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Haemocytes from the crayfish (Parachaeraps bicarinatus) have been found to be cytotoxic for various tumour cell lines. Recognition of the tumour cell appears to be mediated via trypsin labile receptors on the membrane of the haemocyte. From studies using different ratios of target cells to haemocytes, it would appear that the majority of haemocytes possess these cytotoxic properties. [ABSTRACT FROM AUTHOR]

Examines the phagocytosis of bacteria in vitro by haemocytes from the crayfish or Parachaeraps bicarinatus. Dependence of the uptake of bacteria by the cells on recognition factors which may be present either in free in the haemolymph or associated with the plasma membranes of phagocytic cells.

Studies the effect of the depletion of T lymphocytes on the production of ablastin and the termination of the parasitemias in Porton strain rats infected with Trypanosoma lewisi. Antibody resopnse to sheep red blood cells; Challenge with an intracellular bacterial parasite Salmonella typhimurium.

Reports that eosinophils and neutrophils from the blood of infected mice resistant to reinfection were tested for their ability to adhere to the different parasitic larval stages of the murine nematode parasite Nematospiroides dubius. Indication that N. dubius may undergo a series of antigenic changes during its life cycle; Conclusion that antibodies capable of mediating a granulocyte attachment are elicited predominantly against the early tissue developmental forms of the parasite.

Examines the effect of splenectomy on the production of ablastin and the termination of the parasitaemia in rats infected with trypanosoma lewisi. Administration of splenectomy on research subjects either before or during various stages of infection and the course of the parasitaemia compared with untreated control animals; Measurement of ablastin titres in the serum by a sensitive in vitro assay; Ability of the surgically operated animals to eliminate the parasite slowly from the circulation compared to non-operated controls.

Reports on the activation of complement via the alternative pathway by the cuticular surface of the infectious third-stage larvae of Nematospiroides dubius. Promotion of the adherence of mouse peritoneal exudates cells to the larval cubicle during incubation in vitro by the sensitization of larvae with complement or with antibodies from the serum of immune mice; Reduction of the infectivity of larvae sensitized with antibody or complement after incubation with cells from immune mice.

Examines the mechanisms of immunity in nude mice to an infection with Nematospiroides dubius. Reasons behind the susceptibility of nude mice to Nematospiroides infection; Full complement of T cells needed to develop maximum resistance against the infective third-stage larvae.

A quantitative study has been made of the phagocytosis of various particles by the developing chick embryo. The phagocytosis of rough strains of bacteria is much more efficient compared with that of smooth strains. The importance of serum opsonins in promoting phagocytosis and the possible origin of these factors in the chick embryo are discussed. [ABSTRACT FROM AUTHOR]

Describes a method for the partial purification of the opsonins in pig serum which are directed against a strain of Salmonella typhimurium. Factors which occur in the beta-globulin fraction; Occurrence of antibodies produced by specific immunization of the pig in the gamma globulin fraction.

Discusses a study on the capability of the crayfish for adaptive immune response. Measurement of the increase in resistance to infection by a strain of Pseudomonas following treatment with various vaccines; Dependence of the expression of the response on the dose of antigen; Indication of the preparation of vaccines from gram-negative bacteria.

Reports on changes in the adaptive immune response of the crayfish to infection following immunization. Change of the activity of phagocytic cells; Measurement of cell activity by the phagocytosis of erythrocytes; Treatment of the erythrocytes with haemolymph.

Discusses the purification and properties of a hemagglutinin for rat red cells present in the hemolymph of the Murray Mussel by density gradient centrifugation. Claim that purified hemagglutinin is one of several which behave as a homogenous group of proteins; Suggestion that these proteins lack tyrosine and sulphur-containing amino acids.

Describes a method for the quantitative measurement of chemotaxis in amoeba. Chemotactic movement of Hartmannella rhysodes towards a food source; Adaptation of the Boyden method for measuring chemotaxis of rabbit polymorphonuclear cells; Heat stable chemotactic factor.

Studies the distribution of the heat labile protective antigen of Salmonella typhimurium amongst other strains of apparently unrelated gram-negative bacteria. Suggestion that only certain antibodies are effective in promoting killing by phagocytic cells; Evidence that antigen is possessed by a number of different species of bacteria.

Investigates the passive transfer of immunity to mouse typhoid by phagocytic cells harvested from the peritoneal cavity of immune mice. Development of carrier state in mice using Salmonella typhimurium; Presence of cell-bound antibody; Concept of cellular immunity; Effect of trypsin treatment on cell-transfer immunity.

Examines antibody formation in mice vaccinated with living attenuated culture of Salmonella typhimurium. Formation of antibodies during carrier state; 19S macroglobulin response which disappears about a month; Persistence of 7S type antibody for at least six months; Cellular immunity.

Examines carrier state in mouse typhoid induced by Salmonella typhimurium. Immunity to mouse typhoid; Enhanced resistance to superinfection due to the production of specific antibody; Persistence of the bacteria in the reticulo-endothelial system due to a heterogeneity in the bactericidal properties of the population of phagocytic cells.

Using a bactericidal assay for the presence of antibody it was found that 1-day-old chicks had little natural antibody against Salmonella gallinarum. However, in contrast adult hens possessed relatively higher levels. The titre of antibody could not be increased in chicks by prior immunization at the time of hatching. These results are in conflict with those recently reported by Solomon (1968a). [ABSTRACT FROM AUTHOR]