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Biomedical subjects

L N Chernousova

Publications and source records attributed to L N Chernousova.

At least 19 recordsLinked to original sources
PubMed2006

[Mycobacterium tuberculosis strain transmission caused by migratory processes in the Russian Federation (in case of populational migration from the Caucasian Region to Moscow and the Moscow Region)].

The investigation was carried out on 134 M. tuberculosis isolated from 134 patients treated at the Central Research Institute of Tuberculosis, Russian Academy of Medical Sciences. The patients were divided into 2 groups: 1) those who were natives of Moscow and the Moscow Region (MR patients); 2) those who were migrants to the Moscow Region from Azerbaijan, Daghestan, Chechnya, Ingushetia, Karachai-Cherkessia, North Ossetia (the Caucasian Region) (CR patients) who had fallen in the place of birth. Genotyping by the polymorphism of lengths of the restriction fragments containing the insertion sequence IS6110 revealed a genetic diversity of M. tuberculosis strains. The examined M. tuberculosis strains belonged to 13 genotypic families. The W and AI families were prevalent. The family W M. tuberculosis strains isolated from the Caucasians were highly clustered, as confirmed by the overwhelming predominance of the strain variant W148 (19.7%). The spectrum of the strain variants of the W family, and those of the AI family in particular, greatly differed in MR and CR patients. Only one strain variant AI12 occurring both in MR and CR patients was detected. A study of the transmission activity coefficient (TAC) of the families W and AI indicated that the transmission activity of W strains was significantly higher than that of M. tuberculosis strains of the AI family. A comparative analysis of the TAC of M. tuberculosis strains of the AI family demonstrated that the transmission activity of the strains of this family was identical no matter where a patient had fallen ill (1.59 and 1.41% in the Moscow and Caucasian Regions, respectively). Unlike M. tuberculosis strains of the AI family, the TAC of W strains isolated from the patients infected in the Moscow Region (28.17 and 19.05%, respectively), which suggests the more intensive transmission of the pathogen M. tuberculosis of the W family in the Caucasian Region.

Bacterial Typing Techniques↗
PubMed2006

[Antimycobacterial activity of a dry birch bark extract on a model of experimental pulmonary tuberculosis].

The study deals with the evaluation of antimycobacterial activity of betulinol, a dry birch bark extract (BBE), on a model of infection caused by Mycobacterium tuberculosis (MBT). It has established the inhibitory action of betulinol on the in vitro and in vivo growth of MBT and its positive effect on reparative processes in the lung, liver, and spleen of tuberculosis-infected mice.

Animals↗
PubMed2006

[Preponderance of Mycobacterium tuberculosis strains of the family Beijing and risk factors of their transmission in the Samara Region].

Current molecular and epidemiological studies could reveal individual families of Mycobacterium tuberculosis strains. The purpose of the present study was to reveal the spread of Mycobacterium tuberculosis strains of the family Beijing in the Samara Region and to define risk factors for their transmission. This was a cross-sectional populational molecular epidemiological study that showed that the Beijing genotype prevailed among the obtained isolates (66.6%; 586/880) and it was encountered among convicts and young persons (RR 1.3; 95% CI 1.2-1.5 and RR 1.2; 95% CI 1.0-1.3, respectively), which is indicative of active and recent transmission. Multifactorial analysis indicated that male sex (OR 1.5; 95% CI 1.1-1.9), younger age (OR 1.3; 95% CI 1.1-1.7), homelessness (OR 5.6; 95% CI 1.1-6.3), and prior or current confinement (OR 2.0; 95 CI 1.5-2.7) were substantially associated with the risk of contamination with the strain of the Beijung family. Drug resistance, including multidrug resistance, was twice higher among the strains of this family.

Adult↗
PubMed2006

[Efficiency of chemotherapy of destructive pulmonary tuberculosis, based on the results of rapid detection of drug sensitivity to isoniazid and rifampicin with the "TB-Biochip" test system].

To evaluate the efficiency of chemotherapy used in patients with pulmonary tuberculosis by the results of a rapid detection of drug resistance (DR) to isoniazid and rifampicin on a "TB-Biochip" test system versus the standard treatment with its subsequent correction by the data of determination of Mycobacterium tuberculosis (MBT) resistance by the absolute concentration technique (ACT), the study included 208 patients with pulmonary tuberculosis. The patients were divided into 2 groups: 1) those in whom MBT sensitivity to antituberculous agents was determined on a "TB-Biochip" test system to detect mutations in the MBT genes rpoB, katG, inhA, ahpC that were responsible for MBT sensitivity to rifampicin and isoniazid and by ACT; 2) those in whom this was determined by only ACT. The results of a test for MBT sensitivity to rifampicin and isoniazid were obtained within 2 days before chemotherapy in Group 1 and 2 months after chemotherapy in Group 2. In Group 1, antituberculous chemotherapy was used, by taking into account MBT sensitivity to isoniazid, rifampicin, or their combination; in Group 2, the drugs were given by the standard regimens with their subsequent correction following 2 months by the results of ACT. The timely initiation of treatment with reserve drugs in the detection of drug sensitivity in MBT could achieve higher therapeutic efficiency and in a shorter space of time.

Adult↗
PubMed2004

[Experience with fenazid in perperas with respiratory tuberculosis and post-tuberculous changes in the lung].

The paper describes the authors' experience with the new Russian antituberculous agent isonicotinic acid hydrazide (INAH) used in postpartum female patients with different forms of active and inactive pulmonary tuberculosis. The study group comprised 20 puerperas with respiratory tuberculosis of different degrees who received fenazid in a dose of 0.5 g daily for 2-3 months for therapeutic and preventive purposes. The comparison group included 36 puerperas given isoniazid in a daily dose of 0.6 g. The effectiveness of fenazid in treating and preventing respiratory tuberculosis allowed the agent to be used in postpartum period and recommended if there are side effects of isoniazid and altered peripheral blood parameters.

Adult↗
PubMed2004

[Diagnosis of latent primary intrathoracic tuberculosis of respiratory system in the phase of calcification in children].

The paper shows the latent activity of newly diagnosed intrathoracic tuberculosis in the phase of calcification in children: clinical and X-ray changes, tuberculin sensitivity (Manteaux test), the presence of Mycobacterium tuberculosis (MBT) in the sputum and blood (cultivation, bacterioscopy, polymerase chain reaction PCR), the blood levels of acute-phase reagents: haptoglobin and alpha 1-protease inhibitor (alpha 1-PI), immunological parameters, tuberculosis antibodies (TAb), and MBT antigen. Ninety children were examined before treatment. Twenty-five children (Group 1) were found to have single minor calcified masses in one group of intrathoracic lymph nodes or in the lung. Thirty-five children (Group 2) had multiple lymph nodes or foci in the lung in the phase of consolidation and calcification. Thirty children (Group 3, controls) were diagnosed as having intrathoracic tuberculosis in the phase of infiltration. The signs of the latent activity of tuberculosis were detected in all the children of all three groups, being more pronounced in Group 3. Thus, MBT and TAb were revealed in 90% of the children in Group 3 and in 52.9 and 76.0% in Groups 1 and 2, respectively. There were higher levels of alpha 1-PI in 96.6 and 75.0% in Groups 3 and 1, respectively. There were signs of intoxication in 80 and 88% and a hyperergic Mantoux reaction in 44.0 and 43.3%, respectively. The frequency of the signs of activity did not greatly differ. Thus, children with newly diagnosed respiratory tuberculosis in the phase of calcification should be regarded as having the signs of tuberculosis activity, followed up as Group I patients, and prescribed chemotherapy for 3-6 months or more, depending on the extent of the process.

Calcinosis↗
PubMed2004

[Comparative characterization of molecular and microbiological methods for controlling chemotherapy in new cases of pulmonary tuberculosis].

The purpose of the study was to define a role of molecular genetic techniques in the evaluation of the efficacy of short-term chemotherapy in patients with pulmonary tuberculosis. A total of 203 patients with first detected tuberculosis patients who isolated Mycobacterium tuberculosis (MBT) were examined. Microbiological methods (bacterioscopy and seeding) and polymerase chain reaction (PCR) were used to detect MBT in new cases. During chemotherapy, there was a reduction in the number of positive results of both bacterioscopy and PCR, which serves as a sign of abacillation. Following 2 months of chemotherapy, 50% of the patients with negative bacterioscopy and seeding were found to have MBT DNA. In the patients with negative bacterioscopy and seeding, the results of PCR were also negative by month 6. In a group of patients without bacterial isolation, but with positive sputum tests for MBT DNA, the efficiency of chemotherapy was confirmed by the negative results of PCR. The latter is shown to enhance the sensitivity of bacteriological tests for MBT and to reduce the time of obtaining their results.

Antitubercular Agents↗
PubMed2004

[Experimental evidence for Mycobacterium tuberculosis persistence in M. tuberculosis-infected H37RV mice in the treatment with 3 first-line drugs (rifampicin, isoniazid, pyrazinamide)].

To detect Mycobacterium tuberculosis (MBT) DNA in the blood and organs of tuberculosis-infected animals treated by the standard regimen including 3 first-line drugs, to assess the cellular reactions of organs of MBT-infected mice, and to evaluate the effect of rifampicin supplemented to the Cornell treatment regimen on the occurrence of endogenous reactivation of a tuberculous process, 150 BALB/c mice were intravenously infected with the MTB H(3)7Rv strain in a dose of 2.5 x 10(4) CFU/mouse and given chemotherapy with 3 drugs: rifampicin, 12 mg/kg body weight, isoniazid, 5 mg/kg, and pyrazinamide, 35 mg/kg. On day 20 of infection 2, 4, and 6 months after treatment and 2 months after termination of 4- and 6-month courses of therapy, the authors made inoculation, impressionsmears from parenchymatous organs stained by the Romanovsky-Gimse method, and conducted polymerase chain reaction for MBT DNA in the blood and organs of mice. The results indicated that supplementation of rifampicin to the Cornell treatment regimen prevented endogenous reactivation of the process, as confirmed by negative inoculations of the organs of the mice left untreated for 2 months. However, detection of MBT DNA and the cytological picture characteristic of tuberculous inflammation in the blood and organs of mice from these groups suggested that an occult tuberculous process was preserved.

Animals↗
PubMed2004

[Genotypic characteristics of Mycobacterium tuberculosis strains from the Republic of Tyva].

To determine the genetic heterogenicity of Mycobacterium tuberculosis isolated from patients with tuberculosis from different districts of the Republic of Tyva, 71 M. tuberculosis strains IS6110 according to the polymorphism of restriction fragment lengths were typed; of them 32 strains were spoligotyped. The study could genetically characterize the groups of M. tuberculosis strains circulating among patients with tuberculosis in the Republic of Tyva. There was a predominance of the W family of mycobacteria (60.56%). The spoligotyping permitted identification of M. tuberculosis with the spoligotype Beijing in the Republic of Tyva. The mycobacteria belonging to this spoligotype were prevalent and accounted for 50% of the strains. The high proportion of strains with the unique spoligotype (25%) that have not earlier been encountered in the international database is a specific feature of the Mycobacterium population from the Republic of Tyva.

Bacterial Typing Techniques↗
PubMed2004

[A role of the biological chip test in the determination of rifampicin resistance in Mycobacteria in adolescents with active pulmonary tuberculosis].

Forty-nine adolescents with active pulmonary tuberculosis were followed up to assess the biological chip test for the detection of rifampicin resistance in Mycobacterium tuberculosis (MBT). Rifampicin resistance (rpo B gene mutation) was detected in 22 (44.9%) patients. Disseminated processes were detected in a larger proportion of the patients with rifampicin resistance than in those with MBT susceptibility (63.6 and 40.7%, respectively (p < 0.05). Comparison of the data on MBT resistance and susceptibility, which had been obtained by bacteriological studies (nutrient medium cultuvations) and the biological chip test, revealed their agreement in 50% of the cases. A response could be showed after 2-3 months in the former case and after 2-3 days in the latter case. With the biological chip test, the resistance of MBT to rifampicin was additionally established in 38.7% of the patients with negative cultivation tests on admission and during therapy. Follow-ups have demonstrated that MBT resistance to rifampicin preserves longer with the biological microchip test than that with nutrient medium cultivation.

Adolescent↗
PubMed2002

[Clinical value of microchip technology in determination of drug resistance of Mycobacterium tuberculosis].

The patients with multiresistant tuberculosis were divided into 2 groups: the sensitivity of Mycobacteria tuberculosis to antituberculous drugs was evaluated in Group 1 by the methods of absolute concentrations and in Group 2 by biological microchips determining mutations in the rpo3 gene responsible for rifampicin resistance. The results of the drug sensitivity test were obtained after 3 months of treatment in Group 1 and several days prior treatment in Group 2. By taking into account the test results, reserve drugs was used in Group 2 patients. Subsequently, the results of the drug sensitivity tests carried out by the bacteriological method in Group 2 patients showed that isoniazid resistance was simultaneously noted if there were mutations in the rpo-B gene. Timely treatment with reserve drugs exhibited higher efficiency of treatment with its shorter duration in Group 2 than in Group 1.

Adult↗
PubMed2002

[Characterization of an experimental model of endogenously reactivated tuberculosis: detection of Mycobacterial DNA during chemotherapy].

The study was undertaken to determine the value of detection of DNA of Mycobacterium tuberculosis (MBT) during chemotherapy on an experimental model of an endogenously reactivated tuberculous process. A hundred and fifty BALB/C mice were intravenously inoculated by MBT strain H37Rv and received antituberculous chemotherapy (isoniazid and large-dose pyrazinamide) during 4 and 6 months. Solid medium inoculation, bacterioscopy, cytology, polymerase chain reaction were used to show the value of detection of MBT DNA in the viscera and blood in confirming the development of tuberculosis and testifying the preservation of MBT in the body if the treatment regimen was incomplete, which can lead to endogenous reactivation of the process under certain conditions. Gene typing of MBT, as described in?? of the Russian Federation under IS6110 provided evidence for the endogenous pattern of reactivation.

Animals↗
PubMed2001

Detection of rifampicin-resistant Mycobacterium tuberculosis strains by hybridization and polymerase chain reaction on a specialized TB-microchip.

Two alternative methods for identification of rifampicin-resistant strains of Mycobacterium tuberculosis on biological microchips are developed. The methods are based on detection of point mutations and other rearrangements in the rpoB gene region determining rifampicin resistance. Hybridization on TB-microchip detects 30 mutant variants of DNA in rifampicin-resistant strains (about 95% of all resistant forms). Allele-specific microchip PCR shortens the duration of analysis to 1.5 h. These methods can be used in clinical diagnostic laboratories for evaluating drug resistance/sensitivity of tuberculosis agent and for monitoring of the efficiency of antibiotic therapy.

Antibiotics, Antitubercular↗
PubMed2001

[Role of PCR analysis in complex bacteriological studies in phthisiology].

The study was undertaken to assess the role of polymerase chain reaction (PCR) analysis in complex bacteriological studies in diagnosing pulmonary tuberculosis in 197 patients by bacterioscopy, inoculation, and PCR. It was shown that in addition to conventional bacteriological methods, PCR might be used as an additional laboratory study in making a diagnosis in patients with restrictive pulmonary tuberculosis. A combination of cultural inoculation and PCR analysis enhances the sensitivity of bacteriological diagnosis and reduces its duration in oligo- and abacillary patients with tuberculosis. PCR analysis enhances the efficiency of laboratory control over antituberculous chemotherapy.

Bronchitis↗
PubMed2001

[Genotyping mycobacteria, isolated from incarcerated tuberculosis patients].

The aim of the investigation was to genotype clinical Mycobacterium tuberculosis isolates circulating at the penitentiaries of the Ivanovo Region. Mycobacterial strains were genotyped by the polymorphism of the lengths of restrictive fragments containing the insertion sequence 6110 by the routine procedure. The genotypes of Mycobacterium strains were classified in accordance with the PHRI database (New York). The strains were characterized by their sensitivity to antituberculous drugs by the absolute concentration method. The investigations indicated that in terms of the IS6110 genotype there were prevalent Mycobacteria strains belonging to 2 families: a W family (62.5% of the strains) and an AI family (25%). In addition to the monocultures, genotyping also revealed 3 mixed cultures consisting of 2 strains. Determining the drug sensitivity of the genotyped strains demonstrated both drug-sensitive and drug-resistant strains, including multidrug resistance among the strains of the same genotyping family (W or AI).

Antitubercular Agents↗
PubMed2001

[Comparative characterization of the antigenic composition of M. leprae and M. lufu].

The antigenic structure of M. leprae and M. lufu was comparatively studied for the first time. M. lufu was found to have M. leprae-specific protein with a molecular weight of 36 kDa. M. leprae and M. lufu were similar in their fractional composition of proteins and an antibody response to determinants with equal molecular weights in patients with different forms of leprosy and its varying severity. The findings may improve a diagnostic system in leprosy by using M. lufu antigens as an alternative.

Antigens, Bacterial↗
PubMed2000

[Molecular characteristics of multiresistant clinical strains of Mycobacterium tuberculosis isolated in Russia].

The efficiency of tuberculosis control programs is largely determined by methods for rapid diagnosis of the agent. In comparison with the traditional methods, new molecular technologies for characterization of mycobacteria appear to be more promising, because the result can be obtained in almost no time. Sixty-five strains of M. tuberculosis isolated in various regions of Russia were investigated. Drug resistance and strain appurtenance of this sample were determined by classical (absolute concentrations method, IS6110-RFLP) and modern molecular genetic methods (detection of mutations in rpo B gene, DRE-PCR). The spectrum of mutations of the rpoB gene associated with rifampicin resistance was evaluated by direct sequencing. Mutations involving codons 531 (62.7%), 526 (18.6%), and 516 (10.2%) of rpoB gene predominated in the studied sample. The studied strains were discriminated into 52 individual strains by IS6110-RFLP and DRE-PCR typing. Analysis of the resultant genetic variants showed the predominance of M. tuberculosis family W. The efficiency of combined approach to screening for M. tuberculosis is discussed.

DNA-Directed RNA Polymerases↗