Showing papers by "Ghent University published in 1968"
248 citations
TL;DR: A schematic model in the biosynthesis of catecholamines is proposed, suggesting the existence of an important step between decarboxylation and β-hydroxylation, and in the course of uptake experiments dopamine was shown to be most rapidly taken up into the granules.
110 citations
91 citations
TL;DR: The results suggest that dopamine-β-hydroxylase is contained in a sac-like structure, which behaves as an osmotic system and is surrounded by a semi-permeable membrane, which could play a role as a rate limiting factor in the biosynthesis of catecholamines.
62 citations
TL;DR: Spread mixed monolayers at the air—water of cholesterol and phospholipids (dipalmitoyl lecithin and stearoyl-oleoylLeCithin) were investigated using the Goodrich method and the conclusion was drawn that the interaction at theAir—water interface is mainly due to Van der Waals—London attraction forces.
49 citations
TL;DR: In this article, the contraction characteristics of Papillary muscle during changes in acid-base composition of the Bathing-fluid were investigated and compared to those of other muscle types.
Abstract: (1968). Contraction Characteristics of Papillary Muscle During Changes in Acid-Base Composition of the Bathing-Fluid. Archives Internationales de Physiologie et de Biochimie: Vol. 76, No. 4, pp. 624-634.
47 citations
01 Jan 1968
TL;DR: The evolutionary tree of bacteria remains largely invisible, if one uses only phenotypic features.
Abstract: The present day microorganisms are the result of complex evolutionary processes. If these events were known, a three- or multidimensional phylogenetic tree could be constructed with time as one of the axes. Its transverse section with the plane of the present day moment would provide us with a phylogenetic classification. Bacterial classification is mainly built on morphological, physiological, and biochemical features. When many of these data are compared by numerical (or Adansonian) analysis, they provide a fair picture of the degree of relatedness of many bacteria. However, it is nearly impossible to project this picture back into the past because numerical taxonomy covers at most some 20 percent of the bacterial genome, and orthodox bacterial taxonomy covers even less. Furthermore, paleontological, embryological, and comparative anatomical data are lacking for bacteria. Therefore, the evolutionary tree of bacteria remains largely invisible, if one uses only phenotypic features.
45 citations
44 citations
TL;DR: In this paper, a method for deriving finite strains from moire displacement patterns is described, where the components u and v of the displacements at the mesh points of a Lagrangian co-ordinat...
Abstract: A new and accurate method is described for deriving finite strains from moire displacement patterns.The components u and v of the displacements at the mesh points of a Lagrangian co-ordinat...
40 citations
TL;DR: It was found that no initiation codon for polypeptide synthesis coincides with the .5’-end of the RNA molecule, which suggests that both ends of the molecule are joined in a base-paired region.
39 citations
TL;DR: It is concluded that the nosological association of congenital muscular torticollis, multiple spontaneous keloids and cryptorchidism has thus far never been published and the frequent keloidosis in gonadal dysgenesis, may suggest the presence of gene material on the X-chromosome responsible for connective tissue hyperplasia.
Abstract: A kindred is described with a probably new “cervico-dermo-reno-genital syndrome”, comprising a congenital muscular torticollis, multiple spontaneous keloids, cryptorchidism, pyelonephritis and other anomalies. We believe that in this observation a single gene is responsible for the multiple mesodermal and ectodermal defects. Pleiotrophic effects of a single X-linked gene is the most likely possibility for this inborn error of connective tissue. From an extensive review of the literature we may conclude that the nosological association of congenital muscular torticollis, multiple spontaneous keloids and cryptorchidism has thus far never been published. Sex linked or sex limited inheritance for congenital muscular torticollis or multiple keloidosis has not yet been published with certainty. Our observation and the frequent keloidosis in gonadal dysgenesis, may suggest the presence of gene material on the X-chromosome responsible for connective tissue hyperplasia.
TL;DR: The use of marker enzymes in profiling the distribution of different particles in tissue fractionation and the scope and limitations of these methods have been defined already.
Abstract: GROWING interest in the intracellular localization of enzymes has led to the standardization of techniques generally used in tissue fractionation. The scope and limitations of these methods have been defined already, in particular the use of marker enzymes in profiling the distribution of different particles1.
TL;DR: The incorporation of various fats improves the weight gain, although the increase was not related to the amount of fat added, and the addition of fats improves efficiency of food conversion, but varies according to the kind of fat.
Abstract: Synopsis A study, based on data from the literature, was carried out to establish the quantitative effect of increasing levels of various fats on food intake, weight gain and efficiency of food conversion of growing chicks. The fats concerned were soyabean oil, soyabean soapstock, maize oil, lard, grease and tallow. Their effect was studied by using regression analyses. It was found that the addition of fat, both animal fats and vegetable oils, diminishes food intake. The food intake decreases significantly with rising percentages of fat according to a linear function. No differences in effect between various fats could be demonstrated. The incorporation of various fats improves the weight gain, although the increase was not related to the amount of fat added. The improvement in weight gain differs from one fat to an other. The addition of fats improves efficiency of food conversion, but varies according to the kind of fat. Here the improvement is correlated with the level of fat added. The difference in ...
TL;DR: Using a differential method for assaying dopamine-β-hydroxylase, data are not consistent with the presence of these inhibitors in the granules containing catecholamines and with their possible role in the regulation of noradrenaline biosynthesis.
TL;DR: It is concluded that the chloride ion equilibrated between plasma and brain tissue under the conditions of the experiment and changed the bicarbonate concentration of CSF during respiratory changes in the acid-base equilibrium.
Abstract: (4 figures) In recent years the bicarbonate concentration ([HCO,]) in cerebrospinal fluid and in brain has attracted much interest. Several authors studied the buffering systems of the central nervous system in conditions of experimental acidosis and alkalosis and discussed the mechanisms of the observed changes. During metabolic acid-base changes in blood it appeared that pH and [HCOJ in cerebrospinal fluid (CSF) are only very slightly influenced in acute conditions (cfr DE BERSAQUES, 1955, for the literature; DE BERSAQUES and LEUSEN, 1954; ROBIN ef al., 1958; LEUSEN, 1965). More prolonged changes in plasma [HCOJ however are eventually reflected to a certain degree in CSF (for literature see MITCHELL et al., 1965, FENCL ef al., 1966 and MITCHELL, 1966) and variations in [HCOJ in CSF are compensated by changes in the chloride concentration ([Cl-I). Total brain tissue also showed only very small changes in [HCOJ after 6 hours non-respiratory changes in the bicarbonate concentration of blood plasma in the rat (SIESJO, 1964, 1965; SIESJO and PONTBN, 1966a and b). These authors conclude that the chloride ion equilibrated between plasma and brain tissue under the conditions of the experiment. More rapid changes are observed on the other hand in the bicarbonate concentration of CSF during respiratory changes in the acid-base equilibrium. These changes which are rather moderate in acute conditions, become progressively more pronounced with time.
TL;DR: The method uses dopa-C 14 as substrate and a butanol extraction under neutral conditions of pH to separate the formed dopamine from dopa to allow a very rapid and particularly simple determination of dopa decarboxylase activity in samples containing low amount of enzyme.
TL;DR: It has been shown that neither the soluble proteins nor the separated soluble low molecular material of Tenebrio tissue homogenates could activate samples of latent phenolase, and a hypothetical mechanism for the activation process was drawn up considering published data.
01 Sep 1968
TL;DR: In this paper, a Lyapunov function for transient power-system stability was determined for a synchronous machine connected to an infinite bus, which includes pole saliency and damping torques.
Abstract: A Lyapunov function is determined for the problem of transient power-system stability; only the stability of a synchronous machine connected to an infinite bus is considered. It is shown that the obtained Lyapunov function includes governor action, pole saliency and damping torques, and is hence an extension of earlier results.
TL;DR: The p.m.r. IR spectra of trimethyltinchloro-and-fluoroacetates have been studied in this article and it has been shown that the molecules are mainly monomeric and tetragonal, but also some associated species must be present for the dichloro-, trichloro, and trifluoroacetate.
TL;DR: The results of chemical degradation of proline of casein as well as relative specific activities in the isolated products are consistent with the view that ornithine is metabolized, by way of glutamic gamma-semialdehyde, to proline or glutamic acid.
Abstract: 1. Lactating mammary glands of sheep were perfused for several hours in the presence of dl-[2-14C]ornithine or dl-[5-14C]arginine and received adequate quantities of acetate, glucose and amino acids. 2. In the [14C]ornithine experiment 1·4% of the casein and 1% of the expired carbon dioxide came from added ornithine; 96% of the total radioactivity in casein was recovered in proline; 13% of the proline of casein originated from plasma ornithine. 3. In this experiment the results of chemical degradation of proline of casein as well as relative specific activities in the isolated products are consistent with the view that ornithine is metabolized, by way of glutamic γ-semialdehyde, to proline or glutamic acid. 4. In the [14C]arginine experiments 3% of the casein and 1% of the expired carbon dioxide came from arginine; 84% of the arginine and 9% of the proline of casein originated from plasma arginine. 5. In these experiments the relative specific activities of arginine, ornithine and proline in plasma are in agreement with the view that arginine is metabolized by way of ornithine to proline. The conversion of arginine into ornithine is probably catalysed by arginase, so that arginase in mammary tissue may be involved in the process of milk synthesis.
TL;DR: In this article, a relative method for the determination of oxygen in steel via the 16O(n,p)16N reaction by means of 14-MeV neutrons is described.
TL;DR: A comparative study is presented of the mass spectra of progesterone, cortexone, corticosterone, aldosterone, 18-hydroxy-cortexone, cortisol, cortisone, spironolactone and lactones of 18-Hydroxy-Cortexone and of ald testosterone.
TL;DR: From the first observations, an apparently important relation between LDH-3 peaking and tumor response was found to occur and this prompts the present communication.
Abstract: When a malignant growth is developing in a patient, one often observes in the serum a shift of the lactate dehydrogenase (LDH) isozyme pattern towards an increase of LDH-3. Conversely, we considered it interesting to check this pattern when a neoplastic growth is regressing due to some kind of cytostatic treatment, and to compare possible shifts with the LDH of the tumor tissue itself. In these investigations, we have chosen patients with bronchogeniccarcinoma, not only for the relative frequency of the disease but also for the possibility of a radiological follow-up of tumor evolution and also for the rather easy access one has to the tumor itself. This study is not completed yet; however, from our first observations, an apparently important relation between LDH-3 peaking and tumor response was found to occur and this prompts us to the present communication.
TL;DR: Heterogeneity (doubling) of the human complement component C′3, which can be detected by agar gel electrophoresis, has been described in two unrelated families of Flemish stock in Belgium.
Abstract: A GENETICALLY determined heterogeneity (doubling) of the human complement component C′3, which can be detected by agar gel electrophoresis, has been described in two unrelated families of Flemish stock in Belgium1,2. The frequency of this anomaly seems to be extremely low and no clear relationship with a diseased state has been detected. A similar anomaly which does not seem to be genetically determined has also been described3–5. The frequency of this anomaly is somewhat greater than the other and its occurrence has been correlated with the presence of neoplastic disease6.
TL;DR: In this paper, a gas chromatography of the head space was used to follow the evolution of hop aroma under different conditions of storage, and twenty-five compounds were identified in the more volatile fraction of hop extracts.
Abstract: Gas chromatography of the head space was used to follow the evolution of hop aroma under different conditions of storage. Aroma from fresh hops contains mainly myrcene, which disappears as the hops get older. Meanwhile new, more volatile substances are formed, especially by degradation of the well-known α- and β-acids; when hops are kept in closed storage the aroma therefore soon takes a composite character. When the formed volatiles are allowed to escape, the aroma of hops becomes poorer with age, to disappear almost completely in the end. Twenty-five compounds have been identified in the more volatile fraction of hop extracts.
TL;DR: Two precise and accurate methods for the determination of lutetium in the presence of other rare earths and after separation from a mineral, gadolinite, are described in this paper.
TL;DR: The acidity constants and stability constants of Ag(I) complexes of some ω-aminocarboxylic acids have been determined by a pH-metrical method at 25°C and in 0·5 M KNO3 as discussed by the authors.
TL;DR: The most important metallic impurities in titanium which give long-lived isotopes on neutron irradiation can be determined by a rapid anion-exchanged seperation of Ti, Sc, Cr, Na and Ag, after which the resin containing most of the impurities is counted on a high-resolution Ge(Li) γ-spectrometer.