Biomedical subjects

J R Kim

Publications and source records attributed to J R Kim.

At least 37 records · Page 2Linked to original sources

PubMed2001

Dietary hematein ameliorates fatty streak lesions in the rabbit by the possible mechanism of reducing VCAM-1 and MCP-1 expression.

Hematein is a compound isolated from Caesalpinia sappan that has been used in oriental medicine as both an analgesic and an anti-inflammatory agent. In this study, we examined the anti-atherogenic potential of hematein using cholesterol-fed New Zealand White (NZW) rabbits. NZW rabbits were divided into a hematein-supplemented (0.05% in diet) group (n=6), a probucol-supplemented (0.25% in diet) group (n=6), and a control group (n=6). After 8 weeks of treatments, the extent of the atherosclerotic lesions was significantly reduced in the hematein-supplemented group and the probucol-supplemented group without changing plasma lipoprotein levels. Hematein and probucol prevented the up-regulation of the vascular cell adhesion molecule-1 (VCAM-1) expression on the descending aorta induced by cholesterol diet. In culture, hematein also significantly inhibited the secretion of soluble VCAM-1 and of monocyte chemotactic protein-1 (MCP-1) respectively induced by tumor necrotic factor alpha (TNF-alpha) and mildly oxidized low density lipoprotein in human umbilical vein endothelial cell (HUVEC) culture. Also, hematein inhibited monocyte adhesion to endothelial cell and the activation of NF-kappaB in HUVECs stimulated with TNF-alpha. The results of the present study suggest that the anti-atherogenic effect of hematein is not related to control of the plasma lipid profile but probably related to the inhibition of VCAM-1 and MCP-1 expression resulting in an amelioration of lesion development in the rabbit.

Animals↗

PubMed2001

Effects of smoking cessation on changes in blood pressure and incidence of hypertension: a 4-year follow-up study.

We performed the present study to investigate the effects of smoking cessation on changes in blood pressure and incidence of hypertension. We evaluated 8170 healthy male employees at a steel manufacturing company who had received occupational health examinations at the company's health care center in 1994 and were reexamined in 1998. Adjustment covariates were the baseline age, body mass index, cigarette smoking, alcohol consumption, exercise, family history of hypertension, systolic or diastolic blood pressure, and changes in body mass index and alcohol consumption during the follow-up period. The adjusted relative risks of hypertension in those who had quit smoking for <1, 1 to 3, and >/=3 years were 0.6 (95% CI 0.2 to 1.9), 1.5 (95% CI 0.8 to 2.8), and 3.5 (95% CI 1.7 to 7.4), respectively, compared with current smokers. The trends for increased risk of hypertension for longer periods of smoking cessation were observed in subgroups of those who maintained weight as well as those who gained weight after smoking cessation. The adjusted increments in both systolic and diastolic blood pressure were higher in those who had quit for >/=1 year than in current smokers. These trends among weight losers, as well as gainers and maintainers, were similar. We observed progressive increases in blood pressure with the prolongation of cessation in men, although at this time the mechanism remains unknown and must be clarified. This study implies that the cessation of smoking may result in increases in blood pressure, hypertension, or both.

Adult↗

PubMed2001

Trochanteric rotational osteotomy for osteonecrosis of the femoral head.

The rate of success of transtrochanteric rotational osteotomy for osteonecrosis of the femoral head may be improved if patients are preselected using MRI. We have used three criteria for selection for osteotomy (i) minor collapse of the infarcted area, loss of congruity or the crescent sign, without narrowing of the joint space or acetabular involvement (ii) patients younger than 55 years and with a painful hip (iii) patients with an intact area constituting an arc of more than 120 degrees between the central vertical line of the femoral head and the posterior or anterior margin of the necrotic portion as seen on a midsagittal MRI. Seventeen patients were selected, with a follow-up of more than 42 months. A bone scan four weeks after operation showed adequate perfusion of the proximal segment in all hips. The hip score of Merle d'Aubigné et al improved from 13.5 points before operation to 17.2 points at the latest follow-up. Further collapse of the femoral head did not occur. The use of MRI instead of plain radiographs for the selection of patients has improved the success rate of transtrochanteric rotational osteotomy.

Adolescent↗

PubMed2001

A case of intramuscular sparganosis in the sartorius muscle.

Intramuscular sparganosis is not common, and its rarity makes it difficult to be distinguished from soft tissue tumors. A case of rare intramuscular sparganosis is reported. A 44-year-old man presented with a painful mass in the left thigh for 8 months, which was initially diagnosed a as soft tissue tumor. Ultrasonography and MRI revealed a multilobulated mass in the sartorius muscle. After the needle biopsy under the guidance of ultrasonography, sparganum was discovered under microscopic examination of the excised tissue. Surgical excision was performed, and a live larva of sparganum was removed. Sparganosis should be considered in the differential diagnosis of soft tissue tumors, especially among Koreans who have frequently ingested mountain water and consumed raw snakes or frogs.

Adult↗

PubMed2000

Identification of proteins containing cysteine residues that are sensitive to oxidation by hydrogen peroxide at neutral pH.

A procedure for detecting proteins that contain H(2)O(2)-sensitive cysteine (or selenocysteine) residues was developed as a means with which to study protein oxidation by H(2)O(2) in cells. The procedure is based on the facts that H(2)O(2) and biotin-conjugated iodoacetamide (BIAM) selectively and competitively react with cysteine residues that exhibit a low pK(a), and that the decrease in the labeling of cell lysate proteins with BIAM caused by prior exposure of cells to H(2)O(2) or to an agent that induces H(2)O(2) production can be monitored by streptavidin blot analysis. This procedure was applied to rat pheochromocytoma PC12 cells directly treated with H(2)O(2), mouse hippocampal HT22 cells in which H(2)O(2) production was induced by glutamate, and human erythroleukemia K562 cells in which H(2)O(2) production was induced by phorbol myristate acetate. It revealed that several cell proteins contain cysteine or selenocysteine residues that are selectively oxidized by H(2)O(2). Three of these H(2)O(2)-sensitive proteins were identified as a member of the protein disulfide isomerase family, thioredoxin reductase, and creatine kinase, all of which were previously known to contain at least one reactive cysteine or selenocysteine at their catalytic sites. This procedure should thus prove useful for the identification of proteins that are oxidized by H(2)O(2) generated in response to a variety of extracellular agents.

Alkylation↗

PubMed2000

Overexpression of phospholipase Cbeta-1 protects NIH3T3 cells from oxidative stress-induced cell death.

Oxidative stress has been implicated in a wide range of cellular damage which includes DNA oxidation, membrane lipid peroxidation, and apoptosis. In our study, we found that overexpression of PLC-beta1 in NIH3T3 fibroblasts protected them from cell death occuring in response to oxidative stress. Cell death caused by treatment with prooxidant tert-butylhydroperoxide (TBH), H2O2, or CdCl2 was considerably suppressed in PLC-beta1 overexpressed NIH/beta1-14 cells in comparison to control NIH/neo cells. However, overexpression of PLC-beta1 failed to protect the cells from toxicity by diamide or KCN. In addition, while accumulation of c-fos mRNA was observed within 30 min of TBH treatment in vector transfected NIH/neo cells, TBH-induced c-fos mRNA generation was completely suppressed in NIH/beta1-14 cells, while that of c-jun and GAPDH was not affected. These findings suggest that PLC-beta1 may play a role in process that can protect cells from oxidative stress-induced cell death.

3T3 Cells↗

PubMed2000

Proliferation and apoptosis in gastric antral epithelial cells of patients infected with Helicobacter pylori.

We measured cell proliferation and apoptosis in the antral epithelial cells of Helicobacter pylori-infected and H. pylori-uninfected persons, and examined these processes in relation to diagnosis and the histologic parameters of inflammation to investigate their role in cellular turnover in diseases of the upper gastrointestinal tract. The subjects were: 25 patients with antral gastric cancers, 20 with antral gastric ulcers, 18 with duodenal ulcers, and 28 with chronic gastritis, and 4 subjects with normal gastric mucosa. Seventy-two subjects were infected with H. pylori, and 23 subjects, including the 4 with normal gastric mucosa, were uninfected. H. pylori infection was associated with increased apoptosis and cell proliferation in the gastric mucosa, which correlated with the degree of acute inflammation and the density of H. pylori, and these latter two factors correlated with each other. Intestinal metaplasia and glandular atrophy were significantly higher in gastric cancers and gastric ulcers than in duodenal ulcers. Cell proliferation was significantly lower in gastric cancers than in gastric ulcers, but the apoptotic count did not show a significant difference between these diseases. This decreased proliferation in the adjacent mucosa in gastric cancers compared with findings in the other diseases is thought to be closely related to the relatively decreased acute inflammation, which may, partly, contribute to glandular atrophy in the adjacent mucosa of gastric cancer.

Adult↗

PubMed2000

Increased expression of cyclin D1, cyclin E and p21(Cip1) associated with decreased expression of p27(Kip1) in chemically induced rat mammary carcinogenesis.

We induced rat mammary tumors in 7-week-old female Sprague-Dawley rats by intragastric administration of 7,12-dimethylbenz(a)anthracene (DMBA), and analyzed by immunohistochemistry the expression of cyclin D1, cyclin E, p21(Cip1), and p27(Kip1) in carcinomas, atypical tumors, and benign tumors as well as normal mammary glands from the control group. Proliferation status was assessed by immunohistochemistry using bromodeoxyuridine (BrdU). A sequential increase in cyclin D1-, cyclin E-, and p21(Cip1)-positive epithelial cells was observed from normal mammary glands, to atypical tumors, to carcinomas. In contrast, carcinomas showed a significantly lower number of epithelial cells immunoreactive to p27(Kip1) when compared with atypical tumors, benign tumors and normal mammary glands. The immunoreactivities of BrdU, cyclin D1, cyclin E, and p21(Cip1) were positively correlated, whereas that of p27(Kip1) appeared inversely correlated to those of the others. Reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot analysis were also performed to determine the mRNA and protein levels of cyclins and cyclin-dependent kinase inhibitors in tumors and normal mammary glands. The protein levels for cyclin D1, cyclin E and p21(Cip1) in carcinomas and atypical tumors were significantly higher than those in benign tumors, while normal mammary glands showed negligible expression. On RT-PCR, tumors showed higher mRNA levels of cyclin D1 and cyclin E than those of normal mammary glands. Our results suggest that rat mammary carcinogenesis involves increased expression of cyclin D1, cyclin E, and p21(Cip1), associated with decreased expression of p27(Kip1).

9,10-Dimethyl-1,2-benzanthracene↗

PubMed2000

Spontaneous regression of hepatocellular carcinoma--a case report.

Spontaneous regression of cancer is a rare phenomenon seldom described in patients with hepatocellular carcinoma. A 54-year-old Korean woman suffered from cytologically-proved advanced hepatocellular carcinoma, for which she received no treatment. Papanicolaou's smears revealed high cellularity. Many clusters of polygonal cells showed long, thick anastomosing cords covered by flattened endothelial cells. The polygonal cells showed small hepatocytoid appearance, characterized by increased nuclear/cytoplasmic ratio. She remained in good clinical condition and, at 4 years of follow-up, the hepatocellular carcinoma could not be visualized radiologically. To date, only 14 case reports of apparently spontaneous regression of hepatocellular carcinoma have been published in the English literature. The mechanisms underlying this intriguing phenomenon remain unknown.

Carcinoma, Hepatocellular↗

PubMed2000

Overexpression of cyclin D1 and cyclin E in 1,2-dimethylhydrazine dihydrochloride-induced rat colon carcinogenesis.

Deregulation of G1 cyclins has been reported in several human and rodent tumors including colon cancer. To investigate the expression pattern of G1 cyclins in 1,2- dimethyl-hydrazine dihydrochloride (DMH)-induced rat colon carcinogenesis, we studied the expression of cyclin D1 and cyclin E by quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis and immunohistochemistry (IHC). The mRNA level of cyclin D1 was increased 1.2-fold in adenocarcinomas but not significantly in adenomas, when compared with normal rat colonic mucosa (p<0.05). The cyclin E mRNA level was increased 2.7-fold in adenomas and 3.3-fold in adenocarcinomas (p<0.05). The PCNA mRNA level was also increased 1.9-fold in adenomas and 1.8-fold in adenocarcinomas (p<0.05). Immunohistochemical staining revealed exclusive nuclear staining of the neoplastic cells for cyclin D1, cyclin E and PCNA. Cyclin D1 expression was detected in 56.3% of the adenomas and in 61.5% of the adenocarcinomas examined, whereas cyclin E expression was detected in 87.5% of the adenomas and in 92.3% of the adenocarcinomas. Overall, cyclin D1, cyclin E and PCNA expression was significantly increased at both the mRNA and protein levels in normal colonic mucosa, adenomas and adenocarcinomas, but there was no significant difference in the degree of expression of these genes in adenomas and adenocarcinomas. Our results indicate that the overexpression of cyclin D1 and cyclin E may play an important role during the multistage process of rat colon carcinogenesis, at a relatively early stage, and may disturb cell-cycle control in benign adenomas, and thereafter, participate in tumor progression.

1,2-Dimethylhydrazine↗

PubMed1999

Activation of monocytes, T-lymphocytes and plasma inflammatory markers in angina patients.

Inflammation and activation of immune cells have important roles in the pathogenesis of atherosclerosis. We analyzed the plasma levels of inflammatory markers and the degree of activation of peripheral blood monocytes and T-lymphocytes isolated from 12 unstable angina, 12 stable angina, and 12 normal subjects. In 20%-33% of patients, monocytes expressed high basal levels of IL-8, tissue factor, IL-1beta, and monocyte chemoattractant protein-1 mRNA. Furthermore, basal mRNA levels of these cytokines showed strong correlation with each other (p < 0.01 in all combination) but not with tumor necrosis factor-alpha or transforming growth factor-beta1. Plasma level of C-reactive protein was highest in the unstable angina patients (1.63+/-0.70 mg/l) and lowest in the control subjects (0.22+/-0.08 mg/l) (P = 0.03). We also observed a high correlation between C-reactive protein level and the occurrence of minor and major coronary events during 6 months of follow-up. Activation status of T-cells, assessed by the percentage of HLA-DR positive cells, was highest in the unstable angina patients (26.8+/-1.4%) compared with that in the control (14.7+/-1.2%) (P = 0.0053). Our data represent the first case showing that the circulating monocytes in angina patients are activated to a state express numerous proatherogenic cytokines. These results may help to diagnose angina patients according to the inflammatory markers and evaluate the prognosis of the disease.

Aged↗

PubMed1999

Molecular cloning and characterization of a mitochondrial selenocysteine-containing thioredoxin reductase from rat liver.

A thioredoxin reductase (TrxR), named here TrxR2, that did not react with antibodies to the previously identified TrxR (now named TrxR1) was purified from rat liver. Like TrxR1, TrxR2 was a dimeric enzyme containing selenocysteine (Secys) as the COOH-terminal penultimate residue. A cDNA encoding TrxR2 was cloned from rat liver; the open reading frame predicts a polypeptide of 526 amino acids with a COOH-terminal Gly-Cys-Secys-Gly motif provided that an in-frame TGA codon encodes Secys. The 3'-untranslated region of the cDNA contains a canonical Secys insertion sequence element. The deduced amino acid sequence of TrxR2 shows 54% identity to that of TrxR1 and contained 36 additional residues upstream of the experimentally determined NH2-terminal sequence. The sequence of this 36-residue region is typical of that of a mitochondrial leader peptide. Immunoblot analysis confirmed that TrxR2 is localized almost exclusively in mitochondria, whereas TrxR1 is a cytosolic protein. Unlike TrxR1, which was expressed at a level of 0.6 to 1.6 microgram/milligram of total soluble protein in all rat tissues examined, TrxR2 was relatively abundant (0.3 to 0.6 microgram/mg) only in liver, kidney, adrenal gland, and heart. The specific localization of TrxR2 in mitochondria, together with the previous identification of mitochondria-specific thioredoxin and thioredoxin-dependent peroxidase, suggest that these three proteins provide a primary line of defense against H2O2 produced by the mitochondrial respiratory chain.

Amino Acid Sequence↗

PubMed1999

Inhibitory effects of streptozotocin, tumor necrosis factor-alpha, and interleukin-1beta on glucokinase activity in pancreatic islets and gene expression of GLUT2 and glucokinase.

Treatment of streptozotocin (ST), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1beta) resulted in destroying insulin-secreting beta-cells of pancreatic islets and impairment of islet glucose oxidation and glucose-induced insulin secretion. IL-1beta and TNF-alpha inhibited insulin release and glucose utilization and oxidation. It was shown that the inhibitory effects of ST, IL-1beta, and TNF-alpha were due to impaired glucokinase activity. Glucokinase activity was severely impaired by ST, IL-1beta, and TNF-alpha treatments, as confirmed by assaying enzymes and nucleotides associated with glycolysis and glucose oxidation. On the other hand, nitric oxide was a factor of the deleterious effects of IL-1beta, TNF-alpha, and ST on pancreatic islets. Incubation of mouse pancreatic islets with ST at various concentrations of impairing insulin secretion resulted in generation of nitrite, stimulation of islet guanylyl cyclase and accumulation of cGMP, and inhibition of pancreatic islet mitochondrial aconitase activity to degree similar to those raised by IL-1beta and TNF-alpha. When the effects of IL-1beta and TNF-alpha on the gene expression of pancreatic GLUT2 and glucokinase were examined, the level of GLUT2 and glucokinase mRNA in pancreatic islets was significantly decreased. This suggested that IL-1beta and TNF-alpha downregulate gene expression of GLUT2 and glucokinase in pancreatic beta-cells.

Aconitate Hydratase↗

PubMed1999

Reduced expression of CD99 and functional disturbance in anencephalic cortical thymocytes.

In a significant proportion of cases, anencephaly is associated with thymic enlargement, suggesting a possibility that anencephalic fetuses have a functional disturbance in thymocyte differentiation and development. In this report, we demonstrated that CD99 expression was consistently reduced in cortical thymocytes of all anencephalic fetuses. In addition, the CD99-dependent aggregation of immature cortical thymocytes was almost completely impaired and apoptosis of thymocytes was markedly reduced in several cases. These results are in agreement with previous findings that CD99 regulates the aggregation and apoptosis of various types of cells. These data strongly suggest that functional disturbance of thymocytes and thymic hyperplasia are related to the reduced expression of CD99 molecule in anencephalic fetuses.

12E7 Antigen↗

PubMed1999

The effects of two new antagonists of secretory PLA2 on TNF, iNOS, and COX-2 expression in activated macrophages.

Phospholipase A2 (PLA2) regulates eicosanoid and platelet-activating factor production. It also plays an important role in the regulation of critical mediators in inflammatory diseases in which PLA2 activity is significantly enhanced during sepsis and multiple organ failure. Therefore, inhibitors of PLA2 activity offer themselves as target substances in the development of anti-inflammatory drugs. We identified 2 biflavonoids, bilobetin and ginkgetin, that can inhibit PLA2 activity. In experiments using 2-linol-[1-14C]PE as substrate both substances potently inhibited several kinds of type II 14-kDa PLA2 while inhibiting type I 14-kDa PLA2 to a lesser extent. We tested these PLA2 inhibitors for their ability to inhibit the production of tumor necrosis factor alpha (TNFalpha) and 2 enzymes, inducible nitric oxide synthase (iNOS) and inducible cyclooxygenase (COX-2) in an assay system using lipopolysaccharide (LPS)-stimulated Raw264.7 macrophages. In Raw264.7cells, bacterial LPS induced the production of COX-2 and iNOS proteins as well as TNFalpha. The inhibitors consistently inhibited the production of TNFalpha in a dose-dependent manner. Moreover, treatment of the macrophages with bilobetin and ginkgetin shut down the production of nitrite, one of the stable end products of NO released into the culture supernatant. The decrease in NO products was accompanied by a decrease in iNOS protein level as assessed by Western blot probed with specific anti-iNOS antibody. Both inhibitors also reduced the expression of COX-2 protein in the LPS-stimulated cells, which coincided with the reduction in iNOS protein. These results, therefore, suggest that these two sPLA2 inhibitors may be useful for inhibiting the production of inflammatory cytokine and NO production in inflammatory diseases.

Animals↗

PubMed1999

Heart rate and subsequent blood pressure in young adults: the CARDIA study.

The objective of the present study was to examine the hypothesis that baseline heart rate (HR) predicts subsequent blood pressure (BP) independently of baseline BP. In the multicenter longitudinal Coronary Artery Risk Development in Young Adults study of black and white men and women initially aged 18 to 30 years, we studied 4762 participants who were not current users of antihypertensive drugs and had no history of heart problems at the baseline examination (1985-1986). In each race-sex subgroup, we estimated the effect of baseline HR on BP 2, 5, 7, and 10 years later by use of repeated measures regression analysis, adjusting for baseline BP, age, education, body fatness, physical fitness, fasting insulin, parental hypertension, cigarette smoking, alcohol consumption, oral contraceptive use, and change of body mass index from baseline. The association between baseline HR and subsequent systolic BP (SBP) was explained by multivariable adjustment. However, HR was an independent predictor of subsequent diastolic BP (DBP) regardless of initial BP and other confounders in white men, white women, and black men (0.7 mm Hg increase per 10 bpm). We incorporated the part of the association that was already present at baseline by not adjusting for baseline DBP: the mean increase in subsequent DBP was 1.3 mm Hg per 10 bpm in white men, white women, and black men. A high HR may be considered a risk factor for subsequent high DBP in young persons.

Adolescent↗

PubMed1999

Button battery impaction in nasal cavity.

A button battery inserted in the nose of children is an unusual foreign body which is capable of causing extensive tissue damage, resulting from electrical and chemical burns. We report a case of button battery in the nose of a 4-year-old boy presenting with unilateral nasal discharge, and necrosis in the septum and turbinate of the right nasal cavity. Mercury level in concentrated urine was within normal limit. Microscopic examination disclosed extensive liquefaction necrosis with calcification and fibrosis. Numerous dark brown to black granules were noted in the elastic and collagen fibers and interstitium. Dark-field examination of the section revealed brilliantly refractile granules. Polarized microscopy failed to show the granules. Most brown pigments reacted to prussian blue. Tissue mercury analysis yielded a mercury content of 8.01 ppm. We report this case to emphasize the hazards of button battery impaction and to draw attention to the significance of the problem through histopathologic examination.

Child, Preschool↗

PubMed1999

Effects of priming with pancuronium or rocuronium on intubation with rocuronium in children.

Rocuronium is a non-depolarizing neuromuscular blocking agent which has a rapid onset and intermediate duration of action. The goal of this study was to compare the neuromuscular blocking actions of rocuronium with and without a priming dose of pancuronium or rocuronium in children. Thirty patients were randomly allocated into 3 groups. Ten patients received a single dose of 0.6 mg/kg rocuronium (Group I). The others received either 0.015 mg/kg pancuronium (Group II) or 0.06 mg/kg rocuronium (Group III) 3 minutes before an intubating dose of 0.54 mg/kg rocuronium was given. Neuromuscular blockade was measured via accelerographic response to single stimulations (1 Hz) of the ulnar nerve until maximal twitch depression was reached followed by train-of-four (TOF) stimuli (2 Hz) at 15 second intervals for the remainder of recovery. Groups were compared with regard to onset time, duration and recovery indices. The onset time and duration of block did not differ significantly between groups. However, the time to recovery in group II (24.5 +/- 9.9 min) was significantly prolonged compared to that in group I (12.7 +/- 3.1 min) or group III (12.7 +/- 3.9 min). We concluded that the use of rocuronium with a preceding dose of either pancuronium or rocuronium provided no advantage for intubation in children.

Androstanols↗