• Title/Summary/Keyword: mutation pressure

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Two Cases of Prolonged Mutation Difficulty Treated by Pressure Method (압박법으로 교정한 변성기장애지속증)

  • 문영일
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1983.05a
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    • pp.11.1-11
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    • 1983
  • Mutation consisted of abrupt and uncontrolled rises and falls in vocal pitch due to poor coordination of the laryngeal musculature associated with general bodily growth. The male voice drops about 10 semitones after mutation period but the female voice drops about 2 semitones. Symptoms of abnormal voice mutation are many variations in the voice. Sometimes the voice is a true falsetto, high and thin. The au thor experienced two male cases of prolonged mutation difficulty treated by pressure method. The result were excellent with simple maneuver. The author reported the result of treatment for two cases and reviewed the literatures.

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A novel mutation of CLCNKB in a Korean patient of mixed phenotype of Bartter-Gitelman syndrome

  • Cho, Hee-Won;Lee, Sang Taek;Cho, Heeyeon;Cheong, Hae Il
    • Clinical and Experimental Pediatrics
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    • v.59 no.sup1
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    • pp.103-106
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    • 2016
  • Bartter syndrome (BS) is an inherited renal tubular disorder characterized by low or normal blood pressure, hypokalemic metabolic alkalosis, and hyperreninemic hyperaldosteronism. Type III BS is caused by loss-of-function mutations in CLCNKB encoding basolateral ClC-Kb. The clinical phenotype of patients with CLCNKB mutations has been known to be highly variable, and cases that are difficult to categorize as type III BS or other hereditary tubulopathies, such as Gitelman syndrome, have been rarely reported. We report a case of a 10-year-old Korean boy with atypical clinical findings caused by a novel CLCNKB mutation. The boy showed intermittent muscle cramps with laboratory findings of hypokalemia, severe hypomagnesemia, and nephrocalcinosis. These findings were not fully compatible with those observed in cases of BS or Gitelman syndrome. The CLCNKB mutation analysis revealed a heterozygous c.139G>A transition in exon 13 [p.Gly(GGG)465Glu(GAG)]. This change is not a known mutation; however, the clinical findings and in silico prediction results indicated that it is the underlying cause of his presentation.

Lack of Association between the S20G Missense Mutation of Amylin Gene and Essential Hypertension in Korean Population

  • Kang, Byung-Yong;Bae, Joon-Seol;Kim, Jae-Hyoun;Om, Ae-Son;Ryu, Jae-Chun;Eo, Hyun-Seon;Shin, Jae-Hyun;Shin, Jung-Hee;Lee, Chung-Choo;Kim, Ki-Tae
    • Environmental Mutagens and Carcinogens
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    • v.21 no.2
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    • pp.72-76
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    • 2001
  • Essential hypertension is a heterogeneously multifactorial disease in which blood pressure is harmfully high without overt cause. Both genetic and environmental factors have been implicated in its etiology. In view of the regulatory role of this peptide in the carbohydrate metabolism and renin-angiotensin system, amylin gene has been proposed to a candidate gene for essential hypertension. Therefore, we scanned the amylin gene for mutations in 133 Korean normotensives and 61 essential hypertensives by single-strand conformational polymorphism, and found a single heterozygous S20G missense mutation. However, no significant difference was observed between normotensives and essential hypertensives in the distribution of allele and genotype frequencies of this mutation at the amylin gene (P>0.05). This finding suggests that S20G missense mutation of the amylin gene are unlikely to contribute to the etiology of essential hypertension in the Korean population.

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Insights into factors affecting synonymous codon usage in apple mosaic virus and its host adaptability

  • Pourrahim, R.;Farzadfar, Sh.
    • Journal of Plant Biotechnology
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    • v.49 no.1
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    • pp.46-60
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    • 2022
  • The genetic variability and population structure of apple mosaic virus (ApMV) have been studied; however, synonymous codon usage patterns influencing the survival rates and fitness of ApMV have not been reported. Based on phylogenetic analyses of 52 ApMV coat protein (CP) sequences obtained from apple, pear, and hazelnut, ApMV isolates were clustered into two groups. High molecular diversity in GII may indicate their recent expansion. A constant and conserved genomic composition of the CP sequences was inferred from the low codon usage bias. Nucleotide composition and relative synonymous codon usage (RSCU) analysis indicated that the ApMV CP gene is AU-rich, but G- and U-ending codons are favored while coding amino acids. This unequal use of nucleotides together with parity rule 2 and the effective number of codon (ENC) plots indicate that mutation pressure together with natural selection drives codon usage patterns in the CP gene. However, in this combination, selection pressure plays a more crucial role. Based on principal component analysis plots, ApMV seems to have originated from apple trees in Europe. However, according to the relative codon deoptimization index and codon adaptation index (CAI) analyses, ApMV exhibited the greatest fitness to hazelnut. As inferred from the results of the similarity index analysis, hazelnut has a major role in shaping ApMV RSCU patterns, which is consistent with the CAI analysis results. This study contributes to the understanding of plant virus evolution, reveals novel information about ApMV evolutionary fitness, and helps find better ApMV management strategies.

Receptor binding motif surrounding sites in the Spike 1 protein of infectious bronchitis virus have high susceptibility to mutation related to selective pressure

  • Seung-Min Hong;Seung-Ji Kim;Se-Hee An;Jiye Kim;Eun-Jin Ha;Howon Kim;Hyuk-Joon Kwon;Kang-Seuk Choi
    • Journal of Veterinary Science
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    • v.24 no.4
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    • pp.51.1-51.17
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    • 2023
  • Background: To date, various genotypes of infectious bronchitis virus (IBV) have co-circulated and in Korea, GI-15 and GI-19 lineages were prevailing. The spike protein, particularly S1 subunit, is responsible for receptor binding, contains hypervariable regions and is also responsible for the emerging of novel variants. Objective: This study aims to investigate the putative major amino acid substitutions for the variants in GI-19. Methods: The S1 sequence data of IBV isolated from 1986 to 2021 in Korea (n = 188) were analyzed. Sequence alignments were carried out using Multiple alignment using Fast Fourier Transform of Geneious prime. The phylogenetic tree was generated using MEGA-11 (ver. 11.0.10) and Bayesian analysis was performed by BEAST v1.10.4. Selective pressure was analyzed via online server Datamonkey. Highlights and visualization of putative critical amino acid were conducted by using PyMol software (version 2.3). Results: Most (93.5%) belonged to the GI-19 lineage in Korea, and the GI-19 lineage was further divided into seven subgroups: KM91-like (Clade A and B), K40/09-like, QX-like (I-IV). Positive selection was identified at nine and six residues in S1 for KM91-like and QX-like IBVs, respectively. In addition, several positive selection sites of S1-NTD were indicated to have mutations at common locations even when new clades were generated. They were all located on the lateral surface of the quaternary structure of the S1 subunits in close proximity to the receptor-binding motif (RBM), putative RBM motif and neutralizing antigenic sites in S1. Conclusions: Our results suggest RBM surrounding sites in the S1 subunit of IBV are highly susceptible to mutation by selective pressure during evolution.

Plasmodium vivax dhfr Mutations among Isolates from Malarious Areas of Iran

  • Zaman, Jalal;Shahbazi, Abbas;Asgharzadeh, Mohammad
    • Parasites, Hosts and Diseases
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    • v.49 no.2
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    • pp.125-131
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    • 2011
  • The use of sulfadoxine and pyrimethamine (SP) for treatment of vivax malaria is uncommon in most malarious areas, but Plasmodium vivax isolates are exposed to SP because of mixed infections with other Plasmodium species. As P. vivax is the most prevalent species of human malaria parasites in Iran, monitoring of resistance of the parasite against the drug is necessary. In the present study, 50 blood samples of symptomatic patients were collected from 4 separated geographical regions of south-east Iran. Point mutations at residues 57, 58, 61, and 117 were detected by the PCR-RFLP method. Polymorphism at positions 58R, 117N, and 117T of P. vivax dihydrofolate reductase (Pvdhfr) gene has been found in 12%, 34%, and 2% of isolates, respectively. Mutation at residues F57 and T61 was not detected. Five distinct haplotypes of the Pvdhfr gene were demonstrated. The 2 most prevalent haplotypes were F57S58T61S117 (62%) and F57S58T61N117 (24%). Haplotypes with 3 and 4 point mutations were not found. The present study suggested that P. vivax in Iran is under the pressure of SP and the sensitivity level of the parasite to SP is diminishing and this fact must be considered in development of malaria control programs.

Prevalence of negative frequency-dependent selection, revealed by incomplete selective sweeps in African populations of Drosophila melanogaster

  • Kim, Yuseob
    • BMB Reports
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    • v.51 no.1
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    • pp.1-2
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    • 2018
  • Positive selection on a new beneficial mutation generates a characteristic pattern of DNA sequence polymorphism when it reaches an intermediate allele frequency. On genome sequences of African Drosophila melanogaster, we detected such signatures of selection at 37 candidate loci and identified "sweeping haplotypes (SHs)" that are increasing or have increased rapidly in frequency due to hitchhiking. Based on geographic distribution of SH frequencies, we could infer whether selective sweeps occurred starting from de novo beneficial mutants under simple constant selective pressure. Single SHs were identified at more than half of loci. However, at many other loci, we observed multiple independent SHs, implying soft selective sweeps due to a high beneficial mutation rate or parallel evolution across space. Interestingly, SH frequencies were intermediate across multiple populations at about a quarter of the loci despite relatively low migration rates inferred between African populations. This invokes a certain form of frequency-dependent selection such as heterozygote advantage. At one locus, we observed a complex pattern of multiple independent that was compatible with recurrent frequency-dependent positive selection on new variants. In conclusion, genomic patterns of positive selection are very diverse, with equal contributions of hard and soft sweeps and a surprisingly large proportion of frequency-dependent selection in D. melanogaster populations.

A Novel Homozygous CLCNKB Mutation of Classic Bartter Syndrome Presenting with Renal Cysts in 6-year-Old Identical Twin Boys : A Case Report

  • Son, Min Hwa;Yim, Hyung Eun;Yoo, Kee Hwan
    • Childhood Kidney Diseases
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    • v.25 no.1
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    • pp.35-39
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    • 2021
  • Bartter syndrome is an autosomal recessive hypokalemic salt-losing tubulopathy, and classic Bartter syndrome is associated with mutations in the CLCNKB gene. While chronic hypokalemia is known to induce renal cyst formation in different renal diseases, renal cyst formation in Bartter syndrome is rarely reported. Russian six-year-old identical male twins were referred to our hospital for the evaluation of renal cysts, which were incidentally detected on abdominal sonography due to diarrhea. Both twins had shown symptoms of polydipsia, polyuria, and nocturia since they were one year olds. Vital signs including blood pressure were normal in both twins. Renal sonography revealed nephromegaly, increased echogenicity of renal cortex, and various sized multiple cysts in both kidneys for both twins. Laboratory findings included hyponatremia, hypokalemia, hypochloremia, and metabolic alkalosis. Bartter syndrome with renal cysts were suspected. Genetic analysis for both twins confirmed a homozygous c.1614delC deletion on exon 15 of the CLCNKB gene, which was confirmed as a previously unreported variant to the best of our knowledge. They were managed with potassium chloride, nonsteroidal anti-inflammatory drugs, and angiotensin-converting-enzyme inhibitors. Metabolic alkalosis, hypokalemia, hypochloremia, and polyuria partially improved during the short course of treatment. This is the first report of a homozygous mutation in the CLCNKB gene in an identical twin, presenting with renal cysts.

Multi-objective optimal design of laminate composite shells and stiffened shells

  • Lakshmi, K.;Rama Mohan Rao, A.
    • Structural Engineering and Mechanics
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    • v.43 no.6
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    • pp.771-794
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    • 2012
  • This paper presents a multi-objective evolutionary algorithm for combinatorial optimisation and applied for design optimisation of fiber reinforced composite structures. The proposed algorithm closely follows the implementation of Pareto Archive Evolutionary strategy (PAES) proposed in the literature. The modifications suggested include a customized neighbourhood search algorithm in place of mutation operator to improve intensification mechanism and a cross over operator to improve diversification mechanism. Further, an external archive is maintained to collect the historical Pareto optimal solutions. The design constraints are handled in this paper by treating them as additional objectives. Numerical studies have been carried out by solving a hybrid fiber reinforced laminate composite cylindrical shell, stiffened composite cylindrical shell and pressure vessel with varied number of design objectives. The studies presented in this paper clearly indicate that well spread Pareto optimal solutions can be obtained employing the proposed algorithm.

Diffusion-hydraulic properties of grouting geological rough fractures with power-law slurry

  • Mu, Wenqiang;Li, Lianchong;Liu, Xige;Zhang, Liaoyuan;Zhang, Zilin;Huang, Bo;Chen, Yong
    • Geomechanics and Engineering
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    • v.21 no.4
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    • pp.357-369
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    • 2020
  • Different from the conventional planar fracture and simplified Newton model, for power-law slurries with a lower water-cement ratio commonly used in grouting engineering, flow model in geological rough fractures is built based on ten standard profiles from Barton (1977) in this study. The numerical algorithm is validated by experimental results. The flow mechanism, grout superiority, and water plugging of pseudo plastic slurry are revealed. The representations of hydraulic grouting properties for JRCs are obtained. The results show that effective plugging is based on the mechanical mechanisms of the fluctuant structural surface and higher viscosity at the middle of the fissure. The formulas of grouting parameters are always variable with the roughness and shear movement, which play a key role in grouting. The roughness can only be neglected after reaching a threshold. Grouting pressure increases with increasing roughness and has variable responses for different apertures within standard profiles. The whole process can be divided into three stationary zones and three transition zones, and there is a mutation region (10 < JRCs < 14) in smaller geological fractures. The fitting equations of different JRCs are obtained of power-law models satisfying the condition of -2 < coefficient < 0. The effects of small apertures and moderate to larger roughness (JRCs > 10.8) on the permeability of surfaces cannot be underestimated. The determination of grouting parameters depends on the slurry groutability in terms of its weakest link with discontinuous streamlines. For grouting water plugging, the water-cement ratio, grouting pressure and grouting additives should be determined by combining the flow conditions and the apparent widths of the main fracture and rough surface. This study provides a calculation method of grouting parameters for variable cement-based slurries. And the findings can help for better understanding of fluid flow and diffusion in geological fractures.