This study aimed to compare the change in levels of several laboratory values and the development... more This study aimed to compare the change in levels of several laboratory values and the development of adverse events using two commonly used intramuscular testosterone therapy regimens. Men were included if they were 18 years or older and received one of the following testosterone therapy regimens: 100 mg intramuscular once weekly or 200 mg intramuscular once every other week. Primary outcomes were relative changes in total testosterone, free testosterone, estradiol, prostate-specific antigen, and hematocrit at 6 months after initiation of testosterone therapy. Secondary outcomes were any significant rises in estradiol, hematocrit, prostate-specific antigen, and any other treatment-related adverse events requiring cessation of testosterone therapy. A total of 263 men were enrolled. In a subanalysis of men who had a baseline hematocrit below 54% before intramuscular testosterone therapy initiation, we found the following: men who received 100 mg weekly injections were significantly less likely to have hematocrit levels rising above 54% (1/102 (1%) vs. 4/51 (8%); p = 0.023). No significant differences were recorded in the increase in total testosterone, free testosterone, prostate-specific antigen, and estradiol levels between both groups. A higher average serum testosterone over the dosing interval seen with the 200 mg regimen appears to be associated with a higher risk of erythrocytosis.
The pharmacokinetics (PK) and pharmacodynamics of two leuprolide acetate (LA) 45 mg 6‐month depot... more The pharmacokinetics (PK) and pharmacodynamics of two leuprolide acetate (LA) 45 mg 6‐month depot formulations were characterized in prostate cancer patients. Subjects (planned N = 150 in each cohort) received two intramuscular injections of LA Formulation‐A or Formulation‐B administered 24 weeks apart. Samples were collected for the measurement of testosterone, LH (all subjects) and leuprolide (in a subset of subjects approximately N = 24 in each cohort) at the same time points. Leuprolide PK profile showed an initial peak followed by a rapid decline over the first week post‐dose, with mean leuprolide concentrations staying relatively constant through the end of 24‐week period. Mean testosterone and LH serum concentrations showed initial increases above baseline values after the first dose and then decreased to 16.0 ng/dL and 0.6 mIU/mL by Week 4 for Formulation‐A and were maintained at ≤14.3 ng/dL and 0.4 mIU/mL, thereafter, with negligible mean increases after the second dose. Fo...
Aim : To compare the pharmacokinetics and pharmacodynamics of lansoprazole 30 mg administered int... more Aim : To compare the pharmacokinetics and pharmacodynamics of lansoprazole 30 mg administered intravenously in 0.9% NaCl or in polyethylene glycol, or orally.
INTRODUCTION AND OBJECTIVES: The influence of parental demographics on fertility and birth outcom... more INTRODUCTION AND OBJECTIVES: The influence of parental demographics on fertility and birth outcomes is a topic of great interest to both epidemiologists and the lay public. Given logistics and certainty of exposures, data on all births in the US is often reported at the maternal level. While paternal characteristics are also known to influence birth outcomes, generational trends of paternal characteristics of child births within the United States have been poorly characterized. We sought to summarize the demographics of fathers in the US over the past 4 decades as well as describe the patterns of missing paternal data on birth certificates. METHODS: We evaluated 158,621,397 U.S. births spanning from 1973 to 2015 using data from the National Vital Statistics System of the Centers for Disease Control. Paternal, maternal and infant characteristics were analyzed and paternal ages of all births and first births were presented over time along with the mean difference in age between parents. Characteristics of births with known and unknown paternity were also compared. RESULTS: There has been a significant increase in mean paternal age among whites, blacks and asians over the past 40 years. In 1973, the mean paternal age for all births was 27.6, and 24.6 for first births, rising to 31.4 and 29.1, respectively, in 2015. Paternal age increased for all races combined and each race individually. However, interracial differences in mean age were apparent with asians > whites > blacks. The mean age difference between parents was similar over the past 40 years. In 1973, the mean parental age difference was 2.8 years’2.7 years for whites, 3.2 years for blacks and 4.2 years for asians. In 2015, the mean overall difference was 2.5 years with the difference between asian fathers and their partners decreasing the most to 3.2 years. Of all the recorded births in 1973, 91.3% had knowledge of paternal identity. This fell to 85.5% of fathers identified in 1991 and resides at 88.4% in 2015. Over the past decade, mothers younger than 20 years had the lowest proportion of reported paternal identity at 67.7% with black mothers under 20 at 50.4%. Overall, births without paternal identity were more likely associated with young, black mothers who reported less weight gain during pregnancy, and lower birth weight children. CONCLUSIONS: Overall, paternal age is rising in the US in parallel with maternal age, a trend encompassing all races. The proportion of missing paternal data is also increasing in recent years. Given the association between paternal factors and birth characteristics, further understanding of these trends is necessary.
Androgen deprivation therapy (ADT) with gonadotropin-releasing hormone (GnRH) analogs is a standa... more Androgen deprivation therapy (ADT) with gonadotropin-releasing hormone (GnRH) analogs is a standard treatment for advanced prostate cancer. GnRH analog therapy can reduce testosterone to "castrate" levels, historically defined as <50 ng/dL. With the advent of newer assays, a lower threshold of <20 ng/dL has recently been proposed. We report the results of a retrospective analysis of two Phase III trials of 4- and 6-month depot microsphere formulations of leuprolide acetate (LA), a GnRH agonist that has previously demonstrated efficacy in testosterone suppression to <50 ng/dL in patients on ADT. This analysis investigates the ability of these LA formulations to suppress to ≤20 ng/dL levels. In two of five AbbVie/Abbott clinical trials of microsphere formulations of LA for ADT, analytic technology permitting testosterone detection as low as 3 ng/dL was used and thus was selected for this analysis. Both trials were open-label, fixed-dose studies in prostate cancer pa...
The House of Delegates, the democratic policy-making body of the American Medical Association, me... more The House of Delegates, the democratic policy-making body of the American Medical Association, meets twice a year to establish broad policy on health, medical, professional, and governance matters. As in previous years, several resolutions from this June’s meeting were of key interest to urologists.
Introduction: The purpose of this document is to provide guidance for urologists on the integrati... more Introduction: The purpose of this document is to provide guidance for urologists on the integration of advanced practice providers into the urological care setting with a focus on the current state and federal regulatory environment, reimbursement considerations, core competency benchmarks, patient satisfaction with the advanced practice provider‐physician team approach and proposed models of team based integrative care. Methods: Since 1983, the AUA (American Urological Association) has issued its position on allied health professionals, recognizing that in some areas allied health personnel contribute to the care of the patient with genitourinary disease and, therefore, encourages the proper use of allied health personnel. A 2013 AUA survey on workforce revealed that 62% of urologists surveyed were using an advanced practice provider in their practice. In 2012 there were nearly 8,000 advanced practice providers working in urology departments and practices in the United States, including more than 3,300 nurse practitioners and more than 4,000 physician assistants. In 2013 the AUA convened an ad hoc work group of a diverse set of urology providers, including physicians, nurse practitioners and physician assistants. The consensus statement was drafted over 10 months and approved by the AUA Board of Directors in November 2014. Results: Urologists work with advanced practice providers frequently but many may not know the most efficient way to incorporate them into their practice. The consensus statement examines advanced practice provider integration from a regulatory and practice management approach, as well as provides several applicable examples of how this applies to urologists in various clinical settings throughout the United States. Conclusions: This document supports the AUA's policy statement that in a team based approach with a board certified urologist in a supervisory role, allied health personnel contribute to the care of the patient with genitourinary disease and, therefore, encourages the proper use of allied health personnel.
The development of intracytoplasmic sperm injection has made the use of testicular sperm a viable... more The development of intracytoplasmic sperm injection has made the use of testicular sperm a viable option for infertile men with obstructive and nonobstructive azoospermia. Over the past decade, testicular biopsies have been handled and processed using a variety of different methods. Whole biopsy pieces can be effectively cryopreserved in a 10% glycerol diluent (Schiewe et al. 1997 67, S115 abst); however, the ability to find viable, motile sperm post-thaw is improved when prefreeze motility exists. The purpose of this study was to comparatively document in vitro sperm motility enhancement over time at different temperatures, and to prove that an intermediate temperature (28 to 30°C) would optimize sperm longevity for up to 1 week. In this study, 10 men with obstructive azoospermia underwent a surgical, open testicular biopsy procedure. Each biopsy was placed in HEPES buffered-human tubal fluid (mHTF) medium supplemented with 5% human serum albumin (HSA; Irvine Sci., Santa Ana, CA, U...
This study aimed to compare the change in levels of several laboratory values and the development... more This study aimed to compare the change in levels of several laboratory values and the development of adverse events using two commonly used intramuscular testosterone therapy regimens. Men were included if they were 18 years or older and received one of the following testosterone therapy regimens: 100 mg intramuscular once weekly or 200 mg intramuscular once every other week. Primary outcomes were relative changes in total testosterone, free testosterone, estradiol, prostate-specific antigen, and hematocrit at 6 months after initiation of testosterone therapy. Secondary outcomes were any significant rises in estradiol, hematocrit, prostate-specific antigen, and any other treatment-related adverse events requiring cessation of testosterone therapy. A total of 263 men were enrolled. In a subanalysis of men who had a baseline hematocrit below 54% before intramuscular testosterone therapy initiation, we found the following: men who received 100 mg weekly injections were significantly less likely to have hematocrit levels rising above 54% (1/102 (1%) vs. 4/51 (8%); p = 0.023). No significant differences were recorded in the increase in total testosterone, free testosterone, prostate-specific antigen, and estradiol levels between both groups. A higher average serum testosterone over the dosing interval seen with the 200 mg regimen appears to be associated with a higher risk of erythrocytosis.
The pharmacokinetics (PK) and pharmacodynamics of two leuprolide acetate (LA) 45 mg 6‐month depot... more The pharmacokinetics (PK) and pharmacodynamics of two leuprolide acetate (LA) 45 mg 6‐month depot formulations were characterized in prostate cancer patients. Subjects (planned N = 150 in each cohort) received two intramuscular injections of LA Formulation‐A or Formulation‐B administered 24 weeks apart. Samples were collected for the measurement of testosterone, LH (all subjects) and leuprolide (in a subset of subjects approximately N = 24 in each cohort) at the same time points. Leuprolide PK profile showed an initial peak followed by a rapid decline over the first week post‐dose, with mean leuprolide concentrations staying relatively constant through the end of 24‐week period. Mean testosterone and LH serum concentrations showed initial increases above baseline values after the first dose and then decreased to 16.0 ng/dL and 0.6 mIU/mL by Week 4 for Formulation‐A and were maintained at ≤14.3 ng/dL and 0.4 mIU/mL, thereafter, with negligible mean increases after the second dose. Fo...
Aim : To compare the pharmacokinetics and pharmacodynamics of lansoprazole 30 mg administered int... more Aim : To compare the pharmacokinetics and pharmacodynamics of lansoprazole 30 mg administered intravenously in 0.9% NaCl or in polyethylene glycol, or orally.
INTRODUCTION AND OBJECTIVES: The influence of parental demographics on fertility and birth outcom... more INTRODUCTION AND OBJECTIVES: The influence of parental demographics on fertility and birth outcomes is a topic of great interest to both epidemiologists and the lay public. Given logistics and certainty of exposures, data on all births in the US is often reported at the maternal level. While paternal characteristics are also known to influence birth outcomes, generational trends of paternal characteristics of child births within the United States have been poorly characterized. We sought to summarize the demographics of fathers in the US over the past 4 decades as well as describe the patterns of missing paternal data on birth certificates. METHODS: We evaluated 158,621,397 U.S. births spanning from 1973 to 2015 using data from the National Vital Statistics System of the Centers for Disease Control. Paternal, maternal and infant characteristics were analyzed and paternal ages of all births and first births were presented over time along with the mean difference in age between parents. Characteristics of births with known and unknown paternity were also compared. RESULTS: There has been a significant increase in mean paternal age among whites, blacks and asians over the past 40 years. In 1973, the mean paternal age for all births was 27.6, and 24.6 for first births, rising to 31.4 and 29.1, respectively, in 2015. Paternal age increased for all races combined and each race individually. However, interracial differences in mean age were apparent with asians > whites > blacks. The mean age difference between parents was similar over the past 40 years. In 1973, the mean parental age difference was 2.8 years’2.7 years for whites, 3.2 years for blacks and 4.2 years for asians. In 2015, the mean overall difference was 2.5 years with the difference between asian fathers and their partners decreasing the most to 3.2 years. Of all the recorded births in 1973, 91.3% had knowledge of paternal identity. This fell to 85.5% of fathers identified in 1991 and resides at 88.4% in 2015. Over the past decade, mothers younger than 20 years had the lowest proportion of reported paternal identity at 67.7% with black mothers under 20 at 50.4%. Overall, births without paternal identity were more likely associated with young, black mothers who reported less weight gain during pregnancy, and lower birth weight children. CONCLUSIONS: Overall, paternal age is rising in the US in parallel with maternal age, a trend encompassing all races. The proportion of missing paternal data is also increasing in recent years. Given the association between paternal factors and birth characteristics, further understanding of these trends is necessary.
Androgen deprivation therapy (ADT) with gonadotropin-releasing hormone (GnRH) analogs is a standa... more Androgen deprivation therapy (ADT) with gonadotropin-releasing hormone (GnRH) analogs is a standard treatment for advanced prostate cancer. GnRH analog therapy can reduce testosterone to "castrate" levels, historically defined as <50 ng/dL. With the advent of newer assays, a lower threshold of <20 ng/dL has recently been proposed. We report the results of a retrospective analysis of two Phase III trials of 4- and 6-month depot microsphere formulations of leuprolide acetate (LA), a GnRH agonist that has previously demonstrated efficacy in testosterone suppression to <50 ng/dL in patients on ADT. This analysis investigates the ability of these LA formulations to suppress to ≤20 ng/dL levels. In two of five AbbVie/Abbott clinical trials of microsphere formulations of LA for ADT, analytic technology permitting testosterone detection as low as 3 ng/dL was used and thus was selected for this analysis. Both trials were open-label, fixed-dose studies in prostate cancer pa...
The House of Delegates, the democratic policy-making body of the American Medical Association, me... more The House of Delegates, the democratic policy-making body of the American Medical Association, meets twice a year to establish broad policy on health, medical, professional, and governance matters. As in previous years, several resolutions from this June’s meeting were of key interest to urologists.
Introduction: The purpose of this document is to provide guidance for urologists on the integrati... more Introduction: The purpose of this document is to provide guidance for urologists on the integration of advanced practice providers into the urological care setting with a focus on the current state and federal regulatory environment, reimbursement considerations, core competency benchmarks, patient satisfaction with the advanced practice provider‐physician team approach and proposed models of team based integrative care. Methods: Since 1983, the AUA (American Urological Association) has issued its position on allied health professionals, recognizing that in some areas allied health personnel contribute to the care of the patient with genitourinary disease and, therefore, encourages the proper use of allied health personnel. A 2013 AUA survey on workforce revealed that 62% of urologists surveyed were using an advanced practice provider in their practice. In 2012 there were nearly 8,000 advanced practice providers working in urology departments and practices in the United States, including more than 3,300 nurse practitioners and more than 4,000 physician assistants. In 2013 the AUA convened an ad hoc work group of a diverse set of urology providers, including physicians, nurse practitioners and physician assistants. The consensus statement was drafted over 10 months and approved by the AUA Board of Directors in November 2014. Results: Urologists work with advanced practice providers frequently but many may not know the most efficient way to incorporate them into their practice. The consensus statement examines advanced practice provider integration from a regulatory and practice management approach, as well as provides several applicable examples of how this applies to urologists in various clinical settings throughout the United States. Conclusions: This document supports the AUA's policy statement that in a team based approach with a board certified urologist in a supervisory role, allied health personnel contribute to the care of the patient with genitourinary disease and, therefore, encourages the proper use of allied health personnel.
The development of intracytoplasmic sperm injection has made the use of testicular sperm a viable... more The development of intracytoplasmic sperm injection has made the use of testicular sperm a viable option for infertile men with obstructive and nonobstructive azoospermia. Over the past decade, testicular biopsies have been handled and processed using a variety of different methods. Whole biopsy pieces can be effectively cryopreserved in a 10% glycerol diluent (Schiewe et al. 1997 67, S115 abst); however, the ability to find viable, motile sperm post-thaw is improved when prefreeze motility exists. The purpose of this study was to comparatively document in vitro sperm motility enhancement over time at different temperatures, and to prove that an intermediate temperature (28 to 30°C) would optimize sperm longevity for up to 1 week. In this study, 10 men with obstructive azoospermia underwent a surgical, open testicular biopsy procedure. Each biopsy was placed in HEPES buffered-human tubal fluid (mHTF) medium supplemented with 5% human serum albumin (HSA; Irvine Sci., Santa Ana, CA, U...
Uploads
Papers by aaron spitz