• The Korean Journal of Nuclear Medicine
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• v.25 no.2
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• pp.259-265
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• 1991

The purpose of this study is to investigate the ability of I-131 labeled polyclonal human immunoglobulin to localize an infection. In our country, indium-111 labeled leukocyte or Tc-99m labeled IgG are not readily available because of compex, time-consuming procedure and cost. So we tried to localize infection with I-131 labeled IgG which could be easily prepared. Six rats, infected with staphylococcus aureus in a thigh muscle, received I-131 labeled IgG intravenously and I-131 labeled bovine serum albumin (BSA) were injected to other 5 infected rats. Scintigrams were made at 1, 4, 24, 48, 72 hour later. The radiopharmaceutical demonstrated significant accumulation at the site of infection. The accumulation of I-131 labeled IgG at the site of infection was significantly (P<0.05) higher than that of I-131 labeled BSA at 48, 72 hour. Similar finding could be found at 24 hour imaging, but it was not significant statistically. Therefore it was found that vascular permeability alone could not account for the mode of action of I-131 labeled IgG and it was considered that specific binding played a role. In conclusion, focal sites of inflammation can be detected with I-131 labeled nonspecific human polyclonal IgG and it seems that this method can also be applied to localization of human infection.

• Development and Reproduction
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• v.9 no.2
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• pp.65-83
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• 2005

The three important phases in the development of ligand immunoassays are identified and summarized. The competitive radiolabelled hormone measurement had been developed in the first and early in the second generations(1950s to 1960s), such as radioimmunoassays(RIA) or immunoradiometric(saturation) assays(IRMA), and used in all most of the hormone and also analyte in biological samples. In the second generation, ultrasensitive non-isotopic immunoassays(NIA) were developed using monoclonal antibodies(McAb), labelling the McAb and high specific activity non-isotopic labels. After their usefulness, advantages and disadvantages has been evaluated and non-competitive methods are discussed. The chip/microarray based multianalyte ligand assays(microspot or genechip methods) are developed and known as alternative ones in the third generation. We summarize the developments of NIAs and its usefulness, and then introduce briefly the new ligand assays.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.6 no.2
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• pp.208-214
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• 2003

Juvenile polyposis is an uncommon condition characterized by the development of multiple juvenile polyps predominantly in the colon but also in the rest of the gastrointestinal tract. Patients with juvenile polyposis commonly present with rectal bleeding, diarrhea, abdominal pain, anemia, prolapse of the polyp. We experienced a juvenile polyposis in a 7 year-old male patient with protein losing enteropathy who was diagnosed by $^{99M}Tc$-human serum albumin abdominal scintigraphy, colonoscopy, and small bowel series. Proctocolectomy with ileostomy was performed and then protein losing enteropathy was resolved.

• The Korean Journal of Nuclear Medicine
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• v.25 no.1
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• pp.61-67
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• 1991

The usefulness of $^{99m}Tc-labeled$ RBC single photon emission CT (SPECT) scanning in the diagnosis of hepatic heminagiomas was evaluated in 22 patients with various focal hepatic lesions including 15 cases of hemangiomas, 3 cases each of hepatomas and metastasis and 1 case of abscess. The diagnoses were based on ultrasonography and/or CT scanning, clinical stability of lesion for at least 6 months or surgical exploration. Seven cases of 15 hemangiomas were detected by delayed planar RBC scanning, whereas 4 cases were detected by delayed RBC-SPECT scanning. The smallest hemangioma shown by delayed RBC-SPECT scanning was 1.0 cm in diameter. compared with 2.2 cm by planar RBC scanning. One small hemangioma (2.0 cm) located adjacent to the heart was not found by either method. The sensitivities in detecting the hemangioma according to the site by planar imaging were 16.6% $(1.0\sim1.9cm)$, 66.7% $(2.0\sim2.9cm)$ and 83.3% (more than 3.0 cm) and by SPECT were 50.0%, 66.7% and 100%, respectively. Seven cases of non-hemangiomatous lesions did not show any significant increase in activity in the delayed blood pool images. It is concluded that $^{99m}Tc-RBC$ blood-pool SPECT scanning is clearly more sensitive in detecting small hemangioma than planar scanning and is, therefore, a choice of method for the detection of hepatic hemangioma.

• Journal of Food Hygiene and Safety
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• v.24 no.2
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• pp.148-153
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• 2009

In this study, we have developed a fluorescence chromatographic assay for the quantification of total cholesterol in serum, which is a well-known risk predictor for cardiovascular diseases. The new assay system consists of a chromatographic strip in a cartridge, enzyme buffer containing cholesterol esterase, cholesterol oxidase, horseradish peroxidase, and color developer AEC, and a laser fluorescence scanner. The correlation coefficient (r) between cholesterol concentration and relative fluorescence units was 0.968 in the new assay, showing a reliable linearity through the tested range of cholesterol. Recovery test and comparability with a Hitachi 747 instrument showed 106.5-94% and r = 0.939 (p<0.001), respectively. The new assay system for cholesterol was developed as a pre-POCT platform conducted in clinics since it is fast (8 min) and uses a small volume of sample ($5\;{\mu}l$), and it may be applied for on-site diagnostics to replace expensive automated biochemical analyzer.

• Food Science of Animal Resources
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• v.23 no.3
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• pp.278-283
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• 2003

Feasibility tests on using liposomes for detecting food-borne pathogenic bacteria were studied with E. coli 0157:H7 as a model analyte. lmmunoliposomes, whose surface was conjugated with anti-E. coli 0157:H7 IgG and which encapsulated the marker dye, sulforhodamine B, were used for the detection label. Among the feasibility tests, the first test was to use a test-strip on which antibodies to anti-E. coli O157:H7 IgG were immobilized. In this format, immunoliposomes that did not bind to E. coli O157:H7 in sample were captured and then exhibited a visible signal which was inversely related with the number of E. coli O157:H7 in sample. The second test was a direct liposome assay followed by immunomagnetic separation. In this format, immunoliposomes which were bound to E. coli O157:H7 were lysed with detergent and produced a signal which was proportionally related with the number of E. coli O157:H7 in sample. The results from both formats indicate that liposomes can be utilized as a detection label.

• The Korean Journal of Zoology
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• v.32 no.2
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• pp.142-152
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• 1989

We have produced a new monoclonal antibody detecting common acute lymphoblastic leukemia antigen (CALLA) and designated as KP-22. CALIA detected by KP-22 is expressed on the all of the various cefl lines examined including common ALL. Burkitt's lymphoma, human fibroblasts and cultured normal human fibroblasts. However out of cell lines tested, a fraction of J-ALL and all of myelocytic leukemia and all other nonleukemia cell lines except for fibroblast are CALIA negative. Immunoprecipitation of solubilized 125 I-labeled membrane proteins from cultured human fibroblasts and leukemia cell lines with KP-22 revealed a major polypeptide chain with an apparent molecular weight of approximately 100 Kd and 95 Kd, respectively. Even though a microheterogeneity in terms of molecular weight between two CALLAs, the peptide mapping patterns of them &e identical indicating that such a microheterogeneity seems to be partly due to heterogeneous terminal sialic acid compositions added by a posttranslational modification process.

• The Korean Journal of Cytopathology
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• v.19 no.2
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• pp.126-135
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• 2008

Malignant mesothelioma (MM) is a highly lethal neoplasm arising in pleura and the peritoneum and a rapid and accurate diagnosis is crucial for treatment of the disease. However, the sensitivity of cytological analysis using pleural or ascitic fluid is relatively low, yielding an accurate diagnosis in only $32{\sim}79%$ of cases. We tested the diagnostic value of epigenetic alterations in body fluid cytology as a supplement to conventional methods. Paraffin-embedded tissue blocks from 21 MM patients and associated body fluid cytology slides considered no evidence of malignancy were used to test for epigenetic alteration. Using methylation-specific PCR, we detected methylation of RASSF1A and p16 in 47.6% (10/21) of both surgically resected tumor samples, respectively. Body fluid samples of MM also showed abnormal methylation of RASSF1A and p16INK4a genes in 38.1% (8/21) and 33.3% (7/21) of cases. The concordance in the rates of RASSF1A and p16INK4a gene-methylation abnormalities determined from cytology samples and tissue samples were 61.9% (13/21) and 66.7% (14/21), respectively. Combining both genes increases the sensitivity of the test to 57.1 % (12 of 21) of cases. Our results suggest that testing for methylation abnormalities in selected individual genes or gene combinations has diagnostic value as an alternative or adjunct method to conventional cytological diagnosis.

• The Korean Journal of Nuclear Medicine
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• v.24 no.1
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• pp.49-55
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• 1990

For the development of $^{99m}Tc-labelled$ 3-iodo-2,4,6-trimethyl-iminodiacetic acid $(^{99m}Tc-IOTIDA)$, various experiments such as synthesis of IOTIDA, establishment of labelling conditions, determination of radiochemical purity, examination of stability, and organ distribution of rat were carried out. 1) IOTIDA was synthesized with a total yield of 42% from the starting material of 2,4-6-trimethylaniline via chloroacetylation, iodination, and condensation with iminodiacetic acid (IDA). 2) Freeze-dried instant labelling kits were prepared from aqueous solution $(pH\;5.8\sim6.0)$ so as to contain 40 mg IDA compound and 0.4 mg $SnCl_2$, per vial. Labelling of the contents of kit vials with $Na^{99m}TcO_4$, exhibited formation of two kinds of complex which was identified by ITLC-SA. After labelling, complex ( I ) was gradually converted to complex (II) with time. Labelling yield and radiochemical purity were above 99.5% based on the two complexes over-all. 3) $^{99m}Tc-IOTIDA$ maintained high radiochemical purity of above 99% until 6 hours after preparation at room temperature. Instant labelling kits stored at $4^{\circ}C$ for 6 month period also exhibited high labelling yield of above 99%. 4) Results obtained from animal experiments showed that most of the $^{99m}Tc-IOTIDA$ was rapidly excreted through hepatobiliary track into the intestines but with negligible renal excretion.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.179-181
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• 2023

본 논문에서는 GAN 기반의 영상 생성 방법론을 이용해 delayed PET 영상을 생성하는 연구를 수행하였다. PET은 양전자를 방출하는 방사성 동위원소를 표지한 방사성의약품의 체내 분포를 시각화함으로서 암 세포 진단에 이용되는 의료영상 기법이다. 하지만 PET의 스캔 과정에서 방사성의약품이 체내에 분포하는 데에 걸리는 시간이 오래 걸린다는 문제점이 존재한다. 따라서 본 연구에서는 방사성의약품이 충분히 분포되지 않은 상태에서 얻은 PET 영상을 통해 목표로 하는 충분히 시간이 지난 후에 얻은 PET 영상을 생성하는 모델을 GAN (generative adversarial network)에 기반한 image-to-image translation(I2I)를 통해 수행했다. 특히, 생성 전후의 영상 간의 영상 쌍을 고려한 paired I2I인 Pix2pix와 이를 고려하지 않은 unpaired I2I인 CycleGAN 두 가지의 방법론을 비교하였다. 연구 결과, Pix2pix에 기반해 생성한 delayed PET 영상이 CycleGAN을 통해 생성한 영상에 비해 영상 품질이 좋음을 확인했으며, 또한 실제 획득한 ground-truth delayed PET 영상과의 유사도 또한 더 높음을 확인할 수 있었다. 결과적으로, 딥러닝에 기반해 early PET을 통해 delayed PET을 생성할 수 있었으며, paired I2I를 적용할 경우 보다 높은 성능을 기대할 수 있었다. 이를 통해 PET 영상 획득 과정에서 방사성의약품의 체내 분포에 소요되는 시간을 딥러닝 모델을 통해 줄여 PET 이미징 과정의 시간적 비용을 절감하는 데에 크게 기여할 수 있을 것으로 기대된다.