• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.04a
• /
• pp.5-9
• /
• 2004

In this paper, we studied the OCT(Optical Coherence Tomography) system which it has been extensively studied because of having some advantages such as high resolution cross-sectional images, low cost, and small size configuration. A basic principle of OCT system is Michelson interferometer. The characteristics of light source determine the resolution and the transmission depth. As a results, the light source have a commercial SLD with a central wavelength of 1,285 nm and FWHM(Full Width at Half Maximum) of 35.3 nm. The optical delay line part is necessary to equal of the optical path length with scattered light or reflected light from sample. In order to equal the optical path length, the stage which is attached to reference mirror is moved linearly by step motor And the interferometer is configured with the Michelson interferometer using single mod fiber, the scanner can be focused of the sample by using the reference arm. Also, the 2-dimensional cross-sectional images were measured with scanning the transverse direction of the sample by using step motor. After detecting the internal signal of lateral direction at a paint of sample, scanner is moved to obtain the cross-sectional image of 2-demensional by using step motor. Photodiode has been used which has high detection sensitivity, excellent noise characteristic, and dynamic range from 800 nm to 1,700 nm. It is detected mixed small signal between noise and interference signal with high frequency After filtering and amplifying this signal, only envelope curve of interference signal is detected. And then, cross-sectional image is shown through converting this signal into digitalized signal using A／D converter. The resolution of the OCT system is about 30$\mu\textrm{m}$ which corresponds to the theoretical resolution. Also, the cross-sectional image of ping-pong ball is measured. The OCT system is configured with Michelson interferometer which has a low contrast because of reducing the power of feedback interference light. Such a problem is overcomed by using the improved inteferometer. Also, in order to obtain the cross-sectional image within a short time, it is necessary to reduce the measurement time for improving the optical delay line.

• Development and Reproduction
• /
• v.4 no.1
• /
• pp.115-123
• /
• 2000

A few enzymeimmunoassay (EfA) for testosterone (T) have been reported but was not suitable for all biological samples. The present study was designed to develop a rapid, ultrasensitive EIA and to apply this technique for study the physiological changes of T in biological samples. Saliva samples were collected at 06:00～09:00 hour during one menstrual cycle from 18 normally menstruating women and on 09:00～10:00 hour from 20 normal men. The present study shows an established EIA for testosterone, using horseradish peroxidase (HRP), which was covalently bonded to testosterone-3-carboxymethyloxime (T-3-CMO). One batch of T-antisera was also covalently linked to microcrystalline cellulose particles by a mixed anhydride method in order to facilitate separation of bound and free steroids. The established EIA was validated in terms of sensitivity, accuracy, specificity, precisions etc., comparing with conventional radioimmunoassay. The sensitivity of the established EIA was less than 25 pg/tube. The correlation coefficients between the expected T-values and observed T-values measured by EIA or RIA were r=0.985 and r=0.941 respectively. The cross reactivity of antiserum in EIA was a little higher than that of RIA, especially by 5 ${\alpha}$-DHT. The intra- and inter-assay precisions of the present EIA were similar to those of RIA. The present study also demonstrates that the normal T-values in saliva of Korean male ＆ female samples are 265.65${\pm}$15.80 pmol／l and 109.74${\pm}$ 12.01 pmol／l, respectively. The present EIA seems to be established and suitable for use in the endocrinological studies. The advantages of this EIA system also might make the present T-EIA an ideal procedure for use in a routine assay of ordinary laboratory with a conventional spectrophotometer.

• Parasites, Hosts and Diseases
• /
• v.24 no.1
• /
• pp.25-41
• /
• 1986

The applicability of micro-ELISA was evaluated in human neuro-cysticercosis using paired samples of serum and CSF. A total of 355 cases who were mostly neurologic patients was subjected. Cystic fluid of C. cellulosae was used as antigen in protein concentration of $2.5{\;}{\mu}g/ml$. Serum was diluted to 1 : 100 and CSF was undiluted in the assay for the specific IgG antibody level. The differential criterion of the positive reaction was the abs. of o. 18 in both samples. The results were summarized as follows: 1. The overall sensitivity of the micro-ELISA in 71 confirmed neurocysticercosis was 90.1% ; the sensitivity by serum was 77.5% and that by CSF was 83.1%. CSF was a more sensitive and valuable material. Most of the false negative cases of neuro-cysticercosis showed far lower level of abs. rather than marginal. 2. The overall specificity of the micro-ELISA in 52 confirmed other neurologic diseases was 88.5%; the specificities by serum and by CSF were 94.2% respectively. Cases of other neurologic diseases did not show false positive reactions in both samples. 3. When serum was assayed, taeniasis(2/18), sparganosis(2/20), paragonimiasis(1/56), clonorchiasis(1/15) and fascioliasis(1/1) cases showed cross reactions. When CSF was assayed, 2 ot 10 neuro-sparganosis showed cross reactions while none of 9 neuro-paragonimiasis showed it. Out of 71 confirmed neuro-cysticercosis cases, 6 and 11 showed cross reactions by serum and CSF to crude extract antigen of sparganum; but no case did show it to crude extract antigen of Paragonimus westermani. 4. Ventricular CSF showed low or negative levels of IgG antibody than lumbar CSF unless the lesion was at the lateral ventricle itself. 5. Out of 4 racemose cysticercosis cases, 3 showed positive reaction in serum while all of 3 examined CSF were positive. The above results indicated that the serological test for detecting the specific IgG antibody by micro-ELISA using paired samples of serum and CSF was very helpful for clinical differentiation of neuro-cysticercosis from neurologic diseases of other causes.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.17
• /
• pp.7825-7829
• /
• 2015

Background: Egypt has the highest prevalence of HCV infection in the world (~14.7%). Around 10-15% of HCV-infected persons will advance to cirrhosis within the first 20 years. The incidence of HCC is expected to grow in the next two decades, largely due to HCV related cirrhosis, and detection of HCC at an early stage is critical for a favorable clinical outcome. No simple reliable non-invasive marker has been available till now. B2M, a non-glycosylated polypeptide composed of 99 amino acids, is one of the components of HLA class I molecules on the surfaces of all nucleated cells. It has been reported that the level of serum B2M is elevated in patients with chronic hepatitis C and HCV-related HCC when compared to HCV-negative patients or healthy donors. Determining the clinical utility of serum B2M as a marker for disease progression in Egyptian patients with HCV related chronic hepatitis, cirrhosis and hepatocellular carcinoma was the aim of the present study. Materials and Methods: In this analytical cross sectional study 92 participants were included in 4 equal groups: Group (1) non cirrhotic chronic HCV; Group (2) HCV related liver cirrhosis; Group (3) HCC on top of HCV,; and Group (4) healthy controls. History taking, clinical examination, routine labs and abdominal ultrasound were conducted for all patients, PCR and Metavir scores for group (1) patients, and triphasic CT abdomen and AFP for Group (3) patients. B2M levels were measured in serum with a fully-automated IMX system. Results: The mean serum B2M level of Group (1) was $4.25{\pm}1.48{\mu}g/ml$., Group (2) was $7.48{\pm}3.04$, Group (3) was $6.62{\pm}2.49$ and Group (4) was $1.62{\pm}0.63$. Serum B2M levels were significantly higher in diseased than control group (p<0.01) being significantly higher in cirrhosis ($7.48{\pm}3.04$) and HCC groups ($6.62{\pm}2.49$) than the HCV group ($4.25{\pm}1.48$) (p<0.01). There was a significant correlation between B2M Level and ALK, total and direct bilirubin and INR (p<0.05), and a significant inverse correlation between B2M level and albumin, total proteins, HB andWBCS values (p<0.05). There was no significant correlation between B2M level and viral load or Metavir score, largest tumour size or AFP (p>0.05). The best B2M cut-off for HCV diagnosis was 2.6 with a sensitivity of 100%, a specificity of 92%, a positive predictive value (PPV) of 97% and a negative predictive value (NPV) of 100%. The best B2M cut-off for HCC diagnosis was 4.55 which yielded sensitivity, specificity, positive predictive value, negative predictive values of 74%, 62%, 39.5, 87.8% respectively (p-value <0.01) while best cut-off for cirrhosis was 4.9, with sensitivity 74 % and specificity 74%.The sensitivity for HCC diagnosis increased upon B2M and AFP combined estimation to 91%, specificity to 79%, NPV to 95% and accuracy to 83%. Conclusions: Serum B2M level is elevated in HCV related chronic liver diseases and may be used as a marker for HCV disease progression towards cirrhosis and carcinoma.

• BMB Reports
• /
• v.38 no.6
• /
• pp.683-689
• /
• 2005

Antibody to hepatitis B surface antigen (HBsAb) is the important serological marker of the hepatitis B virus (HBV) infection. Conventionally, the hepatitis B surface antigen (HBsAg) obtained from the plasma of HBV carriers is used as the diagnostic antigen for detection of HBsAb. This blood-origin antigen has some disadvantages involved in high cost, over-elaborate preparation, risk of infection, et al. In an attempt to explore the suitable recombinant HBsAg for the diagnostic purpose, the HBV S gene was expressed in Pichia pastoris and the product was applied for detection of HBsAb. Hepatitis B virus S gene was inserted into the yeast vector and the expressed product was analyzed by sodium dodecyl sulphate polyacrolamide gel electrophoresis (SDS-PAGE), immunoblot, electronic microscope and enzyme linked immunosorbent assay (ELISA). The preparations of synthesized S protein were applied to detect HBsAb by sandwich ELISA. The S gene encoding the 226 amino acid of HBsAg carrying ahexa-histidine tag at C terminus was successfully expressed in Pichia pastoris. The His-Tagged S protein in this strain was expressed at a level of about 14.5% of total cell protein. Immunoblot showed the recombinant HBsAg recognized by monoclonal HBsAb and there was no cross reaction between all proteins from the host and normal sera. HBsAb detection indicated that the sensitivity reached 10 mIu (micro international unit)/ml and the specificity was 100% with HBsAb standard of National Center for Clinical Laboratories. A total of 293 random sera were assayed using recombinant S protein and a commercial HBsAb ELISA kit (produced by blood-origin HBsAg), 35 HBsAb positive sera and 258 HBsAb negative sera were examined. The same results were obtained with two different reagents and there was no significant difference in the value of S/CO between the two reagents. The recombinant HBV S protein with good immunoreactivity and specificity was successfully expressed in Pichia pastoris. The reagent for HBsAb detection prepared by Pichia pastoris-derived S protein showed high sensitivity and specificity for detection of HBsAb standard. And a good correlation was obtained between the reagent produced by recombinant S protein and commercial kit produced by blood-origin HBsAg in random samples.

• Pediatric Infection and Vaccine
• /
• v.18 no.1
• /
• pp.48-53
• /
• 2011

Purpose : Early diagnosis of active tuberculosis (TB) in children is difficult. The widely used tuberculin skin test has low sensitivity and cross reactivity with non-tuberculous mycobacteria or Bacille Calmette-Gu$\acute{e}$rin vaccination. Interferon gamma release assays have been shown good diagnostic accuracy for active in adults. But studies in children were limited. The purpose of this study was to examine the performance of enzyme-linked immunospot assay (ELISpot) as an initial test in the diagnosis of active tuberculosis in children. Methods : In a hospital-based study, we prospectively examined the performance of ELISPot in 33 children suspected of active TB. TB was confirmed bacteriologically or histologically. Results : Among 33 patients, 9 had active tuberculosis. When tested, they all had a positive test result from the ELISpot. The sensitivity and specificity of the assay were 100% (95% CI, 66.4-100%) and 95.8% (95% CI, 78.9-99.9%) respectively. Conclusion : ELISpot might be an useful and improved clinical diagnostic method for the detection of active TB in children.

• Korean Journal of Environmental Agriculture
• /
• v.11 no.1
• /
• pp.59-66
• /
• 1992

An enzyme immunoassay(EIA) was developed for the analysis of insecticide endosulfan and its degradation products. The sensitivity and specificity of the antibody produced were examined. Optimal conditions in the ELISA system for residue analysis were also discussed. A mixed suspension of endosulfan-hemocyanin conjugate(ES-KLH) 1.1 mg/ml and Freund's adjuvant was injected subcutaneously to white rabbits and then collected antisera were tested for titers by indirect ELISA(1/24,000). Because of difficulties in the synthesis of endosulfan peroxidase conjugate, amine derivative of endosulfan-diol was synthesized and it showed 40% of conjugate yields(2mg/ml of conjugate). the highest sensitivity obtained enzyme-conjugate was a concentration of 200ng/ml. The detection limit of endosulfan in ELISA system was 5 ppb on the standard curve. In application of ELISA for residue analysis, the recoveries were really 100% both in the spiked soil and apple sample regardless of endosulfan concentration treated. On the other hand, chlorinated hydrocarbons of similar structure with endosulfan showed low cross-reactivity$(2.2%{\sim}29.2%).$

• Journal of Korean Ophthalmic Optics Society
• /
• v.16 no.1
• /
• pp.51-60
• /
• 2011

Purpose: This study was to investigate visual performance and subjective satisfaction with multifocal soft contact lenses at near works in university students. Methods: In a cross-over study design, 26 students (6 male, 20 female) who did not have any ocular disorder with at least 20/20(1.0) binocular vision were fitted with singlevision lenses (SofLens$^{TM}59$, Bausch + Lomb Co. USA) or multifocal lenses (SofLens Multifocal, Bausch + Lomb Co. USA). After 2 weeks, visual performance assessments included visual acuity, stereoacuity and contrast sensitivity function at distance and near. Near point of accommodation, accommodative facility, near point of convergence, vergence facility and near range of clear vision at near were examined. Students' satisfaction and preference were measured using survey questionaries. Results: Subjects maintained at least 20/20 binocular vision with multifocal and single-vision lenses at distance and near. There was no difference between multifocal and single-vision lenses in stereoacuity, contrast sensitivity function and vergence facility at far and near. The near point of accommodation, accommodative facility, near point of convergence and the near range of clear vision with multifocal lenses were better than single-vision lenses. On the survey questionaries, subjects reported that they preferred and satisfied with multifocal lenses with near works, and single-vision lenses with distance works. Conclusions: The majority of university students preferred multifocal to single vision lenses because multifocal lenses provided better visual performance at near works. This study suggests that multifocal lens is helpful for young adult in prolonged near works.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.11
• /
• pp.1928-1936
• /
• 2018

Recently, human infections caused by severe fever with thrombocytopenia syndrome virus (SFTSV), which can lead to fatality, have dramatically increased in East Asia. With the unavailability of vaccines or antiviral drugs to prevent and/or treat SFTSV infection, early rapid diagnosis is critical for prevention and control of the disease. Here, we report the development of a simple, rapid and sensitive portable detection method for SFTSV infection applying reverse transcription-loop mediated isothermal amplification (RT-LAMP) combined with one-pot colorimetric visualization and electro-free reaction platform. This method utilizes a pocket warmer to facilitate diagnosis in a resource-limited setting. Specific primers were designed to target the highly-conserved region of L gene of SFTSV. The detection limit of the RT-LAMP assay was approximately $10^0$ viral genome copies from three different SFTSV strains. This assay exhibited comparable sensitivity to qRT-PCR and 10-fold more sensitivity than conventional RT-PCR, with a rapid detection time of 30 to 60 minutes. The RT-LAMP assay using SFTSV clinical specimens has demonstrated a similar detection rate to qRT-PCR and a higher detection rate compared to conventional RT-PCR. Moreover, there was no observed cross-reactive amplification of other human infectious viruses including Japanese Encephalitis Virus (JEV), Dengue, Enterovirus, Zika, Influenza and Middle East Respiratory Syndrome Coronavirus (MERS-CoV). This highly sensitive, electro- and equipment-free rapid colorimetric visualization method is feasible for resource-limited SFTSV field diagnosis.

• Parasites, Hosts and Diseases
• /
• v.22 no.2
• /
• pp.223-228
• /
• 1984

Seven cases of surgically proven sparganosis were serologically tested by means of microELISA for their specific IgG antibody levels. For that purpose, crude saline extract of spargana from snake, Natrix tigrina lateralis was prepared and used as antigen. The sparganosis sera were also tested with Paragonimus and Cysticercus antigens to observe the cross reactivity. A total of 71 sera from normal control, ectopic and pulmonary paragonimiasis, clonorchiasis, cysticerCOSIS and Taenia saginata cases were also included. Except for one case of old calcified infection, all of 6 human sparganosis showed higher serum levels of specific IgG antibody when the differential point of positive reaction was set at the absorbance value of 0.25 (the sensitivity being 85.7%). In control and other helminthic infections, all except 3 cases of T. saginata infection showed negative reaction to sparganum antigen (the specificity being 90.7%). None of sparganosis cases showed cress reactivity to Paragonimus and Cysticercus antigens. Undiluted cerebrospinal l1uid also showed high levels of antibody when central nervous system was invaded. The serologic diagnosis by means of micro ELISA could be a useful tool in epidemiological study of human sparganosis in susceptible population, as well as in individual diagnosis.