Salmonella, the host and its microbiota

The intestine is host to a diverse bacterial community whose structure, at the phylum level, is maintained through unknown mechanisms. Acute inflammation triggered by enteric pathogens, such as Salmonella enterica serotype Typhimurium (S. Typhimurium), is accompanied by changes in the bacterial community structure marked by an outgrowth of the pathogen. Recent studies show that S. Typhimurium can harness benefit from the host response to edge out the beneficial bacterial species that dominate in the healthy gut. The elucidation of how S. Typhimurium alters the bacterial community structure during gastroenteritis is beginning to provide insights into mechanisms that dictate the balance between the host and its microbiota.     

Cytomixis, its nature, significance and the cytological consequences

Cytomixis is the widespread natural process of intercellular interaction which is characteristic for vegetative and generative tissues in both normal and pathological conditions. The origin significance and genetic control cytomixis still remain not completely clear. The popularity of view of the pathological nature of cytomixis based on its peculiar plants with genetic instability and impaired homeostasis. In the genetic control of cytomixis seem to be involved meiotic genes which are responsible for segregation and organization of chromosomes. Their activity is modified by environmental factors through signal transduction. It is assumed via cytomixis, from one side, the informational contact can be reached and meiosis and gametogenesis are synchronized, with another, increase of the genetic variety and level of the heterozygosis of microsporocytes. The activity of cytomixis varies over wide limits. The greatest influence on its activity have mutagenesis hybridization and polyploidy. In this context cytomixis can fulfill the function of cell selection which is activated by exceeding of the threshold level of the microsporocyte damages (or genetical disbalance).     

泡桐网蝽的发生规律及防治

泡桐网蝽Eteoneus anuglatus Darkeet Maa在湖南宁远、冷水滩等县区1年发生5～6代,以成虫在树枝缝隙及枯草丛、土缝等处群集越冬。8～9月高温干燥时发生严重。人工饲养及田间观察,该虫仅在毛泡桐(Paulownia tomentosa(Thunb) Steud)、泡桐(Paulownia fortunei(Seem) Hems)及榆树(Ulmus pumila L.)上取食为害,以3～7年树龄泡桐受害最重。在成虫和若虫高峰期用40%氧化乐果,50%敌敌畏乳油1200～1500倍或2.5%溴氰菊脂乳油2500倍稀释液喷洒叶面,可控制该虫为害。     

Facile, alternative route to lubeluzole, its enantiomer, and the racemate

Lubeluzole [(S)-9] has been synthesized by a convergent synthesis, alkylation of N-methyl-N-piperidin-4-yl-1,3-benzothiazol-2-amine (4) with (+)-(R)-1-chloro-3-(3,4-difluorophenoxy)propan-2-ol [(+)-(R)-8] being the key step. Alcohol (+)-(R)-8 was obtained from commercially available (R)-epichlorohydrin [(R)-6], while the thiazole derivative 4 was easily obtained starting from N-protected piperidin-4-one (1) in a three-step procedure. The same method was used in order to obtain both the (R)-stereoisomer of lubeluzole [(R)-9] and its racemate [(RS)-9]. Overall yields ranged from 20% to 35%. The enantiomeric excess values for (S)-9 and (R)-9 were 97% and 94% respectively, as analyzed by chiral HPLC.     

Antitumor action of seminal ribonuclease, its dimeric structure, and its resistance to the cytosolic ribonuclease inhibitor

Bovine seminal RNase (BS-RNase) is a homodimeric enzyme with a cytotoxic activity selective for tumor cells. In this study, the relationships of its cytotoxic activity to its dimeric structure and its resistance to the cytosolic RNase inhibitor (cRI) are investigated systematically by site-directed mutagenesis. The results show that (1) the dimericity of BS-RNase is essential for its full cytotoxic action; (2) the role of the dimeric structure in the antitumor activity is that of making the enzyme insensitive to the cytosolic RNase inhibitor; (3) a RNase may not be completely insensitive to cRI to exploit a full cytotoxic potential.     

Consciousness, its criteria and the possible mechanisms]

Consciousness is characterized by the objective and subjective criteria. Accordingly, this is the ability to operation with knowledge, its transmission to other people in abstract form and the feeling of "ego" as a subject of these actions. Objective and subjective signs of the consciousness are provided with the mechanism based on the synthesis of information coming from organs of sensation extracted from memory and coming from the centers of emotions and motivations. As a result of this synthesis the sensation of "ego", appears, and information estranged from it and offered for others is determined. An important role in the informational synthesis is played by the dynamic cortical structures--foci of interaction. In the process of perception they are localized mostly in projective zones of analyzers, at thinking--in associative zones of the cortex. Realization is closely connected with communication and formation of foci of interaction in the verbal zones of the left hemisphere.     

Selectivity, cooperativity, and reciprocity in the interactions between the delta-opioid receptor, its ligands, and G-proteins

A better understanding of signal transduction mechanisms is of critical importance. Methodologies that allow studies to be done while receptors are incorporated into lipid bilayers are advantageous. One such technique is plasmon-waveguide resonance (PWR) spectroscopy, which can follow changes in conformation accompanying protein-ligand, protein-protein, and protein-lipid interactions occurring in G-protein-coupled receptors in real time with high sensitivity and without the need for molecular labeling. Here we investigated several aspects of human delta-opioid receptor (hDOR)-G-protein interactions: 1) the effect of different types of agonists on the interaction with individual G-protein subtypes; 2) the affinities of the separate G-protein alpha and betagamma subunits to different ligand-occupied states of the receptor; and 3) the effect of the presence of the G-protein on the interactions of the ligand with the receptor. To accomplish this we have incorporated the receptor into a solid supported lipid bilayer in the presence of ligand or G-protein and monitored the PWR spectral changes induced by the reciprocal G-protein or ligand interactions. We found a high degree of selectivity in the interactions of different agonist-bound states of the receptor with the different G-protein subtypes. This has important implications for agonist-directed trafficking and selective drug design. Studies with the separated alpha and betagamma subunits show that cooperativity exists in these interactions. The high affinities of the separated subunits to the receptor point to the possibility of independent promotion of specific signaling events. The presence of G-proteins increased the affinity of agonists to the hDOR, and caused faster binding kinetics and different ligand-induced conformational changes. Because ligand also influences G-protein binding, reciprocity exists between these two binding processes.