A lack of correlation between antigen-specific cellular reactions and resistance to Mycobacterium lepraemurium infection in mice.

Following infection subcutaneously in the footpad with 10(7) Mycobacterium lepraemurium organisms C57BL mice were able to limit multiplication of organisms at the infection site for the 6 months studied and to limit organism spread to the draining lymph node. Large numbers of organisms were present in the footpad and draining lymph node of BALB/c mice at 6 months. In spite of this difference in local immunity the changes in cellular reactivity to specific antigen as assessed by the delayed footpad response and the in vitro proliferative response of draining lymph node cells were similar in the two strains over the time studied.

Absorption of macrophage aggregating factor by guinea-pig peritoneal exudate cells.

Lymphokine (LK)-induced aggregation of peritoneal exudate cells (PEC) has been measured using a quantitative technique. Aggregating activity could be removed from LK preparations by absorption of these with PEC and, in addition, the absorbing PEC, on further incubation themselves aggregated. Absorption of aggregating activity to PEC was rapid, being easily measurable at between 2-5 and 10 min although it was difficult to demonstrate at 30 min.

The effect of cyclophosphamide and role suppressor cells in the desensitization of delayed hypersensitivity.

Desensitization of guinea-pigs with ovalbumin (OA) or bovine gamma globulin (BGG) induces strong specific desensitization and is associated with a non-specific energy to tuberculin--PPD. Similarly, it was found that animals receiving desensitizing injections of PPD have suppressed delayed hypersensitivity reactions to OA or BGG. PPD also induced strong specific desensitization.

Suppression of delayed hypersensitivity to tuberculin by antigenic competition. A positive immunoregulatory mechanism sensitive to cyclophosphamide.

Effector mechanisms that produce delayed hypersensitivity reactions to tuberculin are subject to positive immunoregulation. Two different immunoregulatory mechanisms can be demonstrated. One is specific and the other, antigenic competition, is non-specific; both are sensitive to cyclophosphamide (CY).

A canine testicular tumor resembling gonadoblastoma.

A tumor of the left testicle resembling a gonadoblastoma was an incidental finding at necropsy in a 15-year-old male Shetland Sheepdog. This neoplasm was characterized by discrete intratubular aggregates of intimately mixed germ cells and smaller cells resembling Sertoli cells. The latter small cells often formed a single cell layer surrounding the margin of eosinophilic, PAS-positive Call-Exner-like bodies.

Quantitation and in vitro analysis of the inflammatory cells in experimental allergic encephalomyelitis in the guinea-pig.

Inflammatory cells from the meninges of guinea-pigs with acute EAE have been isolated and quantitated. A mean of 7.5 x 10(6) cells were recovered from the brains of animals showing clinical signs of disease in contrast to only 1.

The monocyte-macrophage system in granulomatous inflammation.

Granulomas may be immunologically induced or non-immunologically induced. In immunologically induced granulomas cells of the monocyte-macrophage series take on the appearance of epitheloid cells. Ultrastructurally epithelioid cells may have a secretory appearance with much rough endoplasmic reticulum or take on highly degenerate vesicular appearance.

Immediate hypersensitivity in the guinea pig conjunctiva. III. long-term persistence of the hypersensitive state and characterization of antibodies.

The ocular immediate hypersensitivity reaction in guinea pigs to topically applied normal rabbit serum can be evoked as long as 4 years after sensitization. The reaction was as severe and tended to persist for longer than that evoked 6 months after sensitization. Passive cutaneous anaphylaxis tests showed that very high titres of homocytotropic antibodies were present and that both IgE- and IgG1-like antibodies were involved.

Lymphokine-induced Macrophage aggregation: the possible role of cyclic nucleotides.

The possible role of cyclic nucleotides in guinea pig macrophage aggregation, induced by human lymphokine (LK) has been investigated. Small increases were found in guanosine 3'5'-cyclic monophosphate (cGMP), but not adenosine 3'5'-cyclic monophosphate (cAMP), levels of lymphokine aggregated macrophages. Addition of exogenous dibutyryl (DB) cAMP, L-isoproterenol, or theophylline did not induce macrophage aggregation.

Activation of the alternative pathway of complement by mycobacteria and cord factor.

The ability of a number of mycobacteria and some of their components to activate complement was examined. Mycobacterium bovis BCG (Glaxo strain), Mycobacterium leprae, Mycobacterium lepraemurium, and cord factor activated the alternative pathway of complement in normal human serum and normal and C4-deficient guinea pig sera and generated biologically active products. BCG (Pasteur strain) and muramyl dipeptide did not activate complement.

Immunologic and nonimmunologic activation of macrophages.

Cells of the mononuclear phagocyte system take on different morphological features and appear to have different functions in immunological and nonimmunological granulomas. In immunological granulomas the appearance is of epitheliod cells. Epitheliod cells are of 2 types.

Intestinal adenocarcinoma in a chicken.

An obstructing intestinal stricture 65 cm distal to the pylorus in an aged hen was seen on histologic examination to be caused by a primary intestinal adenocarcinoma.

Ultrastructure of cells of the mononuclear-phagocyte series (MPS) across the leprosy spectrum.

A systematic ultrastructural study of cells of the MPS across the spectrum of leprosy has been carried out. Graded changes in macrophage ultrastructure from the lepromatous to the tuberculoid poles have been shown. Mycobacteria-filled macrophages in lepromatous leprosy are characterised by long cell processes, whereas in borderline tuberculoid leprosy these cells have a rounded appearance and are mainly characterised by numerous intracellular vacuoles.

Isolation and characterization of the inflammatory infiltrate in the central nervous system of the guinea-pig with experimental allergic encephalomyelitis.

The inflammatory infiltrate of the central nervous system in acute experimental allergic encephalomyelitis (EAE) in the guinea-pig has been isolated and characterized. Inflammatory cells found over the surface of the brain and spinal cord and within the leptomeninges have been isolated by washing, and were subsequently identified by a number of methods. By light microscopy approximately 60% were lymphocytes, 30% were cells of the mononuclear phagocyte series, and 5% were neutrophils: the occasional plasma cell and eosinophil were also identified.

Dissociation between tumour resistance and delayed-type hypersensitivity to tumour-associated antigens in the mouse.

A comparison was made in mice between resistance to growth of a syngeneic methylcholanthrene-induced fibrosarcoma (Meth A) and specific delayed-type hypersensitivity to this tumour. Resistance could be induced in 90% of mice following a single injection of 10(4) Meth A cells. This resistance could be transferred by spleen cells but not serum.

Preparation of antisera specific for guinea pig B cells.

Heterologous antisera against guinea pig B lymphocytes have been prepared in rabbits. Sera, obtained 1 week after a third injection of cells from a guinea pig leukemic B cell line (L2C), were absorbed with guinea pig and sheep erythrocytes and guinea pig thymocytes. In the presence of complement, selected antisera killed both L2C cells (85%) and B cells from Hartley outbred guinea pigs (85%).

Studies on lymphokine-induced macrophage aggregation. Specificity and quantitative aspects.

A method for the quantitative measurement of macrophage aggregation by lymphokine preparations has been described previously. This involved the continuous measurement of the light absorbance of stirred suspensions of guinea pig peritoneal exudate cells (PEC). We now show that using a modified method, both aggregation of normal PEC, induced by preformed lymphokine, and direct aggregation of sensitized PEC with specific antigen can be measured.

Consequences of vasectomy: an immunological and histological study related to subsequent fertility.

Studies of 2 groups of patients 2 years and 8 years following vasectomy failed to demonstrate evidence of cell mediated immunity to sperm. Histological examination of testicular tissue from 11 patients undergoing reversal of vasectomy showed significant abnormalities in each. However, subsequent fertility within 15 months occurred in 7 (63.

Complement activation by aluminium and zirconium compounds.

The activation of complement by a number of metal compounds, previously found to induce chronic inflammation, was investigated. Results obtained were compared with complement activation by inulin and zymosan. It was shown that complement activation by these metal compounds did not necessarily involve either the classical or the alternative pathways.

Cystic lymphangioma in a colt.

A 6-month-old Morgan colt was examined because of preputial edema and multiple nodular masses in the left inguinal region. A tentative diagnosis of lymphatic hamartoma was made on the basis of initial biopsy findings. The prognosis for surgical excision was poor due to the progressive expansile growth of the tumor.

A mechanism for the hydroperoxide-mediated inactivation of prostacyclin synthetase.

Hydroxyl radical generation was demonstrated during heme-catalyzed decomposition of 15-hydroperoxy arachidonic acid. The hydroperoxide-mediated inactivation of prostacyclin synthetase seems to be related to the generation of this highly reactive species. A relationship between hydroperoxides and the hydroxyl radical may be important in the modulation of prostacyclin synthesis in diseased states.