Capacity of Abbott RealTime MTB RIF/INH to detect rifampicin- and isoniazid-resistant tuberculosis.

Abbott RealTime MTB RIF/INH Resistance (RT RIF/INH) is a new assay for the detection of resistance to rifampicin (RIF) and isoniazid (INH) in tuberculosis (TB) patients. To evaluate the capacity of RT RIF/INH to detect resistance-associated mutations in target genes. A total of 311 Mycobacterium tuberculosis strains that had been pre-characterised using genotypic methods (GenoType® MTBDRplus, Sanger sequencing) and phenotypic drug susceptibility testing were subjected to DNA extraction on Abbott m2000sp and analysed using RT RIF/INH. Detection of heteroresistant mutations was studied with artificial mixtures of wild-type and mutant DNA. Overall sensitivity and specificity values of RT RIF/INH to detect resistance were respectively 87.2% and 98.4% for RIF and respectively 90.1% and 99.2% for INH. The capacity of RT RIF/INH to detect specific mutations was 100% for katG, inhA and frequent rpoB mutations, and 76% for rare rpoB mutations. Among the latter, two rare mutations were not consistently detected. With heteroresistant samples, RT RIF/INH reported resistance if samples contained at least 75-90% of mutant DNA. RT RIF/INH is a reliable high-throughput assay for the detection of RIF and INH resistance markers. The ability to detect INH resistance also may be of benefit in areas with high rates of INH-resistant, non-multidrug-resistant TB. .

Development of laser induced fluorescence diagnostic for measuring the parameters of plasma containing rare gas species.

Laser induced fluorescence (LIF) technique development activity for measurement of plasma parameters in ITER divertor plasma is described. Helium density is the task of priority, but Doppler measurement of ion (atom) temperatures is also the aim of the program. The concept of ITER scenarios includes injection of "extrinsic" impurities (Ne, Ar, and Kr). It is possible to use the species as tracing elements for measurement of T(i), T(a). The program included modeling experiments on PNX-U (a multicusp trap with microwave argon plasma). Helium was added by puffing into discharge. Temperatures T(i)(Ar(1+)) and T(a)(He(0)) have been measured by scanning laser line across absorption line of species. Summarizing of fluorescence signals provided input data for estimation of Ar(1+) and He(0) densities via interpretative collisional-radiative models. Besides, the collisional-radiative model has been used for estimation of electron density using the ratio of fluorescence signals at 388.9 and 706.5 nm helium lines.

[Induction of T-suppressors of delayed-type hypersensitivity with a background of T-effector formation]. / Induktsiia T-supressorov giperchuvstvitel'nosti zamedlennogo tipa na fone formirovaniia T-éffektorov.

Administration to mice of 10(5) syngeneic splenocytes modified with trinitrobenzene sulfonic acid leads to the formation of a population of T suppressors which are capable to sorb on a specific antigen. In recipients, these cells suppress only one phase of the induction of delayed type hypersensitivity (DTH). Their precursors are sensitive to the action of low doses of cyclophosphamide. The formation of the suppressors in question occurs during the generation of T effectors of DTH. It is suggested that the suppressors described may be attributed to Tc3 which are activated in the lymph nodes as a result of subcutaneous sensitization with antigen, and which are similar to Tc1 but have the Ly 2+ phenotype.

[Isolation and some properties of N-acetyl-beta-D-hexosaminidase from Sarcoscipha coccinea]. / Vydelenie i nekotorye svoistva N-atsetil-beta-D-geksozaminidazy iz Sarcoscipha coccinea.

N-Acetyl-beta-D-hexosaminidase was isolated from the extract of the discomycet Sarcoscipha coccinea and purified 510--550-fold by gel filtration on Sephadex G-200 and by ion-exchange chromatography on KM-Sephadex C-50 and DEAE-Sephadex A-50 or by a combination of hydrophobic and affinity chromatographies. Gel electrophoresis confirmed the homogeneity of the enzyme in both cases. Some properties of purified N-acetyl-beta-D-hexosaminidase (e. g. pH optimum, thermal stability, molecular weight, etc.) were studied. The Michaelis constants and maximal cleavage rates for some substrates were determined. The tissue extract of S. coccinea was found to contain two molecular forms of N-acetyl-beta-D-hexosaminidase. At concentrations of N-acetyl-p-nitrophenyl-beta-D-glucosaminide and D-galactosaminide higher than 0,5 mM the enzyme is inhibited by an excess of the substrate.

[Isolation and properties of N-acetyl-beta-D-hexosaminidase from the fungus Hohenbuechelia serotina]. / Vydelenie i svoistva N-atsetil-beta-D-geksozaminidazy iz griba Hohenbuechelia serotina.

N-Acetyl-beta-D-hexosaminidase (EC 3.2.1.52) isolated from the fruit bodies of Hohenbuechelia serotina (Fr.) splits N-acyl-p-nitrophenyl-beta-D-glucosaminides acylated at the amino group of the aminosugar by fatty acids, substituted benzoic acids and some amino acids and peptides. The enzyme was purified about 210-fold by chromatography on CM-Sephadex C-50 and DEAE--Sephadex A-50 and by gel filtration of Sephadex G-200 with a yield of 4%. The enzyme had pI 6,6. Some properties of the enzyme, pH-optimum, thermal stability and substrate specificity were studied. The Michaelis constants for some p-nitrophenyl-beta-D-glucosaminides were were calculated. p-Nitrophenyl N-acetyl-beta-D-glucosaminides were calculated. p-Nitrophenyl N-acetyl-beta-D-glucosaminide and D-galactosaminide at concentrations more than 0,3 mM inhibited the enzyme.

[Effect of acid polysaccharides on the corticosteroid biosynthesis]. / Vliiani kislykh polisakharidov na biosintez kortikosteroidov.

Repeated administration of carboxymethylchitin and chondroitinsulfate to rats in doses of 20 and 120 mg/kg/24 hours led to reduction (by 40-55%) of the rate of aldosterone and 18-oxycorticosterone biosynthesis by the rat adrenal glands in vitro. Carboxymethylcellulose, algin and hyaluronic acid displayed no inhibitory effect. In case of a single administration of carboxymethylchitin to rats (50 mg/kg) inhibition of the rate of aldosterone and 18-oxycorticosterone biosynthesis was seen 48 hours after the administration of the preparation and lasted four days. No inhibitory effect was induced by the addition of 10 mg/kg of acid polysaccharides into the incubation medium of the adrenal glands.

[Change in aldosterone secretion by the adrenals and in its urinary excretion in rats under the action of acid polysaccharides]. / Izmenenie sekretsii al'dosterona nadpochechnikami i ékskretsii ego s mochoi u krys pri vozdeistvii kislykh polisakharidov

Repeated administration of chondroitin sulfate to rats in doses of 20 and 120 mg/kg/24 hours led to reduction in the level of urinary aldosterone excretion in rats. Carboxymethylcellulose and alginic acid displayed no inhibitory effect. Urinary aldosterone excretion decreased in rats 24 hours after a single administration of chondroitin sulfate; this effect persisted for the following 3-4 days. The maximal reduction of aldosterone excretion (by 50%) occurred on the 3rd and the 4th day after administration of the preparation. Intraperitoneal injection of chondroitin sulfate to rats diminished the rate of aldosterone secretion by the adrenal glands; as to corticosterone secretion--it remained unchanged.