Inhibin B levels in azoospermic subjects with cytologically characterized testicular pathology.

BACKGROUND AND OBJECTIVE: Inhibin B, a heterodimeric glycoprotein of gonadal origin, is the most important circulating form of inhibin in human males and an inverse relationship between inhibin B and FSH plasma levels was been recently observed. Azoospermia represents the end-point of different kinds of testicular damage, ranging from a normal spermatogenic pattern (obstructive forms) to the complete absence of germ cells (Sertoli Cell Only Syndrome, SCOS). Furthermore, azoospermia may be related to maturational disturbances at different levels (spermatogonial, spermatocytic, spermatidic). To better define the relationship between testicular damage and inhibin levels and to evaluate the diagnostic value of this hormone in the management of subjects with azoospermia, we performed specific inhibin B assays in a group of azoospermic subjects affected by different kinds of testicular pathology. PATIENTS: Eighty-nine azoospermic men were studied by testicular ultrasound examination, fine needle aspiration of the testes and hormonal parameters (FSH, LH and testosterone, inhibin B). Thirty normozoospermic subjects were considered as controls for seminal and hormonal parameters. DESIGN AND RESULTS: On the basis of cytological analysis five different testicular appearences were identified in azoospermic patients: (i) Sertoli cell only syndrome (SCOS); (ii) Severe hypospermatogenesis; (iii) Spermatogonial and/or spermatocytic arrest; (iv) Spermatidic arrest; (v) Normal germ line (obstructive forms). No difference in LH and testosterone levels was found among the different groups. A significant negative correlation was present between inhibin B and FSH both in azoospermic men (r = - 0.503, P < 0.0001) and normozoospermic controls (r = -0.361, P < 0.05). Groups characterized by obstructive azoospermia and spermatidic arrest showed inhibin B concentrations similar to normozoospermic subjects (130.7 +/- 73.5, 160.3 +/- 35.1 and 148.5 +/- 46.8 ng/l, respectively), while groups characterized by SCOS, severe hypospermatogenesis and spermatogonial and/or spermatocytic arrest showed mean inhibin B concentrations significantly lower than controls (56.5 +/- 56.0, 57.9 +/- 31.2; 48.9 +/- 16.7 ng/l, respectively). In the group of SCOS, 8 out of 42 subjects (19.0%) showed inhibin B concentrations within the normal range despite high FSH levels. CONCLUSIONS: This study demonstrated that, in humans, spermatids play an important role in the mechanism regulating inhibin B secretion by Sertoli cells. The significance of this hormone as a diagnostic parameter in azoospermic patients does not seem to be specific because it does not permit discrimination between obstructive forms or spermatidic arrest. Furthermore, despite an evident clinical, cytological and hormonal pattern for SCOS, inhibin B levels are normal in some of these patients. The significance of this latter result remains to be elucidated.

Inactivation of the p16 tumor suppressor gene in adrenocortical tumors.

The mechanisms of adrenocortical tumorigenesis are still unknown. Evidence that the majority of adrenocortical tumors are monoclonal in origin suggests that a progressive accumulation of genetic aberrations, due to activation of protooncogenes and/or inactivation of tumor suppressor genes, leads to abnormal cell proliferation through a multistep process. Inactivation of the p16 tumor suppressor gene (p16INK4A), which encodes the cell cycle protein p16, was investigated in a series of 14 adrenocortical tumors. Using 11 polymorphic microsatellite markers spanning the short arm of chromosome 9, we demonstrated that three of seven adrenocortical carcinomas and one of seven adrenocortical adenomas had loss of heterozygosity (LOH) within chromosome 9p21, the region containing p16NK4A. Immunohistochemistry showed the absence of p16 nuclear staining in all adrenocortical tumors with LOH within 9p21, and positive staining in all remaining tumors without LOH. In conclusion, LOH within 9p21 associated with lack of p16 expression occurs in a considerable proportion of adrenocortical malignant tumors, but is rare in adenomas. Inactivation of p16INK4A may contribute to the deregulation of cell proliferation in this neoplastic disease.

Case report: high fertilization rate in conventional in-vitro fertilization utilizing spermatozoa from an oligozoospermic subject presenting microdeletions of the Y chromosome long arm.

A case is reported in which a high fertilization rate was achieved by conventional in-vitro fertilization (IVF), using spermatozoa from an oligozoospermic man carrying a microdeletion of the long arm of the Y chromosome. The patient presented with idiopathic infertility of 10 years duration; the fertility status of his wife was completely normal. After IVF, five out of eight oocytes retrieved showed normal fertilization and four showed normal embryo cleavage. Four embryos were transferred; however, pregnancy did not result. These results demonstrate that spermatozoa from oligozoospermic patients carrying a Yq microdeletion are fully competent in achieving capacitation, acrosome reaction and fertilizing ability during IVF. Therefore, although definitive conclusions cannot be made from a single case report, we suggest that Yq microdeletion analysis should be considered in oligozoospermic patients undergoing conventional IVF.

Paclitaxel is an effective antiproliferative agent on the human NCI-H295 adrenocortical carcinoma cell line.

In view of a potential clinical use, we assessed the antiproliferative effect of paclitaxel on the human steroid-secreting NCI-H295 adrenocarcinoma cell line. By MTT, paclitaxel induced a dose-dependent inhibition of cell proliferation, with IC50 lower than blood levels of the drug achieved in patients treated for other malignancies. Cell exposure to paclitaxel for 24 h at the different IC50S produced a dose-responsive increase in DNA fragmentation, morphologically confirmed by electron microscopy. A time-dependent decrease in aldosterone, cortisol and testosterone was observed. Paclitaxel is an effective antiproliferative agent in this human adrenocortical carcinoma cell line. Apoptosis induced by the drug in involved in neoplastic cell death. A potential role of the drug in the treatment of patients with adrenocortical cancer could be considered.

High frequency of well-defined Y-chromosome deletions in idiopathic Sertoli cell-only syndrome.

Idiopathic Sertoli cell-only syndrome (SCOS) is characterized by azoospermia, small testes, absence of germ cells in the testes, elevated follicle stimulating hormone and normal testosterone concentrations. The Y-chromosome is involved in the regulation of spermatogenesis and in the pathogenesis of a fraction of idiopathic male infertility. An azoospermia factor (AZF) is present on the Y-chromosome long arm euchromatic region (Yq11) and two gene families (DAZ and RBM) have been identified within this region. The aim of this study was to investigate whether a specific pattern of Yq11 microdeletions may be associated with idiopathic SCOS. Eighteen idiopathic subjects showing a testicular cytological picture of bilateral SCOS were selected and tested by polymerase chain reaction for a set of 29 Y-specific sequence-tagged sites (STS). We found Yq microdeletions in 10 out of 18 patients (55.5%) while the fathers or brothers of six out of 10 patients deleted for Yq were shown to carry an intact Y-chromosome. These deletions may therefore be considered as de-novo deletions and the cause of SCOS. The analysis of the microdeletions allowed us to identify two homogeneous regions that have a high incidence of deletion. The smallest deletion, common to all patients, is located in Yq interval 5. We therefore speculate that there is a relationship between specific, well-characterized Yq11 microdeletions and a testicular picture of SCOS, identifying an Y-related region frequently deleted in this syndrome. In conclusion, the findings of this study demonstrate that a large percentage of idiopathic SCOS may be genetically determined and identify an Y-related region that seems to possess one or more still unknown genes essential for spermatogenesis.

Aldosterone-producing adenomas do not contain glucocorticoid-remediable aldosteronism chimeric gene duplications.

In glucocorticoid-remediable aldosteronism (GRA) a chimeric gene has been described with the activity of aldosterone synthase, but the promoter of 11 beta-hydroxylase leading to ectopic expression of aldosterone synthase activity in the zona fasciculata. Similar to GRA, in aldosterone-producing adenomas (APA), the primary regulation of aldosterone production is ACTH, and there is increased production of the 18-oxygenated cortisol compounds, 18-oxocortisol and 18-hydroxycortisol. Because of these hormonal similarities, we tested whether a chimeric GRA-like gene was present in APA from 11 patients. A GRA-like chimeric gene was not found in the DNA from these tumors and, therefore, is not the mechanism responsible for hyperaldosteronism in APA.

Effects of taxol on the human NCI-H295 adrenocortical carcinoma cell line.

We investigated the effects of taxol, an antimicrotubule agent active in different cancers, on the human NCI-H295 steroid-secreting adrenocortical carcinoma cell line. Cells were incubated for 48, 72 or 96 h with taxol 10(-10)-10(-4) M. Cell viability was evaluated by MTT assay with IC50 calculation. Apoptosis was investigated by measuring DNA fragmentation with ELISA assay after cell exposure to taxol at IC50 for 24 h. For secretion studies, aldosterone, cortisol, testosterone and dehydroepiandrosterone-sulphate (DHEA-S) were measured by RIA in the conditioned medium after 96 h exposure to taxol 10(-10)-10(-6) M, and expressed as percentage of steroid production by control cells. By MTT, taxol induced a dose-dependent inhibition of cell proliferation, with ICs50 at 72-96 h corresponding to blood levels achieved in vivo in patients with other types of cancer. Nuclear fragmentation, morphologically confirmed at electron microscopy, showed a 4-fold increase after exposure to taxol. With 10(-6) M taxol, aldosterone decreased to 48%, cortisol to 61%, testosterone to 76% and DHEA-S to 89% of steroid production by control cells. Taxol is an effective cytotoxic and antiproliferative agent in a human adrenocortical steroid-secreting carcinoma cell line. Apoptosis induced by the drug is involved in neoplastic cell death.

Effect of surgical treatment on hypertension in Cushing's syndrome.

The effect of a surgical cure of hypercortisolism on hypertension in 54 patients with Cushing's syndrome was assessed. The correlation between preoperative duration of hypertension and posttreatment blood pressure was significant (P < .01). Restoration of normal cortisol was associated with blood pressure normalization in 39 out of 54 cases. Duration of hypertension of patients with normalized blood pressure was significantly shorter than that of patients with persistent hypertension postoperatively (P < .0001). Duration of hypertension, ie, long-lasting exposure to increased cortisol, appears to be the determinant of persistent hypertension following successful surgery in Cushing's syndrome.

GSTM1 and CYP2D6 genotype frequencies in patients with pituitary tumours: effects on P53, ras and gsp.

We describe studies to determine if susceptibility to pituitary tumours is associated with the putatively high risk GSTM1 null and CYP2D6 EM genotypes. Frequency distributions of these genotypes were similar in cases and controls though the frequency of CYP2D6 PM and GSTM1 B tended to be lower (P = 0.072 and P = 0.095 respectively) in the tumour group. Immunopositivity for p53 was found in 18/97 tumours. In these samples GSTM1 null (39%) and CYP2D6 EM (56%) frequencies were not different to those in controls. The frequencies of CYP2D6 PM and GSTM1 B in the p53 immunonegative tumours tended to be lower (P = 0.055 and P = 0.1185 respectively) than in controls. Mutations in gsp and ras were studied using the polymerase chain reaction and allele specific oligonucleotide analysis. Eight of 19 somatotrophinomas demonstrated mutations in gsp; frequencies of GSTM1 null and CYP02D6 EM were similar to controls. No ras mutations were identified in 55-tumour studies. The data indicate the GSTM1 null and CYP2D6 EM genotypes are not associated with altered expression of p53 or, mutation of gsp and ras in these adenomas and, suggest the CYP2D6 PM genotype is associated with a reduced risk of pituitary adenomas and, that GSTM1*B confers greater protection than GSTM1*A.

Are activating mutations of the adrenocorticotropin receptor involved in adrenal cortical neoplasia?

The objective of this study was to investigate the presence of activating mutations of the ACTH receptor gene in benign and malignant adrenocortical tumours. Genomic DNA was extracted from a variety of adrenocortical neoplasms from 16 patients and the entire ACTH receptor gene was then amplified by the polymerase chain reaction and sequenced. No mutations were detected within the coding region of the ACTH receptor gene in the 16 adrenocortical tumours studied. It is likely that mutations of the coding region of the ACTH receptor gene do not play a major role in adrenocortical tumourigenesis.

Evaluation of critical differences of CEA and CA 15.3 levels in serial samples from patients operated for breast cancer.

In the present investigation we evaluated the variability of tumor marker levels in the follow-up of patients without evidence of disease after resection of primary breast cancer. CEA and CA15.3 were measured using commercially available methods in serial blood samples collected from 170 patients. The coefficient of variation among all samples from each patient, which accounts for the total variability (analytical variability+biological variability), was widely scattered (from 4 to 99% for CEA; from 4 to 52% for CA15.3). The critical difference was calculated using the formula designed by Fraser [CD = 2.77. (CVa2 + CVb2)1/2]. It ranged from 11 to 276 for CEA and from 11 to 144 for CA15.3. From the present findings we conclude that: 1) it is possible to identify individually tailored decision criteria to evaluate tumor marker variations in the follow-up of breast cancer patients; 2) in a considerable number of cases the non-tumor-related variability is too high to allow the early identification of minor tumor marker variations that are of clinical relevance.

Molecular genetic studies of sporadic pituitary tumors.

Tumor formation may result from the activation of dominant oncogenes or by inactivation of recessive, tumor suppressor genes. The role of such mutations in the development of pituitary tumors has been studied. Tumors from 88 patients, representing the 4 major classes of adenoma, were investigated. In DNA extracted from matched leukocyte and tumor samples, allelic deletions were sought with 15 probes identifying restriction fragment length polymorphisms on chromosomes 1, 5, 10, 11, 13, 17, 20, and 22. Evidence of amplification or rearrangement of 10 recognized cellular oncogenes (N-ras, mycL1, mycN, myc, H-ras, bcl1, H-stf1, sea, kraS2, and fos) was sought in tumor DNA. Activating dominant mutations of Gs alpha were detected using the polymerase chain reaction to amplify exons 7-10 and hybridizing the product to normal and mutant allele-specific oligonucleotides. Allelic deletions on chromosome 11 were identified in 16 tumors (18%) representing all 4 major subtypes. Deletions on other autosomes were observed in less than 6% of tumors. Three adenomas had deletions on multiple autosomes, 2 of these were aggressive and recurrent. Mutations of Gs alpha were confirmed to be specific to somatotrophinomas, being identified in 36% of such tumors in this series. No evidence of amplification or rearrangement of other recognized cellular oncogenes was found. Inactivation of a recessive oncogene on chromosome 11 is an important and possibly early event in the development of the four major types of pituitary adenoma, whereas activating mutations of Gs alpha are confirmed to be specific to somatotropinomas. Two aggressive tumors were found to have multiple autosomal losses, suggesting a multistep progression in the development of tumors of this phenotype.

Effect of digoxin on the in vitro secretion of renin and angiotensin II/III immunoreactivity by the human adrenal gland.

Cardiac glycosides in man inhibit renin secretion, probably through a direct effect at the renal level (i.e. inhibition of juxtaglomerular cell Na/K ATPase). Since there is evidence that the human adrenal possesses an intrinsic renin-angiotensin system, we investigated the effect of digoxin on the in vitro generation of renin and angiotensin II/III, as well as of aldosterone, by the human adrenal gland. Minced normal adrenal tissues were studied in a superfusion system, measuring in the 15-min superfusate fractions active renin by immunoradiometric assay and angiotensin II/III and aldosterone by radioimmunoassay, respectively. In a first set of four experiments using different concentrations of digoxin in sequence for 45 min periods, digoxin 10(-5), but not 10(-8) and 10(-6) mol/l, significantly reduced renin and angiotensin II/III output from adrenals, while no change in aldosterone was observed. In a second set of three experiments, the addition of digoxin 10(-5) mol/l for 120 min caused a sustained reduction of renin and angiotensin II/III, but not of aldosterone. In the final experiment, the decrease of renin and angiotensin II/III during superfusion with digoxin 10(-5) mol/l was significantly greater than that observed during superfusion with digoxin in the presence of antidigoxin antibodies. Our data indicate that digoxin at high doses reduces renin and angiotensin II/III but not aldosterone secretion by the human adrenal gland. This suggests two different effects of digoxin, probably both mediated by inhibition of the Na/K ATPase activity, on the adrenal renin-angiotensin- and aldosterone-secreting cells.

Local renin-angiotensin system in human adrenals and aldosteronomas.

The local renin-angiotensin system may regulate adrenal cell growth and function. Angiotensinogen, renin, and angiotensin converting enzyme gene expression were studied in four normal adrenal glands (removed from patients with renal carcinomas) and five aldosterone-secreting adenomas. Northern blot analysis showed expression of angiotensinogen messenger RNA (mRNA) in normal adrenals at levels approximately 35-fold lower than liver and sixfold lower than kidney. Similar angiotensinogen mRNA levels were present in two aldosteronomas, whereas a third had levels approximately 50% of those found in kidney. Renin mRNA was detectable in most normal adrenals and in three adenomas, one of which had relatively high renin mRNA levels. Angiotensin converting enzyme gene was expressed in adrenal tissue and in three adenomas. Portions from these normal adrenals and two of these aldosteronomas, as well as samples from two other adrenals and three aldosteronomas, were also studied in an in vitro superfusion system coupled with active renin radioimmunometric assay, angiotensin II/III, and aldosterone radioimmunoassay. Total amounts of active renin and angiotensin II/III released from normal adrenals during 270 minutes of superfusion were higher than the amounts released from aldosteronomas (312 +/- 35 versus 187 +/- 43 and 823 +/- 100 versus 436 +/- 55 pg/100 mg tissue, respectively; mean +/- SEM, p less than 0.05), whereas aldosterone release from the adenomatous tissue was approximately threefold higher (320 +/- 21 versus 115 +/- 18 ng/100 mg tissue; mean +/- SEM, p less than 0.01). Total amounts of active renin and angiotensin II/III released by normal or adenomatous adrenal samples exceeded threefold to fourfold the amounts extracted from similar samples of the same surgical specimen.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro evidence for local generation of renin and angiotensin II/III immunoreactivity by the human adrenal gland.

The adrenal gland of various mammalian species has been shown to contain all the components of a functional renin-angiotensin system. We investigated the existence of this local system in human adrenal tissues surgically obtained. Eight normal adrenals (cortex and medulla) and 6 aldosterone-producing adenomas (aldosteronomas) were examined. Minced tissues were superfused over 270 min, and 15-min fractions were collected. In the perfusates, active renin was measured by immunoradiometric assay with human anti-renin monoclonal antibodies; immunoreactive angiotensin II/III and aldosterone were measured by radioimmunoassay. Adrenal tissues, either normal or pathological, were found concomitantly to release renin, angiotensin II/III and aldosterone. The pattern of this spontaneous release exhibited a pulsatile character. The total amount of renin and angiotensin II/III secreted during superfusion clearly exceeded the tissue content (determined by extraction). Addition of the angiotensin-converting enzyme inhibitor quinaprilat (4 x 10(-6) mol/l) in the superfusion caused a concomitant decrease of angiotensin II/III and aldosterone secretion by 3 normal tissues, and no change in 2 aldosteronomas. These data provide evidence that the human adrenal gland in vitro generates and releases both renin and angiotensin II/III, and support the hypothesis that locally formed angiotensin II/III may play a role as a paracrine regulator of physiological aldosterone secretion.

Effect of captopril on aldosterone response to potassium infusion in primary aldosteronism.

The effect of captopril on the aldosterone response to potassium was studied in 6 patients with idiopathic adrenal hyperplasia (IAH) and in 4 patients with an aldosterone-producing adenoma (APA), who all have suppressed activity of circulating renin-angiotensin system (RAS). Precaptopril, KCl infusion induced a significant increase in aldosterone in both groups. This increment was significantly blunted by captopril in IAH, but not in APA. Decreased potassium-stimulated aldosterone secretion after captopril in IAH supports the hypothesis that adrenal RAS plays a role in aldosterone production under potassium stimulation.

[Treatment of diabetes insipidus]. / Terapia del diabete insipido.

Although water alone taken in sufficient amount should correct any metabolic abnormality, a proper therapy is available to reduce the symptoms of the diabetes insipidus. In patients with reduced circulating levels of vasopressin, chlorpropamide, clofibrate, idroclorotiazide etc., enhance the effect of vasopressin on the renal tubule or induce a release of vasopressin, thus reducing the diuresis. On the contrary patients with complete diabetes insipidus require replacement therapy. Different forms of extractive vasopressin unfortunately are available: "aqueous vasopressin", "tannate vasopressin" in a suspension of peanut oil etc., are provided of many side-effects because of the impurities in their preparation. DDAVP is a synthetic analogous of natural vasopressin more specific for antidiuresis and with a long-activity. This compound available in a buffered aqueous solution is administrated by blowing into the nose. In our experience, 23 patients with different forms of central diabetes insipidus have successfully treated with 2-3 daily administrations of this drug without any side effect. The recent demonstration that DDAVP given orally exerts an antidiuretic activity in patients with diabetes insipidus is of therapeutic interest. It is conceivable that DDAVP in a properly formulated tablet will become a therapeutic option for the future treatment of patients with central diabetes insipidus.