Polymerization of hemoglobin S in sickle red cells, in deoxygenated conditions, is associated with K1 loss and cellular dehydration. It was previously reported that deoxygenation of sickle cells increases protein tyrosine kinase (PTK) activity and band 3 tyrosine phosphorylation and that PTK inhibitors reduce cell dehydration. Here, the study investigates which PTKs are involved and the mechani...

This study investigated the effect of acute deoxygenation on membrane permeability characteristics of sickle cells. Measured fluxes of Na+ and K+ in ouabain-inhibited cells, of chloride and sulfate exchange in 4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS)-inhibited and untreated cells, and of erythritol, mannitol, and arabinose in cytochalasin B-inhibited cells indicated that a deoxygenat...

Sickle red blood cells (RBC) become dehydrated as a consequence of potassium loss. This process depends at least partly on deoxygenation and may be influenced by the presence of oxygenation/deoxygenation cycles and the frequency of cycling. In this study, sickle RBC were subjected to approximately 180 oxygenation/deoxygenation cycles during 4 hours to evaluate RBC dehydration with cycle periods...

Background: Deoxygenation of sickle erythrocytes activates a cation permeability of unknown molecular identity (Psickle), leading to elevated intracellular [Ca] ([Ca]i) and subsequent activation of KCa 3.1. The resulting erythrocyte volume decrease elevates intracellular hemoglobin S (HbSS) concentration, accelerates deoxygenation-induced HbSS polymerization, and increases the likelihood of cel...

Polymerization of hemoglobin S in sickle red cells, in deoxygenated conditions, is associated with K+ loss and cellular dehydration. It was previously reported that deoxygenation of sickle cells increases protein tyrosine kinase (PTK) activity and band 3 tyrosine phosphorylation and that PTK inhibitors reduce cell dehydration. Here, the study investigates which PTKs are involved and the mechani...

The growing body of clinical and experimental data regarding electromagnetic field (EMF) bioeffects and their therapeutic applications has contributed to a better understanding of the underlying mechanisms of action. This study reports that two EMF modalities currently in clinical use, a pulse-modulated radiofrequency (PRF) signal, and a static magnetic field (SMF), applied independently, incre...

INTRODUCTION Discrepancies of 5-24% between superior vena cava oxygen saturation (ScvO2) and mixed venous oxygen saturation (SvO2) have been reported in patients with severe heart failure. Thenar muscle tissue oxygenation (StO2) measured with near-infrared spectroscopy (NIRS) during arterial occlusion testing decreases slower in sepsis/septic shock patients (lower StO2 deoxygenation rate). The ...

A highly efficient, two-step sequence method for the deoxygenation of hydroxyl groups has been developed. The method involves the preparation of the 2-(2-iodophenyl)ethyl methyl phosphite derivative of an alcohol using methyl dichlorophosphite and 2-(2-iodophenyl)ethanol. Treatment of the phosphite intermediate with (n-Bu)3SnH/AIBN in refluxing benzene cleanly produces the deoxygenation product...

BACKGROUND: This study examined muscle deoxygenation trends before and after a 7-day taper using non-invasive near infrared spectroscopy (NIRS). METHODS: Eleven cyclists performed an incremental cycle ergometer test to determine maximal oxygen consumption (VO2max = 4.68 +/- 0.57 L.min-1) prior to the study, and then completed two or three high intensity (85-90% VO2max) taper protocols after bei...

A cardiopulmonary exercise test (CPX) can provide objective measures of exercise capacity. Specifically, incremental ramp exercise (IRE) and constant work-rate exercise (CWE) protocols are frequently used in clinical practice and for research. The CWE endurance time has shown larger increases than other indexes assessed by IRE after rehabilitation intervention. Muscle oxygen extraction is one o...