Testosterone, androstenedione, cortisol and cortisone levels in human unstimulated, stimulated and parotid saliva.

Background: Recently, measurements of steroids like testosterone, androstenedione, cortisol and cortisone in saliva are more and more applied in diagnostics and scientific studies. This is mainly due to the simple and non-invasive collection of saliva. We aimed to evaluate the optimal way to collect saliva for steroid hormone measurement.

Silicon-mediated changes on some physiological and enzymatic parameters symptomatic of oxidative stress in barley grown in sodic-B toxic soil.

The effect of silicon (Si) on the growth, sodium (Na), chloride (Cl), boron (B) concentrations, lipid peroxidation (MDA), membrane permeability (MP), lypoxygenase activity (LOX), proline (PRO) and H(2)O(2) accumulation, and the activities of major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT and ascorbate peroxidase, APX) of barley grown in original sodic-B toxic soil were investigated. Si applied to the sodic-B toxic soil at 70, 140 and 280 mg kg(-1) levels significantly increased Si concentrations of the plants and counteracted the deleterious effects of sodicity (Na ions) and B on shoot growth. Membrane permeability and the concentrations of H(2)O(2) and MDA increased, while PRO concentration decreased in plants grown in sodic-B toxic soil without Si.

Salicylic acid induced changes on some physiological parameters symptomatic for oxidative stress and mineral nutrition in maize (Zea mays L.) grown under salinity.

It has been proposed that salicylic acid (SA) acts as an endogenous signal molecule responsible for inducing abiotic stress tolerance in plants. The effect of varying salicylic acid (SA) supply (0, 0.1, 0.