摘要:

AbstractThe relation of lifetime alcohol intake to risk of breast cancer in pre‐and postmenopausal women was examined in a case‐control study in western New York. Cases with incident primary histologically confirmed breast cancer diagnosed during the period 1986–1991 (n = 740) and controls, frequency age‐matched women drawn from New York state driver's license records (age65 yrs, n = 810), were interviewed regarding intake of wine, beer, and hard liquor 2, 10, and 20 years ago and at 16 years of age.Although women in this study had generally low intakes of alcohol, there was little evidence of increased risk of breast cancer with intake of alcohol at any of the time periods or with an index of total lifetime intake. There was a weak indication of an increase in risk with beer for intakes of at least one drink per day. This risk was evident for 2, 10, and 20 years ago but not at 16 years of age. In this group with relatively low intakes of alcohol, evidence was weak for an association of increased risk of breast cancer with intake of alcohol, with the possible exception of a weak association with beer intake.

ISSN:0163-5581    

DOI:10.1080/01635589509514356

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

AbstractUsing five‐to eight‐week‐old male F344 rats and a high‐fat (23.5% corn oil) modified AIN‐76A diet, we examined the effects of dietary restriction (a 3‐wk 30% reduction of food intake with respect to ad libitum‐fed controls) or complete fasting (2 days without food) on the activities of hepatic xenobiotic metabolizing enzymes in vitro and on azoxymethane. (AOM) induced formation of C6‐methylguanine and 7‐methylguanine in liver and colon DNA in vivo. Compared with ad libitum‐fed rats, fasting increased total liver cytochrome P450 by 32%, microsomal aniline hydroxylase by 270%, N‐nitrosodimethylamine demethylase by 270%, and azoxymethane hydroxylase by 320%. Liver benzo[a]pyrene (BP) hydroxylase and glutathione‐S‐transferase were decreased by 39% and 21%, respectively, whereas NADPH cytochrome c reductase and UDP glucuronyltransferase were unchanged. DNA methylation in the livers of fasted animals was 20–31% greater six hours after a 15 mg/kg sc injection of AOM than in ad libitum‐fed controls, whereas DNA methylation in the colon was slightly lower. In three‐week diet‐restricted animals, there were small but not statistically significant changes in the various enzyme activities and in AOM‐induced DNA methylation compared with the ad libitum‐fed controls, with the exception of BP hydroxylase, which showed a 26% decrease. However, the trends in the increase or decrease of each parameter, although small in magnitude, were similar to those observed in the case of fasting, suggesting that the effects might become significant if the duration of diet restriction were prolonged. The enhancement of A OM metabolism in rat liver by fasting, leading to increased liver DNA methylation, is different from that produced by chemical inducers, such as ethanol, where no increase in liver DNA methylation is observed.

ISSN:0163-5581    

DOI:10.1080/01635589509514357

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

AbstractNutritional repletion of tumor‐bearing (TB) organisms by means of total parenteral nutrition (TPN) has been associated with gut atrophy, immunosuppression, and increased infection rate. To assess possible molecular mechanisms of intestinal atrophy during TPN, jejunal mucosal polyamine concentrations and biosynthetic activity were assessed in non‐TB (NTB) and TB rats maintained on rat chow or TPN for eight days. As expected, jejunal mucosal protein content was decreased in both groups of rats maintained on TPN. Although mucosal concentration of putrescine was decreased in TB groups and in the NTB group maintained on TPN, levels of spermidine and spermine were decreased only in the NTB‐TPN group. Spermidine levels were elevated significantly in both TB groups. The concentration of spermine was also elevated in the TB‐TPN group but was not changed in the TB group maintained on chow. Activity of ornithine decarboxylase was increased in the NTB‐TPN group but was not altered significantly in either TB group. S‐adenosylmethionine decarboxylase activity was decreased significantly in TB rats maintained on chow and was increased back to control level in the TB‐TPN group. These results suggest that jejunal mucosal polyamines are decreased in NTB rats maintained on TPN. Additionally, it appears that enzyme activity is induced in NTB‐TPN rats, perhaps in response to the reduction in polyamines and gut atrophy. The absence of similar changes in TB rats maintained on TPN suggests that regulatory mechanisms of polyamine biosynthesis, such as product inhibition, may be refractory. In addition, polyamine biosynthesis from other sources, such as tumor tissue, may be affecting the control of intestinal polyamine biosynthesis.

ISSN:0163-5581    

DOI:10.1080/01635589509514358

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

AbstractEpidemiological studies have implicated obesity; high intakes of alcohol, fat, and energy; and low intakes of food plants as risk factors for colorectal cancer. In New Zealand, Polynesians (including Maoris and people from several Pacific Islands) are more likely to be overweight and have higher intakes of fat and energy than Europeans, and they are likely to have similar total intakes of food plants. Yet, in New Zealand, Polynesians have a significantly lower incidence of colorectal cancer than the Europeans. It is possible that the difference in incidence of colorectal cancer is due to differences in consumption of specific food plants by Polynesians and Europeans in New Zealand. Here we have compared the consumption of specific food plants by 429 Maoris, 643 Pacific Islanders, and 4,451 Europeans in paid employment in New Zealand. Of the 51 food plants eaten by New Zealanders, 6 were eaten significantly more frequently and 17 significantly less frequently by the two Polynesian groups than by Europeans. The quantity of any protective chemical components (or other as yet unknown protective factors) in food plants is likely to be related to their botanical classification. Differences in the intake of specific food plants may at least partly explain differences in the incidence of colorectal cancer between Polynesians and Europeans.

ISSN:0163-5581    

DOI:10.1080/01635589509514359

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

AbstractHL‐60 cells, growing as single cells in suspension, exhibit marked cell‐cell adhesion when treated for 24 hours with 10μg/ml RRR‐α‐tocopheryl succinate, also called vitamin E succinate (VES). VES‐induced cell‐cell adhesion is dependent on divalent cations and a functional cytoskeleton and is protein mediated. Cell adhesion molecules CD11a/CD18, CD11b/CD18, CD29, and CD54 do not appear to be mediating VES‐induced cell adhesion. HL‐60 cells treated with VES adhere to fibronectin‐coated plastic and secrete elevated levels of fibronectin. A 72‐kDa fibronectin‐binding membrane molecule was detected on VES‐treated HL‐60 cells, and antibodies to fibronectin were shown to inhibit VES‐induced cell aggregation. VES induction of HL‐60 cell‐cell adhesion is proposed to result from increased amounts of extracellular fibronectin binding to VES‐induced cell surface fibronectin‐binding molecules.

ISSN:0163-5581    

DOI:10.1080/01635589509514360

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

AbstractUsing data from a case‐control study conducted in Northern Italy, we analyzed the relation between alcohol drinking and risk of endometrial cancer. Cases were 726 patients,<75 years of age, admitted to the Ospedale Maggiore (including the 4 largest teaching and general hospitals in the Greater Milan area), the University Obstetrics and Gynecology Clinics, and the National Cancer Institute of Milan with histologically confirmed endometrial cancer. Controls were 2,123 nonhysterectomized patients,2 drinks/day (χ%21trend 11.33, p<0.001). The estimates were similar when wine only (which represents the large majority of all alcohol intake in Italy) was considered, whereas data were less informative for beer and spirits intake only. No relation emerged between duration of alcohol consumption and risk of endometrial cancer. These findings suggest a potential link between alcohol drinking and endometrial cancer risk and are, in any case, inconsistent with a protective role of alcohol in endometrial carcinogenesis. However, several inconsistencies in the epidemiological and biologic evidence leave open the question of causality of this association.

ISSN:0163-5581    

DOI:10.1080/01635589509514361

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

AbstractDiets high in fat and low in dietary fiber have been associated with a higher incidence of colon cancer, possibly by increasing bile acid concentration in the colon. Therefore changes in bile acid metabolism due to beef tallow, corn bran (CB), and soy polysaccharide (SP) feeding were studied. Rats were fed one of four diets for six weeks: 5% beef tallow fiber‐free (LF), 20% beef tallow fiber‐free (HF), 20% beef tallow with CB (HFCB), and 20% beef tallow with SP (HFSP). HF increased fecal output compared with LF, and HFCB and HFSP increased fecal output compared with HF. HF reduced fecal bile acid concentration by two‐thirds compared with LF, although daily bile acid excretion was similar. There was a tendency toward a smaller bile acid quantity in the small intestine with HF than with LF. Neither fiber altered total fecal bile acid concentration or small intestinal bile acid quantity compared with HF. However, 7α‐dehydroxy‐lase activity in the colon was lower with HFSP than with HFCB. Increasing dietary beef tallow from 5% to 20% in animals fed a fiber‐free diet greatly reduced the concentration of bile acids in the large intestine and feces, an effect associated with a reduced risk of colon cancer.

ISSN:0163-5581    

DOI:10.1080/01635589509514362

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

AbstractThe effect of a diet containing 10–40% lyophilized cabbage or broccoli as cruciferous vegetable or 10–40% lyophilized potato as noncruciferous vegetable fed for 14 days on the colon mucosal glutathione (GSH) level was studied in male rats. The GSH levels of the duodenum mucosa and the liver were also measured. Cabbage and broccoli enhanced the colon and duodenum mucosal GSH levels in a dose‐related manner; potato had no effect. All three vegetables had no effect on the liver GSH level.The effect of GSH on colon tumorigenesis induced by 1,2‐dimethylhydrazine (DMH) was also examined in rats. Male Sprague‐Dawley rats were injected with DMH (20 mg/kg body wt) weekly for 20 weeks. DMH lowered the colon mucosal GSH level. GSH (100 mg/day/rat) dissolved in the drinking water and given to rats during and after DMH injections had little or no effect on tumor incidence and total number of colon tumors. Tumors were larger in rats that received GSH than in those that received water. This study shows that the colon mucosal GSH level can be enhanced by feeding rats a diet high in cabbage or broccoli and that GSH added to the drinking water did not affect DMH‐induced colon tumorigenesis under the experimental conditions used.

ISSN:0163-5581    

DOI:10.1080/01635589509514363

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

AbstractTotal parenteral nutrition can be used to overcome amino acid imbalance in cancer patients. Because there is little documentation of treatment for amino acid imbalance in patients with hepatocellular carcinoma (HCC), we designed a study 1) to compare tissue levels of amino acids between HCC and the adjacent liver and 2) to determine which serum amino acids correlate to tumor volume. A significant elevation of methionine and a significant decrease of glycine and cystine were observed in HCC compared with adjacent liver tissue, and a significant correlation was found between tumor volume and serum methionine levels (x =‐0.636, p<0.01). Thus the tumor tissue competes successfully with host tissue for nitrogen substrates, particularly methionine, and an accelerated protein synthesis in HCC consumes large amounts of these amino acids. The possibility of methionine‐depleted treatment could be considered for patients with HCC.

ISSN:0163-5581    

DOI:10.1080/01635589509514364

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor

摘要:

AbstractThe present study deals with the chemopreventive action of the food‐seasoning spices mixture Garam masala on dimethylbenz[a]anthracene (DMBA)‐induced translactational and transplacental carcinogenesis in mice. When pregnant mice were given 10 and 30 mg of Garam masala per day from Days 13–19 of gestation in addition to DMBA (5 mg/day) on Days 15–17 of gestation, the multiple‐site tumor incidence declined significantly from control level of 62% to 19% and 10%, respectively, in F1progeny. Furthermore the mean numbers of tumors per effective F1mouse were reduced from the control value of 1.27 to 0.64 at the lower dose level (10 mg) and 0.23 at the higher dose level (30 mg) of Garam masala. Likewise, when lactating mice were given Garam masala at 10 and 30 mg/day for the first 15 days of lactation in addition to DMBA (3 mg/day) on Days 3, 6, 9,12, and 15 of lactation, the multiple‐site tumor incidence was reduced significantly from control level of 66% to 23% and 14%, respectively, in F1progeny. The mean numbers of tumors per effective F1mouse declined from control value of 1.43 to 0.46 at the lower dose and 0.25 at the higher dose of Garam masala. Further studies are required to analyze the nature of active chemical components and the manner in which they achieve chemoprevention in these complex model systems.

ISSN:0163-5581    

DOI:10.1080/01635589509514365

出版商:Taylor&Francis Group    

年代:1995

数据来源: Taylor