R. F. A. Weber

Decreased Sperm DNA Fragmentation After Surgical Varicocelectomy is Associated With Increased Pregnancy Rate

PURPOSE We prospectively evaluated changes in sperm chromatin structure in infertile patients before and after surgical repair of varicocele, and the impact on the pregnancy rate. MATERIALS AND METHODS Included in the study were 49 men with at least a 1-year history of infertility, a palpable varicocele and oligospermia. World Health Organization semen analysis and sperm DNA damage expressed as the DNA fragmentation index using the sperm chromatin structure assay were assessed preoperatively and postoperatively. Pregnancy (spontaneous and after assisted reproductive technique) was recorded 2 years after surgery. RESULTS Mean sperm count, sperm concentration and sperm progressive motility improved significantly after varicocelectomy from 18.3 x 10(6) to 44.4 x 10(6), 4.8 x 10(6)/ml to 14.3 x 10(6)/ml and 16.7% to 26.6%, respectively (p <0.001). The DNA fragmentation index decreased significantly after surgery from 35.2% to 30.2% (p = 0.019). When the definition of greater than 50% improvement in sperm concentration after varicocelectomy was applied, 31 of 49 patients (63%) responded to varicocelectomy. After varicocelectomy 37% of the couples conceived spontaneously and 24% achieved pregnancy with assisted reproductive technique. The mean postoperative DNA fragmentation index was significantly higher in couples who did not conceive spontaneously or with assisted reproductive technique (p = 0.033). CONCLUSIONS After varicocelectomy sperm parameters significantly improved and sperm DNA fragmentation was significantly decreased. Low DNA fragmentation index values are associated with a higher pregnancy rate (spontaneous and with assisted reproductive technique). We suggest that varicocelectomy should be considered in infertile men with palpable varicocele, abnormal semen analysis and no major female factors.

IS ROUTINE SCROTAL ULTRASOUND ADVANTAGEOUS IN INFERTILE MEN

PURPOSE We determine the value of routine scrotal ultrasonography in the evaluation of male infertility. MATERIALS AND METHODS Scrotal color Doppler ultrasonography reports of 1,372 infertile men were reviewed to assess the prevalence of scrotal abnormalities and compared to clinical findings. RESULTS The prevalence of scrotal abnormalities was 38%. Testicular tumor was found in 0.5%, varicocele in 29.7%, testicular cyst in 0.7%, testicular microlithiasis in 0.9%, epididymal cyst in 7.6% and hydrocele in 3.2% of the cases. Overall, 67% of sonography findings were not evident on palpation, and only 1 of 7 testicular tumors was suspected. Of the varicoceles 60% were not found on physical examination. The rate of testicular tumors (1/200) was higher than that reported for the general European population (1/20,000). CONCLUSIONS Routine scrotal ultrasound provides valuable information in the diagnostic evaluation of infertile men and substantially more pathological conditions are detected compared to clinical palpation. The high prevalence of testicular malignancies underlines the clinical relevance of routine scrotal ultrasonography in infertile men.

Inhibin B: A novel marker of spermatogenesis

Subfertility affects about 15% of all couples. Assessment of spermatogenesis has a central role in the evaluation of the subfertile couple. Classical markers of spermatogenesis, such as semen analysis, testicular biopsy and endocrine evaluation all have their diagnostic limitations. There is a clear need for accurate additional markers of spermatogenesis. Recently, the serum inhibin B level has emerged as a sensitive endocrine marker of spermatogenesis. This paper summarises the prosand consof different markers of spermatogenesis, with specific focus on serum inhibin B. The serum inhibin B level has been shown to be associated with classical markers of spermatogenesis, particularly testicular histology, and to be the most accurate endocrine marker of spermatogenesis. A subnormal serum inhibin B level clearly reflects disturbed spermatogenesis. Before puberty, when no spermatogenesis takes place, inhibin B is a marker of testicular integrity. Clinical applications of serum inhibin B in childhood and adulthood are given, and a view on future directions and research is presented. The serum inhibin B level has proven to be valuable in the evaluation of spermatogenesis, and holds a promise for further research.

Sperm chromatin structure is associated with the quality of spermatogenesis in infertile patients

OBJECTIVE To establish the diagnostic value of sperm chromatin structure assessment for the evaluation of male factor infertility, in addition to conventional andrological workup. DESIGN Cross-sectional controlled study. SETTING A tertiary referral andrology clinic. PATIENT(S) Two hundred seventy-nine male partners of infertile couples. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) The DNA fragmentation index (DFI) determined by the sperm chromatin structure assay (SCSA), semen parameters, serum levels of reproductive hormones, and World Health Organization (WHO) classification of male factor subfertility. RESULT(S) In all patient categories, except those including patients with hypogonadotrophic hypogonadism, sperm antibodies, or normospermia, DFI was significantly higher compared with in proven fertile controls. After classification of the quality of spermatogenesis based on mean testicular volume (<10 ml vs. >15 ml), follicle stimulating hormone (FSH; > 10 U/L vs. <5 U/L), and inhibin-B (<100 nmol/L vs. >150 nmol/L), the DFI was significantly higher in patients with poor spermatogenesis (35.9%) than in patients with normal spermatogenesis (25.9%). In a multiple regression analysis, the teratozoospermia index, sperm vitality, and FSH were significant determinants of the DFI level. Male age was associated with DFI, but leukocytospermia, body mass index, and smoking were not confounders of DFI. CONCLUSION(S) Impaired spermatogenesis, irrespective of the WHO classification of male factor subfertility, is generally associated with an increase of sperm DNA damage.

Evidence for the involvement of corticotropin-releasing factor in the inhibition of gonadotropin release induced by hyperprolactinemia.

The hypothesis was tested that corticotropin-releasing factor (CRF) is involved in the inhibition of gonadotropin secretion during chronic hyperprolactinemia. Two models of hyperprolactinemia were used, namely inoculation with the prolactin (PRL)-secreting tumor 7315b and implantation of isogenic pituitary glands. Gonadectomized, adrenalectomized male rats received a testosterone capsule and a corticosterone pellet and were inoculated subcutaneously with tumor 7315b. Similar rats without tumor served as controls. The rats were studied 3-4 weeks later while anesthetized with urethane. Plasma testosterone and corticosterone were similar in the two groups of rats. Compared to controls, the tumor-bearing rats had significantly higher plasma levels of PRL (100-fold increase) and adrenocorticotropin (ACTH; 3-fold increase), whereas plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH) had significantly decreased to 15 and 40%, respectively. CRF release into hypophysial stalk plasma was higher in rats with tumor 7315b than in controls (298 +/- 23 vs. 197 +/- 28 pg/h), and hypothalamic CRF content had increased from 3.0 +/- 0.3 to 4.3 +/- 0.3 ng. Male rats received 3 pituitary glands under the kidney capsule. Sham-operated rats served as controls. They were studied 5-7 weeks later while anesthetized with urethane. Compared to controls, pituitary-grafted rats had larger adrenals (49 +/- 4 vs. 34 +/- 2 mg), higher plasma PRL (156 +/- 18 vs. 52 +/- 8 ng/ml), ACTH (0.46 +/- 0.05 vs. 0.22 +/- 0.02 ng/ml) and corticosterone (455 +/- 39 vs. 268 +/- 14 ng/ml), and lower plasma levels of LH (21 +/- 2 vs. 41 +/- 6 ng/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Heterogeneous Distribution of ITGCNU in an Adult Testis: Consequences for Biopsy-Based Diagnosis

Carcinoma in situ (CIS) of the testis, also referred to as intratubular germ cell neoplasia unclassified (ITGCNU), is currently accepted as the common precursor for all malignant germ cell tumors of adolescents and adults— that is, the seminomatous and nonseminoma cancers. These preinvasive cells have specific cellular characteristics, which can be used for the early diagnosis—routinely done by morphological analysis, sometimes supported by immunohistochemistry—of tissue obtained by an open surgical biopsy. False-negative biopsy results can occur mostly because of the nonrandom distribution of ITGCNU within the testis, misdiagnosis, or suboptimal tissue treatment and analysis. In this article, we demonstrate the potential pitfalls in the diagnosis of ITGCNU. The results support the use of the highly specific and sensitive immunohistochemical marker OCT3/4 for the diagnosis of ITGCNU and provide evidence for the nonrandom distribution of ITGCNU, which is a significant limitation in the diagnosis of this preinvasive lesion.

Increased serum inhibin B levels after varicocele treatment

OBJECTIVE Inhibin B is secreted by Sertoli cells in response to FSH and is the major feedback regulator of FSH secretion in man. The serum inhibin B level has emerged as a good marker of spermatogenesis and Sertoli cell function. Varicocele has been associated with infertility and disturbed spermatogenesis. We have studied the effect of varicocele treatment on serum inhibin B levels, with the aim of investigating the effect on spermatogenesis and the involvement of the Sertoli cell in varicocele pathophysiology.

Glucocorticoids inhibit gonadotropin-releasing hormone by acting directly at the hypothalamic level

Glucocorticoids, the end-product of the hypothalamic-pituitary-adrenal (HPA) axis, suppress gonadotropin release by acting at the level of the pituitary gland. However, experimental evidence suggests that they may also act at the hypothalamic level to suppress gonadotropin-releasing hormone (GnRH) release. The lack of a direct demonstration of this assumption, prompted us to evaluate the effects of glucocorticoids on hypothalamic GnRH release from individually-incubated hemi-hypothalami explanted from male rats. Since testosterone (T), dihydrotestosterone (DHT), and progesterone suppress GnRH release and androgens potentiate the effects of glucocorticoids on GnRH release, we studied also the interaction of these steroids with glucocorticoids on GnRH release. Corticosterone (B), the main glucocorticoid of the rodents with greater affinity for the type I glucocorticoid receptor, and dexamethasone (DEX), a synthetic type II glucocorticoid receptor agonist, were able to suppress basal GnRH release in a concentration-dependent fashion. DEX induced a more profound suppression of GnRH release. Neither T (0.1 nM) nor DHT (0.01 nM) modulated the suppressive effects of low (10 nM) or high (100 nM) concentrations of B on GnRH release. On the other hand, progesterone counteracted the suppressive effect of low concentrations of B (10 nM) on GnRH release, but had no effect on the suppression caused by a higher concentration of B (100 nM). The ability of glucocorticoids to inhibit directly GnRH release suggests that these stress-responsive hormones act also at the hypothalamic level to suppress the reproductive function. The suppressive effect of B was not modulated by androgens, but it was neutralized by progesterone, al least when B was used at low concentrations. We speculate that this steroid “protects” the GnRH-secreting neuron only during basal, but not stress-induced, HPA axis activity when the concentrations of glucocorticoids are more elevated.

Clinical Laboratory Evaluation of Male Subfertility

Male subfertility is a common problem with a complex etiology, requiring a complete andrological work-up for proper diagnosis. The male reproductive tract is controlled by a well-balanced hormonal system, in which hypothalamic (GnRH), pituitary (LH, FSH) and testicular hormones (androgens, inhibin B) participate. Any disturbance of this hormonal system may therefore lead to testicular dysfunction and interfere with the spermatogenesis process. In addition, also other components along the ductal system, such as epididymis, prostate and seminal vesicles, that improve sperm fertility by contributing their secretions to the semen, might function inadequately and thus fail to enhance the fertilizing capacity of the sperm cells. External factors (heat, chemicals, life style) and anatomical abnormalities (varicocele) were shown to have a negative influence on male fertility. In a number of patients genetic defects can be identified as the cause of their infertility. Laboratory tests are available to assess hormone concentrations, semen composition, accessory gland function and sperm cell function. Conventional semen analysis includes the determination of sperm concentration, semen volume, sperm motility (qualitative and quantitative), sperm morphology, sperm cell vitality, pH, leucocytes and antibodies. The usefulness of the determination of these parameters as predictor of fertility appears to be rather limited, however. Therefore, alternative tests, some based on more functional aspects (sperm penetration, capacitation, acrosome reaction), have been developed. Furthermore, there is an increasing attention for the assessment of DNA integrity, for instance by the flowcytometer-based Sperm Chromation Structure Assay (SCSA), as an additional or alternative parameter of sperm quality. It is likely and desirable that further assays with better predictive value are being developed in the near future.

The effect of cryptorchidism on inhibin B in a subfertile population

objective Prepubertal cryptorchidism may cause fertility problems in adulthood, due to impaired spermatogenesis. Serum inhibin B has emerged as an accurate marker of spermatogenesis. The aim of this study was to evaluate the impact of a history of cryptorchidism on serum inhibin B levels and other markers of spermatogenesis in subfertile men.