• Tuberculosis and Respiratory Diseases
• /
• v.44 no.6
• /
• pp.1245-1255
• /
• 1997

Background : Rifampicin(RFP) is a key component of the antituberculous short-course chemotherapy and the RFP resistance is a marker of multi-drug resistant(MDR) tuberculosis. RPoB gene encodes the $\beta$-subunit of RNA polymerase of M. tuberculosis which is the target of RFP. And rpoB gene mutations are the cause of RFP resistance of M. tuberculosis. Although several reports showed that PCR-SSCP would be a rapid diagnostic method for identifying the RFP resistance, there were few reports Performed using direct, clinical specimens. So we Performed PCR-SSCP analysis of rpoB gene of M. tuberculosis in direct, clinical specimens. Methods : 75 clinical specimens were collected from patients at Asan Medical Center from June to August 1996. After PCR of IS 6110 fragments, 43 both AFB smear-positive and IS6110 fragment PCR-positive specimens were evaluated. The RFP susceptibility test was referred to the referral laboratory of the Korean Tuberculosis Institute. DNA was extracted by bead beater method. And heminested PCR was done using 0.1ul(1uCi) [$\alpha-^{32}P$]-dCTP. SSCP analysis was done using non-denaturating MDE gel electrophoresis. Results : The results of PCR of IS6110 fragments of M. tuberculosis were positive in 55(73%) cases of 75 AFB smear-positive clinical specimens. Of the 55 specimens, RFP susceptibility was confirmed in only 43 specimens. Of the 43 AFB smear-positive and IS6110 fragment-positive specimens, 29 were RFP susceptible and 14 were RFP resistant. All the RFP susceptible 29 strains showed the same mobility compared with that of RFP sensitive H37Rv in SSCP analysis of ropB gene. And all the other RFP resistant 13 strains showed the different mobility. In other words they showed 100% identical results between PCR-SSCP analysis and traditional susceptibility test. Conclusion : The PCR-sseP analysis of rpoB gene in direct clinical specimens could be used as a rapid diagnostic method for detecting RFP resistant M. tuberculosis.

• Tuberculosis and Respiratory Diseases
• /
• v.48 no.1
• /
• pp.24-32
• /
• 2000

Purpose: Microsatellite instability(MSI) is frequently used as an indicator of microsatellite mutator phenotype(MMP) tumors. MSI has been observed in a percentage of non-small cell lung cancer(NSCLC). However, its role in tumorigenesis of NSCLC remains unknown. The frequency and pattern of MSI in NSCLC were evaluated and clinical parameters of MSI-positive tumors with those of MSS(microsatellite stable) tumors were compared. Materials and Methods: Twenty surgically resected NSCLCs were analyzed for 15 microsatellite markers located at chromosomes 3p and 9p. The peripheral blood lymphocytes of patients were used as the source of the normal DNA. Results: 1) Of 20 cases, 8(40%) demonstrated MSI. 2) Instability was observed more frequently in tri- and tetra-nucleotide repeats than in dinucleotide repeats. In all cases, instability appeared as a shift of individual allelic bands. 3) LDH was observed in 10(50%) of 20 tumors analyzed. 4) Of 20 cases, MSI-H tumor(showing MSI in the majority of markers) was absent. There were 5 MSI-L tumors(showing MSI in a greater than 10% of markers). 5) No significant difference was observed between MSI-L tumors and MSI-negative tumors in terms of clinicopathologic features such as pack-year history of smoking, histologic subtype, and(delete) stage of disease. There was also no significant difference in the incidence of LDH in relation to the status of MSI. Conclusion: These data strongly suggest that MSI plays different roles in lung and colon cancer. MMP pathway appears to be far less important in the tumorigenesis of NSCLC, caused mainly by cigarette smoke, with little familial tendency.

• Tuberculosis and Respiratory Diseases
• /
• v.45 no.5
• /
• pp.1039-1046
• /
• 1998

Background: Sleep-related breathing disorders(SRBD) and periodic leg movements disorder(PLMD) are both common, and are considered as separate sleep disorders. However, both disorders show high comorbidity. SRBD and PLMD can result in excessive daytime sleepiness and insomnia due to frequent sleep fragmentation. So, it is very important to consider the presence of PLMD, when we are dealing with the diagnosis and management of SRBD. The objectives of this study were to determine the incidence of PLMD in patients with SRBD, and to describe any differences between patients with and without PLMD. Method: The authors reviewed the sleep recordings of 106 patients with a final diagnosis of SRBD(obstructive sleep apnea or upper airway resistance syndrome), who underwent full nocturnal polysomnography, including the monitoring of the anterior tibialis electromyogram. All sleep records were recorded and scored using the standard criteria. The data was analyzed by the student t-test. Result: 106 patients(M=76, F=30) were included in the analysis. Data revealed a mean age of $49.5{\pm}13.6$ years, a respiratory disturbance index(RDI) of $22.3{\pm}25.4$/hour sleep, a lowest oxygen saturation of $84.9{\pm}11.3%$, a maximal esophageal pressure of $-41.0{\pm}19.1cmH_2O$, and PLM index(PLMI) of $13.1{\pm}22.4$movements/hour sleep. Forty four percent(47 of 106 patients) had a PLMI of greater than 5 on this study. The mean age of the patients with PLMD was significantly higher than that of the patients without PLMD(p<0.005). Female patients with SRBD accompanied more PLMD(p<0.05). The apnea index of the patients with PLMD was significantly lower than that of the patients without PLMD(p<0.01). The percentage of stage 1 sleep in the patients with PLMD was significantly lower than that of the patients without PLMD(p<0.05). Conclusion: The prevalence of PLMD in the patients with SRBD was high at 44.3%. The patients with PLMD were older and had more high RDI in comparison to the patients without PLMD, which was consistent with previous findings. The authors recommend that more careful consideration of PLMD is required when diagnosing and treating SRBD.

• The Journal of Korean Academy of Prosthodontics
• /
• v.47 no.2
• /
• pp.222-231
• /
• 2009

Statements of the problem: Over the past decades, conventional complete dentures were used for various patients although they have incomplete function. Overdentures using dental implants could help the improvement of denture function. Purpose: The purpose of this study was to compare the strains of abutment and bone on implant overdenture between splinted and unsplinted type of prosthesis. Additionally, the strain values of parallel placed implant model and unparallel placed implant model were compared. Material and methods: Two acrylic resin model were prepared and two implants were placed at the canine positions in each model. In the first model, two implant were placed parallel. In the second model, two implants were placed with 10 degree labiolingual divergence. Two types of abutment were connected to the fixtures alternatively. One was splint type of Hader bar, the other was unsplint type of ball abutment. Overdentures were fabricated with corresponding attachment systems and seated on abutments. Strains of abutments and labial bone simulants were measured with electric resistance strain gauges when static load from 100 N to 200 N were applied to overdentures. Results: 1. Splinted type of overdentures using bar and clip showed higher absolute strain values. But the strain was compressive and the load was shared by two implants(P<.05). 2. Unsplinted type overdentures using ball and O-ring showed low absolute strain values(P<.05). 3. Labially inclined implant showed higher tensile strain values in unsplinted type of prosthesis than in splinted type of prosthesis. Lingually inclined implant showed rather low strain values under load(P<.05). 4. Non parallel implant model showed higher absolute strain values than parallel placed implant model comprehensively(P<.05).

• The Journal of Korean Academy of Prosthodontics
• /
• v.49 no.4
• /
• pp.333-340
• /
• 2011

Purpose: The aim of this study was to study the effect of hydroxyapatite (HA) coating crystallinity on the proliferation and differentiation of human osteosarcoma cells. Materials and methods: Surface roughness of the titanium disks increased by anodizing treatment and then HA was coated using ion beam-assisted deposition (IBAD). HA coating was crystallized by heat-treated at different temperature ($100^{\circ}C$, $300^{\circ}C$, $500^{\circ}C$, $800^{\circ}C$). According to the temperature, disks were divided into four groups (HA100, HA300, HA500, HA800). With the temperature, crystallinity of the HA coating was different. Anodized disks were used as control group. The physical properties of the disk surface were evaluated by surface roughness tests, XRD tests and SEM. The effect of the crystallinity of HA coating on HOS cells was studied in proliferation and differentiation. HOS cells were cultured on the disks and evaluated after 1, 3, 5, and 7 days. Growth and differentiation kinetics were subsequently investigated by evaluating cell proliferation and alkaline phosphatase activity. Results: Regardless of the heat-treated temperature, there is no difference on the surface roughness. Crystallinity of the HA was appeared in the groups of HA500, HA800. HOS cells proliferation, ALP activity were higher in HA500 and HA800 group than HA100 and HA300. Conclusion: Within the results of this limited study, heat treatment at $500^{\circ}C$ of HA coating produced by IBAD has shown greater effect on proliferation and differentiation of HOS cells. It is considered that further in vivo study will be necessary.

• Journal of the Korean Chemical Society
• /
• v.33 no.1
• /
• pp.55-64
• /
• 1989

Reduction and equilibrium of vanadium-DTPA (DTPA = diethylenetriaminepentaacetic acid, $H_5A$) complexes at mercury electrodes are studied in 0.5M $NaClO_4$ aqueous solution at 3.2 < pH < 10.5 and 25$^{\circ}$C. At 3.2 < pH < 5.9, the reduction reaction is $V{\cdot}A^{2-}+H^-+e^-=V{\cdot}HA^{2-}$, while at 5.9 < pH < 10.5 it is $V{\cdot}A^{2-}+H^-+e^-=V{\cdot}A^{3-}$. The stability constants of $V{\cdot}HA^{2-}$ and $V{\cdot}A^{3-}$ are found to be $6.46{\times}10^{9}$ and $3.09{\times}10^{14}$, respectively. V(IV)-DTPA undergoes stepwise complexation as $VO^{2+}+H_2A^{3-}=VO{\cdot}HA^{2+}H^{+}$ and $VO{\cdot}HA^{2-}=VO{\cdot}A^{3+}+H$, where acidity constant of $VO{\cdot}HA^{2-}$- is pKa = 7.15. Stability constants of $VO{\cdot}HA^{2-}$ and $VO{\cdot}A^{3-}$ are found to be $1.41{\times}10^{14}$ and $3.80{\times}10^{17}$, respectively. It is detected that $VO^{2+}-DATA$ is reduced irreversibly to $VO^{2-}$ with the transfer coefficient of $\alpha$ = 0.43. At more cathodic overpotential, the reduction is stepwise as V(IV)${\to}$V(III)${\to}$V(II). The first one corresponds to $VO{\cdot}HA^{2-}+e^{-}{\to}VO{\cdot}HA{3+}$ at 3.2 < pH < 7.2 and $VO{\cdot}A^{3-}+e^{-}{\to}VO{\cdot}A^{4-}$ at 7.2 < pH < 10.5. The second is identical to that of V(III). Diffusion coefficients of $VO{\cdot}HA^{2-}$ and $VO{\cdot}A^{3-}$ are found to be $(9.0{\pm}0.3){\times}10^{-6}cm^2/s$ and $(5.9{\pm}0.4){\times}10^{-6}cm^2/ses$, respectively.

• Polymer(Korea)
• /
• v.33 no.6
• /
• pp.555-560
• /
• 2009

Sulfonic acid of the sulfonated 6FDA-based polyimides were exchanged with the monovalent ($Li^+$, $Na^+$, $K^+$) and divalent ($Mg^{2+}$, $Ca^{2+}$, $Ba^{2+}$) ions. The effect of metal cations exchanged sulfonated polyimides was investigated in terms of gas permeability and selectivity for $CO_2$, $O_2$ and $N_2$ gases. Thermogravimetric analysis showed that thermal stability of sulfonated polyimide was improved by exchanged metal cations. The permeabilities of monovalent cation-exchanged, sulfonated polyimide were reduced as the ion radius reduced [$Li^+$(0.059 nm)>$Na^+$(0.102 nm)>$K^+$(0.138 nm)], and those of divalent cations exchanged were determined by the ionic radii and electrostatic crosslinking between the polymer and metal cations, whereas the selectivities of all the metal cation-exchanged, sulfonated polyimides for $CO_2/N_2$ and $O_2/N_2$, were higher than those of sulfonated polyimide membranes. The sulfonated polyimide exchanged with the potassium cation showed the $O_2$ permeability of 89.98 Barrer [$1\times10^{-10}\;cm^3$(STP) $cm/cm^2{\cdot}s{\cdot}cmHg$] and the sulfonated polyimide exchanged with the lithium cation showed the $O_2/N_2$ selectivity of 12.9.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2002.09a
• /
• pp.101-125
• /
• 2002

A lake seismic survey was carried out to investigate possible geohazards for construction of the underground LPG storage at Namyang Lake. The proposed survey site has a land-lake combined geography and furthermore water depth of the lake is shallow. Therefore, various seismic methods such as marine single channel high resolution seismic reflection survey, sonobuoy refraction survey, land refraction survey and land-lake combined refraction survey were applied. Total survey amounts are 34 line-km of high resolution lake seismic survey, 14 lines of sonobuoy refraction survey, 890 m of land refraction survey and 8 lines of land-lake combined refraction survey. During the reflection survey, there were severe water reverberations from the lake bottom obscured subsurface profiling. These strong multiple events appeared in most of the survey area except the northern and southern area near the embankment where seems to be accumulated mainly mud dominated depositions. The sonobuoy refraction profiles also showed the same Phenomena as those of reflection survey. Meanwhile the results of the land-lake combined refraction survey showed relatively better qualities. However, the land refraction survey did not so due to low velocity soil layer and electrical noise. Summarized results from the lake seismic survey are that acoustic basement with relatively flat pattern appeared 30m below water level and showed three types of bedrock such as fresh, moderately weathered and weathered type. According to the results of the combined refraction survey, a velocity distribution pattern of the lake bottom shows three types of seismic velocity zone such as >4.5 km/s, 4.5-4.0km/s and <4.0km/s. The major fault lineament in the area showed NW-SE trend which was different from the Landsat image interpretation. A drilling was confirmed estimated faults by seismic survey.

• Food Science and Preservation
• /
• v.14 no.3
• /
• pp.301-307
• /
• 2007

To efficiently use Korean mung beans, the functional characteristics of mung bean powder(A), unhydrolyzed mung bean flour(B), and mung bean flour hydrolyzed under optimum conditions(C), were compared. The contents of protein, fat, carbohydrate, ash, and water, did not vary greatly with different treatment methods. The color values of (B) and (C) were similar, while the L value of (A) was higher than those of the other samples. Thereducing sugar content of (C) was highest at 292.63 mg%, while the total phenol contents of (A) and (C) were similar at 38.63 mg% and 38.38 mg%, respectively. The molecular weight of (A) was under 17 kDa by SDS-PAGE, and was lower than the molecular weights of the other samples (B, C), which generally ranged from 17 kDa to 72 kDa. The free sugar content of (C) was highest at 1,125.16 mg%, while (A) and (B) yielded values of 86.36 mg% and 54.20 mg%, respectively. Total free amino acid contents were in the order(C)(B)(A), and were 22,116.35 mg%, 2,731.29 mg%, and 578.54 mg%, respectively. The amino acid content of (C) was 8,231.42 mg% and was higher than those of (A) or(B). The DPPH free radical scavenging abilities of (A) and (C) were high, at 62.1% and 57.63%, respectively, while (B) showed a lower value at 19.26%. Fibrinolytic activity was highest(24.01%) in (C), and was 20.69% in (A) and 18.06% in (B). The above results indicate that mung bean flour hydrolyzed under optimal conditions (C) had the highest functional and quality characteristics, in comparisonh with unhydrolyzed flour (B) and mung bean powder (A). Diverse applications of hydrolyzed mung bean flour are anticipated.

• Korean Journal of Food Science and Technology
• /
• v.31 no.6
• /
• pp.1529-1535
• /
• 1999

This study was done for the extraction of carotenoid from Phaffia rhodozyma in combination with PEF and other methods. PEF treatment conditions were $30{\sim}80\;kV/cm,\;100{\sim}1000\;Hz\;and\;100{\sim}1000\;{\mu}s$. In order to increase permeability of yeast cell wall, various methods such as freezing-thawing, mechanical treatment, solvents, permeabilizing agents, and yeast cell wall lytic enzyme were used before PEF treatment. The combination of PEF $(50\;kV/cm,\;300\;Hz,\;1000\;{\mu}s)$ and conventional methods such as solvent and freezing-thawing pre-treatment had no effects on the extraction of carotenoid pigments. The extent of extracted carotenoid by the PEF $treatment(50\;kV/cm,\;300\;Hz,\;1000\;{\mu}s)$ combined with yeast cell wall lytic enzyme and mechanical pre-treatment increased 52% and 69.8% more than the sum of that by each treatment, respectively. Permeabilizing agents, especially Tween 20 and capric acid, enhanced the extraction efficiency of carotenoid pigments from P. rhodozyma cells. These results indicated the feasibility for the continuous extracting carotenoid pigments from P. rhodozyma by PEF combined with other permeabilizing methods.