A novel concept for cleavable linkers applicable to conjugation chemistry - design, synthesis and characterization.

Linkers with disulfide bonds are the only cleavable linkers that utilize physiological thiol gradients as a trigger to initiate the intracellular drug release cascade. Herein, we present a novel concept exploiting the thiol gradient phenomena to design a new class of cleavable linker with no disulfide bond. To support the concept, an electron-deficient sulfonamide-based cleavable linker amenable to conjugation of drug molecules with targeting agents, was developed. Modulating the electron-withdrawing nature of the aryl sulfonamide was critical to the balance between the stability and drug release. Favorable stability and payload release in human serum under physiologically relevant thiol concentrations was demonstrated with two potent cytotoxics. Intracellular payload release was further validated in cell-based assay in context of antibody-drug conjugate generated from monoclonal antibody and sulfonamide containing linker. To support the proposed release mechanism, possible downstream by-products formed from the drug-linker adduct were characterized.

Direct impact of COVID-19 vaccination in Chile: averted cases, hospitalizations, ICU admissions, and deaths.

BACKGROUND: Chile rapidly implemented an extensive COVID-19 vaccination campaign, deploying a diversity of vaccines with a strategy that prioritized the elderly and individuals with comorbidities. This study aims to assess the direct impact of vaccination on the number of COVID-19 related cases, hospital admissions, ICU admissions and deaths averted during the first year and a half of the campaign. METHODS: Via Chile's transparency law, we obtained access to weekly event counts categorized by vaccination status and age. Integrating this data with publicly available census and vaccination coverage information, we conducted a comparative analysis of weekly incidence rates between vaccinated and unvaccinated groups from December 20, 2020 to July 2, 2022 to estimate the direct impact of vaccination in terms of the number of cases, hospitalizations, ICU admissions and deaths averted, using an approach that avoids the need to explicitly specify the effectiveness of each vaccine deployed. RESULTS: We estimated that, from December 20, 2020 to July 2, 2022 the vaccination campaign directly prevented 1,030,648 (95% Confidence Interval: 1,016,975-1,044,321) cases, 268,784 (95% CI: 264,524-273,045) hospitalizations, 85,830 (95% CI: 83,466-88,194) ICU admissions and 75,968 (95% CI: 73,909-78,028) deaths related to COVID-19 among individuals aged 16 years and older. This corresponds to a reduction of 26% of cases, 66% of hospital admissions, 70% of ICU admissions and 67% of deaths compared to a scenario without vaccination. Individuals 55 years old or older represented 67% of hospitalizations, 73% of ICU admissions and 89% of deaths related to COVID-19 prevented. CONCLUSIONS: This study highlights the role of Chile's vaccination campaign in reducing COVID-19 disease burden, with the most substantial reductions observed in severe outcomes.

Regenerative Peripheral Nerve Interface: Surgical Protocol for a Randomized Controlled Trial in Postamputation Pain.

Surgical procedures, including nerve reconstruction and end-organ muscle reinnervation, have become more prominent in the prosthetic field over the past decade. Primarily developed to increase the functionality of prosthetic limbs, these surgical procedures have also been found to reduce postamputation neuropathic pain. Today, some of these procedures are performed more frequently for the management and prevention of postamputation pain than for prosthetic fitting, indicating a significant need for effective solutions to postamputation pain. One notable emerging procedure in this context is the Regenerative Peripheral Nerve Interface (RPNI). RPNI surgery involves an operative approach that entails splitting the nerve end longitudinally into its main fascicles and implanting these fascicles within free denervated and devascularized muscle grafts. The RPNI procedure takes a proactive stance in addressing freshly cut nerve endings, facilitating painful neuroma prevention and treatment by enabling the nerve to regenerate and innervate an end organ, i.e., the free muscle graft. Retrospective studies have shown RPNI's effectiveness in alleviating postamputation pain and preventing the formation of painful neuromas. The increasing frequency of utilization of this approach has also given rise to variations in the technique. This article aims to provide a step-by-step description of the RPNI procedure, which will serve as the standardized procedure employed in an international, randomized controlled trial (ClinicalTrials.gov, NCT05009394). In this trial, RPNI is compared to two other surgical procedures for postamputation pain management, specifically, Targeted Muscle Reinnervation (TMR) and neuroma excision coupled with intra-muscular transposition and burying.

Risks for animal and human health related to the presence of polychlorinated naphthalenes (PCNs) in feed and food.

EFSA was asked for a scientific opinion on the risks for animal and human health related to the presence of polychlorinated naphthalenes (PCNs) in feed and food. The assessment focused on hexaCNs due to very limited data on other PCN congeners. For hexaCNs in feed, 217 analytical results were used to estimate dietary exposures for food-producing and non-food-producing animals; however, a risk characterisation could not be performed because none of the toxicological studies allowed identification of reference points. The oral repeated dose toxicity studies performed in rats with a hexaCN mixture containing all 10 hexaCNs indicated that the critical target was the haematological system. A BMDL20 of 0.05 mg/kg body weight (bw) per day was identified for a considerable decrease in the platelet count. For hexaCNs in food, 2317 analytical results were used to estimate dietary exposures across dietary surveys and age groups. The highest exposure ranged from 0.91 to 29.8 pg/kg bw per day in general population and from 220 to 559 pg/kg bw per day for breast-fed infants with the highest consumption of breast milk. Applying a margin of exposure (MOE) approach, the estimated MOEs for the high dietary exposures ranged from 1,700,000 to 55,000,000 for the general population and from 90,000 to 230,000 for breast-fed infants with the highest consumption of breast milk. These MOEs are far above the minimum MOE of 2000 that does not raise a health concern. Taking account of the uncertainties affecting the assessment, the Panel concluded with at least 99% certainty that dietary exposure to hexaCNs does not raise a health concern for any of the population groups considered. Due to major limitations in the available data, no assessment was possible for genotoxic effects or for health risks of PCNs other than hexaCNs.

Targeted Muscle Reinnervation: Surgical Protocol for a Randomized Controlled Trial in Postamputation Pain.

Over the past decade, the field of prosthetics has witnessed significant progress, particularly in the development of surgical techniques to enhance the functionality of prosthetic limbs. Notably, novel surgical interventions have had an additional positive outcome, as individuals with amputations have reported neuropathic pain relief after undergoing such procedures. Subsequently, surgical techniques have gained increased prominence in the treatment of postamputation pain, including one such surgical advancement - targeted muscle reinnervation (TMR). TMR involves a surgical approach that reroutes severed nerves as a type of nerve transfer to "target" motor nerves and their accompanying motor end plates within nearby muscles. This technique originally aimed to create new myoelectric sites for amplified electromyography (EMG) signals to enhance prosthetic intuitive control. Subsequent work showed that TMR also could prevent the formation of painful neuromas as well as reduce postamputation neuropathic pain (e.g., Residual and Phantom Limb Pain). Indeed, multiple studies have demonstrated TMR's effectiveness in mitigating postamputation pain as well as improving prosthetic functional outcomes. However, technical variations in the procedure have been identified as it is adopted by clinics worldwide. The purpose of this article is to provide a detailed step-by-step description of the TMR procedure, serving as the foundation for an international, randomized controlled trial (ClinicalTrials.gov, NCT05009394), including nine clinics in seven countries. In this trial, TMR and two other surgical techniques for managing postamputation pain will be evaluated.

Biogelx-IKVAV Is An Innovative Human Platelet Lysate-Adipose-Derived Stem Cells Delivery Strategy to Improve Peripheral Nerve Repair.

Adipose-derived stem cells (ADSC) are nowadays one of the most exploited cells in regenerative medicine. They are fast growing, capable of enhancing axonal elongation, support and locally stimulate Schwann cells (SCs), and protect de-innervated muscles from atrophy after a peripheral nerve injury. With the aim of developing a bio-safe, clinically translatable cell-therapy, we assessed the effect of ADSC pre-expanded with human platelet lysate in an in vivo rat model, delivering the cells into a 15 mm critical-size sciatic nerve defect embedded within a laminin-peptide-functionalized hydrogel (Biogelx-IKVAV) wrapped by a poly-ɛ-caprolactone (PCL) nerve conduit. ADSC retained their stemness, their immunophenotype and proliferative activity when tested in vitro. At 6 weeks post-implantation, robust regeneration was observed across the critical-size gap as evaluated by both the axonal elongation (anti-NF 200) and SC proliferation (anti-S100) within the human ADSC-IKVAV filled PCL conduit. All the other experimental groups manifested significantly lower levels of growth cone elongation. The histological gastrocnemius muscle analysis was comparable with no quantitative significant differences among the experimental groups. Taken together, these results suggest that ADSC encapsulated in Biogelx-IKVAV are a potential path to improve the efficacy of nerve regeneration. New perspectives can be pursued for the development of a fully synthetic bioengineered nerve graft for the treatment of peripheral nerve injury.

Identification of prognostic biomarkers for antibiotic associated nephrotoxicity in cystic fibrosis.

BACKGROUND: Our objective was to discover novel urinary biomarkers of antibiotic-associated nephrotoxicity using an ex-vivo human microphysiological system (MPS) and to translate these findings to a prospectively enrolled cystic fibrosis (CF) population receiving aminoglycosides and/or polymyxin E (colistin) for a pulmonary exacerbation. METHODS: We populated the MPS with primary human kidney proximal tubule epithelial cells (PTECs) from three donors and modeled nephrotoxin injury through exposure to 50 µg/mL polymyxin E for 72 h. We analyzed gene transcriptional responses by RNAseq and tested MPS effluents. We translated candidate biomarkers to a CF cohort via analysis of urine collected prior to, during and two weeks after antibiotics and patients were followed for a median of 3 years after antibiotic use. RESULTS: Polymyxin E treatment resulted in a statistically significant increase in the pro-apoptotic Fas gene relative to control in RNAseq of MPS: fold-change = 1.63, FDR q-value = 7.29 × 10-5. Effluent analysis demonstrated an acute rise of soluble Fas (sFas) concentrations that correlated with cellular injury. In 16 patients with CF, urinary sFas concentrations were significantly elevated during antibiotic treatment, regardless of development of AKI. Over a median of three years of follow up, we identified seven cases of incident chronic kidney disease (CKD). Urinary sFas concentrations during antibiotic treatment were significantly associated with subsequent development of incident CKD (unadjusted relative risk = 2.02 per doubling of urinary sFas, 95 % CI = 1.40, 2.90, p < 0.001). CONCLUSIONS: Using an ex-vivo MPS, we identified a novel biomarker of proximal tubule epithelial cell injury, sFas, and translated these findings to a clinical cohort of patients with CF.

The G-alpha Gpa1 directs septin localization in the mating projection of Saccharomyces cerevisiae through its Ubiquitination Domain and Endocytic Machinery.

The yeast mating response uses a G-protein coupled receptor (GPCR), Ste2, to detect mating pheromone and initiate mating projection morphogenesis. The septin cytoskeleton plays a key role in the formation of the mating projection, forming structures at the base of the projection. Desensitization of the Gα, Gpa1, by the Regulator of G-protein Signaling (RGS), Sst2, is required for proper septin organization and morphogenesis. In cells where the Gα is hyperactive, septins are mislocalized to the site of polarity, and the cells are unable to track a pheromone gradient. We set out to identify the proteins that mediate Gα control of septins during the Saccharomyces cerevisiae mating response by making mutations to rescue septin localization in cells expressing the hyperactive Gα mutant gpa1G302S. We found that single deletions of the septin chaperone Gic1, the Cdc42 GAP Bem3, and the epsins Ent1 and Ent2 rescued the polar cap accumulation of septins in the hyperactive Gα. We created an agent-based model of vesicle trafficking that predicts how changes in endocytic cargo licensing alters localization of endocytosis that mirrors the septin localization we see experimentally. We hypothesized that hyperactive Gα may increase the rate of endocytosis of a pheromone responsive cargo, thereby altering where septins are localized. Both the GPCR and the Gα are known to be internalized by clathrin-mediated endocytosis during the pheromone response. Deletion of the GPCR C-terminus to block internalization partially rescued septin organization. However, deletion of the Gpa1 ubiquitination domain required for its endocytosis completely abrogated septin accumulation at the polarity site. Our data support a model where the location of endocytosis serves as a spatial mark for septin structure assembly and that desensitization of the Gα delays its endocytosis sufficiently that septins are placed peripheral to the site of Cdc42 polarity.

Surgical treatments for postamputation pain: study protocol for an international, double-blind, randomised controlled trial.

BACKGROUND: Painful conditions such as residual limb pain (RLP) and phantom limb pain (PLP) can manifest after amputation. The mechanisms underlying such postamputation pains are diverse and should be addressed accordingly. Different surgical treatment methods have shown potential for alleviating RLP due to neuroma formation - commonly known as neuroma pain - and to a lesser degree PLP. Two reconstructive surgical interventions, namely targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI), are gaining popularity in postamputation pain treatment with promising results. However, these two methods have not been directly compared in a randomised controlled trial (RCT). Here, we present a study protocol for an international, double-blind, RCT to assess the effectiveness of TMR, RPNI, and a non-reconstructive procedure called neuroma transposition (active control) in alleviating RLP, neuroma pain, and PLP. METHODS: One hundred ten upper and lower limb amputees suffering from RLP will be recruited and assigned randomly to one of the surgical interventions (TMR, RPNI, or neuroma transposition) in an equal allocation ratio. Complete evaluations will be performed during a baseline period prior to the surgical intervention, and follow-ups will be conducted in short term (1, 3, 6, and 12 months post-surgery) and in long term (2 and 4 years post-surgery). After the 12-month follow-up, the study will be unblinded for the evaluator and the participants. If the participant is unsatisfied with the outcome of the treatment at that time, further treatment including one of the other procedures will be discussed in consultation with the clinical investigator at that site. DISCUSSION: A double-blind RCT is necessary for the establishment of evidence-based procedures, hence the motivation for this work. In addition, studies on pain are challenging due to the subjectivity of the experience and the lack of objective evaluation methods. Here, we mitigate this problem by including different pain evaluation methods known to have clinical relevance. We plan to analyse the primary variable, mean change in NRS (0-10) between baseline and the 12-month follow-up, using the intention-to-treat (ITT) approach to minimise bias and keep the advantage of randomisation. The secondary outcomes will be analysed on both ITT and per-protocol (PP). An adherence protocol (PP population) analysis will be used for estimating a more realistic effect of treatment. TRIAL REGISTRATION: ClincialTrials.gov NCT05009394.

Re-evaluation of the risks to public health related to the presence of bisphenol A (BPA) in foodstuffs.

In 2015, EFSA established a temporary tolerable daily intake (t-TDI) for BPA of 4 µg/kg body weight (bw) per day. In 2016, the European Commission mandated EFSA to re-evaluate the risks to public health from the presence of BPA in foodstuffs and to establish a tolerable daily intake (TDI). For this re-evaluation, a pre-established protocol was used that had undergone public consultation. The CEP Panel concluded that it is Unlikely to Very Unlikely that BPA presents a genotoxic hazard through a direct mechanism. Taking into consideration the evidence from animal data and support from human observational studies, the immune system was identified as most sensitive to BPA exposure. An effect on Th17 cells in mice was identified as the critical effect; these cells are pivotal in cellular immune mechanisms and involved in the development of inflammatory conditions, including autoimmunity and lung inflammation. A reference point (RP) of 8.2 ng/kg bw per day, expressed as human equivalent dose, was identified for the critical effect. Uncertainty analysis assessed a probability of 57-73% that the lowest estimated Benchmark Dose (BMD) for other health effects was below the RP based on Th17 cells. In view of this, the CEP Panel judged that an additional uncertainty factor (UF) of 2 was needed for establishing the TDI. Applying an overall UF of 50 to the RP, a TDI of 0.2 ng BPA/kg bw per day was established. Comparison of this TDI with the dietary exposure estimates from the 2015 EFSA opinion showed that both the mean and the 95th percentile dietary exposures in all age groups exceeded the TDI by two to three orders of magnitude. Even considering the uncertainty in the exposure assessment, the exceedance being so large, the CEP Panel concluded that there is a health concern from dietary BPA exposure.

Risks for human health related to the presence of grayanotoxins in certain honey.

The European Commission asked EFSA for a scientific opinion on the risks for human health of the presence of grayanotoxins (GTXs) in 'certain honey' from Ericaceae plants. The risk assessment included all structurally related grayananes occurring with GTXs in 'certain' honey. Oral exposure is associated with acute intoxication in humans. Acute symptoms affect the muscles, nervous and cardiovascular systems. These may lead to complete atrioventricular block, convulsions, mental confusion, agitation, syncope and respiratory depression. For acute effects, the CONTAM Panel derived a reference point (RP) of 15.3 µg/kg body weight for the sum of GTX I and III based on a BMDL10 for reduced heart rate in rats. A similar relative potency was considered for GTX I. Without chronic toxicity studies, an RP for long-term effects could not be derived. There is evidence for genotoxicity in mice exposed to GTX III or honey containing GTX I and III, showing increased levels of chromosomal damage. The mechanism of genotoxicity is unknown. Without representative occurrence data for the sum of GTX I and III and consumption data from Ericaceae honey, acute dietary exposure was estimated based on selected concentrations for GTX I and III reflecting concentrations measured in 'certain' honeys. Applying a margin of exposure (MOE) approach, the estimated MOEs raised health concerns for acute toxicity. The Panel calculated the highest concentrations for GTX I and III below which no acute effects would be expected following 'certain honey' consumption. The Panel is 75% or more certain that the calculated highest concentration of 0.05 mg for the sum of GTX I and III per kg honey is protective for all age groups regarding acute intoxications. This value does not consider other grayananes in 'certain honey' and does not cover the identified genotoxicity.

PD-1 and CTLA-4 exert additive control of effector regulatory T cells at homeostasis.

At homeostasis, a substantial proportion of Foxp3+ T regulatory cells (Tregs) have an activated phenotype associated with enhanced TCR signals and these effector Treg cells (eTregs) co-express elevated levels of PD-1 and CTLA-4. Short term in vivo blockade of the PD-1 or CTLA-4 pathways results in increased eTreg populations, while combination blockade of both pathways had an additive effect. Mechanistically, combination blockade resulted in a reduction of suppressive phospho-SHP2 Y580 in eTreg cells which was associated with increased proliferation, enhanced production of IL-10, and reduced dendritic cell and macrophage expression of CD80 and MHC-II. Thus, at homeostasis, PD-1 and CTLA-4 function additively to regulate eTreg function and the ability to target these pathways in Treg cells may be useful to modulate inflammation.

Helios+ and RORγt+ Treg populations are differentially regulated by MHCII, CD28, and ICOS to shape the intestinal Treg pool.

Foxp3+ regulatory T cells (Tregs) are essential for intestinal homeostasis. Tregs in the small intestine include Helios+ thymus-derived Tregs (tTregs) and RORγt+ Tregs that differentiate in the periphery after antigenic stimulation (pTregs). TCR and costimulatory signals sustain Tregs with effector phenotypes, including those in the intestine, but it is unknown if tTregs and pTregs have similar requirements for these pathways. We previously used mice lacking peripheral expression of MHCII to demonstrate that the small intestine sustains tTregs independently of peripheral antigen. Here, we show that the effector phenotype and tissue-resident signature of tTregs are also MHCII-independent. Using this model, we define the distinct costimulatory requirements of intestinal tTregs and pTregs. Helios+ effector tTregs proliferate through CD28 and require neither ICOS nor MHCII for maintenance. In contrast, RORγt+ pTregs use CD28 and ICOS. Notably, the differential costimulatory utilization allows tTregs and pTregs to dynamically respond to perturbations to support a fixed number of intestinal Tregs. This suggests that the environmental regulation of costimulatory ligands might shape the subpopulations of intestinal Tregs and promote effective homeostasis and defense. Our data reveal new complexity in effector Treg biology and costimulatory signaling of tTregs and pTregs and highlight the importance of analyzing both subpopulations.

Isolation and Culture of Human Adipose-Derived Stem Cells With an Innovative Xenogeneic-Free Method for Human Therapy.

Considering the increasing impact of stem cell therapy, biosafety concerns have been raised regarding potential contamination or infection transmission due to the introduction of animal-derived products during in vitro manipulation. The xenogeneic components, such as collagenase or fetal bovine serum, commonly used during the cell isolation and expansion steps could be associated with the potential risks of immune reactivity or viral, bacterial, and prion infection in the receiving patients. Following good manufacturing practice guidelines, chemical tissue dissociation should be avoided, while fetal bovine serum (FBS) can be substituted with xenogeneic-free supplements. Moreover, to ensure the safety of cell products, the definition of more reliable and reproducible methods is important. We have developed an innovative, completely xenogeneic-free method for the isolation and in vitro expansion of human adipose-derived stem cells without altering their properties compared to collagenase FBS-cultured standard protocols. Here, human adipose-derived stem cells (hASCs) were isolated from abdominal adipose tissue. The sample was mechanically minced with scissors/a scalpel, micro-dissected and mechanically dispersed in a 10 cm Petri dish, and prepared with scalpel incisions to facilitate the attachment of the tissue fragments and the migration of hASCs. Following the washing steps, hASCs were selected due to their plastic adherence without enzymatic digestion. The isolated hASCs were cultured with medium supplemented with 5% heparin-free human platelet lysate and detached with an animal-free trypsin substitute. Following good manufacturing practice (GMP) directions on the production of cell products intended for human therapy, no antibiotics were used in any culture media.

Cell Dissociation Techniques in Salamanders.

Cell dissociation is an important technique for the study of tissue phenotypes. The method chosen to harvest cells from solid tissues profoundly influences the types of cells recovered. Methodology also shapes any biases that are introduced that can act upon cell surface protein phenotypes or gene expression. Here we describe examples of cell surface phenotypic changes and typical yields, under 4 different isolation conditions (enzymatic/non-enzymatic), using the axolotl spleen, and the regenerating limb. We describe simple methods for evaluating the liberation of viable cells and the downstream characterization of cell diversity using a live-cell flow cytometry approach. Of note, the cellular composition of dissociated cells and surface antigen detection vary with each condition. TrypLE and "no enzyme" protocols give the highest surface marker expression, but poor liberation of non-immune cells in the blastema. Liberase-DH and Liberase-TL have alternative neutral proteases and both give acceptable dissociation of diverse cell types in the blastema. Liberase-TL provides the highest yield of all cell sizes and a larger non-immune fraction. Matching dissociation times between limb blastemas and spleens, we demonstrate the effect of "over-digestion" in soft tissues. In the spleen, the Liberase enzyme cocktails produced the lowest yields, worst viability, and the greatest loss of immune cell surface markers, when compared with non-enzymatic and TrypLE dissociation. These examples provide a template for optimizing protocols for individual tissues while achieving the balance between cell recovery and the mitigation of cellular changes appropriate for downstream applications such as single-cell RNA sequencing and flow cytometry.

Bioengineered nerve conduits and wraps for peripheral nerve repair of the upper limb.

BACKGROUND: Traumatic peripheral nerve injury is common and incurs significant cost to individuals and society. Healing following direct nerve repair or repair with autograft is slow and can be incomplete. Several bioengineered nerve wraps or devices have become available as an alternative to direct repair or autologous nerve graft. Nerve wraps attempt to reduce axonal escape across a direct repair site and nerve devices negate the need for a donor site defect, required by an autologous nerve graft. Comparative evidence to guide clinicians in their potential use is lacking. We collated existing evidence to guide the clinical application of currently available nerve wraps and conduits. OBJECTIVES: To assess and compare the effects and complication rates of licensed bioengineered nerve conduits or wraps for surgical repair of traumatic peripheral nerve injuries of the upper limb. To compare effects and complications against the current gold surgical standard (direct repair or nerve autograft). SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search was 26 January 2022. We searched online and, where not accessible, contacted societies' secretariats to review abstracts from the British Surgical Society of the Hand, International Federation of Surgical Societies of the Hand, Federation of European Surgical Societies of the Hand, and the American Society for Peripheral Nerve from October 2007 to October 2018. SELECTION CRITERIA: We included parallel group randomised controlled trials (RCTs) and quasi-RCTs of nerve repair in the upper limb using a bioengineered wrap or conduit, with at least 12 months of follow-up. DATA COLLECTION AND ANALYSIS: We used standard Cochrane procedures. Our primary outcomes were 1. muscle strength and 2. sensory recovery at 24 months or more. Our secondary outcomes were 3. British Medical Research Council (BMRC) grading, 4. integrated functional outcome (Rosén Model Instrument (RMI)), 5. touch threshold, 6. two-point discrimination, 7. cold intolerance, 8. impact on daily living measured using the Disability of Arm Shoulder and Hand Patient-Reported Outcome Measure (DASH-PROM), 9. sensory nerve action potential, 10. cost of the device, and 11. adverse events (any and specific serious adverse events (further surgery)). We used GRADE to assess the certainty of the evidence. MAIN RESULTS: Five studies involving 213 participants and 257 nerve injuries reconstructed with wraps or conduits (129 participants) or standard repair (128 participants) met the inclusion criteria. Of those in the standard repair group, 119 nerve injuries were managed with direct epineurial repair, and nine autologous nerve grafts were performed. One study excluded the outcome data for the repair using an autologous nerve graft from their analysis, as it was the only autologous nerve graft in the study, so data were available for 127 standard repairs. There was variation in the functional outcome measures reported and the time postoperatively at which they were recorded. Mean sensory recovery, assessed with BMRC sensory grading (range S0 to S4, higher score considered better) was 0.03 points higher in the device group (range 0.43 lower to 0.49 higher; 1 RCT, 28 participants; very low-certainty evidence) than in the standard repair group (mean 2.75 points), which suggested little or no difference between the groups, but the evidence is very uncertain. There may be little or no difference at 24 months in mean touch thresholds between standard repair (0.81) and repair using devices, which was 0.01 higher but this evidence is also very uncertain (95% confidence interval (CI) 0.06 lower to 0.08 higher; 1 trial, 32 participants; very low-certainty evidence). Data were not available to assess BMRC motor grading at 24 months or more. Repair using bioengineered devices may not improve integrated functional outcome scores at 24 months more than standard techniques, as assessed by the Rosén Model Instrument (RMI; range 0 to 3, higher scores better); the CIs allow for both no important difference and a better outcome with standard repair (mean RMI 1.875), compared to the device group (0.17 lower, 95% CI 0.38 lower to 0.05 higher; P = 0.13; 2 trials, 60 participants; low-certainty evidence). Data from one study suggested that the five-year postoperative outcome of RMI may be slightly improved after repair using a device (mean difference (MD) 0.23, 95% CI 0.07 to 0.38; 1 trial, 28 participants; low-certainty evidence). No studies measured impact on daily living using DASH-PROM. The proportion of people with adverse events may be greater with nerve wraps or conduits than with standard techniques, but the evidence is very uncertain (risk ratio (RR) 7.15, 95% CI 1.74 to 29.42; 5 RCTs, 213 participants; very low-certainty evidence). This corresponds to 10 adverse events per 1000 people in the standard repair group and 68 per 1000 (95% CI 17 to 280) in the device group. The use of nerve repair devices may be associated with a greater need for revision surgery but this evidence is also very uncertain (12/129 device repairs required revision surgery (removal) versus 0/127 standard repairs; RR 7.61, 95% CI 1.48 to 39.02; 5 RCTs, 256 nerve repairs; very low-certainty evidence). AUTHORS' CONCLUSIONS: Based on the available evidence, this review does not support use of currently available nerve repair devices over standard repair. There is significant heterogeneity in participants, injury pattern, repair timing, and outcome measures and their timing across studies of nerve repair using bioengineered devices, which make comparisons unreliable. Studies were generally small and at high or unclear risk of bias. These factors render the overall certainty of evidence for any outcome low or very low. The data reviewed here provide some evidence that more people may experience adverse events with use of currently available bioengineered devices than with standard repair techniques, and the need for revision surgery may also be greater. The evidence for sensory recovery is very uncertain and there are no data for muscle strength at 24 months (our primary outcome measures). We need further trials, adhering to a minimum standard of outcome reporting (with at least 12 months' follow-up, including integrated sensorimotor evaluation and patient-reported outcomes) to provide high-certainty evidence and facilitate more detailed analysis of effectiveness of emerging, increasingly sophisticated, bioengineered repair devices.

Perinatal depression: Factors affecting help-seeking behaviours in asylum seeking and refugee women. A systematic review.

Purpose: Perinatal depression is one of the most commonly diagnosed mental health conditions in the general maternity population but whilst the prevalence is thought to be much higher in asylum seeking and refugee (AS&R) women, it is less frequently identified and diagnosed by health care professionals. Method: A systematic review was undertaken to address 'what factors influence help-seeking behaviours in asylum seeking and refugee women with symptoms of perinatal depression'. The review focussed on women accessing care in high income countries. 12 studies met the eligibility criteria and a narrative synthesis was undertaken resulting in two main themes: women's perceptions of depression and access to healthcare and support services. Results: Findings indicated that many of the influences on help-seeking were also present in the general population and women from ethnic minority populations, with the exception of migration experiences; but that women from a AS&R background may experience more of these barriers, exacerbating inequality in access to and engagement with healthcare. Conclusion: Further research is needed to provide more detailed insight into the experiences of asylum seeking and refugee women to identify ways that barriers in help-seeking can be addressed.

Presence of Antibodies to Severe Acute Respiratory Syndrome Coronavirus-2 on Admission Is Associated With Decreased Mortality in COVID-19 Critical Illness.

To determine whether the early serologic response in COVID-19 critical illness is associated with hospital mortality. To evaluate if time-to-seroconversion differs by receipt of dexamethasone therapy. DESIGN: Patients were prospectively enrolled within 24 hours of ICU admission from two University of Washington Hospitals. Plasma was collected on enrollment and on days 3, 7, 10, and 14. SETTING: ICUs between March 2020 and April 2021. PATIENTS: Consecutive adults with COVID-19 admitted to an ICU. MEASUREMENTS AND MAIN RESULTS: We measured longitudinal total antispike protein antibody levels (anti-S abs) and total antinucleocapsid antibody levels (anti-N ab) using a U.S. Food and Drug Administration-authorized Roche instrument. We evaluated whether detectable anti-S abs on ICU admission were associated with host factors, initial disease severity, and hospital mortality. We evaluated whether dexamethasone therapy was associated with time-to-seroconversion. Among 93 unvaccinated participants, 47 (51%) had detectable anti-S abs on ICU admission. There was no difference in Acute Physiology and Chronic Health Evaluation II score or time between first positive severe acute respiratory syndrome coronavirus-2 PCR and ICU admission in those with detectable versus undetectable anti-S abs. Adjusting for age, body mass index, and sex, patients with detectable anti-S abs had a lower risk of inhospital death (hazard ratio, 0.40; 95% CI, 0.17-0.94; p = 0.04). Among 21 patients with undetectable anti-S abs on ICU admission and serial measurements available, time-to-seroconversion was not significantly affected by receipt of dexamethasone therapy. CONCLUSIONS: In COVID-19 critical illness, a significant proportion of patients do not have detectable antibodies at ICU admission, and this is independent of severity of illness. Detectable anti-S abs were associated with lower risk of inhospital death. Despite concern that corticosteroids may impair an appropriate antiviral serologic response, early antibody kinetics were not significantly affected by administration of dexamethasone; however, CIs were wide and require further study.