Exposure to hazardous substances and male reproductive health: a research framework

The discovery in the mid-1970s that occupational exposures to pesticides could diminish or destroy the fertility of workers sparked concern about the effects of hazardous substances on male reproductive health. More recently, there is evidence that sperm quantity and quality may have declined worldwide, that the incidence of testicular cancer has progressively increased in many countries, and that other disorders of the male reproductive tract such as hypospadias and cryptorchidism may have also increased. There is growing concern that occupational factors and environmental chemical exposures, including in utero and childhood exposures to compounds with estrogenic activity, may be correlated with these observed changes in male reproductive health and fertility. We review the evidence and methodologies that have contributed to our current understanding of environmental effects on male reproductive health and fertility and discuss the methodologic issues which confront investigators in this area. One of the greatest challenges confronting researchers in this area is assessing and comparing results from existing studies. We elaborate recommendations for future research. Researchers in the field of male reproductive health should continue working to prioritize hazardous substances; elucidate the magnitude of male reproductive health effects, particularly in the areas of testicular cancer, hypospadias, and cryptorchidism; develop biomarkers of exposure to reproductive toxins and of reproductive health effects for research and clinical use; foster collaborative interdisciplinary research; and recognize the importance of standardized laboratory methods and sample archiving.

Direct exposure of mouse spermatogenic cells to high doses of adenovirus gene therapy vector does not result in germ cell transduction

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 epididymis, or by exposing sperm to the vector immediately prior to or during in vitro fertilization. The adenovirus vector carried the bacterial lacZ gene (Adbeta-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 109 plaque-forming units (PFU) was inserted into the testis or epididymis, 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 Adbeta-Gal into either the testis or epididymis 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.

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

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.

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

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.

Paternity in men with stage I testis tumors on surveillance

PURPOSE

We report long-term paternity in men with stage I testis tumors who were managed initially by surveillance.

PATIENTS AND METHODS

One hundred five patients with clinical stage I nonseminomatous germ cell tumors of the testis were entered on a surveillance protocol and followed up for more than 10 years. Actual fertility potential was assessed by pregnancy.

RESULTS

Of the 105 patients, 41 (39%) have fathered children, which includes 36 of 78 (46%) patients while on active surveillance and five of 27 (19%) patients after treatment for relapse. Of 63 couples who attempted a pregnancy on surveillance or were presumed capable of impregnation (whether they tried or not), 41 (65%) were successful.

CONCLUSION

These results show that the majority of men with stage I testis tumor who are on surveillance after orchiectomy, have a suitable partner, and attempt impregnation achieve a successful pregnancy. Pregnancy rates appear to be less than reported in men who have a nerve-sparing retroperitoneal lymph node dissection (RPLND) because more patients on surveillance require treatment for relapse, which reduces their chances for pregnancy.

MR imaging in male infertility

In patients with male infertility, endorectal magnetic resonance (MR) imaging provides high-resolution images of the prostate gland and ejaculatory apparatus. The multiplanar capability of MR imaging allows production of a detailed map of the reproductive tract for guiding treatment. Causes of male infertility can be classified as congenital, acquired, infectious, or hormonal. Wolffian duct abnormalities include agenesis of the kidney, vas deferens, or seminal vesicle and cysts of the vas deferens, seminal vesicle, or urogenital sinus-ejaculatory duct. Müllerian duct abnormalities are less common and consist of müllerian duct cysts and utricle cysts. Cowper duct cysts and peripheral-zone prostatic cysts are acquired causes of male infertility. Prostatitis, an infectious cause of male infertility, may mimic carcinoma on long repetition time/echo time images. A low testosterone levels is one of the hormonal causes of male infertility. Pitfalls in the interpretation of MR images can be avoided by familiarity with normal and abnormal findings in patients with male infertility.

Intracavernosal Injection Therapy and Other Treatment Options for Erectile Dysfunction

In the United States, almost 30 million men have complete or partial erectile dysfunction. This disorder occurs in approximately 52% of men between 40 and 70 years of age; 70% of affected men younger than 35 years of age have psychogenic causes, and 85% of men older than 50 years of age have organic impotence. Furthermore, erectile dysfunction is exacerbated by the presence of such conditions as heart disease, diabetes, and hyperlipidemia and the medications used to manage them. Thus, a widespread segment of the population is in need of a safe and effective treatment strategy for restoration of normal sexual function. The technique of intracavernosal injection therapy was initially described in the early 1980s. During the subsequent decade, the effectiveness of various drug combinations and the associated side effects were demonstrated. In 1995, prostaglandin E(1) was approved for intra-cavernosal pharmacotherapy. It has proved highly effective for neurogenic, vasculogenic, and psychogenic erectile dysfunction, with reported response rates of 75 to 92%. The major side effect (albeit uncommon) is corporal fibrosis. Other options for treatment of erectile dysfunction are vacuum-erection devices and penile prostheses.

Infection and pyospermia in male infertility. Is it really a problem?

Controversy exists concerning the exact role of genitourinary tract infections in male infertility. This ambiguity is due to the currently conflicting literature coupled with present limitations in obtaining and evaluating the significance of diagnostic tests such as semen cultures and leukocyte counts. In the evaluation of the infertile man for a possible infectious cause, a complete history, physical examination, and urinalysis identify most infectious disorders. In the majority of infertile men who are asymptomatic, evaluation for a subclinical genital tract infection focuses on the accurate determination of seminal leukocytes. The determination of pyospermia may identify those men with a subclinical genital tract infection who require further investigation. Prospective studies using clearly defined criteria, new diagnostic tools, and effective control groups are needed to evaluate better the impact of infection and pyospermia on male infertility.

Evaluation of sperm function. What is available in the modern andrology laboratory?

Tests of sperm function markedly improve the clinician's ability to diagnose male factor infertility accurately. An understanding of the patient's sperm defect may improve the clinical management of male infertility. A wide spectrum of therapeutic options is available to the urologist treating the infertile male. IVF is now routinely employed for many types of male factor infertility with promising results. Micromanipulation has permitted men who, in the not so distant past, were considered infertile to experience fatherhood. In light of these promising therapeutic advances, accurate assessment of sperm function becomes crucial. Treatment options may be selected on the basis of specific functional defects of sperm. Sperm with an inability to bypass cervical mucus may be adequately treated with IUI. Oligospermic men with sperm capable of ova penetration can be treated with IVF, whereas men whose sperm are incapable of zona binding/penetration may be treated with micromanipulation. Sperm function assays provide a rationale for the selection of specific therapies to treat or bypass identified defects, and by providing comprehensive and accurate diagnosis, they make possible individually tailored therapies. Such individualized treatment choices may improve success rates for many male factor patients.

Infection and pyospermia in male infertility

Infections of the male genitourinary tract may contribute to infertility by adversely affecting sperm function, causing anatomical obstruction or initiating a leukocyte response. The majority of infertile males are asymptomatic, and the significance and the criteria for the diagnosis of a genital tract infection are controversial. The evaluation for a genital tract infection focuses on urine and semen cultures as well as on the accurate quantitation of seminal leukocytes. An elevated seminal leukocyte count, pyospermia, can be associated with male infertility and may reflect an infectious or inflammatory disorder. In addition, the role of specific genital tract infections such as chlamydiosis, gonorrhea, ureaplasma and trichomoniasis and their possible association with male infertility is addressed.

Variation in antisperm antibody response following transection of male genital tract in Lewis rats

Genital tracts of male Lewis rats were transected at various levels to determine whether this may influence antisperm antibody response. Adult male rats underwent bilateral transection of the vas deferens (group I, n = 9), mid-epididymis (group II, n = 10), and efferent duct (group III, n = 9). Group IV (n = 10) underwent a sham operation. Sera were collected by retro-orbital puncture before the operative procedure and monthly for 3 months postprocedure. Sperm-reactive immunoglobulins IgG, IgA, and IgM were measured individually as well as combined in serum by enzyme-linked immunosorbent assay (ELISA) using lithium diiodosalicylate (LIS)-solubilized washed rat caudal epididymal sperm. The maximal immune response was seen in all groups at 2 months postprocedure. Antibody response defined as the net ELISA absorbance reading for the combined immunoglobulin group were (mean +/- SEM): group I = 120 +/- 16, group II = 156 +/- 23, group III = 190 +/- 20, and group IV = 116 +/- 22. The highest antibody response was noted in the efferent duct group, which was statistically (p < .05) greater than the sham-operated and vas deferens groups. In the efferent duct group the highest immunoglobulin response was observed in the IgG class, which was significantly higher (p < .05) than the IgA and IgM classes. The transection of the male genital tract at different levels leads to variation in antisperm antibody response and that sperm located at different sites along the genital tract may differ in their autoantigenic potential.