Role of oxoproline in the regulation of neutral amino acid transport across the blood-brain barrier.

1996

Regulation of neutral amino acid transport was studied using isolated plasma membrane vesicles derived from the bovine blood-brain barrier. Neutral amino acids cross the blood-brain barrier by facilitative transport system L1, which may allow both desirable and undesirable amino acids to enter the brain. The sodium-dependent amino acid systems A and Bo,+ are located exclusively on abluminal membranes, in a position to pump unwanted amino acids out. gamma-Glutamyl transpeptidase, the first enzyme of the gamma-glutamyl cycle, is an integral protein of the luminal membrane of the blood-brain barrier. We demonstrate that oxoproline, an intracellular product of the gamma-glutamyl cycle, stimulat…

Oil-Water Interface Templating of Mesoporous Macroscale Structures

1996

Ordered mesostructured porous silicas that are also macroscopically structured were created by control of the interface on two different length scales simultaneously. Micellar arrays controlled the nanometer-scale assembly, and at the static boundary between an aqueous phase and an organic phase, control was achieved on the micrometer to centimeter scale. Acid-prepared mesostructures of silica were made with the p6, Pm3n, and the P63/mmc structures in the form of porous fibers 50 to 1000 micrometers in length, hollow spheres with diameters of 1 to 100 micrometers, and thin sheets up to 10 centimeters in diameter and about 10 to 500 micrometers in thickness. These results might have implicat…

Quasielastic K-nucleus scattering

1996

Quasielastic K^+ - nucleus scattering data at q=290, 390 and 480 MeV/c are analyzed in a finite nucleus continuum random phase approximation framework, using a density-dependent particle-hole interaction. The reaction mechanism is consistently treated according to Glauber theory, keeping up to two-step inelastic processes. A good description of the data is achieved, also providing a useful constraint on the strength of the effective particle-hole interaction in the scalar-isoscalar channel at intermediate momentum transfers. We find no evidence for the increase in the effective number of nucleons participating in the reaction which has been reported in the literature.

Spatially chaotic configurations and functional equations with rescaling

1996

The functional equation is associated with the appearance of spatially chaotic structures in amorphous (glassy) materials. Continuous compactly supported solutions of the above equation are of special interest. We shall show that there are no such solutions for , whereas such a solution exists for almost all . The words `for almost all q' in the previous sentence cannot be omitted. There are exceptional values of q in the interval for which there are no integrable solutions. For example, , which is the reciprocal of the `golden ratio' is such an exceptional value. More generally, if is any Pisot - Vijayaraghavan number, or any Salem number, then is an exceptional value.

Coordinate-free quantization of first-class constrained systems

1996

The coordinate-free formulation of canonical quantization, achieved by a flat-space Brownian motion regularization of phase-space path integrals, is extended to a special class of closed first-class constrained systems that is broad enough to include Yang-Mills type theories with an arbitrary compact gauge group. Central to this extension are the use of coherent state path integrals and of Lagrange multiplier integrations that engender projection operators onto the subspace of gauge invariant states.

Multimode equivalent network representation for planar junctions involving elliptical waveguides

1996

Structure of the phenylalanine hydroxylase gene in Drosophila melanogaster and evidence of alternative promoter usage.

1996

The complete Drosophila melanogaster phenylalanine hydroxylase gene isolated from a genomic library was sequenced. Gene structure consisted of five exons covering a region of around 3 kb. Position of introns in the C-terminal domain was conserved with mammalian aromatic amino acid hydroxylase genes. Putative promoter sequences in the 5'UTR and intron 1 were identified. A novel transcript was detected differing from that previously reported by the inclusion of a part of the intron 1 sequence. It could be produced using an alternative promoter. The deduced open reading frame would code a protein with a small difference at the N-terminus. Expression of the alternative transcripts was examined …

Single-Neutron States inS133n

1996

The location of several single-neutron states in ${}^{133}\mathrm{Sn}$ has been identified. The ${p}_{3/2}$, ${h}_{9/2}$, and ${f}_{5/2}$ states were found at 853.7, 1560.9, and 2004.6 keV, respectively, by measuring $\ensuremath{\gamma}$ rays in coincidence with delayed neutrons following the decay of ${}^{134}\mathrm{In}$. Crucial for obtaining the new data were the improved yields at the mass-separator facility ISOLDE-PSB at CERN. A semiempirically adjusted Woods-Saxon calculation, based on parameters from the Pb region and normalized on the mass data at ${}^{132}\mathrm{Sn}$, reproduces the new single particle energies with good precision.

Recombinant hirudin as a periprocedural antithrombotic in coronary angioplasty for unstable angina pectoris

1996

Percutaneous transluminal coronary angioplasty is often complicated by thrombotic abrupt vessel closure in patients with unstable angina pectoris. The present multicentre trial was performed to determine the feasibility of two-dose regimens of recombinant hirudin (r-hirudin) compared to standard heparin in patients undergoing coronary angioplasty for unstable angina, and to investigate the effects of the different treatment regimen on markers of coagulation activation. At five participating centres, 61 patients were randomly enrolled in one of two sequential groups of r-hirudin (group 1: 0.3 mg.kg-1 i.v. bolus, 0.12 mg.kg-1.h-1 i.v. infusion; 21 patients; group 2: 0.5 mg.kg-1 i.v. bolus, 0.…

Core Histones Are Glutaminyl Substrates for Tissue Transglutaminase

1996

Chicken erythrocyte core histones are glutaminyl substrates in the transglutaminase (TGase) reaction with monodansylcadaverine (DNC) as donor amine. The modification is very fast when compared with that of many native substrates of TGase. Out of the 18 glutamines of the four histones, nine (namely glutamine 95 of H2B; glutamines 5, 19, and 125 of H3; glutamines 27 and 93 of H4; and glutamines 24, 104, and 112 of H2A) are the amine acceptors in free histones. The use of Gln112 of H2A requires a temperature-dependent partial unfolding of the histone, showing that structural determinants are decisive for the glutamine specificity. The structures of H2A and H2B do not appreciably change upon mo…

Virtual versus real nuclear Compton scattering in the Delta(1232) region

1996

[EN] In this paper we calculate the cross section for Virtual Compton Scattering off nuclei in the delta resonance region. We also calculate the background for the process from Coherent Bremsstrahlung in nuclei and explore the regions where the Virtual Compton Scattering cross section dominates. The study also shows that it is possible to extract the cross section for Real Compton Scattering from the Virtual Compton one in a wide range of scattering angles.

Angiographic follow-up results of a randomized study on angioplasty versus bypass surgery (GABI Trial)

1996

Although several randomized trials have been performed to compare the outcomes of percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass surgery (CABG) in patients with multivessel disease, there is little data available on angiographic follow-up results. The present substudy of the German angioplasty versus bypass surgery investigation (GABI Trial) compares the angiographic revascularization status in these two cases 6 months after treatment. Follow-up angiograms were available in 102 CABG patients and 117 PTCA patients. Although the protocol excluded patients with total occlusion, on follow-up 6 months after treatment we found total occlusion of 94 native arterie…

Tenascin in denervated human muscle

1996

Tenascin is a large oligomeric glycoprotein of the extracellular matrix. Its location is limited in innervated muscle tissues. We investigated immunohistologically, using two monoclonal antibodies (mab) against Tenascin, biopsied denervated human muscle of children and adults. Tenascin was present in the interstitial space among denervated muscle fibres. Accumulation of Tenascin in denervated adult muscle tissue was frequent, accumulation in denervated muscle tissue of children was sparse and weak. The two antibodies reacted correspondingly. Tenascin was not only found in the vicinity of atrophic muscle fibres, but also close to normally sized fibres, suggesting an early stage of denervatio…

Influence of the terminal complement-complex on reperfusion injury, no-reflow and arrhythmias: a comparison between C6-competent and C6-deficient rab…

1996

Objective: The complement system has been suggested to play a role in reperfusion injury which may result from an enhanced destruction of myocardial tissue or from an impairment of reflow. We investigated the influence of the C5b-9 complement complex on infarct size, reflow and arrhythmogenesis. Methods: Twenty-eight C6-competent rabbits and 18 rabbits with congenital C6 deficiency were subjected to either 30 min or 2 h of coronary artery occlusion followed by reperfusion. C6 deficiency was confirmed by the complement titration test and immunohistology. The triphenyl tetrazolium chloride method was used to delineate infarct size. Reflow into infarcted areas was evaluated histologically afte…

Direct Solid Phase Microextraction for the Determination of BTEX in Water and Wastewater

1996

Heat shock protein-peptide complexes for use in vaccines

1996

Abstract The heat shock proteins gp96, HSP70, and HSP90 are complexed to a diverse array of cellular proteins and peptides as a consequence of their chaperone functions. There is good experimental evidence that vaccination with these heat shock protein-peptide complexes elicit immune responses against chaperoned peptide antigens. As shown with gp96, this requires internalization of the heat shock protein-peptide complexes by macrophages and processing of the chaperoned peptides for class I restricted presentation. Via this process, primarily CD8+ antigen-specific T cells are primed by gp96 vaccination. This might represent a general mechanism for priming of MHC-class I restricted T cells by…

IgA antiendomysial antibodies on the umbilical cord in diagnosing celiac disease. Sensitivity, specificity, and comparative evaluation with the tradi…

1996

The possibility of assaying antiendomysial antibodies (EmA) on the human umbilical cord instead of monkey esophagus has recently been suggested. We therefore evaluated in patients with celiac disease (CD) the sensitivity and specificity of EmA and of antigliadin antibodies (AGA) for both umbilical cord and monkey esophagus.We studied 36 patients with CD and atrophy of the intestinal mucosa (median age, 1.4 years), 14 patients with CD on gluten-free diet for 8-12 months (median age, 3.0 years), 36 controls without gastrointestinal disease (median age, 4.0 years), and 72 patients with cow's milk protein enteropathy (CMPE) (median age, 1.2 years). AGA and EmA on monkey esophagus were assayed w…

Isomorphous ion substitutions and order-disorder phenomena in highly electrocaloric lead-scandium tantalate solid solutions

1996

Abstract The authors discuss the physical background of the electrocaloric effect in PST ceramics and its solid solutions. The most important contribution to the electrocaloric effect is due to field-induced Fm3m→R3m phase transition in the case of high long range ordering degree of B-ions in the perovskite structure ABO3.

Effects of Tributyltin(IV) Chloride Exposure on Larvae ofCiona intestinalis (Urochordata): An Ultrastructural Study

1996

The effects of tributyltin(IV) chloride (TBT chloride) have been tested on embryos of the ascidian Ciona intestinalis, at two different stages of development: (1) before hatching (coiled larval stage) and (2) 2 h after hatching (swimming larval stage). In vivo observations carried out with a light microscope showed that embryos at the coiled larval stage did not hatch following exposure to TBT chloride. Severe anomalies in the swimming larva, mainly concerning the morphology of the tail, which appeared twisted and squatter than in the controls, were observed. Such anomalies were also found at a functional level, i.e. contractile movements were poor so that the larvae appeared motionless. Ul…

Linked amido-indenyl complexes of titanium

1996

Abstract Titanium complexes Ti( η 5 : η 1 -C 9 H 6 SiMe 2 NCMe 3 )X 2 (X = Cl, Me, CH 2 SiMe 3 , CH 2 Ph) containing the tert -amino-functionalized indenyl ligand C 9 H 6 SiMe 3 NCMe 3 have been synthesized by the reaction of the dilithium derivative Li 2 [C 9 H 6 SiMe 2 NCMe 3 ] with TiCl 3 (THF) 3 followed by oxidation or by the alkylation of the dichloro derivative. Unexpectedly, the reaction of C 9 H 6 (SiMe 3 )(SiMe 2 Cl) with TiCl 4 does not give Ti( η 5 -C 9 H 6 SiMe 2 Cl)Cl 3 .

Environmental Radioactivity and Volcanological Features of Three Islands of the Mediterranean Sea (Pantelleria, Ustica and Vulcano)

1996

Abstract The Mediterranean Sea is an area of great interest for its volcanic activities. This paper presents a comparative study of radiometric and chemical data regarding three volcanic islands located in southern Italy (Pantellena, Ustica, and Vulcano) characterized by different magmatic histories. Measurements of radionulide contents and chemical composition of rock samples belonging to the main lithologies present in the three islands were carried out the observed correlations among radiometric, chemical and mineralogical data reflect the differences in the volcanological genesis and suggest some hypotheses on the magmatic evolution.

Site-selective luminescence study of defects. in gamma-irradiated glassy germanium dioxide

1996

Abstract Luminescence of γ-irradiated samples of GeO2 glass was studied using dye laser excitation in the wavelength region between 590 and 656 nm. An inhomogeneously broadened luminescence band with a peak around 1.86 eV, halfwidth of 0.16 eV and decay constant τ ≈ 5.1 μs was found. At temperatures below 20 K a resonance ZPL and a vibronic peak 710 cm−1 below the laser photon energy emerge when laser is tuned to energies between 1.95–1.89 eV. The site-selective luminescence spectra are qualitatively similar to those of the non-bridging oxygen hole center (NBOHC) in SiO2 glass and are attributed to NBOHC in glassy GeO2. The measured ratio between the energies of the observed local vibration…

A barley (Hordeum vulgare L.) LEA3 protein, HVA1, is abundant in protein storage vacuoles

1996

The HVA1 protein belongs to the LEA3 group, which is expressed during the late stage of seed maturation. It is also induced by exogenous abscisic acid (ABA) and a variety of environmental stresses in germinating barley (Hordeum vulgare L.). In the present work, the potential role of HVA1 was investigated by studying its tissue distribution and subcellular localization in mature and stressed seeds by immuno-microscopic methods. In the mature seed, HVA1 protein was detected in all tissues except the non-living starchy endosperm. During germination the amount of HVA1 protein decreased but did not totally disappear. Incubation with 100 μM ABA, cold treatment or drought stress dramatically incre…

Determination of knee joint cartilage thickness using three-dimensional magnetic resonance chondro-crassometry (3D MR-CCM)

1996

The objective of this article was to analyze the accuracy and precision with which the quantitative distribution of articular cartilage can be determined in the knee joint using MRI. A three-dimensional (3D) technique that accounts for the out-of-plane deviation of the interface normal in strongly curved joint surfaces (3D MR-CCM) has been developed for cartilage thickness measurements. Eight cadaveric knee-joint specimens and six volunteers were imaged using a fat-suppressed gradient-echo sequence at a resolution of 2 x 0.31 x 0.31 mm3. Cartilage volumes and topographical thickness maps were obtained and compared with those derived from anatomical sections by image analysis. The deviation …

Effects of pentachlorophenol in forest soil: a microcosm experiment for testing ecosystem responses to anthropogenic stress

1996

Changes in the structure and function of a soil decomposer community and growth of birch (Betula pendula) due to chemical contamination were studied in laboratory microcosms. Sodium pentachlorophenate (PCP) was added to the humus layer of a simulated forest soil at three nominal concentrations (0, 50 and 500 mg kg-1 dry mass). After two growing periods (48 weeks), there were more small soft-bodied mites, but less collembolans and microbial biomass, in the higher PCP concentration treatment than in the other treatments. Number of enchytraeids were significantly reduced and fungal-feeding nematodes became extinct in the soil with the higher PCP concentration. Soil respiration did not change d…

Influence of Molar Mass Distribution on the Compatibility of Polymers

1996

Abstract Phase equilibria were calculated by means of a new method (direct minimization of the Gibbs energy of mixing) for polymer blends consisting of monodisperse polymer A and polydisperse polymer B. The results obtained for a Schulz-Flory distribution of B (molecular nonuniformity U = (M w/M n) −1 = 1 and 100 components of model B) agree quantitatively with that of computations on the basis of continuous thermodynamics. The influence of U B on the miscibility of A and B in 1:1 mixtures was studied for constant M w of B, quantifying the incompatibility of the polymers by the length of the tie lines. The outcome of these calculations demonstrates that the typical effect of an augmentation…

Quantization of Poisson Lie Groups and Applications

1996

LetG be a connected Poisson-Lie group. We discuss aspects of the question of Drinfel'd:can G be quantized? and give some answers. WhenG is semisimple (a case where the answer isyes), we introduce quantizable Poisson subalgebras ofC ∞(G), related to harmonic analysis onG; they are a generalization of F.R.T. models of quantum groups, and provide new examples of quantized Poisson algebras.

Numerical analysis of thermally induced optical nonlinearity in GaSe layered crystal

1996

A numerical approach to studying thermally induced optical nonlinearity in semiconductors is presented. A transient finite difference algorithm is applied to solve the thermal diffusion equation coupled with the nonlinear absorbance-transmittance of Au/GaSe/Au samples with an applied electric field. The presented analysis can deal with any arbitrary axisymmetric dependence of the input power over the sample and external electric field, and provides information about the steady state and transitory effects in the transmittance.

Oxidative metabolism in a rat hepatoma (N13) and isolated rat hepatocytes: A flow cytometric comparative study

1996

Recently, we have developed a new and fast kinetic method for assessing mitochondrial membrane potential by flow cytometry, based on the quantitation of the initial rate of rhodamine 123 (Rh123) uptake by living cells. This test has proved suitable to detect metabolic and toxic effects on mitochondria. To characterize energy metabolism in a rat hepatoma cell line (N13), we applied this method to assess several metabolic pathways that eventually generate mitochondrial membrane potential. Using this approach, we found that N13 hepatoma cells retain an oxidative capacity comparable with that observed in isolated hepatocytes under the same conditions. These results show that this cell line may …

MORPHOLOGY AND DEVELOPMENT OF SELECTED BADLANDS IN SOUTHEAST SPAIN: IMPLICATIONS OF CLIMATIC CHANGE

1996

Four areas were selected to represent a range of processes characteristic of badland surfaces in southeast Spain: Petrer and Monnegre in Alicante, Vera and Tabernas in Almeria. At Petrer, rilling and swelling processes produce a deeply cracked surface drained by a finely textured network of shallow rills. At Monnegre, piping and rilling are differentially developed on slopes ultimately controlled by basal incision. At Vera, aspect-controlled lichen and vegetation cover produce a sequence of badland development within which the relative importance of piping, mass movement and rilling varies through the sequence. At Tabernas, simple overland flow is the dominant process, but aspect influences…

Nuclear magnetic resonance imaging of airways in humans with use of hyperpolarized3He

1996

The nuclear spin polarization of noble gases can be enhanced strongly by laser optical pumping followed by electron-nuclear polarization transfer. Direct optical pumping of metastable 3He atoms has been shown to produce enormous polarization on the order of 0.4-0.6. This is about 105 times larger than the polarization of water protons at thermal equilibrium used in conventional MRI. We demonstrate that hyperpolarized 3 He gas can be applied to nuclear magnetic resonance imaging of organs with air-filled spaces in humans. In vivo 3 He MR experiments were performed in a whole-body MR scanner with a superconducting magnet ramped down to 0.8 T. Anatomical details of the upper respiratory tract …

Spin resolved photoemission study of Co(0001) films

1996

Abstract Thin ferromagnetic films are of great practical interest as they can exhibit a different magnetic behaviour compared to the bulk crystals due to, e.g., the surface anisotropy. The electronic and magnetic properties of thin cobalt films evaporated on W(110) have been investigated by means of angle and spin resolving photoelectron spectroscopy. The study was focused on electron spin polarization, spin resolved intensities and band structure behaviour in dependence of film thickness, excitation energy, and photoelectron detection angle. In order to interpret the experimental results, we have performed relativistic band structure calculations for the Co(0001) surface. The observed agre…

Prognostic significance of c-erB-2 mRNA in ovarian carcinoma.

1996

The oncogene specific mRNA of c-erbB-2 was detected by the S1 nuclease protection assay in 95 ovarian cancer specimens. In 79 primary carcinomas, we found 16 (20%) with strong expression, 13 (17%) with weak expression, 4 (5%) with very weak expression, and 46 (58%) with no expression. In 3 of 16 recurrencies (19%) a strong expression of c-erbB-2 mRNA was detected, in 2 (12%) weak expression was detected, and in 11 (69%) no expression of c-erbB-2 mRNA was detected. Kaplan-Meier analysis revealed no significant association between strong expression of c-erbB-2 mRNA and survival of the 79 patients with primary cancer. However, in the subgroup of patients with FIGO (International Federation of …

Synthesis of a polystyrene-arm-polybutadiene-arm-poly(methyl methacrylate) triarm star copolymer

1996

The straightforward synthesis of a polystyrene-arm-polybutadiene-arm-poly(methyl methacrylate) triarm star copolymer has been successfully realized by a sequence of reactions which involves the sequential addition of a living polybutadienyllithium to a polystyrene macromonomer with a terminal 1,1-diphenylethylene unit and subsequent polymerization of methyl methacrylate. The high-molecular-weight polystyrene-arm-polybutadiene-arm-poly(methyl methacrylate) star copolymer shows microphase separation into three phases.

Extraction of benzaldehyde from fermentation broth by pervaporation

1996

Abstract The application of pervaporation to extract benzaldehyde produced by microorganisms is considered. A model system was used to study the influence of different parameters and attempts to understand better the mass transfer of this flavour compound. Benzaldehyde was removed from a culture medium from which it was produced by Bjerkandera adusta . The performance of these processes is compared.

Effect of Divalent Cations on the Contractile Response of Rat Aorta to Depolarization before and after Nifedipine Treatment

1996

The influence of the divalent cations, Ca2+, Mg2+ and Ba2+, on the contractile response of the rat aorta to KCl and on the recovery of this response after nifedipine treatment was analyzed. KCl (80 mmol/l) promoted a two-phase (phasic and tonic) contractile response in Krebs solution but, as expected, no contractile response in Ca(2+)-free medium. In Mg(2+)-free medium, the phasic response to KCl was unaffected but the tonic one decreased slowly, suggesting that a long incubation time in the absence of Mg2+ (65 min) promotes a loss of or a change in the intracellular distribution of this ion that modifies Ca2+ entry through L channels or Ca2+ handling. Ba2+ (1.8 mmol/l) contracted the rat a…