Effect of a helium and oxygen mixture on physiological parameters of rats with cerebral arterial air embolism.

Introduction: Cerebral arterial air embolism (CAE) is a serious and potentially dangerous condition that can interrupt the blood supply to the brain and cause stroke. One of the promising gas mixtures for emergency treatment of air embolism is an oxygen-helium mixture. Methods: We modeled CAE in awake rats by injecting air into the common carotid artery. Immediately after CAE, animals were either untreated or underwent hyperbaria, oxygen inhalation, heated air inhalation, or helium-oxygen mixture inhalation. Body temperature, locomotor activity, respiratory and cardiovascular parameters were monitored in the animals before CAE modeling, and 3 and 24 h after CAE modeling. Results: After 3 hours of CAE modeling in awake rats, depression of the nervous, cardiovascular and respiratory systems, as well as decreased body temperature were observed. 24 h after CAE modeling multifocal cerebral ischemia was observed. Normobaric helium-oxygen mixture inhalation, on par with hyperbaric treatment, restored body temperature, locomotor activity, respiratory volume, respiratory rate, and blood pressure 3 hours after CAE, and prevented the formation of ischemic brain damage lesions 24 h after CAE. Discussion: Thus, inhalation of a heated oxygen-helium gas mixture (O2 30% and He 70%) immediately after CAE improves the physiological condition of the animals and prevents the foci of ischemic brain damage formation.

Discerning Comparison of 1 and 0.5% Ethylene Glycol in Sprague-Dawley Rats with Modeled Urolithiasis.

A common method of modeling urolithiasis is the use of 1 and 0.75% ethylene glycol, or a combination of ethylene glycol with other lithogens, but too rapid progression of the disease and multiple organ toxicity have been reported. We developed a urolithiasis model in Sprague-Dawley rats, in which the animals received a relatively low concentration of ethylene glycol (0.5%), but for a long-term period (6 weeks) followed by animal observation during the 6-week recovery period. In urine samples, signs of the urolithiasis development were observed starting from the sixth week: the presence of ketones, decrease in diuresis and urine pH; in the blood, urea, protein, and hematocrit were elevated. However, no leukocytes were detected in the urine; in the blood, no shifts in differential leukocyte count and no elevation in ALT, creatinine, cholesterol, and triglycerides were observed, which indicates the absence of multiple organ failure while using 1% ethylene glycol. In addition, the animals receiving 0.5% ethylene glycol were followed up to 12 weeks in contrast to animals receiving 1% ethylene glycol (the experiment in this case was stopped during the third week for ethical reasons).

Influence of climatic and hydrological factors on structure and composition of peat from northern wetland territories with low anthropogenic impact.

Northern wetlands ecosystems play an important role in the hydrological balance of neighboring areas, where they act as chemical barriers against anthropogenic and technogenic contaminations. Studied region is well known for quantity of peat deposits and the volume of peat resources. Peat can be considered as a highly informative marker for assessing change in environmental conditions. The study presents the results of the first investigation of peat samples, collected from representative ecosystems of northern wetland territories with low anthropogenic impact. Component and element composition of various peat types were studied in a relation to hydrologic, climate and sampling conditions. It was found out that organic and ash contents are more dependent on the type of the bog, than geographic location. Climatic factors are more important for the formation of bitumen. The degradation degree in peat increases proportionally to content of humates. High content of biogenic and lithogenic elements was observed in transition- and low-moor peat. The content of trace elements in peat samples do not depend on the type of the peat. The structural properties of peat were studied by the light microscopy, AFM and dynamic light scattering. It was determined that the conformation of studied peat samples is characterized by elements of asymmetry. The observed particles in the solutions exist in dynamic equilibrium with separated globular macromolecules. The size of these nanoparticles is comparable with the size of the particles of other biopolymers of similar nature. Swelling of peat in liquid water was studied. The relationship between structural specificities, origin of peat and its maximum degree of swelling was found. The degree of swelling can be used as structural-sensitive parameter in further research.

[The load and diversity of hereditary diseases in four raions of Rostov oblast].

The results of a medical genetic survey of the population of four raions (176 535 individuals) of Rostov oblast (Dubovsky, Zimovnikovsky, Myasnikovsky, and Krasnosulinsky raions) are presented. The load of autosomal dominant (AD), autosomal recessive (AR), and X-linked hereditary diseases for urban and rural population was calculated, and the diversity of monogenic hereditary diseases (MHD) was reviewed. The nosological spectrum of MHD constituted 117 diseases (63 diseases with AD inheritance; 38 with AR inheritance; and 16 with X-linked inheritance). The analysis showed that the incidence of MHD among the population of Rostov oblast was 1 : 336. Considerable differentiation in the prevalence rates of MHD (AD, AR, and X-linked pathologies) among certain raions was revealed.

Effects of central endothelin-1 in normotensive and spontaneously hypertensive rats.

Changes in blood pressure and sympathetic nerve activity induced by local injection of endothelin-1 into the rostroventrolateral medulla were studied in narcotized stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive WKY rats. Endothelin-1 produced similar biphasic response in both rat strains: a transient increase in blood pressure and sympathetic nerve activity followed by progressive hypotension and bradycardia. Pretreatment with ETB-receptor antagonist BQ788 inhibited sympathetic activation induced by endothelin-1, while pretreatment with the ETA-receptor antagonist N-acetyl-[D-Trp16]-endothelin-1 abolished the subsequent hypotension. The antihypotensive effect of ETA-receptor blockade was most effective in normotensive rats. Our findings suggest that cardiovascular disorders in SHRSP rats can be related to peculiarities in the rostroventrolateral medullar endothelin system.

[Analysis of RAT2 cells, transformed by the CELO (FAV1) virus, using the polymerase chain reaction]. / Analiz kletok RAT2, transformirovannykh virusom CELO (FAV1), s pomoshch'iu polimeraznoi tsepnoi reaktsii.

DNAs extracted from the RAT2 cells transformed by the CELO virus (strain Phelps) have been analyzed by polymerase chain reaction. Sequences belonging to the left end of the viral genome (according to Ishibashi & Yasue, 1984) were not found in the tested DNAs. On the other hand, the polymerase chain reaction data have revealed the presence of fragments specific of the opposite end. We conclude that this region may have included the genes responsible for cell transformation, at least as far as Phelps viral strain is concerned.

Inhibition of adenovirus replication by the E1A antisense transcript initiated from hsp70 and VA-1 promoters.

The E1A region of the adenoviral genome, important for initiation of virus infection and activation of other viral genes, was chosen as a target for engineering antisense RNA (asRNA) to inhibit adenovirus 5 (Ad5) replication in COS-1 cell culture in vitro. The hsp70 promoter, taken from the appropriate heat-shock-protein gene of Drosophila melanogaster, and the VA-1 RNA promoter, derived from the Ad5 gene coding for low-molecular-mass VA-1 RNA and recognized by RNA polymerase III were used as regulatory elements of transcription. The two types of recombinant constructs contained E1A fragments of 710 bp (hsp70 constructs) or 380 or 740 bp (VA-1 RNA constructs) in reverse orientation relative to the promoter position, as well as a transcription termination signal, the SV40 ori, and the gene controlling Geneticin (antibiotic G418) resistance (G418R). After selection of transfected COS-1 cells in the presence of G418, a number of stable G418R cell lines were raised which expressed engineered asRNAs. Plating of Ad5 suspensions of known titre on monolayers of transfected COS-1 cells clearly showed strong inhibition of adenovirus replication by asRNAs: 75% with the hsp70 promoter and 90% with the VA-1 RNA promoter.

Inhibition of adenovirus 5 replication in COS-1 cells by antisense RNAs against the viral E1a region.

To study the effect of antisense E1a RNA (asRNA) on adenovirus development, two types of adenovirus 5 E1a antisense constructs have been engineered. One was complementary to the viral DNA region [nucleotide (nt) positions 500-720] regulated by the metallothionein-I promoter, and the other was complementary to the DNA regions (nt positions 630-1570) under control of the long terminal repeat Moloney mouse leukosis virus promoter. Both asRNA constructs were cloned into a plasmid containing the simian virus 40 origin of replication, the gene controlling geneticin (G418) resistance (G418R), and other regulatory elements. The COS-1 cells, which contained up to 100 copies of the engineered plasmids, synthesized antiviral asRNAs, which provided 71 to over 95% inhibition of adenoviral replication, in comparison to the control cells not synthesizing asRNAs.

[Changes in the respiratory organs in experimental adenovirus infection]. / Izmeneniia organov dykhaniia pri éksperimental'noi adenovirusnoi infektsii.

An experiment on 6 green monkeys and on 286 cotton newly born rats was made with the aim of studying the lung during experimental adenovirus infection. All the animals during different terms of infection (from 6 hours and up to 40 days) have been studied. Several morphological changes were discovered in the lungs of monkeys and rats after 6 hours of infection and were retained up to the 10-th day of infection. All the components of air-blood barrier and basal membranes were involved in the process, but after 20 day of the experimental adenovirus infection the entire restoration of cellular structure occurred.

[Electrophoretic purification of biologically active structural proteins of the simian adenovirus SA7 in the presence of sodium dodecyl sulfate]. / Elektroforeticheskaia ochistka biologicheski aktivnykh strukturnykh belkov adenovirusa obez'ian SA7 v prisutstvii dodetsilsul'fata natriia.

The modification of disc electrophoresis technique in polyacrylamide gel with sodium dodecylsulphate (SDS) has been elaborated for synchronous isolation of some structural proteins in biologically active form and in preparative quantities from adenoviruses. Virions of SA7 adenovirus were mildly dissociated in SDS solution at 20 degrees C and structural proteins were stained by fluorescamin. After separation the zones of proteins corresponding to the native capsomeres of hexon and protein IV as well as the zones of inner proteins V and VII have been identified as fluorescent at UV-irradiation, excised and extracted by SDS solution. After the removal of SDS by protein precipitation in acetone the preparations of hexon and IV reveal the quaternary structure of native capsomers and full spectrum of antigenic and immunogenic activities of native proteins. Preparations of inner proteins V and VII possess activity in condensing adenoviral DNA. The technique is usable for preparative purification of inner polypeptide VI SA7, as well as capsomers and inner proteins of other adenoviruses.

[Characteristics of rat kidney cell lines transformed by the DNA of human adenovirus type 6]. / Kharakteristika linii kletok pochek krys, transformirovannykh DNA adenovirusa cheloveka tipa 6.

The data on the transforming activity of intact DNA of human adenovirus type 6 and that fragmented by restrictases Bam H I (31.3% of the genome), Bgl 2 (9.3% of the genome), and Hind 3 (7.6% of the genome) in a primary culture of rat kidney cells are presented. The activity of the specimens varied within 1.1-2.1 foci per 1 microgram of DNA. From the transformation foci 5 cell lines were derived and their properties (T-antigen production, integration of adenovirus genome, phenotypic features) were studied.

[Isolation and characteristics of the fibroblast cell line of rats cotransformed by the DNA of simian adenovirus SA7 (C8) and hepatitis B virus]. / Poluchenie i kharakteristika linii kletok fibroblastov krysy, kotransformirovannykh DNK adenovirusa obez'ian SA7 (C8) i virusa gepatita B.

Transformed cell line (SH2) was established by means of co-transfection of primary rat embryonal fibroblasts by DNA of high-oncogenic simian adenovirus SA7 (C-8) and hepatitis B virus. SH2 cells possess a transformed phenotype and high oncogenicity both for allogenic (rats) and xenogenic (hamsters) animals. 100 SH2 cells induce tumours in newborn (3 day) hamsters. 10(4) SH2 cells inoculated to adult hamsters induce tumours in approximately 50% cases on the 20th-30th day. Possible mechanisms of significant stimulation of SH2 cells oncogenic properties after co-transfection by DNA of oncogenic adenovirus SA7 and hepatitis B virus are discussed.

[Analysis of cell lines obtained from tumors induced in Syrian hamsters by SA7 adenovirus and its DNA]. / Analiz linii kletok, poluchennykh iz opukholei, indutsirovannykh u siriiskikh khomiachkov adenovirusom SA7 i ego DNK.

Four cell lines derived from tumors induced by adenovirus SA7, its DNA (intact and fragmented with restrictase Sal-1), as well as isolated C-Sal-1 fragment (19.5% of genome) containing oncogene were studied. All the cell lines had the phenotypic markers of tumor cells, similar tumorigenicity, and produced T- and S-antigens. The line derived from the tumor induced by intact DNA contained the smallest adenovirus SA7 genome region (12%) which suggests that the information required for the synthesis of T and S antigens of adenovirus SA7 lies within the limits of this genome region.

Analysis of sequences of simian adenovirus SA7 (C8) DNA in transformed rat cells and hamster tumour cells.

Different methods of molecular hybridization were used to study DNA sequences of the highly oncogenic simian adenovirus SA7 (C8) present in the genomes of two transformed rat cell lines and in cells from three hamster tumours induced by adenovirus SA7. The entire DNA or the left-hand terminal SalI C fragment (19.5% of the genome) were employed. All cell lines retained an intact left-hand region of the SA7 genome (0 to 12.4 map units). The blot hybridization technique failed to detect any site specificity of integration of SA7 DNA into the cell genome. In all cell lines the expression of the Bg/II D fragment (1.8 to 10 map units) of SA7 DNA was observed. As judged by the patterns of integration of virus sequences into the cell genome, the highly oncogenic simian adenovirus SA7 (C8) is similar to the non-oncogenic human adenoviruses of group C, and is different from the highly oncogenic human adenovirus type 12.

[Isolation of cell lines transformed by highly oncogenic simian adenovirus SA7 and nononcogenic human adenovirus type 6 and their DNAs]. / Poluchenie linii kletok, transformirovannykh vysokoonkogennym adenovirusom obez'ian SA7 i neonkogennym adenovirusom cheloveka tipa 6 i ikh DNK.

Methods for generation of cell lines transformed by highly oncogenic simian adenovirus SA7, nononcogenic human adenovirus type 6 and their DNAs are described. WAG rat kidney cells were used for transformation. To produce 1 focus of transformation, 1.7 X 10(6) PFU of SA7 virus is required. Intact and fragmented DNA of both viruses may be quite effectively used for transformation. For production of 1 transformation focus 1.2 microgram SA7 DNA and 1.1 microgram type 6 adenovirus DNA is required. In most cases, DNA fragmentation increases the transforming activity which has been shown to be associated with the left genome region of both viruses under study.

[Characteristics of integration of monkey adenovirus SA7 DNA fragments with genomes of transformed and tumoral cells]. / Osobennosti integratsii fragmentirovannoi DNK adenovirusa obez'ian SA7 s genomami transformirovannykh i opukholevykh kletok.

Transformed rat cells and hamster tumoral cells, obtained after treatment with DNA of monkey adenovirus SA7 which was fragmented using endonuclease SalI, contained all the SalI fragments of SA7 DNA integrated with the cell genomes. As shown by blotting hybridization distinct deletion did not form in the fragments of viral DNA on integration. Insertion of the SA7 DNA fragments appears to occur into the definite relatively small site of the cell chromosome. In the both cell strains studied a site of the SA7 genome transcribed at coordinates: 1.8-10 units of the physical map. Fragments of viral DNA were methylated in the sites CmCGG and CCmCGGG of these both strains studied.

[Synthesis of adenovirus SA7 and Ad5 DNA in extracts from the nuclei of green monkey kidney cells]. / Sintez DNK adenovirusov SA7 i Ad5 v ékstraktakh iader kletok pochek zelenoi martyshki.

A soluble extract from the nuclei of green monkey kidney cells, infected with adenovirus SA7, carries out replication of SA7 DNA. It was observed, that in vitro DNA synthesis, which is dependent on the exogenously added viral DNA-protein complex as its optimal template, proceeds by a semiconservative mechanism. The data obtained are compared with literary data on soluble enzyme systems from adenovirus-infected cells. The early factors provided by SA7 also supported replication of the DNA-protein complex, prepared from human adenovirus type 5, in nuclear extracts of monkey cells.

[Viral sequences in the genomes of rat and hamster cells transformed by simian adenovirus SA7(C8) and its DNA]. / Virusnye posledovatel'nosti v genome kletok krys i khomiakov, transformirovannykh adenovirusom obez'ian SA7(C8) i ego DNK.

Four cell lines transformed by simian adenovirus SA7 and its DNA were analysed by means of molecular hybridization. Content of viral DNA sequences in different lines varied from 10% (the left end) of the molecule to the entire genomes. Transcription of the D BglII fragment (coordinates 1.8--10) was observed in all examined lines. The integration type of highly oncogenic simian adenovirus SA7 DNA differed from the pattern of integration of the highly oncogenic human adenovirus type 12 and was similar to that of the non-oncogenic adenoviruses in adenovirus-transformed cells.