The mammalian zona pellucida is an extracellular matrix that occurs in growing oocytes, ovulated eggs and pre-implantation embryos, and is known to be involved in several important events during ovarian folliculogenesis and fertilization. Since the zona pellucida is formed at an early stage of oocyte growth, circulating antibodies against zona pellucida may impair ovarian function. In this arti...

This paper deals with the transient analysis of K-out-of-N: G system consisting of Noperatingmachines. To improve system reliability, Y cold standby and S warm standbys spares areprovided to replace the failed machines. The machines are assumed to fail in multiple modes. At leastK-out-of-N machines for smooth functioning of the system. Reliability and mean time to failure areestablished in term...

OBJECTIVES The objectives were to determine the time course for ovarian failure in rats caused by 4-vinylcyclohexene diepoxide (VCD) and develop a model for ovarian cancer in which ovarian neoplasms were chemically induced in an animal that was follicle depleted, but retained residual ovarian tissue. METHODS Initially, female Fisher 344 rats were treated with VCD (to induce ovarian failure) o...

OBJECTIVE To determine the frequency and causes of preterm ovarian failure (menopause before 40 years of age) and early menopause (menopause between 40 and 45 years). DESIGN Cross sectional study. SETTING Menopause clinics in Italy. POPULATION Women attending menopause clinics in Italy. METHODS Between 1997 and 1999 we conducted a large cross sectional study on the characteristics of wo...

Ovarian failure leading to infertility can be caused by improper prenatal development of the fetal gonad or disruption of the complex postnatal process of folliculogenesis due to alterations in intragonadal or extragonadal regulation. It is critical to have physiological models that mimic events occurring during human development to understand, treat, and prevent ovarian failure in women. Many ...

Premature ovarian failure has an overall prevalence of 0.3% to 0.9% in general population. If fertility is a concern, treatment usually consists of estrogen therapy as hormone replacement and oocyte donation. Spontaneous pregnancy in affected women is uncommon. We report a case of a 34-year old woman, who had premature ovarian failure and primary hypothyroidism, and conceived spontaneously elev...