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A V Orlov

Publications and source records attributed to A V Orlov.

At least 19 recordsLinked to original sources
PubMed2002

Polyaniline-modified cholinesterase sensor for pesticide determination.

Cholinesterase sensors based on glassy carbon and planar epoxy graphite electrodes modified with processed polyaniline have been developed and examined for pesticide detection. The modification of electrode surface with polyaniline provides high operational stability and sensitivity towards the pesticides investigated. The detection limits found (coumaphos, 0.002, trichlorfon, 0.04, aldicarb, 0.03, methiocarb, 0.08 mg l(-1)) make it possible to detect the pollutants in the waters on the level of limited threshold levels without sample preconcentration.

Aniline Compounds↗
PubMed2001

[Genetic factors in predisposition to bronchial asthma].

The ratio between the normal (+) and null (0) alleles of the genes encoding glutatione S-transferases M1 (GSTM1) and T1 (GSTT1) were studied in normal individuals from northwestern Russia (control group) and in patients with bronchial asthma (BA). The frequency of the GSTM1 0/0 genotype in the population sample was statistically significantly lower (37.8%) than in the BA patients (82.1%; chi 2 = 16.8; P < 0.001; w chi 2 = 15.7; alpha = 0.01). For the GSTT1 gene, similar data were obtained. The frequency of the GSTT1 0/0 genotype in healthy donors was statistically significantly higher (16.3%) than in the BA patients (73.7%; chi 2 = 28.5; P < 0.001; w chi 2 = 23.22; alpha = 0.01). A significant preponderance of the compound homozygotes for the GSTM1 and GSTT1 null alleles among the BA patients was observed. The frequency of the GSTM1 0/0, GSTT1 0/0 individuals among the patients was 57.9%, while it was only 4.7% among the controls (chi 2 = 27.4; P < 0.001).

Alleles↗
PubMed2000

[Correlation of results of immunocytochemical, electrophysiologic, and molecular studies in patients with cystic fibrosis].

In 13 cystic fibrosis (CF) patients of 5 to 23 years of age with a known mutation spectrum of gene CFTR, sweat chloride values and nasal-potential differences (NPD) were measured and localization characteristics of the protein product of gene CFTR in the cells of nasal epithelium were studied. Sweat Chloride values were normal or boundary (24 to 62 mM/l) in six CF patients. In seven CF patients, these values were significantly above the estimates for the control group. On average, the NPD values were -44.7 +/- 2.2 mV (from -32.5 to -68.9 mV) and -17.2 +/- 1.8 mV (from -6.8 to -30.2 mV) in CF patients and the control group, respectively. Histochemical studies clearly revealed the localization of the CFTR protein on the apical membrane of the nasal epithelium. Depending on the type of mutation, the protein product of gene CFTR was either absent or regularly distributed in the cytoplasm in CF patients; it was not detected in the apical membrane. Thus, NPD measurements and the analysis of the localization of the protein product of gene CFTR in scrapes of nasal epithelium were shown to be additional, highly informative methods of CF diagnostics.

Adolescent↗
PubMed2000

[Characteristics of tissue reaction upon implantation of injected polyacrylamide gel containing silver and hydroxyapatite].

Albino rats were subcutaneously injected with polyacrylamide gel (PAAG) (1 ml) with 20% distilled water, water with silver ions, and 1 and 3% hydroxyapatite (HAP), and tissue reaction was evaluated over 5-90 days postinjection. PAAG containing HAP and silver ions can be used for contour plastic repair of soft tissues; its use is particularly recommended for repair or modification of facial contours with one's own tissue.

Acrylic Resins↗
PubMed1999

Processible polyaniline as an advanced potentiometric pH transducer. Application to biosensors.

An advanced potentiometric pH transducer based on processible polyaniline (PCPAn) is reported on. Both glassy carbon and screen-printed carbon electrodes modified with PCPAn by dip-coating exhibited a fully reversible potentiometric response of approximately 90 mV/pH unit over the range from pH 3 to 9. Such a significantly higher potentiometric response of PCPAn-modified electrodes as compared with those of existing devices is explained on the basis of the thermodynamics of polyaniline redox reactions. The PCPAn-based pH transducers exhibit both good operational stability and prolonged shelf life and display a negligible response toward singly charged cations. The new thick-film pH transducer was employed for designing a potentiometric biosensor for urea. In the model solution which mimics blood serum, the urea-sensitive electrode has a detection limit of 10(-5) M urea and a maximum response of approximately 120 mV. The attractive performance characteristics are advantageous over those of existing pH sensors and offer great promise for sensing and biosensing applications.

Aniline Compounds↗
PubMed1995

[Etiology of the infectious process in pulmonary and mixed forms of mucoviscidosis in children].

The specific features of an infectious process were studied in 150 children treated for mucoviscidosis at the State Pulmonology Research Center, Ministry of Health and Medical Industry of the Russian Federation. Hemophilic bacilli, Staphylococcus aureus, and Pseudomonas aeruginosa were fond to play the leading role in the etiology of the infectious process in the bronchopulmonary system. Pneumococcal infection was first ascertained to be important in the course of the disease. Developmental stages of a pyoinfectious process from the onset of its contamination, acute infection to chronic one were followed up. The most severe, prognostically unfavourable course of the disease was demonstrated to be associated with Pseudomonas aeruginosa infection.

Adolescent↗
PubMed1991

Frequency of the F508 deletion in cystic fibrosis patients from the European part of the USSR.

The frequency of the F508 deletion (delta F508) has been analyzed in 189 cystic fibrosis (CF) patients from the European part of the USSR, viz. 127 northern Slavonians (Leningrad region), 30 southern Slavonians (the Ukraine), 10 central Slavonians (Moscow region), 14 Moldavians (Kishenev region) and 8 Lithuanians (Vilnius region). The distribution of CF+ chromosomes with and without delta F508 varied significantly in the different ethnic groups studied and correlated with the clinical manifestation of CF. The overall frequency of delta F508 in Slavonian patients is equal to 62.5%, approximately 90% of them being heterozygous or homozygous for this mutation. The frequency of the deletion among 99 Slavonian patients with severe disease manifestation (pancreatic insufficiency, PI) is equal to 67.5%, only 12 patients having pancreatic sufficiency (PS, 17.5%). The highest value of delta F508 (77.4%) is registered in PI/CF patients of the southern Slavonian group; it is much less frequent (about 57%) in relevant groups of Slavonians from the northern and central parts of the country. Unusually low frequencies (24% and 26%) of delta F508 are detected in a few samples of Lithuanian and Moldavian CF patients, respectively. All delta F508+CF-chromosomes of Slavonian origin are associated with haplotypes 2.2.2. defined by the restriction fragment length polymorphism sites KM19/PstI, CS.7/Hin6I and MP6d-9/MspI, although a high proportion (about 25%) of unknown mutations is associated with the same haplotype. Haplotype B (allele 1XV2c/TaqI; allele 2 KM19/PstI) accounts for 91% of delta F508+CF chromosomes. Our data are consistent with the hypothesis of a single origin and subsequent diffusion of this major CF mutation; however, its interpopulational dissemination in Eastern Europe does not follow the suggested south-east to north-west gradient in Western Europe. The significance of these data for prenatal diagnosis and carrier screening of CF mutations is briefly discussed.

Chromosome Deletion↗