bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of LAT in Increased CD8
+
T Cell Exhaustion in Trigeminal Ganglia of Mice Latently Infected with Herpes Simplex Virus 1
Authors: Allen Sariah J. , Hamrah Pedram , Gate David , Mott Kevin R. , Mantopoulos Dimosthenis , Zheng Lixin , Town Terrence , Jones Clinton , von Andrian Ulrich H. , Freeman Gordon J. , Sharpe Arlene H. , BenMohamed Lbachir , Ahmed Rafi , Wechsler Steven L. , Ghiasi Homayon
Published: February 2011

Herpes simplex virus (HSV) infection is a classic example of latent viral infection in humans and experimental animal models. The HSV-1 latency-associated transcript (LAT) plays a major role in the HSV-1 latency reactivation cycle and thus in recurrent disease. Whether the presence of LAT leads to generation of dysfunctional T cell responses in the trigeminal ganglia (TG) of latently infected mice is not known. To address this issue, we used LAT-positive [LAT(+)] and LAT-deficient [LAT(−)] viruses to evaluate the effect of LAT on CD8 T cell exhaustion in TG of latently infected mice. The amount of latency as determined by quantitative reverse transcription-PCR (qRT-PCR) of viral DNA in total TG extracts was 3-fold higher with LAT(+) than with LAT(−) virus. LAT expression and increased latency correlated with increased mRNA levels of CD8, PD-1, and Tim-3. PD-1 is both a marker for exhaustion and a primary factor leading to exhaustion, and Tim-3 can also contribute to exhaustion. These results suggested that LAT(+) TG contain both more CD8
+
T cells and more CD8
+
T cells expressing the exhaustion markers PD-1 and Tim-3. This was confirmed by flow cytometry analyses of expression of CD3/CD8/PD-1/Tim-3, HSV-1, CD8
+
T cell pentamer (specific for a peptide derived from residues 498 to 505 of glycoprotein B [gB
498–505
]), interleukin-2 (IL-2), and tumor necrosis factor alpha (TNF-α). The functional significance of PD-1 and its ligands in HSV-1 latency was demonstrated by the significantly reduced amount of HSV-1 latency in PD-1- and PD-L1-deficient mice. Together, these results may suggest that both PD-1 and Tim-3 are mediators of CD8
+
T cell exhaustion and latency in HSV-1 infection.
Chimeric Porcine Circoviruses (PCV) Containing Amino Acid Epitope Tags in the C Terminus of the Capsid Gene Are Infectious and Elicit both Anti-Epitope Tag Antibodies and Anti-PCV Type 2 Neutralizing Antibodies in Pigs
Authors: Beach Nathan M. , Smith Sara M. , Ramamoorthy Sheela , Meng Xiang-Jin
Published: February 2011

A chimeric porcine circovirus (PCV1-2) with the capsid gene of pathogenic PCV2 cloned into the genomic backbone of nonpathogenic PCV1 is attenuated in pigs but elicits protective immunity against PCV2. In this study, short epitope tags were inserted into the C terminus of the capsid protein of the chimeric PCV1-2 vaccine virus, resulting in a tractable marker virus that is infectious both
in vitro
and
in vivo
. Pigs experimentally infected with the epitope-tagged PCV1-2 vaccine viruses produced tag-specific antibodies, as well as anti-PCV2 neutralizing antibodies, indicating that the epitope-tagged viruses could potentially serve as a positive-marker modified live-attenuated vaccine.
Bovine Plasmacytoid Dendritic Cells Are the Major Source of Type I Interferon in Response to Foot-and-Mouth Disease Virus In Vitro and In Vivo
Authors: Reid Elizabeth , Juleff Nicholas , Gubbins Simon , Prentice Helen , Seago Julian , Charleston Bryan
Published: February 2011

Type I interferons (alpha/beta interferons [IFN-α/β]) are the main innate cytokines that are able to induce a cellular antiviral state, thereby limiting viral replication and disease pathology. Plasmacytoid dendritic cells (pDCs) play a crucial role in the control of viral infections, especially in response to viruses that have evolved mechanisms to block the type I IFN signal transduction pathway. Using density gradient separation and cell sorting, we have highly enriched a population of bovine cells capable of producing high levels of biologically active type I IFN. These cells represented less than 0.1% of the total lymphocyte population in blood, pseudoafferent lymph, and lymph nodes. Phenotypic analysis identified these cells as bovine pDCs (CD3−CD14−CD21−CD11c−NK−TCRδ−CD4+MHC II+CD45RB+CD172a+CD32+). High levels of type I IFN were generated by these cellsin vitroin response to Toll-like receptor 9 (TLR-9) agonist CpG and foot-and-mouth disease virus (FMDV) immune complexes. In contrast, immune complexes formed with UV-inactivated FMDV or FMDV empty capsids failed to elicit a type I IFN response. Depletion of CD4 cellsin vivoresulted in levels of type I IFN in serum early during FMDV infection that were significantly lower than those for control animals. In conclusion, pDCs interacting with immune-complexed virus are the major source of type I interferon production during acute FMDV infection in cattle.
Genome Variation in Cryptococcus gattii, an Emerging Pathogen of Immunocompetent Hosts
Authors: D’Souza C. A. , Kronstad J. W. , Taylor G. , Warren R. , Yuen M. , Hu G. , Jung W. H. , Sham A. , Kidd S. E. , Tangen K. , Lee N. , Zeilmaker T. , Sawkins J. , McVicker G. , Shah S. , Gnerre S. , Griggs A. , Zeng Q. , Bartlett K. , Li W. , Wang X. , Heitman J. , Stajich J. E. , Fraser J. A. , Meyer W. , Carter D. , Schein J. , Krzywinski M. , Kwon-Chung K. J. , Varma A. , Wang J. , Brunham R. , Fyfe M. , Ouellette B. F. F. , Siddiqui A. , Marra M. , Jones S. , Holt R. , Birren B. W. , Galagan J. E. , Cuomo C. A.
Published: February 2011

Cryptococcus gattii
recently emerged as the causative agent of cryptococcosis in healthy individuals in western North America, despite previous characterization of the fungus as a pathogen in tropical or subtropical regions. As a foundation to study the genetics of virulence in this pathogen, we sequenced the genomes of a strain (WM276) representing the predominant global molecular type (VGI) and a clinical strain (R265) of the major genotype (VGIIa) causing disease in North America. We compared these
C. gattii
genomes with each other and with the genomes of representative strains of the two varieties of
Cryptococcus neoformans
that generally cause disease in immunocompromised people. Our comparisons included chromosome alignments, analysis of gene content and gene family evolution, and comparative genome hybridization (CGH). These studies revealed that the genomes of the two representative
C. gattii
strains (genotypes VGI and VGIIa) are colinear for the majority of chromosomes, with some minor rearrangements. However, multiortholog phylogenetic analysis and an evaluation of gene/sequence conservation support the existence of speciation within the
C. gattii
complex. More extensive chromosome rearrangements were observed upon comparison of the
C. gattii
and the
C. neoformans
genomes. Finally, CGH revealed considerable variation in clinical and environmental isolates as well as changes in chromosome copy numbers in
C. gattii
isolates displaying fluconazole heteroresistance.

IMPORTANCE
Isolates of
Cryptococcus gattii
are currently causing an outbreak of cryptococcosis in western North America, and most of the cases occurred in the absence of coinfection with HIV. This pattern is therefore in stark contrast to the current global burden of one million annual cases of cryptococcosis, caused by the related species
Cryptococcus neoformans
, in the HIV/AIDS population. The genome sequences of two outbreak-associated major genotypes of
C. gattii
reported here provide insights into genome variation within and between cryptococcal species. These sequences also provide a resource to further evaluate the epidemiology of cryptococcal disease and to evaluate the role of pathogen genes in the differential interactions of
C. gattii
and
C. neoformans
with immunocompromised and immunocompetent hosts.
Contribution to the thermodynamics of complexes of alkali metal cations with dibenzo-18-crown-6 in water-nitrobenzene extraction system
Authors: Makrlík Emanuel , Hálová Jaroslava , Kyrš Miroslav
Published: February 2011

The stability constants for the ML+ complex species, where M+ is an alkali metal cation and L is dibenzo-18-crown-6, in nitrobenzene saturated with water were calculated by employing published equilibrium data. The stability is found to increase in the cation order Li+ < Cs+ < Rb+ < K+ < Na+. For the NaL+, KL+, RbL+, and CsL+ complex cations the individual extraction constants in the water-nitrobenzene system were determined; their values increase in the series Na+ < K+ < Rb+ < Cs+.
X-ray photoelectron spectroscopic study of sulphonamides: Charge distribution and tautomerism
Authors: Exner Otto , Juška Tomáš
Published: February 2011

The X-ray photoelectron spectra of several sulphonamides, N-substituted sulphonamides, and their alkali salts were registered in the solid state. When comparing the salts with the corresponding acids, shifts of the N1s, S2p, and O1s core binding energies were observed which were discussed in terms of the charge distribution in the anion. In the case of N-hydroxybenzenesulphonamide (III) these shifts can also serve to confirm the tautomeric structure of the anion (B) as it has been inferred from other physical methods.
Reaction of 30-nor-18-lupene derivatives with bromine and peracids
Authors: Klinotová Eva , Protiva Jiří , Klinot Jiří , Vystrčil Alois
Published: February 2011

The reaction of diol I and diacetate IIwith one mole of bromine gives rise, depending on conditions, to isomeric dienes III-V and IX or to derivatives substituted in position 21 (VII, VIII). On reaction of diacetate II with two moles of bromine in acetic acid 21,22-disubstituted compounds XI and XII were obtained. Diene V is the intermediate in the formation of dienes IV and IX and derivatives XI and XII. Epoxidation of the 18(19)-double bond in compounds I and II takes place from the β-side and leads for epoxides XIV and XV.
Surface tensions of ternary systems
Authors: Šišková Marie , Hampl Pavel
Published: February 2011

From the thermodynamic condition of equilibrium in a system in a force field, a relation was derived for calculating surface tensions in three- and multicomponent systems. To check the validity of this relation the surface tension of two ternary systems has been measured and the experimental values have been compared with the calculated ones.
Viscosity, electrical conductivity and density of the system ammonium nitrate-dimethyl sulphoxide
Authors: Novák Jindřich , Kodejš Zdeněk , Sláma Ivo
Published: February 2011

The density, viscosity, and electrical conductivity of highly concentrated solutions of ammonium nitrate in dimethyl sulphoxide have been determined over the temperature range 10-60 °C and the concentration range 7-50 mol% of the salt. The variations in the quantities as a function of temperature and concentration have been correlated by empirical equations. A comparison is made between the transport properties for the present system, aqueous solutions of ammonium nitrate, and calcium nitrate solutions in dimethyl sulphoxide.
Trapping of allylic radicals from the gas phase pyrolysis in the adamantane matrix - Isotropic ESR spectra at 77 K
Authors: Mach Karel , Nováková Jana , Dolejšek Zdeněk
Published: February 2011

A simple device has been developed and tested for trapping radicals from the gas phase onto a cold finger kept at 77 K. The yields of allylic radicals obtained by pyrolysis of biallyl hydrocarbons were studied by ESR spectroscopy in dependence on the temperature and pressure of pyrolysis, both in the absence and presence of adamantane. The co-deposition of the radicals with adamantane increased considerably the radical yields and afforded isotropic ESR spectra of allyl radicals (ΔHmin = 0.21 mT) even at 77 K. The adamantane matrix formed from the gas phase appeared to be less rigid than the crystalline one, as the allylic radicals decayed already at 160-177 K. Yields of the trapped allyl radicals were also compared with the radical yields measured by mass spectrometry using analogous pyrolytic device.
Components of the wood-rotting fungus Sarcodontia setosa
Authors: Kopecký Jaroslav , Šaman David , Vaněk Tomáš , Novotný Ladislav
Published: February 2011

From the wood-rotting fungus Sarcodontia setosa (Pers.) DONK a mixture of benzoquinone acids was obtained which was converted to methyl esters Ia-IIIa and separated by preparative HPLC. The presence of the known sarcodontic acid (II), i.e. 15-(6-methoxy-1,4-benzoquinon-2-yl)-2-pentadecenoic acid, and further of 15-(6-methoxy-1,4-benzoquinon-2-yl)pentadecanoic acid (I) and 15-(6-methoxy-1,4-benzoquinon-2-yl)-2,5-pentadecadienoic acid (III) was proved in the mixture. The structures were determined by spectral methods.
Synthesis and reactions of hydroxydiamantanones
Authors: Vodička Luděk , Isaev Sergei D. , Burkhard Jiří , Janků Josef
Published: February 2011

Diamantanone can be oxidized with chromium trioxide in acetic acid solutions to give 11-hydroxy-, 1-hydroxy-, and 9-hydroxy-3-diamantanone as the major products and two diamantanonediones of unelucidated structure as by-products. The Koch-Haaf carboxylation of hydroxydiamantanones results in the formation of the corresponding oxodiamantanecarboxylic acids. Reacted with 100% HNO3, diamantanone transforms into 9-(3-diamantanoyl) nitrate. Reactions of the carbonyl groups of these compounds with H2NOSO2OH lead to hydrazidiamantane derivatives, which oxidized with CrO3 provide the azidiamantane derivatives.
Synthesis of mono- and diacetylenic derivatives of silylferrocene
Authors: El-Agamey Abdel Ghani Ali , Asatiani Levan P.
Published: February 2011

1-Ferrocenyl(methyl)phenylsilane (I) was prepared by silylation of ferrocene at low temperature. Mono- and diacetylenic compounds of silyferrocene were prepared by the interaction of chloroferrocenylsilane with mono- and dilithium acetylenic derivatives, respectively. It has been found that, catalytic hydrogenation of the prepared acetylenic compounds seem to be totally determined by steric considerations.
Possibily of the formation of mixed crystals in the indium phosphate-scandium phosphate system
Authors: Hájek Bohumil , Šantavá Eva , Muck Alexander
Published: February 2011

The powder X-ray diffraction patterns and vibrational spectra were studied for the InPO4-ScPO4 system. The two cations were found mutually partly replaceable in the two phosphate structures involved, D2h17 and D4h19; the orthorhombic D2h17 structure of InPO4 is apt to accept 25 mol.% ScPO4, whereas the tetragonal D4h19 structure of ScPO4 only accepts InPO4 in amounts not exceeding 5 mol.%. The vibrational spectra of TIPO4 are also investigated.
A test of the role of refractive index in correlations between solvent effects on electronic spectra and solvent effects on reaction equilibria and rates
Authors: Bekárek Vojtěch
Published: February 2011

80 correlations have been carried out between the medium-induced changes in equilibrium and kinetic data (Y) and the medium-induced changes in positions of maxima in electronic (both absorption and fluorescence) spectra (Δν) of the Kamlet-Taft type indicators. The correlations have been carried out by means of the equations Y=Y0 + k . Δν and Y=Y0 + k' . Δν/f(n2) using only the Kamlet-Taft select solvents (SSS). The equation involving the function of refreactive index (n), f(n2) = (n2 - 1)/(2n2 + 1), is better than the simple relation between Y and Δν in 93% of the systems studied. The problem of HBD acidity of nitromethane and the relation of the A and B solvent characteristics by Swain and the characteristics of dipolarity of medium by Kamlet-Taft are discussed.
Interpretation of 13C NMR chemical shifts of Hantzsch's pyridines and 1,4-dihydropyridines
Authors: Kurfürst Antonín , Trška Petr , Goljer Igor
Published: February 2011

1H and 13C NMR spectra of twelve 1,4-dihydropyridines I and twelve corresponding pyridine derivatives II have been measured in hexadeuteriodimethyl sulphoxide and interpreted. Correlation equations are given for the chemical shifts of the atoms in the heterocyclic rings of the two series of compounds.
Preparation of α-Fe2O3 (hematite) by oxidation precipitation of aqueous solutions of iron(II) sulphate
Authors: Šubrt Jan , Šolcová Alexandra , Hanousek František , Petřina Antonín , Zapletal Vladimír
Published: February 2011

The oxidation precipitation of aqueous solutions of iron(II) sulphate by oxygen gas was studied; the effect of pH, temperature, and presence of α-FeOOH and α-Fe2O3 crystal nuclei was examined and the conditions for the preparation of phase-pure α-Fe2O3 (hematite) were sought. The hematite prepared contained 3-5% structurally bonded water. The effect of the bonded water on the properties of the product is described and the way of the bonding in the structure is discussed.
Preparation of 5-X-2-(2-nitrovinyl)furans and their reactions with nucleophiles
Authors: Kada Rudolf , Knoppová Viera , Kováč Jaroslav , Maleňáková Irena
Published: February 2011

The title compounds were prepared by condensation of 5-X-2-furaldehydes (X = H, Br, C6H5S, C6H5SO2, 4-CH3-C6H4SO2, 3-O2N-C6H4O) with nitromethane in methanol. 5-Trimethylammonium-2-(2-nitrovinyl)furan bromide (Ii) was obtained from 5-bromo-2-(2-nitrovinyl)furan (Ib) and trimethylamine in benzene; its thermal decomposition in methanol furnished 5-dimethylamino-2-(2-nitrovinyl)furan (Ih). Reactions of 5-X-2-(2-nitrovinyl)furans with nitrogen-containing nucleophiles were investigated.
Solvent effect in dissociation of substituted benzenesulphonamides in dimethylformamide, dimethyl sulphoxide, and acetonitrile
Authors: Ludwig Miroslav , Pytela Oldřich , Večeřa Miroslav
Published: February 2011

Dissociation constants of fifteen substituted arenesulphonamides of general formula XC6H4.SO2NH2 (or X2C6H3SO2NH2) have been measured by potentiometric titration in dimethylformamide, dimethyl sulphoxide, and acetonitrile. The Hammett substitution correlations have been calculated and interpreted for these media. The pKHA values measured and the results published earlier for methanol, ethanol, and water have been treated by multiple linear regresion using the published set of the parameters characterizing solvents and by factor analysis using the short cycle and the target testing method.
Regulation of proline-inhibitable glutamate kinase (EC 2.7.2.11, ATP: γ-L-glutamate phosphotransferase) of winter wheat leaves by monovalent cations and L-proline
Authors: Štefl Miroslav , Vašáková Ludmila
Published: February 2011

Proline-inhibitable glutamate kinase (GK1) of winter leaves is specifically regulated through feedback by L-proline during changes in the concentration of K+- and Na+- ions and in their ratio (K+/Na+). The enzyme is most active at 30 °C at a relatively high K+ + Na+ concentration and a K+/Na+ ratio of 1.8 to 10.2 and at 0 °C at both lower K+ + Na+ concentrations and a K+/Na+ ratio. An increase of the K+ + Na+ concentration to 1.25 mol/l and of the K+/Na+ ratio to 30.2 results in an activity decrease to one half; if, however, Na+ is increased to make K+/Na+ < 1, the activity becomes one tenth of that of the control. GK1 is completely inhibited through feedback by 50 mmol/l L-proline in the medium at pH 7.2 containing 207 + 40 mmol/l K+ + Na+; the inhibitin is switched off by increasing the K+ + Na+ concentration to the optimum, i.e. 357 + 40 mmol/l and this is the condition necessary for the start of L-proline biosynthesis. An additional increase of the K+ + Na+ concentration in the presence of L-proline results in complete inhibition of the enzyme. The changes in the activity of GK1 comply with the recorded data on the changes of L-proline accumulation in plats which parallel the changes of K+ and Na+ concentration in the nutrient medium. The theory of GK1 regulation by L-proline during changes in the ionic strength of the medium, which had been designed in the preceding work, was experimentally confirmed in this study.
Synthesis, IR spectra, and antimicrobial activity of some bis-ammonium salts of N,N'-bis(2-dimethylaminoethyl)methylamine
Authors: Devínský Ferdinand , Masárová Ľubomíra , Lacko Ivan , Mlynarčík Dušan
Published: February 2011

Preparation of 2-bromoethyl alkanoates and alkenoates, N,N'-bis(2-dimethylaminoethyl)methylamine (pentamethyldiethylenetriamine) and some of its bis-ammonium salts is described. IR spectra of the esters and ammonium salts have been interpreted. Antimicrobial activity against Staphylococcus aureus, Escherichia coli and Candida albicans for the bis-ammonium salts has been determined.
13C and 119Sn NMR spectra of some triphenyltin 4-substituted benzoates dissolved in coordinating and non-coordinating solvents
Authors: Lyčka Antonín , Nádvorník Milan , Handlíř Karel , Holeček Jaroslav
Published: February 2011

13C and 119Sn NMR spectra of the title compounds (C6H5)3SnOC(O)C6H4-4-X, where X = H, NH2, OCH3, C(CH3)3, CH3, NHCOCH3, Cl, and NO2, have been studied in coordinating (pentadeuteriopyridine, hexadeuteriodimethyl sulphoxide) and non-coordinating solvents (deuteriochloroform). From the NMR spectral parameters it follows that all the compounds studied, dissolved in the coordinating solvents, form donor-acceptor complexes with one solvent molecule. Discussed are the differences in composition and structure of the compounds in the two types of solvents as well as influence of substituents on values of the parameters of the 13C and 119Sn NMR spectra.
Tumour necrosis factor G-308A polymorphism modifies the effect of home dampness on childhood asthma
Authors: Tsai Ching-Hui , Tung Kuan-Yen , Chen Chang-Hao , Lee Yungling L
Published: February 2011

Objectives

Environmental exposure at home, such as dampness, has been shown to have adverse effects on respiratory health. However, few studies explored the association between home dampness and genetic polymorphisms on childhood asthma. The aim of the study is to evaluate the effects of home dampness and tumour necrosis factor-α gene (TNF-α) on asthma in Taiwanese children.

Methods

The authors investigated 3810 schoolchildren in Taiwan Children Health Study from 14 communities. Children's exposure and disease status were measured from a parental questionnaire. Multiple logistic regression models were fitted to estimate the effects of home dampness exposure andTNF-αgenotypes on the prevalence of asthma and wheeze.

Results

Mildewy odour at home was significantly associated with increased prevalence of lifetime wheeze (OR=1.36, 95% CI 1.05 to 1.77, p for trend=0.04). The effects of water stamp on the wall at home were associated with lifetime asthma and lifetime wheeze. Children with water stamp on the wall at home andTNF-308A allele had increased risks on lifetime asthma, active asthma and lifetime wheeze.TNF-αshowed significant interactive effects with mildewy odour on lifetime asthma (p for interaction=0.01), and with water stamp on the wall at home on lifetime wheeze (p for interaction=0.04). Under stratification byTNF-308genotypes, we found that the frequency of water stamp on the wall was associated with increased risks of all asthma subcategories and lifetime wheeze amongTNF-308GA or AA genotypes (p for trend<0.05).

Conclusions

Home dampness is a risk factor for asthma and wheeze among children, especially for those with theTNF-308A allele.
Aldolase directly interacts with ARNO and modulates cell morphology and acidic vesicle distribution
Authors: Merkulova Maria , Hurtado-Lorenzo Andrés , Hosokawa Hiroyuki , Zhuang Zhenjie , Brown Dennis , Ausiello Dennis A. , Marshansky Vladimir
Published: February 2011

Previously, we demonstrated that the vacuolar-type H+-ATPase (V-ATPase) a2-subunit functions as an endosomal pH sensor that interacts with the ADP-ribosylation factor (Arf) guanine nucleotide exchange factor, ARNO. In the present study, we showed that ARNO directly interacts not only with the a2-subunit but with all a-isoforms (a1–a4) of the V-ATPase, indicating a widespread regulatory interaction between V-ATPase and Arf GTPases. We then extended our search for other ARNO effectors that may modulate V-ATPase-dependent vesicular trafficking events and actin cytoskeleton remodeling. Pull-down experiments using cytosol of mouse proximal tubule cells (MTCs) showed that ARNO interacts with aldolase, but not with other enzymes of the glycolytic pathway. Direct interaction of aldolase with the pleckstrin homology domain of ARNO was revealed by pull-down assays using recombinant proteins, and surface plasmon resonance revealed their high avidity interaction with a dissociation constant: KD = 2.84 × 10−10 M. MTC cell fractionation revealed that aldolase is also associated with membranes of early endosomes. Functionally, aldolase knockdown in HeLa cells produced striking morphological changes accompanied by long filamentous cell protrusions and acidic vesicle redistribution. However, the 50% knockdown we achieved did not modulate the acidification capacity of endosomal/lysosomal compartments. Finally, a combination of small interfering RNA knockdown and overexpression revealed that the expression of aldolase is inversely correlated with gelsolin levels in HeLa cells. In summary, we have shown that aldolase forms a complex with ARNO/Arf6 and the V-ATPase and that it may contribute to remodeling of the actin cytoskeleton and/or the trafficking and redistribution of V-ATPase-dependent acidic compartments via a combination of protein-protein interaction and gene expression mechanisms.
Establishment of esophageal-like non-keratinized stratified epithelium using normal human bronchial epithelial cells
Authors: Oshima Tadayuki , Gedda Karin , Koseki Junichi , Chen Xin , Husmark Johanna , Watari Jiro , Miwa Hiroto , Pierrou Stefan
Published: February 2011

Current experimental models of esophageal epithelium in vitro suffer from either poor differentiation or complicated culture systems. We have established a model to study stratified squamous epithelium in vitro, which is very similar to esophageal epithelium in vivo. A stratified squamous multilayer epithelium was formed by seeding primary normal human bronchial epithelial (NHBE) cells onto collagen- and fibronectin-coated trans-well inserts and then cultivating the cells under air-liquid interface (ALI) conditions in the presence of growth factors and low levels of all-trans-retinoic acid. Trans-epithelial electrical resistance (TEER) measurements revealed the presence of a tight barrier, previously only achievable with esophageal biopsies mounted in Ussing chambers. Molecular markers for desmosomes, cornified envelope, tight junctions, and mature esophageal epithelium were upregulated in the differentiating culture in parallel with functional properties, such as decreased permeability and acid resistance and restoration. Acid exposure resulted in a decrease in TEER, but following 1-h recovery the TEER values were fully restored. Treatment with all-trans-retinoic acid decreased TEER and inhibited the recovery after acid challenge. PPAR-delta agonist treatment increased TEER, and this temporary increase in TEER was consistent with an increase in involucrin mRNA. Global gene expression analysis showed that ALI-differentiated NHBE cells had expression profiles more similar to epithelial biopsies from the esophageal tissue of healthy volunteers than to any other cell line. With respect to morphology, molecular markers, barrier properties, and acid resistance, this model presents a new way to investigate barrier properties and the possible effects of different agents on human esophagus-like epithelium.
Episodic ataxia type 1 mutations affect fast inactivation of K+ channels by a reduction in either subunit surface expression or affinity for inactivation domain
Authors: Imbrici Paola , D'Adamo Maria Cristina , Grottesi Alessandro , Biscarini Andrea , Pessia Mauro
Published: February 2011

Episodic ataxia type 1 (EA1) is an autosomal dominant disorder characterized by continuous myokymia and episodic attacks of ataxia. Mutations in the gene KCNA1 that encodes the voltage-gated potassium channel Kv1.1 are responsible for EA1. In several brain areas, Kv1.1 coassembles with Kv1.4, which confers N-type inactivating properties to heteromeric channels. It is therefore likely that the rate of inactivation will be determined by the number of Kv1.4 inactivation particles, as set by the precise subunit stoichiometry. We propose that EA1 mutations affect the rate of N-type inactivation either by reduced subunit surface expression, giving rise to a reduced number of Kv1.1 subunits in heterotetramer Kv1.1-Kv1.4 channels, or by reduced affinity for the Kv1.4 inactivation domain. To test this hypothesis, quantified amounts of mRNA for Kv1.4 or Kv1.1 containing selected EA1 mutations either in the inner vestibule of Kv1.1 on S6 or in the transmembrane regions were injected into Xenopus laevis oocytes and the relative rates of inactivation and stoichiometry were determined. The S6 mutations, V404I and V408A, which had normal surface expression, reduced the rate of inactivation by a decreased affinity for the inactivation domain while the mutations I177N in S1 and E325D in S5, which had reduced subunit surface expression, increased the rate of N-type inactivation due to a stoichiometric increase in the number of Kv1.4 subunits.
Expression of TASK-2 and its upregulation by B cell receptor stimulation in WEHI-231 mouse immature B cells
Authors: Nam Joo Hyun , Shin Dong Hoon , Zheng Haifeng , Lee Dong-Sup , Park Su Jung , Park Kyung Sun , Kim Sung Joon
Published: February 2011

Stimulation of B cell receptors (BCR ligation) induces apoptosis of immature B cells, which is critical to the elimination of self-reactive clones. In the mouse immature B cell line WEHI-231, the authors previously reported two types of background K+ channels with large (∼300 pS, LKbg) and medium (∼100 pS, MKbg) conductance in divalent cation-free conditions. While the authors have recently identified LKbg as TREK-2, the molecular nature of MKbg is unknown yet. In the present study, the authors found that BCR ligation markedly increased the background K+ conductance of WEHI-231. A single-channel study revealed that MKbg activity is increased by BCR ligation and that the biophysical properties (unitary conductance and pH sensitivity) of MKbg are consistent with those of TWIK-related acid-sensitive K+ channel 2 (TASK-2). The expression of TASK-2 and its upregulation by BCR ligation were confirmed by RT-PCR and immunoblot assays in WEHI-231. The BCR ligation-induced increase of K+ current was prevented by calcineurin inhibitors (cyclosporine A or FK506), and also by TASK-2-specific small interfering RNA (siRNA) transfection (si-TASK-2). Furthermore, si-TASK-2 attenuated the apoptosis of WEHI-231 caused by BCR ligation. TASK-2 activity and its mRNA were also confirmed in the primary splenic B cells of mouse. Summarizing, the authors report for the first time the expression of TASK-2 in B cells and surmise that the upregulation of TASK-2 by BCR ligation is associated with the apoptosis of immature B cells.
Renovascular disease, microcirculation, and the progression of renal injury: role of angiogenesis
Authors: Chade Alejandro R.
Published: February 2011

Emerging evidence supports the pivotal role of renal microvascular disease as a determinant of tubulo-interstitial and glomerular fibrosis in chronic kidney disease. An intact microcirculation is vital to restore blood flow to the injured tissues, which is a crucial step to achieve a successful repair response. The purpose of this review is to discuss the impact and mechanisms of the functional and structural changes of the renal microvascular network, as well as the role of these changes in the progression and irreversibility of renal injury. Damage of the renal microcirculation and deterioration of the angiogenic response may constitute early steps in the complex pathways involved in progressive renal injury. There is limited but provocative evidence that stimulation of vascular proliferation and repair may stabilize renal function and slow the progression of renal disease. The feasibility of novel potential therapeutic interventions for stabilizing the renal microvasculature is also discussed. Targeted interventions to enhance endogenous renoprotective mechanisms focused on the microcirculation, such as cell-based therapy or the use of angiogenic cytokines have shown promising results in some experimental and clinical settings.
Second transmembrane domain modulates epithelial sodium channel gating in response to shear stress
Authors: Abi-Antoun Tania , Shi Shujie , Tolino Lindsey A. , Kleyman Thomas R. , Carattino Marcelo D.
Published: February 2011

Na+absorption and K+secretion in the distal segments of the nephron are modulated by the tubular flow rate. Epithelial Na+channels (ENaC), composed of α-, β-, and γ-subunits respond to laminar shear stress (LSS) with an increase in open probability. Higher vertebrates express a δ-ENaC subunit that is functionally related to the α-subunit, while sharing only 35% of sequence identity. We investigated the response of δβγ channels to LSS. Both the time course and magnitude of activation of δβγ channels by LSS were remarkably different from those of αβγ channels. ENaC subunits have similar topology, with an extracellular region connected by two transmembrane domains with intracellular N and C termini. To identify the specific domains that are responsible for the differences in the response to flow of αβγ and δβγ channels, we generated a series of α-δ chimeras and site-specific α-subunit mutants and examined parameters of activation by LSS. We found that specific sites in the region encompassing and just preceding the second transmembrane domain were responsible for the differences in the magnitude and time course of channel activation by LSS.
Regulation of the water channel aquaporin-2 by posttranslational modification
Authors: Moeller Hanne B. , Olesen Emma T. B. , Fenton Robert A.
Published: February 2011

The cellular functions of many eukaryotic membrane proteins, including the vasopressin-regulated water channel aquaporin-2 (AQP2), are regulated by posttranslational modifications. In this article, we discuss the experimental discoveries that have advanced our understanding of how posttranslational modifications affect AQP2 function, especially as they relate to the role of AQP2 in the kidney. We review the most recent data demonstrating that glycosylation and, in particular, phosphorylation and ubiquitination are mechanisms that regulate AQP2 activity, subcellular sorting and distribution, degradation, and protein interactions. From a clinical perspective, posttranslational modification resulting in protein misrouting or degradation may explain certain forms of nephrogenic diabetes insipidus. In addition to providing major insight into the function and dynamics of renal AQP2 regulation, the analysis of AQP2 posttranslational modification may provide general clues as to the role of posttranslational modification for regulation of other membrane proteins.
Impaired muscle phasing systematically adapts to varied relative angular relationships during locomotion in people poststroke
Authors: Alibiglou Laila , Brown David A.
Published: February 2011

After stroke, hemiparesis will result in impairments to locomotor control. Specifically, muscle coordination deficits, in the form of inappropriately phased muscle-activity patterns, occur in both the paretic and nonparetic limbs. These dysfunctional paretic muscle-coordination patterns can adapt to somatosensory inputs, and also the sensorimotor state of nonparetic limb can influence paretic limb. However, the relative contribution of interlimb pathways for improving paretic muscle-activation patterns in terms of phasing remains unknown. In this study, we investigated whether the paretic muscle-activity phasing can be influenced by the relative angular-spatial relationship of the nonparetic limb by using a split-crank ergometer, where the cranks could be decoupled. Eighteen participants with chronic stroke were asked to pedal bilaterally during each task while surface electromyogram signals were recorded bilaterally from four lower extremity muscles (vastus medialis, rectus femoris, tibialis anterior, and soleus). During each experiment, the relative angular crank positions were manipulated by increasing or decreasing their difference by randomly ordered increments of 30° over the complete cycle [0° (in phase pedaling), 30°, 60°, 90°, 120°, 150°, 180° (standard pedaling), 210°, 240°, 270°, 300°, 330° (out of phase pedaling)]. We found that the paretic and nonparetic muscle phasing in the cycle systematically adapted to varied relative angular relationships, and this systematic relationship was well modeled by a sinusoidal relationship. Also, the paretic uniarticular muscle (vastus medialis) showed larger phase shifts compared with biarticular muscle (rectus femoris). More importantly, for each stroke subject, we demonstrated an exclusive crank-angular relation that resulted in the generation of more appropriately phased paretic muscle activity. These findings provide new evidence to better understand the capability of impaired nervous system to produce a more normalized muscle-phasing pattern poststroke.
Unsupervised quantification of whisking and head movement in freely moving rodents
Authors: Perkon Igor , Košir Andrej , Itskov Pavel M. , Tasič Jurij , Diamond Mathew E.
Published: February 2011

The rodent whisker system has become the leading experimental paradigm for the study of active sensing. Thanks to more sophisticated behavioral paradigms, progressively better neurophysiological methods, and improved video hardware/software, there is now the prospect of defining the precise connection between the sensory apparatus and brain activity in awake, exploring animals. Achieving this ambitious goal requires quantitative, objective characterization of head and whisker kinematics. This study presents the methodology and potential uses of a new automated motion analysis routine. The program provides full quantification of head orientation and translation, as well as the angle, frequency, amplitude, and bilateral symmetry of whisking. The system operates without any need for manual tracing by the user. Quantitative comparison to whisker detection by expert humans indicates that the program's correct detection rate is at >95% even on animals with all whiskers intact. Particular attention has been paid to obtaining reliable performance under nonoptimal lighting or video conditions and at frame rates as low as 100. Variation of the zoom across time is compensated for without user intervention. The program adapts automatically to the size and shape of different species. The outcome of our testing indicates that the program can be a valuable tool in quantifying rodent sensorimotor behavior.
Temporal coding of taste in the parabrachial nucleus of the pons of the rat
Authors: Rosen Andrew M. , Victor Jonathan D. , Di Lorenzo Patricia M.
Published: February 2011

Recent studies have provided evidence that temporal coding contributes significantly to encoding taste stimuli at the first central relay for taste, the nucleus of the solitary tract (NTS). However, it is not known whether this coding mechanism is also used at the next synapse in the central taste pathway, the parabrachial nucleus of the pons (PbN). In the present study, electrophysiological responses to taste stimuli (sucrose, NaCl, HCl, and quinine) were recorded from 44 cells in the PbN of anesthetized rats. In 29 cells, the contribution of the temporal characteristics of the response to the discrimination of various taste qualities was assessed. A family of metrics that quantifies the similarity of two spike trains in terms of spike count and spike timing was used. Results showed that spike timing in 14 PbN cells (48%) conveyed a significant amount of information about taste quality, beyond what could be conveyed by spike count alone. In another 14 cells (48%), the rate envelope (time course) of the response contributed significantly more information than spike count alone. Across cells there was a significant correlation ( r = 0.51; P < 0.01) between breadth of tuning and the proportion of information conveyed by temporal dynamics. Comparison with previous data from the NTS (Di Lorenzo PM and Victor JD. J Neurophysiol 90: 1418–31, 2003 and J Neurophysiol 97: 1857–1861, 2007) showed that temporal coding in the NTS occurred in a similar proportion of cells and contributed a similar fraction of the total information at the same average level of temporal precision, even though trial-to-trial variability was higher in the PbN than in the NTS. These data suggest that information about taste quality conveyed by the temporal characteristics of evoked responses is transmitted with high fidelity from the NTS to the PbN.
Systematic mapping of the monkey inferior colliculus reveals enhanced low frequency sound representation
Authors: Bulkin David A. , Groh Jennifer M.
Published: February 2011

We investigated the functional architecture of the inferior colliculus (IC) in rhesus monkeys. We systematically mapped multiunit responses to tonal stimuli and noise in the IC and surrounding tissue of six rhesus macaques, collecting data at evenly placed locations and recording nonresponsive locations to define boundaries. The results show a modest tonotopically organized region (17 of 100 recording penetration locations in 4 of 6 monkeys) surrounded by a large mass of tissue that, although vigorously responsive, showed no clear topographic arrangement (68 of 100 penetration locations). Rather, most cells in these recordings responded best to frequencies at the low end of the macaque auditory range. The remaining 15 (of 100) locations exhibited auditory responses that were not sensitive to sound frequency. Potential anatomical correlates of functionally defined regions and implications for midbrain auditory prosthetic devices are discussed.
Synchronization of presynaptic input to motor units of tongue, inspiratory intercostal, and diaphragm muscles
Authors: Rice Amber , Fuglevand Andrew J. , Laine Christopher M. , Fregosi Ralph F.
Published: February 2011

The respiratory central pattern generator distributes rhythmic excitatory input to phrenic, intercostal, and hypoglossal premotor neurons. The degree to which this input shapes motor neuron activity can vary across respiratory muscles and motor neuron pools. We evaluated the extent to which respiratory drive synchronizes the activation of motor unit pairs in tongue (genioglossus, hyoglossus) and chest-wall (diaphragm, external intercostals) muscles using coherence analysis. This is a frequency domain technique, which characterizes the frequency and relative strength of neural inputs that are common to each of the recorded motor units. We also examined coherence across the two tongue muscles, as our previous work shows that, despite being antagonists, they are strongly coactivated during the inspiratory phase, suggesting that excitatory input from the premotor neurons is distributed broadly throughout the hypoglossal motoneuron pool. All motor unit pairs showed highly correlated activity in the low-frequency range (1–8 Hz), reflecting the fundamental respiratory frequency and its harmonics. Coherence of motor unit pairs recorded either within or across the tongue muscles was similar, consistent with broadly distributed premotor input to the hypoglossal motoneuron pool. Interestingly, motor units from diaphragm and external intercostal muscles showed significantly higher coherence across the 10–20-Hz bandwidth than tongue-muscle units. We propose that the lower coherence in tongue-muscle motor units over this range reflects a larger constellation of presynaptic inputs, which collectively lead to a reduction in the coherence between hypoglossal motoneurons in this frequency band. This, in turn, may reflect the relative simplicity of the respiratory drive to the diaphragm and intercostal muscles, compared with the greater diversity of functions fulfilled by muscles of the tongue.
A Global Approach with Cutoff Exponential Function, Mathematically Well Defined at the Outset, for Calculating the Casimir Energy: The Example of Scalar Field
Authors: Miltão M. S. R. , Farias Franz A.
Published: February 2011

A global approach with cutoff exponential functions is used to obtain the Casimir energy of a massless
scalar field in the presence of a spherical shell. The proposed method, mathematically well defined at the
outset, makes use of two regulators, one of them to make the sum of the orders of Bessel functions finite
and the other to regularize the integral involving the zeros of Bessel function. This procedure ensures a
consistent mathematical handling in the calculations of the Casimir energy and allows a major comprehension
on the regularization process when nontrivial symmetries are under consideration. In particular, we determine
the Casimir energy of a scalar field, showing all kinds of divergences. We consider separately the contributions of the inner and outer regions of a spherical shell and show that the results obtained are in agreement with
those known in the literature, and this gives a confirmation for the consistence of the proposed approach. The
choice of the scalar field was due to its simplicity in terms of physical quantity spin.
Abnormal Curves on the GoursatSystems of Rn
Authors: Cheaito Mohamad H. , Zeineddine Hassan
Published: February 2011

We study the abnormal and the rigid curves of the
2‐distributions of Rn satisfying everywhere the Goursat condition. We give the
directions for the rigid and the abnormal curves when the systems satisfy the
strong Goursat condition or when they have a singularity of order 2 in each
dimension.
Imaging by Magnifying Endoscopy with NBI Implicates the Remnant Capillary Network As an Indication for Endoscopic Resection in Early Colon Cancer
Authors: Saito Shoichi , Tajiri Hisao , Ohya Tomohiko , Nikami Toshiki , Aihara Hiroyuki , Ikegami Masahiro
Published: February 2011

Introduction. This study examined whether magnifying endoscopy with NBI observation (ME-NBI) could be useful selecting the appropriate treatment for submucosal invasive cancer (SM cancer).Patients and Methods. We analyzed 515 cases of colon tumors excised endoscopically or surgically. We classified capillary network pattern into four types according to the degree of dilatation, irregularity, and distribution of microcapillary features.Results. The comparison of capillary pattern and histological features revealed microcapillary networks by using confocal laser-scanning microscopy and ME-NBI in intramucosal lesion or SM cancer with remnant neoplastic glands at the superficial layer. In contrast, the network was absent in SM cancer with desmoplastic reactions, which invaded deeper into the submucosal layer.Conclusions. The remaining microcapillary network is designed to maintain the architecture of neoplastic glands. Consequently, loss of this network could correlate with depth of tumor invasion and desmoplastic reaction. Therefore, we can decide the appropriate treatment by using ME-NBI method.
Lipid Rafts in Mast Cell Biology
Authors: Silveira e Souza Adriana Maria Mariano , Mazucato Vivian Marino , Jamur Maria Célia , Oliver Constance
Published: February 2011

Mast cells have long been recognized to have a direct and critical role in allergic and inflammatory reactions. In allergic diseases, these cells exert both local and systemic responses, including allergic rhinitis and anaphylaxis. Mast cell mediators are also related to many chronic inflammatory conditions. Besides the roles in pathological conditions, the biological functions of mast cells include roles in innate immunity, involvement in host defense mechanisms against parasites, immunomodulation of the immune system, tissue repair, and angiogenesis. Despite their growing significance in physiological and pathological conditions, much still remains to be learned about mast cell biology. This paper presents evidence that lipid rafts or raft components modulate many of the biological processes in mast cells, such as degranulation and endocytosis, play a role in mast cell development and recruitment, and contribute to the overall preservation of mast cell structure and organization.