[Resistance to protease inhibitors and efficiency of antiviral therapy in patients with chronic hepatitis C].

Aim: To clarify the role of virus resistance in the efficiency of antiviral therapy with protease inhibitors (PIs) chronic hepatitis C (CHC) patients, with moderate sensitivity to interferon-α.

Materials And Methods: Eight Caucasian patients (4 men and 4 women) aged 21 to 65 years (median 52.5 years) with genotype 1b hepatitis C virus (HCV) infection were included in the study.

Base-calling algorithm with vocabulary (BCV) method for analyzing population sequencing chromatograms.

Sanger sequencing is a common method of reading DNA sequences. It is less expensive than high-throughput methods, and it is appropriate for numerous applications including molecular diagnostics. However, sequencing mixtures of similar DNA of pathogens with this method is challenging.

[Long-term entecavir efficacy retention in the treatment of chronic hepatitis B with an outcome to hepatic cirrhosis caused by its resistant virus strain].

The paper gives concise data on the efficacy of entecavir in the treatment of chronic hepatitis B caused by its resistant virus strain and describes a relevant clinical case.

[Expression of drgA gene encoding NAD(P)H:quinone-oxidoreductase in cells of the cyanobacterium Synechocystis sp. PCC 6803].

The gene drgA of the cyanobacterium Synechocystis sp. PCC 6803 encoding soluble NAD(P)H:quinone-oxidoreductase is involved in NADPH oxidation and controls cell sensitivity to nitroaromatic inhibitors as well as resistance to the oxidative stress inducer menadione. The expression of drgA was analyzed by means of Northern blot hybridization and RT-PCR technique.

[Genetic control and mechanisms of salt and hyperosmotic shock resistance in cyanobacteria].

Exposure to high concentrations of environmental NaCl exerts two stress effects on living cells, increasing the osmotic pressure and the concentration of inorganic ions. Salt stress dramatically suppresses the photosynthetic activity in cells of phototrophic organisms, such as cyanobacteria. During salt adaptation, cyanobacterial cells accumulate osmoprotectors, export excessive Na+ with the help of Na+/H+ antiporters, and actively absorb K+ with the help of K+-transporting systems.

Potassium uptake in the unicellular cyanobacterium Synechocystis sp. strain PCC 6803 mainly depends on a Ktr-like system encoded by slr1509 (ntpJ).

The molecular basis of potassium uptake in cyanobacteria has not been elucidated. However, genes known from other bacteria to encode potassium transporters can be identified in the genome of Synechocystis sp. strain PCC 6803.

Functional analysis of the Na+/H+ antiporter encoding genes of the cyanobacterium Synechocystis PCC 6803.

The role of putative Na+/H+ antiporters encoded by nhaS1 (slr1727), nhaS3 (sll0689), nhaS4 (slr1595), and nhaS5 (slr0415) in salt stress response and internal pH regulation of the cyanobacterium Synechocystis PCC 6803 was investigated. For this purpose the mutants (single, double, and triple) impaired in genes coding for Na+/H+ antiporters were constructed using the method of interposon mutagenesis. PCR analyses of DNA demonstrated that mutations in nhaS1, nhaS4, and nhaS5 genes were segregated completely and the mutants contained only inactivated copies of the corresponding genes.

Identification of genes essential for growth at high salt concentrations using salt-sensitive mutants of the cyanobacterium Synechocystis sp. strain PCC 6803.

A collection of 17 salt-sensitive mutants of the cyanobacterium Synechocystis sp. strain PCC 6803 was obtained by random cartridge mutagenesis. The genes coding for proteins essential for growth at high salt concentrations were mapped on the completely known genome sequence of this strain.

[Homology in natural cryptic plasmids of Bacillus subtilis].

Peculiarities of DNA homology in a number of cryptic plasmids isolated from soil bacillary strains and related or identical to Bacillus subtilis were studied. Fragments generated after digestion of one of these plasmids, p1414, were employed as a probe for blot hybridization with identical fragments of other plasmids. The data obtained suggest that nearly all the studied plasmids possess a common homology site that occupies a significant plasmid portion.