Concomitant Cardiac Surgical Procedures in Patients Undergoing HeartMate 3 Left Ventricular Assist Device Implantation.

BACKGROUND: Long-term support with a HeartMate 3 (HM3) left ventricular assist device (LVAD) has improved outcomes of patients with end-stage heart failure. However, there is a paucity of data on the outcomes of patients who underwent concomitant cardiac surgical procedure (CCSP) during HM3-LVAD implantation. OBJECTIVES: To assess our single-center experience with patients who underwent CCSP during the implantation of an HM3-LVAD. METHODS: From December 2016 until April 2022, 131 adult patients underwent HM3-LVAD implantation. A total of 23 patients underwent CCSP during the HM3-LVAD implantation+CCSP, and 108 underwent only HM3-LVAD implantation (HM3-only). RESULTS: The median age was 59 ± 11 years (range 54-67), 82% (n=108) were male, and 76% (n=100) were implanted as a bridge-to-transplant. The concomitant procedures performed during the implantation included 8 aortic valve repairs/replacements, 14 tricuspid valve repairs, 4 patent foramen ovales or atrial septal defect closures, and 3 other cardiac procedures. The mean cardiopulmonary bypass time was 113 ± 58 minutes for the HM3-only group and 155 ± 47 minutes for the HM3+CCSP group (P = 0.007). The mortality rates at 30 days, 6 months, and 12 months post-implantation were 2 (9%), 5 (22%), and 6 (26%) respectively for the HM3+CCSP group, and 7 (6%), 18 (17%), and 30 (28%) for the HM3-only group (P = 0.658, 0.554, and 1.000). CONCLUSIONS: Our experience demonstrated no significant difference in the 30-day, 6-month, and 12-month mortality rates for patients who underwent a CCSP during HM3-LVAD implantation compared to patients who did not undergo CCSP during HM3-LVAD implantation.

Quality Improvement in Anesthetic Management of Patients with Left Ventricular Assist Device Support Presenting for Non-Cardiac Surgery: A Single Center Experience.

With the growing number of left ventricular assist device (LVAD) recipients requiring non-cardiac surgery and the limited availability of cardiac anesthesiologists, our study reviewed non-cardiac surgeries in HeartMate III patients with LVAD at our institution. We focused on anesthesiologist roles, detailing patient characteristics, anesthetic management, and outcomes and identifying improvement opportunities in this specialized care setting. A retrospective chart review was conducted of all patients with LVAD who underwent non-cardiac surgery at our institution between 2017 and 2022. Patient demographics, surgical characteristics, anesthetic management, and 30-day mortality rates were also assessed. A total of 23 patients were identified, with 17 (73.9%) males and a median age of 61 [53.5, 67.5] years. Cardiac anesthesiologists were present in nine (39.1%) cases. Elective surgeries were more common (73.9%), with intermediate-risk surgeries accounting for 52.2% of all surgeries. General anesthesia was administered to 18 patients (78.3%), with a median duration of 40 [24, 63.5] min. A single patient required reoperation because of bleeding, and two patients (8.7%) experienced 30-day mortality. Despite guidelines lacking detail, involving non-cardiac anesthesiologists in certain cases is essential. Sharing our experience aims to enhance the evolving discourse on non-cardiac surgeries for patients with LVAD, improving their outcomes and safety.

Development of a human liver microphysiological coculture system for higher throughput chemical safety assessment.

Chemicals in the systemic circulation can undergo hepatic xenobiotic metabolism, generate metabolites, and exhibit altered toxicity compared with their parent compounds. This article describes a 2-chamber liver-organ coculture model in a higher-throughput 96-well format for the determination of toxicity on target tissues in the presence of physiologically relevant human liver metabolism. This 2-chamber system is a hydrogel formed within each well consisting of a central well (target tissue) and an outer ring-shaped trough (human liver tissue). The target tissue chamber can be configured to accommodate a three-dimensional (3D) spheroid-shaped microtissue, or a 2-dimensional (2D) cell monolayer. Culture medium and compounds freely diffuse between the 2 chambers. Human-differentiated HepaRG liver cells are used to form the 3D human liver microtissues, which displayed robust protein expression of liver biomarkers (albumin, asialoglycoprotein receptor, Phase I cytochrome P450 [CYP3A4] enzyme, multidrug resistance-associated protein 2 transporter, and glycogen), and exhibited Phase I/II enzyme activities over the course of 17 days. Histological and ultrastructural analyses confirmed that the HepaRG microtissues presented a differentiated hepatocyte phenotype, including abundant mitochondria, endoplasmic reticulum, and bile canaliculi. Liver microtissue zonation characteristics could be easily modulated by maturation in different media supplements. Furthermore, our proof-of-concept study demonstrated the efficacy of this coculture model in evaluating testosterone-mediated androgen receptor responses in the presence of human liver metabolism. This liver-organ coculture system provides a practical, higher-throughput testing platform for metabolism-dependent bioactivity assessment of drugs/chemicals to better recapitulate the biological effects and potential toxicity of human exposures.

Identification of differentially recognized T cell epitopes in the spectrum of tuberculosis infection.

There is still incomplete knowledge of which Mycobacterium tuberculosis (Mtb) antigens can trigger distinct T cell responses at different stages of infection. Here, a proteome-wide screen of 20,610 Mtb-derived peptides in 21 patients mid-treatment for active tuberculosis (ATB) reveals IFNγ-specific T cell responses against 137 unique epitopes. Of these, 16% are recognized by two or more participants and predominantly derived from cell wall and cell processes antigens. There is differential recognition of antigens, including TB vaccine candidate antigens, between ATB participants and interferon-gamma release assay (IGRA + /-) individuals. We developed an ATB-specific peptide pool (ATB116) consisting of epitopes exclusively recognized by ATB participants. This pool can distinguish patients with pulmonary ATB from IGRA + /- individuals from various geographical locations, with a sensitivity of over 60% and a specificity exceeding 80%. This proteome-wide screen of T cell reactivity identified infection stage-specific epitopes and antigens for potential use in diagnostics and measuring Mtb-specific immune responses.

Phase II Study of Eribulin plus Pembrolizumab in Metastatic Soft-tissue Sarcomas: Clinical Outcomes and Biological Correlates.

PURPOSE: Eribulin modulates the tumor-immune microenvironment via cGAS-STING signaling in preclinical models. This non-randomized phase II trial evaluated the combination of eribulin and pembrolizumab in patients with soft-tissue sarcomas (STS). PATIENTS AND METHODS: Patients enrolled in one of three cohorts: leiomyosarcoma (LMS), liposarcomas (LPS), or other STS that may benefit from PD-1 inhibitors, including undifferentiated pleomorphic sarcoma (UPS). Eribulin was administered at 1.4 mg/m2 i.v. (days 1 and 8) with fixed-dose pembrolizumab 200 mg i.v. (day 1) of each 21-day cycle, until progression, unacceptable toxicity, or completion of 2 years of treatment. The primary endpoint was the 12-week progression-free survival rate (PFS-12) in each cohort. Secondary endpoints included the objective response rate, median PFS, safety profile, and overall survival (OS). Pretreatment and on-treatment blood specimens were evaluated in patients who achieved durable disease control (DDC) or progression within 12 weeks [early progression (EP)]. Multiplexed immunofluorescence was performed on archival LPS samples from patients with DDC or EP. RESULTS: Fifty-seven patients enrolled (LMS, n = 19; LPS, n = 20; UPS/Other, n = 18). The PFS-12 was 36.8% (90% confidence interval: 22.5-60.4) for LMS, 69.6% (54.5-89.0) for LPS, and 52.6% (36.8-75.3) for UPS/Other cohorts. All 3 patients in the UPS/Other cohort with angiosarcoma achieved RECIST responses. Toxicity was manageable. Higher IFNα and IL4 serum levels were associated with clinical benefit. Immune aggregates expressing PD-1 and PD-L1 were observed in a patient that completed 2 years of treatment. CONCLUSIONS: The combination of eribulin and pembrolizumab demonstrated promising activity in LPS and angiosarcoma.

Correction: Recommended reporting items for epidemic forecasting and prediction research: The EPIFORGE 2020 guidelines.

[This corrects the article DOI: 10.1371/journal.pmed.1003793.].

Treating Heparin-Induced Thrombocytopenia in Patients Undergoing HeartMate 3 Left Ventricular Assist Device Implantation.

BACKGROUND: Unfractionated heparin is the preferred anticoagulant used during open heart surgeries, including left ventricular assist device (LVAD) implantation. In cases in which patients are heparin-induced thrombocytopenia positive (HIT+), the accepted practice has been to substitute heparin with bivalirudin. This practice may be associated with significant bleeding and adverse outcomes. OBJECTIVES: To review our experience with HIT+ patients who were heparin-induced thrombocytopenia with thrombosis negative (HITT-) and who underwent HeartMate 3 LVAD implantation using heparin intraoperatively rather than bivalirudin. METHODS: From 2016 to 2022, 144 adult patients were implanted with HeartMate 3 LVAD at our center. Among them, 7 were detected as HIT+ but HITT- and therefore were prescribed intraoperatively with heparin and treated pre- and postoperatively with bivalirudin. We reviewed the preoperative, intraoperative, and postoperative characteristics as well as short-term mortality and the complication rates of these HIT+ patients. RESULTS: The median age of our cohort was 56 years (51-60), 71% were male (n=5), all were INTERMACS Level 1, and most were bridged to transplant (n=6, 86%). The 30-day mortality rate post-implantation was 0%. The average 24-hour chest drain postoperative output was 1502.86 ± 931.34 ml. There were no intraoperative pump thromboses, perioperative thromboses, cerebrovascular accidents, or gastrointestinal bleeding within the first 24 hours postoperative. One patient required a revision due to bleeding. CONCLUSIONS: Intraoperative unfractionated heparin may be administered to patients who are HIT+ and HITT- while undergoing LVAD implantation. However, further investigation is required.

Community-Engaged Research Ethics Training (CERET): developing accessible and relevant research ethics training for community-based participatory research with people with lived and living experience using illicit drugs and harm reduction workers.

BACKGROUND: Community-based participatory research (CBPR) can directly involve non-academic community members in the research process. Existing resources for research ethics training can be inaccessible to team members without an academic background and do not attend to the full spectrum of ethical issues that arise through community-engaged research practices. We detail an approach to capacity building and training in research ethics in the context of CBPR with people who use(d) illicit drugs and harm reduction workers in Vancouver's Downtown Eastside neighborhood. METHODS: A project team comprised of academic and community experts in CBPR, research ethics, and harm reduction met over five months to develop the Community-Engaged Research Ethics Training (CERET). The group distilled key principles and content from federal research ethics guidelines in Canada, and developed case examples to situate the principles in the context of research with people who use(d) illicit drugs and harm reduction workers. In addition to content related to federal ethics guidelines, the study team integrated additional content related to ethical issues that arise through community-based research, and ethical principles for research in the Downtown Eastside. Workshops were evaluated using a pre-post questionnaire with attendees. RESULTS: Over the course of six weeks in January-February 2020, we delivered three in-person workshops for twelve attendees, most of whom were onboarding as peer research assistants with a community-based research project. Workshops were structured around key principles of research ethics: respect for persons, concern for welfare, and justice. The discussion-based format we deployed allowed for the bi-directional exchange of information between facilitators and attendees. Evaluation results suggest the CERET approach was effective, and attendees gained confidence and familiarity with workshop content across learning objectives. CONCLUSIONS: The CERET initiative offers an accessible approach to fulfill institutional requirements while building capacity in research ethics for people who use(d) drugs and harm reduction workers. This approach recognizes community members as partners in ethical decision making throughout the research process and is aligned with values of CBPR. Building capacity around intrinsic and extrinsic dimensions of research ethics can prepare all study team members to attend to ethical issues that arise from CBPR.

Supervised smoking facility access, harm reduction practices, and substance use changes during the COVID-19 pandemic: a community-engaged cross-sectional study.

BACKGROUND: The potential public health benefits of supervised smoking facilities (SSFs) are considerable, and yet implementation of SSFs in North America has been slow. We conducted this study to respond to significant knowledge gaps surrounding SSF utilization and to characterize substance use, harm reduction practices, and service utilization following the onset of the COVID-19 pandemic. METHODS: A questionnaire was self-administered at a single site by 175 clients using an outdoor SSF in Vancouver, Canada, between October-December 2020. Questionnaire responses were summarized using descriptive statistics. Multinomial logistic regression techniques were used to examine factors associated with increased SSF utilization. RESULTS: Almost all respondents reported daily substance use (93% daily use of opioids; 74% stimulants). Most used opioids (85%) and/or methamphetamine (66%) on the day of their visit to the SSF. Respondents reported drug use practice changes at the onset of COVID-19 to reduce harm, including using supervised consumption sites, not sharing equipment, accessing medically prescribed alternatives, cleaning supplies and surfaces, and stocking up on harm reduction supplies. Importantly, 45% of SSF clients reported using the SSF more often since the start of COVID-19 with 65.2% reporting daily use of the site. Increased substance use was associated with increased use of the SSF, after controlling for covariates. CONCLUSIONS: Clients of the SSF reported increasing not only their substance use, but also their SSF utilization and harm reduction practices following the onset of COVID-19. Increased scope and scale of SSF services to meet these needs are necessary.

Identification of differentially recognized T cell epitopes in the spectrum of Mtb infection.

Tuberculosis caused by Mycobacterium tuberculosis is one of the leading causes of death from a single infectious agent. Identifying dominant epitopes and comparing their reactivity in different tuberculosis (TB) infection states can help design diagnostics and vaccines. We performed a proteome-wide screen of 20,610 Mtb derived peptides in 21 Active TB (ATB) patients 3-4 months post-diagnosis of pulmonary TB (mid-treatment) using an IFNγ and IL-17 Fluorospot assay. Responses were mediated exclusively by IFNγ and identified a total of 137 unique epitopes, with each patient recognizing, on average, 8 individual epitopes and 22 epitopes (16%) recognized by 2 or more participants. Responses were predominantly directed against antigens part of the cell wall and cell processes category. Testing 517 peptides spanning TB vaccine candidates and ESAT-6 and CFP10 antigens also revealed differential recognition between ATB participants mid-treatment and healthy IGRA+ participants of several vaccine antigens. An ATB-specific peptide pool consisting of epitopes exclusively recognized by participants mid-treatment, allowed distinguishing participants with active pulmonary TB from healthy interferon-gamma release assay (IGRA)+/- participants from diverse geographical locations. Analysis of longitudinal samples indicated decreased reactivity during treatment for pulmonary TB. Together, these results show that a proteome-wide screen of T cell reactivity identifies epitopes and antigens that are differentially recognized depending on the Mtb infection stage. These have potential use in developing diagnostics and vaccine candidates and measuring correlates of protection.

Mitochondrial phosphatidylethanolamine modulates UCP1 to promote brown adipose thermogenesis.

Thermogenesis by uncoupling protein 1 (UCP1) is one of the primary mechanisms by which brown adipose tissue (BAT) increases energy expenditure. UCP1 resides in the inner mitochondrial membrane (IMM), where it dissipates membrane potential independent of adenosine triphosphate (ATP) synthase. Here, we provide evidence that phosphatidylethanolamine (PE) modulates UCP1-dependent proton conductance across the IMM to modulate thermogenesis. Mitochondrial lipidomic analyses revealed PE as a signature molecule whose abundance bidirectionally responds to changes in thermogenic burden. Reduction in mitochondrial PE by deletion of phosphatidylserine decarboxylase (PSD) made mice cold intolerant and insensitive to ß3 adrenergic receptor agonist-induced increase in whole-body oxygen consumption. High-resolution respirometry and fluorometry of BAT mitochondria showed that loss of mitochondrial PE specifically lowers UCP1-dependent respiration without compromising electron transfer efficiency or ATP synthesis. These findings were confirmed by a reduction in UCP1 proton current in PE-deficient mitoplasts. Thus, PE performs a previously unknown role as a temperature-responsive rheostat that regulates UCP1-dependent thermogenesis.

Transitions in care between hospital and community settings for individuals with a substance use disorder: A systematic review.

BACKGROUND AND AIMS: Individuals with a substance use disorder (SUD) have high rates of hospital service utilization including emergency department (ED) presentations and hospital admissions. Acute care settings offer a critical opportunity to engage individuals in addiction care and improve health outcomes especially given that the period of transition from hospital to community is challenging. This review summarizes literature on interventions for optimizing transitions in care from hospital to community for individuals with a SUD. METHODS: The literature search focused on key terms associated with transitions in care and SUD. The search was conducted on three databases: MEDLINE, CINAHL, and PsychInfo. Eligible studies evaluated interventions acting prior to or during transitions in care from hospital to community and reported post-discharge engagement in specialized addiction care and/or return to hospital and were published since 2010. RESULTS: Title and abstract screening were conducted for 2337 records. Overall, 31 studies met inclusion criteria, including 7 randomized controlled trials and 24 quasi-experimental designs which focused on opioid use (n = 8), alcohol use (n = 5), or polysubstance use (n = 18). Interventions included pharmacotherapy initiation (n = 7), addiction consult services (n = 9), protocol implementation (n = 3), screening, brief intervention, and referral to treatment (n = 2), patient navigation (n = 4), case management (n = 1), and recovery coaching (n = 3). CONCLUSIONS: Both pharmacologic and psychosocial interventions implemented around transitions from acute to community care settings can improve engagement in care and reduce hospital readmission and ED presentations. Future research should focus on long-term health and social outcomes to improve quality of care for individuals with a SUD.

Opioid agonist therapy engagement and crystal methamphetamine use: The impact of unregulated opioid use in Vancouver, Canada.

BACKGROUND: Crystal methamphetamine use has substantially increased among people who use opioids in recent years, yet the impact of opioid agonist therapy (OAT) on crystal methamphetamine use remains poorly characterized. Therefore, we sought to examine the relationship between OAT engagement and crystal methamphetamine use and to assess if this relationship differs according to the ongoing use of unregulated opioids. METHODS: Data was collected from two harmonized ongoing prospective cohorts of people who use drugs in Vancouver, Canada, between December 2005 and March 2020. We employed multivariable generalized estimating equations to study the relationship between OAT engagement and crystal meth use stratified by ongoing unregulated opioid use. RESULTS: Of 1742 participants who reported frequent opioid use at baseline, the median age was 42 years, and 61.3% were male. Multivariable analyses showed that compared to those who had not received OAT for at least one year: in the absence of ongoing unregulated opioid use, individuals who recently discontinued (adjusted Odds Ratio [aOR] = 0.47, 95% CI = 0.27-0.79), newly initiated (aOR = 0.52, 95% CI = 0.31-0.89), or were retained on OAT (aOR = 0.48, 95% CI = 0.31-0.72) reported a lower frequency of crystal methamphetamine use; in the presence of ongoing unregulated opioid use, individuals who newly initiated OAT reported a greater crystal methamphetamine use frequency (aOR = 1.24, 95% CI = 1.02-1.51). CONCLUSIONS: We demonstrated a differential relationship between OAT engagement and crystal methamphetamine use that was conditional on the ongoing use of unregulated opioids. Our findings highlight the complexity of OAT implementation and suggest that polysubstance use patterns should be an important consideration for care providers when devising comprehensive treatment strategies and prognosticating treatment effects.

Mitochondrial pyruvate supports lymphoma proliferation by fueling a glutamate pyruvate transaminase 2-dependent glutaminolysis pathway.

The fate of pyruvate is a defining feature in many cell types. One major fate is mitochondrial entry via the mitochondrial pyruvate carrier (MPC). We found that diffuse large B cell lymphomas (DLBCLs) consume mitochondrial pyruvate via glutamate-pyruvate transaminase 2 to enable α-ketoglutarate production as part of glutaminolysis. This led us to discover that glutamine exceeds pyruvate as a carbon source for the tricarboxylic acid cycle in DLBCLs. As a result, MPC inhibition led to decreased glutaminolysis in DLBCLs, opposite to previous observations in other cell types. We also found that MPC inhibition or genetic depletion decreased DLBCL proliferation in an extracellular matrix (ECM)-like environment and xenografts, but not in a suspension environment. Moreover, the metabolic profile of DLBCL cells in ECM is markedly different from cells in a suspension environment. Thus, we conclude that the synergistic consumption and assimilation of glutamine and pyruvate enables DLBCL proliferation in an extracellular environment-dependent manner.

Concurrent inhibition of CDK2 adds to the anti-tumour activity of CDK4/6 inhibition in GIST.

BACKGROUND: Advanced gastrointestinal stromal tumour (GIST) is characterised by genomic perturbations of key cell cycle regulators. Oncogenic activation of CDK4/6 results in RB1 inactivation and cell cycle progression. Given that single-agent CDK4/6 inhibitor therapy failed to show clinical activity in advanced GIST, we evaluated strategies for maximising response to therapeutic CDK4/6 inhibition. METHODS: Targeted next-generation sequencing and multiplexed protein imaging were used to detect cell cycle regulator aberrations in GIST clinical samples. The impact of inhibitors of CDK2, CDK4 and CDK2/4/6 was determined through cell proliferation and protein detection assays. CDK-inhibitor resistance mechanisms were characterised in GIST cell lines after long-term exposure. RESULTS: We identify recurrent genomic aberrations in cell cycle regulators causing co-activation of the CDK2 and CDK4/6 pathways in clinical GIST samples. Therapeutic co-targeting of CDK2 and CDK4/6 is synergistic in GIST cell lines with intact RB1, through inhibition of RB1 hyperphosphorylation and cell proliferation. Moreover, RB1 inactivation and a novel oncogenic cyclin D1 resulting from an intragenic rearrangement (CCND1::chr11.g:70025223) are mechanisms of acquired CDK-inhibitor resistance in GIST. CONCLUSIONS: These studies establish the biological rationale for CDK2 and CDK4/6 co-inhibition as a therapeutic strategy in patients with advanced GIST, including metastatic GIST progressing on tyrosine kinase inhibitors.

Design, Synthesis, and In Vivo Evaluation of C1-Linked 4,5-Epoxymorphinan Haptens for Heroin Vaccines.

In our continuing effort to develop effective anti-heroin vaccines as potential medications for the treatment of opioid use disorder, herein we present the design and synthesis of the haptens: 1-AmidoMorHap (1), 1-AmidoMorHap epimer (2), 1 Amido-DihydroMorHap (3), and 1 Amido-DihydroMorHap epimer (4). This is the first report of hydrolytically stable haptenic surrogates of heroin with the attachment site at the C1 position in the 4,5-epoxymorophinan nucleus. We prepared respective tetanus toxoid (TT)-hapten conjugates as heroin vaccine immunogens and evaluated their efficacy in vivo. We showed that all TT-hapten conjugates induced high antibody endpoint titers against the targets but only haptens 2 and 3 can induce protective effects against heroin in vivo. The epimeric analogues of these haptens, 1 and 4, failed to protect mice from the effects of heroin. We also showed that the in vivo efficacy is consistent with the results of the in vitro drug sequestration assay. Attachment of the linker at the C1 position induced antibodies with weak binding to the target drugs. Only TT-2 and TT-3 yielded antibodies that bound heroin and 6-acetyl morphine. None of the TT-hapten conjugates induced antibodies that cross-reacted with morphine, methadone, naloxone, or naltrexone, and only TT-3 interacted weakly with buprenorphine, and that subtle structural difference, especially at the C6 position, can vastly alter the specificity of the induced antibodies. This study is an important contribution in the field of vaccine development against small-molecule targets, providing proof that the chirality at C6 in these epoxymorphinans is a vital key to their effectiveness.

Looking back and moving forward: Addressing health inequities after COVID-19.

We will likely look back on 2020 as a turning point. The pandemic put a spotlight on existing societal issues, accelerated the pace of change in others, and created some new ones too. For example, concerns about inequalities in health by income and race are not new, but they became more apparent to a larger number of people during 2020. The speed and starkness of broadening societal conversation, including beyond the direct effects of COVID-19, create an opportunity and motivation to reassess our understanding of health. Perhaps more importantly, it is an opportunity to reduce inequities in who has access to, who uses, and who benefits from the resources that promote health and well-being. To this end, we offer three questions to guide thinking about health and health inequities after 2020: (1) what do we mean by "health" and "health inequality and inequity"? (2) what are the structures and policies we put in place to support or promote health, and how effective are they? And (3) who has the power to shape structures and policies, and whose interests do those structures and policies serve?

Quantifying Cell-Derived Changes in Collagen Synthesis, Alignment, and Mechanics in a 3D Connective Tissue Model.

Dysregulation of extracellular matrix (ECM) synthesis, organization, and mechanics are hallmark features of diseases like fibrosis and cancer. However, most in vitro models fail to recapitulate the three-dimensional (3D) multi-scale hierarchical architecture of collagen-rich tissues and as a result, are unable to mirror native or disease phenotypes. Herein, using primary human fibroblasts seeded into custom fabricated 3D non-adhesive agarose molds, a novel strategy is proposed to direct the morphogenesis of engineered 3D ring-shaped tissue constructs with tensile and histological properties that recapitulate key features of fibrous connective tissue. To characterize the shift from monodispersed cells to a highly-aligned, collagen-rich matrix, a multi-modal approach integrating histology, multiphoton second-harmonic generation, and electron microscopy is employed. Structural changes in collagen synthesis and alignment are then mapped to functional differences in tissue mechanics and total collagen content. Due to the absence of an exogenously added scaffolding material, this model enables the direct quantification of cell-derived changes in 3D matrix synthesis, alignment, and mechanics in response to the addition or removal of relevant biomolecular perturbations. To illustrate this, the effects of nutrient composition, fetal bovine serum, rho-kinase inhibitor, and pro- and anti-fibrotic compounds on ECM synthesis, 3D collagen architecture, and mechanophenotype are quantified.

Using passive surveillance technology for overdose prevention: Key ethical and implementation issues.

Passive surveillance technology has the potential to increase safety through monitoring spaces where people are at risk of overdose. One key opportunity for the use of passive surveillance technology to prevent overdose fatality is in bathrooms where people may be using drugs. However, uncertainty remains with regards to how to attain informed consent, implications for data storage and privacy and potential negative socio-legal ramifications for people who use drugs. In addition, there are issues regarding responsibility and liability for the devices. Transparency with regards to data privacy and security may also be needed before bathroom users will feel comfortable with such solutions. In this article, we discuss these issues and offer recommendations to provide a foundation for future research and policy development.

Effects of Left Ventricular Versus Traditional Chest Compressions in a Traumatic Pulseless Electrical Activity Model.

BACKGROUND: Prehospital cardiopulmonary resuscitation has commonly been considered ineffective in traumatic cardiopulmonary arrest because traditional chest compressions do not produce substantial cardiac output. However, recent evidence suggests that chest compressions located over the left ventricle (LV) produce greater hemodynamics when compared to traditional compressions. We hypothesized that chest compressions located directly over the LV would result in an increase in return of spontaneous circulation (ROSC) and hemodynamic variables, when compared to traditional chest compressions, in a swine model of traumatic pulseless electrical activity (PEA). METHODS: Transthoracic echocardiography was used to mark the location of the aortic root (traditional compressions) and the center of the LV on animals (n = 34) that were randomized to receive chest compressions in one of the two locations. Animals were hemorrhaged to mean arterial pressure <20 to simulate traumatic PEA. After 5 minutes of PEA, basic life support (BLS) with mechanical cardiopulmonary resuscitation was initiated and performed for 10 minutes followed by advanced life support for an additional 10 minutes. Hemodynamic variables were averaged over the final 2 minutes of BLS and advanced life support periods. RESULTS: Six of the LV group (35%) achieved ROSC compared to eight of the traditional group (47%) (P = .73). There was an increase in aortic systolic blood pressure (P < .01), right atrial systolic blood pressure (P < .01), and right atrial diastolic blood pressure (P = .02) at the end of BLS in the LV group compared to the traditional group. CONCLUSIONS: In our swine model of traumatic PEA, chest compressions performed directly over the LV improved blood pressures during BLS but not ROSC.