Publications by authors named "Baek Kim"

272 Publications

Nucleic acid binding by SAMHD1 contributes to the antiretroviral activity and is enhanced by the GpsN modification.

Nat Commun 2021 02 2;12(1):731. Epub 2021 Feb 2.

Department of Biochemistry and Structural Biology, UT Health San Antonio, San Antonio, TX, USA.

SAMHD1 impedes infection of myeloid cells and resting T lymphocytes by retroviruses, and the enzymatic activity of the protein-dephosphorylation of deoxynucleotide triphosphates (dNTPs)-implicates enzymatic dNTP depletion in innate antiviral immunity. Here we show that the allosteric binding sites of the enzyme are plastic and can accommodate oligonucleotides in place of the allosteric activators, GTP and dNTP. SAMHD1 displays a preference for oligonucleotides containing phosphorothioate bonds in the Rp configuration located 3' to G nucleotides (GpsN), the modification pattern that occurs in a mechanism of antiviral defense in prokaryotes. In the presence of GTP and dNTPs, binding of GpsN-containing oligonucleotides promotes formation of a distinct tetramer with mixed occupancy of the allosteric sites. Mutations that impair formation of the mixed-occupancy complex abolish the antiretroviral activity of SAMHD1, but not its ability to deplete dNTPs. The findings link nucleic acid binding to the antiretroviral activity of SAMHD1, shed light on the immunomodulatory effects of synthetic phosphorothioated oligonucleotides and raise questions about the role of nucleic acid phosphorothioation in human innate immunity.
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http://dx.doi.org/10.1038/s41467-021-21023-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7854603PMC
February 2021

Disproportionate presence of adenosine in mitochondrial and chloroplast DNA of .

iScience 2021 Jan 29;24(1):102005. Epub 2020 Dec 29.

School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.

Ribonucleoside monophosphates (rNMPs) represent the most common non-standard nucleotides found in the genome of cells. The distribution of rNMPs in DNA has been studied only in limited genomes. Using the ribose-seq protocol and the Ribose-Map bioinformatics toolkit, we reveal the distribution of rNMPs incorporated into the whole genome of a photosynthetic unicellular green alga, . We discovered a disproportionate incorporation of adenosine in the mitochondrial and chloroplast DNA, in contrast to the nuclear DNA, relative to the corresponding nucleotide content of these organelle genomes. Our results demonstrate that the rNMP content in the DNA of the algal organelles reflects an elevated ATP level present in the algal cells. We reveal specific biases and patterns in rNMP distributions in the algal mitochondrial, chloroplast, and nuclear DNA. Moreover, we identified the orthologous genes for all three subunits of the RNase H2 enzyme using GeneMark-EP + gene finder.
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http://dx.doi.org/10.1016/j.isci.2020.102005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7809514PMC
January 2021

Analysis of Secondary Surgeries after Immediate Breast Reconstruction for Cancer Compared with Risk Reduction.

Plast Reconstr Surg Glob Open 2020 Dec 17;8(12):e3312. Epub 2020 Dec 17.

Department of Oncoplastic Breast and Reconstructive Surgery, St. James's University Hospital, Leeds, United Kingdom.

This study sets out to compare reconstructive practice between patients undergoing immediate breast reconstruction (IBR) for cancer and those who opted for risk reduction (RR), with an emphasis on examining patterns of secondary surgery.

Methods: Data collection was performed for patients undergoing mastectomy and IBR at a teaching hospital breast unit (2013-2016).

Results: In total, 299 patients underwent IBR (76% cancer versus 24% RR). Implant-based IBR rate was similar in both groups (58% cancer versus 63% RR). Reconstruction loss (5.3% cancer versus 4.2% RR) and complication (16% cancer versus 12.9% RR) rates were similar. Cancer patients were more likely to undergo secondary surgery (68.4% versus 56.3%; = 0.025), including contralateral symmetrization (22.8% versus 0%) and conversion to autologous reconstruction (5.7% versus 1.4%). Secondary surgeries were mostly planned for cancer patients (72% planned versus 28% unplanned), with rates unaffected by adjuvant therapies. This distribution was different in RR patients (51.3% planned versus 48.7% unplanned). The commonest secondary procedure was lipomodeling (19.7% cancer versus 23.9% RR). For cancer patients, complications resulted in a significantly higher unplanned secondary surgery rate (82.5% versus 38.8%; = 0.001) than patients without complications. This was not evident in the RR patients, where complications did not lead to a significantly higher unplanned surgery rate (58.9% versus 35.2%; = 0.086).

Conclusions: Most of the secondary surgeries were planned for cancer patients. However, complications led to a significantly higher rate of unplanned secondary surgery. Approximately 1 in 4 RR patients received unplanned secondary surgery, which may be driven by the desire to achieve an optimal aesthetic outcome.
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http://dx.doi.org/10.1097/GOX.0000000000003312DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7787276PMC
December 2020

Identification of factors that influence the decision to take chemoprevention in patients with a significant family history of breast cancer: results from a patient questionnaire survey.

Breast Cancer Res Treat 2021 Jan 3. Epub 2021 Jan 3.

Department of Oncoplastic Breast and Reconstructive Surgery, St. James's University Hospital, Beckett Street, Leeds, LS9 7TF, UK.

Purpose: Chemoprevention reduces the risk of developing breast cancer in women with increased family history (FH) risk of breast cancer. However, chemoprevention uptake remains low and the reasons for this remain unclear.

Methods: Patients with moderate- or high-risk FH of breast cancer were counselled about chemoprevention (n = 1620; September 2015 to July 2018) in breast clinics. A postal questionnaire survey was subsequently sent to these patients in order to explore the potential factors influencing their decision on chemoprevention uptake.

Results: 518 patients (32%) completed the questionnaire survey; 75% were pre-menopausal and the majority had moderate as opposed to high-risk FH (87.5% vs. 12.5%). Breast cancer chemoprevention uptake rate was 10.8% (56/518). The identified incentives were more commonly stated for patients who took chemoprevention when compared to those who refused chemoprevention. The commonest incentives were breast cancer prevention (89.3% vs. 61.7%; p = 0.001), belief in the effectiveness of chemoprevention (76.8% vs. 63.4%; p = 0.048), and personal perception of breast cancer risk (67.9% vs. 45.5%; p = 0.002). Similarly, the identified barriers were more commonly stated for patients who refused chemoprevention when compared to those who took chemoprevention. The commonest barriers were side effects (79.4% vs. 55.4%; p = 0.001) and lack of information (53% vs. 28.6%; p = 0.001).

Conclusion: Despite its proven efficacy, chemoprevention uptake in patients with a significant FH of breast cancer remains low. We have identified important factors which influence the patient's decision making. Future clinic consultations should focus on exploring these factors to aid patient decision making.
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http://dx.doi.org/10.1007/s10549-020-06046-xDOI Listing
January 2021

The pathology of gastric and duodenal polyps: current concepts.

Histopathology 2021 Jan;78(1):106-124

Department of Pathology, H. Lee Moffitt Cancer Center and Research Institute and Departments of Pathology and Oncologic Sciences, University of South Florida, Tampa, FL, USA.

The liberal use of upper endoscopy has led to an increased detection of gastric and duodenal polyps, which are identified in as many as 6 and 4.6% of patient examinations, respectively. Gastroduodenal polyps are a heterogeneous group of lesions that can be neoplastic or non-neoplastic (e.g. hyperplastic or heterotopical). Most polyps present characteristic topographical features, as well as endoscopic appearance and size. Evaluation of the surrounding mucosa is essential in assessing the underlying pathology (e.g. Helicobacter pylori, autoimmune gastritis or inherited polyposis syndromes). Phylogenetically, gastric and duodenal polyps can be classified according to the epithelial compartment from which they derive. Polyps that arise from the surface epithelium can either be of foveolar or intestinal type, and they can develop from either the native mucosa or the metaplastic epithelium (gastric intestinal metaplasia or duodenal foveolar metaplasia). Other polyps develop from the deeper glandular component, such as pyloric/oxyntic gland derived subtypes. In this review we focus upon epithelial polyps, with an emphasis on the most common and clinically relevant lesions, and present recently described entities.
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http://dx.doi.org/10.1111/his.14275DOI Listing
January 2021

Full color-tunable vertically stacked quantum dot light emitting diodes for next-generation displays and lighting.

Nanoscale 2020 Dec;12(48):24403-24410

NanoPhotonica Inc., 747 SW 2nd Ave., Suite # 395, Gainesville, FL 32601, USA..

We report solution-processed color tunable vertically stacked electroluminescent red, green, and blue quantum dot light emitting diodes (QLEDs). These QLEDs can be independently driven to produce all primary, secondary, and white lights. We have fabricated the device by chemical and electrical isolation of each QLED with transparent polymers and by the use of transparent electrodes. These stacked QLEDs can be used for next-generation display and lighting applications that need high pixel density along with quantum dots' intrinsic benefits such as low turn-on voltage, color purity, and solution processability.
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http://dx.doi.org/10.1039/d0nr06721kDOI Listing
December 2020

Additive values of pelvic tomosynthesis in comparison to pelvic radiography alone for the diagnosis of sacroiliitis in patients with suspected axial spondyloarthritis.

Skeletal Radiol 2020 Nov 14. Epub 2020 Nov 14.

Medical Science Research Center, Korea Unversity Ansan Hospital, 123, Jeokgeum-ro, Danwon-gu, Ansan-si, Gyeonggi-do, 15355, Republic of Korea.

Objectives: To compare inter-reader agreement and diagnostic confidence in detecting sacroiliitis by the modified New York criteria (mNY) on digital radiography (DR) versus digital pelvic tomosynthesis assisted DR (DR+DPT), and to evaluate changes in the presence of axial spondyloarthritis (axSpA) according to the Assessment of Spondyloarthritis International Society (ASAS) criteria.

Methods: One hundred and thirty-eight patients who underwent both DR and DPT with suspicious axSpA in our rheumatologic clinic were included from February 2017 to February 2018. Three radiologists independently graded sacroiliitis and confidence level on DR first and then re-graded them on DPT in a paired manner. Agreement, confidence, and diagnostic accuracy were evaluated for readers. Changes in the presence of disease by mNY and ASAS criteria were assessed between DR alone and DR+DPT.

Results: On DR alone, 73 patients were assessed with radiographic sacroiliitis, and 85 were classified into axSpA by the ASAS criteria; however, 78 and 85, respectively, were classified on DR+DPT. With the assistance of DPT, 17 and 12 patients changed to the disease positivity according to the mNY and ASAS criteria, respectively; the negative results changed to positive in 11 and six patients, respectively. For all readers, agreement improved with DPT (0.79 to 0.89). DR+DPT achieved higher diagnostic accuracy (AUC, P < 0.05).

Conclusion: The combination of DR and DPT achieved a higher diagnostic performance than that of DR alone, with better agreement. On DR+DPT, the diagnoses of 9.0% of patients with suspicious axSpA (12 of 134) were changed to the status of disease by the ASAS criteria.
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http://dx.doi.org/10.1007/s00256-020-03626-2DOI Listing
November 2020

The significance of histological activity measurements in immune checkpoint inhibitor colitis.

Aliment Pharmacol Ther 2021 01 4;53(1):150-159. Epub 2020 Nov 4.

Department of Pathology, Henry L. Moffitt Cancer Center & Research Institute, Tampa, FL, USA.

Background: Colitis is a significant complication of immune checkpoint inhibitors (ICI). Currently, clinical and endoscopic severity are used to guide therapy.

Aims: To investigate associations between clinical, endoscopic, and histological features with outcomes METHODS: We identified 149 patients from seven institutions with biopsy-proven ICI colitis. Biopsies were evaluated for histological features including the Geboes score, and the Robarts histopathological index (RHI) was calculated. Clinical, endoscopic, and histological data were tested for associations with biological use and adverse colitis outcomes (biological-refractory colitis, colectomy or death from colitis).

Results: Three mutually exclusive histological patterns were identified: acute colitis, chronic active colitis and microscopic colitis. Microscopic colitis was associated with older age (68.5 vs 61 years for acute colitis pattern, P = 0.02) and longer time to colitis (5.5 vs 3 months for the other patterns, P = 0.05). Biological use was associated with earlier time to colitis (2 vs 3 months, P = 0.04) and higher RHI (18 vs 12, P = 0.007). On multivariate analysis, RHI ≥14 was associated with biological use with an odds ratio of 4.5 (95% CI 1.4-13.8; P = 0.01). Adverse colitis outcomes were associated with shorter time to colitis (2 vs 3 months, P = 0.008) and higher RHI (24 vs 14, P = 0.001). On multivariate analysis, RHI ≥24 was associated with adverse colitis outcomes with an odds ratio 9.5 (95% CI 2.1-42.3 P = 0.003).

Conclusion: Histological activity as measured by RHI is the only factor independently associated with biological use and adverse colitis outcomes. Prospective studies are needed to validate these findings to determine if histological activity should be incorporated into therapeutic algorithms.
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http://dx.doi.org/10.1111/apt.16142DOI Listing
January 2021

A Mutated PB1 Residue 319 Synergizes with the PB2 N265S Mutation of the Live Attenuated Influenza Vaccine to Convey Temperature Sensitivity.

Viruses 2020 10 31;12(11). Epub 2020 Oct 31.

Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, New York, NY 14642, USA.

Current influenza vaccines have modest efficacy. This is especially true for current live attenuated influenza vaccines (LAIV), which have been inferior to the inactivated versions in recent years. Therefore, a new generation of live vaccines may be needed. We previously showed that a mutation at PB1 residue 319 confers enhanced temperature sensitivity and attenuation in an LAIV constructed in the genetic background of the mouse-adapted Influenza A Virus (IAV) strain A/PR/8/34 (PR8). Here, we describe the origin/discovery of this unique mutation and demonstrate that, when combined with the PB2 N265S mutation of LAIV, it conveys an even greater level of temperature sensitivity and attenuation on PR8 than the complete set of attenuating mutations from LAIV. Furthermore, we show that the combined PB1 L319Q and PB2 N265S mutations confer temperature sensitivity on IAV polymerase activity in two different genetic backgrounds, PR8 and A/Cal/04/09. Collectively, these findings show that the PB2 LAIV mutation synergizes with a mutation in PB1 and may have potential utility for improving LAIVs.
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http://dx.doi.org/10.3390/v12111246DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7693792PMC
October 2020

COVID-19 in children across three Asian cosmopolitan regions.

Emerg Microbes Infect 2020 Dec;9(1):2588-2596

Department of Respiratory Medicine, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Hospital), Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.

As another wave of COVID-19 outbreak has approached in July 2020, a larger scale COVID-19 pediatric Asian cohort summarizing the clinical observations is warranted. Children confirmed with COVID-19 infection from the Republic of Korea, the Hong Kong Special Administrative Region (HKSAR) and Wuhan, China, during their first waves of local outbreaks were included. Their clinical characteristics and the temporal sequences of the first waves of local paediatric outbreaks were compared. Four hundred and twenty three children with COVID-19 were analyzed. Wuhan had the earliest peak, followed by Korea and HKSAR. Compared with Korea and Wuhan, patients in HKSAR were significantly older (mean age: 12.9 vs. 10.8 vs. 6.6 years,  < 0.001, respectively) and had more imported cases (87.5% vs. 16.5% vs. 0%,  < 0.001, respectively). The imported cases were also older (13.4 vs. 7.6 years,  < 0.001). More cases in HKSAR were asymptomatic compared to Korea and Wuhan (45.5% vs. 22.0% vs. 20.9%,  < 0.001, respectively), and significantly more patients from Wuhan developed fever (40.6% vs. 29.7% vs. 21.6%, =0.003, respectively). There were significantly less imported cases than domestic cases developing fever after adjusting for age and region of origin ( = 0.046). 5.4% to 10.8% of patients reported anosmia and ageusia. None developed pediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PMIS-TS). In general, adolescents were more likely to be asymptomatic and less likely to develop fever, but required longer hospital stays. In conclusion, majority patients in this pediatric Asian cohort had a mild disease. None developed PIMS-TS. Their clinical characteristics were influenced by travel history and age.
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http://dx.doi.org/10.1080/22221751.2020.1846462DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7723019PMC
December 2020

Non-conventional dysplasias of the tubular gut: a review and illustration of their histomorphological spectrum.

Histopathology 2020 Oct 30. Epub 2020 Oct 30.

Department of Pathology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.

The increasing use of gastrointestinal endoscopic procedures has led to the recognition by histopathologists of non-conventional (or special-type) dysplasias of the gastrointestinal tract. These lesions can be recognised in association with prevalent underlying gastrointestinal conditions, such as Barrett oesophagus, chronic atrophic gastritis, and inflammatory bowel disease. The diagnosis of these special types can be challenging, and their biological behaviours are not fully characterised. The aim of this review is to provide a global view of non-conventional dysplastic lesions observed in the various segments of the tubular gastrointestinal tract and describe their salient features. Furthermore, as the clinical implications of these various subtypes have not been broadly tested in practice and are not represented in most management guidelines, we offer guidance on the best management practices for these lesions.
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http://dx.doi.org/10.1111/his.14294DOI Listing
October 2020

Repurposing Nucleoside Analogs for Human Coronaviruses.

Antimicrob Agents Chemother 2020 12 16;65(1). Epub 2020 Dec 16.

Center for AIDS Research, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA

Coronavirus disease 2019 (COVID-19) is a serious illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or CoV-2). Some reports claimed certain nucleoside analogs to be active against CoV-2 and thus needed confirmation. Here, we evaluated a panel of compounds and identified novel nucleoside analogs with antiviral activity against CoV-2 and HCoV-OC43 while ruling out others. Of significance, sofosbuvir demonstrated no antiviral effect against CoV-2, and its triphosphate did not inhibit CoV-2 RNA polymerase.
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http://dx.doi.org/10.1128/AAC.01652-20DOI Listing
December 2020

Enhanced enzyme kinetics of reverse transcriptase variants cloned from animals infected with SIVmac239 lacking viral protein X.

J Biol Chem 2020 Dec 2;295(50):16975-16986. Epub 2020 Oct 2.

Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia, USA

HIV Type 1 (HIV-1) and simian immunodeficiency virus (SIV) display differential replication kinetics in macrophages. This is because high expression levels of the active host deoxynucleotide triphosphohydrolase sterile α motif domain and histidine-aspartate domain-containing protein 1 (SAMHD1) deplete intracellular dNTPs, which restrict HIV-1 reverse transcription, and result in a restrictive infection in this myeloid cell type. Some SIVs overcome SAMHD1 restriction using viral protein X (Vpx), a viral accessory protein that induces proteasomal degradation of SAMHD1, increasing cellular dNTP concentrations and enabling efficient proviral DNA synthesis. We previously reported that SAMHD1-noncounteracting lentiviruses may have evolved to harbor RT proteins that efficiently polymerize DNA, even at low dNTP concentrations, to circumvent SAMHD1 restriction. Here we investigated whether RTs from SIVmac239 virus lacking a Vpx protein evolve during infection to more efficiently synthesize DNA at the low dNTP concentrations found in macrophages. Sequence analysis of RTs cloned from Vpx (+) and Vpx (-) SIVmac239-infected animals revealed that Vpx (-) RTs contained more extensive mutations than Vpx (+) RTs. Although the amino acid substitutions were dispersed indiscriminately across the protein, steady-state and pre-steady-state analysis demonstrated that selected SIVmac239 Vpx (-) RTs are characterized by higher catalytic efficiency and incorporation efficiency values than RTs cloned from SIVmac239 Vpx (+) infections. Overall, this study supports the possibility that the loss of Vpx may generate SIVmac239 RT variants that can counteract the limited availability of dNTP substrate in macrophages.
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http://dx.doi.org/10.1074/jbc.RA120.015273DOI Listing
December 2020

Audit of routine preoperative blood test requests for patients undergoing elective breast surgery: Less is more.

J Perioper Pract 2020 Sep 28:1750458920952755. Epub 2020 Sep 28.

Department of Oncoplastic Breast and Reconstructive Surgery, St James's University Hospital, Leeds, UK.

In 2016, the National Institute for Health and Care Excellence updated guidelines on preoperative blood tests for elective surgery; with failure of adherence having implications for both patients and healthcare providers. A local audit was performed on 919 patients undergoing elective breast surgery that determined compliance and the financial implications of performing inappropriate preoperative blood tests against the National Institute for Health and Care Excellence guideline. Initial findings of an unacceptable quantity of inappropriate blood tests led to the education of the pre-assessment clinic staff regarding the guidelines along with the development of a poster to guide the ordering of appropriate tests. A re-audit of 451 patients assessed impact of interventions which resulted in a significant reduction in the number of blood tests requested with a 71% reduction in financial expenditure. The blood tests considered inappropriate in both the initial and re-audit did not add any relevant clinical information and abnormal results did not alter the clinical course of the patient.
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http://dx.doi.org/10.1177/1750458920952755DOI Listing
September 2020

Treatment of multiple craniofacial osteomas by endoscopic approach.

Arch Craniofac Surg 2020 Aug 20;21(4):261-263. Epub 2020 Aug 20.

Department of Plastic and Reconstructive Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.

Osteomas are benign osteogenic neoplasms that usually occur as solitary craniofacial lesions. Multiple osteomas are rare, particularly those that do not occur as part of an associated syndrome. We report a case of a 72-year-old woman who presented with multiple bony protrusions over the forehead and scalp. She denied any diagnosis of syndromes that are known to be associated with osteomas. Surgical excision was performed by endoscopically resecting more than 30 osteomas of the frontal and bilateral parietal bones. Compared with conventional surgical excision through a direct incision, endoscopic-assisted surgery is a simple and effective method for the treatment of multiple craniofacial osteomas and is associated with excellent cosmetic outcomes and no neurovascular complications.
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http://dx.doi.org/10.7181/acfs.2020.00402DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7463131PMC
August 2020

Clinical Characteristics and Viral RNA Detection in Children With Coronavirus Disease 2019 in the Republic of Korea.

JAMA Pediatr 2021 01;175(1):73-80

Department of Pediatrics, St Vincent's Hospital, The Catholic University of Korea, Suwon, Korea.

Importance: There is limited information describing the full spectrum of coronavirus disease 2019 (COVID-19) and the duration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA detection in children.

Objective: To analyze the full clinical course and the duration of SARS-CoV-2 RNA detectability in children confirmed with COVID-19 in the Republic of Korea, where rigorous public health interventions have been implemented.

Design, Setting, And Participants: This case series of children with COVID-19 was conducted in 20 hospitals and 2 nonhospital isolation facilities across the country from February 18, 2020, to March 31, 2020. Children younger than 19 years who had COVID-19 were included.

Exposures: Confirmed COVID-19, detected via SARS-CoV-2 RNA in a combined nasopharyngeal and oropharyngeal swab or sputum by real-time reverse transcription-polymerase chain reaction.

Main Outcomes And Measures: Clinical manifestations during the observation period, including the time and duration of symptom occurrence. The duration of SARS-CoV-2 RNA detection was also analyzed.

Results: A total of 91 children with COVID-19 were included (median [range] age, 11 [0-18] years; 53 boys [58%]). Twenty children (22%) were asymptomatic during the entire observation period. Among 71 symptomatic cases, 47 children (66%) had unrecognized symptoms before diagnosis, 18 (25%) developed symptoms after diagnosis, and only 6 (9%) were diagnosed at the time of symptom onset. Twenty-two children (24%) had lower respiratory tract infections. The mean (SD) duration of the presence of SARS-CoV-2 RNA in upper respiratory samples was 17.6 (6.7) days. Virus RNA was detected for a mean (SD) of 14.1 (7.7) days in asymptomatic individuals. There was no difference in the duration of virus RNA detection between children with upper respiratory tract infections and lower respiratory tract infections (mean [SD], 18.7 [5.8] days vs 19.9 [5.6] days; P = .54). Fourteen children (15%) were treated with lopinavir-ritonavir and/or hydroxychloroquine. All recovered, without any fatal cases.

Conclusions And Relevance: In this case series study, inapparent infections in children may have been associated with silent COVID-19 transmission in the community. Heightened surveillance using laboratory screening will allow detection in children with unrecognized SARS-CoV-2 infection.
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http://dx.doi.org/10.1001/jamapediatrics.2020.3988DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7455883PMC
January 2021

The B-MaP-C study: Breast cancer management pathways during the COVID-19 pandemic. Study protocol.

Int J Surg Protoc 2020 29;24:1-5. Epub 2020 Jul 29.

The Nightingale Breast Cancer Centre, Wythenshawe Hospital, Manchester M23 9LT, UK.

Introduction: Approximately 55,000 women in the United Kingdom are diagnosed with new breast cancer annually. Since emerging in December 2019, SARS-CoV-2 (coronavirus disease 2019, COVID-19) has become a global pandemic, affecting healthcare delivery worldwide. In response to the pandemic, multiple guidelines were issued to assist with rationalising breast cancer care. The primary aim of the B-MaP-C study is to audit and describe breast cancer management of patients newly diagnosed with breast cancer during the COVID-19 pandemic against pre-COVID-19 management practice in the UK. The implications of changes to management will be determined and the impact of a COVID-19 diagnosis on the patient's breast cancer management will be determined.

Methods And Analysis: This is a multi-centre collaborative audit of consecutive breast cancer patients undergoing treatment decisions during the acute and recovery phases of the COVID-19 pandemic. All patients with newly diagnosed primary breast cancer, whose treatment was decided in a multidisciplinary meeting from the 16th March 2020, are eligible for inclusion.

Ethics And Dissemination: As this is an audit ethical approval is not required. Each participating centre is required to register the study locally and obtain local governance approvals prior to commencement of data collection. Local audit data will be available to individual participating units for governance purposes. The results of the data analysis will be submitted for publication, as well as disseminated via the ABS newsletter and a webinar. All data will be presented at national and international conferences, circumstances permitting.

Registration Details: Each participating centre received local governance audit registration.
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http://dx.doi.org/10.1016/j.isjp.2020.07.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7388760PMC
July 2020

Breast Cancer Surgery During the COVID-19 Pandemic Peak in the UK: Operative Outcomes.

Cureus 2020 Jul 19;12(7):e9280. Epub 2020 Jul 19.

Breast Surgery, Leeds Teaching Hospitals NHS Trust, Leeds, GBR.

Introduction  The COVID-19 pandemic caused widespread changes in delivery of breast cancer care, aiming to protect vulnerable patients whilst minimising compromise to oncological outcomes. This multicentre observational study aimed to establish early surgical outcomes from breast cancer surgery performed during the peak of the COVID-19 pandemic.  Materials and methods  Data were collected on consecutive patients that underwent breast surgery in four units between 16 March and 24 April 2020. Outcome data at 30 days post-operation were collected, including documented COVID-19 cases in patients and reported cases in healthcare workers directly involved in their care. Recommended modifications to practice to reduce COVID-19 transmission risk, both to patients and healthcare workers in each centre, are described.  Results  A total of 202 patients underwent surgery in four hospitals delivering breast services in the West Yorkshire region over the six-week period at the peak of the pandemic. The age ranged from 28 to 91 years (median 57, interquartile range, 48-65) with 22% having co-morbidities linked to COVID-19, e.g. diabetes or respiratory disease. No patients presented post-operatively with COVID-19 symptoms and at 30 days there had not been any identified COVID-19 cases. There were no unexpected critical care admissions or deaths. One healthcare worker involved in the delivery of breast surgery was diagnosed with COVID-19 during this time and made an uneventful recovery.  Conclusion  Breast cancer surgery, in selected groups and with meticulous adherence to measures designed to reduce COVID-19 transmission, does not appear to be associated with elevated risk to patients or healthcare workers.
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http://dx.doi.org/10.7759/cureus.9280DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7431302PMC
July 2020

Clinical Characteristics of COVID-19: Clinical Dynamics of Mild Severe Acute Respiratory Syndrome Coronavirus 2 Infection Detected by Early Active Surveillance.

J Korean Med Sci 2020 Aug 17;35(32):e297. Epub 2020 Aug 17.

Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.

Background: There is limited information describing the presenting characteristics and dynamic clinical changes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection diagnosed in the early phase of illness. This study is a case series of patients with coronavirus disease 2019 (COVID-19) admitted to 11 hospitals in Korea.

Methods: Patients with confirmed SARS-CoV-2 infection by positive polymerase chain reaction (PCR) testing of respiratory specimens by active surveillance that were finally discharged between February 20 and April 30, 2020 were included. Patients were classified into mild and non-mild groups on initial admission according to oxygen demand and Sequential Organ Failure Assessment score, and the mild group was followed up and subgrouped into non-aggravation and aggravation groups.

Results: A total of 161 patients with SARS-CoV2 infection were enrolled. Among the mild group of 136 patients, 11.7% of patients experienced clinical aggravation during hospitalization, but there was no initial clinical parameter on admission predicting their aggravation. Fever (odds ratio [OR], 4.56), thrombocytopenia (OR, 12.87), fever (OR, 27.22) and lactate dehydrogenase (LDH) > 300 U/L (OR, 18.35), and CRP > 1 mg/dL (OR, 11.31) significantly indicated aggravation in the 1st, 2nd, 3rd, and 4th 5-day periods, respectively. PCR positivity lasted for a median of 22 days and 32 days after the onset of illness in the non-aggravation and aggravation groups, respectively.

Conclusion: Old age was associated with early severe presentation. Clinical aggravation among asymptomatic or mild patients could not be predicted initially but was heralded by fever and several laboratory markers during the clinical course.
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http://dx.doi.org/10.3346/jkms.2020.35.e297DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7431284PMC
August 2020

Mechanistic cross-talk between DNA/RNA polymerase enzyme kinetics and nucleotide substrate availability in cells: Implications for polymerase inhibitor discovery.

J Biol Chem 2020 09 31;295(39):13432-13443. Epub 2020 Jul 31.

Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia, USA

Enzyme kinetic analysis reveals a dynamic relationship between enzymes and their substrates. Overall enzyme activity can be controlled by both protein expression and various cellular regulatory systems. Interestingly, the availability and concentrations of intracellular substrates can constantly change, depending on conditions and cell types. Here, we review previously reported enzyme kinetic parameters of cellular and viral DNA and RNA polymerases with respect to cellular levels of their nucleotide substrates. This broad perspective exposes a remarkable co-evolution scenario of DNA polymerase enzyme kinetics with dNTP levels that can vastly change, depending on cell proliferation profiles. Similarly, RNA polymerases display much higher values than DNA polymerases, possibly due to millimolar range rNTP concentrations found in cells (compared with micromolar range dNTP levels). Polymerases are commonly targeted by nucleotide analog inhibitors for the treatments of various human diseases, such as cancers and viral pathogens. Because these inhibitors compete against natural cellular nucleotides, the efficacy of each inhibitor can be affected by varying cellular nucleotide levels in their target cells. Overall, both kinetic discrepancy between DNA and RNA polymerases and cellular concentration discrepancy between dNTPs and rNTPs present pharmacological and mechanistic considerations for therapeutic discovery.
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http://dx.doi.org/10.1074/jbc.REV120.013746DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7521635PMC
September 2020

The correlation between follow-up MRI findings and laboratory results in pyogenic spondylodiscitis.

BMC Musculoskelet Disord 2020 Jul 2;21(1):428. Epub 2020 Jul 2.

Department of Radiology, Korea University Ansan Hospital, Gyeonggi-do, Korea.

Background: Although MRI is the gold-standard imaging method in the diagnosis of spondylodiscitis, role of follow-up imaging is debated and there can be discrepancies with regard to the significance of bony or soft tissue responses to treatment. Purpose of our study is to test whether the MRI changes on follow-up imaging correlate with laboratory findings of treatment response.

Methods: A total of 48 patients with pyogenic spondylodiscitis who underwent baseline and follow-up MRI were retrospectively reviewed. The extent of bone marrow edema, paravertebral soft tissue inflammation, and disc height were compared on baseline and follow-up MRIs with the C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels obtained from the medical records at baseline and on follow-up. Relationships between the MRI and laboratory changes were analyzed using the Spearmann correlation test.

Results: The mean MRI follow-up period was 42.25 days. Based on the CRP (resolved: n = 19, resolving: n = 19, and aggravated: n = 10), there was significant correlation between the laboratory results and the changes in the bone and soft tissues (p < 0.01, both). The correlation was best with soft tissue changes (rho: 0.48) followed by bony changes (rho: 0.41). Based on the ESR (resolved: n = 8, resolving: n = 22, and worsened: n = 18), the correlation was stronger with bone changes (rho: 0.45, p < 0.01) than it was with soft tissue changes (rho: 0.39, p = 0.01).

Conclusion: Follow-up MRI findings of pyogenic spondylodiscitis show variable tissue responses. CRP was best correlated with soft tissue changes, while ESR showed the best association with bony changes.
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http://dx.doi.org/10.1186/s12891-020-03446-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7333318PMC
July 2020

The lncRNA lincNMR regulates nucleotide metabolism via a YBX1 - RRM2 axis in cancer.

Nat Commun 2020 06 25;11(1):3214. Epub 2020 Jun 25.

Division of RNA Biology & Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany.

Long intergenic non-coding RNA-Nucleotide Metabolism Regulator (lincNMR) is a long non-coding RNA (lncRNA) which is induced in hepatocellular carcinoma. Its depletion invokes a proliferation defect, triggers senescence and inhibits colony formation in liver, but also breast and lung cancer cells. Triple-label SILAC proteomics profiles reveal a deregulation of key cell cycle regulators in lincNMR-depleted cells like the key dNTP synthesizing enzymes RRM2, TYMS and TK1, implicating lincNMR in regulating nucleotide metabolism. LincNMR silencing decreases dNTP levels, while exogenous dNTPs rescues the proliferation defect induced by lincNMR depletion. In vivo RNA Antisense Purification (RAP-MS) identifies YBX1 as a direct interaction partner of lincNMR which regulates RRM2, TYMS and TK1 expression and binds to their promoter regions. In a Chick Chorioallantoic Membrane (CAM) in vivo model, lincNMR-depleted tumors are significantly smaller. In summary, we discover a lincRNA, lincNMR, which regulates tumor cell proliferation through a YBX1-RRM2-TYMS-TK1 axis governing nucleotide metabolism.
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http://dx.doi.org/10.1038/s41467-020-17007-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7316977PMC
June 2020

Tetraspanin CD81 regulates HSV-1 infection.

Med Microbiol Immunol 2020 Aug 4;209(4):489-498. Epub 2020 Jun 4.

Centro de Biología Molecular, "Severo Ochoa" (C.S.I.C.-U.A.M.), Universidad Autónoma de Madrid, C/Nicolás Cabrera 1, 28049, Madrid, Spain.

Different members of the tetraspanin superfamily have been described to regulate different virus infectious cycles at several stages: viral entry, viral replication or virion exit or infectivity. In addition, tetraspanin CD81 regulates HIV reverse transcription through its association with the dNTP hydrolase SAMHD1. Here we aimed at analysing the role of CD81 in Herpes simplex virus 1 infectivity using a neuroblastoma cell model. For this purpose, we generated a CD81 KO cell line using the CRISPR/Cas9 technology. Despite being CD81 a plasma membrane protein, CD81 KO cells showed no defects in viral entry nor in the expression of early protein markers. In contrast, glycoprotein B and C, which require viral DNA replication for their expression, were significantly reduced in CD81 KO infected cells. Indeed, HSV-1 DNA replication and the formation of new infectious particles were severely compromised in CD81 KO cells. We could not detect significant changes in SAMHD1 total expression levels, but a relocalization into endosomal structures was observed in CD81 KO cells. In summary, CD81 KO cells showed impaired viral DNA replication and produced greatly diminished viral titers.
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http://dx.doi.org/10.1007/s00430-020-00684-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7271138PMC
August 2020

Ribonucleotide incorporation in yeast genomic DNA shows preference for cytosine and guanosine preceded by deoxyadenosine.

Nat Commun 2020 05 15;11(1):2447. Epub 2020 May 15.

School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.

Despite the abundance of ribonucleoside monophosphates (rNMPs) in DNA, sites of rNMP incorporation remain poorly characterized. Here, by using ribose-seq and Ribose-Map techniques, we built and analyzed high-throughput sequencing libraries of rNMPs derived from mitochondrial and nuclear DNA of budding and fission yeast. We reveal both common and unique features of rNMP sites among yeast species and strains, and between wild type and different ribonuclease H-mutant genotypes. We demonstrate that the rNMPs are not randomly incorporated in DNA. We highlight signatures and patterns of rNMPs, including sites within trinucleotide-repeat tracts. Our results uncover that the deoxyribonucleotide immediately upstream of the rNMPs has a strong influence on rNMP distribution, suggesting a mechanism of rNMP accommodation by DNA polymerases as a driving force of rNMP incorporation. Consistently, we find deoxyadenosine upstream from the most abundant genomic rCMPs and rGMPs. This study establishes a framework to better understand mechanisms of rNMP incorporation in DNA.
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http://dx.doi.org/10.1038/s41467-020-16152-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7229183PMC
May 2020

Imaging appearance of post-arthroscopic radiocarpal chondrolysis: comparison with osteoarthritis associated with scapholunate dissociation.

Acta Radiol 2021 Mar 7;62(3):377-387. Epub 2020 May 7.

Department of Radiology, Korea University Anam Hospital, Seoul, Republic of Korea.

Background: Since the diagnosis of post-arthroscopic chondrolysis is very difficult, it can be underdiagnosed and confused with other diseases in clinical practice.

Purpose: To propose imaging features of post-arthroscopic radiocarpal chondrolysis (PRCC) and to compare these with osteoarthritis associated with scapholunate dissociation which are the most common misdiagnoses of PRCC.

Material And Methods: To identify missed diagnoses of PRCC, 994 magnetic resonance imaging scans performed in 910 patients were retrospectively reviewed. After the identification of 73 patients who exhibited significant radiocarpal cartilage loss, 11 were diagnosed with PRCC. Since scapholunate advanced collapse was the most common incorrect diagnosis of PRCC (4/11), the imaging findings were compared among the 11 patients with PRCC and 14 patients with osteoarthritis caused by scapholunate dissociation who were diagnosed in the same period. The following imaging features were evaluated: scapholunate dissociation; the center of disease and grade of radiocarpal joint destruction; characteristics of bone marrow edema; the presence of radial styloid and distal scaphoid osteophytes; and the extent of joint effusion and synovitis.

Results: The imaging diagnosis of PRCC was significantly differentiated from osteoarthritis associated with scapholunate dissociation based on occurrence at a younger age, bone marrow edema crossing the joint, center of disease in the proximal radioscaphoid joint, and absence of radial styloid and scaphoid osteophytes ( < 0.05). PRCC occasionally presented with arch-shape bone marrow edema based on the proximal carpal row.

Conclusion: The diagnosis of PRCC can be aided if its characteristic imaging findings are differentiated from other disease entities in patients with a history of arthroscopy.
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http://dx.doi.org/10.1177/0284185120922819DOI Listing
March 2021

A Phase 2 Multi-institutional Study of Nivolumab for Patients With Advanced Refractory Biliary Tract Cancer.

JAMA Oncol 2020 06;6(6):888-894

Department of Gastrointestinal Oncology, H. Lee Moffitt Cancer Center, Tampa, Florida.

Importance: Currently, there is no established second-line systemic treatment for biliary tract cancer (BTC). Preclinical data have demonstrated that the presence of tumor-infiltrating CD8 T cells and programmed cell death 1 ligand 1-expressing tumor cells in the tumor microenvironment of BTC supports the rationale of using programmed cell death 1 protein blockade immunotherapy in BTC.

Objective: To evaluate anticancer activity of nivolumab in patients with advanced refractory BTC.

Design, Setting, And Participants: In this single-group, multicenter phase 2 study of nivolumab, 54 patients with histologically confirmed BTC whose disease progressed while undergoing treatment with at least 1 line but no more than 3 lines of systemic therapy were enrolled between October 5, 2016, and December 26, 2018. Analysis was performed on an intention-to-treat basis.

Interventions: Nivolumab, 240 mg, was delivered intravenously every 2 weeks for 16 weeks, and then 480 mg was delivered intravenously every 4 weeks until disease progression or unacceptable toxic effects occurred.

Main Outcomes And Measures: The primary end point was investigator-assessed objective response rate, and the secondary end points were progression-free survival, overall survival, and incidence of adverse events.

Results: A total of 54 patients (27 men and 27 women; median age, 65 years [range, 28-86 years]) enrolled, and 46 (22 men and 24 women; median age, 65 years [range, 28-86 years]) were examined for objective response with radiologic imaging. The investigator-assessed objective response rate was 22% (10 of 46), including 1 unconfirmed partial response, with a disease control rate of 59% (27 of 46). Central independent review found an objective response rate of 11% (5 of 46), including 1 unconfirmed partial response, with a disease control rate of 50% (23 of 46). All patients who responded to treated (hereafter referred to as responders) had mismatch repair protein-proficient tumors. The median duration of investigator-assessed response was not reached, with a median follow-up of 12.4 months. Among the intention-to-treat population, median progression-free survival was 3.68 months (95% CI, 2.30-5.69 months) and median overall survival was 14.24 months (95% CI, 5.98 months to not reached). Programmed cell death 1 ligand 1 expression in tumors was associated with prolonged progression-free survival (hazard ratio, 0.23; 95% CI, 0.10-0.51; P < .001). The most common treatment-related grade 3 or 4 toxic effects were hyponatremia (3 of 54 [6%]) and increased alkaline phosphatase (2 of 54 [4%]).

Conclusions And Relevance: This study found that nivolumab was well tolerated and showed modest efficacy with durable response in patients with refractory BTC. Further studies are warranted to verify the findings and evaluate biomarkers for improved treatment selection for patients.

Trial Registration: ClinicalTrials.gov Identifier: NCT02829918.
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http://dx.doi.org/10.1001/jamaoncol.2020.0930DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7193528PMC
June 2020

A Comparative Study on the Ferroelectric Performances in Atomic Layer Deposited HfZrO Thin Films Using Tetrakis(ethylmethylamino) and Tetrakis(dimethylamino) Precursors.

Nanoscale Res Lett 2020 Apr 7;15(1):72. Epub 2020 Apr 7.

Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National University, Seoul, 08826, Republic of Korea.

The chemical, physical, and electrical properties of the atomic layer deposited HfZrO thin films using tetrakis(ethylmethylamino) (TEMA) and tetrakis(dimethylamino) (TDMA) precursors are compared. The ligand of the metal-organic precursors strongly affects the residual C concentration, grain size, and the resulting ferroelectric properties. Depositing HfZrO films with the TDMA precursors results in lower C concentration and slightly larger grain size. These findings are beneficial to grow more ferroelectric-phase-dominant film, which mitigates its wake-up effect. From the wake-up test of the TDMA-HfZrO film with a 2.8 MV/cm cycling field, the adverse wake-up effect was well suppressed up to 10 cycles, with a reasonably high double remanent polarization value of ~40 μC/cm. The film also showed reliable switching up to 10 cycles with the 2.5 MV/cm cycling field without involving the wake-up effect but with the typical fatigue behavior.
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http://dx.doi.org/10.1186/s11671-020-03301-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7138889PMC
April 2020

SAMHD1 Functions and Human Diseases.

Viruses 2020 03 31;12(4). Epub 2020 Mar 31.

Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30032, USA.

Deoxynucleoside triphosphate (dNTP) molecules are essential for the replication and maintenance of genomic information in both cells and a variety of viral pathogens. While the process of dNTP biosynthesis by cellular enzymes, such as ribonucleotide reductase (RNR) and thymidine kinase (TK), has been extensively investigated, a negative regulatory mechanism of dNTP pools was recently found to involve sterile alpha motif (SAM) domain and histidine-aspartate (HD) domain-containing protein 1, SAMHD1. When active, dNTP triphosphohydrolase activity of SAMHD1 degrades dNTPs into their 2'-deoxynucleoside (dN) and triphosphate subparts, steadily depleting intercellular dNTP pools. The differential expression levels and activation states of SAMHD1 in various cell types contributes to unique dNTP pools that either aid (i.e., dividing T cells) or restrict (i.e., nondividing macrophages) viral replication that consumes cellular dNTPs. Genetic mutations in SAMHD1 induce a rare inflammatory encephalopathy called Aicardi-Goutières syndrome (AGS), which phenotypically resembles viral infection. Recent publications have identified diverse roles for SAMHD1 in double-stranded break repair, genome stability, and the replication stress response through interferon signaling. Finally, a series of SAMHD1 mutations were also reported in various cancer cell types while why SAMHD1 is mutated in these cancer cells remains to investigated. Here, we reviewed a series of studies that have begun illuminating the highly diverse roles of SAMHD1 in virology, immunology, and cancer biology.
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http://dx.doi.org/10.3390/v12040382DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7232136PMC
March 2020

Retrospective analysis of risk factors of hypotensive bradycardic events during shoulder arthroscopic surgery under interscalene blockade in the sitting position.

Korean J Anesthesiol 2020 11 27;73(6):542-549. Epub 2020 Mar 27.

Department of Anesthesiology and Pain Medicine, Daegu Catholic University School of Medicine, Daegu, Korea.

Background: Hypotensive bradycardic events (HBEs) are a frequent adverse event in patients who underwent shoulder arthroscopic surgery under interscalene block (ISB) in the sitting position. This retrospective study was conducted to investigate the independent risk factors of HBEs in shoulder arthroscopic surgery under ISB in the sitting position.

Methods: A total of 2,549 patients who underwent shoulder arthroscopic surgery under ISB and had complete clinical data were included in the study. The 357 patients who developed HBEs were included in the HBEs group, and the remaining 2,192 in the non-HBEs group. The potential risk factors for HBEs, such as age, sex, past medical history, anesthetic characteristics, and intraoperative medications were collected and compared between the groups. Statistically significant variables were included in a logistic regression model to further evaluate the independent risk factors for HBEs in shoulder arthroscopic surgery under ISB.

Results: The incidence of HBEs was 14.0% (357/2549). Logistic regression analysis revealed that the intraoperative use of hydralazine (odds ratio [OR] 4.2, 95% CI 2.9-6.3), propofol (OR 2.1, 95% CI 1.3-3.6), and dexmedetomidine (OR 3.9, 95% CI 1.9-7.8) before HBEs were independent risk factors for HBEs in patients who received shoulder arthroscopic surgery under ISB.

Conclusions: The intraoperative use of antihypertensives such as hydralazine and sedatives such as propofol or dexmedetomidine leads to increased risk of HBEs during shoulder arthroscopic surgery under ISB in the sitting position.
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http://dx.doi.org/10.4097/kja.20035DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7714633PMC
November 2020

Comparison of the Seroprevalence of Measles Antibodies among Healthcare Workers in Two Korean Hospitals in 2019.

Infect Chemother 2020 Mar 21;52(1):93-97. Epub 2020 Jan 21.

Department of Internal Medicine, Inje University Sanggye Paik Hospital, Seoul, Korea.

We performed a point seroprevalence survey of measles among healthcare workers (HCWs) at two Korean teaching hospitals in 2019. A total of 2,830 HCWs underwent an antibody test. The overall seropositivity of measles was 93.1%. The seroprevalence of measles was lowest in HCWs aged 20 - 24 years (81.2%), followed by those aged 25 - 29 years (90.1%). The rates of anti-measles IgG positivity were significantly different between the two hospitals (97.0% vs. 89.4%, <0.001). These results suggest that the seropositivity of measles in HCWs may differ depending on the hospital's vaccination policy.
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http://dx.doi.org/10.3947/ic.2020.52.1.93DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7113453PMC
March 2020