• Animal Systematics, Evolution and Diversity
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• 제26권2호
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• pp.99-104
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• 2010

The subfamily Murinae is a very controversial group concerning their phylogenetic relationship. Previous studies could not resolve phylogeny among four genera Apodemus, Micromys, Mus and Rattus of the Muridae. In the present study, eight rodent species resident in South Korea were collected and phylogenetically analyzed based on sequence data of five mitochondrial and nuclear DNA regions: 12S rRNA, cytochrome b gene (cyt b), cytochrome oxidase II (COII), control region of mitochondrial DNA, and a thyroglobulin (Tg) of nuclear DNA. According to the phylogeny of the concatenated data, M. musculus separated early in Murinae (ML 100%; BA 1.00 pp) and the genus Rattus grouped with the harvest mouse, M. minutes; these were separated from the genus Apodemus with relatively strong support (ML 74%; BA 0.76 pp). The Siberian chipmunk population was also examined using the five genes to obtain better resolution. The phylogeny for Korean rodents determined using the 12S rRNA, cyt b, COII and control regions discriminated the Siberian chipmunk populations from Korea, Russia, and China.

• Nuclear Engineering and Technology
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• 제54권12호
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• pp.4652-4659
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• 2022

Among the detector materials available at room temperature, thallium bromide (TlBr), which has a relatively high atomic number and density, is widely used for gamma camera imaging. This study aimed to verify the usefulness of TlBr through quantitative evaluation by modeling detectors of various compound types using Monte Carlo simulations. The Geant4 application for tomographic emission was used for simulation, and detectors based on cadmium zinc telluride and cadmium telluride materials were selected as a comparison group. A pixel-matched parallel-hole collimator with proven excellent performance was modeled, and phantoms used for quality control in nuclear medicine were used. The signal-to-noise ratio (SNR), contrast to noise ratio (CNR), sensitivity, and full width at half maximum (FWHM) were used for quantitative analysis to evaluate the image quality. The SNR, CNR, sensitivity, and FWHM for the TlBr detector material were approximately 1.05, 1.04, 1.41, and 1.02 times, respectively, higher than those of the other detector materials. The SNR, CNR and sensitivity increased with increasing detector thickness, but the spatial resolution in terms of FWHM decreased. Thus, we demonstrated the feasibility and possibility of using the TlBr detector material in comparison with commercial detector materials.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1527-1532
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• 2023

The noise reduction algorithm using the non-local means (NLM) approach is very efficient in nuclear medicine imaging. In this study, the applicability of the NLM noise reduction algorithm in single-photon emission computed tomography (SPECT) images with a brain phantom and the optimization of the NLM algorithm by changing the smoothing factors according to various reconstruction methods are investigated. Brain phantom images were reconstructed using filtered back projection (FBP) and ordered subset expectation maximization (OSEM). The smoothing factor of the NLM noise reduction algorithm determined the optimal coefficient of variation (COV) and contrast-to-noise ratio (CNR) results at a value of 0.020 in the FBP and OSEM reconstruction methods. We confirmed that the FBP- and OSEM-based SPECT images using the algorithm applied with the optimal smoothing factor improved the COV and CNR by 66.94% and 8.00% on average, respectively, compared to those of the original image. In conclusion, an optimized smoothing factor was derived from the NLM approach-based algorithm in brain SPECT images and may be applicable to various nuclear medicine imaging techniques in the future.

• Molecular & Cellular Toxicology
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• 제2권4호
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• pp.223-228
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• 2006

Several plant-derived cannabinoids and endogenous ligands for cannabinoid receptors such as 2-arachidonyl-glycerol have been known to inhibit interleukin-2 (IL-2) expression. In the present study, we utilized arachidonylethanolamide (AEA), a putative endogenous ligand for cannabinoid receptors, to determine whether AEA modulated the expression of IL-2. AEA inhibited phorbol 12-myristate 13-acetate (PMA) plus ionomycin (Io)-induced IL-2 protein secretion and mRNA expression in EL-4 mouse T-cells as determined by ELISA and RT-PCR, respectively. To further characterize the inhibitory mechanism of AEA at the transcriptional level, we performed promoter study for IL-2 gene in PMA/Io-stimulated EL-4 cells. AEA decreased the transcriptional activity of the nuclear factor of activated T-cells (NF-AT) as well as the IL-2 promoter activity. These results suggest that AEA suppresses IL-2 expression and that the inhibition is mediated, at least in part, through the down-regulation of NF-AT.

• 대한핵의학회지
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• 제32권6호
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• pp.516-524
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• 1998

목적: 현재 Re-188 표지 단일클론항체는 종양의 방사면역치료제로서 주목받고 있으며 많은 연구가 진행되고 있다. 이 연구에서는 골수성 백혈구 세포에 존재하는 NCA-95에 대한 단일클론항체 CEA79.4를 사용하여 Re-188의 항체 표지법을 개발하고 그 특성을 분석하여 Tc-99m 표지항체와 비교하고자하였다. 대상 및 방법: 표지는 항체에 방사성 핵종을 직접 붙이는 직접법을 사용하였다. 환원제인 ${\beta}$-mercaptoethanol로 단일클론항체 CEA79.4를 환원하여 SH-기를 생성시키고 여기에 발생기로부터 얻은 Tc-99m과 Re-188을 표지 하였다. Tc-99m의 표지를 위해서는 pH 6.5인 PBS에서 반응시켰으며 착화제와 환원제로 MDP kit를 사용하였다. Re-188은 50 mM acetate buffered saline (ABS, pH 5.3)에서 stannous tartrate를 환원제로 사용하여 표지 하였다. 표지효율은 ITLC로 확인하였으며 표지항체는 PD-10 칼럼을 이용하여 분리하였다. 분리한 표지항체를 1% 사람혈청 알부민과 비타민 C를 넣어 산화를 방지하고 실온과 사람혈청(5% $CO_2$, $37^{\circ}C$)에서 안정성 검사를 실시하였다. 대장암세포주인 SNU-C4와 세포결합검사를 실시하여 면역반응성과 항원에 대한 친화상수를 측정하였다. 또한 정상 ICR 마우스에 꼬리정맥으로 주사하여 1, 14, 24시간에 체내분포를 보았다. 결과: Tc-99m의 항체 표지효율은 $92.4{\pm}5.9%$ (n= 15)이고 Re-188은 $84.7{\pm}4.6%$ (n=4)로 우수한 표지효율을 보였다. 표지항체의 체외안정성검사를 실시한 결과 실온에서는 Tc-99m 표지항체의 경우 24시간까지 90% 정도로 안정하였으나 Re-188 표지항체는 70% 정도를 유지하였다. 사람혈청에서는 Tc-99m 표지항체는 24시간에 60% 이상이었으나 Re-188은 50% 이하로 낮았다. Tc-99m과 Re-188의 표지항체의 면역반응성은 각각 59.2%, 41.6%, 친화상수는 $6.59{\times}10^9\;M^{-1}$, $4.2{\times}10^9\;M^{-1}$ 이었다. 또한 정상 마우스에서 체내 분포는 비 특이적으로 집적되지 않고 배설되어 유사한 경향을 보였다. 결론: 기존의 Tc-99m 표지법과 같은 원리를 이용하여 단일클론항체 CEA79.4를 Re-188과 표지하였다. Re-188-CEA79.4는 면역반응성과 친화력등 체외 면역학적 특성과 체내분포에서 Tc-99m 표지항체와 큰 차이를 보이지 않았다. 따라서 Re-188-CEA79.4는 골수성 백혈병, 림프종 등 질병의 방사면성역치료에 적용 할 수 있을 것이다.

• Nuclear Medicine and Molecular Imaging
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• 제42권4호
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• pp.307-313
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• 2008

목적: 혈관내피성장인자(VEGF)와 그 수용체는 종양의 성장과 전이에 매우 중요한 역할을 한다 3개의 수용체가 알려져 있는데 그 중에서도 VEGFR2 (Flk-1/KDR)가 종양 angiogenesis에 매우 밀접하게 관련한 것으로 알려져 있다. 본 연구에서는 마우스 Flk-1 항체로 알려진 DC101에 I-131을 표지하여 매우 공격적인 종양으로 알려진 흑색 종의 치료 정도를 확인해 보고자 하였다. 방법: 하이브리도마 세포에서 Flk-1 항체인 DC101을 분리하여 western blot, ELISA, maldi-tof 방법을 이용하여 순도를 확인하고 항체 에 chloramin T를 이용하여 I-131을 표지하였다. 누드마우스에 B16F10세포를 주사하여 흑색종 모델을 만들고 평균 $200-250\;mm^3$으로 키워 $^{131}I$-DC101을 주사하여 영상과 시간별 장기섭취율(%ID/g)을 비교하고, 종양내 Flk-1 발현을 확인하기 위하여 면역염색 등을 시행하였다. 흑색종 동물모델을 5개 군으로 나누어 각각 치료를 시행하였다. 1군은 PBS만을, 2군은 $^{131}I$-DC101 $50\;{\mu}g(200\;{\mu}Ci)$을, 3군은 DC101 $50\;{\mu}g$을, 4군은 $^{131}I$-DC101 $30\;{\mu}g(200\;{\mu}Ci)$을, 5군은 $^{131}I$-DC101 $15\;{\mu}g(200\;{\mu}Ci)$을 각각 매 3일 ${\sim}$ 4일마다 주사하고 전체 5회를 주사하였고 종양볼륨을 측정하였다. 결과: $^{131}I$-DC101을 흑색종 모델에 정맥주사하고 78시간까지 영상을 얻은 결과 시간에 따라 종양섭취가 증가 하는 영상을 보였다. 시간대별 장기섭취를 정확히 확인하기 위하여 1시간, 6시간, 24시간, 48시간, 72시간 장기섭취율을 비교한 결과 시간에 따라 혈액내 방사능치가 서서히 감소하였고 다른 장기의 섭취도 시간에 따라 감소하였고 종양의 섭취는 48시간까지 증가하였다가 그 이후는 감소하였다. 흑색종 동물모델에 $^{131}I$-DC101 치료를 시행한 결과 3번째 주사까지는 각군간의 유의한 차이를 보이지 않다가 4번째 주사를 시행한 때부터 1군과 2군, 또는 1군과 4군간의 유의한 차이를 보이기 시작했다. 또한 5번째 주사 이후에는 5군에서도 유의한 차이를 보여 I-131 에 의한 효과가 뚜렷해짐을 확인하였다. 결론 마우스 Flk-1 항체로 알려진 DC101을 흑색종 모델에 정맥내 주사하였을 때, 종양성장억제 효과를 보이지 않는 항체양에서도 I-131을 표지하여 치료를 시행했을 경우에는 효율적인 종양성장억제 효과를 보였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.9835-9839
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• 2014

Fisetin is an effective compound extracted from lacquer which has been used in the treatment of various diseases. Preliminary data indicate that it also exerts specific anti-cancer effects. However, the manner in which fisetin regulates cancer growth remains unknown. In this study, we elucidated interference of fisetin with targets of the nuclear factor ${\kappa}B$ signal transduction pathway activated by Epstein-Barr virus encoding latent membrane protein 1 (LMP1)in nasopharyngeal carcinoma (NPC) cells, Results showed that fisetin inhibited the survival rate of CNE-LMP1 cells and NF-${\kappa}B$ activation caused by LMP1. Fisetin also suppressed nuclear translocation of NF-${\kappa}B$ (p65) and $I{\kappa}B{\alpha}$ phosphorylation, while inhibiting CyclinD1, all key targets of the NF-${\kappa}B$ signal transduction pathway. It was suggested that interference effects of fisetin with signal transduction activated by LMP1 encoded by the Epstein-Barr virus may play an important role in its anticancer potential.

• 대한핵의학회지
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• 제36권1호
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• pp.8-18
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• 2002

Early and accurate diagnosis of tumors using positron omission tomography (PET) has been the focus of considerable interest due to its high metastasis and mortality rates at late detection. PET radiopharmaceuticals-which exhibit a high tumor-to-background uptake ratio, and appropriate metabolic characteristics, and pharmacokinetics-are attractive tools for tumor imaging. Tumor imaging by these radiopharmaceuticals are based on metabolic and receptor imaging. The former is based on accelerated metabolism in tumor tissue compared to normal tissue and the rate roughly corresponding to the rate of growth of tumors. Radiopharmaceuticals for this purpose include radiolabeled sugars, amino acids, and nucleosides which detect increased glucose utilization, protein synthesis, and DNA synthesis, respectively. Tumor receptor imaging is based on the proliferation of tumor cells regulated by many hormones and growth factors, which bind to the corresponding receptors and exhibit the biological responses Radiopharmaceuticals used to image the tumor receptor systems may be ligands for the specific receptors and antibodies for the growth factor receptors. Some antitumor agents have been labeled with radionuclides and used to study in vivo biodistribution and pharmacokinetics in humans. This overview describes typical PET radiopharmaceuticals used for tumor imaging based on their uptake mechanisms.

• Nuclear Medicine and Molecular Imaging
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• 제42권sup1호
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• pp.172-176
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• 2008

FDG PET has been used as a diagnostic tool for localization of seizure focus for last 2-3 decades. In this article, the clinical usefulness of FDG PET in the management of patients with epilepsy has been reviewed, which provided the evidences to justify the medicare reimbursement for FDG PET in management of patients with epilepsy. Literature review demonstrated that FDG PET provides an important information in localization of seizure focus and determination whether a patients is a surgical candidate or not. FDG PET has been reported to have high diagnostic performance in localization of seizure focus in neocortical epilepsy as well as temporal lobe epilepsy regardless of the presence of structural lesion on MRI. Particularly, FDG PET can provide the additional information when the results from standard diagnositic modality such as interictal or video-monitored EEG, and MRI are inconclusive or discordant, and make to avoid invasive study. Furthermore, the presence of hypometabolism and extent of metabolic extent has been reported as an important predictor for seizure free outcome. However, studies suggested that more accurate localization and better surgical outcome could be expected with multimodal approach by combination of EEG, MRI, and functional studies using FDG PET or perfusion SPECT rather than using a single diagnostic modality in management of patients with epilepsy. Complementary use of FDG PET in management of epilepsy is worth for good surgical outcome in epilepsy patients.

• 동의생리병리학회지
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• 제28권1호
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• pp.63-68
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• 2014

The fruit of Tribulus terrestris L. (Zygophyllaceae) is an important source of traditional Korean and Chinese medicines. In this study, NNMBS223, consisting of the ethanol extract of T. terrestris, showed potent anti-inflammatory activities in RAW264.7 macrophages. We investigated the effect of NNMBS223 in suppressing the protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and production of iNOS-derived nitric oxide (NO), COX-2-derived prostaglandin E2 (PGE2) in lipopolysaccharide (LPS)-stimulated macrophages. In addition, NNMBS223 induced expression of heme oxygenase (HO)-1 through nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) in macrophages. The effects of NNMBS223 on LPS-induced production of NO and PGE2 were partially reversed by the HO activity inhibitor tin protoporphyrin (SnPP). These findings suggest that Nrf2-dependent increases in expression of HO-1 induced by NNMBS223 conferred anti-inflammatory activities in LPS stimulated RAW264.7 macrophages.