• Clinical and Experimental Pediatrics
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• 제53권3호
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• pp.273-285
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• 2010

Completion of the human genome project has allowed a deeper understanding of molecular pathophysiology and has provided invaluable genomic information for the diagnosis of genetic disorders. Advent of new technologies has lead to an explosion in genetic testing. However, this overwhelming stream of genetic information often misleads physicians and patients into a misguided faith in the power of genetic testing. Moreover, genetic testing raises a number of ethical, legal, and social issues. Diagnostic genetic tests can be divided into three primary but overlapping categories: cytogenetic studies (including routine karyotyping, high-resolution karyotyping, and fluorescent in situ hybridization studies), biochemical tests, and DNA-based diagnostic tests. DNA-based testing has grown rapidly over the past decade and includes preandpostnatal testing for the diagnosis of genetic diseases, testing for carriers of genetic diseases, genetic testing for susceptibility to common non-genetic diseases, and screening for common genetic diseases in a particular population. Theoretically, once a gene's structure, function, and association with a disease are well established, the clinical application of genetic testing should be feasible. However, for routine applications in a clinical setting, such tests must satisfy a number of criteria. These criteria include an acceptable degree of clinical and analytical validity, support of a quality assurance program, possibility of modifying the course of the diagnosed disease with treatment, inclusion of pre-and postnatal genetic counseling, and determination of whether the proposed test satisfies cost-benefit criteria and should replace or complement traditional tests. In the near future, the application of genetic testing to common diseases is expected to expand and will likely be extended to include individual pharmacogenetic assessments.

• The Journal of Advanced Prosthodontics
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• 제10권6호
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• pp.408-414
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• 2018

PURPOSE. This study aimed to assess the effect of non-thermal plasma on the shear bond strength of resin cements to polyetherketoneketone (PEKK) in comparison to other surface treatment methods. MATERIALS AND METHODS. Eighty PEKK discs were subjected to different surface treatments: (1) Untreated (UT); (2) Non-thermal plasma (NTP); (3) Sandblasting with $50{\mu}m$ $Al_2O_3$ particles (SB); and (4) Sandblasting + Non-thermal plasma (SB+NTP). After each surface treatment, the contact angle was measured. Surface conditioning with Visio.Link was applied in all groups after pre-treatment. RelyX Unicem resin cement was bonded onto the PEKK specimens. After fabrication of the specimens, half of each group (n=10) was initially tested, while the other half was subjected to thermocycling ($5^{\circ}C$ to $55^{\circ}C$ at 10,000 cycles). Shear bond strength (SBS) testing was performed using a universal testing machine, and failure modes were assessed using stereomicroscopy. The SBS results were analyzed statistically using one-way ANOVA followed by Tukey's post hoc test. Independent t-test was used to examine the effect of thermocycling (P<.05). RESULTS. The highest SBS values with or without thermocycling were observed with PEKK specimens that were treated with SB+NTP followed by the SB group. The lowest SBS results were observed in the UT groups. CONCLUSION. The shear bond strength between PEKK and resin cements was improved using non-thermal plasma treatment in combination with sandblasting.

• Journal of Genetic Medicine
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• 제4권1호
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• pp.1-5
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• 2007

Unprecedented amount of genetic information being generated from the result of Human Genome Project (HGP) and advances in genetic research is already forcing changes in the paradigm of health and disease. The ultimate goal of genetic medicine is to use genetic information and technology to develop new ways of treatment or even prevention of the disease on an individual level for 'personalized medicine'. Genetics is play ing an increasingly important role in the diagnosis, monitoring and management of common multifactorial diseases in addition to rare single-gene disorders. While wide range of genetic testing have provided benefits to patients and family, uncertainties surrounding test interpretation, the current lack of available medical options for the diseases, and risks for discrimination and social stigmatization may remain to be resolved. However an increasing number of genetic tests are becoming commercially available, including direct to consumer genetic testing, yet public is often unaw are of their clinical and social implications. The personal nature of information generated by a genetic test, its power to affect major life decisions and family members, and its potential misuse raise important ethical considerations. Therefore appropriate genetic counseling is needed for patient to be informed with the benefits, limitations and risks of genetic tests, prior to informed consent for the tests. Physician also should be familiar with the legal and ethical issues involved in genetic testing to tell patients how w ell a particular genetic risk factor relates with likelihood of disease, and be able to provide appropriate genetic counseling. Genetic counseling become a mandatory requirement as global standard for many genetic testing such as prenatal diagnosis, presymtomatic DNA diagnostic tests and cancer susceptibility gene test for familial cancer syndrome. In oder to meet the challenge of genetic medicine of 21 century in korean health care system, professional education program and certification board for medical genetics specialist including non-MD genetic counselors should be addressed by medical society and regulatory policy of national health insurance reimbursement for genetic counseling to be in place to promote the implementation of clinical genetic service including genetic counseling for proper genetic testing.

• Annals of Laboratory Medicine
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• 제38권6호
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• pp.545-554
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• 2018

Background: The increasing morbidity and mortality rates associated with Acinetobacter baumannii are due to the emergence of drug resistance and the limited treatment options. We compared characteristics of colistin-resistant Acinetobacter baumannii (CR-AB) clinical isolates recovered from patients with and without prior colistin treatment. We assessed whether prior colistin treatment affects the resistance mechanism of CR-AB isolates, mortality rates, and clinical characteristics. Additionally, a proper method for identifying CR-AB was determined. Methods: We collected 36 non-duplicate CR-AB clinical isolates resistant to colistin. Antimicrobial susceptibility testing, Sanger sequencing analysis, molecular typing, lipid A structure analysis, and in vitro synergy testing were performed. Eleven colistin-susceptible AB isolates were used as controls. Results: Despite no differences in clinical characteristics between patients with and without prior colistin treatment, resistance-causing genetic mutations were more frequent in isolates from colistin-treated patients. Distinct mutations were overlooked via the Sanger sequencing method, perhaps because of a masking effect by the colistin-susceptible AB subpopulation of CR-AB isolates lacking genetic mutations. However, modified lipid A analysis revealed colistin resistance peaks, despite the population heterogeneity, and peak levels were significantly different between the groups. Conclusions: Although prior colistin use did not induce clinical or susceptibility differences, we demonstrated that identification of CR-AB by sequencing is insufficient. We propose that population heterogeneity has a masking effect, especially in colistin non-treated patients; therefore, accurate testing methods reflecting physiological alterations of the bacteria, such as phosphoethanolamine-modified lipid A identification by matrix-assisted laser desorption ionization-time of flight, should be employed.

• 대한임상검사과학회지
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• 제45권1호
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• pp.21-25
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• 2013

Acinetobacter baumannii is an aerobic, gram-negative and glucose-non-fermenting bacterium, which has emerged as a serious opportunistic pathogen. Many clinical microbiology laboratories use the Vitek 2 system for the routine antimicrobial susceptibility testing process, including testing on A. baumannii isolates. However, in case of amikacin, it is now recommended to perform additional antimicrobial susceptibility testing for A. baumannii strains due to the relatively lower minimum inhibitory concentration (MIC) in the Vitek 2 system compared to conventional reference methods. In our study, we assessed MIC for amikacin susceptibility testing of A. baumannii isolates in the Vitek 2 system, the agar dilution, Etest, and disk diffusion method. We collected 40 gentamicin-resistant, A. baumannii strains (amikacin MIC by Vitek 2:${\leq}2{\mu}g/mL$, 2 isolates; $4{\mu}g/mL$, 34 isolates; $8{\mu}g/mL$, 4 isolates) from a University hospital and compared the Vitek 2 system to other reference methods for testing susceptibility to amikacin. The Vitek 2 system showed major errors in all of the 40 isolates, yielding a low MIC. The results of our study strongly suggested that the Vitek 2 system was not a reliable method to test the MICs of gentamicin; ranging from ${\geq}16{\mu}g/mL$ for amikacin susceptibility. Other tests, such as agar dilution, Etest, or disk diffusion methods, should be paralleled to determine the MIC of amikacin in A. baumannii.

• Journal of Genetic Medicine
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• 제15권2호
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• pp.79-86
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• 2018

Purpose: This study aimed to evaluate the clinical usefulness of non-invasive prenatal testing (NIPT) as an alternative testing of invasive diagnostic testing in pregnancies with ultrasound abnormalities. Materials and Methods: This was a retrospective study of pregnant women with abnormal ultrasound findings before 24 weeks of gestation between April 2016 and March 2017. Abnormal ultrasound findings included isolated increased nuchal translucency, structural anomalies, and soft markers. The NIPT or diagnostic test was conducted and NIPT detected trisomy 21 (T21), T18, T13 and sex chromosomal abnormalities. We analyzed the false positive and residual risks of NIPT based on the ultrasound findings. Results: During the study period, 824 pregnant women had abnormal ultrasound findings. Among the study population, 139 patients (16.9%) underwent NIPT. When NIPT was solely performed in the patients with abnormal ultrasound findings, overall false positive risk was 2.2% and this study found residual risks of NIPT. However, the discordant results of NIPT differed according to the type of abnormal ultrasound findings. Discordant results were significant in the group with structural anomalies with 4.4% false positive rate. However, no discordant results were found in the group with single soft markers. Conclusion: This study found different efficacy of NIPT according to the ultrasound findings. The results emphasize the importance of individualized counseling for prenatal screening or diagnostic test based on the type of abnormal ultrasound.

• Communications for Statistical Applications and Methods
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• 제13권3호
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• pp.787-794
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• 2006

In group testing, the test unit consists of a group of individuals and each group is tested to classify units from a population as infected or non-infected or estimate the infection rate. If the test group is infected, one or more individuals in the group are presumed to be infected. It is assumed in group testing that classification of group as positive or negative is without error. But, the possibility of false negatives as a result of dilution effects happens often in practice, specially in many clinical researches. In this paper, dilution effect models in group testing are discussed and estimation methods of infection rate are proposed when a dilution effect exists.

• 한국간호교육학회지
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• 제19권4호
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• pp.675-683
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• 2013

Purpose: Nineteen articles were analyzed to gather opinions and nursing implications about NIPT recently launched. Methods: Nineteen articles were selected from EBSCO (eBook business collection), Google Scholar, and two Korean academic d-bases with key words 'prenatal screening testing', 'prenatal genetic diagnostic testing', NIPT or 'cell free DNA (cfDNA)'. Authors developed a framework for analyzing the 19 articles including opinions and suggestions for future implications. Results: Eleven articles written by the first author affiliated with medicine or genetics, viewed NIPT as promising because of safety, accuracy, early detectability and cost effectiveness. Articles written by journalists or authors affiliated with history and ethics were concerned with the possible risk of ELSI (ethical, legal, social issues), erratic interpretation of test results, and lack of genetic counseling service. Conclusion: With consideration of Korean clinical, and legal circumstances, not only pregnant women and families but also health professionals must prepare for clinical NIPT implications including updating prenatal genetic testing, counseling services, protecting ELSI and amulticultural team approach.

• The Korean Journal of Physiology and Pharmacology
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• 제24권6호
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• pp.441-452
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• 2020

In vivo animal models are limited in their ability to mimic the extremely complex systems of the human body, and there is increasing disquiet about the ethics of animal research. Many authorities in different geographical areas are considering implementing a ban on animal testing, including testing for cosmetics and pharmaceuticals. Therefore, there is a need for research into systems that can replicate the responses of laboratory animals and simulate environments similar to the human body in a laboratory. An in vitro two-dimensional cell culture model is widely used, because such a system is relatively inexpensive, easy to implement, and can gather considerable amounts of reference data. However, these models lack a real physiological extracellular environment. Recent advances in stem cell biology, tissue engineering, and microfabrication techniques have facilitated the development of various 3D cell culture models. These include multicellular spheroids, organoids, and organs-on-chips, each of which has its own advantages and limitations. Organoids are organ-specific cell clusters created by aggregating cells derived from pluripotent, adult, and cancer stem cells. Patient-derived organoids can be used as models of human disease in a culture dish. Biomimetic organ chips are models that replicate the physiological and mechanical functions of human organs. Many organoids and organ-on-a-chips have been developed for drug screening and testing, so competition for patents between countries is also intensifying. We analyzed the scientific and technological trends underlying these cutting-edge models, which are developed for use as non-animal models for testing safety and efficacy at the nonclinical stages of drug development.

• 대한유전성대사질환학회지
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• 제23권2호
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• pp.21-30
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• 2023

Inherited metabolic disorders (IMD) are a group of disorders caused by defects in specific biochemical pathways. Up to 85% of IMD display predominantly neurological manifestations by affecting neurodevelopment or causing neurodegeneration. These neurometabolic disorders present with a variety of neurological and non-neurological manifestations. Early diagnosis of IMD is important because some disorders can be treated or improved with specific treatment if detected early. For prompt diagnosis and treatment, it is important to suspect IMD by being familiar with the clinical characteristics, biochemical abnormalities, and characteristic neuroimaging patterns that appear in IMD. Genetic testing, including next-generation sequencing, is also important in diagnosing IMD. During the follow-up of patients with IMD, it is necessary to conduct regular physical and neurological examinations in addition to disease-specific management.