Enterohemorrhagic Escherichia coli infection stimulates Shiga toxin 1 macropinocytosis and transcytosis across intestinal epithelial cells.

Gastrointestinal infection with Shiga toxins producing enterohemorrhagic Escherichia coli causes the spectrum of gastrointestinal and systemic complications, including hemorrhagic colitis and hemolytic uremic syndrome, which is fatal in ∼10% of patients. However, the molecular mechanisms of Stx endocytosis by enterocytes and the toxins cross the intestinal epithelium are largely uncharacterized. We have studied Shiga toxin 1 entry into enterohemorrhagic E.

Gamma-tocotrienol induced apoptosis is associated with unfolded protein response in human breast cancer cells.

Gamma-tocotrienol (γ-T3) is a member of the vitamin E family. Tocotrienols (T3s) are powerful antioxidants and possess anticancer, neuroprotective and cholesterol-lowering properties. Tocotrienols inhibit the growth of various cancer cell lines without affecting normal cells.

Shiga toxin 1 interaction with enterocytes causes apical protein mistargeting through the depletion of intracellular galectin-3.

Shiga toxins (Stx) 1 and 2 are responsible for intestinal and systemic sequelae of infection by enterohemorrhagic Escherichia coli (EHEC). However, the mechanisms through which enterocytes are damaged remain unclear. While secondary damage from ischemia and inflammation are postulated mechanisms for all intestinal effects, little evidence excludes roles for more primary toxin effects on intestinal epithelial cells.

Macropinocytosis in Shiga toxin 1 uptake by human intestinal epithelial cells and transcellular transcytosis.

Shiga toxin 1 and 2 production is a cardinal virulence trait of enterohemorrhagic Escherichia coli infection that causes a spectrum of intestinal and systemic pathology. However, intestinal sites of enterohemorrhagic E. coli colonization during the human infection and how the Shiga toxins are taken up and cross the globotriaosylceramide (Gb3) receptor-negative intestinal epithelial cells remain largely uncharacterized.

Paxillin-beta-catenin interactions are involved in Rac/Cdc42-mediated endothelial barrier-protective response to oxidized phospholipids.

Oxidized phospholipids may appear in the pulmonary circulation as a result of acute lung injury or inflammation. We have previously described barrier-protective effects of oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (OxPAPC) on human pulmonary endothelial cells (EC) mediated by small GTPases Rac and Cdc42. This work examined OxPAPC-induced focal adhesion (FA) and adherens junction (AJ) remodeling and potential interactions between FA and AJ protein complexes involved in OxPAPC-induced EC barrier enhancement.

Tiam1 and betaPIX mediate Rac-dependent endothelial barrier protective response to oxidized phospholipids.

Oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (OxPAPC) exhibits potent barrier protective effects on pulmonary endothelium, which are mediated by small GTPases Rac and Cdc42. However, upstream mechanisms of OxPAPC-induced small GTPase activation are not known. We studied involvement of Rac/Cdc42-specific guanine nucleotide exchange factors (GEFs) Tiam1 and betaPIX in OxPAPC-induced Rac activation, cytoskeletal remodeling, and barrier protective responses in the human pulmonary endothelial cells (EC).

Expression of mutated mouse myocilin induces open-angle glaucoma in transgenic mice.

We developed a genetic mouse model of open-angle glaucoma by expression of mutated mouse myocilin (Myoc) in transgenic (Tg) mice. The Tyr423His point mutation, corresponding to the severe glaucoma-causing Tyr437His mutation in the human MYOC gene, was introduced into bacterial artificial chromosome DNA encoding the full-length mouse Myoc gene and long flanking regions. Both wild-type (Wt) and Tg animals expressed Myoc in tissues of the irido-corneal angle and the sclera.

Mutated mouse and human myocilins have similar properties and do not block general secretory pathway.

Purpose: The present study compared properties of wild-type and mutated mouse and human myocilin (Myoc) proteins as a prerequisite for development of a mouse model of glaucoma.

Methods: cDNA encoding full-length mouse Myoc was cloned into the p3XFLAG-CMV-14 vector. Tyr423His and Ile463Ser mutations were introduced into the mouse Myoc protein by in vitro mutagenesis.

Hypothalamic control of mitogen-induced proliferative responses and luteinizing hormone-releasing hormone levels in thymus and peripheral blood of rat fetuses.

The role of endogenous luteinizing hormone-releasing hormone (LHRH) in the development of concanavalin A (ConA)-induced proliferative responses was studied in rat fetuses. Preliminary treatment of fetuses in utero with either the LHRH receptor antagonist or anti-LHRH antibodies resulted in the suppression of ConA-induced proliferative responses of thymocytes. LHRH and LHRH-immunopositive cells, morphologically similar to thymocytes, were detected in intact fetal thymus.

Gene expression profile of the human trabecular meshwork: NEIBank sequence tag analysis.

Purpose: To characterize the gene expression pattern in the human trabecular meshwork (TM) and identify candidate genes for glaucoma by expressed sequence tag (EST) analysis as part of the NEIBank project.

Methods: RNA was extracted from dissected human TM and used to construct unamplified, un-normalized cDNA libraries in the pSPORT1 vector. More than 4000 clones were sequenced from the 5' end.

Poly[1-(trimethylsilyl)-1-propine] as chromatographic adsorbent and prospects of its application in packed and capillary columns.

The application of film-forming organic polymers, which are in common use in membrane technology, as chromatographic adsorbents for packed and capillary columns has been suggested. The chromatographic characteristics of poly[1-(trimethylsilyl)-1-propine] (PTMSP) as an adsorbent were studied. The film-forming properties of PTMSP simplify manufacturing of capillary and packed gas-solid columns.

Effect of efficiency improvement by injecting a sample at a lower carrier gas velocity in isothermal gas-liquid chromatography.

The effect of efficiency improvement of chromatographic system by injecting a sample at a lower carrier gas velocity (in comparison with the carrier gas velocity at subsequent separation) was studied experimentally and theoretically in isothermal gas-liquid chromatography. The suggested technique is based on sample introduction in the programmed carrier gas velocity operation mode: the injection is realized at low carrier gas velocity, then the velocity is increased rapidly up to the operation value. The technique can be applied in chromatographic practice.

Ammonia as carrier gas in capillary gas-liquid chromatography.

Influence of helium and ammonia as carrier gases on retention of neutral solutes on polyethylene glycol has been studied theoretically and experimentally. It was shown that the influence of ammonia on the retention varied significantly depending on the solute's nature. For example, the influence is great for C22 n-alkane and it is small for phenol.

Ammonia as a carrier gas for acidic-basic chromatography.

The influence of ammonia as a basic carrier gas on the retention of acidic and basic solutes was experimentally studied. Use of the basic carrier gas (ammonia) leads to an increase in retention of acidic solutes. A simplified theory on the influence of carrier gas basicity influence on the retention of acidic and basic solutes was developed.

Luteinizing hormone-releasing hormone in thymus and hypothalamus of rat fetuses: suppressing effect of antagonist and of antibodies on concanavalin A-induced proliferation of thymocytes.

The effect of endogenous luteinizing hormone-releasing hormone (LHRH) on the proliferation induced by concanavalin A (Con A) in rat fetal thymocytes was studied. A selective antagonist (2 microg per fetus) or antibodies to LHRH (20 microl per fetus) were injected in utero into 20-day-old rat fetuses, and this resulted in a two- or fivefold decrease in the Con A-induced proliferation of thymocytes, respectively. In combined culture of the antagonist (10-5-10-6 M) with fetal thymocytes, the proliferative response was not decreased.

Hypothalamo-pituitary control of the cell-mediated immunity in rat embryos: role of LHRH in regulation of lymphocyte proliferation.

The role of the neuroendocrine system in the development of cell-mediated immunity has been studied in fetal rats. The spontaneous and mitogen-induced proliferation of liver lymphocytes and thymocytes was evaluated in vitro in rats at the 22nd prenatal day following surgical ablation of the forebrain (encephalectomy) or of the entire brain and pituitary (decapitation) in rat fetuses in utero at the 18th day. Non-operated and sham-operated fetuses served as controls.

Use of equations for the description of experimental dependence of the height equivalent to a theoretical plate on carrier gas velocity in capillary gas-liquid chromatography.

Optimal equation for fitting the experimental data on the height equivalent to a theoretical plate (HETP) versus carrier gas velocity in GLC was determined. The data obtained by authors and the literary data by other investigators were used for the comparative study of Van Deemter, Golay and the little known Golay-Guiochon equations. The Golay-Guiochon equation takes into account instrumental contribution and other sources of additional band broadening.

Opioid agonist modulation of cytoplasmic free Ca2+ level in concanavalin A-stimulated mouse lymphocytes.

In this study the influence of mu-, delta-, and kappa-selective opioid agonists (DAMGO, DSLET, and dynorphin A (1-13)) on cytoplasmic free Ca2+ ([Ca2+]i) level in normal and concanavalin-A (Con A)-activated mouse lymphocytes was investigated. [Ca2+]i was measured using the fluorescent dye FURA-2AM. The opioid peptides at 10-12-10-7 M induced some increase in [Ca2+]i in non-activated lymphocytes.

Conditioned motor reactions in free-moving elasmobranchs and bony fishes.

Food-getting conditioned motor reflexes to light and darkness discrimination were developed in elasmobranchs (the sharks Scyllium canicula and Galleus canis) and bony fishes (Mugil capitocum). Several distinctions in ecological and conditioned motor behavior were observed in sharks with low and high degrees of organization. There were significant differences between elasmobranchs and bony fishes in ecological and food-getting behavior and in conditioned reflex reactions.

Studies of complex forms of behavior in various vertebrates.

In the evolutionary series of vertebrates, a correlation was established between degrees of structural and functional organization of the brain and features of the formation of complex behavioral acts. Gradual evolution of a complex sequence of motor, food-obtaining, conditioned reflexes, and a capacity for visual discrimination in the phylogenetic line of vertebrates (cartilaginous and marine bony fishes, reptiles, and mammals--insectivores, rodents, and primates) was disclosed.

Relations between immunological and neurological memory: learning ability in rats during immunostimulation.

The effect of an immunostimulator, Freund's complete adjuvant (FCA), on the ability of Wistar rats to learn in a visual discrimination test was studied by foodgetting and electric-shock avoidance methods. A significant improvement in learning ability was demonstrated under the influence of FCA when the negative reinforcement method was used, but a worsening when the positive reinforcement method was used. Analysis of the dynamics of extinction of the reflexes formed gave similar results.

[Studies on projections of somatic afferentation in the neocortex of the hedgehog Erinaceus europaeus].

Cortical projections of the somatic system in the hedgehog cortex were studied by means of the evoked potential (EP) technique. The EPs were shown to arise at a large area of the lateral cortex, the area in question being enlarged under chloralose anaesthesia. In the focus of projection of corresponding modalities the EPs posessed the least latency.

Structural and functional bases for frontal lobe participation in the organizationof complex behavior in cats.

The differences in the cytoarchitectonic organization and the thalamocortical projections to the anterior and posterior cortical fields in cats provide the basis for judgements about their unequal roles in entire behavior acts. Extracellular recordings of anterior frontal neuronal activity have revealed the predominance of the nonspecific type of afferent activation of gyrus proreus neurons; complex integrative properties of gigantopyramidal neurones [posterior frontal regions] have been observed. Participation of the posterior frontal fields in afferent synthesis and in programming motor activity has been shown in behavioral studies.