• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.25-25
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• 2018

The Fukushima Daiichi Nuclear Power Plant accident in March 2011 caused severe radioactive contamination in the surrounding environment. Since the accident, much attention has been paid to the biological and genetic consequences of organism inhabiting the contaminated area. The effect of radiation exposure on genetic mutation rates is little known, especially for low doses and in situ conditions. Evaluating DNA mutation by low levels of radiation dose is difficult due to the rare mutation event and lack of sequence information before the accident. In this study, correlations with air dose levels and somatic DNA mutation rates were evaluated using Next Generation Sequencer for the clonal plant, Phyllostachys edulis. This bamboo is known to spread an identical clone throughout Japan, and it has the advantage that we can compare genetic mutation rate among identical clone growing different air dose levels. We collected 94 samples of P. edulis from 14 sites with air dose rates from $0.04{\sim}7.80{\mu}Gy/h$. Their clonal identity was confirmed by analysis using 24 microsatellite markers, and then, sequences among samples were compared by MIG sequence. The sequence data were obtained from 2,718 loci. About ~200,000 bp sequence (80 bp X 2,718 loci) were obtained for each sample, and this corresponds to about 0.01% of the genome sequence of P. edulis. In these sequences, 442 loci showed polymorphism patterns including recent origin mutation, old mutation, and sequence errors. The number of mutations per sample ranged from 0 to 13, and did not correlate with air dose levels. This result indicated that DNA mutations have not accumulated in P. edulis living in the air doses levels less than $10{\mu}Gy/h$. Our study also suggests that mutation rates can be assessed by selecting an appropriate experimental approach and analyzing with next generation sequencer.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.965-971
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• 2016

Aims: To investigate the distribution of epidermal growth factor receptor (EGFR) mutations, and explore any relationships with clinical characteristics in non-small-cell lung carcinoma (NSCLC) patients. Materials and Methods: EGFR mutations were assessed by ADx-ARMS in 261 NSCLC patients from West China Hospital of Sichuan University. Relationships between EGFR mutation and clinical characteristics were analyzed by SPSS. Results: The EGFR mutation rate was 48.7% (127/261), 19-del and L858R mutations occurred predominantly, accounting for 33.1% and 40.9%, respectively, in mutated cases. Moreover, 10.2% patients were found to carry double mutations. EGFR mutations occurred more frequently in women (57.5%) than in men (41.8%) (P=0.01), and were more frequent in non-smokers (61.2%) than in former or current smokers (31.2%) (P<0.00). In addition, they were more common in adenocarcinomas (52.8%) and adenosquamous carcinomas (42.8%) than in squamous cell carcinomas (14.8%) (p<0.00). However, only smoking history and pathological types, rather than gender, proved to be associated with EGFR mutations on multivariate logistic regression analysis. No significant differences in pathological stage and metastasis status were found between EGFR wild-type and mutated cases, although EGFR mutation type was related to pathological type (p=0.00) - 19-del, L858R and other mutation types respectively occurred in 34.2%, 42.5% and 23.3% of adenocarcinomas, but in 14.3%, 0% and 85.7% of non-adenocarcinomas. Conclusions: The EGFR mutation rate was 48.7% in NSCLCs in Southwest China, so that nearly 40% patients might benefit from targeted therapies. Smoking status and pathological types were independent predictors of EGFR mutation, while EGFR mutation type was related to only pathological type, rather than smoking status.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5101-5104
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• 2012

Background: Genetic mutation is a significant factor in colon CA pathogenesis. Familial adenomatous polyposis (FAP) is an autosomal dominant hereditary disease characterized by multiple colorectal adenomatous polyps affecting a number of cases in the family. This report focuses on a family with attenuated familial adenomatous polyposis (AFAP) with exon 4 mutation, c.481C>T p.Q161X of the APC gene. Methods: We analyzed 20 members of a family with AFAP. Clinical and endoscopic data were collected for phenotype determination. Genetic analysis was also performed by direct sequencing of the APC gene. Result: Five patients with a phenotype of AFAP were found. Endoscopic polyposis was demonstrated among the second generation with genotype mutation of the disease (age > 50 years) consistent with delayed phenotypic adenomatous polyposis in AFAP. APC gene mutation was identified in exon 4 of the APC gene, with mutation points of c.481C>T p.Q161X. Laparoscopic subtotal colectomy was performed to prevent carcinogenesis. Conclusion: A family with attenuated familial adenomatous polyposis of APC related to exon 4 mutation, c.481C>T p.Q161X, was reported and the phenotypic finding was confirmed by endoscopic examination. Genetic mutation analysis might be advantageous in AFAP for long term colon cancer prevention and management due to subtle or asymptomatic phenotype presentation in early adulthood.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.2
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• pp.66-72
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• 2013

Fine Needle Aspiration Biopsy Cytology (FNABC), which is known as the most accurate and cost-effective method for diagnosis of the thyroid nodule, may still result in indeterminate cases that are cellular paucity and show minor nuclear atypia. However, most cases are associated with suspicion of papillary thyroid carcinoma (PTC). A B-type Raf kinase (BRAF) mutation was found in about half of PTCs which is currently helping us to differentiate malignancies from benign lesions. Cases studied included 46 histological, confirmed PTC cases. FNABC 102 cell paucity and 74 atypia benign cases were previously diagnosed as suspicious of PTC using cytologic examination. These cases were analyzed for BRAF mutation by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with a new restriction enzyme. In this study, the sensitivity and specificity were calculated and, BRAF mutation was detected by means of a histological method in 23 of 46 cases of PTC and no mutation was found in 22 cases. However, one case was not detected. In using FNABC, BRAF mutation was detected in 6 of 102 cases in cell paucity and in 11 of 74 cases in the atypia. Two cases were not detected in the atypia. The sensitivity and specificity of PCR-RFLP in FNABC were 60% and 97.4% respectively. Assessment of Formalin Fixed Paraffin Embedding (FFPE) block demonstrated similarly a 51.1% positive and 48.9% negative in PTC. Evaluation of BRAF mutation revealed high specificity and low sensitivity in using FNABC method. This study suggests that BRAF mutation analysis should be useful for the clinical diagnosis of PTC in FNABC with cytological findings suspicious for PTC.

• International journal of thyroidology
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• v.11 no.2
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• pp.123-129
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• 2018

Background and Objectives: Hypermethylation of the tumor suppressor gene RASSF1A and activating mutation of BRAF gene have been recently reported in thyroid cancers. To investigate the role of these two epigenetic and genetic alterations in thyroid tumor progression, methylation of RASSF1A and BRAF mutation were examined in thyroid tumors. Materials and Methods: During 2007 to 2017, 69 papillary carcinomas, 18 nodular hyperplasia, 3 follicular carcinomas, and 13 follicular adenomas were selected. The methylation-specific polymerase chain reaction (MSP) technique was used in detecting RASSF1A methylation and polymerase chain reaction (PCR)-single-stranded conformation polymorphism and sequencing were used for BRAF gene mutation study. Results: The hypermethylation of the RASSF1A gene was found in 84.6%, 100% and 57.9% of follicular adenomas, follicular carcinomas, and papillary carcinomas, respectively. Nodular hyperplasia showed a hypermethylation in 33.3%. The BRAF mutation at V600E was found in 60.7% of papillary carcinoma and 27.0% of nodular hyperplasia, but none of follicular neoplasms. The BRAF mutation was correlated with the lymph node metastasis and MACIS clinical stage. There is an inverse correlation between RASSF1A methylation and BRAF mutation in thyroid lesions. Conclusion: Epigenetic inactivation of RASSF1A through aberrant methylation is considered to be an early step in thyroid tumorigenesis, and the BRAF mutation plays an important role in the carcinogenesis of papillary carcinoma, providing a genetic marker.

• Journal of Microbiology
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• v.39 no.2
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• pp.102-108
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• 2001

DNA damage response has a central role in the maintenance of genomic integrity while mutations in related genes may result in a range of disorders including neoplasic formations. The uvsZl characterized in this report is a navel uvs mutation in Aspergillus nidulans, resulting in a nucleotide excision repair (NER) phenotype: UV-sensitivity before DNA synthesis (quiescent cells), high UV-induced mutation frequency and probable absence of involvement with mitotic and meiotic recombinations. The mutation is recessive and nan-allelic to the previously characterized uvsA101 mutation, also located on the paba-y interval on chromosome I. uvsZl skewed wild-type sensitivity to MMS, which suggests non-involvement of this mutation with BER. Epitasis tests showed that the uvsZ gene product is probably involved in the same repair pathways as UVSB or UVSH proteins. Although mutations in these proteins result in an NER phenotype, UVSB is related with cell cycle control and UVSH is associated with the post-replicational repair pathway. The epistatic interaction among uvsZl and uvsB413 and uvsH77 mutations indicates that different repair systems may be related with the common steps of DNA damage response in Aspergillus nidulans.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.10
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• pp.45-50
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• 1971

For the purpose of finding out the effect of heat treatment on biological response and mutation rate, rice seeds were heat treated before and after gamma irradiation. 1. At a dose of 20 KR, pre-irradiation heat treatment showed reduced biological damage and increased mutation rate as compared with non-heat treatment. 2. Mutation frequency was increased in post-treatment of heat shock than in pre-irradiation heat treatment and non-heat treatment. 3. Pre-irradiation heat treatment at 6$0^{\circ}C$ for 30 minutes markedly reduced the biological damage and increased the mutation rate. 4. Mutation spectrum in heat treatment was different from non-treatment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.8
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• pp.2805-2826
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• 2021

In most cases, the routing policy of networks shows a preference for a static one-to-one mapping of communication pairs to routing paths, which offers adversaries a great advantage to conduct thorough reconnaissance and organize an effective attack in a stress-free manner. With the evolution of network intelligence, some flexible and adaptive routing policies have already proposed to intensify the network defender to turn the situation. Routing mutation is an effective strategy that can invalidate the unvarying nature of routing information that attackers have collected from exploiting the static configuration of the network. However, three constraints execute press on routing mutation deployment in practical: insufficient route mutation space, expensive control costs, and incompatibility. To enhance the availability of route mutation, we propose an OpenFlow-based route mutation technique called Polymorphic Path Transferring (PPT), which adopts a physical and virtual path segment mixed construction technique to enlarge the routing path space for elevating the security of communication. Based on the Markov Decision Process, with considering flows distribution in the network, the PPT adopts an evolution routing path scheduling algorithm with a segment path update strategy, which relieves the press on the overhead of control and incompatibility. Our analysis demonstrates that PPT can secure data delivery in the worst network environment while countering sophisticated attacks in an evasion-free manner (e.g., advanced persistent threat). Case study and experiment results show its effectiveness in proactively defending against targeted attacks and its advantage compared with previous route mutation methods.

• Annals of Pediatric Endocrinology and Metabolism
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• v.23 no.4
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• pp.229-234
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• 2018

X-linked hypophosphatemic rickets is caused by loss-of-function mutations in PHEX, which encodes a phosphate-regulating endopeptidase homolog. We report a 26-year-old man with X-linked hypophosphatemic rickets who showed decreased serum phosphate accompanied by bilateral genu valgum and short stature. He had received medical treatment with vitamin D (alfacalcidol) and phosphate from the age of 3 to 20 years. He underwent surgery due to valgus deformity at the age of 14 and 15. Targeted gene panel sequencing for Mendelian genes identified a nonsense mutation in PHEX (c.589C>T; p.Gln197Ter) and a mosaic pattern where only 38% of sequence reads showed the variant allele. This mutation was not found in his mother, who had a normal phenotype. This is a case of a sporadic nonsense mutation in PHEX and up to date, this is the first case of a mosaic mutation in PHEX in Korea.

• Genomics & Informatics
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• v.20 no.2
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• pp.24.1-24.8
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• 2022

Hypomyelinating leukodystrophy type 2 (HLD2), is an inherited genetic disease of the central nervous system caused by recessive mutations in the gap junction protein gamma 2 (GJC2/GJA12). HLD2 is characterized by nystagmus, developmental delay, motor impairments, ataxia, severe speech problem, and hypomyelination in the brain. The GJC2 sequence encodes connexin 47 protein (Cx47). Connexins are a group of membrane proteins that oligomerize to construct gap junctions protein. In the present study, a novel missense mutation gene c.760G>A (p.Val254Met) was identified in a patient with HLD2 by performing whole exome sequencing. Following the discovery of the new mutation in the proband, we used Sanger sequencing to analyze his affected sibling and parents. Sanger sequencing verified homozygosity of the mutation in the proband and his affected sibling. The autosomal recessive inheritance pattern was confirmed since Sanger sequencing revealed both healthy parents were heterozygous for the mutation. PolyPhen2, SIFT, PROVEAN, and CADD were used to evaluate the function prediction scores of detected mutations. Cx47 is essential for oligodendrocyte function, including adequate myelination and myelin maintenance in humans. Novel mutation p.Val254Met is located in the second extracellular domain of Cx47, both extracellular loops are highly conserved and probably induce intramolecular disulfide interactions. This novel mutation in the Cx47 gene causes oligodendrocyte dysfunction and HLD2 disorder.