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.
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.
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.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.