Targeting intracellular Neu1 for coronavirus infection treatment.

There are currently no effective therapies for COVID-19 or antivirals against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and vaccines appear less effective against new SARS-CoV-2 variants; thus, there is an urgent need to understand better the virulence mechanisms of SARS-CoV-2 and the host response to develop therapeutic agents. Herein, we show that host Neu1 regulates coronavirus replication by controlling sialylation on coronavirus nucleocapsid protein. Coronavirus nucleocapsid proteins in COVID-19 patients and in coronavirus HCoV-OC43-infected cells were heavily sialylated; this sialylation controlled the RNA-binding activity and replication of coronavirus. Neu1 overexpression increased HCoV-OC43 replication, whereas Neu1 knockdown reduced HCoV-OC43 replication. Moreover, a newly developed Neu1 inhibitor, Neu5Ac2en-OAcOMe, selectively targeted intracellular sialidase, which dramatically reduced HCoV-OC43 and SARS-CoV-2 replication in vitro and rescued mice from HCoV-OC43 infection-induced death. Our findings suggest Neu1 inhibitors could be used to limit SARS-CoV-2 replication in patients with COVID-19, making Neu1 a potential therapeutic target for COVID-19 and future coronavirus pandemics.

Differential impact of PI3K/AKT/mTOR signaling on tumor initiation and progression in animal models of prostate cancer.

BACKGROUND: The PI3K/AKT/mTOR signaling pathway is essential for initiation and progression of prostate cancer. However, there has been no a comprehensive comparison for the role of these signaling nodes in prostate tumor initiation and progression. METHODS: With genetically engineered animal models, we compared the impact of prostate-specific deletions of Pten, Tsc1, and Tsc2 and activation of Akt1 on tumor initiation and progression. Also, we assessed the expression and genetic alterations of PTEN, AKT1, TSC1, and TSC2 in human primary prostate cancers. RESULTS: For the genetically engineered mice, prostate conditional knockout (cKO) of Pten, Tsc1, and Tsc2 led to initiation and progression of mouse prostatic neoplasia hyperplasia (mPIN). Akt1 transgenic mice developed more aggressive mPINs than mice with Tsc1 or Tsc2 single-cKO, but the effect was more moderate than that for Pten single-cKO or Tsc1/Tsc2 double-cKO mice. Functional analyses showed that Pten single-cKO, AKT1 activation, and Tsc1/Tsc2 double-cKO induced cell proliferation more than Tsc1 or Tsc2 single-cKO, but only Pten single-cKO and AKT1 activation reduced epithelial adhesion. All cKO or AKT1 activation enhanced the phosphorylation of p-S6 (S235/236) but only Pten single-cKO and Tsc1/Tsc2 double-cKO enhanced the phosphorylation of p-AKT (S473) and p-4EBP1 (T37/46/70). In human prostate cancers, PTEN, but not AKT1, TSC1, or TSC2 had frequent genetic alterations. However, as key signaling nodes, AKT1, TSC1, and TSC2 may be responsible for PTEN loss-mediated tumor initiation and progression. CONCLUSION: Our results for genetically engineered mouse models suggest a differential role of the PI3K/AKT/mTOR signaling nodes in prostate cancer initiation and progression, but the underlying molecular mechanisms remain unaddressed.

Patient Awareness of CKD: A Systematic Review and Meta-analysis of Patient-Oriented Questions and Study Setting.

RATIONALE & OBJECTIVE: Patient awareness of disease is the first step toward effective management and disease control. Awareness of chronic kidney disease (CKD) has consistently been shown to be low, but studies estimating patient awareness of CKD have used different methods. We sought to determine whether the estimated prevalence of CKD awareness differed by the wording used to ascertain awareness or by setting characteristics. STUDY DESIGN: Systematic review and meta-analysis. SETTING & STUDY POPULATIONS: Adults with CKD not receiving dialysis. SELECTION CRITERIA FOR STUDIES: We included studies that estimated CKD awareness, determined CKD status by laboratory criteria, and provided the exact question wording used to ascertain awareness. DATA EXTRACTION: 2 reviewers independently extracted data for each study; discordance was resolved by a third independent reviewer. ANALYTICAL APPROACH: Mixed-effects models were used to calculate pooled CKD awareness estimates and 95% CIs. RESULTS: 32 studies were included. Publication year ranged from 2004 to 2017, with study populations ranging from 107 to 28,923 individuals. CKD awareness in individual studies ranged from 0.9% to 94.0%. Pooled CKD awareness was 19.2% (95% CI, 10.0%-33.6%) overall and was 26.5% (95% CI, 11.9%-48.9%) among individuals with an estimated glomerular filtration rate < 60 mL/min/1.73 m2. "Kidney problem" was the most sensitive question for CKD awareness (58.7%; 95% CI, 32.4%-80.8%); "weak or failing kidneys" was the least sensitive (12.3%; 95% CI, 4.5%-29.4%). CKD awareness was highest among patients from nephrology practices (86.2%; 95% CI, 74.9%-93.0%) and lowest in the general population (7.3%; 95% CI, 5.0%-10.5%). LIMITATIONS: Significant heterogeneity across studies overall and among examined subgroups of wording and study setting. CONCLUSIONS: Differently worded questions may lead to widely different estimates of CKD awareness. Consistent terminology is likely needed to most effectively surveil and leverage CKD awareness to improve management and disease control.

Correlation of Quantitative Measurements with Diabetic Disease Severity Using Multiple En Face OCT Angiography Image Averaging.

PURPOSE: To evaluate the effect of averaging en face OCT angiography (OCTA) images on quantitative measurements of the retinal microvasculature and their correlation to diabetic retinopathy (DR) disease severity. DESIGN: Cross-sectional cohort study. PARTICIPANTS: One hundred five eyes (65 patients) comprising 28 eyes from 19 healthy, aged-matched control participants, 14 eyes from 9 diabetics without DR, and 63 eyes from 37 diabetics with varying levels of DR. METHODS: Spectral-domain CIRRUS 5000 (Carl Zeiss Meditec, Dublin, CA) OCTA images with no macular edema or significant motion artifact were acquired 5 times with the 3 × 3-mm scan pattern. En face images of the superficial retinal layer (SRL) and deep retinal layer were registered and averaged. Vessel length density (VLD), perfusion density (PD), and foveal avascular zone (FAZ) parameters were measured on averaged versus single OCTA images. MAIN OUTCOME MEASURES: Univariate and multivariate linear regression correlated quantitative metrics to DR severity and best-corrected visual acuity (BCVA). RESULTS: Eighty-four eyes (55 patients) met the inclusion criteria. Almost uniformly, lower VLD and PD parameters were associated significantly with worse DR severity and BCVA. Multivariate linear regression for DR severity resulted in an R2 value of 0.82 and 0.77 for single and averaged groups, respectively. No variables remained associated significantly with DR severity in multivariate analysis with single images, but in averaged images, increased superior SRL PD significantly predicted worse DR severity (coefficient, 52.7; P = 0.026). Multivariate linear regression for BCVA had an R2 value of 0.42 and 0.47 for single and averaged groups, respectively. Foveal avascular zone size was not associated with DR severity when single OCTA images (P = 0.98) were considered, but was highly associated when using averaged images (coefficient, 6.18; P < 0.001). Foveal avascular zone size was predictive for logarithm of the minimum angle of resolution BCVA with averaged images (0.21; P = 0.004), but not with single images (P = 0.31). CONCLUSIONS: Averaging of en face OCTA images improves the visualization of capillaries, particularly increasing the clarity of the FAZ borders, and therefore improves the correlation of vessel density and FAZ-specific parameters to DR severity and BCVA.

Closed-loop optimization of fast-charging protocols for batteries with machine learning.

Simultaneously optimizing many design parameters in time-consuming experiments causes bottlenecks in a broad range of scientific and engineering disciplines1,2. One such example is process and control optimization for lithium-ion batteries during materials selection, cell manufacturing and operation. A typical objective is to maximize battery lifetime; however, conducting even a single experiment to evaluate lifetime can take months to years3-5. Furthermore, both large parameter spaces and high sampling variability3,6,7 necessitate a large number of experiments. Hence, the key challenge is to reduce both the number and the duration of the experiments required. Here we develop and demonstrate a machine learning methodology  to efficiently optimize a parameter space specifying the current and voltage profiles of six-step, ten-minute fast-charging protocols for maximizing battery cycle life, which can alleviate range anxiety for electric-vehicle users8,9. We combine two key elements to reduce the optimization cost: an early-prediction model5, which reduces the time per experiment by predicting the final cycle life using data from the first few cycles, and a Bayesian optimization algorithm10,11, which reduces the number of experiments by balancing exploration and exploitation to efficiently probe the parameter space of charging protocols. Using this methodology, we rapidly identify high-cycle-life charging protocols among 224 candidates in 16 days (compared with over 500 days using exhaustive search without early prediction), and subsequently validate the accuracy and efficiency of our optimization approach. Our closed-loop methodology automatically incorporates feedback from past experiments to inform future decisions and can be generalized to other applications in battery design and, more broadly, other scientific domains that involve time-intensive experiments and multi-dimensional design spaces.

CORRELATION OF EN FACE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY AVERAGING VERSUS SINGLE-IMAGE QUANTITATIVE MEASUREMENTS WITH RETINAL VEIN OCCLUSION VISUAL OUTCOMES.

PURPOSE: To demonstrate the effect of averaging multiple en face optical coherence tomography angiography images on the correlation between retinal microvasculature quantitative metrics and best-corrected visual acuity (BCVA) in eyes with retinal vein occlusion. METHODS: A cross-sectional cohort with unilateral retinal vein occlusion was imaged in both eyes. Five 3 mm × 3-mm spectral domain optical coherence tomography angiography images were averaged, and quantitative parameters from averaged versus single images were correlated with logMAR BCVA. Regression analyses were performed to correlate quantitative metrics with BCVA. RESULTS: Ten patients (5 male, average age 64.3 years) were included. Among retinal vein occlusion eyes, vessel length density was significantly less in averaged versus a single image for both the superficial retinal layer (15.5 ± 2.5 vs. 17.8 ± 2.4/mm, P = 0.05) and deep retinal layer (16.2 ± 1.4 vs. 18.5 ± 1.6/mm, P = 0.003). Multivariate linear regression showed an increased R value with averaging (0.93 to 0.95, for single and averaged groups, respectively). Foveal avascular zone circularity was associated with BCVA on single images (coefficient = -0.96, P = 0.002), but not with averaged images (P = 0.063). CONCLUSION: Scan averaging of en face optical coherence tomography angiography images improves the clarity of vessels and may allow for more accurate quantification of vessel metrics. Quantitative metrics are significantly associated with BCVA, and averaging does not further improve this association compared with single-scan analysis.

SPECTRAL DOMAIN VERSUS SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF THE RETINAL CAPILLARY PLEXUSES IN SICKLE CELL MACULOPATHY.

PURPOSE: To compare the spectral domain and swept source optical coherence tomography angiography findings in two cases of sickle cell maculopathy. METHODS: A 53-year-old man and a 24-year-old man both with sickle cell disease (hemoglobin SS) presented with no visual complaints; Humphrey visual field testing demonstrated asymptomatic paracentral scotomas that extended nasally in the involved eyes. Clinical examination and multimodal imaging including spectral domain and swept source optical coherence tomography, and spectral domain optical coherence tomography angiography and swept source optical coherence tomography angiography (Carl Zeiss Meditec Inc, Dublin, CA) were performed. RESULTS: Fundus examination of both patients revealed subtle thinning of the macula. En-face swept source optical coherence tomography confirmed the extent of the thinning correlating with the functional paracentral scotomas on Humphrey visual field. Swept source optical coherence tomography B-scan revealed multiple confluent areas of inner nuclear thinning and significant temporal retinal atrophy. En-face 6 × 6-mm spectral domain optical coherence tomography angiography of the macula demonstrated greater loss of the deep capillary plexus compared with the superficial capillary plexus. Swept source optical coherence tomography angiography 12 × 12-mm imaging captured the same macular findings and loss of both plexuses temporally outside the macula. CONCLUSION: In these two cases of sickle cell maculopathy, deep capillary plexus ischemia is more extensive within the macula, whereas both the superficial capillary plexus and deep capillary plexus are involved outside the macula likely due to the greater oxygen demands and watershed nature of these areas. Swept source optical coherence tomography angiography clearly demonstrates the angiographic extent of the disease correlating with the Humphrey visual field scotomas and confluent areas of inner nuclear atrophy.

GRAFT-VERSUS-HOST DISEASE PANUVEITIS AND BILATERAL SEROUS DETACHMENTS: MULTIMODAL IMAGING ANALYSIS.

PURPOSE: To report the multimodal imaging findings and follow-up of a case of graft-versus-host disease-induced bilateral panuveitis and serous retinal detachments after allogenic bone marrow transplant for acute myeloid leukemia. METHODS: A 75-year-old black man presented with acute decreased vision in both eyes for 1 week. Clinical examination and multimodal imaging, including spectral domain optical coherence tomography, fundus autofluorescence, fluorescein angiography, and swept-source optical coherence tomography angiography (Investigational Device; Carl Zeiss Meditec Inc) were performed. RESULTS: Clinical examination of the patient revealed anterior and posterior inflammation and bilateral serous retinal detachments. Ultra-widefield fundus autofluorescence demonstrated hyperautofluorescence secondary to subretinal fluid; and fluorescein angiography revealed multiple areas of punctate hyperfluorescence, leakage, and staining of the optic discs. Spectral domain and enhanced depth imaging optical coherence tomography demonstrated subretinal fluid, a thickened, undulating retinal pigment epithelium layer, and a thickened choroid in both eyes. En-face swept-source optical coherence tomography angiography did not show any retinal vascular abnormalities but did demonstrate patchy areas of decreased choriocapillaris flow. An extensive systemic infectious and malignancy workup was negative and the patient was treated with high-dose oral prednisone immunosuppression. Subsequent 6-month follow-up demonstrated complete resolution of the inflammation and bilateral serous detachments after completion of the prednisone taper over a 3-month period. CONCLUSION: Graft-versus-host disease panuveitis and bilateral serous retinal detachments are rare complications of allogenic bone marrow transplant for acute myeloid leukemia and can be diagnosed with clinical and multimodal imaging analysis. This form of autoimmune inflammation may occur after the recovery of T-cell activity within the donor graft targeting the host. Infectious and recurrent malignancy must be ruled out before initiation of immunosuppression, which can affectively treat this form of graft-versus-host disease.

Spectral-Domain Optical Coherence Tomography Angiography of Central Retinal Artery Occlusion.

The authors report the use of optical coherence tomography angiography (OCTA) to determine retinal blood flow in a patient with central retinal artery occlusion (CRAO). Spectral-domain OCTA (SD-OCTA) was performed on an eye with CRAO. En face vascular images were constructed using an optical microangiography algorithm. The retinal vasculature was clearly imaged with high fidelity; areas of perfused retina were identified with exquisite detail. This study supports use of OCTA in diagnosing and monitoring CRAOs. Future research is warranted to recognize full potential of this imaging modality. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:467-470.].

Swept-Source Optical Coherence Tomography and OCT Angiography of Minocycline-Induced Retinal and Systemic Hyperpigmentation.

This is a report of an 80-year-old man with a history of rosacea and rhinophyma treated for 15 years with oral minocycline who developed significant minocycline-induced hyperpigmentation. He also had a history of Fuchs' endothelial dystrophy and had undergone penetrating keratoplasty in the right eye. Best-corrected visual acuity was 20/60 in both eyes. Examination revealed slate-grey hyperpigmentation of his body, face, and sclera and black, confluent pigmentation in the central maculae of both eyes. Green wavelength fundus autofluorescence demonstrated speckled hyperautofluorescence in the right eye, and swept-source OCT and OCTA demonstrated pigmented epithelial detachments and significant signal blocking without choroidal neovascularization.

Swept-source optical coherence tomography angiography for choroidal neovascularization after bevacizumab and photodynamic therapy.

PURPOSE: To report the swept-source optical coherence tomography angiography (SS-OCTA) findings after bevacizumab anti-vascular endothelial growth factor (anti-VEGF) and full-fluence photodynamic therapy (PDT) for choroidal neovascularization. DESIGN: Case report. METHODS: An 87-year-old, Chinese male presented with a shadow and decreased vision to 20/160 in his left eye (OS). Clinical examination, color photographs, swept-source optical coherence tomography (SS-OCT), widefield dye-fluorescein angiography (FA) and SS-OCTA revealed an extrafoveal, subretinal choroidal neovascularization (CNV) in the superior macula. Bevacizumab anti-VEGF and full-fluence PDT was initiated. RESULTS: Initial imaging with conventional color photography and FA demonstrated a classic CNV with significant early hyperfluorescence and late leakage. SS-OCT demonstrated subretinal hyperreflective material, fluid and hemorrhage emanating from a subretinal, type 2 neovascularization (NV). SS-OCTA showed a mixed lesion with a type 2, subretinal component with segmentation above the retinal pigment epithelium (RPE) and a type 1, sub-RPE component below. Treatment with anti-VEGF and PDT led to immediate regression of the CNV. One month after treatment, SS-OCTA demonstrated significant resolution of the type, 2 subretinal component and decreased flow and size of the type 1 sub-RPE lesion. CONCLUSION: We report the first SS-OCTA images of successfully treated extrafoveal NV after combination PDT and ant-VEGF therapy. Early treatment of extrafoveal NV may improve our ability to treat mixed type 1 and 2 NV before these neovascular complexes mature from repetitive anti-VEGF treatment.

Simple filter microchip for rapid separation of plasma and viruses from whole blood.

Sample preparation is a significant challenge for detection and sensing technologies, since the presence of blood cells can interfere with the accuracy and reliability of virus detection at the nanoscale for point-of-care testing. To the best of our knowledge, there is not an existing on-chip virus isolation technology that does not use complex fluidic pumps. Here, we presented a lab-on-a-chip filter device to isolate plasma and viruses from unprocessed whole blood based on size exclusion without using a micropump. We demonstrated that viruses (eg, HIV) can be separated on a filter-based chip (2-µm pore size) from HIV-spiked whole blood at high recovery efficiencies of 89.9% ± 5.0%, 80.5% ± 4.3%, and 78.2% ± 3.8%, for viral loads of 1000, 10,000 and 100,000 copies/mL, respectively. Meanwhile, 81.7% ± 6.7% of red blood cells and 89.5% ± 2.4% of white blood cells were retained on 2 µm pore-sized filter microchips. We also tested these filter microchips with seven HIV-infected patient samples and observed recovery efficiencies ranging from 73.1% ± 8.3% to 82.5% ± 4.1%. These results are first steps towards developing disposable point-of-care diagnostics and monitoring devices for resource-constrained settings, as well as hospital and primary care settings.

2-(Diethylamino)ethanethiol, a new reagent for the odorless deprotection of aromatic methyl ethers.

A new reagent for the deprotection of aromatic methyl ethers, 2-(diethylamino)ethanethiol, is reported. This compound, commercially available as its HCl salt, affords the corresponding phenols in good to excellent yields on a wide variety of substrates. A clear advantage of this method over the use of more common thiols, such as ethanethiol, is the easy extraction of both the deprotecting reagent and the byproduct 2-(diethylamino)ethyl methyl sulfide into the aqueous phase by quenching with dilute acid, which allows an essentially odorless workup.