• Title/Summary/Keyword: Preclinical Study

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Development of Energy Harvesting Technologies Platform for Self-Power Rechargeable Pacemaker Medical Device. (자가발전 심장박동기를 위한 에너지 수확 플랫폼 개발)

  • Park, Hyun-Moon;Lee, Jung-Chul;Kim, Byunng-Soo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.3
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    • pp.619-626
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    • 2019
  • The advances of semiconductor and circuitry technology dovetailed with nano processing techniques have further enhanced micro-miniaturization, sensitivity, longevity and reliability in MID(Medical Implant Device). Nevertheless, one of the remaining challenges is whether power can sufficiently and continuously be supplied for the operation of the MID. Self-powered MID that harvest biomechanical energy from human motion, respiratory and muscle movement are part of a paradigm shift. In this paper, we developed a rechargeable pacemaker through self-power generation with the triboelectric nanogenerator. We demonstrate a fully implanted pacemaker based on an implantable triboelectric nanogenerator, which act as a storage as well as active movement on a large-animal(dog) scale. The self-power pacemaker harvested from animal motion is 2.47V, which is higher than the required pacemaker device sensing voltage(1.35V).

Comparative preclinical assessment of the use of dehydrated human amnion/chorion membrane to repair perforated sinus membranes

  • Chang, Yun-Young;Kim, Su-Hwan;Goh, Mi-Seon;Yun, Jeong-Ho
    • Journal of Periodontal and Implant Science
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    • v.49 no.5
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    • pp.330-343
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    • 2019
  • Purpose: The aim of this study was to evaluate the use of dehydrated human amnion/chorion membrane (dHACM) to repair perforated sinus membranes in rabbits. Methods: Bilateral surgical windows (7.5-mm diameter) were prepared on the nasal bones of 14 rabbits. Standardized circular perforations (5-mm diameter) were made in the sinus membrane by manipulating implant twist drills. The perforated sinus membranes were repaired using dHACM or a resorbable collagen membrane (CM). The negative control (NC) group did not undergo perforated sinus membrane repair, while the positive control (PC) group underwent sinus augmentation without perforations. The same amount of deproteinized porcine bone mineral was grafted in all 4 groups. After 6 weeks, micro-computed tomography (micro-CT) and histomorphometric evaluations were conducted. Results: The micro-CT analysis revealed that the total augmented volume was not significantly different among the groups. In the dHACM group, newly formed bone filled the augmented area with remaining biomaterials; however, non-ciliated flat epithelium and inflammatory cells were observed on the healed sinus membrane. Histometric analysis showed that the percentage of newly formed bone area in the dHACM group did not differ significantly from that in the CM group. The dHACM group showed a significantly higher percentage of newly formed bone area than the NC group, but there was no significant difference between the dHACM and PC groups. Conclusions: dHACM could be a feasible solution for repairing sinus membrane perforations that occur during sinus floor augmentation.

Anti-inflammatory and Anti-gastritis Effect of Sogunjung-tang Mixed Soft Extract (소건중탕 혼합단미연조엑스의 항염증 및 항위염 효과)

  • Kim, Myoung-Jin;Choi, Hye-Min;Nam, Won-Hee;Kim, Se-Jin;Son, Su-Mi;Kim, Jung-Ok
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.35 no.6
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    • pp.235-241
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    • 2021
  • Sogunjung-tang (SGJT) is traditional herbal prescriptions used to treat abdominal pain. In this study, we evaluated the effect on inflammation and gastritis through SGJT formulation development. SGJT composition herbal medicine was boiled in water at 95~100℃ for 3 hours and then concentrated. Sogunjung-tang mix soft extract (STM) was prepared using pharmaceutical excipients such as purified water, sodium benzoate, β-cyclodextrin and CMC-Na. Anti-inflammatory experiment was conducted using STM and lipopolysaccharide (LPS) in RAW 264.7 cells. Cell survival was measured by MTT method. Nitric oxide (NO) was measured using griess reagents, and pro inflammatory cytokines were measured by enzyme-linked immunosorbent assay and RT-PCR. Also, we verified STM validity in acute gastritis using the ICR mouse. STM was administered oral for three days. And 150 mM HCl in 60% ethanol was oral administered 0.5 mL one hour after the last drug administration. Mice were sacrificed 1 hour after 150 mM HCl in 60% ethanol administration. The gastric mucosa was visually observed. STM were not toxic in RAW 264.7 cells. Treatment of STM inhibited the production of NO and inflammatory cytokine at the protein and mRNA levels. Also, in the acute gastritis model with the mouse, the treatment of STM improved gastric mucosal bleeding and edema. In summary, it was confirmed that the treatment of STM exerts anti-inflammatory and anti-gastritis effects. Therefore, we suggest that STM may provide a preclinical evidence for the prevention and treatment of inflammatory and gastritis diseases.

Clinical application of genome-wide single nucleotide polymorphism genotyping and karyomapping for preimplantation genetic testing of Charcot-Marie-Tooth disease

  • Kim, Min Jee;Park, Sun Ok;Hong, Ye Seul;Park, Eun A;Lee, Yu Bin;Choi, Byung-Ok;Lee, Kyung-Ah;Yu, Eun Jeong;Kang, Inn Soo
    • Journal of Genetic Medicine
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    • v.19 no.1
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    • pp.7-13
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    • 2022
  • Purpose: Preimplantation genetic testing for monogenic disorders (PGT-M) has been successfully used to prevent couples with monogenic disorders from passing them on to their child. Charcot-Marie-Tooth Disease (CMT) is a genetic disorder characterized by progressive extremity muscle degeneration and loss of sensory function. For the first time in Korea, we report our experience of applying single nucleotide polymorphism genotyping and karyomapping for PGT-M of CMT disease. Materials and Methods: Prior to clinical PGT-M, preclinical tests were performed using genotypes of affected families to identify informative single-nucleotide polymorphisms associated with mutant alleles. We performed five cycles of in vitro fertilization PGT-M in four couples with CMT1A, CMT2A, and CMT2S in CHA Fertility Center, Seoul Station. Results: From July 2020 through August 2021, five cycles of PGT-M with karyomapping in four cases with CMT1 and CMT2 were analyzed retrospectively. A total of 17 blastocysts were biopsied and 15 embryos were successfully diagnosed (88.2%). Ten out of 15 embryos were diagnosed as unaffected (66.7%). Five cycles of PGT-M resulted in four transfer cycles, in which four embryos were transferred. Three clinical pregnancies were achieved (75%) and the prenatal diagnosis by amniocentesis for all three women confirmed PGT-M of karyomapping. One woman delivered a healthy baby uneventfully and two pregnancies are currently ongoing. Conclusion: This is the first report in Korea on the application of karyomapping in PGT-M for CMT patients. This study shows that karyomapping is an efficient, reliable and accurate diagnostic method for PGT-M in various types of CMT diseases.

Effect of the size of the bony access window and the collagen barrier over the window in sinus floor elevation: a preclinical investigation in a rabbit sinus model

  • Sim, Jeong-Eun;Kim, Sangyup;Hong, Ji-Youn;Shin, Seung-Il;Chung, Jong-Hyuk;Lim, Hyun-Chang
    • Journal of Periodontal and Implant Science
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    • v.52 no.4
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    • pp.325-337
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    • 2022
  • Purpose: The aim of this study was to investigate the effect of (1) the size of the bony access window and (2) collagen membrane coverage over the window in sinus floor elevation in a rabbit sinus model. Methods: Small bony access windows (SW; ø 2.8 mm) were made in 6 rabbits and large windows (LW; ø 6 mm) in 6 other rabbits. Both sinuses in each rabbit were allocated to groups with or without coverage of a collagen membrane (CM) on the window, resulting in 4 groups: SW, LW, SW+CM, and LW+CM. After 4 weeks of healing, micro-computed tomographic, histologic, and histomorphometric analyses were performed. Results: Bony healing in the window area was incomplete in all groups, but most bone graft particles were well confined in the augmented cavity. Histologically, the pattern of new bone formation was similar in all groups. Histomorphometrically, the percentage of newly formed bone was greater in the groups with CM than in the groups without CM, and in the groups with SW than in the groups with LW (12.92%±6.40% in the SW+CM group, 4.21%±7.73% in the SW group, 10.45%±4.81% in the LW+CM group, 11.77%±3.83% in the LW group). The above differences were not statistically significant (P>0.05). Conclusions: The combination of a small bony access window and the use of a collagen membrane over the window favored new bone formation compared to other groups, but this result should be further investigated due to the limitations of the present animal model.

Targeting Catecholamines to Develop New Drugs for Attention Deficit Hyperactivity Disorder (주의력결핍 과잉행동장애 치료제 개발을 위한 카테콜아민계 표적화)

  • Sung-Cherl Jung;Chang-Hwan Cho;Hye-Ji Kim;Eun-A Ko;Min-Woo Ha;Oh-Bin Kwon
    • Journal of Medicine and Life Science
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    • v.18 no.3
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    • pp.41-48
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    • 2021
  • The prevalence of attention deficit hyperactivity disorder (ADHD), a developmental neuropsychiatric disorder, is high among children and adolescents. The pathogenesis of ADHD is mediated with genetic, biological, and environmental factors. Most therapeutic drugs for ADHD have so far targeted biological causes, primarily by regulating catecholaminergic neurotransmitters. However, ADHD drugs that are clinically treated have various problems in their addictiveness and drug stability; thus, it is recommended that efficacy and safety should be secured through simultaneous prescription of multiple drugs rather than a single drug treatment. Accordingly, it is necessary to develop drugs that newly target pathogenic mechanisms of ADHD. In this study, we attempt to confirm the possibility of developing new drugs by reviewing dopamine-related developmental mechanisms of neurons and their correlation with ADHD. Histone deacetylase inhibitors (HDACi) can regulate the concentration of intracellular dopamine in neurons by expressing vesicular monoamine transporter 2 and inducing the exocytosis of neurotransmitters to the synaptic cleft, thereby promoting the development of neurons and signal transmission. This cellular modulation of HDACi is expected to treat ADHD by regulating endogenous catecholamines such as dopamine. Although studies are still in the preclinical stage, HDAC inhibitors clearly have potential as a therapeutic agent with low addictiveness and high efficacy for ADHD treatment.

Evaluation and Genome Mining of Bacillus stercoris Isolate B.PNR1 as Potential Agent for Fusarium Wilt Control and Growth Promotion of Tomato

  • Rattana Pengproh;Thanwanit Thanyasiriwat;Kusavadee Sangdee;Juthaporn Saengprajak;Praphat Kawicha;Aphidech Sangdee
    • The Plant Pathology Journal
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    • v.39 no.5
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    • pp.430-448
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    • 2023
  • Recently, strategies for controlling Fusarium oxysporum f. sp. lycopersici (Fol), the causal agent of Fusarium wilt of tomato, focus on using effective biocontrol agents. In this study, an analysis of the biocontrol and plant growth promoting (PGP) attributes of 11 isolates of loamy soil Bacillus spp. has been conducted. Among them, the isolates B.PNR1 and B.PNR2 inhibited the mycelial growth of Fol by inducing abnormal fungal cell wall structures and cell wall collapse. Moreover, broad-spectrum activity against four other plant pathogenic fungi, F. oxysporum f. sp. cubense race 1 (Foc), Sclerotium rolfsii, Colletotrichum musae, and C. gloeosporioides were noted for these isolates. These two Bacillus isolates produced indole acetic acid, phosphate solubilization enzymes, and amylolytic and cellulolytic enzymes. In the pot experiment, the culture filtrate from B.PNR1 showed greater inhibition of the fungal pathogens and significantly promoted the growth of tomato plants more than those of the other treatments. Isolate B.PNR1, the best biocontrol and PGP, was identified as Bacillus stercoris by its 16S rRNA gene sequence and whole genome sequencing analysis (WGS). The WGS, through genome mining, confirmed that the B.PNR1 genome contained genes/gene cluster of a nonribosomal peptide synthetase/polyketide synthase, such as fengycin, surfactin, bacillaene, subtilosin A, bacilysin, and bacillibactin, which are involved in antagonistic and PGP activities. Therefore, our finding demonstrates the effectiveness of B. stercoris strain B.PNR1 as an antagonist and for plant growth promotion, highlighting the use of this microorganism as a biocontrol agent against the Fusarium wilt pathogen and PGP abilities in tomatoes.

The Effectiveness of 448-kHz Capacitive Resistive Monopolar Radiofrequency for Subcutaneous Fat Reduction in a Porcine Model

  • Kwon, Tae-Rin;Lee, Sung-Eun;Kim, Jong Hwan;Jeon, Yong Jae;Jang, You Na;Yoo, Kwang Ho;Kim, Beom Joon
    • Medical Lasers
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    • v.8 no.2
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    • pp.64-73
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    • 2019
  • Background and Objectives The effectiveness of many physiotherapy modalities in reducing subcutaneous fat has been investigated in numerous previous studies. However, to the best of our knowledge, there have been no attempts to determine the effectiveness of physiotherapy modalities in body contouring. The present report determined the effect of 448-kHz capacitive resistive monopolar radiofrequency (CRMRF) in a porcine model. Materials and Methods This study investigated the effect of selective destruction of the subcutaneous fat layer in abdominal fat tissue using CRMRF. The effects of two types of CRMRF (capacitive electric transfer (CET) and resistive electric transfer (RET)) treatment were evaluated using regular digital photography in addition to thermal imaging evaluation, ultrasound measurement, hematological evaluation, and histologic analyses (H&E (hematoxylin and eosin), Oil red O, and immunohistochemistry staining). Results Preclinical evaluation was performed to obtain the data for comparison of the safety and efficacy of the subcutaneous fat reduction after applying CRMRF using CET and RET. After treatment, the thermal transmission was effective, and a 42-47℃ temperature change was observed in the fat layer while an approximately temperature of 42℃ was confirmed on the skin surface. Moreover, after the application of both types of CRMRF treatment, fibrotic septa were observed in the adipose tissue induced by heat at the treatment sites. TUNEL staining was also performed to confirm the process of apoptosis in the adipocytes. Conclusion These results suggest that both CET and RET for CRMRF treatment are safe and effective for subcutaneous fat reduction in a porcine model.

Cynomolgus Macaque Model for COVID-19 Delta Variant

  • Seung Ho Baek;Hanseul Oh;Bon-Sang Koo;Green Kim;Eun-Ha Hwang;Hoyin Jung;You Jung An;Jae-Hak Park;Jung Joo Hong
    • IMMUNE NETWORK
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    • v.22 no.6
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    • pp.48.1-48.13
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    • 2022
  • With the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, which are randomly mutated, the dominant strains in regions are changing globally. The development of preclinical animal models is imperative to validate vaccines and therapeutics against SARS-CoV-2 variants. The objective of this study was to develop a non-human primate (NHP) model for SARS-CoV-2 Delta variant infection. Cynomolgus macaques infected with Delta variants showed infectious viruses and viral RNA in the upper (nasal and throat) and lower respiratory (lung) tracts during the acute phase of infection. After 3 days of infection, lesions consistent with diffuse alveolar damage were observed in the lungs. For cellular immune responses, all macaques displayed transient lymphopenia and neutrophilia in the early stages of infection. SARS-CoV-2 Delta variant spike protein-specific IgM, IgG, and IgA levels were significantly increased in the plasma of these animals 14 days after infection. This new NHP Delta variant infection model can be used for comparative analysis of the difference in severity between SARS-CoV-2 variants of concern and may be useful in the efficacy evaluation of vaccines and universal therapeutic drugs for mutations.

Nursing Students' Clinical Competence and Decision-Making: Impact of a Multiple-components Practice-based Learning (간호학생의 임상수행능력과 임상의사결정: 다중요소 실습기반교육의 효과)

  • Xianqi Gao;Yoonjeong Lee;Moonkyoung Park
    • Journal of Industrial Convergence
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    • v.22 no.3
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    • pp.79-89
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    • 2024
  • This study is a one-group pre-post experimental design that investigates the effects of a practice-based learning program with multiple components on the clinical competence of nursing students, and clinical decision-making. From May 4 to 29, 2020, a total of 60 third-year nursing students with no clinical practice experience were divided into two teams and participated in multi-component practice-based education for two weeks each, and the data of the final 51 students were included in the analysis. Following the practicum, there was a significant increase in clinical competence (t=-4.74, p<.001) and self-confidence in clinical decision-making (t=-8.41, p<.001), and a decrease in anxiety related to clinical decision-making (t=2.54, p=.014). The findings suggest that a multi-component, practice-based learning approach for nursing students can enhance their clinical competence, reduce preclincal anxiety and increase confidence in clinical decision-making in patient care.