Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Survival, body weight, and site-specific tumor rates in untreated, corn oil gavage, and water gavage control Fischer 344 (F344/N) rats from 88 National Toxicology Program (NTP) long term carcinogenicity studies were evaluated to determine which factors were primarily responsible for inter-study variability. For male rats, previously-reported decreases in leukemia and increases in body weight, survival, and pancreatic acinar cell tumors attributable to corn oil gavage were confirmed. Corn oil did not appear to affect tumor rates in female rats. The gavage technique per se did not appear to influence tumor rates in rats of either sex. Previously reported time-related increases in certain site-specific neoplasia in control rats appeared to have stabilized in recent years, but control tumor rates are still much greater than those seen a decade ago. More recent studies continue to show increasing rates of leukemia and mammary gland tumors and decreasing survival. Female rats also continue to show time-related increases in maximum mean body weight. Inter-laboratory variability in body weight and in the rates of a number of site-specific neoplasms were also significant. High mean body weights in control groups were found to be associated with increased rates of mammary and pituitary tumors. Our evaluation supports the view that if historical control data are to be utilized in the interpretation of experimental results, primary emphasis should be given to lab and route of administration-specific tumor rates for studies that are contemporary to the study under evaluation. It also suggests that certain experimental design changes (e.g., dietary modifications) may be needed to reduce tumor rates and to increase survival.
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PMID:Effects of corn oil, time-related changes, and inter-laboratory variability on tumor occurrence in control Fischer 344 (F344/N) rats. 141 Nov 31

Consulting toxicologists began in 1982 to question the use and potential involvement of oil gavage test-compound administration in unexpected NTP carcinogenesis responses. Investigations have focused on corn oil gavage alternatives, vehicle type and volume, alteration of MTD, teratogenic effects, disposition of test compounds, and target tissues. Micoencapsulation will require considerable development research to make it a suitable alternative. Vehicle type and volume appear to have different effects on the apparent MTD, teratogenicity and disposition of very similar compounds. Only two tissue effects have been observed in the NTP oil gavage bioassay data. First, there is a sporadic and weak association with exocrine pancreatic acinar cell proliferative lesions; these lesions are highly correlated with overweight male Fischer 344/N rats. Second, leukemia is reduced about 50 percent in the male Fischer 344/N rats; this is a strong association which results in an 8-10 percent increase in survival. The protective effect of corn oil gavage is remarkable and there is no significant enhancement of tumor development. Corn oil gavage under the conditions of the NTP carcinogenesis bioassay does contribute to overnutrition and undesirable increased body weight, especially in male Fischer 344/N rats. The NTP and NCTR research programs include research plans to address critical oil gavage, diet composition feeding regimen, exercise and hormonal status questions. Results of these studies will point the way to improving long-term carcinogenesis and toxicity testing.
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PMID:Oil gavage test-compound administration effects in NTP carcinogenesis-toxicity testing. 309 53

Corn oil administered by oral gavage decreases the spontaneous incidence of mononuclear cell leukemia (MNCL) in male Fischer rats used as vehicle controls in long-term carcinogenesis experiments. We used an MNCL transplant model, an in situ MNCL cell proliferation assay and immune competence assays to explore mechanism(s) underlying the effects of corn oil gavage on MNCL development in male rats. Relative to non-gavaged or water-gavaged rats, corn oil-gavaged rats had approximately 25% lower MNCL incidence as well as longer MNCL latency and increased survival. There were no differences in body weight or caloric intake between treatment groups, as corn oil-gavaged rats compensated for calories supplied by the gavaged oil by consuming less food. These data indicate that transplanted MNCL cells grew slower in corn oil-gavaged rats than in non-gavaged or water-gavaged rats and suggest that corn oil gavage may exert its effects through a decrease in protein or other nutrients. Five-day proliferation rates of cultured MNCL cells in diffusion chambers implanted in male corn oil-gavaged rats were 40% less than in water-gavaged rats, suggesting nutrition-sensitive endogenous factors mediate the suppression of MNCL cell proliferation in corn oil-gavaged rats. Corn oil-gavaged rats had 54% lower serum growth hormone (GH) levels, and replacement of GH into corn oil-gavaged rats by osmotic minipump infusion increased in situ MNCL cell proliferation to rates observed in water-gavaged animals. Corn oil-gavaged rats also showed enhanced cellular immune competence as measured by mitogen stimulation, natural cytotoxicity and immunofluorescence assays. Taken together, these findings suggest corn oil administered by oral gavage may decrease MNCL development by slowing MNCL cell proliferation, mediated at least in part by altered levels of diffusible factors such as GH, and/or by enhancing immune competence.
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PMID:Inhibition of rat mononuclear cell leukemia by corn oil gavage: in vivo, in situ and immune competence studies. 831 8

Amount and type of fat and energy density of diets may influence tumor incidences. The purpose of this report is to summarize the influence of corn oil gavage and different nonpurified diets on spontaneous tumor incidences in 64 diet and 59 corn oil gavage control groups in two-year studies involving approximately 6,100 control Fischer 344 rats of each sex. The maximum mean body weight attained during the course of the study, survival at 106 weeks of age, and spontaneous tumor incidences of groups fed different nonpurified diets with or without corn oil gavage were summarized and evaluated for differences. Male rats fed NIH-07 open-formula diet with or without corn oil gavage had significantly higher body weight, lower survival, and higher incidence of pancreatic acinar cell tumors than rats fed commercial proprietary diets with or without corn oil gavage. Female rats fed NIH-07 diet with or without corn oil gavage had significantly higher body weights and pancreatic tumor incidences than groups fed commercial diets. Time-related trends could account for other apparent differences in tumor incidences between the groups fed commercial and NIH-07 diets. Corn oil gavage significantly increased the body weight and pancreatic tumor incidences but decreased the incidence of leukemia, a lethal tumor, which resulted in higher survival in male rats. Corn oil gavage significantly lowered the body weight and anterior pituitary tumor incidence in female rats. The pancreatic acinar cell tumor incidence appears to be due to a combination of fat intake and body weight.
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PMID:Influence of corn oil and diet on body weight, survival, and tumor incidences in F344/N rats. 844 12

The types and levels of fats in the diet are known to affect the incidence of certain neoplasms in humans and rodents. In long-term toxicity and carcinogenicity studies in rodents, the level of dietary fat is altered by using oil as a vehicle to administer unpalatable or volatile chemicals. Control male rats receiving a corn oil vehicle have a higher incidence of pancreatic proliferative lesions and a lower incidence of mononuclear cell leukemia than untreated control males. Therefore, the National Toxicology Program (NTP) designed studies to evaluate the role of several oils in altering cancer rates in male rats. The NTP study reported here was part of a larger program that included cooperative agreements with Dartmouth Medical School, Northwestern Medical School, and the University of Missouri. The program was designed to study the mechanisms by which corn oil induces pancreatic cancer. To evaluate corn oil as well as two other gavage vehicles for potential toxicity, corn oil, safflower oil, and tricaprylin were administered by gavage to male F344/N rats for 2 years. The rats that received corn oil were also made available to the university investigators for study of the corn oil-induced pancreatic lesions. Each vehicle was administered by gavage at volumes of 2.5, 5, or 10 mL/kg body weight once daily for 5 days per week. In the corn oil study, a control of 10 mL saline/kg was also included. To evaluate the potential role of corn oil in promoting a pancreatic proliferative effect, 500 mg dichloromethane/kg body weight was administered in 2.5, 5, or 10 mL corn oil/kg body weight for 2 years to male F344/N rats. Dichloromethane was chosen because the chemical appeared to cause pancreatic proliferative lesions when administered by gavage in a corn oil vehicle but not when the exposure was by inhalation. In each of these studies, the term "dose" refers to the volume of gavage vehicle administered. 2-YEAR STUDIES OF CORN OIL, SAFFLOWER OIL, AND TRICAPRYLIN: Survival and Body Weights: Two-year survival was increased in male rats receiving corn oil (untreated control, 26/50; saline control, 32/50; 2.5 mL/kg, 33/50; 5 mL/kg, 38/50; 10 mL/kg, 40/50) primarily due to a dose-related decreased incidence of mononuclear cell leukemia. The mean body weights of all dosed groups were at least 5% higher than those of the untreated and saline controls by week 48, but the mean body weights of groups receiving 2.5 or 5 mL corn oil/kg decreased during the final weeks of the study (after week 89) and were similar to those of the controls at the end of the study. Two-year survival was slightly increased in male rats receiving safflower oil relative to that of the controls (untreated control, 30/50; 2.5 mL/kg, 33/50; 5 mL/kg, 40/50; 10 mL/kg, 36/50). The mean body weight of male rats receiving 10 mL safflower oil/kg was at least 5% greater than that of the controls after week 45 and was 16% greater by the end of the study. Two-year survival of high-dose tricaprylin males was lower than that of the controls (untreated control, 31/50; 2.5 mL/kg, 30/50; 5 mL/kg, 31/50; 10 mL/kg, 23/53) due to moribund kills and deaths that appeared to be related to toxicity. The mean body weight of the high-dose group was lower than that of the controls throughout the study, although the difference was less than 5% after week 61. Pathology Findings: In the corn oil study, there were significant dose-related increased incidences of pancreatic exocrine hyperplasia and adenoma (hyperplasia: 8/50, 28/47, 28/50, 35/50; adenoma: 1/50, 8/47, 10/50, 23/50; carcinoma: 0/50, 0/47, 1/50, 0/50 in the untreated control, 2.5, 5, and 10 mL/kg groups, respectively). The incidence and severity of nephropathy decreased with dose (incidence [mean severity grade]: 47/50 [2.1], 43/48 [1.8], 45/50 [1.4], 40/49 [1.2]). The incidences of pheochromocytomas (benign, malignant, or complex) of the adrenal medulla were also decreased in dosed rats (23/49, 21/50, 5/50, 9/50). The incidence of mononuclear cell leukemia was significantly decreased in rats dosed with corn oil (27/50, 16/50, 11h corn oil (27/50, 16/50, 11/50, 7/50). In rats receiving safflower oil, the incidences of pancreatic exocrine hyperplasia and adenoma increased significantly with dose (hyperplasia: 8/50, 14/50, 29/49, 30/50; adenoma: 1/50, 7/50,15/49, 28/50; carcinoma: 0/50, 0/50, 0/49, 1/50 in the untreated control, 2.5, 5, and 10 mL/kg groups, respectively). There was a decrease in the severity, but not in the incidence, of nephropathy, a common lesion in aging F344/N rats (incidence [mean severity grade]: 49/50 [2.0], 50/50 [1.8], 47/50 [1.1], 49/49 [1.1]). There were decreased incidences of mononuclear cell leukemia (33/50, 19/50, 18/50, 7/51). In the tricaprylin study, there were significant dose-related increased incidences of pancreatic exocrine hyperplasia and adenoma (hyperplasia: 8/49, 9/49, 18/49, 28/50; adenoma: 2/49, 6/49,13/49,18/50 in the untreated control, 2.5, 5, and 10 mL/kg groups, respectively). The incidence of proliferative lesions of the forestomach increased significantly with dose (basal cell hyperplasia: 4/50, 7/50, 12/49, 21/52; squamous cell papilloma: 0/50, 0/50, 3/50, 10/53). The incidence of nephropathy was significantly decreased in high-dose rats, and the severity of nephropathy decreased with dose (incidence [mean severity grade]: 46/50 [2.0], 42/50 [1.5], 45/50 [1.7], 27/49 [0.9]). In high-dose rats, the incidence of mononuclear cell leukemia was decreased (23/50, 28/50, 22/50, 9/53). 2-YEAR STUDY OF DICHLOROMETHANE IN CORN OIL: Survival and Body Weights: Two-year survival increased slightly with dose in the three groups receiving 500 mg dichloromethane/kg in 2.5, 5, or 10 mL corn oil/kg (23/50, 28/50, 31/50) due to a dose-related decrease in the incidence of mononuclear cell leukemia. The rats receiving 500 mg dichloromethane/kg without corn oil were sacrificed within the first 3 weeks of the study due to the severe toxicity of dichloromethane. The final mean body weight of the high-dose rats was greater than the final mean body weights of groups receiving dichloromethane in 2.5 or 5 mL corn oil/kg. Pathology Findings: There was a dose-related increase in the incidence of pancreatic proliferative exocrine lesions in rats receiving dichloromethane in 2.5, 5, and 10 mL corn oil/kg (hyperplasia: 28/50, 38/50, 44/50; adenoma: 9/50,19/50, 41/50; carcinoma: 0/50,1/50, 3/50). The incidences of pancreatic exocrine hyperplasia and adenoma in rats receiving dichloromethane in 5 or 10 mL, but not 2.5 mL, corn oil were increased compared to the incidences in rats receiving comparable volumes of corn oil alone (hyperplasia: 2.5 mL, 28/47; 5 mL, 28/50;10 mL, 35/50; adenoma: 8/47,10/50, 23/50; carcinoma: 0/47,1/50, 0/50). There were significantly increased incidences of pituitary gland pars distalis adenoma in rats receiving dichloromethane in corn oil (20/50, 18/49, 16/49) when compared to those in rats receiving comparable volumes of corn oil alone (10/50, 6/49, 7/50). The incidence of mammary gland adenoma and fibroadenoma (combined) was significantly increased in rats receiving dichloromethane in 10 mL corn oil/kg (7/50) when compared to rats receiving dichloromethane in 2.5 mL corn oil/kg (1/50), but was not significantly increased when compared to the group receiving 10 mL of corn oil alone (3/50). The incidences of mammary gland adenoma and fibroadenoma (combined) were 7/50 for the untreated safflower oil controls and 6/50 for the untreated tricaprylin controls. The incidence of mononuclear cell leukemia decreased in the group receiving dichloromethane in 10 mL corn oil/kg (13/50,14/50, 5/50). GENETIC TOXICOLOGY: Neither safflower oil nor corn oil was mutagenic in Salmonella typhimurium strains TA97, TA98, TA100, or TA1535, with or without S9. Tricaprylin, in contrast, was mutagenic in strain TA1535 with, but not without, S9. Tricaprylin did not induce mutations in strains TA97, TA98, or TA100, with or without S9. SUMMARY: These studies were designed to evaluate the effects of various concentrations of an oil very high in polyunsaturated fat (safflower oil), an oil containing high levels of polyunsaturated and monounsaturated fats (corn oil), and an oil containing saturated medium-chain fatty acids (tricaprylin) on the incidence and pattern of neoplasms in the F344/N rat. In addition, safflower oil and tricaprylin were evaluated as replacements for the corn oil vehicle. These studies demonstrate that safflower oil and tricaprylin do not offer significant advantages over corn oil as a gavage vehicle in long-term rodent studies. Corn oil, safflower oil, and tricaprylin each caused hyperplasia and adenoma of the exocrine pancreas, decreased incidences of mononuclear cell leukemia, and reduced incidences or severity of nephropathy in male F344/N rats. There was an increased incidence of squamous cell papillomas of the forestomach in F344/N rats receiving 10 mL tricaprylin/kg. Further, the use of corn oil as a gavage vehicle may have a confounding effect on the interpretation of chemical-induced proliferative lesions of the exocrine pancreas and mononuclear cell leukemia in male F344/N rats. Synonyms: Corn Oil - Maize oil, Maydol Tricaprylin - Trioctanoin; 1,2,3-trioctanoyl glycerol; Glycerol trioctanoate
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PMID:NTP Comparative Toxicology Studies of Corn Oil, Safflower Oil, and Tricaprylin (CAS Nos. 8001-30-7, 8001-23-8, and 538-23-8) in Male F344/N Rats as Vehicles for Gavage. 1261 5

Ampicillin trihydrate is a broad-spectrum semi-synthetic penicillin that is effective in the treatment of gram-positive and gram-negative bacterial infections produced by Streptococcus, Bacillus anthracis, Haemophilus influenzae, Neisseria gonorrhoeae, and Escherichia coli. This antibiotic is used in the treatment of upper respiratory tract infections, genital and urinary tract infections, and otitis media in children. Toxicology and carcinogenesis studies of ampicillin trihydrate (97%-99% pure) were conducted by administering the chemical in corn oil by gavage to groups of 50 F344/N rats and 50 B6C3F1 mice of each sex, 5 days per week for 103 weeks. Male and female rats received doses of 0, 750, or 1,500 mg/kg, and male and female mice received doses of 0, 1,500, or 3,000 mg/kg. Doses selected for the 2-year studies were based on the lack of body weight effects and histopathologic effects at 2,400 mg/kg in the 14-day studies and 3,000 mg/kg in the 13-week studies. Clinical signs in the 13-week studies included diarrhea at 3,000 mg/kg in male and female rats and male mice. Corn oil suspensions containing more than 300 mg ampicillin trihydrate/ml were too viscous to be administered by gavage; therefore, a high dose of 1,500 mg/kg was selected for rats and a high dose of 3,000 mg/kg was selected for mice. During the 2-year studies, mean body weights of male and female rats were similar to or slightly increased over those of the corresponding vehicle control groups. Mean body weights of low dose and high dose male mice were similar to those of the corresponding vehicle group during year 1 of the study but were slightly below those of the vehicle control group during the last half of the study. Mean body weights of low dose and high dose female mice were greater than those of the vehicle controls throughout most of the study. No significant differences in survival were observed in groups of rats or mice of either sex. Clinical signs observed in dosed rats included diarrhea, excessive urination, and chromodacryorrhea and in dosed mice included increased salivation and decreased activity. In male rats, administration of ampicillin trihydrate was associated with an increased incidence of mononuclear cell leukemia (vehicle control, 5/50; low dose, 14/50; high dose, 13/50). Malignant lymphomas were observed in one additional vehicle control male rat and two low dose male rats. Lymphocytic leukemia was seen in one high dose rat. High dose male rats showed increased incidences of pheochromocytomas of the adrenal gland medulla (13/50; 12/50; 23/49). Malignant pheochromocytomas were observed in 1/50 vehicle control, 5/50 low dose, and 1/49 high dose male rats. The incidence of adrenal gland medullary hyperplasia was not increased in male rats (14/50; 10/50; 8/49). There were increased incidences of C-cellhyperplasia of the thyroid gland in low dose male and high dose female rats. High dose male rats showed increased incidences of hyperkeratosis and acanthosis of the forestomach. In male and female mice, ampicillin trihydrate administration was associated with increased incidences of forestomach lesions, including ulcers, inflammation, hyperkeratosis, acanthosis, and evidence of fungal infection. Ampicillin trihydrate was not mutagenic in Salmonella typhimurium strains TA98, TA100, TA1535, or TA1537 in the presence or absence of Aroclor 1254-induced male Syrian hamster or male Sprague-Dawley rat liver S9 when tested according to preincubation protocol. Ampicillin trihydrate was not mutagenic in L5178Y mouse lymphoma cells with or without metabolic activation. Ampicillin trihydrate did not cause chromosomal aberrations or sister-chromatid exchanges in Chinese hamster ovary cells with or without metabolic activation. An audit was conducted for these 2-year studies. Animal/carcass identification discrepancies were observed in rats and mice. The most common findings were the failure to clip some toes in rats and opened ear holes in mice. A review of the inlife data (including body weights, clinical observations, and dosing records) indicrecords) indicated that animals had not been interchanged among groups. The data are considered adequate to support the conclusions. Under the conditions of these 2-year gavage studies, there was equivocal evidence of carcinogenicity of ampicillin trihydrate for male F344/N rats as shown by increased incidences of pheochromocytomas of the adrenal medulla and by marginally increased incidences of mononuclear cell leukemia. There was no evidence of carcinogenicity for female F344/N rats receiving 750 or 1,500 mg/kg or for male and female B6C3F1 mice receiving 1,500 or 3,000 mg/kg per day. Nonneoplastic lesions of the forestomach were seen in male rats and male and female mice. Synonyms and trade names: Acillin; Amcap; Amcill; Aminobenzylpencillin trihydrate; a-Aminobenzylpencillin trihydrate; Amperil; Ampichel; Ampikel; Ampinova; Amplin; Cymbi; Divercillin; Liffampil; Morepen; Pen A; Pensyn; Polycillin; Princillin; Principen; Ro-ampen; Trafarbiot
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PMID:NTP Toxicology and Carcinogenesis Studies of Ampicillin Trihydrate (CAS No. 7177-48-2) in F344/N Rats and B6C3F1 Mice (Gavage Studies). 1274 35