showing 36 of ~574560 from 574555 documents
ALTERED RATIO BETWEEN AXON CALIBER AND MYELIN THICKNESS IN SURAL NERVES OF CHILDREN
1978
ABSTRACT Maturation of myelin sheaths in normal sural nerves of children proceeds more slowly than axon growth. This asynchronous development of axons and myelin sheaths results in a statistically significant change of the ratio between axon caliber and myelin thickness during normal development. Therefore, myelin thickness of individual nerve fibers must be related to the size of the axons as well as to the age of the individuals studied. Abnormalities of the relationship between myelin thickness and axon diameter (primary hypomyelination of large, or small, or all fibers) were clearly identified in cases with metachromatic leukodystrophy, KRABBE's, DEJERINE-SOTTAS’, COCKAYNE'S and SANFILI…
The role of computed tomography in the diagnosis of brain tumors in infants and children.
1978
CT has considerably facilitated the diagnosis of intracranial tumors, especially in infants and children. The authors review their experience with a series of 260 children with proven brain tumors. In most cases CT is so conclusive that other diagnostic techniques are no longer often needed. Pneumoencephalography in particular has largely been replaced by CT in recent years in the authors' departments, and the frequency of central ventriculography with contrast material has decreased substantially. Particular diagnostic difficulties with regard to tumors near to or within the caudal brain stem, some posterior fossa tumors, small vermian tumors, and tumors of the cerebral hemispheres are dis…
Sudrabaino mākoņu novērojumu žurnāls, 1978: Sigulda
1978
Digitalizēts mezosfēras mākoņu 1978. gada SIGULDAS novērojumu žurnāls: novērojumu sezonas naktis, novērotāji, MK identifikācija, meteoroloģiskā situācija, informācija par uzņemtajām fotogrāfijām. --//-- Mesospheric cloud observation data in Sigulda, 1978, digitized observation log: observation season nights, observers, MC identification, meteorological situation, information about the photos taken.
El cuaternario continental de la plana de Castelló (Estudio)
1978
Un ensemble de l’âge du Fer à Varennes-sur-Seine (Seine-et-Marne)
1978
National audience
Occurrence of Carcinogens in Surface Water and Drinking Water
1978
Initiation and Modulation of ECF Generation and Secretion from Human Polymorphonuclear NeutrophilsX.
1978
The primary mediators which are involved in inflammatory processes are histamine, the slow reacting substance of anaphylaxis (SRS-A), the platelet aggregating factor (PAF) and the eosinophil chemotactic factor (ECF). These mediators are primarily localized within mast cells and basophil leucocytes, which represent the target cells of allergic reaction. Binding of IgE to mast cells and basophil leucocytes and addition of the appropriate antigen then leads to the activation of the target cells with a subsequent release of their mediators. SRS and ECF have also been found in a non mast cell source, e.g. in human PMNs. ECF can be generated and released from human PMNs by different stimuli, such…
ANALYSIS OF THE DOSE-RESPONSE CURVE TO SODIUM NITRITE IN ISOLATED RAT AORTA
1978
Democracia: del heroismo a la coña
1978
Quasi Competition — a New Aspect
1978
The model of quasi competition put forward in 1967 is reinvestigated under the aspect that only large (N ∞) populations are considered. Under this new angle the conclusion that myomas develop from single cells seems better justified than the original discussion indicated.
SPECIES-DEPENDENT STEREOSPECIFIC SERUM PROTEIN BINDING OF PHENPROCOUMON
1978
The role of choline in the release of acetylcholine in isolated hearts.
1978
1. The concentrations of acetylcholine, choline and noradrenaline were estimated in the perfusate (overflow) of isolated hearts of chickens, cats, rabbits and guinea pigs. Neurotransmitter release was evoked by stimulation of both vagus nerves and by direct stimulation of the heart (field stimulation). 2. In the absence of exogenous choline and physostigmine, field stimulation at 20 Hz for 20 min caused an overflow of acetylcholine from the hearts of the 4 species investigated. During vagal stimulation, however, acetylcholine was detected only in the perfusate of the chicken heart. 3. Field stimulation for 2 min caused an overflow of 193 pmol g−1 min−1 acetylcholine and of 666 pmol g−1 min−…
Un sociólogo, en la oposición. Vidal Beneyto: "Lo difícil, consolidar la democracia"
1978
Archivo de arte valenciano, 1978, año 49
1978
Revista editada por Real Academia de Bellas Artes de San Carlos
Educació, treball infantil i femení
1978
El document forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de València. Traducció al català de fragments escrits per Marx i Engels sobre educació i ensenyament
Studien zum Vorgang der Wasserstoffübertragung, 45. Elektroreduktion aromatischer Carbonsäureester
1977
Bei der Elektroreduktion der Benzoesaureester 1 in Alkoholen an einer Quecksilberkathode mit quartare Ammoniumleitsalzen entsteht ein Gemisch von partiell kernhydrierten Reaktionsprodukten und Benzylalkohol (Tabelle 3). Elektroreduziert man jedoch in Gegenwart von Essigsaure, so wird die Kernhydrierung vollstandig unterdruckt und es entstehen ca. 70% Benzylalkohol (3) neben ca. 30% 1,2-Diphenylethylenglykol (9) als Hydrodimerem (Tabelle 4). Benzoesaure-phenylester (2h) wird nahezu ausschlieslich zu Benzylalkohol (3) elektroreduziert; Substituenten an der Benzoesaure (Verbindungen 2a-i) verandern diesen Reaktionsablauf nicht, wenn in Gegenwart von Essigsaure gearbeitet wird (Tabelle 8).Gleic…
Studien zum Vorgang der Wasserstoffübertragung 46. Zur kathodischen Spaltung von Alkyl- und Cycloalkyl(triphenyl)-phosphoniumsalzen; Abhängigkeit der…
1977
Die kathodische Spaltung von Methyl-, Butyl- und einiger Cycloalkyl(triphenyl)phosphoniumsalze wurde potentiostatisch und galvanostatisch durchgefuhrt. Beim Methyl(triphenyl)-phosphoniumsalz hangt die prozentuale Zusammensetzung der Spaltprodukte: Triphenylphosphin und Methyl(diphenyl)phosphin sowohl vom Potential als auch von der Temperatur ab, die sich ihrerseits wieder gegenseitig beeinflussen. Zusatze unterschiedlich strukturierter quartarer Ammoniumsalze als Leitsalz verandern das prozentuale Verhaltnis (C6H5)3P/(C6H5)2PCH3 nicht, wohl aber der Zusatz von Essigsaure, welche die Bildung von Methyl(diphenyl)phosphin begunstigt. - Bei den Cycloalkyl(triphenyl)phosphoniumsalzen mit Cyclohe…
Enzymic control of irreversible binding of metabolically activated benzo(a)pyrene in perfused rat liver by monooxygenase activity.
1977
Addition of [3H]-benzo(a)pyrene to the perfusion medium of isolated rat livers results in irreversible binding of radioactivity to DNA, RNA and protein. Binding to DNA accounted for about 0.1% of the total radioactivity which was bound in livers from animals treated with oil or saline and was increased by a factor of 3–5 after pretreatment of the animals with β-naphthoflavone or with phenobarbital. When the inhibitiors of monooygenase activity, α-naphthoflavone or metyrapone, were present in the perfusion medium, irreversible binding was reduced in livers from both β-naphthoflavone- and phenobarbital-pretreated animals, irrespective of the inhibitor used.
Species differences in activating and inactivating enzymes related to the control of mutagenic metabolites
1977
Microsomal monooxygenases catalyze the biosynthesis of epoxides from olefinic and aromatic compounds whilst microsomal epoxide hydratase and cytoplasmic glutathione S-transferases are responsible for their further biotransformation. Although catalytically very efficient the cytoplasmic glutathione S-transferases play, due to their subcellular localization, a minor role in the inactivation of epoxides derived from large lipophilic compounds and were, therefore, not included in this study. It was shown with such a lipophilic compound, benzo(a)pyrene, as a model substance and with liver enzyme mediated bacterial mutagenesis as biological endpoint that species and strain differences in epoxide …
The effect of nacom (L-dopa and L-carbidopa) on growth hormone secretion in 75 patients with short stature.
1977
The stimulatory effect of Nacom (250 mg L-Dopa and 25 mg L-Carbidopa) on the HGH secretion was evaluated in 75 short stature patients. The number of blood samples was restricted to only three (0, 45 and 90 min). 63 patients reached adequate HGH concentrations after the ingestion of 1 tablet Nacom (84%). Somatotropin levels increased from 2.08 (Sx 0.28) to a maximal HGH value of 14.22 (Sx 0.87) ng/ml. When the stimulatory effect of Nacom was compared with the standard method of arginine infusion in children with normal stature the arginine test was not superior to the Nacom-test. The Nacom-test appears to be a simple and reliable screening method for HGH deficiency, particularly in outpatien…
Inactivation of electrophilic metabolites by glutathione S-transferases and limitation of the system due to subcellular localization
1977
Benzo(a)pyrene was activated to metabolites mutagenic for Salmonella typhimurium TA 98 by liver microsomes from control and phenobarbital treated mice. Under these conditions benzo(a)pyrene 4,5-oxide accounts for most of the mutagenicity. We have therefore investigated (1) the conjugation of benzo(a)pyrene 4,5-oxide with glutathione and (2) the effect of glutathione on the mutagenicity of benzo(a)pyrene.
Dual role of epoxide hydratase in both activation and inactivation of benzo(a)pyrene.
1977
The effect of epoxide hydratase upon the mutagenicity of benzo(a)pyrene was investigated using two Salmonella typhimurium strains (TA 1537 and TA 98). These two bacterial strains were found to differ characteristically in their susceptibility to different mutagens biologically produced from benzo(a)pyrene providing a diagnostic tool to investigate which types of mutagenic metabolites were produced in various metabolic situations. The results showed that the pattern of mutagenic metabolites produced by microsomes from methylcholanthrene-treated mice was very different from that produced by microsomes from phenobarbital-treated or untreated mice. However in all cases at least two mutagenic me…
The obsolescent renal glomerulus ? Collapse, sclerosis, hyalinosis, fibrosis
1977
By light and electron microscopical examination it is shown that four structural components can contribute to obsolescent glomeruli: capillary basement membranes, enriched mesangium matrix, “vascular” hyalin and collagen fibers. Each of these components can bring about glomerular damage alone. One non-reactive form — a glomerular collapse with only basement membrane remnants — can be separated from three reactive forms: the accumulation of mesangium matrix (sclerosis or matrix-sclerosis), deposition of vascular hyalin (hyalinosis in the narrow sense), and fiber development within the former urinary space (fibrosis or fibro-sclerosis). The use of the term “fibrinoid” in place of the descript…
Heart rate and perceptual response to exercise with different pedalling speed in normal subjects and patients.
1977
The perceived exertion rating (RPE) scale of Borg was used to investigate the relationship between perceived exertion and pedalling rate. Normal subjects and patients with chronic obstructive lung disease (Cold) were studied in repeated test series. Work load, applied in a random order, varied from 2.5 to 10 mkp/s (patients) and 5 to 20 mkp/s (normals). Pedalling rate varied from 2.5 to 10 mkp/s (patients) and 5 to 20 mkp/s (normals). Pedalling rate varied from 40 to 60, 80, 100 rpm. At constant work load, RPE decreases during increasing pedalling rate. With respect to validity, RPE, showing a closer relationship to work load than to heart rate, seems to reflect perception of physical stres…
Electron resonance scattering from mercury
1977
The differential cross section and the spin polarisation of electrons scattered elastically from mercury have been measured as a function of collision energy in the range 4.0 to 6.0 eV for several selected scattering angles. The observed data can be understood if one assumes that resonances are formed at 4.55 eV in the 2S1/2, at 4.71 eV in the 2D3/2 and at 4.94 eV and 5.51 eV respectively in the 2D5/2 scattering state.
Neuronal network characteristics in the cat superior colliculus
1977
The system theoretical description of the superficial layers of neurons in the cat's superior colliculus is based on homogeneous linear space-time filters. The most important neurophysiological findings on the superior colliculus are simulated on the digital computer by generating suitable coupling functions and matching the space and time parameters. It is shown that the neurophysiological measurements can be interpreted by varying a few system parameters. The curves of velocity dependent responses, direction specificity and the effects of the colliculus specific surround are examined in particular. Computer simulation shows that such a surround can evaluate small moving stimuli differentl…
Sélection auto-sélection dans l'enseignement universitaire français
1977
International audience
Gruppen, deren nichtlineare Charaktere von symplektischem Typ sind
1977
A note on the closed graph theorem
1977
The pupillary response to mental overload
1977
The hypothesis that the pupil constricts below base level in situations of mental overload was tested. Subjects had to perform in a four-alternative forced-choice task at 75%, 100%, and 125% the speed of their maximum processing capacity. No indication of a pupillary constriction in the overload situation was found. The pupil dilated under all three conditions. The pupil diameter of male subjects significantly decreased after the sharp increase at the beginning of the experimental phases, while the female subjects’ pupil diameter remained at the same level after the initial increase. The amount of dilation depended on information load for male subjects only. Results were taken as further in…
Tensorprodukte von Charakteren der symmetrischen Gruppe
1977
Zur S�ttigung einer Formation endlicher aufl�sbarer Gruppen
1977
Effectiveness of theophylline to increase cyclic AMP levels and force of contraction in electrically paced guinea-pig auricles. Comparison with isopr…
1977
The effects of theophylline (3×10−5 M–5×10−3 M), isoprenaline (10−6 M), excess calcium (7.2 mM) and ouabain (3×10−7 M) on force of contraction and c-AMP content were studied in electrically driven (frequency 3 Hz) left auricles isolated from guinea pigs pretreated with reserpine.
Testing for intraregional economic homogeneity : a comment
1977
IV. An Improved Separation Method for Twenty two Compounds Related to Purine and 6-Thiopurine Metabolism Using High-Pressure Liquid Cation-Exchange C…
1977
Abstract An improved method is described for the separation of 22 compounds normally related to purine and 6-thiopurine metabolism in biological materials using high-pressure liquid cation-exchange chromatography on strongly acidic exchange resin. The column (0.18 × 100 cm) is eluted with 0.4 ᴍ ammonium formate, pH 4.6, at a linear flow velocity of 5.2 cm · min-1 at 50 °C. The elution volumes of sulphate anions, allopurinol, 6-thioxanthine, adenine, adenosine, and guanosine are demonstrated additionally to further 16 purine and 6-thiopurine compounds.
128. Operationstechnische Fehler bei Osteosynthesen an der oberen Extremit�t
1977
Die meisten MiBerfolge bei Osteosynthesen gehen auf technische Fehler zuruck. Fur die operative Versorgung von Schaftfrakturen an der oberen Extremitat stellt heute die Plattenosteosynthese die Therapie der Wahl dar. Am Humerus sind breite AO-Platten indiziert, wobei jedes Fragment mit mindestens drei, beBer mit vier Schrauben fixiert werden muB. Fur den Unterarm stehen die schmalen AO-Platten zur Verfugung; eine Verankerung in jeweils funf Kortikales gilt dabei als Mindestforderung.