Monitoring mouse papillomavirus-associated cancer development using longitudinal Pap smear screening.

A substantial percentage of the population remains at risk for cervical cancer due to pre-existing human papillomavirus (HPV) infections, despite prophylactic vaccines. Early diagnosis and treatment are crucial for better disease outcomes. The development of new treatments heavily relies on suitable preclinical model systems. Recently, we established a mouse papillomavirus (MmuPV1) model that is relevant to HPV genital pathogenesis. In the current study, we validated the use of Papanicolaou (Pap) smears, a valuable early diagnostic tool for detecting HPV cervical cancer, to monitor disease progression in the MmuPV1 mouse model. Biweekly cervicovaginal swabs were collected from the MmuPV1-infected mice for viral DNA quantitation and cytology assessment. The Pap smear slides were evaluated for signs of epithelial cell abnormalities using the 2014 Bethesda system criteria. Tissues from the infected mice were harvested at various times post-viral infection for additional histological and virological assays. Over time, increased viral replication was consistent with higher levels of viral DNA, and it coincided with an uptick in epithelial cell abnormalities with higher severity scores noted as early as 10 weeks after viral infection. The cytological results also correlated with the histological evaluation of tissues harvested simultaneously. Both immunocompromised and immunocompetent mice with squamous cell carcinoma (SCC) cytology also developed vaginal SCCs. Notably, samples from the MmuPV1-infected mice exhibited similar cellular abnormalities compared to the corresponding human samples at similar disease stages. Hence, Pap smear screening proves to be an effective tool for the longitudinal monitoring of disease progression in the MmuPV1 mouse model. IMPORTANCE: Papanicolaou (Pap) smear has saved millions of women's lives as a valuable early screening tool for detecting human papillomavirus (HPV) cervical precancers and cancer. However, more than 200,000 women in the United States alone remain at risk for cervical cancer due to pre-existing HPV infection-induced precancers, as there are currently no effective treatments for HPV-associated precancers and cancers other than invasive procedures including a loop electrosurgical excision procedure (LEEP) to remove abnormal tissues. In the current study, we validated the use of Pap smears to monitor disease progression in our recently established mouse papillomavirus model. To the best of our knowledge, this is the first study that provides compelling evidence of applying Pap smears from cervicovaginal swabs to monitor disease progression in mice. This HPV-relevant cytology assay will enable us to develop and test novel antiviral and anti-tumor therapies using this model to eliminate HPV-associated diseases and cancers.

Inhibition of EGFR attenuates EGF-induced activation of retinal pigment epithelium cell via EGFR/AKT signaling pathway.

AIM: To explore the effect of epidermal growth factor receptor (EGFR) inhibition by erlotinib and EGFR siRNA on epidermal growth factor (EGF)-induced activation of retinal pigment epithelium (RPE) cells. METHODS: Human RPE cell line (ARPE-19 cells) was activated by 100 ng/mL EGF. Erlotinib and EGFR siRNA were used to intervene EGF treatment. Cellular viability, proliferation, and migration were detected by methyl thiazolyl tetrazolium (MTT) assay, bromodeoxyuridine (BrdU) staining assay and wound healing assay, respectively. EGFR/protein kinase B (AKT) pathway proteins and N-cadherin, α-smooth muscle actin (α-SMA), and vimentin were tested by Western blot assay. EGFR was also determined by immunofluorescence staining. RESULTS: EGF treatment for 24h induced a significant increase of ARPE-19 cells' viability, proliferation and migration, phosphorylation of EGFR/AKT proteins, and decreased total EGFR expression. Erlotinib suppressed ARPE-19 cells' viability, proliferation and migration through down regulating total EGFR and AKT protein expressions. Erlotinib also inhibited EGF-induced an increase of proliferative and migrative ability in ARPE-19 cells and clearly suppressed EGF-induced EGFR/AKT proteins phosphorylation and decreased expression of N-cadherin, α-SMA, and vimentin proteins. Similarly, EGFR inhibition by EGFR siRNA significantly affected EGF-induced an increase of cell proliferation, viability, and migration, phosphorylation of EGFR/AKT proteins, and up-regulation of N-cadherin, α-SMA, and vimentin proteins. CONCLUSION: Erlotinib and EGFR-knockdown suppress EGF-induced cell viability, proliferation, and migration via EGFR/AKT pathway in RPE cells. EGFR inhibition may be a possible therapeutic approach for proliferative vitreoretinopathy (PVR).

Hepatocyte growth factor promotes retinal pigment epithelium cell activity through MET/AKT signaling pathway.

AIM: To explore the effects of hepatocyte growth factor (HGF) on retinal pigment epithelium (RPE) cell behaviors. METHODS: The human adult retinal pigment epithelial cell line-19 (ARPE-19) were treated by HGF or mesenchymal-epithelial transition factor (MET) inhibitor SU11274 in vitro. Cell viability was detected by a Cell Counting Kit-8 assay. Cell proliferation and motility was detected by a bromodeoxyuridine incorporation assay and a wound healing assay, respectively. The expression levels of MET, phosphorylated MET, protein kinase B (AKT), and phosphorylated AKT proteins were determined by Western blot assay. The MET and phosphorylated MET proteins were also determined by immunofluorescence assay. RESULTS: HGF increased ARPE-19 cells' viability, proliferation and migration, and induced an increase of phosphorylated MET and phosphorylated AKT proteins. SU11274 significantly reduced cell viability, proliferation, and migration and decreased the expression of MET and AKT proteins. SU11274 suppressed HGF-induced increase of viability, proliferation, and migration in ARPE-19 cells. Additionally, SU11274 also blocked HGF-induced phosphorylation of MET and AKT proteins. CONCLUSION: HGF enhances cellular viability, proliferation, and migration in RPE cells through the MET/AKT signaling pathway, whereas this enhancement is suppressed by the MET inhibitor SU11274. HGF-induced MET/AKT signaling might be a vital contributor of RPE cells survival.

Immune Responses in Oral Papillomavirus Clearance in the MmuPV1 Mouse Model.

Human papillomavirus (HPV)-induced oropharyngeal cancer now exceeds HPV-induced cervical cancer, with a noticeable sex bias. Although it is well established that women have a more proficient immune system, it remains unclear whether immune control of oral papillomavirus infections differs between sexes. In the current study, we use genetically modified mice to target CCR2 and Stat1 pathways, with the aim of investigating the role of both innate and adaptive immune responses in clearing oral papillomavirus, using our established papillomavirus (MmuPV1) infection model. Persistent oral MmuPV1 infection was detected in Rag1ko mice with T and B cell deficiencies. Meanwhile, other tested mice were susceptible to MmuPV1 infections but were able to clear the virus. We found sex differences in key myeloid cells, including macrophages, neutrophils, and dendritic cells in the infected tongues of wild type and Stat1ko mice but these differences were not observed in CCR2ko mice. Intriguingly, we also observed a sex difference in anti-MmuPV1 E4 antibody levels, especially for two IgG isotypes: IgG2b and IgG3. However, we found comparable numbers of interferon-gamma-producing CD8 T cells stimulated by E6 and E7 in both sexes. These findings suggest that males and females may use different components of innate and adaptive immune responses to control papillomavirus infections in the MmuPV1 mouse model. The observed sex difference in immune responses, especially in myeloid cells including dendritic cell (DC) subsets, may have potential diagnostic and prognostic values for HPV-associated oropharyngeal cancer.

Compact Point-of-Care Device for Self-Administered HIV Viral Load Tests from Whole Blood.

Human immunodeficiency virus (HIV) is a significant problem to consider as it can lead to acquired immune deficiency syndrome (AIDS). Fortunately, AIDS is manageable through antiretroviral therapy (ART). However, frequent viral load monitoring is needed to monitor the effectiveness of the therapy. The current reverse transcription-polymerase chain reaction (RT-PCR) viral load monitoring is highly effective, but is challenged by being resource-intensive and inaccessible, and its turnaround time does not meet demand. An unmet need exists for an affordable, rapid, and user-friendly point-of-care device that could revolutionize and ensure therapeutic effectiveness, particularly in resource-limited settings. In this work, we explored a point-of-care HIV viral load device to address this need. This device can perform streamlined plasma separation, viral RNA extraction, and real-time reverse transcription loop-mediated isothermal amplification (RT-LAMP) semiquantitative testing in an ultracompact device. We developed an absorption-based membrane plasma separation method suitable for finger-prick blood samples, achieving an efficiency of 80%. We also designed a syringe-based RNA extraction method for on-site plasma processing with a viral recovery efficiency of 86%. We created a portable device with a smartphone interface for real-time semiquantitative RT-LAMP, which is useful for monitoring viral load. The device uses lyophilized reagents, processed with our lyophilization method, which remain stable for 16 weeks. The device can accurately categorize viral load into low, medium, and high categories with 95% accuracy. We believe this point-of-care HIV self-test device, offering convenience and long-term storage, could aid patients in home-based ART treatment monitoring.

Clinical efficacy and changes of serum VEGF-A, VEGF-B, and PLGF after conbercept treating neovascular age-related macular degeneration.

AIM: To evaluate the clinical efficacy and systemic safety profile of conbercept in clinical practice on vascular endothelial growth factor (VEGF)-A, VEGF-B, and placental growth factor (PLGF) levels after intravitreal injections for the neovascular age-related macular degeneration (AMD). METHODS: Thirty-five patients (35 eyes) with neovascular AMD received intravitreal injections of conbercept treatment with pro re nata protocol. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were detected before the intravitreal injection and at 1, 3, and 12mo after conbercept treatment. The levels of serum VEGF-A, VEGF-B, and PLGF were measured by enzyme-linked immunosorbent assay before the injection and 1 and 12mo after conbercept treatments. RESULTS: At baseline, the mean BCVA score was 39.89±14.64 letters. The mean BCVA scores were 51.03±15.78, 56.71±14.38, and 52.49±10.16 letters at 1, 3, and 12mo after conbercept treatment, and the BCVA improvements were all significant, respectively (P<0.05). At baseline, the mean CRT was 436.7±141.9 µm. At 1, 3, and 12mo after conbercept treatment, the mean CRT values were 335.1±147.8, 301.1±116.5, and 312.2±98.22 µm, and the CRT improvements were all significant, respectively (P<0.05). At baseline, 1 and 12mo after conbercept treatment, the mean levels of serum VEGF-A were 1013.8±454.3, 953.1±426.4, and 981.5±471.7 pg/mL, the mean levels of serum VEGF-B were 46.93±24.76, 42.99±19.16, and 45.32±18.76 pg/mL, the mean levels of serum PLGF at these points were 251.7±154.9, 241.3±166.7, and 245.6±147.2 pg/mL, respectively. Compared with the baseline, the levels of serum VEGF-A, VEGF-B, and PLGF did not significantly change at 1 and 12mo after conbercept treatment, respectively (P>0.05). CONCLUSION: Conbercept intravitreal injection leads to BCVA and CRT improvement, however, it does not significantly affect systemic serum VEGF-A, VEGF-B, and PLGF levels at 1 and 12mo after intravitreal injection treating neovascular AMD.

Hydrogen peroxide-induced oxidative damage and protective role of peroxiredoxin 6 protein via EGFR/ERK signaling pathway in RPE cells.

Introduction: Damage to retinal pigment epithelium (RPE) cells caused by oxidative stress is closely related to the pathogenesis of several blinding retinal diseases, such as age-related macular degeneration (AMD), retinitis pigmentosa, and other inherited retinal degenerative conditions. However, the mechanisms of this process are poorly understood. Hence, the goal of this study was to investigate hydrogen peroxide (H2O2)-induced oxidative damage and protective role of peroxiredoxin 6 (PRDX6) protein via EGFR/ERK signaling pathway in RPE cells. Methods: Cells from a human RPE cell line (ARPE-19 cells) were treated with H2O2, and then cell viability was assessed using the methyl thiazolyl tetrazolium assay. Cell death and reactive oxygen species (ROS) were detected by flow cytometry. The levels of PRDX6, epidermal growth factor receptor (EGFR), P38 mitogen-activated protein kinase (P38MAPK), c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) were detected by Western blot assay. PRDX6 and EGFR were also detected via immunofluorescence staining. Results: Our results show that H2O2 inhibited cell viability, induced cell death, and increased ROS levels in ARPE-19 cells. It was also found that H2O2 decreased the levels of PRDX6, EGFR, and phosphorylated ERK but increased the levels of phosphorylated P38MAPK and JNK. PRDX6 overexpression was found to attenuate H2O2-induced inhibition of cell viability and increased cell death and ROS production in ARPE-19 cells. PRDX6 overexpression also increased the expression of EGFR and alleviated the H2O2-induced decrease in EGFR and phosphorylated ERK. Moreover, inhibition of epidermal growth factor-induced EGFR and ERK signaling in oxidative stress was partially blocked by PRDX6 overexpression. Discussion: Our findings indicate that PRDX6 overexpression protects RPE cells from oxidative stress damage caused by decreasing ROS production and partially blocking the inhibition of the EGFR/ERK signaling pathway induced by oxidative stress. Therefore, PRDX6 shows promise as a therapeutic target for the prevention of RPE cell damage caused by oxidative stress associated with retinal diseases.

The CKD-EPI 2021 Equation and Other Creatinine-Based Race-Independent eGFR Equations in Chronic Kidney Disease Diagnosis and Staging.

BACKGROUND: Recent debate on the race correction factor in creatinine-based estimated glomerular filtration rate (eGFR) has led to the development of a new race-independent equation (Chronic Kidney Disease Epidemiology Collaboration, CKD-EPI_2021). Previously, some institutions have already modified the early version of the CKD-EPI or Modification of Diet in Renal Disease (MDRD) equations by removing the race factors (CKD-EPI_2009_non-Black (NB), MDRD_NB) for Black populations although this approach remains controversial. METHODS: In this study, the CKD-EPI_2009_NB, MDRD_NB, and European Kidney Function Consortium (EKFC) equations were compared directly with the CKD-EPI_2021 equation in eGFR calculation, chronic kidney disease (CKD) diagnosis, and staging in a local population. RESULTS: These 3 previous methods underestimated eGFR compared to CKD-EPI_2021 for eGFR < 90 mL/min/1.73 m2 but overestimated eGFR at the high end (>120 mL/min/1.73 m2). Around the CKD diagnosis cutoff (60 mL/min/1.73 m2), both MDRD_NB and EFKC equations resulted in an increase in CKD cases compared to CKD-EPI_2021. CKD-EPI_2009_NB demonstrated a similar trend although the difference was not statistically significant. In a population with low eGFR (<60 mL/min/1.73 m2), the EKFC equation showed a CKD staging pattern significantly different from that by CKD-EPI_2021, but all 3 previous methods resulted in a similar number of end-stage renal failure cases. In general, the EKFC equation demonstrated a weaker agreement in eGFR calculation and concordance in classification with the CKD-EPI_2021 equation than MDRD_NB and CKD-EPI_2009_NB. CONCLUSIONS: Our study provides a direct visual comparison to demonstrate the potential clinical impact between 3 previously used race-independent methods and the CKD-EPI_2021 equation and aids the communication with healthcare providers during the implementation of this new equation.

STAMP-Based Digital CRISPR-Cas13a for Amplification-Free Quantification of HIV-1 Plasma Viral Loads.

Quantification of HIV RNA in plasma is critical for identifying the disease progression and monitoring the effectiveness of antiretroviral therapy. While RT-qPCR has been the gold standard for HIV viral load quantification, digital assays could provide an alternative calibration-free absolute quantification method. Here, we reported a Self-digitization Through Automated Membrane-based Partitioning (STAMP) method to digitalize the CRISPR-Cas13 assay (dCRISPR) for amplification-free and absolute quantification of HIV-1 viral RNAs. The HIV-1 Cas13 assay was designed, validated, and optimized. We evaluated the analytical performances with synthetic RNAs. With a membrane that partitions ∼100 nL of reaction mixture (effectively containing 10 nL of input RNA sample), we showed that RNA samples spanning 4 orders of dynamic range between 1 fM (∼6 RNAs) to 10 pM (∼60k RNAs) could be quantified as fast as 30 min. We also examined the end-to-end performance from RNA extraction to STAMP-dCRISPR quantification using 140 µL of both spiked and clinical plasma samples. We demonstrated that the device has a detection limit of approximately 2000 copies/mL and can resolve a viral load change of 3571 copies/mL (equivalent to 3 RNAs in a single membrane) with 90% confidence. Finally, we evaluated the device using 140 µL of 20 patient plasma samples (10 positives and 10 negatives) and benchmarked the performance with RT-PCR. The STAMP-dCRISPR results agree very well with RT-PCR for all negative and high positive samples with Ct < 32. However, the STAMP-dCRISPR is limited in detecting low positive samples with Ct > 32 due to the subsampling errors. Our results demonstrated a digital Cas13 platform that could offer an accessible amplification-free quantification of viral RNAs. By further addressing the subsampling issue with approaches such as preconcentration, this platform could be further exploited for quantitatively determining viral load for an array of infectious diseases.

AACC Guidance Document on Cervical Cancer Detection: Screening, Surveillance, and Diagnosis.

BACKGROUND: Persistent genital infection with high-risk human papilloma virus (hrHPV) causes the vast majority of cases of cervical cancer. Early screening, ongoing surveillance, and accurate diagnosis are crucial for the elimination of cervical cancer. New screening guidelines for testing in asymptomatic healthy populations and management guidelines for managing abnormal results have been published by professional organizations. CONTENT: This guidance document addresses key questions related to cervical cancer screening and management including currently available cervical cancer screening tests and the testing strategies for cervical cancer screening. This guidance document introduces the most recently updated screening guidelines regarding age to start screening, age to stop screening, and frequencies of routine screening as well as risk-based management guidelines for screening and surveillance. This guidance document also summarizes the methodologies for the diagnosis of cervical cancer. Additionally, we propose a report template for human papilloma virus (HPV) and cervical cancer detection to facilitate interpretation of results and clinical decision-making. SUMMARY: Currently available cervical cancer screening tests include hrHPV testing and cervical cytology screening. The screening strategies can be primary HPV screening, co-testing with HPV testing and cervical cytology, and cervical cytology alone. The new American Society for Colposcopy and Cervical Pathology guidelines recommend variable frequencies of screening and surveillance based on risk. To implement these guidelines, an ideal laboratory report should include the indication for the test (screening, surveillance, or diagnostic workup of symptomatic patients); type of test (primary HPV screening, co-testing, or cytology alone); clinical history of the patient; and prior as well as current testing results.

Comparison of Performance between the Elecsys 4th and 5th Generation STAT Cardiac Troponin T Immunoassays.

OBJECTIVE: To evaluate the analytical and clinical performance of the 5th GEN cTnT assay by comparing it with the 4th GEN assay. METHODS: Imprecision, analytical measurement range (AMR), reference interval, and quantitative comparison were studied. Qualitative comparisons of the two assays for randomly selected patients with the cTnT test orders and patients with elevated N-terminal proB-type natriuretic peptide (NT-proBNP), decreased estimated glomerular filtration rate (eGFR), and increased procalcitonin were performed. RESULTS: Within-run and between-run CVs of the 5th GEN assay were 0.6-2.3% and 3.1-5.0% with AMR of 8-10,000 ng/L and reference interval of <19 ng/L. Regression analysis of the two assays showed linear relationship: y (5th GEN)=0.899x (4th GEN)+26, r=0.9993 with a positive bias of the 5th GEN assay in samples with cTnT <150 ng/L and a negative bias in samples with cTnT >500 ng/L compare to the 4th GEN assay. Agreement was 88.1% (95% CI: 80.4 to 93.1%) between the two methods according to the 99th percentile threshold. In patients with elevated NT-proBNP, decreased eGFR, and increased procalcitonin, agreements were 79.4%, 92.7%, and 100%. CONCLUSION: The 5th GEN cTnT assay demonstrates excellent precision and acceptable AMR. Compared to the 4th GEN assay, the 5th GEN assay shows a negative bias for samples with cTnT >500 ng/L but a positive bias for samples with cTnT <150 ng/L and identifies more patients with elevated cTnT.

Passive Immunization with a Single Monoclonal Neutralizing Antibody Protects against Cutaneous and Mucosal Mouse Papillomavirus Infections.

We have established a mouse papillomavirus (MmuPV1) model that induces both cutaneous and mucosal infections and cancers. In the current study, we use this model to test our hypothesis that passive immunization using a single neutralizing monoclonal antibody can protect both cutaneous and mucosal sites at different time points after viral inoculation. We conducted a series of experiments involving the administration of either a neutralizing monoclonal antibody, MPV.A4, or control monoclonal antibodies to both outbred and inbred athymic mice. Three clinically relevant mucosal sites (lower genital tract for females and anus and tongue for both males and females) and two cutaneous sites (muzzle and tail) were tested. At the termination of the experiments, all tested tissues were harvested for virological analyses. Significantly lower levels of viral signals were detected in the MPV.A4-treated female mice up to 6 h post-viral inoculation compared to those in the isotype control. Interestingly, males displayed partial protection when they received MPV.A4 at the time of viral inoculation, even though they were completely protected when receiving MPV.A4 at 24 h before viral inoculation. We detected MPV.A4 in the blood starting at 1 h and up to 8 weeks postadministration in some mice. Parallel to these in vivo studies, we conducted in vitro neutralization using a mouse keratinocyte cell line and observed complete neutralization up to 8 h post-viral inoculation. Thus, passive immunization with a monoclonal neutralizing antibody can protect against papillomavirus infection at both cutaneous and mucosal sites and is time dependent. IMPORTANCE This is the first study testing a single monoclonal neutralizing antibody (MPV.A4) by passive immunization against papillomavirus infections at both cutaneous and mucosal sites in the same host in the mouse papillomavirus model. We demonstrated that MPV.A4 administered before viral inoculation can protect both male and female athymic mice against MmuPV1 infections at cutaneous and mucosal sites. MPV.A4 also offers partial protection at 6 h post-viral inoculation in female mice. MPV.A4 can be detected in the blood from 1 h to 8 weeks after intraperitoneal (i.p.) injection. Interestingly, males were only partially protected when they received MPV.A4 at the time of viral inoculation. The failed protection in males was due to the absence of neutralizing MPV.A4 at the infected sites. Our findings suggest passive immunization with a single monoclonal neutralizing antibody can protect against diverse papillomavirus infections in a time-dependent manner in mice.

Elevated hCG Concentration in a Patient after an Unsuccessful in vitro Fertilization.

A patient had a positive serum human chorionic gonadotropin (hCG) 22 days after a failed in vitro fertilization (IVF). The result was confirmed by repeating the test using quantitative and qualitative assays after 48 hours, but the quantitative result did not double compared to the previous concentration. Heterophilic antibody interference was ruled out. The above results indicated true-positive hCG, but inconsistent with normal pregnancy. Medical history excluded hCG produced by pituitary gland, malignancy and exogenous hCG use. Ectopic pregnancy (EP) was suspected and methotrexate was initiated. Ultrasound showed periadnexal fluid suggesting separation phenomenon on the right adnexal EP and hCG was decreased one weeks after the treatment. Two weeks later, hCG became negative. The above data suggest that the elevated hCG was most likely due to EP following IVF.

Preterm labor tests: current status and future directions.

Preterm labor (PTL) is a severe issue of neonatal healthcare because its related to preterm birth (PTB) is the leading cause of neonatal mortality and the most common reason for antenatal hospitalizations. The PTB rate is about 11% globally and it is similar in the United States. PTB poses a significant economic burden on the healthcare system. Early diagnosis of PTL is the key to reducing PTB rate, neonatal mortality, and long-term neurological impairment in children. The diagnosis of PTL is usually based on clinical criteria, but the accuracy of the diagnosis is poor. To predict the risk of PTL more accurately, tests of biomarkers with variable clinical diagnostic performances have been developed and some of them have been applied clinically. In this article, we analyze the performance characteristics of these biomarkers, such as sensitivity, specificity, positive predictive value, and negative predictive value, as well as the clinical utility of current biomarkers so that clinical laboratorians and clinicians can better understand the limitations of these tests and utilize them wisely. We also summarize the current recommendations on clinical utilization of PTL biomarkers. Finally, we explore the prospects of future omics-based novel biomarkers, which may improve prediction of PTL in the future.

Rapid detection of novel coronavirus SARS-CoV-2 by RT-LAMP coupled solid-state nanopores.

The current pandemic of COVID-19 caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2) has raised significant public health concerns. Rapid and accurate testing of SARS-CoV-2 is urgently needed for early detection and control of the disease spread. Here, we present an RT-LAMP coupled glass nanopore digital counting method for rapid detection of SARS-CoV-2. We validated and compared two one-pot RT-LAMP assays targeting nucleocapsid (N) and envelop (E) genes. The nucleocapsid assay was adopted due to its quick time to positive and better copy number sensitivity. For qualitative positive/negative classification of a testing sample, we used the glass nanopore to digitally count the RT-LAMP amplicons and benchmarked the event rate with a threshold. Due to its intrinsic single molecule sensitivity, nanopore sensors could capture the amplification dynamics more rapidly (quick time to positive). We validated our RT-LAMP coupled glass nanopore digital counting method for SARS-CoV-2 detection by using both spiked saliva samples and COVID-19 clinical nasopharyngeal swab samples. The results obtained showed excellent agreement with the gold standard RT-PCR assay. With its integration capability, the electronic nanopore digital counting platform has significant potential to provide a rapid, sensitive, and specific point-of-care assay for SARS-CoV-2.

Analytical and Clinical Analysis of Two Automated Anti-SARS-CoV-2 Immunoassays in Pre-Pandemic and Pandemic Patient Populations.

BACKGROUND: In the absence of a safe, effective vaccine, the worldwide spread of COVID-19 (SARS-CoV-2) infection will continue. Laboratory tests with ideal precision, sensitivity, and specificity should be used in public health and clinical settings to gauge the extent of virus exposure. Toward this end, we evaluated the analytical and clinical performance of the Abbott SARS-CoV-2 IgG and the Roche Anti-SARS-CoV-2 immunoassays. METHODS: Quality control, pooled COVID-19, and non-COVID-19 patient specimens were used for the imprecision study. Two hundred and forty-six specimens from 70 patients with COVID-19 diagnosis were tested to study the sensitivity. Seventy-three non-COVID-19 control specimens were measured to study the specificity. All specimens were analyzed by both assays. RESULTS: Total analytic variability (CV) of the negative and positive controls were 5.5% and 3.6% for the Abbott assay and 4.5% and 1.9% for the Roche assay. Both assays demonstrated 100% qualitative reproducibility of negative and positive controls. The clinical specificities of the Abbott and the Roche assays were 100% (95% CI: 94%-100%) and 97% (95% CI: 90%-100%), respectively. The clinical sensitivities of the Abbott assay were 49% (95% CI: 41%-56%), 86% (95% CI: 74%-93%), and 100% (95% CI: 76%-100%) for samples collected at 0-6 days, 7-13 days, and ≥14 days after the first RT-PCR, while the sensitivities of the Roche assay were 55% (95% CI: 47%-62%), 86% (95% CI: 74%-93%), and 100% (95% CI: 76%-100%). CONCLUSIONS: This study demonstrates similar analytical and clinical performance of the Abbott and the Roche SARS-CoV-2 antibody assays, but the Roche assay may be slightly more sensitive for patients tested within 0-6 days after first positive RT-PCR of SARS-CoV-2.COVID-19 is a respiratory infectious disease caused by SARS-CoV-2. Laboratory tests with ideal precision, sensitivity, and specificity should be used in public health and clinical settings. We analyzed analytical and clinical performance of the Roche and Abbott SARS-CoV-2 antibody assays in pre-pandemic and pandemic patient populations. Additionally, we analyzed the sensitivity of both assays in patients at different stages of the disease. The 2 assays showed similar analytical and clinical performance, but the Roche assay may be slightly more sensitive for patients tested within 0-6 days after first positive RT-PCR of SARS-CoV-2. Our findings help other clinical labs select appropriate assays for SARS-CoV-2 antibody testing.

Initial subduction-related magmatism in southern Alaska identified by geochemistry and zircon Hf-O isotopes.

Abundant arc-type magmatic and metamorphic rocks exist on Earth today, which provide insights into the equilibrium state of the subduction process. However, magmatic samples generated during the initial stage of subduction is largely unknown. This hinders our understanding of the subduction initiation process and by inference, the onset of plate tectonics as well as the history of crustal formation. To address this issue, we carried out a comprehensive geochemical-geochronological study of a suite of Late Triassic to mid-Jurassic plutonic rocks from southern Alaska that potentially represent magmas from the initial to mature stages of arc formation. While all studied samples show typical arc-type geochemical signatures, i.e., enrichment of large ion lithophile elements (LILEs) and depletion of high field strength elements (HFSEs) relative to the heavy rare earth elements (HREEs), the Late Triassic trondhjemites show unique geochemical features such as strongly positive εHf(t) and εNd(t) coupled with lower δ18O (average 4.77‰ ± 0.09‰). These signatures, along with its higher zircon saturation temperatures compared with younger plutonic rocks, are best explained by shallow partial melting of subducting high-temperature hydrothermally altered lower oceanic crust (i.e., gabbro). If true, these surprising findings would open up new ways to study subduction initiation which would have important bearing on future research on the onset of global plate tectonics and the formation of the continental crust.