Viral Load Kinetics of SARS-CoV-2 Infection in Saliva in Korean Patients: a Prospective Multi-center Comparative Study

김성은,Lee Ji Yeon,Lee Ahrang,Kim Soosung,Park Kyung-Hwa,Jung Sook-In,Kang Seung-Ji,Oh Tae Hoon,Kim Uh Jin,Lee Seung Yeob,Kee Seung-Jung,장희창 대한의학회 2020 Journal of Korean medical science Vol.35 No.31

Background: This study was performed to compare the viral load and kinetics of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in saliva with those in standard nasopharyngeal/oropharyngeal (NP/OP) swabs. Methods: Fifteen patients with SARS-CoV-2 infection from four hospitals were prospectively enrolled and matched samples of nasopharyngeal/oropharyngeal swabs and saliva were collected at Day 1 of admission and every other day till consequently negative for two times. Real-time reverse transcription polymerase chain reaction (rRT-PCR) was performed to detect the envelope (E) and RNA-dependent RNA polymerase (RdRP) genes. Results: The cycle threshold values of saliva were comparable to those of NP/OP swabs overall (P = 0.720, Mann–Whitney U test). However, the overall sensitivity of rRT-PCR using saliva was 64% (34/53), which is lower than the 77% (41/53) using NP/OP swabs. The sensitivity of rRT-PCR using saliva was especially lower in early stage of symptom onset (1–5 days; 8/15; 53%) and in patients who did not have sputum (12/22; 55%). Conclusion: Saliva sample itself is not appropriate for initial diagnosis of coronavirus disease 2019 (COVID-19) to replace NP/OP swabs, especially for the person who does not produce sputum. COVID-19 cannot be excluded when the test using saliva is negative, and it is necessary to retest using NP/OP swabs.

Air and Environmental Contamination Caused by COVID-19 Patients: a Multi-Center Study

김어진,Lee Seung Yeob,Lee Ji Yeon,Lee Ahrang,Kim Seung Eun,Choi Ok-Ja,Lee Ji Suk,기승정,장희창 대한의학회 2020 Journal of Korean medical science Vol.35 No.37

Background: The purpose of this study was to determine the extent of air and surface contamination of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in four health care facilities with hospitalized coronavirus disease 2019 (COVID-19) patients. Methods: We investigated air and environmental contamination in the rooms of eight COVID-19 patients in four hospitals. Some patients were in negative-pressure rooms, and others were not. None had undergone aerosol-generating procedures. On days 0, 3, 5, and 7 of hospitalization, the surfaces in the rooms and anterooms were swabbed, and air samples were collected 2 m from the patient and from the anterooms. Results: All 52 air samples were negative for SARS-CoV-2 RNA. Widespread surface contamination of SARS-CoV-2 RNA was observed. In total, 89 of 320 (27%) environmental surface samples were positive for SARS-CoV-2 RNA. Surface contamination of SARS- CoV-2 RNA was common in rooms without surface disinfection and in rooms sprayed with disinfectant twice a day. However, SARS-CoV-2 RNA was not detected in a room cleaned with disinfectant wipes on a regular basis. Conclusion: Our data suggest that remote (> 2 m) airborne transmission of SARS-CoV-2 from hospitalized COVID-19 patients is uncommon when aerosol-generating procedures have not been performed. Surface contamination was widespread, except in a room routinely cleaned with disinfectant wipes.

피부감작능 평가 대체시험법간 위양성 및 위음성 화학물질에 대한 인체 세포주 활성화방법의 전수에 따른 예측력 평가

조아랑 ( Ahrang Cho ),여경욱 ( Kyenguk Yeo ),정미숙 ( Misook Jung ),이재희 ( Jaehee Lee ),양수정 ( Sujeong Yang ),( Ravi Gautam ),이기용 ( Giyong Lee ),조지훈 ( Jihun Jo ),( Manju Acharya ),( Anju Maharjan ),김창열 ( Changyu 한국동물실험대체법학회 2020 동물실험대체법학회지 Vol.14 No.1

The in vitro alternative assay for evaluating skin sensitizing potentials (SSP) called human Cell Line Activation Test (h-CLAT) has been recently adopted as an international test guideline. The present study was proceeded to pursue the domestic establishment and expansion of h-CLAT. The standard operational procedure was prepared in detail by the lead laboratory (LL) and transferred to one participating laboratory (PL). The LL demonstrated technical proficiency for the 10 substances listed in OECD TG 442E. The PL also demonstrated a certain level of proficiency, in that 4-phenylenediamine and 4-aminobenzoic acid distributed with coded names were correctly classified as positive and negative on SSP, respectively, and other indices including 75% cell viability (CV75) and relative fluorescence intensity (RFI) % for CD54 and CD86 were fell within the reference range. Methyl methacrylate, nickel chloride, and resorcinol, which are inconsistent in predicting SSP through various alternative test methods, were unanimously predicted as negative, positive, and positive on SSP by the two laboratories for the first time through h-CLAT. Both chlorobenzene and sodium lauryl sulfate with the existing h-CLAT report as positive and negative, respectively, were predicted as negative by the PL, which could contribute toward overall categorization into non-skin sensitizer.

Downregulation of WC1+ gamma delta T cells in cattle exposed to higher level of airborne endotoxin

katharine roque,Jaehee Lee,Gyeongdong Lim,Eunsob Song,Ahrang Jo,Eungyong Kim,Sojung Sin,Changyeol Kim,Hyung Ah Kim,Yong Heo 한국실험동물학회 2016 한국실험동물학회 학술발표대회 논문집 Vol.2016 No.08

Molecular Mechanism of Atopic Dermatitis Induction Following Sensitization and Challenge with 2,4-Dinitrochlorobenzene in Mouse Skin Tissue

JiYoun Kim,JaeHee Lee,SoJung Shin,AhRang Cho,Yong Heo 한국독성학회 2018 Toxicological Research Vol.34 No.1

Laboratory animal models have been developed to investigate preventive or therapeutic effect of medicinal products, or occurrence or progression mechanism of atopic dermatitis (AD), a pruritic and persistent inflammatory skin disease. The murine model with immunologic phenomena resembling human AD was introduced, which demonstrated skewedness toward predominance of type-2 helper T cell reactivity and pathophysiological changes similar as human AD following 2,4-dinitrochlorobenzene (DNCB) sensitization and challenge. Molecular mechanism on the DNCB-mediated AD was further evaluated. Skin tissues were collected from mice treated with DNCB, and each tissue was equally divided into two sections; one for protein and the other for mRNA analysis. Expression of filaggrin, an important protein for keratinocyte integrity, was evaluated through SDS-PAGE. Level of mRNA expression for cytokines was determined through semi-quantitative reverse transcriptase polymerase chain reaction. Expression of filaggrin protein was significantly enhanced in the mice treated with DNCB compared with the vehicle (acetone : olive oil = 4 : 1 mixture) treatment group or the normal group without any treatment. Level of tumor necrosis factor-alpha and interleukin-18 mRNA expression, cytokines involved in activity of type-1 helper T (TH1) cell, was significantly downregulated in the AD group compared with other control groups. These results suggest that suppression of TH1 cell-mediated immune response could be reflected into the skin tissue of mice treated with DNCB for AD induction, and disturbance of keratinocyte integrity might evoke a compensatory mechanism.

Intra- and inter-laboratory reproducibility and predictivity of the HaCaSens assay: A skin sensitization test using human keratinocytes, HaCaT

Chung, Hyewon,Quan, Hailian,Jung, Daun,Ravi, Gautam,Cho, Ahrang,Kang, Mi Jeong,Kim, Eunju,Che, Jeong-Hwan,Lee, Eung-Seok,Jeong, Tae Cheon,Heo, Yong,Seok, Seung Hyeok Elsevier 2018 Toxicology in vitro Vol.46 No.-

<P><B>Abstract</B></P> <P>Due to considerable constraints in using animals for risk assessment, much effort has been directed at developing non-animal test methods. Developing assays for skin sensitization, the leading cause of contact dermatitis, is particularly important, but there are currently no <I>in vitro</I> skin sensitization tests that completely replace animal tests.</P> <P>HaCaSens, a simple skin sensitization test using non-transformed HaCaT cells, predicts keratinocyte activation by skin sensitizers with 75% sensitivity, 83% specificity and 77% accuracy in a previous study using 22 coded substances. Although the data show promising results, the number of tested substances is insufficient to prove predictive capacity. Moreover, reproducibility among different laboratories has not been studied.</P> <P>Here, three laboratories participated in a validation in order to assess HaCaSens feasibility for official validation. To examine transferability, intra- and inter-lab reproducibility and predictive capacity, HaCaSens was assessed on a set of 30 test substances coordinated by the Validation Management Team (VMT). The results showed satisfactory transferability as well as intra- and inter-laboratory reproducibility. Further assessment of its predictive capacity on 20 test substances demonstrated a sensitivity of 81.8% (18/22), specificity of 87.5% (7/8), and accuracy of 83.3% (25/30) in identifying skin sensitizers, which is comparable with presently validated assays, KeratinoSens™ and LuSens.</P> <P>This validation study shows that the HaCaSens assay is easily transferable, reproducible and highly predictable for identifying skin sensitizers.</P> <P><B>Highlights</B></P> <P> <UL> <LI> HaCaSens assay is performed in three laboratories with a set of 30 test substances. </LI> <LI> Intra- and inter-laboratory validation shows satisfactory accuracy over 83%. </LI> <LI> Compared with other similar assays, the HaCaSens acquired better accuracy. </LI> <LI> This study can be a reliable support for proposing HaCaSens as a promising assay. </LI> </UL> </P>

미 연준의 지준타겟팅 제도 운영경험과 정책적 시사점

나승호 ( Seungho Nah ),김용건 ( Yonggun Kim ),김도완 ( Dowan Kim ),이승철 ( Seungcheol Lee ),이아랑 ( Ahrang Lee ) 한국경제학회 2023 한국경제포럼 Vol.16 No.2

본고는 최근 우리 경제가 처한 상황이 Volcker 연준의장의 재임시절과 유사한 점을 고려하여 당시 연준이 사용했던 지준타겟팅 제도가 인플레이션 억제에 주효했던 이유와 한국의 통화정책 운용수단으로서 도입하는 것의 타당성을 검토하였다. Volcker의 정책체계 개혁(monetary policy reform)은 만성적·주기적 인플레이션의 원인이 통화공급의 경기순응성에 있다는 인식 하에 통화량 통제가능성 강화, 연방기금금리(Federal Funds Rate)의 신축성 확보 등을 통해 연준에 대한 민간의 신뢰도를 회복(기대경로 회복)하고 금융긴축의 실효성(금리경로 강화)을 확보한 것으로 평가 가능하다. 또한 통화량 목표 제시 등 정책의 개방성 및 투명성을 제고하고 고금리 정책이 초래할 의회, 언론, 시장의 비판을 우회한 점도 커뮤니케이션 전략상 효과적이었다고 평가할 수 있다. 그러나 통화와 실물간의 관계가 여전히 불안정하고 통화량에 대한 통제가능성이 낮다는 점, 금융시장의 불안정을 초래할 수 있다는 점 등에서 현재의 한국 경제에서도 지준(통화량)타겟팅 제도의 정책적 유효성이 담보될 지는 회의적이며 금리중심 통화정책의 유효성이 여전한 상황에서 기존 체제를 포기해야 할 근거도 미약한 것으로 보인다. Considering that the situation in which the Korean economy is currently facing is similar to that of Fed Chairman Volcker during his tenure, this paper examines the reasons why the reserve targeting system adopted by the Fed in 1979 was effective in suppressing inflation and the feasibility of introducing it as a tool for operating monetary policy in Korea. Volcker’s monetary policy reform, recognizing that the cause of chronic and recurrent inflation is the procyclicality of the money supply, reinforced the controllability of the money supply and secured the flexibility of the FFR, thereby restoring the public’s trust in the Fed and securing the effectiveness of monetary tightening. In addition, it can be evaluated as an effective communication strategy in that it improved the openness and transparency of the policy through the announcement of the short term money supply target, and circumvented criticism from the Congress, the media, and the market that the high interest rate policy would lead to. However, given the fact that the relationship between money and real activites is still unstable, the controllability of the money supply is low, and that the monetary targeting system can cause instability in the financial market, it is skeptical whether the effectiveness of the policy will be guaranteed in Korea. Besides, in a situation where interest rate-centered monetary policy is still effective, the grounds for abandoning the existing system also seem weak.