"Tumor-selective treatment of metastatic pancreatic cancer with an engineered, probiotic living drug".

Pancreatic ductal adenocarcinoma (PDAC) poses significant challenges for effective treatment, with systemic chemotherapy often proving inadequate due to poor drug delivery and the tumor's immunosuppressive microenvironment. Engineered bacteria present a novel approach to target PDAC, leveraging their ability to colonize tumors and deliver therapeutic payloads. Here, we engineered probiotic Escherichia coli Nissle 1917 (EcN) to produce the pore-forming Theta toxin (Nis-Theta) and evaluated its efficacy in a preclinical model of PDAC. Probiotic administration resulted in selective colonization of tumor tissue, leading to improved overall survival compared to standard chemotherapy. Moreover, this strain exhibited cytotoxic effects on both primary and distant tumor lesions while sparing normal tissues. Importantly, treatment also modulated the tumor microenvironment by increasing anti-tumor immune cell populations and reducing immunosuppressive markers. These findings demonstrate the potential of engineered probiotic bacteria as a safe and effective therapeutic approach for PDAC, offering promise for improved patient outcomes.

Tumour-selective activity of RAS-GTP inhibition in pancreatic cancer.

Broad-spectrum RAS inhibition has the potential to benefit roughly a quarter of human patients with cancer whose tumours are driven by RAS mutations1,2. RMC-7977 is a highly selective inhibitor of the active GTP-bound forms of KRAS, HRAS and NRAS, with affinity for both mutant and wild-type variants3. More than 90% of cases of human pancreatic ductal adenocarcinoma (PDAC) are driven by activating mutations in KRAS4. Here we assessed the therapeutic potential of RMC-7977 in a comprehensive range of PDAC models. We observed broad and pronounced anti-tumour activity across models following direct RAS inhibition at exposures that were well-tolerated in vivo. Pharmacological analyses revealed divergent responses to RMC-7977 in tumour versus normal tissues. Treated tumours exhibited waves of apoptosis along with sustained proliferative arrest, whereas normal tissues underwent only transient decreases in proliferation, with no evidence of apoptosis. In the autochthonous KPC mouse model, RMC-7977 treatment resulted in a profound extension of survival followed by on-treatment relapse. Analysis of relapsed tumours identified Myc copy number gain as a prevalent candidate resistance mechanism, which could be overcome by combinatorial TEAD inhibition in vitro. Together, these data establish a strong preclinical rationale for the use of broad-spectrum RAS-GTP inhibition in the setting of PDAC and identify a promising candidate combination therapeutic regimen to overcome monotherapy resistance.

Wearable Technology: A Wellbeing Option for Serving Police Officers and Staff? A Comparison of Results of a Pilot Study with Firearms Officers and a Group of Mixed Officers and Staff.

The high-stress nature of policing contributes to deterioration of officer health and wellbeing as well as high levels of absenteeism and attrition. Wearable technology (WT) has been identified as a potential tool that can help in improving officer health and wellbeing. This pilot study aimed to give initial insight into acceptability and engagement with WT amongst officers. The study also aimed to uncover any notable areas for exploration in future research within the domain of officer health and wellbeing. Two groups were observed, firearms officers and a mixed group of officers. Participants wore the WT for an extended period, completed a variety of health and wellbeing questionnaires and discussed their experience in focus groups. Firearms officers and mixed group officers displayed similar sleep efficiency, but firearms officers have worse sleep consistency and sleep performance. Firearms officers appear to have higher HRV and a slightly lower resting heart rate. Both groups display reasonable acceptance of the use of WT, speaking favorably during the focus groups of how monitoring the data had improved their quality of life in terms of their understanding of sleep, wellbeing and how they had consequently completed lifestyle modification. WT offers some promise in managing officer health and wellbeing; studies with larger sample sizes are needed to confirm this.

Tumor Explants Elucidate a Cascade of Paracrine SHH, WNT, and VEGF Signals Driving Pancreatic Cancer Angiosuppression.

The sparse vascularity of pancreatic ductal adenocarcinoma (PDAC) presents a mystery: What prevents this aggressive malignancy from undergoing neoangiogenesis to counteract hypoxia and better support growth? An incidental finding from prior work on paracrine communication between malignant PDAC cells and fibroblasts revealed that inhibition of the Hedgehog (HH) pathway partially relieved angiosuppression, increasing tumor vascularity through unknown mechanisms. Initial efforts to study this phenotype were hindered by difficulties replicating the complex interactions of multiple cell types in vitro. Here we identify a cascade of paracrine signals between multiple cell types that act sequentially to suppress angiogenesis in PDAC. Malignant epithelial cells promote HH signaling in fibroblasts, leading to inhibition of noncanonical WNT signaling in fibroblasts and epithelial cells, thereby limiting VEGFR2-dependent activation of endothelial hypersprouting. This cascade was elucidated using human and murine PDAC explant models, which effectively retain the complex cellular interactions of native tumor tissues. SIGNIFICANCE: We present a key mechanism of tumor angiosuppression, a process that sculpts the physiologic, cellular, and metabolic environment of PDAC. We further present a computational and experimental framework for the dissection of complex signaling cascades that propagate among multiple cell types in the tissue environment. This article is featured in Selected Articles from This Issue, p. 201.

Tumor-selective effects of active RAS inhibition in pancreatic ductal adenocarcinoma.

Broad-spectrum RAS inhibition holds the potential to benefit roughly a quarter of human cancer patients whose tumors are driven by RAS mutations. However, the impact of inhibiting RAS functions in normal tissues is not known. RMC-7977 is a highly selective inhibitor of the active (GTP-bound) forms of KRAS, HRAS, and NRAS, with affinity for both mutant and wild type (WT) variants. As >90% of human pancreatic ductal adenocarcinoma (PDAC) cases are driven by activating mutations in KRAS, we assessed the therapeutic potential of RMC-7977 in a comprehensive range of PDAC models, including human and murine cell lines, human patient-derived organoids, human PDAC explants, subcutaneous and orthotopic cell-line or patient derived xenografts, syngeneic allografts, and genetically engineered mouse models. We observed broad and pronounced anti-tumor activity across these models following direct RAS inhibition at doses and concentrations that were well-tolerated in vivo. Pharmacological analyses revealed divergent responses to RMC-7977 in tumor versus normal tissues. Treated tumors exhibited waves of apoptosis along with sustained proliferative arrest whereas normal tissues underwent only transient decreases in proliferation, with no evidence of apoptosis. Together, these data establish a strong preclinical rationale for the use of broad-spectrum RAS inhibition in the setting of PDAC.

Generation and ex vivo culture of murine and human pancreatic ductal adenocarcinoma tissue slice explants.

Traditional 2D/3D co-culture models typically do not reflect the cellular heterogeneity of pancreatic ductal adenocarcinoma (PDAC) tumors, while in vivo models can be slow and ill-suited to mechanistic investigations. Here, we present a protocol for culturing murine PDAC explants and a corresponding human PDAC model using tissue slice explants. We describe steps for sponge production, preparation of media and materials, tissue collection, and sectioning. We then detail procedures for explant plating, daily culture, and collection of samples.

Pain Perception in Contact Sport Athletes: A Scoping Review.

Contact sports athletes are regularly facing acute physical pain in part of their sport; however, the literature investigating pain perception in these athletes remains scarce. This scoping review aimed to explore the literature surrounding pain perception in contact sport athletes and to compile and understand how it is studied. The search strategy consisted of using index terms and keywords in the MEDLINE, EMBASE, SPORTDiscus, Web of Science, PsycINFO, CINAHL and ProQuest Dissertations & Theses Global search engines. Results from 11 studies revealed that a mix of team contact sports and combat sports are studied and are included under the umbrella of contact sports. These athletes are being compared with non-athletes as well as athletes from non-contact sports. The cold pressor test and the pain pressure test are the two predominant methods used to investigate physical pain. This review highlights the need to clearly define sports based on contact levels expected in play to better define the types of pain athletes are facing in their practice. Athletes' level of play as well as years of experience should also be more rigorously reported. While contact sport athletes seem to have a higher level of pain tolerance than both active controls and non-contact athletes, the methods of pain testing are not always justified and appropriate in relation to the pain induced during contact sports. Future experimental studies should use pain testing methods relevant to the pain experienced during contact sports and to better justify the rationale for the choice of these methods.

Racial and ethnic disparities among donor oocyte banks in the United States.

OBJECTIVE: To determine whether racial and ethnic distributions of oocyte donors contributing to US oocyte banks differ from the demographics of US women and donor oocyte recipients. DESIGN: Cross-sectional study. SETTING: United States donor oocyte banks, US census, and fertility clinics reporting to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System. PATIENTS: Oocyte donors from 12 banks, women aged 18-44 years based on the 2019 census, and US recipients of cryopreserved donor oocytes from 2012 to 2015. INTERVENTION: None. MAIN OUTCOME MEASURE: Proportions of donors identifying as each racial and ethnic group. RESULTS: Of the 1,574 oocyte donors, 678 (43.1%) identified as white compared with 54.8% of US women and 69.1% of donor oocyte recipients. Proportions of donors identifying as Hispanic or two or more races were larger than those of US women and donor oocyte recipients (Hispanic: 24.1% vs. 20.8%, and 24.1% vs. 8.8%, respectively; two or more races: 16.1% vs. 2.3%, and 16.1% vs. 0.5%, respectively). African American donors were underrepresented compared with US women (8.9% vs. 14.0%) and oocyte recipients (8.9% vs. 10.8%). Although the proportion of Asian donors was similar to that of US women (7.7% vs. 7.1%), Asian donors were underrepresented compared with donor oocyte recipients (7.7% vs. 10.6%). CONCLUSION: Racial and ethnic distribution of oocyte donors differs significantly from the demographics of US women and cryopreserved donor oocyte recipients. These data suggest a need for targeted recruitment of African American and Asian oocyte donors.

Generation of orthotopic patient-derived xenograft models for pancreatic cancer using tumor slices.

Orthotopic patient-derived xenograft models recapitulate the genomic complexity of the original tumor and some aspects of local microenvironment, useful for rapid development and validation of personalized treatment strategies. Here, we precisely describe a protocol for generating tumor slices from human or murine-derived pancreatic cancer. They are then implanted directly into the murine pancreas, monitored using ultrasound, with a 90% success rate. This assay creates a clinically relevant in vivo model facilitating personalized treatment development.

Peripartum Cardiomyopathy.

IMPORTANCE: Peripartum cardiomyopathy is a rare form of heart failure due to left ventricular systolic dysfunction that affects women late in pregnancy and the postpartum period. A diagnosis of exclusion, peripartum cardiomyopathy can be difficult to diagnose in the context of the normal physiologic changes of pregnancy and requires a high index of suspicion. EVIDENCE ACQUISITION: Original research articles, review articles, and guidelines on peripartum cardiomyopathy were reviewed. RESULTS: The etiology of peripartum cardiomyopathy remains poorly defined, but theories include genetic predisposition, as well as myocardial inflammation and angiogenic dysregulation. Risk factors for this condition include hypertensive disorders of pregnancy, Black race, and maternal age older than 30 years. Patients with peripartum cardiomyopathy are at increased risk of acute clinical decompensation, cardiac arrhythmias, thromboembolic complications, and death. Primary treatment modalities include initiation of a medication regimen aimed at the optimization of preload and reduction of afterload. Maternal clinical status is the primary determinant for timing of delivery. CONCLUSIONS: Prompt diagnosis and medical management by an interdisciplinary care team are vital for improving outcomes in patients with peripartum cardiomyopathy.

Environmental and Aerosolized Severe Acute Respiratory Syndrome Coronavirus 2 Among Hospitalized Coronavirus Disease 2019 Patients.

During April and May 2020, we studied 20 patients hospitalized with coronavirus disease 2019 (COVID-19), their hospital rooms (fomites and aerosols), and their close contacts for molecular and culture evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Among >400 samples, we found molecular evidence of virus in most sample types, especially the nasopharyngeal (NP), saliva, and fecal samples, but the prevalence of molecular positivity among fomites and aerosols was low. The agreement between NP swab and saliva positivity was high (89.5%; κ = 0.79). Two NP swabs collected from patients on days 1 and 7 post-symptom onset had evidence of infectious virus (2 passages over 14 days in Vero E6 cells). In summary, the low molecular prevalence and lack of viable SARS-CoV-2 virus in fomites and air samples implied low nosocomial risk of SARS-CoV-2 transmission through inanimate objects or aerosols.