PubMed Health⌕ Search

Biomedical subjects

J M Talent

Publications and source records attributed to J M Talent.

25 records · Page 2Linked to original sources
PubMed1976

Isolation of rabbit muscle glucosephosphate isomerase by a single-step substrate elution.

A simple method has been developed for the rapid isolation of crystalline glucosephosphate isomerase (EC 5.3.1.9) from rabbit muscle. The enzyme is first bound to cellulose phosphate by adding the ion exchanger to a solution of the crude tissue extract. After filtering and washing the cellulose with buffer, the isomerase is specifically eluted in a batch process by its substrate, glucose 6-phosphate. The entire procedure is very rapid and results in a good recovery (at least 50%) of the enzyme with specific activity of approximately 900 units per mg. The enzyme is homogeneous by polyacrylamide gel electrophoresis in the presence of absence of sodium dodecyl sulfate and by analytical ultracentrifugation.

Animals↗
PubMedDate not supplied

Pilot study of oral polymeric N-acetyl-D-glucosamine as a potential treatment for patients with osteoarthritis.

Glucosamine and its derivatives, such as glucosamine sulfate and N-acetyl-D-glucosamine (NAG), have been shown to be effective in the treatment of patients with osteoarthritis. Unfortunately, the half-life of glucosamine in the blood is relatively short; therefore, a sustained-release form of the compound would be highly desirable. The purpose of this pilot study was to determine whether the polymeric form of NAG (POLY-Nag) could provide a longer-lasting oral source of NAG. Ten healthy subjects each ingested 1 g/d of either NAG or POLY-Nag for 3 days. After a 4-day washout period, each subject was crossed over to receive the other compound for 3 days. Serum samples were collected and analyzed using high-performance liquid chromatography. Results show that orally ingested NAG and POLY-Nag are absorbed, resulting in increased serum levels of NAG, and POLY-Nag appears to be at least as effective as NAG. Serum levels of NAG had decreased by 48 hours after cessation of ingestion of NAG or POLY-Nag but were still above baseline levels. Increases in serum glucosamine levels indicate that NAG and POLY-Nag are converted to glucosamine in vivo. In conclusion, POLY-Nag may provide a source of serum glucosamine for treatment of patients with osteoarthritis. Longer and more rigorous pharmaco-kinetic and clinical studies need to be done.

Absorption↗
PubMedDate not supplied

Molecular wear and tear leads to terminal marking and the unstable isoforms of aging.

Our studies focus on the mechanisms of molecular wear and tear, terminal marking, protein degradation, and how these processes are altered with age. Molecular wear and tear directly links catalysis with postsynthetic terminal marking. For example, the binding of ligands and catalysis cause conformational changes that are transmitted from the catalytic center to the site of terminal marking and enhance the rates of specific covalent modifications, such as deamidation or oxidation. These oxidations or deamidations can introduce "KFERQ motifs" into proteins, which may permit them to be recognized and transported to the site(s) of complete degradation. Terminally marked proteins accumulate in aging cells and tissues and account for many of the health problems of the elderly. Two-dimensional protein fingerprinting coupled with immunostaining permits identification and characterization of these proteins. Free-radical traps or caloric restriction, which may prevent the formation or enhance the degradation of terminally marked proteins, may be useful in the prevention or treatment of age-associated health problems, including dementia.

Aged↗