MHC Expression in Human Embryonic Stem Cells and Embryoid Bodies / 대한이식학회지

PURPOSE: Human embryonic stem (ES) cell is pluripotent cell derived from a group of cells called the inner cell mass and has the ability to reproduce itself for long periods and give rise to types of cells that develop from the three germ layers. Due to its pluripotency, ES cell holds the promise of being able to replace cells that are damaged or destroyed by many devastating diseases. However, the potential for the recipient of an ES cell transplant to reject this cell as foreign is very high. Thus, it is essential to determine whether human ES cells express MHC antigens. The purpose of this study is to characterize the stem cell properties of our cell line (SNUhES1) and the expression profile of MHC antigens on the surface of these cells and their differentiated derivatives, embryoid bodies (EBs). METHODS: The ES cells were grown on STO fibroblast in DMEM-F12. The EBs were grown in the same medium with exception that it lacked LIF and bFGF. The expression of self-renewal-associated genes and three germ layer cell-specific genes in ES cells and EBs were measured by RT-PCR at varying time point of incubation (1, 7, 14 and 28 day). The expression of MHC molecules were measured by RT-PCR and FACS analysis. RESULTS: The SNUhES1 cells expressed all self-renewal- associated genes (Fgf4, FoxD3, Oct4, Sox2 and TERT) we tested. During the differentiation three germ layer cell-specific genes in EBs were expressed as following order: ecto-, meso- and endodermal cell-specific genes. MHC class I proteins (HLA-ABC and beta2m) on the surfaces of ES cells and EBs were expressed in very low levels. MHC class II proteins (HLA-DP, -DQ and -DR) and HLA-G were not expressed on the surface of these cells. However, the expression of MHC class II proteins were detected in 1% more or less cells of 28-day-old EBs which were hardly detected in the population of 1-day-old EBs. CONCLUSION: These data imply that SNUhES1 cells and EBs have stem cell properties. Although they express very low MHC antigens, further investigation determining whether the MHC expression in the ES cells and EBs may alter under inflammatory condition which can be occurred in damaged tissue or through surgical process.

Relationship between total IgE and Epstein Barr virus infection during infancy and early childhood / 천식및알레르기

BACKGROUND: The 'hygiene hypothesis', the apparent inverse relationship between certain childhood infections and the subsequent development of asthma and atopy, has been gaining attention and is currently now considered one of the most plausible explanations for the cause of asthma and atopy currently. OBJECTIVE: We tried to evaluate the relationship between Epstein Barr virus infection in infancy and early childhood with total IgE, the hallmark of atopy. with these results, we observed the changing pattern of total IgE levels according to the ages that EBV infection occured. METHODS: The study population, a total of 75 patients were divided by age: under 2 years of age, under 3 years of age, under 4 years of age and then they were divided into the two groups : EBNA negative and EBNA positive groups. EBNA and IgE were measured by ELISA and CLA respectively. We analyzed the relationships between age, sex, family history, atopic predisposition, total eosinophils, log IgE, and positivity of EBNA stastically. RESULTS: Prevalence of EBNA positivity was 26% in children 1-3 years of age. Among the six variables, log IgE showed statistically significant difference in the two groups under 2 years of age and under 3 years of age. In the group of under 2 years of age, mean log IgE in EBNA positive group was 0.7 IU/mL and EBNA negative group was 1.3 IU/mL, these differences were significant statistically (p<0.05). In the group of under 3 years of age , mean log IgE in EBNA positive group was 0.8 IU/mL and EBNA negative group was 1.5 IU/mL, these differences were statistically significant(p<0.05). CONCLUSION: This study showed that Ebstein Barr virus infection before 3 years of age is associated with lower log IgE. This means that there is a possibility of a negative influence in the prevalence of allergic disease by EBV infection in children before 3 years of age.

Estimation of the Possible Age for Using Various Types of Inhaler by In-Check Inspiratory Flow Meter(TM)

PURPOSE: It is important to select and use kinds of Inhaler appropriate to the age of the patient and severity of symptoms. Several kinds of Inhaler have been developed and recommended according to each inhaler's resistance and usage method. We evaluated the usable age of 4 inhalers (turbulent flow inhalers, multi unit dose inhalers, breath actuated MDI, and autohalers) by measuring peak inspiratory flow(PIF) using In-Check(TM) Inspiratory Flow Meter. METHODS: Ninety three patients aged from 3 to 7 years(mean 57+/-12.9 mo.) who had admitted to CHA hospital from July 2000 to April 2001 were enrolled. Study patients were divided into 4 groups according to age:3-4 years of age(group A, n=31), 4-5 years of age(group B, n=32), 5-6 years of age(group C, n=18), and 6-7 years of age(group D, n=12). RESULTS: Out of total 93 patients, 23(71%), 27(84%), 17(94%) patients of each group A, B, C and all 12 patients of group D could use the 4 types of inhaler through adequated education. In all four groups, height, body weight and age were significantly correlated(P<0.05). Usable age, height and weight of children who can use turbulent flow inhaler(TFI) were each 8 year 7 month old, 144 cm, 32.0 kg, and those of multi unit dose inhaler(MUD) were 2 year 10 month old, 92 cm, 12.0 kg. Also that of breath-actuated MDI were 1 yr 8 months, 83 cm, 8.5 kg and that of autohaler were 2 yr 8 months, 91 cm, 11.0 kg. CONCLUSION: We concluded that the ability to use inhalers correlated with height, weight and age of the patients. Multi unit dose inhalers, Breath actuated MDI and Autohaler are useful after 3 years of age through adequate education.