Intrinsically determined turnover underlies broad heterogeneity in plasma-cell lifespan.

Antibodies produced by antibody-secreting plasma cells (ASCs) underlie multiple forms of long-lasting immunity. Here we examined the mechanisms regulating ASC turnover and persistence using a genetic reporter to time-stamp ASCs. This approach revealed ASC lifespans as heterogeneous and falling on a continuum, with only a small fraction surviving for >60 days. ASC longevity past 60 days was independent of isotype but correlated with a phenotype that developed progressively and ultimately associated with an underlying "long-lived" ASC (LL ASC)-enriched transcriptional program. While some of the differences between LL ASCs and other ASCs appeared to be acquired with age, other features were shared with some younger ASCs, such as high CD138 and CD93. Turnover was unaffected by altered ASC production, arguing against competition for niches as a major driver of turnover. Thus, ASC turnover is set by intrinsic lifespan limits, with steady-state population dynamics governed by niche vacancy rather than displacement.

It takes a sec(22b) to accrue plasma cells.

A recent study shows that the SNARE protein Sec22b plays a key role in antibody-secreting plasma cell accrual. Without Sec22b, antibody titres were diminished, and plasma cells rare to undetectable. The few plasma cells that were detected were functionally compromised, with altered organelle morphology and deficient antibody production.

Evaluation of Minimal Important Difference and Responder Definition in the EORTC QLQ-PAN26 Module for Assessing Health-Related Quality of Life in Patients with Surgically Resected Pancreatic Adenocarcinoma.

BACKGROUND: Although the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-PAN26 is widely used to assess health-related quality of life (HRQoL), its group-level minimal important difference (MID) and individual-level responder definition (RD) are not established; we calculated MID and RD using HRQoL data from the APACT trial in patients with surgically resected pancreatic cancer who received adjuvant chemotherapy. METHODS: HRQoL was assessed using EORTC QLQ-C30 and QLQ-PAN26 at baseline, during treatment, at end of treatment, and during follow-up. Distribution-based MIDs were estimated using 0.5 × baseline standard deviation (SD) and reliability-based (intraclass correlation) standard error of measurement (SEM). Anchor-based MIDs and RDs (anchor, QLQ-C30 overall health) were estimated using a linear mixed model. RESULTS: Overall, 772 patients completed the baseline assessment. Distribution-based MIDs (0.5 × SD) for QLQ-PAN26 scales ranged from 12 to 13, except hepatic symptoms (≈8), pancreatic pain (≈10), and sexual dysfunction (≈17); those for stand-alone items ranged from 12 to 16. The SEM values were similar. Among scales/items sufficiently correlated (r > 0.30) with the anchor, MIDs ranged from 5 to 9. Within-patient QLQ-PAN26 RD estimates varied by direction (deterioration vs. improvement) and scale/item, but all values were lower than the true possible within-patient change (e.g. 16.7 points for a two-item scale) given a one-category change on the raw scale. CONCLUSIONS: Compared with distribution-based MIDs, anchor-based MIDs were twice as sensitive in detecting group-level changes in QLQ-PAN26 scales/items. For interpreting clinically meaningful change, RDs cannot be less than the true minimum of the scale. The group-level MID may help clinicians/researchers interpret HRQoL changes. TRIAL REGISTRATION: ClinicalTrials.gov NCT01964430; Eudra CT 2013-003398-91.

Impact of mass drug administration of azithromycin for trachoma elimination on prevalence and azithromycin resistance of genital Mycoplasma genitalium infection.

BACKGROUND: Mass drug administration (MDA) of 20 mg/kg (maximum 1 g in adults) azithromycin for ocular Chlamydia trachomatis (CT) infection is a key component of the WHO trachoma elimination strategy. However, this dose may be suboptimal in Mycoplasma genitalium infection and may encourage emergence of antimicrobial resistance (AMR) to azithromycin. OBJECTIVES: To determine the effect of MDA for trachoma elimination on M. genitalium prevalence, strain type and azithromycin resistance. METHODS: A secondary analysis of CT-negative vulvovaginal swabs from three outpatient antenatal clinics (Honiara, Solomon Islands) from patients recruited either pre-MDA, or 10 months post-MDA in two cross-sectional surveys was carried out. Swabs were tested for M. genitalium infection using Fast Track Diagnostics Urethritis Plus nucleic acid amplification assay. M. genitalium-positive samples were subsequently tested for azithromycin resistance by sequencing domain V of the 23S rRNA DNA region of M. genitalium and underwent phylogenetic analysis by dual locus sequence typing. RESULTS: M. genitalium prevalence was 11.9% (28/236) in women pre-MDA and 10.9% (28/256) 10 months post-MDA (p=0.7467). Self-reported receipt of azithromycin as part of MDA was 49.2% in women recruited post-MDA and 17.9% (5/28) in those who tested M. genitalium positive. Of samples sequenced (21/28 pre-MDA, 22/28 post-MDA), all showed a macrolide susceptible genotype. Strain typing showed that sequence types diverged into two lineages, with a suggestion of strain replacement post-MDA. CONCLUSION: A single round of azithromycin MDA in an island population with high baseline M. genitalium prevalence did not appear to impact on either prevalence or azithromycin resistance, in contrast to reported decreased genital CT prevalence in the same population. This may be due to limitations such as sample size, including CT-negative samples only, and low MDA coverage. Further investigation of the impact of multiple rounds of MDA on M. genitalium azithromycin AMR in antibiotic experienced and naïve populations is warranted.

A randomized, controlled trial of negative pressure wound therapy of pressure ulcers via a novel polyurethane foam.

The objectives of the study were (1) to look for any local, clinically apparent response, within and around a debrided wound, to a novel biocompatible polyurethane foam during repeated, short-term implantation, and (2) to assess the material's efficacy as a negative pressure wound therapy (NPWT) interface compared with a widely used, commercially available foam. Twenty pressure ulcers in 18 patients underwent surgical debridement, then randomization to receive novel treatment or control foam as the wound interface for NPWT. Dressing changes every 2-3 days allowed qualitative wound assessment and quantitative measurement to compare outcomes. No adverse reaction was observed in any patient receiving the new foam. The new "novel foam" performed as a NPWT interface as effectively as the control "standard foam." In deep wounds, the new foam was easier to remove, fragmented less, and showed less retention than the control foam. No marginal in-growth occurred, making removal less traumatic and reducing bleeding from cavity wall granulations. The results support previous large animal studies, and independent ISO10993 testing, that the new foam is safe and biocompatible. Its efficacy as an NPWT interface, nontraumatic removal with low fragmentation and retention rate, favors the new material, especially in deep cavity wounds.

Instant clot forming and antibacterial wound dressings: Achieving hemostasis in trauma injuries with S-nitroso-N-acetylpenicillamine-tranexamic acid-propolis formulation.

Wound infection and excessive blood loss are the two major challenges associated with trauma injuries that account for 10% of annual deaths in the United States. Nitric oxide (NO) is a gasotransmitter cell signaling molecule that plays a crucial role in the natural wound healing process due to its antibacterial, anti-inflammatory, cell proliferation, and tissue remodeling abilities. Tranexamic acid (TXA), a prothrombotic agent, has been used topically and systemically to control blood loss in reported cases of epistaxis and combat-related trauma injuries. Its properties could be incorporated in wound dressings to induce immediate clot formation, which is a key factor in controlling excessive blood loss. This study introduces a novel, instant clot-forming NO-releasing dressing, and fabricated using a strategic bi-layer configuration. The layer adjacent to the wound was designed with TXA suspended on a resinous bed of propolis, which is a natural bioadhesive possessing antibacterial and anti-inflammatory properties. The base layer, located furthest away from the wound, has an NO donor, S-nitroso-N-acetylpenicillamine (SNAP), embedded in a polymeric bed of Carbosil®, a copolymer of polycarbonate urethane and silicone. Propolis was integrated with a uniform layer of TXA in variable concentrations: 2.5, 5.0, and 7.5 vol % of propolis. This design of the TXA-SNAP-propolis (T-SP) wound dressing allows TXA to form a more stable clot by preventing the lysis of fibrin. The lactate dehydrogenase-based platelet adhesion assay showed an increase in fibrin activation with 7.5% T-SP as compared with control within the first 15 min of its application. A scanning electron microscope (SEM) confirmed the presence of a dense fibrin network stabilizing the clot for fabricated dressing. The antibacterial activity of NO and propolis resulted in a 98.9 ± 1% and 99.4 ± 1% reduction in the colony-forming unit of Staphylococcus aureus and multidrug-resistant Acinetobacter baumannii, respectively, which puts forward the fabricated dressing as an emergency first aid for traumatic injuries, preventing excessive blood loss and soil-borne infections.

The Association Between Physical Distancing Behaviors to Avoid COVID-19 and Health-Related Quality of Life in Immunocompromised and Nonimmunocompromised Individuals: Patient-Informed Protocol for the Observational, Cross-Sectional EAGLE Study.

BACKGROUND: Immunocompromised individuals are known to respond inadequately to SARS-CoV-2 vaccines, placing them at high risk of severe or fatal COVID-19. Thus, immunocompromised individuals and their caregivers may still practice varying degrees of social or physical distancing to avoid COVID-19. However, the association between physical distancing to avoid COVID-19 and quality of life has not been comprehensively evaluated in any study. OBJECTIVE: We aim to measure physical distancing behaviors among immunocompromised individuals and the association between those behaviors and person-centric outcomes, including health-related quality of life (HRQoL) measures, health state utilities, anxiety and depression, and work and school productivity impairment. METHODS: A patient-informed protocol was developed to conduct the EAGLE Study, a large cross-sectional, observational study, and this paper describes that protocol. EAGLE is designed to measure distancing behaviors and outcomes in immunocompromised individuals, including children (aged ≥6 mo) and their caregivers, and nonimmunocompromised adults in the United States and United Kingdom who report no receipt of passive immunization against COVID-19. We previously developed a novel self- and observer-reported instrument, the Physical Distancing Scale for COVID-19 Avoidance (PDS-C19), to measure physical distancing behavior levels cross-sectionally and retrospectively. Using an interim or a randomly selected subset of the study population, the PDS-C19 psychometric properties will be assessed, including structural validity, internal consistency, known-group validity, and convergent validity. Associations (correlations) will be assessed between the PDS-C19 and validated HRQoL-related measures and utilities. Structural equation modeling and regression will be used to assess these associations, adjusting for potential confounders. Participant recruitment and data collection took place from December 2022 to June 2023 using direct-to-patient channels, including panels, clinician referral, patient advocacy groups, and social media, with immunocompromising diagnosis confirmation collected and assessed for a randomly selected 25% of immunocompromised participants. The planned total sample size is 3718 participants and participant-caregiver pairs. Results will be reported by immunocompromised status, immunocompromising condition category, country, age group, and other subgroups. RESULTS: All data analyses and reporting were planned to be completed by December 2023. Results are planned to be submitted for publication in peer-reviewed journals in 2024-2025. CONCLUSIONS: This study will quantify immunocompromised individuals' physical distancing behaviors to avoid COVID-19 and their association with HRQoL as well as health state utilities. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR1-10.2196/52643.

Comparative effectiveness of sotrovimab versus no treatment in non-hospitalised high-risk COVID-19 patients in north west London: a retrospective cohort study.

BACKGROUND: We assessed the effectiveness of sotrovimab vs no early COVID-19 treatment in highest-risk COVID-19 patients during Omicron predominance. METHODS: Retrospective cohort study using the Discover dataset in North West London. Included patients were non-hospitalised, aged ≥12 years and met ≥1 National Health Service highest-risk criterion for sotrovimab treatment. We used Cox proportional hazards models to compare HRs of 28-day COVID-19-related hospitalisation/death between highest-risk sotrovimab-treated and untreated patients. Age, renal disease and Omicron subvariant subgroup analyses were performed. RESULTS: We included 599 sotrovimab-treated patients and 5191 untreated patients. Compared with untreated patients, the risk of COVID-19 hospitalisation/death (HR 0.50, 95% CI 0.24, 1.06; p=0.07) and the risk of COVID-19 hospitalisation (HR 0.43, 95% CI 0.18, 1.00; p=0.051) were both lower in the sotrovimab-treated group; however, statistical significance was not reached. In the ≥65 years and renal disease subgroups, sotrovimab was associated with a significantly reduced risk of COVID-19 hospitalisation, by 89% (HR 0.11, 95% CI 0.02, 0.82; p=0.03) and 82% (HR 0.18, 95% CI 0.05, 0.62; p=0.007), respectively. CONCLUSIONS: Risk of COVID-19 hospitalisation in sotrovimab-treated patients aged ≥65 years and with renal disease was significantly lower compared with untreated patients. Overall, risk of hospitalisation was also lower for sotrovimab-treated patients, but statistical significance was not reached.

Sonographic appearance of invasive ductal carcinoma of the breast according to histologic grade.

OBJECTIVE: The purpose of this study was to compare the efficacy of the sonographic features in the BI-RADS lexicon for predicting malignancy grade of invasive ductal breast carcinoma in women assigned a BI-RADS category of 4 or 5. MATERIALS AND METHODS: Two radiologists retrospectively evaluated 299 consecutive cases of grades 1-3 invasive ductal breast carcinoma presenting as a mass in consensus by using the BI-RADS sonographic lexicon. Histologic grade was established on surgical specimens. Effect sizes were calculated via the Goodman and Kruskal tau, an asymmetric measure of strength of nominal association, and results were interpreted in terms of proportional reduction in error. RESULTS: Thirty-eight lesions (13%) were grade 1, 153 (51%) were grade 2, and 108 (36%) were grade 3, with the majority of all masses showing an irregular shape (84%) and hypoechoic echotexture (82%). Of the sonographic features examined, malignancy grade was best predicted by posterior acoustics (τ = 0.13, p < 0.001), lesion boundary (τ = 0.05, p < 0.001), and margin (τ = 0.04, p = 0.001). Among grade 3 lesions, there were significantly more lesions with posterior enhancement (53 vs 27.6; adjusted standardized residuals (z(res)) = 7; p < 0.001), abrupt interfaces (68 vs 51.2; z(res) = 4; p < 0.001), and microlobulated margins (12 vs 5.8; z(res) = 3; p = 0.001) than would be expected. CONCLUSION: Malignancy grade was slightly to moderately predicted by margin, lesion boundary, and acoustic sonographic features. In particular, grade 3 invasive ductal breast carcinomas were more likely than expected to display microlobulated margins, abrupt interfaces, and posterior enhancement.

Development and Validation of a Visual Symptom-Specific Patient-Reported Outcomes Instrument for Adults With Cataract Intraocular Lens Implants.

PURPOSE: To develop a patient-reported outcome measure for capturing visual and ocular symptoms before and after implantation of intraocular lenses (IOLs) for treatment of cataracts. DESIGN: Questionnaire development and validation study. METHODS: The Questionnaire for Visual Disturbances (QUVID) was developed based on a literature and instrument review; 13 clinician interviews among ophthalmologists in the United States and Europe; and 67 hybrid qualitative patient interviews among adult patients in the United States and Australia before and/or after monofocal, traditional multifocal, or trifocal IOL implantation. Assessment of the QUVID's psychometric properties was conducted via a noninterventional cross-sectional study of previously treated cataract patients in the United States, Canada, and Australia (n = 150), and assessment of ability to detect meaningful change via 2 pivotal US clinical trials among patients with trifocal or extended vision IOL compared with monofocal IOL controls (n = 457). RESULTS: The QUVID includes subitems about the bothersomeness of 7 visual symptoms: starburst, halo, glare, hazy vision, blurred vision, double vision, and dark areas. The postoperative version contains 1 item asking the respondents whether their symptoms bothered them enough to want another surgery, if the IOL was the cause. CONCLUSIONS: The QUVID was reviewed by the US Food and Drug Administration and found appropriate as a fit-for-purpose measure, demonstrating requisite evidence for content validity, construct validity, reliability, and ability to detect change.

Long-lived plasma cells accumulate in the bone marrow at a constant rate from early in an immune response.

Vaccines work largely by generating long-lived plasma cells (LLPCs), but knowledge of how such cells are recruited is sparse. Although it is clear that LLPCs preferentially originate in germinal centers (GCs) and relocate to survival niches in bone marrow where they can persist for decades, the issues of the timing of LLPC recruitment and the basis of their retention remain uncertain. Here, using a genetic timestamping system in mice, we show that persistent PCs accrue in bone marrow at an approximately constant rate of one cell per hour over a period spanning several weeks after a single immunization with a model antigen. Affinity-based selection was evident in persisting PCs, reflecting a relative and dynamic rather than absolute affinity threshold as evidenced by the changing pattern of VH gene somatic mutations conveying increased affinity for antigen. We conclude that the life span of persistent, antigen-specific PCs is in part intrinsic, preprogrammed, and varied and that their final number is related to the duration of the response in a predictable way. This implies that modulating vaccines to extend the duration of the GC reaction will enhance antibody-mediated protective immunity.

DHODH inhibition modulates glucose metabolism and circulating GDF15, and improves metabolic balance.

Dihydroorotate dehydrogenase (DHODH) is essential for the de novo synthesis of pyrimidine ribonucleotides, and as such, its inhibitors have been long used to treat autoimmune diseases and are in clinical trials for cancer and viral infections. Interestingly, DHODH is located in the inner mitochondrial membrane and contributes to provide ubiquinol to the respiratory chain. Thus, DHODH provides the link between nucleotide metabolism and mitochondrial function. Here we show that pharmacological inhibition of DHODH reduces mitochondrial respiration, promotes glycolysis, and enhances GLUT4 translocation to the cytoplasmic membrane and that by activating tumor suppressor p53, increases the expression of GDF15, a cytokine that reduces appetite and prolongs lifespan. In addition, similar to the antidiabetic drug metformin, we observed that in db/db mice, DHODH inhibitors elevate levels of circulating GDF15 and reduce food intake. Further analysis using this model for obesity-induced diabetes revealed that DHODH inhibitors delay pancreatic ß cell death and improve metabolic balance.

Paclitaxel inhibits killing by murine cytotoxic T lymphocytes in vivo but not in vitro.

To kill antigen-specific target cells (TCs), cytotoxic T lymphocytes (CTLs) reorganise their microtubule cytoskeleton to deliver lytic granules to the TCs. We used two drugs that stabilise microtubules, paclitaxel and peloruside, to determine how the stabilising microtubule network affects CTL function in vitro and in vivo. In vitro, neither paclitaxel nor peloruside inhibited antigen-specific killing, lytic granule delivery to the cell surface, nor interferon-gamma release by murine CTLs. In contrast, in an in vivo murine model of antigen-induced killing, a single dose of paclitaxel had a significant inhibitory effect on killing by CTLs. Furthermore, the inhibitory effect of paclitaxel was not caused by specific deletion of the effector CTL population in drug-treated mice. The findings reveal that microtubule-stabilising drug treatment can lead to immediate impairment of CTL function without affecting lytic granule release. The results also suggest that patients undergoing taxane anti-cancer therapy may be impaired in their ability to fight infection before the anti-mitotic effects of paclitaxel are apparent.

The Amount of BCL6 in B Cells Shortly after Antigen Engagement Determines Their Representation in Subsequent Germinal Centers.

It is unknown whether the incremental increases in BCL6 amounts in antigen-activated B cells influence the unfolding differentiation before germinal center (GC) formation. By comparing shortly after immunization the distribution of conventional B cells to those enforced to express BCL6 at the upper quartile of normal and those lacking BCL6 altogether, we determined that B cell representation in the stages before the GC compartment was related to BCL6 amounts. This was not by increased proliferation or suppression of early plasmablast differentiation, but rather by preferential recruitment and progression through these early stages of B cell activation, culminating in preferential transition into GC. Once established, this bias was stable in GC over several weeks; other BCL6-regulated GC B cell behaviors were unaffected. We propose that setting BCL6 amounts very early in activated B cells will be central in determining clonal representation in the GC and thus memory populations.

An Assessment of Clinically Important Differences on the Worst Pain Severity Item of the Modified Brief Pain Inventory in Patients with Diabetic Peripheral Neuropathic Pain.

Objectives: Using patient global impression of change (PGIC) as an anchor, an approximately 30% reduction on an 11-point numeric pain intensity rating scale (PI-NRS) is considered a clinically important difference (CID) in pain. Our objective was to define the CID for another pain measure, the worst pain severity (WPS) item of the modified Brief Pain Inventory (m-BPI). Methods: In this post hoc analysis of a double-blind, placebo-controlled, phase 2 study, 452 randomized patients with diabetic peripheral neuropathic pain (DPNP) were followed over 5 weeks, with m-BPI data collected weekly and PGIC at treatment conclusion. Receiver operating characteristic (ROC) curves (via logistic regression) were used to determine the changes in the m-BPI-WPS score that best predicted ordinal clinical improvement thresholds (i.e., "minimally improved" or better) on the PGIC. Results: Similar to the PI-NRS, a change of -3 (raw) or -33.3% from the baseline on the m-BPI-WPS optimized prediction for the "much improved" or better PGIC threshold and represents a CID. There was a high correspondence between observed and predicted PGIC categories at each PGIC threshold (ROC AUCs were 0.78-0.82). Conclusions: Worst pain on the m-BPI may be used to assess clinically important improvements in DPNP studies. Findings require validation in larger studies.

Reconstruction of Extensive Calvarial Exposure After Major Burn Injury in 2 Stages Using a Biodegradable Polyurethane Matrix.

OBJECTIVES: To share our experience of an extensive calvarial reconstruction in a severely burn-injured, elderly patient in a 2-stage procedure utilizing a novel biodegradable temporizing matrix (NovoSorb BTM), followed by autograft. MATERIALS AND METHODS: A 66-year-old patient with 75% full-thickness burns, including 7% total body surface area head and neck, with calvarial exposure of approximately 350 cm(2), complicated by acute renal failure and smoke inhalation injury. Exposed calvarium was burred down to diploe and biodegradable temporizing matrix was applied. Over the next 29 days, the biodegradable temporizing matrix integrated by vascular and tissue ingrowth from the diploe. Delamination and grafting occurred, however, at 43 days postimplantation of biodegradable temporizing matrix due to skin graft donor-site constraints. RESULTS: Graft take was complete, yielding a robust and aesthetically pleasing early result (26 days post-graft application). CONCLUSIONS: Biodegradable temporizing matrix offers an additional resource for reconstructive surgeons faced with fragile patients and complex wounds.

Bilateral upper limb trainer with virtual reality for post-stroke rehabilitation: case series report.

PURPOSE: Stroke is a leading cause of disability with many survivors having upper limb (UL) hemiparesis. UL rehabilitation using bilateral exercise enhances outcomes and the Bilateral Upper Limb Trainer (BUiLT) was developed to provide symmetrical, bilateral arm exercise in a 'forced' and self-assistive manner, incorporating virtual reality (VR) to provide direction and task specificity to users as well as action observation-execution and greater motivation to exercise. METHODS: The BUiLT + VR system was trialled on five post-stroke participants with UL hemiparesis: one sub-acute and four chronic. The intervention was supplied for 45 min, 4 days/week for 6 weeks. The Fugl-Meyer Upper Extremity score (FMA-UE) was used as the primary outcome measure. Secondary outcome measures used were UL isometric strength and the Intrinsic Motivation Inventory (IMI) questionnaire. RESULTS: The BUiLT + VR therapy increased FMA-UE scores from 1 to 5 and overall strength in the shoulder and elbow. Motivation at the end of intervention was positive. CONCLUSIONS: Therapy using the BUiLT + VR system is reliable, can be administered safely and has a positive trend of benefit as measured by the FMA-UE, isometric strength testing and IMI questionnaire.

Rattus Psychologicus: construction of preferences by self-stimulating rats.

Behavioral economists have proposed that human preferences are constructed during their elicitation and are thus influenced by the elicitation procedure. For example, different preferences are expressed when options are encountered one at a time or concurrently. This phenomenon has been attributed to differences in the "evaluability" of a particular attribute when comparison to an option with a different value of this attribute is or is not available. Research on the preferences of laboratory animals has often been carried out by means of operant-conditioning methods. Formal treatments of operant behavior relate preferences to variables such as the strength and cost of reward but do not address the evaluability of these variables. Two experiments assessed the impact of procedural factors likely to alter the evaluability of an opportunity cost ("price"): the work time required for a rat to earn a train of rewarding electrical brain stimulation. The results support the notion that comparison between recently encountered prices is necessary to render the price variable highly evaluable. When price is held constant over many trials and test sessions, the evaluability of this variable appears to decline. Implications are discussed for the design of procedures for estimating subjective reward strengths and costs in operant-conditioning experiments aimed at characterizing, identifying and understanding neural circuitry underlying evaluation and choice.