Biomedical subjects

Kyung Joon Cha

Publications and source records attributed to Kyung Joon Cha.

2 recordsLinked to original sources

PubMed2006

Profiling of differentially expressed genes in human stem cells by cDNA microarray.

Stem cells are unique cell populations with the ability to undergo both self-renewal and differentiation, although a wide variety of adult stem cells as well as embryonic stem cells have been identified and stem cell plasticity has recently been reported. To identify genes implicated in the control of the stem cell state as well as the characteristics of each stem cell line, we analyzed the expression profiles of genes in human embryonic, hematopoietic (CD34+ and CD133+), and mesenchymal stem cells using cDNA microarrays, and identified genes that were differentially expressed in specific stem cell populations. In particular we were able to identify potential hESC signature-like genes that encode transcription factors (TFAP2C and MYCN), an RNA binding protein (IMP-3), and a functionally uncharacterized protein (MAGEA4). The overlapping sets of 22 up-regulated and 141 down-regulated genes identified in this study of three human stem cell types may also provide insight into the developmental mechanisms common to all human stem cells. Furthermore, our comprehensive analyses of gene expression profiles in various adult stem cells may help to identify the genetic pathways involved in self-renewal as well as in multi-lineage specific differentiation.

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PubMed2005

The optimal depth of central venous catheter for infants less than 5 kg.

To avoid fatal complications of central venous catheterization such as cardiac tamponade, the tip of the central venous catheter (CVC) should be placed outside of the cardiac chamber. To suggest a guideline for a proper depth of CVC in infants, we measured the distance from the skin puncture site to the junction between superior vena cava and right atrium (SVC-RA junction) by using transesophageal echocardiography (TEE). Fifty infants less than 5 kg undergoing surgery for congenital heart disease were enrolled in this prospective study. After the induction of general anesthesia, CVC was inserted via the right subclavian vein. After the tip of the CVC was placed at the SVC-RA junction using TEE guidance, the length of the CVC inserted beneath the skin was measured. The measured distance had a high correlation with the patient's height, weight, and age (r = 0.88, 0.76, and 0.64, respectively). In infants smaller than 5 kg, the following guideline can avoid intraatrial placement of the CVC: a depth between 40 and 45 mm for infants 2.0-3.0 kg in weight, 45-50 mm for those 3.0-3.9 kg, and 50-55 mm for those more than 4.0 kg.

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