Triphenyltin chloride induces spindle microtubule depolymerisation and inhibits meiotic maturation in mouse oocytes.

Meiosis produces haploid gametes for sexual reproduction. Triphenyltin chloride (TPTCL) is a highly bioaccumulated and toxic environmental oestrogen; however, its effect on oocyte meiosis remains unknown. We examined the effect of TPTCL on mouse oocyte meiotic maturation in vitro and in vivo. In vitro, TPTCL inhibited germinal vesicle breakdown (GVBD) and first polar body extrusion (PBE) in a dose-dependent manner. The spindle microtubules completely disassembled and the chromosomes condensed after oocytes were exposed to 5 or 10µgmL(-1) TPTCL. γ-Tubulin protein was abnormally localised near chromosomes rather than on the spindle poles. In vivo, mice received TPTCL by oral gavage for 10 days. The general condition of the mice deteriorated and the ovary coefficient was reduced (P<0.05). The number of secondary and mature ovarian follicles was significantly reduced by 10mgkg(-1) TPTCL (P<0.05). GVBD decreased in a non-significant, dose-dependent manner (P>0.05). PBE was inhibited with 10mgkg(-1) TPTCL (P<0.05). The spindles of in vitro and in vivo metaphase II oocytes were disassembled with 10mgkg(-1) TPTCL. These results suggest that TPTCL seriously affects meiotic maturation by disturbing cell-cycle progression, disturbing the microtubule cytoskeleton and inhibiting follicle development in mouse oocytes.

Non-chimerism and chimerism pseudo dicentric Y chromosome: two case reports about azoospermia and cytogenetic/molecular genetic analysis in the Chinese population.

OBJECTIVE: To report the cytogenetic and molecular genetic analysis of the first two cases of non-chimerism and chimerism karyotype in Chinese male patients who suffer from azoospermia, which may be caused by pseudo dicentric Y chromosomes. DESIGN: Case study. SETTING: Academic reproductive medicine center. PATIENTS: Two male patients with azoospermia, carrying pseudo dicentric Y chromosome. INTERVENTIONS: Review the records of inquiry, testicular biopsy, pathological examination, semen routine examination, endocrine evaluation, cytogenetic chromosomal analysis, and FISH detection of peripheral blood to evaluate Y chromosome deletion. MAIN OUTCOME MEASURES: To investigate the possible association among pseudo dicentric Y, chimeric status and azoospermia. RESULTS: Two patients were both diagnosed with azoospermia by a variety of andrology inspections. Further chromosomal analysis and FISH indicated their pseudo dicentric Y chromosome and different chimerism status. PCR confirmed simultaneous deletions of AZFb and AZFc regions in the Y chromosome of both patients. CONCLUSIONS: Pseudodicentric Y chromosome affecting the long arm may lead to a male phenotype by duplicating the sex-determining region of Y chromosome (SRY) fragment and chimeric status may further impact patient's hormone levels, which obstruct spermatogenesis. However, the deletion of the azoospermia factor (AZF) is likely the key factor that causes azoospermia.

[Sperm selection in assisted reproductive technology: an update].

Sperm selection plays an important role in assisted reproductive technology. In recent years, sperm evaluation is not limited to the assessment of sperm motility and morphology, but involves more other sperm characteristics such as sperm ultrastructure, DNA integrity, apoptosis and membrane. Assessment based on these characteristics is becoming the aim of sperm selection. This article gives an overview on several newly developed techniques for sperm selection according to different technical principles, such as electrophoretic separation, zeta potential, HA binding, Annexin V binding, intracytoplasmic morphologically selected sperm injection (IMSI) and microfluidic sperm sorter, which have all been applied to IVF or ICSI with the exception of microfluidic sperm sorter. It also introduces the advantages, disadvantages and application effects of these techniques.

[Ring 22 chromosome syndrome induced azoospermia: a case report and literature review].

OBJECTIVE: To investigate the clinical phenotype and genetic characteristics of an azoospermia patient with ring 22 chromosome syndrome. METHODS: We analyzed the clinical data of an azoospermia patient with ring 22 chromosome syndrome and reviewed relevant literature. RESULTS: The patient was a short 29-year-old male, with bilateral testes small in size and soft in texture. Seminal examination indicated azoospermia. Chromosome analysis showed the karyotype of the patient to be 46, XY, r (22) (p11, q25). The level of testosterone was low, and the testicular tissue was brittle and easy to break. Pathological microscopy revealed reduced number of Sertoli cells and germ cells in the seminiferous tubules and thinner layers of cells. All the germ cells were spermatogonia. Neither spermatocytes nor sperm cells were found, which suggested complete spermatogenic failure. Mild interstitial fibrosis was visible in part of the seminiferous tubule walls. CONCLUSION: Patients with ring 22 chromosome syndrome usually represent normal clinical phenotypes. However, this kind of genetic abnormality often induces severe testicular damage and spermatogenic arrest, which may result in azoospermia.

[Globozoospermia syndrome: an update].

Globozoospermia syndrome is a rare teratozoospermia, with an incidence of less than 0.1%. It is characterized by round sperm head, absence of acrosome, and messy sperm body and tail, but without other special clinical features. The absence of acrosome could reduce the activation ability of oocytes, and consequently decrease their fertilization ability. The assisted reproductive technique remains the only means for such patients to produce offspring. The pathogenesis of globozoospermia syndrome is not yet clear, though it is found to be related with 4 genes in the mouse and 1 on the human autosome. This article gives an overview on the clinical features, pathogenesis and genetics of globozoospermia syndrome, as well as the fertilizability and reproductivity of such patients.

[Congenital adrenal hyperplasia complicated by testicular adrenal rest tumors: one-case clinical analysis].

OBJECTIVE: To investigate the early diagnosis and treatment of congenital adrenal hyperplasia (CAH) complicated by testicular adrenal rest tumors (TART). METHODS: We retrospectively analyzed the clinical data of 1 case of late-onset CAH complicated by TART diagnosed and treated in Xiamen Women and Children Health Care Hospital. RESULTS: The patient was a 15 years old boy, short statured and dark skinned, with skin pigmentation in the gum and external genital, secondary sex characteristics of the adult and irregular tubercles palpable in the bilateral testes. Laboratory examinations showed obviously increased levels of ACTH, 17-KS, DHEA-S and progesterone and evidently decreased levels of FSH, LH and CO. The low-dose dexamethasone suppression test reduced ACTH and DHEA-S to normal. Imaging examinations revealed soft tissue density in the bilateral adrenal glands, especially on the right, and irregularly increased volume of the bilateral testes, particularly on the left, with heterogeneous signals and septas and surrounded by the fluid signals. Histopathological examinations showed the eosinophilic cytoplasm to be polygon- or round-shaped, interstitium-like cells arranged in line, and lipopigment in the endochylema. Immunohistochemical results were negative for testicular interstitial cell tumor. The clinical signs of the patient were improved after 3 months of dexamethasone treatment, the hyperplastic nodules in the left testis decreased obviously and those in the right testis disappeared after 6 months, and the hyperplastic nodules in the adrenal glands vanished after 9 months. CONCLUSION: Based on the clinical manifestations and the results of auxiliary examinations, this case was diagnosed as late-onset CAH complicated by TART, which was attributed to the continued surge of ACTH induced by corticoadrenal insufficiency. Sufficient dexamethasone treatment could make the TART decrease or disappear and the CAH vanish; it could also improve the clinical symptoms and bring the laboratory results to normal.

A Case of Bilateral Testicular Tumors Subsequently Diagnosed as Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency.

21-hydroxylase deficiency (21-OHD) caused congenital adrenal hyperplasia (CAH) is a group of autosomal recessive genetic disorders resulting from mutations in genes involved with cortisol (CO) synthesis in the adrenal glands. Testicular adrenal rest tumors (TARTs) are rarely the presenting symptoms of CAH. Here, we describe a case of simple virilizing CAH with TARTs, in a 15-year-old boy. The patient showed physical signs of precocious puberty. The levels of blood adrenocorticotropic hormone (ACTH), urinary 17-ketone steroids (17-KS), dehydroepiandrosterone sulfate (DHEA-S), and serum progesterone (PRGE) were elevated, whereas those of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and CO were reduced. Computed tomography (CT) of the adrenal glands and magnetic resonance imaging (MRI) of the testes showed a soft tissue density (more pronounced on the right side) and an irregularly swollen mass (more pronounced on the left side), respectively. Pathological examination of a specimen of the mass indicated polygonal/circular eosinophilic cytoplasm, cord-like arrangement of interstitial cells, and lipid pigment in the cytoplasm. Immunohistochemistry results precluded a diagnosis of Leydig cell tumors. DNA sequencing revealed a hackneyed homozygous mutation, I2g, on intron 2 of the CYP21A2 gene. The patient's symptoms improved after a three-month of dexamethasone therapy. Recent radiographic data showed reduced hyperplastic adrenal nodules and testicular tumors. A diagnosis of TART should be considered and prioritized in CAH patients with testicular tumors. Replacement therapy using a sufficient amount of dexamethasone in this case helps combat TART.

Axin-1 Regulates Meiotic Spindle Organization in Mouse Oocytes.

Axin-1, a negative regulator of Wnt signaling, is a versatile scaffold protein involved in centrosome separation and spindle assembly in mitosis, but its function in mammalian oogenesis remains unknown. Here we examined the localization and function of Axin-1 during meiotic maturation in mouse oocytes. Immunofluorescence analysis showed that Axin-1 was localized around the spindle. Knockdown of the Axin1 gene by microinjection of specific short interfering (si)RNA into the oocyte cytoplasm resulted in severely defective spindles, misaligned chromosomes, failure of first polar body (PB1) extrusion, and impaired pronuclear formation. However, supplementing the culture medium with the Wnt pathway activator LiCl improved spindle morphology and pronuclear formation. Downregulation of Axin1 gene expression also impaired the spindle pole localization of γ-tubulin/Nek9 and resulted in retention of the spindle assembly checkpoint protein BubR1 at kinetochores after 8.5 h of culture. Our results suggest that Axin-1 is critical for spindle organization and cell cycle progression during meiotic maturation in mouse oocytes.