Ratio Estimates, the Delta Method, and Quantal Response Tests for Increased Carcinogenicity

Bieler, Gayle; Williams, Rick

doi:10.2307/2532200

Cited by 135 publications

(127 citation statements)

References 10 publications

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“…Consequently, the combined incidence of adenomas and carcinomas in females was further analyzed using the continuity-corrected Poly-3 trend test with the Bieler-Williams modification that takes survival into consideration (Bieler and Williams, 1993). The Poly-3 trend test is the default trend test of the National Toxicology Program (NTP), even when survival is not affected as in the case of α-methylstyrene (NTP, 2007).…”

Section: Iid1 Inhalation-mousementioning

confidence: 99%

Evaluating Soil Solarization for Weed Control and Strawberry (Fragariaxananassa) Yield in Annual Plasticulture Production

Samtani¹,

Derr²,

Conway³

et al. 2017

Weed Technol

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Field studies were initiated in the 2013-14 and 2014-15 growing seasons to evaluate the potential of soil solarization (SS) treatments for their efficacy on weed control and crop yields and to compare SS to 1,3-dichloropropene (1,3-D)+chloropicrin (Pic) fumigation. Each replicate was a bed with dimension 10.6 m long by 0.8 m wide on top. The center 4.6 m length of each bed, referred to as plots, was used for strawberry plug transplanting and data collection. Treatments included: i) 1,3-D+Pic (39% 1,3-dichloropropene+59.6% chloropicrin) that was shank-fumigated in beds at 157 kg ha−1and covered with VIF on August 30 in both seasons; ii) SS for a 6 wk duration initiated on August 15, 2013 and August 21, 2014 by covering the bed with 1 mil clear polyethylene tarp; iii) SS for a 4wk duration initiated on September 6, 2013 and September 3, 2014; iv) SS 4 wk treatment initiated September 6, 2013 and September 3, 2014 and replaced with black VIF on October 4, 2013 and October 1, 2014 and v) a nontreated control covered with black VIF on October 4, 2013 and October 1, 2014. In both seasons, following completion of the preplant treatments, ‘Chandler’ strawberry was planted in two rows at a 36 cm in-row spacing in plots during the first wk of October. Over both seasons, the 6 wk SS treatment consistently lowered the weed density compared to the nontreated control. Weed density in the 6wk SS treatment was not statistically different from the 4wk SS treatments in the 2013-14 growing season. In both seasons, crop yield in the 4 wk SS was significantly lower than other treatments.

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Section: Iid1 Inhalation-mousementioning

confidence: 99%

Evaluating Soil Solarization for Weed Control and Strawberry (Fragariaxananassa) Yield in Annual Plasticulture Production

Samtani¹,

Derr²,

Conway³

et al. 2017

Weed Technol

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“…The resulting survival-adjusted estimate of π ci is . Bieler and Williams (1993) noted that is a random variable and proposed a corrected variance estimator, which under the assumption that π c1 = π c2 = ⋯ = π ck is given by where , and the plus sign indicates summation over the missing index.…”

Section: Introductionmentioning

confidence: 99%

Incorporating Historical Control Data When Comparing Tumor Incidence Rates

Peddada

Dinse

Kissling

2007

Journal of the American Statistical Association

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Animal carcinogenicity studies, such as those conducted by the U.S. National Toxicology Program (NTP), focus on detecting trends in tumor rates across dose groups. Over time, the NTP has compiled vast amounts of data on tumors in control animals. Currently, this information is used informally, without the benefit of statistical tests for carcinogenicity that directly incorporate historical data on control animals. This article proposes a survival-adjusted test for detecting doserelated trends in tumor incidence rates, which incorporates data on historical control rates and formally accounts for variation in these rates among studies. An extensive simulation, based on a wide range of realistic situations, demonstrates that the proposed test performs well in comparison to the current NTP test, which does not incorporate historical control data. In particular, our test can aid in interpreting the occurrence of a few tumors in treated animals that are rarely seen in controls. One such example, which motivates our work, concerns the analysis of histiocytic sarcoma in the NTP's 2-year cancer bioassay of benzophenone. Whereas the occurrence of three histiocytic sarcomas in female rats was not significant according to the current NTP testing procedure (P = 0.074), it was highly significant (P = 0.004) when control data from six recent historical studies were included and our test was applied to the combined data.

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“…All reported p values for the survival analyses are two-sided. For neoplasm and nonneoplastic lesion incidences, continuity-corrected Poly-3 tests were used to test for exposure-related trends and pairwise comparisons of each exposure group to the control group, and reported p values are one-sided (Bieler and Williams 1993;Portier and Bailer 1989;Bailer and Portier 1988). 500 ppm 1-BP was significantly less than that of the controls.…”

Section: Methodsmentioning

confidence: 99%

Multisite Carcinogenicity and Respiratory Toxicity of Inhaled 1-Bromopropane in Rats and Mice

et al. 2011

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Two-year 1-bromopropane (1-BP) inhalation studies were conducted because of the potential for widespread exposure, the lack of chronic toxicity and carcinogenicity data, and the known carcinogenicity of structurally related compounds. Male and female F344/N rats and B6C3F1/N mice were exposed by inhalation to 0, 62.5 (mice only), 125, 250, or 500 (rats only) ppm 1-BP for 6 hr/day, 5 days/week for 105 weeks. Exposure of male and female rats to 1-BP resulted in significantly increased incidences of adenomas of the large intestine and skin neoplasms. In male rats, the incidence of malignant mesothelioma of the epididymis was statistically significantly increased at 500 ppm, but the biological significance of this common lesion is unclear. Incidences of pancreatic islet adenoma in male rats were significantly increased at all concentrations relative to concurrent controls but were within the historical control range for inhalation studies. There was no evidence of carcinogenic activity of 1-BP in male B6C3F1 mice; however, significantly increased incidences of alveolar/bronchiolar neoplasms of the lung were present in female mice. Exposure to 1-BP also resulted in increased incidences of nonneoplastic lesions in the nose of rats and mice, the larynx of rats and male mice, the trachea of female rats and male and female mice, and the lungs of mice. Inflammatory lesions with Splendore Hoeppli (S-H) material were present primarily in the nose and skin of exposed male and female rats, indicating that 1-BP caused immunosuppression.

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Ratio Estimates, the Delta Method, and Quantal Response Tests for Increased Carcinogenicity

Cited by 135 publications

References 10 publications

Evaluating Soil Solarization for Weed Control and Strawberry (Fragariaxananassa) Yield in Annual Plasticulture Production

Evaluating Soil Solarization for Weed Control and Strawberry (Fragariaxananassa) Yield in Annual Plasticulture Production

Incorporating Historical Control Data When Comparing Tumor Incidence Rates

Multisite Carcinogenicity and Respiratory Toxicity of Inhaled 1-Bromopropane in Rats and Mice

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