Background: in vitro maturation (IVM) of oocytes has increasing potential applications in assisted reproductive technology (ART), during which germinal vesicle (GV) oocytes cultured in vitro to produce mature (MII arrested) ones. Although functional, IVM oocytes have low developmental competence compared to in vivo matured oocytes; possibly because IVM comprises asynchrony between nuclear and c...

PURPOSE Multiple small case series have reported sperm in the ejaculate and spontaneous pregnancies in patients with nonobstructive azoospermia after varicocele repair. We hypothesized that men with favorable testicular histopathology on testis biopsy such as maturation arrest or hypospermatogenesis would have a higher probability of success than those with more ablative pathology, eg Sertoli-c...

Oocytes are released from meiotic prophase I arrest through a process termed oocyte maturation. We present here a genetic characterization of oocyte maturation, using C. elegans as a model system. We show that two TIS11 zinc finger-containing proteins, OMA-1 and OMA-2, express specifically in maturing oocytes and function redundantly in oocyte maturation. Oocytes in oma-1;oma-2 mutants initiate...

The developmental competence of oocytes during in vitro maturation (IVM) is compromised due to asynchronous nuclear and cytoplasmic maturation. To improve IVM efficiency, a pre-maturation culture or two-step maturation strategy has been established, involving meiosis arrest induced by pharmacological agents to provide oocytes with sufficient time to synchronize the maturation of the nucleus and...

Taraxacum officinale has been used in Jordan folk medicine to treat male infertility. A recent study has proved a contradictory effect of the whole plant aqueous extract. The aim of the current study was to determine if the leaves of T. officinale have similar anti-fertility activities, and whether this effect is mediated through the regulation of spermatogonial stem cells (SS...

Background: Oocyte maturation is usually defined as the period of progression from the first to the second meiotic arrest and involves coordinated nuclear and cytoplasmic modification. Ca2+ signals are known as important regulators of oocyte maturation. Extracellular Ca2+ is important for first polar body formation, normal meiosis kinetics, and for preserving the chromosome and spindle configur...

In human testes, stem cells such as spermatogonia need to produce progeny cells continually. Telomere length is maintained throughout spermatogenesis, i.e. from spermatogonia to spermatozoon, and telomerase is reported to be present in the testes. In this study, we measured the activity of telomerase in the human testes of 16 cases of idiopathic azoospermia, 10 of obstructive azoospermia, and 1...

The ability of Mycobacterium tuberculosis to grow in macrophages is critical to the virulence of this important pathogen. One way M. tuberculosis is thought to maintain a hospitable niche in macrophages is by arresting the normal process of phagosomes maturing into acidified phagolysosomes. The process of phagosome maturation arrest by M. tuberculosis is not fully understood, and there has rema...