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Biomedical subjects

Y B Park

Publications and source records attributed to Y B Park.

At least 19 recordsLinked to original sources

Miliary tuberculosis and acute respiratory distress syndrome.

OBJECTIVE: Miliary tuberculosis is a life-threatening disease caused by the haematogenous spread of Mycobacterium tuberculosis. We evaluated the clinical manifestations of 34 patients with miliary tuberculosis. DESIGN: A retrospective case review. RESULTS: The diagnosis of miliary tuberculosis was based on the identification of miliary nodules on chest radiography and one of the three following criteria: 1) acid-fast bacilli smear and/or culture positive in clinical specimens (22/34), 2) histopathological identification of TB granuloma (6/34), and 3) radiological and clinical improvement after anti-tuberculosis treatment (6/34). The median age (+/-SD) of the patients was 42.7 +/- 21.6 years, with two peaks, in the age group 20-30 and in those over 60. There were 16 underlying diseases in 14 patients, of which liver cirrhosis was the most common. The drug sensitivity pattern was available for 17 isolates of M. tuberculosis: 14 were sensitive, while the other three were resistant to at least one anti-tuberculosis drug. Eight patients developed acute respiratory distress syndrome (ARDS), five of whom died during intensive care. Platelet count, serum albumin and liver enzyme level at the time of admission were significant factors both for ARDS development and for survival. CONCLUSION: ARDS caused by miliary TB is associated with a high fatality rate; scope remains for improvement in its management.

Adolescent↗

Molecular cloning and characterization of a novel low temperature-induced gene, blti2, from barley (Hordeum vulgare L.).

The Suppression Subtractive Hybridization (SSH) was used to isolate large numbers of low temperature-induced genes from the cold-treated winter barley (Hordeum vulgare L. cv. Dongbori). One hundred and sixty blti (barley low temperature-induced) cDNA clones were obtained. Northern blot analyses showed that several blti clones were differentially expressed by treatment of low temperature, NaCl, dehydration and ABA. One of the clones, blti2, was induced from 3 to 72 h after cold treatment while its transcript was detected only at 12 h after ABA treatment, indicating that the expression of blti2 by low temperature was regulated by an ABA-independent pathway. The full-length cDNA sequences were 944 nucleotides long and the open reading frame consisted of 492 nucleotides encoding 164 amino acids. Nucleotide sequences showed no sequence homology with the previously reported low temperature-responsive (LTR) barley genes, and the deduced amino acid sequences revealed that the blti2 contains three membrane-spanning regions. These results suggest that blti2 is a novel transmembrane protein induced by low temperature.

Amino Acid Sequence↗

Antioxidative activity of naringin and lovastatin in high cholesterol-fed rabbits.

The consumption of a cholesterol-enriched diet increases the degree of lipid peroxidation, which is one of the early processes of atherosclerosis. The aim of this trial was to determine the antioxidative effects of the citrus bioflavonoid, naringin, a potent cholesterol-lowering agent, compared to the cholesterol-lowering drug, lovastatin, in rabbits fed a high cholesterol diet. Male rabbits were served a high-cholesterol (0.5%, w/w) diet or high-cholesterol diet supplemented with either naringin (0.5% cholesterol, 0.05% naringin, w/w) or lovastatin (0.5% cholesterol, 0.03% lovastatin, w/w) for 8 weeks to determine the plasma and hepatic lipid peroxide, plasma vitamin A and E levels, and hepatic hydrogen peroxide levels, along with the hepatic antioxidant enzyme activities and gene expressions. Only the lovastatin group showed significantly lower plasma and hepatic lipid peroxide levels compared to the control group. The naringin supplementation significantly increased the activities of both hepatic SOD and catalase by 33% and 20%, respectively, whereas the lovastatin supplementation only increased the catalase activity by 23% compared to control group. There was no difference in the GSH-Px activities between the various groups. Content of H2O2 in hepatic mitochondria was significantly lower in groups supplemented with lovastatin and naringin than in control group. However, there was no difference in cytosolic H2O2 content in liver between groups. The concentration of plasma vitamin E was significantly increased by the naringin supplementation. When comparing the antioxidant enzyme gene expression, the mRNA expression of SOD, catalase and GSH-Px was significantly up-regulated in the naringin-supplemented group. Accordingly, these results would appear to indicate that naringin, a citrus bioflavonoid, plays an important role in regulating antioxidative capacities by increasing the SOD and catalase activities, up-regulating the gene expressions of SOD, catalase, and GSH-Px, and protecting the plasma vitamin E. In contrast, lovastatin exhibited an inhibitory effect on the plasma and hepatic lipid peroxidation and increased the hepatic catalase activity in high-cholesterol fed rabbits.

Animals↗

Oligoclonal B lymphocyte expansion in the synovium of a patient with Behçet's disease.

OBJECTIVE: Plasma cell infiltration is observed in recurrent arthritis associated with Behçet's disease (BD). The immune mechanism underlying B lymphocyte proliferation in the synovium is unclear. One hypothesis involves nonspecific polyclonal activation and another involves antigen-driven activation. The present study was undertaken to test both hypotheses and identify immunoglobulin genes that are clonally expanded in the synovium. METHODS: Peripheral blood lymphocytes (PBL) and synovial cells from a patient with BD and PBL from a healthy control subject were obtained. Complementarity-determining region 3 (CDR3) fingerprinting analysis and nucleotide sequence analysis of Ig transcripts derived from clonally expanded B lymphocytes were performed in parallel. RESULTS: Of 44 mu heavy chain clones of the VH4 family identified in the synovial tissue from the BD patient, 8 clones showed identical nucleotide sequences, and therefore, 18.2% were clonally expanded. For y heavy chain, 4 of 50 clones of the VH3 family showed nearly identical sequences; therefore, 4-8% were clonally expanded. The kappa light chain did not show a dominant band, but a clone with a 12-amino acid CDR3 showed 3% clonal expansion. Somatic mutations were frequently observed, with a high ratio of replacement to silent mutations in the CDRs compared with the framework regions. Three Ig genes expressed in the clonally expanded B lymphocytes were derived from germline gene segments reported to be involved in the production of autoantibodies. CONCLUSION: These results support the hypothesis that antigen-driven clonal B lymphocyte proliferation occurs in the synovium in BD. Immunoglobulin transcripts clonally expanded in the synovium were identified.

Adult↗

Inhibition of nitric oxide synthesis increases apoptotic cardiomyocyte death and myocardial angiotensin-converting enzyme gene expression in ischemia/reperfusion-injured myocardium of rats.

Cardiomyocyte apoptosis is an important pathogenic mechanism in myocardial ischemia/reperfusion (I/R) injury. It has been shown that nitric oxide (NO) and the renin-angiotensin system (RAS) are closely related, and both systems regulate apoptotic cell death. However, the effects of NO modulation on myocardial apoptotic cell death and changes in the RAS in the I/R-injured myocardium have not been studied. Female Sprague-Dawley rats were randomized into three groups: NO synthesis inhibitor, N(G)-nitro-L-arginine-methyl ester (L-NAME, 10mg/kg); NO precursor, L-arginine (540mg/kg); and vehicle. The rats were then subjected to 45 min coronary occlusion followed by 4 h reperfusion. The TdT-mediated in situ nick and labeling (TUNEL) indices were 39.9%+/-0.8% at the border and 30.9%+/-1.2% at the center of the I/R area in the vehicle group. L-NAME administration significantly increased these TUNEL-positive cells to 45.3%+/-1.9% and 37.9%+/-1.3%, respectively (P < 0.05 each). L-arginine administration reduced the TUNEL index at the border zone with marginal significance (P = 0.08 vs vehicle group). I/R injury significantly reduced the angiotensin-converting enzyme (ACE) mRNA expression in the left (ventricular) free wall of vehicle group rats. However, ACE mRNA expression was 1.9 times greater in the L-NAME group than that in the vehicle group (P < 0.05). This study showed that the inhibition of NO synthesis increased apoptotic cardiomyocyte death and local ACE mRNA expression in the I/R-injured myocardium. Our observations indicate that NO, ACE, and apoptotic cardiomyocyte death are related to each other during I/R injury.

Animals↗

A phase I/IIa study on intra-articular injection of holmium-166-chitosan complex for the treatment of knee synovitis of rheumatoid arthritis.

Previous animal studies have established that the intra-articular injection of holmium-166-chitosan complex (DW-166HC) causes effective necrosis of the inflamed synovium with litle leakage of radioactivity from the injected joint. Based on these findings, we conducted a phase I/IIa study to examine the biodistribution of DW-166HC and to assess the safety of DW-166HC for the treatment of knee synovitis in patients with rheumatoid arthritis (RA). A total of 16 patients [1 man, 15 women; median age 49 (range 36-65) years] who had RA knee synovitis refractory to disease-modifying anti-rheumatic drug treatments of > 3 months' duration were randomly assigned to three treatment groups with different radiation doses of DW-166HC: 370 MBq (n = 6), 555 MBq (n = 5) and 740 MBq (n = 5). In each treatment group, blood and urine radioactivity were analysed by beta counter and biodistribution of the injected DW-166HC was evaluated using a gamma scan camera. Clinical assessment was done according to three variables (evaluation method): knee joint pain (visual analogue scale), range of motion (goniometry) and joint swelling (circumference of knee joint). The duration of follow-up observation was 3 months. Following the intra-articular injection of DW-166HC, the blood radioactivity was little changed from the baseline measurement and the accumulated radioactivity excreted in urine was minimal. Gamma scan study indicated that most of the injected radiochemical was localized within the injected joint cavity, and the extra-articular leakage was negligible at 24 h after the injection: brain, 0.3%; lung, 0.6%; abdomen, 0.7%; and pelvis, 0.8%. Major adverse events were transient post-injection knee joint pain and swelling. These results suggest that DW-166HC might be a safe agent for radiation synovectomy, particularly for the treatment of knee synovitis of RA, and further trials in a larger patient population are warranted to evaluate the therapeutic efficacy of DW-166HC.

Adult↗

The co-expression of p53 protein and P-glycoprotein is correlated to a poor prognosis in osteosarcoma.

Multidrug resistance (MDR), mediated by P-glycoprotein (P-gp), is an in vitro phenomenon observed within tumour cells, suggesting cross-resistance to unrelated drugs, and expression of P-gp may therefore affect the prognosis and incidence of recurrence after treatment. The mutant p53 protein causes reduced tumour suppression. Co-expression of p53 and P-gp is related to short survival, increased tumour activity and drug resistance. The purpose of this study was to measure the expression of p53 protein and P-gp in osteosarcoma tissue and assess its prognostic significance. Fifty-two tumour specimens were evaluated. The correlation between p53 and P-gp expression was significant (P=0.0008). In univariate analysis of survival, p53 protein was not significant (P=0.2) but P-gp was significant (P=0.0001). The co-expression of p53 and P-gp was the strongest indicator of a short survival according to multivariate analysis (P=0.0004).

ATP Binding Cassette Transporter, Subfamily B, Mem↗

The cytotoxic effect of methotrexate loaded bone cement on osteosarcoma cell lines.

We mixed various amounts of methotrexate with bone cement and measured the absorbance daily for 4 weeks. The cytotoxic effects on SaOS2 and MG63 osteosarcoma cells were examined by the MTT assay, and analysed according to the methotrexate concentration and the elapsed time. The amount of eluted methotrexate was greatest during the first day, and then decreased rapidly reaching a plateau in the third week. The number of viable tumour cells decreased significantly after 72 h, and they were hardly seen after 1 week.

Antimetabolites, Antineoplastic↗

Off-pump coronary artery bypass may decrease the patency of saphenous vein grafts.

BACKGROUND: There is concern that a hypercoagulable status is caused after coronary artery bypass grafting without cardiopulmonary bypass (off-pump coronary artery bypass grafting, or OPCAB) and may potentially endanger the patency of the anastomosis. The aims of this study were: (1) to compare 1-year graft patency after OPCAB with that of conventional coronary artery bypass grafting (CABG) and that of on-pump beating CABG; and (2) to demonstrate any differences in patency of various conduits among the three groups. METHODS: We analyzed the results of 122 consecutive OPCAB cases (group 1) compared with those of 65 consecutive conventional CABG cases (group II) and those of 19 consecutive on-pump beating CABG cases (group III). In group I, coronary angiography (CAG) was performed immediately postoperatively and 1 year after surgery. In groups II and III, CAG was performed 1 year after surgery. Graft patency was graded as grade A (excellent), grade B (fair), or grade O (occluded). RESULTS: The average number of distal anastomoses in groups I, II, and III were 3.1 +/- 1.1, 3.7 +/- 0.9, and 3.6 +/- 0.9, respectively. In group I, postoperative CAG was performed in 92% of patients (112/122) before discharge. The patency rate (grade A + B) was 96.4% (162/168) for arterial grafts, and 85.6% (160/187) for saphenous vein grafts (SVG). One-year follow-up CAG was performed in 74% of patients (90/122). The patency rate was 97.8% (132/135) for arterial grafts and 67.9% (106/156) for SVG. In group II, 1-year follow-up CAG was performed in 65% of patients (42/65). The patency rate (grade A + B) was 93.5% (43/46) for arterial grafts and 88.3% (98/111) for SVG. In group III, 1-year follow-up CAG was performed in 89% of patients (17/19). The patency rate (grade A + B) was 100% (19/19) for arterial grafts and 86.8% (33/38) for SVG. CONCLUSIONS: Our results demonstrate that the patency rate ot SVG after OPCAB was significantly lower than that of arterial grafts in the early postoperative CAG (p < 0.001), and was also significantly lower than those of SVG of group II (p < 0.001) and group III (p < 0.01) in the postoperative 1-year CAG, although there was no significant difference in 1-year patency of arterial grafts among the three groups. Our data suggest that a specific perioperative anticoagulant therapy may be advisable in patients undergoing OPCAB with SVG.

Anastomosis, Surgical↗

Lipid-lowering and antioxidative activities of 3,4-di(OH)-cinnamate and 3,4-di(OH)-hydrocinnamate in cholesterol-fed rats.

BACKGROUND: Polyphenols appear to have antioxidant activities and may mediate lipid lowering. METHODS: Four groups of rats, a high-cholesterol control (HC), HC+lovastatin, HC+3,4-di(OH)-cinnamate, and HC+3,4-di(OH)-hydrocinnamate, were given a semi-synthetic diet. The cinnamate derivative or lovastatin (0.1 g/100 g) supplements were given for 6 weeks. RESULTS: The plasma total cholesterol concentration was significantly lowered by the 3,4-di(OH)-cinnamate supplement compared to the control or lovastatin group. The 3,4-di(OH)-cinnamate and 3,4-di(OH)-hydrocinnamate supplements significantly lowered both the hepatic cholesterol and triglyceride levels, while lovastatin only lowered the hepatic cholesterol. The hepatic HMG-CoA reductase activities were significantly lower in the 3,4-di(OH)-cinnamate and 3,4-di(OH)-hydrocinnamate groups than in the control or lovastatin group. The ACAT activity was only significantly lower in the lovastatin group compared to the other groups. With regards the hepatic antioxidant enzyme system, the CAT activity was significantly higher in the 3,4-di(OH)-cinnamate and 3,4-di(OH)-hydrocinnamate groups compared to the control or lovastatin group. The two cinnamate derivatives resulted in an increased hepatic GSH-Px activity. Meanwhile, all the supplements significantly lowered the hepatic thiobarbituric acid reactive substances (TBARS) content. However, the 3,4-di(OH)-cinnamate and 3,4-di(OH)-hydrocinnamate supplements did not alter the neutral sterol and total fecal sterol. CONCLUSIONS: Both cinnamate derivatives were potent in lipid-lowering and altering the antioxidative enzyme. Furthermore, these results also suggest that 3,4-di(OH)-cinnamate is more effective than 3,4-di(OH)-hydrocinnamate in its lipid-lowering action.

Animals↗

Interactive effect of hesperidin and vitamin E supplements on cholesterol metabolism in high cholesterol-fed rats.

Certain bioflavonoids are potent antioxidants and have pharmacologic effects similar to those of vitamin E. Accordingly, the interactive effect of hesperidin and vitamin E was studied with respect to cholesterol metabolism and the antioxidant status. Hesperidin supplement (0.1%, wt/wt) with comparable levels of vitamin E was provided with a high-cholesterol (1%, wt/wt) diet to rats for 5 weeks. The amount of vitamin E included in the hesperidin-free and hesperidin diets was either a low (low-E) or a normal (normal-E) level. The hesperidin supplement and different levels of dietary vitamin E did not significantly alter the concentrations of plasma triglycerides. However, the inclusion of hesperidin significantly lowered the concentration of plasma cholesterol in both the low-vitamin E group and the normal-vitamin E group compared to the hesperidin-free groups (p < 0.05). The hepatic triglyceride content was significantly lowered by the hesperidin supplement, as opposed to the plasma triglyceride content, regardless of the vitamin E level in the diet. The hepatic HMG-CoA reductase activity was significantly lowered by the hesperidin supplement with both the low-vitamin E and the normal-vitamin E compared to the hesperidin-free groups (p < 0.05). The hepatic HMG-CoA reductase activity was also significantly lowered with an increase in the dietary vitamin E within the hesperidin and hesperidin-free groups. The excretion of fecal neutral sterol and acidic sterols tended to be lower with the hesperidin supplement. Neither dietary hesperidin nor vitamin E significantly changed the hepatic antioxidant enzyme activity. This data indicates that hesperidin lowers the concentration of plasma cholesterol and the hepatic triglyceride content regardless of the dietary vitamin E level. However, the concentration of plasma cholesterol in the hesperidin-free groups was dependent on the dietary vitamin E level. This information may contribute to understanding the interactive effect of hesperidin and vitamin E on cholesterol biosynthesis in high cholesterol-fed rats.

Animals↗

Vitamin C prevents radiation-induced endothelium-dependent vasomotor dysfunction and de-endothelialization by inhibiting oxidative damage in the rat.

1. The present study was undertaken to determine whether endothelial function or morphology was altered in aortic rings of rats after irradiation, to investigate the mechanism of radiation effects on the endothelium and to examine the effect of vitamin C treatment against radiation-induced damage of the endothelium. 2. Female Sprague-Dawley rats were randomized into four groups (control, radiation, radiation + vitamin C, radiation + vitamin C + NG-nitro-L-arginine methyl ester (L-NAME); n = 10 for each group and n = 7 for the control group) and were irradiated with 10 Gy of 137Cs as a radiation source. Segments of the thoracic aorta were obtained and isometric tension, levels of 8-hydroxydeoxyguanosine (OH-dG) and immunohistochemical staining were measured. 3. Irradiation significantly impaired the acetylcholine-induced vasodilation of aortic segments, an effect that could be prevented by pretreatment with vitamin C (500 mg/kg per day). This beneficial effect of vitamin C was abolished by the addition of L-NAME (100 microg/kg per day), an inhibitor of nitric oxide (NO) synthesis. Irradiation significantly increased the level of OH-dG in the aorta (1.02 +/- 0.27 vs 2.61 +/- 0.78 OH-dG/105 deoxyguanosine (dG) for control and irradiated tissues, respectively; P < 0.01), an increase that was prevented by vitamin C treatment (1.59 +/- 0.23 OH-dG/105 dG; P < 0.01). Irradiation caused significant de-endothelialization (von Willebrand factor (vWF) staining was 93 +/- 7 vs 100% in irradiated and control tissues, respectively; P < 0.05) and this was prevented by vitamin C treatment (vWF staining 98 +/- 3%; P < 0.05). 4. Radiation caused endothelial damage and impaired NO production through oxidative injury, resulting in a selective impairment of endothelial-dependent vasodilation that could be prevented by vitamin C, partly through anti-oxidant mechanisms.

Acetylcholine↗

The value of contrast echocardiography in the diagnosis of patent ductus arteriosus with Eisenmenger's syndrome.

When patent ductus arteriosus (PDA) is complicated by pulmonary hypertension resulting in a right-to-left shunt, an erroneous diagnosis of primary pulmonary hypertension may be made, even after echocardiographic examination. Among the 8 patients referred to our echocardiography laboratory with the diagnosis of primary pulmonary hypertension between June 1994 and November 1999, 2 patients were found to have PDA with Eisenmenger's syndrome. Patent ductus arteriosus with Eisenmenger's syndrome can be diagnosed by the opacification of the abdominal aorta without opacification of the left-sided chambers during contrast echocardiography.

Adolescent↗

Naringin has an antiatherogenic effect with the inhibition of intercellular adhesion molecule-1 in hypercholesterolemic rabbits.

Naringin, a bioflavonoid found in citrus fruit peel, is known to have an antioxidative effect, but its effect on atherosclerosis has not been studied. This study evaluated the effect of naringin on blood lipid levels and aortic fatty streaks, and its action mechanism in hypercholesterolemic rabbits. Male New Zealand white rabbits were fed a 0.25% cholesterol diet and divided into an untreated group (n = 4), a naringin-treated group (n = 5; 500 mg/kg per day), and a lovastatin-treated group (n = 5; 20 mg/kg per day). After 8 weeks, blood was sampled and analyzed biochemically. Aorta and liver were harvested and examined histologically. Cholesterol level in rabbits fed the 0.25% cholesterol diet reached 17 times normal and decreased in the rabbits fed naringin and lovastatin, whose effects were not statistically significant (p > 0.05). However, both naringin and lovastatin effectively decreased the area of fatty streak in thoracic aorta on macroscopic analysis (p < 0.05) and significantly reduced subintimal foam cell infiltration on microscopic morphometry (p < 0.05). These foam cells were macrophages on immunohistochemical analysis. Naringin treatment inhibited hypercholesterolemia-induced intercellular adhesion molecule-1 (ICAM-1) expression on endothelial cells. Hypercholesterolemia caused fatty liver and elevation of liver enzymes, which was prevented by naringin but not by lovastatin. Naringin significantly reduced fatty streak formation and neointimal macrophage infiltration and also inhibited the expression of ICAM-1 in endothelial cells, suggesting that suppression of ICAM-1 contributed to the antiatherogenic effect. Naringin, unlike lovastatin, has a hepatoprotective action.

Animals↗

Effects of Puerariae Flos and Puerariae Radix extracts on antioxidant enzymes in ethanol-treated rats.

This study was performed to investigate the effect of Puerariae Flos (PF) and Puerariae Radix (PR) water extracts on the activities and mRNA expression of three hepatic antioxidant enzymes in ethanol-treated rats. Male Sprague-Dawley rats were divided into four groups, a control, ethanol-treated, ethanol plus PF-treated, and ethanol plus PR-treated group with seven rats per group. Ethanol (25 % v/v, 5 g/kg body weight) was orally administered once a day for 5 weeks. The PF and PR water extracts were supplemented in a diet based on 1.2 g of raw PF or PR/kg body weight/day. Ethanol administration without the PF or PR supplement significantly lowered the activities of hepatic Cu/Zn SOD and catalase (CAT), whereas it increased the hepatic GSH-Px activity. However, the PF and PR supplementation resulted in a significant increase in the Cu/Zn SOD and/or CAT activities and a significant decrease in the GSH-Px activity in the ethanol-treated rats. The mRNA levels of these antioxidant enzymes in the ethanol-treated rats were normalized to the control level by the PF or PR supplement. The hepatic glutathione content, which was significantly lower in the ethanol-treated group than in the control group, was also normalized to the control level by supplementing with either PF or PR. The PF or PR supplement resulted in lowering the hepatic malondialdehyde to the control level in the ethanol-treated rats.

Animals↗