[Recombinant small heat shock protein from Acholeplasma laidlawii increases the Escherichia coli viability in thermal stress by selective protein rescue].

In both prokaryotes and eukaryotes, the survival at temperatures considerably exceeding the optimum is supported by intense synthesis of the so-called heat shock proteins (HSPs), which act to overcome the adverse effects of heat stress. Among mycoplasmas (class Mollicutes), which have significantly reduced genomes, only some members of the Acholeplasmataceae family possess small HSPs of the α-crystallin type. Overproduction of a recombinant HSP IbpA (Hsp20) from the free-living mycoplasma Acholeplasma laidlawii was shown to increase the resistance of Escherichia coli to short-term heat shock. It has been long assumed that IbpA prevents protein aggregation and precipitation thereby increasing viability of E. coli cells. Several potential target proteins interacting with IbpA under heat stress were identified, including biosynthetic enzymes, enzymes of energy metabolism, and components of the protein synthesis machinery. Statistical analysis of physicochemical properties indicated that IbpA interaction partners significantly differ in molecular weight, charge, and isoelectric point from other members of the E. coli proteome. Upon shortterm exposure to increased temperature, IbpA was found to preferentially interact with high-molecular weight proteins having a pI of about 5.1, significantly lower than the typical values of E. coli proteins.

Thio Derivatives of 2(5H)-Furanone as Inhibitors against Bacillus subtilis Biofilms.

Gram-positive bacteria cause a wide spectrum of infectious diseases, including nosocomial infections. While in the biofilm, bacteria exhibit increased resistance to antibiotics and the human immune system, causing difficulties in treatment. Thus, the development of biofilm formation inhibitors is a great challenge in pharmacology. The gram-positive bacterium Bacillus subtilis is widely used as a model organism for studying biofilm formation. Here, we report on the effect of new synthesized 2(5H)-furanones on the biofilm formation by B.subtilis cells. Among 57 compounds tested, sulfur-containing derivatives of 2(5H)-furanone (F12, F15, and F94) repressed biofilm formation at a concentration of 10 µg/ml. Derivatives F12 and F94 were found to inhibit the biosynthesis of GFP from the promoter of the eps operon encoding genes of the biofilm exopolysaccharide synthesis (EPS). Using the differential fluorescence staining of alive/dead cells, we demonstrated an increased bacterial sensitivity to antibiotics (kanamycin and chloramphenicol) in the presence of F12, F15, and F94, with F12 being the most efficient one. The derivative F15 was capable of disrupting an already formed biofilm and thereby increasing the efficiency of antibiotics.

[Effectiveness of diagnostics and treatment of complicated hypertensive disease taking into account results of 3 day arterial pressure monitoring].

UNLABELLED: Empirical choice of antihypertensive therapy (AGT) for patients with complicated hypertensive disease (HD) encounters difficulties due to high variability of arterial pressure (AP) and inadequate response to intake of medicines. The objective methods for the choice of AGT methods are absent. AIM: To evaluate effectiveness ofthe choice of AGT taking account of AP profile calculated based on the analysis of results of 3 day AP monitoring in patients with complicated HDfor whom the empirical prescription of medicines does not give the desirable result. MATERIALS AND METHODS: The study included 51 patients aged 56 +/- 19 yr with HD 18 +/- 13 yr in duration without adequate control of AP despite combined AGT AD was measured (BPLab, Nizhni Novgorod) every 30 min for 3 days, the AP profile was calculated by special FORM-based algorithm. Peak time and magnitude were calculated, the first and second derivatives of the process were determined, AGT was prescribed at the computed AD maximum points. RESULTS: Systolic and diastolic AP decreased within 2 weeks after AGT The number of patients with enhancedAP in the daytime and at night and those with highly variable AP decreased from 33 to 11% (chi2 = 8.4, p < 0.005), from 61 to 33% (chi2 = 10.1, p < 0.005), from 51 to 26% (chi2 = 8.2, p<0.005) respectively. The number ofpatients with inadequate lowering of night-time AP and those with abnormally high fluctuations of AP decreased from 53 to 24% (chi2 = 9.3, p < 0.005) and from 31 to 15%, (p < 0.005) respectively. The frequency of intake of AGT drugs did not change. CONCLUSION: Approximation of real AP circadian profile fluctuations based on results of 3 day monitoring is a sensitive diagnostic tool facilitating the choice of rational AGT for patients with markedly altered circadian rhythms when empirical prescription of AGT does not ensure desired control ofAP

[The C-terminus of transcription factor TnrA from Bacillus subtilis controls DNA-binding domain activity but is not required for dimerization].

The transcription factor ThrA, which belongs to the MerR transcription regulators, in Bacillus subtilis cells controls genes of nitrogen metabolism under conditions of nitrogen limitation. As all the DNA-binding proteins, it is present as a dimer in cells, but the dimerization site is still unknown. The multiple alignment of TnrA homologs from the other Bacilli allowed to identify the putative dimerization sites. Using the C-terminal truncated TnrA proteins it is established, that, in contrast to other MerR-proteins, the TnrA C-terminus does not participate in dimerization. The surface plasmon resonance has revealed that C-terminus truncations of TnrA do not inactivate its DNA-binding activity. By contrary, it increased an affinity to DNA, confirming that C-terminus controls the DNA-binding activity in a full-length TnrA.

[Antiarrhythmic activity of omega-3 polyunsaturated fatty acids in patients with stable ischemic heart disease and ventricular rhythm disturbances].

UNLABELLED: The purpose of this investigation is to evaluate the influence of purified highly-concentrated omega-3 polyunsaturated fatty acids (90% omega-3 polyunsaturated fatty acids 1 g/day) on the severe ventricular arrythmias in patients with stable coronary heart disease (CHD) without concomitant left ventricular contractivity impairment. MATERIALS AND METHODS: 43 patients with stable CHD (26 male and 17 female, aged 66.2 +/- 8.3) with ejection fraction above 45% with unstable paroxysms of ventricular tachycardia detected at Holter ECG monitoring that received 1 g/day omega-3 polyunsaturated fatty acids during 1 month. 23 patients continued treatment for one month extra, while 20 stopped receiving after one month. ECG monitoring was repeated monthly. RESULTS: In one month after started receiving 90% omega-3 polyunsaturated fatty acids the mean heart rate reduced by 2.4%, the number of single extrasystoles reduced by 20.1% (p=0.01), the number of paired extrasystoles reduced by 47% (p=0.0018) and the number of paroxysms reduced by 49% (p=0.0029). In 41.9% patients no paroxysms have been registered after one month. When continuously receiving omega-3 polyunsaturated fatty acids during the second month, the treatment efficiency increases, while the receiving been stopped after one month, the effect is reduced but remains. CONCLUSION: 1 g/day omega-3 polyunsaturated fatty acids application in patients with stable CHD without myocardium contraction dysfunction suffering from ventricular arrhythmias (4B grade after B.Lown) with no direct indications for implantable cardioverter defibrillator therapy results in significant reduction of arrhythmia.