Clean-Up Human Embryonic Stem Cell Lines Using Humanized Culture Condition

Human embryonic stem cell (hESC) culture system has been changing culture conditions from conventional to xeno-free for therapeutic cell applications, and N-glycolylneuraminic acid (Neu5Gc) could be a useful indicator of xenogeneic contaminations in hESCs because human cells can no longer produce it genetically. We set up the humanized culture condition using commercially available humanized materials and two different adaptation methods: sequential or direct. SNUhES4 and H1 hESC lines, previously established in conventional culture conditions, were maintained using the humanized culture condition and were examined for the presence of Neu5Gc. The hESCs showed the same morphology and character as those of the conventional culture condition. Moreover, they were negative for Neu5Gc within two passages without loss of pluripotency. This study suggested that this method can effectively cleanse previously established hESC lines, bringing them one step closer to being clinical-grade hESCs.

Human Amniotic Fluid Cells Support Expansion Culture of Human Embryonic Stem Cells / 대한불임학회지

OBJECTIVE: This study was performed to evaluate the possibility of prolonged culture of human embryonic stem cells (hESC; SNUhES2) on human amniotic fluid cells (hAFC), which had been storaged after karyotyping. METHOD: The hAFC was prepared for feeder layer in the presence of Chang's medium and STO medium (90% DMEM, 10% FBS) at 37degrees C in a 5% CO2 in air atmosphere. Prior to use as a feeder layer, hAFC was mitotically inactivated by mitomycin C. The hESCs on hAFC were passaged mechanically every seven days with ES culture medium (80% DMEM/F12, 20% SR, bFGF). RESULTS: The hAFC feeder layer support the growth of undifferentiated state of SNUhES2 for at least 59 passages thus far. SNUhES2 colonies on hAFC feeder appeared slightly angular and flatter shape as compared with circular and thicker colonies observed with STO feeder layer and showed higher level with complete undifferentiation in seven days. Like hESC cultured on STO feeders, SNUhES2 grown on hAFC expressed normal karyotype, positive for alkaline phosphatase activity, high telomerase activity, Oct-4, SSEA-3, SSEA-4, Tra-1-60 and Tra-1-81 and formed embryoid bodies (EBs). CONCLUSION: The hAFC supports undifferentiated growth of hESC. Therefore, these results may help to provide a clinically practicable method for expansion of hESC for cell therapies.

Prenatal Aneuploidy Detection in Uncultured Amniotic Fluid Interphase Cells by Fluorescence in situ Hybridization (FISH) / 대한불임학회지

OBJECTIVE: The aim of the present study was to evaluate the clinical efficiency of fluorescent in situ hybridization (FISH) in the prenatal diagnosis of chromosomal aneuploidy. METHODS: We reviewed data of 268 cases to identify women undergoing genetic amniocentesis at cytogenetic laboratory, from January 2000 to December 2002. Amniotic fluid was submitted for both rapid FISH on uncultured interphase amniocytes using a commercially available DNA probe for chromosome 13, 18, 21, X, Y and standard karyotyping on cultured metaphase amniocytes. Results from FISH and full karyotype were compared. RESULTS: There were 251 cases (84%) normal and 17 cases (16%) abnormal in FISH results. All 17 cases of trisomy 13, 18, 21 including two cases of mosaicism and sex chromosome aneuploidies which are detected by FISH were confirmed with conventional cytogenetics and there was no false positive result. Twenty two cases had karyotypically proven abnormalities that could not have been detected by the targeted FISH. CONCLUSION: Interphase FISH analysis of uncultured amniotic fluid cells has been shown to be an effective and reliable technique for rapid fetal aneuploidy screening during pregnancy as an adjunctive test to conventional cytogenetics.

Fragile X Premutation in Patients with Idiopathic Premature Ovarian Failure / 대한산부인과학회잡지

OBJECTIVE: To explore the incidence of fragile X premutation in patients with idiopathic premature ovarian failure, particularly in the Korean population. DESIGN: A prospective study. MATERIALS AND METHODS: Eighty-three women affected by idiopathic premature ovarian failure were recruited for this study. Patient with known causes of premature ovarian failure were excluded: cytogenetic abnormalities, prior chemotherapy, prior bilateral oophorectomy. DNA was extracted from peripheral blood. Fragile X (FRAXA) premutation was evaluated by PCR amplification of and Southern blot analysis for FMR1 gene. RESULTS: The FRAXA premutation was detected in three (3.6%) out of 83 patients with idiopathic premature ovarian failure. CONCLUSION: This result suggests that fragile X premutation screening is indicated in patients with idiopathic premature ovarian failure, particularly in the Korean population.

Detection of Y Chromosome-specific Sequences in Patients with Turner Syndrome / 대한산부인과학회잡지

Existence of Y derived chromosome in Turner patients is significant due to the risk of gonadoblastoma development, but cytogenetic analysis may fail to detect low levels of Y chromosomal materials. Recent studies using PCR based methods showed higher sensitivity to detect Y-specific sequences, in patients who were Y chromosome-negative cytogenetically. In this study PCR was performed on 44 Turner patients with no Y chromosome by cytogenetic analysis to detect the SRY, AMELY, ZFY, and DYZ1 sequences. Of seven patients whose karyotypes were 45,X/46,X,+mar, three patients were positive for SRY, ZFY, and AMELY. DYZ1 sequences was negative in them. And any of SRY, ZFY, AMELY, and DYZ1 sequences was detected in the remaining 37 patients. This result shows that PCR analysis for Y-specific sequences in Turner patients, especially in patients who have marker chromosome is a significant effort.