Beta-keratin expression in avian tongue cell aggregates.

Rotation-mediated aggregation was used to test the capacity of early embryonic tongue cells from different regions of the tongue to reorganize histotypically and terminally differentiate in vitro. Cells dissociated from the anterior ventral (AV) or posterior ventral (PV) surface of the 12 day embryonic tongue were cultured 6 days, fixed, and embedded in paraffin. Indirect immunofluorescence microscopy was used to demonstrate the occurrence and distribution of beta-keratins, the presence of which represented regional and differentiation specific markers of late tongue development. Aggregates of AV cells were organized into a beta-keratin-producing stratified epithelium. Similar PV aggregates formed only an alpha-keratin-producing stratified epithelium. The epithelial cells of these tongue tissues constructs expressed alpha- and beta-keratins in a manner consistent with the temporal and histotypical expression of keratins observed in vivo.     

Races of Ammomanes deserti in Arabia.

T he Arabian patchwork of differently-coloured races of the "Desert Lark" (see Ibis, 1936, pp. 332–4) can now be exhibited in a more definite shape than three years ago, since we have much additional material to work on.     

Structural variations in actins. A study of the immunological reactivity of the N-terminal region.

The antigenicity of the N-terminal region of skeletal-muscle actin was analysed. Two epitopes, corresponding to the 1-7 and 18-28 sequences, were determined. The antibodies specific for the first epitope discriminate skeletal-muscle actin from cardiac-muscle and smooth-muscle actins. The antibodies specific for the second epitope interact with all the actins tested, ranging from invertebrate to higher-vertebrate actins.     

An immunological determination of specific activities of enzymes: its use in quantification of cross reactivity between enzymes of different origins.

An immunological method is presented which enables the determination of the specific activity of a pure enzyme without its extensive purification. The method consists essentially in the specific fixation of immunologically related enzymes to an immunoadsorbent containing specific antibodies raised against the wild-type form of the enzyme. We applied this method to determine the specific activity of plasmid-coded beta-galactosidases and to quantify the extent of cross-reaction between these enzymes and Escherichia coli beta-galactosidase.     

Disturbances in immunological reactivity in women with tuboperitoneal sterility

The role of immune disturbances on the systemic and local levels is evaluated and the immunological mechanisms of tuboperitoneal sterility as the basis for the development of the methods of immunocorrection is grounded.     

The influence of chlortetracycline on the immunological reactivity of chickens

Morphological examination of spleen and bursa of Fabricius of chickens fed on a diet without or with the addition of chlortetracycline (50, 100 and 200 CTC mg/kg) has shown that both low and high doses of antibiotic in the diet do not influence significantly the structure and reactivity of the lymphatic tissue following the antigenic stimulation. Certain differences were found in the number of lymphatic follicles in the spleen between control and experimental animals which received the highest dose 200 mg CTC/kg but even the greatest differences found on the fifth day after vaccination were not significant (P<0.1). On the other hand, the study of the level of agglutinin titres in the blood of control and experimental broilers has shown that the doses 100 and 200 mg CTC/kg in the diet have significantly influenced their production. After such doses the latent period was slightly lenghtened and both the highest and the average titres were lowered during the whole postvaccinal period to a degree which correlated the magnitude of dosage of the antibiotic.     

Characteristics of the immunological reactivity of the body in the streptococcal carrier state

The use of the discrete dynamic method for the treatment of data obtained in the survey of streptococcus carriers has made it possible to find out that their immune status is determined not so much by the quantitative changes in the results of individual immunological tests (for the bactericidal activity of the blood serum, lysozyme, IgG, IgM, IgA and the phagocytic activity of neutrophils), but, to a greater extent, by the interrelations of these characteristics. Significant differences in the interrelations of various humoral characteristics and in their relationship to the phagocytic process have been detected in the group of carriers as compared with the control group.     

Effect of carminomycin on the immunological reactivity of the body]

The morpho-functional state of the muscle lymphoid tissue of mice treated with karmionmycin (LD50, 1.1 mg/kg) was studied experimentally. Development of a number of changes evident of the cell disorganization in the lymphoid tissue was shown. The cytological shifts in the thymus and spleen were reversible, while the destructive period in the strumous gland was more prolonged. The morpho-structural normalization of the spleen did not coincide with reduction of its immunological function. The studies on the karminomycin effect on the kinetics of the primary immune response showed dependence of the antibiotic effect on the temporal ratio between the antigenic stimulus and the drug administration. The antibiotic had no effect on the inductive phase of the primary immune response but significantly suppressed its productive phase. On reproduction of the secondary immune response, a decrease in the content of the antibody-forming cells in the spleen was observed, production of the circulating antibodies remaining unchanged.     

Possible role of acrolein in oxazaphosphorine-induced enhancement of immunological reactivity

Summary The aim of the present study was to analyze further the immunopotentiating effects of low doses of oxazaphosphorines. We examined 4-hydroperoxycyclophosphamide (4-HC) and mafosfamide, which degrade spontaneously in water without requiring liver enzymes to become active. Both drugs, at concentrations ranging from 0.01 µM to 1 µM, enhanced mitogenic responses of human lymphocytes. Higher concentrations were toxic. Acrolein, which is one of the degradation products of oxazaphosphorines, had similar effects. Immunopotentiation was not monocyte-dependent. Attempts to inactivate released acrolein with human serum reduced toxicity but the immunostimulating property of the drugs remained Similar effects were noted when lymphocytes were exposed to acrolein dissolved in serum. 2-Mercaptoethanesulfonate (mesna), which is highly reactive with acrolein, reduced the toxicity of solutions of both oxazaphosphorines and acrolein. Immunopotentiation was not clearly demonstrable since mesna itself enhanced the responses. Pretreatment of lymphocytes with 4-HC or mafosfamide did not reduce the capacity of concanavalin A to induce suppressor cells. It is speculated that acrolein may play a role in oxazaphosphorine-induced enhancements of immune responses.