A spectroscopic investigation of cobalt(II) substituted alkaline phosphatase.

The electronic and 1H NMR spectra are reported for the cobalt(II) alkaline phosphatase (EC 3.1.3.

Immunoblot analysis of Salmonella typhi lipopolysaccharide (LPS) using typhoid sera.

Lipopolysaccharide (LPS) of Salmonella typhi has been analyzed by immunoblotting with pooled sera from typhoid patients. Pooled typhoid sera have recognized all the antigenic determinants of S. typhi LPS, giving a strong reaction with the repeating units on the O-side chains as well as with the core region.

A sensitive spectrophotometric method for the determination of superoxide dismutase activity in tissue extracts.

Superoxide dismutase (EC 1.15.1.

Immunoaffinity purification of rat liver transketolase: evidence for multiple forms of the enzyme.

Rat liver transketolase (TK) has been purified, in a single step, by immunoaffinity chromatography on specific TK antibodies covalently linked to Sepharose 4B. The procedure described also involves the raising and isolation of rabbit TK antibodies to the conventionally purified enzyme [F. Paoletti (1983) Arch.

Immune mechanisms for hepatic fibrogenesis. T-lymphocyte-mediated stimulation of fibroblast collagen production in chronic active hepatitis.

Lymphocytes can produce soluble factors capable of enhancing fibroblast proliferation and collagen synthesis. T-lymphocytes, adherent cells and undifferentiated peripheral blood mononuclear cells from patients with HBsAg-positive chronic active hepatitis and from HBsAg healthy carriers were triggered with purified HBsAg and tested for their ability to enhance collagen production by human dermal fibroblast cultures. Purified HBsAg did not induce any proliferative response in the mononuclear cell cultures.

Purification and properties of transketolase from fresh rat liver.

Transketolase has been purified from rat liver. The final product is judged to be homogeneous by the criteria of gel filtration on Sephadex G-200 and Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The estimated Mr's are 139,000 for the native protein and 69,000 for the dissociated subunits.

The role of respiration in tumor cell transition from the noncycling to the cycling state.

Resting Yoshida AH130 hepatoma cells, harvested at the plateau of tumor development in vivo, were recruited into the cycling state following transfer to an in vitro system whereby these cells were incubated in the autologous ascites plasma diluted with buffered saline and enriched with glucose. In this system, cell recruitment into the phase of DNA synthesis (S phase) strictly depends on the activity of the respiratory chain and is abolished by anaerobiosis as well as by antimycin A, although the intracellular levels of ATP and the rate of protein synthesis are practically unaffected by these treatments. Furthermore, 2,4-dinitrophenol, at concentrations which uncouple the respiratory phosphorylation and hence enhance both glycolysis and oxygen consumption, does not hinder cell promotion into S phase.

Studies on the kinetics of initial cycle progression in vitro of ascites tumour cells subsequent to isolation from ascites fluid.

A method is described for determining the duration of cell cycle phases traversed by cells responding to release from proliferation restraint. Experiments have been performed with arrested Yoshida ascites hepatoma cells allowed to re-enter the growing stage after transfer of cells from the late stage of ascites into an in vitro incubation system. Experimentally, this method requires information on the rate of incorporation of labelled thymidine and on the rate of increase in cell number.

Protein metabolism in tumor cells at various stages of growth in vivo.

Protein metabolism of Yoshida ascites hepatoma cells was studied in the early phase of logarithmic proliferation and in the following stage in which cell mass remains constant (resting phase). The rate of protein synthesis was measured by a short-time incorporation of [(8)H]lysine, while degradation was concurrently assessed by following the decrease of specific activity of [(14)C]lysine-labeled proteins. Most of the labeled amino acid injected intraperitoneally into the animal was immediately available for the tumor cells, with only a minor loss towards the extra-ascitic compartment.