Fisetin for COVID-19 in skilled nursing facilities: Senolytic trials in the COVID era

The burden of senescent cells (SnCs), which do not divide but are metabolically active and resistant to death by apoptosis, is increased in older adults and those with chronic diseases. These individuals are also at the greatest risk for morbidity and mortality from SARS-CoV-2 infection. SARS-CoV-2 complications include cytokine storm and multiorgan failure mediated by the same factors as often produced by SnCs through their senescence-associated secretory phenotype (SASP). The SASP can be amplified by infection-related pathogen-associated molecular profile factors. Senolytic agents, such as Fisetin, selectively eliminate SnCs and delay, prevent, or alleviate multiple disorders in aged experimental animals and animal models of human chronic diseases, including obesity, diabetes, and respiratory diseases. Senolytics are now in clinical trials for multiple conditions linked to SnCs, including frailty; obesity/diabetes; osteoporosis; and cardiovascular, kidney, and lung diseases, which are also risk factors for SARS-CoV-2 morbidity and mortality. A clinical trial is underway to test if senolytics decrease SARS-CoV-2 progression and morbidity in hospitalized older adults. We describe here a National Institutes of Health-funded, multicenter, placebo-controlled clinical trial of Fisetin for older adult skilled nursing facility (SNF) residents who have been, or become, SARS-CoV-2 rtPCR-positive, including the rationale for targeting fundamental aging mechanisms in such patients. We consider logistic challenges of conducting trials in long-term care settings in the SARS-CoV-2 era, including restricted access, consent procedures, methods for obtaining biospecimens and clinical data, staffing, investigational product administration issues, and potential solutions for these challenges. We propose developing a national network of SNFs engaged in interventional clinical trials.     

Preclinical to Clinical Translation of CNS Transporter Occupancy of TD-9855, a Novel Norepinephrine and Serotonin Reuptake Inhibitor

Background:

Monoamine reuptake inhibitors exhibit unique clinical profiles that reflect distinct engagement of the central nervous system (CNS) transporters.

Methods:

We used a translational strategy, including rodent pharmacokinetic/pharmacodynamic modeling and positron emission tomography (PET) imaging in humans, to establish the transporter profile of TD-9855, a novel norepinephrine and serotonin reuptake inhibitor.

Results:

TD-9855 was a potent inhibitor of norepinephrine (NE) and serotonin 5-HT uptake in vitro with an inhibitory selectivity of 4- to 10-fold for NE at human and rat transporters. TD-9855 engaged norepinephrine transporters (NET) and serotonin transporters (SERT) in rat spinal cord, with a plasma EC₅₀ of 11.7ng/mL and 50.8ng/mL, respectively, consistent with modest selectivity for NET in vivo.Accounting for species differences in protein binding, the projected human NET and SERT plasma EC₅₀ values were 5.5ng/mL and 23.9ng/mL, respectively. A single-dose, open-label PET study (4–20mg TD-9855, oral) was conducted in eight healthy males using the radiotracers [¹¹C]-3-amino-4- [2-[(di(methyl)amino)methyl]phenyl]sulfanylbenzonitrile for SERT and [¹¹C]-(S,S)-methylreboxetine for NET. The long pharmacokinetic half-life (30–40h) of TD-9855 allowed for sequential assessment of SERT and NET occupancy in the same subject. The plasma EC₅₀ for NET was estimated to be 1.21ng/mL, and at doses of greater than 4mg the projected steady-state NET occupancy is high (>75%). After a single oral dose of 20mg, SERT occupancy was 25 (±8)% at a plasma level of 6.35ng/mL.

Conclusions:

These data establish the CNS penetration and transporter profile of TD-9855 and inform the selection of potential doses for future clinical evaluation.     

Differential immune imprinting by influenza virus vaccination and infection in nonhuman primates

Immune memory of a first infection with influenza virus establishes a lasting imprint. Recall of that memory dominates the response to later infections or vaccinations by antigenically drifted strains. Early childhood immunization before infection may leave an imprint with different characteristics. We report here a comparison of imprinting by vaccination and infection in a small cohort of nonhuman primates (NHPs). We assayed serum antibody responses for binding with hemaglutinnins (HAs) both from the infecting or immunizing strain (H3 A/Aichi 02/1968) and from strains representing later H3 antigenic clusters (“forward breadth”) and examined the effects of defined HA mutations on serum titers. Initial exposure by infection elicited strong HA-binding and neutralizing serum antibody responses but with little forward breadth; initial vaccination with HA from the same strain elicited a weaker response with little neutralizing activity but considerable breadth of binding, not only for later H3 HAs but also for HA of the 2009 H1 new pandemic virus. Memory imprinted by infection, reflected in the response to two immunizing boosts, was largely restricted (as in humans) to the outward-facing HA surface, the principal region of historical variation. Memory imprinted by immunization showed exposure to more widely distributed epitopes, including sites that have not varied during evolution of the H3 HA but that yield nonneutralizing responses. The mode of initial exposure thus affects both the strength of the response and the breadth of the imprint; design of next-generation vaccines will need to take the differences into account.

Antigenic exposures determine the acquisition and development of adaptive immunity. The humoral response in a naive individual yields both antibody-secreting plasma cells that recognize the new antigen and memory B cells that can respond to future encounters with related antigens. The combination of these two components can confer long-lasting protection against antigenically stable pathogens. For antigenically diverse pathogens and those that evolve to evade immune pressure (e.g., influenza virus and HIV), serum responses often confer incomplete immunity to future variants (1, 2).The hemagglutinin (HA) and neuraminidase (NA) define the serotype of an influenza virus isolate (3). Antigenic shifts occur when novel animal influenza viruses can transmit to humans, spread rapidly, and initiate pandemics, owing to absence of any preexisting immunity (4, 5). Historically, the descendants of pandemic viruses have become endemic seasonal variants that undergo antigenic drift as they evolve over time to evade dominant human herd immunity (6, 7). For most adults, both processes have shaped human immunity to influenza.Immune memory causes a primary infection to impart an enduring imprint (8–11). Despite a lifetime of repeated exposures to divergent influenza viruses, the relative strength of an individual’s immune response to vaccination or infection correlates with the antigenic similarity of the vaccine or infecting strain to that person’s initial exposure. Until recently, the first encounter was invariably an infection. Because of recent changes in vaccine policy in the United States and Europe, infants and toddlers are now encouraged to receive influenza vaccines before they experience an influenza infection (12, 13). We have little information, however, about the immunological memory to influenza virus established when the primary exposure is vaccination rather than infection.Using nonhuman primates (rhesus macaques) as a model, we have examined how the mode of influenza exposure affects both primary and secondary antibody responses. We found that an initial exposure by infection elicited strong, strain-specific, HA-binding, and neutralizing serum antibody responses. Initial exposure by immunization with the HA protein from the strain used in the infection arm of the study elicited relatively weaker HA-binding responses that lacked neutralization potency but had greater interseasonal forward breadth. Subsequent exposures, by immunization, generated antibodies with increased interseasonal breadth in infected animals and neutralizing activity in the initially immunized monkeys. Initially infected macaques maintained responses that were strongly imprinted by the infecting strain, while those initially immunized with protein retained a serum repertoire that cross-reacted with heterologous HAs. Moreover, the distribution of epitopes bound by serum IgG was different in the two cases. These data suggest that the mode of HA exposure influences its immune imprint and that next-generation vaccine design will need to take this influence into account.     

The effect of the steroidal androgen receptor antagonist, Win 49,596, on the prostate and testis of beagle dogs.

The effect of the steroidal androgen receptor antagonist Win 49,596 on the prostate and testis was studied in beagle dogs and was compared to the effects of the nonsteroidal androgen receptor antagonist ICI 176,334 and the steroidal 5 alpha-reductase inhibitor MK-906. Win 49,596 was shown to bind to the androgen receptor from normal canine prostate with a Ki of 2.2 microM. After 16 weeks of treatment, prostate size, as estimated by transrectal ultrasonography, was unchanged in intact controls and was 26% of the initial size in castrate controls. Oral doses of Win 49,596 from 0.625-40 mg/kg.day for 16 weeks caused dose-dependent prostatic regression and a dose-related increase in both the incidence and severity of glandular atrophy of the prostate. Prostatic secretory function was also inhibited by Win 49,596 treatment. The effects of Win 49,596 at 40 mg/kg.day on prostatic weight, total DNA, histomorphology, and secretory function were similar to those of castration, while the effects of Win 49,596 at 10 mg/kg.day were similar to those of ICI 176,334 at 0.25 mg/kg.day and MK-906 at 1.0 mg/kg.day. No effects on testicular weight, daily sperm production, or spermatogenesis were observed; however, mild Leydig cell hyperplasia was observed in two dogs treated with 40 mg/kg.day Win 49,596. In addition, at 10 and 40 mg/kg.day Win 49,596, moderate but variable increases in serum testosterone levels were observed. In summary, Win 49,596 caused regression of the hypertrophic canine prostate without effects on spermatogenesis and/or sexual function, supporting its possible use in the treatment of human benign prostatic hypertrophy/hyperplasia.     

Stigma,sex work,and substance use: a comparative analysis

Stigma is a widely used concept in social science research and an extensive literature claims that stigmatisation contributes to numerous negative health outcomes. However, few studies compare groups that vary in the extent to which they are stigmatised and even fewer studies examine stigma's independent and mediating effects. This article addresses these gaps in a comparative study of perceived stigma and drug use among three low‐income feminised service occupations: sex work, food and alcoholic beverage serving, and barbering and hairstyling. An analysis of longitudinal data shows positive associations between sex work, perceived stigma, and socially less acceptable drug use (for example, heroin and cocaine), and that stigma mediates part of the link between sex work and the use of these drugs. Our overall findings suggest that perceived stigma is pronounced among those who work in the sex industry and negatively affects health independently of sex work involvement.     

Use of a midstream clean catch mobile application did not lower urine contamination rates in an ED

Objectives

Urine microscopy is a common test performed in emergency departments (EDs). Urine specimens can easily become contaminated by different factors, including the collection method. The midstream clean-catch (MSCC) collection technique is commonly used to reduce urine contamination. The urine culture contamination rate from specimens collected in our ED is 30%. We developed an instructional application (app) to show ED patients how to provide a MSCC urine sample. We hypothesized that ED patients who viewed our instructional app would have significantly lower urine contamination rates compared to patients who did not.