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The ability of two strains of Lactobacillus acidophilus, CRL 640 and CRL 800, to survive and retain their biological activities under frozen storage was determined. Freezing and thawing, as well as frozen storage, damaged the cell membrane, rendering the microorganisms sensitive to sodium chloride and bile salts. Both lactic acid production and proteolytic activity were depressed after 21 days at -20 degreesC, whereas beta-galactosidase activity per cell unit was increased. Cell injury was partially overcome after repair in a salt-rich medium. Copyright 1998 Academic Press. 相似文献
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Isolation of mutant genes for human leukocyte alpha2-interferon by a method of localized mutagenesis
V A Petrenko G F Sivolobova L N Semenova A N Boldyrev V A Karginov 《Molekuliarnaia genetika, mikrobiologiia i virusologiia》1985,(8):38-44
An efficient method to obtain the mutant genes for human leucocyte alpha 2-interferon (IFN) has been elaborated.The technique includes the following main stages: cloning of interferon gene in M13mp8 DNA; isolation of double-stranded hybrid DNA complex, containing IFN gene as a single-stranded fragment; selective modification of a single-stranded hybrid DNA by sodium bisulphite; the repair of hybrid DNA by DNA polymerase I from Escherichia coli, transformation of Escherichia coli JN103 cells by double-stranded circular DNA, containing the selectively modified gene IFN. The technique is based on the protection of bacteriophage M13 genome from mutagen induced damage by means of converting phage DNA into the double-stranded structure leaving the single-stranded fragment to be mutagenized prone to mutagen action. This is achieved by reannealing of single-stranded M13mpB DNA hydrolyzed by restriction endonuclease BamHI. The technique preserves the infectiousness of vector DNA under the conditions permitting modification of up to 10% cytosine residues in IFN gene. Every clone resulting from transformation of Escherichia coli by modified DNA carried mutations in IFN gene, identified by sequencing after Sanger. 相似文献
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V V Kravchenko O I Serpinski? G F Sivolobova T N Shubina 《Molekuliarnaia biologiia》1987,21(1):194-199
A plasmid vector pNIMB has been constructed (starting) from the pUR222 plasmid as a result of substitution of the polylinker containing restriction sites: PstI, SalGI, AccI, HindII, BamHI EcoRI and by other synthetic linkers with additional sites for HindIII and HgaI. Plasmid pNIMB does not differ from the parent one phenotypically. Compared to pUR222 the vector contains an additional site for cloning HindIII fragments of DNA and allows to clone SalGI/BamHI- and PstI/SalGI-fragments. Cloning of DNA fragments in all seven unique sites of pNiMB gives the possibility for sequencing the fragments avoiding their isolation from the gel. Moreover, this vector may be useful for cloning and directed assembly of chemically synthesised DNA fragments when the endonuclease HgaI sites are used. 相似文献
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Shustov AV Kochneva GV Sivolobova GF Grazhdantseva AA Gavrilova IV Akinfeeva LA Rakova IG Aleshina MV Bukin VN Orlovskiĭ VG Bespalov VS Zelicoff AP Netesov SV 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2004,(5):20-25
The occurrence of markers, genotypic variability of isolates and risk factors for viral hepatitis C (HCV) were studied in 4 groups of residents of the Novosibirsk region (altogether 2,000 persons). Anti-HCV IgG were detected within the range from 4.6% among medical personnel to 48% among the patients of the drug-abuse clinic. The detection rate of HCV RNA in seropositive samples varied from 79.3% to 86.3%. The determination of genotype was carried out for 388 isolates: 1b--50.3%, 2a--4.4%, 2c--0.3%, 3a--44.8%. The highest risk indices with respect to HCV among the residents of the region were linked with the drug use (OR=77.5; p<0.05) as well as with risky behavior and low social status. The elevated numbers of seropositive persons were detected among unemployed (OR=16.3), alcohol abusers (OR=3.9), persons having more than 4 sex partners in their lifetime (OR=4.3) and persons having homosexual contacts (OR=6.6). In some groups blood transfusions also played a definite role in the transmission of HCV. In the analysis, carried out separately for two different genotypes the intravenous use of drugs was perceptibly stronger linked with VHC of genotype 3 (OR=85.5) in comparison with HCV of genotype 1 (OR=49.3) and genotype 2 (OR=41.1). Genotype 1 prevailed in the older age group and genotype 3, among young people. 相似文献
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An immunocytochemical approach was used to localize myosin with respect to individual fibers in rat skeletal muscle. Transverse cryostat sections of rat diaphragm, a fast-twitch muscle, were exposed to fluorescein-labeled immunoglobulin against purified chicken pectoralis myosin. Fluorescence microscopy revealed a differential response among fiber types, identified on the basis of mitochondrial content. All white and intermediate fiber but only about half of the red fiber reacted with his antimyosin. In addition, an alkali-stable ATPase had the same pattern of distribution among fibers, which is consistent with the existence of two categories of red fibers. The positive response of certain red fibers indicates either that their myosin has antigenic determinants in common with "white" myosin, or that the immunogen contained a "red" myosin. Myosin, extracted from a small region of the pectorlis which consists entirely of white fibers, was used to prepare an immunoadsorbent column to isolate antibodies specific for white myosin. This purified anti-white myosin reacted with the same fibers of the rat diaphragm that had reacted with the white, intermediate, and some red fibers are sufficiently homologous to share antigenic determinants. In a slow-twitch muscle, the soleus, only a minority of the fiber reacted with antipectoralis myosin. The majority failed to respond; hence, they are not equivalent to intermediate fibers of the diaphragm; despite their intermediate mitochondrial content. Immunocytochemical analysis of two different musles of the rat has demonstrated that more than one isoenzyme of myosin can exist in a single muscle, and that individual fiber types can be recognized by immunological differences in their myosin. We conclude that, in the rat diaphragm, there are at least two immunochemically distinct types of myosin and four types of muscle fibers: white, intermediate, and two red. We suggest that these fibers correspond to the four types of motor units described by Burke et al. (Burke, R. E., D. N. Levine, P. Tsairis, and F. E. Zajac, III 1973. J. Physiol. (Lond) 234:723-748.)in the cat gastrocnemius.` 相似文献
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Kachko AV Ershov AE Gavrilova IV Shustov AV Kochneva GV Sivolobova GF Grazhdantseva AA Bukin VN Komissarova MA Netesov SV 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2005,(2):25-30
The occurrence rate of HGV/GBV-C RNA, genotypic variety of isolates and various risk factors of infection with HGV/GBV-C were evaluated in 500 patients of the narcological dispensary of Novosibirsk. The occurrence rate of HGV/GBV-C RNA among all examined blood sera was 33.6%. At the same time in blood sera with HCV markers the occurrence rate of HGV/ GBV-C was 42.9% and in sera with negative results for markers HCV--25%. For gene typing of obtained isolates the direct sequencing of the amplification products of fragment NS3B and the phylogenetic analysis of the sequences thus obtained were used. Almost all isolates subjected to gene typing belonged to genotype 2, widespread in Europe, and only 1 isolate was classified with genotype 4. Statistically significant (p<0.05) risk of HGV/GBV-C infection among the examined subjects was linked with the intravenous use of drugs (OR 2.15), risky sexual behavior (OR 1.8) and the presence of virus hepatitis C (OR 2.26). 相似文献
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Background
Enhancements in sequencing technology have recently yielded assemblies of large genomes including rat, mouse, human, fruit fly, and zebrafish. The availability of large-scale genomic and genic sequence data coupled with advances in microarray technology have made it possible to study the expression of large numbers of sequence products under several different conditions in days where traditional molecular biology techniques might have taken months, or even years. Therefore, to efficiently study a number of gene products associated with a disease, pathway, or other biological process, it is necessary to be able to design primer pairs or oligonucleotides en masse rather than using a time consuming and laborious gene-by-gene method. 相似文献9.
G. V. Kochneva I. N. Babkina T. A. Lupan A. A. Grazhdantseva P. V. Yudin G. F. Sivolobova A. N. Shvalov E. G. Popov I. V. Babkin S. V. Netesov P. M. Chumakov 《Molecular Biology》2013,47(5):733-742
The chicken anemia virus gene that encodes apoptin, a selective killer of cancer cells, was synthe-sized and inserted into the vaccinia virus (strain L-IVP) genome. The insertion replaces a major part of the viral C11R gene that encodes viral growth factor, which is important for virulence. The recombinant virus VVdGF-ApoS24/2 was obtained by transient dominant selection using the gene of puromycin resistance as a selective marker. The expression of the apoptin gene from a synthetic early-late promoter of vaccinia virus ensured the efficient accumulation of the target protein in VVdGF-ApoS24/2-infected cells. Although recombinant apoptin carried the signal peptide of the virus growth factor at the N-end, the protein was not secreted into the culture medium. The recombinant virus VVdGF-ApoS24/2 exhibited significantly higher selective lytic activity in human cancer cell lines (A549, A431, U87MG, RD, and MCF7) than the parent strain L-IVP and its VVdGF2/6 variant with C11R deletion. These results suggest that the use of apoptin can be an efficient means of enhancing the natural anticancer activity of vaccinia virus. 相似文献
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Marcela Víquez-Zamora Myluska Caro Richard Finkers Yury Tikunov Arnaud Bovy Richard GF Visser Yuling Bai Sjaak van Heusden 《BMC genomics》2014,15(1)