1.Assessment of Genotoxic Hazard in Petrochemical Workers.
Jai Dong MOON ; Soon Phal SUH ; Jung Sun PARK ; Jin Hyung CHO ; Ki Won AHN
Korean Journal of Occupational and Environmental Medicine 1998;10(1):53-60
In order to evaluate the genotoxic hazard among workers potentially exposed to low level petrochemical substances, the analyses of micronuclei (MN) and sister chromatid exchanges (SCEs) in lymphocytes were performed in 46 male workers (as exposed group) and 46 nonexposed subjects (as control group). Mean frequencies of MN and SCEs (respectively, 12.9/1000 cells and 6.5/cell) in exposed group were very significantly higher than those (10.2/1000 cells and 5.4/cell) in control group. And there were also significant differences in mean frequencies of MN and SCEs adjusted for age, employment duration, smoking, and drinking between two groups. Median frequencies of MN and SCEs in exposed group were very significantly higher than those in control group. Frequencies of SCEs were higher in smokers than in non-smoker. Frequencies of MN in smokers, however, were similiar to those of non-smoker. Interaction between exposure and smoking on MN and SCEs induction was not observed. The results suggest that there is genotoxic hazard in high risk group like workers handling carcinogens in petrochemical plants and the analyses of MN and SCEs are useful biomarkers for the exposure to hazard substances even at the level below the exposure limit.
Biological Markers
;
Carcinogens
;
Drinking
;
Employment
;
Humans
;
Lymphocytes
;
Male
;
Sister Chromatid Exchange
;
Smoke
;
Smoking
2.A Survey of Health-related Lifestyle of the ROKAF Pilots.
Dong Won KIM ; Hae Chul AHN ; Ki Young CHUNG ; Chan KIM
Korean Journal of Aerospace and Environmental Medicine 2005;15(1):11-17
BACKGROUND: The present study was undertaken to know health-related lifestyles of Republic of Korea Air Force (ROKAF) pilots and to investigate prevalence of obesity of them.METHODS: 1284 KAF pilots were checked their height, weight, and body composition (% body fat). We also tried questionnaires on their health-related lifestyles which included the effort to be healthy, whether they know weight training is beneficial to G-tolerance, exercise habit and smoking history. RESULTS: Pilots' attitude for health promotion was relatively passive. Many of them know that weight training is good for their G-tolerance, but only 8.1% of the pilots carried out that training. They engaged much more in aerobic training, and also fighter pilots are less participated in weight training than transport pilots. The prevalence of obesity (29.4%) determined by bioelectrical impedance analysis was much higher than that assessed on the basis of height and weight (BMI, body mass index). It is suggested that many pilots who were normal in BMI have abdominal or visceral obesity. CONCLUSION: The health promotion program and physical conditioning program related to increasing G tolerance of KAF pilots flying high-performance aircraft are very important. These programs must be organized and progressed with flight surgeon and Aeromedical center in Chung-ju as leaders.
Aircraft
;
Body Composition
;
Chungcheongbuk-do
;
Diptera
;
Electric Impedance
;
Health Promotion
;
Life Style*
;
Obesity
;
Obesity, Abdominal
;
Prevalence
;
Republic of Korea
;
Smoke
;
Smoking
;
Surveys and Questionnaires
3.Enhancement of radiation effect using beta-lapachone and underlying mechanism.
Ki Jung AHN ; Hyung Sik LEE ; Se Kyung BAI ; Chang Won SONG
Radiation Oncology Journal 2013;31(2):57-65
Beta-lapachone (beta-Lap; 3,4-dihydro-2, 2-dimethyl-2H-naphthol[1, 2-b]pyran-5,6-dione) is a novel anti-cancer drug under phase I/II clinical trials. beta-Lap has been demonstrated to cause apoptotic and necrotic death in a variety of human cancer cells in vitro and in vivo. The mechanisms underlying the beta-Lap toxicity against cancer cells has been controversial. The most recent view is that beta-Lap, which is a quinone compound, undergoes two-electron reduction to hydroquinone form utilizing NAD(P)H or NADH as electron source. This two-electron reduction of beta-Lap is mediated by NAD(P)H:quinone oxidoreductase (NQO1), which is known to mediate the reduction of many quinone compounds. The hydroquinone forms of beta-Lap then spontaneously oxidizes back to the original oxidized beta-Lap, creating futile cycling between the oxidized and reduced forms of beta-Lap. It is proposed that the futile recycling between oxidized and reduced forms of beta-Lap leads to two distinct cell death pathways. First one is that the two-electron reduced beta-Lap is converted first to one-electron reduced beta-Lap, i.e., semiquinone beta-Lap (SQ).- causing production of reactive oxygen species (ROS), which then causes apoptotic cell death. The second mechanism is that severe depletion of NAD(P)H and NADH as a result of futile cycling between the quinone and hydroquinone forms of beta-Lap causes severe disturbance in cellular metabolism leading to apoptosis and necrosis. The relative importance of the aforementioned two mechanisms, i.e., generation of ROS or depletion of NAD(P)H/NADH, may vary depending on cell type and environment. Importantly, the NQO1 level in cancer cells has been found to be higher than that in normal cells indicating that beta-Lap may be preferentially toxic to cancer cells relative to non-cancer cells. The cellular level of NQO1 has been found to be significantly increased by divergent physical and chemical stresses including ionizing radiation. Recent reports clearly demonstrated that beta-Lap and ionizing radiation kill cancer cells in a synergistic manner. Indications are that irradiation of cancer cells causes long-lasting elevation of NQO1, thereby sensitizing the cells to beta-Lap. In addition, beta-Lap has been shown to inhibit the repair of sublethal radiation damage. Treating experimental tumors growing in the legs of mice with irradiation and intraperitoneal injection of beta-Lap suppressed the growth of the tumors in a manner more than additive. Collectively, beta-Lap is a potentially useful anti-cancer drug, particularly in combination with radiotherapy.
Animals
;
Apoptosis
;
Benzoquinones
;
Cell Death
;
Electrons
;
Humans
;
Hydroquinones
;
Injections, Intraperitoneal
;
Leg
;
Mice
;
NAD
;
Naphthoquinones
;
Necrosis
;
Radiation Tolerance
;
Radiation, Ionizing
;
Reactive Oxygen Species
;
Recycling
;
Substrate Cycling
4.Effect of Enoxacin(Flumark) in Urinary Tract Infection - Clinical and Antimicrobial Susceptibility Evaluation-.
Young Kyoon KIM ; Eun Sik LEE ; Sung Won LEE ; Ky Hyun CHUNG ; Ahn Ki LEE
Korean Journal of Urology 1987;28(4):541-548
Effect of Enoxacin (Flumark), an oral pyridone carboxylic acid, in the urinary tract infection was evaluated clinically and susceptibility of 292 strains of microorganism isolated from urine to the various antimicrobial agents was tested and compared. Thirty six patients with urinary tract infection were given with 300 to 600mg of Enoxacin daily for 7 to 14 days according to severity of urinary tract infection. The clinical symptoms and urinary findings improved in 30 patients (83.3%) and no clinical response was achieved in 6 patients (16.7%), but revealing 100% response in 9 patients of acute uncomplicated cystitis. In the antimicrobial susceptibility test, Enoxacin was much superior to aminoglycoside, especially against Pseudomonas aeruginosa. Serratia spp., Enterobacter spp. and other Pseudomonas spp.. Enoxacin is a very effective and safe antimicrobial agent in treatment of the urinary tract infection.
Anti-Infective Agents
;
Cystitis
;
Enoxacin
;
Enterobacter
;
Humans
;
Pseudomonas
;
Pseudomonas aeruginosa
;
Serratia
;
Urinary Tract Infections*
;
Urinary Tract*
5.Myxoid Liposarcoma.
Tae Hyung KIM ; Jong Woo KIM ; Sang Won KIM ; Dong Seok KIM ; Ki Young AHN
Annals of Dermatology 1996;8(2):144-148
No abstract available.
Liposarcoma, Myxoid*
6.Role of Heat Shock Protein, P70 in Spermatogenic Arrest.
Hyun Joo KIM ; Won Young SON ; Tae Young AHN ; Tae Ki YOON ; Kwang Yul CHA
Korean Journal of Urology 2000;41(1):129-137
No abstract available.
Heat-Shock Proteins*
;
Hot Temperature*
7.Role of Heat Shock Protein, P70 in Spermatogenic Arrest.
Hyun Joo KIM ; Won Young SON ; Tae Young AHN ; Tae Ki YOON ; Kwang Yul CHA
Korean Journal of Urology 2000;41(1):129-137
No abstract available.
Heat-Shock Proteins*
;
Hot Temperature*
8.The Clinical Aspects of Orbital Fractures Proven by Computed Tomography.
Journal of the Korean Ophthalmological Society 1997;38(12):2077-2083
Computed tomography can be diagnostic with orbital fractures, because it provides detailed visualization of anatomical relationship on both the bones and soft tissues of the orbits. By identifying a group of patient at high risk for enophthalmos and persistent diplopia, we were able to decise the indication of operation. From January 1991 to December 1996, the authors reviewed of 106 consecutive patients(118 eyes)with orbital fractures proven by computed tomography respectively. Among them, 13 patients were repaired surgically. The results were as follows. Orbital fractures occurred most frequently between the ages of 21 and 40 years of men, and the most common cause of those was traffic accident. The incidence of orbital fracture was higher on the left side of orbit. In single wall fractures, the most common involved wall was medial wall, followed by inferior, superior and lateral wall in order. In combined wall fractures, medial and inferior wall fractures were most common. The associated symptoms and signs of orbital fracture were periorbital swelling, lid laceration, diplopia, and enophthalmos in turn. Subciliary approach was used for repair of the fracture. The surgical intervention was done within 2 weeks.
Accidents, Traffic
;
Diplopia
;
Enophthalmos
;
Humans
;
Incidence
;
Lacerations
;
Male
;
Orbit*
;
Orbital Fractures*
9.Inhibitory of γ-aminobutyric acid on the contractility of isolated rat vas deferens.
Ki Young AHN ; Oh Cheol KWON ; Jeoung Hee HA ; Kwang Youn LEE ; Won Joon KIM
Yeungnam University Journal of Medicine 1992;9(2):382-395
GABA is an inhibitory neurotransmitter in central nervous system and produce sedative, antianxiety and muscle relaxing effects via GABA(A) receptor or GABA(B) receptor. Recently it is known that GABA is widely distributed throughout peripheral organs and may play a physiological role in certain organ. The vas deferens is innervated by species-difference. These study, therefore, was performed to investigate the mode and the mechanism of action of GABA on the norepinephrine-, ATP- and electric stimulation-induced contraction of vas deferens of rat. Sprague-Dawley rats were sacrificed by cervical dislocation. The smooth muscle strips were isolated from the prostatic portion and were mounted in the isolated muscle bath. PSS in the bath was aerated with 95/5%-O₂/CO₂ at 33℃. Muscle tensions were measured by isometric tension transducer and were recorded by biological recording system. 1. GABA, muscimol, a GABA(A) agonist, and baclofen, a GABA(B) agonist inhibited the electric field stimulation (EFS, 0.2Hz, 1mSec, 80V, monophasic square wave)-induced contraction with a rank order of potency of GABA greater than baclofen greater than muscimol. 2. The inhibitory effect of GABA was antagonized by delta aminovaleric acid (DAVA), a GABA(B) antagonist, but not by bicuculline, a GABA(A) intagonist. 3. The inhibitory effect of baclofen was antagonized by DAVA, but the effect of muscimol was not antagonized by bicuculline. 4. Exogenous norepinephrine (NE) and ATP contracted muscle strip concentration dependently, but the effect of acetylcholine was negligible and GABA did not affect the NE-and ATP-induced contractions. 5. GABA, baclofen and muscimol did not affect basal tone, and GABA did not affect the NE-and ATP-induced contractions. 6. EFS-induced contraction was inclucling 2 distinctable components. The first phasic component was inhibited by beta gamma-methylene ATP (mATP), a desensitizing agent of APT receptor and the second tonic component was reduced by pretreatment of reserpine (3 mg/Kg, IP). 7. GABA inhibited the EFS-induced contraction of reserpinized strips, but not the mATP-treated strips. These results suggest that in the prostatic portion of the rat vas deferens, adrenergic and purinergic neurotransmissions are exist, and GABA inhibits the release of ATP via presynaptic GABA(B) receptor on the excitatory neurons.
Acetylcholine
;
Adenosine Triphosphate
;
Animals
;
Baclofen
;
Baths
;
Bicuculline
;
Central Nervous System
;
Dislocations
;
gamma-Aminobutyric Acid
;
Muscimol
;
Muscle, Smooth
;
Neurons
;
Neurotransmitter Agents
;
Norepinephrine
;
Rats*
;
Rats, Sprague-Dawley
;
Receptors, GABA-A
;
Reserpine
;
Transducers
;
Vas Deferens*
10.The Painful Os Subfibulare: Report of Four Cases
Won Kap LEE ; Soon Ok AHN ; Min LEE ; Ki Ho SHIN
The Journal of the Korean Orthopaedic Association 1982;17(6):1223-1226
The os subfibulare is a relatively uncommon bony anomaly of the foot. It is usually found between the malleolus and talus and ossifies during adolescence or preadolescence. It can be demonstrated on routine anteroposterior ankle film of the foot. In 4 patients presented, the abnormality caused pain and frequent episodes of ankle strain. The pain was relieved in all patients treated by excision of the accessory bone.
Adolescent
;
Ankle
;
Foot
;
Humans
;
Talus