Macrophage mediated mesoscale brain mechanical homeostasis mechanically imaged via optical tweezers and Brillouin microscopy in vivo.

Tissues are active materials where epithelial turnover, immune surveillance, and remodeling of stromal cells such as macrophages all regulate form and function. Scattering modalities such as Brillouin microscopy (BM) can non-invasively access mechanical signatures at GHz. However, our traditional understanding of tissue material properties is derived mainly from modalities which probe mechanical properties at different frequencies. Thus, reconciling measurements amongst these modalities remains an active area. Here, we compare optical tweezer active microrheology (OT-AMR) and Brillouin microscopy (BM) to longitudinally map brain development in the larval zebrafish. We determine that each measurement is able to detect a mechanical signature linked to functional units of the brain. We demonstrate that the corrected BM-Longitudinal modulus using a density factor correlates well with OT-AMR storage modulus at lower frequencies. We also show that the brain tissue mechanical properties are dependent on both the neuronal architecture and the presence of macrophages. Moreover, the BM technique is able to delineate the contributions to mechanical properties of the macrophage from that due to colony stimulating factor 1 receptor (CSF1R) mediated stromal remodeling. Here, our data suggest that macrophage remodeling is instrumental in the maintenance of tissue mechanical homeostasis during development. Moreover, the strong agreement between the OT-AM and BM further demonstrates that scattering-based technique is sensitive to both large and minute structural modification in vivo.

Cell-specific cargo delivery using synthetic bacterial spores.

Delivery of cancer therapeutics to non-specific sites decreases treatment efficacy while increasing toxicity. In ovarian cancer, overexpression of the cell surface marker HER2, which several therapeutics target, relates to poor prognosis. We recently reported the assembly of biocompatible bacterial spore-like particles, termed "SSHELs." Here, we modify SSHELs with an affibody directed against HER2 and load them with the chemotherapeutic agent doxorubicin. Drug-loaded SSHELs reduce tumor growth and increase survival with lower toxicity in a mouse tumor xenograft model compared with free drug and with liposomal doxorubicin by preferentially accumulating in the tumor mass. Target cells actively internalize and then traffic bound SSHELs to acidic compartments, whereupon the cargo is released to the cytosol in a pH-dependent manner. We propose that SSHELs represent a versatile strategy for targeted drug delivery, especially in cancer settings.

Organ specific microenvironmental MR1 expression in cutaneous melanoma.

The microenvironment is an important regulator of intertumoral trafficking and activity of immune cells. Understanding how the immune system can be tailored to maintain anti-tumor killing responses in metastatic disease remains an important goal. Thus, immune mediated eradication of metastasis requires the consideration of organ specific microenvironmental cues. Using a xenograft model of melanoma metastasis in adult zebrafish, we perturbed the dynamic balance between the infiltrating immune cells in the metastatic setting using a suite of different transgenic zebrafish. We employed intravital imaging coupled with metabolism imaging (FLIM) to visualize and map the organ specific metabolism with near simultaneity in multiple metastatic lesions. Of all the MHC complexes examined for brain and skeletal metastases, we determined that there is an organ specific expression of mhc1uba (human ortholog, MR1) for both the melanoma cells and the resident and infiltrating immune cells. Specifically, immune clusters did not express mhc1uba in brain metastatic lesions in immune competent fish. Finally, the differential immune response drove organ specific metabolism where tumor glycolysis was increased in brain metastases compared to skeletal and parental lines as measured using fluorescence lifetime imaging microscopy (FLIM). As MR1 belongs to the MHC class I molecules and is a target of immunotherapeutic drugs, we believe that our data presents an opportunity to understand the relationship between organ specific tumor metabolism and drug efficacy in the metastatic setting.

Identifying drivers of breast cancer metastasis in progressively invasive subpopulations of zebrafish-xenografted MDA-MB-231.

Cancer metastasis is the primary cause of the high mortality rate among human cancers. Efforts to identify therapeutic agents targeting cancer metastasis frequently fail to demonstrate efficacy in clinical trials despite strong preclinical evidence. Until recently, most preclinical studies used mouse models to evaluate anti-metastatic agents. Mouse models are time-consuming and expensive. In addition, an important drawback is that mouse models inadequately model the early stages of metastasis which plausibly leads to the poor correlation with clinical outcomes.Here, we report an in vivo model based on xenografted zebrafish embryos where we select for progressively invasive subpopulations of MDA-MB-231 breast cancer cells. A subpopulation analogous to circulating tumor cells found in human cancers was selected by injection of MDA-MB-231 cells into the yolk sacs of 2 days post-fertilized zebrafish embryos and selecting cells that migrated to the tail. The selected subpopulation derived from MDA-MB-231 cells were increasingly invasive in zebrafish. Isolation of these subpopulations and propagation in vitro revealed morphological changes consistent with activation of an epithelial-mesenchymal transition program. Differential gene analysis and knockdown of genes identified gene-candidates (DDIT4, MT1X, CTSD, and SERPINE1) as potential targets for anti-metastasis therapeutics. Furthermore, RNA-splicing analysis reinforced the importance of BIRC5 splice variants in breast cancer metastasis. This is the first report using zebrafish to isolate and expand progressively invasive populations of human cancer cells. The model has potential applications in understanding the metastatic process, identification and/or development of therapeutics that specifically target metastatic cells and formulating personalized treatment strategies for individual cancer patients.

Size-Specific Filtration Performance of N95 Respirators After Decontamination by Moist Heat Incubation.

Background: Decontamination and reuse of respirators have been proposed to mitigate the shortage of respirators during pandemics. The U.S. National Institute for Occupational Safety and Health (NIOSH)'s respirator filtration efficiency (FE) test has been used to confirm that decontamination procedures maintain minimum FE above 95% for N95s and similar respirators. However, it was hypothesized that the limited range of test particle sizes may not include the most penetrating particle size (MPPS) for all respirators, especially after decontamination by moist heat incubation (MHI). Materials and Methods: A custom-designed apparatus was used to measure size-specific FE for respirators across particle size bins between aerodynamic diameter of 0.07 and 1.97 µm using an electrical low-pressure impactor. FEs were measured for two N95 respirator models before and after 10 cycles of MHI. In addition, pressure drop through the respirator materials and scanning electron microscope (SEM) images of respirator layers were obtained before and after MHI. Results: For Kimtech™ brand N95 respirators, FE was not reduced at any size after MHI. For Safe Life brand N95s, FE was below 95% before MHI and decreased significantly after MHI. The MPPS for this respirator was outside the range defined in NIOSH test protocol, and increased after MHI. There was no appreciable change to the pressure drop through the two respirator models after MHI, nor was any deterioration in fiber integrity visible in SEM images. Conclusions: Based on the results of the present study and other studies in the literature, MHI can be used to decontaminate respirators without significant decrease in FE. However, potential effects of MHI on FE need to be assessed for each respirator model. The ability to evaluate size-specific FE across a wide range of particle sizes is important in identifying the MPPS and associated FE of respirators before and after MHI.

Fifteen-year experience with pericardiectomy at a tertiary referral center.

PURPOSE: Pericardiectomy has traditionally carried relatively high perioperative mortality and morbidity, with few published reports of intermediate- and long- term outcomes. We investigated our 15-year experience performing pericardiectomy at our institution. METHODS: Retrospective study of all patients who underwent pericardiectomy at our institution between 2005 and 2019. Baseline demographics, intraoperative details, and postoperative outcomes including long-term survival were analyzed. RESULTS: Sixty-three patients were included in the study. 66.7% of subjects underwent isolated pericardiectomy while 33.3% underwent pericardiectomy concomitantly with another cardiac surgical procedure. The most common indications for pericardiectomy were constrictive (79.4%) and hemorrhagic (9.5%) pericarditis. Preoperatively, 76.2% of patients were New York Heart Association class II and III, while postoperatively, 71.4% were class I and II. One-, three-, five-, and ten- year overall mortality was 9.5, 14.3, 20.6, and 25.4%, respectively. Overall pericarditis recurrence rate was 4.8%. CONCLUSION: Pericardiectomy carries relatively high overall mortality rates, which likely reflects underlying disease etiology and comorbidities. Patients with prior cardiac intervention, history of dialysis, and immunocompromised state are associated with worse outcomes.

Subxiphoid Endoscopic Epicardial Ventricular Tachycardia Ablation.

Ventricular tachycardia refractory to traditional therapies such as medical management and endocardial catheter ablation poses a risk for sudden cardiac death and poor quality of life. We describe a patient who was successfully treated for refractory symptomatic ventricular tachycardia using hybrid endocardial and minimally invasive epicardial ablation with a subxiphoid approach.

Inter-Rater Reliability of Web-Based Calibrated Peer Review within a Pharmacy Curriculum.

Objective. To assess the inter-rater reliability of student evaluations submitted through a web-based calibrated peer review system versus faculty evaluations in a Doctor of Pharmacy (PharmD) curriculum. Methods. Two calibrated peer review assignments were integrated into two sequential pharmacotherapy-based courses in the first professional year of the PharmD curriculum. To assess the inter-rater reliability of student peer and self-evaluations compared to faculty evaluations, 50 student submissions from each assignment were randomly selected for faculty evaluation, using the same evaluation criteria used by students. Statistical analysis was performed to assess the difference between the scores given by students versus faculty members and the correlation between the combined and individual assignment scores given by students versus faculty members. Results. Mean faculty scores did not significantly differ from student peer or self-evaluation scores. When the assignments were combined, there was a significant fair correlation between scores assigned by peers and those assigned by faculty members, and between scores assigned by students (self-evaluation) and faculty members. For individual assignments, one showed significant positive correlations for both peer and self-assessment compared to faculty, while the other assignment did not. Conclusion. Incorporating longitudinal calibrated peer review activities into the PharmD curriculum demonstrated fair inter-rater reliability between scores assigned by pharmacy student and faculty members. Further research on calibrated peer review is needed in pharmacy education to evaluate its reliability and utility. However, the current study suggests that the use of a web-based calibrated peer review system within a pharmacy curriculum could provide additional opportunities for critical evaluation and student self-assessment, as well as encourage more open-ended communication activities without increasing the grading burden on faculty members.

Multi-focal Lytic Lesions in a Patient with Myelofibrosis: A Case Report.

Myelofibrosis is a rare disorder that is classified as one of the myeloproliferative disorders. This particular disorder results in the abnormal proliferation of hematopoietic stem cells in the bone marrow. In some cases, such as ours, pathologic fractures can occur due to skeletal manifestations. We report on a rare finding of rapidly progressive lytic lesions in multiple regions throughout the body. This presentation of myelofibrosis behaving in a metastatic-like fashion has not been previously described.

Protecting Student Anonymity in Research Using a Subject-Generated Identification Code.

BACKGROUND: Within nursing education research, protection of students as human subjects must be the highest priority. This protection can be provided via student anonymity. A subject-generated identification code, comprised of responses to a series of questions, can link data across time points while protecting student anonymity. METHOD: Two studies, focused on palliative care education, used a subject-generated identification code to link student data across multiple time points. Refinements to the code were made between studies to further enhance anonymity and response consistency. RESULTS: The subject-generated identification code fostered linking of student responses across three time points in study one and two time points in study two. CONCLUSION: There are many benefits to utilizing a subject-generated identification code in nursing education studies. Researchers must consider the need for a data management expert and balancing transposition errors and the power to differentiate between responses.

Palliative Care Educational Interventions for Prelicensure Health-Care Students: An Integrative Review.

To provide adequate care, students from all health-care professions require education regarding palliative and end-of-life (EOL) care prior to entering professional practice. In particular, students need proper training to be equal members of interprofessional teams providing palliative and EOL care. However, limited information is currently available about the effectiveness of educational interventions relating to palliative and EOL care. Thus, an assessment of educational interventions to utilize in providing this education is warranted. The purpose of this integrative review was to critically evaluate the impact of palliative or EOL care interventional studies on learning outcomes for prelicensure health-care students. Articles published from 2001 to present that utilizied palliative or EOL care educational interventions for prelicensure students from any health-care profession and also evaluated preidentified learning outcomes were included in the review. The final sample comprised 34 articles. Four studies utilized interprofessional interventions, whereas the remaining taught students from a single profession. Trends in sample sizes, teaching interventions, learning outcomes, and outcome measures are discussed. Teaching interventions reviewed were primarily focused on student learning outcomes specific to knowledge and attitudes. Future studies should implement interprofessional educational interventions, utilize reliable and valid outcome measures, and evaluate their impact on different learning outcomes, such as self-efficacy, comfort, and communication.