Georges Kostov

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The stability of the two isoforms of poplar plastocyanin (PCa and PCb) was studied with differential scanning calorimetry (DSC) technique. It was shown that the thermal unfolding of both isoforms is an irreversible process with two endothermic and one exothermic peaks. The melting temperature of PCb was found to be 1.3+/-0.2 K degrees higher than of PCa,(More)
The immunological response of calves vaccinated against herpes is explained and the epizootic effectiveness of the Soviet vaccine ltf 130 applied in Bulgaria is assessed. The antigenic relation of the vaccine's strain with the agent causing herpes in Bulgaria was revealed by parallel investigation on serum RCB of calves suffering from herpes and of calves(More)
The oxidation of acid-soluble calf skin collagen type I caused by metal-dependent free radical generating systems, Fe(II)/H2O2 and Cu(II)/H2O2, was found to bring down in a specific, discrete way the collagen thermal stability, as determined by microcalorimetry and scanning densitometry. Initial oxidation results in splitting of the collagen denaturational(More)
The thermal stability of acid-soluble collagen type I from calf skin in salt solutions is studied by high-sensitivity differential scanning calorimetry. Three concentration ranges have been clearly distinguished in the dependence of collagen thermal stability on ion concentration. At concentrations below 20 mM, all studied salts reduce the temperature of(More)
Obtained were allergens from Brucella abortus 99 and Yersinia enterocolitica Type 9 through hydrolysis with hydrochloric acid after M. M. Ivanov and with acetic acid after Kirzhaev. They were tested on guinea pigs that were infected with Yersinia enterocolitica Type 9 through different ways. To M. M. Ivanov's allergens all infected animals responded(More)
A Brucella buffered antigen, stained with Bengal rose by a method of the authors, was obtained. It showed a high distinguishing capacity with regard to the nonspecific agglutinations after Huddleson and Wright at a negative complement-fixation test for brucellosis with sera from cattle, pigs, sheep, and horses. Such differentiation, however, proved to be(More)
Attempts to stimulate the immunity against Newcastle disease in birds aged 2 months, of the Leghorn breed, were carried out. It was found that levamisol at the rate of 3 mg/kg body weight given once, parenterally, 24 hours prior to or after the immunization of the birds with a live La Sota vaccine or given three times, parenterally or orally, did not(More)
Boyden's multilayer method was made use of to study the resistance to mercaptoetanol, and to temperature effects as well as the fixation capacity of macrophages of other animal species as regards cytophil antibodies from sera of guinea pigs immunized with a live culture of Salmonella abortusovis. It was found that they are resistant to heating at 56 degrees(More)
Investigations were carried out on the protective action of therapeutic doses of levamisole (Pharmachim) on mice with a LD100 Salmonella gallinarum infection. Studied was also the effect of levamisole on the immunologic response of guinea pigs infected with Salmonella cholerae suis. It was found that therapeutic amounts of 3 mg/kg levamisole applied to mice(More)