Experiments were conducted to determine whether the nitrate flux to the leaves or the nitrate content of the leaves regulated the nitrate reductase activity (NRA) in leaves of intact maize (Zea mays L.) seedlings having low water potentials (psi(w)) when other environmental and endogenous factors were constant. In seedlings that were desiccated slowly, the nitrate flux, leaf nitrate content, an...

Nitrate-independent nitrate reductase (NR) activity is generally found in legume root nodules. Therefore, the effects of nitrate on plant NR activity and mRNA were investigated in the root nodules of Lotus japonicus (L. japonicus). Both NR activity and mRNA levels in roots and root nodules were up-regulated by the addition of nitrate. In the absence of nitrate, NR activity and mRNA were detecte...

Human oral cavities represent a novel environment with a constant supply of concentrated nitrate. For humans, over 80% of dietary nitrate originates from fruit and vegetables. With a healthy, balanced diet, rich in fruit and vegetables, the concentration of nitrate in saliva can reach up to more than three times the European drinking water standard. The physiological function of the active excr...

In plants, the nitrate transporters, NRT1.1 and NRT2.1, are mainly responsible for nitrate uptake. Intriguingly, both nitrate transporters are located in a complementary manner in different cells layers of the mature root suggesting that their coordination should occur during nitrate uptake and plant growth. This hypothesis was examined on 5-d-old rape seedlings grown on agar medium supplemente...

BACKGROUND Venous blood sampling is usually performed using a tourniquet to help locate and define peripheral veins to achieve successful and safe venipuncture. Despite widespread usage of tourniquets for venipuncture by medical and laboratory staff, very few are aware of the effects of tourniquet application on laboratory parameters. In addition, definitive guidelines regarding when and how to...

BACKGROUND Findings from national surveys suggest that everyone in the United States is exposed to perchlorate. At high doses, perchlorate, thiocyanate, and nitrate inhibit iodide uptake into the thyroid and decrease thyroid hormone production. Small changes in thyroid hormones during pregnancy, including changes within normal reference ranges, have been linked to cognitive function declines in...

BACKGROUND Considerable evidence suggests that hyperhomocysteinemia is an independent vascular risk factor that promotes atherosclerosis by inducing endothelial dysfunction. Although folic acid reduces hyperhomocysteinemia, the effect on adverse vascular events is unknown. We hypothesized that in patients with chronic renal failure, a condition associated with both hyperhomocysteinemia and athe...

The present interest in the determination of thiocyanate in serum, following the injection or ingestion of its salts, is twofold. First, in order to control hypertension by administering thiocyanate, the dosage must be regulated by frequently checking serum levels, as pointed out by Barker (1) and Wald, Lindberg, and Barker (2). Secondly, the determination of extracellular fluid, as originally ...

BACKGROUND Postoperative cognitive dysfunction (POCD) has been an important complication of cardiac surgery over the years. Neurocognitive dysfunction can affect quality of life and lead to social, functional, emotional, and financial problems in the patient's life. To reduce POCD, we sought to identify the association between cognitive dysfunction and perioperative factors in patients undergoi...