Generation of megakaryocytic progenitors from human embryonic stem cells in a feeder- and serum-free medium.

Background: The production of human platelets from embryonic stem cells in a defined culture system is a prerequisite for the generation of platelets for therapeutic use. As an important step towards this goal, we report the differentiation of human embryonic stem cells (hESCs) towards the megakaryocyte (Mk) lineage using a 'spin embryoid body' method in serum-free differentiation medium.

Methodology And Principal Findings: Immunophenotypic analyses of differentiating hESC identified a subpopulation of cells expressing high levels of CD41a that expressed other markers associated with the Mk lineage, including CD110, CD42b and CD61.

Supersensitive fluorescent semen analysis: validation on azoospermic and oligozoospermic samples.

Objective: To compare the clinical utility of a supersensitive fluorescent semen analysis (SSSA) procedure published by Cooper et al. (2006) with a conventional World Health Organization (WHO)-based semen analysis technique in males with severe oligozoospermia or azoospermia who are undergoing fertility assessment.

Design: Prospective single-center study.

A QF-PCR system to detect chromosome 13 aneuploidy from as few as ten cells.

Complete and partial trisomies of chromosome 13 are characterized by abnormal fetal development and birth defects. Despite the severe abnormalities associated with trisomy 13, some couples elect not to undergo invasive prenatal diagnosis (PND) due to the 0.5%-1.