摘要:

AbstractThe RRR‐α‐tocopheryl succinate form of vitamin E inhibits the proliferation of estrogen receptor‐positive and estrogen receptor‐negative human breast cancer cell lines in a dose‐dependent mannerin vitro. Analyses of cell‐conditioned medium from RRR‐α‐tocopheryl succinate growth‐inhibited cells revealed the presence of a potent antiproliferative activity. Characterization of the antiproliferative activity as transforming growth factor‐β(TGF‐β) was established by 1) growth inhibition of the TGF‐β‐responsive Mv1Lu‐CCL‐64 mink lung and murine CTLL‐2 cell lines, 2) combination of physical characteristics including heat stability, acid stability, and Bio‐Gel P‐60 column chromatography elution profile, and 3) neutralization of the antiproliferative activity in the conditioned media by antibodies specific for TGF‐β.

ISSN:0163-5581    

DOI:10.1080/01635589309514254

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

AbstractThe effect of RRR‐α‐tocopheryl succinate (VES) on lectin‐induced chicken T cell proliferation was investigated. The T cell mitogens concanavalin A and phytohemagglutinin induce chicken thymic and splenic T cell proliferation. Addition of VES to thein vitrocultures inhibited T cell proliferation in a dose‐dependent manner. Addition of VES to spleen cell cultures at different times after mitogen stimulation also suppressed T cell mitogenesis, suggesting that VES is not mediating its antiproliferative effects by interfering with ligand (mitogen)‐receptor binding or early ligand‐bound receptor‐signaling events. Three lines of evidence suggest that the growth‐inhibitory properties of VES are unique and may not involve antioxidant properties. 1) Three other forms of vitamin E,dl‐α‐tocopherol,d‐α‐tocopherol, andd‐α‐tocopherol acetate, do not inhibit the proliferation of mitogen‐stimulated chicken spleen cells. 2) Spleen cells were treated with an inhibitor of nonspecific esterases to prevent the conversion of VES, which does not exhibit antioxidant properties to d‐a‐tocopherol, a lipid‐soluble antioxidant. Treatment of spleen cells with the inhibitor did not affect VES's growth‐inhibitory properties. 3) Trolox, a water‐soluble vitamin E analogue with potent antioxidant properties and two Hpid‐soluble antioxidants, butylated hydroxyanisole and butylated hydroxytoluene, did not inhibit mitogen‐induced T cell proliferation. Attempts to reverse VES's antiproliferative effects by addition of exogenous interleukin‐2 or addition of sodium selenite, an enhancer of interleukin‐2 receptors, failed. Acetylsalicylic acid had no effect on VES's inhibition of mitogen‐activated T cell proliferation. These studies support the role of VES as a growth inhibitor of lectin‐activated normal T cells in chickens.

ISSN:0163-5581    

DOI:10.1080/01635589309514255

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

AbstractCancer and its therapies frequently produce anorexia and cachexia. In this study, the acute (3 days) and chronic (4 wks) nutrition‐related effects of cancer therapy with recombinant human tumor necrosis factor (rHuTNF) were investigated and described. Nutritional status, as measured by body weight and body composition (body fat and lean‐to‐fat ratio) with use of bioelectrical impedance, did not appear to deteriorate. None of the serum lipids changed significantly, but triglycerides did rise modestly over four weeks of therapy. Glucose and the peptide hormones (insulin, C‐peptide, glucagon, and pancreatic polypeptide) thought to affect appetite did not change with rHuTNF therapy. Therefore, although TNF is thought to contribute to wasting in animal models, it had no negative effect on nutritional status in our small sample. The lack of adverse effect noted in this study is possibly due to the low dose level of rHuTNF or to adaptation.

ISSN:0163-5581    

DOI:10.1080/01635589309514256

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

AbstractThe proliferative activity was evaluated in colorectal biopsies of 39 healthy subjects living in two distinct geographical areas, Trieste in northern and Florence in central Italy. Subjects living in Trieste had a significantly higher mitotic activity compared with subjects living in Florence (mitoses/cells counted×100 were 0.17±0.04 in Trieste and 0.089±0.02 in Florence). The results of a dietary questionnaire also showed that subjects in Trieste consumed significantly fewer starches, fibers, nitrites, and proteins. However, no correlation was evident between the consumption of these nutrients and intestinal proliferation.

ISSN:0163-5581    

DOI:10.1080/01635589309514257

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

AbstractPreviously we have shown that astaxanthin, a carotenoid without provitamin A activity, enhancesin vitroantibody (Ab) production to sheep red blood cells in normal B6 mice. In this study, we further attempted to examine the mechanisms of this enhancing action of carotenoids on specific Ab productionin vitroin relation to different antigen (Ag) stimuli, cytokine production, and T‐and B‐cell interactions in both normal and autoimmune strains of mice. When the actions of carotenoids were tested in normal strains of mice, we found that astaxanthin enhancedin vitroAb production to T cell‐dependent Ag, but not to T‐independent Ag, and did not augment total immunoglobulin production. Astaxanthin exerted maximum enhancing actions when it was present at the initial period of Ag priming. This action of astaxanthin was abolished when T cells were depleted from spleen cell suspensions and appeared to require direct interactions between T and B cells. The results also indicated that carotenoids may modulate the production of interferon‐τin this assay system. When the actions of carotenoids were tested in autoimmune‐prone MRL and NZB mice, the enhancing action of astaxanthin onin vitroAb production was less significant. Furthermore, carotenoids did not potentiate or augment spontaneous Ab and immunoglobulin production by spleen cells in these strains.Taken together, carotenoids without provitamin A activity may be able to augmentin vitrospecific Ab production to T cell‐dependent Ag partly through affecting the initial stage of Ag presentation without facilitating polyclonal B‐cell activation or autoantibody production.

ISSN:0163-5581    

DOI:10.1080/01635589309514258

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

AbstractWe describe our studies to produce an extract of soybeans with anticarcinogenic activity that we believe will be useful as a human cancer chemopreventive agent for several different organs. The anticarcinogenic activity of the extract is thought to be due to chymotrypsin inhibitor activity, which is due to the Bowman‐Birk protease inhibitor (BBI) present in the extract, termed BBI concentrate (BBIC). We describe the contents of BBIC, the ability of BBIC to inhibit malignant transformationin vitroin terms of its chymotrypsin inhibitor activity, and the results of long‐term toxicity studies in which mice and rats were exposed to high levels of BBIC for long periods of time.

ISSN:0163-5581    

DOI:10.1080/01635589309514259

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

AbstractThe relationship between beer consumption and the risk of colon and rectal cancer was considered in a case‐control study conducted in northern Italy. The study was based on 828 histologically confirmed incident cases of colon cancer, 498 of rectal cancer, and 2,024 controls in hospital for a wide spectrum of acute, nonneoplastic, nonalcohol‐related diseases. Beer drinking was reported by 6% of colon cancer cases, 7% of rectal cancer cases, and 10% of controls; regular beer drinkers (≥1 drinks/day) made up 2.6% of colon cancer cases, 3.2% of rectal cancer cases, and 4.1% of controls. Thus the multivariate relative risks (RR) for irregular drinkers were 0.6 [95% confidence interval (CI) 0.4–1.0] for colon and 0.7 (95% CI 0.4–1.2) for rectum. Corresponding values for regular drinkers were 0.7 (95% CI 0.4–1.2) for colon and 0.9 (95% CI 0.5–1.5) for rectal cancer. Despite the low frequency of beer drinking in this study, and hence its limited statistical power, the originality of the population in terms of colorectal cancer incidence, patterns of risk factor exposure, and the large dataset provide interesting and useful confirmation that moderate beer drinking is not associated with elevated colon or rectal cancer risk.

ISSN:0163-5581    

DOI:10.1080/01635589309514260

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

AbstractIncreasing levels of dietary corn oil have been correlated with inhibition of 12‐O‐tetradecanoyl‐phorbol‐13‐acetate‐(TPA) promoted skin tumetigenesis in mice (Leyton et al.Cancer Res.51, 907–915, 1991). This study was undertaken to assess the effects of dietary com oil on several events associated with tumor promotion. Three semipurified diets containing 15% (wt/wt) total fat with increasing levels of linoleate (0.8%, 4.5%, and 8.4%) supplied by corn oil were fed to mice for at least four weeks. Although incorporation of linoleate into epidermal phosphatidylcholine increased with increasing amounts of dietary corn oil, the elongated desaturated product of linoleate, arachidonate, was similar or decreased slightly in mice fed the three diets. Minimal activity ofδ6‐desaturase, the rate‐limiting enzyme in the conversion of linoleate to arachidonic acid, was found in the epidermis compared with the liver, suggesting that linoleate is not converted to arachidonic acid in the skin. Subcellular distribution of protein kinase C was altered in mice fed 0.8% linoleate, where 69% of protein kinase C activity was in the cytosol compared with 78% and 74% for groups fed 4.5% and 8.4% linoleate, respectively. Activation of partially purified protein kinase C isolated from mouse epidermis by linoleate was significantly lower (p<0.01) than that isolated by arachidonic acid. TPA‐induced vascular permeability was significantly greater (p<0.05), whereas hyperplasia 48 hours after TPA treatment was significantly lower, in mice fed the 8.4% linoleate diet. However, TPA induction of omithine decarboxylase activity did not appear to be significantly modified by dietary linoleate. These data suggest that cellular processes associated with carcinogenesis are affected by the level of dietary linoleate.

ISSN:0163-5581    

DOI:10.1080/01635589309514261

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

AbstractCaraway oil, supplemented in diet or painted on the skin, inhibited 7,12‐dimethylbenz[a]anthracene‐(DMBA) and croton oil‐induced skin tumors in female BALB/c mice. The inhibition was manifested by disappearance of carcinomas, reduced incidence and number of papillomas, delay of their appearance, retardation of their development, and regression of already established papillomas. Caraway oil is more effective when topically applied than when supplemented in the diet.

ISSN:0163-5581    

DOI:10.1080/01635589309514262

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor

摘要:

AbstractThe relationship between dietary factors and the risk of breast cancer was investigated in a case‐control study conducted in the Canton of Vaud, Switzerland as a pilot phase for a larger cooperative study within the SEARCH Programme of the International Agency for Research on Cancer (Lyon, France). A total of 107 incident, histologically confirmed cases of breast cancer and 318 controls admitted to hospital for acute, nonhormone‐related, gynecological, metabolic, or neoplastic disorders were interviewed. Significant direct trends in risk were observed with total energy intake [relative risk (RR) for highest vs. lowest intake tertile = 1.9] and, after allowance for energy intake, with frequency of consumption of various types of meat (RR = 2.1 for the highest tertile), cheese (RR = 2.7), and alcohol (RR = 2.1). Significant protections, on the order of 40–60% reductions for the highest vs. lowest consumption tertile, were conferred by total green vegetable consumption, selected types of vegetables and fruits (cucumbers, onions, pears), and a summary index ofβ‐carotene intake (RR = 0.4 for highest consumption tertile). Thus the present study confirmed the existence of an unfavorable dietary pattern for breast cancer risk (characterizedby high‐calorie, selected sources of animal fat and alcohol intake). Moreover, a significant protection could be gained by consuming a diet rich in vegetables and perhaps fruits.

ISSN:0163-5581    

DOI:10.1080/01635589309514263

出版商:Taylor&Francis Group    

年代:1993

数据来源: Taylor