Innovative Approaches for Improving the Quality and Resilience of Spring Barley Seeds: The Role of Nanotechnology and Phytopathological Analysis.

This study emphasizes the importance of seed quality in the context of yield formation. Based on the research data, this paper emphasizes the role of proper diagnosis of seed-borne pathogens in ensuring high and stable grain yields. Particular attention is paid to the study of the effect of the treatment of mother plants with fullerenol-based nanopreparations on the qualitative characteristics of spring barley seeds. The results showed that such treatment contributes to the increase in varietal purity, weight of 1000 grains as well as to the increase of nutrient and moisture reserves in seeds. Phytopathological analysis confirmed the presence of various diseases such as Alternaria, helminthosporiosis, fusarium, mold and mildew on the seeds. However, some samples showed a high resistance to pathogens, presumably due to the use of carbon nanopreparations. These results open new perspectives for the development of strategies to improve barley yield and disease resistance through seed optimization.

Color Confinement and Screening in the θ Vacuum of QCD.

QCD perturbation theory ignores the compact nature of the SU(3) gauge group that gives rise to the periodic θ vacuum of the theory. We propose to modify the gluon propagator to reconcile perturbation theory with the anomalous Ward identities for the topological current in the θ vacuum. As a result, the gluon couples to the Veneziano ghost describing the tunneling transitions between different Chern-Simons sectors of the vacuum; we call the emerging gluon dressed by ghost loops a "glost." We evaluate the glost propagator and find that it has the form G(p)=(p(2)+χ(top)/p(2))(-1) where χ(top) is the Yang-Mills topological susceptibility related to the η' mass by the Witten-Veneziano relation; this propagator describes the confinement of gluons at distances ∼χ(top)(-1/4)≃1 fm. The same functional form of the propagator was originally proposed by Gribov as a solution to the gauge copies problem that plagues perturbation theory. The resulting running coupling coincides with the perturbative one at p(2)≫√[χ(top)], but in the infrared region either freezes (in pure Yang-Mills theory) or vanishes (in full QCD with light quarks), in accord with experimental evidence. Our scenario makes explicit the connection between confinement and topology of the QCD vacuum; we discuss the implications for spin physics, high energy scattering, and the physics of quark-gluon plasma.

Inhibition of tumor cell migration by LD22-4, an N-terminal fragment of 24-kDa FGF2, is mediated by Neuropilin 1.

LD22-4, an 86-amino acid fragment of the basic fibroblast growth factor, is an inhibitor of cell migration. LD22-4 inhibits the migration of various tumor cells, endothelial cells, and fibroblasts in vitro and suppresses tumor growth and angiogenesis in vivo. LD22-4 is effective in the presence of multiple growth factors, either alone or in combination, as well as haptotactic factors. LD22-4 inhibits the rate of malignant gliomas prepared from U87MG cells in an orthotopic mouse model by 90% compared with untreated mice. Using U87MG cells, we identified the LD22-4 membrane receptor as neuropilin 1 (NRP1). The identification of NRP1 as the LD22-4 receptor was based upon mass spectrometric analysis of proteins that bind to LD22-4, immunoprecipitation of an NRP1-LD22-4 complex formed during incubation of LD22-4 with U87MG cells, LD22-4-NRP1 coimmunoprecipitation studies, and binding of LD22-4 to HEK293 cells expressing NRP1. In contrast, NRP1 binding of an inactive mutant of LD22-4 was substantially reduced. As is typical of NRP1-binding proteins, LD22-4 itself binds to heparin and requires heparan sulfate for binding to cells. The addition of heparin to migration assays increased the inhibitory activity of LD22-4. In addition to a heparin-binding region, LD22-4 contains a 5-amino acid C-terminus that matches an NRP1 consensus binding sequence. Thus, direct binding experiments, dependence on heparan sulfate, and the presence of a NRP1 consensus binding sequence indicate that NRP1 is the binding site of LD22-4 and mediates inhibition of cell migration.

Gluon saturation effects on J / psi production in heavy ion collisions.

We consider a novel mechanism for J / psi production in nuclear collisions arising due to the high density of gluons. The resulting J / psi production cross section is evaluated as a function of rapidity and centrality. We compute the nuclear modification factor and show that the rapidity distribution of the produced J / psi's is significantly more narrow in AA collisions due to the gluon saturation effects. Our results indicate that gluon saturation in the colliding nuclei is a significant source of J / psi suppression and can explain the experimentally observed rapidity and centrality dependencies of the effect.

FAK mediates the inhibition of glioma cell migration by truncated 24 kDa FGF-2.

A truncated form of 24kDa FGF-2 consisting of 86 NH(2)-terminal amino acids (ATE+31) inhibits cell migration in vitro and tumor development and angiogenesis in vivo. Focal adhesion kinase (FAK) is phosphorylated on tyrosine and serine sites after cell stimulation by growth factors. This study examined the effect of ATE+31 on FAK phosphorylation in human glioma cells. FAK and Pyk phosphorylation were evaluated at serines known to be involved with cell migration. We demonstrated that ATE+31 at 3 x 10(-11)M decreases phosphorylation levels of Tyr(407)-FAK and Ser(732)-FAK in the presence of platelet-derived growth factor (PDGF), that ATE+31 in the presence of PDGF alters the distribution of FAK and other phosphotyrosine proteins in the adhesion contacts, and that ATE+31 in the presence of PDGF has no effect on the activation of Pyk2. These data suggest that the inhibition of cell migration by ATE+31 occurs via Tyr(407)-FAK and Ser(732)-FAK.

Cancer therapy through control of cell migration.

Cell migration plays a pivotal role in a many biological process that are essential for development, repair, and pathogenesis. Thus, inhibition of migration has the potential of limiting or suppressing the development of various diseases. Much of the focus on the therapeutic treatment of cancer has involved compounds that target cell proliferation and subsequent cell death. However, targeting migration is another approach that has not been pursued but holds promise for alternative means of therapy. One such potential therapeutic is a small protein that inhibits the migration of a number of cell types. This protein is derived from the amino terminal end of the 24 kDa form of fibroblast growth factor, and suppresses migration in the presence of a variety of growth factors. Analysis of the protein in mouse models shows that it inhibits in vivo angiogenesis and tumor growth at low concentrations. Thus, inhibition of migration is a viable alternative to more traditional methods of therapeutically treating tumors. Further study of the mechanism of inhibition can lead to the development of novel drugs targeting a distinctive cell process.

NF1 regulatory element functions as a repressor of tissue plasminogen activator expression.

OBJECTIVE: Analysis of the distribution of endothelial cell tissue plasminogen activator (tPA) in the vasculature of rodents and primates demonstrated that tPA is constitutively expressed predominantly in small artery endothelial cells of brain and lung. The regulatory elements responsible for the highly selective expression of arterial endothelial cell tissue plasminogen activator were sought. METHODS AND RESULTS: Transcription factor binding sites were defined by electrophoretic mobility-shift assay (EMSA) analysis using rat lung and brain nuclear extracts and the tPA promoter sequence from -609 to +37 bp. Protein binding to the promoter was found to be mediated by an NF1 site between -158 and -145 bp upstream from the transcriptional start site. Specific binding was confirmed through mutational analysis and competition binding studies. Infection of endothelial cells with a tPA promoter-green fluorescent protein (GFP) (-609 to +37 bp) reporter construct resulted in expression of the GFP, whereas no expression was found in smooth muscle cells. Mutation of the NF1 site increased the GFP expression indicating that the element acts as a repressor. CONCLUSIONS: These results suggest that the 600 bp of the tPA promoter upstream of the transcription start site conveys cell specificity to tPA expression and that an NF1 site within this region acts as a repressor.

Suppression of tumor growth and angiogenesis in vivo by a truncated form of 24-kd fibroblast growth factor (FGF)-2.

Efforts to treat tumors have routinely depended on disruption of cell proliferation by a variety of methods, many involving stimulation of apoptosis. We have previously shown that a truncated form of 24-kd basic fibroblast growth factor consisting of the amino terminal 86 amino acids inhibits migration of tumor and endothelial cells in vitro. In the present study, this peptide was tested for its ability to suppress angiogenesis and tumor growth using the murine dorsal skin-fold chamber model in vivo. Treatment of MCF-7 breast carcinoma tumor spheroids with this peptide resulted in cessation of the angiogenic response and a significant reduction in tumor size. Blood vessels that did form were poorly developed. In addition to inhibiting angiogenesis, the peptide also inhibited migration of Lewis lung carcinoma cells away from the tumor core before onset of angiogenesis indicating that the peptide-mediated inhibition of migration affects both angiogenesis and tumor growth independently. Despite inhibition of tumor cell migration, the peptide had no effect on neutrophil or eosinophil chemotaxis. This study demonstrates that the truncated form of 24-kd basic fibroblast growth factor is effective in suppressing tumor development in vivo through inhibition of angiogenesis as well as inhibition of tumor cell migration without compromising other homeostatic events.

Inhibition of cell migration and angiogenesis by the amino-terminal fragment of 24kD basic fibroblast growth factor.

The 24-kDa form of basic fibroblast growth factor inhibits the migration of endothelial cells and mammary carcinoma cells while continuing to promote cell proliferation. This molecule consists of the 18-kDa fibroblast growth factor sequence plus an additional 55 amino acids at the amino-terminal end. Antibody neutralization studies suggested that the inhibition of migration is associated with these 55 amino acids, whereas the promotion of proliferation localizes to the 18-kDa domain. To determine whether 24kD basic fibroblast growth factor could be modified to eliminate its effect on cell proliferation but retain its inhibition of migration, portions of the carboxyl-terminal end of 24kD fibroblast growth factor were deleted, and the products were tested on MCF-7 and endothelial cells. A protein consisting of the 55 amino acids of the amino-terminal end and the first 31 amino acids of 18kD basic fibroblast growth factor (ATE+31) inhibited migration by 80% but did not promote cell growth. Arginine to alanine substitutions within the first 21 amino acids of the carboxyl-terminal end substantially reduced the efficacy of ATE+31, whereas substitutions in the remaining part of the molecule had no effect. Competition binding experiments showed that ATE+31 does not compete with 24kD basic fibroblast growth factor for binding to fibroblast growth factor receptor 1. In an in vivo matrigel plug assay, 150 nm ATE+31 peptide reduced angiogenesis by 80%. These studies demonstrate that the amino-terminal end of 24kD basic fibroblast growth factor is responsible for an activity that inhibits the migration rates of cultured cells as well as the angiogenic response in vivo.