Reported thresholds of self-motion perception are influenced by testing paradigm

Journal of Neurology - Different testing paradigms have been proposed to investigate perceptual self-motion thresholds. They can differ regarding the amount of possible motions that patients have...     

Structure of the <Emphasis Type="Italic">M. tuberculosis</Emphasis> population in Mongolia according to the results of genotyping of large-sequence polymorphisms

We performed genotyping of 112 tuberculosis agent isolates from patients suffering from lung tuberculosis in Mongolia using the RD9, RD7, TbD1, RD105, and RD750 loci. Genotypes of all the obtained isolates were characterized by preservation of the RD9, RD7, and RD750 loci and by a deletion in the locus TbD1. A deletion of RD105 was found in 65 (58%) isolates. The isolates were classified into two groups, East Asian and European-American ones, by the results of genotyping.     

RD7 genotyping of <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> strains isolated from patients with lung tuberculosis in various areas of Kazakhstan

A three-primer PCR assay has been designed for detecting possible deletions in the RD7 chromosomal region of the Mycobacterium tuberculosis complex. The assay gives rise to amplicons of different sizes depending on the presence or absence of deletions. The PCR assay was applied to 176 isolates from lung tuberculosis cases collected in various areas of Kazakhstan in the summer of 2004. Prior to assay, the isolates were characterized by culture and biochemical tests. The RD7 genotyping showed neither polymorphism nor deletions in the RD7 genome region. Some strains were additionally characterized by a PCR-RFLP analysis of the gyrB and hsp64 genes. The RFLP patterns corresponded to M. tuberculosis. The results of the study were consistent with certain previous studies, which indicates the population stability of RD7 in M. tuberculosis strains. Species identification of the isolates showed that M. tuberculosis sensu stricto was the principal causative agent of human lung tuberculosis in Kazakhstan.     

Polymorphism of herpes simplex virus type 1 and 2 DNA from laboratory strains and clinical material from patient with genital herpes

Polymerase chain reaction (PCR), that can amplify a fragment of the DNA-polymerase gene of 4 herpes viruses, i.e. herpes simplex viruses, type 1 (HSV-1), herpes simplex viruses, type 2 (HSV-2), Epstein-Barr virus and cytomegalovirus, was made use of to study the genetic polymorphism of HSV-1 and HSV-2 strains. The obtained amplicons were analyzed by the method of restriction-size fragments' polymorphism (RSFP) with restrictases Rsal, Taql and Hinfl. Four HSV-1 strains had an identical restriction profile. Strain G (HSV-2) also displayed the expected restriction profiles, however, contradictory results were obtained for strain BH (HSV-2): the restriction profiles with restrictases Hinfl and Rsal corresponded to HSV-2, and the restriction profile with Taql corresponded to HSV-1. The sequencing of appropriate fragments of strains G and BH revealed a dot-type mutation localized in Taql restriction site. The thus worked out PCR was used jointly with RSFP in the genotyping of 75 urogenital samples obtained from women with genital herpes who were treated at Moscow patient-care facilities. HSV-1 and HSV-2 were detected in 18 (24%) and 57 (76%) of samples, respectively. No changes were registered in the restriction profile for HSV-2 among the investigated samples and all of them had the restriction profile similar to that of strain G. The conclusion is that genital herpes associated with HSV-2 is genetically stable within its Moscow population.     

Detection and species identification of four human herpesviruses using polymerase chain reaction coupled with restriction endonuclease analysis

A polymerase chain reaction (PCR) based assay for detection and species identification of four human herpesviruses, including herpes simplex virus types 1 and 2, Epstein-Barr virus, and cytomegalovirus was developed. The detection of the herpesviruses was achieved by seminested PCR with three primers targeting well-conserved regions within the DNA-polymerase gene. Virus species were identified by simple restriction enzyme digestion of the amplified products with TaqI or RsaI. In comparison with mono-specific nested PCR assays the tetra-specific assay demonstrated similar specificity and sensitivity with reference and clinical samples. The tetra-specific assay is sensitive, cost effective, and can be used for examination of clinical samples of different origin.     

Determination of antibodies against cyclic citrullinated peptide in rheumatoid arthritis

The ability of the synthetic peptide IMG-5, that reproduces one of the antigenic determinants of the protein filaggrin, to show antigenic activity was studied when anti-cyclic citrullinated peptide antibodies (ACCPAb) to filaggrin were found in the serum samples of patients with rheumatoid arthritis (RA). The binding of IMG-5 to ACCPAb has been shown to be specific (dose-dependent and reversible). The serum samples from patients with RA, controls, and donors show a significant difference in the interaction of the synthetic peptide with ACCPAb (p < 0.005 and p < 0.0001, respectively). The level of IgM rheumatoid factor (RF) detected in patients with RA differs greatly from that in the controls. In the patients with RA versus the controls, the specificity of ACCPAb determination was as high as 87; and the sensitivity was 40.5%. When ACCPAbs were determined using the commercial kit CCP, the specificity and sensitivity were 94 and 47.3%, respectively. The specificity of RF detection was equal to 50% and the sensitivity was 70%. The sensitivity of the test using IMG-5 is a maximum in X-ray stage IRA (69.2%) and falls in its stage III (26.7%). On the contrary, the sensitivity of the commercial kit and RF determination increases from X-ray stage I (46.2 and 53.8%, respectively) to II (66.7 and 80%). The sensitivity of the used tests in varying RA activities has demonstrated that they are most effective in patients with moderate RA activity. The concurrent detection of ACCPAb and RF increases the probability of differentiating RA from other rheumatic diseases.     

Restriction fragment length polymorphism of the DNA of typhus group rickettsiae.

The DNA of 10 strains of Rickettsia prowazekii, 5 strains of Rickettsia typhi and 1 strain of Rickettsia canada was investigated by restriction fragment length polymorphism analysis. Interspecies differences were characterized by a great number of noncomigrating bands. Using the endonuclease HindIII and PstI fragments comigration as a quantitative criterion, genetic similarity coefficient was calculated for the pair Rickettsia prowazekii/Rickettsia typhi-32.0%, for Rickettsia prowazekii/Rickettsia canada-22.7%, and for Rickettsia typhi/Rickettsia canada-23.5%. Intraspecies differences expressed are very subtle and concern 1-2 noncomigrating fragments. The investigated strains of Rickettsia prowazekii and Rickettsia typhi can be divided into 2 groups without any correlation to the source and period of isolation, or to strain passage history.