In vitro Development of Zona Pellucida-free Porcine Zygotes Cultured Individually after Vitrification.

BACKGROUND: Cryopreservation of zona pellucida (ZP)-free embryos provides more options for somatic cell nuclear transfer, particularly during handmade cloning. OBJECTIVE: This study investigated whether the removal of the ZP affects the development of porcine zygotes after vitrification and warming. MATERIALS AND METHODS: We determined the appropriate volume of the corresponding medium for the individual culture of ZP-intact and -free embryos and evaluated the protection effect of ZP during cryopreservation on the resulting development of the vitrified-warmed zygotes. RESULTS: The volume of culture medium influenced the development of ZP-intact zygotes, and a volume of 15 µL was most suitable for their development. However, the volume of culture medium did not modify the development of ZP-free zygotes. The removal of the ZP before vitrification did not adversely affect embryonic development or quality of the resulting blastocysts. CONCLUSION: Our results suggest that the removal of the ZP does not cause detrimental effects to the development of vitrified-warmed zygotes.

Comparison of blood loss with different high-flux and high-efficiency hemodialysis membranes.

UNLABELLED: Iron deficiency is a common problem in patients on chronic HD. Earlier studies have shown significant blood loss per HD session. To identify whether the new more biocompatible high-flux or high-efficiency membranes are also responsible for significant blood loss during HD, we quantitated the amount of blood loss associated with 4 commonly used membranes (F-50, F-80, CA-210, and CT-190). The residual blood in each compartment of extracorporeal circuit was quantitated after total lysis of the red blood cells (RBC), hemoglobin assay, and calculation of the RBC volume using the patient's hemoglobin and hematocrit concentrations just prior to the study. The average residual RBC volume in different membranes was 0.2-0.3 ml. The residual RBC volume in the dialysis lines (arterial or venous) was 0.1-0.2 ml and did not correlate with the residual RBC volume in the dialysis membranes. The residual RBC volume in the whole extracorporeal circuit (HD membrane, arterial and venous lines) ranged from 0.5 to 0.6 ml. It was significantly higher with F-50 vs. CA-210. The residual RBC volume in the dialysis membrane was significantly higher in the F-80 vs. CA-210 and CT-190 dialyzers. There was also significant difference in the residual RBC volume in the arterial lines of F-50 vs. CT-190, and F-50 vs. F-80 dialyzers. CONCLUSION: Our results demonstrate for the first time that the total RBC loss per HD session is minimal in chronic HD patients.

Primary hyperoxaluria in an adult with renal failure, livedo reticularis, retinopathy, and peripheral neuropathy.

We present the case of a young woman who developed renal failure of unknown cause, and after 2 months of maintenance hemodialysis developed livedo reticularis, retinopathy, and peripheral sensory neuropathy. The patient was subsequently shown to have primary oxalosis type I, a rare autosomal recessive error of metabolism characterized by accumulation of calcium oxalate crystals in the kidneys, eyes, skin, and other organs. Intravascular obstruction, caused by deposition of calcium oxalate crystals in cutaneous arterioles, is thought to be responsible for the ischemic livedo reticularis lesions observed in this patient. A method is described for measuring serum glycolate by isotope dilution gas chromatography-mass spectrometry (GC-MS). An approach to the diagnosis and management is also briefly mentioned.