Search

It is found that herpetic keratoconjunctivitis in rabbits and generalized herpes infection in humans is associated with virus-specific arterial damage. Experiments on rabbits show that virus-induced morphological changes in the aorta can be corrected with furavir. The role of herpes infection as a possible risk factor in atherogenesis is considered.

As shown by the results of the analysis, viruses ECHO 30 circulating over the period of the last 8 years in Belarus, belonged to 3 different genetic subtypes which earlier or simultaneously circulated in other European states. The outbreaks of enterovirus infections (EVI) were facilitated by the appearance of a genetic viral subtype, relatively "new" for human population, and which had not earlier circulated on this territory. Thus, the development of outbreak morbidity in 2003 was caused by a change in the dominating subtype of virus ECHO 30, which caused the outbreak of 1997. The relatively "soft" rise of morbidity in 2004 was due to the continued circulation of the same subtype of virus ECHO 30, that in 2003. The largest outbreaks of EVI in the Republic of Belarus had a number of considerable differences: the outbreak of 1997 in Gomel was characterized by the genetic heterogeneity of infective agents, being simultaneously geographically localized within the limits of one city. However, during the outbreaks of 2003 the circulation of genetically closely related viruses of the one subtype among the population of geographically remote regions of the country was registered.

The clinical and epidemiological patterns as well as the results of the laboratory verification of the outbreak of enterovirus infection (EVI) in Minsk during the period of summer-autumn, 2000, are presented. During this outbreak a variety of clinical forms were observed, the serous meningitis being prevalent (57.5%). Practically simultaneous occurrence of infection on the territory of all administrative districts of the city, the predominant involvement of children aged up to 14 years into the outbreak, a high proportion of simultaneous casualities in the multiple foci. A number of circulating enteroviruses (EV)--ECHO 30, ECHO 6 of three serotypes and Coxsackie B5--were simultaneously isolated from clinical material. EV of the same serotypes were isolated from tap drinking water, and neutralizing antibodies to these serotypes were often detected in the patients blood sera. Infectious EV were also present in samples of bottled water and in water reservoirs used for bathing. The routes of EV transmission and the improvement of EVI control are discussed.

Diagnostic efficacy of different markers of enterovirus cardiac infection (EVCI) has been evaluated. Testing of clinical samples from patients with myocarditis (n=50), dilatation cardiomyopathy (n=122), ischemic heart disease (n=34) and from healthy donors (n=50) revealed diagnostically significant markers in patients suspected for enterovirus cardiac infection: antienterovirus IgM in the patient's blood serum, the expression of viral proteins by myocardium cells and the presence of genome RNA and replicative intermediate in cardiac cells. The results obtained were used for developing up-to-date scheme of the EVCI diagnosis which included the data from the case history, the preliminary rapid diagnosis and the molecular biological study of the cardiac biopsies.

A method of a modified nest-type polymerase chain reaction (MN-PCR), made in one tube, was elaborated that enhances the sensitivity and cuts the risk of cross-contamination in enteroviruses (EV) detection. The method, as described in detail above, was used to detect EV RNA in 76.9% and 31.25% of examined autopsy samples (13 liquor and 16 cardiac-tissue samples, respectively). It enabled the detection of EV RNA in 6.25% of samples that used to be negative, when tested by MN-PCR in 2 tubes. MN-PCR with one tube is a reliable, sensitive and specific diagnostic tool; it can be recommended for the routine diagnostics of enterovirus infection.

The conducted virologic, serological and molecular-and-biological investigations showed that virus Coxsakie B4, isolated from cerebrospinal fluid and rhinopharyngeal lavages of patients, was the main etiological agent, which caused mainly an outbreak of enterovirus infection in the city of Vitebsk in 2001. Coxsakie B4 viruses were found in 30% of samples by using the cultural method and in 76.9% of samples--by polymerase chain reaction (PCR) while carrying out the sanitary-and-virologic investigations in drinking water, including in infection foci. Besides, we found infectious non-cytolitic enteroviruses (EV) with changed biological properties (which could not be detected by the classic cultural method) in drinking water by using the method of PCR integrated with cell culture in the "-" strand of EV RNA. Peculiar clinical-and-epidemiological characteristics of the disease outbreak, i.e. "explosive" onset, multiple clinical forms, mixed EV infections and disease decay after drinking-water chlorination, as well as the isolation of one and the same EV serotype from patients and from water testify to a possible water origin of the outbreak.

Data on the usage of chemical inhibitors nifan and belvtazid, which possess a selective and antienteroviral effect, in the primary identification of enteroviruses and their differentiation into polio- and non-poliomyelytic ones isolated from human clinical materials or the environment by using the cell culture are presented in the article. The method is recommended for the practical use by the virology service in the diagnostics of enteroviral infections and in the identification of cytopathic agents isolated from the enviroment.

Changes in the levels of total phospholipids and phospholipid fractions of pulmonary surfactant fractions of albino mice intranasally infected with influenza A/Aichi/2/68(H3N2) virus in a dose of 5 LD50 were studied. Reproduction of influenza virus in mice is paralleled by fluctuations in the level of total lipids and changes in the phospholipid components of pulmonary surfactant. Antiviral drugs remantadin and deitiforine injected in accordance with the treatment and prophylaxis protocol to infected animals exerted a protective effect as regards the studied pulmonary surfactant phospholipids.

In recent years outbreak of enterovirus infections caused by Echovirus-30 were rather frequently registered in different European countries. A major outbreak caused by this virus took place during the summer-autumn period of 1997 in the city of Gomel, Belarus. Sanitary epidemiological and molecular epidemiological studies made it possible to determine that the outbreak was water-borne. The sequence analysis of Echovirus-30 strains isolated from water and the cerebrospinal fluid of patients revealed a minor divergence between them (0.2%) indicative of their practical identity. The comparison of the Belorussian isolates with the strains isolated in Europe in 1994-1998 also showed a small percentage of differences in their genomes, which showed that the outbreak of Echovirus-30 infection was probably brought to Belarus from the territories of European countries.

Concentrating properties of a new adsorbent, active aluminum oxide, towards poliomyelitis virus type III and simian rotavirus are studied using virus contamination of sewage and drinking water. Optimal concentrations of the adsorbent for effective adsorption of both rota- and polioviruses are established (1.5 and 1 g/liter, respectively) at pH typical of sewage and drinking water (7.0-8.5), as well as the optimal time of virus contact with the adsorbent (30 min). Elution conditions are determined: 3% elution agent beef extract and pH 8.5-9.5 are optimal for both viruses. Active aluminum oxide is recommended as an adsorbent for elimination of enteroviruses from water objects.

Indirect immunofluorescence (IIF) and RT-PCR were used for rapid diagnosis of enterovirus infection during an outbreak of aseptic meningitis in Gomel. IgM to enterovirus were detected in 93.6% sera by IIF and in 71.4% cerebrospinal fluid specimens by RT-PCR. IIF takes only 1.5-2 h and RT-PCR 6-7 h. The methods are recommended for rapid diagnosis of enterovirus infection.

Experimental and clinical studies showed a number of virus infections to be accompanied by lipidemic disorders. Experimentally, dyslipidemias were found in tick-borne encephalitis (TBE) in mice, rotavirus infection in rabbits, and amyotrophic leukospongiosis in guinea pigs. The possibility of correcting the virus-induced lipidemic disorders with an antiviral drug, lincomycin, was demonstrated in TBE in mice. Dynamic study of the lipidemic status of patients with virus hepatitis A revealed marked dyslipidemia of the atherogenic type which was stable and persisted up to the time of clinical recovery. The data obtained supplement the current concepts concerning the pathogenesis of virus infections.

Herpes ophthalmicus (HO) patients were examined for lipid spectrum of the serum. The tests revealed dyslipidemia (DLE) with a distinctive rise in the levels of total cholesterol (CS), alpha-CS and beta-CS. The severity of the lipidemic shifts correlated with that of the infection. DLE was more marked in recurrent HO. Clinical evidence was consistent with experimental findings. In rabbit models, herpetic keratoconjunctivitis was characterized by pronounced lipidemic alterations correctable with antiherpetic drug furavir. The results are discussed in terms of herpetic infection pathogenesis and its role in the development of atherosclerosis.

Experimental investigations on the spectrum and degree of the expression of trental antiviral activity were carried out. The investigations were done in cell cultures and laboratory animals using laboratory strains (including drug-resistant ones) of 13 viruses, causative agents of human and animal infections. The drug demonstrated its activity against 8 viruses of 7 families. It was highly active against 5 viruses: herpes simplex virus (including its acyclovir-resistant strain), vaccinia virus (including its methisazone-resistant strain), rotavirus and tick-borne encephalitis virus. As regards other viruses, its activity was less pronounced (hepatitis JA virus) or low (vesicular stomatitis virus, West Nile virus). It was concluded that, being a cardiovascular drug, trental was an effective broad spectrum virus inhibitor.

Currently used cardiovascular drugs such as nicotinamide, strophanthin, corglycon, curantyl, cavinton, papaverin hydrochloride, nicotinic acid, xantinole nicotinate, isoptin, parmidin and halidor were studied by the program of antiviral drug screening. The majority of them (9 out of 11) were shown to have antiviral activity which was rather individual by its specificity and level. Laboratory strains of 9 viruses inducing the most common infections in man and animals, i.e. Herpes simplex, poxvaccine, influenza, vesicular stomatitis, respiratory syncytial infection, VEE, ECHO. Lassa fever and rotavirus infection were tested. The characteristic feature of the drugs was their high specific activity against the DNA-containing viruses and rotavirus. The three drugs papaverin hydrochloride, strophanthin and corglycon proved to be the most promising. Their antiviral activity was confirmed on a model of herpes infection in mice. The paper discusses whether the phenomenon discovered in the official drugs is important in the therapy of somatic patients.

The influence of herpes simplex virus on lipid exchange and accumulation by blood vessels cells was studied. In acute herpes infection in rabbits, typical dyslipidemia characterised by a rise in the content of total cholesterol, low and very low density lipoprotein cholesterol and triglycerides in the absence of manifest changes in concentration of high density lipoprotein was detected. HSV infection of smooth muscle cell culture of human embryo aorta was accompanied by increased accumulation of free lipids in the cells. The use of antiherpetic preparations during the infection led to correction of the lipid spectrum of the infected animals and was accompanied by normalization of intracellular lipid contents. A possible pathogenetic role of HSV in atherogenesis which may be connected with at least two processes: the development of lipidemic disturbances and formation of pathologic lipid depot in the arterial wall, is discussed.

Upon mixed infection of cultured cells by influenza viruses A/WSN/33 and B/Lee/40 the produced virions contain in their envelopes either hemagglutinin B/Lee/40, or hemagglutinins of both viruses, depending on their concentration ratio during infection. In the first case the population contains RNA segments and nucleoproteins (NP) of both viruses, in the second-exclusively RNA and NP of virus A/WSN/33. Results of immunoprecipitation with monoclonal antibodies to protein of virus A/WSN/33 with further analysis of immunoprecipitates by electrophoresis in polyacrylamide gels did not reveal the presence of virus ribonucleoproteins, containing NP of both viruses. The data obtained demonstrate the high of specificity of protein-protein recognition during reassembly of virion inner structures.

A study was made of the effect of antiviral drugs remantadine and deitephorine on dynamics in the changes in structure-function parameters, mitotic activity, protein and nucleic acid synthesis in the Madin-Darby canine kidney cell culture. The application of methodical complex and regression analysis methods, the approximation of experimental data with analytical functions showed general regularity in the monolayer cell population response to the effect of drugs. In the response of cell populations three phases are distinguished: the first phase--transient inhibition; the second phase--relative compensation; the third phase--pathological cell destructive process.

A new modification of the method for cultivation of cells from blood vessel explants has been proposed, and on its basis several cell lines from different vessels of human embryo and adult subjects have been derived. The sensitivity of vessel cells to viruses was studied on a model of aorta cell culture using a wide spectrum of RNA and DNA viruses. All the strains under study with the exception of respiratory-syncytial virus (RSV) and encephalomyocarditis (EMC) virus induced a productive infection in the cells. The infection with RSV and EMC was abortive. The possibility of virus replication in vessel cells was confirmed by isolation of adenovirus from a human renal artery biopsy.

Simultaneous infection of MDCK cells with influenza A and B viruses at an equal multiplicity of infection leads to the synthesis of the proteins of both viruses. In the population of virions the hemagglutinin of influenza B virus prevails, whereas NP proteins of both viruses are present in similar quantities. Trypsin treatment of the double-infected cells resulting in the cleavage of the hemagglutinin molecules at the cell surface allows revealing the predominance of influenza B hemagglutinin on cell surface, although both hemagglutinins are accumulated in the cells. An impairment of the hemagglutinin transport to the cell surface as a possible additional mechanism of heterotypic interference and its possible effect on the polypeptide content of the phenotypically mixed virions are discussed.

Protein A-containing formaldehyde-fixed S. aureus (strain Cowan) was incubated with an antiviral serum or with a monospecific serum against NP protein, washed, and used as immunosorbent in order to isolate viral ribonucleoproteins (nucleocapsids) containing intact viral RNA from the extracts of influenza virus infected [3H]-uridine-labelled cells.

The antiviral effect of chemical agents remantadine and deutephorine on the reproductive apparatus of MDCK-cells was studied. It was established that the action of the chemical agents during 3-4 days induced enhancement in pathologically transformed mitoses. This enhancement was in direct proportion to the doses used and to the cultivation time. Dose dependent enhancement of the total pathological mitoses number was simultaneous with the redistribution of mitoses into groups: the relative number of pathologies connected with chromosome damage became lower and the number of degenerating mitoses grew. Computer regression analysis showed the linear dependence between the chemical agent dose and the number of mitoses in the metaphase, that gives an indirect evidence of statmokinetic action of the agents under study.