[Synthesis of beta-maltosides, derivatives of p-nitrophenol, 2-chloro-4-nitrophenol, and 4-methylumbelliferone, and their use as substrates for determining alpha-glucosidase activity].

Synthesis of beta-maltosides, p-nitrophenyl-beta-D-maltoside and 4-methylumbelliferyl-beta-D-maltoside, based on interaction of hepta-acetate-beta-D-maltosyl fluoride with the corresponding trimethylsilyl ethers of p-nitrophenol and 4-methylumbelliferone is described. 2-Chloro-4-nitrophenyl-beta-D-maltoside was synthesized by interaction of hepta-acetate-alpha-D-maltosyl bromide with 2-chloro-4-nitrophenol in two phase system using phase transfer catalyst. The method of assay of neutral alpha-glucosidase from human kidney and urine using synthesized beta-maltosides (p-nitrophenyl-beta-D-maltoside, 2-chloro-4-nitrophenyl-beta-D-maltoside and 4-methylumbelliferyl-beta-D-maltoside) as substrates and beta-glucosidase as an auxiliary enzyme is proposed.

[The concentration of calcium and its fractions during heart surgery using extracorporeal circulation].

Changes in the concentration of calcium and its fractions have been studied in 115 patients subject to standard bypass techniques. It has been found that calcium homeostasis disturbances do really develop and are caused by the use of solutions that are not balanced with blood in their calcium content. The main source of calcium in hemodiluents was gelatinol.

[Selective ultrafiltration: a new variant of hemoconcentration during surgery with artificial circulation].

The authors provide an experience with a novel alternative of ultrafiltration hemoconcentration applied to 26 patients in surgery involving extracorporeal circulation. The advantages of the new procedure are maintenance of higher colloid-osmotic pressure, prevention of hyperglycemia, lower body elimination of biologically active compounds and drugs than those observed during the routine procedure of ultrafiltration comprising extracorporeal circulation.

[The dynamics of parathyroid hormone and calcitonin in surgery with artificial circulation].

The use of considerable amounts of gelatinol in hypothermal perfusion determined the occurrence of marked hypercalcemia. The hormonal mechanism (parathyroid hormone and calcitonin) responsible for hypercalcemia compensation proved to be inefficient under hypothermal perfusion. A forced diuresis failed to result in rapid normalization of blood calcium concentrations.