The Influence of Diabetes on Thrombotic Profiles and Outcomes on Patients with Peripheral Artery Disease.

BACKGROUND: Elevated glycated hemoglobin (HbA1c) is associated with vascular complications, including arterial thrombosis post-revascularization. However, the objective relationship between levels of HbA1c and coagulation profiles has not been established. This study aims to determine the association between specific coagulation parameters and variations in HbA1c in patients undergoing lower extremity revascularization. METHODS: Patients with Peripheral Artery Disease (PAD) undergoing revascularization were prospectively evaluated between December 2020 and July 2023. Patients were categorized based on their HbA1c levels, and their thromboelastography with platelet mapping (TEG-PM) results were compared at baseline, post-operatively day 1, 1 month, 3 months and 6 months. The parameters included Maximum Amplitude (MA) with both adenosine diphosphate (ADP) and arachidonic acid (AA), as well as ADP and AA percent aggregation indicating clot strength. The study further assessed the differences in these parameters between groups with varying HbA1c levels through the use of unpaired Student t test for pairwise analysis and Mann-Whitney U tests. RESULTS: Among 830 samples, those with HbA1c above 6.5 demonstrated a significant increase in ADP MA (52.6 vs. 43.5, p<0.01), AA MA (36.6 vs. 29.65, p<0.05), clot strength without platelets ActF MA (activator F: 13.10 vs. 10.80, p<0.01), and heparin neutralized uninhibited clot strength from thrombin activation HKH MA (heparinized kaolin with heparinase: 61.10 vs. 57.70, p<0.01) values at baseline. Post-operatively, patients with HbA1c levels greater than 6.5 had higher median functional fibrinogen CFF FLEV levels (citrated functional fibrinogen: 40.95 vs. 371.35, p<0.05) and higher formation of fibrin in response to stimulation of thrombin by tissue factor CFF MA values (22.90 vs. 20.40, p<0.05) when measured within 36 hours of intervention, with these trends staying consistent during the 1-month follow-up visit. The trend analysis revealed a progressive increase in ADP MA values with rising HbA1c values, indicating a unit increase in the thrombotic risk relationship. Regression analysis showed a positive relationship between HbA1c and both ADP MA (a 2.261 unit increase for each unit increase in HbA1c) and AA MA. The R-square values indicate that HbA1c only explains a small percentage of the variance in these parameters, suggesting the confounding influence of other factors contributing to thrombosis. CONCLUSION: Elevated HbA1c levels appear to be associated with pro-thrombotic tendencies in clot dynamics as measured by TEG-PM, particularly in parameters related to platelet function. HbA1c explains a limited proportion of the variability in these measures, emphasizing the need for a comprehensive approach to evaluating clotting profiles in patients. This study lays the groundwork for further investigation into personalized antithrombotic strategies for patients with varying HbA1c levels.

The Use of Clot Strength as a Predictor of Thrombosis in Peripheral Artery Disease.

OBJECTIVES: Graft/stent thrombosis is the leading cause of amputation in patients over 60, and while dual antiplatelet therapy is the standard of care, there is a significant variability in platelet response and limited guidance on measuring effectiveness. Thromboelastography with platelet mapping (TEG-PM) can objectively detail an individual's coagulation profile, namely the strength of the clot and its response to antiplatelet medication. Although TEG-PM has been used for predicting postoperative bleeding and assessing platelet dysfunction in TBI, its application in thrombosis diseases such as peripheral artery disease (PAD) remains unexplored. The aim of this observational study was to determine if objective measures of clot strength could predict a high clinical risk of thrombosis. METHODS: Patients > 60 years with peripheral artery disease (PAD) undergoing revascularization were prospectively evaluated from 2021-2023. They were clinically followed for one year to detect any thrombotic events. TEG-PM was used to objectively evaluate coagulation profiles in patients at 1, 3, 6, and 9 months. These follow-up periods were chosen based on studies showing that 1-3 month intervals in the first year after lower extremity revascularization (LER) optimize therapy and risk control. The TEG-PM data preceding a thrombotic/stenotic event in patients with thrombosis was compared to the last known well TEG-PM event in those without a thrombotic/stenotic event. We stratified the groups based on the occurrence of thrombosis/stenotic events. Descriptive statistics were applied to characterize each group and a chi-square test was conducted to assess the variance between both groups. An unpaired t-test was ran to identify differences in platelet function. ROC analysis was performed to determine the optimal TEG-PM cutoff for predicting a higher risk of thrombosis. RESULTS: One hundred and fifty-eight patients were analyzed, from whom 28 (17.7%) experienced a thrombotic event. The thrombosis cohort exhibited significantly greater MAADP, MAFibrin, and MAThrombin [50.2 vs. 40.0, p<0.05], [18.19 vs. 14.64, p<0.05] and [63.8 vs. 58.5, p<0.05] respectively indicative of greater clot strength. By ROC analysis, the optimal predictor cutoff for MAADP, indicating a higher risk of thrombosis, was >42mm [p<0.05] with 82% sensitivity and 50% specificity. CONCLUSIONS: An increase in clot strength was found to be predictive of thrombosis/stenosis within 30 days. Using a MAADP cutoff greater than 42mm might serve as an alternative approach to tailor the use of antiplatelet medication, potentially reducing the risk of thrombosis.

Diminished Immune Cell Adhesion in Hypoimmune ICAM-1 Knockout Pluripotent Stem Cells.

Hypoimmune gene edited human pluripotent stem cells (hPSCs) are a promising platform for developing reparative cellular therapies that evade immune rejection. Existing first-generation hypoimmune strategies have used CRISPR/Cas9 editing to modulate genes associated with adaptive (e.g., T cell) immune responses, but have largely not addressed the innate immune cells (e.g., monocytes, neutrophils) that mediate inflammation and rejection processes occurring early after graft transplantation. We identified the adhesion molecule ICAM-1 as a novel hypoimmune target that plays multiple critical roles in both adaptive and innate immune responses post-transplantation. In a series of studies, we found that ICAM-1 blocking or knock-out (KO) in hPSC-derived cardiovascular therapies imparted significantly diminished binding of multiple immune cell types. ICAM-1 KO resulted in diminished T cell proliferation responses in vitro and in longer in vivo retention/protection of KO grafts following immune cell encounter in NeoThy humanized mice. The ICAM-1 KO edit was also introduced into existing first-generation hypoimmune hPSCs and prevented immune cell binding, thereby enhancing the overall hypoimmune capacity of the cells. This novel hypoimmune editing strategy has the potential to improve the long-term efficacy and safety profiles of regenerative therapies for cardiovascular pathologies and a number of other diseases.

Osteosarcoma through the Lens of Bone Development, Signaling, and Microenvironment.

In this work, we review the multifaceted connections between osteosarcoma (OS) biology and normal bone development. We summarize and critically analyze existing research, highlighting key areas that merit further exploration. The review addresses several topics in OS biology and their interplay with normal bone development processes, including OS cell of origin, genomics, tumor microenvironment, and metastasis. We examine the potential cellular origins of OS and how their roles in normal bone growth may contribute to OS pathogenesis. We survey the genomic landscape of OS, highlighting the developmental roles of genes frequently altered in OS. We then discuss the OS microenvironment, emphasizing the transformation of the bone niche in OS to facilitate tumor growth and metastasis. The role of stromal and immune cells is examined, including their impact on tumor progression and therapeutic response. We further provide insights into potential development-informed opportunities for novel therapeutic strategies.

Expanding Access to Noninvasive Prenatal Diagnosis for Monogenic Conditions to Consanguineous Families.

BACKGROUND: Cell-free fetal DNA exists within the maternal bloodstream during pregnancy and provides a means for noninvasive prenatal diagnosis (NIPD). Our accredited clinical service offers definitive NIPD for several autosomal recessive (AR) and X-linked conditions using relative haplotype dosage analysis (RHDO). RHDO involves next-generation sequencing (NGS) of thousands of common single nucleotide polymorphism (SNPs) surrounding the gene of interest in the parents and an affected or unaffected offspring to conduct haplotype phasing of the high- and low-risk alleles. NGS is carried out in parallel on the maternal cell-free DNA, and fetal inheritance is predicted using sensitive dosage calculations performed at sites where the parental genotypes differ. RHDO is not currently offered to consanguineous couples owing to the shared haplotype between parents. Here we test the expansion of RHDO for AR monogenic conditions to include consanguineous couples. METHODS: The existing sequential probability ratio test analysis pipeline was modified to apply to SNPs where both parents are heterozygous for the same genotype. Quality control thresholds were developed using 33 nonconsanguineous cases. The performance of the adapted RHDO pipeline was tested on 8 consanguineous cases. RESULTS: The correct fetal genotype was predicted by our revised RHDO approach in all conclusive cases with known genotypes (n = 5). Haplotype block classification accuracies of 94.5% and 93.9% were obtained for the nonconsanguineous and consanguineous case cohorts, respectively. CONCLUSIONS: Our modified RHDO pipeline correctly predicts the genotype in fetuses from consanguineous families, allowing the potential to expand access to NIPD services for these families.

An Introduction to Processing, Fitting, and Interpreting Transient Absorption Data.

Transient absorption (TA) spectroscopy is a powerful time-resolved spectroscopic method used to track the evolution of excited-state processes through changes in the system's absorption spectrum. Early implementations of TA were confined to specialized laboratories, but the evolution of commercial turn-key systems has made the technique increasingly available to research groups across the world. Modern TA systems are capable of producing large datasets with high energetic and temporal resolution that are rich in photophysical information. However, processing, fitting, and interpreting TA spectra can be challenging due to the large number of excited-state features and instrumental artifacts. Many factors must be carefully considered when collecting, processing, and fitting TA data in order to reduce uncertainty over which model or set of fitting parameters best describes the data. The goal of data preparation and fitting is to reduce as many of these extraneous factors while preserving the data for analysis. In this method, beginners are provided with a protocol for processing and preparing TA data as well as a brief introduction to selected fitting procedures and models, specifically single wavelength fitting and global lifetime analysis. Commentary on a number of commonly encountered data preparation challenges and methods of addressing them is provided, followed by a discussion of the challenges and limitations of these simple fitting methods.

Controlling excited-state dynamics via protonation of naphthalene-based azo dyes.

Azo dyes are a class of photoactive dyes that constitute a major focus of chemical research due to their applications in numerous industrial functions. This work explores the impact of protonation on the photophysics of four naphthalene-based azo dyes. The pKa value of the dyes increases proportionally with decreasing Hammett parameter of p-phenyl substituents from 8.1 (R = -H, σ = 0) to 10.6 (R = -NMe2, σ = -0.83) in acetonitrile. Protonation of the dyes shuts down the steady-state photoisomerization observed in the unprotonated moieties. Fluorescence measurements reveal a lower quantum yield with more electron-donating p-phenyl substituents, with overall lower fluorescence quantum yields than the unprotonated dyes. Transient absorption spectroscopy reveals four excited-state lifetimes (<1 ps, ∼3 ps, ∼13 ps, and ∼200 ps) exhibiting faster excited-state dynamics than observed in the unprotonated forms (for 1-3: 0.7-1.5 ps, ∼3-4 ps, 20-40 ps, 20-300 min; for 4: 0.7 ps, 4.8 ps, 17.8 ps, 40 ps, 8 min). Time-dependent density functional theory (TDDFT) elucidates the reason for the loss of isomerization in the protonated dyes, revealing a significant change in the lowest excited state potential energy nature and landscape upon protonation. Protonation impedes relaxation along the typical rotational and inversion isomerization axes, locking the dyes into a trans-configuration that rapidly decays back to the ground state.

Acid Violet 3: A Base-Activated Water-Soluble Photoswitch.

Acidic azo dyes are widely used for their vibrant colors. However, if their photophysics were better understood and controllable, they could be integrated into many more applications such as photosensing, photomedicine, and nonlinear optics. Here, the proton-controlled photophysics of a widely used acid, hydrazo dye, acid violet 3 (AV3) is explored. Density functional theory is used to predict the ground- and excited-state potential energy surfaces, and the proposed photoisomerization mechanism is confirmed with spectroscopic experiments. The ground-state and first two excited-state surfaces of the three readily accessible protonation states, AV3-H, AV3, and AV3+H, are investigated along both the dihedral rotation and inversion coordinates. The deprotonated AV3-H undergoes photoisomerization with blue light (λex = 453 nm) through a dihedral rotation mechanism. Upon the formation of the cis-isomer, the reversion of AV3-H is predicted to occur through a mixed rotational and inversion mechanism. In contrast, AV3 and its protonated form, AV3+H, do not undergo photoisomerization because there is no driving force for either the rotation or inversion of the azo bond in the excited state. In addition, when the azo bond is acidic, the ground-state dihedral rotation reversion mechanism barrier is lower. The mechanistic insights gained here through the combination of theory and experiment provide a roadmap to control the reactivity of AV3 across 11 orders of magnitude of proton concentration, making them interesting candidates for a range of pharmaceuticals.

Discovery of VH domains that allosterically inhibit ENPP1.

Ectodomain phosphatase/phosphodiesterase-1 (ENPP1) is overexpressed on cancer cells and functions as an innate immune checkpoint by hydrolyzing extracellular cyclic guanosine monophosphate adenosine monophosphate (cGAMP). Biologic inhibitors have not yet been reported and could have substantial therapeutic advantages over current small molecules because they can be recombinantly engineered into multifunctional formats and immunotherapies. Here we used phage and yeast display coupled with in cellulo evolution to generate variable heavy (VH) single-domain antibodies against ENPP1 and discovered a VH domain that allosterically inhibited the hydrolysis of cGAMP and adenosine triphosphate (ATP). We solved a 3.2 Å-resolution cryo-electron microscopy structure for the VH inhibitor complexed with ENPP1 that confirmed its new allosteric binding pose. Finally, we engineered the VH domain into multispecific formats and immunotherapies, including a bispecific fusion with an anti-PD-L1 checkpoint inhibitor that showed potent cellular activity.

Osteosarcoma PDX-Derived Cell Line Models for Preclinical Drug Evaluation Demonstrate Metastasis Inhibition by Dinaciclib through a Genome-Targeted Approach.

PURPOSE: Models to study metastatic disease in rare cancers are needed to advance preclinical therapeutics and to gain insight into disease biology. Osteosarcoma is a rare cancer with a complex genomic landscape in which outcomes for patients with metastatic disease are poor. As osteosarcoma genomes are highly heterogeneous, multiple models are needed to fully elucidate key aspects of disease biology and to recapitulate clinically relevant phenotypes. EXPERIMENTAL DESIGN: Matched patient samples, patient-derived xenografts (PDX), and PDX-derived cell lines were comprehensively evaluated using whole-genome sequencing and RNA sequencing. The in vivo metastatic phenotype of the PDX-derived cell lines was characterized in both an intravenous and an orthotopic murine model. As a proof-of-concept study, we tested the preclinical effectiveness of a cyclin-dependent kinase inhibitor on the growth of metastatic tumors in an orthotopic amputation model. RESULTS: PDXs and PDX-derived cell lines largely maintained the expression profiles of the patient from which they were derived despite the emergence of whole-genome duplication in a subset of cell lines. The cell lines were heterogeneous in their metastatic capacity, and heterogeneous tissue tropism was observed in both intravenous and orthotopic models. Single-agent dinaciclib was effective at dramatically reducing the metastatic burden. CONCLUSIONS: The variation in metastasis predilection sites between osteosarcoma PDX-derived cell lines demonstrates their ability to recapitulate the spectrum of the disease observed in patients. We describe here a panel of new osteosarcoma PDX-derived cell lines that we believe will be of wide use to the osteosarcoma research community.

Framework humanization optimizes potency of anti-CD72 nanobody CAR-T cells for B-cell malignancies.

BACKGROUND: Approximately 50% of patients who receive anti-CD19 CAR-T cells relapse, and new immunotherapeutic targets are urgently needed. We recently described CD72 as a promising target in B-cell malignancies and developed nanobody-based CAR-T cells (nanoCARs) against it. This cellular therapy design is understudied compared with scFv-based CAR-T cells, but has recently become of significant interest given the first regulatory approval of a nanoCAR in multiple myeloma. METHODS: We humanized our previous nanobody framework regions, derived from llama, to generate a series of humanized anti-CD72 nanobodies. These nanobody binders were inserted into second-generation CD72 CAR-T cells and were evaluated against preclinical models of B cell acute lymphoblastic leukemia and B cell non-Hodgkin's lymphoma in vitro and in vivo. Humanized CD72 nanoCARs were compared with parental ("NbD4") CD72 nanoCARs and the clinically approved CD19-directed CAR-T construct tisangenlecleucel. RNA-sequencing, flow cytometry, and cytokine secretion profiling were used to determine differences between the different CAR constructs. We then used affinity maturation on the parental NbD4 construct to generate high affinity binders against CD72 to test if higher affinity to CD72 improved antitumor potency. RESULTS: Toward clinical translation, here we humanize our previous nanobody framework regions, derived from llama, and surprisingly discover a clone ("H24") with enhanced potency against B-cell tumors, including patient-derived samples after CD19 CAR-T relapse. Potentially underpinning improved potency, H24 has moderately higher binding affinity to CD72 compared with a fully llama framework. However, further affinity maturation (KD<1 nM) did not lead to improvement in cytotoxicity. After treatment with H24 nanoCARs, in vivo relapse was accompanied by CD72 antigen downregulation which was partially reversible. The H24 nanobody clone was found to have no off-target binding and is therefore designated as a true clinical candidate. CONCLUSION: This work supports translation of H24 CD72 nanoCARs for refractory B-cell malignancies, reveals potential mechanisms of resistance, and unexpectedly demonstrates that nanoCAR potency can be improved by framework alterations alone. These findings may have implications for future engineering of nanobody-based cellular therapies.

Using a novel in-mask non-invasive ventilator microphone to improve talker intelligibility in healthy and hospitalised adults.

Purpose: Non-invasive ventilation (NIV) provides respiratory support without invasive endotracheal intubation but can hinder patients' ability to communicate effectively. The current study presents preliminary results using a novel in-mask ventilator microphone to enhance talker intelligibility while receiving NIV.Method: A proof-of-concept study assessed sentence intelligibility of five healthy adult talkers using a prototype model of the microphone under continuous positive airway pressure (CPAP; 5/5 cm H2O) and bilevel positive airway pressure (BiPAP; 8/4 cm H2O) ventilator conditions. A pilot study then assessed intelligibility, subjective comprehensibility and naturalness, and patient- and conversation partner-reported communication outcomes for eight patients undergoing therapeutic NIV while being treated in an intensive care unit (ICU).Result: Intelligibility increased significantly with the microphone on in the BiPAP condition for healthy volunteers. For patients undergoing NIV in an ICU, intelligibility, comprehensibility, and patient and conversation partner ratings of conversation satisfaction significantly improved with the microphone on. Patients with lower baselines without the microphone in certain measures (intelligibility, comprehensibility) generally showed a greater microphone benefit than patients with higher baselines.Conclusion: Use of a novel microphone integrated into NIV improved intelligibility during ventilation for both healthy volunteers and patients undergoing therapeutic NIV. Additional clinical studies will define precise benefits and implications of such improved intelligibility.

Pemphigus Vulgaris: More Than Just a Skin Disease.

INTRODUCTION: Pemphigus is a group of autoimmune diseases of the skin and mucous membranes that is characterized by multiple bullae formation. It is caused by autoantibodies directed against the cell surface of keratinocytes, resulting in the loss of cell-cell adhesion of keratinocytes. This disease can be very debilitating and difficult to treat if large surface areas are involved. METHODS: We performed a retrospective review of a complex case of pemphigus vulgaris in a 24-year-old man who develop partial-thickness skin lesions distributed throughout the entire body with a total body surface of 80% short after an episode of strep throat treated with amoxicillin. RESULTS: The patient had a complicated hospital course in which the standard treatment of the disease led to adverse effects that were successfully managed at our busy burn center. CONCLUSIONS: Pemphigus vulgaris is a complex skin disease in which treatment techniques carry their risk and must be tailored to the patient's specific needs. Treatment of this conditions at a burn center would be beneficial as demonstrated with conditions like Stevens-Johnson syndrome and toxic epidermal necrolysis.

Mass Spectrometry and Pharmacological Approaches to Measuring Cooption and Reciprocal Activation of Receptor Tyrosine Kinases.

Receptor tyrosine kinases (RTKs) can show extensive crosstalk, directly and indirectly. Elucidating RTK crosstalk remains an important goal in the clinical combination of anti-cancer therapies. Here, we present mass spectrometry and pharmacological approaches showing the hepatocyte growth factor receptor (MET)-promoting tyrosine phosphorylation of the epidermal growth factor receptor (EGFR) and other membrane receptors in MET-amplified H1993 NSCLC cells. Conversely, in H292 wt-EGFR NSCLC cells, EGFR promotes the tyrosine phosphorylation of MET. Reciprocal regulation of the EGFR and insulin receptor (IR) was observed in the GEO CRC cells, where inhibition of the EGFR drives tyrosine phosphorylation of the insulin receptor. Similarly, in platelet-derived growth factor receptor (PDGFR)-amplified H1703 NSCLC cells, inhibition of the EGFR promotes the tyrosine phosphorylation of the PDGFR. These RTK interactions are used to illustrate basic principles applicable to other RTK signaling networks. More specifically, we focus on two types of RTK interaction: (1) co-option of one RTK by another and (2) reciprocal activation of one receptor following the inhibition of a distinct receptor.

Emergency Medical Services handoff of patients in cardiac arrest in the Emergency Department: A retrospective video review study of duration and details of handoff.

STUDY OBJECTIVES: We aimed to evaluate the duration and frequency of communication between EMS (Emergency Medical Services) and ED (Emergency Department) staff during handoff and the subsequent time to critical cardiac care (rhythm determination, defibrillation) using CA (cardiac arrest) video review. METHODS: A single-center retrospective study of video-recorded adult CAs between August 2020 and December 2022 was performed. Two investigators assessed the communication of 17 data points, time intervals, EMS initiation of handoff, and type of EMS agency. Median times from initiation of handoff to first ED rhythm determination and defibrillation were compared between the groups above versus below the median number of data points communicated. RESULTS: Overall, 95 handoffs were reviewed. The handoff was initiated in a median of 2 seconds (interquartile range (IQR) 0-10) after arrival. EMS initiated handoff in 65 (69.2%) patients. The median number of data points communicated was 9 and median duration was 66 seconds (IQR 50-100). Age, location of arrest, estimated down time, and medications administered were communicated > 80% of the time, initial rhythm 79%, and bystander cardiopulmonary resuscitation and witnessed arrest < 50%. The median times from initiation of handoff to first ED rhythm determination and defibrillation were 188 (IQR 106-256) and 392 (IQR 247-725) seconds, though not statistically different between handoffs with <9 vs. ≥9 data points communicated (p > 0.40). CONCLUSION: There is no standardization for handoff reports from EMS to ED staff for CA patients. Using video review, we demonstrated the variable communication during handoff. Improvements to this process could reduce the time to critical cardiac care interventions.

Patient Perspectives Regarding Clinician Communication During Telemedicine Compared With In-Clinic Abortion.

OBJECTIVE: To explore patient perspectives regarding patient-clinician communication during telemedicine medication abortion compared with traditional, facility based, in-clinic visits. METHODS: We conducted semi-structured interviews with participants who received either live, face-to-face telemedicine or in-clinic medication abortion from a large, reproductive health care facility in Washington State. Using Miller's conceptual framework for patient-doctor communication in telemedicine settings, we developed questions exploring participants' experiences of the medication abortion consultation, including the clinician's verbal and nonverbal interpersonal approach and communication of relevant medical information, and the setting where care was received. We used inductive-deductive constant comparative analysis to identify major themes. We summarize patient perspectives using patient-clinician communication terms outlined in Dennis' quality abortion care indicator list. RESULTS: Thirty participants completed interviews (aged 20-38 years), 20 of whom had medication abortion by telemedicine and 10 who received in-clinic services. Participants who received telemedicine abortion services reported high-quality patient-clinician communication, which came from their freedom to choose their consultation location, and reported feeling more relaxed during clinical encounters. In contrast, most in-clinic participants portrayed their consultations as lengthy, chaotic, and lacking comfort. In all other domains, both telemedicine and in-clinic participants reported similar levels of interpersonal connection to their clinicians. Both groups appreciated medical information about how to take the abortion pills and relied heavily on clinic-based printed materials and independent online resources to answer questions during the at-home termination process. Both telemedicine and in-clinic participant groups were highly satisfied with their care. CONCLUSION: Patient-centered communication skills used by clinicians during facility based, in-clinic care translated well to the telemedicine setting. However, we found that patients who received medication abortion through telemedicine favorably ranked their patient-clinician communication overall as compared with those in traditional, in-clinic settings. In this way, telemedicine abortion appears to be a beneficial patient-centered approach to this critical reproductive health service.

Ultra-fast excited-state dynamics of substituted trans-naphthalene azo moieties.

In this work we untangle the ultrafast deactivation of high-energy excited states in four naphthalene-based azo dyes. Through systematic photophysical and computational study, we observed a structure-property relationship in which increasing the electron donating strength of the substituent leads to longer lived excited states in these organic dyes and faster thermal reversion from the cis to trans configuration. In particular, azo dyes 1-3 containing less electron donating substituents show three distinct excited-state lifetimes of ∼0.7-1.5 ps, ∼3-4 ps, and 20-40 ps whereas the most electron donating dimethyl amino substituted azo 4 shows excited-state lifetimes of 0.7 ps, 4.8 ps, 17.8 ps and 40 ps. While bulk photoisomerization of all four moieties is rapid, the cis to trans reversion lifetimes vary by a factor of 30 with τreversion decreasing from 276 min to 8 min with increasing electron donating strength of the substituent. In order to rationalize this change in photophysical behavior, we explored the excited-state potential energy surfaces and spin-orbit coupling constants for azo 1-4 through density functional theory. The increase in excited-state lifetime for 4 can be attributed to geometric and electronic degrees of freedom of the lowest energy singlet excited-state potential energy surface.

Advance provision of medication for induced abortion: A qualitative study of patient perspectives.

OBJECTIVES: To examine potential users' perspectives regarding the provision of abortion medications for future use or "advance provision." STUDY DESIGN: In this qualitative study, we partnered with an independent reproductive health care clinic in Washington State to conduct semistructured, in-depth interviews with 22 individuals who obtained a medication abortion between August 2021 and January 2022. We asked participants their views on advance provision of abortion medications. Interviews were transcribed and deidentified. Inductive content analysis was used to identify major themes. RESULTS: Participants in our sample generally reacted positively to the idea of abortion medications for future use. Having pills in advance could improve timeliness and convenience of care and decrease the stigma associated with their use. Participants stressed the importance of adequate information regarding medication use, what to expect, and potential side effects. Most concerns about advance provision related to the safety and efficacy of medication abortion. CONCLUSIONS: This study found that individuals who recently obtained a medication abortion supported the provision of abortion medications for future use. IMPLICATIONS: Patient-centered educational materials, with adequate information for self-managing pregnancy termination, can be shared at time of prescription. Clinicians have an opportunity to offer these safe and effective medications in advance of need and increase timely access to this essential health care service. User concerns regarding abortion medications for future use should inform clinical innovation and evaluative research of service options.

Development and characterization of new patient-derived xenograft (PDX) models of osteosarcoma with distinct metastatic capacities.

Models to study metastatic disease in rare cancers are needed to advance preclinical therapeutics and to gain insight into disease biology, especially for highly aggressive cancers with a propensity for metastatic spread. Osteosarcoma is a rare cancer with a complex genomic landscape in which outcomes for patients with metastatic disease are poor. As osteosarcoma genomes are highly heterogeneous, a large panel of models is needed to fully elucidate key aspects of disease biology and to recapitulate clinically-relevant phenotypes. We describe the development and characterization of osteosarcoma patient-derived xenografts (PDXs) and a panel of PDX-derived cell lines. Matched patient samples, PDXs, and PDX-derived cell lines were comprehensively evaluated using whole genome sequencing and RNA sequencing. PDXs and PDX-derived cell lines largely maintained the expression profiles of the patient from which they were derived despite the emergence of whole-genome duplication (WGD) in a subset of cell lines. These cell line models were heterogeneous in their metastatic capacity and their tissue tropism as observed in both intravenous and orthotopic models. As proof-of-concept study, we used one of these models to test the preclinical effectiveness of a CDK inhibitor on the growth of metastatic tumors in an orthotopic amputation model. Single-agent dinaciclib was effective at dramatically reducing the metastatic burden in this model.

Elucidation of complex triplet excited state dynamics in Pd(II) biladiene tetrapyrroles.

Pd(II) biladienes have been developed over the last five years as non-aromatic oligotetrapyrrole complexes that support a rich triplet photochemistry. In this work, we have undertaken the first detailed photophysical interrogation of three homologous Pd(II) biladienes bearing different combinations of methyl- and phenyl-substituents on the frameworks' sp3-hybridized meso-carbon (i.e., the 10-position of the biladiene framework). These experiments have revealed unexpected excited-state dynamics that are dependent on the wavelength of light used to excite the biladiene. More specifically, transient absorption spectroscopy revealed that higher-energy excitation (λexc ∼ 350-500 nm) led to an additional lifetime (i.e., an extra photophysical process) compared to experiments carried out following excitation into the lowest-energy excited states (λexc = 550 nm). Each Pd(II) biladiene complex displayed an intersystem crossing lifetime on the order of tens of ps and a triplet lifetime of ∼20 µs, regardless of the excitation wavelength. However, when higher-energy light is used to excite the complexes, a new lifetime on the order of hundreds of ps is observed. The origin of the 'extra' lifetime observed upon higher energy excitation was revealed using density functional theory (DFT) and time-dependent DFT (TDDFT). These efforts demonstrated that excitation into higher-energy metal-mixed-charge-transfer excited states with high spin-orbit coupling to higher energy metal-mixed-charge-transfer triplet states leads to the additional excitation deactivation pathway. The results of this work demonstrate that Pd(II) biladienes support a unique triplet photochemistry that may be exploited for development of new photochemical schemes and applications.