Influence of Biological Model on the Formation of the Pathogenic Properties of the West Nile Virus Isolate.

Various biological models are used to isolate West Nile virus, but their role as a selection factor that facilitates selection of isolates with certain properties is usually not evaluated. We compared pathogenic properties of three strains of the West Nile virus obtained from one sample of virus-containing material using different models: WNV Volgograd 900m/18 (on the model of suckling mice), WNV Volgograd 900a/18 (on C6/36 cells) and WNV Volgograd 900v/18 (on Vero cells). WNV Volgograd 900m/18 strain demonstrated virulent (LD50 5×103±0.005×104 PFU, p≤0.05) and neuroinvasive properties, induced viremia and pathomorphological changes in the liver, lymph nodes, and brain of nonlinear white mice. WNV Volgograd 900v/18 strain had similar characteristics except for neuroinvasiveness. WNV Volgograd 900a/18 variant demonstrated minimum virulence (LD50 5×104±0.005×104 PFU, p≤0.05), did not cause neurological symptoms, and was not isolated from the blood of infected animals.

Current state of chikungunya fever laboratory diagnosis (review of literature).

The article is about methods of chikungunya fever laboratory diagnosis. An algorithm for the study of biological material for the presence of antibodies against chikungunya virus and virus antigens is presented. The overview describes the information about commercial immunodiagnostic and genodiagnostic kits and their detailed specifications. The information presented in the review will be useful for doctors of clinical laboratory diagnostics to choose a method and an acceptable test system for laboratory confirmation of Chikungunya fever diagnosis, as well as differential diagnosis with other fevers, which have similar symptoms, common geographical distribution and carriers of infection.

Determination of coal ash content by the combined x-ray fluorescence and scattering spectrum.

An alternative method is proposed for the determination of the inorganic constituent mass fraction (ash) in solid fuel by the ratio of Compton and Rayleigh X-ray scattering peaks IC/IR subject to the iron fluorescence intensity. An original X-ray optical scheme with a Ti/Mo (or Sc/Cu) double-layer secondary radiator allows registration of the combined fluorescence-and-scattering spectrum at the specified scattering angle. An algorithm for linear calibration of the Compton-to-Rayleigh IC/IR ratio is proposed which uses standard samples with two certified characteristics: mass fractions of ash (Ad) and iron oxide (WFe2O3 ). Ash mass fractions have been determined for coals of different deposits in the wide range of Ad from 9.4% to 52.7% mass and WFe2O3 from 0.3% to 4.95% mass. Due to the high penetrability of the probing radiation with energy E > 17 keV, the sample preparation procedure is rather simplified in comparison with the traditional method of Ad determination by the sum of fluorescence intensities of all constituent elements.

[The development and application of reagents kit for detection RNA of the causative agents of melioidosis and glanders by transcription-based amplification (NASBA) in real-time.]

The polymorphism of clinical manifestations of melioidosis and glanders and their high mortality require improvement of diagnostics for detection of this agents. The perspectivity of development of transcription-based amplification real-time NASBA diagnostic kits is determined by high analytical sensitivity and the opportunity to perfom the verification of the results of other methods for pathogenic Burkholderia species detection. The fragment of 23S rRNA gene was selected as the target for development of real-time NASBA kit. The high specificity of the constructed oligonucleotides was confirmed during the analysis of wide range of heterological strains of microorganisms and sequencing of amplified fragments of 23S rRNA gene. The analytical sensitivity of the developed kit allowed to detect Burkholderia pseudomallei and Burkholderia mallei in concentration of 1×101 microbial cells per ml. The high functional characteristics of developed kit as well as the possibility to use it in case of appereance of discordant result during the detection of pathogenic Burkholderia species were demonstrated while studying biological samples.

Rapid diagnostics of urinary iodine using a portable EDXRF spectrometer.

A method for urinary iodine diagnostics using a portable energy-dispersion X-ray fluorescent (EDXRF) spectrometer is proposed. The principle of the method consists in excitation of the sample atoms fluorescence by the energy spectrum intentionally formed from the spectrum of an X-ray tube using an optimized X-ray scheme. The optimization by the criterion of the minimum detection limit for L-series iodine fluorescence lines included the calculation of optimal atomic numbers for materials of a re-radiator and a filter, and their thicknesses, the collimation system parameters, and an X-ray tube voltage. Experimentally achieved detection limits were 45 and 75 µg/L by I-Lα and I-Lß lines, respectively, at the theoretically extreme value 30 µg/L. This sensitivity is found to be sufficient for urinary iodine diagnostics in the range from 50 to 200 µg/L. The results obtained from different patients have shown the satisfactory convergence for the iodine concentration determination by Lα and I-Lß fluorescence lines. The simple sample preparation procedure and comparably small sizes of the apparatus allows rapid researches directly in clinical settings.

[The comparative evalution of informativeness of immunologic and molecular genetic methods and means during stages of specific indication of melioidosis agent].

The reference-center of monitoring of agents of glanders and melioidosis carried out testing of reagents kits for diagnostic of agent of melioidosis and other close-related species of Burkholderiae in vitro. At the stage of specific identification of pathogenic Burkholderiae the diagnostic possibilities of commercial and experimental kits of reagents for express- and rapid analysis were evaluated. The criteria of evaluation of diagnostic value of kits of reagents were sensitivity, specificity and time of implementation of studies. The analysis with application of mono- and multi-locus amplification systems, including real-time polymerase chain reaction permitted during 5-6 hours to implement identification and differentiation of Burkholderia pseufomallei, B. thailandensis and B. cepacia.

[Use of electron paramagnetic resonance in assessing viscosity of blood lipids in diabetes mellitus in children]. / Ispol'zovanie élektronnogo paramagnitnogo rezonansa v otsenke viazkosti lipidov krovi pri sakharnom diabete u detei.

Viscosity of blood serum lipids was studied in children with insulin-dependent diabetes involving nitroxyl containing probes-registered by means of radiospectrometer RE 1307. The following parameters were studied: the ratios between values exhibiting the probe distribution in polar and hydrophobic phases [formula: see text] as well as between content of low polar (I+1) and high polar (I-1) spectral components. The "f' value showed the state of lipid density and the ratio [formula: see text] allowed to estimate the lipid microviscosity. 34 children of 7-15 years old with insulin-dependent diabetes were examined in dynamics of treatment under stationary conditions. Distinct metabolic impairments and aggravation of the lipid peroxidation syndrome were mainly responsible for pronounced increase in lipid viscosity. The procedure of spin probes may contribute to study of diabetes pathogenesis as well as to serve as a diagnostic means in evaluation of the disease complications at early stages.

[Diagnostic value of detection of blood levels of lactate, pyruvate and 2,3-diphosphoglycerate in children with diabetes mellitus]. / Diagnosticheskoe znachenie opredeleniia urovnia laktata, piruvata i 2,3-difosfoglitserata v krovi pri sakharnom diabete u detei.

Measurements were made of lactate, pyruvate and 2,3-diphosphoglycerate in 69 children admitted to the hospital in a state of diabetic ketoacidosis of different intensity. Depending on the intensity of metabolic abnormalities, the content of lactate and pyruvate was found to be increased, whereas that of 2,3-diphosphoglycerate to be lowered. Measurements of the content of lactate and the lactate/pyruvate ratio enables carrying out differential diagnosis between the ketoacidotic and lactacidotic varieties of diabetic coma.