Topical application of gemcitabine generates microvesicle particles in human and murine skin.

Chemotherapy has remained the mainstay for the treatment of multiple types of cancers. In particular, topical use of chemotherapy has been used for skin cancers. Though effective, topical chemotherapy has been limited due to adverse effects such as local and even systemic toxicities. Our recent studies demonstrated that exposure to pro-oxidative stressors, including therapeutic agents induces the generation of extracellular vesicles known as microvesicle particles (MVP) which are dependent on activation of the Platelet-activating factor-receptor (PAFR), a G-protein coupled receptor present on various cell types, and acid sphingomyelinase (aSMase), an enzyme required for MVP biogenesis. Based upon this premise, we tested the hypothesis that topical application of gemcitabine will induce MVP generation in human and murine skin. Our ex vivo studies using human skin explants demonstrate that gemcitabine treatment results in MVP generation in a dose-dependent manner in a process blocked by PAFR antagonist and aSMase inhibitor. Importantly, gemcitabine-induced MVPs carry PAFR agonists. To confirm the mechanisms, we employed PAFR-expressing and deficient (Ptafr-/- ) mouse models as well as mice deficient in aSMase enzyme (Spmd1-/- ). Similar to the findings using pharmacologic tools, genetic-based approaches demonstrate that gemcitabine-induced MVP release in WT mice was blunted in Ptafr-/- and Spmd1-/- mice. These findings demonstrate a novel mechanism by which local chemotherapy can generate bioactive components as a bystander effect in a process that is dependent upon the PAFR-aSMase pathway.

Implementation and Modification of Developmental Care Rounds in the Cardiac Intensive Care Unit.

In 2019, an interprofessional team at Texas Children's Hospital designed and instituted developmental care rounds to better coordinate developmentally appropriate care within the cardiac intensive care unit. During the first 2 years, we conducted 230 developmental care rounds on 169 patients; for these rounds, family participation was greater than 85%. Since their inception, these rounds have undergone several modifications, including changes to the patient selection criteria and team role delegation. Importantly, the structure of these rounds has evolved to prominently integrate family members' perspectives and experiences. Lessons learned through developmental care rounds have formed a foundation for implementing other developmentally appropriate practices and initiatives throughout the hospital's Heart Center.

Comparing the efficacy of initial percutaneous transhepatic biliary drainage and endoscopic retrograde cholangiopancreatography with stenting for relief of biliary obstruction in unresectable cholangiocarcinoma.

BACKGROUND: In patients with cholangiocarcinoma (CC), management of biliary obstruction commonly involves either up-front percutaneous transhepatic biliary drainage (PTBD) or initial endoscopic retrograde cholangiopancreatography (ERCP) with stent placement. The objective of the study was to compare the efficacy and of initial ERCP with stent placement with efficacy of initial PTBD in management of biliary obstruction in CC. METHODS: A single-center database of patients with unresectable CC treated between 2006 and 2017 was queried for patients with biliary obstruction who underwent either PTBD or ERCP. Groups were compared with respect to patient, tumor, procedure, and outcome variables. RESULTS: Of 87 patients with unresectable CC and biliary obstruction, 69 (79%) underwent initial ERCP while 18 (21%) underwent initial PTBD. Groups did not differ significantly with respect to age, gender, or tumor location. Initial procedure success did not differ between the groups (94% ERCP vs 89% PTBD, p = 0.339). Total number of procedures did not differ significantly between the two groups (ERCP median = 2 vs. PTC median = 2.5, p = 0.83). 21% of patients required ERCP after PTBD compared to 25% of patients requiring PTBD after ERCP (p = 1.00). Procedure success rate (97% ERCP vs. 93% PTBD, p = 0.27) and rates of cholangitis (22% ERCP vs. 17% PTBD, p = 0.58) were similar between the groups. Number of hospitalizations since initial intervention did not differ significantly between the two groups (ERCP median = 1 vs. PTC median = 3.5, p = 0.052). CONCLUSIONS: In patients with CC and biliary obstruction, initial ERCP with stent placement and initial PTBD both represent safe and effective methods of biliary decompression. Initial ERCP and stenting should be considered for relief of biliary obstruction in such patients in centers with advanced endoscopic capabilities.

Myeloid-Derived Suppressor Cells and Pancreatic Cancer: Implications in Novel Therapeutic Approaches.

Pancreatic ductal adenocarcinoma (PDAC) remains a devastating human malignancy with poor prognosis and low survival rates. Several cellular mechanisms have been linked with pancreatic carcinogenesis and also implicated in inducing tumor resistance to known therapeutic regimens. Of various factors, immune evasion mechanisms play critical roles in tumor progression and impeding the efficacy of cancer therapies including PDAC. Among immunosuppressive cell types, myeloid-derived suppressor cells (MDSCs) have been extensively studied and demonstrated to not only support PDAC development but also hamper the anti-tumor immune responses elicited by therapeutic agents. Notably, recent efforts have been directed in devising novel approaches to target MDSCs to limit their effects. Multiple strategies including immune-based approaches have been explored either alone or in combination with therapeutic agents to target MDSCs in preclinical and clinical settings of PDAC. The current review highlights the roles and mechanisms of MDSCs as well as the implications of this immunomodulatory cell type as a potential target to improve the efficacy of therapeutic regimens for PDAC.