The acrosome is a large secretory vesicle of the sperm head that carries enzymes responsible for the digestion of the oocyte's investments. The event leads to sperm penetration and allows fertilization to occur. Release of the acrosomal enzymes is mediated by the interaction between sperm acrosomal and plasma membranes (acrosome reaction). Biochemical characterization of the acrosomal membrane ...

Numerous studies have reported the capacity of the lectin, concanavalin A, to agglutinate selected cell-types. The finding that cells transformed in culture, embryonic cells, and malignant cells are all agglutinated by this substance, may contribute to our understanding of the oncogenic process. The present study compared the response to concanavalin A of rat hepatocytes derived from livers of ...

[*] R. E. McDonald, Dr. B. G. Davis Dyson Perrins Laboratory Department of Chemistry, University of Oxford South Parks Road, Oxford, OX1 3QY (UK) Fax: (+44)1865-275-674 E-mail: [email protected] Dr. D. J. Hughes Syngenta Jealott's Hill International Research Centre Bracknell, Berkshire, RG42 6EY (UK) [**] We thank the UK Engineering and Physical Sciences Research Council and Syngenta for ...

AIM To explore the influence of Escherichia coli on the motility of human spermatozoa and its possible mechanism. METHODS Highly motile preparations of spermatozoa from normozoospermic patients were coincubated with Escherichia coli for 4 hours. At 1, 2 and 4 hours of incubation, sperm motility was determined. The factor responsible for sperm immobilization without agglutination was isolated ...

1. O’Rand MG, Widgren EE, Fisher SJ. Characterization of the rabbit sperm membrane autoantigen, RSA, as a lectin-like zona binding protein. Dev Biol. 1988;129:231-240. 2. Lim SH, Wang Z, Chiriva-Internati M, Xue Y. Sperm protein 17 is a novel cancer-testis antigen in multiple myeloma. Blood. 2001;97:1508-1510. 3. Chiriva-Internati M, Wang Z, Salati E, Timmins P, Lim SH. Tumor vaccine for ovaria...

Exactly 100 years ago, F.R. Lillie reported chemotaxis in animal sperm for the first time (Lillie, 1912). Chemo-taxis refers to the directed movement of a cell or organism to the source of a chemical gradient; the chemical agent that elicits this movement is called a chemoattrac-tant. Chemotaxis had previously been shown by Pfeffer (1884) for fern spermatozoids; however, attempts to demonstrate...

BACKGROUND Contraceptive vaccines can provide valuable alternatives to current methods of contraception. We describe here the development of sperm-reactive human single chain variable fragment (scFv) antibodies of defined sperm specificity for immunocontraception. METHODS Peripheral blood leukocytes (PBL) from antisperm antibody-positive immunoinfertile and vasectomized men were activated wit...

L&in-induced agglutination is a complex process determined by several factprs such as the nature of lectin (valency, binding constant) the properties of cell membrane (fluidity, distribution of lectin receptor sites) and the metabolic state of the cell (microvilli, microtubules, microfilament) [l-3] . In order to assess quantitatively the effect of each of these factors, one has to obtain the t...