Microfluidic-assisted single-cell RNA sequencing facilitates the development of neutralizing monoclonal antibodies against SARS-CoV-2.

As a class of antibodies that specifically bind to a virus and block its entry, neutralizing monoclonal antibodies (neutralizing mAbs) have been recognized as a top choice for combating COVID-19 due to their high specificity and efficacy in treating serious infections. Although conventional approaches for neutralizing mAb development have been optimized for decades, there is an urgent need for workflows with higher efficiency due to time-sensitive concerns, including the high mutation rate of SARS-CoV-2. One promising approach is the identification of neutralizing mAb candidates via single-cell RNA sequencing (RNA-seq), as each B cell has a unique transcript sequence corresponding to its secreted antibody. The state-of-the-art high-throughput single-cell sequencing technologies, which have been greatly facilitated by advances in microfluidics, have greatly accelerated the process of neutralizing mAb development. Here, we provide an overview of the general procedures for high-throughput single-cell RNA-seq enabled by breakthroughs in droplet microfluidics, introduce revolutionary approaches that combine single-cell RNA-seq to facilitate the development of neutralizing mAbs against SARS-CoV-2, and outline future steps that need to be taken to further improve development strategies for effective treatments against infectious diseases.

Computer-tailored intervention increases colorectal cancer screening among low-income African Americans in primary care: Results of a randomized trial.

INTRODUCTION: Although African Americans have the highest colorectal cancer (CRC) incidence and mortality rates of any racial group, their screening rates remain low. STUDY DESIGN/PURPOSE: This randomized controlled trial compared efficacy of two clinic-based interventions for increasing CRC screening among African American primary care patients. METHODS: African American patients from 11 clinics who were not current with CRC screening were randomized to receive a computer-tailored intervention (n = 335) or a non-tailored brochure (n = 358) designed to promote adherence to CRC screening. Interventions were delivered in clinic immediately prior to a provider visit. Univariate and multivariable logistic regression models analyzed predictors of screening test completion. Moderators and mediators were determined using multivariable linear and logistic regression analyses. RESULTS: Significant effects of the computer-tailored intervention were observed for completion of a stool blood test (SBT) and completion of any CRC screening test (SBT or colonoscopy). The colonoscopy screening rate was higher among those receiving the computer-tailored intervention group compared to the nontailored brochure but the difference was not significant. Predictors of SBT completion were: receipt of the computer-tailored intervention; being seen at a Veterans Affairs Medical Center clinic; baseline stage of adoption; and reason for visit. Mediators of intervention effects were changes in perceived SBT barriers, changes in perceived colonoscopy benefits, changes in CRC knowledge, and patient-provider discussion. Moderators of intervention effects were age, employment, and family/friend recommendation of screening. CONCLUSION: This one-time computer-tailored intervention significantly improved CRC screening rates among low-income African American patients. This finding was largely driven by increasing SBT but the impact of the intervention on colonoscopy screening was strong. Implementation of a CRC screening quality improvement program in the VA site that included provision of stool blood test kits and follow-up likely contributed to the strong intervention effect observed at that site. The trial is registered at ClinicalTrials.gov as NCT00672828.

Lutein Complex Supplementation Increases Ocular Blood Flow Biomarkers in Healthy Subjects.

Introduction: To investigate the effects of a lutein complex supplementation on ocular blood flow in healthy subjects. Materials and Methods: Sixteen healthy female patients (mean age 36.8 ± 12.1 years) were enrolled in this randomized, placebo-controlled, double-blinded, two-period crossover study. Subjects received daily an oral dose of the lutein with synergistic phytochemicals complex (lutein (10 mg), ascorbic acid (500 mg), tocopherols (364 mg), carnosic acid (2.5 mg), zeaxanthin (2 mg), copper (2 mg), with synergistic effects in reducing pro-inflammatory mediators and cytokines when administered together in combination) and placebo during administration periods. Measurements were taken before and after three-week supplementation periods, with crossover visits separated by a three-week washout period. Data analysis included blood pressure, heart rate, intraocular pressure, visual acuity, contrast sensitivity detection, ocular perfusion pressure, confocal scanning laser Doppler imaging of retinal capillary blood flow, and Doppler imaging of the retrobulbar blood vessels. Results: Lutein complex supplementation produced a statistically significant increase in mean superior retinal capillary blood flow, measured in arbitrary units (60, p = 0.0466) and a decrease in the percentage of avascular area in the superior (-0.029, p = 0.0491) and inferior (-0.023, p = 0.0477) retina, as well as reduced systolic (-4.06, p = 0.0295) and diastolic (-3.69, p = 0.0441) blood pressure measured in mmHg from baseline. Data comparison between the two supplement groups revealed a significant decrease in systemic diastolic blood pressure (change from pre- to post-treatment with lutein supplement (mean (SE)): -3.69 (1.68); change from pre- to post-treatment with placebo: 0.31 (2.57); p = 0.0357) and a significant increase in the peak systolic velocity (measured in cm/sec) in the central retinal artery (change from pre- to post-treatment with lutein supplement: 0.36 (0.19); change from pre- to post-treatment with placebo: -0.33 (0.21); p = 0.0384) with lutein complex supplement; data analyses from the placebo group were all non-significant. Discussion: In healthy participants, oral administration of a lutein phytochemicals complex for three weeks produced increased ocular blood flow biomarkers within retinal vascular beds and reduced diastolic blood pressure compared to placebo.

The effects of antioxidants on ocular blood flow in patients with glaucoma.

PURPOSE: To investigate the effects of an antioxidant dietary supplement that includes Ginkgo biloba, on retinal and retrobulbar blood flow in patients with open-angle glaucoma (OAG). METHODS: Forty-five patients with confirmed OAG were enroled in a randomized, double blinded, placebo-controlled cross-over study. Baseline and postadministration measurements of intraocular pressure (IOP), ocular perfusion pressure (OPP), retrobulbar blood flow, and retinal capillary blood flow were non-invasively measured (ultrasound and laser Doppler modalities, respectively) before and one month after antioxidant nutraceuticals and placebo administration. Changes in measurements between the active supplement and placebo arms were evaluated using paired t-tests, with p < 0.05 considered statistically significant. RESULTS: Antioxidant supplementation produced a statistically significant increase in peak systolic and/or end diastolic blood flow velocities in all retrobulbar blood vessels compared to placebo. Vascular resistance was also reduced in central retinal and nasal short posterior ciliary arteries following antioxidant administration. Additionally, antioxidant supplementation increased superior and inferior temporal retinal capillary mean blood flow and the ratio of active to non-active retina capillaries compared to placebo. CONCLUSION: One-month oral administration of antioxidants produced increases in biomarkers of ocular blood flow within retinal and retrobulbar vascular beds in patients with OAG.

Autoregulation and neurovascular coupling in the optic nerve head.

Impairments of autoregulation and neurovascular coupling in the optic nerve head play a critical role in ocular pathologies, especially glaucomatous optic neuropathy. We critically review the literature in the field, integrating results obtained in clinical, experimental, and theoretical studies. We address the mechanisms of autoregulation and neurovascular coupling in the optic nerve head, the current methods used to assess autoregulation--including measurements of optic nerve head blood flow (or volume and velocity)--blood flow data collected in the optic nerve head as pressure or metabolic demand is varied in healthy and pathologic conditions, and the current status and potential of mathematical modeling work to further the understanding of the relationship between ocular blood flow mechanisms and diseases such as glaucoma.