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Biomedical subjects

Ji Hoon Kim

Publications and source records attributed to Ji Hoon Kim.

22 records · Page 2Linked to original sources

Differential expression of nephrin in acquired human proteinuric diseases.

BACKGROUND: The slit-diaphragm protein nephrin is an essential component of the glomerular filtration barrier. It is not clear whether renal injury in patients with acquired proteinuric diseases is associated with altered regulation of the nephrin gene or protein. METHODS: We examined expression patterns of nephrin protein and messenger RNA (mRNA) in renal biopsy specimens from patients with minimal lesion (n = 7), focal segmental glomerulosclerosis (FSGS; n = 14), or membranous nephropathy (MN; n = 7) and controls (n = 8) by immunohistochemistry, immunoelectron microscopy, in situ hybridization, and polymerase chain reaction (PCR) amplification of nephrin complementary DNA. RESULTS: In normal kidney, nephrin staining showed a diffuse interrupted linear pattern along the glomerular basement membrane (GBM). Nephrin staining in minimal lesion specimens showed a finely granular pattern along the GBM and was positive in cell bodies of visceral glomerular epithelial cells. Nephrin staining was most disrupted in FSGS specimens. Immunoelectron microscopy showed that nephrin-specific gold particles were almost absent in effaced foot processes in proteinuric patients. An in situ hybridization study showed significantly decreased nephrin mRNA-expressing cells in cases of FSGS and MN compared with controls. Reverse-transcription PCR showed significantly lower levels of nephrin mRNA in cases of FSGS and MN than controls, but no significant difference between minimal lesion cases and controls. Relative levels of glomerular nephrin mRNA correlated inversely with percentage of glomeruli with sclerosis in proteinuric diseases. CONCLUSION: These results suggest that nephrin-expression patterns in proteinuric diseases are different according to the specific glomerular disease or severity of glomerular damage.

Adolescent↗

Exogenous nitric oxide inhibits VCAM-1 expression in human peritoneal mesothelial cells. Role of cyclic GMP and NF-kappaB.

Leukocyte adhesion to mesothelium is an important step during peritonitis, which is mediated by adhesion molecules including vascular cell adhesion molecule-1 (VCAM-1). We investigated the effect of exogenous nitric oxide (NO) on VCAM-1 expression in cultured human peritoneal mesothelial cells and its signal transduction pathway. Mesothelial cells were exposed to tumor necrosis factor-alpha (TNF-alpha) in the presence or absence of NO donors, 3-morpholino-sydnonimine (SIN-1) and nitroprusside (NP). VCAM-1 mRNA and protein expression were measured by Northern blot analysis and flow cytometry. Nuclear factor-kappaB (NF-kappaB) binding activity was determined by electrophoretic mobility shift assay. Both SIN-1 and NP inhibited the TNF-alpha induced VCAM-1 mRNA expression in a dose dependent manner (0.25-2 mM). SIN-1 also suppressed the cell surface expression of VCAM-1 molecule. Furthermore, SIN-1 and NP inhibited the VCAM-1 mRNA expression induced by interleukin-1beta or lipopolysaccharide as well. NF-kappaB inhibitor, PDTC dose dependently inhibited the TNF-alpha induced VCAM-1 mRNA expression. SIN-1 inhibited the TNF-alpha- induced NF-kappaB binding activity. Analogue of cGMP (8-bromo-cGMP) had no significant effect on TNF-alpha-induced VCAM-1 mRNA expression and guanylate cyclase inhibitor (ODQ) also had no significant influence on the inhibitory effect of SIN-1. These results suggest that exogenous NO inhibits VCAM-1 expression via suppression of NF-kappaB through a cGMP-independent pathway.

Cells, Cultured↗

Cystic tumors in the anterior mediastinum. Radiologic-pathological correlation.

Anterior mediastinal neoplasms comprise a diverse group of tumors and occasionally manifest as a cystic lesion. We retrospectively reviewed computed tomography (CT) scans in 46 patients with pathologically proved cystic anterior mediastinal tumors. We categorize them into a pure cystic mass and a cystic tumor with a solid portion. In this pictorial essay, the radiologic appearances of cystic anterior mediastinal tumors are described with CT and illustrated with their gross and histopathological findings on resected specimen.

Bronchi↗

CT and MR imaging of the buccal space: normal anatomy and abnormalities.

The buccal space is an anatomical compartment lying anterior to the masticator space and lateral to the buccinator muscle. Since the major purpose of imaging is to define the likely anatomic origin and also the extent of a given lesion, thorough knowledge of the normal anatomy of the buccal space is essential, and this knowledge can aid the physician in narrowing down the list of possible maladies on the differential diagnosis. We illustrate here in this paper the important anatomic landmarks and typical pathologic conditions of the buccal space such as the developmental lesions and the neoplastic lesions. Knowledge of the expected pathologic conditions is useful for the radiologist when interpreting facial CT and MR images.

Facial Neoplasms↗