1.SARS-CoV-2 Omicron Variant of Concern: Everything You Wanted to Know about Omicron but Were Afraid to Ask
Dong Hoon SHIN ; Davey M. SMITH ; Jun Yong CHOI
The Korean Journal of Gastroenterology 2022;63(11):977-983
As soon as the first case of the omicron variant of severe acute respiratory syndrome coronavirus 2 was reported in November 2021, it quickly spread worldwide with the emergence of several subvariants. Compared to previous variants, omicron was heavily mutated, especially for those in the Spike (S) protein and its receptor-binding domain. These mutations allowed the viruses to evade immune responses (i.e., previous infections and vaccine-elicited) and increase in transmissibility. Although vaccine effectiveness is decreased for omicron, boosters remain effective for protecting against severe diseases. Also, bivalent vaccines have been developed to increase vaccine effectiveness. Interestingly, although omicron is highly infectious, it has less morbidity and mortality compared to previously identified variants, such as delta. Additionally, the mutations that allow the virus to evade immune responses also allow it to evade many of the monoclonal antibodies developed at the beginning of the pandemic for treatment. Here, we reviewed the omicron variant’s epidemiology, genetics, transmissibility, disease severity, and responsiveness to vaccine and treatments.
2.SARS-CoV-2 Omicron Variant of Concern: Everything You Wanted to Know about Omicron but Were Afraid to Ask
Dong Hoon SHIN ; Davey M. SMITH ; Jun Yong CHOI
Yonsei Medical Journal 2022;63(11):977-983
As soon as the first case of the omicron variant of severe acute respiratory syndrome coronavirus 2 was reported in November 2021, it quickly spread worldwide with the emergence of several subvariants. Compared to previous variants, omicron was heavily mutated, especially for those in the Spike (S) protein and its receptor-binding domain. These mutations allowed the viruses to evade immune responses (i.e., previous infections and vaccine-elicited) and increase in transmissibility. Although vaccine effectiveness is decreased for omicron, boosters remain effective for protecting against severe diseases. Also, bivalent vaccines have been developed to increase vaccine effectiveness. Interestingly, although omicron is highly infectious, it has less morbidity and mortality compared to previously identified variants, such as delta. Additionally, the mutations that allow the virus to evade immune responses also allow it to evade many of the monoclonal antibodies developed at the beginning of the pandemic for treatment. Here, we reviewed the omicron variant’s epidemiology, genetics, transmissibility, disease severity, and responsiveness to vaccine and treatments.
3.Advances of Cancer Therapy by Nanotechnology.
Xu WANG ; Yiqing WANG ; Zhuo Georgia CHEN ; Dong M SHIN
Cancer Research and Treatment 2009;41(1):1-11
Recent developments in nanotechnology offer researchers opportunities to significantly transform cancer therapeutics. This technology has enabled the manipulation of the biological and physicochemical properties of nanomaterials to facilitate more efficient drug targeting and delivery. Clinical investigations suggest that therapeutic nanoparticles can enhance efficacy and reduced side effects compared with conventional cancer therapeutic drugs. Encouraged by rapid and promising progress in cancer nanotechnology, researchers continue to develop novel and efficacious nanoparticles for drug delivery. The use of therapeutic nanoparticles as unique drug delivery systems will be a significant addition to current cancer therapeutics.
Drug Delivery Systems
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Nanoparticles
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Nanostructures
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Nanotechnology
4.Circumferential Bending Test of Lumbar 4-5 Segment and Biomechanical Investigation of Stability for Anterior Lumbar Interbody Cages and Supplemental Posterior Instrumentation.
Ki Chan AN ; Jang Seok CHOI ; Young Chang KIM ; Dong Reol SHIN ; Jung Woog SHIN ; Jae Do KIM ; R M PUNO
Journal of Korean Society of Spine Surgery 2002;9(2):59-69
STUDY DESIGN: Compare the effectiveness of three types of cages used in each case separately with that of cages supplemented by posterior fixation such as transfacet screws and transpedicular screws. OBJECTIVES: To determine whether any important information could be obtained when anterolateral and/or posterolateral bending is imposed. SUMMARY OF LITERATURE REVIEW: Most lumbar spine biomechanical bending tests have been performed on flexion-extension and lateral bending only. MATERIALS AND METHODS: Flexibility was tested through the unconstrained eccentric compression-bending of isolated L4-L5 motion segments. A total of sixteen fresh frozen human cadaveric lumbosacral spine specimens(range of ages : 42+/-13 years 12 males and 4 females) were tested in this investigation. In each case bending load was applied in flexion(0 degree direction), then in 30 degree increments around the transverse plane until flexion was repeated at the 360 degree loading direction. Specimens underwent anterior interbody instrumentation with three different types of cage at L4-5 in three groups, respectively. After testing the interbody fusion constructs, the L4-L5 segments were first stabilized posteriorly using transfacet screws and then retested using transpedicular screw instrumentation. RESULTS: In the intact model, the increase in deflection angle was twice compared with that of the previous point starting from 120 degree up to 150 degree. The pure extensional motion showed the largest deflection angles which are 3.5 times higher than those in pure flexion in average. All three types of cages showed the similar results that were obtained from the intact model.
Cadaver
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Humans
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Male
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Pliability
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Spine
5.A Study of Drug Content and Cell Cytotoxicity of Paclitaxel-eluting Stents Coated with Various Biopolymer.
Dong Gon KIM ; Il Gyun SHIN ; Gi Han KIM ; Seong Hyeon KIM ; Ju Ho LEE ; Byoyng Yun KI ; Jae Woon NAH ; Tae Suk SUH ; Sang Ho KIM
Korean Journal of Medical Physics 2009;20(3):125-131
In this study, the paclitaxel eluting stent (PES) was prepared by coating a biliary stent with paclitaxel using various biopolymer such as poly (vinyl acetate) (PVAc), poly (lactic-co-glycolic acid) (PLGA), Silicone rubber for restenosis prevention in gastrointestinal disease by a dip-coating method. Drug contents of PES were increased as surface area of stent, concentration and molecular weight of coating polymer increase. In 1H-NMR specta, we know that drug did not change by confirming specific peaks of paclitaxel in PES. As shown in SEM image, PES prepared using various biopolymer is coated clearly and regularly except Silicone rubber coating polymer. In in vitro cell cytotoxicity test, bare stent showed low cytotoxic effect against CT-26 colon carcinoma cell line on 3 day. However, PES coated with PLGA 502H showed the highest cytotoxicity because PLGA 502H is biodegradable polymer and has less molecular weight than other coating polymer. These results suggest that PES coated various biopolymer can be prevented restenosis in gastrointestinal disease.
Biopolymers
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Cell Line
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Colon
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Gastrointestinal Diseases
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Lactic Acid
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Molecular Weight
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Paclitaxel
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Polyglycolic Acid
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Polymers
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Silicone Elastomers
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Stents
6.A Study on Fatigue Characteristic of Stent Using Finite Element Analysis.
Han Ki KIM ; Il Gyun SHIN ; Dong Gon KIM ; Seong Hyeon KIM ; Ju Ho LEE ; Byoyng Yun KI ; Tae Suk SUH ; Sang Ho KIM
Korean Journal of Medical Physics 2009;20(3):119-124
Stents are frequently used throughout the human body. They keep pathways open in vascular or nonvascular duct for a long time. Therefore its stability is very important factor. In recent years, aconsiderable amount of research has been carried out in order to estimate mechanical properties of the stent such as expansion pressure behavior, radial recoil and longitudinal recoil using FEM (Finite element analyses). However, published works on simulation of stent fatigue behavior using FEM are relatively rare. In this paper, a nonlinear finite-element method was employed to analyses the compression of a stent using external pressure and fatigue behavior. Finite element analyses for the stent system were performed using NASTRAN FX. In conclusion this paper shows how the stent is behaved in the body, and its fatigue behavior.
Fatigue
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Finite Element Analysis
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Human Body
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Stents
7.Role of Cerebrospinal Fluid Biomarkers in Clinical Trials for Alzheimer's Disease Modifying Therapies.
Ju Hee KANG ; Na Young RYOO ; Dong Wun SHIN ; John Q TROJANOWSKI ; Leslie M SHAW
The Korean Journal of Physiology and Pharmacology 2014;18(6):447-456
Until now, a disease-modifying therapy (DMT) that has an ability to slow or arrest Alzheimer's disease (AD) progression has not been developed, and all clinical trials involving AD patients enrolled by clinical assessment alone also have not been successful. Given the growing consensus that the DMT is likely to require treatment initiation well before full-blown dementia emerges, the early detection of AD will provide opportunities to successfully identify new drugs that slow the course of AD pathology. Recent advances in early detection of AD and prediction of progression of the disease using various biomarkers, including cerebrospinal fluid (CSF) Abeta1-42, total tau and p-tau181 levels, and imagining biomarkers, are now being actively integrated into the designs of AD clinical trials. In terms of therapeutic mechanisms, monitoring these markers may be helpful for go/no-go decision making as well as surrogate markers for disease severity or progression. Furthermore, CSF biomarkers can be used as a tool to enrich patients for clinical trials with prospect of increasing statistical power and reducing costs in drug development. However, the standardization of technical aspects of analysis of these biomarkers is an essential prerequisite to the clinical uses. To accomplish this, global efforts are underway to standardize CSF biomarker measurements and a quality control program supported by the Alzheimer's Association. The current review summarizes therapeutic targets of developing drugs in AD pathophysiology, and provides the most recent advances in the
Alzheimer Disease*
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Biomarkers*
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Cerebrospinal Fluid*
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Consensus
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Decision Making
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Dementia
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Humans
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Pathology
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Quality Control
8.Update on Transarterial Chemoembolization with Drug-Eluting Microspheres for Hepatocellular Carcinoma.
Yasir M NOURI ; Jin Hyoung KIM ; Hyun Ki YOON ; Heung Kyu KO ; Ji Hoon SHIN ; Dong Il GWON
Korean Journal of Radiology 2019;20(1):34-49
Conventional transcatheter arterial chemoembolization (c-TACE) is a widely used first-line palliative treatment for patients with unresectable hepatocellular carcinoma (HCC). Despite the effectiveness of c-TACE, to date, technique and procedure scheduling has not yet been standardized. Drug-eluting microspheres (DEMs) were therefore introduced to ensure more sustained and tumor-selective drug delivery for permanent embolization. These DEMs can load various drugs and release them in a sustained manner over a prolonged period. This approach ensures the delivery of high concentrations of chemotherapeutic agents to tumors, without increasing systemic concentrations, and promote tumor ischemia and necrosis. This review summarizes the recent advances in the use of DEM-TACE to treat HCC.
Carcinoma, Hepatocellular*
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Humans
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Ischemia
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Liver
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Microspheres*
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Necrosis
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Palliative Care