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Browsing Center for Research in Reproduction and Contraception by Author "Anawalt, Bradley D."
Now showing items 1-20 of 20
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Acyline: the first study in humans of a potent, new gonadotropin-releasing hormone antagonist
Bremner, William J.; Amory, John K.; Herbst, Karen L.; Anawalt, Bradley D. (Endocrine Society, 2002-07)Acyline is a novel GnRH antagonist found in animal studies to be a potent suppressor of circulating gonadotropin and testosterone (T) levels. We conducted the first study of acyline administration to humans. ... -
Cognitive effects of short-term manipulation of serum sex steroids in healthy young men
Cherrier, M. M.; Bremner, William J.; Herbst, Karen L.; Amory, John K.; Craft, S.; Matsumoto, Alvin M.; Anawalt, Bradley D. (Endocrine Society, 2002-07)We examined the effects of sex steroids on cognitive functioning by exogenously manipulating circulating T levels in a group of healthy young men. Thirty-two men were randomized to receive 8 wk of treatment ... -
Combined administration of levonorgestrel and testosterone induces more rapid and effective suppression of spermatogenesis than testosterone alone: a promising male contraceptive approach
Paulsen, C. Alvin; Christensen, Richard B.; Matsumoto, Alvin M.; Bremner, William J.; Bebb, Richard A.; Anawalt, Bradley D. (Endocrine Society, 1996-02)Studies using high dose testosterone (T) administration in normal men as a male contraceptive have resulted in azoospermia rates of only 50-70%. Previous studies of T and progestogen combinations have shown ... -
Daily testosterone and gonadotropin levels are similar in azoospermic and nonazoospermic normal men administered weekly testosterone: implications for male contraceptive development
Matsumoto, Alvin M.; Bremner, William J.; Amory, John K.; Anawalt, Bradley D. (American Society of Andrology, 2001-11)Weekly intramuscular administration of testosterone esters such as testosterone enanthate (TE) suppresses gonadotropins and spermatogenesis and has been studied as a male contraceptive. For unknown reasons, ... -
Desogestrel plus testosterone effectively suppresses spermatogenesis but also causes modest weight gain and high-density lipoprotein suppression
Mulders, Titia M. T.; Matsumoto, Alvin M.; Bremner, William J.; Coelingh-Bennink, Herjan J. T.; Anawalt, Bradley D.; Herbst, Karen L. (Elsevier, 2000-10)OBJECTIVE: To test the hypothesis that oral desogestrel (DSG) plus testosterone would uniformly and rapidly suppress sperm concentrations in young men as effectively as levonorgestrel (LNG) plus testosterone ... -
Exogenous testosterone (T) alone or with finasteride increases physical performance, grip strength, and lean body mass in older men with low serum T
Anawalt, Bradley D.; Tenover, J. Lisa; Bowman, F. DuBois; Bremner, William J.; Matsumoto, Alvin M.; Page, Stephanie T.; Amory, John K. (Endocrine Society, 2005-03)Testosterone (T) therapy in older men with low serum T levels increases lean body mass and decreases fat mass. These changes might improve physical performance and strength; however, it has not been established ... -
Exogenous testosterone or testosterone with finasteride increases bone mineral density in older men with low serum testosterone
Sutton, Paul R.; Bremner, William J.; Easley, Kirk A.; Tenover, J. Lisa; Matsumoto, Alvin M.; Anawalt, Bradley D.; Amory, John K.; Watts, Nelson B. (Endocrine Society, 2004-02)Older men, particularly those with low serum testosterone (T) levels, might benefit from T therapy to improve bone mineral density (BMD) and reduce fracture risk. Concerns exist, however, about the impact of ... -
Immature spermatids are not prevalent in semen from men who are receiving androgen-based contraceptive regimens
Matsumoto, Alvin M.; Bremner, William J.; McLachlan, Robert I.; Anawalt, Bradley D.; Zhengwei, Yang; Wreford, Nigel G. (Elsevier, 1998-01)OBJECTIVE: To determine whether immature spermatids increase in semen in response to hormonal contraceptive treatments. Such a finding would support the existence of a defect in spermiogenesis, which in turn ... -
Intramuscular testosterone enanthate plus very low dosage oral levonorgestrel suppresses spermatogenesis without causing weight gain in normal young men: a randomized clinical trial
Coviello, Andrea D.; Matsumoto, Alvin M.; Herbst, Karen L.; Bremner, William J.; Page, Stephanie T.; Anawalt, Bradley D.; Amory, John K. (American Society of Andrology, 2005-05)The development of a safe, well-tolerated, effective, and reversible male hormonal contraceptive would be a major clinical advance for couples planning their family size and for control of population growth. ... -
Intratesticular testosterone concentrations comparable with serum levels are not sufficient to maintain normal sperm production in men receiving a hormonal contraceptive regimen
Zirkin, Barry R.; Herbst, Karen L.; Yan, Xiaohua; Matsumoto, Alvin M.; Brown, Terry R.; Anawalt, Bradley D.; Amory, John K.; Wright, William W.; Jarow, Jonathan P.; Coviello, Andrea D.; Bremner, William J. (American Society of Andrology, 2004-11)Intratesticular testosterone (ITT) is thought to play a key role in the control of spermatogenesis in man but is rarely measured. The purposes of this study were 1) to examine the relationship between ... -
Klinefelter's Syndrome
Paulsen, C. Alvin; Bremner, William J.; Amory, John K.; Anawalt, Bradley D. (Elsevier, 2000-07) -
Low-dose human chorionic gonadotropin maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression
Yan, Xiaohua; Herbst, Karen L.; Sutton, Paul R.; Bremner, William J.; Wright, William W.; Anawalt, Bradley D.; Amory, John K.; Brown, Terry R.; Jarow, Jonathan P.; Zirkin, Barry R.; Coviello, Andrea D.; Matsumoto, Alvin M. (Endocrine Society, 2005-05)In previous studies of testicular biopsy tissue from healthy men, intratesticular testosterone (ITT) has been shown to be much higher than serum testosterone (T), suggesting that high ITT is needed relative ... -
A lower dosage levonorgestrel and testosterone combination effectively suppresses spermatogenesis and circulating gonadotropin levels with fewer metabolic effects than higher dosage combinations
Matsumoto, Alvin M.; Bremner, William J.; Anawalt, Bradley D.; Bebb, Richard A. (American Society of Andrology, 1999-05)Studies using exogenous high-dosage testosterone (T) or a combination regimen of physiologic T plus high-dosage levonorgestrel (LNG) administration in normal men have shown that oligoazoospermia (<3 ... -
The male contraceptive regimen of testosterone and levonorgestrel significantly increases lean mass in healthy young men in 4 weeks, but attenuates a decrease in fat mass induced by testosterone alone
Matsumoto, Alvin M.; Amory, John K.; Bremner, William J.; Herbst, Karen L.; Anawalt, Bradley D. (Endocrine Society, 2003-03)In hypogonadal men, testosterone (T) in replacement dosages is known to increase fat-free mass (lean mass) and decrease fat mass. In young eugonadal men, similar dosages of T increase lean mass, but much higher dosages of ... -
Preoperative supraphysiological testosterone in older men undergoing knee replacement surgery
Camuso, Matthew R.; Matsumoto, Alvin M.; Chansky, Kari L.; Bremner, William J.; Anawalt, Bradley D.; Hoey, Chris T.; Amory, John K.; Chansky, Howard A. (Blackwell Publishing, 2002-10)OBJECTIVES: Older patients undergoing knee replacement surgery can recover more slowly than younger patients and require extended rehabilitation. Because administration of supraphysiological testosterone (T) ... -
Relationship between serum gonadotropins and spermatogenic suppression in men undergoing steroidal contraceptive treatment
Ugoni, Antony; Bremner, William J.; Pruysers, Enid; Meriggiola, M. Cristina; Anawalt, Bradley D.; Matsumoto, Alvin M.; McLachlan, Robert I.; Robertson, David M. (Endocrine Society, 2004-01)This study aimed to establish whether the degree of suppression of serum FSH and LH was related to sperm concentration in three testosterone (T) plus progestin contraceptive regimens. We measured serum FSH ... -
Serum inhibin B levels reflect Sertoli cell function in normal men and men with testicular dysfunction
Groome, Nigel P.; Bremner, William J.; Matsumoto, Alvin M.; McNeilly, Alan S.; Illingworth, Peter J.; Anawalt, Bradley D.; Bebb, Richard A. (Endocrine Society, 1996-09)We used a recently developed ELISA format to test the hypothesis that inhibin B is the physiologically active form of inhibin in men. We measured and compared inhibin A, inhibin B, and pro-alpha-C-related ... -
A single dose of the potent gonadotropin-releasing hormone antagonist acyline suppresses gonadotropins and testosterone for 2 weeks in healthy young men
Amory, John K.; Page, Stephanie T.; Bremner, William J.; Anawalt, Bradley D.; Herbst, Karen L.; Coviello, Andrea D. (Endocrine Society, 2004-12)Acyline is a novel GnRH antagonist that reliably inhibits gonadotropins and testosterone (T) levels in men for 48 h after a single dose up to 75 microg/kg. In this study we examined gonadotropin and T levels in 28 healthy ... -
Suppression of spermatogenesis in man induced by Nal-Glu gonadotropin releasing hormone antagonist and testosterone enanthate (TE) is maintained by TE alone
Swerdloff, R. S.; Bremner, William J.; Wang, C.; Anawalt, Bradley D.; Berman, N.; Steiner, B.; Bagatell, Carrie J. (Endocrine Society, 1998-10)GnRH antagonists plus testosterone (T) suppress LH and FSH levels and inhibit spermatogenesis to azoospermia or severe oligozoospermia. High-dose T treatment alone has been shown to be an effective male ... -
Testosterone administration suppresses adiponectin levels in men
Coviello, Andrea D.; Bremner, William J.; Amory, John K.; Matsumoto, Alvin M.; Anawalt, Bradley D.; Page, Stephanie T.; Herbst, Karen L. (American Society of Andrology, 2005-01)Testosterone (T) administration to men increases lean body mass and decreases fat mass. Adiponectin is produced by adipocytes and is thought to influence insulin sensitivity. In this study, we sought to ...