Summary.-The presence of Fc receptors on the surface of cell suspensions obtained from a transplanted isogeneic methylcholanthrene induced murine fibrosarcoma has been investigated by determining the capacity of such cells to form rosettes with antibody coated SRBC.These studies indicate that a large percentage of cells in the tumour had Fc receptors on their surface. The proportion of such cells was increased by reducing the number of cells transplanted, by administering cyclophosphamide to the host, and on occasions by the i.p. injection of C. parvum. It was largely unaffected by the route of tumour cell transplantation or by T cell depletion of the host before transplantation but appeared to decline in older (i.e. larger) tumours. Both phagocytic and non-phagocytic cells had Fc receptors on their surface. The phagocytic population appeared to be affected most by procedures which altered the overall percentage of Fc receptor bearing cells. The Fc receptor bearing tumour cells were separated from those devoid of Fc receptors on the basis of their adherent properties. Upon transplantation to isogeneic hosts both populations gave rise to tumours containing a high percentage of Fc receptor bearing cells. These studies suggest that many of the Fc receptor bearing cells in our tumour are probably infiltrating cells of host origin. Their significance in relation to tumour growth remains to be established. DETAILED studies during the past few years have convincingly demonstrated that normal and malignant lymphoid and reticuloendothelial cells may have on their surface receptors for antigen/antibody complexes and aggregated JgG, the so-called Fc receptors (reviewed by Kerbel and Davies, 1974). A number of observations also indicate that a significant proportion of the cells in certain nonlymphoreticular tumours may also possess Fc receptors (Milgrom et al., 1968;Cohen, Gurner and Coombs, 1971;Tonder, Morse and Humphrey, 1974;Kerbel and Davies, 1974). These Fc receptors have been demonstrated by both cryostat haemadsorption techniques (Milgrom et al., 1968;Tonder et al., 1974) and by conventional rosetting procedures with suspensions of tumour cells and antibody coated sheep erythrocytes (Cohen et al., 1971;Kerbel and Davies, 1974). The tumours studied included a variety of human adenocarcinomata and epidermoid carcinomata (Tonder et al., 1974), tumours of murine connective and epithelial tissue (Kerbel and Davies, 1974) and a transmissible venereal tumour in the dog (Cohen et al., 1971 (MacLennan, 1972). Furthermore, if the major proportion of Fc receptor bearing cells in tumours is macrophages, then this would provide an additional method for monitoring the macrophage content of tumours and establishing their importance in relationship to tumour growth.In view of these possibilities, we have investigated the Fc receptor bearing cell content of a transplanted syngeneic, methyleholanthrene induced mouse fibrosarcoma. We have been particularly MATERIALS AND METHODSMice. The experiments were performed in inbred CBA mice ...

The synthesis and biological investigation of the series of amide and ester derivatives 10-20 of 5-(4-chlorobenzoyl)amino-3-methyl-4-isothiazolecarboxylic acid 5 are presented. Because the amide series of 5-benzoylamino-3-methyl-4-isothiazolecarboxylic acid 2 has been studied extensively and from this series denotivir (vratizolin) 4 became the antiviral drug. The influence of exchanging the N-benzoyl for a N-(4-chlorobenzoyl) group at position 5 of the isothiazole ring on the pharmacological activity of 5-benzoylamino-3-methyl-4-isothiazolecarboxylic acid 2 derivatives is dealt with here. The effect of structure modifications in the carboxylic group of the 5-(4-chlorobenzoyl)amino-3-methyl-4-isothiazolecarboxylic acid 5 series of derivatives on their biological activity is discussed. Some of the tested 5-(4-chlorobenzoyl)amino-3-methyl-4-isothiazolecarboxylamides revealed significant anti-inflammatory activity in carrageenan induced edema and air-pouch inflammation tests. Physicochemical properties of 6-(4-chlorophenyl)-3-methylisothiazolo[5,4-d]-4H-1,3-oxazin-4-one 6 are described. Its use in the synthesis of isothiazole derivatives and its reactivity are also presented.

No abstract

No abstract

Multiple sclerosis (MS) is frequently accompanied by visual symptoms including those related to retinal disorders. Since they may be a consequence of an autoimmune reaction, we examined whether sera of patients with diagnosed MS and changes in visual-evoked potentials contain antibodies against retinal antigens (retAgs). Immunoblot analysis revealed that MS sera recognized mainly a 46-kD antigen, a 41-kD antigen, retinal arrestin, to a smaller extent also 70-, 56-, 43-, and 36-kD proteins. Patients whose sera showed the highest reactivity with 41- and 46-kD antigens had deficiencies in visual acuity, visual fields, ophthalmoscopy, and electroretinograms. Our observation suggests that antibodies to these retAgs may play a role in the origin of ophthalmologic impairment in MS.