[Pathophysiological aspects of wound healing in normal and diabetic foot].

The main cause of long-term healing of ulcers in patients with diabetic foot is considered to be direct mechanical damage when walking due to reduced sensitivity to due to neuropathy, hyperglycemia, infection and peripheral artery disease. These factors determine the standard approaches to the treatment of diabeticfoot, which include: offloading, glycemic control, debridement of ulcers, antibiotic therapy and revascularization. Recently, however, disturbances in the healing process of the skin in diabetes recognized an additional factor affecting the timing of healing patients with diabetic foot. Improved understanding and correction of cellular, molecular and biochemical abnormalities in chronic wound in combination with standard of care for affords new ground for solving the problem of ulcer healing in diabetes.

[Role of viscosity and permeability of erythrocyte plasmatic membrane in controlling the oxygen transport effectiveness by human hemoglobin on completion of space flight].

Plasmatic membrane viscosity and permeability and hemoporphyrine conformation in human hemoglobin were studied on completion of long-duration space flight (LSF). Reversible increases in viscosity and selective permeability (Na+/H+ -turnover) of erythrocyte plasmatic membrane were observed immediately after and in the period of recovery from LSF. Viscosity of lipids in both external and internal locations of plasmatic membrane in human erythrocytes was changed after LSF. The reversible rise of the Na+/H+ -turnover is likely to alter intracellular pH and oxygen binding with hemoglobin. The former is confirmed by the concurrent reversible decline in the deoxyhemoglobin ability to bind oxygen and the oxyhemoglobin ability to retain oxygen. In LSF and during readaptation to the normal gravity blood levels of hemoglobin and free iron are known to be reduced and may be answerable for the hypoxic state of human organism.

Ion transport, membrane fluidity and haemoglobin conformation in erythrocyte from patients with cardiovascular diseases: Role of augmented plasma cholesterol.

Tissue hypoxia, which plays a key role in the development of renal and vascular complications of cardiovascular diseases (CVD), might be considered a consequence of vascular remodeling and/or attenuated oxygen (O(2)) delivery by erythrocytes. Using Raman spectroscopy (RS), we observed that erythrocytes from patients with CVD exhibit changes in the conformation of haemoglobin (Hb) haemoporphyrin (HP), reflecting its lower O(2) transport capacity. Hypertriglyceridemia and hypercholesterolemia are well-known hallmarks of CVD. This study examined the role of plasma lipids in the regulation of erythrocyte membrane viscosity, oxy-Hb content as well as Na(+)/H(+) exchange and Ca(2+)-ATPase, whose activities are altered in patients with CVD. HP conformation was assessed by RS of blood samples. Membrane fluidity was estimated at depths of 0.6-0.8 and 2.2nm by electron-paramagnetic resonance spectroscopy of erythrocytes loaded with spin-labeled 5-doxylstearic acid and 16-doxylstearic acid, respectively. Ion-selective electrodes were employed for the study of H(+) and Ca(2+) fluxes. Both oxy-Hb content and erythrocyte membrane fluidity were decreased in essential hypertension and coronary artery disease patients and negatively correlated with plasma cholesterol but not triglyceride content. This observation allows us to assume that decreased oxy-Hb content in patients with CVD is caused by high plasma cholesterol via attenuation of erythrocyte membrane fluidity and its permeability to O(2). Plasma cholesterol level correlated positively and negatively with erythrocyte Na(+)/H(+) exchange and Ca(2+)-ATPase, respectively. However, in contrast to membrane fluidity, the impact of these ion transporters in oxy-Hb regulation under baseline conditions seems to be negligible. We propose that decreased oxy-Hb content contributes to the reduced O(2) tissue supply seen in patients with CVD.

Role of viscosity and permeability of the erythrocyte plasma membrane in changes in oxygen-binding properties of hemoglobin during diabetes mellitus.

Changes in viscosity and permeability of the plasma membrane and conformation of erythrocyte hemoglobin hematoporphyrin were found in patients with diabetes mellitus. The decrease in oxygen binding and increase in deoxyhemoglobin concentration during diabetes mellitus were accompanied by changes in viscosity and permeability of the membrane for Na+, H+, Ca2+, and K+. Our results suggest that oxygen-binding properties of hemoglobin depend on viscosity and permeability of the erythrocyte plasma membrane.

Role of ionic transport in regulation of hemoglobin affinity for oxygen in diabetes mellitus.

The rate of Na(+)/H(+) exchange is increased by 24%, activities of Ca-dependent K+ channels is increased by 13%, and activity of erythrocyte Ca(2+)-ATPase decreased by 17% in patients with diabetes mellitus concomitant with essential hypertension in comparison with patients with essential hypertension without disorders of carbohydrate metabolism. Changes in activity of Na(+)/H(+) exchange, Ca-dependent K(+) channels, and erythrocyte Ca(2+)-ATPase and increased oxygen affinity of hemoglobin are due to increased glucose concentration in the plasma and are leveled by olifen.

Study on conformational changes in hemoglobin protoporphyrin in essential hypertension.

Changes in protoporphyrin conformation, partial pressures of O2 and CO2, and the mechanisms responsible for regulation of pCa and pH in erythrocytes were studied in essential hypertension (EH). Changes in protoporphyrin conformation in EH were accompanied by a decrease in the partial pressure of O2 and an increase in the partial pressure of CO2. This was associated with increased activities of Na+/H+-exchange and Ca2+-dependent K+-channels and with a decreased activity of Ca2+-ATPase. The changes in protoporphyrin conformation in EH are suggested to decrease the efficiency of O2 metabolism in hemoglobin and increase the values of intracellular pCa and pH of erythrocytes.

Efflux of cyclic adenosine monophosphate from cells: mechanisms and physiological implications.

Although cyclic nucleotides are hydrophilic compounds, extracellular cAMP (cAMPo) rapidly accumulates during the activation of adenylate cyclase. This review considers the kinetic characteristics of cAMP transport through the plasma membrane and its physiological implications. The influx and efflux of cAMP occur via different carriers. At physiological concentrations of cAMPo, the influx of cAMP does not significantly contribute to regulation of the intracellular content of the cyclic nucleotide, but it is responsible for the accumulation of cAMPi in experiments at [cAMP]o approximately 1 mM. In contrast, the high rate of cAMP efflux is mainly responsible for normalization of [cAMP]i during long-term activation of adenylate cyclase. The possible involvement of ATP-binding cassette proteins (ABC proteins) in the efflux of cAMP from the cell is considered. In procaryotes cAMPo is a signal molecule during the generation of cell colonies, acting on special receptors that interact with GTP-binding proteins. Such receptors have not been found in vertebrates, and in most cases the signal functions of cAMPo are mediated by its degradation by extracellular enzymes with subsequent activation of adenosine receptors.

[The recording of maximal Ca-ATPase activity in intact human erythrocytes by using a Ca-selective electrode]. / Registratsiia maksimal'noi aktivnosti Ca-ATFazy v intaktnykh éritrotsitakh cheloveka pri pomoshchi Ca-selektivnogo élektroda.

The method for recording Ca-ATPase activity in intact erythrocytes was devised. The parameters of Ca2+ efflux, mediated by Ca-ATPase were investigated in Ca(2+)-loaded red blood cells, using Ca(2+)-selective electrode. The red blood cell calcium concentration was modified using the ionophore A23187 in Ca(2+) medium. Recording Ca efflux from RBC may be used as a routine method for the differential diagnosis of patients with essential hypertension and other forms of cell pathology.

[Familial and nonfamilial forms of arterial hypertension]. / Semeinye i nesemeinye formy arterial'noi gipertonii.

Family and nonfamily hypertension (FH, NFH) forms were studied among patients with essential hypertension and symptomatic hypertension. Na-Li countertransport in FH patients against NFH ones proved significantly increased. However, CA2+ velocity mediated by Ca ATPase in them was less than in NFH subjects. Plasma filtration and hemosorption reduced arterial pressure more effectively in NFH patients. Surgical treatment in patients with symptomatic arterial hypertension is more successful in reducing arterial pressure in NFH subjects.

[Distribution of calcium in unmyelinated and myelinated nerve trunks]. / Raspredelenie kal'tsii v nemielinovykh i mielinovykh nervnykh stvolakh.

Exchange of Ca2+ between non-myelinated and myelinated nerves at the surface of axoglial complex of the nerve seems to be one of the extracellular systems controlling the Ca2+ level.