Objective: The purpose of the present study was to investigate the relation between the dose of tumor cell inoculation (especially the doses less than minimum required to evoke tumor growth) and the anti-tumor immune system, particularly lymphoblast formation and cytotoxic activity of lymphcytes. Method: We inoculated rats with various doses of SST-2 tumor cells and examined natural killer (NK) cell activity and lymphoblast formation in vitro. Result: The results showed that the cytotoxicities against SST-2 cells and lymphoblast formation of lymphocytes were enhanced by small dose inoculation of tumor cells that could not induce tumor growth. Conclusion: It was suggested that was lymphocutes play an important role as an anti-tumor immune system at small doses of tumor inoculation, which appears to reflect an early stage of tumor growth in vivo. It was also suggested that SST-2 tumor inoculation might be a useful model for studying the anti-tumor immune response in SHR rats.
Neoplasms ; SST ; tumor growth ; Immune response ; Lymphoblast

We report a case of bone marrow necrosis preceding infantile acute lymphoblastic leukaemia (ALL). Bone marrow necrosis is a rare antemortem event and has been known to be present in many conditions, notably in haematological malignancies like acute lymphoblastic leukaemia. This case was a 6-month-old Chinese boy who was referred to Hospital Universiti Kebangsaan Malaysia for further investigation of pancytopaenia, high-grade fever, bloody diarrhoea and petechial rashes for one week. His first bone marrow aspirate revealed bone marrow necrosis. His clinical condition improved after ten days. However, his full blood picture then revealed the presence of 5% blast cells. His subsequent marrow 2 weeks later revealed acute lymphoblastic leukaemia (FAB-L1) and immunophenotyping showed precursor B acute lymphoblastic leukaemia-null type. He was started on United Kingdom Acute Lymphoblastic leukaemia (UK ALL) Infantile Leukaemia protocol, however, he defaulted treatment after 3 days. Mode of presentation, mechanism of disease and laboratory investigations and outline of treatment will be discussed.
Acute ; Lymphoblast ; Bone Marrow ; Necrosis ; week