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Biomedical subjects

Y Jang

Publications and source records attributed to Y Jang.

At least 37 records · Page 2Linked to original sources
PubMed2001

Cross-cultural comparability of the Geriatric Depression Scale: comparison between older Koreans and older Americans.

It is becoming increasingly clear that, in order to better understand the implications of global aging, more cross-cultural research is needed. In the present study, the structure and validity of the Geriatric Depression Scale-Short Form (GDS-SF) was examined in Korean and US samples of older adults. The participants included 153 older adults living in Korea (mean age=65.9 years) and 459 older adults from Florida (mean age=72.4 years). All participants completed the original or translated versions of the GDS-SF, as well as additional demographic and health-related measures. The results indicated that the GDS-SF exhibited good reliability in both samples. However, the results of a principal components analysis indicated that the structure was not well replicated across the two samples. In general, the present study suggests that, despite great efforts to make the questionnaires equivalent in the two cultures, the concept of depression for older adults may vary greatly in Korea and the USA. Possible explanations for cross-cultural differences are discussed, as well as implications.

Aged↗
PubMed2001

Differences in body fat distribution and antioxidant status in Korean men with cardiovascular disease with or without diabetes.

BACKGROUND: Abnormal body fat distribution and reduced antioxidant status have been shown to be effective markers of risk of cardiovascular disease (CVD). OBJECTIVE: The objective of this study was to determine the differences in body fat distribution and antioxidant status in healthy men (control subjects) and in men with CVD with or without diabetes. DESIGN: An oral-glucose-tolerance test was performed and CVD patients were subdivided into groups according to the presence or absence of diabetes. Adipose tissue areas were calculated from computed tomography scans made at the L1 and L4 vertebrae. Fasting serum concentrations of lipids, testosterone, insulin-like growth factor I, antioxidants, and plasma homocysteine were determined. RESULTS: There were no significant differences in mean age, body mass index (in kg/m(2)), or blood pressure between the groups. The visceral fat area at the L1 vertebra was nonsignificantly greater in CVD patients without diabetes than in control subjects, whereas it was significantly greater in CVD patients with diabetes than in control subjects at both the L1 and L4 vertebrae. Both groups of CVD patients had higher plasma concentrations of homocysteine and lower serum insulin-like growth factor I concentrations and superoxide dismutase activities than did control subjects. Serum ss-carotene and lycopene concentrations were lowest in the CVD patients with diabetes. CONCLUSION: The concurrent presence of CVD and diabetes is associated with a greater negative effect on the risk factors typically associated with significant declines in health status.

Adipose Tissue↗
PubMed2001

Consumption of whole grain and legume powder reduces insulin demand, lipid peroxidation, and plasma homocysteine concentrations in patients with coronary artery disease: randomized controlled clinical trial.

Our objective was to evaluate whether isocaloric replacement of refined rice with whole grains and other plant products as a form of powder reduces coronary artery disease (CAD) risk factors, such as insulin demand and lipid peroxidation in CAD patients. Seventy-six male patients with CAD were randomly assigned to either a group ingesting a whole-grain meal daily or a control group for 16 weeks. In the whole-grain group, serum concentrations of glucose and insulin decreased by 24% and 14%, respectively, without altering body weight and energy intake, whereas daily intakes of fiber and vitamin E increased by 25% and 41%, respectively. Consumption of whole grains and legume powder in CAD patients without diabetes decreased fasting levels of glucose and insulin. The areas under the curve for insulin and glucose during the oral glucose tolerance test were also decreased. CAD patients with diabetes in the whole-grain group also showed reductions in fasting glucose and in the area under the curve for glucose. In the whole-grain group, plasma malondialdehyde and homocysteine and urinary 8-epi-prostaglandin F(2alpha) concentrations decreased by approximately 28%. Also, lipid-corrected concentrations of alpha-carotene, retinol, tocopherols, and lycopene increased by 11% to 40%, and the percentage composition of n-6 fatty acids of serum phospholipid increased by 14% in the whole-grain group. The replacement of refined rice with whole grain and legume powder as a source of carbohydrate in a meal showed significant beneficial effects on glucose, insulin, and homocysteine concentrations and lipid peroxidation in CAD patients. These effects are likely to substantially reduce the risk factors for CAD and diabetes.

Area Under Curve↗
PubMed2001

Stenting with intravenous abciximab infusion for the treatment of left main coronary artery thrombosis during coronary angioplasty.

A 67-year-old female patient complained of exertional precordial chest pain with radiation to the left shoulder occurring over a two-month period. An acute non-Q wave anterior myocardial infarction was diagnosed. On the third day of admission, coronary angiography revealed two-vessel disease with 73% luminal narrowing of the proximal left anterior descending coronary artery and 50% luminal narrowing of the mid-right coronary artery. The initial attempt to implant a NIR stent (Boston Scientific/Scimed, Inc., Maple Grove, Minnesota) was unsuccessful. We report on the successful rescue implantation of two MAC (Maximum Arterial re-Creation) stents (Advanced Medical Technologies, Germany), in conjunction with the infusion of abciximab for the treatment of an abrupt closure due to thrombus of the left main coronary artery.

Abciximab↗
PubMed2000

Suppressive mechanism of salmosin, a novel disintegrin in B16 melanoma cell metastasis.

We have previously reported that salmosin, a novel disintegrin, was isolated from Korean snake (Agkistrodon halys brevicaudus) venom and significantly inhibited solid tumor growth in mice by perturbation of tumor-specific angiogenesis via blocking alphavbeta3 integrin expressed on vascular endothelial cells. In this study, we investigated the functional specificity of salmosin in tumor cell metastasis. Recombinant salmosin expressed in E. coli that has the RGD sequence markedly inhibited both B16F10 melanoma cell adhesion to the extracellular matrix proteins as well as B16F10 melanoma cell invasion through Matrigel-coated filter. The inhibition by salmosin can be caused by blocking integrins expressed on the surface of B16F10 melanoma cells. Salmosin significantly inhibited the proliferation of B16F10 melanoma cells on the plate coated with collagen I in a dose-dependent manner. In vivo B16F10 melanoma experimental metastasis, salmosin showed remarkable significant inhibitory effect on lung tumor colonization in a concentration-dependent manner. These results clearly demonstrate that antimetastatic activity of salmosin resulted from blocking the integrin-mediated adherence and alphavbeta3 integrin-mediated proliferation of the melanoma cells.

Animals↗
PubMed2000

Optimization of regulated LTR-mediated expression.

Retroviral vectors are ideally suited to the study of gene function, allowing efficient, stable expression. Many biological systems (e.g., cell cycle, apoptosis) require the use of regulated expression systems. We therefore developed a regulated retroviral vector system, TRA99, based on a tetracycline transactivator-dependent LTR, where the MMLV enhancer was replaced with a tetracycline-response element. Using fluorescence-activated flow cytometric analysis of a destabilized green fluorescent protein to monitor expression levels, we optimized the minimal promoter configuration with respect to both activated and repressed transcription. The TRA99 vectors demonstrate regulated expression with activated levels comparable to those of standard retroviral vectors and repressed levels indistinguishable from background. This was achieved without using an internal promoter cassette, thus retaining the cis-packaging elements requisite for helper-mediated transfer.

Animals↗
PubMed2000

Is the left atrial v. wave the determinant of peak pulmonary artery pressure in patients with pure mitral stenosis?

A large left atrial (LA) v. wave can be observed in patients with pure mitral stenosis (MS) because of decreased LA compliance. Few data are available regarding the relation between the magnitude of the LA v wave and pulmonary artery pressure in MS. We hypothesized that pulmonary artery pressure may be higher in patients with decreased LA compliance and thus a large v. wave. We analyzed the right-sided cardiac and transseptal catheterization data in 113 patients (16 men and 97 women, mean age 39 years) with pure rheumatic MS in sinus rhythm. Peak systolic, diastolic, and mean pulmonary artery pressures were measured with right-sided cardiac catheterization. The magnitude of LA a and v. waves were measured through transseptal catheterization. Two-dimensional and Doppler echocardiography were also performed to measure LA size, mitral valve area, mean mitral gradient, and valvular regurgitation. Multiple regression analysis was performed to identify the most important factor in the determination of pulmonary artery pressure. A large v wave, defined if peak v wave height exceeded the mean LA pressure by > or =10 mm Hg, was observed in 43 of 113 patients (38%). Increased pulmonary artery systolic pressure (> or =50 mm Hg) was observed in 38 patients (34%). Univariate analysis showed that the factors associated with increased pulmonary artery systolic pressure were smaller mitral valve area, higher mean mitral gradient, higher mean LA pressure, and higher LA v. wave; among them, LA v wave (p <0. 001) and mean mitral gradient (p<0.001) were significant independent factors for pulmonary artery systolic pressure in multivariate analysis. In conclusion, in patients with pure MS and sinus rhythm, the magnitude of the LA v. wave is strongly associated with pulmonary artery pressure. This finding may suggest that LA compliance is a major contributing factor determining pulmonary artery pressure in pure MS.

Adult↗
PubMed2000

A simple self-rating assessment method of residual work capability for occupational permanent disabilities.

BACKGROUND: To explore the validity, reliability, and determinants of a simple self-rating assessment method of residual work capability (RWC) after occupational permanent disabilities. METHODS: Five hundred and thirty-nine compensated permanent disability workers answered three consecutive visual analogue questionnaires wherein they self-rated their residual work capability in terms of speed (RWCS), quality (RWCQ) and a combination of speed and quality (RWCC). At two major hospitals in Taiwan, 169 of these subjects were evaluated with physical capacity assessment (PCA), cognition and sensation assessment (CSA), the work ability index (WAI), and the 12-item Chinese health questionnaire (CHQ-12). RESULTS: High test-retest reliability (Pearson's correlation coefficient 0.77) and satisfactory concurrent validity were shown for RWCS and RWCC. All PCA, CSA and WAI showed significant correlation with RWCs, while CHQ-12 displayed borderline correlation. Employment status after injury and status of the victim's salary as the main source of income for his/her family before injury, were the major determinants of RWCs, in addition to the scales of PCA, CSA and WAI. CONCLUSIONS: The RWCC resulting from the self-rating method may be used as a simple assessment of a victim's residual work capability after occupational permanent disabilities.

Accidents, Occupational↗
PubMed2000

Quantitative genetics of female choice in an ultrasonic pyralid moth, Achroia grisella: variation and evolvability of preference along multiple dimensions of the male advertisement signal.

The mating system of Achroia grisella (Lepidoptera: Pyralidae) is characterized by male ultrasonic advertisement signalling to which females orientate. Although males provide no direct, somatic benefits to their mates, females prefer males whose signal characters are more exaggerated than the population means. Previous studies showed that the signal characters influencing mate attraction are highly repeatable and heritable. We measured the phenotypic and additive genetic variances (heritability) of female preference in A. grisella, as this additive genetic variance is one of the genetic assumptions of indirect models of sexual selection. We determined the preference index of female A. grisella by repeated phonotaxis trials in which a choice of simulated male signals was presented. These playback experiments showed that female preference indices varied but were repeatable within individuals. Specifically, females differ in the relative importance of the several signal characters during mate assessment. A subsequent half-sib breeding design revealed an amount of additive genetic variance for the female preference index (h(s)2 = 0.212, SE = 0.1347, P = 0.0611; CVA = 0.1826). Our study highlights the importance of careful preparation of test signals and experimental design for quantifying individual variation in (female) preference along multiple signal dimensions.

Animals↗
PubMed2000

Identification of new single-nucleotide polymorphisms in the thrombin receptor gene and their effects on coronary artery diseases in Koreans.

1. The thrombin receptor (the protease-activated receptor-1; PAR-1) is located on vascular cells as well as platelets and may play important roles in atherosclerotic disorders, such as coronary artery diseases (CAD). In the present study, we searched for genetic polymorphisms of the PAR-1 gene and evaluated their effects on CAD by association analysis. 2. We identified six polymorphisms in the 5'-untranslated region of the PAR-1 gene by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP); five single-nucleotide polymorphisms (SNP) at -2355 (A to G), -2333 (T to G), -1428 (G to A), -1071 (C to T) and -561 (A to G) and a simple sequence repeat (SSR) polymorphism between -1935 and -1841. Five SNP were in strong linkage disequilibrium with each other to make three major haplotypes, the frequency of which was over 90% of all possible haplotypes. 3. For association analysis, 150 patients who had CAD (CAD+), 58 subjects who had no stenosis on the coronary angiogram and 186 reference subjects who had no clinical evidence of CAD were used from the Korean population. The genotype frequencies of the SNP were in Hardy-Weinberg equilibrium, except A-561G in CAD+. The association of these SNP as well as of the SSR with CAD was not evident. This result suggests no major roles of the PAR-1 gene in CAD in Koreans.

5' Untranslated Regions↗
PubMed2000

Transsphenoidal supradiaphragmatic intradural approach: technical note.

Presellar extension of the bone window combined with removal of the sellar floor results in the transsphenoidal supradiaphragmatic intradural approach. One tuberculum sella meningioma and another suprasellar Rathke's cleft cyst confined to the pituitary stalk were removed via this approach. The presellar extension of the bone window was performed with the sublabial transseptal transsphenoidal technique. Furthermore, the dissection of the anterior intercavernous sinus, diaphragma sella, and arachnoid trabecula has allowed a wide surgical field of pre- and suprasellar areas and facilitates safe removal of lesions without significant surgical complications in selected cases.

Adult↗
PubMed2000

Enhanced detection of left atrial spontaneous echo contrast by transthoracic harmonic imaging in mitral stenosis.

BACKGROUND: Spontaneous echo contrast (SEC) of the left atrium is associated with increased risk of thromboembolism in patients with mitral stenosis (MS). The determination of the presence and severity of left atrial (LA) SEC is of prognostic importance in these patients. Harmonic imaging (HI), a novel echocardiographic technique that differs from conventional fundamental imaging (FI) in that it involves transmitting ultrasound at one frequency and receiving at twice the transmitted frequency, produces better endocardial border definition and myocardial opacification. However, there are no data about its value for the detection of LA SEC. The purpose of this study was to investigate the utility of transthoracic noncontrast tissue HI in the detection of LA SEC in patients with MS. METHODS: Seventy-four consecutive patients with MS (49 women, mean age 51 years) underwent standard transthoracic echocardiography (TTE) in both HI and FI modes and transesophageal echocardiography (TEE) to determine the presence and severity of LA SEC. Left atrial SEC was graded by TEE as either mild (only seen at high gain) or severe (visible in the entire left atrium at normal gain control of the equipment). The control group comprised 30 patients randomly selected from patients who did not have LA SEC at the TEE examination. RESULTS: Atrial fibrillation was found in 46 patients (62.2%). The mean mitral valve area and mean mitral gradient were 1.0+/-0.3 cm(2) and 8.2+/-4.1 mm Hg, respectively. Nine patients (12.2%) had episodes of systemic embolism; 8 had stroke, and 1 had peripheral embolism. Left atrial thrombus was found in 11 patients (14.9%) by TEE. Left atrial SEC was present in all but one patient by TEE (mild in 35 patients, severe in 38). Fundamental imaging with TTE, however, revealed LA SEC in only 5 (6.8%) of the 73 patients. In contrast, with HI, LA SEC could be detected in 63 (86.3%) patients. In the detection of severe LA SEC, the sensitivities of FI and HI were 13.2% (5/38) and 100% (38/38), respectively. Left atrial SEC was not observed in control subjects by either FI or HI. CONCLUSIONS: Transthoracic HI significantly enhances the detection of LA SEC in patients with MS.

Adolescent↗
PubMed2000

Expression of osteopontin in calcified coronary atherosclerotic plaques.

Advanced atherosclerosis is often associated with dystrophic calcification and remodeling of extracellular matrix of vascular wall. Recently many studies have documented a general relationship between calcification and severity of coronary disease, and discussed the feasibility of electron beam computed tomography for detecting and quantifying the coronary artery calcification in the patients. The present study investigated the expression and the localization of osteopontin, one of noncollagenous bone matrix protein, within the calcified coronary arteries. Autopsy-derived coronary artery specimens were scanned and reconstructed to visualize the pattern of coronary calcification using a novel microscopic computed tomography technique. The localization of the osteopontin were evaluated by immunohistochemial stain with LF7. The present study showed that the pattern of coronary calcification is variable and the expression of osteopontin is localized mainly to calcified lesion. The smooth muscle cells in addition to macrophage expressed osteopontin protein in human coronary atherosclerotic plaques. Soluble osteopontin released near to the sites of vascular calcification may represent an adaptive mechanism aimed at regulating the process of vascular calcification.

Aged↗
PubMed2000

Expression of leptin receptor (Ob-R) in human atherosclerotic lesions: potential role in intimal neovascularization.

Neovascularization of the adventitial vasa vasorum with extension into the intima of atherosclerotic lesions is frequently observed, but its pathophysiological significance is still subject to debate. Recently, leptin, the product of the Ob gene, was identified. Leptin, via activation of the endothelial receptor (Ob-R), generates a growth signal involving a tyrosine kinase-dependent intracellular pathway and promotes angiogenic processes. We hypothesized that a high concentration of leptin within vasa vasorum and plaque itself, may influence inflammatory and vascular neovascularization coupling with functional upregulation of the vascular endothelial growth factor (VEGF). Microscopic computerized tomography was utilized for the spatial distribution of vasa vasorum and intimal neovascularization from atherosclerotic human coronary arteries. Atherosclerotic coronary arteries showed a dense plexus of microvessels in the adventitia and plaque itself. Microscopic analysis from human atherosclerotic aortas revealed an increase in the intimal thickness with neovascularization. The immunoreactivity for Ob-R, VEGF and matrix metalloproteinase (MMP) increased in atherosclerotic plaque, predominantly in the endothelial lining of the intimal neovessel and macrophages/foam cells. Our observation of a prominent colocalization between Ob-R, VEGF and MMP supports this hypothesis and these factors participate in the neovascularization of atherosclerotic lesions. The present study is the first report on vascular tissue and it opens a promising perspective concerning future investigations of leptin-dependent modulation of atherogenesis and vascular neovascularization under pathophysiolgical conditions.

Adult↗
PubMed2000

Coexpression of cyclooxygenase-2 and matrix metalloproteinases in human aortic atherosclerotic lesions.

Inflammation appears to have a major role in the development of atherosclerosis. Cyclooxygenase-2 (COX-2) is involved in the inflammatory response via the generation of prostanoids that, in turn, are involved in the production of matrix metalloproteinases (MMPs). This study aimed to investigate atherosclerosis in human aortas for in situ tissue distribution of COX-2, MMPs including MMP-9 and membrane type 1 MMP (MT1-MMP), and tissue inhibitor of metalloproteinase-2 (TIMP-2). Immunohistochemical studies were performed on atherosclerotic lesions of aortas from patients with aortic aneurysms (n = 4) and dissections (n = 3) by using antibodies to COX-2, MMP-9, MT1-MMP, and TIMP-2. Control tissues were obtained from traumatically dissected aortas (n = 2). All specimens from diseased aortas had atherosclerotic lesions ranging from fatty streak to atheromatous plaques. In control, there was no expression of COX-2, MMP-9, and MT1-MMP in all aortic layers. Immunoreactivity for COX-2 was predominantly noted in macrophages and smooth muscle cells (SMCs) of the intima including atherosclerotic plaque itself and the medial layer of the plaque base, as well as in SMCs and endothelial lining of the vasa vasorum in the adventitia. Immunoreactivity for MMP-9 and MT1-MMP was found in the same distribution as that of COX-2. Additionally, the expression of TIMP-2 increased in relation to MMP-9 expression. This study demonstrates that COX-2 is coexpressed with MMP-9 and MT1-MMP, not only by macrophages and SMCs in atherosclerotic lesions, but also in endothelial lining of the vasa vasorum of human aortas. Thus, vascular inflammatory reactions may influence extracellular matrix remodeling by coactivation of MMPs in the development of atherosclerosis and, in turn, the progression of disease.

Animals↗
PubMed2000

Apoptosis in dilated cardiomyopathy.

OBJECTIVE: Cardiomyopathy, a popular diagnosis that always obscures more than it reveals, nevertheless has several characteristic histological features. These prominently include widespread focal myocardial fibrosis and associated hypertrophy of surviving cardiac myocyte. In fact, focal noninflammatory degeneration (not necrosis) has been demonstrated as a feature of many forms of cardiac hypertrophy. We hypothesized that this loss of myocardial cells in dilated cardiomyopathy (DCMP) may result from cell death by apoptosis. METHODS: Endomyocardial biopsy specimens from the right ventricles of six patients who suffered from DCMP were studied, and myocardial specimens from two persons who died in motor vehicle accidents were used as negative controls. For identification of apoptosis, immunohistochemistry with terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling was performed. In addition, apoptosis was confirmed morphologically by confocal laser scanning microscopy with propidium iodide. RESULTS: Apoptosis, that was represented by an apoptotic index ranging from 19.8 to 25.4%, could be extensively seen in myocytes and also rarely in non-myocytes of interstitium and vascular endothelium. Morphologically, there were a lot of nuclei with clumps of condensed chromatin, suggestive of apoptosis. CONCLUSION: The present study demonstrated that myocyte loss in DCMP might be mainly due to the apoptosis of myocytes and interstitial cells, rather than inflammation or cell necrosis.

Adult↗
PubMed2000

[Quick RNA extraction from specified morphological region in frozen sections and its RT-PCR application].

OBJECTIVE: To establish a method for quick RNA extraction from specified histological region in frozen sections so as to avoid cross RNA contamination among different types of cells/tissues and to achieve specific RT-PCR amplification. METHODS: Prepare serial frozen sections 5microm in thickness for histological and immunocytochemical examination. Based on the results, make one or two pieces of 20 microm section and select a specified region for quick RNA extraction and RT-PCR analysis. RESULTS: RNA extraction can be finished within an hour and the data of RT-PCR obtained within 6 hours. Besides the high performance, this method can efficiently exclude pseudo positive or pseudo negative results caused by inter-cellular RNA contamination. CONCLUSION: This method is an important complement to the current techniques for RNA extraction and RT-PCR.

Frozen Sections↗