Influence of ondansetron on thiopental hypnotic requirements

Ondansetron, a selective 5-HT3 antagonist has been proved to be an effective antiemetic agent for prophylaxis of nausea and vomiting after surgery. This study was conducted to determine whether ondansetron changes thiopental requirements for induction of anesthesia in patients unpremedicated and premedicated with diazepam. One hundred sixty eight adult female patients classified as American Society of Anesthesiologists (ASA) physical status I (normal healthy patient) or II (patient with mild systemic disease) participated in this prospective, double blinded, randomized study. Patients were assigned to receive either 0.07 mg/Kg diazepam orally or no premedication. They then received saline and ondansetron 0.1 mg/Kg or 0.2 mg/Kg intravenously 5 minutes before thiopental induction. Thiopental was administered at a rate of 25 mg/min until the patient lost the ability to open eyes on command. Thiopental requirements were not significantly different among groups. The results indicate that ondansetron in clinically used doses does not influence the hypnotic requirements of thiopental.     

Characterization and Differentiation of the Tumor Microenvironment (TME) of Orthotopic and Subcutaneously Grown Head and Neck Squamous Cell Carcinoma (HNSCC) in Immunocompetent Mice

For the development and evaluation of new head and neck squamous cell carcinoma (HNSCC) therapeutics, suitable, well-characterized animal models are needed. Thus, by analyzing orthotopic versus subcutaneous models of HNSCC in immunocompetent mice, we evaluated the existence of adenosine-related immunosuppressive B- and T lymphocyte populations within the tumor microenvironment (TME). Applying the SCC VII model for the induction of HNSCC in immunocompetent C3H/HeN mice, the cellular TME was characterized after tumor initiation over time by flow cytometry. The TME in orthotopic grown tumors revealed a larger population of tumor-infiltrating lymphocytes (TIL) with more B cells and CD4⁺ T cells than the subcutaneously grown tumors. Immune cell populations in the blood and bone marrow showed a rather distinct reaction toward tumor induction and tumor location compared to the spleen, lymph nodes, or thymus. In addition, large numbers of immunosuppressive B- and T cells were identified within the TME but also in secondary lymphoid organs, independently of the tumor initiation site. The altered immunogenic TME may influence the response to any treatment attempt. Moreover, when analyzing the TME and other lymphoid organs of tumor-bearing mice, we observed conditions reflecting largely those of patients suffering from HNSCC suggesting the C3H/HeN mouse model as a suitable tool for studies aiming to target immunosuppression to improve anti-cancer therapies.