Peter T K Chan

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The luminal environment along the epididymal duct is important for spermatozoal maturation. This environment is unique and created by the blood-epididymal barrier, which is formed by tight and adhering junctions. For the human epididymis, little information exists on the proteins that comprise these junctions. Our objectives were to assess the gene(More)
Human spermatogonial stem cells (SSCs) play critical roles in lifelong maintenance of male fertility and regeneration of spermatogenesis. These cells are expected to provide an important resource for male fertility preservation and restoration. A basic strategy has been proposed that would involve harvesting testis biopsy specimens from a cancer patient(More)
BACKGROUND Testicular cancer and Hodgkin's disease are among the most common malignancies to affect young men of reproductive age. Although both are associated with high rates of infertility, sperm banking (SB) remains underutilized by both diagnostic groups. Reasons for this remain elusive. METHODS This study used a qualitative design. In-depth(More)
Seminal oxidative stress occurs when there is an increased production of reactive oxygen species (ROS) and/or a decrease of antioxidant activity, promoting impaired sperm function. Peroxiredoxins (PRDX) are abundant in human semen and are important antioxidant enzymes, which act as ROS scavengers and modulators in ROS-dependent signaling. Our aim was to(More)
The epididymis is responsible for posttesticular sperm maturation. Sperm maturation is dependent on the luminal microenvironments along the epididymis. Though the role of the epididymis is well established, the molecular and cellular mechanisms responsible for sperm maturation remain to be elucidated, particularly in the human, as limited biological tools(More)
OBJECTIVE To prospectively analyse the outcomes of microsurgical vasoepididymostomy using the intussusception technique, as vasoepididymostomy is considered the most challenging reconstructive microsurgery in urology. PATIENTS AND METHODS From 1998 to 2003, of 324 men with obstructive azoospermia who had undergone microsurgical reconstruction of the(More)
PURPOSE Vasoepididymostomy remains one of the most technically challenging procedures in all of microsurgery. The technique has evolved from an end-to-end, to an end-to-side technique, then to intussusception end-to-side methods. We recently reported the superiority of 2-suture longitudinal and 3-suture triangulation intussusception techniques in rats. In(More)
OBJECTIVES Vasoepididymostomy outcomes are heavily dependent on the surgeon's microsurgical experience and skill. To avoid back-walling the tubular lumen, the needles are generally placed inside-out through the vasal lumen using double-armed microsutures. These double-armed sutures for infertility microsurgery are very expensive and may be difficult to(More)
OBJECTIVE To investigate whether there are intra-individual and/or inter-individual variations in sperm aneuploidy frequencies within the normal male population, and, if this is the case, whether they are sporadic or time-stable variants. DESIGN Prospective study. SETTING University research laboratory. PATIENT(S) Ten men aged 18-32 years. (More)
PURPOSE The objective of our study was to evaluate the reproductive outcome of male cancer survivors treated with intracytoplasmic sperm injection (ICSI) using cryopreserved sperm and compare it with the same treatment in non-cancer males. METHODS We retrospectively analyzed database derived from cancer and non-cancer patients undergoing sperm(More)