Biomedical subjects

Byung Joo Park

Publications and source records attributed to Byung Joo Park.

6 recordsLinked to original sources

PubMed2006

Phase separating bulk metallic glass: a hierarchical composite.

Phase separating systems present a unique opportunity for designing composites with hierarchical microstructure at different length scales. We report here our success in synthesizing phase separating metallic glasses exhibiting the entire spectrum of microstructural possibilities expected from a phase separating system. In particular, we report novel core shell and hierarchical structures of spherical glassy droplets, resulting from critical wetting behavior and limited diffusion. We also report synthesis of a bulk phase separating glass in a metallic glass system. The combination of unique core shell and hierarchical structures in metallic glass systems opens a new avenue for the microstructure design of metallic glasses.

Journal Article↗

PubMed2006

Randomized phase II study of gemcitabine plus cisplatin versus etoposide plus cisplatin for the treatment of locally advanced or metastatic non-small cell lung cancer: Korean Cancer Study Group experience.

BACKGROUND: Several randomized trials have demonstrated superior response rates and survivals for new agent platinum doublets than for older platinum doublets in advanced non-small cell lung cancer (NSCLC), however, few trials have been performed in Asian populations. Thus, we conducted a randomized study to compare gemcitabine-cisplatin (GP) with etoposide-cisplatin (EP) in Korean patients with advanced NSCLC. METHODS: Patients with histologically confirmed, locally advanced or metastatic NSCLC were randomized to receive either gemcitabine 1250 mg/m2 on days 1 and 8 plus cisplatin 75 mg/m2 on day 1, or etoposide 100 mg/m2 on days 1-3 plus cisplatin 75 mg/m2 on day 1. Treatment was repeated every 21 days in both groups. The primary endpoint was response rate. RESULTS: Between May 2000 and December 2001, 83 patients at 9 Korean centers were enrolled in this study. The GP arm showed a significantly higher response rate (52.6% versus 19.4%; P = 0.002), a longer time to progression (4.3 months in both arms; P = 0.018) and a marginally significant prolongation of overall survival (18.3 months versus 10.9 months; P = 0.059) than the EP arm. Grades 3 and 4 thrombocytopenia (18% versus 0%) was more common in the GP arm whereas grades 3 and 4 neutropenia was more common in EP arm (48.7% versus 71.8%). Other toxicities were comparable in both arms. CONCLUSION: GP provided a significantly higher response rate and a longer time to progression than EP and should be considered a standard treatment in advanced NSCLC in Korean population.

Adenocarcinoma↗

PubMed2003

Effect of pregnancy and menopause on facial wrinkling in women.

Women appear to be at greater risk of developing wrinkles with age than men. To evaluate the effect of pregnancy and menopause on facial wrinkling, a total of 186 Korean women volunteers aged between 20 and 89 years were interviewed for information on menstrual and reproductive factors. An 8-point photographic scale developed for assessing the severity of wrinkles in Asian skin was used. Cumulative sun exposure, both occupational and recreational, was estimated. In Korean women, the risk of facial wrinkling increases significantly with increasing number of full-term pregnancies (OR = 1.835, 95% confidence interval (CI) 1.017-3.314) and menopausal age (number of years since menopause) (OR = 3.909, 95% CI 1.071-14.275), while hormone replacement therapy is associated with a significantly lower risk for the development of facial wrinkling in postmenopausal women (OR = 0.221, 95% CI 0.047-0.949). Hypo-oestrogenism may play a part in the decrease of skin collagen leading to skin wrinkling in postmenopausal women.

Adult↗

PubMed2002

Hepatitis B virus infection and B-cell non-Hodgkin's lymphoma in a hepatitis B endemic area: a case-control study.

Several studies have reported a higher prevalence of chronic hepatitis C virus (HCV) infection in patients with B-cell non-Hodgkin's lymphoma and suggested a pathogenic role for HCV, but studies on hepatitis B virus (HBV) infection and non-Hodgkin's lymphoma are limited. To determine the association between HBV infection and non-Hodgkin's lymphoma, we performed a case-control study in Korea, a hepatitis B endemic area. We recruited 222 patients newly diagnosed with non-Hodgkin's lymphoma at Seoul National University Hospital between January 1997 and December 1998 as cases. Four age- and sex-matched controls were selected for each case, and the control groups comprised of 439 patients with non-hematological malignancy (control group 1) and 444 subjects with non-malignant conditions (control group 2). Relative risk of developing non-Hodgkin's lymphoma among individuals tested positive for hepatitis B surface antigen was calculated after controlling for other potential risk factors of lymphoma, such as smoking, alcohol drinking, transfusion history and HCV infection. Hepatitis B surface antigen was positive in 28 of 222 patients (12.6%) with non-Hodgkin's lymphoma compared with 32 of 439 (7.3%) in control group 1, and 21 of 444 (4.7%) in control group 2 (P = 0.001). The crude odds ratio for B-cell non-Hodgkin's lymphoma among the HBV carriers was 2.54 (1.46 - 4.45) and the adjusted odds ratio was 3.30 (1.69 - 6.45) by multivariate analysis. The present study suggests that the risk of B-cell non-Hodgkin's lymphoma is increased in HBV carriers and warrants further investigation of the possible role of hepatitis B virus in the pathogenesis of B-cell non-Hodgkin's lymphoma.

Adolescent↗

PubMed2002

A cohort study on the association between psychotropics and hip fracture in Korean elderly women.

To test the hypothesis that the intake of psychotropics may increase the risk of hip fracture, a cohort study was conducted upon elderly Korean women. The Korean Elderly Pharmacoepidemiology Cohort was constructed from members of the Korea Medical Insurance Corporation over 65 yr of age who were living in Busan Metropolitan City in 1993. Study participants (n=6,043) were female respondents to a self-administered question survey. Information on the intake of psychotropics was obtained from the drug prescription database, which contained all psychotropic prescriptions during any hospital admission over the two-year period between January 1, 1993 and December 31, 1994. The cohort follow-up has been conducted with information on hip fracture being collected from the Korea Medical Insurance Corporation medical treatment claims database over the four year period between January 1, 1993 and December 31, 1996. Three hundred and three subjects had received 745 psychotropics prescriptions and 56 cases of hip fracture were found. After adjusting for age, body mass index, and drinking history, it was found that the intake of psychotropics significantly increased the risk of hip fracture (adjusted odds ratio, 4.24; 95% confidence interval, 1.89-9.52). This study suggests that the intake of psychotropics might be an important risk factor for hip fracture in elderly Korean women.

Aged↗

PubMedDate not supplied

Added value of coronal reformations for duty radiologists and for referring physicians or surgeons in the CT diagnosis of acute appendicitis.

OBJECTIVE: To assess the added value of coronal reformation for radiologists and for referring physicians or surgeons in the CT diagnosis of acute appendicitis. MATERIALS AND METHODS: Contrast-enhanced CT was performed using 16-detector-row scanners in 110 patients, 46 of whom had appendicitis. Transverse (5-mm thickness, 4-mm increment), coronal (5-mm thickness, 4-mm increment), and combined transverse and coronal sections were interpreted by four radiologists, two surgeons and two emergency physicians. The area under the receiver operating characteristic curve (Az value), sensitivity, specificity (McNemar test), diagnostic confidence and appendiceal visualization (Wilcoxon signed rank test) were compared. RESULTS: For radiologists, the additional coronal sections tended to increase the Az value (0.972 vs. 0.986, p = 0.076) and pooled sensitivity (92% [95% CI:88, 96] vs. 96% [93, 99]), and enhanced appendiceal visualization in true-positive cases (p = 0.031). For non-radiologists, no such enhancement was observed, and the confidence for excluding acute appendicitis declined (p = 0.013). Coronal sections alone were inferior to transverse sections for diagnostic confidence as well as appendiceal visualization for each reader group studied (p < 0.05). CONCLUSION: The added value of coronal reformation is more apparent for radiologists compared to referring physicians or surgeons in the CT diagnosis of acute appendicitis.

Acute Disease↗