , Dexmedetomidina/efeitos adversos , Método Duplo-Cego , Hidratação , Humanos , Hipnóticos e Sedativos/administração & dosagem , Hipnóticos e Sedativos/efeitos adversos , Injeções Intravenosas , Masculino , Medição da Dor , Dor Pós-Operatória/epidemiologia , Náusea e Vômito Pós-Operatórios/epidemiologia , Análise de Regressão , Tamanho da Amostra , Ressecção Transuretral da Próstata , Resultado do Tratamento
5.
Br J Anaesth ; 103(5): 750-4, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19797249

RESUMO

BACKGROUND: The administration of low-dose bupivacaine can limit the distribution of spinal block to reduce adverse haemodynamic effects. Intrathecal opioids can enhance analgesia in combination with subtherapeutic doses of local anaesthetics. We aimed at comparing the efficacy of intrathecal fentanyl and sufentanil with low-dose diluted bupivacaine for transurethral prostatectomy (TURP) in elderly patients. METHODS: Seventy patients undergoing TURP were randomly allocated into two groups. Group F (n=35) received fentanyl 25 microg+bupivacaine 0.5% (0.8 ml)+normal saline 0.3 ml and Group S (n=35) received sufentanil 5 microg+bupivacaine 0.5% (0.8 ml)+normal saline 0.7 ml--in total, bupivacaine 0.25% (1.6 ml) intrathecally. Onset and duration of the sensory block, the degree of the motor block, side-effects, and the perioperative analgesic requirements were assessed. RESULTS: The median peak level of the sensory block was significantly higher in Group S than in Group F (P=0.049). Group S required fewer perioperative analgesics than Group F (P=0.008). The time to the first analgesic request was longer in Group S (P=0.025). There were no differences between the groups for the onset and recovery time of the sensory block, degree of the motor block, quality of anaesthesia, or adverse effects. CONCLUSIONS: Low-dose diluted bupivacaine with fentanyl 25 microg or sufentanil 5 microg can provide adequate anaesthesia without haemodynamic instability for TURP in elderly patients. However, sufentanil was superior to fentanyl in the quality of the spinal block produced.


Assuntos
Adjuvantes Anestésicos/administração & dosagem , Raquianestesia/métodos , Fentanila/administração & dosagem , Sufentanil/administração & dosagem , Ressecção Transuretral da Próstata , Idoso , Idoso de 80 Anos ou mais , Anestésicos Locais/administração & dosagem , Bupivacaína/administração & dosagem , Método Duplo-Cego , Humanos , Masculino , Pessoa de Meia-Idade , Hiperplasia Prostática/cirurgia
6.
Theriogenology ; 62(8): 1473-82, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15451256

RESUMO

This study was conducted to develop a serum-free, defined medium for IVM of pig oocytes. Modified North Carolina State University (mNCSU)-23 media with or without supplementation with both epidermal growth factor (EGF) and gonadotrophin were used as base media. In separate experiments, each base medium was supplemented with porcine follicular fluid (pFF), polyvinyl alcohol (PVA), PVA and essential amino acids (EAA), PVA and nonessential amino acids (NEAA) or PVA with both EAA and NEAA. Averaged across these five treatments, the percentage of blastocyst formation was higher (P < 0.05) in the base medium supplemented with EGF and gonadotrophins. In both base media, the addition of NEAA yielded similar percentages of maturation (81-82% versus 75-80%), sperm penetration (89-93% versus 80-86%) and blastocyst formation (4-18% versus 4-13%) as media supplemented with pFF. Although similar benefits were found after the addition of EAA, their addition was associated with lower (P < 0.05) maturation (66%) and sperm penetration (58%) than when pFF was added to the base medium without EGF and gonadotrophins. However, decreased maturation after EAA addition was not detected in the base medium containing EGF and gonadotrophins. Within the same base medium, monospermy, male pronucleus formation, cleavage and blastocyst formation were not affected by the treatments; and combined addition of EAA and NEAA did not further improve oocyte development. In conclusion, a maturation system using a defined mNCSU-23 medium supplemented with EGF, gonadotrophins and EAA or NEAA was developed which yielded a similar number of blastocysts compared with a pFF-containing medium.


Assuntos
Aminoácidos/farmacologia , Desenvolvimento Embrionário/efeitos dos fármacos , Fertilização in vitro/veterinária , Oócitos/efeitos dos fármacos , Oócitos/crescimento & desenvolvimento , Suínos/embriologia , Aminoácidos Essenciais/farmacologia , Animais , Blastocisto/fisiologia , Meios de Cultura , Técnicas de Cultura Embrionária/veterinária , Fator de Crescimento Epidérmico/farmacologia , Feminino , Líquido Folicular , Masculino , Álcool de Polivinil , Interações Espermatozoide-Óvulo
7.
J Nutr ; 131(3s): 1041S-5S, 2001 03.
Artigo em Inglês | MEDLINE | ID: mdl-11238812

RESUMO

Diallyl sulfide (DAS) is a flavor compound derived from garlic and is sequentially converted to diallyl sulfoxide (DASO) and diallyl sulfone (DASO(2)) by cytochrome P(450) 2E1 (CYP2E1). These compounds have been shown to reduce the incidence of a multitude of chemically induced tumors in animal models. The impediment of phase I activation of these carcinogens is hypothesized to be accountable for the reduction in tumor incidence. Indeed, DAS, DASO and DASO(2) are competitive inhibitors of CYP2E1. DASO(2), in addition, is a suicide inhibitor of CYP2E1. These compounds have been shown to reduce carbon tetrachloride-, N-nitrosodimethylamine- and acetaminophen-induced toxicity in rodents. All three chemicals are substrates for CYP2E1. The protective effect was observed when the organosulfur compounds were given before, during or soon after chemical treatment. DAS and DASO(2) inhibited the bioactivation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and related lung tumorigenesis in A/J mice. Because CYP2E1 does not play a key role in NNK activation, the inhibition of other CYP enzymes active in NNK metabolism is likely. DAS also has been shown to induce other CYP and phase II enzymes as well as decrease hepatic catalase activity. All of these effects are observed at concentrations much higher than what is normally ingested by humans. The biological activities of garlic and its related compounds at lower concentrations that mimic human consumption remain to be studied further.


Assuntos
Compostos Alílicos/farmacologia , Anticarcinógenos/metabolismo , Inibidores do Citocromo P-450 CYP2E1 , Alho , Fígado/efeitos dos fármacos , Nitrosaminas/metabolismo , Plantas Medicinais , Sulfetos/farmacologia , Compostos Alílicos/metabolismo , Animais , Carcinógenos , Citocromo P-450 CYP2E1/metabolismo , Ativação Enzimática , Indução Enzimática/efeitos dos fármacos , Inibidores Enzimáticos , Glutationa Transferase/efeitos dos fármacos , Glutationa Transferase/metabolismo , Incidência , Fígado/enzimologia , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/prevenção & controle , Roedores , Sulfetos/metabolismo , Sulfonas/metabolismo , Sulfóxidos/metabolismo
8.
J Korean Med Sci ; 15(3): 303-8, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10895973

RESUMO

We undertook this work to compare the treatment efficacies and the changes of quality of life after pelvic floor muscle (PFM) exercise and the functional electrical stimulation (FES)-biofeedback treatment, both of which are being widely used as conservative treatment methods for female urinary incontinence. We randomly selected 60 female incontinence patients who visited our department and divided them evenly into two groups. They were treated for a period of 6 weeks. The subjective changes in the severity of incontinence and discomfort in daily and social life were measured using a translated version of the questionnaire by Jackson. Objective changes of pelvic muscle contraction force were measured using a perineometer. Pre- and post-treatment maximal pelvic floor muscle contractile (PMC) pressure and changes in the severity of urinary incontinence and discomfort of the two groups showed statistically significant differences (p<0.001). In particular the FES-biofeedback group showed significantly increased maximal PMC pressure and a decreased severity of urinary incontinence and discomfort compared to the intensive PFM exercise group (p<0.001). In conclusion, FES-biofeedback proved more effective than simple PFM exercise.


Assuntos
Biorretroalimentação Psicológica , Terapia por Exercício , Incontinência Urinária por Estresse/terapia , Atividades Cotidianas , Terapia por Exercício/métodos , Feminino , Humanos , Contração Muscular , Músculos , Diafragma da Pelve , Resultado do Tratamento , Incontinência Urinária por Estresse/fisiopatologia , Incontinência Urinária por Estresse/prevenção & controle , Incontinência Urinária por Estresse/psicologia
9.
J Biochem Mol Toxicol ; 13(3-4): 127-34, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10098897

RESUMO

Diallyl sulfide (DAS) is a flavor compound derived from garlic and is active in the inhibition of chemically induced cytotoxicity and carcinogenicity in animal models. This study was conducted to examine the effects of the treatment of DAS and garlic homogenates on the activities of catalase, glutathione peroxidase, and superoxide dismutase. Male Sprague-Dawley rats were treated with DAS i.g. at daily doses of 50 or 200 mg/kg for 8 days, causing the hepatic catalase activity to decrease by 55 and 95%, respectively. Such a decrease in hepatic catalase activity was also observed when the DAS treatment was extended to 29 days. Western blot analysis showed that the DAS treatments resulted in corresponding decreases in the liver catalase protein level. No significant change in the catalase activity in the kidney, lung, and brain was observed with the treatments, but a slight decrease in heart catalase activity was observed. These treatments did not cause significant changes in superoxide dismutase and glutathione peroxidase activities in these tissues. Treatment with DAS at a daily dose of 200 mg/kg for 1-7 days resulted in a gradual decrease in the liver catalase activity to 5% of the control level, but it did not decrease the erythrocyte catalase activity. Treatment of rats with fresh garlic homogenates (2 or 4 g/kg, i.g., daily for 7 days) caused a 35% decrease in liver catalase activity. A/J mice treated with DAS and garlic homogenates also showed a decrease in the liver catalase activity. Diallyl sulfone (DASO2), a DAS metabolite, however, did not effectively decrease catalase activity in mice. The catalase activity was not inhibited by either DAS or DASO2 in vitro. The present results demonstrate that treatment with DAS and garlic homogenates decrease the hepatic catalase level in rats and mice.


Assuntos
Compostos Alílicos/farmacologia , Catalase/antagonistas & inibidores , Alho/química , Fígado/efeitos dos fármacos , Plantas Medicinais , Sulfetos/farmacologia , Animais , Catalase/sangue , Catalase/metabolismo , Eritrócitos/enzimologia , Feminino , Glutationa Peroxidase/metabolismo , Fígado/enzimologia , Masculino , Camundongos , Ratos , Ratos Sprague-Dawley , Sulfonas/farmacologia , Superóxido Dismutase/metabolismo
11.
Cancer Res ; 54(17): 4641-7, 1994 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-8062257

RESUMO

Previous studies in our laboratory showed that decaffeinated green tea and black tea extracts inhibited 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced tumorigenicity in A/J female mice. In order to understand the mechanism of the inhibitory action, we examined the effects of decaffeinated green tea, black tea, and tea components on the metabolic activation of NNK in vitro and in vivo in this animal model. When added to incubation mixtures containing mouse lung microsomes, decaffeinated green tea and black tea extracts and their fractions, at concentrations up to 0.4 mg/ml, inhibited NNK oxidation and NNK-induced DNA methylation. Among the tea components examined, (-)-epigallocatechin-3-gallate was the most potent inhibitor with 50% inhibitory concentrations of about 0.12 mM for both NNK oxidation and DNA methylation. At these concentrations, (-)-epigallocatechin-3-gallate inhibited the catalytic activities of several P450 enzymes and was more potent against P450 1A and 2B1 than 2E1. When decaffeinated green or black tea extracts were given to female A/J mice as the sole source of drinking fluid before an i.p. injection of NNK (100 mg/kg body weight), a statistically significant inhibition of lung DNA methylation, however, was not observed, although a significant reduction in lung tumor multiplicity was observed. The results suggest that, although inhibition of the metabolic activation of NNK and the subsequent DNA alkylation by tea extracts can be demonstrated in vitro, this mechanism may not be important for the inhibitory action of tea against lung tumorigenesis.


Assuntos
Bebidas , Carcinógenos/metabolismo , DNA/metabolismo , Neoplasias Pulmonares/induzido quimicamente , Nitrosaminas/metabolismo , Chá , Animais , Catequina/farmacologia , Feminino , Flavonoides/farmacologia , Pulmão/metabolismo , Metilação/efeitos dos fármacos , Camundongos , Microssomos/metabolismo , Piridinas/metabolismo
13.
Carcinogenesis ; 13(5): 901-4, 1992 May.
Artigo em Inglês | MEDLINE | ID: mdl-1587006

RESUMO

Diallyl sulfide (DAS), a component of garlic oil, has been shown to inhibit tumorigenesis by several chemical carcinogens. Our previous work demonstrated that DAS inhibited the metabolic activation of carcinogenic nitrosamines, including the tobacco-specific 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), in rat lung and nasal mucosa microsomes. In the present study, the effects of DAS on the tumorigenicity and the metabolism of NNK in A/J mouse lung were examined. Female A/J mice at 7 weeks of age were pretreated with DAS (200 mg/kg body wt in corn oil, p.o) daily for 3 days. Two hours after the final DAS treatment, the mice were either given a single dose of NNK (2 mg/mouse, i.p.) and kept for an additional 16 weeks for determining the production of pulmonary tumors, or were killed immediately so as to measure the microsomal activity in metabolizing NNK. In comparison to the vehicle control group, DAS pretreatment significantly decreased the incidence of NNK-induced lung tumors (37.9 versus 100%) and the tumor multiplicity (0.6 versus 7.2 tumors/mouse). In pulmonary metabolism of NNK, DAS pretreatment reduced the rates of formation of keto aldehyde, keto alcohol, NNAL-N-oxide, and NNK-N-oxide by 70-90%. In addition, the formation of NNK oxidative metabolites from NNK in the liver microsomes from DAS-pretreated mice was remarkably reduced. DAS also inhibited the metabolism of NNK in mouse lung microsomes in vitro. These results demonstrate that DAS is an effective chemopreventive agent against NNK-induced lung tumorigenesis, probably by inhibiting the metabolic activation of NNK.


Assuntos
Compostos Alílicos , Carcinógenos/metabolismo , Alho , Neoplasias Pulmonares/induzido quimicamente , Pulmão/metabolismo , Microssomos Hepáticos/metabolismo , Nitrosaminas/metabolismo , Plantas Medicinais , Sulfetos/farmacologia , Animais , Feminino , Neoplasias Pulmonares/prevenção & controle , Camundongos
14.
Cancer Res ; 52(7): 1943-7, 1992 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-1551122

RESUMO

The effect of p.o. administration of tea on nitrosamine-induced carcinogenesis was investigated. Female A/J mice were given N-nitrosodiethylamine (NDEA) (10 mg/kg) p.o. once a week for 8 weeks and were killed 16 weeks after the last dose. More than 90% of the mice had forestomach and lung tumors. The animals had an average of 8.3 forestomach and 2.5 lung tumors/mouse. With 0.63 or 1.25% green tea infusion (12.5 g green tea leaves brewed with 1 liter of boiling water) as the sole source of drinking water for the entire experimental period, the pulmonary tumor incidence was decreased by 18 or 44%, and the tumor multiplicity was reduced by 36 or 60%, respectively. The treatments also decreased the forestomach tumor incidence by 18 or 26% and tumor multiplicity by 59 or 63%, respectively. Administration of 0.63 or 1.25% green tea infusion, either during the NDEA treatment period only or starting 1 week after the completion of NDEA treatment, also decreased the pulmonary tumor incidence and multiplicity and the forestomach tumor multiplicity. The inhibitory effects of green tea infusion were also observed in a similar experiment using a higher dosage of NDEA (20 mg/kg). Treatment of female A/J mice with a single dose (103 mg/kg) of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) resulted in the formation of pulmonary adenomas in almost all of the animals with an average of 9.3 tumors/mouse after 16 weeks. When 0.6% decaffeinated green tea or black tea extract was given during the NNK-treatment period, tumor multiplicity was reduced by 67 or 65%, respectively. When the tea extract was given after the NNK-treatment period until the end of the experiment, 0.6% green tea extract decreased the tumor incidence and multiplicity by 30 and 85%, respectively. In this protocol, 0.6% black tea extract reduced tumor multiplicity by about 63% but did not significantly affect the tumor incidence. The results clearly demonstrated an inhibitory action of green tea and black tea on nitrosamine-induced tumorigenesis.


Assuntos
Carcinógenos/toxicidade , Dietilnitrosamina/toxicidade , Neoplasias Pulmonares/prevenção & controle , Nitrosaminas/toxicidade , Neoplasias Gástricas/prevenção & controle , Chá , Animais , Feminino , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos A , Valores de Referência , Neoplasias Gástricas/induzido quimicamente , Neoplasias Gástricas/patologia
15.
J Nutr ; 120(12): 1718-26, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2262816

RESUMO

To study the molecular mechanisms by which dietary lipids affect the levels of cytochrome P450 (P450) isozymes, male Sprague-Dawley rats were fed either fat-free (FF) or 20% corn oil (CO) diet in combination with one of the following three treatments: no inducer, phenobarbital (PB) and acetone. Dietary CO did not affect the constitutive level of P450IIB (PB-inducible), but it affected the induction of P450IIB by PB treatment. The induction of P450IIB by PB in the CO group as determined by 7-pentoxy-resorufin O-dealkylase activity and immunochemically detected protein level was twofold higher than that in the FF group, and this difference was also reflected in the level of mRNA for this enzyme. In contrast, dietary CO increased the constitutive level of P450IIE (ethanol-inducible) twofold as indicated by N-nitrosodimethylamine demethylase activity and immunochemically detectable protein, but it had no effect on the induction of P450IIE by acetone. The induced level of P450IIE by acetone in the CO group did not differ from that in the FF group as measured by the enzyme activity and protein level. It was demonstrated that dietary CO affects P450IIB and IIE activities by altering the concentration of the isozymes rather than by modulating their catalytic activities. In addition, dietary CO increased the microsomal testosterone 6 beta-hydroxylase activity but not 7 alpha- and 2 alpha-hydroxylase activities, suggesting an increase in P450IIIA and/or IIC13 but not in IIA1 and IIC11, respectively. Dietary CO also affected the constitutive and induced levels of glutathione S-transferase (GST) isozymes in a different manner: it increased the constitutive level of GST-B but not that of GST-A. Nevertheless, it was important for the induction of both GST-A and GST-B by PB treatment. The results suggest that lipid nutrition affects xenobiotic metabolism activities by altering constitutive and inducible levels of certain P450 and GST isozymes.


Assuntos
Óleo de Milho/farmacologia , Sistema Enzimático do Citocromo P-450/biossíntese , Gorduras Insaturadas na Dieta/farmacologia , Glutationa Transferase/biossíntese , Isoenzimas/biossíntese , Microssomos Hepáticos/enzimologia , Acetona/farmacologia , Animais , Western Blotting , Peso Corporal/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/genética , Indução Enzimática/efeitos dos fármacos , Fígado/anatomia & histologia , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , Fenobarbital/farmacologia , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos , Testosterona/metabolismo
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