Publications by authors named "Brian Richardson"

Reversibly switchable fluorescent proteins (rsFPs) are essential tools in super-resolution imaging. The mechanism operating in the widely applied negative switching rsFPs has been studied in detail. Much less attention has been paid to the positive switching rsFP variants, which offer the potential benefit of emissive states that do not photoswitch during measurement.

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We identified 4 cases of presumptive autochthonous melioidosis during 1983-2024 in Georgia, USA. Epidemiologic investigation identified no recent international travel before illness; all cases were geographically linked, and 3 patients became ill after a severe weather event. Bioinformatic analyses revealed Burkholderia pseudomallei genome sequences were highly related, suggesting a shared exposure.

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Confounding and exposure measurement error can introduce bias when drawing inference about the marginal effect of an exposure on an outcome of interest. While there are broad methodologies for addressing each source of bias individually, confounding and exposure measurement error frequently co-occur, and there is a need for methods that address them simultaneously. In this paper, corrected score methods are derived under classical additive measurement error to draw inference about marginal exposure effects using only measured variables.

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Background: There has been tremendous progress in reducing vertical transmission of HIV in the past two decades due to the broad availability of antiretroviral therapy (ART) globally. Despite this progress, new paediatric infections are still occurring.

Methods: In a pilot study, we evaluated a combination adherence support package, which included an adapted motivational interviewing-informed counselling approach (Integrated Next Step Counselling, iNSC) and an optional adherence supporter, for pregnant and breastfeeding women living with HIV.

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Previous studies have shown that the majority of long-lived cells harboring persistent HIV-1 proviral genomes originates from viruses circulating in the year prior to antiretroviral therapy (ART) initiation, but a smaller proportion originates from viruses circulating much earlier in untreated infection. These observations suggest that discrete biological factors influence the entry and persistence of viruses into the persistent proviral pool, and there may be periods earlier in untreated infection with increased seeding. Therefore, we examined the timing of formation of the long-lived pool of infected cells that persists during ART in seven women (after a median of 5.

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Background: Conifers, mainly of the genus Pinus, have invaded natural and productive landscapes worldwide. Controlling dense conifer invasions is challenging and requires both effective initial control methods and long-term site management to prevent re-invasion. Broadcast aerial herbicide application is often the preferred treatment method for dense infestations of pines with high rates of complex herbicide mixtures used.

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Objectives: To eliminate vertical transmission of HIV, global institutions recommend using a risk-guided approach for HIV prevention services in antenatal and postnatal settings. Identifying predictors of maternal HIV acquisition can inform the development of risk-guided approaches, but individual studies of predictors can have limited power and generalizability.

Methods: We conducted a systematic review and narrative synthesis to identify common predictors of maternal HIV acquisition in sub-Saharan Africa (SSA).

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Article Synopsis
  • MUC1 peptide vaccines are being studied as a way to boost immunity against colon cancer in individuals with a history of premalignant colon adenomas, and trials showed varied responses among participants.
  • Researchers analyzed blood samples from vaccine responders and non-responders to identify potential early biomarkers that could indicate long-term immune memory and reduce adenoma recurrence.
  • The study found that MUC1 responders had distinct immune profiles, including higher CD4 cell counts and specific activated pathways, suggesting these factors could help predict who is likely to benefit from the vaccine and assist in developing personalized cancer preventive strategies.
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A gene cluster responsible for the degradation of nicotinic acid (NA) in has recently been identified, and the structures and functions of the resulting enzymes are currently being evaluated to establish pathway intermediates. One of the genes within this cluster encodes a flavin monooxygenase (BnFMO) that is hypothesized to catalyze a hydroxylation reaction. Kinetic analyses of the recombinantly purified BnFMO suggest that this enzyme catalyzes the hydroxylation of 2,6-dihydroxynicotinic acid (2,6-DHNA) or 2,6-dihydroxypyridine (2,6-DHP), which is formed spontaneously by the decarboxylation of 2,6-DHNA.

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Filters with high throughput, minimal dead volume, and greater sensitivity to particle size are needed, which traditional benchtop filtration cannot provide. Leveraging microfabrication techniques developed by the electronics and optics industries, the filters presented here feature a unique serpentine "NanoRidge" structure, offering a continuous filtration gap spanning over three meters on a compact 4 × 14.5 mm footprint.

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Article Synopsis
  • * The newly developed multi-ancestry PRS showed a strong correlation with LUAD risk, indicating that individuals in the highest PRS percentile had significantly increased risk compared to those in the lowest.
  • * Findings suggest that those in the highest risk category have a lifetime risk of about 6.69%, and they reach the average population's 10-year risk for LUAD by age 41, highlighting the importance of multi-ancestry PRS for better risk assessment in this group.
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The landscape of survival analysis is constantly being revolutionized to answer biomedical challenges, most recently the statistical challenge of censored covariates rather than outcomes. There are many promising strategies to tackle censored covariates, including weighting, imputation, maximum likelihood, and Bayesian methods. Still, this is a relatively fresh area of research, different from the areas of censored outcomes (i.

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Hematopoietic stem cells (HSCs) adapt to organismal blood production needs by balancing self-renewal and differentiation, adjusting to physiological demands and external stimuli. Although sex differences have been implicated in differential hematopoietic function in males versus females, the mediators responsible for these effects require further study. Here, we characterized hematopoiesis at a steady state and during regeneration following hematopoietic stem cell transplantation (HST).

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Self-antigens abnormally expressed on tumors, such as MUC1, have been targeted by therapeutic cancer vaccines. We recently assessed in two clinical trials in a preventative setting whether immunity induced with a MUC1 peptide vaccine could reduce high colon cancer risk in individuals with a history of premalignant colon adenomas. In both trials, there were immune responders and non-responders to the vaccine.

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The late stages of Golgi maturation involve a series of sequential trafficking events in which cargo-laden vesicles are produced and targeted to multiple distinct subcellular destinations. Each of these vesicle biogenesis events requires activation of an Arf GTPase by the Sec7/BIG guanine nucleotide exchange factor (GEF). Sec7 localization and activity is regulated by autoinhibition, positive feedback, and interaction with other GTPases.

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People living with HIV on antiretroviral therapy often have undetectable virus levels by standard assays, but "latent" HIV still persists in viral reservoirs. Eliminating these reservoirs is the goal of HIV cure research. The quantitative viral outgrowth assay (QVOA) is commonly used to estimate the reservoir size, that is, the infectious units per million (IUPM) of HIV-persistent resting CD4+ T cells.

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Objective: Microglia/macrophages line the border of demyelinated lesions in both cerebral white matter and the cortex in the brains of multiple sclerosis patients. Microglia/macrophages associated with chronic white matter lesions are thought to be responsible for slow lesion expansion and disability progression in progressive multiple sclerosis, whereas those lining gray matter lesions are less studied. Profiling these microglia/macrophages could help to focus therapies on genes or pathways specific to lesion expansion and disease progression.

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Outside the protection of Earth's magnetic field, organisms are constantly exposed to space radiation consisting of energetic protons and other heavier charged particles. With the goal of crewed Mars exploration, the production of fresh food during long duration space missions is critical for meeting astronauts' nutritional and psychological needs. However, the biological effects of space radiation on plants have not been sufficiently investigated and characterized.

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A long-lived latent reservoir of HIV-1-infected CD4 T cells persists with antiretroviral therapy and prevents cure. We report that the emergence of latently infected primary CD4 T cells requires the activity of histone deacetylase enzymes HDAC1/2 and HDAC3. Data from targeted HDAC molecules, an HDAC3-directed PROTAC, and CRISPR-Cas9 knockout experiments converge on a model where either HDAC1/2 or HDAC3 targeting can prevent latency, whereas all three enzymes must be targeted to achieve latency reversal.

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Background: The adjuvanted recombinant zoster vaccine (RZV) is highly effective even in adults over 80 years old. The high efficacy of RZV is attributed to its highly reactogenic adjuvant, AS01, but limited studies have been done on AS01's activation of human immune cells.

Methods: We stimulated peripheral blood mononuclear cells (PBMC) with AS01 and used flow cytometry and RNA Sequencing (RNAseq) to analyze the impacts on human primary cells.

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Article Synopsis
  • The late stages of Golgi maturation involve producing cargo-laden vesicles that are targeted to various subcellular locations, relying on the activation of Arf GTPases by the Sec7/BIG guanine nucleotide exchange factor (GEF).
  • Sec7's localization and activity are controlled by mechanisms like autoinhibition, positive feedback, and interactions with other GTPases, but the full details of this regulation remain unclear.
  • The study presents the cryoEM structure of autoinhibited Sec7, revealing its regulatory domains, and explains the transition to an active form on organelle membranes through functional experiments and structural predictions.
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Introduction: Significant heterogeneity exists within the tumor-infiltrating CD8 T cell population, and exhausted T cells harbor a subpopulation that may be replicating and may retain signatures of activation, with potential functional consequences in tumor progression. Dysfunctional immunity in the tumor microenvironment is associated with poor cancer outcomes, making exploration of these exhausted T cell subpopulations critical to the improvement of therapeutic approaches.

Methods: To investigate mechanisms associated with terminally exhausted T cells, we sorted and performed transcriptional profiling of CD8 tumor-infiltrating lymphocytes (TILs) co-expressing the exhaustion markers PD-1 and TIM-3 from large-volume melanoma tumors.

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Human immunodeficiency virus (HIV) is associated with persistent immune activation and dysfunction in people with HIV despite treatment with antiretroviral therapy (ART). Modulation of the immune system may be driven by: low-level HIV replication, co-pathogens, gut dysbiosis /translocation, altered lipid profiles, and ART toxicities. In addition, perinatally acquired HIV (PHIV) and lifelong ART may alter the development and function of the immune system.

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Ribosomal proteins play diverse roles in development and disease. Most ribosomal proteins have canonical roles in protein synthesis, while some exhibit extra-ribosomal functions. Previous studies in our laboratory revealed that ribosomal protein L13a (RPL13a) is involved in the translational silencing of a cohort of inflammatory proteins in myeloid cells.

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Background: Daily oral pre-exposure prophylaxis (PrEP) can reduce HIV incidence in pregnant and breastfeeding women, but adherence is essential.

Methods: We conducted a pilot randomized trial to evaluate an intervention package to enhance antenatal and postnatal PrEP use in Lilongwe, Malawi. The intervention was based on patient-centered counseling adapted from previous PrEP studies, with the option of a participant-selected adherence supporter.

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