Generation of Negative Air Ions by Plants upon Pulsed Electrical Stimulation Applied to Soil

Generation of negative air ions (NAI) by pot plants (aloe Aloe arborescens, haworthia Haworthia rasalata, echinopsis Echinopsis tubiflora, mammillaria Mammillaria prolifera, opuntia Opuntia brunnescens, spider plant Chlorophytum comosum, and jade plant Crassula portulacea) was studied when high-voltage pulses were applied to soil. Plants that generated low amounts of NAI (such as jade plant and echinopsis) elevated NAI level 2–3 times over the mean background level. Plants that produced moderate amounts of NAI (haworthia, opuntia, and mammillaria) increased the NAI level hundredfold, whereas highly active plants (aloe and spider plant) increased the NAI level thousand times. Aloe plants can maintain constant NAI concentration in the ambient air (125 ± 15 × 10³ ions/cm³) for a long time (7–8 h). Negative air ions were predominantly generated by the leaf tips. The capacity of aloe to produce NAI considerably reduced with plant age and was lost, although reversibly, at temperatures below 8.5°C. The rate of NAI generation considerably depended on weather conditions. It was demonstrated that superoxide anion radical is one of NAI species generated by plants.     

Better understanding of phosphoinositide 3-kinase (PI3K) pathways in vasculature: Towards precision therapy targeting angiogenesis and tumor blood supply

The intracellular PI3K-AKT-mTOR pathway is involved in regulation of numerous important cell processes including cell growth, differentiation, and metabolism. The PI3Kα isoform has received particular attention as a novel molecular target in gene therapy, since this isoform plays critical roles in tumor progression and tumor blood flow and angiogenesis. However, the role of PI3Kα and other class I isoforms, i.e. PI3Kβ, γ, δ, in the regulation of vascular tone and regional blood flow are largely unknown. We used novel isoform-specific PI3K inhibitors and mice deficient in both PI3Kγ and PI3Kδ (Pik3cg^–/–/Pik3cd^–/–) to define the putative contribution of PI3K isoform(s) to arterial vasoconstriction. Wire myography was used to measure isometric contractions of isolated murine mesenteric arterial rings. Phenylephrine-dependent contractions were inhibited by the pan PI3K inhibitors wortmannin (100 nM) and LY294002 (10 μM). These vasoconstrictions were also inhibited by the PI3Kα isoform inhibitors A66 (10 μM) and PI-103 (1 μM), but not by the PI3Kβ isoform inhibitor TGX 221 (100 nM). Pik3cg^–/–/Pik3cd^–/–-arteries showed normal vasoconstriction. We conclude that PI3Kα is an important downstream element in vasoconstrictor GPCR signaling, which contributes to arterial vasocontraction via α₁-adrenergic receptors. Our results highlight a regulatory role of PI3Kα in the cardiovascular system, which widens the spectrum of gene therapy approaches targeting PI3Kα in cancer cells and tumor angiogenesis and regional blood flow.     

Amygdala: Neuroanatomy and neurophysiology of fear

This review is devoted to neuroanatomical and neurophysiological mechanisms of Pavlovian fear conditioning with a focus on the amydgalae, two subcortical nuclear groups, as primary structures responsible for controlling conditioned fear responses, and synaptic plasticity at their afferent and efferent projections as a cellular mechanism to mediate the formation and retention of fear memory. We survey current data on anatomical organization of the amygdaloid complex, as well as on its afferent and efferent projections and their functional significance. A special consideration is given to auditory inputs to the amygdala to analyze the mechanisms of aversive conditioning to sensory (acoustic) stimuli.     

Peculiarities of dopamine receptors on the membrane of spinal cord multipolar neurons of the brook lamprey Lampetra planeri

On isolated multiporal neurons of spinal cord of amniocoete larva of the brook lamprey Lampetra planeri, by the patch-clamp method in configuration "the whole cell", a modulating effect of dopamine on potential-activated Na+ currents was studied. Application of dopamine (10 microM) was shown to produce a complex action on the sodium current amplitude. In some cases a decrease of the amplitude, on average, by 13.5 +/- 2.2% was found, while in others--an increase, on average, by 8.6 +/- 6.1%. The modulation dopamine effect was not accompanied by any changes either of the threshold of the current appearance or of resistance of neuronal cell membranes. Pharmacological analysis with use of dopamine agonist has shown that the agonist of D1-receptors (-)-SKF-38393 (10 microM) decreases the Na+ current amplitude, whereas the agonist of D2-receptors (-)-quinpirole (10 microM) can produce in different cells both an increase, by 30.7 +/- 17.0 %, and a decrease, by 13.2 +/- 3.1%, of the Na+ current amplitude. The obtained data indicate the existence of D1- and D2-receptors on the membrane of multipolar spinal neurons of the amniocoete larva of the brook lamprey. Study of action of antagonists has shown that the antagonist of D1-receptors (+)-SCH-23390 (10 microM) does not affect action of the agonist of D1-receptors (-)-SKF-38393 (10 microM); the antagonist of D2-receptors (-)-sulpiride (10 microM) blocks completely effects both of the agonist of D1-receptors (-)-SKF-38393 (10 microM) and of the agonist of D2-receptors (-)-quinpirole (10 microM). The antagonist of D1-receptors (+)-SCH-23390 (10 microM) produced no effect on action of the agonist of D1-receptors (-)-SKF-38393 (10 microM). The obtained data indicate peculiarities of dopamine receptors of Cyclostomata as compared with those in mammals.     

A double-edged sword: supramolecular complexes of triazavirine display multicenter binding effects which influence aggregate formation

Communicated by Ramaswamy H. Sarma     

p27(Kip1) ubiquitination and degradation is regulated by the SCF(Skp2) complex through phosphorylated Thr187 in p27.

Many tumorigenic processes affect cell-cycle progression by their effects on the levels of the cyclin-dependent kinase inhibitor p27(Kip1) [1,2]. The phosphorylation- and ubiquitination-dependent proteolysis of p27 is implicated in control of the G1-S transition in the cell cycle [3-6]. To determine the factors that control p27 stability, we established a cell-free extract assay that recapitulates the degradation of p27. Phosphorylation of p27 at Thr187 was essential for its degradation. Degradation was also dependent on SCF(Skp2), a protein complex implicated in targeting phosphorylated proteins for ubiquitination [7-10]. Immunodepletion of components of the complex - Cul-1, Skp1, or Skp2 - from the extract abolished p27 degradation, while addition of purified SCF(Skp2) to Skp2- depleted extract restored the capacity to degrade p27. A specific association was observed between Skp2 and a p27 carboxy-terminal peptide containing phosphorylated Thr187, but not between Skp2 and the non-phosphorylated peptide. Skp2-dependent associations between Skp1 or Cul-1 and the p27 phosphopeptide were also detected. Isolated SCF(Skp2) contained an E3 ubiquitin ligase activity towards p27. Our data thus suggest that SCF(Skp2) specifically targets p27 for degradation during cell-cycle progression.     

Viability of micrococci and lactobacilli upon freezing and freeze-drying in the presence of different cryoprotectants

Studies were conducted on the viability of Micrococcus varians strain M₉₅ and Lactobacillus plantarum strain L₄ upon freezing and freeze-drying using five cryoprotectants (sucrose, lactose, sodium glutamate, peptone, dry nonfat milk) singly or in combinations with gelatin, glutamic acid, and sodium acetate. The number of survivals was determined immediately after treatment and after storage at room temperature or refrigeration temperatures, under vacuum or in air. Dry nonfat milk and peptone introduced at the levels of 8 and 5%, respectively, to broth culture, were found to be the best cryoprotectants providing a 100% viability determined immediately after the treatment of the strains under investigation.Immediately after freezing and freeze-drying, the numbers of viable micrococci remain high, the percentage viability in the presence of almost all the protectants used being 100%. During storage, those numbers decrease rapidly, reaching zero in 3 months upon storage at room temperature in air. The storage ability of lactobacilli is considerably better and, regardless of the fact that the percentage viability decreases, sufficient numbers of viable cells remain after 6 months of storage at both test temperatures.The best results are obtained on storing the microoganisms under vacuum in ampoules under reduced temperatures (+5 °C).     

Synthesis of 6-aminohexylglycosides of a polysaccharide from Streptococcus group A and its fragments

Polycondensation of 4-O-benzoyl-1,2-O-(1-cyanoethylidene)-3-O-(3,4-di-O-benzoyl-2-O-tr ityl-alpha-L- rhamnopyranosyl)-beta-L-rhamnopyranose in the presence of 6-phthalimidohexyl-3,4-di-O-benzoyl-2-O-trityl-alpha-L- rhamnopyranoside affords, after deprotection, the polysaccharide built up of the repeating dissaccharide units----2) Rha (alpha 1----3) Rha (alpha 1----and containing 6-aminohexyl residue at the reducing end. This polysaccharide possesses the structure of the group A-variant streptococcal polysaccharide. Synthesis of 6-aminohexyl glycosides of 2- and 3-O-alpha-L-rhamnopyranosyl-alpha-L-rhamnopyranoses, which corresponds to the repeating units of the above polysaccharide, is described.     

The value of the x-ray study method in the diagnosis of celiac-sprue]

The authors describe some features of x-ray symptoms of Gee-Herter disease with relation to severity and a period of disease. Altogether 106 adult patients with this disease were followed up, of them 78 patients with diagnosis of Gee-Herter disease, confirmed by histology of intestinal biopsy specimens, were selected for analysis. Three groups of patients with different x-ray symptoms were singled out. Some distinctive features of differential diagnosis and complications of Gee-Herter disease in adults were noted.