Nucleic acid liquids.

The confluence of recent discoveries of the roles of biomolecular liquids in living systems and modern abilities to precisely synthesize and modify nucleic acids (NAs) has led to a surge of interest in liquid phases of NAs. These phases can be formed primarily from NAs, as driven by base-pairing interactions, or from the electrostatic combination (coacervation) of negatively charged NAs and positively charged molecules. Generally, the use of sequence-engineered NAs provides the means to tune microsopic particle properties, and thus imbue specific, customizable behaviors into the resulting liquids. In this way, researchers have used NA liquids to tackle fundamental problems in the physics of finite valence soft materials, and to create liquids with novel structured and/or multi-functional properties. Here, we review this growing field, discussing the theoretical background of NA liquid phase separation, quantitative understanding of liquid material properties, and the broad and growing array of functional demonstrations in these materials. We close with a few comments discussing remaining open questions and challenges in the field.

Neuroimaging of Acute Ischemic Stroke: Multimodal Imaging Approach for Acute Endovascular Therapy / 대한뇌졸중학회지

Advances in acute ischemic stroke (AIS) treatment have been contingent on innovations in neuroimaging. Neuroimaging plays a pivotal role in the diagnosis and prognosis of ischemic stroke and large vessel occlusion, enabling triage decisions in the emergent care of the stroke patient. Current imaging protocols for acute stroke are dependent on the available resources and clinicians’ preferences and experiences. In addition, differential application of neuroimaging in medical decision-making, and the rapidly growing evidence to support varying paradigms have outpaced guideline-based recommendations for selecting patients to receive intravenous or endovascular treatment. In this review, we aimed to discuss the various imaging modalities and approaches used in the diagnosis and treatment of AIS.

Endovascular versus Medical Management of Acute Basilar Artery Occlusion: A Systematic Review and Meta-Analysis of the Randomized Controlled Trials / 대한뇌졸중학회지

Background@#and Purpose The optimal management of patients with acute basilar artery occlusion (BAO) is uncertain. We aimed to evaluate the safety and efficacy of endovascular thrombectomy (EVT) compared to medical management (MM) for acute BAO through a meta-analysis of randomized controlled trials (RCTs). @*Methods@#We performed a systematic review and meta-analysis of RCTs of patients with acute BAO. We analyzed the pooled effect of EVT compared to MM on the primary outcome (modified Rankin Scale [mRS] of 0–3 at 3 months), secondary outcome (mRS 0–2 at 3 months), symptomatic intracranial hemorrhage (sICH), and 3-month mortality rates. For each study, effect sizes were computed as odds ratios (ORs) with random effects and Mantel-Haenszel weighting. @*Results@#Four RCTs met inclusion criteria including 988 patients. There were higher odds of mRS of 0-3 at 90 days in the EVT versus MM group (45.1% vs. 29.1%, OR 1.99, 95% confidence interval [CI] 1.04–3.80; P=0.04). Patients receiving EVT had a higher sICH compared to MM (5.4% vs. 0.8%, OR 7.89, 95% CI 4.10–15.19; P<0.01). Mortality was lower in the EVT group (35.5% vs. 45.1%, OR 0.64, 95% CI 0.42–0.99; P=0.05). In an analysis of two trials with BAO patients and National Institutes of Health Stroke Scale (NIHSS) <10, there was no difference in 90-day outcomes between EVT versus MM. @*Conclusion@#In this systematic review and meta-analysis, EVT was associated with favorable outcome and decreased mortality in patients with BAO up to 24 hours from stroke symptoms compared to MM. The treatment effect in BAO patients with NIHSS <10 was less certain. Further studies are of interest to evaluate the efficacy of EVT in basilar occlusion patients with milder symptoms.

Clinical and Safety Outcomes of Endovascular Therapy 6 to 24 Hours After Large Vessel Occlusion Ischemic Stroke With Tandem Lesions / 대한뇌졸중학회지

Background@#and Purpose Effect of endovascular therapy (EVT) in acute large vessel occlusion (LVO) patients with tandem lesions (TLs) within 6–24 hours after last known well (LKW) remains unclear. We evaluated the clinical and safety outcomes among TL-LVO patients treated within 6–24 hours. @*Methods@#This multicenter cohort was divided into two groups, based on LKW to puncture time: early window (<6 hours), and late window (6–24 hours). Primary clinical and safety outcomes were 90-day functional independence measured by the modified Rankin Scale (mRS: 0–2) and symptomatic intracranial hemorrhage (sICH). Secondary outcomes were successful reperfusion (modified Thrombolysis in Cerebral Infarction score ≥2b), first-pass effect, early neurological improvement, ordinal mRS, and in-hospital and 90-day mortality. @*Results@#Of 579 patients (median age 68, 32.1% females), 268 (46.3%) were treated in the late window and 311 (53.7%) in the early window. Late window group had lower median National Institutes of Health Stroke Scale score at admission, Alberta Stroke Program Early Computed Tomography Score, rates of intravenous thrombolysis, and higher rates for perfusion imaging. After adjusting for confounders, the odds of 90-day mRS 0–2 (47.7% vs. 45.0%, adjusted odds ratio [aOR] 0.71, 95% confidence interval [CI] 0.49–1.02), favorable shift in mRS (aOR 0.88, 95% CI 0.44–1.76), and sICH (3.7% vs. 5.2%, aOR 0.56, 95% CI 0.20–1.56) were similar in both groups. There was no difference in secondary outcomes. Increased time from LKW to puncture did not predicted the probability of 90-day mRS 0–2 (aOR 0.99, 95% CI 0.96–1.01, for each hour delay) among patients presenting <24 hours. @*Conclusion@#EVT for acute TL-LVO treated within 6–24 hours after LKW was associated with similar rates of clinical and safety outcomes, compared to patients treated within 6 hours.

Anesthetic Management and Outcomes of Endovascular Treatment of Basilar Artery Occlusion: Results From the ATTENTION Registry / 대한뇌졸중학회지

Background@#and Purpose To examine the clinical and safety outcomes after endovascular treatment (EVT) for acute basilar artery occlusion (BAO) with different anesthetic modalities. @*Methods@#This was a retrospective analysis using data from the Endovascular Treatment for Acute Basilar Artery Occlusion (ATTENTION) registry. Patients were divided into two groups defined by anesthetic modality performed during EVT: general anesthesia (GA) or non-general anesthesia (non-GA). The association between anesthetic management and clinical outcomes was evaluated in a propensity score matched (PSM) cohort and an inverse probability of treatment weighting (IPTW) cohort to adjust for imbalances between the two groups. @*Results@#Our analytic sample included 1,672 patients from 48 centers. The anesthetic modality was GA in 769 (46.0%) and non-GA in 903 (54.0%) patients. In our primary analysis with the PSM-based cohort, non-GA was comparable to GA concerning the primary outcome (adjusted common odds ratio [acOR], 1.01; 95% confidence interval [CI], 0.82 to 1.25; P=0.91). Mortality at 90 days was 38.4% in the GA group and 35.8% in the non-GA group (adjusted risk ratio, 0.95; 95% CI, 0.83 to 1.08; P=0.44). In our secondary analysis with the IPTW-based cohort, the anesthetic modality was significantly associated with the distribution of modified Rankin Scale at 90 days (acOR: 1.45 [95% CI: 1.20 to 1.75]). @*Conclusion@#In this nationally-representative observational study, acute ischemic stroke patients due to BAO undergoing EVT without GA had similar clinical and safety outcomes compared with patients treated with GA. These findings provide the basis for large-scale randomized controlled trials to test whether anesthetic management provides meaningful clinical effects for patients undergoing EVT.

Borderzone Infarcts and Recurrent Cerebrovascular Events in Symptomatic Intracranial Arterial Stenosis: A Systematic Review and Meta-Analysis / 대한뇌졸중학회지

Background@#and Purpose Intracranial arterial stenosis (ICAS)-related stroke occurs due to three primary mechanisms with distinct infarct patterns: (1) borderzone infarcts (BZI) due to impaired distal perfusion, (2) territorial infarcts due to distal plaque/thrombus embolization, and (3) plaque progression occluding perforators. The objective of the systematic review is to determine whether BZI secondary to ICAS is associated with a higher risk of recurrent stroke or neurological deterioration. @*Methods@#As part of this registered systematic review (CRD42021265230), a comprehensive search was performed to identify relevant papers and conference abstracts (with ≥20 patients) reporting initial infarct patterns and recurrence rates in patients with symptomatic ICAS. Subgroup analyses were performed for studies including any BZI versus isolated BZI and those excluding posterior circulation stroke. The study outcome included neurological deterioration or recurrent stroke during follow-up. For all outcome events, corresponding risk ratios (RRs) and 95% confidence intervals (95% CI) were calculated. @*Results@#A literature search yielded 4,478 records with 32 selected during the title/abstract triage for full text; 11 met inclusion criteria and 8 studies were included in the analysis (n=1,219 patients; 341 with BZI). The meta-analysis demonstrated that the RR of outcome in the BZI group compared to the no BZI group was 2.10 (95% CI 1.52–2.90). Limiting the analysis to studies including any BZI, the RR was 2.10 (95% CI 1.38–3.18). For isolated BZI, RR was 2.59 (95% CI 1.24–5.41). RR was 2.96 (95% CI 1.71–5.12) for studies only including anterior circulation stroke patients. @*Conclusion@#This systematic review and meta-analysis suggests that the presence of BZI secondary to ICAS may be an imaging biomarker that predicts neurological deterioration and/or stroke recurrence.

Tissue Clock Beyond Time Clock: Endovascular Thrombectomy for Patients With Large Vessel Occlusion Stroke Beyond 24 Hours / 대한뇌졸중학회지

Background@#and Purpose Randomized trials proved the benefits of mechanical thrombectomy (MT) for select patients with large vessel occlusion (LVO) within 24 hours of last-known-well (LKW). Recent data suggest that LVO patients may benefit from MT beyond 24 hours. This study reports the safety and outcomes of MT beyond 24 hours of LKW compared to standard medical therapy (SMT). @*Methods@#This is a retrospective analysis of LVO patients presented to 11 comprehensive stroke centers in the United States beyond 24 hours from LKW between January 2015 and December 2021. We assessed 90-day outcomes using the modified Rankin Scale (mRS). @*Results@#Of 334 patients presented with LVO beyond 24 hours, 64% received MT and 36% received SMT only. Patients who received MT were older (67±15 vs. 64±15 years, P=0.047) and had a higher baseline National Institutes of Health Stroke Scale (NIHSS; 16±7 vs.10±9, P<0.001). Successful recanalization (modified thrombolysis in cerebral infarction score 2b-3) was achieved in 83%, and 5.6% had symptomatic intracranial hemorrhage compared to 2.5% in the SMT group (P=0.19). MT was associated with mRS 0–2 at 90 days (adjusted odds ratio [aOR] 5.73, P=0.026), less mortality (34% vs. 63%, P<0.001), and better discharge NIHSS (P<0.001) compared to SMT in patients with baseline NIHSS ≥6. This treatment benefit remained after matching both groups. Age (aOR 0.94, P<0.001), baseline NIHSS (aOR 0.91, P=0.017), Alberta Stroke Program Early Computed Tomography (ASPECTS) score ≥8 (aOR 3.06, P=0.041), and collaterals scores (aOR 1.41, P=0.027) were associated with 90-day functional independence. @*Conclusion@#In patients with salvageable brain tissue, MT for LVO beyond 24 hours appears to improve outcomes compared to SMT, especially in patients with severe strokes. Patients’ age, ASPECTS, collaterals, and baseline NIHSS score should be considered before discounting MT merely based on LKW.

α-Syn overexpression, NRF2 suppression, and enhanced ferroptosis create a vicious cycle of neuronal loss in Parkinson's disease.

Parkinson's disease (PD) is the second most common neurodegenerative disorder, affecting millions each year. Most PD cases (∼90%) are sporadic, resulting from the age-dependent accumulation of pathogenic effects. One key pathological hallmark of PD progression is the accumulation of alpha-synuclein (α-syn), which has been shown to negatively affect neuronal function and viability. Here, using 3- and 6-month-old Nrf2+/+ and Nrf2-/- mice overexpressing human α-syn (PD model), we show that loss of NRF2 increases markers of ferroptosis across PD-relevant brain regions. Increased ferroptosis was associated with an age- and genotype-dependent increase in α-syn pathology and behavioral deficits. Finally, we demonstrate that α-syn overexpression sensitizes neuronal cells and ex vivo brain slices to ferroptosis induction, which may be due to α-syn decreasing NRF2 protein levels. Altogether, these results indicate that NRF2 is a critical anti-ferroptotic mediator of neuronal survival, and that the vicious cycle of α-syn overexpression and NRF2 suppression, leading to enhanced neuronal ferroptotic cell death, could represent a targetable and currently untapped means of preventing PD onset and progression.

Molecular basis for antiviral activity of pediatric neutralizing antibodies targeting SARS-CoV-2 Spike receptor binding domain

Neutralizing antibodies (NAbs) hold great promise for clinical interventions against SARS-CoV- 2 variants of concern (VOCs). Understanding NAb epitope-dependent antiviral mechanisms is crucial for developing vaccines and therapeutics against VOCs. Here we characterized two potent NAbs, EH3 and EH8, isolated from an unvaccinated pediatric patient with exceptional plasma neutralization activity. EH3 and EH8 cross-neutralize the early VOCs and mediate strong Fc-dependent effector activity in vitro. Structural analyses of EH3 and EH8 in complex with the receptor-binding domain (RBD) revealed the molecular determinants of the epitope-driven protection and VOC-evasion. While EH3 represents the prevalent IGHV3-53 NAb whose epitope substantially overlaps with the ACE2 binding site, EH8 recognizes a narrow epitope exposed in both RBD-up and RBD-down conformations. When tested in vivo, a single-dose prophylactic administration of EH3 fully protected stringent K18-hACE2 mice from lethal challenge with Delta VOC. Our study demonstrates that protective NAbs responses converge in pediatric and adult SARS-CoV-2 patients.

Therapeutic Trends of Cerebrovascular Disease during the COVID-19 Pandemic and Future Perspectives / 대한뇌졸중학회지

As of May 2022, there have been more than 400 million cases (including re-infections) of the systemic acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), and nearly 5 million deaths worldwide. Not only has the coronavirus disease 2019 (COVID-19) pandemic been responsible for diagnosis and treatment delays of a wide variety of conditions, and overwhelmed the allocation of healthcare resources, it has impacted the epidemiology and management of cerebrovascular disease. In this narrative review, we summarize the changing paradigms and latest data regarding the complex relationship between COVID-19 and cerebrovascular disease. Paradoxically, although SARS-CoV-2 has been associated with many thrombotic complications—including ischemic stroke—there have been global declines in ischemic stroke and other cerebrovascular diseases. These epidemiologic shifts may be attributed to patient avoidance of healthcare institutions due to fear of contracting the novel human coronavirus, and also related to declines in other transmissible infectious illnesses which may trigger ischemic stroke. Despite the association between SARS-CoV-2 and thrombotic events, there are inconsistent data regarding targeted antithrombotics to prevent venous and arterial events. In addition, we provide recommendations for the conduct of stroke research and clinical trial planning during the ongoing COVID-19 pandemic, and for future healthcare crises.

Global Impact of the COVID-19 Pandemic on Cerebral Venous Thrombosis and Mortality / 대한뇌졸중학회지

Background@#and Purpose Recent studies suggested an increased incidence of cerebral venous thrombosis (CVT) during the coronavirus disease 2019 (COVID-19) pandemic. We evaluated the volume of CVT hospitalization and in-hospital mortality during the 1st year of the COVID-19 pandemic compared to the preceding year. @*Methods@#We conducted a cross-sectional retrospective study of 171 stroke centers from 49 countries. We recorded COVID-19 admission volumes, CVT hospitalization, and CVT in-hospital mortality from January 1, 2019, to May 31, 2021. CVT diagnoses were identified by International Classification of Disease-10 (ICD-10) codes or stroke databases. We additionally sought to compare the same metrics in the first 5 months of 2021 compared to the corresponding months in 2019 and 2020 (ClinicalTrials.gov Identifier: NCT04934020). @*Results@#There were 2,313 CVT admissions across the 1-year pre-pandemic (2019) and pandemic year (2020); no differences in CVT volume or CVT mortality were observed. During the first 5 months of 2021, there was an increase in CVT volumes compared to 2019 (27.5%; 95% confidence interval [CI], 24.2 to 32.0; P<0.0001) and 2020 (41.4%; 95% CI, 37.0 to 46.0; P<0.0001). A COVID-19 diagnosis was present in 7.6% (132/1,738) of CVT hospitalizations. CVT was present in 0.04% (103/292,080) of COVID-19 hospitalizations. During the first pandemic year, CVT mortality was higher in patients who were COVID positive compared to COVID negative patients (8/53 [15.0%] vs. 41/910 [4.5%], P=0.004). There was an increase in CVT mortality during the first 5 months of pandemic years 2020 and 2021 compared to the first 5 months of the pre-pandemic year 2019 (2019 vs. 2020: 2.26% vs. 4.74%, P=0.05; 2019 vs. 2021: 2.26% vs. 4.99%, P=0.03). In the first 5 months of 2021, there were 26 cases of vaccine-induced immune thrombotic thrombocytopenia (VITT), resulting in six deaths. @*Conclusions@#During the 1st year of the COVID-19 pandemic, CVT hospitalization volume and CVT in-hospital mortality did not change compared to the prior year. COVID-19 diagnosis was associated with higher CVT in-hospital mortality. During the first 5 months of 2021, there was an increase in CVT hospitalization volume and increase in CVT-related mortality, partially attributable to VITT.

Engineered ACE2-Fc counters murine lethal SARS-CoV-2 infection through direct neutralization and Fc-effector activities

Soluble Angiotensin-Converting Enzyme 2 (ACE2) constitutes an attractive antiviral capable of targeting a wide range of coronaviruses utilizing ACE2 as their receptor. Here, using structure-guided approaches, we developed divalent ACE2 molecules by grafting the extracellular ACE2-domain onto a human IgG1 or IgG3 (ACE2-Fc). These ACE2-Fcs harbor structurally validated mutations that enhance spike (S) binding and remove angiotensin enzymatic activity. The lead variant bound tightly to S, mediated in vitro neutralization of SARS-CoV-2 variants of concern (VOCs) with sub-nanomolar IC50 and was capable of robust Fc-effector functions, including antibody-dependent-cellular cytotoxicity, phagocytosis and complement deposition. When tested in a stringent K18-hACE2 mouse model, it delayed death or effectively resolved lethal SARS-CoV-2 infection in a prophylactic or therapeutic setting utilizing the combined effect of neutralization and Fc-effector functions. These data confirm the utility of ACE2-Fcs as valuable agents in preventing and eliminating SARS-CoV-2 infection and demonstrate that ACE2-Fc therapeutic activity require Fc-effector functions.

Associations between SARS-CoV-2 variants and risk of COVID-19 hospitalization among confirmed cases in Washington State: a retrospective cohort study

BackgroundThe COVID-19 pandemic is dominated by variant viruses; the resulting impact on disease severity remains unclear. Using a retrospective cohort study, we assessed the hospitalization risk following infection with seven SARS-CoV-2 variants. MethodsOur study includes individuals with positive SARS-CoV-2 RT-PCR in the Washington Disease Reporting System with available viral genome data, from December 1, 2020 to January 14, 2022. The analysis was restricted to cases with specimens collected through sentinel surveillance. Using a Cox proportional hazards model with mixed effects, we estimated hazard ratios (HR) for hospitalization risk following infection with a variant, adjusting for age, sex, calendar week, and vaccination. Findings58,848 cases were sequenced through sentinel surveillance, of which 1705 (2.9%) were hospitalized due to COVID-19. Higher hospitalization risk was found for infections with Gamma (HR 3.20, 95%CI 2.40-4.26), Beta (HR 2.85, 95%CI 1.56-5.23), Delta (HR 2.28 95%CI 1.56-3.34) or Alpha (HR 1.64, 95%CI 1.29-2.07) compared to infections with ancestral lineages; Omicron (HR 0.92, 95%CI 0.56-1.52) showed no significant difference in risk. Following Alpha, Gamma, or Delta infection, unvaccinated patients show higher hospitalization risk, while vaccinated patients show no significant difference in risk, both compared to unvaccinated, ancestral lineage cases. Hospitalization risk following Omicron infection is lower with vaccination. ConclusionInfection with Alpha, Gamma, or Delta results in a higher hospitalization risk, with vaccination attenuating that risk. Our findings support hospital preparedness, vaccination, and genomic surveillance. SummaryHospitalization risk following infection with SARS-CoV-2 variant remains unclear. We find a higher hospitalization risk in cases infected with Alpha, Beta, Gamma, and Delta, but not Omicron, with vaccination lowering risk. Our findings support hospital preparedness, vaccination, and genomic surveillance.

Rodent-Borne Orthohantaviruses in Vietnam, Madagascar and Japan.

Hantaviruses are harbored by multiple small mammal species in Asia, Europe, Africa, and the Americas. To ascertain the geographic distribution and virus-host relationships of rodent-borne hantaviruses in Japan, Vietnam, Myanmar, and Madagascar, RNAlater™-preserved lung tissues of 981 rodents representing 40 species, collected in 2011-2017, were analyzed for hantavirus RNA by RT-PCR. Our data showed Hantaan orthohantavirus Da Bie Shan strain in the Chinese white-bellied rat (Niviventer confucianus) in Vietnam, Thailand; orthohantavirus Anjo strain in the black rat (Rattus rattus) in Madagascar; and Puumala orthohantavirus Hokkaido strain in the grey-sided vole (Myodes rufocanus) in Japan. The Hokkaido strain of Puumala virus was also detected in the large Japanese field mouse (Apodemus speciosus) and small Japanese field mouse (Apodemus argenteus), with evidence of host-switching as determined by co-phylogeny mapping.

Circulating macroprolactin exhibits molecular heterogeneity and is not exclusively an antibody complex.

BACKGROUND: Macroprolactin (macPRL) is considered to be solely a prolactin antibody complex. We examined macPRL heterogeneity in samples from thirteen patients suspected of macroprolactinemia. METHODS: Polyethylene glycol (PEG) precipitation, gel permeation (GPC), protein-G affinity, and Lectin affinity chromatography were used to investigate the nature of macPRL. RESULTS: Using PEG, 8, 3, and 2 samples were macPRL positive, negative, and indeterminate respectively. Using GPC, prolactin appeared at high (H) (≥150 kDa), mid (M) (≥30 < 150 kDa), and low (L) (<30 k Da) forms. For macPRL positive samples, 52.3 to 95.0%, 3.6 to 34.1%, and 1.4 to 34.5% appeared at the (H), (M), and (L) regions respectively, compared with samples negative for macPRL with 1.2 to 5.1%, 60.0 to 79.4%, and 15.4 to 38.9% prolactin activity respectively. macPRL positive samples showed 30.4 to 86.5% binding to protein G column compared with negative samples at 1.2 to 5.1%. GPC-separated forms showed macPRL is heterogenous being either antibody bound (protein G studies) or glycosylated aggregates (lectin studies). Samples with identified macPRL forms were analysed using 4 immunoassay analysers. CONCLUSIONS: Samples with (H) and (M) macPRL forms showed significant positive bias in 2 immunoassays. The study is limited by the small number of samples and a larger scale study is required.

Environmental sampling for SARS-CoV-2 at a reference laboratory and provincial hospital in central Viet Nam, 2020

@#Objective: To determine whether environmental surface contamination with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurred at a provincial hospital in Viet Nam that admitted patients with novel coronavirus disease 2019 (COVID-19) and at the regional reference laboratory responsible for confirmatory testing for SARS-CoV-2 in 2020. Methods: Environmental samples were collected from patient and staff areas at the hospital and various operational and staff areas at the laboratory. Specimens from frequently touched surfaces in all rooms were collected using a moistened swab rubbed over a 25 cm2 area for each surface. The swabs were immediately transported to the laboratory for testing by real-time reverse transcription polymerase chain reaction (RT-PCR). Throat specimens were collected from staff at both locations and were also tested for SARS-CoV-2 using real-time RT-PCR. Results: During the sampling period, the laboratory tested 6607 respiratory specimens for SARS-CoV-2 from patients within the region, and the hospital admitted 9 COVID-19 cases. Regular cleaning was conducted at both sites in accordance with infection prevention and control (IPC) practices. All 750 environmental samples (300 laboratory and 450 hospital) and 30 staff specimens were negative for SARS-CoV-2. Discussion: IPC measures at the facilities may have contributed to the negative results from the environmental samples. Other possible explanations include sampling late in a patient’s hospital stay when virus load was lower, having insufficient contact time with a surface or using insufficiently moist collection swabs. Further environmental sampling studies of SARS-CoV-2 should consider including testing for the environmental presence of viruses within laboratory settings, targeting the collection of samples to early in the course of a patient’s illness and including sampling of confirmed positive control surfaces, while maintaining appropriate biosafety measures.

Genetic Diversity and Phylogeography of Thottapalayam thottimvirus (Hantaviridae) in Asian House Shrew (Suncus murinus) in Eurasia.

Murid and cricetid rodents were previously believed to be the principal reservoir hosts of hantaviruses. Recently, however, multiple newfound hantaviruses have been discovered in shrews, moles, and bats, suggesting a complex evolutionary history. Little is known about the genetic diversity and geographic distribution of the prototype shrew-borne hantavirus, Thottapalayam thottimvirus (TPMV), carried by the Asian house shrew (Suncus murinus), which is widespread in Asia, Africa, and the Middle East. Comparison of TPMV genomic sequences from two Asian house shrews captured in Myanmar and Pakistan with TPMV strains in GenBank revealed that the Myanmar TPMV strain (H2763) was closely related to the prototype TPMV strain (VRC66412) from India. In the L-segment tree, on the other hand, the Pakistan TPMV strain (PK3629) appeared to be the most divergent, followed by TPMV strains from Nepal, then the Indian-Myanmar strains, and finally TPMV strains from China. The Myanmar strain of TPMV showed sequence similarity of 79.3-96.1% at the nucleotide level, but the deduced amino acid sequences showed a high degree of conservation of more than 94% with TPMV strains from Nepal, India, Pakistan, and China. Cophylogenetic analysis of host cytochrome b and TPMV strains suggested that the Pakistan TPMV strain was mismatched. Phylogenetic trees, based on host cytochrome b and cytochrome c oxidase subunit I genes of mitochondrial DNA, and on host recombination activating gene 1 of nuclear DNA, suggested that the Asian house shrew and Asian highland shrew (Suncus montanus) comprised a species complex. Overall, the geographic-specific clustering of TPMV strains in Asian countries suggested local host-specific adaptation. Additional in-depth studies are warranted to ascertain if TPMV originated in Asian house shrews on the Indian subcontinent.

Differences in metabolic and liver pathobiology induced by two dietary mouse models of nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is a growing epidemic linked to metabolic disease. The first stage of NAFLD is characterized by lipid accumulation in hepatocytes, but this can progress into nonalcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma (HCC). Western diets, high in fats, sugars, and cholesterol, are linked to NAFLD development. Murine models are often used to study NAFLD; however, there remains debate on which diet-induced model best mimics both human disease progression and pathogenesis. In this study, we performed a side-by-side comparison of two popular diet models of murine NAFLD/NASH and associated HCC, a high-fat diet supplemented with 30% fructose water (HFHF) and a Western diet high in cholesterol (WDHC), and these were compared with a common grain-based chow diet (GBD). Mice on both experimental diets developed liver steatosis, and WDHC-fed mice had greater levels of hepatic inflammation and fibrosis than HFHF-fed mice. In contrast, HFHF-fed mice were more obese and developed more severe metabolic syndrome, with less pronounced liver disease. Despite these differences, WDHC-fed and HFHF-fed mice had similar tumor burdens in a model of diet-potentiated liver cancer. Response to diet and resulting phenotypes were generally similar between sexes, albeit delayed in females. This study shows that modest differences in diet can significantly uncouple glucose homeostasis and liver damage. In conclusion, long-term feeding of either HFHF or WDHC is a reliable method to induce NASH and diet-potentiated liver cancer in mice of both sexes; however, the choice of diet involves a trade-off between severity of metabolic syndrome and liver damage.

Correlation of ELISA based with random access serologic immunoassays for identifying adaptive immune response to SARS-CoV-2

Public health emergency of SARS-CoV-2 has facilitated diagnostic testing as a related medical countermeasure against COVID-19 outbreak. Numerous serologic antibody tests have become available through an expedited federal emergency use only process. This paper highlights the analytical characteristic of an ELISA based assay by AnshLabs and three random access immunoassay (RAIA) by DiaSorin, Roche, and Abbott that have been approved for emergency use authorization (EUA), at a tertiary academic center in a low disease-prevalence area. The AnshLabs gave higher estimates of sero-prevalence, over the three RAIA methods. For positive results, AnshLabs had 93.3% and 100% concordance with DiaSorin or Abbott and Roche respectively. For negative results, AnshLabs had 69.7% and 73.0% concordance with DiaSorin and Roche or Abbott respectively. All discrepant samples that were positive by AnshLabs and negative by RAIA tested positive by all-in-one step SARS-CoV-2 Total (COV2T) assay performed on the automated Siemens Advia Centaur XPT analyzer. None of these methods, however, are useful in early diagnosis of SARS-CoV-2.

SARS-CoV-2 seroprevalence and neutralizing activity in donor and patient blood from the San Francisco Bay Area

We report very low SARS-CoV-2 seroprevalence in two San Francisco Bay Area populations. Seropositivity was 0.26% in 387 hospitalized patients admitted for non-respiratory indications and 0.1% in 1,000 blood donors. We additionally describe the longitudinal dynamics of immunoglobulin-G, immunoglobulin-M, and in vitro neutralizing antibody titers in COVID-19 patients. Neutralizing antibodies rise in tandem with immunoglobulin levels following symptom onset, exhibiting median time to seroconversion within one day of each other, and there is >93% positive percent agreement between detection of immunoglobulin-G and neutralizing titers.