system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Animals, Antineoplastic Agents, Body Weight, Enzyme-Linked Immunosorbent Assay, Female, Interferon-gamma, Interleukin-2, L-Lactate Dehydrogenase, Melanoma, Experimental, Mice, Mice, Inbred C57BL, T-Lymphocytes, Cytotoxic, Tumor Necrosis Factor-alpha, Weightlessness Simulation.
user
Does [ Simulated weightlessness inhibit antitumor immunity of T lymphocytes in melanoma-bearing mice ]? Context: To investigate the effects of simulated weightlessness on antitumor immunity of T lymphocytes in mice. The malignant melanoma was xenografted by subcutaneous injection of B16 cells into the right hind limb of every mouse. The mice suspended by tail at a -15 degree to 20 degree head-down tilt were used as simulated weightlessness models. The effects of simulated weightlessness on tumor volume and survival time were observed. T the numbers of leucocytes, lymphocytes and T lymphocyte subsets in peripheral blood of tumor-bearing mice under simulated weightlessness were monitored by an automatic hemacytometer and a flow cytometer. The effects of simulated weightlessness on the production of IL-2, TNF-α and IFN-γ in T lymphocytes and the cytotoxicities of tumor-specific CTLs to tumor cells were analyzed by ELISA and LDH release. Compared with control group, the tumors grew faster, the survival times were shorter, the number of lymphocytes, the ratio of lymphocytes, CD3(+);, CD4(+);/CD3(+); and CD8(+);/CD3(+); T lymphocytes in peripheral blood dropped, and the proliferation of splenic T lymphocytes induced by mitogen was reduced (P<0.05 or P<0.01) in the simulated weightlessness group. The production of IL-2, TNF-α and IFN-γ induced by tumor cells and cytotoxicities of tumor-specific CTLs to tumor cells were inhibited in mice under simulated weightlessness (P<0.05 or P<0.01).
assistant
Simulated weightlessness inhibits antitumor immunity of T lymphocytes. Final Decision: yes