Aminooxyacetic acid (АОА), inhibitor of 1-aminocyclopropane-1-carboxilic acid (AСС) synthesis, suppresses self-incompatibility-induced programmed cell death in self-incompatible Petunia hybrida L. pollen tubes.

Self-incompatibility (SI) is genetically determined reproductive barrier preventing inbreeding and thereby providing the maintenance of plant species diversity. At present, active studies of molecular bases of SI mechanisms are underway. S-RNAse-based SI in Petunia hybrida L. is a self-/non-self recognition system that allows the pistil to reject self pollen and to accept non-self pollen for outcrossing. In the present work, using fluorescent methods including the TUNEL method allowed us to reveal the presence of markers of programmed cell death (PCD), such as DNA fragmentation, in growing in vivo petunia pollen tubes during the passage of the SI reaction. The results of statistical analysis reliably proved that PCD is the factor of S-RNAse-based SI. It was found that preliminary treatment before self-pollination of stigmas of petunia self-incompatible line with aminooxyacetic acid (AOA), inhibitor of ACC synthesis, led to stimulation of pollen tubes growth when the latter did not exhibit any hallmarks of PCD. These data argue in favor of assumption that ethylene controls the passage of PCD in incompatible pollen tubes in the course of S-RNAse-based SI functioning. The involvement of the hormonal regulation in SI mechanism in P. hybrida L. is the finding observed by us for the first time.

REORGANIZATION OF INTERPHASE MICROTUBULES IN ROOT CELLS OF MEDICAGO SATIVA L. DURING ACCLIMATION TO OSMOTIC AND SALT STRESS CONDITION.

We have investigated the organization of microtubule system in interphase cells of Medicago sativa L. roots during acclimation to salt and osmotic stress at different concentrations of NaCl, Na2SO4 and mannitol. We have identified several morphological changes in tubulin cytoskeleton that appear during the acclimation to salt and osmotic stress in the cells of different root tissues: 1) decreased density of cortical microtubule network, 2) random orientation of cortical microtubule bundles, 3) non-uniform density of the bundles, 4) thickening of the bundles, 5) fragmentation of the bundles, 6) formation of centers of converging microtubule. Reduced density of the microtubule network and thickening of the bundles was detected during osmotic and salt stress, yet random orientation of cortical microtubules was observed under osmotic stress and not found during salt stress. Fragmentation of microtubule bundles was apparent during salt stress and less evident at high concentration of mannitol. Formation of centers of converging microtubule was common under prolonged action of sodium sulfate, less common under sodium chloride and not found after mannitol treatment. Our data show that cortical microtubules in alfalfa root cells rearrange not only in response to different ions, but also to osmotic pressure. Thus, the signaling pathways and molecular mechanisms inducing reorganization of the microtubule system may be triggered not only by sodium cations but also by sulfate and chloride anion at the concentrations that do not cause irreversible cell damage. Our study show that the osmotic and salt stress differently affect the cortical microtubules, and their reorganization in response to stress depends on the salt cations as well as anions might also show additional effect under salt stress.

[HEPATIC ENCEPHALOPATHY AND TISSUE ZINC LEVELS IN LIVER DISEASE, DIAGNOSIS AND TREATMENT].

UNLABELLED: THE PURPOSE OF THE REVIEW: Description One of the complications of liver disease--hepatic encephalopathy as well as its relationship with the content of zinc in the body. THE MAIN PROVISIONS: The review provides the key moments of the pathophysiology and clinical hepatic encephalopathy. The basic drugs and treatment regimens of hepatic encephalopathy. Data are considered the original author's research on the relationship of gravity of hepatic encephalopathy and tissue zinc levels in patients with hepatitis and cirrhosis of viral etiology. The data of modern meta-analyzes of complex treatment of hepatic encephalopathy and the role of L-ornithine-L-aspartate. CONCLUSION: Understanding the pharmacological mechanisms of action of L-ornithine-L-aspartate allow gastroenterologist physicians and general practitioners to adequately apply the drug, select the required readings and prioritize the treatment of patients with liver diseases at different stages of the disease. Should be included in the treatment regimen of hepatic encephalopathy zinc supplements.

[Chronic hepatitis C--clinical and autonomic characteristics].

The article presents the results of a survey of 62 patients with chronic hepatitis C and 103 patients with liver cirrhosis of viral etiology. Besides clinical parameters studied autonomic features by analysis of heart rate variability at rest and active orthostasis. Indicators of frequency and spectral analysis of heart rate in study patients with chronic hepatitis C and cirrhosis of viral etiology confirmed increase in sympathetic activity and weakening of parasympathetic activity in all respects, with the sympathetic influence of enhanced active orthostasis. Indices of regulatory systems of the autonomic nervous system (stress index and the index of autonomic regulation) also indicated a statistically significant predominance sympathicotonia at rest and active orthostasis, indicating serious violations of adaptation in the examinees.

[Abnormal floral meristem development in transgenic tomato plants do not depend on the expression of genes encoding defense-related PR-proteins and antimicrobial peptides].

In this study, the morphological and cytoembryological analyses of the tomato plants transformed with the genes encoding chitin-binding proteins (ac and RS-intron-Shir) from Amaranthus caudatus L. andA. retroflexus L., respectively, as well as the gene amp2 encoding hevein-like antimicrobial peptides from Stellaria media L., have been performed. The transgenic lines were adapted to soil and grown the greenhouse. The analysis of putative transgenic tomato plants revealed several lines that did not differ phenotypically from the wild type plants and three lines with disruption in differentiation of the inflorescence shoot and the flower, as well as the fruit formation (modified plants of each line were transformed with a single gene as noted before). Abnormalities in the development of the generative organs were maintained for at least six vegetative generations. These transgenic plants were shown to be defective in the mail gametophyte formation, fertilization, and, consequently, led to parthenocarpic fruits. The detailed analysis of growing ovules in the abnormal transgenic plants showed that the replacement tissue was formed and proliferated instead of unfertilized embryo sac. The structure of the replacement tissue differed from both embryonic and endosperm tissue of the normal ovule. The formation of the replacement tissue occurred due to continuing proliferation of the endothelial cells that lost their ability for differentiation. The final step in the development of the replacement tissue was its death, which resulted in the cell lysis. The expression of the genes used was confirmed by RT-PCR in all three lines with abnormal phenotype, as well as in several lines that did not phenotypically differ from the untransformed control. This suggests that abnormalities in the organs of the generative sphere in the transgenic plants do not depend on the expression of the foreign genes that were introduced in the tomato genome. Here, we argue that agrobacterial transformation affects, directly or indirectly, expression of genes encoding for transcription factors that can activate a gene cascade responsible for the normal plant development.

[Influence of genotype, explant type and component of culture medium on in vitro callus induction and shoot organogenesis of tomato (Solanum lycopersicum L.)].

The influence of explant type as well as of the type of growth regulators and concentration on callus induction processes and somatic organogenesis of shoots was studied in vitro on four tomato genotypes of Russian breeding. Cytological study of callus tissue was conducted. It was established that tomato varieties possess a substantially greater ability to indirect shoot organogenesis compared with the F1 hybrid. The highest frequency of somatic organogenesis of shoots, as well as their number per explant, was observed for most of the genotypes studied during the cultivation of cotyledons on Murashige-Skoog culture medium containing 2 mg/l of zeatin in combination with 0.1 mg/l of 3-indoleacetic acid. An effective protocol of indirect somatic organogenesis of shoots from different explants of tomato varieties with a frequency of more than 80% was developed.

[The capacities of current test systems to verify early HIV infection].

The purpose of the present investigation was to comparatively evaluate the performance characteristics of the test systems designed to verify the positive results of screening survey for HIV infection, such as the solid-phase immunoassay DS-EIA-HIV-AB/AG-SPECTR (Diagnosticheskiye Sistemy (Diagnostic Systems) Research-and-Production Association, Nizhni Novgorod) and tests based on immune blotting (IB). The investigation examined 15 seroconversion panels produced by ZeptoMetrix (USA) and BBI (USA). The use of the DS-EIA-HIV-AB/AG-SPECTR test system determined 88 of the 167 seroconversion panels as HIV positive. The IB-based tests revealed only 45 of the 167 samples as positive. Consequently, the application of the DS-EIA-HIV-AB/AG-SPECTR test system is more effective than the IB-based tests in early HIV infection.

[A novel enzyme immunoassay system for the detection of HIV-1 p24 antigen with a sensitivity of 0.5 pg/ml].

A "DS-EIA-HIV-AG-Screen" enzyme immunoassay system has been devised to detect HIV-1 p24 antigen with a sensitivity of 0.5 pg/ml the use of which permits reduction of a seronegative window phase as compared with the tests showing a lower sensitivity threshold. The "DS-EIA-HIV-AG-Screen" system developed may be used to screen donor blood and to examine risk-group individuals for the early diagnosis of HIV infection.

[Development and assessment of a new test for verification of tests for HIV-infection markers].

The OOO "Research-and-Production Association "Diagnostic Systems" has developed a "DC-EIA-HIV-AT/AG-SPECTRUM" screening enzyme immunoassay system designed to detect separately antibodies to certain HIV-1 and HIV-2 proteins, as well as antigen p24. The determination of antibodies of all classes and the marker of early-stage infection antigen p24 with a high (5 pg/ml) sensitivity substantially reduces the number of void results obtained in the use of immunoblots. The developed "DC-EIA-HIV-AT/AG-SPECTRUM" plate system is an effective tool to support positive screening results and may be used at the final stage of laboratory diagnosis of HIV infection.

[Evaluation of diagnostic efficiency of the recombinant protein modeling immunodominant epitope V3 of envelope gp120 for immunoenzyme detection for HIV-1 infection antibodies].

The third hypervariable domain V3 of the human immunodeficiency virus type 1 gpl20 envelope glycoprotein contains neutralizing epitopes and plays an important role in the diagnosis of HIV infection . Neutralizing antibodies bind to conserved epitope with sequence GPG of V3 loop. The effect of sequence variation on the antigenic properties of the V3 epitope gp120 was studied using five synthetic peptides. The amino acid sequence of the peptide corresponding to the V3 region gp120 of HIV-1 subtype C showed the highest immunoreactivity. The DNA fragment encoding V3-C region gp120 was synthesized by polymerase chain reaction and cloned into pET41b vector. The recombinant plasmid was expressed in the E. coli cells, and recombinant protein was purified using glutathione-S sepharose affinity chromatography. The serological activity of the recombinant protein was tested using ELISA and compared to activity of similar synthetic peptide. The results of this study showed that most immunoreactive agent was the amino acid sequence of V3 region gp120 of HIV-1 subtype C. The recombinant antigen comprising this sequence was more antigenic than synthetic peptide with the same sequence. The evaluation of this antigen shows that this protein is a good candidate for the immunoassay development.

[Comparison of the diagnostic value of recombinant antigens and synthetic peptides that mimic the immunogenic epitopes of the envelop protein gp41 in the enzyme immunodetection of HIV-1 antibodies].

The study was undertaken to comparatively examine the efficiency of HIV antibody detection by enzyme immunoassay using recombinant antigens and synthetic peptides containing the most immunodominant region of the human immunodeficiency virus envelop protein gp41-cytotoxic T-lymphocytic (CTL) epitope. The application of the synthetic peptides that mimic this region has been to be inadequately effective. The recombinant proteins that contain the CTL epitope may be successfully used for the diagnosis of HIV-1, by using enzyme immunoassay as they show a higher sensitivity in detecting antibodies than do the synthetic peptises.

[A point mutation in the coat protein gene affects long distance transport of the tobacco mosaic virus]. / Tochechnaia mutatsiia v gene belka obolochki vliiaet na dal'nii transport virusa tabachnoi mozaiki.

A mutation resulting in substitution of positively charged Lys53 with negatively charged Glu in the coat protein was introduced in the infectious cDNA copy of the genome of wild-type tobacco mosaic virus strain U1. Kinetic analysis of long-distance virus transport in plants showed that systemic distribution of the mutant virus was delayed by 5-6 days as compared with the wild-type one. On evidence of RNA sequencing in the mutant progeny, Glu50 of the coat protein was substituted with Lys after passage I to compensate for the loss of the positive charge at position 53. Electron microscopy revealed atypical inclusions (rodlike structures, multiple electron-dense globular particles) in the nuclear interchromatin space of leaf mesophyll cells infected with the mutant but not with the wild-type virus.

On the mechanism of accentuation of the first heart sound in mitral stenosis.

In 10 patients with mitral stenosis, catheterization of the left ventricle and the left atrium has revealed a considerable increase in dp/dt at the moment of closure of the mitral valve in comparison with 10 healthy controls. Systolic and diastolic pressure and the contractility indicators (dp/dtmax and dp/dtmax/P) did not differ from the values found in the controls, and Vmax was even reduced. Simultaneously with the change in the dp/dt ratio at the moment of the mitral valve closure there occurred also a proportional change in the Ist heart sound amplitude. The authors therefore suggest that besides anatomical changes, a role in the accentuation of the Ist heart sound in mitral stenosis is played also by the haemodynamic factor - the dp/dt ratio at the moment of the mitral valve closure.