Biomedical subjects

H C Jang

Publications and source records attributed to H C Jang.

14 recordsLinked to original sources

PubMed2006

A rural-urban comparison of the characteristics of the metabolic syndrome by gender in Korea: the Korean Health and Genome Study (KHGS).

The number of cases of the metabolic syndrome is increasing dramatically in Western countries. However, the evaluation of the metabolic syndrome is limited in Asian countries. Thus, our objectives were: 1) to investigate parameters of the metabolic syndrome defined by the National Cholesterol Education Program (NCEP)-Adult Treatment Panel III (ATPIII) in the subjects representing Korean general population and 2) the modification of which factor is most effective in reducing the metabolic syndrome. A total of 10,044 (5024 rural and 5020 urban) Korean men and women in the age range 40-69 yr voluntarily participated in this community-based cross-sectional study (a rural and an urban community was selected). Anthropometric parameters (weight, height, waist and hip circumference and blood pressure), social factors (smoking, alcohol, exercise and education status) as well as biochemical parameters (fasting glucose and insulin, lipids and body composition) were measured. Twenty-six point one per cent of the total subjects were classified as having the metabolic syndrome. Age- and sex-adjusted prevalences were 29.3 and 22.3% in the rural and urban community, respectively (p< 0.01). Abdominal obesity (46.9%) and high blood pressure (45.2%) were major components in the rural community; hypertriglyceridemia (37.6%) and low HDL-cholesterolemia (37.0%) in the urban community. In conclusion, abdominal obesity in the rural community and dyslipidemia in the urban community should be a main subject of intervention, aimed at reducing the prevalence of the metabolic syndrome in Korea. Given the rapid progression of the Korean economy over the past 30 yr, the prevalence of the metabolic syndrome is expected to increase continuously. A strategy to prevent this expected extraordinary event should be conducted at a national level.

Adult↗

PubMed2002

Nonassociation of interleukin-1 receptor antagonist genotypes with bone mineral density, bone turnover status, and estrogen responsiveness in Korean postmenopausal women.

Interleukin-1 receptor antagonist (IL-1ra), a natural inhibitor of interleukin-1 (IL-1), completely inhibits the stimulatory effects of IL-1 on bone resorption. Bioactivity of IL-1 increases in the estrogen-deficient state with an increased IL-1:IL-1ra ratio and decreases after estrogen replacement therapy with a decreased IL-1:IL-1ra ratio. An association was found between an 86 basepair variable number tandem-repeat (VNTR) polymorphism of the IL-1ra gene and an increased production of IL-1ra in a cultured monocyte system. The IL-1ra VNTR polymorphism, therefore, is an attractive candidate gene for osteoporosis susceptibility as well as hormone responsiveness after estrogen replacement. We examined the association of this VNTR polymorphism with bone mass, bone turnover, and the change of bone mineral density (BMD) after 1 year of hormone replacement therapy (HRT). The frequencies of the five alleles were as follows: A1, 90.8% (410 bp, four repeats); A2, 7.2% (240 bp, two repeats); A3, 1.6% (500 bp, five repeats); A4, 0.4% (326 bp, three repeats); and A5, 0% (595 bp, six repeats), in 714 healthy ethnically Korean postmenopausal women, aged 41-74 years (55.2 +/- 6.3 years mean +/- SD). Spine (L2-4) and femoral neck BMD were not significantly different among IL-1ra genotypes, and no significant genotypic differences were found in bone markers. There were no differences in genotypic proportions when we categorized the subjects into a high-loss group and a normal-loss group with regard to levels of bone marker. No significant genotypic differences were found in changes in lumbar and femoral neck BMD and those in bone markers before and after 1 year of HRT in 312 women. Our data suggest that these IL-1ra polymorphisms are not associated with BMD, bone turnover, or the change of BMD after 1 year of HRT in Korean women.

Adult↗

PubMed2001

Metabolic characteristics and prevalence of osteoporosis among women in Tae-An area.

Understanding the metabolic changes in women is one of the important ways to prevent and treat osteoporosis. To reveal the metabolic characteristics of 289 healthy women aged between 35-65 yr in Tae-An, Korea we evaluated the association between bone mass assessed by broadband ultrasound attenuation (BUA) using quantitative ultrasound 2 (QUS2) and various parameters such as age, body mass index, serum levels of alkaline phosphatase, calcium, phosphorus, parathyroid hormone, 25(OH)D, and urinary ratios of calcium/creatinine and deoxypyridinoline (Dpyd)/creatinine. Among the subjects, 3.0% were osteoporotic, and 40.9% were osteopenic. When the subjects were classified according to their years since menopause (YSM) and age, the prevalence of osteoporosis increased along with an increase of YSM and age. Bone turnover markers such as serum alkaline phosphatase and fasting urinary Dpyd/creatinine were significantly higher in the group with low bone mass than in the normal group. In summary, this study shows, by use of biochemical markers of bone turnover and QUS2, the prevalence of osteoporosis in women aged between 35-65 in Tae-An was 3.0% and the risk of low bone mass increased with the bone turnover markers.

Adult↗

PubMed2001

Identification of a mutation in the human raloxifene response element of the transforming growth factor-beta 3 gene.

The human transforming growth factor-beta 3 (TGF-beta 3) is an important cytokine to maintain bone mass by inhibiting osteoclast differentiation. Recently raloxifene response element (RRE), a new enhancer with a polypurine sequence for estrogen receptor (ER)-mediated gene activation, was identified on the TGF-beta 3 gene. Functional analysis of the RRE-mediated pathway has shown that this would be an important pathway for bone preserving effect. We found a novel mutation in the RRE sequence by single-strand conformational polymorphism analysis in one of 200 Korean women. Cloning and sequencing revealed a heterozygote in which one allele had an insertion of 20 nucleotides (AGAGAGGGAGAGGGAGA GGG) between nucleotide +71 and +72 and a point mutation at nucleotide +75 (G-A transition), and the other allele had normal sequence. The insertion was a nearly perfect tandem duplication of the wild type DNA sequence. The bone mineral density of the affected woman was not much lower than that of age-matched controls. Transient transfection of the mutant allele showed no significantly different activity compared with that of the wild type allele. These observations suggest that the heterozygote variation of the RRE sequence seems not to be operative in determination of bone mass.

Estrogen Antagonists↗

PubMed2001

Deflazacort increases osteoclast formation in mouse bone marrow culture and the ratio of RANKL/OPG mRNA expression in marrow stromal cells.

Information on precise effects of deflazacort on bone cell function, especially osteoclasts, is quite limited. Therefore, the present study was undertaken to test effects of deflazacort on osteoclast-like cell formation in mouse bone marrow cultures and on the regulation of osteoprotegerin (OPG) and its ligand (RANKL) mRNA expressions by RT-PCR in the ST2 marrow stromal cells. TRAP-positive mononuclear cells increased after the treatment of deflazacort at 10(-9) to 10(-7) M alone for 6 days in a dose-dependent manner. Number of TRAP-positive multi-nucleated cells (MNCs) increased significantly with combined treatment of deflazacort at 10(-7) M and 1,25-(OH)2D3 at 10(-9) M compared to that of cultures treated with 1,25-(OH)2D3 alone (p<0.05). Exposure to deflazacort at 10(-7) M in the presence of 1,25-(OH)2D3 at 10(-9) M in the last 3-day culture had greater stimulatory effect on osteoclast-like cell formation than that of the first 3-day culture did. Deflazacort at 10(-10) -10(-6) M downregulated OPG and upregulated RANKL in mRNA levels in a dose-dependent manner. These observations suggest that deflazacort stimulate osteoclast precursor in the absence of 1,25-(OH)2D3 and enhance differentiation of osteoclasts in the presence of 1,25-(OH)2D3. These effects are, in part, thought to be mediated by the regulation of the expression of OPG and RANKL mRNA in marrow stromal cells.

Animals↗

PubMed1998

Short stature in Korean women: a contribution to the multifactorial predisposition to gestational diabetes mellitus.

We examined the associations between demographic characteristics including short stature and the prevalence of gestational diabetes mellitus (GDM) in Korean women. In this study, a total of 9005 pregnant women underwent universal screening for GDM. Oral glucose tolerance tests (100 g OGTT) were performed in positive screenees (1 h plasma glucose > or = 7.2 mmol/l) and GDM was diagnosed using National Diabetes Data Group criteria. Women with GDM were older and heavier than those with a positive screen and normal OGTT, as well as those with a negative screen. However, height of women with GDM was significantly shorter than those with a positive screen and normal OGTT, and a negative screen. When the study subjects were stratified according to height quartiles, the plasma glucose at the screening test decreased as height increased. Furthermore, the prevalence of GDM was highest in the shortest quartile (< or = 157 cm) group; the odds ratio for GDM was two times greater compared with the highest quartile (> or = 163 cm) group, even after controlling for age and body mass index (BMI). In addition, multiple logistic regression analysis revealed that greater prepregnancy BMI, age, weight gain, a parental history of diabetes mellitus, and shorter maternal height were directly and independently associated with the prevalence of GDM. We have found that short stature is an independent risk factor for GDM in the racially homogeneous population of Seoul, Korea. It is suggested that this propensity may be conveyed primarily by environmental influences. However, genetic factors may also modify the response to the environmental insult. Our findings also emphasize the heterogeneity of factors which predispose to GDM.

Adult↗

PubMed1997

Increased macrosomia and perinatal morbidity independent of maternal obesity and advanced age in Korean women with GDM.

OBJECTIVE: To examine the impact of gestational diabetes mellitus(GDM) on perinatal outcome in a setting where influences of maternal age and obesity would be minimal. RESEARCH DESIGN AND METHODS: A case-control study was done to compare the outcome of pregnancy in 65 women with GDM and 153 women with normal carbohydrate metabolism matched for age, height, and prepregnancy weight. RESULTS: The frequencies of preeclampsia and primary cesarean sections were higher and delivery was earlier in pregnancies complicated by GDM. Birth weight, symmetry index, and chest circumference were greater, and macrosomia and need for phototherapy were more common in offspring of mothers with GDM. Cord-serum C-peptide and insulin concentrations were higher in the infants of mothers with GDM and were strongly correlated with birth weight and symmetry index. However, maternal age, prepregnancy weight, and prepregnancy BMI were not correlated with birth weight. Postprandial glucose levels during the first 2 weeks after diagnosis of GDM had associations with the infants' birth weight, symmetry index, and cord insulin concentration in the diet-treated patients with GDM. CONCLUSIONS: Antepartum maternal glucose metabolism was significantly associated with fetal hyperinsulinemia and excessive fetal growth in relatively nonobese Korean women. These findings support a direct role for metabolic factors in the adverse outcomes in pregnancies complicated by GDM.

Adult↗

PubMed1997

Factors responsible for computed electrogastrographic parameters in humans.

OBJECTIVES: Clinical knowledge about myoelectrical frequency is well known, but the factors responsible for recorded myoelectrical amplitude remain less clear. METHODS: We assembled an electrogastrographic system that could automatically compute the dominant myoelectrical frequency and power and power ratio. We enrolled 50 healthy volunteers (25 men and 25 women) to study their myoelectrical characteristics. Three surface electrodes were placed in the fundic, stomach body, and antral positions for two 30-min recordings in the fasting and postprandial states. RESULTS: The three different electrodes recorded similar dominant frequencies of about 3 cpm before and after a meal. The fasting dominant powers from these electrodes were 52.9 +/- 14.7, 44.6 +/- 11.5, and 50.1 +/- 15.1 dB, respectively (p < 0.01), whereas the postprandial dominant powers were 61.6 +/- 28.8, 54.3 +/- 26.6, and 61.9 +/- 27.8 dB, respectively (p < 0.01). Meal ingestion did increase the power (p < 0.05). Women had a lower dominant power than men (p < 0.001). Moreover, the dominant powers of each electrode were significantly correlated with body mass index (r = 0.3-0.36, p < 0.05) regardless of meal ingestion. The postprandial power ratio was not influenced by electrode position, gender, or body mass index. CONCLUSIONS: Myoelectrical dominant frequencies and power ratios are similar throughout the whole stomach area, whereas a lower power area exists on the stomach body. Gender-related variation in dominant power seems to be an effect of body size. The power ratio is the only reliable parameter for expressing myoelectrical amplitude.

Adult↗

PubMed1996

An assembled electrogastrographic device to examine the meal effect on gastric slow wave.

We have assembled an electrogastrographic device based on the main components of amplifiers, a band-pass filter, an analogue/digital converter, low band-pass digital filters and a personal computer. The analysis software uses autoregressive moving average modelling to compute the frequency of slow waves and uses fast Fourier transformation for power spectral computation. Twenty healthy young male volunteers were enrolled in the study to test meal-elicited responses of the slow wave. Subjects underwent a 15 min recording while fasting and then a standard breakfast, which included 250 mL milk and a cake with a total of 1.45 kj, was ingested within 5 min. The post-prandial 15 min recording was immediately resumed after the meal. A slight but significant increase in the frequency of slow waves was seen in post-prandial measurement (mean +/- s.d., 0.0506 +/- 0.0005 vs 0.0497 +/- 0.0005 Hz; P < 0.0001). Moreover, a significant enhancement of the power of slow waves was elicited following the meal (36.0 +/- 3.1 vs 27.6 +/- 3.1 dB; P < 0.0001). We conclude that this assembled electrogastrographic device is a reliable means of monitoring gastric myoelectrical activity because the phenomenon of post-prandial responses of slow waves in either frequency or power is well demonstrated.

Eating↗

PubMed1995

Screening for gestational diabetes mellitus in Korea.

OBJECTIVES: To examine the effect of clinical characteristics on the prevalence of gestational diabetes mellitus (GDM) and to find the most effective screening program for GDM in Korea. METHODS: Universal screening with a 50-g glucose load at 24-28 weeks' gestation, as recommended by the Third International Workshop-Conference on Gestational Diabetes Mellitus, was carried out among 3581 consecutive Korean women. Women with a 1-h plasma glucose > or = 130 mg/dl underwent a 3-h 100-g oral glucose tolerance test. The women's clinical characteristics and risk factors for GDM were recorded at the time of the screening test. RESULTS: The overall prevalence of GDM in Korean women was 2.2 cases/100. Although only 1.3% of this population was obese, the prevalence of GDM was found to be significantly increased with increasing body mass index. When 135 mg/dl is used as a threshold, the number of women requiring a diagnostic test decreases to 19.5%, enabling identification of 98.8% of women with GDM. CONCLUSION: Universal screening using 135 mg/dl as a threshold and early screening of those with two or more risk factors represent the most effective paradigm for Korea.

Adult↗

PubMed1994

Effects of hormone replacement therapy on lipoprotein(a) and lipids in postmenopausal women.

High concentrations of lipoprotein(a) [Lp(a)], an independent risk factor for atherosclerosis, cannot be managed by the usual lipid-lowering agents. It has been suggested that Lp(a) levels are related to female sex hormones. Estrogen replacement therapy makes the lipid profiles favorable for delaying atherosclerosis in postmenopausal women. The effects of the combination therapy of estrogen and progesterone on lipids are controversial. This study was designed to evaluate the effect of female sex hormones on the concentration of Lp(a) and to clarify the influence of progesterone on the effect of estrogen in postmenopausal women. Postmenopausal women (n = 184) were divided into four groups: control; 0.625 mg conjugated equine estrogen (CEE) plus 10 mg medroxyprogesterone acetate (MPA); 0.625 mg CEE plus 5 mg MPA; and 0.625 mg CEE only. Medication for 2 months lowered the concentrations of Lp(a) by 20% in all treated groups. The decrease was more pronounced in subjects with a relatively higher basal Lp(a) concentration. Estrogen replacement therapy raised the concentration of high-density lipoprotein cholesterol and decreased low-density lipoprotein cholesterol without changing total cholesterol. The combination therapy of estrogen and progesterone abolished the effect of estrogen on high-density lipoprotein cholesterol. Hormone replacement therapy lowered Lp(a) levels in postmenopausal women. The effect was prominent in subjects with high basal Lp(a) levels. This decrease may be one of the mechanisms of the cardioprotective effects of estrogen. The cardioprotective effect of estrogen cannot be applied to the combination therapy due to the adverse effect of progesterone on high-density lipoprotein cholesterol.

Adult↗

PubMed1994

The influence of body size to the parameters of gastric slow wave: studied with an assembled electrogastrography.

An electrogastrographic (EGG) device has been assembled, it consisted of the following main components: amplifiers, band-pass filter, analog/digital converter, low band-pass digital filters which could pick up signals between 0.02 Hz (1.2 cpm) and 0.1 Hz (6 cpm), and a personal computer. The analysis softwares employed autoregressive moving average modelling to compute frequency of slow wave, and overlapping Welch periodogram of fast Fourier transform for power computation. In order to study the influence of body size to the EGG parameters, 28 healthy males (age: 18-45 years) without any gastric dysmotor disorders were enrolled to record fasting EGG. Another 28 age-matched females were enrolled to record and to compare the EGG parameters. Of the EGG frequencies, both males and females were approximate to 0.05 Hz (NS). However, the EGG power values were markedly different between the male and female measurements (Mean +/- SD: 57.3 +/- 16.6 dB vs. 46.8 +/- 14.7 dB, p < 0.01). Correction with body mass index eliminated this difference. Of all measured EGG power values, a positive correlation with body mass index was seen (r = 0.39, p < 0.005). We conclude that a different EGG power value exists between the male and female subjects, body size is probable an important factor to elicit this difference.

Adult↗

PubMed1989

Impaired interleukin-2 receptor expression on lymphocytes from patients with chronic active hepatitis type B.

To evaluate cell mediated immunopathogenic mechanisms in chronic hepatitis B virus (HBV) infection, we investigated the changes of T4/T8 ratios from the peripheral blood, the percentages of IL-2 receptor expression after stimulation of mitogens (Con A, PHA) and a specific antigen (Hepatitis type B surface antigen, HBs), and the proliferative response mediated by IL-2 receptors after rIL-2 stimulation on mixed mononuclear cell. These experiments were performed comparatively in 5 groups which consisted of serologically negative normal subjects, chronic HBV carriers, patients with chronic active hepatitis (CAH) type B, patients with acute hepatitis (AH) type B, and the antibody positive healthy subjects. There were significant decreases of T4/T8 ratios in chronic HBV carriers, in patients with CAH type B, and in patients with AH type B, compared with negative normal controls. There were no significant differences between patients with CAH type B and the HBs negative normal controls in the percentage of IL-2 receptor positive cells after in-vitro HBs-stimulation and the proliferative response assessed by the incorporation of 3H-thymidine, whereas in patients with AH type B there were significant increases in both. Thus, in addition to a relatively decreased T4/T8 ratio, the impairment of IL-2 receptor expression on the lymphocytes after HBs-stimulation caused a defective response of cellular proliferation, and this might be one of the leading immunopathogenic roles in chronic HBV infection.

Adult↗

PubMed1989

Percutaneous transcatheteral biliary biopsy (PTBB)--a report of two cases.

In two patients with obstructive jaundice, percutaneous transhepatic cholangiography (PTC) and percutaneous transhepatic biliary drainage (PTBD) were performed. During PTBD, the percutaneous transcatheteral biliary biopsy (PTBB) with the biopsy forceps of the gastrofiberscope was performed through the biliary stent catheter. Biopsy specimens were successfully obtained and histopathologic findings were satisfactory in both cases.

Aged↗