			Home About us Contact

Preservation Medium (preservation + medium)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Reduction of intramembranous particles in the periacrosomal plasma membrane of boar spermatozoa during in vitro capacitation: A statistical study

DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 3 2000
Fumie Suzuki-Toyota
Membrane remodeling in the periacrosomal plasma membrane (PAPM) of boar spermatozoa during incubation in capacitation medium was examined by the freeze-fracture technique. In the preservation medium (PM) group, the major small (about 8 nm) intramembranous particles (IMP) and the minor large (> 10 nm) IMP were distributed evenly in the PAPM. The IMP-free area increased during capacitation. To correct the IMP-free area, arithmetically redistributed (ARD)-IMP density was used for statistical analysis. In the PM group, the mean density ± SD of large IMP was 379 ± 64 and 266 ± 58/,m2, and that of small IMP was 1450 ± 155 and 672 ± 252/,m2 in protoplasmic (P) and external (E) faces, respectively. During capacitation, the significant (P < 0.01) reduction of large IMP density was encountered only in the E face of a few incubation groups, while that of the small IMP density occurred in the P face by 2 h. Consequently, reduction of the total IMP density of both faces was not significant in the large IMP, but it was significant (P < 0.01) in the small IMP. One-fifth of the total small IMP density reduced by 2 h. Filipin-sterol complexes (FSC) were numerous in the PAPM, and FSC-free areas also increased during capacitation. The mechanism of IMP-free area formation and the behavior of the small IMP in the PAPM during capacitation were discussed in relation to membrane stability. [source]

Cold liver ischemia-reperfusion injury critically depends on liver T cells and is improved by donor pretreatment with interleukin 10 in mice

HEPATOLOGY, Issue 6 2000
Olivier Le Moine M.D.
Kupffer cells are thought to mediate most of the deleterious effects of liver ischemia-reperfusion injury. The role of liver T cells and the impact of resident cell deactivation by interleukin 10 (IL-10) have never been addressed. Using a model of ex vivo liver cold ischemia and reperfusion, we assessed liver injury, tumor necrosis factor (TNF) and interferon gamma (IFN-,) release from livers of balb/c mice, nude mice, nude mice reconstituted with T cells, and gadolinium balb/c pretreated mice. The anti-inflammatory cytokine IL-10 was then used to define the best strategy of administration potentially able to modulate ischemia-reperfusion injury. For this purpose IL-10 was administered to the donor before liver harvesting, in the preservation medium during cold ischemia or during reperfusion. TNF and IFN-, were released time dependently and paralleled liver injury after reperfusion of cold preserved livers. Reperfused livers from nude or gadolinium pretreated mice disclosed a dramatic decrease in TNF and IFN-, release. Tissue injury was reduced by 51% in the absence of T cells and by 88% when Kupffer cells were deactivated. This effect was reverted by T-cell transfer to nude mice. Only donor pretreatment with IL-10 or IL-10 infusion during reperfusion led to a significant decrease in liver injury, TNF, and IFN-, release (,66% or ,41%, ,95% or ,94%, and ,70% or ,70%, respectively). In conclusion, liver resident T cells are critically involved in cold ischemia-reperfusion injury and pretreatment of the donor with IL-10 decreases liver injury and the release of T-cell, and macrophage-dependent cytokines. [source]

Presence of methylated arginine derivatives in orthotopic human liver transplantation: Relevance for liver function

LIVER TRANSPLANTATION, Issue 1 2003
Paloma Martín-Sanz
Orthotopic liver transplantation (OLT) is a frequent option in the treatment of liver diseases. During the cold ischemia period of the donor liver, there is an accumulation of metabolites that are potent inhibitors of the cytokine-inducible and endothelial nitric oxide synthase isoenzymes. We identified the presence of L - N -monomethylarginine and asymmetric dimethylarginine (ADMA) as the main inhibitors by means of analytic high-pressure liquid chromatography and mass spectrometry techniques. An average ADMA concentration of 450 ,mol/L was measured in the preservation medium of donor livers with poor outcomes after OLT. A statistically significant relationship was observed between the concentration of methylated arginine derivatives in the graft and liver function after OLT. These data suggest that measurement of methylated arginine, released after liver protein catabolism, might provide an indication of functional status of the liver that can help the development of strategies intended to improve graft viability. [source]

Association between freezing agent and acrosome damage of human spermatozoa from subnormal and normal semen

ANDROLOGIA, Issue 6 2001
M. E. Hammadeh
Summary. This experimental study compares the effects of human sperm preservation medium (HSPM) with TEST,yolk buffer (TYB) as cryoprotectants of human spermatozoa with respect to the integrity of the acrosome after the freeze,thawing procedure. Fifty-six semen samples were included in this study; 18 were subnormal (G1) and 38 were normal (G2) based on World Health Organization criteria, except for morphology, which was evaluated according to strict criteria. Each semen sample was divided into two parts: the first part was prepared for cryopreservation by the addition of HSPM (1:1) and the second by addition of TYB (1:1). Freezing was performed in liquid nitrogen vapour. Smears were made before freezing and after the thawing process for evaluation of acrosome integrity using fluorescent-lectin labelling. The mean percentage of spermatozoa with intact acrosomes in the subnormal group was 77.0 ± 7.2% before freezing and decreased significantly (P < 0.001) after thawing: to 63.7 ± 8.2% with the use of HSPM and 66.8 ± 8.7% with the use of TYB. The corresponding values in the normal semen samples were 83.4 ± 9.2%, 76.0 ± 8.8% and 77.9 ± 9.2%, respectively. It is obvious that the decrease in the mean percentage of spermatozoa with intact acrosome was significantly higher when using HSPM in comparison with TYB, not only for G1 (,14.9 ± 1.9% versus ,11.8 ± 1.4%) but also for G2 samples (,13.8 ± 1.5% versus ,11.9 ± 1.3%). In conclusion, TYB should be recommended for freeze,thawing of human spermatozoa as the first-choice cryoprotectant, for normal as well as subnormal semen samples, in order to protect the sperm acrosome from the deleterious effects of the freeze,thawing procedure. [source]