showing 36 of ~574560 from 574555 documents
Exophthalmos and basilar impression. A contribution to differential diagnosis of endocrine orbitopathy.
1988
We report on a male patient with exophthalmos of unclear etiology, basilar impression, syringohydromyelia and type II Arnold-Chiari malformation. Two diseases involving the orbital region were to be considered in differential diagnostic terms: endocrine orbitopathy and osseous orbit dysplasia. The typical physical appearance associated with basilar impression as well as suppurative keratitis in Lagophthalmos was striking. Tetraspasticity with pareses, bulbar symptoms, proximally pronounced muscular atrophy as well as a left hemihypesthesia was shown neurologically. Although the orbit CT was normal, sonography revealed thickened ocular muscles. There was euthyroidism in diffuse goiter with n…
Determination of lead in treated crayfish Procambarus clarkii: accumulation in different tissues.
1988
The continual loading of trace metals into our environment represents a water pollution problem due to their toxic effects on aquatic biota. In addition, metal ions can be incorporated into food chains and concentrated by aquatic organisms to a level that affects their physiological state. There are several investigations on the toxic effects and bioaccumulation of lead in fishes, molluscs, and crustaceans. Lake Albufera (Valencia, Spain) and the surrounding rice-field waters are subjected to large loads of sewage and toxic industrial residues (including heavy metals) from many urban wastewaters in the area. In 1978, the American red crayfish Procambarus clarkii (Girard) appeared in Lake Al…
Understanding, Truth and Explanation
1988
In this paper I intend to discuss the relationship between understanding, truth, and explanation, starting from the problem of the interpretation of alien belief systems. The examination of this will lead us to present an analysis of the structure of understanding, and to defend its cognitive universality in so far as any identification of reality reproduces the structure of the process of understanding. This cognitive universality does not necessarily exclude, however, the possibility of reducing understanding to causal relations. With respect to this, I shall discuss the plausibility of the views of Quine, Searle and Davidson on the kind of relation that holds between cognitive processes …
Differential antiepileptic effects of the organic calcium antagonists verapamil and flunarizine in neurons of organotypic neocortical explants from n…
1988
Effects of the organic calcium antagonists verapamil and flunarizine on pentylenetetrazol induced paroxysmal depolarizations were tested in organotypic neocortical explants taken from neonatal rats. In these in vitro experiments the papaverin derivative verapamil depressed, and finally abolished, epileptic discharges in all cases. The piperazine derivative flunarizine, however, which is known to suppress epileptic discharges in hippocampal CA3 neurons (Bingmann and Speckmann 1986), showed no significant antiepileptic effects in the explanted neocortical neurons. Thus, the present findings may indicate that the suppressive action of flunarizine on the generation of paroxysmal depolarizations…
Microsomal and cytosolic epoxide hydrolases, the peroxisomal fatty acid beta-oxidation system and catalase. Activities, distribution and induction in…
1988
A number of structurally unrelated hypolipidaemic agents and certain phthalate-ester plasticizers induce hepatomegaly and proliferation of peroxisomes in rodent liver, but there is relatively limited data regarding the specific effects of these drugs on liver non-parenchymal cells. In the present study, liver parenchymal, Kupffer and endothelial cells from untreated and fenofibrate-fed rats were isolated and the activities of two enzymes associated with peroxisomes (catalase and the peroxisomal fatty acid beta-oxidation system) as well as cytosolic and microsomal epoxide hydrolase were measured. Microsomal epoxide hydrolase, cytosolic epoxide hydrolase and catalase activities were 7-12-fold…
Determination of the partial electron capture- and spontaneous-fission half-lives of254No
1988
The isotope254No was produced in the fusion reaction48Ca +208Pb. Using the velocity filter SHIP and radiochemical techniques it was found that the nuclide254No with a half-life of 55 s decays byα, EC, and spontaneous-fission. Deduced partial half-lives are (61±2) s forα-decay, (550−160+370) s for EC and [2.2−1.0+2.0]×104 s for spontaneous fission.
Spectrophotometric Determination of Cystine with O-Phthalaldehyde in the Absence of Thiol
1988
Abstract A spectrophotometric method for the determination of cystine with o-phthalaldehyde (OPA) in the absence of thiol is described. When cystine is heated at 60[ddot]C for 30 min in a low excess of OPA (pH 9.5), a very stable derivative with 1:2 stoichiometry (cystine:OPA) and an absorption maximum at 335 nm (E = 4600) is formed. At pH < 1 the derivative is protonated (protonation constants: log K1 = 5.88 and log K2 = 3.70 at I = 0.1 and 20[ddot]C) and another absorption band at 440 nm (E = 3800) appears, which allows the determination of cystine in the presence of other amino acids.
Modulation by docosahexaenoic acid of the epinephrine-stimulated adenylate cyclase activity of the bovine retina.
1988
This work shows that unsaturated fatty acids enhance the epinephrine-stimulated adenylate cyclase activity in bovine retina. The modulating effect on the epinephrine-stimulated formation of cyclic AMP seems to be linked to the degree of unsaturation of the fatty acid. Treatment of the intact retina with docosahexaenoic acid in the concentration range 0.5 X 10(-6)-1 X 10(-3) M does not affect the enzyme activity measured in the absence of the hormone but markedly increases the cyclase activity when the tissue is incubated in the presence of 0.1 mM epinephrine. Docosahexaenoic acid enhances the maximal response to epinephrine without affecting the apparent ED50 value for this effector. Docosa…
Sekundärer Immundefekt bei Niereninsuffizienz am Beispiel der Hepatitis B-Impfung
1988
In dialysis patients the immune response to hepatitis B-vaccination is greatly impaired. In vitro the non-responders show a failure of the monocytes to support the process of primary T-cell activation. This defect results in a lack of interleukin 2-production and an enhanced sensitivity of the interleukin-2 receptor system. Addition of low doses of interleukin-2 fully reconstitutes the deficient immune response in vitro. Furthermore, the local application of low dose interleukin-2 during a standard vaccination with 40 µg hepatitis B-vaccine normalizes the non-responder state in vivo.
A Knowledge-Based System for the Automatic Generation of Plant Shutdown and Startup Schedules
1988
Abstract When the shutdown of a plant, or part of it, has been decided as consequence of a major fault, the generation of a safe shutdown schedule may be, for large and complex plants, a very difficult and delicate task. The same problem may be found when the plant must be restarted after the fault has been repaired, for the generation of a start-up schedule. The use of a knowledge-based system appears to be a suitable answer to this problem, allowing a high level of safety and a very fast generation process. The paper examines the process knowledge that needs to be included in such a knowledge-based system and proposes some knowledge representation forms that appear suitable for the task t…
Clonal analysis of human T lymphocytes infiltrating the liver in chronic active hepatitis B and primary biliary cirrhosis
1988
Human T lymphocytes infiltrating the liver in chronic active hepatitis B (CAH-B) and primary biliary cirrhosis were isolated from liver biopsy cores, cloned by limiting dilution technique and expanded in vitro. Phenotypic and functional analysis demonstrates that this tissue infiltrate represents a heterogeneous cell population. However, when compared to peripheral blood lymphocytes of the same patients, a marked enrichment for T8+ cytotoxic T cells was found to exist at a local site in both types of chronic liver disease. These data provide support for the notion that liver cell injury in CAH-B and PBC may be mediated by a common immunologic mechanism likely executed by cells of the T line…
Determination of resonance parameters in QCD by functional analysis methods
1988
A mathematically rigorous method based on functional analysis is used to determine resonance parameters of an amplitude from its given asymptotic expression in the space-like region. This method is checked on a model amplitude where both the asymptotic expression and the exact function are known. This method is then applied to the determination of the mass and the width of the ρ-meson from the corresponding space-like asymptotic QCD expression.
Three dimensional hydrodynamics of ultrarelativistic heavy ion collisions
1988
We have utilized a 2+1 dimensional numerical code based on Flux Corrected Transport method to find a solution for 3+1 dimensional cylindrically symmetric hydrodynamic flow of hadronic matter which is assumed to be formed in extremely high energy heavy ion collisions. The hydrodynamics is supplemented with a decoupling calculation in order to produce measurable particle distributions. This numerical procedure is applied here to Landau type initial conditions which have been fixed using a simple geometrical picture for a central O+Pb collision at 200 GeV/nucleon. The bag equation of state for nonbaryonic matter is used to simulate the deconfinement phase transition to quark gluon plasma. The …
Discussion: “Chaotic Motion of an Elastic-Plastic Beam” (Poddar, B., Moon, F. C., and Mukherjee, S., 1988, ASME J. Appl. Mech., 55, pp. 185–189)
1988
Discussion on caotic motion of a pinned beam subjected to pulse loading
Shape coexistence in theN=59 isotone97Sr
1988
Experimental evidence for shape coexistence in the N=59 isotone97Sr is presented. The ground state and the lowest excited levels are confirmed to be spherical. At 585.1 keV, a K=3/2 rotational band built on the v[422 3/2] Nilsson configuration has been identified. Nilsson orbital assignments for three further levels of deformed origin are proposed. The results are compared to RPA shell-model predictions.
Molecular dynamics simulation of epitaxial growth of the Si(001) surface
1988
Abstract Molecular beam epitaxy on a Si(100) substrate has been studied using a molecular dynamics method with the Stillinger-Weber model potential. At high substrate temperature, 800 K, well ordered crystalline layers are found to grow underneath an amorphous overlayer of approximately 5 A thick. A limiting temperature for epitaxial growth is found to be 480 K, below which the growth does not produce ordered layers. When the sample deposited below 480 K is heated up to 800 K and the deposition is started again the original adatoms start to form ordered atomic layers. Thus the collisions of the deposited atoms in addition to the substrate temperature seem to play an essential role in the gr…
Large Fibres in Urinary Calculi—-Promoters of Stone Formation
1988
Large fibres (phi 10-20 microns, length up to 5,000 microns) are sometimes imbedded in urinary calculi. It may be that these fibres can catch sediment particles and promote stone growth. By scanning electron microscopy the morphology of the fibres was studied as well as the relationship of the fibres with crystalline stone components. The reported findings suggest that the fibres are possibly formed in the tubuli as the result of an hitherto unknown defect.
Cytokeratin Analysis of Pilomatrixoma: Changes in Cytokeratin-Type Expression During Differentiation
1988
The various structural components of pilomatrixoma (calcifying epithelioma of Malherbe) were studied for the expression of hair-specific (trichocytic) cytokeratins as well as epithelial cytokeratins, using immunoperoxidase as well as epithelial cytokeratins, using immunoperoxidase and immunofluorescence microscopy of frozen sections as well as two-dimensional gel electrophoresis and immunoblotting. Trichocyte-type cytokeratins were detected in only a minor subpopulation of basophilic cells but more prominently in most “transitional” cells as well as in “shadow” cells. in contrast, antibodies against certain epithelial cytokeratins (including antibody KA1 against cytokeratins of stratified s…
Peptide neuroanatomy of adjuvant-induced arthritic inflammation in rat
1988
The influence of adjuvant-induced arthritis of the rat on central and peripheral peptide neuroanatomy was investigated by immunohistochemistry. The most striking feature of arthritic rats was the differential intensification of neuronal proenkephalin- and prodynorphin-related staining in dorsal horn. Changes were ipsilateral in monoarthritic and bilateral in polyarthritic rats as compared to controls. Opioid responsive neurons were target of substance P (SP) and calcitonin gene-related peptide (CGRP) fibers. Changes of SP and CGRP predominated in peripheral inflamed tissue and consisted of intensified immunostaining and an apparent sprouting of sensory fibers particularly around venules, in…
Laser induced thermal profiles in thermally and optically thin films
1988
The temperature field generated by the weak absorption of a gaussian laser beam in an optically and thermally thin film bounded by two transparent plates is discussed. An analytical solution of the problem is presented together with an algorithm for the numerical integration. The influence of the finite thermal conductivity of the plates is shown in an example.
Gene encoding capsid protein VP1 of foot-and-mouth disease virus A quasispecies model of molecular evolution
1988
A phylogenetic tree relating the VP1 gene of 15 isolates of foot-and-mouth disease virus (FMDV) of serotypes A, C, and O has been constructed. The most parsimonious tree shows that FMDV subtypes and isolates within subtypes constitute sets of related, nonidentical genomes, in agreement with a quasispecies mode of evolution of this virus. The average number of nucleotide replacements per site for all possible pairs of VP1 coding segments is higher among representatives of serotype A than serotype C or O. In comparing amino acid sequences, the values of dispersion index (variance/mean value) are greater than 1, with the highest values scored when all sequences are considered. This indicates a…
Plant regeneration from isolated cells ofLavandula latifolia medicus
1988
Single cells were obtained from hypocotyl-derived callus ofLavandula latifolia Medicus. Cells were plated in Murashige and Skoog medium supplemented with indoleacetic acid (IAA), benzyladenine (BA), and several IAA-BA combinations. Cell division required the simultaneous presence of IAA and BA in the culture medium, but callus formation was only achieved with 0.1 or 1 mg/liter IAA and 2 mg/liter BA. To induce organogenesis, calli were transferred to various regeneration media. Shoot-bud differentiation efficiency depended on the composition of both the callus induction and the shoot regeneration media, best results being obtained when calli grown in 1 mg/liter IAA and 2 mg/liter BA were sub…
Polymeric amphiphiles with hydrophilic main chain spacers: Studies in monolayers and Langmuir-Blodgett multilayers
1988
A methacrylic lipid was polymerized to form an amphiphilic homopolymer and random copolymers with various levels of acrylic acid comonomers. The behavior of these polymeric lipids was investigated in monolayers at the air-water interface and in Langmuir-Blodgett multilayers on polymer foil supports. The acrylic acid acts as a hydrophilic spacer along the polymer backbone, and improves the ability of the polymer to self-organize into highly ordered monolayers and ultimately LB multilayers. It is shown that the quality and stability of the multilayers increase substantially with the increase in comonomer content.
Evaluation of the clonidine-suppression test in the diagnosis of pheochromocytoma
1988
In this study we examined the preoperative value of the clonidine-suppression test in 15 patients with surgically proved pheochromocytomas. The result of the clonidine-suppression test was pathological (epinephrine plus norepinephrine above 500 ng/l 3 h after clonidine) in 10 of 15 patients (66%). These patients had relatively large tumors and higher basal norepinephrine plasma levels. Out of the 5 cases without a pathological clonidine test 4 had normal basal plasma catecholamine levels with the result that the clonidine test could not be properly applied and 1 case produced a false negative result. These 5 cases generally had smaller tumors and lower plasma catecholamine levels. Two of th…
Measurement of the ground state hyperfine splitting in207Pb II
1988
The ground state hyperfine splitting of simply ionized lead has been determined using pulsed laser excitation of electrodynamically confined ions. We obtain ΔV(6P1/2)=12.85(10) GHz
Clinical and ultrastructural observations of maturing human frontal cortex. Part I (Biopsy material of hydrocephalic infants).
1988
Three of 30 human cerebral cortex biopsies from infants treated for hydrocephalus by shunt operation are described. The descriptions include an account of their case history, the clinical methods, and the operational procedures. The biopsy specimens were studied in semithin and ultrathin sections. Attention is drawn to normal synapse formation but also to neuronal degenerative changes due to hydrocephalus.
The relativistic mean-field model at large densities
1988
The extrapolation properties of the relativistic mean-field model are investigated in nuclear matter. The results of a recent relativistic Bethe-Brueckner-Gatdstone calculation are taken as ‘data”. Fits in a window of normal nuclear densities are extrapolated to large densities and compared with the ‘data’. We find large discrepancies which hint at an insufficiency of the model in its present parametrisation.
Detection and quantification of patulin and griseofulvin by high pressure liquid chromatography in different strains of Penicillium griseofulvum Dier…
1988
Patulin and griseofulvin production by twelve strains ofPenicillium griseofulvum Dierckx, eleven of which were isolated from pistachio (Pistacia vera) nuts and the other was supplied by the Spanish Collection of Type Culture, was investigated. Six strains of the eleven isolated had ability to produce patulin and griseofulvin in Yes medium. All the strains studied had no ability to produce patulin in Wickerham medium. Griseofulvin production was significant in both media but higher in Wickerham.These metabolites were separated and determined in the chloroform extracts of cultures by high performance liquid chromatography with ultraviolet detection. The best conditions were: acetonitrile - wa…
Les voies de recherche en distribution
1988
International audience; Cet article passe en revue les travaux récents consacrés à trois axes de recherche en distribution: l'analyse des canaux, et notamment la problématique des relations entre producteurs et distributeurs, la stratégie de la firme de distribution, et enfin la relation du consommateur avec le point de vente.
syn ‐[2.2](1,3)Cyclophane durch doppelte Photocyclodimerisierung
1988
Durch doppelte Cyclodimerisierung wird in einer Photolyse in Losung aus dem 1,3-disubstituierten Benzol 3 das syn[2.2](1,3)Cyclophan 4 erhalten. Eine kombinierte Belichtung Festkorper/Losung ergibt bei 5 das analoge System 6 mit Estergruppen. Beide Reaktionen erfolgen streng regiospezifisch durch Kopf-Kopf-Verknupfung und stereospezifisch bezuglich der syn-Geometrie im Cyclophan und der trans-Konfiguration der Vierringsubstituenten. Die einzige stereochemische Freiheit besteht in der Anordnung der Vierringe, wobei die Isomeren 4/6a,b,c, den drei moglichen Rotameren in 3 und 5 entsprechen. Wahrend das Gerust von 4 starr ist, zeigt 6 bei Raumtemp. eine langsame Inversion des zentralen 10-Ring…
pH distributions in spontaneous and isotransplanted rat tumours.
1988
Spontaneous mammary tumours of the rat with various degrees of malignancy exhibit similar tissue pH distributions. The mean pH (+/- s.d.) of dysplasia is 7.05 +/- 0.20. In benign tumours the mean pH is 6.95 +/- 0.19 and in malignant tumours it is 6.94 +/- 0.19. In contrast, tumours with the same degree of malignancy but different histologies show different pH distributions. Benign tumours with a higher percentage of fibrous tissue exhibit less acidic pH values than those with larger portions of epithelial cells (delta pH = 0.38 pH units). The pH distribution in the benign tumours is independent of the tumour wet weight up to stages of very advanced growth. In the malignant tumours, a trend …
Neuroblastom bei Morbus Recklinghausen
1988
Le haut risque d'apparition d'un pheochromocytome dans la maladie de Recklinghausen est connu. Par contre l'apparition d'un neuroblastome est plutot considere comme une coincidence. La scintigraphie a l' 131 I-meta-iodo-benzylguanidine a permis le diagnostic dans le cas rapporte ici
Subtyping of group specific component (GC) in human semen, blood and vaginal fluid by isoelectric focusing in immobilized pH gradients.
1988
The group specific component (GC) is stable and well suited for forensic casework. Isoelectric focusing of common GC variants from semen, seminal fluid, vaginal fluid and semen stains, on Immobiline DryPlates, pH 4.5-5.4, is of practical value in criminal investigations of sexual deliquencies. GC is present in normospermia and azoospermia seminal fluids and found in about 20% of the vaginal secretions. The GC patterns observed were similar and in accordance with the bands of the individual GC type in plasma/serum.
Purification and characterization of rat-liver cytosolic epoxide hydrolase.
1988
Rat liver cytosolic epoxide hydrolase has been purified and characterized. The enzyme was purified from tiadenol-induced rat liver 540-fold with respect to trans-stilbene oxide as a substrate. Similar purification was obtained with the substrates trans-beta-ethyl styrene oxide and styrene 7,8-oxide, the specific activities decreasing in the order trans-beta-ethyl styrene oxide greater than styrene 7,8-oxide greater than trans-stilbene oxide. The enzyme exerts highest activity at pH 7.4 Km and Vmax of the pure enzyme for trans-stilbene oxide were 1.7 microM and 205 nmol x min-1 x mg protein-1 respectively. With trans-stilbene oxide as a substrate, the inhibition by organic solvents (2.5% by …
Conservative treatment of initial breast cancer
1988
The results of conservative surgical techniques (quadrantectomy or tumorectomy), axillary dissection and radiotherapy in 58 patients with initial breast cancer (Tt No, Mo) treated between June 1979 and December 1986 are reported. The disease-free survival rates after 5 and 8 years were 84% and 76% respectively. Four cases developed local recurrences (6.9%); 2 cases developed distant metastases involving lung and bone, and 1 case developed bone metastases without local recurrence. Two patients with local recurrence underwent radical life-saving mastectomy and are now free from disease.
Linear response in multipolar glasses
1988
We consider the unified hamiltonian with a bilinear coupling, describing the Ising-, vector-, Potts-, octupolar-glass and other glasses [1, 2]. We systematically derive the response to a homogeneous tensor-field as well as the response to an inhomogeneous random tensor-field. We investigate the overlap distribution function and its first and second moment. In all these considerations, we recover the results of the Ising spin glass for sufficiently symmetric multipolar glasses, but we also obtain differnt results for less symmetric glasses.