High-sensitivity express immunochromatographic method for detection of plant infection by tobacco mosaic virus.

A highly sensitive express immunochromatography method for molecular diagnosis of plant virus infections was elaborated on the example of a model object - tobacco mosaic virus (TMV). The analysis time does not exceed 5 min, and the lower limit of TMV detection in non-clarified leaf extract (2-4 ng/ml) is comparable with the sensitivity of the enzyme-linked immunosorbent assay of the virus. A single measurement requires 0.1-0.2 ml tested solution (extract from 10-20 mg of leaf material). The sensitivity of TMV determination in the leaf tissue extract was increased by more than one order of magnitude using signal enhancement by silver and is 0.1 ng/ml. In this case, analysis time did not exceed 25 min. The simplicity of this method makes it especially convenient in express diagnosis of numerous analyzed specimens. The prototype of a diagnostic kit for serial analyses of plant viral infections both in laboratory and field conditions was elaborated.

[Comparative study of structural stabylity of potato virus X coat protein molecules in solution and in the virus particles].

With help of several optical methods and differential scanning calorimetry we studied the structure and stability of molecules of coat protein (CP) of filamentous of potato virus X (PVX) in free state and in the virions. According to the results of all these methods, at room temperature (25 degrees C) free PVX CP subunits possess some fixed tertiary structure but this structure is highly unstable and is completely disrupted at temperatures as low as 35 degrees C. The free PVX CP tertiary structure was also disrupted by very low sodium dodecylsulfate and cetyltrimetylammonium bromide concentrations: 3 to 5 moleculs of the surfactants per the CP molecule were sufficient to induce its total disruption. At the same time, these treatments did not result in any changes in the PVX CP secondary structure. Incorporation of the CP subunits into the PVX virions resulted in a strong increase in their stability to effects of increased temperatures and surfactants. This combination of highly labile tertiary structure and rather stable secondary structure of free PVX CP subunits may represent a structural basis for recently observed capacity of the PVX CP moleculs to assume two different functional states in the virion.

Complete nucleotide sequence and genome organization of a tobamovirus infecting cruciferae plants.

Genomic RNA sequence of a tobamovirus infecting cruciferae plants (cr-TMV) was determined. The RNA is composed of 6312 nucleotides and contains four ORFs encoding the proteins of 122K (ORF1), 178K (ORF2), 29K (ORF3) and 18K (capsid protein, ORF4). ORF4 overlaps ORF3 by 74 nucleotides and the overlapping region can be folded into a stable hairpin structure. The 3'-terminal region of the cr-TMV RNA preceding the tRNA-like structure was shown to form six potentially stable pseudoknots.

The occurrence of mixed infections of turnip mosaic, cauliflower mosaic and cucumber mosaic viruses in winter oilseed rape from the territory of Uzbekhistan.

Turnip mosaic, cauliflower mosaic and cucumber mosaic viruses (TuMV, CaMV and CMV) were isolated and identified from winter oilseed rape plants from Uzbekhistan. This is the first record on the occurrence of CaMV and of mixed infection of rape with the three aforementioned viruses from the territory of the former Soviet Union.

[Optical rotatory dispersion by 5 viruses of the tobacco mosaic virus group and their components]. / Dispersiia opticheskogo vrashcheniia piati virusov gruppy virusa tabachnoi mozaiki i ikh komponentov.

Optical rotatory dispersion (ORD) spectra in 250 to 350 nm region were measured for preparations of five TMV-like viruses (TMV vulgare, HR and U2 strains of TMV dolihosenation mosaic virus and cucumber virus 4) and also for RNA and protein preparations of these viruses. The data obtained testify against the possibility that the double peak with maxima at 286 and 293 nm observed in ORD of all the five viruses is due to interaction of tryptophan residues in virus coat protein with the RNA of the virul particle. The spectra of intravirus RNA of the five viruses, calculated as the difference between ORD of the intact virus and of its coat protein, were found to differ significantly from each other and from ORD of free RNA. ORD spectra of hybrid viruses, reconstituted from RNA of one virus and coat protein of another, proved to be identical to the ORD of the virus, whose protein was used in reconstitution. We suppose that the difference in ORD of the intravirus RNA of the five viruses reflect differences of RNA-protein interactions in them.

[Study of the process of thermal aggregation of several representative tobamovirus coat proteins]. / Izuchenie protsessa termicheskoi agregatsii belkov obolochki neskol'kikh predstavitelei tobamovirusov.

The role of the specific region of the tobacco mosaic virus (TMV) coat protein (CP) molecule (called "70A degree-region") in the regulation of ordered and unordered CP aggregation was investigated. CPs of the wild type TMV (strain U1), of temperature sensitive mutant with two amino acid substitutions in the "70A degree-region", and of cucumber virus 3 which is related to TMV but has a completely different structure in the "70A degree-region" were used. With the help of two different tests the processes of temperature-induced unordered aggregation of these three CPs were compared in solutions of different ionic strength and pH. On the basis of the data obtained it was concluded that the "70A-region" represents the most thermolabile region in the TMV CP molecule and that local thermal denaturation of this region results in unordered aggregation, when solution conditions (ionic strength and pH) favor formation of relatively large ordered aggregates (20S-"disks" or helical repolymerized protein).

[On the etiology of aortal insufficiency]. / K voprosu ob étiologii aortal'noi nedostatochnosti.

The authors describe the results of valvulometry, traditional histological and cytological investigations of dissected valves of 1084 patients and an analysis of causes of aortal insufficiency as compared to the literature data for the last 80 years. The main causes of heart valve diseases are considered to be mesenchymal dysplasia and infective endocarditis.

[A method of isolation and preparation of the radial artery for direct revascularization of the myocardium]. / Metodika vydeleniia i podgotovki luchevoi arterii dlia priamoi revaskuliarizatsii miokarda.

The authors describe a technique of the isolation, preparation and use of the radial artery for the aortocoronary shunting for ischemic heart disease. The method is anatomically valid and approbated in 300 operations on the open heart. Safety and efficiency of using the radial artery is due to its not traumatic isolation, original preparing for shunting and medicamental prevention of its spasm.

[Early results of surgical treatment of infective endocarditis]. / Neposredstvennye rezul'taty khirurgicheskogo lecheniia infektsionnogo éndokardita.

Operations were performed on 183 patients with infective endocarditis and injury of the valve apparatus of the heart. Duration of the disease was from 5 weeks to 9 years. Insufficiency of circulation of the III-IV functional class was noted in 92% of the patients. High activity of the infective process observed in 30% of the patients by the moment of operation did not influence the results of surgical treatment. Postoperative lethality was 7.6%.

[Thrombectomy as a method of surgical treatment of thrombosis of a mechanical prosthesis of the heart valve (a description of three cases)]. / Trombéktomiia kak metod khirurgicheskogo lecheniia tromboza mekhanicheskogo proteza klapana serdtsa (opisanie trekh sluchaev).

The article presents three clinical observations of successful thrombectomies in patients with thromboses of modern bicuspid prostheses of the heart (MEDINZH-2, Carbo Medics) which was 21.4% of all operations (14) for acute thrombosis of the artificial heart valve. It should be taken into consideration that such kind of operation is possible when there are easily removed small loose thrombus, good fixation of the prosthesis and a complete endothelization of the cuff.

[Surgical procedure in complicated mitral stenosis]. / Khirurgicheskaia taktika pri oslozhnennom mitral'nom stenoze.

The experience with the surgical treatment of complicated forms of mitral stenosis in 110 patients with the III and IV classes of the disease according to the classification of the New York Heart Association was analyzed. Closed mitral commissurotomy was performed in 36 patients, opened commissurotomy--in 33 patients, prosthetics of the mitral valve was made in 41 patients. Closed mitral commissurotomy is believed to be the simplest method of correction of the duct in mild calcinosis and deformity of the mitral valve, and fixed thrombosis of the left auricle. Opened mitral commissurotomy was justified in case of thrombosis of the left auricle and mild calcinosis and deformity of the valve. Substitution of the valve is indicated in cases of massive calcinosis and rough deformity of the valve and subvalvular structures when valve-preserving operations are impossible.

[Excretory function of the kidneys during artificial circulation in patients operated on for acquired heart defects]. / Vydelitel'naia funktsiia pochek vo vremia iskusstvennogo krovo- obrashcheniia u bol'nykh, operirovannykh po povodu priobretennykh porokov serdtsa.

The authors have shown that the suppression of the excretory function of the kidneys during the period of artificial circulation is considerably dependent on the concentration of vasopressin in blood and the associated spasm of renal vessels. The use of morphine as the main medicine for general anesthesia with the dose of 3 mg/kg as compared with the dose 2 mg/kg, gives less level of vasopressin in blood and thus reduces symptoms of antidiuresis in response to the action of strong stressogenic factors.

[Immediate results of using the radial artery in direct revascularization of the myocardium]. / Neposredstvennye rezul'taty ispol'zovaniia luchevoi arterii dlia priamoi revaskuliarizatsii miokarda.

The authors discuss results of more than 300 operations of the aorto-coronary bypass using the radial artery as a shunt. An analysis of the initial state of the patients, the intraoperative, early postoperative and intrahospital periods was made. Special attention was given to specific features of the isolating and using the radial artery grafts. Specific complications resulting from the application of them were analyzed and recommendations are given for prophylactics of such complications. The experiences with using the radial arteries allow to recommend it in revascularization of the myocardium. It is one of the ways of improving immediate and long-term results of operations on patients with ischemic heart disease.

[Ion-balanced cardioplegic solutions in cardiac surgery]. / Ionosbalansovannye kardioplegicheskie rastvory v khirurgii serdtsa.

A comparative analysis of effectiveness of anti-ischemic defense of the myocardium performed in operations on the heart in 128 patients has shown that use of ion-balanced solutions is preferential since it allows reducing intrahospital lethality related with acute cardiac insufficiency from 13.3% to 6.3%.

[Rare causes of the dysfunction of mechanical bicuspid heart valves]. / Redkie prichiny disfunktsii mekhanicheskikh dvustvorchatykh klapanov serdtsa.

The authors share the observations from their cardiosurgical practice showing that one of the causes of sudden death or of rapid worsening of the state of patients with implanted bicuspid artificial valves might be their dysfunction resulting both from breakage of the hinged mechanisms of the valve with its dislocation and migration and from the disturbed mobility of the valve cusp due to a thrombus formed in the atrium. The observations show that the "ideal" construction of the valve is to be created.