• 대한핵의학회지
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• 제38권1호
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• pp.1-20
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• 2004

Bone scan is one of the most frequently peformed studios in nuclear medicine. In bone scan, the amount of radiolsotope taken up by lesion depends primarily on the local rate of bone turnover rather than on the bone mass. Bone scan is extremely sensitive for defecting bony abnormalities. However, abnormalities that appear on bone scan may not always represent disease. The normal scan appearances may be affected not only by skeletal physiology and anatomy but also by a variety of technical factors which can influence image quality. Many normal variants and artifacts may appear on bone scan. They could simulate a pathologic process and could mislead into the wrong diagnostic interpretation. Therefore, their recognition is necessary to avoid misdiagnosis. A nuclear medicine physician should be aware of variable appearance of the normal variants and artifacts on bone scan. In this article, a variety of normal variants and artifacts mimicking real pathologic lesion in bone scan interpretation are discussed and illustrated.

• Journal of Genetic Medicine
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• 제12권1호
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• pp.1-5
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• 2015

De novo variants (DNVs) can arise during parental germ cell formation, fertilization, and the processes of embryogenesis. It is estimated that each individual carries 60-100 such spontaneous variants in the genome, most of them benign. However, a number of recent studies suggested that DNVs contribute to the pathogenesis of a variety of human diseases. Applications of DNVs include aiding in clinical diagnosis and identifying disease-causing genetic factors in patients with atypical symptoms. Therefore, understanding the roles of DNVs in a trio, with healthy parents and an affected offspring, would be crucial in elucidating the genetic mechanism of disease pathogenesis in a personalized manner.

• 말소리와 음성과학
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• 제7권3호
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• pp.27-35
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• 2015

The purpose of this study is to examine the lexical representation of phonological variants derived from optional vs. obligatory phonological processes. Given that place assimilation is optionally processed, whereas nasal assimilation is obligatory in Korean, a long-term repetition priming experiment was conducted, using a shadowing task. Korean speakers shadowed words containing either assimilated or unassimilated consonants in three priming conditions and their shadow responses were evaluated. It was shown that in both place and nasal assimilations, shadowing latencies for unassimilated stimuli were longer than those for assimilated stimuli in the mismatched condition. These results suggest that even in the optional assimilation, assimilated variants were processed more easily and faster than the canonical variants. The present results argue against the frequency-based account of multiple lexical representation (Connine, 2004; Connine & Pinnow, 2006; Ranbom & Connine, 2007; $B{\ddot{u}rki$, Ernestus, & Frauenfelder, 2010; $B{\ddot{u}rki$, Alario, & Frauenfelder, 2011).

• Genomics & Informatics
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• 제19권4호
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• pp.36.1-36.11
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• 2021

Predicting individual traits and diseases from genetic variants is critical to fulfilling the promise of personalized medicine. The genetic variants from genome-wide association studies (GWAS), including variants well below GWAS significance, can be aggregated into highly significant predictions across a wide range of complex traits and diseases. The recent arrival of large-sample public biobanks enables highly accurate polygenic predictions based on genetic variants across the whole genome. Various statistical methodologies and diverse computational tools have been introduced and developed to computed the polygenic risk score (PRS) more accurately. However, many researchers utilize PRS tools without a thorough understanding of the underlying model and how to specify the parameters for the best performance. It is advantageous to study the statistical models implemented in computational tools for PRS estimation and the formulas of parameters to be specified. Here, we review a variety of recent statistical methodologies and computational tools for PRS computation.

• 한국환경농학회지
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• 제17권3호
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• pp.195-199
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• 1998

이온화방사선을 이용하여 느타리(Pleurotus ostreatus)의 담자포자(basidiospore)로부터 섬유소 분해능이 뛰어난 변이주를 유도하고자 본 실험을 수행하였다. 담자포자를 감마선조사 후 MUF(4-methylumbelliferyl) 반응기를 이용하여 세포외분비효소의 활성도를 측정하였다. 방사선유기 변이주에서 RAPD(random amplified polymorphic DNA)의 양상을 조사하여 유전유사도를 분석하였다. 검색한 45종의 균주들은 MUF의 기질에 따라 다양한 기질분해도를 보였으며, 이 중에서 섬유소 분해능이 뛰어난 3개의 변이주 2KG-1, 2KG-2와 20KG-1를 선발하였다. RAPD 양상을 통해 조사한 변이주의 유전유사도는 대조군에 대해 $50%{\sim}52%$였고, 변이주간에는 $49%{\sim}57%$로 나타나 방사선조사에 의해 유전적 다양성이 증가되었음을 알 수 있었다. 본 연구에서 방사선조사에 의해 유기된 변이주는 섬유소성 생물폐자원의 재활용에 있어서 매우 유용하게 활용될 수 있을 것으로 기대된다.

• The Korean Journal of Physiology and Pharmacology
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• 제21권1호
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• pp.11-17
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• 2017

Crohn's disease (CD) is a chronic inflammatory bowel disease with multifactorial causes including environmental and genetic factors. Several studies have demonstrated that the organic cation/carnitine transporter 1 (OCTN1) non-synonymous variant L503F is associated with susceptibility to CD. However, it was reported that L503F is absent in Asian populations. Previously, we identified and functionally characterized genetic variants of the OCTN1 promoter region in Koreans. In that study, four variants demonstrated significant changes in promoter activity. In the present study, we determined whether four functional variants of the OCTN1 promoter play a role in the susceptibility to or clinical course of CD in Koreans. To examine it, the frequencies of the four variants of the OCTN1 promoter were determined by genotyping using DNA samples from 194 patients with CD and 287 healthy controls. Then, associations between genetic variants and the susceptibility to CD or clinical course of CD were evaluated. We found that susceptibility to CD was not associated with OCTN1 functional promoter variants or haplotypes showing altered promoter activities in in vitro assays. However, OCTN1 functional promoter haplotypes showing decreased promoter activities were significantly associated with a penetrating behavior in CD patients (HR=2.428, p=0.009). Our results suggest that the OCTN1 functional promoter haplotypes can influence the CD phenotype, although these might not be associated with susceptibility to this disease.

• 한국자원식물학회지
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• 제23권6호
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• pp.541-549
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• 2010

The present study researched morphological characteristics and analyzed the genetic diversity by using RAPD in Calanthe species, native plant in Jeju, Korea. Twenty-six samples were selected by flower color, and 19 horticultural traits were investigated to study morphological characteristics. The C. discolor had the smallest leaf, the length and width of dorsal sepal, lateral sepal, petal, central lip, lateral lip, and flower stalk length were shortest and/or smallest except the spur and ovary length in Calanthe species, but those of Calanthe discolor for. sieboldii (Dence.) Ohwi (Calanthe discolor for. sieboldii) were the largest and/or biggest, and those of variants were the intermediate between C. discolor and C. discolor for. sieboldii, but spur length was the longest in C. discolor, the shortest in C. discolor for. sieboldii, and intermediate in the variants. Ovary length in C. discolor was shortest and C. discolor for. sieboldii and variants were similar with each other. The flower colors of C. discolor were brownish red, the value of CIE Lab was between 40 and 50. The flower color of C. discolor for. sieboldii was yellowish; the value of CIE Lab was between 110 and 130. And variants had various colors between 50 and 70 in the value of CIE Lab. After analyzing multiple band patterns of PCR products, 154 bands were selected as polymorphic RAPD markers. The analysis of Genetic distance of Calanthe species using RAPD showed that C. discolor and C. discolor for. sieboldii are more distant from each other than variants, and demonstrated the fact that genetic position of variants is between the other two species.

• Journal of Gastric Cancer
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• 제20권1호
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• pp.29-40
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• 2020

Purpose: Gastrointestinal stromal tumors (GISTs) frequently harbor activating gene mutations in either KIT or platelet-derived growth factor receptor A (PDGFRA) and are highly responsive to several selective tyrosine kinase inhibitors. In this study, a targeted next-generation sequencing (NGS) assay with an Oncomine Focus Assay (OFA) panel was used for the genetic characterization of molecular targets in 30 Korean patients with GIST. Materials and Methods: Using the OFA that enables rapid and simultaneous detection of hotspots, single nucleotide variants (SNVs), insertion and deletions (Indels), copy number variants (CNVs), and gene fusions across 52 genes relevant to solid tumors, targeted NGS was performed using genomic DNA extracted from formalin-fixed and paraffin-embedded samples of 30 GISTs. Results: Forty-three hotspot/other likely pathogenic variants (33 SNVs, 8 Indels, and 2 amplifications) in 16 genes were identified in 26 of the 30 GISTs. KIT variants were most frequent (44%, 19/43), followed by 6 variants in PIK3CA, 3 in PDGFRA, 2 each in JAK1 and EGFR, and 1 each in AKT1, ALK, CCND1, CTNNB1, FGFR3, FGFR4, GNA11, GNAQ, JAK3, MET, and SMO. Based on the mutation types, majority of the variants carried missense mutations (60%, 26/43), followed by 8 frameshifts, 6 nonsense, 1 stop-loss, and 2 amplifications. Conclusions: Our study confirmed the advantage of using targeted NGS with a cancer gene panel to efficiently identify mutations associated with GISTs. These findings may provide a molecular genetic basis for developing new drugs targeting these gene mutations for GIST therapy.

• 한국축산식품학회지
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• 제26권1호
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• pp.121-126
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• 2006

Major milk proteins have considerable variane which comes from substitution and deletions in their amino arid sequences. Variants in genes that code for milk proteins, such as ${\beta}$-lactoglobulin (${\beta}-LG$) have been established as genetic markers for milk production and milk protein composition in dairy cattle. The effect of ${\beta}-LG$ variant on milk production traits, such as milk yield. fat yield, protein yield, fat percentage and protein percentage, was estimated for 482 Holstein cows in the first lactation. The ${\beta}-LG$ variants were determined by PCR-RFLP technique at the DNA level. Single trait linear model was used for the statistical analysis of the data. Results of this study indicated that ${\beta}-LG$ variants affected significantly protein yield (p<0.05) and fat percentage (p<0.05). Animals with the AA variant produced 31kg of milk protein more than animals with the BB variant. On the contrary, cows with the BB variant had fat percentage higher by 0.35 and 0.32% compared with cows with the AA and AB variants, respectively. No associations between the ${\beta}-LG$ variants and milk yield, protein percentage and fat yield were found Therefore, milk production traits could be improved through ${\beta}-LG$ typing by increasing the frequency of A variant for protein yield or the frequency of B variant for fat content in Holstein dairy cattle population.

• Molecules and Cells
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• 제25권3호
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• pp.376-384
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• 2008

The glial fibrillary acidic protein (GFAP) is traditionally used as a marker for astrocytes of the brain, and more recently for the hepatic stellate cells (HSCs) of the liver. Several GFAP splice variants have been previously reported in the astrocytes of the CNS and in the non-myelinating Schwann cells of the PNS. In this study, we investigate whether GFAP splice variants are present in the HSCs and their expression as a function of HSCs activation. Furthermore, the regulation of these transcripts upon treatment with interferon gamma ($IFN-{\gamma}$) will be explored. Using semi-quan-titative RT-PCR and real-time PCR, we examine the expression and regulation of GFAP splice variants in HSCs as well as their respective half-life. We discover that most of the GFAP splice variants ($GFAP{\alpha}$, ${\beta}$, ${\delta}$, ${\varepsilon}$ and $\kappa$) found in the neural system are also expressed in quiescent and culture-activated primary HSCs. Interestingly, $GFAP{\alpha}$ is the predominant form in quiescent and culture-activated primary HSCs, while $GFAP{\beta}$, predominates in the SV40-immortalized activated HSC-T6. $GFAP{\delta}$, ${\varepsilon}$ and ${\kappa}$ have similar half-lives of 10 hours, while $GFAP{\beta}$ has a half-life of 17 hours. Treatment of HSC-T6 with $IFN-{\gamma}$ results in a significant 1.29-fold up-regulation of $GFAP{\alpha}$ whereas the level of the other transcripts remains unchanged. In summary, $GFAP{\alpha}$, ${\beta}$, ${\delta}$, ${\varepsilon}$ and $\kappa$ are present in HSCs. They are differentially regulated on the transcription level, implying a role of the 5' and 3' untranslated regions.