An analysis of suspected microplastics in the muscle and gastrointestinal tissues of fish from Sarasota Bay, FL: exposure and implications for apex predators and seafood consumers.

Microplastics have been found in the gastrointestinal (GI) fluid of bottlenose dolphins (Tursiops truncatus), inhabiting Sarasota Bay, FL, suggesting exposure by ingestion, possibly via contaminated fish. To better understand the potential for trophic transfer, muscle and GI tissues from 11 species of dolphin prey fish collected from Sarasota Bay were screened for microplastics (particles <5 mm diameter). Suspected microplastics were found in 82% of muscle samples (n=89), and 97% of GI samples (n=86). Particle abundance and shapes varied by species (p<0.05) and foraging habit (omnivore vs. carnivore, p<0.05). Pinfish (Lagodon rhomboides) had the highest particle abundance for both tissue types (muscle: 0.38 particles/g; GI: 15.20 particles/g), which has implications for dolphins as they are a common prey item. Findings from this study support research demonstrating the ubiquity of estuarine plastic contamination and underscore the risks of ingestion exposure for wildlife and potentially seafood consumers.

Cost-Effectiveness And Health Impact Of Increasing Emergency Department Pediatric Readiness In The US.

The quality of emergency department (ED) care for children in the US is highly variable. The National Pediatric Readiness Project aims to improve survival for children receiving emergency services. We conducted a cost-effectiveness analysis of increasing ED pediatric readiness, using a decision-analytic simulation model. Previously published primary analyses of a nationally representative, population-based cohort of children receiving emergency services at 747 EDs in eleven states provided clinical and cost parameters. From a health care sector perspective, we used a 3 percent annual discount rate and quantified lifetime costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). We performed probabilistic, one-way, and subgroup sensitivity analyses. Increasing ED pediatric readiness yields 69,100 QALYs for the eleven-state cohort, costing $9,300 per QALY gained. Achieving high readiness nationally yields 179,000 QALYs at the same ICER (with implementation costs of approximately $260 million). Implementing high ED pediatric readiness for all EDs in the US is highly cost-effective.

Fetal bone engraftment reconstitutes the immune system in pigs with severe combined immunodeficiency.

Genetic modification of genes such as recombination activating gene 2 (RAG2) or interleukin-2 receptor-γ (IL2RG) results in pigs exhibiting severe combined immunodeficiency (SCID). Pigs presenting a SCID phenotype are important animal models that can be used to establish xenografts and to study immune system development and various immune-related pathologies. However, due to their immunocompromised nature, SCID pigs have shortened lifespans and are notoriously difficult to maintain. The failure-to-thrive phenotype makes the establishment of a breeding population of RAG2/IL2RG double-knockout pigs virtually impossible. Here, to overcome this limitation, we investigated whether reconstituting the immune system of SCID piglets with a fetal bone allograft would extend their lifespan. Following intramuscular transplantation, allografts gave rise to lymphocytes expressing T cell (CD3, CD4 and CD8), B cell (CD79α) and natural killer cell (CD335) lineage markers, which were detected in circulation as well in the spleen, liver, bone marrow and thymic tissues. The presence of lymphocytes indicates broad engraftment of donor cells in the recipient SCID pigs. Unlike unreconstituted SCID pigs, the engrafted animals thrived and reached puberty under standard housing conditions. This study demonstrates a novel method to extend the survival of SCID pigs, which may improve the availability and use of SCID pigs as a biomedical animal model.

A 2-hydroxybutyrate-mediated feedback loop regulates muscular fatigue.

Several metabolites have been shown to have independent and at times unexpected biological effects outside of their metabolic pathways. These include succinate, lactate, fumarate, and 2-hydroxyglutarate. 2-Hydroxybutyrate (2HB) is a byproduct of endogenous cysteine synthesis, produced during periods of cellular stress. 2HB rises acutely after exercise; it also rises during infection and is also chronically increased in a number of metabolic disorders. We show here that 2HB inhibits branched-chain aminotransferase enzymes, which in turn triggers a SIRT4-dependent shift in the compartmental abundance of protein ADP-ribosylation. The 2HB-induced decrease in nuclear protein ADP-ribosylation leads to a C/EBPß-mediated transcriptional response in the branched-chain amino acid degradation pathway. This response to 2HB exposure leads to an improved oxidative capacity in vitro. We found that repeated injection with 2HB can replicate the improvement to oxidative capacity that occurs following exercise training. Together, we show that 2-HB regulates fundamental aspects of skeletal muscle metabolism.

Development and Validation of a Bayesian Network Predicting Intubation Following Hospital Arrival Among Injured Children.

BACKGROUND: Inadequate airway management can contribute to preventable trauma deaths. Current machine learning tools for predicting intubation in trauma are limited to adult populations and include predictors not readily available at the time of patient arrival. We developed a Bayesian network to predict intubation in injured children and adolescents using observable data available upon or immediately after patient arrival. METHODS: We obtained patient demographic, injury, resuscitation, and transportation characteristics from trauma registries from four American College of Surgeons-verified level 1 pediatric trauma centers from January 2010 through December 2021. We trained and validated a Bayesian network to predict emergent intubation after pediatric injury. We evaluated model performance using the area under the receiver operating and calibration curves. RESULTS: The final model, TITAN (Timing of Intubation in Trauma Analysis Network), incorporated five factors: Glasgow Coma Scale, mechanism of injury, injury type (e.g., penetrating, blunt), systolic blood pressure, and age. The model achieved an area under the receiver operating characteristic curve of 0.83 (95% CI 0.80, 0.85) and had a calibration curve slope of 0.98 (95% CI 0.67, 1.29). TITAN had high specificity (98%), negative predictive value (97%), and accuracy (96%) at a binary probability threshold of 22.6%. CONCLUSION: The TITAN Bayesian network predicts the risk of intubation in pediatric trauma patients using five factors that are observable early in trauma resuscitation. Prospective validation of the model performance with patient outcomes is needed to assess real-life application benefits and risks. LEVEL OF EVIDENCE: Prognostic and Epidemiological, Level III.

Regulation of the hematopoietic stem cell pool by C-Kit-associated trogocytosis.

Hematopoietic stem cells (HSCs) are routinely mobilized from the bone marrow (BM) to the blood circulation for clinical transplantation. However, the precise mechanisms by which individual stem cells exit the marrow are not understood. This study identified cell-extrinsic and molecular determinants of a mobilizable pool of blood-forming stem cells. We found that a subset of HSCs displays macrophage-associated markers on their cell surface. Although fully functional, these HSCs are selectively niche-retained as opposed to stem cells lacking macrophage markers, which exit the BM upon forced mobilization. Macrophage markers on HSCs could be acquired through direct transfer by trogocytosis, regulated by receptor tyrosine-protein kinase C-Kit (CD117), from BM-resident macrophages in mouse and human settings. Our study provides proof of concept that adult stem cells utilize trogocytosis to rapidly establish and activate function-modulating molecular mechanisms.

Impaired Skeletal Development by Disruption of Presenilin-1 in Pigs and Generation of Novel Pig Models for Alzheimer's Disease.

Background: Presenilin 1 (PSEN1) is one of the genes linked to the prevalence of early onset Alzheimer's disease. In mice, inactivation of Psen1 leads to developmental defects, including vertebral malformation and neural development. However, little is known about the role of PSEN1 during the development in other species. Objective: To investigate the role of PSEN1 in vertebral development and the pathogenic mechanism of neurodegeneration using a pig model. Methods: CRISPR/Cas9 system was used to generate pigs with different mutations flanking exon 9 of PSEN1, including those with a deleted exon 9 (Δexon9). Vertebral malformations in PSEN1 mutant pigs were examined by X-ray, micro-CT and micro-MRI. Neuronal cells from the brains of PSEN1 mutant pigs were analyzed by immunoflourescence, followed by image analysis including morphometric evaluation via image J and 3D reconstruction. Results: Pigs with a PSEN1 null mutation (Δexon9-12) died shortly after birth and had significant axial skeletal defects, whereas pigs carrying at least one Δexon9 allele developed normally and remained healthy. Effects of the null mutation on abnormal skeletal development were also observed in fetuses at day 40 of gestation. Abnormal distribution of astrocytes and microglia in the brain was detected in two PSEN1 mutant pigs examined compared to age-matched control pigs. The founder pigs were bred to establish and age PSEN1ΔE9/+ pigs to study their relevance to clinical Alzheimer's diseases. Conclusions: PSEN1 has a critical role for normal vertebral development and PSEN1 mutant pigs serves as novel resources to study Alzheimer's disease.

Extended survival of 9- and 10-gene-edited pig heart xenografts with ischemia minimization and CD154 costimulation blockade-based immunosuppression.

BACKGROUND: Xenotransplantation has made significant advances recently using pigs genetically engineered to remove carbohydrate antigens, either alone or with addition of various human complement, coagulation, and anti-inflammatory ''transgenes''. Here we evaluated results associated with gene-edited (GE) pig hearts transplanted in baboons using an established costimulation-based immunosuppressive regimen and a cold-perfused graft preservation technique. METHODS: Eight baboons received heterotopic abdominal heart transplants from 3-GE (GalKO.ß4GalNT2KO.hCD55, n = 3), 9-GE (GalKO.ß4GalNT2KO.GHRKO.hCD46.hCD55. TBM.EPCR.hCD47. HO-1, n = 3) or 10-G (9-GE+CMAHKO, n = 2) pigs using Steen's cold continuous perfusion for ischemia minimization. Immunosuppression (IS) included induction with anti-thymocyte globulin and αCD20, ongoing αCD154, MMF, and tapered corticosteroid. RESULTS: All three 3-GE grafts functioned well initially, but failed within 5 days. One 9-GE graft was lost intraoperatively due to a technical issue and another was lost at POD 13 due to antibody mediated rejection (AMR) in a baboon with a strongly positive pre-operative cross-match. One 10-GE heart failed at POD113 with combined cellular and antibody mediated rejection. One 9-GE and one 10-GE hearts had preserved graft function with normal myocardium on protocol biopsies, but exhibited slowly progressive graft hypertrophy until elective necropsy at POD393 and 243 respectively. Elevated levels of IL-6, MCP-1, C-reactive protein, and human thrombomodulin were variably associated with conditioning, the transplant procedure, and clinically significant postoperative events. CONCLUSION: Relative to reference genetics without thrombo-regulatory and anti-inflammatory gene expression, 9- or 10-GE pig hearts exhibit promising performance in the context of a clinically applicable regimen including ischemia minimization and αCD154-based IS, justifying further evaluation in an orthotopic model.

Factors associated with correction of personal protective equipment nonadherence in a multidisciplinary emergency department setting: A retrospective video review.

BACKGROUND: Despite local and national recommendations, health care provider adherence to personal protective equipment (PPE) varied during the COVID-19 pandemic. Previous studies have identified factors influencing initial PPE adherence but did not address factors influencing behaviors leading to correction after initial nonadherence. METHODS: We conducted a retrospective video review of 18 pediatric resuscitations involving aerosol-generating procedures from March 2020 to December 2022 to identify factors associated with nonadherence correction. We quantified adherent and nonadherent providers, instances of PPE nonadherence, and time to correction. We also analyzed correction behaviors, including provider actions and correction locations. RESULTS: Among 434 providers, 362 (83%) were nonadherent with at least 1 PPE. Only 186 of 1,832 instances of nonadherence were corrected, primarily upon room entry and during patient care. Correction time varied by PPE type and nonadherence level (incomplete vs absent). Most corrections were self-initiated, with few reminders from other providers. DISCUSSION: Potential barriers to correction include a lack of social pressure and external reminders. Solutions include optimizing PPE availability, providing real-time feedback, and educating on double gloving. CONCLUSIONS: Most providers were nonadherent to PPE requirements during high-risk infection transmission events. The low correction rate suggests challenges in promoting collective responsibility and maintaining protective behaviors during medical emergencies.

Systemic and local regulation of hematopoietic homeostasis in health and disease.

Hematopoietic stem cells (HSCs) generate all blood cell lineages responsible for tissue oxygenation, life-long hematopoietic homeostasis and immune protection. In adulthood, HSCs primarily reside in the bone marrow (BM) microenvironment, consisting of diverse cell types that constitute the stem cell 'niche'. The adaptability of the hematopoietic system is required to respond to the needs of the host, whether to maintain normal physiology or during periods of physical, psychosocial or environmental stress. Hematopoietic homeostasis is achieved by intricate coordination of systemic and local factors that orchestrate the function of HSCs throughout life. However, homeostasis is not a static process; it modulates HSC and progenitor activity in response to circadian rhythms coordinated by the central and peripheral nervous systems, inflammatory cues, metabolites and pathologic conditions. Here, we review local and systemic factors that impact hematopoiesis, focusing on the implications of aging, stress and cardiovascular disease.

Analysis of the diverse antigenic landscape of the malaria protein RH5 identifies a potent vaccine-induced human public antibody clonotype.

The highly conserved and essential Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) has emerged as the leading target for vaccines against the disease-causing blood stage of malaria. However, the features of the human vaccine-induced antibody response that confer highly potent inhibition of malaria parasite invasion into red blood cells are not well defined. Here, we characterize 236 human IgG monoclonal antibodies, derived from 15 donors, induced by the most advanced PfRH5 vaccine. We define the antigenic landscape of this molecule and establish that epitope specificity, antibody association rate, and intra-PfRH5 antibody interactions are key determinants of functional anti-parasitic potency. In addition, we identify a germline IgG gene combination that results in an exceptionally potent class of antibody and demonstrate its prophylactic potential to protect against P. falciparum parasite challenge in vivo. This comprehensive dataset provides a framework to guide rational design of next-generation vaccines and prophylactic antibodies to protect against blood-stage malaria.

Preclinical development of a stabilized RH5 virus-like particle vaccine that induces improved antimalarial antibodies.

Plasmodium falciparum reticulocyte-binding protein homolog 5 (RH5) is a leading blood-stage malaria vaccine antigen target, currently in a phase 2b clinical trial as a full-length soluble protein/adjuvant vaccine candidate called RH5.1/Matrix-M. We identify that disordered regions of the full-length RH5 molecule induce non-growth inhibitory antibodies in human vaccinees and that a re-engineered and stabilized immunogen (including just the alpha-helical core of RH5) induces a qualitatively superior growth inhibitory antibody response in rats vaccinated with this protein formulated in Matrix-M adjuvant. In parallel, bioconjugation of this immunogen, termed "RH5.2," to hepatitis B surface antigen virus-like particles (VLPs) using the "plug-and-display" SpyTag-SpyCatcher platform technology also enables superior quantitative antibody immunogenicity over soluble protein/adjuvant in vaccinated mice and rats. These studies identify a blood-stage malaria vaccine candidate that may improve upon the current leading soluble protein vaccine candidate RH5.1/Matrix-M. The RH5.2-VLP/Matrix-M vaccine candidate is now under evaluation in phase 1a/b clinical trials.

Gene editing of pigs to control influenza A virus infections.

Proteolytic activation of the haemagglutinin (HA) glycoprotein by host cellular proteases is pivotal for influenza A virus (IAV) infectivity. Highly pathogenic avian influenza viruses possess the multibasic cleavage site of the HA which is cleaved by ubiquitous proteases, such as furin; in contrast, the monobasic HA motif is recognized and activated by trypsin-like proteases, such as the transmembrane serine protease 2 (TMPRSS2). Here, we aimed to determine the effects of TMPRSS2 on the replication of pandemic H1N1 and H3N2 subtype IAVs in the natural host, the pig. The use of the CRISPR/Cas 9 system led to the establishment of homozygous gene edited (GE) TMPRSS2 knockout (KO) pigs. Delayed IAV replication was demonstrated in primary respiratory cells of KO pigs in vitro. IAV infection in vivo resulted in a significant reduction of virus shedding in the upper respiratory tract, and lower virus titers and pathological lesions in the lower respiratory tract of TMPRSS2 KO pigs as compared to wild-type pigs. Our findings support the commercial use of GE pigs to mitigate influenza A virus infection in pigs, as an alternative approach to prevent zoonotic influenza A transmissions from pigs to humans.

White Matter Hyperintensities and Mild TBI in Post-9/11 Veterans and Service Members.

INTRODUCTION: The neurobehavioral significance of white matter hyperintensities (WMHs) seen on magnetic resonance imaging after traumatic brain injury (TBI) remains unclear, especially in Veterans and Service Members with a history of mild TBI (mTBI). In this study, we investigate the relation between WMH, mTBI, age, and cognitive performance in a large multisite cohort from the Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium. MATERIALS AND METHODS: The neuroimaging and neurobehavioral assessments for 1,011 combat-exposed, post-9/11 Veterans and Service Members (age range 22-69 years), including those with a history of at least 1 mTBI (n = 813; median postinjury interval of 8 years) or negative mTBI history (n = 198), were examined. RESULTS: White matter hyperintensities were present in both mTBI and comparison groups at similar rates (39% and 37%, respectively). There was an age-by-diagnostic group interaction, such that older Veterans and Service Members with a history of mTBI demonstrated a significant increase in the number of WMHs present compared to those without a history of mTBI. Additional associations between an increase in the number of WMHs and service-connected disability, insulin-like growth factor-1 levels, and worse performance on tests of episodic memory and executive functioning-processing speed were found. CONCLUSIONS: Subtle but important clinical relationships are identified when larger samples of mTBI participants are used to examine the relationship between history of head injury and radiological findings. Future studies should use follow-up magnetic resonance imaging and longitudinal neurobehavioral assessments to evaluate the long-term implications of WMHs following mTBI.

Changes in Emergency Department Pediatric Readiness and Mortality.

Importance: High emergency department (ED) pediatric readiness is associated with improved survival, but the impact of changes to ED readiness is unknown. Objective: To evaluate the association of changes in ED pediatric readiness at US trauma centers between 2013 and 2021 with pediatric mortality. Design, Setting, and Participants: This retrospective cohort study was performed from January 1, 2012, through December 31, 2021, at EDs of trauma centers in 48 states and the District of Columbia. Participants included injured children younger than 18 years with admission or injury-related death at a participating trauma center, including transfers to other trauma centers. Data analysis was performed from May 2023 to January 2024. Exposure: Change in ED pediatric readiness, measured using the weighted Pediatric Readiness Score (wPRS, range 0-100, with higher scores denoting greater readiness) from national assessments in 2013 and 2021. Change groups included high-high (wPRS ≥93 on both assessments), low-high (wPRS <93 in 2013 and wPRS ≥93 in 2021), high-low (wPRS ≥93 in 2013 and wPRS <93 in 2021), and low-low (wPRS <93 on both assessments). Main Outcomes and Measures: The primary outcome was lives saved vs lost, according to ED and in-hospital mortality. The risk-adjusted association between changes in ED readiness and mortality was evaluated using a hierarchical, mixed-effects logistic regression model based on a standardized risk-adjustment model for trauma, with a random slope-random intercept to account for clustering by the initial ED. Results: The primary sample included 467 932 children (300 024 boys [64.1%]; median [IQR] age, 10 [4 to 15] years; median [IQR] Injury Severity Score, 4 [4 to 15]) at 417 trauma centers. Observed mortality by ED readiness change group was 3838 deaths of 144 136 children (2.7%) in the low-low ED group, 1804 deaths of 103 767 children (1.7%) in the high-low ED group, 1288 deaths of 64 544 children (2.0%) in the low-high ED group, and 2614 deaths of 155 485 children (1.7%) in the high-high ED group. After risk adjustment, high-readiness EDs (persistent or change to) had 643 additional lives saved (95% CI, -328 to 1599 additional lives saved). Low-readiness EDs (persistent or change to) had 729 additional preventable deaths (95% CI, -373 to 1831 preventable deaths). Secondary analysis suggested that a threshold of wPRS 90 or higher may optimize the number of lives saved. Among 716 trauma centers that took both assessments, the median (IQR) wPRS decreased from 81 (63 to 94) in 2013 to 77 (64 to 93) in 2021 because of reductions in care coordination and quality improvement. Conclusions and Relevance: Although the findings of this study of injured children in US trauma centers were not statistically significant, they suggest that trauma centers should increase their level of ED pediatric readiness to reduce mortality and increase the number of pediatric lives saved after injury.

Equity in the Setting of Heart Failure Diagnosis: An Analysis of Differences Between and Within Clinician Practices.

BACKGROUND: Timely heart failure (HF) diagnosis can lead to earlier intervention and reduced morbidity. Among historically marginalized patients, new-onset HF diagnosis is more likely to occur in acute care settings (emergency department or inpatient hospitalization) than outpatient settings. Whether inequity within outpatient clinician practices affects diagnosis settings is unknown. METHODS: We determined the setting of incident HF diagnosis among Medicare fee-for-service beneficiaries between 2013 and 2017. We identified sociodemographic and medical characteristics associated with HF diagnosis in the acute care setting. Within each outpatient clinician practice, we compared acute care diagnosis rates across sociodemographic characteristics: female versus male sex, non-Hispanic White versus other racial and ethnic groups, and dual Medicare-Medicaid eligible (a surrogate for low income) versus nondual-eligible patients. Based on within-practice differences in acute diagnosis rates, we stratified clinician practices by equity (high, intermediate, and low) and compared clinician practice characteristics. RESULTS: Among 315 439 Medicare patients with incident HF, 173 121 (54.9%) were first diagnosed in acute care settings. Higher adjusted acute care diagnosis rates were associated with female sex (6.4% [95% CI, 6.1%-6.8%]), American Indian (3.6% [95% CI, 1.1%-6.1%]) race, and dual eligibility (4.1% [95% CI, 3.7%-4.5%]). These differences persisted within clinician practices. With clinician practice adjustment, dual-eligible patients had a 4.9% (95% CI, 4.5%-5.4%) greater acute care diagnosis rate than nondual-eligible patients. Clinician practices with greater equity across dual eligibility also had greater equity across sex and race and ethnicity and were more likely to be composed of predominantly primary care clinicians. CONCLUSIONS: Differences in HF diagnosis rates in the acute care setting between and within clinician practices highlight an opportunity to improve equity in diagnosing historically marginalized patients.

Neuropsychological Profiles of Deployment-Related Mild Traumatic Brain Injury: A LIMBIC-CENC Study.

BACKGROUND AND OBJECTIVES: Traumatic brain injury (TBI) is a concern for US service members and veterans (SMV), leading to heterogeneous psychological and cognitive outcomes. We sought to identify neuropsychological profiles of mild TBI (mTBI) and posttraumatic stress disorder (PTSD) among the largest SMV sample to date. METHODS: We analyzed cross-sectional baseline data from SMV with prior combat deployments enrolled in the ongoing Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium prospective longitudinal study. Latent profile analysis identified symptom profiles using 35 indicators, including physical symptoms, depression, quality of life, sleep quality, postconcussive symptoms, and cognitive performance. It is important to note that the profiles were determined independently of mTBI and probable PTSD status. After profile identification, we examined associations between demographic variables, mTBI characteristics, and PTSD symptoms with symptom profile membership. RESULTS: The analytic sample included 1,659 SMV (mean age 41.1 ± 10.0 years; 87% male); among them 29% (n = 480) had a history of non-deployment-related mTBI only, 14% (n = 239) had deployment-related mTBI only, 36% (n = 602) had both non-deployment and deployment-related mTBI, and 30% (n = 497) met criteria for probable PTSD. A 6-profile model had the best fit, with separation on all indicators (p < 0.001). The model revealed distinct neuropsychological profiles, representing a combination of 3 self-reported functioning patterns: high (HS), moderate (MS), and low (LS), and 2 cognitive performance patterns: high (HC) and low (LC). The profiles were (1) HS/HC: n=301, 18.1%; (2) HS/LC: n=294, 17.7%; (3) MS/HC: n=359, 21.6%; (4) MS/LC: n=316, 19.0%; (5) LS/HC: n=228, 13.7%; and (6) LS/LC: n=161, 9.7%. SMV with deployment-related mTBI tended to be grouped into lower functioning profiles and were more likely to meet criteria for probable PTSD. Conversely, SMV with no mTBI exposure or non-deployment-related mTBI were clustered in higher functioning profiles and had a lower likelihood of meeting criteria for probable PTSD. DISCUSSION: Findings suggest varied symptom and functional profiles in SMV, influenced by injury context and probable PTSD comorbidity. Despite diagnostic challenges, comprehensive assessment of functioning and cognition can detect subtle differences related to mTBI and PTSD, revealing distinct neuropsychological profiles. Prioritizing early treatment based on these profiles may improve prognostication and support efficient recovery.

Conceptus Estrogen and prostaglandins provide the maternal recognition of pregnancy signal to prevent Luteolysis during early pregnancy in the pig†.

Conceptus estrogens and prostaglandins have long been considered the primary signals for maternal recognition of pregnancy (MRP) in the pig. However, loss-of-function studies targeting conceptus aromatase genes (CYP19A1 and CYP19A2) and prostaglandin-endoperoxide synthase 2 (PTGS2) indicated that conceptuses can not only signal MRP without estrogens or prostaglandins but can maintain early pregnancy. However, complete loss of estrogen production leads to abortion after day 25 of gestation. Although neither conceptus estrogens nor prostaglandins had a significant effect on early maintenance of CL function alone, the two conceptus factors have a biological relationship. To investigate the role that both conceptus estrogens and prostaglandins have on MRP and maintenance of pregnancy, a triple loss-of function model (TKO) was generated for conceptus CYP19A1, CYP19A2 and PTGS2. In addition, a conceptus CYP19A2-/- model (A2KO) was established to determine the role of placental estrogen during later pregnancy. Estrogen and prostaglandin synthesis were greatly reduced in TKO conceptuses which resulted in a failure to inhibit luteolysis after day 15 of pregnancy despite the presence of conceptuses in the uterine lumen. However, A2KO placentae not only maintained functional CL but were able to maintain pregnancy to day 32 of gestation. Despite the loss of placental CYP19A2 expression, the allantois fluid content of estrogen was not affected as the placenta compensated by expressing CYP19A1 and CYP19A3, which are normally absent in controls. Results suggest conceptuses can signal MRP through production of conceptus PGE or stimulating PGE synthesis from the endometrium through conceptus estrogen. Failure of conceptuses to produce both factors results in failure of MRP and loss of pregnancy.

Development of an improved blood-stage malaria vaccine targeting the essential RH5-CyRPA-RIPR invasion complex.

Reticulocyte-binding protein homologue 5 (RH5), a leading blood-stage Plasmodium falciparum malaria vaccine target, interacts with cysteine-rich protective antigen (CyRPA) and RH5-interacting protein (RIPR) to form an essential heterotrimeric "RCR-complex". We investigate whether RCR-complex vaccination can improve upon RH5 alone. Using monoclonal antibodies (mAbs) we show that parasite growth-inhibitory epitopes on each antigen are surface-exposed on the RCR-complex and that mAb pairs targeting different antigens can function additively or synergistically. However, immunisation of female rats with the RCR-complex fails to outperform RH5 alone due to immuno-dominance of RIPR coupled with inferior potency of anti-RIPR polyclonal IgG. We identify that all growth-inhibitory antibody epitopes of RIPR cluster within the C-terminal EGF-like domains and that a fusion of these domains to CyRPA, called "R78C", combined with RH5, improves the level of in vitro parasite growth inhibition compared to RH5 alone. These preclinical data justify the advancement of the RH5.1 + R78C/Matrix-M™ vaccine candidate to Phase 1 clinical trial.

Surgical Protocol for Partial Heart Transplantation in Growing Piglets.

Partial heart transplantation is a new approach to deliver growing heart valve implants. Partial heart transplants differ from heart transplants because only the part of the heart containing the necessary heart valve is transplanted. This allows partial heart transplants to grow, similar to the valves in heart transplants. However, the transplant biology of partial heart transplantation remains unexplored. This is a critical barrier to progress of the field. Without knowledge about the specific transplant biology of partial heart transplantation, children with partial heart transplants are empirically treated like children with heart transplants because the valves in heart transplants are known to grow. In order to progress the field, an animal model for partial heart transplantation is necessary. Here, we contribute our surgical protocol for partial heart transplantation in growing piglets. All aspects of partial heart transplantation, including the donor procedure, the recipient procedure, and recipient perioperative care are described in detail. There are important nuances in the conduct of virtually all aspects of open heart surgery that differs in piglets from humans. Our surgical protocol, which is based on our experience with 34 piglets, will allow other investigators to leverage our experience to seek fundamental knowledge about the nature of partial heart transplants. This is significant because the partial heart transplant model in piglets is complex and very resource intensive.