While the role of creatine in preventing muscle (peripheral) fatigue for high performance athletes is well understood, its biochemical role in prevention of mental (central) fatigue is not. Creatine is abundant in muscles and the brain and after phosphorylation used as an energy source for adenosine triphosphate synthesis. Using double-blind placebo-controlled paradigm, we demonstrated that die...

In order to clarify the reaction mechanism of Mryptophan 2,3-dioxygenase (L-tryptophan: oxygen oxidoreductase, EC 1.13.1.12), a hemoprotein, spectral and kinetic studies were carried out with highly puritied enzyme preparations from Pseudomonas fluorescens (ATCC 11299). A new spectrally distinct species of the enzyme heme omx; 418,545, and 580 mp) was observed during the steady state of the cat...

A laser photolysis technique has been developed to assess the quantitative significance of the delay time of hemoglobin S gelation to the pathophysiology of sickle cell disease. Changes in the saturation of hemoglobin S with carbon monoxide produced by varying the intensity of a photolytic laser beam were used to simulate changes in the saturation of oxyhemoglobin S produced by variations in ox...

Using a newly developed perfused rat brain model, we examined direct effects of each change in cerebral blood flow (CBF) and oxygen metabolic rate on cerebral hemoglobin oxygenation to interpret near-infrared spectroscopy signals. Changes in CBF and total hemoglobin (tHb) were in parallel, although tHb showed no change when changes in CBF were small (< or =10%). Increasing CBF caused an increas...

BACKGROUND Aerobic adaptations following interval training are supposed to be mediated by increased local blood supply. However, knowledge is scarce on the detailed relationship between exercise duration and local post-exercise blood supply and oxygen availability. This study aimed to examine the effect of five different exercise durations, ranging from 30 to 240 s, on post-exercise muscle oxyg...

During surgical treatment for cerebrovascular diseases, cortical hemodynamics are often controlled by bypass graft surgery, temporary occlusion of arteries, and surgical removal of veins. Since the brain is vulnerable to hypoxemia and ischemia, interruption of cerebral blood flow reduces the oxygen supply to tissues and induces irreversible damage to cells and tissues. Monitoring of cerebral he...

A pilot human study is conducted to evaluate the potential of using diffuse photon density wave (DPDW) methodology at near-infrared (NIR) wavelengths (685 to 830 nm) to monitor changes in tissue hemoglobin concentration in diabetic foot ulcers. Hemoglobin concentration is measured by DPDW in 12 human wounds for a period ranging from 10 to 61 weeks. In all wounds that healed completely, gradual ...

RATIONALE AND OBJECTIVES This study measures hemodynamic properties such as blood flow and hemoglobin concentration and oxygenation in the healthy human breast under a wide range of compressive loads. Because many breast-imaging technologies derive contrast from the deformed breast, these load-dependent vascular responses affect contrast agent-enhanced and hemoglobin-based breast imaging. MET...

OBJECTIVE To determine whether the inferior turbinate, which contains swelling bodies, and the nasal septum (Kiesselbach area), characterized by a dense arterial mesh, exhibit different swelling mechanisms in allergic nasal reactions. DESIGN Two optical rhinometers were used to examine 11 patients in the clinic. Optical rhinometry is based on the transillumination of the nasal septum and infe...