-
[show abstract]
[hide abstract]
ABSTRACT: Low cycle fatigue tests were conducted to investigate the cyclic deformation behavior and the energy-based criterion of AZ31
magnesium alloy. The alloy exhibited an asymmetric hysteresis loop due to the twinning and detwinning effect. The cyclic stress
responses showed cyclic hardening at all total strain amplitudes. To evaluate the plastic strain energy, the Halford-Morrow
equation and a modified equation for magnesium alloy were compared. The effect of twinning on the total plastic strain energy
dissipated during fatigue life was discussed. The variations of the twin and dislocation densities were also investigated
using optical microscopy and transmission electron microscopy, respectively.
Keywordsalloys–extrusion–fatigue–microstructure–twinning
Metals and Materials International 05/2012; 17(2):207-213. · 1.18 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We analyzed the outcomes of our conservative treatment for pediatric trigger thumb. Since March 2004, we have used conservative treatment for all patients with pediatric trigger thumb. We prospectively analyzed 30 patients in whom 35 thumbs were affected (10 right, 15 left, 5 bilateral). The mean age at diagnosis was 28 (11-50) months. The treatment consisted of passive exercises performed by the children's mothers, 10-20 times daily. How reliably this was performed is unproven. Trigger thumb severity was graded as 0A (extension beyond 0°), 0B (extension to 0°), 1 (active extension with triggering), 2 (passive extension with triggering), and 3 (cannot extend either actively or passively i.e. locked). At diagnosis, six of the 35 thumbs (17%) were grade 1, 25 (71%) were grade 2, and four (11%) were grade 3. After a mean follow-up period of 63 (range, 49-73) months, 28 thumbs (80%) were grade 0A or 0B, 5 (14%) were grade 1 and 2 (6%) were grade 2. The bilateral cases and the patients who initially had grade 3 severity had significantly more unfavorable results than the other patients. This study suggests that conservative treatment for pediatric trigger thumb is a successful method, although cases that present with bilateral involvement or locking (grade 3) should be considered for early surgical release.
The Journal of hand surgery, European volume. 03/2012; 37(3):220-4.
-
[show abstract]
[hide abstract]
ABSTRACT: Mucin hypersecretion is frequently observed in many inflammatory diseases of the human respiratory tract. As mucin hypersecretion refers to uncontrolled mucin expression and secretion during inflammation, studies examining the negative control mechanisms of mucin hypersecretion are vital in developing novel therapeutic medications. We hypothesized that the c-Ets1 induced by interleukin (IL)-1β would decrease MUC5AC overproduction by inhibiting the interaction of NF-κB with cAMP response element-binding protein (CREB) in vivo. Stimulation with IL-1β caused the direct binding of NF-κB and CREB to the MUC5AC promoter, thus increasing MUC5AC gene expression. However, IL-1β-induced MUC5AC messenger RNA levels were surprizingly downregulated by c-Ets1 (located -938 to -930). Interestingly, c-Ets1 also suppressed IL-1β-induced MUC5AC gene expression in vitro and in vivo by disrupting the interaction of NF-κB with CREB on the MUC5AC promoter. In addition, c-Ets1 also inhibited significant morphologic changes and inflammatory cell infiltration after IL-1β exposure in mouse lungs infected with either wild-type or shRNA-c-Ets1. Moreover, reactive oxygen species produced by NOX4 increased c-Ets1 gene expression and MUC5AC gene expression in alveolar macrophages from bronchoalveolar lavage fluid. These results suggest a molecular paradigm for the establishment of a novel mechanism underlying the negative regulation of mucin overproduction, thus enhancing our understanding of airway inflammation.
Mucosal Immunology 03/2012; 5(2):207-15. · 6.96 Impact Factor
-
American Journal of Neuroradiology 01/2011; 32(3):E57. · 2.93 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Plasma cell granulomas, inflammatory pseudotumours and myofibroblastomas are synonymous with characteristic plasma cell infiltration in various body organs including the pancreas, liver, retroperitoneum and mediastinal structures causing idiopathic fibrosclerosis. Recently, a new concept has arisen regarding the relationship between immunoglobulin (Ig)G4-positive cell infiltration and idiopathic systemic fibrosclerosis. We report two cases showing IgG4-positive cell infiltration in the lung presenting as lung nodules with or without extrapulmonary manifestations.
The British journal of radiology 07/2010; 83(991):e150-3. · 2.11 Impact Factor
-
Endoscopy 01/2010; 42 Suppl 2:E73-4. · 5.21 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To evaluate the radiological and clinical findings in patients with pulmonary aspergillosis after solid organ transplantation.
This study included 13 consecutive patients (five liver, four kidney, and four heart transplant; 10 male and three female; median age 54 years; range 13-63 years) with histologically confirmed pulmonary aspergillosis after solid organ transplantation at a tertiary referral hospital. Chest radiographs and computed tomography (CT) examinations performed for diagnosis were available in all patients. Radiological findings, such as lesion characteristics, location, and associated findings, were assessed retrospectively by two radiologists. The changes in radiological findings and clinical response after treatment were also assessed. Clinical findings, such as time of onset, initial symptoms, clinical course, and laboratory findings, were reviewed.
The most common radiographic and CT findings were pulmonary nodules or masses (n=12). The number of nodules or masses was less than 10 in eight patients. Associated findings were surrounding ground-glass opacity (n=4), central low density (n=8), central air cavity (n=5), and air bronchogram (n=3). Follow-up radiographs and/or CT after treatment showed improvement in eight patients, persistence in two, and deterioration in three. The onset time of pulmonary aspergillosis was a median of 32 days (range 15-165 days). The most common symptom at diagnosis was fever (n=6). Ten of 13 patients did not have leucopaenia. There were two aspergillosis-associated deaths during the follow-up period.
The most common radiological finding of pulmonary aspergillosis after solid organ transplantation is multiple nodules or masses, which commonly appear within 1 month following transplantation.
Clinical Radiology 07/2008; 63(6):673-80. · 1.95 Impact Factor
-
Endoscopy 03/2007; 39 Suppl 1:E333-4. · 5.21 Impact Factor
-
B S Lee,
S M Kim,
J K Seong,
S H Kim,
H Y Jeong,
H Y Lee, K S Song,
D Y Kang,
S M Noh,
K S Shin,
J S Cho
Endoscopy 06/2005; 37(5):490-3. · 5.21 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Pericardial rupture following blunt chest trauma is rare, and is not usually diagnosed pre-operatively. If pericardial rupture is not recognized and treated promptly, it may be fatal owing to cardiac herniation. We report a case of traumatic herniation of the heart for which a CT scan and MRI made a major contribution to the diagnosis.
British Journal of Radiology 06/2005; 78(929):447-9. · 1.31 Impact Factor
-
Journal of Thrombosis and Haemostasis 04/2005; 3(3):593-5. · 5.73 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Mesenchymal tumours of the thorax are uncommon and may originate from the muscle, bone, cartilage, vessel, nerves, fat and fibrous tissue. These tumours occur at different sites including the lung, pleura, mediastinum or chest wall. Mesenchymal tumours tend to show protean and non-specific imaging characteristics. However, in some instances, the imaging characteristics of the tumour may allow a specific diagnosis to be made, such as with lipoid or vascular tumours.
Clinical Radiology 01/2004; 58(12):934-44. · 1.95 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An elevated plasma level of factor VII is a risk factor for coronary artery disease. We investigated environmental, familial, and genetic influences on factor VII activity in 508 family members of 87 probands who underwent elective coronary arteriography. Maximum likelihood methods were used to fit several genetic and non-genetic models of inheritance to these data to determine whether an unobserved Mendelian major gene could explain the familial distribution of factor VII. Factor VII activities were adjusted for age, gender, body mass index, smoking, alcohol consumption, menopause status, and triglycerides prior to this segregation analysis (this model accounted for 33.5% of the total variation). Adjusted factor VII activities showed strong familial aggregation with an estimated parent-offspring correlation of 0.34, sibling correlation of 0.36 and a smaller spouse correlation of 0.16. Regressive models were used to test genetic and non-genetic models in these 87 families. Mendelian single-locus models with either two or three underlying genotypic distributions of factor VII activities were best supported by these data. Essentially, these Mendelian models suggest most individuals come from a low distribution (mean, 116%), with a few individuals homozygous for a high allele drawn from a distribution with a mean of 166%. Future linkage studies may be worthwhile to further clarify the mechanisms controlling factor VII activity.
Blood Coagulation and Fibrinolysis 02/2002; 13(1):25-33. · 1.24 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Adenocarcinoma of the esophagus has been reported to be increasing in incidence in a number of regions throughout the world, while the incidence of squamous cell carcinoma (SCCA) of the esophagus is mostly stable or decreasing. To evaluate the increasing tendency of adenocarcinoma of the esophagus.
We studied retrospectively the records of patients with histologically proven esophageal cancer between 1970 and 1999 at the Yonsei Medical Center.
Total cases of esophageal cancer were 969 patients of which the cases of adenocarcinoma and SCCA were 27 patients and 918 patients, respectively. The ratio of esophageal adenocarcinoma to SCCA was 0.0375 in the 1970s, 0.0241 in the 1980s and 0.0292 in the 1990s. There was no statistical difference (p = 0.811) in the ratios of adenocarcinoma of the esophagus between the three consecutive 10-year groups.
In conclusion, unlike the US and other western countries, it seems that the ratio of esophageal adenocarcinoma compared to SCCA has not increased among patients with esophageal carcinoma at the Yonsei Medical Center.
The Korean Journal of Internal Medicine 01/2002; 16(4):250-3.
-
Thrombosis and Haemostasis 11/2001; 86(4):1130. · 5.04 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The purpose of this study was to evaluate whether edge enhancement could improve the visibility of subtle findings on soft copies of neonatal chest radiographs.
Two radiologists reviewed 82 soft-copy neonatal chest radiographs before and after the application of edge enhancement on our picture archiving and communication system (PACS). The visibility of a pneumothorax (n = 22), central venous catheter (n = 32), umbilical arterial catheter (n = 36), endotracheal tube (n = 40), and normal anatomic structures (the minor fissure, anterior segmental bronchus of the right upper lobe, and aortic arch, n = 57) was evaluated. Six of 22 soft-copy images depicting a pneumothorax were excluded from the evaluation of image quality either because of the large size of the pneumothorax itself (n = 7) or because of the lack of confirmatory evidence that would have been provided by an additional lateral decubitus (n = 6) or cross-table lateral radiograph (n = 3). Image quality was evaluated by visual grading analysis.
The visibility of a pneumothorax (p < 0.01), vascular catheters (p < 0.001), the minor fissure (p < 0.001), and the anterior segmental bronchus of the right upper lobe (p < 0.001) improved significantly after applying edge enhancement to soft copies of neonatal chest radiographs, whereas the visibility of the aortic arch did not improve. Evaluations of the improvements in the visibility of the endotracheal tube were inconsistent.
Application of edge enhancement to soft copies of neonatal chest radiographs helps radiologists to identify small pneumothoraces, vascular catheters, and delicate normal structures, thereby improving the detection of subtle chest findings in the neonatal intensive care unit.
American Journal of Roentgenology 09/2001; 177(2):437-40. · 2.78 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The purpose of this study was to compare observer performance for detecting urinary calculi using abdominal computed radiography with hard-copy versus soft-copy images and with a high-resolution video monitor versus a liquid-crystal-display (LCD) monitor.
We compared observer performance for detecting urinary calculi using three sets of radiographs-hard-copy images, soft-copy images displayed on a LCD monitor (1280 x 1024 bits), and soft-copy images displayed on a high-resolution video monitor using receiver operating characteristic curve analysis with a continuous rating scale. Computed radiography was archived with a 2140 x 1760 pixel resolution and a 10-bit depth. The selected data set included 62 images: 27 images showing proven urinary calculi smaller than 6 mm and three in number, and 35 images containing no proven abnormalities. Eleven radiologists (three genitourinary radiologists and eight general radiologists) participated in the study. Interpretations of three sets of randomly distributed radiographs were performed individually in three separate sessions at 1-week intervals.
No statistically significant differences were found in the area under the receiver operating characteristic curve for detecting urinary calculi or in the interpreting times between soft-copy and hard-copy images; the mean areas under the receiver operating characteristic curve of hard-copy images, soft-copy images displayed on an LCD monitor, and soft-copy images displayed on a high-resolution video monitor were 0.579, 0.610, and 0.732, respectively. However, soft-copy images showed relatively improved diagnostic accuracy among less experienced radiologists (p < 0.05).
For detecting urinary calculi, soft-copy images offered a diagnostic accuracy similar to or slightly more accurate than that of hard-copy images obtained in a laser-printed film-based environment. The diagnostic performance with soft-copy images viewed on an LCD monitor was comparable to that of soft-copy images viewed on a high-resolution video monitor.
American Journal of Roentgenology 09/2001; 177(2):331-5. · 2.78 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Idiopathic pulmonary fibrosis (IPF) was reported to be associated with increased risk of lung cancer as a result of the occurrence of atypical or dysplastic epithelial changes in fibrosis which progressed to invasive malignancy. In that situation, the cancer will develop in the area of major fibrosis. To investigate the direct relationship between fibrosis and cancer development, the real concordance rate of the two lesions in the chest computed tomography (CT) was analysed and compared to the histological types of lung cancer. The subjects included 63 patients with combined lung cancer and IPF (IPF-CA), 218 patients with lone IPF, and 2,660 patients with primary lung cancer. All patients were diagnosed at Asan Medical Center during the same period. The age, percentage of smokers, and the male sex were significantly higher in IPF-CA compared with lone IPF. The odds ratio of smoking was 2.71 compared to nonsmoking IPF controls. In IPF-CA, 56% of the cancer was located in the periphery of the lung and 52% in the upper lobe. The majority of the cancers (64%) were found in the nonfibrotic area at chest CT. The most frequent cell type was squamous cell carcinoma (35%), and there was no significant difference in the cancer cell type between IPF-CA and total lung cancer population. These findings suggest that in combined lung cancer and idiopathic pulmonary fibrosis patients, the features of the lung cancer are similar to the total lung cancer population.
European Respiratory Journal 07/2001; 17(6):1216-9. · 5.89 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Hyperhomocysteinemia is known to be associated with an increased risk of myocardial infarction, stroke, peripheral arterial disease, and venous thrombosis. Gene polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MS) may account for reduced enzyme activity and hyperhomocysteinemia. A recent study has documented evidence of polygenic regulation of plasma homocyteine. We report here on a case of occlusive stroke at young age and hyperhomocysteinemia with homozygous VN (677C to T) variant in the MTHFR gene as well as homozygous D/D (2756G to A) variant in the MS gene.
Experimental and Molecular Medicine 07/2001; 33(2):106-9. · 2.48 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Protein C is a vitamin K dependent serine protease zymogen, which has a regulatory influence over the coagulation cascade via the inhibition of factors Va and VIIIa. Hereditary protein C deficiency is associated with an increased risk of thromboembolic disease. A multitude of families displaying protein C (PROC) gene defects have been reported, and a number of DNA sequence polymorphisms are known to occur in the PROC gene. We have identified a previously undescribed silent substitution (C8516T) by direct DNA sequencing in a Korean patient with thrombosis and protein C deficiency. In addition, a rare T allelic frequency (0.016) was determined in 123 patients with acquired or hereditary protein C deficiency.
Yonsei Medical Journal 07/2001; 42(3):364-6. · 1.14 Impact Factor
