The formation and properties of macrophage polykaryons (inflammatory giant cells)

Tuberculosis of the cervix: cytology as an aid to diagnosis

Two cases of tuberculous cervicitis are presented. The presence in cervical smears of both epithelioid and Langhans' giant cells, which are described, should raise a strong suspicion of tuberculosis.

The influence of the thymus on multinucleate giant cell formation

Glass coverslips were implanted in nude athymic mice and normal controls and the development of multinucleated giant cells on the implant investigated. Although the percentage of the surface area of the coverslip covered by cellular exudate was reduced in older implants (12 days or more) in athymic mice, the proportion of nuclei within syncytia was the same as in normal controls. It is concluded that the multinucleated giant cells in this type of inflammatory lesion are not thymus derived nor is the efficiency of fusion between their precursor mononuclear phagocytes thymus dependent. The number of exuded mononuclear phagocytes on the other hand may be influenced directly or indirectly by the thymus.

Tumor-host cell hybrids in radiochimeras reconstituted with bone marrow and thymus grafts

CBA/H and CBA/HT676 radiation chimeras were prepared by lethal irradiation and subsequent reconstitution with bone marrow of the host karyotype and thymocytes of the opposite karyotype. After T- and B-cell chimerism had been established, the animals were inoculated with SEWA or TA3Ha ascites tumor--donor cell hybrids were isolated following the explantation of TA3Ha tumor in selective HAT medium and by selecting for adherent cells from SEWA. The T6T6 chromosomal marker served to distinguish between the type of cell involved in the fusion. In all hybrids the donor component was a nonthymus-derived cell.

Induction of DNA synthesis in rat peritoneal macrophages in culture by a pleural inflammatory exudate

Peritoneal macrophages in culture are blocked in the G0 phase of the cell cycle, but retain many of their functional characteristics such as phagocytic ability. Peritoneal macrophages have been thought to be a terminal cell type. It has been investigated whether such properties could be modified by a substance released in acute inflammatory exudates. For this purpose a pleural exudate obtained from rats injected with dextran (40,000) 4 hours before, was centrifuged to eliminate cells, sterilized by filtration on Millipore filter 0.22 mum and diluted 50% with 199 medium culture. This medium was used to treat normal and activated peritoneal macrophages in culture. The effects were observed 24, 48, 72, 96 hours after the beginning of treatment. An enhancement of spreading and capacity of phagocytosis was observed 24 hours after the beginning of treatment. After 48 hours, the number of cells incorporating tritiated thymidine increased and became highest 4 days later. These phenomena were also obtained with pleural exudate of inbred rats (Lewis, Wag) treating macrophages of the same strain and with rat pleural exudate treating mouse macrophages. No effects were observed with dextran alone. The chemical nature of the stimulatory factor remains to be elucidated.

Inflammatory mechanisms in the newborn

Both the vascular and cellular aspects of inflammation were studied in rats aged from 6 hours to 2 months. The onset of a vascular permeability reaction was found to vary according to the age of rat and type of permeability agent injected. Induction of acute inflammations (turpentine pleurisy, 48/80 and dextran-induced foot oedema) in new born rats revealed a marked reduction of exudate/oedema formation compared with adult rats. These observations were related to a lack of histamine and 5-HT-mediated increased vascular permeability during the inflammatory reactions of newborn rats. Qualitative differences were observed between the acute inflammatory pleural cell exudates of newborn and adult rats after intra-pleural injection of dextran. In contrast to adults, polymorphs were observed to dominate the newborn reaction, and the peak accumulation of these cells was delayed. The mononuclear cells of 4-day lesions induced by sub-cutaneous implantation of glass coverslips showed a higher rate of mitosis in newborn animals, compared with adults. Ultrastructural studies of the mononuclear cells of peritoneal exudates induced by carrageenan indicated that those of newborn rats contained fewer lysosomes than adults. The Golgi apparatus of newborn mononuclear cells was observed to be poorly-developed compared with adult mononuclear cells.

The effect of cyclophosphamide, methotrexate and X-irradiation on the ultrastructure and endocytic capacity of murine peritoneal macrophages

100 mg/kg cyclophosphamide given subcutaneously daily for 5 days and whole-body X-irradiation (500 r) had an appreciable effect on the phagocytosis of E. coli by mouse peritoneal macrophages. Less bacteria were ingested by cells from the treated mice as compared with control cells. In contrast, whole-body X-irradiation had a stimulatory effect on pinocytosis as compared with cells from cyclophosphamide treated mice or control mice. Morphological changes in the cells from animals treated with cyclophosphamide or X-rays were evident. The cells were larger than normal macrophages and contained large amounts of lipid and phagolysosomes and had more vacuoles as compared with control cells. Many giant cells were present in the treated mice. Treatment of mice with methotrexate for 5 days, although affecting the cells morphologically in that they were larger than normal cells and had many vacuoles did not appear to have any effect on either phagocytosis or pinocytosis. Cells from methotrexate treated animals did not contain the large quantities of lipid seen in cells from the cyclophosphamide treated and X-irradiated mice.

The response of the newborn rat to injury. II. Histopathological aspects and mononuclear cell turnover

Histopathological investigations of skin lesions induced by subcutaneous implantation of glass coverslips were carried out in rats between birth and adulthood. Differences were found between the cellular reactions of newborn and adult rats to this irritant. An increased number of cells was found in the skin lesions of newborn rats, compared with adults. Uptake of a 30-min. pulse of tritiated thymidine by mononuclear cells was found to be higher in newborn skin lesions than in those of adult rats. The reverse was observed for the mononuclear cells adherent to implanted glass coverslips. Giant cells were less evident on coverslips removed from the skin of newborn rats.