1.Arthroscopic treatment of the discoid meniscus.
Jin Hwan AHN ; Cheol Jin OH ; Seung Ki KIM
The Journal of the Korean Orthopaedic Association 1991;26(3):854-862
No abstract available.
2.Factors that Influence MSAFP Concentration at Late Normal Singleton Pregnancies.
Mi Hye PARK ; Seung Cheol KIM ; Jung Ja AHN ; Bock Hi WOO
Korean Journal of Obstetrics and Gynecology 1997;40(1):78-84
This study was purosed to investigate maternal and fetal clinical parameters effecting on maternal serum alpha-fetoprotein(MSAFP) levels at late normal singleton pregnancies. The subjects of this study were 171 pregnant women with gestational age of 36 to 42 weeks, and didn`t have any medical or gynecologic diseases. They delivered fetuses within three days after blood test of MSAFP. MSAFP levels were measured by enzyme-immunoassay. The analysed clinical parameters included fetal sex, fetal weight, gestatioal age, maternal age, gravidity, parity, maternal weight and maternal total weight gain during pregnancy. The results were as follows: At uncomplicated late pregnancies, 1. Male fetus bearers had higher MSAFP(mean: 191.8 ng/ml, SD: 80.8 ng/ml, n=79) than female-fetus bearers(mean 153.6 ng/ml, SD 73.0 ng/ml, n=92)(p=0.0014). 2. Multiparas had higher MSAFP(mean: 192.7 ng/ml, SD: 77.9 ng/ml, n=80) than nulliparas(mean: 152.3 ng/ml, SD 75.1 ng/ml, n=91)(p=0.0007). 3. MSAFP did not have correlation with maternal age, maternal weight, maternal total wight gain during pregnancy, gestational age, fetal weight. According to the above results, fetal sex and parity are the factors that influences MSAFP levels at uncomplicated late pregnancies. So MSAFP values should be interpreted with cautions.
Female
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Fetal Weight
;
Fetus
;
Genital Diseases, Female
;
Gestational Age
;
Gravidity
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Hematologic Tests
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Humans
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Male
;
Maternal Age
;
Parity
;
Pregnancy*
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Pregnant Women
;
Weight Gain
3.The value of preoperative CA125 assay in patients with pelvic masses .
Seung Il KIM ; Cheol UM ; Jin Sub AHN ; Byung Chan OH ; Jong Duck KIM
Korean Journal of Obstetrics and Gynecology 1992;35(3):372-378
No abstract available.
Humans
4.Investigation of Developmental Changes of Convergence Ratios of MNTB-LSO Synapses in Circling Mice.
Korean Journal of Anatomy 2009;42(3):171-177
The developmental changes of convergence ratios of medial nucleus of trapezoid body (MNTB) axons to single lateral superior olive (LSO) neuron were investigated using voltage clamp technique in homologous (cir/cir) circling mice, animal model for the congenital deafness with autosomal recessive inheritance. As the developmental reduction of convergence ratio reported in rats indicates the presence of synaptic refinement, we aimed to find out whether the similar reduction of convergence ratio also occurs in circling mice. Heterologous (+/cir) mice were used as control and mice younger than postnatal (P) day 4 or older than P9 were used. The convergence ratios of MNTB axons to single LSO neuron were 29.16+/-2.7 (n=12,
Animals
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Axons
;
Brain Stem
;
Deafness
;
Humans
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Mice
;
Models, Animal
;
Neurons
;
Olea
;
Rats
;
Synapses
;
Wills
5.Abrupt Change in Electrophysiological Properties Begins From Postnatal Day 7 Before Hearing Onset in the Developing Mice Auditory Cortical Layer II/III Neurons
Clinical and Experimental Otorhinolaryngology 2019;12(3):279-286
OBJECTIVES: In the developing auditory cortex, maturation of electrophysiological properties and cell types before and after hearing onset has been reported previously. However, the exact timing of firing pattern change has not been reported. In this study, firing pattern change was investigated from postnatal day 3 (P3) to P12 in auditory cortical layer II/III neurons to investigate whether firing pattern changes dramatically after a specific point during development. METHODS: ICR mice pups aged from P3 to P12 were sacrificed to obtain 300-mm-thick brain slices containing the primary auditory cortex. From cortical layer II/III neurons, the patterns of action potential firing generated by current injection were examined using whole cell current clamp technique and the characteristics of Na⁺ currents involved in action potential firing were investigated using whole cell voltage clamp technique. RESULTS: From P3 to P6, most cells did not show action potential firing (29 of 46 cells), and some cells responding to current injection showed a single action potential at the initial depolarizing current step (17 of 46 cells). This firing pattern changes from P7. From P7 to P9, cells begin to show regular spiking to current injection. The spiking frequency increased after P10. In studying Na⁺ current with whole cell voltage clamp, Na⁺ current densities increased gradually (32.0±2.0 pA/pF [P3–P6, n=7], 51.2±2.0 pA/pF [P7–P9, n=13], and 69.5±3.7 pA/pF [P10–P12, n=13]) in low external [Na⁺] condition. Na⁺ current recovery was accelerated and inactivation curves shifted to hyperpolarization with age. CONCLUSION: As regular spiking cells were observed from P7 but never from P3 to P6, P7 might be regarded as an important milestone in the development of auditory cortical layer II/III neurons. This change might mainly result from the increase in Na⁺ current density.
Action Potentials
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Animals
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Auditory Cortex
;
Brain
;
Fires
;
Hearing
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Mice
;
Mice, Inbred ICR
;
Neurons
6.Clinical Experience of the Tibial Plateau Fracture
Jin Hwan AHN ; Sang Eun LEE ; Cheol Jin OH ; Seung Key KIM
The Journal of the Korean Orthopaedic Association 1990;25(3):684-691
The intra-articular tibial plateau fracture can induce many complications of the knee joint after conservative treatment or operative treatment. Recent experience could decrease the complications with accurate anatomical reduction, stable internal fixation and early knee ROM exercise, but still unsatisfactory results were reported from 20% to 40%. The authors analyzed the 30 cases that could be follow-up from 1 year to 6 years and were treated with operative methods, and the following results were obtained. 1. The most common cause of injury was traffic accident (14 cases-46.4%). 2. The most common fracture type by Hohls classification was type VI (13 cases-43.1%). 3. According to Blokker's criteria, 26 cases (86.7%) among 30 cases had satisfactory results. 4. The one of the most important factor influencing end results was thught to be the anatomical reduction of the articular margin.
Accidents, Traffic
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Classification
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Follow-Up Studies
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Knee
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Knee Joint
7.Tetanus-induced LTD of Developing MNTB-LSO Synapses in Rat is Dependent on Postsynaptic Ca2+.
The Korean Journal of Physiology and Pharmacology 2007;11(3):79-84
Because synaptic refinement of medial nucleus of trapezoid body (MNTB) - lateral superior olive (LSO) synapses is most active during the first postnatal week and the long term depression (LTD) has been suggested as one of its mechanisms, LTD of MNTB-LSO synapses was investigated in neonatal rat brain stem slices with the whole cell voltage clamp technique. In Mg2+ free condition, tetanus (10 stimuli at 10 Hz for 2 min) in the current clamp mode induced a robust LTD of isolated D, L-APV-sensitive postsynaptic currents (PSCs) for more than 30 min (n=6, 2.4+/-0.4% of the control), while isolated CNQX-sensitive PSCs were not suppressed (n=6, 95.3+/-1.6%). Tetanus also elicited similar LTD in the isolated GABAergic/glycinergic PSCs (n=5, 3.6+/-0.5%) and mixed PSCs (GABAergic/glycinergic/glutamatergic) (n=4, 2.2+/-0.7%). However, such a strong LTD was not observed in the mixed PSCs when 10 mM EGTA was added in the internal solution (n=10), indicating that postsynaptic Ca2+ rise is needed for the strong LTD. This robust LTD might contribute to the active synaptic refinement occurring during the first postnatal week.
Animals
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Brain Stem
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Depression
;
Egtazic Acid
;
Olea
;
Rats*
;
Synapses*
;
Synaptic Potentials
;
Tetanus
8.Inhibition of K⁺ outward currents by linopirdine in the cochlear outer hair cells of circling mice within the first postnatal week.
Shin Wook KANG ; Ji Woong AHN ; Seung Cheol AHN
The Korean Journal of Physiology and Pharmacology 2017;21(2):251-257
Inhibition of K⁺ outward currents by linopirdine in the outer hair cells (OHCs) of circling mice (homozygous (cir/cir) mice), an animal model for human deafness (DFNB6 type), was investigated using a whole cell patch clamp technique. Littermate heterozygous (+/cir) and ICR mice of the same age (postnatal day (P) 0 –P6) were used as controls. Voltage steps from –100 mV to 40 mV elicited small inward currents (–100 mV~–70 mV) and slow rising K⁺ outward currents (–60 mV ~40 mV) which activated near –50 mV in all OHCs tested. Linopirdine, a known blocker of K⁺ currents activated at negative potentials (I(K,n)), did cause inhibition at varying degree (severe, moderate, mild) in K⁺ outward currents of heterozygous (+/cir) or homozygous (cir/cir) mice OHCs in the concentration range between 1 and 100 µM, while it was apparent only in one ICR mice OHC out of nine OHCs at 100 µM. Although the half inhibition concentrations in heterozygous (+/cir) or homozygous (cir/cir) mice OHCs were close to those reported in I(K,n), biophysical and pharmacological properties of K⁺ outward currents, such as the activation close to –50 mV, small inward currents evoked by hyperpolarizing steps and TEA sensitivity, were not in line with I(K,n) reported in other tissues. Our results show that the delayed rectifier type K⁺ outward currents, which are not similar to I(K,n) with respect to biophysical and pharmacological properties, are inhibited by linopirdine in the developing (P0~P6) homozygous (cir/cir) or heterozygous (+/cir) mice OHCs.
Animals
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Deafness
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Hair Cells, Auditory, Outer*
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Humans
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Mice*
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Mice, Inbred ICR
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Models, Animal
;
Tea
9.Decreased Immunoreactivities of the Chloride Transporters, KCC2 and NKCC1, in the Lateral Superior Olive Neurons of Kanamycin-treated Rats.
Myung Whan SUH ; Seung Cheol AHN
Clinical and Experimental Otorhinolaryngology 2012;5(3):117-121
OBJECTIVES: From our previous study about the weak expressions of potassium-chloride (KCC2) and sodium-potassium-2 chloride (NKCC1) co-transporters in the lateral superior olive (LSO) in circling mice, we hypothesized that partially damaged cochlea of circling mice might be a cause of the weak expressions of KCC2 or NKCC1. To test this possibility, we reproduced the altered expressions of KCC2 and NKCC1 in the LSO of rats, whose cochleae were partially destroyed with kanamycin. METHODS: Rat pups were treated with kanamycin from postnatal (P)3 to P8 (700 mg/kg, subcutaneous injection, twice a day) and sacrificed for immunohistochemical analysis, scanning electron microscope (SEM) and auditory brain stem response. RESULTS: The SEM study revealed partially missing hair cells in P9 rats treated with kanamycin, and the hearing threshold was elevated to 63.8+/-2.5 dB SPL (4 ears) at P16. Both KCC2 and NKCC1 immunoreactivities were more prominent in control rats on P16. On 9 paired slices, the mean densities of NKCC1 immunoreactivities were 118.0+/-1.0 (control) and 112.2+/-1.2 (kanamycin treated), whereas those of KCC2 were 115.7+/-1.5 (control) and 112.0+/-0.8 (kanamycin treated). CONCLUSION: We concluded that weak expressions of KCC2 and NKCC1 in circling mice were due to partial destruction of cochleae.
Animals
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Brain Stem
;
Cochlea
;
Electrons
;
Hair
;
Hearing
;
Injections, Subcutaneous
;
Kanamycin
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Mice
;
Neurons
;
Olea
;
Rats
;
Symporters
10.Electrophysiologic Characteristics of Successfully Ablated Midseptal Accessory Pathway.
Seung Hwan LEE ; Jong Cheol RYU ; Geon Young KIM ; Shinki AHN ; Moon Hyoung LEE ; Sung Soon KIM
Korean Circulation Journal 1997;27(7):758-766
BACKGROUND: Catheter ablation using radiofrequency energy has been established as the most important mode of treatment in patients with accessory pathway. However the ablation of midseptal accessory pathways had been recognized as being more difficult to ablate than other located pathway because of the low incidence and the difficult localization of ablation site. This paper describes the electrophysiologic characteristics of successfully ablated midseptal accessory pathway using radiofrequency energy. METHOD: Routine electrophysiologic studies were performed in 13 patients with midseptal accessorypathway. Guided by the recording of VA interval, the ablation catheter was positioned in all patients in an area bounded anteriorly by the tip electrode of the His bundle catheter and posteriorly by the coronary sinus ostium. Local electrograms during orthodromic atrioventricular reentrant tachycardia or right ventricular apical pacing were compared for 13 patients with midseptal accessory pathway and consequent 13 patients with posteroseptal accessory pathway. RESULT: 13 patients with midseptal accessory pathway; eight with constant Wolff-Parfinson-White syndrome, one with intermittent Wolff-Parkinson-White syndrome and four with concealed bypass track underwent attempts at ablation of their pathway using radiofrequency energy. 11 accessory pathways were successfully ablated without complication during the firstsession. A second attempt at ablation was made in two patients with success(one; recurred case, the other one; failed case at the first session). In the surface 12-Lead ECG, all eight patientswith constant Wolff-Pakinsin-White syndrome had not shownen Qrs complex at lead 3. Two patient with midseptal accessory pathway had transient left bundle branch block during orthodromic tachycardia. The VA interval during left bundle branch block was not change compared to that during narrow complex tachycardia in both. In all patients with midseptal accessory pathway, the VA interval in his bundle electrogram were almost similar to that in the coronary sinus ostial electrogram, which was not observed in the patients with posteroseptal accessory pathway. CONCLUSION: We suggest that VA interval during orthodromic tachycardia and right ventricular apcial pacing is the most reliable market for identifying midseptal accessory pathway, especially distinguishing from posteroseptal accessory pathway.
Bundle of His
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Bundle-Branch Block
;
Catheter Ablation
;
Catheters
;
Coronary Sinus
;
Electrocardiography
;
Electrodes
;
Electrophysiologic Techniques, Cardiac
;
Humans
;
Incidence
;
Tachycardia
;
Wolff-Parkinson-White Syndrome