The supernatant fluid of axenically grown E. histolytica inhibits chemotaxis, chemokinesis and random mobility of human mononuclear phagocytes (MP) as measured in Boyden chambers. Human polymorphonuclear phagocytes (PMN) locomotion is apparently unaffected. The factor was found in comparable amounts in the supernatant fluid of axenic cultures of four E. histolytica strains that differed in their human pathogenicity and virulence, as well as in two entamoebas non-pathogenic for man. This dialysable and thermolabile MP-locomotion inhibiting entamoeba product (EP) can be absorbed out by incubation with MP, but not with lymphocytes, while partial absorption was observed using PMN. The MP-locomotion inhibitory effect of this EP was cancelled by inhibiting protein synthesis in the MP by means of cycloheximide. In vivo, this EP caused a delay in MP migration in Rebuck skin windows. The molecular weight of this EP lies between 478 and 765 by gel-sieve chromatography. Our results suggest a direct effect upon the cytoskeletal and locomotive apparatus of the MP. This MP-locomotion inhibiting EP could contribute to the paucity of the inflammatory reaction observed in the advanced stages of invasive amoebiasis and consequently also to the lack of scar tissue formation upon healing of amoebic lesions.

Duringthe preimplantation period, morphological and functional characteristics

No abstract

The presence of rabbit spermatozoa in the uterine horn of the doe over a 10-hr period induced an increase in the incorporation of leucine-14C and orotate-3H [from 230 +/- 50 to 520 +/- 32 and 146 +/- 41 to 432 +/- 40 (dpm 10(3) mg DNA; Mean +/- SEM)] into endometrial proteins and nucleic acids. The addition of actinomycin D or cyclohexamide significantly inhibited this process. The intraluminal administration of dibutyryl cyclic AMP (dbcAMP) (control group) induced an increase two times greater than that produced by spermatozoa. The increase in the incorporation of radioactive precursors into endometrial macromolecules induced by the spermatozoa is independent of the uterine carbonic anhydrase activation produced by this cell.

No abstract