Biomedical subjects

Dae Hyun Kim

Publications and source records attributed to Dae Hyun Kim.

23 records · Page 2Linked to original sources

PubMed2004

Induction of endothelial apoptosis by 4-hydroxyhexenal.

Lipid peroxidation and its products such as 4-hydroxy-2-nonenal (HNE) and 4-hydroxyhexenal (HHE) are known to affect redox balance during aging and various degenerative processes, including vascular dysfunction. Deterioration of the endothelial cells that line the vascular wall is known to be an underlying cause of vascular dysfunction. At present, little is known about the mechanism by which HHE induces endothelial cell death (i.e. apoptosis), although HNE-induced apoptotic cell death has been reported. The aim of this study was to determine whether apoptosis induced by HHE in endothelial cells involves peroxynitrite (ONOO(-)). Our results show that in endothelial cells HHE triggers apoptotic cell death by inducing apoptotic Bax coupled with a decrease in anti-apoptotic Bcl-2. Results show that HHE induces reactive oxygen species (ROS), nitric oxide, and ONOO(-) generation, leading to redox imbalance. Furthermore, the antioxidant N-acetyl cysteine, ROS scavenger, and penicillamine, an ONOO(-) scavenger, were found to block HHE-mediated apoptosis. We used confocal laser microscopy to estimate the ability of these inhibitors to attenuate HHE-induced intracellular ONOO(-) levels thus confirming the oxidative mediation of apoptosis in endothelial cells. These findings strongly suggest that accumulated HHE triggers reactive species-mediated endothelial apoptosis, leading to vascular dysfunction as well as vascular aging. During aging, increased lipid peroxidation and its associated production of HHE may exacerbate the weakened redox balance, leading to various chronic degenerative processes including vascular dysfunction.

Aldehydes↗

PubMed2004

Peroxynitrite scavenging mode of alaternin isolated from Cassia tora.

Peroxynitrite (ONOO-), formed from the reaction of superoxide (.O2-) and nitric oxide (NO), is a potent oxidant that contributes to the oxidation of various cellular constituents, including lipids, amino acids, sulfhydryls and nucleotides. It can cause cellular injury, such as DNA fragmentation and apoptotic cell death. ONOO- toxicity is also reported to be involved in inflammatory and neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease and atherosclerosis. Moreover, the necessity for a strong ONOO- scavenger is important because of the lack of endogenous enzymes that protect against the damage caused by ONOO-. The aim of this study was to evaluate the ability of natural products to scavenge ONOO-. We tested various plant extracts for their ONOO- scavenging activity. Among them, extract from Cassia tora, which is well known as an oriental herb in traditional medicine, showed potent ONOO- scavenging activity. Further analysis identified the phenolic active components, alaternin and nor-rubrofusarin glucose, as potent ONOO- scavengers. Spectrophotometric analysis demonstrated that alaternin and nor-rubrofusarin glucose led to a decrease in the ONOO- -mediated nitration of tyrosine through electron donation. In bovine serum albumin, alaternin, but not nor-rubrofusarin glucose, showed significant inhibition of ONOO- -mediated nitration in a dose-dependent manner. We believe alaternin can be developed as an effective ONOO- scavenger for the prevention of ONOO- -associated diseases.

Cassia↗

PubMed2003

[Diagnostic usefulness of intradermal test for clonorchiasis in patients with pancreatobiliary diseases].

BACKGROUND/AIMS: The diagnosis of clonorchiasis is based on demonstrating eggs in stool or bile. It is believed that bile examination is the most precise method for detecting eggs. We evaluated diagnostic usefulness of intradermal test (IDT) by comparing it with the result of bile examination. METHODS: For 88 patients with pancreatobiliary diseases, we examined Clonorchis sinensis eggs in bile and performed IDT for clonorchiasis. The bile was obtained from endoscopic nasobiliary or percutaneous transhepatic biliary drainage tubes. RESULTS: We calculated ROC curve to decide the cut-off value of IDT in determining diagnostic accuracy on the basis of bile examination. We chose a value of 40 mm2, which significantly improved the sensitivity, without reducing the specificity. With a cut-off value of 40 mm2, the sensitivity, specificity, positive and negative predictive values of IDT were 81.5%, 67.2%, 52.4%, and 89.1%, respectively. The value of IDT was not affected by age and showed no difference between benign and malignant diseases. However, in egg-positive patients, the mean value was lower in malignant diseases than in benign diseases. CONCLUSIONS: In patients with pancreatobiliary diseases, IDT with a cut-off value of 40 mm2 seems to be a valuable supplementary diagnostic test for clonorchiasis in view of its high sensitivity.

Aged↗

PubMed2002

Pulmonary aspergillosis in immunocompetent hosts without underlying lesions of the lung: radiologic and pathologic findings.

OBJECTIVE: The purpose of this study was to determine the radiologic and pathologic findings associated with pulmonary aspergillosis in immunocompetent hosts without underlying lesions of the lung. CONCLUSION: In immunocompetent hosts without preexisting lesions of the lung, pulmonary aspergillosis may manifest on CT primarily as a single nodule or mass with or without an air crescent or as a localized consolidation.

Adult↗

PubMedDate not supplied

Determinants of non-compliance with lipid-lowering therapy in hyperlipidemic patients.

PURPOSE: In order to assess the determinants of non-compliance with a lipid-lowering therapy, a prospective study of the hyperlipidemic Korean subjects was carried out. METHODS: A total of 1019 patients was observed by 46 family physicians for the period of 1 year from January 1999 to January 2000. To ascertain the compliance associated with a lipid lowering drug (Simvastatin), we regularly followed up the hyperlipidemic patients at intervals of 4, 12 and 24 weeks. The criterion for evaluating compliance is to measure clinic attendance. Using a structured questionnaire, patients and physicians were asked about risk factors for the compliance. RESULTS: During the first 24 weeks of treatment, the lipid-lowering medication was continued by 52.3% and discontinued by 19.7%. The remaining 28% dropped out. Patient-related factors for non-compliance were young age, current smoker, lack of low fat diet and exercise, new user, no concomitant medication, and occurrence of adverse reactions. Physician-related factors for non-compliance were low patients' satisfaction with the physician, small number of hyperlipidemic patients per month and working in a relatively small hospital. CONCLUSIONS: Compliance with the lipid-lowering therapy was relatively low and several factors for non-compliance were detected.

Adult↗