Obtaining and Characteristic of Antibodies to Vibrio cholerae Protective Antigens Conjugated with Gold Nanoparticles.

Gold nanoparticle conjugates with Vibrio cholerae antigens were synthesized. The animals were immunized with the obtained conjugates. Rabbit polyclonal antibodies to the antigens were obtained, which showed high specific activity.

Blood testosterone in rats: correlation of the level of individual anxiety and its impairment after "death threat".

Studies of identical groups of male Wistar rats after preliminary selection to give groups including extreme behavioral types with low and high rankings on the anxiety scale showed that blood testosterone concentrations in intact rats (controls) correlated negatively with anxiety ranking, i.e., minimal hormone concentrations (no greater than 5 nM) corresponded to high levels of anxiety - with a predominance of passive defensive behavioral components on testing.

[Prophage CTXphi genome variability and its role in alteration of Vibrio cholerae El Tor virulence characteristics].

Comparative analysis of CTXphi prophage genome of 366 V. cholerae El Tor strains isolated from infected people and water was carried out using the polymerase chain reaction. Four groups of vibrios, which carry different combinations of ctxA, zot, and ace genes from core region of CTXphi prophage coding key (cholera enterotoxin) and accessory (Zot and Ace toxins) pathogenicity factors, were determined: ctxA(+) zot(-) ace(+), ctxA(-) zot(+) ace(+), ctxA(-) zot(+) ace(-), ctxA(-) zot(-) ace(+).

[An avirulent vibrio cholerae strain--producer of the cholera toxin B subunit: obtaining and molecular genetic analysis].

The conjugative recombinant plasmid pIEM3 (KmR TcR) was constructed in order to introduce the cloned ctxB gene encoding the cholera toxin B subunit into the Vibrio cholerae cells. The plasmid was obtained as a result of co-integration of two plasmids: a conjugative plasmid, pIEM1(KmR), carrying mini-kan transposon and IS1 element, as well as the pCTdelta27(TcR) plasmid that is a derivative of the pBR322 which carries the cloned ctxB gene. The avirulent Vibrio cholerae strain eltor biovar deprived (according to the PCR analysis) of the key structural and regulatory pathogenicity genes and carrying a mutation in a single gene of the O1 antigen was chosen as the pIEM3 plasmid carrier strain.

[Blood testosterone in rats: correlation with individual anxiety and its derangement after the "death threat"].

After preliminary testing on a multiparameter scale, test and experimental groups of Wistar male rats were formed on the principle of identical distribution of individuals with different anxiety levels. A negative Spearman correlation between the testosterone blood concentration and the level of anxiety was observed in intact rats: the minimum hormonal concentrations (lower than 5 nmol/l) were found in rats with high anxiety, whereas the maximum concentrations (up to 16 nmol/l) corresponded to the higher anxiety level (prevalence of passive defense reactions during testing). After a sort-term exposure to life-threatening situation (viewing of a boa's attacking and devouring two victim rats from the test group), the correlation was deranged because of appearance of a scatter in testosterone blood concentration (from 3 to 21 nmol/l) in rats with low anxiety.