Roger S. Rittmaster

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BACKGROUND We conducted a study to determine whether dutasteride reduces the risk of incident prostate cancer, as detected on biopsy, among men who are at increased risk for the disease. METHODS In this 4-year, multicenter, randomized, double-blind, placebo-controlled, parallel-group study, we compared dutasteride, at a dose of 0.5 mg daily, with placebo.(More)
Hypophosphatemia is a genetically heterogeneous disease. Here, we mapped an autosomal recessive form (designated ARHP) to chromosome 4q21 and identified homozygous mutations in DMP1 (dentin matrix protein 1), which encodes a non-collagenous bone matrix protein expressed in osteoblasts and osteocytes. Intact plasma levels of the phosphaturic protein FGF23(More)
J. Curtis Nickel *, Claus G. Roehrborn , Michael P. O’Leary , David G. Bostwick , Matthew C. Somerville , Roger S. Rittmaster f Department of Urology, Queen’s University, Kingston General Hospital, Kingston, ON, Canada Department of Urology, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA Department of Surgery, Harvard Medical(More)
To determine whether hyperinsulinemia can directly reduce serum sex hormone-binding globulin (SHBG) levels in obese women with the polycystic ovary syndrome, six obese women with this disorder were studied. Before study, ovarian steroid production was suppressed in each woman by the administration of 7.5 mg of a long-acting GnRH agonist, leuprolide depot,(More)
BACKGROUND Several germline single nucleotide polymorphisms (SNPs) have been consistently associated with prostate cancer (PCa) risk. OBJECTIVE To determine whether there is an improvement in PCa risk prediction by adding these SNPs to existing predictors of PCa. DESIGN, SETTING, AND PARTICIPANTS Subjects included men in the placebo arm of the(More)
To determine the hormonal effects of MK-906, an orally active 5 alpha-reductase inhibitor, on serum androgens and androgen conjugates, 12 healthy men were given 10, 20, 50, and 100 mg MK-906 2 weeks apart in randomized order in a 4-period crossover design. Serum testosterone (T), dihydrotestosterone (DHT), androstanediol glucuronide, and androsterone(More)
Treatment of osteoporosis with PTH causes a marked increase in vertebral bone mineral density (BMD). However, this effect is rapidly reversed when the treatment is stopped. The purpose of the present study was to determine whether the bisphosphonate alendronate could preserve or enhance bone density in patients previously treated with PTH. Sixty-six(More)
PURPOSE We determined the performance of PCA3 alone and in the presence of other covariates as an indicator of contemporaneous and future prostate biopsy results in a population with previous negative biopsy and increased serum prostate specific antigen. MATERIALS AND METHODS Urine PCA3 scores were determined before year 2 and year 4 biopsies from(More)
OBJECTIVES Both normal and pathological growth of the prostate is dependent on dihydrotestosterone (DHT) synthesis, which is catalysed by two 5alpha-reductase (5alphaR) isoenzymes, 5alphaR1 and 5alphaR2, of which only 5alphaR2 has traditionally been viewed as important in the prostate. The objective of this study was to evaluate the role of both isoenzymes(More)
PURPOSE In the prostate testosterone is converted to dihydrotestosterone by 5alpha-reductase type 1 and/or 2. Although 5alpha-reductase type 2 is predominant in normal prostates, type 1 is increased in cancer vs benign tissue. It is unclear whether 5alpha-reductase type 1/2 levels correlate with cancer grade. We compared the relative expression of(More)