Biomedical subjects
Publications and source records attributed to D V Novikov.
A direct nondiffractive tomographic algorithm is proposed for the determination of the crystal structure from real-space projections obtained by illuminating the sample with white x rays. This approach was applied to the pattern of the directional fine structure in absorption of white x rays recorded for a GaP crystal and allowed for a determination of the electron density distribution within the unit cell.
We have analyzed factors causing stress during out-patient dental treatment. The psychological characteristic of people with prevalence of sthenical and asthenical features were given and dependence of the effect of the medicine on individual features was shown.
Parametric down conversion of X-ray photons in diamond crystals was detected in two experiments, both using the phase-matching scheme first employed in the X-ray regime by Eisenberger & McCall [Phys. Rev. Lett. (1971), 26, 684-688]. The conversion events were detected by a combination of time-correlation spectroscopy and energy discrimination, using Si drift-chamber detectors. The time-correlation spectra give a direct comparison of the conversion rate over the accidental coincidence rate. Mechanisms for possible detection of false events and ways to cross check against them are discussed in detail.
X-ray atomic resolution holography is a new method for direct evaluation of three-dimensional electron density distribution in solids. The practical implementation of the multiple-energy technique on a synchrotron radiation source as well as image reconstruction from the experimental data are described. Holograms at several different energies were processed together to suppress twin images and artifacts from long-range-order effects in the experimental data sets. Reconstructed images of copper atoms in Cu(2)O crystals are presented.
Nucleotide sequence of a 356 nt fragment of the NS5 region of the hepatitis G virus (HGV) genome was determined in 7 strains isolated in Russia, Kazakhstan, and Kyrghyzstan. Philogenetic analysis showed that all isolated strains genetically differed from the West African strain described previously (type 1) and are closely related to strains isolated in the USA and South-Eastern Asia (type 2). Hence, the strains from Russia, Kazakhstan, and Kyrghyzstan belong to type 2 variant of HGV genome.
Study of prevalence of hepatitis G virus (HGV) markers in different risk groups showed the presence of HGV RNA in 3.2% blood donors, 24.2% patients with hepatitis C (HCV), and 28% patients with hemophilia. HGV antibodies were detected in 11.3% donors, 16.0% patients with HCV, 13.4% patients with hemophilia, and 8.5% HIV-infected subjects. Anti-E1 HGV were more often detected in the absence of HGV RNA. Antibodies to HGV E2 protein were significantly more often detected in adult HCV patients but not in adolescent patients aged 8-15 years.
Two strains of West Nile virus, Vlg 27889 and Ast 986, were isolated from the brain of a dead man and from the blood of a patient, respectively, during an outbreak of serous meningitis and meningoencephalitis in July-September, 1999, in the Volgograd and Astrakhan regions. Analysis of parts of genome of the strains cloned from cell culture by reverse transcription and polymerase chain reaction demonstrated their identity and appurtenance to group I West Nile viruses.
Five overlapping cDNA fragments of hepatitis C virus (HCV) isolate 274933RU, obtained by RT-PCR, were amplified and cloned. Complete nucleotide RNA sequence has been determined. The genomic organization of 274933RU was, from 5' to 3' terminals, 5' UTR (341 nt), polyprotein ORF (9033 nt), 3' UTR (40 nt except for the poly(U-UC) and polypyrimidine stretch), and X-tail (98 nt). Phylogenetic analysis of the core and NS5 genes showed that the isolated strain belonged to HCV 1b subtype.
The RT-PCR assay for the detection of all human enteroviruses was used to analyze fecal samples, cerebrospinal fluid (CSF), respiratory tract swabs, and sera from 204 patients with symptoms of viral infection. Enteroviruses were detected in 31.37% of cases. The proposed method analyzes every type of clinical samples. The relative detection rate of enteroviruses in different samples was 70.64% in feces, 10.4% in SCF, 17.24% in swabs, and 21.14% in the sera. The use of serum in addition to other testing samples increased the rate of enterovirus detection at 18.25%. Developing techniques may be used for the diagnosis of acute enterovirus infections with different clinical manifestations.
The case study comprises a description of a method used for producing the full-length cDNA complementary to influenza virus segments made through the recombination of homologous DNA fragments in the process of polymerase chain reaction (PCR). The detailed protocol of the method is presented alongside with a discussion of the advantages of the suggested approach.
The levels of soluble CD38 (sCD38), CD50 (sCD50), and CD95 (sCD95) antigens and HLA class I (sHLA-I) were determined in the serum samples from persons infected with hepatitis G virus (HGV). HGV monoinfection was accompanied by a rise in the serum content of sCD38, sCD50, and sCD95 antigens. The serum presence of HGV RNA and anti-E2 HGV antibodies was characterized by the normal content of sCD38 and sCD95 while the level of sCD50 was elevated and the serum content of sHLA-I was decreased. If the serum contained only anti-E2 HGV antibodies, the level of sCD50 remained increased 4-fold. It is suggested that the higher adhesion-inhibiting level of sCD50 is a reason of a weak immune response to HGV and hence of a long HGV persistence in the body.