Vitrification of a small number of spermatozoa in normozoospermic and severely oligozoospermic samples.

Despite broad utilization of sperm cryopreservation, little progress has been made to modify freezing protocols or to improve rates of sperm survival. Vitrification is an alternative method for freezing human spermatozoa without toxic permeable cryoprotectants (CPAs). The purpose of our study was to optimize the vitrification and post thaw recovery of a small number of spermatozoa using only nonpermeating CPAs in a closed straw system in normozoospermic and severely oligozoospermic samples.

Ontogeny of human umbilical cord perivascular cells: molecular and fate potential changes during gestation.

Human umbilical cord-derived perivascular cells (PVCs) are a recently characterized source of mesenchymal stromal cells that has gained much interest in the field of cellular therapeutics. However, very little is known about the changes in fate potential and restrictions that these cells undergo during gestational development. This study is the first to examine the phenotypic, molecular, and functional properties of first trimester (FTM)-derived PVCs, outlining properties that are unique to this population when compared to term (TERM) counterparts.

The three-dimensional image analysis of the chromocenter in motile and immotile human sperm.

Chromosomes in human spermatozoa are arranged non-randomly with the centromeres of non-homologous chromosomes forming a chromocenter. We have compared motile and immotile sperm populations in normozoospermic patients to determine if there is any dissimilarity in the formation of the chromocenter and the nuclear position of chromosome 17. Based on the differences between motile and immotile populations, we propose for the 'optimal' nuclear organization to be defined as containing 1 to 3 chromocenter(s) with central radial and median longitudinal position for the centromere of chromosome 17.

Acrosomal status and mitochondrial activity of human spermatozoa vitrified with sucrose.

This study investigates the ability of sucrose to protect spermatozoa against mitochondrial damage, artificial cryoinduction of capacitation, and acrosome reaction. Spermatozoa were isolated using the swim-up procedure performed using three different media: (a) human tubal fluid (HTF, control) medium; (b) HTF with 1% human serum albumin (HSA); and (c) HTF with 1% HSA and 0.25 M sucrose.

Vitrification of human laser treated blastocysts within cut standard straws (CSS): novel aseptic packaging and reduced concentrations of cryoprotectants.

Vitrification of laser treated human blastocysts using reduced concentrations of permeable cryoprotectants was carried out by submerging cut standard straws (CSS) into liquid nitrogen. The CSS were made by cutting a standard 0.25 ml straw at an angle of approximately 45 degrees .