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Biomedical subjects

Hyosoon Park

Publications and source records attributed to Hyosoon Park.

12 recordsLinked to original sources

Relationships among serum leptin, leptin receptor gene polymorphisms, and breast cancer in Korea.

Leptin plays an important role in the regulation of body fat homeostasis, and potential associations of leptin receptor gene (LEPR) polymorphisms with obesity have been suggested. Obesity is considered to relate to breast cancer. We assessed the role of leptin in relation to breast cancer. We measured the serum leptin concentrations of 45 Korean pre-treatment patients with breast cancer and 45 age-matched controls. By direct sequencing, we investigated four leptin receptor gene (LEPR) polymorphisms at codons 109, 223, 656, and 1019. There was no significant difference between the mean leptin concentrations of the patient and control groups in both pre- and post-menopausal women. The frequencies of the wild-type for LEPR codons 109, 223, and 1019 were very low. No increased risk estimate was found for the four LEPR polymorphisms. Our results indicate that it is difficult to explain breast cancer on the basis of serum leptin concentrations or polymorphisms in the LEPR gene.

Adult↗

Long-term effects of green tea ingestion on atherosclerotic biological markers in smokers.

OBJECTIVES: Smoking is a risk factor for coronary artery disease and triggers vascular injury by platelet aggregation and induces atherosclerosis through induction of oxidative stress. Green tea is known to have antioxidant capacity and anti-platelet activity. DESIGN AND METHODS: Twenty adult male smokers ingested 600 mL of green tea for 4 weeks. Their lipid profile, C-reactive protein (CRP), total antioxidant capacity, oxidized LDL, soluble VCAM-1, soluble ICAM-1, and soluble P-selectin were measured at baseline and 2 and 4 weeks after green tea ingestion. RESULTS: Plasma soluble P-selectin (sP-selectin) levels decreased significantly after 2 and 4 weeks of green tea ingestion compared with those before green tea ingestion (P < 0.001). Plasma concentrations of oxidized LDL decreased significantly after green tea ingestion (P < 0.05). CONCLUSIONS: The results of this study suggest the effect of green tea on sP-selectin and oxidized LDL.

Adult↗

A prospective study of a new immunochemical fecal occult blood test in Korean patients referred for colonoscopy.

OBJECTIVES: The exquisite performance characteristics of an immunochemical fecal occult blood test (IFOBT) are well understood. We evaluated the diagnostic validity of a new IFOBT for colorectal neoplasia in patients undergoing colonoscopy and compared its results with two other commercially available IFOBTs. DESIGN AND METHODS: Eighty-five consecutive patients referred for colonoscopy were studied. We performed three different IFOBTs, namely, HM-Jack, Instant-View, and a newly developed OcculTech on each fecal specimen. RESULTS: OcculTech was easy to perform and had a sensitivity, specificity, and positive predictive value of 58.3%, 76.3%, and 27.9%, respectively, for the detection of colorectal cancers and >or=1 cm adenomas. OcculTech showed higher sensitivity than the automatic analyzer, HM-Jack. No improvement was obtained by combining tests. CONCLUSIONS: The OcculTech test had performance characteristics comparable to the two other IFOBTs. This study confirms the usefulness of the OcculTech test for colorectal neoplasia screening.

Adenoma↗

The effects of green tea ingestion over four weeks on atherosclerotic markers.

BACKGROUND: The objective of this study was to evaluate the effects of green tea ingestion over four weeks on atherosclerotic biological markers. METHODS: After a one-week baseline period, 12 healthy male volunteers aged 28--42 years drank 600 mL of green tea daily for four weeks. Lipid profile, oxidized low-density lipoprotein (ox-LDL), total antioxidant capacity (TAC), C-reactive protein (CRP) and soluble cell adhesion molecules were measured at baseline and after two and four weeks ingestion of green tea. RESULTS: There was no significant change in the concentrations of lipid profile, TAC, CRP, soluble intercellular adhesion molecule-1 (sICAM-1), or soluble E-selectin after ingestion of green tea. The levels of ox-LDL and soluble vascular cell adhesion molecule-1 (sVCAM-1) were significantly decreased after four weeks of green tea ingestion (Wilcoxon signed rank test, P=0.006). CONCLUSIONS: The results of this study suggest an in vivo anti-oxidative effect for green tea and an influence of green tea on atherosclerotic biological markers. The effect of green tea seen on ox-LDL and sVCAM-1 provides a potential mechanism for the cardiovascular benefits of regular ingestion of green tea.

Adult↗

Molecular cytogenetic analysis of gene rearrangements in childhood acute lymphoblastic leukemia.

The aims of this study were to estimate the incidences of BCR/ABL, MLL, TEL/AML1 rearrangements, and p16 deletions in childhood acute lymphoblastic leukemia (ALL), to identify new abnormalities, and to demonstrate the usefulness of interphase fluorescence in situ hybridization (FISH). We performed G-banding analysis and FISH using probes for BCR/ABL, MLL, TEL/AML1 rearrangements, and p16 deletions on 65 childhood ALL patients diagnosed and uniformly treated at a single hospital. Gene rearrangements were identified in 73.8% of the patients using the combination of G-banding and FISH, while the chromosomal abnormalities were identified in 49.2% using G-banding alone. Gene rearrangements were disclosed by FISH in 24 (72.7%) of 33 patients with normal karyotype or no mitotic cell in G-banding. Among the gene rearrangements detected by FISH, the most common gene rearrangement was p16 deletion (20.3%) and the incidences of others were 14.1% for TEL/AML1, 11.3% for MLL, and 1.8% for BCR/ABL translocations. Infrequent or new aberrations such as AML1 amplification, MLL deletion, ABL deletion, and TEL/AML1 fusion with AML1 deletion were also observed. We established the rough incidences of gene rearrangements in childhood ALL, found new abnormalities and demonstrated the diagnostic capability of interphase FISH to identify cryptic chromosome aberrations.

Adolescent↗

Lack of association between oxidized LDL-cholesterol concentrations and haptoglobin phenotypes in healthy subjects.

BACKGROUND: The haptoglobin (Hp) 2-2 phenotype has been known to have less antioxidative activity than Hp 1-1 and Hp 2-1. However, few have reported the relationship between oxidative stress and Hp phenotypes by using oxidized LDL. The relationship between Hp phenotypes and oxidative stress was therefore investigated in healthy adults. METHODS: The serum Hp concentrations, albumin, uric acid, iron, L-ascorbic acid, total antioxidant status and oxidized LDL concentrations were measured and analysed in 200 healthy Korean men and women with Hp 2-1 and Hp 2-2 phenotypes. RESULTS: The serum concentrations of Hp were significantly higher in the Hp 2-1 compared with the Hp 2-2 phenotype. However, serum concentrations of total antioxidant status and oxidized LDL did not show any statistical differences in either sex. The L-ascorbic acid concentrations in serum showed lower values in the Hp 2-2 compared with the Hp 2-1 phenotype, for both sexes (P < 0.05). CONCLUSIONS: The concentration of L-ascorbic acid, the first line antioxidant, was lower in the Hp 2-2 than in the Hp 2-1 phenotype; this did not significantly affect the total antioxidant status, and there was no significant difference in oxidized LDL for either group in healthy adults.

Albumins↗

Low-density lipoprotein subclass and its correlating factors in diabetics.

OBJECTIVES: Small dense LDL, low density lipoprotein (LDL) particles with small size and high density, is regarded as a significant risk factor for cardiovascular diseases. Diabetes mellitus is one of the conditions accompanied by increased small dense LDL. We analyzed LDL subclass in type 2 diabetics and normal controls with LipoPrint LDL System to investigate the LDL heterogeneity in diabetics and factors affecting it. DESIGN AND METHODS: We selected 40 normal controls and 40 type 2 diabetics with fasting blood glucose level over 7.0 mmol/L and HbA1c level over 7%. LDL subclass was determined with LipoPrint LDL System. LipoPrint LDL System fractionates LDL into seven parts (LDL1-7) by size and LDL3 to LDL7 are defined as small-sized LDL. In addition we estimated 'the percent of small-sized LDL over whole LDL' and defined it as 'small-sized LDL proportion'. RESULTS: Mean small-sized LDL proportion was significantly higher in diabetics (23.4%) than in controls (11.8%) (p<0.001) and small-sized LDL proportion showed positive correlation with blood levels of glucose, HbA1c, total cholesterol, triglyceride, and oxidized LDL and negative correlation with HDL cholesterol level in univariate analysis (p<0.001). Of these parameters, triglyceride, HbA1c, oxidized LDL were statistically significant variables contributing to the small-sized LDL proportion in stepwise multiple regression analysis. CONCLUSIONS: We analyzed small-sized LDL proportion in type 2 diabetics and found that it was significantly increased in diabetics than control subjects and it was independently correlated with triglyceride, HbA1c, oxidized LDL in descending order, which are reflecting lipid metabolism, glycation, and oxidative stress, respectively.

Adult↗

Marker chromosomes in Korean patients: incidence, identification and diagnostic approach.

The identification of marker chromosomes is important for genetic counseling. However, the origin or composition can rarely be defined with conventional cytogenetic technique alone. In this study, we investigated the incidences and types of marker chromosomes in Korean patients and attempted to establish a cost-effective diagnostic approach for marker chromosomes. We reviewed the karyotypes of 2,984 patients that were requested for the cytogenetic analysis between 1997 and 2003 at the Samsung Medical Center. Ten marker chromosomes were found and identified using fluorescent in situ hybridization (FISH). Among the ten marker chromosomes, six were supernumerary marker chromosomes (SMCs) and the rest were marker chromosomes in Turner syndrome (TS). The incidence of SMCs was 2.01/1,000, slightly higher than that previously reported. Five of six SMCs were satellited marker chromosomes. Three bisatellited marker chromosomes originated from chromosome 15 and two from chromosome 22. The origin of one SMC could not be identified. All marker chromosomes in TS originated from X- or Y chromosome. The application of FISH is indispensable to identify marker chromosomes, and the appropriate selection of probes is necessary for cost-effective analysis. For analyzing satellited marker chromosomes, application of probes for chromosome 15 followed by those for chromosome 22 is recommended and in cases of TS, probes for sex chromosomes should take precedence.

Adolescent↗

Frequencies of C282Y and H63D mutations and transferrin saturation indices in the Korean population.

Hereditary hemochromatosis (HHC) is an autosomal recessive disorder that damages various organs because of the deposition of excess iron. At the human hemochromatosis (HFE) gene, two mutations of C282Y and H63D have been reported. The frequencies of C282Y and H63D mutations vary among ethnic groups. At present, the most suitable screening test for HHC is the assessment of transferrin saturation (TS). We investigated the distribution of TS and the frequencies of C282Y and H63D mutations among Koreans. TS was measured in 2152 subjects who visited the health promotion center for a checkup. The mean (+/-SD) of TS was 41.7+/-15.4%. We randomly selected 240 subjects and tested them for C282Y and H63D mutations using PCR-restriction fragment length polymorphism (RFLP). All 240 randomly selected samples were found to be G/G homozygous non-mutated for C282Y. Of the 240 subjects, 18 (7.5%) were found to be C/G heterozygous and 222 subjects were C/C homozygous non-mutated for H63D. In this study, the C282Y mutation was not found in the Korean population, and the H63D mutation showed allele frequency of 3.8%. The mean TS in this study was higher than that of Caucasians.

Adult↗

The development of systematic quality control method using laboratory information system and unity program.

Quality control (QC) process is performed to detect and correct errors in the laboratory, of which systematic errors are repeated and affect all the laboratory process thereafter. This makes it necessary for all the laboratories to detect and correct errors effectively and efficiently. We developed an on-line quality assurance system for detection and correction of systematic error, and linked it to the Unity Plus/Pro (Bio-Rad Laboratories, Irvine, USA), a commercially available quality management system. The laboratory information system based on the client-server paradigm was developed using NCR3600 (NCR, West Columbia, USA) as the server and database for server was Oracle 7.2 (Oracle, Belmont, USA) and development tool was Powerbuilder (Powersoft Burlignton, UK). Each QC material is registered and gets its own identification number and tested the same way as patient sample. The resulting QC data is entered into the Unity Plus/Pro program by in-house data entering program or by manual input. With the implementation of in-house laboratory information system (LIS) and linking it to Unity Plus/Pro, we could apply Westgard's multi-rule for higher error detection rate, resulting in more systematic and precise quality assurance for laboratory product, as well as complementary to conventional external quality assessment.

Chemistry, Clinical↗

Clinical pathologist in Korea--training program and its roles in laboratories.

A rapid development of practice of laboratory medicine in Korea owes its success to the clinical pathologists (CP), who have played a role of a pathfinder for laboratories. The Korean CP postgraduate education (residency) program is unique in that it is exclusively for laboratory medicine. The training program for clinical pathologists includes diagnostic hematology, diagnostic immunology, clinical microbiology, clinical chemistry, blood bank, diagnostic genetics, informatics and laboratory management. The program has produced a strong group of about 600 laboratory physicians, officially clinical pathologists since 1963. Most of Korean clinical pathologists work as laboratory directors, directors of university hospital laboratories or teaching faculty members in medical schools. The roles of clinical pathologists are laboratory management, interpretation of laboratory test results, clinical consulting services to clinicians and patients, ordering secondary tests after reviews of requested test results and utilization management. The clinical pathologists have developed clinical laboratories to be a main contributor for improved medical practice. During the last 40 years under the turbulent healthcare system, clinical pathologists have significantly contributed to safeguard the laboratory interests. The education program and the role of clinical pathologists are described.

Curriculum↗