Effects of prolonged low-level cadmium exposure on the tadpole immune system.

Uninjected (Group I) and sheep erythrocyte (SRBC)-injected (Group II) Rana tadpoles were exposed to varying sublethal concentrations of cadmium (Cd) for 6 weeks. In order to assess possible effects on the tadpole immune system we determined pre-B, B mu, and plasma cell (PC mu) frequencies in liver and mesonephros of Group I larvae, and hemagglutinating antibody (HA) titers of Group II animals. Group I and Group II control animals were cultivated in water with no added Cd (0 ppm), while treatments were set at 0.

Human mononuclear leukocyte transglutaminase activity is enhanced by streptococcal erythrogenic toxin and a staphylococcal mitogenic factor associated with toxic shock syndrome.

Transglutaminase activity in human peripheral lymphocytes is enhanced after incubation of the cells with concanavalin A. Streptococcal proliferative factor toxin (erythrogenic toxin) from Streptococcus pyogenes and Toxic shock syndrome toxin from Staphylococcus aureus were purified and tested for their ability to enhance transglutaminase activity. Mononuclear leukocyte transglutaminase activity was enhanced 3-5-fold 30 min after incubation with either toxin.

Keratolinin: the soluble substrate of epidermal transglutaminase from human and bovine tissue.

Substrates of human and bovine epidermal transglutaminase (glutaminyl-peptide gamma-glutamyltransferase, R-glutaminyl-peptide:amine-gamma-glutamyltransferase, EC 2.3.2.

Biochemistry of transglutaminases and cross-linking in the skin.

Transglutaminase is a calcium-dependent enzyme found widely in nature. It catalyzes the formation of epsilon-(gamma-glutamyl)lysine bonds that participate in processes varying from fibrin clot formation to epidermal cell envelope formation. Epidermal transglutaminase is localized to the granular layer of the epidermis.

Type IV collagen from chicken muscular tissues. Isolation and characterization of the pepsin-resistant fragments.

Type IV collagen has been isolated from adult chicken gizzard after limited pepsin digestion and subsequent differential salt fractionation in acidic and neutral conditions. After denaturation, three fragments (called F1, F2, and F3) were isolated by agarose gel filtration and carboxymethylcellulose chromatography. F1 and F2 possessed apparent molecular weights of 53 000 and 50 000, respectively, and were consistently isolated in a 2:1 proportion.

Isolation and partial characterization of basement membrane-like collagens from bovine thoracic aorta.

Collagen polymorphism was investigated in the bovine thoracic aortic media after extraction by a technique involving reduction of disulfide bonds followed by limited pepsin digestion. Type I, III, IV and V collagens were all fractionated from each other in the native state by differential salt precipitation both in acidic and neutral conditions. Type IV and V collagen were both found to be similar, if not identical, to the same collagens isolated from other tissues, the Type IV collagen fraction clearly containing two different alpha-sized components.

Separation of spleen colony forming units (CEU-S) from mouse bone marrow cells using velocity sedimentation in an isokinetic gradient of Ficoll in tissue culture medium.

Spleen colony forming cells (CFU-S) from mouse bone marrow were concentrated using velocity sedimentation in an isokinetic gradient of Ficoll (polysucrose) in tissue culture medium. Following separation, CFU-S were found as a sharp modal population of cells which was discrete from the modal populations of lymphocytes and other cell types. Despite the wide separation of lymphocytes, granulocytes and CFU-S in the density gradient, there was no appreciable resolution of CFU-S specifically committed to erythroid, granulocytic or undifferentiated colony formation.