摘要:

AbstractNon‐caseating epithelioid granulomas have been induced in rats by the subcutaneous injection of BCG vaccine and their cellular disaggregation to yield isolated epithelioid cells has been achieved using collagenase. Ultrastructurally epithelioid cells in both intact granulomas and disaggregated cell suspensions showed a spectrum of appearances ranging from cells with conspicuous rough surfaced endoplasmic reticulum (“plasmacytoid epithelioid cells”) to cells containing numerous cytoplasmic membrane‐bound vesicles (“vesicular epithelioid cells”). Numerous intermediate forms were present. Endocytosed material was inconspicuous.Investigation of disaggregated 4, 10 and 28 day lesions showed that the proportion of vesicular epithelioid cells increased with maturation of the granulomas. Nevertheless a full spectrum of epithelioid cell morphology was present as early as 4 days.It is suggested that mononuclear phagocyte cells entering the granuloma transform into vesicular epithelioid cells via an intermediate plasmacytoid stage.The successful isolation of viable epithelioid cells from granulomas may allow th function of these cells to be evalua

ISSN:0022-3417    

DOI:10.1002/path.1711360102

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractIsolated epithelioid cells from disaggregated rat BCG granulomas show a morphological spectrum from “plasmacytoid” to “vesicular” forms on electron microscopy. Functional studies on these isolated cells showed that all epithelioid cells exhibited poor trypsin‐resistant glass adherence and poor phagocytosis of latex, zymosan, antibody coated and complement coated erythrocytes when compared with macrophages, especially at the vesicular end of the spectrum. A high proportion of all epithelioid cell types was found to have Fc surface receptors but C3 receptors were reduced on vesicular cells compared with the plasmacytoid variety. The findings indicate that the progressive transformation of mononuclear phagocyles into vesicular epithelioid cells through plasmacytoid intermediates is accompanied by a concomitant modification of cell function. The significance of these changes is

ISSN:0022-3417    

DOI:10.1002/path.1711360103

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractOsteoclasts were incubated on a glass or plastic substrate and the effect of calcitonin (CT) on their behaviour was observed. Before exposure to CT the osteoclasts were actively motile, the cytoplasm advancing behind broad pseudopodial (lamellipodial) processes which showed intense ruflling activity. CT caused cessation of lamellipodial activity within minutes, followed by gradual fragmentation and retraction of lamellipodia. Complete osteoclast quiescence was regularly induced by concentrations of CT above 50 pg/ml, and lesser degrees of quiescence were induced at concentrations down to 10 pg/ml. This quiescent state was reversed on removing CT from the medium, and was abrogated by prior treatement of osteoclasts with trypsin. The quiescent state did not reduce the longevity of the cells in culture. nor did it affect their resistance to removal from glass by trypsin. CT showed no influence on the pseudopodial activity of osteoblasts, peritoneal macrophages or inflammatory giant cells. Osteoclast quiescence seems to be a reversible state induced by the interaction of CT with a trypsin‐sensitive CT receptor, present on osteoclasts. The range of concentrations which induce partial osteoclast quiescence are within the physiological range of serum concentrations in man, and this suggests that CT plays a physiological role in the regulation of osteoclast activity. The behavioural change induced by CT in osteoclasts may help to identify the precursor cell of the osteoclast and may assist investigations into the mechanism of control ofosteoclasi

ISSN:0022-3417    

DOI:10.1002/path.1711360104

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractPrimary subcutaneous infection of rats with BCG leads to a three stage local reaction. There is first a short‐lived simple granuloma corresponding with high levels of cell mediated immunity (CMI). This is followed by an explosive phase of necrosis and local Mycobacterial multiplication corresponding with low levels of CMI and high levels of circulating anti‐BCG antibody. Finally the lesion resolves via an epithelioid cell granuloma as bacteria fall in number and CMI returns.Reinfection with BCG produces quite different lesions when initiated at different stages of the primary infection. Reinfection during the short first stage causes a self‐healing epithelioid granuloma. Reinfection during the long second stage produces a florid necrotic, bacilli‐laden lesion. Reinfection during the third stage produces only a vestigial, transient granuloma.It is suggested that the evolution of tuberculous lesions depends on the interplay of CMI, bacillary load and circulating antibody. A large antigenic load in the presence of high antibody titres causes necrosis and bacillary multiplication, whereas reduced bacterial numbers plus antibody and high CMI lead to compact granulomas and healing. The first situation may be analogous to immune complex disease in antigen excess and the second to complexes in antibody excess.An analogy is drawn between the reinfection experiments and natural infection after BCG vaccination in humans. It is postulated that BCG vaccination in man may be followed by a phase in which antibody is high relative to CMI. If because of high prevalence rates, natural infection with large doses of bacilli was more likely to occur at this time, the results might help to explain the failure of BCG prophylaxis in India and comparable countries, as opposed to its success in

ISSN:0022-3417    

DOI:10.1002/path.1711360105

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractAfter BCG were complexed with homologous anti‐ BCG serum IgM was found to be firmly bound to the organisms. Preparations were made at antigen/antibody equivalence and at two‐fold and four‐fold antibody excess. They were injected subcutaneously into rats. At equivalence the mixtures provoked rapidly developing necrotic destructive lesions containing many bacilli, Injection of mixtures at antibody excess caused the rapid formation of epithelioid cell granulomas without necrosis and containing few bacilli.Compared with the injection of BCG alone, injection of comparable numbers of IgM‐complexed bacilli at equivalence led to more rapid necrosis but also more rapid resolution of the granulomas which followed. Delayed‐type skin reactions to PPD took longer to develop after injection of complexed BCG, usually as long as 4 weeks. The delay varied directly with the degree of antibody excess. This failure to detect cell mediated immunity was reflected in the histology of the draining lymph nodes which differed strikingly from that seen after injection of BCG alone. In animals injected with bacilli in excess antibody, epithelioid cell granulomas formed and viable bacilli were apparently eliminated before skin reactions to PPD developed. It is concluded that circulating immunoglobulin, perhaps IgM in particular, is likely to play a significant role in the pathogenesis of tuberculosis and similar diseases and that the relative ratio of antigen to antibody within the lesions may be crucial in influencing the balance between tissue destruction an

ISSN:0022-3417    

DOI:10.1002/path.1711360106

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

ISSN:0022-3417    

DOI:10.1002/path.1711360101

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY