Transplantation Approaches Research Articles

Treatment of high-risk myelodysplastic syndromes.

Myelodysplastic syndrome (MDS) is considered to be a heterogeneous myeloid malignancy with a common origin in the hematopoietic stem cell compartment and is generally divided into lower- and higher-risk forms. While the treatment goals for lower-risk MDS are to decrease transfusion requirements and transformation into acute leukemia, the major aims for higher-risk MDS are to prolong survival and ultimately cure the patient. Although novel agents such as luspatercept and imetelstat have recently been approved as new treatment options for lower-risk MDS, hypomethylating agents currently remain the only approved non-transplant option for higher-risk MDS and are the standard of care for patients not eligible for allogeneic hematopoietic stem cell transplantation (HSCT). Combinations with other drugs as first-line treatment have to date not proven more efficacious than monotherapy in higher-risk MDS, and outcome after the failure of treatment with hypomethylating agents is poor. The only potential cure and standard of care for eligible patients is HSCT and even though the number of transplanted - especially older - MDS patients has increased over time due to better management and greater donor availability, the majority of MDS patients will not be eligible for this curative approach. Current challenges include decreasing the relapse risk, the main cause of HSCT failure. This review summarizes current knowledge on the options of transplant and non-transplant treatment approaches for these patients and demonstrate the unmet clinical need for more effective therapies.

P-1668. Perioperative Antibiotic Use for Heart Transplantation at Children’s Hospitals in the United States

Abstract Background Data on perioperative antibiotic use for pediatric heart transplantation are scarce, although such information can inform the optimal approaches for perioperative antibiotic prophylaxis. Methods We identified children undergoing heart transplantation in the Pediatric Health Information System database. The primary outcomes of interest were perioperative antibiotics other than cefazolin single therapy and prolonged duration (defined as more than 1 postoperative calendar days) of postoperative antibiotics.Figure 1.Rate of the Use of Cefazolin Single Therapy at the Time of Transplantation Surgery in Children’s Hospitals by Transplantation VolumeHospitals that performed 50 or more transplantations were included in this FigureThe hospital with the rate of 0% (#28) was a 4th-quartile transplantation volume hospital Results Cefazolin was used predominantly (i.e. > 50% of cases) as part of the perioperative antibiotic regimen at 22 of 28 (78.6%) hospitals, while only 12 of 28 hospitals (42.9%) predominantly used cefazolin as a single therapy. The predominant use of two or more antibiotics (with or without cefazolin) perioperatively was seen in 12 of 28 hospitals (42.9%). The median postoperative duration of antibiotics was 2 calendar days (interquartile range: 1-3). Patients undergoing transplantation at higher transplantation volume hospitals were less likely to receive antibiotics other than cefazolin single therapy or to receive prolonged duration (odds ratio, OR: 0.45 [95% confidence interval, CI: 0.38-0.53], and OR: 0.76 [95%CI: 0.63-0.91], respectively, for the 4th quartile hospitals).Figure 2.Factors Associated with the Use of Perioperative Antibiotic Other Than Cefazolin Single Therapy among Children Undergoing Heart Transplantationa obtained using multivariable logistic regressionAbbreviations: CI, confidence interval; ECMO, extracorporeal membrane oxygenationHospitals that performed 50 or more transplantations were included Conclusion Perioperative antibiotic use for heart transplantation varies substantially across children’s hospitals. Higher transplantation volume hospitals were more likely to use cefazolin single therapy and shorter durations of antibiotics although there remain rooms for improvement. Careful review of the best available evidence should be incorporated in developing institutional perioperative antibiotic approaches for heart transplantation, particularly at low-volume hospitals.Figure 3:Factors Associated with Postoperative Duration of Antibiotics More Than 1 Calendar Daysa obtained using multivariable logistic regressionAbbreviations: CI, confidence interval; ECMO, extracorporeal membrane oxygenationHospitals that performed 50 or more transplantations were included Disclosures Kengo Inagaki, MD, AstraZeneka: Grant/Research Support

Artificial Intelligence in Predicting Ocular Hypertension After Descemet Membrane Endothelial Keratoplasty.

Descemet membrane endothelial keratoplasty (DMEK) has emerged as a novel approach in corneal transplantation over the past two decades. This study aims to identify predisposing risk factors for post-DMEK ocular hypertension (OHT) and develop a preoperative predictive model for post-DMEK OHT. Patients who underwent DMEK at Gangnam Severance Hospital between 2017 and 2024 were included in the study. Four machine learning models-XGBoost, random forest, CatBoost, and logistic regression-were trained to assess feature importance and develop a predictive classifier. An ensemble of these four models was used as the final predictive model. The ensemble model identified clinically significant patients for prediction or exclusion. A total of 106 eyes from patients who underwent DMEK were analyzed, with 31 eyes (29.2%) experiencing post-DMEK OHT. The final ensemble model achieved clinically significant classification for 61 eyes (57.5%) in the total patient population. Significant risk factors identified in all four models included angle recess area (ARA), best-corrected visual acuity, donor graft size, angle-to-angle distance, crystalline lens rise, and central corneal thickness. The average accuracy, precision, recall, area under the receiver operating characteristic curve, and area under the precision-recall curve values of the ensemble model obtained by a 5-fold cross-validation were 80.2%, 60.0%, 59.7%, 82.3%, and 68.0%, respectively. This study identified significant risk factors for post-DMEK OHT and highlighted the importance of ocular topographic measures in risk assessment. The development of a final machine learning model to differentiate between clinically predictable patient groups demonstrates the clinical utility of the proposed model for predicting post-DMEK OHT.

Advancements in Regenerative Medicine for Articular Cartilage Repair in the Management of Osteoarthritis: A Review of Modern Treatment Methods

Osteoarthritis (OA) is the most common form of chronic joint diseases, and its treatment still remains difficult with the current state of medicine. In this review, modern regenerative methods used in the repair of articular cartilage, both traditional techniques and innovative cellular therapies, are described. It focuses on the most updated treatment modalities, discussing, among other methods, microfracture, osteochondral grafts, autologous chondrocyte implantation (ACI), novel approaches of matrix-assisted autologous chondrocyte transplantation (MACT) and mesenchymal stem cell (MSC) treatments, with especial regard toward the use of platelet-rich plasma (PRP) in relation to other intra-articular injections, namely hyaluronic acid and ozone therapy. The regenerative treatments analyzed in this review have great potential in cartilage defect repair and possible symptom alleviation for OA; long-term efficacy, however, and limitations of cost and invasiveness do have to be more extensively considered. Another discussion concerns macrophages, modulators of the inflammatory environment of the joint, and whether they could serve as potential therapeutic targets. The need for further investigation, in order to modify the existing methods and create other effective regenerative approaches in patients suffering from OA, is presented.

Impact of dairy calf management practices on the intestinal tract microbiome pre-weaning.

Introduction. Microbiota in the gastrointestinal tract (GIT) consisting of the rumen and hindgut (the small intestine, cecum and colon) in dairy calves play a vital role in their growth and development. This review discusses the development of dairy calf intestinal microbiomes with an emphasis on the impact that husbandry and rearing management have on microbiome development, health and growth of pre-weaned dairy calves.Discussion. The diversity and composition of the microbes that colonize the lower GIT (small and large intestine) can have a significant impact on the growth and development of the calf, through influence on nutrient metabolism, immune modulation, resistance or susceptibility to infection, production outputs and behaviour modification in adult life. The colonization of the calf intestinal microbiome dynamically changes from birth, increasing microbial richness and diversity until weaning, where further dynamic and drastic microbiome change occurs. In dairy calves, neonatal microbiome development prior to weaning is influenced by direct and indirect factors, some of which could be considered stressors, such as maternal interaction, environment, diet, husbandry and weaning practices. The specific impact of these can dictate intestinal microbial colonization, with potential lifelong consequences.Conclusion. Evidence suggests the potential detrimental effect that sudden changes and stress may have on calf health and growth due to management and husbandry practices, and the importance of establishing a stable yet diverse intestinal microbiome population at an early age is essential for calf success. The possibility of improving the health of calves through intestinal microbiome modulation and using alternative strategies including probiotic use, faecal microbiota transplantation and novel approaches of microbiome tracking should be considered to support animal health and sustainability of dairy production systems.

The gut microbiota mediates memory impairment under high‐altitude hypoxia via the gut–brain axis in mice

Hypoxia is a predominant risk factor at high altitudes, and evidence suggests that high‐altitude hypoxia alters the gut microbiota, which plays an essential regulatory role in memory function. However, the causal relationship between the gut microbiota and memory impairment under hypoxic conditions remains unclear. In this study, we employed a high‐altitude hypoxia model combined with fecal microbiota transplantation (FMT) approach in mice to explore the effects of the gut microbiota on memory impairment in a hypoxic environment. We observed that high‐altitude hypoxia exposure reduced short‐ and long‐term memory and hippocampus‐dependent fear memory abilities, along with decreased relative abundance of Ligilactobacillus and Muribaculum. Moreover, hypoxic conditions increased intestinal and blood–brain barrier permeability. FMT from hypoxia‐exposed mice into naïve antibiotic‐treated mice resulted in similar memory impairments, Ligilactobacillus and Muribaculum abundance changes, and increased intestinal/blood–brain barrier permeability. Correlation analysis showed a robust positive association between Ligilactobacillus and Muribaculum with hippocampus‐dependent contextual fear memory. Likewise, Ligilactobacillus was positively correlated with short‐term memory. Therefore, Ligilactobacillus and Muribaculum may be key microbes in reducing memory ability in hypoxia, with the intestinal and blood–brain barriers as primary pathways. Our findings provide further evidence for the potential regulatory mechanism by which gut microbiota dysbiosis may contribute to memory impairment in a high‐altitude environment.

Supportive care in transplantation: A patient-centered care model to better support kidney transplant candidates and recipients.

Kidney transplantation (KT), although the best treatment option for eligible patients, entails maintaining and adhering to a life-long treatment regimen of medications, lifestyle changes, self-care, and appointments. Many patients experience uncertain outcome trajectories increasing their vulnerability and symptom burden and generating complex care needs. Even when transplants are successful, for some patients the adjustment to life post-transplant can be challenging and psychological difficulties, economic challenges and social isolation have been reported. About 50% of patients lose their transplant within 10 years and must return to dialysis or pursue another transplant or conservative care. This paper documents the complicated journey patients undertake before and after KT and outlines some initiatives aimed at improving patient-centered care in transplantation. A more cohesive approach to care that borrows its philosophical approach from the established field of supportive oncology may improve patient experiences and outcomes. We propose the "supportive care in transplantation" care model to operationalize a patient-centered approach in transplantation. This model can build on other ongoing initiatives of other scholars and researchers and can help advance patient-centered care through the entire care continuum of kidney transplant recipients and candidates. Multi-dimensionality, multi-disciplinarity and evidence-based approaches are proposed as other key tenets of this care model. We conclude by proposing the potential advantages of this approach to patients and healthcare systems.

Mitochondrial replenishment as a treatment for Alzheimer’s Disease

AbstractBackgroundFindings have demonstrated that mitochondrial dysfunction is vital to Alzheimer’s Disease (AD) pathogenesis and progression. This study explored an innovative treatment strategy involving transfer of polymer‐functionalized, healthy mitochondria to AD neurons. We hypothesized that this organelle transplantation approach would restore mitochondrial function and bioenergetics, preventing aberrant neuronal dynamics associated with AD.MethodNeuronal cells (SH‐SY5Y) were stimulated with amyloid‐β (Aβ1‐42). Mitochondria were functionalized with dextran‐triphenylphosphonium (Dex‐TPP/Mt) and administered to neurons. Internalization of Dex‐TPP/Mt was assessed, as was the effect of mitochondrial transfer on Aβ‐treated SH‐SY5Y cell ROS levels, mitochondrial membrane potential, mitochondrial dynamics, ATP levels, and apoptosis.ResultDex‐TPP/Mt underwent efficient internalization into Aβ‐treated SH‐SY5Y cells. The treatment reduced intracellular ROS levels and restored mitochondrial membrane potential. Mitochondrial quality control was also re‐established, as mitochondrial fusion and fission processes were balanced and mitophagy reduced. Dex‐TPP/Mt treated neurons also increased ATP levels. Notably, mitochondrial transfer modulated the Bax/Bcl‐2 ratio, inhibited caspase‐3 activation, and suppressed the pJNK pathway, highlighting reduced neuronal apoptosis that was confirmed by Annexin V assay.ConclusionMitochondrial transfer has potential as a therapeutic approach for AD. The treatment highlighted herein effectively mitigated the impact of Aβ on neuronal health by targeting mitochondrial dysfunction and oxidative stress. This opens several avenues for similar strategies aimed at addressing dysregulated bioenergetics and mitochondrial dynamics in AD.

Effects of ultrasound-guided external oblique intercostal plane block on the postoperative analgesia after open liver surgery: study protocol for a randomised controlled trial

BackgroundOpen liver surgery remains a primary surgical approach for complex liver resections and liver transplantation. However, the postoperative pain management is still a major challenge. Ultrasound-guided external oblique intercostal (EOI) plane block is a novel approach of regional anaesthesia and has a great potential to relieve postoperative pain after upper abdominal surgeries. This study aims to investigate the efficacy and safety of ultrasound-guided EOI plane block in managing postoperative pain after open liver surgery.MethodsSeventy-four participants scheduled for open liver surgery will be randomly assigned to either the intervention group, receiving an ultrasound-guided EOI plane block with a single dose of 30 ml 0.375% ropivacaine, or the control group, which will not receive this block. All participants will be provided with opioid-based patient-controlled intravenous analgesia (PCIA) postoperatively. The primary outcome is resting pain score at 3 h postoperatively, assessed using numerical rating scale. Secondary outcomes include pain score at 6, 24, 48, and 72 h postoperatively, perioperative opioid consumption, remedial analgesics within 72 h postoperatively, PCIA usage within postoperative 72 h, postoperative recovery, length of hospital stay, postoperative side effects, block-related complications, and ropivacaine plasma concentration of participants receiving the block.DiscussionThis study is a randomised controlled trial to evaluate the efficacy and safety of ultrasound-guided EOI plane block for postoperative analgesia after open liver surgery. As regional anaesthesia plays an important role in the multimodal pain management, EOI plane block may prove to be an effective regional technique for enhancing postoperative pain relief and contributing to enhanced recovery after open liver surgery.Trial registrationChinese Clinical Trial Registry ChiCTR2200065745. Registered on November 14, 2022.

Repair effects of thermosensitive hydrogels combined with iPSC-derived corneal endothelial cells on rabbit corneal endothelial dysfunction

Considering the limitations of human corneal endothelial cell proliferation as well as the severe shortage of corneal donations, it is imperative to develop improved methods of corneal endothelial cell transplantation. The purpose of this study was to construct a modified corneal endothelial cell transplantation approach using thermosensitive hydrogels combined with induced pluripotent stem cells (iPSCs)-derived human corneal endothelial cells (hCECs). In this study, thermosensitive hydrogels hydroxypropyl chitin/carboxymethyl chitosan (HPCH/CMCS) were fabricated, and their hydrogels properties and biocompatibility were investigated. Our results demonstrated that HPCH/CMCS hydrogels exhibited superior transparency, appropriate mechanical properties and favorable biocompatibility. A two-step induction method of small molecule compounds was employed, by which iPSCs were differentiated into hCECs via neural crest cells (NCCs). Additionally, a rabbit corneal endothelial dysfunction model was established in vivo, aiming to evaluate the safety and effectiveness of the combined method. Slit lamp microscope results indicated that significant transparency improvement could be noted in HPCH/CMCS/hCECs group (P = 0.006), whereas the corneal transparency was not homogeneous in different areas. Moreover, histological examinations and immunofluorescence analysis revealed that HPCH/CMCS/hCECs group showed a higher density of corneal endothelial cells and positive expressions of related markers. This study may provide ideas and experimental basis for the combined application of hydrogels and iPSC-derived corneal endothelial cells for corneal endothelial dysfunction. Statement of SignificanceCorneal transplantation is the most effective treatment for corneal endothelial dysfunction, which is challenged by issues such as corneal donor shortages and immune rejection. In this study, we proposed a combined transplantation method of cells and hydrogels for corneal endothelial dysfunction. We modified the protocols to obtain corneal endothelial cells from iPSCs by a two-step induction method. Besides, thermosensitive hydrogels with satisfactory biocompatibility and degradability were fabricated as fixation and support carriers of iPSC-derived corneal endothelial cells for in vivo transplantation. Experimental results demonstrated that this method could locally repair corneal endothelial dysfunction in rabbits, with the repaired corneas expressing relevant markers. This study presented a preliminary attempt to combine hydrogels and cells for corneal endothelial dysfunction.

Developing endoscopic cell sheet delivery device using a beating human heart simulator and a pig model for minimally invasive cardiac regenerative therapy

Abstract Introduction Recently, clinical trials have commenced for cardiac regenerative therapy utilizing stem cells in patients with heart failure. Among the various transplantation approaches, there is a growing demand for less invasive methods to transplant sheet/patch-shaped cell products onto the heart surface, rather than resorting to conventional open surgery. This is particularly important considering the need for immunosuppressants due to allogeneic cell transplantation. Objective This study aims to develop a device for endoscopic transplantation of cell sheets onto the beating heart surface. Methods Prototype devices, initially developed in our prior study using a static heart model (Regenerative Therapy, 2020), were refined to better suit the cell sheet transplantation procedure onto a beating heart. We constructed a three-dimensional (3D) model of a beating heart located inside a thoracic cavity model, based on human computed tomography data and a 3D printer dedicated to simulating endoscopic surgical procedures. Human mesenchymal stromal cell (MSC)-derived cell sheets were prepared using temperature-responsive culture dishes and transferred onto a beating heart model pulsating at 80 beats per minute. We assessed the technical feasibility (N=8). Furthermore, skeletal muscle tissue was harvested from the thigh of the Clawn miniature pigs, and skeletal myoblasts were cultured from enzymatically digested tissue to create a cell sheet for autologous transplantation (8.0×10⁶ cells/sheet). Subsequently, the cell sheets labeled with Hoechst 33342 were endoscopically transplanted onto the pig heart surface (N=2). The pigs were sacrificed one week later, and the engraftment of the cell sheet was histologically evaluated. Results Successful deployment of MSC sheets onto the beating heart model was achieved in all procedures with one trial (100% success rate). The procedure duration from device insertion to the completion of cell sheet transplantation averaged 142±19 seconds. In experiments on autologous transplantation of myoblast cell sheets, two cases were successfully accomplished, with the transplanted cell sheet positive for Hoechst 33342 observed on the heart surface. Conclusion We have developed an endoscopic cell sheet delivery device using a pulsating heart model and a pig model, which holds promise for minimally invasive cardiac regenerative therapy in the future. Further investigations into the safety of the procedure are warranted for the clinical application of this system.

Lobar graft evaluation in cadaveric lobar lung redo transplantation after living-donor lobar lung transplantation: a case report

BackgroundLung transplantation is a vital option for patients with end-stage lung disease. However, it faces a significant challenge due to the shortage of compatible donors, which particularly affects individuals with small chest cavities and pediatric patients. The novel approach of cadaveric lobar lung transplantation is a promising solution to alleviate the donor shortage crisis. Both the mid-term and long-term outcomes of lobar lung transplantation are comparable to those of standard lung transplantation. However, patients undergoing lobar lung transplantation reported a significantly higher rate of primary graft dysfunction compared to patients undergoing standard lung transplantation. Therefore, careful donor selection is critical to improve outcomes after lobar transplantation. However, no established method exists to evaluate each lung lobar graft of deceased donors. This case report describes a case of cadaveric lobar lung transplantation to overcome size mismatch and donor shortage, with particular emphasis on lobar graft evaluation.Case presentationA 39-year-old woman with scleroderma-related respiratory failure was listed for deceased donor lung transplantation due to a rapidly progressing disease. Faced with a long waiting list and impending mortality, she underwent bilateral living-donor lobar lung transplantation donated by her relatives. Post-transplant complications included progressive pulmonary vein obstruction and pleural effusion, which ultimately required retransplantation. An oversized donor with pneumonia in the bilateral lower lobes was allocated. Lung ultrasound was used to evaluate each lung lobar graft during procurement. The right upper and middle lobes and left upper lobe were confirmed to be transplantable, and lobar lung redo transplantation was performed. The patient’s post-transplant course was uneventful, and she was discharged home and returned to her daily activities.ConclusionsThis case highlights the clinical impact of cadaveric lobar lung transplantation as a feasible and effective strategy to overcome the shortage of donor lungs, especially in patients with small thoracic cavities. By establishing donor lung evaluation techniques and overcoming anatomical and logistical challenges, cadaveric lobar lung transplantation can significantly expand the donor pool and offer hope to those previously considered ineligible for transplantation.

Very Early-Onset Inflammatory Bowel Disease: Insights into Etiology, Diagnosis, and Treatment Strategies

Very early-onset inflammatory bowel disease: is a subtype of inflammatory bowel disease (IBD) and is defined by its onset in children younger than 6 years of age. The etiology includes the interplay of various factors such as genetic predisposition, environmental factors, gut microbiota and strong family history. The clinical presentation can present with both gastrointestinal symptoms such as bloody and/or mucus-containing diarrhea, recurrent vomiting, peri annal symptoms like fistulas, abscesses and perinatal skin tags and also present as extra-intestinal symptoms like intermittent fevers, arthritis, folliculitis, uveitis etc. In this article we discuss about various treatment methods used in Very early-onset inflammatory bowel disease (VEO IBD) including medical therapy, surgical therapy, hematopoietic stem cell transplantation and nutritional approach. In this systematic review, we have tried to summarized the current knowledge about Very early-onset inflammatory bowel disease

Syntax-preserving program slicing for C-based software product lines

Program slicing is a well-established technique for identifying a reduced subset of a program based on pre-defined criteria, leading to complexity reduction in subsequent activities. Despite extensive study over the past 40 years, slicing techniques for software product lines (SPLs) remain notably scarce. The absence of dedicated SPL slicing approaches hinders their efficient analysis and maintenance, limiting the ability to focus only on relevant parts of the SPL. One reason for this deficiency is the complex nature of a common variability implementation: the use of C preprocessor #ifdef-annotations within C code. A slicing approach for C-based SPLs must address the intricate interplay between the C code and the functionality introduced by the C preprocessor. Effectively handling these intricacies will unleash the full potential of SPL analysis. In this paper, we present a novel syntax-preserving program slicing approach for C-based SPLs. Unlike existing methods, our approach enables the computation of program slices through an integrated analysis of both C and CPP code, while preserving the original program syntax (no element of its syntax is disregarded or changed). This preservation ensures that the resulting program slices remain authentic subsets of the SPL, making them suitable inputs for variability-aware analyses. Additionally, we demonstrate the practical applicability of these slices in the context of software transplantation, showcasing their potential for facilitating functionality transfer between different program versions. In contrast to existing transplantation approaches, our solution works without test cases, removing the need for product configuration and execution. Consequently, the variability implementation (along with all other contained preprocessor code) is preserved during the transplantation. We empirically evaluate our approach on four distinct open-source SPLs, showcasing its effectiveness in generating diverse program slices tailored to different slicing criteria. We asses the accuracy of our code representation, the time required for slicing and transplantation, the size reduction achieved through the slices, and the functionality of our variability-aware transplantation approach.

Impact of Viruses on Prokaryotic Communities and Greenhouse Gas Emissions in Agricultural Soils.

Viruses are abundant and ubiquitous in soil, but their importance in modulating greenhouse gas (GHG) emissions in terrestrial ecosystems remains largely unknown. Here, various loads of viral communities are introduced into paddy soils with different fertilization histories via a reciprocal transplant approach to study the role of viruses in regulating greenhouse gas emissions and prokaryotic communities. The results showed that the addition of viruses has a strong impact on methane (CH4) and nitrous oxide (N2O) emissions and, to a minor extent, carbon dioxide (CO2) emissions, along with dissolved carbon and nitrogen pools, depending on soil fertilization history. The addition of a high viral load resulted in a decrease in microbial biomass carbon (MBC) by 31.4%, with changes in the relative abundance of 16.6% of dominant amplicon sequence variants (ASVs) in comparison to control treatments. More specifically, large effects of viral pressure are observed on some specific microbial communities with decreased relative abundance of prokaryotes that dissimilate sulfur compounds and increased relative abundance of Nanoarchaea. Structural equation modeling further highlighted the differential direct and indirect effects of viruses on CO2, N2O, and CH4 emissions. These findings underpin the understanding of the complex microbe-virus interactions and advance current knowledge on soil virusecology.

Identification of pharmacological inducers of a reversible hypometabolic state for whole organ preservation

Drugs that induce reversible slowing of metabolic and physiological processes would have great value for organ preservation, especially for organs with high susceptibility to hypoxia-reperfusion injury, such as the heart. Using whole-organism screening of metabolism, mobility, and development in Xenopus, we identified an existing drug, SNC80, that rapidly and reversibly slows biochemical and metabolic activities while preserving cell and tissue viability. Although SNC80 was developed as a delta opioid receptor activator, we discovered that its ability to slow metabolism is independent of its opioid modulating activity as a novel SNC80 analog (WB3) with almost 1000 times less delta opioid receptor binding activity is equally active. Metabolic suppression was also achieved using SNC80 in microfluidic human organs-on-chips, as well as in explanted whole porcine hearts and limbs, demonstrating the cross-species relevance of this approach and potential clinical relevance for surgical transplantation. Pharmacological induction of physiological slowing in combination with organ perfusion transport systems may offer a new therapeutic approach for tissue and organ preservation for transplantation, trauma management, and enhancing patient survival in remote and low-resource locations.

Identification of pharmacological inducers of a reversible hypometabolic state for whole organ preservation.

Drugs that induce reversible slowing of metabolic and physiological processes would have great value for organ preservation, especially for organs with high susceptibility to hypoxia-reperfusion injury, such as the heart. Using whole-organism screening of metabolism, mobility, and development in Xenopus, we identified an existing drug, SNC80, that rapidly and reversibly slows biochemical and metabolic activities while preserving cell and tissue viability. Although SNC80 was developed as a delta opioid receptor activator, we discovered that its ability to slow metabolism is independent of its opioid modulating activity as a novel SNC80 analog (WB3) with almost 1000 times less delta opioid receptor binding activity is equally active. Metabolic suppression was also achieved using SNC80 in microfluidic human organs-on-chips, as well as in explanted whole porcine hearts and limbs, demonstrating the cross-species relevance of this approach and potential clinical relevance for surgical transplantation. Pharmacological induction of physiological slowing in combination with organ perfusion transport systems may offer a new therapeutic approach for tissue and organ preservation for transplantation, trauma management, and enhancing patient survival in remote and low-resource locations.

Deficiency of Tlr7 and Irf7 in mice increases the severity of COVID-19 through the reduced interferon production

Toll-like receptor 7 (Tlr7) deficiency-accelerated severe COVID-19 is associated with reduced production of interferons (IFNs). However, the underlying mechanisms remain elusive. To address these questions, we utilize Tlr7 and Irf7 deficiency mice, single-cell RNA analysis together with bone marrow transplantation approaches. We demonstrate that at the early phase of infection, SARS-CoV-2 causes the upregulation of Tlr7, Irf7, and IFN pathways in the lungs of the infected mice. The deficiency of Tlr7 and Irf7 globally and/or in immune cells in mice increases the severity of COVID-19 via impaired IFN activation in both immune and/or non-immune cells, leading to increased lung viral loads. These effects are associated with reduced IFN alpha and gamma levels in the circulation. The deficiency of Tlr7 tends to cause the reduced production and nuclear translocation of interferon regulatory factor 7 (IRF7) in the lungs of the infected mice, indicative of reduced IRF7 activation. Despite higher amounts of lung viral antigen, Tlr7 or Irf7 deficiency resulted in substantially reduced production of antibodies against SARS-CoV-2, thereby delaying the viral clearance. These results highlight the importance of the activation of TLR7 and IRF7 leading to IFN production on the development of innate and adaptive immunity against COVID-19.

Effective and durable repigmentation for stable vitiligo: A randomized within-subject controlled trial assessing treatment with autologous skin cell suspension transplantation

BackgroundVitiligo lesions are often challenging to repigment with conventional medical therapies. Surgical autologous melanocyte transfer methods can be utilized for stable vitiligo but demand specialized skills and equipment. A point-of-care autologous cell harvesting device was designed enabling simple preparation of autologous skin cell suspension (ASCS) containing melanocytes, keratinocytes, and fibroblasts providing a straightforward approach for cellular transplantation. ObjectiveTo evaluate the safety and effectiveness of ASCS for repigmentation of stable vitiligo lesions among adults. MethodsA US multicenter, randomized, within-subject controlled trial compared ASCS to NB-UVB only (Control) in similar vitiligo lesions. ASCS was applied after laser skin resurfacing and followed by NB-UVB treatment. The primary effectiveness endpoint was the proportion of lesions achieving ≥80% repigmentation at week-24. Repigmentation durability was assessed at week-52. ResultsAmong 25 subjects, 36% of ASCS-treated lesions achieved ≥80% repigmentation at week-24 compared to 0% for Control (p<0.025), with durability through week-52. The safety profile of ASCS was acceptable, with favorable patient- and investigator-reported outcomes. LimitationsStudy sample size limited robust subgroup analyses. ConclusionApplication of ASCS is a safe and effective treatment for repigmentation of stable vitiligo lesions with the potential to improve health-related quality of life and reduce burden of disease.

Long-term survival after unrelated donor marrow transplantation for aplastic anaemia after optimized conditioning regimen: a retrospective multicentre cohort study

Almost all acquired severe aplastic anaemia is immune mediated and characterised by hypocellular bone marrow and ≥2 affected haematopoietic lineages. The optimal preparartive regimen for unrelated donor transplantation remains to be established. We aimed to study long-term outcomes after unrelated donor transplantation for severe aplastic anaemia with de-escalation of cyclophosphamide (Cy) dose in steps of 50mg/kg (150, 100, 50, 0mg/kg) in combination with total body irradiation (TBI) 2Gy, anti-thymocyte globulin (ATG) and fludarabine. Ninety-six patients with severe aplastic anaemia aged ≤65 years with adequate organ function enrolled on a trial of human leukocyte antigen (HLA)-matched or 1 HLA-locus mismatched unrelated donor marrow transplantation conducted between 02/2006 and 12/2013 in the United States (NCT00326417). Exclusion criteria were Karnofsky performance status of less than 60, clonal cytogenetic abnormalities and inherited marrow failure syndormes. The primary outcome was day-100 engraftment (achievement of absolute neutrophil recovery to at least 0.5×109/L without subsequent decline) and day-100 survival. The trial determined the lowest effective Cydose as 50mg/kg (n=38) for day-100 engraftment and survival. Cy dose 100mg/kg (n=41) was also acceptable. Accrual to Cy doses 150mg/kg (n=15) and 0mg/kg (n=3) was terminated early for toxicities. The current study is an extended follow up of patients enrolled on the trial (NCT00326477) and includes 76 of 96 patients alive ≥1 year after transplantation. There were 20 deaths in the first year after transplantation (Cy 0mg/kg [n=2], Cy 50mg/kg [n=1], Cy 100mg/kg [n=10], Cy 150mg/kg [n=7]). Patients were followed prospectively from transplantation and data reported using standardized data collection forms until death, loss to follow up or last contact through November 2023. The incidence of graft failure was calculated using the cumulative incidence estimator and the probability of survival using the Kaplan-Meier estimator. The median follow up of the cohort is 8.02 (IQR) 5.16-10.12) years. With Cy 50mg/kg, there was one graft failure and five deaths ≥1 year after transplantation. With Cy 100mg/kg there was only one late death and no graft failure. The 8-year probabilities of survival were 85.0% (95% CI 67.3-93.5) and 75.6% (95% CI 59.4-86.1) after Cy50mg/kg and 100mg/kg, respectively, P=0.31. With Cy 0mg/kg and 150mg/kg, there were no graft failures or death ≥1 year after transplantation. Regardless of Cy dose 12 of 15 patients aged ≥50 years died. Cy 50mg/kg or 100mg/kg with TBI 2Gy, ATG and fludarabine are effective conditioning regimens for unrelated donor marrow transplants for aplastic anaemia. Identification of an optimized transplantation approach for patients aged ≥50 years is needed. US National Institutes of Health.