Disease relevance of SCO

• Quantitative measurements on testicular biopsies revealed the highest CK-18 expression in the mixed atrophy biopsies (22 men), a lower expression in the Sertoli cell-only (SCO) biopsies (12 men), and minimal residual staining in the group considered as representing normal spermatogenesis (six obstructive azoospermia patients) [1].
• Since all markers in Sertoli cell nodules revealed a staining pattern identical to that in neoplastic Sertoli cells, but different to that in Sertoli cells of SCO tubules with hyperplasia, it may be speculated that Sertoli cell tumours in adult men may originate from Sertoli cell nodules [2].
• Testes of infertile adult patients often exhibit numerous histological signs of testicular dysgenesis syndrome (TDS) such as microliths, Sertoli cell only (SCO) tubules, tubules containing carcinoma in situ and immature seminiferous tubules (Sertoli cell nodules) [2].
• Neuropeptide signaling and hydrocephalus: SCO with the flow [3].
• This may provide a valuable prognostic tool for infertility clinics performing testicular sperm extraction, as it would enable the exclusion of AZFa patients with a complete SCO syndrome [4].

High impact information on SCO

• Two important players are the subcommissural organ/Reissner's fiber (SCO/RF) complex and the ventricular ependymal (vel) cells that together facilitate the flow of the CSF through the narrow canals of the ventricular system [3].
• In this issue of the JCI, Lang et al. demonstrate that overexpression of the pituitary adenylate cyclase-activating polypeptide (PACAP) type I (PAC1) receptor gene results in abnormal development of the SCO and vel cells, leading to congenital hydrocephalus (see the related article beginning on page 1924) [3].
• To investigate the molecular function of the SCO proteins, we characterized the mitochondrial copper delivery pathway in SCO1 and SCO2 patient backgrounds [5].
• Inhibin B levels were (mean +/- SEM) 238+/-32 pg/mL in men with normal spermatogenesis (n = 9), 102+/-18 pg/mL in men with spermatogenetic arrest (n = 15), 98+/-16 pg/mL in hypospermatogenesis (n = 23), 41+/-6 pg/mL in focal Sertoli cell-only syndrome (SCO; n = 26), and 27+/-8 pg/mL in complete SCO (n = 18) [6].
• In testes with SCO, high inhibin beta(B) subunit mRNA labeling density was observed in both Sertoli cells and Leydig cells, whereas beta(B) subunit immunostaining was negative for Sertoli cells and faintly positive for Leydig cells [7].

Biological context of SCO

• Considering also the size of the tubules, lumen and epithelia, a Y-chromosomal microdeletion represents an intermediate state between an idiopathic SCO and normal spermatogenesis [8].
• Testicular histology of two patients bearing distal Yq11 deletions showed two different spermatogenic defects including Sertoli cell-only (SCO) syndrome and maturation arrest, while the patient with microdeletions in the proximal Yq11 showed a SCO phenotype [9].
• Abnormal phenotypes included hypospermatogenesis, Sertoli cell-only (SCO) seminiferous tubules, germ-cell arrest and abnormal spermiogenesis and were accompanied, in some, with abnormal serum levels of reproductive hormones [10].
• Immunohistochemical methods localized the corresponding proteins in testicular biopsies from adult men (age range, 28-44 years) without testicular pathologies and from infertile patients with either Sertoli cell only (SCO) syndrome or severe hypospermatogenesis and germ cell arrest (GA) [11].
• In most tubules devoid of germinal cells (including SCO, Sertoli cell only syndromes) or lacking spermatocytes and spermatids, the Sertoli cells' nuclei showed a global increase in histone H4 acetylation [12].

Anatomical context of SCO

• As control groups we analysed testes from patients with idiopathic Sertoli cell-only (SCO) syndrome (n = 11), mixed atrophy (n = 10) and complete spermatogenesis (n = 11) [8].
• CONCLUSION(S): Differentiated germ cells are present in biopsies of men histologically diagnosed as SCO [13].
• Hybridization signals were found within the seminiferous epithelium exclusively in Sertoli cell cytoplasm associated with normal spermatogenesis and in epithelia showing different signs of impairment, including SCO [14].
• Immunoreactive cell bodies, as well as nerve fibers, were more readily detected in SCO and GA biopsies [11].
• Forelimb muscle mass-to-body mass ratio decreased by 27% with SCO but recovered with ECO [15].

Associations of SCO with chemical compounds

• This approach enabled identification of small focal concentrations of spermatogenesis in a biopsy previously classified as being SCO by hematoxylin and eosin staining [16].
• Results indicate an increase in activity as the oxygen-to-sulfur ratio increases (SO2 > SCO > CS2) with products ranging from association to break down of the met-car cluster [17].
• In VOO, the major constituents of the above analytical classes were, respectively, oleic acid, trilinolein, waxes C36, unsaturated volatile C6 aldehydes (trans-2-hexenal most markedly), and the same prominent sterols and superior alcohols found in SCO [18].
• In addition, the elevation in testicular MDA levels between the SCO and the moderate hypospermatogenesis, and the moderate hypospermatogenesis and the maturation arrest groups was significant (P<0.05) [19].
• RESULTS: Previous diagnostic Bx showed the following histopathological results: 5 patients with MA, 4 with Hypo and 5 SCO [20].

Other interactions of SCO

• The cytokeratin immunopositive-stained tubules were associated either with arrest in spermatogenesis or with SCO [1].
• The OAT or AZOO patients with Sertoli cell only syndrome (SCO) had mutations in the CFTR gene with similar frequencies to that in the general Polish population [21].
• The deletions in the AZF locus were detected in 20% of SCO patients, 11.5% of AZOO patients with maturation arrest and in 5% of CRYPTO patients [21].
• CONCLUSION: GDNF expression differs among patients with SCO [22].
• GPX activity was 177% greater in ECO than in SCO [15].

Analytical, diagnostic and therapeutic context of SCO

• In addition, by immunohistochemistry the cellular localization of the two subunits of inhibin B (alpha and betaB) were examined in adult testicular tissue with normal spermatogenesis, spermatogenic arrest, or Sertoli cell only tubules (SCO) as well as in normal testicular tissue from an infant and a prepubertal boy [23].
• SETTING: The Geriatric Rehabilitation inpatient unit of the SCO Health Service in Ottawa, Canada. PARTICIPANTS: One hundred ten patients, with a mean age of 82 years [24].
• BACKGROUND: Microdissection testicular sperm extraction (TESE) has provided new hope for successful sperm retrieval to patients with Sertoli cell-only syndrome (SCO) [22].
• INTERVENTIONS: Standard (SCO) and transpulmonary thermodilution CO measurement (TPCO) measurements were simultaneously performed in triplicate by central venous injection of cooled saline solution [25].
• The purpose of this study was to quantify the users' opinions of a SCO, and see whether factors found important for knee orthoses in past studies hold true for a stance control orthosis as well [26].

References