Dependence of Pinus sylvestris (Pinaceae) Radial Growth on Meteorological Conditions and Anthropogenic Air Pollution: Data from Northwestern Part of Murmansk Oblast.

The influence of meteorological factors and anthropogenic air pollution on the radial growth of the Scots pine Pinus sylvestris L. was studied as dependent on the distance from the Pechenganickel mining and metallurgical plant (Nikel, Murmansk region). Three (control, buffer, and impact) zones of the pollution gradient were identified based on the contents of main polluting elements (S, Ni, and Cu) in the forest litter. A significant weakening of pine stands was observed in the impact zone and attributed to the combined effect of long-term anthropogenic pollution of the 1970s and unfavorable weather events of the mid-1980s. As the emission decreased from 1988 to 2018, the radial increment of P. sylvestris was observed to increase significantly (by up to 44%) in the impact zone and to remain much the same in the control and buffer zones. More recently, the radial increment of trees in the impact zone reached and even exceeded the values observed in the control zone, although the trees examined were relatively old. The finding demonstrated again the high adaptive capacity of P. sylvestris.

Structure of Ground Vegetation and Natural Regeneration of Tree Species in 12- to 15-Year-Old Bilberry Pine Forest-Clear-cut Complex of Middle Taiga Subzone.

Abstract-Logging in mature stands where part of the forest is harvested in one or several cuts and part is retained (clearcutting and alternate strip cutting) results in the formation of an ecotone complex (EC), which includes a forest (F) zone, a forest edge (FE) as a transition from the forest to the clear-cut under the canopy, a clear-cut edge (CE) as a transition from the forest to the clear-cut outside of the canopy, and the clear-cut proper (C). The composition and structure of ground vegetation and natural regeneration of woody species (Pinus sylvestris L., Picea abies (L.) H. Karst., Betula sp., Populus tremula L., Sorbus aucuparia L., and Juniperus communis L.) were studied in a bilberry pine forest-clear-cut ecotone complex 12-15 years after stand removal. Specific structural features of ground vegetation and undergrowth (including tree regeneration) were observed in each of the four zones of the ecotone complex formed after logging of the mature forest. A typical forest habitat (zone F) showed a minimum number of young regeneration of Pinus sylvestris, Picea abies, Betula sp., Populus tremula, and Sorbus aucuparia and the highest abundance of the lingonberry V. vitis-idaea L. and bilberry Vaccinium myrtillus L. with a maximum height and a maximum yield of bilberry plants. The amount of tree regeneration in the FE zone was much the same as in the F zone. The projective cover, maximum shoot height, and yield of bilberry and the maximum shoot height of lingonberry in the FE zone were significantly lower than in the F zone. The transitional zone on the clear-cut side (CE) and the clear-cut proper (C) strikingly differed from the forest (F and FE) zones of the ecotone complex by a greater number of deciduous and pine regeneration and a low abundance of dwarf shrubs. The clear-cut proper (C) differed from the CE zone by a higher abundance of grasses and forbs and an established tree regeneration layer composed of pine, birch, and aspen.

[Dimethyl suberimidate as a specific inductor of apoptosis in transformed cells]. / Dimetilsuberimidat kak spetsificheskii induktor apoptoza transformirovannykh kletochnykh kul'tur.

A modification of protein-protein interactions can be considered to be a way to regulate cell death. Chemical cross-linking agents have been traditionally used for protein complexing. This study has been undertaken to test a possibility to induce and(or) to modify cell death by a homobifunctional cross-linker dimethyl suberimidate (DMS). It was shown that the protein cross-linking by DMS resulted in a death of transformed cells by apoptosis. DMS-induced apoptosis was accompanied by cell cycle perturbations and down-regulation of p21/Waf1 mRNA expression. The RT-PCR analysis of bcl-2 family genes revealed the engagement of mitochondria in DMS-induced cytotoxicity. Then, the influence of DMS treatment on TNF-dependent and Fas-mediated apoptosis was investigated. Cell pre-incubation with DMS resulted in their increasing sensitivity for the TNF cytotoxic effect, though activities of anti-Fas cytotoxic antibodies were inhibited. The effects observed are probably due to cross-linking of TNF-receptors. Thus, this study first demonstrated that a chemical cross-linker DMS in capable of inducing apoptosis in transformed cells and modifying TNF-dependent and Fas-mediated apoptosis.

Cell death induced by chemical homobifunctional cross-linkers. Cross-linker induced apoptosis.

Physical association of proteins that underlies cytotoxic signal induction and transduction suggests a possibility of regulating cell response by modifying protein-protein interactions. For protein complexing, chemical cross-linking agents have been traditionally used. However, the ability of various cross-linkers to induce and modify cell responses, cell death in particular, is still obscure. We have undertaken the investigation to test the apoptosis-inducing and modifying properties of the homobifunctional cross-linkers-dimethyl suberimidate (DMS) and 1,5-bis(succinimido-oxycarbonyloxy)pentane (BSOCOP). The functional groups of these cross-linkers are different but both are able to interact with available amino groups. It was shown that bifunctional cross-linkers, unlike their monofunctional analogues, are capable of inducing cell death in transformed cells, thus indicating the crucial role of cross-linking in cell killing. DMS- and BSOCOP-treated cells were shown to undergo cell death by apoptosis, though the signaling pathways were distinct. DMS inhibited bcl-X(L) and bak but not bax gene expression, while BSOCOP potentiated bax mRNA synthesis immediately after application. Cell pre-incubation with DMS, but not with BSOCOP, resulted in an increasing sensitivity to TNF, although activities of anti-Fas cytotoxic antibodies were then inhibited. Thus, this study has demonstrated for the first time that chemical cross-linkers are capable of inducing apoptosis by themselves and modifying the TNF-dependent and Fas-mediated cell death that may have potential therapeutic significance.

[The automated "SynChrom" system for solid-phase synthesis of peptides and liquid column chromatography. I. Principles of design and structural constituents]. / Avtomatizirovannyi kompleks dlia tverdofaznogo sinteza peptidov i zhidkostnoi kolonochnoi khromatografii "SinKhron". I. Printsipy postroeniia i strukturnye sostavliaiushchie.

An automatic modular SynChrom system was designed for solid phase synthesis and chromatographic purification of peptides. Structural constituents and organization and operation of the system in solid phase peptide synthesis and liquid column chromatography modes are described. Swellographic monitoring of the course of synthesis was used. Hydraulic diagrams, operation algorithm and software description are presented.

[The automated "SynChrom" system for solid-phase synthesis of peptides and liquid column chromatography. II. Use in the solid-phase synthesis of peptides and liquid column chromatography]. / Avtomatizirovannyi kompleks dlia tverdofaznogo sinteza peptidov i zhidkostnoi kolonochnoi khromatografii "SinKhrom". II. Ispol'zovanie v tverdofaznom sinteze peptidov i zhidkostnoi kolonochnoi khromatografii.

Automatic solid phase peptide synthesis using the SynChrom system is described. Problems of swellographic monitoring are discussed. Combined monitoring (swellographic, spectrophotometric, and manometric) of all steps of the synthetic cycle are suggested. Potential applications of the system to liquid column chromatography were demonstrated.

[Optimization of a protocol for automatic solid phase synthesis of peptides using a variable volume flow reactor]. / Optimizatsiia protokola tverdofaznogo avtomaticheskogo sinteza peptidovs ispol'zovaniem protochnogo reaktora peremennogo ob''ema]

The protocol for solid phase peptide synthesis using automatic synthesizers MilliGen/Biosearch 9500 and 9600 with built-in variable volume flow-reactors has been elaborated. The data of swellographic monitoring were used for optimization of process parameters. The peptides involving from 10 to 21 amino acid residues were synthesized using developed protocol. Significant economy of reagents and solvents has been demonstrated for synthesis of good quality peptides.

[Use of a series of synthetic peptides and purified major histocompatibility complex I (H-2K(b)) molecules for inhibiting T-suppressors, specific for the K(b) molecule, and their induction by peptides in vivo]. / Ispol'zovanie nabora sinteticheskikh peptidov i ochishchennoi molekuly glavnogo kompleksa gistosovmetimosti klassa I (H-2K(b)) dlia ingibirovaniia T-supressorov, spetsifichnykh k toi zhe molekule K(b), i ikh induktsiia peptidami in vivo.

Six synthetic peptides of the MHC class 1 molecule corresponding to individual H-2kb participants in amino acid sequences of domains alpha 1 (peptide 1 and 2) and alpha 2 (peptide 3, 4, 5, 6) were selected. Kb-specific suppressor T cells (Ts) were in vivo in mice, then pretreated with a set of peptides and assayed by proliferation decrease in the third-partial mixed lymphocyte culture (MLC). Effector function of Ts was abolished by the complex of the alpha 2-domain peptides (but not by the alpha 1-domain peptides) and decreased by each peptide (4, 5, 6) of the alpha 2-domain. Both alpha 1 and alpha 2 domain peptides, added at high concentrations, decreased the otherwise efficient enrichment of Ts during the absorption-elution procedure on the syngeneic macrophage (MP) monolayers. A similar significant effect was observed the purified Kb molecule (100 mg/ml) on the allogeneic MP monolayer. Interaction between Ts receptors with some MHC peptides indicates effector Ts activation in vivo by induction with peptides 5+6 of the alpha 2 domain. The fine mechanisms of interaction between MHC class I molecule epitopes and T cell receptors (TCR) of each of the T cell subsets separately are under study now.

Utilization of the MHC class I (H-2Kb) purified molecule and its synthetic peptides for inhibition of Kb-specific suppressor T cells and their induction in vivo by the MHC peptides.

Six synthetic peptides of the MHC class I molecule corresponding to individual H-2Kb participants in amino acid sequences of domains alpha 1 (peptide 1 and 2) and alpha 2 (peptides 3, 4, 5, 6) were selected. Kb-specific suppressor T cells (Ts) were induced in vivo in mice, then pretreated with a set of peptides and assayed by proliferation decrease in a three-cell lymphocyte culture (MLC). The effector function of Ts was abolished by the complex of the alpha 2-domain peptides (but not by the alpha 1-domain peptides) and decreased by particular peptides separately (4, 5, 6) of the alpha 2-domain. Both alpha 1- and alpha 2-domain peptides, added in high concentration, decreased otherwise efficient enrichment of Ts during the absorption-elution procedure on the syngeneic macrophage (M psi) monolayers. A similar significant effect was observed using the purified Kb molecule (100 micrograms/ml) in the allogeneic M psi monolayer. Interaction between Ts receptors and some MHC peptides indicates in effector Ts activation in vivo by induction with peptides 5 and 6 of the alpha 2-domain. The fine mechanisms of interaction between MHC class I molecule epitopes and T-cell receptors of each of the T-cell subsets separately are presently being studied.

[Mechanisms of immunodeficiency in HIV infection and ways of overcoming it]. / Mekhanizmy immunodefitsita pri infektsii VICh i puti ego preodoleniia.

Though antibodies against HIV-1 appearing in the course of infection are successfully used for the diagnostic purposes, their accumulation on the earlier step leads to: firstly, to the rapid generation of the immunodeficiency by different mechanisms and secondly, to inefficiency of immunotherapy. One of the causes for immunodeficiency seems to be antibodies which are induced in the HIV-infected person by the HIV peptides homologous to the MHC class II molecules by their amino acid sequences. 73% of HIV-1 positive sera are shown to react with human B-lymphoma cells expressing surface class II molecule. The binding is caused by the antibodies preventing the murine monoclonal anti-HLA.DR Ab interaction with B-lymphoma. Three amino acid sequences are identified in both alpha- and beta-chain of the HLA.DR antigen, these sequences being homologous to HIV-1 gp120 or gp42 molecules for 50 to 70%. Using synthetic peptides it was shown that HIV-1-infected persons contain antibodies which cross-react to the homologous peptides of the HIV-1 and of the MHC class II. It is supposed that such antibodies shield the class II molecule on the surface of their own antigen-presenting cell which may lead to immunodeficiency caused by the anti-HIV-1 antibody.

Antibodies to MHC class II peptides are present in HIV-1-positive sera.

Seventy-five per cent of sera from HIV-1-infected individuals bind to the human B-lymphoma cells bearing the major histocompatibility class II molecule in enzyme-linked immunosorbent assay (ELISA). The binding is caused by the antibodies against the class II molecule present in the serum samples which prevent the interaction of murine anti-HLA.DR monoclonal antibody with B lymphoma in FACS analysis. The three highly conserved amino acid sequences in alpha- and beta-chains of the class II molecule and three homologous fragments in HIV-1 gp120 and gp41 were identified by computer search and synthesized. Using these peptides it was demonstrated that 28-48% of HIV-positive sera contain antibodies that cross-react with the peptide of HIV-1 origin and with the peptide from the class II molecule as well.

The direct binding of an HIV fragment with granulocytes from healthy subjects and infected patients.

The binding of the synthetic fragment from the CD4 binding site of HIV (gp 120) with polymorphonuclear neutrophils (PMN) in 13 healthy donors and 31 HIV-infected patients was studied using a biotin-streptavidin-texas-red complex. The largest percentage of PMN-bound peptide was reached at a final peptide concentration of 10 micrograms/ml. The increase of peptide concentration did not raise the per cent of positive PMN. Preliminary incubation of PMN or mononuclear cells with non-biotinylated peptide abolished subsequent binding of these cells with biotinylated peptide, while preliminary treatment of the cells by anti-CD4 monoclonal antibody did not lead to such abrogation. It was revealed that about 14% of PMN but no lymphocytes from healthy donors were able to bind peptide. The number of such PMN in HIV-infected patients was significantly less (6.3 +/- 8.9%, P less than 0.05). A connection between peptide-bound PMN and their functional activity was found. The percentage of such cells was 13.0 +/- 11.5% in patients with normal values in a stimulated nitroblue tetrazolium reduction test and only 2.6 +/- 2.8% in patients with low values in this test (P less than 0.05).

The synthetic peptide from HIV increases functional activity of granulocytes in healthy subjects.

The influence of HIV lysate and eight synthetic peptides which are fragments of HIV proteins on the functional activity of polymorphonuclear neutrophils (PMN) was tested in 12 healthy subjects. PMN activity in nitroblue tetrazolium reduction (NBT test) and PMN chemiluminescence (CL) was studied. Only one peptide was found to result in a significant increase in NBT test on the whole blood. This was the oligopeptide (G-97) from the CD4-binding site of HIV-1 gp120. The increase of CL response of PMN in the presence of G-97 was revealed after only 15 min preincubation. The same effect in the presence of sera from healthy or infected patients at the persistent generalized lymphadenopathy stage was achieved by increasing the time of preincubation to 30 min. G-97 did not influence the proliferative activity of lymphocytes.

Influence of HIV antigens on functional activity of neutrophilic granulocytes in.

The effect of nine HIV antigens, including eight synthetic peptides, on the functional activity of granulocytes was studied using the reduction of nitroblue tetrazolium test (NBT test). Some peptides partly suppressed the functional activity of granulocytes. The most pronounced suppression was caused by ImVL (HIV-1 lysate immobilized on plates for ELISA) and SP-7 (a synthetic peptide from the gp41 protein of HIV-1). The degrees to which the functional activity of granulocytes was suppressed by ImVL and SP-7 was in inverse proportion to the specific antibody concentrations. No correlation was found between the reduction in the NBT test value and the amount of CD4+, CD8+ cells on CD4/8 ratio.