Platelet-activating factor (PAF) is a potent proinflammatory negotiator that shows a distinct spectrum of biological and pharmacological effects and participates in a wide range of pathophysiological conditions. In the reproductive system, PAF has been shown to have an important role in initiating ovulation, progesterone production and chemokine production. The purpose of this article was to review the roles of PAF, a well-known family of messenger phospholipids, in the reproductive process, especially in ovulation. This review highlights the interesting parallels between PAF's mechanism in ovulation and inflammatory process.

The mammalian zona pellucida (ZP) is an extracellular matrix that surrounds ovarian oocytes, ovulated eggs, and preimplantation embryos, and it plays several important roles at different stages of reproduction. Newly developed technologies such as transgenic mouse production, database analysis of signal networks, and live-cell imaging have revealed novel findings about the ZP and fertilization. Assisted reproductive technology has also provided new insights into human ZP morphology and function. Recent micromanipulation technologies such as intracytoplasmic sperm injection, are very helpful for treatment of ZP-related infertility. This article describes the current understanding of the following aspects of the mammalian ZP: I) ZP structure, II) ZP functions, III) ZP-related infertility and IV) ZP-based immunocontraceptive vaccines.

The combination of ICSI and a sperm chromosome assay provides a useful opportunity to directly investigate relationships between chromosomal aberrations and head morphology, motility or in vitro aging. An increase of aneuploidy was identified in sperm with large heads. Structural chromosome aberrations were frequently found in elongated heads. These types of sperm should therefore be avoided for ICSI and can easily be identified under a microscope. In sperm with normal heads, the chromosomal aberration rate was initially low but increased gradually after removal of the seminal plasma (3.3% to 15.9%); in immotile sperm, the increase of DNA damage was more pronounced (4.5% to 48.1%). Therefore, there are motile and immotile sperm populations in human ejaculates that are potentially vulnerable to in vitro culture conditions. Since these sperm can maintain DNA integrity in the seminal plasma for at least 3 h, and even after cryopreservation, the seminal plasma appears to be an efficient suppressor of DNA damage. We report here our attempts at using ICSI using sperm stored in the seminal plasma (SP-ICSI) to treat infertile patients with normozoospermia and provide data to confirm the safety of this technique. For poor quality semen, SP-ICSI may be more effective in achieving a successful outcome.

Implantation is essential for successful reproduction. In humans, uterine receptivity is restricted to the mid-secretory phase, days 19 to 24 of the menstrual cycle; and this period is called the window of implantation (WOI). Large populations of decidual leukocytes infiltrate the implantation site, and the levels of cytokines, prostaglandins (PGs), and leukocytes are up-regulated in the endometrium during implantation. Implantation is like a local wound healing process which is characterized by a strong Th1, pro-inflammatory response in which high levels of pro-inflammatory cytokines such as IL-6, LIF, IL-8, and TNFα are involved. In addition, cyclooxygenase (COX)-2 expression increases between days 2 to 5, suggesting that PGs are necessary for the process of stromal cell decidualization in early pregnancy. Recently, it was reported that endometrial biopsies taken during spontaneous cycles that preceding IVF treatment improved the rate of implantation, clinical pregnancies, and live births in patients with recurrent implantation failure. These results suggest an ininflammatory environment is not adequately induced in some IVF patients with recurrent implantation failure in the absence of local injury provoked by biopsy treatment, further suggesting that uterine receptivity is mediated by the expression of molecules associated with a pro-inflammatory process.