Ruthenium-Cathepsin Inhibitor Conjugates for Green Light-Activated Photodynamic Therapy and Photochemotherapy.

Dysregulated cathepsin activity is linked to various human diseases including metabolic disorders, autoimmune conditions, and cancer. Given the overexpression of cathepsin in the tumor microenvironment, cathepsin inhibitors are promising pharmacological agents and drug delivery vehicles for cancer treatment. In this study, we describe the synthesis and photochemical and biological assessment of a dual-action agent based on ruthenium that is conjugated with a cathepsin inhibitor, designed for both photodynamic therapy (PDT) and photochemotherapy (PCT). The ruthenium-cathepsin inhibitor conjugate was synthesized through an oxime click reaction, combining a pan-cathepsin inhibitor based on E64d with the Ru(II) PCT/PDT fragment [Ru(dqpy)(dppn)], where dqpy = 2,6-di(quinoline-2-yl)pyridine and dppn = benzo[i]dipyrido[3,2-a:2',3'-c]phenazine. Photochemical investigations validated the conjugate's ability to release a triazole-containing cathepsin inhibitor for PCT and to generate singlet oxygen for PDT upon exposure to green light. Inhibition studies demonstrated the conjugate's potent and irreversible inactivation of purified and intracellular cysteine cathepsins. Two Ru(II) PCT/PDT agents based on the [Ru(dqpy)(dppn)] moiety were evaluated for photoinduced cytotoxicity in 4T1 murine triple-negative breast cancer cells, L929 fibroblasts, and M0, M1, and M2 macrophages. The cathepsin inhibitor conjugate displayed notable selectivity for inducing cell death under irradiation compared to dark conditions, mitigating toxicity in the dark observed with the triazole control complex [Ru(dqpy)(dppn)(MeTz)]2+ (MeTz = 1-methyl-1H-1,2,4-triazole). Notably, our lead complex is among a limited number of dual PCT/PDT agents activated with green light.

Interferon gamma immunoPET imaging to evaluate response to immune checkpoint inhibitors.

Introduction: We previously developed a 89Zr-labeled antibody-based immuno-positron emission tomography (immunoPET) tracer targeting interferon gamma (IFNγ), a cytokine produced predominantly by activated T and natural killer (NK) cells during pathogen clearance, anti-tumor immunity, and various inflammatory and autoimmune conditions. The current study investigated [89Zr]Zr-DFO-anti-IFNγ PET as a method to monitor response to immune checkpoint inhibitors (ICIs). Methods: BALB/c mice bearing CT26 colorectal tumors were treated with combined ICI (anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and anti-programmed death 1 (PD-1)). The [89Zr]Zr-DFO-anti-IFNγ PET tracer, generated with antibody clone AN18, was administered on the day of the second ICI treatment, with PET imaging 72 hours later. Tumor mRNA was analyzed by quantitative reverse-transcribed PCR (qRT-PCR). Results: We detected significantly higher intratumoral localization of [89Zr]Zr-DFO-anti-IFNγ in ICI-treated mice compared to untreated controls, while uptake of an isotype control tracer remained similar between treated and untreated mice. Interestingly, [89Zr]Zr-DFO-anti-IFNγ uptake was also elevated relative to the isotype control in untreated mice, suggesting that the IFNγ-specific tracer might be able to detect underlying immune activity in situ in this immunogenic model. In an efficacy experiment, a significant inverse correlation between tracer uptake and tumor burden was also observed. Because antibodies to cytokines often exhibit neutralizing effects which might alter cellular communication within the tumor microenvironment, we also evaluated the impact of AN18 on downstream IFNγ signaling and ICI outcomes. Tumor transcript analysis using interferon regulatory factor 1 (IRF1) expression as a readout of IFNγ signaling suggested there may be a marginal disruption of this pathway. However, compared to a 250 µg dose known to neutralize IFNγ, which diminished ICI efficacy, a tracer-equivalent 50 µg dose did not reduce ICI response rates. Discussion: These results support the use of IFNγ PET as a method to monitor immune activity in situ after ICI, which may also extend to additional T cell-activating immunotherapies.

Predicting physical distancing on recreational trails during COVID-19.

The emergence of Coronavirus 19 led to societal and behavioral changes, including intensified use of many public parks and trails for mental respite and leisure time physical activity. As visitors sought stress-relief in the great outdoors, they also encountered stressful situations as they navigated risk exposure. Recommendations to physically distance between parties was a key component to reduce risk, but compliance is unknown in the outdoor arena. This observational study of more than 10 000 trail user encounters documented distancing and enabled predictive analysis that revealed wider trails, smaller groups and signage led to greater distancing compliance. Managers and planners can integrate these findings immediately and in consideration of future trail designs to minimize risk exposure. Management implications: Select site features increase odds of distancing compliance and can inform management decisions and designs immediately and in addressing future use surges: wider trails, unpaved surfaces, and COVID-19 signage.As distancing compliance waned with time but signage increased compliance, innovative and dynamic signs may sustain compliance and multi-media communications should be considered.Both activity size and group type influence distancing so considering group size recommendations and activity separation are in order.

COVID-19 compliance among urban trail users: Behavioral insights and environmental implications.

Public green spaces provide physical and mental respite, which have become essential and elevated services during the COVID-19 pandemic. As visitation to public parks and recreation areas increased during the pandemic, the challenge of maintaining visitor safety and protecting environmental resources was exacerbated. A key visitor safety practice during the COVID-19 onset was maintaining a physical distance of six feet (1.8 m) between groups. A novel data set documented and compared physical distancing compliance and off-trail behavior on multiple-use trails across multiple states and within select U.S. communities, attending to the impact of select environmental factors. Nearly 6000 observations revealed physical distancing compliance varied and the environmental factors of trail width, density, and signage influenced its variability. Similarly, off-trail movement was related to trail width and density. Clearly the environment matters as people negotiate the 'new normal' of physical distancing during physical activity and outdoor recreation participation. Given the ongoing COVID-19 pandemic and likelihood of future health crises, this project provides important information and insight for trail and other public green space management, monitoring, and modelling moving forward. Management implications: As both trail width and visitor density impacted physical distancing, a combination of trail design that accommodates distancing requirements and density management practices that provide sufficient trail user spacing is essential to retain safe and active trail use.Off-trail movement was influenced by both trail width and density, so ensuring safe off-trail spaces exist and using durable off-trail materials can minimize disturbance and protect visitors.Signage is inconsistently significant to influence trail-compliant distancing behavior, but optimizing its placement and content may improve effectiveness.Compliant trail behavior varied by trail width, visitor density, and trail location; therefore, site-specific information is necessary to understand possible visitor behavior and design/implement mitigation strategies.

Cases and context: Mask-related behaviors among U.S. trail visitors during the COVID-19 pandemic.

The challenge of simultaneously providing outdoor recreation opportunities while protecting the public from SARS-CoV-2 virus and COVID-19 transmission, as well as future pandemics, remains foremost on managers' minds. Safe spaces and cultures are paramount for managers and visitors alike. Recommended protective measures against COVID-19 included physically distancing 1.8 m (six-feet) between parties and mask-wearing when distancing is not possible. Adoption of these protective measures is relatively unknown but essential to inform recreation management and planning through future health crises. Such adoption is likely influenced by both the pandemic context and site context, particularly related to visitor density. An observational study assessed mask-wearing behaviors among trail walkers on multiple trails in the United States from November 2020 through May 2021. Trained observers identified if walking groups were prepared to mask or had masks correctly worn as well as if encounters were compliant with the 1.8 m recommendations. Data collected across seven U.S. states enabled comparisons of mask-related behaviors across sites as well as considerations to: the influence of the pandemic context in terms of cases and vaccination rates, mask mandates, and trail density. Results from nearly 3000 encounters revealed significant variance in visible masks, low compliance of mask-wearing in encounters less than 1.8 m, significant influence of both COVID-19 cases and vaccination rates on mask wearing at half the sites, and no impact of state-level mask mandates when controlling for cases and vaccinations. Integrating public health data can inform predictions of compliant behaviors, or lack thereof, and needs exist to advance a safety culture.

Host genetic background regulates the capacity for anti-tumor antibody-dependent phagocytosis.

Background: Antitumor antibody, or targeted immunotherapy, has revolutionized cancer treatment and markedly improved patient outcomes. A prime example is the monoclonal antibody (mAb) trastuzumab, which targets human epidermal growth factor receptor 2 (HER2). However, like many targeted immunotherapies, only a subset of patients benefit from trastuzumab long-term. In addition to tumor-intrinsic factors, we hypothesize that host genetics may influence subsequent immune activation. Methods: To model the human population, we produced F1 crosses of genetically heterogeneous Diversity Outbred (DO) mice with BALB/c mice (DOCF1). Distinct DOCF1 mice were orthotopically implanted with the BALB/c-syngeneic TUBO mammary tumor line, which expresses the HER2 ortholog rat neu. Treatment with anti-neu mAb clone 7.16.4 began once tumors reached ∼200 mm 3 . Genetic linkage and quantitative trait locus (QTL) effects analyses in R/qtl2 identified loci associated with tumor growth rates. Locus validation was performed with BALB/c F1 crosses with recombinant-inbred Collaborative Cross (CC) strains selected for therapy-associated driver genetics (CCxCF1). The respective roles of natural killer (NK) cells and macrophages were investigated by selective depletion in vivo. Ex vivo macrophage antibody-dependent phagocytosis (ADCP) assays were evaluated by confocal microscopy using 7.16.4-opsonized E2Crimson-expressing TUBO tumor cells. Results: We observed a divergent response to anti-tumor antibody therapy in DOCF1 mice. Genetic linkage analysis detected a locus on chromosome 10 that correlates to a robust response to therapy, which was validated in CCxCF1 models. Single-cell RNA sequencing of tumors from responder and non-responder models identified key differences in tumor immune infiltrate composition, particularly within macrophage (Mφ) subsets. This is further supported by ex vivo analysis showing Mφ ADCP capacity correlates to in vivo treatment outcomes in both DOCF1 and CCxCF1 models. Conclusions: Host genetics play a key regulatory role in targeted immunotherapy outcomes, and putative causal genes are identified in murine chromosome 10 which may govern Mφ function during ADCP.

Chemotherapy and Abdominal Wall Closure Technique Increase the Probability of Postoperative Ventral Incisional Hernia in Patients With Colon Cancer.

BACKGROUND: Chemotherapy is associated with postoperative ventral incisional hernia (PVIH) after right hemicolectomy (RHC) for colon cancer, and abdominal wall closure technique may affect PVIH. We sought to identify clinical predictors of PVIH. METHODS: We retrospectively analyzed patients who underwent RHC for colon cancer from 2008-2018 and later developed PVIH. Time to PVIH was analyzed with Kaplan-Meier analysis, clinical predictors were identified with multivariable Cox proportional hazards modeling, and the probability of PVIH given chemotherapy and the suture technique was estimated with Bayesian analysis. RESULTS: We identified 399 patients (209 no adjuvant chemotherapy and 190 adjuvant chemotherapy), with an overall PVIH rate of 38%. The 5-year PVIH rate was 55% for adjuvant chemotherapy, compared with 38% for none (log-rank P < .05). Adjuvant chemotherapy (hazard ratio [HR] 1.65, 95% confidence interval [CI] 1.18-2.31, P < .01), age (HR .99, 95% CI .97-1.00, P < .01), body mass index (HR 1.02, 95% CI 1.00-1.04, P < .01), and neoadjuvant chemotherapy (HR 1.92, 95% CI 1.21-3.00, P < .01) were independently associated with PVIH. Postoperative ventral incisional hernia was more common overall in patients who received adjuvant chemotherapy (46% compared with 30%, P < .01). In patients who received adjuvant chemotherapy, the probability of PVIH for incision closure with #1 running looped polydioxanone was 42%, compared with 59% for incision closure with #0 single interrupted polyglactin 910. DISCUSSION: Exposure to chemotherapy increases the probability of PVIH after RHC, and non-short stitch incision closure further increases this probability, more so than age or body mass index. The suture technique deserves further study as a modifiable factor in this high-risk population.

FOXQ1 recruits the MLL complex to activate transcription of EMT and promote breast cancer metastasis.

Aberrant expression of the Forkhead box transcription factor, FOXQ1, is a prevalent mechanism of epithelial-mesenchymal transition (EMT) and metastasis in multiple carcinoma types. However, it remains unknown how FOXQ1 regulates gene expression. Here, we report that FOXQ1 initiates EMT by recruiting the MLL/KMT2 histone methyltransferase complex as a transcriptional coactivator. We first establish that FOXQ1 promoter recognition precedes MLL complex assembly and histone-3 lysine-4 trimethylation within the promoter regions of critical genes in the EMT program. Mechanistically, we identify that the Forkhead box in FOXQ1 functions as a transactivation domain directly binding the MLL core complex subunit RbBP5 without interrupting FOXQ1 DNA binding activity. Moreover, genetic disruption of the FOXQ1-RbBP5 interaction or pharmacologic targeting of KMT2/MLL recruitment inhibits FOXQ1-dependent gene expression, EMT, and in vivo tumor progression. Our study suggests that targeting the FOXQ1-MLL epigenetic axis could be a promising strategy to combat triple-negative breast cancer metastatic progression.

Using the Collaborative Cross and Diversity Outbred Mice in Immunology.

The Collaborative Cross (CC) and the Diversity Outbred (DO) stock mouse panels are the most powerful murine genetics tools available to the genetics community. Together, they combine the strength of inbred animal models with the diversity of outbred populations. Using the 63 CC strains or a panel of DO mice, each derived from the same 8 parental mouse strains, researchers can map genetic contributions to exceptionally complex immunological and infectious disease traits that would require far greater powering if performed by genome-wide association studies (GWAS) in human populations. These tools allow genes to be studied in heterozygous and homozygous states and provide a platform to study epistasis between interacting loci. Most importantly, once a quantitative phenotype is investigated and quantitative trait loci are identified, confirmatory genetic studies can be performed, which is often problematic using the GWAS approach. In addition, novel stable mouse models for immune phenotypes are often derived from studies utilizing the DO and CC mice that can serve as stronger model systems than existing ones in the field. The CC/DO systems have contributed to the fields of cancer immunology, autoimmunity, vaccinology, infectious disease, allergy, tissue rejection, and tolerance but have thus far been greatly underutilized. In this article, we present a recent review of the field and point out key areas of immunology that are ripe for further investigation and awaiting new CC/DO research projects. We also highlight some of the strong computational tools that have been developed for analyzing CC/DO genetic and phenotypic data. Additionally, we have formed a centralized community on the CyVerse infrastructure where immunogeneticists can utilize those software tools, collaborate with groups across the world, and expand the use of the CC and DO systems for investigating immunogenetic phenomena. © 2022 Wiley Periodicals LLC.

Protocolized Training of Advanced Practice Providers for Robotic Surgery Improves the Quality of Intraoperative Assistance.

BACKGROUND: The expansion of robotic surgery requires identifying factors of competent robotic bedside assisting. Surgical trainees desire more robotic console time, and we hypothesized that protocolized robotic surgery bedside training could equip Advanced Practice Providers (APPs) to meet this growing need. No standardized precedent exists for training APPs. METHODS: We designed a pilot study consisting of didactic and clinical skills. APPs completed didactic tests followed by proctored clinical skills checklists intraoperatively. Operating surgeons scored trainees with 10-point Likert scale (< 5 not confident, > 5 = confident). APPs scoring > 5 advanced to a solo practicum. Competence was defined as: didactic test score > 75th percentile, completing < 5 checklists, scoring > 5 on the practicum. The probability of passing the practicum was calculated with Bayes theorem. RESULTS: Of 10 APP trainees, 5 passed on initial attempt. After individualized development plans, 4 passed retesting. Differences in trainee factors were not statistically significant, but the probability of passing the practicum was < 50% if more than four checklists were needed. CONCLUSIONS: Clinical experience, not didactic knowledge, determines the probability of intraoperative competence. Increasing clinical proctoring did not result in higher probability of competence. Early identification of APPs needing individualized improvement increases the proportion of competent APPs.

Targeted therapy of pyrrolo[2,3-d]pyrimidine antifolates in a syngeneic mouse model of high grade serous ovarian cancer and the impact on the tumor microenvironment.

Novel therapies are urgently needed for epithelial ovarian cancer (EOC), the most lethal gynecologic malignancy. In addition, therapies that target unique vulnerabilities in the tumor microenvironment (TME) of EOC have largely been unrealized. One strategy to achieve selective drug delivery for EOC therapy involves use of targeted antifolates via their uptake by folate receptor (FR) proteins, resulting in inhibition of essential one-carbon (C1) metabolic pathways. FRα is highly expressed in EOCs, along with the proton-coupled folate transporter (PCFT); FRß is expressed on activated macrophages, a major infiltrating immune population in EOC. Thus, there is great potential for targeting both the tumor and the TME with agents delivered via selective transport by FRs and PCFT. In this report, we investigated the therapeutic potential of a novel cytosolic C1 6-substituted pyrrolo[2,3-d]pyrimidine inhibitor AGF94, with selectivity for uptake by FRs and PCFT and inhibition of de novo purine nucleotide biosynthesis, against a syngeneic model of ovarian cancer (BR-Luc) which recapitulates high-grade serous ovarian cancer in patients. In vitro activity of AGF94 was extended in vivo against orthotopic BR-Luc tumors. With late-stage subcutaneous BR-Luc xenografts, AGF94 treatment resulted in substantial anti-tumor efficacy, accompanied by significantly decreased M2-like FRß-expressing macrophages and increased CD3+ T cells, whereas CD4+ and CD8+ T cells were unaffected. Our studies demonstrate potent anti-tumor efficacy of AGF94 in the therapy of EOC in the context of an intact immune system, and provide a framework for targeting the immunosuppressive TME as an essential component of therapy.

Evaluation of an ImmunoPET Tracer for IL-12 in a Preclinical Model of Inflammatory Immune Responses.

The immune cytokine interleukin-12 (IL-12) is involved in cancer initiation and progression, autoimmunity, as well as graft versus host disease. The ability to monitor IL-12 via imaging may provide insight into various immune processes, including levels of antitumor immunity, inflammation, and infection due to its functions in immune signaling. Here, we report the development and preclinical evaluation of an antibody-based IL-12-specific positron emission tomography (PET) tracer. To mimic localized infection and stimulate IL-12 production, BALB/c mice were administered lipopolysaccharide (LPS) intramuscularly. [89Zr]Zr-DFO-αIL12 tracer was given one hour post LPS administration and PET images were taken after 5, 24, 48, and 72 hours. We observed significantly higher uptake in LPS-treated mice as compared to controls. Biodistribution of the tracer was evaluated in a separate cohort of mice, where tracer uptake was elevated in muscle, spleen, lymph nodes, and intestines after LPS administration. To evaluate the utility of [89Zr]Zr-DFO-αIL12 as an indicator of antigen presenting cell activation after cancer immunotherapy, we compared PET imaging with and without intratumoral delivery of oncolytic adenovirus expressing granulocyte-macrophage colony-stimulating factor (Adv/GM-CSF), which we have shown promotes anti-tumor immunity. BALB/c mice were inoculated orthotopically with the mouse mammary carcinoma line TUBO. Once TUBO tumors reached a volume of ~50 mm3, mice were treated with either three intratumoral injections of 108 PFU Adv/GM-CSF or vehicle control, given every other day. Upon the last dose, [89Zr]Zr-DFO-αIL12 was injected intravenously and 72 hours later all mice were imaged via PET. Tumor-specific uptake of [89Zr]Zr-DFO-αIL12 was higher in Adv/GM-CSF treated mice versus controls. Tissues were harvested after imaging, and elevated levels of macrophages and CD8+ Tc cells were detected in Adv/GM-CSF treated tumors by immunohistochemistry. We validated that IL-12 expression was induced after Adv/GM-CSF by qRT-PCR. Importantly, expression of genes activated by IL-12 (IFNγ, TNFα, and IL-18) were unaffected after IL-12 imaging relative to mice receiving an IgG control tracer, suggesting the tracer antibody does not significantly disrupt signaling. Our results indicate that targeting soluble cytokines such as IL-12 by PET imaging with antibody tracers may serve as a noninvasive method to evaluate the function of the immune milieu in situ.

A diversity outbred F1 mouse model identifies host-intrinsic genetic regulators of response to immune checkpoint inhibitors.

Immune checkpoint inhibitors (ICI) have improved outcomes for a variety of malignancies; however, many patients fail to benefit. While tumor-intrinsic mechanisms are likely involved in therapy resistance, it is unclear to what extent host genetic background influences response. To investigate this, we utilized the Diversity Outbred (DO) and Collaborative Cross (CC) mouse models. DO mice are an outbred stock generated by crossbreeding eight inbred founder strains, and CC mice are recombinant inbred mice generated from the same eight founders. We generated 207 DOB6F1 mice representing 48 DO dams and demonstrated that these mice reliably accept the C57BL/6-syngeneic B16F0 tumor and that host genetic background influences response to ICI. Genetic linkage analysis from 142 mice identified multiple regions including one within chromosome 13 that associated with therapeutic response. We utilized 6 CC strains bearing the positive (NZO) or negative (C57BL/6) driver genotype in this locus. We found that 2/3 of predicted responder CCB6F1 crosses show reproducible ICI response. The chromosome 13 locus contains the murine prolactin family, which is a known immunomodulating cytokine associated with various autoimmune disorders. To directly test whether prolactin influences ICI response rates, we implanted inbred C57BL/6 mice with subcutaneous slow-release prolactin pellets to induce mild hyperprolactinemia. Prolactin augmented ICI response against B16F0, with increased CD8 infiltration and 5/8 mice exhibiting slowed tumor growth relative to controls. This study highlights the role of host genetics in ICI response and supports the use of F1 crosses in the DO and CC mouse populations as powerful cancer immunotherapy models.

Metalloimmunotherapy with Rhodium and Ruthenium Complexes: Targeting Tumor-Associated Macrophages.

Tumor associated macrophages (TAMs) suppress the cancer immune response and are a key target for immunotherapy. The effects of ruthenium and rhodium complexes on TAMs have not been well characterized. To address this gap in the field, a panel of 22 dirhodium and ruthenium complexes were screened against three subtypes of macrophages, triple-negative breast cancer and normal breast tissue cells. Experiments were carried out in 2D and biomimetic 3D co-culture experiments with and without irradiation with blue light. Leads were identified with cell-type-specific toxicity toward macrophage subtypes, cancer cells, or both. Experiments with 3D spheroids revealed complexes that sensitized the tumor models to the chemotherapeutic doxorubicin. Cell surface exposure of calreticulin, a known facilitator of immunogenic cell death (ICD), was increased upon treatment, along with a concomitant reduction in the M2-subtype classifier arginase. Our findings lay a strong foundation for the future development of ruthenium- and rhodium-based chemotherapies targeting TAMs.

RNA binding protein RBMS3 is a common EMT effector that modulates triple-negative breast cancer progression via stabilizing PRRX1 mRNA.

The epithelial-to-mesenchymal transition (EMT) has been recognized as a driving force for tumor progression in breast cancer. Recently, our group identified the RNA Binding Motif Single Stranded Interacting Protein 3 (RBMS3) to be significantly associated with an EMT transcriptional program in breast cancer. Additional expression profiling demonstrated that RBMS3 was consistently upregulated by multiple EMT transcription factors and correlated with mesenchymal gene expression in breast cancer cell lines. Functionally, RBMS3 was sufficient to induce EMT in two immortalized mammary epithelial cell lines. In triple-negative breast cancer (TNBC) models, RBMS3 was necessary for maintaining the mesenchymal phenotype and invasion and migration in vitro. Loss of RBMS3 significantly impaired both tumor progression and spontaneous metastasis in vivo. Using a genome-wide approach to interrogate mRNA stability, we found that ectopic expression of RBMS3 upregulates many genes that are resistant to degradation following transcriptional blockade by actinomycin D (ACTD). Specifically, RBMS3 was shown to interact with the mRNA of EMT transcription factor PRRX1 and promote PRRX1 mRNA stability. PRRX1 is required for RBMS3-mediated EMT and is partially sufficient to rescue the effect of RBMS3 knockdown in TNBC cell lines. Together, this study identifies RBMS3 as a novel and common effector of EMT, which could be a promising therapeutic target for TNBC treatment.

An integrated approach to monitoring and estimating COVID-19 risk exposure among leisure-time physical activity participants.

BACKGROUND: Leisure time physical activity (LTPA) provides both health benefits and risks, particularly during a pandemic. During the COVID-19 pandemic, significant increases in close-to-home LTPA raised concerns for public health and land managers alike. This project illustrates a novel, integrated monitoring approach to estimating COVID-19 risk exposure during trail-related LTPA, with implications for other public spaces. METHODS: COVID-19 risk exposure was conservatively calculated from the integration of in-person observations of LTPA trail groups and automated monitoring of trail traffic volumes in spring 2020. Trained observers tracked 1,477 groups. Traffic volume estimates and observed distance data were integrated, considering occlusion and total trail traffic volume. RESULTS: 70% of groups had one or more encounters. Among individual users, 38.5% were 100% compliant across all events observed but 32.7% were not compliant. Considering trail traffic volumes and annual daily traffic volume, exposure to risk of COVID-19 was conservatively estimated at 61.5% among individual trail users. CONCLUSIONS: Monitoring opportunities and challenges of health risk exposure exist. Adjusted exposure measures based on volume counts can approximate numbers of unique individuals exposed, inform management actions, efficacy and policy decisions.

The current state of robotic retromuscular repairs-a qualitative review of the literature.

BACKGROUND: The management of ventral incisional hernias (VIH) has undergone many iterations over the last 5 years due to evolution in surgical techniques and advancement in robotic surgery. Four general principles have emerged: mesh usage, retromuscular mesh placement, primary fascial closure, and usage of minimally invasive techniques when possible. The application of robotic retromuscular repairs in VIH allow these principles to be applied simultaneously. This qualitative review attempts to answer what robotic retromuscular repairs are described, which patients are selected for these techniques, and what are current outcomes. METHODS: Using the key words: "robotic retromuscular repair", "robotic Rives Stoppa", and "robotic transversus abdominis release", a PubMed search of articles written up to December 2019 was critically reviewed. RESULTS: 44 articles were encountered, 9 high-quality articles were analyzed for this manuscript. Level of evidence ranged from 2B to 2C. Robotic TAR patients had BMI of 33 kg/m2, defect sizes ranging from 7-14 cm wide to 12-19 cm long, longer OR times, no difference in surgical site events, and shorter length of stay (LOS). The techniques to perform robotic Rives Stoppa (RS) were heterogeneous; however, extended totally extraperitoneal (ETEP) approach is most described. Defect width for RS repairs ranged 4-7 cm and LOS was less than 1 day. Complication rates were low, there is no long-term data on hernia recurrence, and information on cost is limited. CONCLUSION: In short-term follow-up, robotic retromuscular repairs show promise that VIH can be repaired with intramuscular mesh, few complications, and shorter LOS. Data on hernia recurrence, long-term complications, and rigorous cost analysis are needed to demonstrate generalizability.

Diversity Outbred Mice Reveal the Quantitative Trait Locus and Regulatory Cells of HER2 Immunity.

The genetic basis and mechanisms of disparate antitumor immune response was investigated in Diversity Outbred (DO) F1 mice that express human HER2. DO mouse stock samples nearly the entire genetic repertoire of the species. We crossed DO mice with syngeneic HER2 transgenic mice to study the genetics of an anti-self HER2 response in a healthy outbred population. Anti-HER2 IgG was induced by Ad/E2TM or naked pE2TM, both encoding HER2 extracellular and transmembrane domains. The response of DO F1 HER2 transgenic mice was remarkably variable. Still, immune sera inhibited HER2+ SKBR3 cell survival in a dose-dependent fashion. Using DO quantitative trait locus (QTL) analysis, we mapped the QTL that influences both total IgG and IgG2(a/b/c) Ab response to either Ad/E2TM or pE2TM. QTL from these four datasets identified a region in chromosome 17 that was responsible for regulating the response. A/J and NOD segments of genes in this region drove elevated HER2 Ig levels. This region is rich in MHC-IB genes, several of which interact with inhibitory receptors of NK cells. (B6xA/J)F1 and (B6xNOD)F1 HER2 transgenic mice received Ad/E2TM after NK cell depletion, and they produced less HER2 IgG, demonstrating positive regulatory function of NK cells. Depletion of regulatory T cells enhanced response. Using DO QTL analysis, we show that MHC-IB reactive NK cells exert positive influence on the immunity, countering negative regulation by regulatory T cells. This new, to our knowledge, DO F1 platform is a powerful tool for revealing novel immune regulatory mechanisms and for testing new interventional strategies.

In vivo Imaging Technologies to Monitor the Immune System.

The past two decades have brought impressive advancements in immune modulation, particularly with the advent of both cancer immunotherapy and biologic therapeutics for inflammatory conditions. However, the dynamic nature of the immune response often complicates the assessment of therapeutic outcomes. Innovative imaging technologies are designed to bridge this gap and allow non-invasive visualization of immune cell presence and/or function in real time. A variety of anatomical and molecular imaging modalities have been applied for this purpose, with each option providing specific advantages and drawbacks. Anatomical methods including magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound provide sharp tissue resolution, which can be further enhanced with contrast agents, including super paramagnetic ions (for MRI) or nanobubbles (for ultrasound). Conjugation of the contrast material to an antibody allows for specific targeting of a cell population or protein of interest. Protein platforms including antibodies, cytokines, and receptor ligands are also popular choices as molecular imaging agents for positron emission tomography (PET), single-photon emission computerized tomography (SPECT), scintigraphy, and optical imaging. These tracers are tagged with either a radioisotope or fluorescent molecule for detection of the target. During the design process for immune-monitoring imaging tracers, it is important to consider any potential downstream physiologic impact. Antibodies may deplete the target cell population, trigger or inhibit receptor signaling, or neutralize the normal function(s) of soluble proteins. Alternatively, the use of cytokines or other ligands as tracers may stimulate their respective signaling pathways, even in low concentrations. As in vivo immune imaging is still in its infancy, this review aims to describe the modalities and immunologic targets that have thus far been explored, with the goal of promoting and guiding the future development and application of novel imaging technologies.

Use of non-operative treatment and interval cholecystectomy for cholecystitis in patients with cancer.

BACKGROUND: Early cholecystectomy (EC) for acute cholecystitis (AC) is standard. Often patients with cancer are not EC candidates and require non-surgical treatments. We analyzed factors associated with non-surgical treatments and progression to interval cholecystectomy (IC). MATERIALS AND METHODS: We performed a case-control study reviewing consults for AC from 2001 to 2017 in a tertiary cancer center. Study patients had cancer, abdominal pain, and positive imaging studies. Univariate analysis and regression modeling evaluated associations between non-surgical management, resolution of AC, and IC. RESULTS: 206 patients met the criteria. 20 underwent EC, 132 took antibiotics (ABX), and were treated with 54 percutaneous cholecystostomy tubes (PCTs). AC resolution was higher with PCT versus ABX (94% vs. 80%, p=0.02). Univariate analysis revealed higher absolute neutrophil counts (ANCs) and longer length of stay in PCT, and logistic regression revealed independent associations of abdominal malignancy (OR=6.66, 95% CI 1.36 to 32.6, p=0.09), abdominal radiation (OR=0.09, 95% CI 0.02 to 0.53, p<0.01), and PCT with resolution of AC (OR=4.89, 95% CI 1.18 to 20.2, p=0.01). IC rate was 43%, and median time to IC after was 45 to 67 days. Multivariate analysis revealed nausea/vomiting and increasing platelets are independently associated with IC. Recent chemotherapy increases odds of IC in the presence of rising ANC (OR=1.14, 95% CI 1.00 to 1.30, p=0.05). CONCLUSION: PCT has a higher success rate of resolving AC than ABX. Abdominal malignancy increases odds of resolution; abdominal radiation decreases odds. Nausea/vomiting and recent chemotherapy, coupled with rising ANC are associated with IC, but less than 50% of patients return for operation. PCT may not be a bridge to IC in our population.Level of evidence II.