Natan Bar-chama - Academia.edu (original) (raw)

Papers by Natan Bar-chama

Research paper thumbnail of P-576

Fertility and Sterility, Sep 1, 2006

Research paper thumbnail of Elevated Sperm Dna Fragmentation is Not Correlated with Embrionic Mosaicism in Patients Undergoing Ivf with PGT-A

Research paper thumbnail of Male reproduction and environmental and occupational exposures: a review of epidemiologic methods Reproducción masculina y exposiciones ambientales u ocupacionales: una revisión de métodos epidemiológicos

DOAJ (DOAJ: Directory of Open Access Journals), Nov 1, 1999

Concerns that chemical exposures in the environment have been detrimental to male sexual developm... more Concerns that chemical exposures in the environment have been detrimental to male sexual development and fertility have been heightened by reports of declining sperm counts over the past 50 years. Marked geographic variation has been found in semen quality and in the incidence of testicular cancer and certain urogenital defects. Debate continues over the existence, magnitude and significance of these trends, and how best to evaluate the hypothesis that in utero and childhood exposures to estrogenic compounds may be to blame. Epidemiologic methods for assessing the impact of hazardous substances on male reproductive health have been developed mainly in the area of occupational medicine, and this paper will review the currently recommended methods. These include questionnaires to determine reproductive history and sexual function; reproductive hormone profiles; and semen analyses such as sperm concentration, motility, and morphology. New research tools that show significant promise from the fields of clinical reproductive medicine and reproductive toxicology are discussed as possible additions to epidemiologic studies, including assays of sperm function and genetic integrity, and biomarkers of DNA damage. For population-based studies involving occupational groups or communities with environmental exposures, issues related to the cost, validity, precision and utility of these methods must be carefully considered.

Research paper thumbnail of Is paternal age associated with embryo aneuploidy?

Fertility and Sterility, Mar 1, 2018

BACKGROUND: Fertility nurses bear much of the responsibility for counseling patients through all ... more BACKGROUND: Fertility nurses bear much of the responsibility for counseling patients through all steps of their fertility journey. Rapid advances in reproductive technology make continuing education for nurses with this critical information for patients a priority. Standard nursing education does not provide the foundational knowledge of cell biology to be fully prepared to counsel patients on the results of cellular division and the impact of embryonic growth and molecular development on patient's choices. OBJECTIVE: To determine if focused training for reproductive nurses on topics of embryology and genetics improved self-efficacy and confidence scores. MATERIALS AND METHODS: A training program was created in partial fulfillment of an applied dissertation in health education. A need was identified with fertility nurses in whom additional training on embryology and reproductive genetics was needed. A 5 point Likert scale survey measuring nursing confidence was created to measure four domains of interest by ranking each statement as strongly disagree (1), disagree (2), neutral (3), agree (4), and strongly agree (5). The data were collected before the educational program and two weeks after exposure to document information retention and changes in confidence. The self-efficacy data sheet was created by the researcher and validated using the Cronbach's alpha. Demographic data were also collected. The data were de-identified utilizing a unique four-digit number created by each subject. This four-digit number on the pre-and post-test allowed the results to be linked. Data were analyzed using Pearson's R correlation test. RESULT(S): 41 reproductive endocrinology nurses completed the pre-and post-intervention assessments. The Cronbach's alpha for the 11 statement Likert scale survey was 0.8595, which indicates high internal validity and excellent reliability, and showed the self-efficacy scores for embryology and genetics counseling, and the need for future training were statistically significant between baseline and post-test, p<0.05. Specifically, nurses' confidence in educating patients on embryology and genetics went from slightly negative to a positive perception. A weak positive correlation between years of experience and self-confidence was observed, pre-and post-test p¼ 0.043 and p¼0.018, respectively. General self-confidence scores at baseline and post-test remained high, greater than 4.0 (agree-strongly agree) for the four statements. When qualitative assessment was also conducted with free-text answers after the intervention, two themes emerged, confidence and desire for more knowledge. 97.5% found the training worthwhile and 66% reported improved self-confidence, 28% said their confidence was similar, and 7% reported less confidence as they felt they had more to learn. CONCLUSION(S): Reproductive endocrinology nurses are central in the patient-facing role. Focused education on new topics should be part of the ongoing training of fertility nurses to provide knowledge and confidence for effective patient counseling. FINANCIAL SUPPORT: The research was conducted in partial fulfillment of a Doctorate in Health Education; no financial support was received.

Research paper thumbnail of Male factor infertility and aneuploidy: do couples with male factor infertility have a lower rate of euploid embryos?

Fertility and Sterility, Sep 1, 2016

to NOA and the repeated failures group (43.1AE7.8, 40.7AE8.8, 41.9AE5.8 respectively, p<0.0001). ... more to NOA and the repeated failures group (43.1AE7.8, 40.7AE8.8, 41.9AE5.8 respectively, p<0.0001). Mean female age was higher in the repeated failure group (35.9AE4.8, 34.8AE4.5, 37.1AE4.0, p<0.0001). Male FSH level was significantly higher in NOA (p<0.0001). The chance of finding sperm and likelihood of having an embryo transfer were significantly lower in this group (p<0.0001). There were more embryos fertilized in OA 5.79AE4.4 compared to NOA 5.2AE4.4 and 4.6AE4.2 in repeated failures (p¼0.003). There was no difference in the number of embryos transferred. Patients with OA were more likely to have a positive pregnancy test (37%, 27%, 28.5% respectively, p¼0.02). However there was no difference in the clinical pregnancy rate (31.8%, 23.9%, 25.4% respectively, p¼0.07) or in live birth rate (20.4%, 17.7%, 15.5% respectively, p¼0.3). There was no statistically significant difference in miscarriage rate between the groups (35.7%, 25.9%, 38.7% respectively, p¼0.33). CONCLUSIONS: Surgical sperm retrieval has revolutionized treatment in men with OA and NOA. There has been some debate as to whether surgically retrieved sperm is preferable to ejaculate in other populations, such as repeated failures. This study found that the likelihood of finding sperm, the number of fertilized embryos and the likelihood of embryo transfer were significantly lower in NOA. However, the clinical pregnancy rate and live birth rate were not statistically significantly different in all groups. An interesting finding is the higher than average miscarriage rate in the repeated failure group as well as a lower live birth rate, although this is not statistically significant. Age might be a contributor to this. Further study is needed to determine the benefit of surgically retrieved sperm in this group.

Research paper thumbnail of 1019 Oral Delivery of Melanotanûii (MT-II) in the Rodent Model

The Journal of Urology, Apr 1, 2013

INTRODUCTION AND OBJECTIVES: Melanotan û II (MT-II) is a synthetic cyclic peptide that functions ... more INTRODUCTION AND OBJECTIVES: Melanotan û II (MT-II) is a synthetic cyclic peptide that functions as a centrally acting melanocortin analog. In humans, subcutaneous (SC) administration of MT-II has demonstrated efficacy and safety for psychogenic as well as organic erectile dysfunction (ED) (Wessells, H., N. et al. (2000). Int J Impot Res 12 Suppl 4: S74-9). Our objective was to determine if MT-II absorption through the gastrointestinal tract can be achieved in the rodent model using a novel oral drug delivery technology. METHODS: Male Sprague-Dawley rats (SD rat) were purchased from Taconic Farms Inc. (Hudson, NY USA) weighing 250 grams. SD rats where administered MT-II either subcutaneously (SC) or orally by dosing syringe after a 2 minute inhalation anesthesia. Prior to the oral experiment rats were placed in a fasting state for 12 hours. The novel oral delivery technology is solely comprised of pharmacopeia agents recognized as "GRAS", (an acronym used by the US Food and Drug Administration for the phrase Generally Recognized As Safe) and contains no new chemical entities (NCEs). MT-II was dosed at 160 g/kg for the control SC injections (nϭ5), 800 g/kg in 2 oral experiments (nϭ9) and 1,600 g/kg for the third oral experiment (nϭ4). The tablets where prepared by a standard simple mixture method and compression procedure. 150 l of blood was collected per sample at specific time points using the tail clipping method and stored at-20 degrees Celsius pending further blood analyses. The blood serums were analyzed for MT-II by liquid chromatography/tandem mass spectrometry (LC-MS/MS). RESULTS: The pharmacokinetic (PK) profile of the novel oral MT-II formulation is characterized by a rapid T max. The calculated bioavailability is in excess of 25% when comparing oral versus SC administration. See attached figure. CONCLUSIONS: We have for the first time demonstrated the ability to deliver the synthetic protein MT-II orally in the rodent model. The pharmacokinetic profile achieved is clinically useful and supportive of proceeding with formulation optimization and initial human studies. Melanotan-II (MT-II) a centrally acting synthetic melanocortin analog may in the future provide an oral as needed therapy for men with erectile dysfunction.

Research paper thumbnail of O-65

Fertility and Sterility, Sep 1, 2006

Research paper thumbnail of Post-processed semen specimens with deficits in strict morphology may not require intracytoplasmic sperm injection (ICSI) to achieve good reproductive outcomes

Fertility and Sterility, Sep 1, 2003

Fertility and Sterility, Volume 80, Issue null, Pages 98-99, September 2003, Authors:Natan Bar-Ch... more Fertility and Sterility, Volume 80, Issue null, Pages 98-99, September 2003, Authors:Natan Bar-Chama; Jason Barritt; Marlena Duke; Kathleen Miller; Richard Scott; Alan Copperman. ...

Research paper thumbnail of Male reproduction and environmental and occupational exposures: a review of epidemiologic methods

Salud Publica De Mexico, Nov 1, 1999

Concerns that chemical exposures in the environment have been detrimental to male sexual developm... more Concerns that chemical exposures in the environment have been detrimental to male sexual development and fertility have been heightened by reports of declining sperm counts over the past 50 years. Marked geographic variation has been found in semen quality and in the incidence of testicular cancer and certain urogenital defects. Debate continues over the existence, magnitude and significance of these trends, and how best to evaluate the hypothesis that in utero and childhood exposures to estrogenic compounds may be to blame. Epidemiologic methods for assessing the impact of hazardous substances on male reproductive health have been developed mainly in the area of occupational medicine, and this paper will review the currently recommended methods. These include questionnaires to determine reproductive history and sexual function; reproductive hormone profiles; and semen analyses such as sperm concentration, motility, and morphology. New research tools that show significant promise from the fields of clinical reproductive medicine and reproductive toxicology are discussed as possible additions to epidemiologic studies, including assays of sperm function and genetic integrity, and biomarkers of DNA damage. For population-based studies involving occupational groups or communities with environmental exposures, issues related to the cost, validity, precision and utility of these methods must be carefully considered. Golden AL, Moline JM, Bar-Chama N. Reproducción masculina y exposiciones ambientales u ocupacionales: Una revisión de métodos epidemiológicos. Salud Publica Mex 1999;41 supl 2:S93-S105. S95 salud pública de méxico / vol.41, suplemento 2 de 1999 Male reproduction and environmental exposures ARTÍCULO DE REVISIÓN

Research paper thumbnail of Initial experience with processed human cadaveric allograft skin for reconstruction of the corpus cavernosum in repair of distal extrusion of a penile prosthesis

Urology, Jun 1, 1999

We describe our initial experience with the novel application of processed human cadaveric allogr... more We describe our initial experience with the novel application of processed human cadaveric allograft skin in reconstruction of a damaged corpus cavernosum associated with distal extrusion of a penile prosthesis. The material was evaluated for ease of reconstruction, adequacy of repair, and outcome. Human processed dermis allograft requires no intraoperative harvesting, is technically easy to fashion, and offers adequate tensile strength in the reconstruction of damaged corpora cavernosa. This initial experience with processed human cadaveric dermis in reconstruction of damaged corpora cavernosa is encouraging. Further evaluation to define the long-term efficacy and scope of application of this material in urologic reconstructive procedures is warranted.

Research paper thumbnail of Direct Exposure of Mouse Spermatogenic Cells to High Doses of Adenovirus Gene Therapy Vector Does Not Result in Germ Cell Transduction

Human Gene Therapy, Aug 10, 2000

The potential for adenovirus gene therapy vectors to gain access to male germ cells was rigorousl... more The potential for adenovirus gene therapy vectors to gain access to male germ cells was rigorously tested in the mouse by injecting high titers of the vector directly into the testis and epididym is, or by exposing sperm to the vector immediately prior to or during in vitro fertilization. The adenovirus vector carried the bacterial lacZ gene (Adb-Gal) driven by the Rous sarcoma virus (RSV) promoter, and infection was assessed by testing for lacZ expression, either with antibodies to LacZ protein or by staining for LacZ enzymatic activity. A total of 10 9 plaque-forming units (PFU) was inserted into the testis or epididym is, and in vitro fertilization was performed after sperm were exposed either to 10 or 100 PFU per sperm cell. lacZ expression was examined within testes for several weeks after injection, and in preimplantation embryos produced by in vitro fertilization with sperm exposed to the gene therapy vector. Direct injection of Adb-Gal into either the testis or epididym is resulted in lacZ expression only within the interstitium of the testis and not within seminiferous tubules. Despite direct exposure of spermatogenic cells or mature sperm to high titers of virus, lacZ expression was likewise not detected in embryos. These findings are consistent with the conclusion that the risk is minimal for germ line integration of adenovirus vectors exposed to male reproductive cells.

Research paper thumbnail of Male partner age is not associated with increased rate of embryonic aneuploidy

Fertility and Sterility, Sep 1, 2015

Research paper thumbnail of The morphology of extracted testicular sperm correlates with fertilization but not pregnancy rates

BJUI, Dec 1, 2007

tissue retrieval. Sperm were classified as being either normal, having an amorphous head, having ... more tissue retrieval. Sperm were classified as being either normal, having an amorphous head, having a mid-piece defect or having multiple defects. The calculated percentage of abnormal sperm injected was compared with the normal fertilization rate using Pearson's correlation coefficient, and pregnancy rates between groups were compared using chi-square analysis. RESULTS Fifteen cycles had all morphologically normal sperm; 21 cycles had 50-99% normal forms and 39 cycles had < 50% normal sperm. There was a highly significant correlation between the percentage of normal sperm used for ICSI and fertilization rates (P = 0.007). Overall, 43 clinical pregnancies resulted in this series, i.e. three among the group with all normal sperm injected, 12 in the group with 50-99% normal sperm and 28 in the group with < 50% normal forms. There were also 11 pregnancies in cycles that used no normal forms. Pregnancy

Research paper thumbnail of P-037 Hypogonadism secondary to occupational exposure of cadmium

Fertility and Sterility, 1997

Research paper thumbnail of Early use of a phosphodiesterase inhibitor after brachytherapy restores and preserves erectile function

BJUI, Dec 1, 2006

To investigate whether the early use of phosphodiesterase inhibitors (PDEIs) after brachytherapy ... more To investigate whether the early use of phosphodiesterase inhibitors (PDEIs) after brachytherapy (BT) is associated with better erectile function, as of men potent before BT 38-70% have erectile dysfunction afterward. We evaluated a prospectively created database of 2500 patients who had had BT at our institution since 1992. We measured baseline age, cancer stage, Gleason grade, prostate specific antigen (PSA) level at diagnosis, implant type, use of neoadjuvant and adjuvant hormonal suppression therapy, use of external beam radiotherapy in conjunction with interstitial therapy, and follow-up PSA levels. Men were stratified by their use of PDEIs at &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1 year (early group) or &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;1 year after implantation (late group). We excluded all men who did not have baseline Sexual Health Inventory for Men (SHIM) scores and at least one follow-up SHIM score; the latter were obtained at 6-month intervals after BT. Data were analysed using the Mann-Whitney U-test. In all, 210 men met the inclusion criteria; 85 began using PDEIs within a year of BT, and 125 started after a year. The mean time to PDEI use was 191 days in the early and 595 days in the late group. The median age was 62 years in the early and 63 years in the late group (P = 0.02). Baseline Gleason scores did not differ, nor did PSA levels between the groups. Of men in the early group, 48% received neoadjuvant and/or adjuvant hormonal suppression therapy, vs half of men in the late group. Baseline SHIM scores were not significantly different, nor were scores at the first two follow-up assessments, but the scores at 18-36 months after BT were significantly different. The early use of PDEIs after BT is associated with a significant improvement in and maintenance of erectile function compared with late use. Men undergoing BT should be encouraged to use PDEIs early after implantation, to preserve erectile function.

Research paper thumbnail of Elevated Sperm Dna Fragmentation Does Not Result in Increased Pregnancy Loss Rates After Single, Euploid Frozen Embryo Transfer

Fertility and Sterility, Sep 1, 2021

Research paper thumbnail of Maternal age, embryo quality, and cigarette smoking are not correlated with granulosa cell oxidative DNA damage in women undergoing IVF

Fertility and Sterility, Sep 1, 2001

Embryo viability assessment: the amount of platelet-activating factor produced by human embryos i... more Embryo viability assessment: the amount of platelet-activating factor produced by human embryos is related to pregnancy outcome.

Research paper thumbnail of SDD/SDFA Testing in infertile men who have failed IUI – predictor of successful IVF outcomes?

Fertility and Sterility, Sep 1, 2007

Spermatozoa were successfully retrieved in 512 of 970 (52.8%) TESE procedures. Mean age of the me... more Spermatozoa were successfully retrieved in 512 of 970 (52.8%) TESE procedures. Mean age of the men, serum hormone levels and testicular volume did not show any difference between successful and failed recovery attempts. The success rates of sperm recovery as correlated to their etiological patterns are 48.5% in men with nonmosaic KS, 67.7% in men with orchidopexy operation, 50% in AZFc microdeletion and 77% in men with a history of mumps orchitis. The success of sperm recovery was significantly higher (63%) in men with KS who were younger than 35 years of age as compare to men older age (25%). CONCLUSIONS: Micro-TESE is successful technique in azoospermic men with atrophic testis due to KS, mumps orchitis or cryptorchidism. The younger age of men with KS has higher rate of successful sperm recovery with micro-TESE.

Research paper thumbnail of A comparison of IVF/ICSI results with frozen epididymal sperm (FZEPS) versus fresh testicular sperm (FRST) in azoospermic men

The Journal of Urology, Apr 1, 1999

Research paper thumbnail of Medical Implications of Erectile Dysfunction

Medical Clinics of North America, 2011

Erectile dysfunction (ED) is a common condition in aging men, with a prevalence of 52% in men age... more Erectile dysfunction (ED) is a common condition in aging men, with a prevalence of 52% in men aged 40 to 70 years. It is frequently associated with several comorbid conditions, including cardiovascular disease, lower urinary tract symptoms, and testosterone deficiency. These conditions often have major consequences on the quality of life of patients and require adequate evaluation by the primary care practitioner. Complaints of ED, therefore, serve as a marker for these conditions and give the practitioner an opportunity to prevent the consequences of a delay in treatment. In this article, the evidence behind these associations is described.

Research paper thumbnail of P-576

Fertility and Sterility, Sep 1, 2006

Research paper thumbnail of Elevated Sperm Dna Fragmentation is Not Correlated with Embrionic Mosaicism in Patients Undergoing Ivf with PGT-A

Research paper thumbnail of Male reproduction and environmental and occupational exposures: a review of epidemiologic methods Reproducción masculina y exposiciones ambientales u ocupacionales: una revisión de métodos epidemiológicos

DOAJ (DOAJ: Directory of Open Access Journals), Nov 1, 1999

Concerns that chemical exposures in the environment have been detrimental to male sexual developm... more Concerns that chemical exposures in the environment have been detrimental to male sexual development and fertility have been heightened by reports of declining sperm counts over the past 50 years. Marked geographic variation has been found in semen quality and in the incidence of testicular cancer and certain urogenital defects. Debate continues over the existence, magnitude and significance of these trends, and how best to evaluate the hypothesis that in utero and childhood exposures to estrogenic compounds may be to blame. Epidemiologic methods for assessing the impact of hazardous substances on male reproductive health have been developed mainly in the area of occupational medicine, and this paper will review the currently recommended methods. These include questionnaires to determine reproductive history and sexual function; reproductive hormone profiles; and semen analyses such as sperm concentration, motility, and morphology. New research tools that show significant promise from the fields of clinical reproductive medicine and reproductive toxicology are discussed as possible additions to epidemiologic studies, including assays of sperm function and genetic integrity, and biomarkers of DNA damage. For population-based studies involving occupational groups or communities with environmental exposures, issues related to the cost, validity, precision and utility of these methods must be carefully considered.

Research paper thumbnail of Is paternal age associated with embryo aneuploidy?

Fertility and Sterility, Mar 1, 2018

BACKGROUND: Fertility nurses bear much of the responsibility for counseling patients through all ... more BACKGROUND: Fertility nurses bear much of the responsibility for counseling patients through all steps of their fertility journey. Rapid advances in reproductive technology make continuing education for nurses with this critical information for patients a priority. Standard nursing education does not provide the foundational knowledge of cell biology to be fully prepared to counsel patients on the results of cellular division and the impact of embryonic growth and molecular development on patient's choices. OBJECTIVE: To determine if focused training for reproductive nurses on topics of embryology and genetics improved self-efficacy and confidence scores. MATERIALS AND METHODS: A training program was created in partial fulfillment of an applied dissertation in health education. A need was identified with fertility nurses in whom additional training on embryology and reproductive genetics was needed. A 5 point Likert scale survey measuring nursing confidence was created to measure four domains of interest by ranking each statement as strongly disagree (1), disagree (2), neutral (3), agree (4), and strongly agree (5). The data were collected before the educational program and two weeks after exposure to document information retention and changes in confidence. The self-efficacy data sheet was created by the researcher and validated using the Cronbach's alpha. Demographic data were also collected. The data were de-identified utilizing a unique four-digit number created by each subject. This four-digit number on the pre-and post-test allowed the results to be linked. Data were analyzed using Pearson's R correlation test. RESULT(S): 41 reproductive endocrinology nurses completed the pre-and post-intervention assessments. The Cronbach's alpha for the 11 statement Likert scale survey was 0.8595, which indicates high internal validity and excellent reliability, and showed the self-efficacy scores for embryology and genetics counseling, and the need for future training were statistically significant between baseline and post-test, p<0.05. Specifically, nurses' confidence in educating patients on embryology and genetics went from slightly negative to a positive perception. A weak positive correlation between years of experience and self-confidence was observed, pre-and post-test p¼ 0.043 and p¼0.018, respectively. General self-confidence scores at baseline and post-test remained high, greater than 4.0 (agree-strongly agree) for the four statements. When qualitative assessment was also conducted with free-text answers after the intervention, two themes emerged, confidence and desire for more knowledge. 97.5% found the training worthwhile and 66% reported improved self-confidence, 28% said their confidence was similar, and 7% reported less confidence as they felt they had more to learn. CONCLUSION(S): Reproductive endocrinology nurses are central in the patient-facing role. Focused education on new topics should be part of the ongoing training of fertility nurses to provide knowledge and confidence for effective patient counseling. FINANCIAL SUPPORT: The research was conducted in partial fulfillment of a Doctorate in Health Education; no financial support was received.

Research paper thumbnail of Male factor infertility and aneuploidy: do couples with male factor infertility have a lower rate of euploid embryos?

Fertility and Sterility, Sep 1, 2016

to NOA and the repeated failures group (43.1AE7.8, 40.7AE8.8, 41.9AE5.8 respectively, p<0.0001). ... more to NOA and the repeated failures group (43.1AE7.8, 40.7AE8.8, 41.9AE5.8 respectively, p<0.0001). Mean female age was higher in the repeated failure group (35.9AE4.8, 34.8AE4.5, 37.1AE4.0, p<0.0001). Male FSH level was significantly higher in NOA (p<0.0001). The chance of finding sperm and likelihood of having an embryo transfer were significantly lower in this group (p<0.0001). There were more embryos fertilized in OA 5.79AE4.4 compared to NOA 5.2AE4.4 and 4.6AE4.2 in repeated failures (p¼0.003). There was no difference in the number of embryos transferred. Patients with OA were more likely to have a positive pregnancy test (37%, 27%, 28.5% respectively, p¼0.02). However there was no difference in the clinical pregnancy rate (31.8%, 23.9%, 25.4% respectively, p¼0.07) or in live birth rate (20.4%, 17.7%, 15.5% respectively, p¼0.3). There was no statistically significant difference in miscarriage rate between the groups (35.7%, 25.9%, 38.7% respectively, p¼0.33). CONCLUSIONS: Surgical sperm retrieval has revolutionized treatment in men with OA and NOA. There has been some debate as to whether surgically retrieved sperm is preferable to ejaculate in other populations, such as repeated failures. This study found that the likelihood of finding sperm, the number of fertilized embryos and the likelihood of embryo transfer were significantly lower in NOA. However, the clinical pregnancy rate and live birth rate were not statistically significantly different in all groups. An interesting finding is the higher than average miscarriage rate in the repeated failure group as well as a lower live birth rate, although this is not statistically significant. Age might be a contributor to this. Further study is needed to determine the benefit of surgically retrieved sperm in this group.

Research paper thumbnail of 1019 Oral Delivery of Melanotanûii (MT-II) in the Rodent Model

The Journal of Urology, Apr 1, 2013

INTRODUCTION AND OBJECTIVES: Melanotan û II (MT-II) is a synthetic cyclic peptide that functions ... more INTRODUCTION AND OBJECTIVES: Melanotan û II (MT-II) is a synthetic cyclic peptide that functions as a centrally acting melanocortin analog. In humans, subcutaneous (SC) administration of MT-II has demonstrated efficacy and safety for psychogenic as well as organic erectile dysfunction (ED) (Wessells, H., N. et al. (2000). Int J Impot Res 12 Suppl 4: S74-9). Our objective was to determine if MT-II absorption through the gastrointestinal tract can be achieved in the rodent model using a novel oral drug delivery technology. METHODS: Male Sprague-Dawley rats (SD rat) were purchased from Taconic Farms Inc. (Hudson, NY USA) weighing 250 grams. SD rats where administered MT-II either subcutaneously (SC) or orally by dosing syringe after a 2 minute inhalation anesthesia. Prior to the oral experiment rats were placed in a fasting state for 12 hours. The novel oral delivery technology is solely comprised of pharmacopeia agents recognized as "GRAS", (an acronym used by the US Food and Drug Administration for the phrase Generally Recognized As Safe) and contains no new chemical entities (NCEs). MT-II was dosed at 160 g/kg for the control SC injections (nϭ5), 800 g/kg in 2 oral experiments (nϭ9) and 1,600 g/kg for the third oral experiment (nϭ4). The tablets where prepared by a standard simple mixture method and compression procedure. 150 l of blood was collected per sample at specific time points using the tail clipping method and stored at-20 degrees Celsius pending further blood analyses. The blood serums were analyzed for MT-II by liquid chromatography/tandem mass spectrometry (LC-MS/MS). RESULTS: The pharmacokinetic (PK) profile of the novel oral MT-II formulation is characterized by a rapid T max. The calculated bioavailability is in excess of 25% when comparing oral versus SC administration. See attached figure. CONCLUSIONS: We have for the first time demonstrated the ability to deliver the synthetic protein MT-II orally in the rodent model. The pharmacokinetic profile achieved is clinically useful and supportive of proceeding with formulation optimization and initial human studies. Melanotan-II (MT-II) a centrally acting synthetic melanocortin analog may in the future provide an oral as needed therapy for men with erectile dysfunction.

Research paper thumbnail of O-65

Fertility and Sterility, Sep 1, 2006

Research paper thumbnail of Post-processed semen specimens with deficits in strict morphology may not require intracytoplasmic sperm injection (ICSI) to achieve good reproductive outcomes

Fertility and Sterility, Sep 1, 2003

Fertility and Sterility, Volume 80, Issue null, Pages 98-99, September 2003, Authors:Natan Bar-Ch... more Fertility and Sterility, Volume 80, Issue null, Pages 98-99, September 2003, Authors:Natan Bar-Chama; Jason Barritt; Marlena Duke; Kathleen Miller; Richard Scott; Alan Copperman. ...

Research paper thumbnail of Male reproduction and environmental and occupational exposures: a review of epidemiologic methods

Salud Publica De Mexico, Nov 1, 1999

Concerns that chemical exposures in the environment have been detrimental to male sexual developm... more Concerns that chemical exposures in the environment have been detrimental to male sexual development and fertility have been heightened by reports of declining sperm counts over the past 50 years. Marked geographic variation has been found in semen quality and in the incidence of testicular cancer and certain urogenital defects. Debate continues over the existence, magnitude and significance of these trends, and how best to evaluate the hypothesis that in utero and childhood exposures to estrogenic compounds may be to blame. Epidemiologic methods for assessing the impact of hazardous substances on male reproductive health have been developed mainly in the area of occupational medicine, and this paper will review the currently recommended methods. These include questionnaires to determine reproductive history and sexual function; reproductive hormone profiles; and semen analyses such as sperm concentration, motility, and morphology. New research tools that show significant promise from the fields of clinical reproductive medicine and reproductive toxicology are discussed as possible additions to epidemiologic studies, including assays of sperm function and genetic integrity, and biomarkers of DNA damage. For population-based studies involving occupational groups or communities with environmental exposures, issues related to the cost, validity, precision and utility of these methods must be carefully considered. Golden AL, Moline JM, Bar-Chama N. Reproducción masculina y exposiciones ambientales u ocupacionales: Una revisión de métodos epidemiológicos. Salud Publica Mex 1999;41 supl 2:S93-S105. S95 salud pública de méxico / vol.41, suplemento 2 de 1999 Male reproduction and environmental exposures ARTÍCULO DE REVISIÓN

Research paper thumbnail of Initial experience with processed human cadaveric allograft skin for reconstruction of the corpus cavernosum in repair of distal extrusion of a penile prosthesis

Urology, Jun 1, 1999

We describe our initial experience with the novel application of processed human cadaveric allogr... more We describe our initial experience with the novel application of processed human cadaveric allograft skin in reconstruction of a damaged corpus cavernosum associated with distal extrusion of a penile prosthesis. The material was evaluated for ease of reconstruction, adequacy of repair, and outcome. Human processed dermis allograft requires no intraoperative harvesting, is technically easy to fashion, and offers adequate tensile strength in the reconstruction of damaged corpora cavernosa. This initial experience with processed human cadaveric dermis in reconstruction of damaged corpora cavernosa is encouraging. Further evaluation to define the long-term efficacy and scope of application of this material in urologic reconstructive procedures is warranted.

Research paper thumbnail of Direct Exposure of Mouse Spermatogenic Cells to High Doses of Adenovirus Gene Therapy Vector Does Not Result in Germ Cell Transduction

Human Gene Therapy, Aug 10, 2000

The potential for adenovirus gene therapy vectors to gain access to male germ cells was rigorousl... more The potential for adenovirus gene therapy vectors to gain access to male germ cells was rigorously tested in the mouse by injecting high titers of the vector directly into the testis and epididym is, or by exposing sperm to the vector immediately prior to or during in vitro fertilization. The adenovirus vector carried the bacterial lacZ gene (Adb-Gal) driven by the Rous sarcoma virus (RSV) promoter, and infection was assessed by testing for lacZ expression, either with antibodies to LacZ protein or by staining for LacZ enzymatic activity. A total of 10 9 plaque-forming units (PFU) was inserted into the testis or epididym is, and in vitro fertilization was performed after sperm were exposed either to 10 or 100 PFU per sperm cell. lacZ expression was examined within testes for several weeks after injection, and in preimplantation embryos produced by in vitro fertilization with sperm exposed to the gene therapy vector. Direct injection of Adb-Gal into either the testis or epididym is resulted in lacZ expression only within the interstitium of the testis and not within seminiferous tubules. Despite direct exposure of spermatogenic cells or mature sperm to high titers of virus, lacZ expression was likewise not detected in embryos. These findings are consistent with the conclusion that the risk is minimal for germ line integration of adenovirus vectors exposed to male reproductive cells.

Research paper thumbnail of Male partner age is not associated with increased rate of embryonic aneuploidy

Fertility and Sterility, Sep 1, 2015

Research paper thumbnail of The morphology of extracted testicular sperm correlates with fertilization but not pregnancy rates

BJUI, Dec 1, 2007

tissue retrieval. Sperm were classified as being either normal, having an amorphous head, having ... more tissue retrieval. Sperm were classified as being either normal, having an amorphous head, having a mid-piece defect or having multiple defects. The calculated percentage of abnormal sperm injected was compared with the normal fertilization rate using Pearson's correlation coefficient, and pregnancy rates between groups were compared using chi-square analysis. RESULTS Fifteen cycles had all morphologically normal sperm; 21 cycles had 50-99% normal forms and 39 cycles had < 50% normal sperm. There was a highly significant correlation between the percentage of normal sperm used for ICSI and fertilization rates (P = 0.007). Overall, 43 clinical pregnancies resulted in this series, i.e. three among the group with all normal sperm injected, 12 in the group with 50-99% normal sperm and 28 in the group with < 50% normal forms. There were also 11 pregnancies in cycles that used no normal forms. Pregnancy

Research paper thumbnail of P-037 Hypogonadism secondary to occupational exposure of cadmium

Fertility and Sterility, 1997

Research paper thumbnail of Early use of a phosphodiesterase inhibitor after brachytherapy restores and preserves erectile function

BJUI, Dec 1, 2006

To investigate whether the early use of phosphodiesterase inhibitors (PDEIs) after brachytherapy ... more To investigate whether the early use of phosphodiesterase inhibitors (PDEIs) after brachytherapy (BT) is associated with better erectile function, as of men potent before BT 38-70% have erectile dysfunction afterward. We evaluated a prospectively created database of 2500 patients who had had BT at our institution since 1992. We measured baseline age, cancer stage, Gleason grade, prostate specific antigen (PSA) level at diagnosis, implant type, use of neoadjuvant and adjuvant hormonal suppression therapy, use of external beam radiotherapy in conjunction with interstitial therapy, and follow-up PSA levels. Men were stratified by their use of PDEIs at &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1 year (early group) or &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;1 year after implantation (late group). We excluded all men who did not have baseline Sexual Health Inventory for Men (SHIM) scores and at least one follow-up SHIM score; the latter were obtained at 6-month intervals after BT. Data were analysed using the Mann-Whitney U-test. In all, 210 men met the inclusion criteria; 85 began using PDEIs within a year of BT, and 125 started after a year. The mean time to PDEI use was 191 days in the early and 595 days in the late group. The median age was 62 years in the early and 63 years in the late group (P = 0.02). Baseline Gleason scores did not differ, nor did PSA levels between the groups. Of men in the early group, 48% received neoadjuvant and/or adjuvant hormonal suppression therapy, vs half of men in the late group. Baseline SHIM scores were not significantly different, nor were scores at the first two follow-up assessments, but the scores at 18-36 months after BT were significantly different. The early use of PDEIs after BT is associated with a significant improvement in and maintenance of erectile function compared with late use. Men undergoing BT should be encouraged to use PDEIs early after implantation, to preserve erectile function.

Research paper thumbnail of Elevated Sperm Dna Fragmentation Does Not Result in Increased Pregnancy Loss Rates After Single, Euploid Frozen Embryo Transfer

Fertility and Sterility, Sep 1, 2021

Research paper thumbnail of Maternal age, embryo quality, and cigarette smoking are not correlated with granulosa cell oxidative DNA damage in women undergoing IVF

Fertility and Sterility, Sep 1, 2001

Embryo viability assessment: the amount of platelet-activating factor produced by human embryos i... more Embryo viability assessment: the amount of platelet-activating factor produced by human embryos is related to pregnancy outcome.

Research paper thumbnail of SDD/SDFA Testing in infertile men who have failed IUI – predictor of successful IVF outcomes?

Fertility and Sterility, Sep 1, 2007

Spermatozoa were successfully retrieved in 512 of 970 (52.8%) TESE procedures. Mean age of the me... more Spermatozoa were successfully retrieved in 512 of 970 (52.8%) TESE procedures. Mean age of the men, serum hormone levels and testicular volume did not show any difference between successful and failed recovery attempts. The success rates of sperm recovery as correlated to their etiological patterns are 48.5% in men with nonmosaic KS, 67.7% in men with orchidopexy operation, 50% in AZFc microdeletion and 77% in men with a history of mumps orchitis. The success of sperm recovery was significantly higher (63%) in men with KS who were younger than 35 years of age as compare to men older age (25%). CONCLUSIONS: Micro-TESE is successful technique in azoospermic men with atrophic testis due to KS, mumps orchitis or cryptorchidism. The younger age of men with KS has higher rate of successful sperm recovery with micro-TESE.

Research paper thumbnail of A comparison of IVF/ICSI results with frozen epididymal sperm (FZEPS) versus fresh testicular sperm (FRST) in azoospermic men

The Journal of Urology, Apr 1, 1999

Research paper thumbnail of Medical Implications of Erectile Dysfunction

Medical Clinics of North America, 2011

Erectile dysfunction (ED) is a common condition in aging men, with a prevalence of 52% in men age... more Erectile dysfunction (ED) is a common condition in aging men, with a prevalence of 52% in men aged 40 to 70 years. It is frequently associated with several comorbid conditions, including cardiovascular disease, lower urinary tract symptoms, and testosterone deficiency. These conditions often have major consequences on the quality of life of patients and require adequate evaluation by the primary care practitioner. Complaints of ED, therefore, serve as a marker for these conditions and give the practitioner an opportunity to prevent the consequences of a delay in treatment. In this article, the evidence behind these associations is described.