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Biomedical subjects

S W Han

Publications and source records attributed to S W Han.

At least 19 recordsLinked to original sources
PubMed2006

Association of aortic plaque with intracranial atherosclerosis in patients with stroke.

OBJECTIVE: To determine whether there is a relationship between aortic plaques and intracranial (IC) atherosclerosis. METHODS: We reviewed 922 patients with stroke who had both transesophageal echocardiography and cerebral angiography. The plaques of these patients were classified as either complex aortic plaques (CAP), which protruded > or =4 mm or were present as mobile lesions in the proximal aorta, or simple aortic plaques (SAP), which were <4 mm or present in the descending aorta. Cerebral artery atherosclerosis was classified as either an IC or extracranial (EC) atherosclerosis. RESULTS: Among the 922 patients, we found aortic plaques in 237 patients (26%). There were 111 (47%) patients of SAP, 74 (31%) patients with CAP, and 52 (22%) patients that had both SAP and CAP. Angiography showed IC or EC atherosclerosis in 511 patients (55%). The presence of aortic plaques was significantly associated with IC or EC atherosclerosis. The significance appeared to be due to the strong association between the presence of SAP and IC atherosclerosis (51% SAP vs 35% no plaques; odds ratio = 1.94, 95% CI: 1.17 to 3.21). In the multiple logistic regression analysis, SAP were independent predictors of IC atherosclerosis CONCLUSIONS: The presence of simple aortic plaques may be a marker of advanced vascular disease. Detection of simple aortic plaques during transesophageal echocardiography may have clinical implications because patients with these plaques frequently had concomitant intracranial atherosclerosis, a risk factor for stroke.

Aged↗
PubMed2006

Fibronectin induces cell proliferation and inhibits apoptosis in human bronchial epithelial cells: pro-oncogenic effects mediated by PI3-kinase and NF-kappa B.

The extracellular matrix glycoprotein, fibronectin, influences a variety of cellular functions including adhesion, migration, survival, differentiation, and growth. Fibronectin has also been shown to increase the migration and proliferation of human lung carcinoma cells. However, the role of fibronectin in controlling lung airway epithelial cell phenotype remains unknown. Here, we demonstrate that fibronectin stimulates the proliferation of human bronchial epithelial cells (BEAS-2B and 16-HBE). Of note, fibronectin induced the mRNA and protein expression of c-Myc and cyclin D1, while it decreased the expressions of cyclin-dependent kinase inhibitor p21 (WAF-1/CIP1/MDA-6) (p21) and the tumor suppressor gene phosphatase and tensin homolog deleted on chromosome ten (PTEN). Fibronectin also stimulated the phosphorylation of the phosphatidylinositol 3 kinase (PI3-K) downstream signal Akt. The inhibitor of PI3-K, Wortmannin, and anti-alpha5beta1 integrin antibodies abrogated the effect of fibronectin on c-Myc, cyclin D1, p21, and PTEN expression. The stimulatory effect of fibronectin was mediated by nuclear factor kappaB (NF-kappaB) since fibronectin induced the expression of the p65 component of NF-kappaB and enhanced NF-kappaB DNA binding. Furthermore, we found that p65 small interfering RNA inhibited the effect of fibronectin on c-Myc, cyclin D1, p21, PTEN expression, and on fibronectin-induced cell proliferation. Finally, we found that fibronectin inhibits apoptosis by reducing DNA fragmentation and inhibiting the activities of caspases 3/7. Taken together, our findings demonstrate that fibronectin stimulates human bronchial epithelial cell growth and inhibits apoptosis through activation of NF-kappaB, which, in turn, increases the expression of c-Myc and cyclin D1 and decreases p21 and PTEN via alpha5beta1 integrin-dependent signals that include PI3-K/Akt. Therefore, alternations in the extracellular matrix composition of the lung, with increased fibronectin, might promote epithelial cell growth and thereby contribute to oncogenesis in certain settings.

Apoptosis↗
PubMed2005

Influence of VEGF gene polymorphisms on the severity of ankylosing spondylitis.

OBJECTIVES: To investigate the role of polymorphisms of the vascular endothelial growth factor (VEGF) gene in susceptibility to ankylosing spondylitis (AS), and their relationship to clinical features and radiographic severity. METHODS: This study included 157 patients with AS and 140 healthy unrelated controls. Polymorphisms of the VEGF gene were analysed by the polymerase chain reaction (PCR)-restriction fragment length polymorphism assay and amplification refractory mutation system-PCR. Haplotypes were reconstructed using the Bayesian algorithm. Radiographic severity was assessed by the Bath Ankylosing Spondylitis Radiological Index (BASRI). RESULTS: The genotype frequencies of the polymorphisms were in Hardy-Weinberg equilibrium. The distributions of genotypes and alleles did not differ between AS patients and controls. Among the six haplotypes reconstructed based on the tight linkage disequilibrium at positions -2578, -1154 and -634 (pairwise linkage disequilibrium coefficient, r = 0.361-0.706), no haplotype was associated with susceptibility to AS. Clinical features were analysed for the four haplotypes (CGC, CGG, AAG, AGG) which were prevalent. In carriers of the AGG haplotype, the frequency of cervical spine involvement was significantly higher (P = 0.002, P(corr) = 0.036) and that of patients showing a BASRI score >6 was also higher (P = 0.025, P(corr) = 0.45). CONCLUSIONS: This study demonstrates that polymorphisms of the VEGF gene may contribute to disease severity in AS.

Adult↗
PubMed2005

Spatial chemical inhomogeneity and local electronic structure of Mn-doped Ge ferromagnetic semiconductors.

We have investigated the chemical distributions and the local electronic structure of potential diluted magnetic semiconductor Ge0.94Mn0.06 single crystals using scanning photoelectron microscopy (SPEM), x-ray absorption spectroscopy (XAS), and photoemission spectroscopy (PES). The SPEM image shows the stripe-shaped microstructures, which arise from the chemical phase separation between the Mn-rich and Mn-depleted phases. The Mn 2p XAS shows that the Mn ions in the Mn-rich region are in the divalent high-spin Mn2+ states but that they do not form metallic Mn clusters. The Mn 3d PES spectrum exhibits a peak centered at approximately 4 eV below E(F) and the negligible spectral weight near E(F). This study suggests that the observed ferromagnetism in Ge1-xMnx arises from the phase-separated Mn-rich phase.

Journal Article↗
PubMed2005

Relationship between gene polymorphisms and prevalence of myocardial infarction among diabetic and non-diabetic subjects.

This study was aimed to examine cholesteryl ester transfer protein (CETP), apolipoprotein AI and CIII gene polymorphisms, and to verify whether these genetic determinants are associated with the prevalence of myocardial infarction (MI) or type 2 diabetes. The TaqIB restriction fragment length polymorphism (RFLP) in intron I of the CETP gene, the MspI in the third intron of the APOAI gene, and also SstI in the 3' untranslated region of the APOCIII gene were determined using standard methods. The prevalence of these polymorphisms was compared between diabetic (n = 119), and non-diabetic (n = 100) middle-aged individuals of both sexes. We found a higher prevalence of the B2B2 genotype of the CETP gene among diabetics than that observed in non-diabetics (P < 0.05), and a lower prevalence of this genotype among patients with previous MI (P < 0.02). The MspI polymorphisms of the APOAI gene showed that M1++ genotype was found mainly in diabetic patients (P < 0.04). Conversely, the SstI polymorphism of APOCIII gene was not significantly associated with either MI or diabetes. Therefore, among these genetic polymorphisms, TaqIB of CETP and MspI of apolipoprotein AI appeared to help significantly to identify diabetic individuals. In particular, the former may have an additional role in the primary prevention of coronary disease.

Apolipoprotein A-I↗
PubMed2004

Hemodynamic changes in limb shaking TIA associated with anterior cerebral artery stenosis.

Limb shaking TIA is a rare but well-known feature of severe carotid artery stenosis. The authors report a patient who developed recurrent shaking movements of a leg. An angiogram showed the focal stenosis of the anterior cerebral artery. Ictal and postacetazolamide SPECT scans suggested a local hyperfunction of cortical neurons and an impaired hemodynamic reserve in the vicinity of the ischemic area.

Acetazolamide↗
PubMed2004

VEGF gene polymorphisms and susceptibility to rheumatoid arthritis.

OBJECTIVES: To investigate polymorphisms of the VEGF gene in patients with rheumatoid arthritis (RA), their relationship to clinical features and the radiographic progression of joint disease. METHODS: One hundred and forty patients with RA and 149 healthy unrelated controls were recruited. We examined four polymorphisms of the VEGF gene which are reported to be associated with production of vascular endothelial growth factor (VEGF), using polymerase chain reaction (PCR) restriction fragment length polymorphism assay and amplification refractory mutation system (ARMS) PCR. Haplotypes were predicted by Bayesian algorithm using the Phase program. RESULTS: All four polymorphisms were in Hardy-Weinberg equilibrium in both patients and controls. The frequency of the 936 T allele, which has been associated with lower production of VEGF, was significantly increased in RA patients compared with controls (22.7 vs 13.4%, P = 0.002). The frequencies of two haplotypes (CGCT and AAGT) which were predicted using the Phase program were significantly increased in RA patients compared with controls [33 vs 14%, odds ratio (OR) 2.636, 95% confidence interval (CI) 1.38-5.04 for CGCT; 17 vs 6%, OR 3.08, 95% CI 1.20-7.92 for AAGT]. The carriers of the susceptible haplotypes in RA patients had a younger age at disease onset but did not show a difference in the progression rate of radiographic joint destruction. CONCLUSIONS: Our data suggest that the VEGF gene may play a role in the development of RA

Adult↗
PubMed2004

Observation of the decay psi(2S)-->K0SK0L.

The decay psi(2S)-->K(0)(S)K(0)(L) is observed using psi(2S) data collected with the Beijing Spectrometer at the Beijing Electron-Positron Collider; the branching fraction is determined to be B(psi(2S)-->K(0)(S)K(0)(L))=(5.24+/-0.47+/-0.48)x10(-5). Compared with J/psi-->K(0)(S)K(0)(L), the psi(2S) branching fraction is enhanced relative to the prediction of the perturbative QCD "12%" rule. The result, together with the branching fractions of psi(2S) decays to other pseudoscalar meson pairs (pi(+)pi(-) and K+K-), is used to investigate the relative phase between the three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.

Journal Article↗
PubMed2004

A comparison of the discriminatory power of the Inflammatory Bowel Disease Questionnaire and the SF-36 in people with ulcerative colitis.

The aim of this study was to compare the discriminatory power of a generic and a condition-specific quality of life measure (the Medical Outcomes Study Short-Form 36 (SF-36) and the Inflammatory Bowel Disease Questionnaire (IBDQ)) with respect to sub-groups defined by disease-related and other factors, in a sample of patients with ulcerative colitis. Disease activity was generally more highly correlated with IBDQ scores than with SF-36 scores. The only significant differences with respect to disease extent were in the SF-36 energy/vitality and social function domains. Age was negatively and weakly to moderately correlated with the physical domains of the SF-36 but positively though weakly correlated with scores on the IBDQ emotional domain and those domains of the SF-36 related to mental well-being. Co-existing chronic illness, even on controlling for age, was associated with significantly poorer scores on the generic measure, but had little influence on IBDQ scores. In conclusion, generic and disease-specific measures of quality of life appear to be complementary rather than interchangeable. We recommend the use of both types of measure in parallel.

Adult↗
PubMed2004

TGF-beta1 polymorphism determines the progression of joint damage in rheumatoid arthritis.

OBJECTIVE: To determine whether transforming growth factor-beta1 (TGF-beta1) polymorphisms are associated with susceptibility to rheumatoid arthritis (RA) and to analyse whether they can affect the progression of radiographic severity. METHODS: A total of 143 RA patients and 148 healthy unrelated controls were tested for the TGF-beta1 polymorphisms using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). RESULTS: The TGF-beta1 polymorphisms were not associated with susceptibility to RA, although there was a trend that -509C/T and the 869T/C polymorphisms were associated with RA in the male population. The progression of radiographic severity, which was defined by a modified Sharp score plotted against disease duration, was significantly faster in the carrier of T allele at the -509 (p=0.048). CONCLUSION: Our data support the hypothesis that TGF-beta1 polymorphism may determine the progression of joint destruction in RA.

Adult↗
PubMed2003

Observation of a near-threshold enhancement in the pp mass spectrum from radiative J/psi-->gammapp decays.

We observe a narrow enhancement near 2m(p) in the invariant mass spectrum of pp pairs from radiative J/psi-->gammapp decays. No similar structure is seen in J/psi-->pi(0)pp decays. The results are based on an analysis of a 58 x 10(6) event sample of J/psi decays accumulated with the BESII detector at the Beijing electron-positron collider. The enhancement can be fit with either an S- or P-wave Breit-Wigner resonance function. In the case of the S-wave fit, the peak mass is below 2m(p) at M=1859(+3)(-10) (stat)+5-25(syst) MeV/c(2) and the total width is Gamma<30 MeV/c(2) at the 90% confidence level. These mass and width values are not consistent with the properties of any known particle.

Journal Article↗
PubMed2003

Endoscopic hemoclipping using a transparent cap in technically difficult cases.

BACKGROUND AND STUDY AIMS: Technical difficulties have been experienced in endoscopic hemoclipping on the posterior wall of the body of the stomach because the angle of approach is tangential. It has been suggested that the use of a transparent cap on the tip of the endoscope could help to solve this problem. The purpose of this study was to examine the efficacy of endoscopic hemoclipping using a transparent cap over the tip of the endoscope. PATIENTS AND METHODS: A total of 74 patients with a bleeding peptic ulcer or stigmata of recent hemorrhage underwent endoscopic hemoclipping. Technical difficulty in hemoclipping was experienced in 18 patients and the transparent cap was used in these cases. We therefore conducted a nonrandomized prospective study to compare bleeding control with the hemoclip with and without the aid of a transparent cap. RESULTS: There were no statistically significant differences between the patients treated with the cap and those treated without the cap with regard to the initial hemostasis rate (94.4 % vs. 91.1 %), the rebleeding rate (11.7 % vs. 11.8 %), or the permanent hemostasis rate (94.4 % vs. 96.4 %). CONCLUSIONS: Although there was no statistically significant difference between patients treated with or without a transparent cap, hemoclipping with the aid of the cap made it possible to clip a lesion too tangential to be clipped without it. However, this study did not compare conventional hemoclipping with hemoclipping using a cap because the cap was only used in cases in which conventional clipping had failed.

Duodenal Ulcer↗
PubMed2002

Two cases of steakhouse syndrome associated with nutcracker esophagus.

The most common type of esophageal food-related foreign body is the meat bolus, which is frequently associated with underlying esophageal stenosis. Herein, we report two cases of meat bolus impaction associated with nutcracker esophagus. In the first case, the 63-year-old male patient had chest discomfort and swallowing difficulty after ingestion of butcher's meat. In the second case, the 55-year-old male patient had complained of swallowing difficulty after ingestion of chicken. In both cases, no pathologic findings were observed endoscopically after removal of the esophageal meat bolus. We performed esophageal manometry, which showed very high amplitudes of esophageal pressure in the mid- and distal esophagus. These findings were consistent with nutcracker esophagus. These cases show that esophageal motility disorder may be the cause of esophageal foreign body impaction, and esophageal manometry should be performed for evaluation of the cause of foreign body, especially in an endoscopically normal patient.

Deglutition Disorders↗
PubMed2002

Knowledge and attitudes of Korean parents towards their son's circumcision: a nationwide questionnaire study.

OBJECTIVE: To evaluate knowledge about the foreskin and circumcision, and to understand the attitudes of parents to circumcision in Korea, where circumcision in childhood is widely practised with no particular religious or medical background. SUBJECTS AND METHODS: A nationwide study involving questionnaires was conducted on 5500 parents with at least one son attending elementary school. Responses were obtained from one of the parents. RESULTS: The response rate was 76.1% (4183); circumcision was most common in boys when aged 11 years, followed by neonatal circumcision. Of the parents, 91.3% believed that circumcision is necessary, while 2.1% believed it to be unnecessary. The principal reasons given for circumcision were 'to improve penile hygiene' (82.4%), followed by 'to improve future sexual potency' (7.5%). Among those who did not believe circumcision to be necessary, the most common reason was the expectation of spontaneous retraction of the prepuce with age (55.1%). Most (88.4%) of the parents believed that smegma is not a clean material, and is infected by microorganisms. Most parents (80.6%) thought that circumcision would prevent genital tract infection of the future spouse. Peer pressure was one of the most influential factors in deciding upon circumcision; 41.9% of the parents were anxious that their child might be ridiculed by his peer group unless he was circumcised, while 27.4% of the parents believed that their child might be ridiculed if he was circumcised. Mothers were more positive about circumcision than fathers (P < 0.05). Parents with a higher education and higher socio-economic status were also more positive about circumcision (P < 0.05). Mothers were prone to emphasize improved sexual potency (P < 0.05). There was no significant difference in response between urban and rural areas. CONCLUSION: This study indicates that common beliefs held by parents about the prepuce or circumcision differ significantly from current medical knowledge, and these beliefs have a major influence on the practice of circumcision in Korea. More clinical research on the natural history of the foreskin is needed, and it is critical that both children and parents are informed about the potential benefits and disadvantages of circumcision.

Adolescent↗