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126 result(s) for "Alexander, Megan V."
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Maternal Race and Clinical Vigilance in Obstetric Hemorrhage Management
Background/Objectives: Previous literature has described that non-white pregnant patients are at increased risk of severe morbidity from obstetric hemorrhage (OBH). Here, we investigate whether such disparities are secondary to delay in the administration of postpartum oxytocin for non-white patients compared to white patients. Methods: This is a retrospective cohort study of all deliveries from 2018 to 2019, comparing (1) Hispanic white or non-white race (HW/NWR) pregnant people and (2) non-Hispanic white (NHW) pregnant people. Our primary outcome was the time from delivery to the first dose of postpartum oxytocin, and our secondary outcome was the frequency of other hemorrhage interventions. Results: Out of 3832 patients with self-identified race and ethnicity recorded in their patient record, 644 patients identified as NHW, and 3188 patients identified as HW/NWR. We found no difference in time to first dose of postpartum oxytocin (p = 0.51), and there was also no difference in the frequency of other hemorrhage-related interventions. Conclusions: Our study found no delay in the administration of postpartum oxytocin for non-white patients.
Decreasing barriers to the utilization of cryopreserved sperm in male cancer survivors: an expert review and guide
Abstract Background Sperm cryopreservation offers male cancer patients a critical opportunity to preserve fertility prior to gonadotoxic therapy, yet utilization of banked sperm remains modest, typically under 10%. A structured understanding of barriers across the cancer survivorship continuum is needed to support patients in utilization of cryopreserved sperm in alignment with their reproductive goals. Materials and Methods This expert review synthesizes current evidence and clinical experience to explore the multifaceted barriers to cryopreserved sperm use and propose specific solutions. Key intervention timepoints are examined, including the post-treatment fertility return visit, long-term cryopreservation while remote from family building, readiness for family building, and posthumous considerations. We subsequently outline an optimal Oncofertility Patient Care Pathway. Results Multiple clinical, psychosocial, and financial obstacles limit the transition from sperm banking to use. Approximately one-third of survivors do not attend post-treatment fertility return visits, reducing opportunities for counseling and longitudinal reproductive planning. Psychological factors—including fear of cancer recurrence and delayed readiness for family building—contribute to prolonged storage. Many patients remain underinformed about the efficacy and processes of assisted reproductive techniques, while financial concerns are significant. These intersecting barriers hinder use of cryopreserved sperm. Opportunities exist to intervene at key timepoints, as outlined in the Oncofertillity Patient Care Pathway. Conclusion A multidisciplinary and structured oncofertility pathway, such as detailed in this review, is needed to support cancer survivors in achieving their reproductive goals. Enhanced counseling, technology-enabled follow-up systems, targeted psychological support, and policies promoting broader insurance coverage for assisted reproduction represent key strategies to overcome existing barriers.
Association between duration of intrapartum oxytocin exposure and obstetric hemorrhage
Purpose Prolonged duration of intrapartum oxytocin exposure is included as a risk factor within widely adopted obstetric hemorrhage risk stratification tools. However, the duration of exposure that confers increased risk is poorly understood. This study aimed to assess the association between duration of intrapartum oxytocin exposure and obstetric blood loss, as measured by quantitative blood loss, and hemorrhage-related maternal morbidity. Methods This was a retrospective cohort study of all deliveries from 2018 to 2019 at a single medical center. We included patients who had received any intrapartum oxytocin, and we categorized them into 1 of 5 groups: > 0–2, ≥ 2–4, ≥ 4–6, ≥ 6–12, and ≥ 12 h of intrapartum oxytocin exposure. The primary outcomes were mean quantitative blood loss, proportion with obstetric hemorrhage (defined as quantitative blood loss ≥ 1000 mL), and proportion with obstetric hemorrhage-related morbidity, a composite of hemorrhage-related morbidity outcomes. Secondary outcomes were hemorrhage-related pharmacologic and procedural interventions. A stratified analysis was also conducted to examine primary and secondary outcomes by delivery mode. Results Of 5332 deliveries between January 1, 2018 and December 31, 2019 at our institution, 2232 (41.9%) utilized oxytocin for induction or augmentation. 326 (14.6%) had exposure of > 0–2 h, 295 (13.2%) ≥ 2–4 h, 298 (13.4%) ≥ 4–6 h, 562 (25.2%) ≥ 6–12 h, and 751 (33.6%) ≥ 12 h. Across all deliveries, there was higher mean quantitative blood loss ( p <  0.01) as well as increased odds of obstetric hemorrhage (adjusted odds ratio [aOR] 1.52, 95% confidence interval [CI] 1.21–1.91) for those with ≥ 12 h of oxytocin compared to all groups between > 0-12 h of exposure. In our stratified analysis, ≥ 12 h of oxytocin exposure was associated with higher mean quantitative blood loss ( p =  0.04) and odds of obstetric hemorrhage in vaginal deliveries (aOR 1.47, 95% CI: 1.03–2.11), though not in cesarean deliveries (aOR 1.16, 95% CI 0.82–1.62). There were no differences in proportion with obstetric hemorrhage-related morbidity across all deliveries ( p =  0.40) or in the stratified analysis. Conclusion Intrapartum oxytocin exposure of ≥ 12 h was associated with increased quantitative blood loss and odds of obstetric hemorrhage in vaginal, but not cesarean, deliveries.
CD11b suppresses TLR activation of nonclassical monocytes to reduce primary graft dysfunction after lung transplantation
Primary graft dysfunction (PGD) is the leading cause of postoperative mortality in lung transplant recipients and the most important risk factor for development of chronic lung allograft dysfunction. The mechanistic basis for the variability in the incidence and severity of PGD between lung transplant recipients is not known. Using a murine orthotopic vascularized lung transplant model, we found that redundant activation of Toll-like receptors 2 and 4 (TLR2 and -4) on nonclassical monocytes activates MyD88, inducing the release of the neutrophil attractant chemokine CXCL2. Deletion of Itgam (encodes CD11b) in nonclassical monocytes enhanced their production of CXCL2 and worsened PGD, while a CD11b agonist, leukadherin-1, administered only to the donor lung prior to lung transplantation, abrogated CXCL2 production and PGD. The damage-associated molecular pattern molecule HMGB1 was increased in peripheral blood samples from patients undergoing lung transplantation after reperfusion and induced CXCL2 production in nonclassical monocytes via TLR4/MyD88. An inhibitor of HMGB1 administered to the donor and recipient prior to lung transplantation attenuated PGD. Our findings suggest that CD11b acts as a molecular brake to prevent neutrophil recruitment by nonclassical monocytes following lung transplantation, revealing an attractive therapeutic target in the donor lung to prevent PGD in lung transplant recipients.
Recurring Trans-Atlantic Incursion of Clade 2.3.4.4b H5N1 Viruses by Long Distance Migratory Birds from Northern Europe to Canada in 2022/2023
In December 2022 and January 2023, we isolated clade 2.3.4.4b H5N1 high-pathogenicity avian influenza (HPAI) viruses from six American crows (Corvus brachyrhynchos) from Prince Edward Island and a red fox (Vulpes vulpes) from Newfoundland, Canada. Using full-genome sequencing and phylogenetic analysis, these viruses were found to fall into two distinct phylogenetic clusters: one group containing H5N1 viruses that had been circulating in North and South America since late 2021, and the other one containing European H5N1 viruses reported in late 2022. The transatlantic re-introduction for the second time by pelagic/Icelandic bird migration via the same route used during the 2021 incursion of Eurasian origin H5N1 viruses into North America demonstrates that migratory birds continue to be the driving force for transcontinental dissemination of the virus. This new detection further demonstrates the continual long-term threat of H5N1 viruses for poultry and mammals and the subsequent impact on various wild bird populations wherever these viruses emerge. The continual emergence of clade 2.3.4.4b H5Nx viruses requires vigilant surveillance in wild birds, particularly in areas of the Americas, which lie within the migratory corridors for long-distance migratory birds originating from Europe and Asia. Although H5Nx viruses have been detected at higher rates in North America since 2021, a bidirectional flow of H5Nx genes of American origin viruses to Europe has never been reported. In the future, coordinated and systematic surveillance programs for HPAI viruses need to be launched between European and North American agencies.
SIV/SARS-CoV-2 coinfection in rhesus macaques impacts viral shedding, host immunity, the microbiome, and viral evolution
People living with HIV (PLWH) have an increased risk of severe COVID-19, including prolonged viral shedding and emergence of mutations. To investigate the simian immunodeficiency virus (SIV) macaque model for HIV/SARS-CoV-2 coinfection, seven SIV+ rhesus macaques were co-infected with SARS-CoV-2. COVID-19 in all macaques was mild. SARS-CoV-2 replication persisted in the upper, but not the lower respiratory tract for 14 days post-infection. Animals showed impaired generation of anti-SARS-CoV-2 antibodies and T-cells. Animals also displayed transient changes in microbial communities in the upper airway and gastrointestinal tract. Evidence of SARS-CoV-2 evolution was observed in the upper respiratory tract. This study demonstrates that SIV/SARS-CoV-2 coinfection in rhesus macaques recapitulates aspects of COVID-19 in PLWH. We show that SIV impairs anti-SARS-CoV-2 immunity, potentially leading to prolonged viral shedding, altered pathogenesis, and viral evolution. This highlights the importance of HIV status in COVID-19 and supports the use of this model for HIV/SARS-CoV-2 coinfection.
Atrial Remodeling Is Directly Related to End-Diastolic Left Ventricular Pressure in a Mouse Model of Ventricular Pressure Overload
Atrial fibrillation (AF) is often preceded by underlying cardiac diseases causing ventricular pressure overload. It was our aim to investigate the progression of atrial remodeling in a small animal model of ventricular pressure overload and its association with induction of AF. Male mice were subjected to transverse aortic constriction (TAC) or sham operation. After four or eight weeks, echocardiographic measurements and hemodynamic measurements were made and AF induction was tested. The hearts were either fixed in formalin or ventricles and atria were separated, weighed and snap-frozen for RNA analysis. Four weeks of pressure overload induced ventricular hypertrophy and minor changes in the atria. After eight weeks a significant reduction in left ventricular function occurred, associated with significant atrial remodeling including increased atrial weight, a trend towards an increased left atrial cell diameter, atrial dilatation and increased expression of markers of hypertrophy and inflammation. Histologically, no fibrosis was found in the left atrium. But atrial gene expression related to fibrosis was increased. Minor changes related to electrical remodeling were observed. AF inducibility was not different between the groups. Left ventricular end diastolic pressures were increased and correlated with the severity of atrial remodeling but not with AF induction. Permanent ventricular pressure overload by TAC induced atrial remodeling, including hypertrophy, dilatation and inflammation. The extent of atrial remodeling was directly related to LVEDP and not duration of TAC per se.
Determinants of response and resistance to CD19 chimeric antigen receptor (CAR) T cell therapy of chronic lymphocytic leukemia
Tolerance to self-antigens prevents the elimination of cancer by the immune system 1 , 2 . We used synthetic chimeric antigen receptors (CARs) to overcome immunological tolerance and mediate tumor rejection in patients with chronic lymphocytic leukemia (CLL). Remission was induced in a subset of subjects, but most did not respond. Comprehensive assessment of patient-derived CAR T cells to identify mechanisms of therapeutic success and failure has not been explored. We performed genomic, phenotypic and functional evaluations to identify determinants of response. Transcriptomic profiling revealed that CAR T cells from complete-responding patients with CLL were enriched in memory-related genes, including IL-6/STAT3 signatures, whereas T cells from nonresponders upregulated programs involved in effector differentiation, glycolysis, exhaustion and apoptosis. Sustained remission was associated with an elevated frequency of CD27 + CD45RO – CD8 + T cells before CAR T cell generation, and these lymphocytes possessed memory-like characteristics. Highly functional CAR T cells from patients produced STAT3-related cytokines, and serum IL-6 correlated with CAR T cell expansion. IL-6/STAT3 blockade diminished CAR T cell proliferation. Furthermore, a mechanistically relevant population of CD27 + PD-1 – CD8 + CAR T cells expressing high levels of the IL-6 receptor predicts therapeutic response and is responsible for tumor control. These findings uncover new features of CAR T cell biology and underscore the potential of using pretreatment biomarkers of response to advance immunotherapies. An IL-6/STAT3 signature and memory CD8 T cell subset in preinfusion chimeric antigen receptor–expressing T cells associate with response in patients with high-risk chronic lymphocytic leukemia.
Atezolizumab plus stereotactic ablative radiotherapy for medically inoperable patients with early-stage non-small cell lung cancer: a multi-institutional phase I trial
Stereotactic ablative radiotherapy (SABR) is a standard-of-care for medically-inoperable-early-stage non-small cell lung cancer (NSCLC). One third of patients progress and chemotherapy is rarely used in this population. We questioned if addition of the immune-checkpoint-inhibitor (ICI) atezolizumab to standard-of-care SABR can improve outcomes. We initiated a multi-institutional single-arm phase I study (NCT02599454) enrolling twenty patients with the primary endpoint of maximum tolerated dose (MTD); secondary endpoints of safety and efficacy; and exploratory mechanistic correlatives. Treatment is well tolerated and full dose atezolizumab (1200 mg) is the MTD. Efficacy signals include early responses (after 2 cycles of ICI, before initiation of SABR) in 17% of patients. Biomarkers of functional adaptive immunity, including T cell activation in the tumor and response to ex-vivo stimulation by circulating T cells, are highly predictive of benefit. These results require validation and are being tested in a phase III randomized trial. Stereotactic ablative radiotherapy (SABR) is standard-of-care for patients with medically inoperable early-stage non-small cell lung cancer (NSCLC), however the risk of systemic recurrences remains high. Here the authors report the results of a phase I study testing the addition of atezolizumab (anti-PD-L1) to SABR in high risk, medically inoperable, early-stage, NSCLC.
Accelerated lysine metabolism conveys kidney protection in salt-sensitive hypertension
Hypertension and kidney disease have been repeatedly associated with genomic variants and alterations of lysine metabolism. Here, we combined stable isotope labeling with untargeted metabolomics to investigate lysine’s metabolic fate in vivo. Dietary 13 C 6 labeled lysine was tracked to lysine metabolites across various organs. Globally, lysine reacts rapidly with molecules of the central carbon metabolism, but incorporates slowly into proteins and acylcarnitines. Lysine metabolism is accelerated in a rat model of hypertension and kidney damage, chiefly through N- alpha -mediated degradation. Lysine administration diminished development of hypertension and kidney injury. Protective mechanisms include diuresis, further acceleration of lysine conjugate formation, and inhibition of tubular albumin uptake. Lysine also conjugates with malonyl-CoA to form a novel metabolite Nε-malonyl-lysine to deplete malonyl-CoA from fatty acid synthesis. Through conjugate formation and excretion as fructoselysine, saccharopine, and Nε-acetyllysine, lysine lead to depletion of central carbon metabolites from the organism and kidney. Consistently, lysine administration to patients at risk for hypertension and kidney disease inhibited tubular albumin uptake, increased lysine conjugate formation, and reduced tricarboxylic acid (TCA) cycle metabolites, compared to kidney-healthy volunteers. In conclusion, lysine isotope tracing mapped an accelerated metabolism in hypertension, and lysine administration could protect kidneys in hypertensive kidney disease. Kidney metabolism in disease is important but not well understood. Here, using isotope-guided metabolomics, the authors show that lysine’s metabolic activity conveys kidney protection in hypertension through accelerated metabolism and physiological effects on tubular function.