Harriet Richardson

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BACKGROUND Tamoxifen and raloxifene have limited patient acceptance for primary prevention of breast cancer. Aromatase inhibitors prevent more contralateral breast cancers and cause fewer side effects than tamoxifen in patients with early-stage breast cancer. METHODS In a randomized, placebo-controlled, double-blind trial of exemestane designed to detect(More)
Little is known about the average duration of type-specific human papillomavirus (HPV) infections and their patterns of persistence. The objectives of this study were to evaluate the rate of acquisition and clearance of specific HPV types in young women. Female university students (n = 621) in Montreal were followed for 24 months at 6-month intervals. At(More)
BACKGROUND Previous studies have been inconsistent about the degree of sexual transmissibility of cervical human papillomavirus (HPV) infection. The authors hypothesize that risk factors for HPV infection vary according to HPV type. GOAL To estimate the prevalence of HPV infection in asymptomatic women and to identify risk factors for overall HPV(More)
Circadian (clock) genes have been linked with several functions relevant to cancer, and epidemiologic research has suggested relationships with breast cancer risk for variants in NPAS2, CLOCK, CRY2 and TIMELESS. Increased breast cancer risk has also been observed among shift workers, suggesting potential interactions in relationships of circadian genes with(More)
Long-term, night shiftwork has been identified as a potential carcinogenic risk factor. It is hypothesized that increased light at night exposure during shiftwork reduces melatonin production, which is associated with increased cancer risk. Sleep duration has been hypothesized to influence both melatonin levels and cancer risk, and it has been suggested(More)
BACKGROUND Exemestane can prevent breast cancer in postmenopausal women. Because of potential widespread use, we examined the safety of exemestane on bone health. METHODS In this nested safety substudy of the MAP.3 trial (a randomised, placebo-controlled, double-blind trial of exemestane 25 mg a day for the primary prevention of breast cancer), we(More)
The authors estimated plausible ranges of the probability of human papillomavirus (HPV) transmission per coital act among newly forming couples by using stochastic computer simulation. Comparative empirical data were obtained in 1996-2001 from a cohort study of female university students in Montreal, Canada. Female prevalence and frequency of sexual(More)
The rearing period has a key influence on the later performance of cattle, affecting future fertility and longevity. Producers usually aim to breed replacement heifers by 15 months to calve at 24 months. An age at first calving (AFC) close to 2 years (23 to 25 months) is optimum for economic performance as it minimises the non-productive period and(More)
UNLABELLED Human papillomavirus type 6 (HPV6) is the major etiological agent of anogenital warts and laryngeal papillomas and has been included in both the quadrivalent and nonavalent prophylactic HPV vaccines. This study investigated the global genomic diversity of HPV6, using 724 isolates and 190 complete genomes from six continents, and the association(More)
OBJECTIVE To evaluate the association between exposure to chlorinated solvents and cancer. METHODS We conducted a case-control study of occupational exposures and cancer in Montreal, Quebec, Canada, including 3730 cancer cases and 533 population controls. Occupational exposures were derived using a combination of subject-reported job history and expert(More)