Experimental Study of the Effects of Nanodispersed Ceria on Wound Repair.

We studied the effects of nanodispersed ceria on wound healing in vitro and in vivo. It was found that cerium dioxide stimulated wound healing, which manifested in shrinkage of burn wound area (by 1.5 times) and intensification (by 2.4 times) marginal epithelialization.

[Restriction endonuclease Asi256I recognizing the nucleotide sequence 5'-GATC-3'].

A strain producing a restriction endonuclease was isolated from soil samples and identified as the Arthrobacter sp. strain Ck256. The enzyme produced by this strain was termed Asi2561. The isolation procedure for this enzyme was described, and the optimal conditions for its function were determined. It was shown that the restriction endonuclease Asi256I is a true isoschizomer of MboI, it has a temperature optimum of 6 degrees C, and can be used in molecular-biological and genetic-engineering studies performed at low temperatures.

[Application of peptide phage libraries for obtaining peptides specific to mouse lung adenocarcinoma]. / Ispol'zovanie peptidnykh fagovykh bibliotek dlia polucheniia peptidov, spetsifichnykh k adenokartsinome legkogo myshei.

Peptides binding, in vivo, with mouse lung adenocarcinoma, were selected from a peptide phage library containing above 100 million of different permutations. The selected phages carrying specific peptides accumulated in the tumor node, after intravenous injections made in A/Sn mice with induced adenocarcinoma, and persisted there even in 24 h after injections; whereas, they were detected in small quantities or not detected at all in other tissues (e.g. lungs and muscles). The selected bacteriophages were shown to accumulate not only in the primary tumor node but also in the lung with multiple metastases. Finally, amino acid sequences of exposed peptides were defined.

[Restriction endonuclease Sst 12I from a strain of Streptomyces sp. recognizing the nucleotide sequence 5'-CTGCAG-3']. / Endonukleasa restriktsii Sst12I iz shtamma Streptomyces sp., uznaiushchaia posledovatel'nost' nukleotidov 5'-CTGCAG-3'.

A new restriction endonuclease Sst12I belonging to the II type and recognizing the sequence 5'-CTGCAG-3' was isolated from the bacterial strain Streptomyces sp. St-12. The enzyme hydrolyzes DNA between adenine and guanine residues; thus, it is a true isoschizomer of restrictase PstI. In contrast to PstI, the restriction endonuclease Sst12I hydrolyses DNA both at 37 degrees and 55 degrees C and remains active after long-term storage.

[Testing and isolation of high-purity restriction endonucleases]. / Testirovanie i vydelenie vysokoochishchennykh éndonukleaz restriktsii.

A new method of testing restriction nucleases is proposed. This method is based on high-temperature treatment of crude cell extracts. Disrupted cells were heated at 50-60 degrees C, centrifuged, and assayed for restrictases. This method provides the opportunity for screening new enzymes in microbial strains enriched with nonspecific restrictases. High-temperature treatment of cell extracts of certain producers reduces the number of steps of the procedure used for isolating high-purity restrictases; the resulting preparations are capable of maintaining high enzymatic activity during long-term storage. It was shown that high-temperature treatment can be applied not only to thermophilic but also to mesophilic strains of microorganisms of different taxa.

[Clinico-diagnostic significance of fibronectin level determination in severely burnt]. / Kliniko-diagnosticheskoe znachenie opredeleniia urovnia fibronektina u tiazheloobozhzhennykh.

Fibronectin content was determined in plasma and granulation tissues of burnt wounds in burnt patients as well as in plasma and wound exudate of patients operated on for large postoperative abdominal hernia and in whom for several days after surgery the continuous discharge of the wound exudate through the drainage tubes was observed. The same data were observed in fibroblast cultures and nutritional medium in which they have been cultured. It was established that dynamic determination of plasma fibronectin in burn disease allows to estimate the adequacy of the treatment to timely predict probability of development of complications and the outcome of the disease, while determination of fibronectin content in the granulation tissues of burn wounds indicates optimal terms for transplantation of fibroblasts and autotransplants as well as a significant increase of the effectiveness of surgical treatment for victims with spacious burns.

[Use of a phage peptide library in mapping the group-specific hemagglutinating domain of alpha-virus glycoprotein E2]. / Ispol'zovanie fagovoi biblioteki peptidov v kartirovanii gruppospetsificheskogo gemaggliutiniruiushchego domena glikoproteina E2 al'fa-virusa.

Phage display peptide library f88-4/15 (G. P. Smith, USA) was used for mapping the hemagglutination activity domain of glycoprotein E2 of alphaviruses. Using affinity selection and ELISA, we selected the clones binding monoclonal antibody 4H5 to Venezuelan equine encephalomyelitis virus and inhibiting alphavirus hemagglutinating activity. Analysis of the similarity between the peptides amino acid sequences with the alphavirus glycoprotein E2 sequences revealed a structural motive of 4 amino acid residues (HTSR) which was identified in the 85-88 region. Bacteriophages F36 and F19 contained motives corresponding to 102-SXXM-105 and 109-AXXP-112 regions in alphavirus proteins E2. These data permit us to propose that the detected regions are fragments of a group-specific alphavirus hemagglutination domain.

[Isolation and identification of an antibiotic from culture 8-86]. / Vydelenie i identifikatsiia antibiotika iz kul'tury 8-86.

An antibiotic complex was isolated from culture 8-86 referred to Bacillus. The complex consisted of components 8-86A and 8-86B active against gram-negative organisms. By its physico-chemical properties such as IR and UV spectra, amino acid composition, specific rotation and fatty acid composition component 8-86B was shown to be close to polymyxin F.