Isolation and characterization of heat-stable allergens from shrimp (Penaeus indicus)

Shrimp are among the more common causes of immediate hypersensitivity reactions to food. To characterize better the allergenic substances within shrimp, extracts from heated shrimp were systematically examined with solid-phase radioimmunoassay and sera from patients clinically sensitive to shrimp. Two heat-stable protein allergens, designated as Sa-I and Sa-II, were identified from boiled shrimp (Penaeus indicus) extracts. Sa-I was isolated by ultrafiltration, Sephadex G-25, and diethylaminoethyl-Sephacel chromatography, whereas Sa-II, the major allergen, was purified by successive chromatography on diethylaminoethyl-Sephacel, Bio-Gel P-200, and Sepharose 4B columns. Sa-I, which was homogeneous by polyacrylamide gel electrophoresis (PAGE), elicited a single band on sodium dodecyl sulfate-PAGE corresponding to a molecular weight of 8.2 kd. Sa-II was also found to be homogeneous by PAGE, crossed immunoelectrophoresis, and immunoblotting. On sodium dodecyl sulfate-PAGE, it elicited a single band with a molecular weight of 34 kd. Sa-II was found to contain 301 amino acid residues and was particularly rich in glutamate/glutamine and aspartate/asparagine. Solid-phase radioimmunoassay-inhibition studies revealed that Sa-I and Sa-II share 54% of the allergenic epitopes, suggesting that Sa-I may be a fragment of Sa-II.SDS-PAGE, Sodium dodecyl sulfate-polyacrylamide gel electrophoresis; MW, Molecular weight; BSA, Bovine serum albumin; DEAE, Diethylaminoethyl; SPRIA, Solid-phase radioimmunoassay; CIE, Crossed immunoelectrophoresis .

Fin de millénaire eli maailmanlopun satiiri : Frédéric Beigbederin Au secours pardon, Marie Darrieussecqin Truismes ja Michel Houellebecqin La Possibilité d'une île

Pro gradu -työni käsittelee ranskalaisen nykykirjallisuuden yhteiskunnallista suuntausta, jota kirjallisuudentutkija Ruth Cruickshank kutsuu fin de millénaire -kirjallisuudeksi. Tutkimani teokset ovat Frédéric Beigbederin Au secours pardon (2007), Marie Darrieussecqin Truismes (1996) ja Michel Houellebecqin La Possibilité d'une île (2005). Pohdin, millaisena ja millaisin keinoin teokset kuvaavat seksuaalisuutta ja sen tulevaisuudennäkymiä kulutusyhteiskunnassa, ja millaisiin yhteiskunnallisiin olosuhteisiin niiden havainnot perustuvat. Hahmottelen reittejä, joita pitkin globaalin mittakaavan yhteiskunnalliset muutokset vaikuttavat ihmisten intiimeihin tunteisiin ja ihmissuhteisiin. Seksuaalisuuden tarkastelun avulla osoitan, että ranskalaisessa nykykirjallisuudessa ilmenee varsin yhteneviä näkemyksiä ja uhkakuvia aikamme sosiaalisesta todellisuudesta. Tällä tavoin tarkennan ja vankennan vielä hajanaista fin de millénaire -käsitettä. Fin de millénaire -kirjallisuuden oma lajityyppi on massakulttuurin, esimerkiksi viihteen ja mainosten, kielestä vaikutteita ammentava dystopian ja satiirin liitto. Kuten Cruickshank kirjoittaa, fin de millénaire -kirjallisuus heijastaa Ranskassa vuosituhannen vaihteessa korostunutta tunnetta käännekohtaan saapumisesta. Dystopian ohella voidaankin puhua myös apokalyptisesta tekstistä, etenkin siksi, että teokset tarjoavat niukasti ratkaisuja kuvaamiinsa ongelmiin. Eritoten Houellebecqin ja Beigbederin teokset käsittelevät tarpeiden luomista kuluttajille seksuaalivietin ja seksuaalisen kilpailun avulla. Kutsun tätä järjestelmää halutaloudeksi, ja käytän sen toiminnan analysoimisessa apuna Michel Foucault'n käsityksiä vallasta ja Jean Baudrillardin käsityksiä kulutusyhteiskunnasta. Halutalouden sosiaalisia seurauksia ovat vieraantuminen, seksuaalisten hierarkioiden jyrkentyminen ja valinnanvapauden kaventuminen. Teosten kuvaamassa yhteiskunnassa erilaiset esimerkiksi sukupuolen, iän ja ulkonäön perusteella rakentuvat seksuaaliset hierarkiat käyvät yhä merkittävämmiksi. Au secours pardon ja La Possibilité d'une île kuvaavat tapahtumaketjua, jossa etenkin heteromiehistä yhä useampi luisuu seksuaaliseen kurjuuteen muun muassa naisten emansipaation sekä yleisen nuoruuden ja kauneuden palvonnan myötä. Truismesissa taas kuvitellaan yhteiskunta, johon feminismi ei ole päässyt vaikuttamaan mutta pornoistuminen on; naisten ruumiista on tullut miesten yhteistä omaisuutta ja seksuaalinen väkivalta on arkipäivää. Sen maailmassa viehättävä ulkonäkö on naisille miltei elinehto. Yleistäen Houellebecqin ja Beigbederin teokset edustavat miesnäkökulmaa ja Darrieussecqin teos naisnäkökulmaa. Teosten näkemyksiä naisten ja miesten välisistä valtasuhteista pohdin naisten seksuaalisesta vallasta kirjoittaneen Henry Laasasen käyttökelpoisten käsitteiden avulla. Kolmea teosta yhdistävät kuvaukset kulttuurista, jossa ihmissuhteet ovat kaupankäyntiä ja seksuaalinen viehätysvoima määrittelee ihmisen arvon. Darrieussecqin teos on lähitulevaisuuteen sijoittuva dystopia, jossa Beigbederin ja Houellebecqin kuvaama arvoliberalismia ja taloudellista liberalismia yhdistävä kulttuuri on vaihtunut uuskonservatiiviseen ja kaksinaismoralistiseen, naisia räikeästi sortavaan yhteiskuntaan. Teoksen kertoja vähättelee itseensä kohdistuvia koskemattomuuden loukkauksia ja pahoittelee kertomuksensa käänteiden säädyttömyyttä varsinkin kuvatessaan omaa haluaan ja seksuaalista subjektiuttaan. Katson teoksen kritisoivan kirjallisuudentutkija Shirley Ann Jordanin termein poliittisen korrektiuden tyranniaa ja peräänkuuluttavan suoraa puhetta pornografiasta ja naisen halusta. Seksuaalisuus toimii tutkimuksessani lähtökohtana, jonka avulla teoksista nousee esiin julma ja rakkaudeton, säälimättömän kilpailun ja väkivallan täyttämä yhteiskunta. Viime kädessä teosten kuvaama maailmanloppu on se, että rakkaus katoaa ihmisten välisistä suhteista, koska rakkaudessa ei ole voiton tavoittelun kannalta mitään järkeä. Satiirin keinojen, kuten päättymättömän ja monikerroksisen ironian, yhdistyminen dystopiaan pelastaa teokset osoittelevalta moralisoinnilta ja tekee niistä toimivaa yhteiskunnallista kirjallisuutta.

Mechanism of interaction of O-amino-D-serine with sheep liver serine hydroxymethyltransferase

The mechanism of interaction of 0-amino-D-serine (OADS) with sheep liver serine hydroxymethyltransferase (EC 2.1.2.1) (SHMT) was established by measuring changes in the enzyme activity,absorption spectra, circular dichroism (CD) spectra, and stopped-flow spectrophotometry. OADS was a reversible noncompetitive inhibitor (Ki = 1.8 pM) when serine was the varied substrate. The first step in the interaction of OADS with the enzyme was the disruption of enzyme-Schiff base, characterized by the rapid disappearance of absorbance at 425 nm (6.5 X lo3 M-' s-') and CD intensity at 430 nm. Concomitantly,there was a rapid increase in absorbance and CD intensity at 390 nm. The spectral properties of this intermediate enabled its identification as pyridoxal 5'-phosphate (PLP). These changes were followed by a slow unimolecular step (2 X s-') leading to the formation of PLP-OADS oxime, which was confirmed by its absorbance and fluorescence spectra and retention time on high-performance liquid chromatography. The PLP-OADS oxime was displaced from the enzyme by the addition of PLP as evidenced by the restoration of complete enzyme activity as well as by the spectral properties. The unique feature of the mechanism proposed for the interaction of OADS with sheep liver SHMT was the formation of PLP as an intermediate.

Search on a hypercubic lattice using a quantum random walk. I. d > 2

Random walks describe diffusion processes, where movement at every time step is restricted to only the neighboring locations. We construct a quantum random walk algorithm, based on discretization of the Dirac evolution operator inspired by staggered lattice fermions. We use it to investigate the spatial search problem, that is, to find a marked vertex on a d-dimensional hypercubic lattice. The restriction on movement hardly matters for d > 2, and scaling behavior close to Grover's optimal algorithm (which has no restriction on movement) can be achieved. Using numerical simulations, we optimize the proportionality constants of the scaling behavior, and demonstrate the approach to that for Grover's algorithm (equivalent to the mean-field theory or the d -> infinity limit). In particular, the scaling behavior for d = 3 is only about 25% higher than the optimal d -> infinity value.

Search on a hypercubic lattice using a quantum random walk. II. d = 2

We investigate the spatial search problem on the two-dimensional square lattice, using the Dirac evolution operator discretized according to the staggered lattice fermion formalism. d = 2 is the critical dimension for the spatial search problem, where infrared divergence of the evolution operator leads to logarithmic factors in the scaling behavior. As a result, the construction used in our accompanying article A. Patel and M. A. Rahaman, Phys. Rev. A 82, 032330 (2010)] provides an O(root N ln N) algorithm, which is not optimal. The scaling behavior can be improved to O(root N ln N) by cleverly controlling the massless Dirac evolution operator by an ancilla qubit, as proposed by Tulsi Phys. Rev. A 78, 012310 (2008)]. We reinterpret the ancilla control as introduction of an effective mass at the marked vertex, and optimize the proportionality constants of the scaling behavior of the algorithm by numerically tuning the parameters.

Eigenvalues of kinematical conservation laws (KCL) based 3-D weakly nonlinear ray theory (WNLRT)

System of kinematical conservation laws (KCL) govern evolution of a curve in a plane or a surface in space, even if the curve or the surface has singularities on it. In our recent publication K. R. Arun, P. Prasad, 3-D kinematical conservation laws (KCL): evolution of a surface in R-3-in particular propagation of a nonlinear wavefront, Wave Motion 46 (2009) 293-311] we have developed a mathematical theory to study the successive positions and geometry of a 3-D weakly nonlinear wavefront by adding an energy transport equation to KCL. The 7 x 7 system of equations of this KCL based 3-D weakly nonlinear ray theory (WNLRT) is quite complex and explicit expressions for its two nonzero eigenvalues could not be obtained before. In this short note, we use two different methods: (i) the equivalence of KCL and ray equations and (ii) the transformation of surface coordinates, to derive the same exact expressions for these eigenvalues. The explicit expressions for nonzero eigenvalues are important also for checking stability of any numerical scheme to solve 3-D WNLRT. (C) 2010 Elsevier Inc. All rights reserved.

Enhanced Pair Hydrophobicity in the Water-Dimethylsulfoxide (DMSO) Binary Mixture at Low DMSO Concentrations

We observe a surprisingly sharp increase in the pair hydrophobicity in the water climethylsulfoxide (DMSO) binary mixture at small DMSO concentrations, with the mole fraction of DMSO (x(D)) in the range 0.12-0.16. The increase in pair hydrophobicity is measured by an increase in the depth of the first minimum in the potential of mean force (PMF) between two methane molecules. However, this enhanced hydrophobicity again weakens at higher DMSO concentrations. We find markedly unusual behavior of the pure binary mixture (in the same composition range) in the diffusion coefficient of DMSO and in the local composition fluctuation of water, We find that, in the said composition range, the average coordination number of the methyl groups (of distinct DMSO) varies between 2.4 and 2.6, indicating the onset of the formation of a chain-like extended connectivity in an otherwise stable tetrahedral network comprising of water and DMSO molecules. We propose that the enhanced pair hydrophobicity of the binary mixture at low DMSO concentrations is due to the participation of the two methane molecules in the local structural order and the emerging molecular associations in the water-DMSO mixture.

N-2-(4-Methyl-2-quinolyl)phenyl]acetamide: a P1 structure with Z=4

The title compound, C18H16N2O, crystallizes in the triclinic space group P1, with four independent molecules in the asymmetric unit wherein two molecules have an irregular -ac, -ac, +ap conformation (ap, antiperiplanar; ac, anticlinal), while the other molecules exhibit a different, +ac, +ac, +ap conformation. The planar (r.m.s. deviation = 0.006 A in each of the four molecules) quinoline ring systems of the four molecules are oriented at dihedral angles of 32.8 (2), 33.4 (2), 31.7 (2) and 32.3 (2)degrees with respect to the benzene rings. Intramolecular N-H...N interactions occur in all four independent molecules. The crystal packing is stabilized by intermolecular N-H...O and C-H...O hydrogen bonds, and are further consolidated by C-H...pi and pi-pi stacking interactions centroid-centroid distances = 3.728 (3), 3.722 (3), 3.758 (3) and 3.705 (3) A].

A helical peptide containing a majority of valyl residues. The crystal structure of t-butyloxy- carbonyl-(L-valyl-_-aminoisobutyryl)3-L-valyl methyl ester onohydrate

The monohydrate of the heptapeptide t-butyloxycarbonyl-(L-valyl-α-aminoiso-butyryl)3-L-valyl methyl ester crystallizes in the orthorhombic space group P212121 with four molecules in a unit cell with the dimensions α= 9.375, b = 19.413 and c = 25.878 ÅA. The structure has been solved by direct methods and refined to an R value of 0.059 for 3633 observed reflections. The molecule in the structure exists as a slightly distorted 310-helix stabilized by five 4 -> 1 intramolecular hydrogen bonds, indicating the overwhelming influence of α-aminoisobutyryl (Aib) residues in dictating helical fold even when a majority of residues in the peptide have a low intrinsic propensity to be in helices. Contrary to what is expected in helical structures, the valyl side chains, two of which are disordered, exhibit all three possible conformations. The molecules arrange themselves in a head-to-tail fashion along the c-axis. The columns thus generated pack nearly hexagonally in the crystal.

Non-enzymatic Degradation of (1→3)(1→4)-β-D-glucan in Aqueous Processing of Oats

Cereal water-soluble β-glucan [(1→3)(1→4)-β-D-glucan] has well-evidenced health benefits and it contributes to the texture properties of foods. These functions are characteristically dependent on the excellent viscosity forming ability of this cell wall polysaccharide. The viscosity is affected by the molar mass, solubility and conformation of β-glucan molecule, which are further known to be altered during food processing. This study focused on demonstrating the degradation of β-glucan in water solutions following the addition of ascorbic acid, during heat treatments or high pressure homogenisation. Furthermore, the motivation of this study was in the non-enzymatic degradation mechanisms, particularly in oxidative cleavage via hydroxyl radicals. The addition of ascorbic acid at food-related concentrations (2-50 mM), autoclaving (120°C) treatments, and high pressure homogenisation (300-1000 bar) considerably cleaved the β-glucan chains, determined as a steep decrease in the viscosity of β-glucan solutions and decrease in the molar mass of β-glucan. The cleavage was more intense in a solution of native β-glucan with co-extracted compounds than in a solution of highly purified β-glucan. Despite the clear and immediate process-related degradation, β-glucan was less sensitive to these treatments compared to other water-soluble polysaccharides previously reported in the literature. In particular, the highly purified β-glucan was relatively resistant to the autoclaving treatments without the addition of ferrous ions. The formation of highly oxidative free radicals was detected at the elevated temperatures, and the formation was considerably accelerated by added ferrous ions. Also ascorbic acid pronounced the formation of these oxidative radicals, and oxygen was simultaneously consumed by ascorbic acid addition and by heating the β-glucan solutions. These results demonstrated the occurrence of oxidative reactions, most likely the metal catalysed Fenton-like reactions, in the β-glucan solutions during these processes. Furthermore, oxidized functional groups (carbonyls) were formed along the β-glucan chain by the treatments, including high pressure homogenisation, evidencing the oxidation of β-glucan by these treatments. The degradative forces acting on the particles in the high pressure homogenisation are generally considered to be the mechanical shear, but as shown here, carbohydrates are also easily degraded during the process, and oxidation may have a role in the modification of polysaccharides by this technique. In the present study, oat β-glucan was demonstrated to be susceptible to degradation during aqueous processing by non-enzymatic degradation mechanisms. Oxidation was for the first time shown to be a highly relevant degradation mechanism of β-glucan in food processing.

Vibrational Spectra and Normal Coordinate Analysis of N-Methyl Thiourea

The infrared spectra of N-methylthiourea (NMTU) and its N-deuterated and S-methylated species were measured. Assignment of the infrared and Raman spectra of NMTU has been accomplished by correlation with thiourea and by use of infrared band shifts on N-deuteration as well as S-methylation. Normal coordinate analysis was performed for all the fundamentals of NMTU and NMTU-d3, the assignments obtained from the force field calculations being discussed in relation to those in other related thioureas and thioamides. The potential barriers to the internal rotations for the �NH2, �CH3, and �CN groups were estimated from the force constants.