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Biomedical subjects

Jin Kim

Publications and source records attributed to Jin Kim.

At least 55 records · Page 3Linked to original sources
PubMed2005

Ectopic bone formation associated with recombinant human bone morphogenetic proteins-2 using absorbable collagen sponge and beta tricalcium phosphate as carriers.

The ectopic bone formation of recombinant human bone morphogenetic protein-2(rhBMP-2) was evaluated using absorbable collagen sponges (ACS) and beta tricalcium phosphate (beta-TCP) as carriers in a rat subcutaneous assay model. Subcutaneous pockets were created on the back of rats. The pockets were implanted with rhBMP-2/ACS, rhBMP-2/beta-TCP, ACS alone, and beta-TCP alone. The rats were sacrificed at 2 or 8 weeks for histological and immunohistochemical evaluation. At 2 weeks, bone formation was evident in both the rhBMP-2/ACS and rhBMP-2/beta-TCP sites. At 8 weeks, the quantity of the new bone with a more advanced stage of remodeling had increased further in the rhBMP-2/beta-TCP sites. However, the newly formed bone observed at 2 weeks was not found in the rhBMP-2/ACS sites. On immunohistochemical observation, osteopontin staining was observed on both the rhBMP-2/ACS (2 weeks) and rhBMP-2/beta-TCP (2 and 8 weeks) sites. Osteocalcin was not detected in any of the samples. The lack of space-providing capacity of ACS may be one of the major factors responsible for its failure to maintain the newly induced bone. Therefore, a carrier for BMPs should provide space for bone formation and maturation during the more advanced healing stages.

Absorbable Implants↗
PubMed2005

Laparoscopy-assisted exploration of obscure gastrointestinal bleeding after capsule endoscopy: the Korean experience.

BACKGROUND: Obscure gastrointestinal bleeding (OGB) is generally defined as recurrent acute or chronic bleeding for which no source has been identified by routine radiologic and endoscopic examination. The aim of this study was to report our early experiences detecting small bowel bleeding by capsule endoscopy (CE) and the results of laparoscopy assisted surgery for OGB. MATERIALS AND METHODS: Seventy-five patients with OGB were examined by CE. Twelve of 24 patients in the active bleeding group underwent laparoscopic or laparoscopy assisted surgery and we carried out intraoperative enteroscopy to find the focus of the bleeding. RESULTS: Laparoscopic localization of the lesion was successful for 4 patients-those with Meckel's diverticulum, gastrointestinal stromal tumor, lymphoma, and ischemic necrosis. In 3 cases in which there was no natural passage of the capsule endoscope, lesions were identified by small bowel exploration through simple palpation by hand. Intraoperative enteroscopy was performed extracorporeally in 5 cases through a minilaparotomy window using an extended incision of a port site less than 7 cm in length. The lesions that were identified by CE preoperatively were resected successfully, via laparoscopic or laparoscopy-assisted surgery. The gastrointestinal bleeding has not recurred during the postoperative follow-up period (mean, 10.6 months). CONCLUSION: The laparoscopic approach can be chosen for surgical management of OGB patients with active bleeding whose lesions have been identified by CE. This approach allows minimally invasive surgical treatment for ongoing OGB.

Adolescent↗
PubMed2005

Rosiglitazone protects against cyclosporine-induced pancreatic and renal injury in rats.

Rosiglitazone (RGTZ) has protective effect against various types of injury. This study was performed to evaluate the effect of RGTZ on pancreatic and renal injury caused by cyclosporine (CsA). CsA (15 mg/kg) and RGTZ (3 mg/kg) were administered alone and together to the rats for 28 days. The effect of RGTZ on CsA-induced pancreatic injury was evaluated by intraperitoneal glucose tolerance test (IPGTT), plasma insulin concentrations and pancreatic beta-cell morphology. The effect of RGTZ on CsA-induced renal injury was evaluated by assessing renal function and pathology; mediators of inflammation and fibrosis such as angiotensin II (AngII), osteopontin (OPN) and transforming growth factor-beta1 (TGF-beta1) and apoptotic cell death. Four weeks of CsA treatment caused diabetes, renal dysfunction, typical pathologic lesions (arteriolopathy, interstitial fibrosis and inflammatory cells infiltration) and apoptotic cell death. RGTZ treatment decreased blood glucose concentration, increased plasma insulin concentration and preserved pancreatic beta islet mass. RGTZ treatment improved renal function and histopathology. Pro-inflammatory and pro-fibrotic molecules such as AngII, OPN and TGF-beta1, and apoptotic cell death also decreased with RGTZ treatment. These data suggest that RGTZ has a protective effect against CsA-induced pancreatic and renal injury.

Angiotensin II↗
PubMed2005

A case of fatal hyperinfective strongyloidiasis with discovery of autoinfective filariform larvae in sputum.

The autoinfective filariform larva of Strongyloides stercoralis causes hyperinfection in immunosuppressed hosts. Here we report on the case of a male patient who was admitted to the emergency room at Gwangju Veterans Hospital with a complaint of dyspnea, and who was receiving corticosteroid therapy for asthma. Many slender larvae of S. stercoralis with a notched tail were detected in Papanicolaou stained sputum. They measured 269 +/- 21.2 microm in length and 11 +/- 0.6 microm in width. The esophagus extended nearly half of the body length. The larvae were identified putatively as autoinfective third-stage filariform larvae, and their presence was fatal. The autoinfective filariform larva of S. stercoralis has not been previously reported in Korea.

Aged↗
PubMed2005

[The prevalence and clinical characteristics of hepatitis-delta infection in Korea].

BACKGROUND/AIMS: The prevalence of hepatitis delta virus (HDV) infection has been estimated as being approximately 5% among global HBsAg carriers. The anti-delta positive rate in Koreans had been reported as being 0.85% in 1985. While the prevalence of HBV has been decreased from nearly 10% to 5% during the past twenty years, there have been no more studies on the anti-delta prevalence in Koreans. The aim of this study was to estimate the anti-delta prevalence in Koreans and to study the clinical characteristics of anti-delta positive patients in a single center. METHODS: Serum anti-delta was measured in one hundred ninety four HBsAg-positive patients who were admitted to our hospital from February 2003 to August 2003. We checked the genotypes of the HBV in the anti-delta positive patients. The clinical features of the anti-delta positive patients were compared to those clinical features of the anti-delta negative patients from the aspect of age, gender, mode of transmission, the positivity of HBeAg and serum HBV DNA. RESULTS: Serum anti-delta was positive in seven patients among the 194 subjects, giving a 3.6% positive rate. Among these seven patients, six had hepatocellular carcinoma (HCC) and the other one had cholangiocarcinoma. All of the anti-delta positive patients had the C genotype of HBV. The anti-delta positive patients showed significantly suppressed HBV DNA replication compared to the anti-delta negative patients. CONCLUSIONS: In Koreans, anti-delta was positive mainly in HCC patients with an approximate prevalence of 4%, and this rate has not changed much for the past twenty years. HBV DNA replication was suppressed by HDV infection.

Adult↗
PubMed2004

Expression of endothelial nitric oxide synthase in developing rat kidney.

Endothelium-derived nitric oxide (NO) is synthesized within the developing kidney and may play a crucial role in the regulation of renal hemodynamics. The purpose of this study was to establish the expression and intrarenal localization of the NO-synthesizing enzyme endothelial NO synthase (eNOS) during kidney development. Rat kidneys from 14 (E14)-, 16 (E16)-, 18 (E18)-, and 20-day-old (E20) fetuses and 1 (P1)-, 3 (P3)-, 7 (P7)-, 14 (P14)-, and 21-day-old (P21) pups were processed for immunocytochemical and immunoblot analysis. In fetal kidneys, expression of eNOS was first observed in the endothelial cells of the undifferentiated intrarenal capillary network at E14. At E16, strong eNOS immunoreactivity was observed in the endothelial cells of renal vesicles, S-shaped bodies (stage II glomeruli), and stage III glomeruli at the corticomedullary junction. At E18-20, early-stage developing glomeruli located in the subcapsular region showed less strong eNOS immunoreactivity than those of E16. The eNOS-positive immature glomeruli were observed in the nephrogenic zone until 7 days after birth. In fetal kidneys, eNOS was also expressed in the medulla in the endothelial cells of the capillaries surrounding medullary collecting ducts. After birth, eNOS immunostaining gradually increased in the developing vascular bundles and peritubular capillaries in the medulla and was highest at P21. Surprisingly, eNOS was also expressed in proximal tubules, in the endocytic vacuolar apparatus, only at P1. The strong expression of eNOS in the early stages of developing glomeruli and vasculature suggests that eNOS may play a role in regulating renal hemodynamics of the immature kidney.

Age Factors↗
PubMed2004

Expression of epidermal growth factor in the developing rat kidney.

Epidermal growth factor (EGF) is important in mammalian renal development. In our study, we investigated the detailed distribution and the time of the first appearance of EGF in developing rat kidney. Kidneys from embryonic 18 (E18)- and 20-day-old (E20) fetuses, postnatal 1 (P1)-, 3 (P3)-, 7 (P7)-, 14 (P14)-, and 21-day-old (P21) pups, and adults were processed for immunohistochemistry and electronmicroscopy. In adult rat kidney, EGF immunoreactivity was found in distal tubule including the thick ascending limb (TAL) and portion 1 of distal convoluted tubule (DCT1), whereas no EGF immunoreactivity was seen in portion 2 of distal convoluted tubule (DCT2) and connecting tubule. In developing kidney, EGF-positive cells first appeared at P3 and were localized in the middle portion of the differentiating TAL of the corticomedullary junction. By P7, the abundance of EGF expression had dramatically increased in the medullary TAL. Between P14 and P21, EGF immunoreactivity was found in the TAL and the DCT for the first time. However, EGF-positive and EGF-negative cells were in the TAL in developing rat kidney. EGF-positive cells did not differ from negative cells in the expression of sodium transport proteins or in the proliferation rate at P3 and P7. In the TAL, smooth-surfaced cells had strong EGF immunoreactivity, but no EGF immunoreactivity was seen in the rough-surfaced cells with well-developed microvilli. Our results suggest that the expression of EGF in developing kidney plays an important role in the regulation of growth and differentiation of the loop of Henle during kidney development and that this may act in the paracrine mode.

Animals↗
PubMed2004

Maturation of TonEBP expression in developing rat kidney.

Tonicity-responsive enhancer binding protein (TonEBP) is a transcriptional activator of the Rel family. In the renal medulla, TonEBP stimulates genes encoding proteins involved in cellular accumulation of organic osmolytes, the vasopressin-regulated urea transporters (UT-A), and heat shock protein 70. To understand the role of TonEBP in the development of urinary concentrating ability, TonEBP expression during rat kidney development was investigated. In embryonic kidneys, TonEBP immunoreactivity was detected 16 days postcoitus in the cytoplasm of the endothelial cells surrounding the medullary collecting ducts (MCD). By 20 days, TonEBP was detected in most tubular profiles in the medulla, including the loop of Henle and MCD, and interstitial cells. The intensity of TonEBP immunoreactivity was much higher in the vasa recta than the tubules. In addition, immunoreactivity was localized predominantly to the cytoplasm. On postnatal day 1, two major changes were observed. TonEBP immunoreactivity shifted to the nucleus, and the intensity of TonEBP immunoreactivity of the tubules increased dramatically. These changes were associated with an increase in TonEBP and sodium-myo-inositol cotransporter mRNA abundance. Thereafter, TonEBP expression in tubular profiles increased moderately. The adult pattern of TonEBP expression was established at postnatal day 21 coincident with full maturation of the renal medulla. Thus expression of TonEBP in developing kidneys occurred predominantly in the medulla and preceded expression of its target genes, including UT-A. These data suggest that TonEBP contributes to the development of urine-concentrating ability.

Animals↗
PubMed2004

Controlled release of atenolol from the ethylene-vinyl acetate matrix.

The present study was carried out to evaluate the possibility of using the polymer EVA membrane as an EVA matrix system for transdermal delivery of atenolol. The effects of drug concentration, temperature, and plasticizers on drug release were studied from the atenolol-EVA matrix. The release rate of drug from the EVA matrix increased with increased temperature and drug loading doses. The flux of atenolol versus the reciprocal of the loading dose yielded a straight line. The release of atenolol from the EVA matrix follows a diffusion-controlled model, where the quantity released per unit area is proportional to the square root of time. Among the plasticizers used such as alkyl citrates and phthalates, tributyl citrate (TBC) showed the best enhancing effects. Enhancement factor of TBC was 1.51 from the EVA matrix at 37 degrees C. The controlled release of atenolol system could be developed using the EVA polymer including the plasticizer.

Administration, Cutaneous↗
PubMed2004

Effect of epidermal growth factor on the developing rat renal papilla.

BACKGROUND: Apoptosis plays an important role in the morphogenesis of the renal papilla. During kidney development, ATL is derived from the TAL in the inner medulla by apoptotic deletion of a fraction of TAL cells and the transformation of the remaining TAL cells. EGF is an important regulator of apoptosis in the kidney. HYPOTHESIS: Exogenously administered EGF in postnatal rat affects renal papilla growth with cell proliferation and apoptosis in the loop of Henle. METHODS: Rat pups received subcutaneous injections of EGF (0.3 microg/g body weight) or saline four times a day from after birth. Rats were sacrificed and the kidneys were preserved for immunohistochemistry on day 4 and day 7. The TAL was identified with antibody directed against Na-K-ATPase or BSC1, and type A intercalated cells were identified with antibody to anion exchanger 1 (AE1). Apoptosis was detected with TUNEL method, and cell proliferation with immunostaining for PCNA. RESULTS--PRIMARY AND SECONDARY: EGF treatment resulted in the following: (1) reduced kidney weight; (2) shortened length of renal papilla; (3) delayed transformation of the cuboidal epithelium into the squamous epithelium of the ATL; (4) delayed elimination of type A intercalated cells in the medullary collecting duct; (5) decreased both apoptotic index and PCNA-positive cells in the TAL and the collecting duct of the renal medulla. CONCLUSION: These findings suggest that exogenous EGF delays the development of loop of Henle in the renal papilla by reducing both apoptosis and cell proliferation.

Animals↗
PubMed2004

Long-term treatment with cyclosporine decreases aquaporins and urea transporters in the rat kidney.

The aim of this study was to evaluate the long-term effects of cyclosporine (CsA) treatment on urinary concentration ability. Rats were treated daily for 4 wk with vehicle (VH; olive oil, 1 ml/kg sc) or CsA (15 mg/kg sc). The influence of CsA on the kidney's ability to concentrate urine was evaluated using functional parameters and expression of aquaporins (AQP1-4) and of urea transporters (UT-A-1-3, and UT-B). Plasma vasopressin levels and the associated signal pathway were evaluated, and the effect of vasopressin infusion on urine concentration was observed in VH- and CsA-treated rats. Toxic effects of CsA on tubular cells in the medulla as well as the cortex were evaluated with aldose reductase (AR), Na-K-ATPase-alpha(1) expression, and by determining the number of terminal transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells. Long-term CsA treatment increased urine volume and fractional excretion of sodium and decreased urine osmolality and free-water reabsorption compared with VH-treated rats. These functional changes were accompanied by decreases in the expression of AQP (1-4) and UT (UT-A2, -A3, and UT-B), although there was no change in AQP2 in the cortex and outer medulla and UT-A1 in the inner medulla (IM). Plasma vasopressin levels were not significantly different between two groups, but infusion of vasopressin restored CsA-induced impairment of urine concentration. cAMP levels and Gsalpha protein expression were significantly reduced in CsA-treated rat kidneys compared with VH-treated rat kidneys. CsA treatment decreased the expression of AR and Na-K-ATPase-alpha(1) and increased the number of TUNEL-positive renal tubular cells in both the cortex and medulla. Moreover, the number of TUNEL-positive cells correlated with AQP2 or UT-A3) expression within the IM. In conclusion, CsA treatment impairs urine-concentrating ability by decreasing AQP and UT expression. Apoptotic cell death within the IM at least partially accounts for the CsA-induced urinary concentration defect.

Animals↗
PubMed2004

Over-expression of c-raf-1 proto-oncogene in liver cirrhosis and hepatocellular carcinoma.

Liver cirrhosis accompanies at least 70% of hepatocellular carcinomas world-wide. To evaluate the dysregulation of apoptosis and the MAPK pathway in hepatocarcinogenesis, we investigated the expression profiles of the genes involved in apoptosis and MAPK pathway in cirrhosis and hepatocellular carcinoma. A total of 94 tissue specimens (61 cirrhosis and 33 hepatocellular carcinoma) obtained from 67 patients were analyzed by microarray, quantitative PCR and Western blot experiments. Of 71 apoptosis-associated genes, c-raf-1 and S6 were up-regulated in 42.9% and 32.1% of 28 cirrhosis tissues, respectively, and both genes were well correlated in a five-cluster K-means analysis. For c-raf-1 and down stream genes in the MAPK pathway, c-raf-1, MEK, and MAPK were up-regulated in 40%, 80%, and 86.7% of 45 cirrhosis specimens, respectively, and in 50%, 63.6%, and 59.1% of 22 hepatocellular carcinoma specimens, respectively. Western blot analysis showed that activated Raf-1 was over-expressed in 91.2% (52/57) of cirrhosis and in 100% (30/30) of hepatocellular carcinoma. The expression level of Raf-1 in 14 of 26 paired samples (53.8%) was significantly higher in hepatocellular carcinoma than in cirrhosis ( [Formula: see text] -fold, [Formula: see text] ). These results suggest that the activation of Raf-1 plays an important role in the development of hepatocellular carcinoma.

Journal Article↗
PubMed2004

Expression of transforming growth factor-beta-inducible gene-h3 in normal and cyclosporine-treated rat kidney.

Up-regulation of transforming growth factor-beta (TGF-beta) is known to play an important role in the tubulointerstitial injury of chronic cyclosporin A (CsA) nephropathy, but the expression of the TGF-beta-inducible gene-h3 (betaig-h3) is undetermined. In this study we examined betaig-h3 expression and its relationship to tubulointerstitial injury in a rat model of chronic CsA nephropathy. Sprague-Dawley rats kept on a low-salt diet (0.05% sodium) were treated daily for 4 weeks with subcutaneous injections of vehicle (olive oil, 1 mL/kg) or CsA (15 mg/kg). The expression of betaig-h3 messenger RNA (mRNA) and protein was evaluated with the use of in situ hybridization, immunohistochemical methods, and immunoblotting. We also compared renal function, histologic findings (tubulointerstitial fibrosis), and expression of TGF-beta1 among treatment groups. In vehicle-treated kidney, betaig-h3 mRNA and protein were constitutively expressed in the outer medulla and cortex, which was confined to the terminal portion of afferent arterioles, the S3 segment of the proximal tubules, and distal convoluted tubules. CsA treatment significantly up-regulated betaig-h3 expression in the interstitium, especially in expanded and fibrotic areas. Quantitative analysis revealed that CsA induced a significant (twofold) increase in betaig-h3 mRNA and protein, and this increase was correlated with up-regulation of TGF-beta1 expression (r =.943, P <.001) and the tubulointerstitial fibrosis score (r =.746, P =.05). Our observations indicate that an increase in betaig-h3 expression, along with TGF-beta1 up-regulation, is closely associated with tubulointerstitial fibrosis in a rat model of chronic CsA nephropathy.

Animals↗
PubMed2004

Hybrid odontogenic tumor of calcifying odontogenic cyst and ameloblastic fibroma.

Odontogenic tumors composed of 2 distinct types of lesions are unusual. We report an odontogenic tumor that was composed of calcifying odontogenic cyst and ameloblastic fibroma that occurred in the right posterior maxilla of a 22-year-old Korean woman. The tumor had a cystic component with an ameloblastic epithelial lining and conglomerates of so-called ghost cells, and there were deposits of dentinoid material adjacent to the cyst. These are features characteristic of calcifying odontogenic cyst. Enamel organ-like epithelial islands were observed within a dental papilla-like stroma of the cyst wall. Additionally, a solid portion of the tumor had characteristic features of ameloblastic fibroma, i.e., a myxoid cellular stroma with numerous elongated islands of ameloblastic epithelium. Ghost cell masses were found in the area of ameloblastic fibroma as well. The distribution of the ghost cells suggests that this is a hybrid lesion rather than a collision tumor.

Adult↗
PubMed2004

Effect of chlorophyllin on normothermic storage of human periodontal ligament cells.

The purpose of the present study was to evaluate whether chlorophyllin could serve as an effective constituent of a storage medium to enhance the human periodontal ligament (PDL) cell viability. Freshly isolated PDL cells from premolars extracted from healthy people were stored at 37 degrees C for 6 h in various solutions: F-medium and Hank's balanced salt solution (HBSS), supplemented with chlorophyllin. From MTT viability assays, the highest cell viability was found in the PDL cells stored in HBSS supplemented with 500 nM chlorophyllin, and the chlorophyllin-treated cells showed a dose-dependent response to concentration. Additionally, the results from flow cytometry showed that 77 to 80% of the PDL cells were in the G0/G1 phases of the cell cycle, which suggested that most were in a stable stage. These result showed that HBSS, supplemented with chlorophyllin, may be a useful solution for preserving the viability of PDL cells.

Antioxidants↗
PubMed2004

Indomethacin enhances shuttling of aquaporin-2 despite decreased abundance in rat kidney.

The effect of nonsteroidal antiinflammatory drugs on the regulation of aquaporin-2 (AQP2) water channels in the kidney was determined. Male Sprague-Dawley rats were injected with indomethacin (5 mg/kg twice a day intraperitoneally) for 2 d. The control group was injected with vehicle. The expression of AQP2 proteins was determined in the kidney by immunoblotting and immunohistochemistry. The expression of G(salpha) and type VI adenylyl cyclase was determined by immunoblotting. The activity of adenylyl cyclase complexes was determined by stimulated accumulation of cAMP. Immunoblotting revealed that indomethacin markedly decreased the expression of AQP2. Accordingly, however, the ratio of AQP2 expression in the membrane fraction versus that in the cytoplasmic fraction was increased. The urinary excretion of AQP2 proteins also increased. Immunohistochemistry demonstrated almost exclusive apical labeling of AQP2 with scanty cytoplasmic localization along the collecting duct. The expression of G(salpha) and adenylyl cyclase VI proteins was decreased. The generation of cAMP provoked by arginine vasopressin, sodium fluoride, or forskolin was blunted. These results suggest that indomethacin increases the shuttling of AQP2 while it decreases its abundance in the collecting duct.

Adenylyl Cyclases↗
PubMed2004

The myoepithelial cell differentiation of mucoepidermoid carcinoma in a collagen gel-based coculture model.

BACKGROUND: Mucoepidermoid carcinomas (MECs) are the most common malignant tumor of the salivary glands; however, the histogenesis of MECs has been still controversial. This study was undertaken to investigate the histogenesis of MECs by the examination of their collagen gel-based coculture tissue and transplanted tumors. METHODS: Two cell lines from a primary and a metastatic MECs were established and characterized by the mutational analysis of the p53 gene and in vivo tumorigenicity in athymic nude mice. Collagen gel-based organotypic cocultures were performed, and the ultrastructural and immunohistochemical findings were examined. RESULTS: Two cell lines demonstrated p53 point mutation at the same codon. A metastatic cell line of MEC showed in vivo tumorigenicity. Transplanted tumors and the collagen gel-based culture tissues showed poorly differentiated squamous cell carcinomas devoid of mucous cell differentiation; however, they disclosed the differentiation of myoepithelial cells. CONCLUSIONS: MECs appear to be centered on the squamous cell differentiation, and the specific differentiation of myoepithelial or mucous cells seems to be modulated by the property of microenvironment.

3T3 Cells↗