Agreement between the GAITRite walkway system and a stopwatch-footfall count method for measurement of temporal and spatial gait parameters.

Objective: To determine the agreement for measurements of stride length, cadence, and walking speed obtained from the GAITRite system and the stopwatch-footfall count technique.

Design: Criterion standard.

Setting: Research laboratory in a physical therapy education program.

Ascorbic acid-dependent cytoprotection of ovarian cells by leukocyte and nonleukocyte peroxidases.

Luteal cells contain high levels of ascorbic acid that is secreted by stimulation with agents like luteinizing hormone (LH) and prostaglandin F2 alpha (PGF2 alpha). One role for interstitial ascorbic acid, we propose, may be the detoxification of H2O2 by regeneration of catalytically active peroxidase. By serving as a preferred secondary substrate, ascorbic acid regenerates the catalytically active peroxidase that is inhibited irreversibly by H2O2 alone.

Prostaglandin f2alpha treatment in vivo, but not in vitro, stimulates protein kinase C-activated superoxide production by nonsteroidogenic cells of the rat corpus luteum.

Luteal regression is associated with the generation of reactive oxygen species (ROS). To determine the nature of the ROS generator, cells isolated from luteinized rat ovaries were examined for ROS production using luminol-amplified chemiluminescence (LCL). Cells cultured for 2-48 h exhibited minimal LCL, but there was a significant (30- to 50-fold), rapid (maximum at 3-5 min), and dose-dependent increase in LCL in response to phorbol ester (phorbol 12-myristate 13-acetate; TPA; ED50 = 0.

Accumulation of ascorbate by endocrine-regulated and glucose-sensitive transport of dehydroascorbic acid in luteinized rat ovarian cells.

The corpus luteum is notable for very high levels of ascorbic acid. In luteal cells, ascorbic acid depletion occurs as a result of consumption during radical scavenging, inhibition of ascorbic acid uptake, and stimulation of its secretion. Oxidation of ascorbic acid generates dehydroascorbic acid (DHAA).

Hormone induction of ascorbic acid transport in immature granulosa cells.

Ascorbic acid serves a vital role as an antioxidant, and like FSH, it inhibits apoptosis of granulosa cells in cultured follicles. In contrast, reactive oxygen species block the action of FSH and induce DNA damage in these cells. As the uptake of ascorbic acid by granulosa cells may be a site for regulation, we examined the nature of this process and whether uptake is under hormone control.