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A M Belker

Publications and source records attributed to A M Belker.

At least 19 recordsLinked to original sources
PubMed1998

The presence of Müllerian inhibiting substance binding sites in human sperm.

PURPOSE: The binding of Müllerian inhibiting substance (MIS) to human sperm was investigated using immunohistological techniques. MATERIALS AND METHODS: Sperm from 5 normal donors and 6 subfertile men were studied. Whole or thin-sectioned sperm were incubated without or with recombinant human MIS (0.5 microg./ml.). MIS binding was identified under light microscopy (LM) using rabbit anti-human MIS antibodies tagged with goat IgG-horseradish peroxidase and diaminobenzidine as substrate, or by scanning and transmission electron microscopy (SEM and TEM) using gold labeled goat IgG. Intracellular MIS binding in sperm sections was examined by TEM. Antibodies were omitted in the controls. RESULTS: Under LM, DAB staining was present on sperm incubated with or without MIS and absent on controls. Using SEM, gold particles were found primarily on the surfaces of the sperm head with less binding to the tail. With TEM, the clustering of gold particles around the head of sperm represents MIS binding, but very few or no gold particles could be found associated with the sperm tail. MIS binding was also found associated with intracellular structures, but only within the head of the sperm. Overall, less gold particle binding was present in subfertile compared with normal sperm. CONCLUSIONS: These results suggest that MIS is bound to the sperm surface and sperm from normally fertile men have increased MIS binding. The function of MIS in sperm is unknown, but the presence of MIS binding suggests a direct role(s) in sperm function.

Anti-Mullerian Hormone↗
PubMed1998

Percutaneous testicular sperm aspiration: a convenient and effective office procedure to retrieve sperm for in vitro fertilization with intracytoplasmic sperm injection.

PURPOSE: After intracytoplasmic sperm injection was established to facilitate in vitro fertilization in men with the most severe semen abnormalities, the use of testicular sperm to achieve conception became feasible. We investigated the use of a method of percutaneous needle aspiration previously used for diagnostic purposes to obtain testicular sperm for intracytoplasmic sperm injection. MATERIALS AND METHODS: A method of percutaneous aspiration of sperm was developed to facilitate intracytoplasmic sperm injection. A total of 69 testicular aspirations were performed for diagnostic purposes and 179 to obtain sperm on the day of egg retrieval for couples undergoing in vitro fertilization with intracytoplasmic sperm injection. The procedures were performed in an outpatient facility. Most patients received intravenous sedation and a few received only local anesthesia. RESULTS: Sperm adequate for intracytoplasmic sperm injection were obtained in all men with obstructive azoospermia, including those with significant testicular atrophy and those with anejaculation or necrospermia. Adequate numbers of sperm for intracytoplasmic sperm injection were retrieved less reliably in men with nonobstructive azoospermia. The number of sperm correlated positively with testicular size. Morbidity and discomfort were nonexistent. Sperm were obtained from 43 of 69 men undergoing diagnostic and 170 of 179 men undergoing therapeutic aspiration. Sperm motility ranged from 0 to 20% and viability from 55 to 85%. CONCLUSIONS: Percutaneous testicular sperm aspiration is a cost-effective method to retrieve sperm for intracytoplasmic sperm injection in select men with obstructive azoospermia, anejaculation and necrospermia, and some with nonobstructive azoospermia.

Equipment Design↗
PubMed1997

The feasibility of cryopreservation of sperm harvested intraoperatively during vasectomy reversals.

PURPOSE: Intracytoplasmic sperm injection during in vitro fertilization involves the microinjection of a single sperm into each egg from the partner. Pregnancies have resulted from this powerful new technology when fewer than 100 motile sperm were present in the semen, or when sperm were obtained from the epididymis or testicle by open operations or needle aspirations. Some surgeons have cryopreserved sperm obtained from the vas or epididymis during vasectomy reversals. However, cryopreservation of nonmotile sperm serves no useful purpose. MATERIALS AND METHODS: We performed a retrospective analysis of 603 vasectomy reversals in which the intraoperative vasal and/or epididymal fluid was examined microscopically. The motility of the sperm obtained intraoperatively was used as a gauge for the potential use of such sperm for in vitro fertilization and intracytoplasmic sperm injection after cryopreservation and thawing, should the vasectomy reversal fail. RESULTS: Motile sperm were present in the intraoperative vasal or epididymal fluid in 35% of all vasectomy reversals (34% of first and 39% of repeat procedures). The percentage of reversals in which motile sperm were present in the intraoperative fluid was not related to the time from vasectomy until reversal. CONCLUSIONS: The absence of motile sperm in the intraoperative vasal or epididymal fluid precludes consideration of sperm cryopreservation during vasectomy reversals. Although to our knowledge the minimum percentage of sperm motility needed for in vitro fertilization and intracytoplasmic sperm injection after cryopreservation and thawing has not been established, our results provide surgeons with information to judge the merit of sperm harvesting and cryopreservation during vasectomy reversals.

Cryopreservation↗
PubMed1996

Clinical guidelines panel on erectile dysfunction: summary report on the treatment of organic erectile dysfunction. The American Urological Association.

PURPOSE: The American Urological Association convened the Clinical Guidelines Panel on Erectile Dysfunction to analyze the literature regarding available methods for treating organic erectile dysfunction and to make practice recommendations based on the treatment outcomes data. MATERIALS AND METHODS: The panel searched the MEDLINE data base for all articles from 1979 through 1994 on treatment of organic erectile dysfunction and meta-analyzed outcomes data for oral drug therapy (yohimbine), vacuum constriction devices, vasoactive drug injection therapy, penile prosthesis implantation and venous and arterial surgery. RESULTS: Estimated probabilities of desirable outcomes are relatively high for vacuum constriction devices, vasoactive drug injection therapy and penile prosthesis therapy. However, patients must be aware of potential complications. The outcomes data for yohimbine clearly indicate a therapy with marginal efficacy. For venous and arterial surgery, based on reported outcomes, chances of success do not appear high enough to justify routine use of such surgery. CONCLUSIONS: For the standard patient, defined as a man with acquired organic erectile dysfunction and no evidence of hypogonadism or hyperprolactinemia, the panel recommends 3 treatment alternatives: vacuum constriction devices, vasoactive drug injection therapy and penile prosthesis implantation. Based on the data to date, yohimbine does not appear to be effective for organic erectile dysfunction and, thus, it should not be recommended as treatment for the standard patient. Venous surgery and arterial surgery in men with arteriolosclerotic disease are considered investigational and should be performed only in a research setting with long-term followup available.

Erectile Dysfunction↗
PubMed1996

The presence of müllerian inhibiting substance in human seminal plasma.

Müllerian inhibiting substance (MIS), produced by testicular Sertoli cells, is present in adult male serum. The first aim of this study was to determine if MIS is present in seminal plasma. Using an enzyme-linked immunosorbent assay (ELISA), we measured MIS concentrations in seminal plasma from 23 donors exhibiting normal (WHO criteria) sperm qualities, and 169 patients with subnormal sperm parameters. The second aim of this study was to examine a potential relationship between MIS and sperm motility. MIS concentrations in seminal plasma ranged from 0.5 to 3.6 ng/ml in donors and from 0.5 to 17.8 ng/ml in patients. Motility index (MI, mean +/- SEM) for all patient samples was lower compared with donors (113.3 +/- 3.2 and 198.3 +/- 13.5, P < 0.00001), while mean MIS concentration +/- SEM) was higher (4.2 +/- 0.3 and 1.4 +/- 0.2, P < 0.0003). When the patients were stratified into Groups I (motility < 50%, n = 42) and II (motility > 50%, n = 127), the MI (mean +/- SEM) values were 62.3 +/- 3.8 and 130.2 +/- 2.7 respectively (P < 0.0001 for both compared with donors) and mean MIS concentrations (+/- SEM) were 5.4 +/- 0.6 and 3.9 +/- 0.3, respectively (P < 0.0001 and P < 0.001 compared with donors). The inverse relationship between MIS concentration in seminal plasma and motility index suggests that MIS may have a function in modulating motility.

Adult↗
PubMed1995

Development of a new alloplastic spermatocele demonstrating successful sperm retrieval in an animal model.

OBJECTIVE: To create an alloplastic spermatocele capable of repeated sperm aspiration. The alloplastic spermatocele has long been a theoretical solution to infertility for those patients with congenital absence of the vas deferens or irreversible obstruction of the male reproductive ductal system. Recent studies have suggested that sperm from efferent ducts are capable of fertilization. Clinical use of alloplastic spermatoceles for collection of epididymal sperm has resulted in unacceptably low pregnancy rates. Improvement in spermatocele function may occur if a microsurgical anastomosis is performed to the epididymis. DESIGN: A newly designed alloplastic spermatocele was implanted in 17 mature male rabbits. The faceplate of the device had a 0.7-mm orifice, allowing direct precise microsurgical anastomosis to a specific loop of the epididymal tubule. RESULTS: Sperm retrieval was possible in 16/17 (94%) animals. Repeated successful aspirations (total of 73) were performed in all but one animal. The total number of sperm collected per spermatocele averaged 115 x 10(6) (range 0 to 734 x 10(6)). The sperm motility varied widely between animals and specimens, with a maximum average of 21.6% motile sperm/aspirate per animal. All spermatoceles eventually occluded (mean time of occlusion 14 days; range 3 to 30 days). The prostheses with the attached epididymides were examined histologically. CONCLUSIONS: This prototype alloplastic spermatocele allows repeated high density sperm retrieval over a short period of time. Low sperm motility may be less problematic clinically as new techniques of IVF become available.

Animals↗
PubMed1994

Partial obstruction of the male ductal system: fact or fiction?

Andrologists sometimes experience difficulty deciding if a patient is azoospermic because of obstruction or because of testicular failure to produce sperm. When the testicular biopsy reveals that relatively small numbers of mature sperm are being produced, azoospermia may be the clinical manifestation of this condition. However, some patients who have ductal obstruction also have decreased levels of testicular sperm production ("hypospermatogenesis"). This discussion will concern: (a) the evidence that partial ductal obstruction may exist; (b) the clinical manifestations of partial ductal obstruction; (c) methods of diagnosis of partial ductal obstruction; and (d) treatment of partial ductal obstruction.

Ejaculatory Ducts↗
PubMed1994

Principles of microsurgery.

Microsurgical techniques have been used to perform a variety of urologic procedures. Basic microsurgical principles are discussed in this article and information is presented regarding instrumentation techniques and the operation of microscopes and microsurgical instruments. Many useful hints to increase the ease of performing microsurgery are discussed and clearly defined.

Equipment Design↗
PubMed1991

Results of 1,469 microsurgical vasectomy reversals by the Vasovasostomy Study Group.

During a 9-year period 1,469 men who underwent microsurgical vasectomy reversal procedures were studied at 5 institutions. Of 1,247 men who had first-time procedures sperm were present in the semen in 865 of 1,012 men (86%) who had postoperative semen analyses, and pregnancy occurred in 421 of 810 couples (52%) for whom information regarding conception was available. Rates of patency (return of sperm to the semen) and pregnancy varied depending on the interval from the vasectomy until its reversal. If the interval had been less than 3 years patency was 97% and pregnancy 76%, 3 to 8 years 88% and 53%, 9 to 14 years 79% and 44% and 15 years or more 71% and 30%. The patency and pregnancy rates were no better after 2-layer microsurgical vasovasostomy than after modified 1-layer microsurgical procedures and they were statistically the same for all patients regardless of the surgeon. When sperm were absent from the intraoperative vas fluid bilaterally and the patient underwent bilateral vasovasostomy rather than vasoepididymostomy, patency occurred in 50 of 83 patients (60%) and pregnancy in 20 of 65 couples (31%). Neither presence nor absence of a sperm granuloma at the vasectomy site nor type of anesthesia affected results. Repeat microsurgical reversal procedures were less successful. A total of 222 repeat operations produced patency in 150 of 199 patients (75%) who had semen analyses and pregnancy was reported in 52 of 120 couples (43%).

Adult↗
PubMed1990

The high rate of noncompliance for post-vasectomy semen examination: medical and legal considerations.

The records of 1,029 consecutive patients undergoing bilateral vasectomy were reviewed. Of the 1,029 patients 375 (36%) never returned postoperatively and the partners of 2 of these 375 later became pregnant. A total of 560 patients (54%) was followed until the recommended demonstration of azoospermia occurred on 2 consecutive occasions. There were 84 patients (8%) who did not return after the first demonstration of azoospermia, while 7 (1%) still had sperm in the semen at the last examination. Three other patients had persistent nonmotile sperm postoperatively; 2 of them underwent repeat vasectomy followed by azoospermia and 1 was placed in a special clearance category of sterility as described. We discuss practical and legal considerations regarding the management of noncompliant patients.

Female↗
PubMed1990

Transrectal prostate ultrasonography as a diagnostic and therapeutic aid for ejaculatory duct obstruction.

Preoperative transrectal ultrasonography was used to establish the diagnosis of ejaculatory duct obstruction and also to determine the distal level of extension of the obstructed system within prostatic parenchyma. Transrectal ultrasonography not only established the diagnosis but also enabled precise transurethral resection into the obstructed system. Prostatic ultrasound facilitates evaluation and treatment of azoospermia caused by ejaculatory duct obstruction and may eliminate the need for vasography in such cases.

Adult↗
PubMed1990

Vasectomy: an appraisal for the obstetrician-gynecologist.

Data regarding the efficacy of vasectomy are limited, but the procedure appears to be highly effective. Efficacy may vary by the method of vas occlusion. Death attributable to vasectomy in the United States is exceedingly rare, and major perioperative morbidity is quite uncommon. No long-term adverse health effects have been documented, and much evidence supports the conclusion that vasectomy does not increase the risk of subsequent atherosclerosis. Vasectomy, like tubal sterilization, should be considered a permanent decision, because reversal surgery is expensive and requires substantial surgical expertise. Although vasectomy reversal is often successful, it cannot be guaranteed even in the best of circumstances, and when the vasectomy has caused epididymal obstruction, reversal is often unsuccessful. Vasectomy represents a safe and effective alternative to tubal sterilization for couples who decide that the male should be sterilized.

Female↗