Showing papers by "Utrecht University published in 1973"
TL;DR: It is concluded that thisospholipid fraction (which contains the majority of the choline-containing phospholipids and some phosphatidylethanolamine) forms the outer monolayer of the membrane.
1,022 citations
TL;DR: A new concept for the haemolytic behaviour of mixtures ofospholipases is proposed, based upon a highly asymmetric distribution of the phospholipids in a bimolecular leaflet, and taking into account some aspects of the action of phospholIPases towards red cell ghosts.
404 citations
TL;DR: To eliminate the large excess of adenovirus coat proteins, synthesised in human cells, which are known to bind to DNA, the authors used African green monkey cells as hosts and found that in these cells viral DNA synthesis occurs at a normal rate but late viral capsid proteins are not produced or are synthesisedin very small amounts.
Abstract: DURING productive infection of human cells with types 2 or 5 adenovirus a number of proteins specific for the infected cells, but not found in the intact virion, can be detected by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (SDS)1, 2. None of these proteins, however, has been isolated in a native state and therefore their functions remain obscure. The observation that replicating adenovirus DNA contained extensive single stranded regions (refs 3, 4 and U. Petterson, personal communication) led us to look for proteins specific for infected cells that bind only to single stranded DNA and may be involved directly in DNA replication. Such a class of proteins, originally described by Alberts and Frey5, has now been found in a number of prokaryotic systems5–7 as well as in mammalian cells8, 9 and they are known, at least in the case of T4 gene 32 protein, to be required for DNA replication and genetic recombination5. To eliminate the large excess of adenovirus coat proteins, synthesised in human cells, which are known to bind to DNA10, we used African green monkey cells as hosts. In these cells viral DNA synthesis occurs at a normal rate but late viral capsid proteins are not produced or are synthesised in very small amounts11.
235 citations
TL;DR: The results indicate that when cholesterol is present in membrane with lipids in both the crystalline and liquid-crystalline state, cholesterol preferentially interacts with these lipids which are in the liquid- crystals state.
222 citations
TL;DR: The observed specificity, the effects of different solutes, differences in fatty acid chain length of the lipids and the increase in area at constant pressure demonstrate that ionic and hydrophobic forces are involved in the interaction of A1 basic protein and lipids.
195 citations
TL;DR: The fatty acid composition and cholesterol content of the membrane lipids of Acholeplasma laidlawii B were systematically altered and the rates at which glycerol and erythritol passively diffuse into intact cells and into liposomes prepared from the total membrane lipid were measured.
179 citations
TL;DR: The tetrapeptide ACTH 4-7 is found to be the short peptide that still bears the essential elements required for the behavioral effects of ACTH, and the chapter tries to increase the behavioral potency of the sequence ACTH4-9 by introducing certain structural modifications.
Abstract: Publisher Summary This chapter describes the influence of peptides derived from corticotrophin (ACTH) on performance In the study reported in the chapter, two approaches are followed First, it sought the small peptide sequence of ACTH that possesses essentially the same behavioral effects as ACTH itself Second, the chapter tries to increase the behavioral potency of the sequence ACTH 4-9 by introducing certain structural modifications Attention is focused on the dissociation between behavioral activity and melanocyte stimulating hormone (MSH)-like potency The influence of peptides derived from ACTH on acquisition and extinction of conditioned avoidance behavior in rats was studied The tetrapeptide ACTH 4-7 is found to be the short peptide that still bears the essential elements required for the behavioral effects The improved performance of hypophysectomized rats treated with ACTH or fragments of ACTH is neither due solely to improved motor and/or sensory capacities nor to an increase in the level of general activity
167 citations
TL;DR: In this paper, the exchange of phosphatidyicholine between two separate monolayers and between monolayer and liposomes was investigated, and the phosphatidylcholine exchange protein from beef liver acted in those systems as a carrier of the substance.
Abstract: The exchange of phosphatidyicholine was investigated between two separate monolayers and between monolayer and liposomes. The phosphatidylcholine exchange protein from beef liver acted in those systems as a carrier of phosphatidyicholine.
147 citations
TL;DR: Freeze-etch electron microscopy demonstrated that filipin induces the formation of aggregates 150–250Ain diameter, in the membranes of rat erythrocytes, in cholesterol-containing membranes of Acholeplasma laidlawii cells and in egg lecithin-cholesterol liposomes.
147 citations
TL;DR: In the anaerobic reaction of soybean lipoxygenase with linoleic acid and enzymically formed hydroperoxy linolesic acid the involvement of linoleoic acid radicals is demonstrated.
138 citations
TL;DR: It is concluded that cholesterol, by preventing the crystallization of membrane lipids maintains them in a state of fluidity essential for the optimal manifestation of several key activities of the membrane.
TL;DR: The combination of sphingomyelinase andospholipase C produced haemolysis of human and pig erythrocytes and extensive degradation of all the phospholipid classes in the ghosts thus produced; in contrast, the combination of these two enzymes failed to produce lysis of ox and sheep ery throat cells.
TL;DR: It is demonstrated that the liquefying effect of cholesterol on the membrane lipids of A. laidlawii can be very important in maintaining proper membrane functioning in growing cells.
TL;DR: In this article, the authors compared conductivity data for In2O3 both from literature and from new measurements and concluded that non-stoichiometric In 2O3 is an n-type semiconductor.
TL;DR: Freeze-etch results with liposomes consisting of two lecithins are consistent with differential scanning calorimetric experiments and band patterns are found along with smooth areas when the material is quenched from a temperature between the two peaks.
TL;DR: The mean urinary production rate of D and DS were lower in the breast cancer patients than in the normal subjects, and the difference was significant (p < 0.025) for DS.
Abstract: Urinary production rates of dehydroepiandrosterone (D) and dehydroepiandrosterone sulfate (DS) by isotope dilution, and the blood production rate of androstenedione (A) by continuous infusion technique have each been measured in 8 normal postmenopausal women. Both measurements were done in a group of 6 breast cancer patients. The cancer patients were at the time of the primary operation at least 6 yr postmenopausal; at the time of the study they were at least 3 yr after the operation. All of them were in good health and free of demonstrable recurrence of the tumor. The contribution of D and DS to urinary estrogens and the conversion of A to estrone were each determined in 8 normal postmenopausal women. Both measurements were done in the 6 breast cancer patients. The mean urinary production rate of D and DS were lower in the breast cancer patients than in the normal subjects. The difference was significant (p < 0.025) for DS. In the breast cancer patients the excretion of ll-deoxo-17-oxosteroids (11- DOKS)...
TL;DR: The mechanism of fluorescence enhancement of lipoxygenase induced by oxygen is discussed in relation to similar observations previously described for fluorescent molecules contained in a solid polyvinyl matrix.
TL;DR: Peptide maps showed that the N-terminal part of the protein molecule (positions 20–113) is preserved in the lipid phase of the A1 basic protein lipid interaction, which is characteristic for the myelin lipids.
TL;DR: Experimental data indicate that the aminergic fibres in the pars intermedia exert an inhibitory influence on MSH-release.
Abstract: In tadpoles of Xenopus laevis the histochemical distribution of monoamines in the tel-, di- and mesencephalon was studied. Catecholamines are present in some mitral cells of the olfactory bulb, the neurons of the preoptic recess organ (PRO), the neurons of the paraventricular organ (PVO) and cells in the vicinity of the PVO, namely the so-called PVO-accompanying cells, the nucleus infundibularis dorsalis (NID) and in the nucleus reticularis mesencephali (NRM). The PRO, PVO, and NID are composed of liquor-contacting neurons. With the Falck-technique, in the PVO and NID two types of fluorescent cells were observed: green cells, containing a catecholamine and yellow-orange cells, presumably containing a tryptamine. Tryptaminergic neurons occur in the NRM and in the area of the raphe nucleus. Extensive tracts of fluorescent fibres originating in the hindbrain ascend to the area praeoptica and the septum, striatum and epistriatum of the telencephalon. Also, fibre connections could be traced from the PVO to the area praeoptica, to the thalamus and to the nucleus ventromedialis tuberis. The PVO and/or NID give rise to a catecholaminergic tract running towards the hypophysis. Fibres of this tract partly terminate in the developing median eminence and partly in the pars intermedia. Experimental data indicate that the aminergic fibres in the pars intermedia exert an inhibitory influence on MSH-release.
TL;DR: Differences in A 1 basic protein-lipid interaction in different animals arising from differences in lipid composition and fatty acid composition of the different lipid species combined with minor changes in the protein sequence could explain the species variability of the encephalitogenic sites of the A 1basic protein.
TL;DR: The amino- and organic acids together incorporated about 85 per cent of the total radioactivity of mussel homogenate both after 24 and 48 hr of anaerobiosis, and the incorporation of radioactivity by the amino acids was mainly confined to alanine and glutamic acid.
Abstract: 1. 1. The distribution of radioactivity over different classes of chemical compounds from glucose- ul - 14 C injected into the sea mussel Mytilus edulis was examined after 24 and 48 hr of anaerobiosis. 2. 2. The amino- and organic acids together incorporated about 85 per cent of the total radioactivity of mussel homogenate both after 24 and 48 hr of anaerobiosis. 3. 3. The incorporation of radioactivity by the amino acids was mainly confined to alanine and glutamic acid. The level of alanine remained much the same after 24 or 48 hr of incubation but the level of glumatic acid increased. 4. 4. The incorporation of radioactivity by the organic acids was mainly confined to succinate.
TL;DR: The products of the hydrolysis of 1-acyl-glycerylphosphorylcholine containing long chain acyl groups were shown to be free fatty acid and glyceryl phosphoryl choline, whereas long chain phosphatidylcholine was not attacked at all.
TL;DR: In this article, the authors analyzed the effect of thermal convection and diffusion on mass transfer in a gaseous phase and derived an expression for the ratio of the mass transfer by thermal convections and diffusion in a closed-tube process.
TL;DR: In this paper, the Faddeev formalism was applied to the local two-body S-wave potentials and the results were compared with those of the separable potential model.
TL;DR: It is concluded that the action of DDT and allethrin in the lateral-line organ is not primarily on the hair cells, but on the impulse-generating process in the afferent nerve terminal, probably by an effect on the sodium conductance of the membrane.
TL;DR: The segregation of the lipids and their specific associations with the basic proteins are discussed in relation to the structure of myelin.
TL;DR: It is demonstrated that red disease, an acute disease of pike fry, with unknown aetiology, causing severe losses in Dutch pike culture, is caused by a rhabdovirus.
Abstract: RED disease has been described as an acute disease of pike fry, with unknown aetiology, causing severe losses in Dutch pike culture1. Its name was derived from the haemorrhagic lesions in the trunk, usually situated above the pelvic fins, and visible as bilateral red swollen areas in the diseased fry. In a serious outbreak during the spring of 1972 at a hatchery near Lelystad, only 0.6% of about 1,850,000 cultured young pike reached a length of 4 to 5 cm and could be used for stocking inland fishing waters. About 86% of the total mortality rate was due to red disease. Healthy fry placed in the same tank as diseased fry became infected, and it was concluded that the disease could be transmitted through water. No evidence was obtained that the disease was caused by bacteria. Here we describe work which demonstrates that the disease is caused by a rhabdovirus.
TL;DR: In this article, a complete interpretation of 220 MHz PMR spectra and the accurate chemical shifts and coupling constants, obtained after computer simulation of the spectra, of a number of TMS-mono and disaccharides are given.