W J Barcellona

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The location and characteristics of carbohydrate-containing structures within the intact sheath of Volvox were studied by 3,3'-diaminobenzidine tetrahydrochloride-osmium, colloidal iron, colloidal thorium, ruthenium red and periodic acid-silver methenamine staining. The sheath consists of external and internal fibrillar layers separated by a tripartite(More)
The incorporation of radioactivity into various cells in the sequence of spermatogenesis was measured by preparing highly purified spermatozoan nuclei from the cauda epididymidis of mice at daily intervals after injection of (3H)thymidine. The stages of differentiation of these sperm at the time of thymidine administration were calculated from the kinetics(More)
Mouse testicular cells were examined ultrastructurally to determine whether the cells are damaged during the preparation of single-cell suspensions or during cell separation. The testicular cells were dissociated from seminiferous tubules by trypsinization and were fixed immediatley; fixed after being held in suspension for 4 h at 4 degrees C; or fixed(More)
Large granulomas (greater than 2 millimeters in diameter), stimulated by the presence of and formed around necrotic larval tissue in the inner demibranchs of Corbicula fluminea, are eliminated by autotomy. Granulocytes invade and destroy ctenidial epithelium adjacent to the granuloma, causing it and the granuloma to slough away into the mantle cavity, where(More)
Cis-Pt(II)-uracil staining reveals nucleic acids in a relatively specific manner when applied alone for 1 h to rat brain tissue specimens. Poor contrast and resolution are observed when glutaraldehyde-fixed and epoxyembedded thin sections are post-stained with cis-Pt(II)-uracil alone. Counterstaining thin sections with uranyl acetate decreases staining(More)
Corynebacterium xerosis cell-wall fractions were studied by electron microscopy and analysed for immunomodulating activity. Dramatic splenomegaly occurred following the injection of whole cells or a purified cell-wall fraction (PF), but not with a further purified peptidoglycan (PEP) fraction. Both PF and PEP acted as B-cell mitogens and had adjuvant(More)
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