Biosynthesis of chlorophyll P-680 of photosystem II in greening leaves of plants adapted to heat shock

In etiolated pea and maize leaves illuminated after incubation at 38 degreesC, a new dark reaction was shown manifested in the bathochromic shift of spectral bands and accompanied by esterification of the product of protochlorophyllide photochemical reduction--Chld 684/676: Chld 684/676 --> Chl 688/680. After completion of the reaction a rapid (20-30 sec) quenching of the fluorescence of the reaction product (Chl 688/680) was observed. The reaction Chld 684/676 --> Chl 688/680 is inhibited under anaerobic conditions and in the presence of cyanide; the reaction accompanied by Chl 688/680 fluorescence quenching is not observed in pea mutants with impaired function of photosystem II reaction centers. The spectral properties of the formed Chl form with the absorption maximum at 680 nm, fluorescence quenching, and simultaneous synthesis of pheophytin suggest that the reaction is connected with the chlorophyll of photosystem II reaction center--P-680.     

Glycopeptide antibiotics: eremomycin, vancomycin, and teicoplanin. Comparison of several parameters of pharmacokinetics and antimicrobial activity

Pharmacokinetic parameters of eremomycin (Institute of New Antibiotics, the USSR Academy of Medical Sciences), teichoplanin (Lepetit) and vancomycin (Eli Lilly) were compared after their intravenous administration to rats in the same dose of 50 mg/kg. It was shown that the area under the concentration time curve of eremomycin was 2 times smaller than that of teichoplanin and 6 times larger than that of vancomycin. The mean retention time of eremomycin was close to that of teichoplanin and 1.6 times higher than that of vancomycin. Bioavailability of eremomycin and teichoplanin after their extravascular administration was the same and amounted to 94 per cent. Antibacterial activity of eremomycin against methicillin resistant strains of staphylococci was 4 times higher than that of teichoplanin and vancomycin.     

Inactivating action of bacteria on the lipolytic activity of solizyme and its prevention by antibacterial drugs]

Bacteria capable of producing exoproteases were isolated from intermediate products of microbial lipase. The proteolytic enzymes produced by the bacteria were able to inactivate 20 to 80 per cent of the lipase depending on the time of incubation, protease production by the contaminating microbe and the experimental conditions. Antibiotics and antiseptics inhibiting growth of bacteria prevented or limited their inactivating action on lipase. Except catamine, the tested antimicrobial drugs as such had no effect on lipase activity.     

Ultrastructure of the tail appendage in microphallid cercariae (Trematoda, Microphallidae)

The tail structure of larvae of Maritrema subdolum and Microphallus claviformes is similar in essence. Its wall is made by the tegument and underlying layers of muscles. The syncytial anucleated tegumental lamina with the only type of secretory inclusions forms regular circular folds along the tail. The outer muscle layer is formed by the smooth muscular cells. It is underlaid by the longitudinal cross-striated muscles with the strongly pronounced sarcomere organization. The nucleus-containing bodies of the muscle cells occupy the axial part of the tail excepting the central cavity. The functional joining of tail and body musculatures is provided by thick muscle bundles in the caudal department of the larval body.     

Study of immunosuppressive activity of a synthetic decapeptide corresponding to an ACTH-like sequence of human immunoglobulin G1.

The synthetic ACTH-like decapeptide H-Val-Lys-Lys-Pro-Gly- Ser-Ser-Val-Lys-Val-OH, corresponding to amino acid residues 11-20 of the variable part of the human IgG1 heavy chain (referred to as immunocortin) was found to have an immunosuppressive effect on cells in vitro: it inhibits blast transformation of mouse thymocytes and reduces spontaneous motility of mouse peritoneal macrophages as well as their bactericidal activity against the virulent bacterial strain Salmonella typhimurium 415. Tritium-labeled immunocortin binds with high affinity to ACTH receptors on thymocytes and macrophages (Kd 2. 1 and 2.5 nM, respectively) and activates adenylate cyclase in these cells. Thus, the interaction of immunocortin with the target cell includes the following main steps: binding to the receptor, activation of adenylate cyclase, and elevation of the intracellular content of cAMP.