Comparative study of the morphology and sensitivity to damaging factors of capsular and acapsular variants of Escherichia coli CA 189

E. coli strain SA 189 has been isolated from a calf with E. coli infection. The cultivation of this strain on a solid culture medium has resulted in its dissociation into two variants due to the loss of the capsule by the cells of the initial culture. Both variants of E. coli strain SA 189 (capsular and acapsular) are equally sensitive to antibiotics. The capsular variant has a narrower range of sensitivity of colicins and shows greater resistance to the bactericidal action of normal blood serum than the acapsular one. Bacteria belonging to these two variants differ perceptibly in the kinetics of disturbances in the barrier properties of their membrane apparatus under the action of cetyltrimethylammonium bromide, a cation detergent. The conditions permitting the differentiation of the capsular and acapsular forms of E. coli strain SA 189 by the kinetics of the damaging action of this detergent have been experimentally selected.     

An electron microscopic study of the intercellular contact of a vaccinal strain of Francisella tularensis with gram-negative and gram-positive bacteria

The use of transmission electron microscopy (the negative contrast and ultrathin section techniques) has made it possible to show that F. tularensis vaccine strain is capable, under normal conditions and in mixtures with other gram-negative and gram-positive bacteria, of forming cell aggregations with close contacts between cells, this contact being probably irreversible. The ultrastructure of bacteria taking part in the formation of intercellular contacts remains intact.     

Multiple forms of cytochrome P-450. Characteristics of isolated aminopyrine-N-demethylase (cytochrome P-450AP)

A previously unidentified cytochrome P-450AP possessing the highest aminopyrine-N-demethylase activity has been isolated from liver microsomes of 4-isopropylaminoantipyrine-induced rats, using affinity chromatography in combination with ion-exchange chromatography with subsequent separation on hydroxyl apatite. Using radioisotope techniques, it was found that 4-isopropylaminoantipyrine induces cytochrome P-450AP synthesis de novo. The isolated cytochrome P-450AP has the following characteristics: Mr = 49,000 Da. CO-peak maximum at 450.5 mm, rate of aminopyrine demethylation in a reconstituted system-20 nmol HCHO/min/nmol of cytochrome P-450, benzphetamine-15. The hemoprotein synthesis is paralleled with the synthesis of a protein with Mr of 51,000 Da. Immunochemical analysis permitted to identify the latter protein as cytochrome P-450b. It was demonstrated that cytochrome P-450AP does not interact with the antibodies to the major phenobarbital-induced form, i.e., with cytochrome P-450b.     

Study of rat erythrocyte superoxide dismutase activity during a toxic regimen of interrupted hyperbaric oxygenation]

Development of toxic manifestations in rats under conditions of hyperoxia was accompanied by a significant lowering of the rat erythrocyte superoxide dismutase activity. The incubation of control rats hemolysate with hydrogen peroxide (10(-3)M) or with kumole peroxide (1.6 10(-4)M) also led to pronounced fall of the initial erythrocyte superoxide dismutase activity. As supposed, the lowering of the erythrocyte superoxide dismutase activity under hyperoxia could be due to the formation of peroxidation products.     

Genetic map of the transposable phage D3112 of Pseudomonas aeruginosa

Using a large group of newly isolated deletion mutants of prophage D3112 the location of all known mutations of D3112 phage was more precisely defined. The mutations affecting establishment of lysogenic state were mapped in two regions of the genome- 0-1.3 and 29-30 kb. The replicative A gene is mapped between 1.3 and 4.9 kb, the second replicative B gene being situated on the right of the A gene, between 4.9 and 9.4 kb. The C gene which is responsible for positive regulation of phage late genes' expression is mapped within the 9-12 kb region. It is suggested that promoter of the gene C is situated within the same interval. Mutations were isolated in the Lys gene which is responsible for host cell lysis. The gene is located within the interval 14-22 kb of the physical map. The order of morphogenetic genes in the late genome region was also established.     

Classification evaluation of electroencephalograms for determining fitness for operator training

A procedure for classification estimation of EEG and electroencephalographic criteria to predict successes of training in operator professions are suggested. Methodic peculiarities of the electroencephalographic examination of people engaged in operator work are determined.