The Effect of Glucose and Poloxamer 188 on Red-Blood-Cell Aggregation

Glucose metabolism disorders contribute to the development of various diseases. Numerous studies show that these disorders not only change the normal values of biochemical parameters but also affect the mechanical properties of blood. To show the influence of glucose and poloxamer 188 (P188) on the mechanical properties of a red-blood-cell (RBC) suspension, we studied the aggregation of the cells. To show the mechanisms of the mechanical properties of blood, we studied the effects of glucose and poloxamer 188 (P188) on red-blood-cell aggregation. We used a model in which cells were suspended in a dextran 70 solution at a concentration of 2 g/dL with glucose and P188 at concentrations of 0–3 g/dL and 0–3 mg/mL, respectively. RBC aggregation was determined using an aggregometer, and measurements were performed every 4 min for 1 h. Such a procedure enabled the incubation of RBCs in solution. The aggregation index determined from the obtained syllectograms was used as a measure of aggregation. Both the presence of glucose and that of P188 increased the aggregation index with the incubation time until saturation was reached. The time needed for the saturation of the aggregation index increased with increasing glucose and P188 concentrations. As the concentrations of these components increased, the joint effect of glucose and P188 increased the weakening of RBC aggregation. The mechanisms of the observed changes in RBC aggregation in glucose and P188 solutions are discussed.

Hemorheological Parameters in Diabetic Patients: Role of Glucose Lowering Therapies

Diabetes mellitus influences several important hemorheological parameters including blood viscosity, erythrocyte aggregation and deformability. In the present study, 159 type-2 diabetic patients and 25 healthy controls were involved. Patient’s age, body weight, body mass index (BMI), smoking habits, physical activity, history of cardiovascular diseases, current antidiabetic therapy and concomitant medication were recorded. Patients were grouped according to their antidiabetic treatment with insulin, or with one or more of the following antidiabetic drugs: metformin, sulfonylureas, acarbose, or no antidiabetic therapy. Hemorheological measurements (hematocrit, erythrocyte aggregation, plasma fibrinogen, whole blood and plasma viscosity), von Willebrand factor activity, and platelet aggregation measurements were performed. Platelet aggregation was investigated with the method of Born. Plasma viscosity and red blood cell aggregation were significatly higher in diabetes. No significant difference was found in hemorheological parameters between different antidiabetic regimens. Whole blood and plasma viscosity and red blood cell aggregation correlated with glucose levels but not with HbA1C levels. In conclusion, plasma and whole blood viscosity, as well as red blood cell aggregation appear to be associated with concurrent hyperglycemia, but not with the quality of glycemic control or the applied antidiabetic treatment. Platelet aggregation induced by ADP or epinephrine does not seem to be associated with diabetes even at subthreshold doses.

Сосудистая проницаемость и микрогемореология при системной склеродермии: возможности метода конъюнктивальной микроскопии

In this article, the authors draw attention of readers to the capabilities of the conjunctival microscopy (CM) the method for studying the processes of vascular permeability and microhemorheology in patients with systemic sclerosis (SS). An original simultaneous examination of 48 patients with SS (mean age 51±1,7 years) and a comparable age group (4,74±2,3 years) of the control group of people without any diseases that might affect microcirculation (MC) by the CM-method was performed. The results demonstrated high informativeness of the CM-method in the diagnostics and assessment of vascular permeability and intravascular red blood cell aggregation (RBCA) in SS. The main changes in MC during SS revealed by the CM-method are the increase in vascular permeability and enhancement of RBCA in all types of microvessels. Key words: vascular permeability, intravascular red blood cell aggregation, conjunctival microscopy, systemic sclerosis.

Vibration motor-integrated low-cost, miniaturized system for rapid quantification of red blood cell aggregation

A low-cost portable device was developed with a coin vibration motor for quantification of red blood cell aggregation.