Byung Yong Kang

Two polymorphisms of lnterleukin-4 gene in Korean adult periodontitis

Adult periodontitis is a multifactorial disease characterized by multple genetic and environmental factors. In view of the importance of interleukin-4 (IL-4) gene as a genetic factor for adult periodontitis, we investigated the relationship between two polymorphisms (-590 C → T polymorphism and 70 bp repeat polymorphism) of the human IL-4 gene and adult periodontitis in the Korean population. Genomic DNA was extracted from white blood cells of 32 adult periodontitis patients and 150 normal controls, respectively. There were no significant differences in the allele, genotype and haplotype distributions of two polymorphisms between normal controls and adult periodontitis group. Therefore, our results suggest that IL-4 gene locus contributes little to the interindividual susceptibility for adult periodontitis in Korean population.

Injuries in national Olympic level judo athletes: an epidemiological study

Purpose To present an epidemiological study of injuries found among South Koreas National level Judo athletes as a foundation for future injury prevention and skill enhancement in this group. Methods This study is a prospective study on a 4-year injury assessment held from January 2010 to December 2013 at the training centre in South Korea for National Level athletes. Athletes weight class, gender, injury location and injury grade (grade I=1–3 treatment days, grade II=4–7 treatment days, and grade III ≥8 treatment days) were analysed. Results There were a total of 782 injuries recorded during this period, equalling to four injuries per athlete annually. Almost half of these injuries (47%) were grade I injuries. Injury occurrence was the highest in the Lower body (44.2%). This was then followed by injuries in the upper body (29.8%), trunk (20.3%) and head and neck (5.6%). Men and women showed similar, non-significantly different trends in the proportion of body parts injured. Women experienced more grade III injuries than males (p=0.0228). Comparison between women in different weight classes also showed that heavyweights incurred more grade III injuries than lightweights (p=0.0087). Lightweights had a higher rate of injury than heavyweights in males and females, although this was statistically significant only among males (p<0.001). Conclusions Many body regions are prone to injury in the elite judo population. Women, especially those in the heavyweight classification, were more prone to severe injuries. Lightweights experienced more injuries than heavyweights among male athletes. Specifically, further studies are needed to confirm these findings and to address the impact of rapid weight loss practices on injury risk to implement effective preventive measures.

Genetic Variation in the Renin-Angiotensin System and Response to Endurance Training

Objective: To investigate the relationship between genetic variation in the renin-angiotensin system and the effect of 12-week endurance training in Korean women. Materials and Methods: Seventeen women who participated in an endurance training program for 12 weeks were genotyped for the angiotensinogen M235T polymorphism, angiotensin II type 1 receptor A1166C polymorphism, angiotensin-converting enzyme (ACE) T-3892C polymorphism, and angiotensin II type 2 receptor C3123A polymorphism. The following clinical parameters were measured before and after the endurance training program: blood pressure, body composition, ventilatory response, total cholesterol, triglyceride, and glucose. Results: Of the genetic markers investigated, the frequency of the T allele for the ACE T-3892C polymorphism was significantly associated with the response in body mass index and VO2max after 12 weeks of endurance training (p< 0.05). None of the other polymorphisms were significantly associated with the effect of training. Conclusion: The significant association between ACE T-3892C and the change in body mass index and VO2max in Korean women are attributed to training, suggesting that this genetic variation is a useful genetic marker for clarifying the interindividual response to endurance training.

Association between genetic variation of the insulin receptor gene and essential hypertension in the Korean population

Essential hypertension is a multifactorial disease, and has been shown to be associated with insulin resistance. The relationship between the genetic variation of the insulin receptor (INSR) gene and essential hypertension in Korean population was investigated by the Nsi I restriction fragment length polymorphism (RFLP) pattern of this gene. The observed genotype frequencies of INSR gene were not deviated from those expected for the Hardy‐Weinberg equilibrium (HWE), but a significant association was observed between essential hypertension and N1 allele of Nsi I RFLP at the INSR gene (χ2‐test; P<0.05). Moreover, the frequency of N1 allele was significantly different between normotensives and essential hypertensives in subgroups that were not obese (χ2‐test; P<0.05). These data suggest that the Nsi I RFLP of INSR gene may be a useful genetic marker for essential hypertension in Korean population.

Hepatoprotective and Anti-fatigue Effects of Lactic Acid Bacteria

This study was carried out to investigate the effect of LAB (Lactic acid bacteria: Lactobacillus acidophilus, Bifidobacterium bifidum and Streptococcus thermophilus) on detoxication of damaged liver in carbon tetrachloride (CCl₄) and ethanol (25%)-treated rats. Rats had been daily (twice a day) pretreated with saline (0.5 ㎖/㎏: untreated group), CCl₄ (0.5 ㎖/㎏: other groups) for 6 days. At seventh day, after treating rat with CCl₄ and then, mixture of LAB (10 11 /0.5 ㎖: LAB group), saline (0.5 ㎖/㎏: untreated group, CCl₄ group), and biphenyl dimethyl dicarboxylate (DDB) (50 ㎎/㎏: DDB group) were treated orally with CCl₄ for 8 days. Ethanol is treated as the same manner instead of CCl₄. To investigate the hepatoprotective effect, rats treated with CCl₄ and ethanol were analyzed with serum GOT and GPT level. The GOT and GPT levels of LAB group was lower than the level of CCl₄ and DDB group. Especially, compared with data of CCl₄ group, GPT activity showed statistically significant result in the significance level of p ＜ 0.05. The LAB group treated with ethanol also showed lower level of GOT and GPT than the other control groups treated with ethanol. The triglyceride level of serum decreased more in a group treated special materials (DDB and LAB group) than ethanol group. As well, the effect of LAB on the antifatigue has been investigated. The animals (10/group) were divided into 4 groups (untreated group, Carrier group, Red-ginseng group, LAB group). Each group was given carrier (0.9 ㎎/0.2 ㎖), red ginseng extract (200 ㎎/㎏), and mixture of LAB (10 11 /0.2 ㎖). Special materials were given for three weeks. After finishing treating through oral, horizontal wire test, rotarod test, and forced swimming test were performed. The time of resistance to fatigue of the group, fed with mixture of LAB, was longer than the time when mice treated with red-ginseng that the effect was already revealed. The result of this study revealed that LAB could decrease hepatocelluar injury compared with rats treated orally with CCl₄ and ethanol, and could also decrease fatigue.

Genetic polymorphisms of t‐PA and PAI‐1 genes in the Korean population

Abnormalities in fibrinolysis system is associated with risk of hypertension. In this report, the Alu repeat insertion/deletion (I/D) polymorphism of tissue plasminogen activator (t‐PA) and the Hind III RFLP of plasminogen activator inhibitor‐1 (PAI‐1) genes were investigated in 115 normotensives and 83 patients with hypertension, and their association with anthropometrical data and plasma biochemical parameters were analyzed. There were no significant differences in the gene frequencies of the two candidate genes between normotensives and hypertensives, respectively. Our results indicate lack of associations between the two polymorphisms in t‐PA and PAI‐1 genes and risk of hypertension in the population under study. However, the Hind III RFLP of PAI‐1 gene was significantly associated with plasma glucose level, suggesting its role in glucose metabolism. It needs to be tested whether this RFLP of PAI‐1 gene is associated with insulin resistance syndrome or non‐insulin dependent diabetes mellitus (NIDDM) in the Korean population.

Association between an AluI Polymorphism in the Calcitonin Receptor Gene and Quantitative Ultrasound Parameters in Korean Men

Objective: The purpose of this study was to investigate the association between an AluI RFLP of the calcitonin receptor (CTR) gene and quantitative ultrasound (QUS) parameters in Korean men, and the interaction with nutrition as a lifestyle factor. Materials and Methods: Broadband ultrasound attenuation, speed of sound and stiffness index of the calcaneus were measured using an ultrasound bone densitometer in 201 Korean men (mean age ± SD: 51.6 ± 11.7 years). The PCR-RFLP method was used to analyze an AluI polymorphism in the CTR gene. Results: In all subjects, the distribution of CC, CT and TT genotypes occurred with frequencies of 87.1, 12.4 and 0.5%, respectively. When stratified by omnivore and vegetarian groups, there was a significant association between an AluI polymorphism in the CTR gene and QUS parameters such as speed of sound and stiffness index in only vegetarian subjects. Conclusion: Our data suggest that the AluI polymorphism of the CTR gene can be useful as a genetic marker in the interindividual susceptibility of QUS parameters by the interaction with nutritional status as a lifestyle factor.

Apolipoprotein(a) Gene Polymorphism in the Korean Population: Is There Any Relevance to Essential Hypertension?

Objective: To investigate the role of the apolipoprotein(a) [Apo(a)] gene in predicting essential hypertension in the Korean population, we undertook a case-control study using the TTTTA repeat and the Met/Thr polymorphisms of the Apo(a) gene. Methods: The study subjects consisted of 74 essential hypertensives and 211 normotensive individuals. For polymorphism analysis, DNA was amplified by polymerase chain reaction (PCR). In the case of the Met/Thr polymorphism, amplified PCR products were digested with the restriction enzyme KspI. Genotyping was performed by a 10% nondenaturing polyacrylamide gel. Results: There were no significant differences in the allele and genotype frequencies of these polymorphisms between normotensive and essential hypertensive subjects (p > 0.05). Furthermore, levels of lipoprotein(a) in the plasma were not significantly associated with the different genotypes of the Apo(a) gene in either group (p > 0.05). Conclusion: The polymorphisms of these two loci on the Apo(a) gene are unlikely to contribute to the etiology of essential hypertension in the Korean population.

Human G‐protein β3 subunit C825T polymorphism is associated with serum total cholesterol and LDL‐cholesterol levels in Koreans

Abstract Essential hypertension results from the complex interaction between genetic and environmental factors. A C825T polymorphism of the gene encoding G‐protein β3 subunit (GNB3), associated with enhanced G‐protein coupled signaling and increased Na+‐H+ exchanger, has been implicated in the development of essential hypertension in several human populations, especially in Caucasian population. We examined the disease relevance of this candidate gene by performing an association study in a study group of Korean heritage. Participants comprised 109 essential hypertensives and 109 normotensives, respectively. Genotyping was performed with PCR‐βsaJI restriction digestion method. Observed genotype frequencies were in Hardy‐Weinberg equilibrium in all groups. Genotype and allele frequencies did not differ significantly between normotensives and essential hypertensives (P>0.05). However, the serum total cholesterol (TC) and LDL‐cholesterol levels were significantly higher in subjects with the TT genotype compared to those with the CC or CT genotypes in normotensives of our study subjects (P<0.05). Thus, these results suggest that GNB3/C825T polymorphism might be significantly associated with abnormality in serum lipid metabolism.

Genetic analysis of kallikrein‐kinin system in the Korean hypertensives

The kallikrein‐kinin system affects regulation of blood pressure, and genes encoding for the components of this system have been considered as good candidates for hypertension. To evaluate the relationship between genetic polymorphisms of candidate genes involved in this system and hypertension, we performed case‐control studies using genetic markers in Korean normotensives and hypertensives, respectively. By association study, there was a marginal association with hypertension in AA genotype distribution of A1789G polymorphism in the hKLK1 gene (P=0.0754). Thus, this genetic polymorphism may weakly contribute to the susceptibility to hypertension in Koreans. We also observed that significant linkage disequilibrium exists among three polymorphic sites in the hKLK1 gene studied, suggesting that the three genetic polymorphisms can be useful as genetic markers in clinical association studies. Further studies using larger sample sizes and more genetic markers will be needed to clarify genetic influence of kallikrein‐kinin system for hypertension.