Design of a Small Unmanned Aircraft System for Bridge Inspections.

Bridge inspections are an important procedure for maintaining the infrastructure vital to our economy and well-being. The current methodology of utilizing specialized equipment such as snooper trucks and scaffolding to support manned-inspections poses a significant financial cost, disrupts traffic, and is dangerous to the inspectors and public. The advent of unmanned aerial systems (UAS), more commonly called drones, presents a practical solution that promises reduced cost, enhanced safety, and is significantly less intrusive than previous methodologies. Current limitations in the implementation of UAS include the reliance on a skilled operator and/or the requirement for a UAS to operate in a cluttered, GPS-denied environment. A solution to these challenges is presented in this paper by utilizing commercial off-the-shelf (COTS) hardware including laser rangefinders, optical flow sensors, and live video telemetry. Included in the system is the obstacle avoidance equipped drone and a ground station intended to be manned by a pilot and bridge inspector. The proposed custom-fabricated UAS was implemented during eight inspections of Florida Department of Transportation (FDOT) bridges. The UAS was able to navigate under GPS-denied and obstacle-laden bridge decks with position-hold performance comparable to, if not better than, a COTS unit in an unobstructed environment. The position hold capability maintained an altitude of ±12.8 cm with a horizontal hold of ±435 cm. Details of the hardware, algorithm development, and suggestions for future research are discussed in this paper.

Cytokine/chemokine profiles in squamous cell carcinoma correlate with precancerous and cancerous disease stage.

Actinic Keratosis (AK), Intraepidermal Carcinoma (IEC), and Squamous Cell Carcinoma (SCC) are generally considered to be advancing stages of the same disease spectrum. However, while AK often regress spontaneously, and IEC often regress in response to immune-activating treatments, SCC typically do not regress. Therefore, it is vital to define whether fundamental immunological changes occur during progression to SCC. Here we show that proinflammatory cytokine expression, chemokine expression, and immune cell infiltration density change during progression to SCC. Our findings suggest a switch from predominantly proinflammatory cytokine production to chemokine production is a key feature of progression from precancer to cancer. Together, these observations propose a model that can underpin current research and open new avenues of exploration into the clinical significance of these profiles with respect to immunotherapeutic or other treatment outcomes.

Clinically-Relevant Rapamycin Treatment Regimens Enhance CD8+ Effector Memory T Cell Function In The Skin and Allow their Infiltration into Cutaneous Squamous Cell Carcinoma.

Patients receiving immunosuppressive drugs to prevent organ transplant rejection exhibit a greatly increased risk of developing cutaneous squamous cell carcinoma (SCC). However, not all immunosuppressive drugs confer the same risk. Randomised, controlled trials demonstrate that switching renal transplant recipients receiving calcineurin inhibitor-based therapies to mammalian target of rapamycin (mTOR) inhibitors results in a reduced incidence of de novo SSC formation, and can even result in the regression of pre-existing premalignant lesions. However, the contribution played by residual immune function in this setting is unclear. We examined the hypotheses that mTOR inhibitors promote the enhanced differentiation and function of CD8+ memory T cells in the skin. Here, we demonstrate that the long-term oral administration of rapamycin to achieve clinically-relevant whole blood drug target thresholds, creates a "low rapamycin dose" environment in the skin. While both rapamycin and the calcineurin inhibitor tacrolimus elongated the survival of OVA-expressing skin grafts, and inhibited short-term antigen-specific CD8+ T cell responses, rapamycin but not tacrolimus permitted the statistically significant infiltration of CD8+ effector memory T cells into UV-induced SCC lesions. Furthermore, rapamycin uniquely enhanced the number and function of CD8+ effector and central memory T cells in a model of long-term contact hypersensitivity provided that rapamycin was present during the antigen sensitization phase. Thus, our findings suggest that patients switched to mTOR inhibitor regimens likely experience enhanced CD8+ memory T cell function to new antigen-challenges in their skin, which could contribute to their lower risk of de novo SSC formation and regression of pre-existing premalignant lesions.

Cytokines, Chemokines, and Other Biomarkers of Response for Checkpoint Inhibitor Therapy in Skin Cancer.

Immunotherapy for skin malignancies has ushered in a new era for cancer treatments by demonstrating unprecedented durable responses in the setting of metastatic Melanoma. Consequently, checkpoint inhibitors are now the first-line treatment of metastatic melanoma and widely used as adjuvant therapy for stage III disease. With the observation that higher tumor mutational burden correlates with a better response, checkpoint inhibitors are tested in other skin cancer types of known high tumor mutational burden with promising results and recently became the first-ever FDA-approved treatment for metastatic Merkel cell carcinoma. The emerging new standards-of-care will necessitate more precise biomarkers and predictors for treatment response and immune-related adverse events. Measurable immune-related mediators are currently under investigation as factors that promote or block the response to cancer immunotherapy and may provide insights into the underlying immune response to the tumor. Cytokines and chemokines are such mediators and are crucial for facilitating the recruitment and activation of specific subsets of leukocytes within the microenvironment of skin cancers. The exact mechanisms of how these meditators, both immunological and non-immunological, operate in the tumor microenvironment is an area of active research, so to reliable biomarkers of responses to cancer immunotherapy. Here, we will review and summarize the expanding body of literature for immune-related biomarkers pertaining to Melanoma, Basal cell carcinoma, Squamous cell carcinoma, and Merkel cell carcinoma, highlighting clinically relevant checkpoint inhibitor therapy biomarker advancements.

Sirolimus Increases T-Cell Abundance in the Sun Exposed Skin of Kidney Transplant Recipients.

BACKGROUND: Kidney transplant recipients (KTRs) receiving the mammalian target of rapamycin inhibitor sirolimus may display a reduced risk of skin cancer development compared to KTRs receiving calcineurin inhibitors. Despite studies investigating the effects of these 2 drug classes on T cells in patient blood, the effect these drugs may have in patient skin is not yet known. METHODS: Fifteen patients with chronic kidney disease (not recipients of immunosuppressive drugs), and 30 KTRs (15 receiving a calcineurin inhibitor, and 15 receiving sirolimus) provided matched samples of blood, sun exposed (SE) and non-SE skin. The abundance of total CD8+ and CD4+ T cells, memory CD8+ and CD4+ T cells, and regulatory T (Treg) cells in each sample was then assessed by flow cytometry. RESULTS: Sirolimus treatment significantly increased absolute numbers of CD4+ T cells, memory CD8+- and CD4+ T cells, and Treg cells in SE skin versus paired samples of non-SE skin. No differences were found in the absolute number of any T cell subset in the blood. Correlation analysis revealed that the percentage of T cell subsets in the blood does not always accurately reflect the percentage of T-cell subsets in the skin of KTRs. Furthermore, sirolimus significantly disrupts the balance of memory CD4+ T cells in the skin after chronic sun exposure. CONCLUSIONS: This study demonstrated that immunosuppressive drug class and sun exposure modify the abundance of multiple T-cell subsets in the skin of KTRs. Correlation analysis revealed that the prevalence of Treg cells in KTR blood does not accurately reflect the prevalence of Treg cells in KTR skin.

CD4+CD8ß+ double-positive T cells in skin-draining lymph nodes respond to inflammatory signals from the skin.

CD4+CD8+ double-positive (DP), mature, peripheral T cells are readily detectable in a variety of species and tissues. Despite a common association with autoimmune and malignant skin disorders, however, little is understood about their role or function. Herein, we show that DP T cells are readily detectable in the blood, spleen, and peripheral lymph nodes of naïve C57BL/6 mice. DP T cells were also present in Jα18-/- and CD1d-/- mice, indicating that these cells are not NK-T cells. After skin administration of CASAC adjuvant, but not Quil A adjuvant, both total DP T cells and skin-infiltrating DP T cells increased in number. We explored the possibility that DP T cells could represent aggregates between CD4+ and CD8+ single-positive T cells and found strong evidence that a large proportion of apparent DP T cells were indeed aggregates. However, the existence of true CD4+CD8+ DP T cells was confirmed by Amnis ImageStream (Millipore Sigma, Billerica, MA, USA) imaging. Multiple rounds of FACS sorting separated true DP cells from aggregates and indicated that conventional analyses may lead to ∼10-fold overestimation of DP T cell numbers. The high degree of aggregate contamination and overestimation of DP abundance using conventional analysis techniques may explain discrepancies reported in the literature for DP T cell origin, phenotype, and function.

Antigen-encoding bone marrow terminates islet-directed memory CD8+ T-cell responses to alleviate islet transplant rejection.

Islet-specific memory T cells arise early in type 1 diabetes (T1D), persist for long periods, perpetuate disease and are rapidly reactivated by islet transplantation. As memory T cells are poorly controlled by 'conventional' therapies, memory T-cell mediated attack is a substantial challenge in islet transplantation and this will extend to application of personalized approaches using stem-cell derived replacement ß cells. New approaches are required to limit memory autoimmune attack of transplanted islets or replacement ß cells. Here we show that transfer of bone marrow encoding cognate antigen directed to dendritic cells, under mild, immune-preserving conditions inactivates established memory CD8+ T-cell populations and generates a long-lived, antigen-specific tolerogenic environment. Consequently, CD8+ memory T cell-mediated targeting of islet-expressed antigens is prevented and islet graft rejection alleviated. The immunological mechanisms of protection are mediated through deletion and induction of unresponsiveness in targeted memory T-cell populations. The data demonstrate that hematopoietic stem cell-mediated gene therapy effectively terminates antigen-specific memory T-cell responses and this can alleviate destruction of antigen-expressing islets. This addresses a key challenge facing islet transplantation and importantly, the clinical application of personalized ß-cell replacement therapies using patient-derived stem cells.

Optimizing inter-professional communications in surgery: protocol for a mixed-methods exploratory study.

BACKGROUND: Effective nurse-physician communication is critical to delivering high quality patient care. Interprofessional communication between surgical nurses and surgeons, often through the use of pagers, is currently characterized by information gaps and interprofessional tensions, both sources of workflow interruption, potential medical error, impaired educational experience, and job satisfaction. OBJECTIVE: This study aims to define current patterns of, and understand enablers and barriers to interprofessional communication in general surgery, in order to optimize the use of communication technologies, teamwork, provider satisfaction, and quality and safety of patient care. METHODS: We will use a mixed-methods multiphasic approach. In phase 1, a quantitative and content analysis of alpha-numeric pages (ANP) received by general surgery residents will be conducted to develop a paging taxonomy. Frequency, timing (on-call vs regular duty hours), and interval between pages will be described using a 4-week sample of pages. Results will be compared between pages sent to junior and senior residents. Finally, using an inductive analysis, two independent assessors will classify ANP thematically. In Phase 2, a qualitative constructivist approach will explore stakeholders' experiences with interprofessional communication, including paging, through interviews and shadowing of 40 residents and 40 nurses at two institutions. Finally, a survey will be developed, tested, and administered to all general surgery nurses and residents at the same two institutions, to evaluate their attitudes about the effectiveness and quality of interprofessional communication, and assess their satisfaction. RESULTS: Describing the profile of current pages is the first step towards identifying areas and root causes of IPC inefficiency. This study will identify key contextual barriers to surgical nurse-house staff communication, and existing interprofessional knowledge and practice gaps. CONCLUSIONS: Our findings will inform the design of a guideline and tailored intervention to improve IPC in order to ensure high quality patient care, optimal educational experience, and provider satisfaction.

Barriers to implementing the World Health Organization's Trauma Care Checklist: A Canadian single-center experience.

BACKGROUND: Management of trauma patients is difficult because of their complexity and acuity. In an effort to improve patient care and reduce morbidity and mortality, the World Health Organization developed a trauma care checklist. Local stakeholder input led to a modified 16-item version that was subsequently piloted. Our study highlights the barriers and challenges associated with implementing this checklist at our hospital. METHODS: The checklist was piloted over a 6-month period at St. Michael's Hospital, a Level 1 trauma center in Toronto, Canada. At the end of the pilot phase, individual, semistructured interviews were held with trauma team leaders and nursing staff regarding their experiences with the checklist. Axial coding was used to create a typology of attitudes and barriers toward the checklist, and then, vertical coding was used to further explore each identified barrier. Checklist compliance was assessed for the first 7 months. RESULTS: Checklist compliance throughout the pilot phase was 78%. Eight key barriers to implementing the checklist were identified as follows: perceived lack of time for the use of the checklist in critically ill patients, unclear roles, no memory trigger, no one to enforce completion, not understanding its importance or purpose, difficulty finding physicians at the end of resuscitation, staff/trainee changes, and professional hierarchy. CONCLUSION: The World Health Organization Trauma Care Checklist was a well-received tool; however, consideration of barriers to the implementation and staff adoption must be done for successful integration, with special attention to its use in critically ill patients. LEVEL OF EVIDENCE: Therapeutic/care management, level V.

Comparative immune phenotypic analysis of cutaneous Squamous Cell Carcinoma and Intraepidermal Carcinoma in immune-competent individuals: proportional representation of CD8+ T-cells but not FoxP3+ Regulatory T-cells is associated with disease stage.

Squamous Cell Carcinoma (SCC) is a type of non-melanoma skin cancer prevalent in immune-suppressed transplant recipients and older individuals with a history of chronic sun-exposure. SCC itself is believed to be a late-stage manifestation that can develop from premalignant lesions including Intraepidermal Carcinoma (IEC). Notably, while SCC regression is rare, IEC typically regresses in response to immune modifying topical treatments, however the underlying immunological reasons for these differential responses remain unclear. This study aimed to define whether IEC and SCC are associated with distinct immune profiles. We investigated the immune cell infiltrate of photo-damaged skin, IEC, and SCC tissue using 10-colour flow cytometry following fresh lesion digest. We found that IEC lesions contain higher percentages of CD3+ T-cells than photo-damaged skin, however, the abundance of CD3-CD56+ Natural Killer (NK) cells, CD11c+HLA-DR+ conventional Dendritic Cells (cDC), BDCA-2+HLA-DR+ plasmacytoid DC (pDC), FoxP3+ Regulatory T-cells (T-reg), Vα24+Vß11+ invariant NKT-cells, and γδ Tcells did not alter with disease stage. Within the total T-cell population, high percentages of CD4+ T-cells were associated with SCC, yet CD8+ T-cells were less abundant in SCC compared with IEC. Our study demonstrates that while IEC lesions contain a higher proportion of T-cells than SCC lesions in general, SCC lesions specifically display a lower abundance of CD8+ T-cells than IEC. We propose that differences in CD8+ T-cell abundance contribute critically to the different capacity of SCC and IEC to regress in response to immune modifying topical treatments. Our study also suggests that a high ratio of CD4+ T-cells to CD8+ T-cells may be a immunological diagnostic indicator of late-stage SCC development in immune-competent patients.

IL-17 suppresses immune effector functions in human papillomavirus-associated epithelial hyperplasia.

Persistent infection with high-risk human papillomaviruses (HPV) causes epithelial hyperplasia that can progress to cancer and is thought to depend on immunosuppressive mechanisms that prevent viral clearance by the host. IL-17 is a cytokine with diverse functions in host defense and in the pathology of autoimmune disorders, chronic inflammatory diseases, and cancer. We analyzed biopsies from patients with HPV-associated cervical intraepithelial neoplasia grade 2/3 and murine skin displaying HPV16 E7 protein-induced epithelial hyperplasia, which closely models hyperplasia in chronic HPV lesions. Expression of IL-17 and IL-23, a major inducer of IL-17, was elevated in both human HPV-infected and murine E7-expressing lesions. Using a skin-grafting model, we demonstrated that IL-17 in HPV16 E7 transgenic skin grafts inhibited effective host immune responses against the graft. IL-17 was produced by CD3(+) T cells, predominantly CD4(+) T cells in human, and CD4(+) and γδ T cells in mouse hyperplastic lesions. IL-23 and IL-1ß, but not IL-18, induced IL-17 production in E7 transgenic skin. Together, these findings demonstrate an immunosuppressive role for IL-17 in HPV-associated epithelial hyperplasia and suggest that blocking IL-17 in persistent viral infection may promote antiviral immunity and prevent progression to cancer.

An inventory of Canadian trauma systems: opportunities for improving access to trauma care.

OBJECTIVE: Despite evidence that patients suffering major traumatic injuries have improved outcomes when cared for within an organized system, the extent of trauma system development in Canada is limited. We sought to compile a detailed inventory of trauma systems in Canada as a first step toward identifying opportunities for improving access to trauma care. METHODS: We distributed a nationwide online and mail survey to stakeholders intended to evaluate the extent of implementation of specific trauma system components. Targeted stakeholders included emergency physicians, trauma surgeons, trauma program medical directors and program managers, prehospital providers, and decision makers at the regional and provincial levels. A "snowball" approach was used to expand the sample base of the survey. Descriptive statistics were generated to quantify the nature and extent of trauma system development by region. RESULTS: The overall response rate was 38.7%, and all levels of stakeholders and all provinces/territories were represented. All provinces were found to have designated trauma centres; however, only 60% were found to have been accredited within the past 10 years. Components present in 50% or fewer provinces included an inclusive trauma system model, interfacility transfer agreements, and a mechanism to track bed availability within the system. CONCLUSION: There is significant variability in the extent of trauma system development in Canada. Although all provinces have designated trauma centres, opportunities exist in many systems to implement additional components to improve the inclusiveness of care. In future work, we intend to quantify the strength of the relationship between different trauma system components and access to definitive trauma care.

Tolerance induction with gene-modified stem cells and immune-preserving conditioning in primed mice: restricting antigen to differentiated antigen-presenting cells permits efficacy.

Bone marrow (BM) or hematopoietic stem cell (HSC) transplantation is used as curative therapy for hematologic malignancies. Incorporation of gene therapy to drive tolerogenic expression of antigens is a promising strategy to overcome the limited long-term efficacy of autologous HSC transplantation for autoimmune diseases. HSC engraftment and tolerance induction is readily achieved after myeloablative or immune-depleting conditioning regardless of the cellular compartment in which antigen is expressed. It is unclear whether the efficiency of engraftment and tolerance induction is influenced by targeting antigen to specific cellular compartments. This is particularly important when using clinically feasible low-intensity conditioning aimed at preserving infectious immunity in individuals where immunologic memory exists to the autoantigen to be expressed. Here we demonstrate that, under immune-preserving conditions, confining expression of a transgenically expressed antigen to dendritic cells permits stable, long-term engraftment of genetically modified BM even when recipients are immune to the expressed antigen. In contrast, broader expression within the hematopoietic compartment leads to graft rejection and therapeutic failure because of antigen expression in HSCs. These findings are relevant to the clinical application of genetically engineered HSCs and provide evidence that careful selection of promoters for HSC-mediated gene therapy is important, particularly where tolerance is sought under immune-preserving conditions.