Growth of Salmonella on chilled meat.

Growth rates of a mixture of Salmonella serotypes inoculated on beef from a commercial abattoir were measured at chill temperatures. The minimum recorded mean generation times were 8.1 h at 10 degrees C; 5.

Lymphocyte function in experimental African trypanosomiasis. III. Loss of lymph node cell responsiveness.

The relationship between immunosuppression and suppressor cell activity in the lymphoid organs of animals with experimental African trypanosomiasis has been examined further. In the present study we measure the primary in vitro PFC response to SRBC by spleen and lymph node cells from Trypanosoma rhodesiense infected or drug-cured C57BL/6 mice. Passive transfer experiments with this culture system tested for the presence or absence of suppressor cells.

The prickly lettuce agglutinin. I. Isolation from leaves of the prickly lettuce plant (Lactuca scariole).

An agglutinin has been isolated from leaves of the prickly lettuce plant (Lactuca scariole). The prickly lettuce agglutinin (PLA) agglutinates erythrocytes of the mouse and rat, and binds to, but does not agglutinate erythrocytes of other species. PLA can be precipitated from crude plant extracts by cold acetone and ammonium sulfate treatment, is sensitive to proteolytic enzyme activity, and contains carbohydrate residues, suggesting that it is a glycoprotein.

Effects of theophylline treatment on mouse B-16 melanoma cells in vitro.

The effects of theophylline treatment on mouse B-16 melanoma cell growth, metabolism, and membrane antigen expression in vitro were studied. Theophylline treatment inhibited DNA synthesis and the cell growth rate, and caused an elevation of intracellular cAMP levels. Cells treated with theophylline became elongated and assumed a normal fibroblast-like morphology.

Rimantadine but not amantadine protects Fischer rat embryo cells from transformation induced by 3-methylcholanthrene or benzo(a)pyrene.

The antiviral drugs amantadine hydrochloride and rimantadine hydrochloride were tested as to their oncogenic potential using a serial line of Fischer rat embryo cells that previously had been shown to be an accurate indicator of chemicals known to be oncogenic in animal studies. Neither compound was found to have transforming activity. At slightly toxic levels, rimanbadine hydrochloride, but not amantadine hydrochloride, protected the same cell line from the transformation induced by the polycyclic hydrocarbons 3-methylcholanthrene and benzo(a)pyrene.

Dose-related effects of ethanol on avoidance-avoidance conflict behavior in the rat.

The effects of ethanol on avoidance-avoidance conflict behavior were examined, utilizing a 3- x -3 factorial design in which rats were trained and tested after drinking sugar-water solutions containing 0, 3, or 6% ethanol. Avoidance tendencies were established by initially training rats to escape from electric shock by running in one direction in a white alley, and in the opposite direction in a black alley. In subsequent shock free conflict tests, the rats were placed into an alley with one black wall and one white wall, an environment in which incompatible tendencies to avoid both ends of the alley were aroused.

Transforming activities of trichloroethylene and proposed industrial alternatives.

Three chlorinated hydrocarbons, proposed or already in use as industrial substitutes for the hydrocarbon trichloroethylene, were tested for in vitro transforming potential in a Fischer rat embryo cell system (F1706), which previously has been shown to be sensitive to transformation by chemical carcinogens. Trichloroethylene and the three substitutes (1, 1, 1 trichloroethane, tetrachloroethylene and methylene chloride) all were found to induce transformation, the three substitutes being equal or more efficient transforming agents.

Primary fibrosarcoma of the skull. Case report.

A case of primary fibrosarcoma of the skull is presented. Only one other case with this uncommon site of occurrence of this tumor has been previously reported.

Cell wall protein in Bacillus subtilis.

The cell wall of Bacillus subtilis 168 contains protein that is refractory to removal by salts, detergents, and denaturants.

Lymphocyte function in experimental african trypanosomiasis: mitogenic effects of trypanosome extracts in vitro.

Extracts of Trypanosoma brucei and Trypanosoma congolense were incubated in vitro with nonimmune lymphocytes of mice, rats, guinea pigs, and rabbits in order to test for mitogenic effects or for other characteristics of polyclonal B lymphocyte activators. Trypanosome extracts (TE) were not mitogenic for spleen cells of mice, rats, and guinea pigs in vitro, nor did the parasite extracts alter the mitogenic responses of lymphocytes from these animals to known B- and T-cell mitogens. TE also failed to induce polyclonal antibody synthesis in mouse spleen cell cultures in an in vitro antibody response system, in contrast to the effects of bacterial lipopolysaccharide, a known polyclonal B cell activator.

Suppression of cell-mediated immunity in experimental African trypanosomiasis.

Adult New Zealand white rabbits were experimentally infected with a parasitic African hemoflagellate, Trypanosoma congolense, and were subsequently tested for in vivo and in vitro aspects of cell-mediated immune function. Chronically infected rabbits were sensitized to mycobacterial protein and skin-tested with purified protein derivative; all infected animals demonstrated much milder skin-test responses to antigen than control groups. Similarly, peripheral blood lymphocyte responses in vitro to purified protein derivative and, as well, to phytohemagglutinin were markedly suppressed.

Tests for antibody- and cell-mediated hypersensitivity to trypanosome antigens in rabbits infected with Trypanosoma congolense.

Rabbits infected with Trypanosoma congolense were tested for immediate and delayed-type hypersensitivity responses to parasite antigens. Positive skin-test reactions were exclusively of the Arthus type, as shown by sequential histological analyses which revealed that more than 90% of the infiltrating cells at 24 hr postinjection were polymorphonuclear neutrophils. Skin reactions could be elicited in normal rabbits by intradermal injection of trypanosome antigen-antibody complexes.

Autoimmunity in experimental Trypanosoma congolense infections of rabbits.

Autoimmunity in rabbits with experimental Trypanosoma congolense infections was investigated. Complement-fixing (CF) and precipitating autoantibodies to normal allogeneic and autologous tissues were found in the sera of all infected rabbits tested; the titers of CF autoantibody occurring during infection were significantly higher than normally occurring titers of autoantibody in pre-infection serum samples. Autoantibody did not cross-react with trypanosome antigens, and Wassermann antibody was not detected in normal or infected rabbit sera.