ABSTRACT
In mouse bone marrow cultures plated at low cell density, stromal colonies formed from colony-forming unit fibroblastic (CFUf) failed to develop unless the cultures were supplemented with irradiated feeder cells. Colony-stimulating activity was produced by irradiated bone marrow and spleen cells and by platelets, was dose dependent, not species specific and was maximal at high serum concentration. The efficiency of CFUf colony formation was 1.7 x 10(-4) for mechanically disaggregated and 14.6 x 10(-4) for trypsinised bone marrow cells. The colonies formed in the presence of feeder cells comprised hundreds of fibroblasts. In the absence of feeder cells, small fibroblast foci and single fibroblasts only were present in cultures. PDGF, IL-3 and EGF did not substitute for the colony-stimulating activity of feeder cells. These results suggest that CFUf colony formation requires growth factor(s) released by platelets and megakaryocytes which remain to be identified.
Subject(s)
Blood Platelets/physiology , Bone Marrow Cells , Fibroblasts/cytology , Growth Substances/physiology , Megakaryocytes/physiology , Animals , Bone Marrow/metabolism , Cells, Cultured , Colony-Forming Units Assay , Colony-Stimulating Factors/biosynthesis , Epidermal Growth Factor/pharmacology , Interleukin-3/pharmacology , Mice , Mice, Inbred CBA , Platelet-Derived Growth Factor/pharmacology , Spleen/cytology , Spleen/metabolism , Stromal Cells/cytologyABSTRACT
Bone formation in organ cultures of intact marrow fragments from mouse is described. Marrow explants were cultured on the top surface of a millipore filter at a gas-liquid interface. Observations with both light- and electron microscopes demonstrated the formation of a well-organised trabecular matrix lined with osteoblast-like cells. The tissue and cells were positive for alkaline-phosphatase activity. Large amounts of thick, well-banded collagen fibrils and matrix vesicles typical of those found in bone were present. The tissue became mineralised in the presence of 10 mM Na-beta-glycerophosphate; in its absence a similar trabecular matrix developed but mineralisation did not take place.
Subject(s)
Bone Development , Bone Marrow Cells , Animals , Bone Marrow/ultrastructure , Collagen/analysis , Mice , Mice, Inbred Strains , Microscopy, Electron , Organ Culture Techniques , Osteoblasts/cytology , Osteoblasts/ultrastructureABSTRACT
Sera from healthy people and from patients with schizophrenia were heated at 56 degrees for 30 min and then kept at 4 degrees . These sera were then tested for cytotoxicity and by the indirect immunofluorescence method with thymocytes, bone-marrow cells, and lymph-node cells of adult C(3)H mice. The cytotoxicity index for mouse thymocytes of sera from 60 healthy donors ranged from 0.00 to 0.4, with an average of 0.08. That of sera from 35 patients with schizophrenia ranged from 0.29 to 0.91, with an average of 0.71. The cytotoxicity index for mouse bone-marrow cells of sera from healthy donors ranged from 0.03 to 0.23, whereas that of sera from patients with schizophrenia ranged from 0.00 to 0.14. Sera of patients at dilutions of 1:8-1:32 displayed immunofluorescence of almost 100% of thymocytes and 58-78% of lymphocytes, whereas sera of healthy donors displayed none. We thus conclude that the sera of patients with schizophrenia contain antibodies against thymic antigens localized on thymocytes and thymus-derived lymphocytes.
