Competition between diffusion and electroconvection at an ion-selective surface in intensive current regimes.

Considering diffusion near a solid surface and simplifying the shape of concentration profile in diffusion-dominated layer allowed Nernst and Brunner to propose their famous equation for calculating the solute diffusion flux. Intensive (overlimiting) currents generate electroconvection (EC), which is a recently discovered interfacial phenomenon produced by the action of an external electric field on the electric space charge formed near an ion-selective interface. EC microscale vortices effectively mix the depleted solution layer that allows the reduction of diffusion transport limitations. Enhancement of ion transport by EC is important in membrane separation, nano-microfluidics, analytical chemistry, electrode kinetics and some other fields. This paper presents a review of the actual understanding of the transport mechanisms in intensive current regimes, where the role of diffusion declines in the profit of EC. We analyse recent publications devoted to explore the properties of different zones of the diffusion layer. Visualization of concentration profile and fluid current lines are considered as well as mathematical modelling of the overlimiting transfer.

[Molecular typing of the strains of Bordetella pertussis circulating in St. Petersburg during an outbreak of the disease].

Growth of the whooping-cough morbidity during the last years in Russia and other countries with 40-year-long history of immunization gave rise to significant interest of researchers to variability of the Bordetella pertussis population. Comparative assay of the genomes of the B. pertussis strains circulating in St. Petersburg in 1998-2000 and strains used to produce domestic vaccines AKDS was performed using the pulse-field electrophoresis and sequencing. It was found that most strains of B. pertussis circulating during this period were distinguished from the vaccine strains by the DNA-profile and structure of genes involved in encoding of biosynthesis of the S1 subunit of the whooping-cough toxin (ptxS1) and pertactin (prn). It was shown that 62% of wild-type strains had electrophoretic profiles IV alpha and IV beta, whereas vaccine strains had electrophoretic profiles II and III. Circulation of strains with profiles IV alpha and IV beta was found to correlate with the whooping-cough morbidity rate in vaccinated children. Our results and data of other researchers were compared and analyzed.

[The morbidity and immunological structure of the population in viral hepatitis A at different phases in the development of multiyear epidemic cycles]. / Zabolevaemost' i immunologicheskaia struktura naseleniia pri virusnom gepatite A v raznye fazy razvitiia mnogoletnikh épidemicheskikh tsiklov.

For the first time population immunity to virus hepatitis A has been studied during three different phases of prolonged morbidity cycles of this infection, and the results of this study have been compared with the data on morbidity in different age groups. Pronounced variability of the immunological structure of the population in different age groups, found to be related to the dynamics of hepatitis A morbidity, has been established. Fluctuations in immunity level are most pronounced among children aged 1-6 and 7-14 years, having the least proportion of seropositive persons. A new epidemic cycle is started among these groups of the population, and at the first stage this cycle is manifested by an increase in the intensity of the latently developing epidemic process. This is followed by the activation of registered morbidity among the whole of the population. Seroepidemiological study may be used both for prognostication purposes and in the system of surveillance on this infection.

[A prognostic model of hepatitis A morbidity]. / Prognosticheskaia model' zabolevaemosti gepatitom A.

The growing interest to the study of the processes of the spread of hepatitis A (HA) in big cities of our country has stimulated the development of a new prognostic model at the Gamaleia Research Institute of Epidemiology and Microbiology. The model specifically takes into account a number of factors linked with the dynamics of the development of the disease in 6 stages and some regularities in the seasonal rises of HA morbidity. Quantitative relations in the mathematical model are determined by a system of nonlinear integral-differential equations with the first order partial derivatives and under the integral type boundary conditions, which increases the strictness of modeling of HA. The use of this new model has made it possible to carry out the prognostic-analytical study of HA morbidity among children in Perm and to evaluate a decrease in HA morbidity due to the hypothetical vaccination of children in spring months.

[HB viral infection in kidney diseases in children]. / HB-virusnaia infektsiia pri zabolevaniiakh pochek u detei.

A total of 142 children aged 2-15 years with different nephropathies, among them 94 children with glomerulonephritis (GN), 26 children with pyelonephritis and 22 children with oxalate nephropathy, were examined. The diagnosis was histologically confirmed in 36 children. Mesangial proliferative GN was detected in 22 patients and membrane proliferative GN, in 14 children. The presence of the markers of HBV infection (HBsAg, anti-HBs and anti-HBc total immunoglobulins, anti-HBc IgM) was detected in the sera of all patients by the enzyme immunoassay. As the result of this examination, essential changes in the distribution of different markers of HBV infection in children with nephropathies were detected. The combination of HBsAg with anti-HBc IgM proved to be the most characteristic feature of patients with the nephrotic syndrome; this was indicative of active HBV infection, and in patients with the mixed form of GN this combination occurred twice as frequently. The established correlation between the activity of HBV infection and the severity of the course of GN made it possible to suggest the participation of HBV in the pathogenesis of GN. This suggestion was indirectly confirmed by a higher detection rate of HBsAg and anti-HBc IgM in patients with the membrane proliferative form of GN.

[The incidence of detecting HB viral infection in the families of patients with kidney diseases]. / Chastota vyiavleniia HB-virusnoi infektsii v sem'iakh bol'nykh s zabolevaniiami pochek.

A total of 33 families were surveyed with a view to determine the presence of viral hepatitis B markers in persons with diagnosed renal diseases. In all patients markers of hepatitis B virus infection (HBsAg, anti-HBs antibodies, anti-HBc total and IgM antibodies) were determined in the enzyme immunoassay. Those families in which examinees with renal pathology were found to have markers of hepatitis B virus infection exhibited a high level of contamination with hepatitis B virus. A high proportion of examinees with viral hepatitis B was established in the families where mothers were found to have markers of hepatitis B virus infection. These facts indicate that everyday contacts play an important role in the transmission of the virus. The study points out that in the family foci of hepatitis B virus infection non-manifest or slightly manifest forms of this infection are mainly registered.

[The factors that affect the results of the serological diagnosis of HIV infection and the screening for anti-HIV]. / Faktory, vliiaiushchie na rezul'taty serologicheskoi diagnostiki VICh-infektsii i skrining na anti-VICh.

The laboratory diagnosis of HIV infection and screening for anti-HIV have determined the factors that influence the results of studies performed by ELISA and Western immunoblot. The factors include sensitivity and specificity of the test systems used, storage conditions of and transportation conditions for serum, errors of procedures for reactions, etc. Correlation is between the inactivation of the sera studied and the initial antibody titers during their storage at elevated temperatures. To obtain more valid results of HIV infection serodiagnosis it is necessary to use some test systems differing in the principles of setting up a reaction.

[The evaluation of the late effect of the multiple administration of immunoglobulin on hepatitis A morbidity in organized collectives]. / Otsenka otdalennogo vliianiia mnogokratnogo vvedeniia immunoglobulina na zabolevaemost' gepatita A v organizovannykh kollektivakh.

The analysis of influence in multiple injections of immunoglobulin (IG) on a level of morbidity and the efficiency of IG prophylaxis against hepatitis A in organized collectives made it possible to reveal the following common features: there is a direct dependency between morbidity level and average geometrical anti-IG titers, as well as the number of injections; there is inverse dependency between IG protection activity and the same factors; there is a lack of prophylaxis effect in anti-IG titers 1:32 or more. The authors frame a hypothesis that the reason of epidemic upgrowth of long standing hepatitis A morbidity dynamics in military collectives was conditioned by the wide application of IG in the 70s for children and teenagers.

[The use of computers and mathematical methods for optimizing epidemic control measures with respect to measles infection]. / Ispol'zovanie EVM i matematicheskikh metodov dlia optimizatsii protivoépidemicheskikh meropriiatii v otnoshenii korevoi infektsii.

The potentialities of computers for the study of the effectiveness of immunization have been demonstrated and the mathematical model for the prediction of the proportion of children, seronegative to measles, derived on the basis of the data on the average measles morbidity in different groups for a given period. A multifactor analysis of a large scope of data obtained in seroepidemiological survey and a retrospective analysis of measles morbidity on the basis of data collected in two districts of Moscow have been carried out with the use of computers and mathematical methods.

[The validation of the expediency of a review of the times for revaccinating children against measles]. / Obosnovanie tselesoobraznosti peresmotra srokov revaktsinatsii detei protiv kori.

Basing on the results of seroepidemiological study, carried out in two districts of Moscow by different methods, cluster selection method including, the authors have developed the following recommendations aimed at improving the strategy of revaccination against measles: (1) selective revaccination of only seronegative children or those with poor antimeasles immunity should be carried out, thus making it possible to reduce the number of susceptible children and diminish the risk of postimmunization reactions and complications; (2) when determining the groups of children to be revaccinated and the age suitable for revaccination, one should bear in mind the specific local features of the epidemic process in measles and the morbidity values, as well as the data on antimeasles immunity in children of different age groups; (3) serologic monitoring of the quality and immunologic effectiveness of different batches of live measles vaccine permits timely removal of nonstandard batches from practical use, thus improving the efficacy of vaccinal prophylaxis of measles.

[A comparative evaluation of the immunological efficacy of ADPT vaccine and ADT-M anatoxin in the immunization of children against diphtheria and tetanus]. / Sravnitel'na otsenka immunologicheskoi éffektivnosati AKDS-vaktsiny i ADS-M-anatoksina pri immunizatsii detei protiv difterii i stolbniaka.

Comparative study of the immunological effectiveness of adsorbed diphtheria-pertussis-tetanus (DPT) vaccine and adsorbed diphtheria-tetanus toxoid with reduced antigen content (adsorbed DT toxoid R) in the immunization of children, carried out in accordance with the vaccination schedule, was made. Immune response to the injection of adsorbed DPT vaccine was higher than after immunization with adsorbed DT toxoid R, as evidenced by antibody titers. It was probably due to differences in the number of injections constituting the course of immunization: it consisted of 3 injections and 1 booster injection for adsorbed DPT vaccine and 2 injections and 1 booster injection for adsorbed DT toxoid R. Immunization with adsorbed DPT vaccine produced immunity which was retained for a longer period. These results are indicative of the expediency of the primary immunization of children with adsorbed DT toxoid R introduced in three injections in order to ensure more stable and prolonged postvaccinal (mainly antidiphtheria) immunity.

[The immune structure of occupational groups of the population in relation to Legionella pneumophila serogroup 1]. / Izuchenie immunnoi struktury nekotorykh professional'nykh grupp naseleniia v otnoshenii Legionella pneumophila serogruppy 1.

The immune structure of different professional groups with respect to L. pneumophila has been studied. A wide spread of Legionella infection among subway construction workers, subway personnel and railroad conductors has been established, which makes it possible to regard these professions as high risk groups susceptible to Legionella infection. The risk factors for this group are as follows: work in the atmosphere of high dust content with air supply by means of air conditioners, contact with soil in the process of earthwork. The bacteriological study of water samples obtained in dining cars has resulted in the isolation of two strains of L. pneumophila, serogroup I, which confirms the possibility of cases of Legionella infection among railroad personnel.

[Clinical picture and treatment of Legionella pneumonia in children]. / Klinicheskaia kartina i lechenie legionelleznoi pnevmonii u detei.

Data on the clinical and laboratory study involving 150 children with the verified diagnosis of pneumonia observed as inpatients within a period from 1984 to 1988 are presented. To elucidate the pneumonia etiology, blood sera to the causative agents of influenza and parainfluenza, adenovirus, RS virus, Mycoplasma pneumoniae and Legionella pneumophila were assayed. An increase in the number of neutralizing antibodies to L. pneumophila was observed in 17.3 per cent of the patients. The majority of them simultaneously showed positive serological shifts with respect to the respiratory viruses. A specific clinical picture of pneumonia in the patients with the confirmed legionella infection was stated. The description of the treatment results is retrospective.

[Changes in the interferon status of patients with viral hepatitis B when genetically engineered alpha 2-interferon is used]. / Izmenenie interferonovogo statusa u bol'nykh virusnym gepatitom B pri ispol'zovanii genno-inzhenernogo al'fa 2-interferona.

The status of the interferon (IF) system in patients with acute viral hepatitis B (AVHB) was studied, and its importance as a criterion in the evaluation of the effectiveness of interferon therapy was demonstrated. The clinical study of alpha 2-IF was done in 152 patients with AVHB of moderate severity. The preparation was inoculated intramuscularly or intravenously in a dose of 1 X 10(6) IU twice daily for 5-10 days, a course dose being 10,000,000-20,000,000 IU. Considerable disorders in the functioning of the IF system and significant differences in the interferon status of patients in the study and control groups were demonstrated. The influence of alpha 2-IF on the time course of the interferon status depended on the clinical variants of the disease and the time of the preparation administration. The parameters of the IF system correlated with clinical manifestations of the disease and duration of hepatitis B virus persistence in the blood. This made it possible to use them as a criterion in the evaluation of the therapeutic effectiveness of alpha 2-IF.

[Serological and epidemiological characteristics of acute pneumonias caused by Mycoplasma pneumoniae in Belgorod]. / Serologicheskaia i épidemiologicheskaia kharakteristika ostrykh pnevmonii, vyzvannykh Mycoplasma pneumoniae, v Belgorode.

The etiology of the outbreaks of acute pneumonia in Belgorod was established and their epidemiological features were studied. The mycoplasmal etiology of all cases of acute pneumonia in children and adults, appearing alongside acute respiratory infections resulting from the preceding outbreaks caused by influenza viruses A/Prague/, B/Leningrad/369/75, and all types of parainfluenza viruses, was shown. The droplet mechanism of the transfer of infection was established, which was confirmed by the severity of the outbreak and a high rate of infection of the medical staff at hospitals for children and adults, where patients with mycoplasma-induced pneumonia were treated.

[Legionella infections in children]. / Legionelleznaia infektsiia u detei.

The authors provide the results of observing 150 patients with acute pneumonia verified on x-ray. Comprehensive serological studies enabled the legionellosis etiology of pneumonia to be established in 17.3% of cases in sporadic morbidity of children. The disease was marked by the peculiarity of the clinical manifestations, demanding nonstandard treatment approaches.