scholarly journals Dose-response effects of dietary fiber on NMU-induced mammary tumorigenesis, estrogen levels and estrogen excretion in female rats

1996 ◽  
Vol 17 (1) ◽  
pp. 45-52 ◽  
Author(s):  
L.A. Cohen ◽  
Z. Zhao ◽  
E. Zang ◽  
A. Rivenson
Keyword(s):  
Dietary Fiber ◽  
Dose Response ◽  
Mammary Tumorigenesis ◽  
Female Rats

scholarly journals Dietary fiber intake from fresh and preserved food and risk of nasopharyngeal carcinoma: observational evidence from a Chinese population

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhi-Ming MAI ◽  
Roger Kai-Cheong NGAN ◽  
Dora Lai-Wan KWONG ◽  
Wai-Tong NG ◽  
Kam-Tong Yuen ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Dietary Fiber ◽  
Dose Response ◽  
Sun Exposure ◽  
Fiber Intake ◽  
Total Dietary Fiber ◽  
Dietary Fiber Intake ◽  
Fresh Vegetables ◽  
Incident Cases

Abstract Background The role of dietary fiber intake on risk of nasopharyngeal carcinoma (NPC) remains unclear. We examined the associations of dietary fiber intake on the risk of NPC adjusting for a comprehensive list of potential confounders. Methods Using data from a multicenter case-control study, we included 815 histologically confirmed NPC incident cases and 1502 controls in Hong Kong, China recruited in 2014–2017. Odds ratios (ORs) of NPC (cases vs controls) for dietary fiber intake from different sources at different life periods (age 13–18, age 19–30, and 10 years before recruitment) were evaluated using unconditional logistic regression, adjusting for sex, age, socioeconomic status, smoking and drinking status, occupational hazards, family history of cancer, salted fish, and total energy intake in Model 1, Epstein-Barr virus viral capsid antigen serological status in Model 2, and duration of sun exposure and circulating 25-hydroxyvitamin D in Model 3. Results Higher intake of total dietary fiber 10 years before recruitment was significantly associated with decreased NPC risk, with demonstrable dose-response relationship (P-values for trend = 0.001, 0.020 and 0.024 in Models 1–3, respectively). The adjusted ORs (95% CI) in the highest versus the lowest quartile were 0.51 (0.38–0.69) in Model 1, 0.48 (0.33–0.69) in Model 2, and 0.48 (0.33–0.70) in Model 3. However, the association was less clear after adjustment of other potential confounders (e.g. EBV) in the two younger periods (age of 13–18 and 19–30 years). Risks of NPC were significantly lower for dietary fiber intake from fresh vegetables and fruits and soybean products over all three periods, with dose-response relationships observed in all Models (P-values for trend for age 13–18, age 19–30 and 10 years before recruitment were, respectively, 0.002, 0.009 and 0.001 for Model1; 0.020, 0.031 and 0.003 for Model 2; and 0.022, 0.037 and 0.004 for Model 3). No clear association of NPC risk with dietary fiber intake from preserved vegetables, fruits and condiments was observed. Conclusion Our study has shown the protective role of dietary fiber from fresh food items in NPC risk, but no association for total dietary fiber intake was observed, probably because total intake also included intake of preserved food. Further studies with detailed dietary information and in prospective settings are needed to confirm this finding, and to explore the possible underlying biological mechanisms.

scholarly journals Association between dietary fiber and endometrial cancer: a dose-response meta-analysis

2007 ◽  
Vol 86 (6) ◽  
pp. 1730-1737 ◽  
Author(s):  
Elisa V Bandera ◽  
Lawrence H Kushi ◽  
Dirk F Moore ◽  
Dina M Gifkins ◽  
Marjorie L McCullough
Keyword(s):  
Endometrial Cancer ◽  
Dietary Fiber ◽  
Dose Response ◽  
Meta Analysis

CAFFEINE-INDUCED ULCEROGENESIS IN THE RAT

1962 ◽  
Vol 40 (11) ◽  
pp. 1473-1476 ◽  
Author(s):  
C. J. Pfeiffer ◽  
G. H. Gass
Keyword(s):  
Dose Response ◽  
Statistical Evaluation ◽  
Female Rats ◽  
Gastric Ulcers ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Stomach Tube ◽  
Male And Female ◽  
Male And Female Rats ◽  
Ulcerogenic Effect

The present investigation has demonstrated that administration of caffeine alkaloid (6.25 mg/kg, 25 mg/kg, and 100 mg/kg) by stomach tube induces acute gastric ulcers in the fundus, pylorus, and antrum of fasting male and female rats. The ulcers are histologically characterized as superficial erosions of the glandular mucosa. Statistical evaluation of ulcer indices indicated a linear, log dose–response relationship for caffeine alkaloid, and a similar ulcerogenic effect in both male and female rats.

Subchronic Toxicity of Thalidomide in Rodents After 13 Weeks of Oral Administration

1999 ◽  
Vol 18 (5) ◽  
pp. 337-352 ◽  
Author(s):  
Steve K. Teo ◽  
Nancy J. Trigg ◽  
Mary E. Shaw ◽  
J. Michael Morgan ◽  
Steve D. Thomas
Keyword(s):  
Food Consumption ◽  
Dose Response ◽  
Clinical Chemistry ◽  
Female Rats ◽  
Male Rats ◽  
Lumbar Spinal Cord ◽  
High Dose ◽  
Significant Finding ◽  
Lower Body ◽  
Body Weights

The subchronic toxicology of thalidomide was determined in CD-1 mice and F344 rats. Animals (10/sex/dose) were orally dosed at 30,300, and 3000 mg/kg/day over 13 weeks. Control animals were given 1% carboxymethylcellulose. No thalidomide-related mortality occurred throughout the study. Some species and sex differences were seen. In mice, thalidomide had no effect on body weight, food consumption, ophthalmic function or clinical chemistry/hematology, but a dose-dependent orange-pink urine was observed in both sexes. The discoloration was probably due to chromogenic breakdown products of thalidomide. The only significant finding in the mouse study was dose-related hepatic centrilobular hypertrophy in the males. This appeared only at the highest dose in the females. The hypertrophy was correlated with increased liver weight for the high dose of both sexes suggesting enzyme induction. In rats, thalidomide produced lower body weights in both sexes compared to control with a dose-response more evident in males. Male rats dosed at 30, 300, and 3000 mg/kg had body weights that were 8, 11, and 19% below control weight just before necropsy. Corresponding female rats were only 6–7% below control weights at all dose levels. Lower food consumption was observed in male rats and varied between 6–13% below control with no dose-response. Decreased forelimb strength was noted in males and could be due to the lower body weights. Functional observational battery tests and histopathology of the sural nerve and lumbar spinal cord sections suggested that the rat did not develop thalidomide-induced peripheral neuropathy. Mild anemia and leukopenia were seen only in some treated males. A decrease in total and free T4 was more consistent in females. Both sexes had lower thymus weights with no histological correlate compared to control. The no-observed-adverse-effect level for mice and female rats were 3000 mg/kg and 30 mg/kg for male rats.

Dietary and other Modulators of Carcinogenesis

1983 ◽  
Vol 2 (3) ◽  
pp. 307-319
Author(s):  
Adrianne E. Rogers
Keyword(s):  
Dose Response ◽  
Tumor Development ◽  
Mammary Tumorigenesis ◽  
Chemical Carcinogenesis ◽  
Contributory Factor ◽  
Nutritional Factors ◽  
Carcinogen Metabolism ◽  
Response Data ◽  
B Virus ◽  
Dietary Content

Nutritional or dietary status and interactions between carcinogens and nutrient absorption, storage or metabolism influence carcinogenesis in many experimental animal models and probably in people. Use of dose-response data to indicate a threshold exposure for carcinogenesis must include consideration of dietary and nutritional factors that may alter the dose response. Two models in rats in which there is clear evidence of dietary or nutritional modulation of chemical carcinogenesis are mammary tumors induced by 7, 12-dimethylbenzanthracene (DMBA) or N-nitrosomethyl-urea (NMU) and hepatocarcinomas induced by many compounds. Mammary tumorigenesis is increased by increasing dietary content of some, but not all, fats. The time in tumor development at which fats act varies. Their mechanisms of action are not known but appear to include effects on the hormonal mileu and possibly mammary gland cell turnover and response to hormones. Hepatocarcinogenesis by chemicals is increased by dietary deficiency of the lipotropes methionine, choline and folate, possibly through alteration of carcinogen metabolism and increased hepatocyte DNA synthesis. The same deficiency induces cirrhosis. In humans, cirrhosis induced by alcoholism, viral hepatitis or unknown factors increases the risk for hepatocarcinoma. Alcohol-induced folate or other deficiency can be a contributory factor in the alcoholics. Infection with hepatitis B virus is increased in alcoholics and in patients with hepatocarcinoma and may be an initiating or modulating factor for tumors.

scholarly journals A Rapid, Sensitive and Reliable Assay for Inhibin Bioactivity

1987 ◽  
Vol 40 (1) ◽  
pp. 105 ◽  
Author(s):  
V WK Lee ◽  
Noelene Colvin ◽  
Helen Quigg ◽  
Lynne Atley ◽  
Julie McMaster ◽  
...  
Keyword(s):  
Dose Response ◽  
Culture Media ◽  
Rete Testis ◽  
Female Rats ◽  
Pituitary Cells ◽  
Response Curves ◽  
Cell Content ◽  
Practical Capacity ◽  
Pituitary Glands ◽  
Dose Response Curves

A rapid 2-day quantitative assay for inhibin bioactivity based on FSH secretion from pituitary cells of immature female rats is described. The bioassay exhibited steeper slopes, improved precision and greater (fourfold) sensitivity compared with a previously established pituitary FSH cell content assay. Whole pituitary glands were used for the preparation of pituitary cells and the method for cell dispersion required a single enzymatic treatment with trypsin. Cells (180000 viable cells per well) were dispensed into culture media containing inhibin and incubated for 48 h. Media were removed and assayed for FSH by radioimmunoassay. Using a ram rete testis fluid preparation as standard the inhibin dose-response curves of 25 consecutive experiments showed indices of precision of - O� 08(mean)[range - 0�04 to - 0�17] and Finney's G values of 0�017[0�003-0�06]. The mean ED40 was 0�17 units of in hi bin activity per well with interassay variation of 16�2% at this point of the dose-response curve. The assay had a practical capacity of 400 wells, permitting the measurement of dose-response curves of at least 40 unknowns with three dose points and triplicate wells per dose. The assay is specific for inhibin-containing preparations from several animal species. Overall, the assay is simple, precise, and sensitive, indicative of its applicability to the measurement of inhibin samples with low inhibin bioactivity and to the screening of large numbers of fractions during inhibin purification.

scholarly journals Grain and dietary fiber intake and bladder cancer risk: a pooled analysis of prospective cohort studies

2020 ◽  
Vol 112 (5) ◽  
pp. 1252-1266
Author(s):  
Evan Y W Yu ◽  
Anke Wesselius ◽  
Siamak Mehrkanoon ◽  
Maree Brinkman ◽  
Piet van den Brandt ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Cohort Studies ◽  
Dietary Fiber ◽  
Dose Response ◽  
Lower Risk ◽  
Regression Models ◽  
Whole Grains ◽  
Whole Grain ◽  
Total Dietary Fiber ◽  
Reduced Risk

ABSTRACT Background Higher intakes of whole grains and dietary fiber have been associated with lower risk of insulin resistance, hyperinsulinemia, and inflammation, which are known predisposing factors for cancer. Objectives Because the evidence of association with bladder cancer (BC) is limited, we aimed to assess associations with BC risk for intakes of whole grains, refined grains, and dietary fiber. Methods We pooled individual data from 574,726 participants in 13 cohort studies, 3214 of whom developed incident BC. HRs, with corresponding 95% CIs, were estimated using Cox regression models stratified on cohort. Dose–response relations were examined using fractional polynomial regression models. Results We found that higher intake of total whole grain was associated with lower risk of BC (comparing highest with lowest intake tertile: HR: 0.87; 95% CI: 0.77, 0.98; HR per 1-SD increment: 0.95; 95% CI: 0.91, 0.99; P for trend: 0.023). No association was observed for intake of total refined grain. Intake of total dietary fiber was also inversely associated with BC risk (comparing highest with lowest intake tertile: HR: 0.86; 95% CI: 0.76, 0.98; HR per 1-SD increment: 0.91; 95% CI: 0.82, 0.98; P for trend: 0.021). In addition, dose–response analyses gave estimated HRs of 0.97 (95% CI: 0.95, 0.99) for intake of total whole grain and 0.96 (95% CI: 0.94, 0.98) for intake of total dietary fiber per 5-g daily increment. When considered jointly, highest intake of whole grains with the highest intake of dietary fiber showed 28% reduced risk (95% CI: 0.54, 0.93; P for trend: 0.031) of BC compared with the lowest intakes, suggesting potential synergism. Conclusions Higher intakes of total whole grain and total dietary fiber are associated with reduced risk of BC individually and jointly. Further studies are needed to clarify the underlying mechanisms for these findings.

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