Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 46 (1986), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: 4-Methylumbelliferyl (4-MU) lipase activity in human and mouse brain, measured with 4-MU palmitate, was characterized with respect to effects of pH and detergents, and subcellular and myelin localization. Purified myelin isolated by Norton's procedure [J. Neurochem. 21, 749–757 (1983)] contained higher specific activity of 4-MU lipase, particularly in alkaline pH. Myelin lipase activity was markedly affected by the addition of different types of detergents, the amount of detergents added, and substrate. The optimal pH in myelin was bimodal—pH 4.5 and up to 8.0, respectively. These data indicate that myelin possesses 4-MU lipase activity at alkaline pH, with lower levels at acidic pH.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 27 (1976), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The lipid composition of the brain, including myelin, was studied in detail in two cases with a variant form of metachromatic leukodystrophy (multiple sulphatase deficiency type).In the white matter, the sulphatide concentration was 3–4 times higher than the normal level in both cases. There was a significant accumulation of cholesterol sulphate in the brain, liver and kidney of both cases. The ganglioside pattern in the grey and white matter was abnormal, with a higher proportion of GM3, GM2 and GD3-gangliosides. Non-lipid hexosamine contents were increased 1.5-2 times in brain, 8–10 times in liver and 2–3 times in kidney. Increased amounts of glucocerobroside, ceramide lactoside and ceramide trihexoside were present in grey and white matter of both cases.Recovery of purified myelin from two patients’brains was much less than from control (1–20% in case 1 and 20–30% in case 2). The lipid composition of myelin was almost normal except for a higher proportion of sulphatide, with a decreased amount of cerebroside. The fatty acid compositions of myelin sulphatide and sphingomyelin were almost normal, while non-hydroxy fatty acids of cerebroside contained less long-chain fatty acids, as characterized by a significant increase of C16:0 and C18:0 fatty acids. The myelin polypeptide pattern by SDS-disc gel electrophoresis showed a relative decrease of basic protein and of proteolipid protein.A possible mechanism of myelin loss in MSD is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 18 (1971), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— Seven sphingoglycolipids were isolated from the white matter of a patient with globoid cell leucodystrophy (Krabbe's disease). After purification by saponification and column and preparative thin-layer chromatography, these compounds were analysed for the carbohydrate composition and sequence and for fatty acid composition by paper and gas-liquid chromatography. The compounds were identified as gluco- and galactocerebrosides, lactosyl-ceramide, digalactosy I-glucosyl-ceramide, two types of tetrahexosyl-ceramides (asialo-ganglioside and globoside), and sulphatide. Glucocerebrosideconstituted 13 percent of total cerebroside in white matter, but sulphatide contained only galactose. Galactocere-broside and sulphatide exhibited compositions of fatty acids similar to those in normal white matter, with only minor abnormalities. Other sphingoglycolipids showed fatty acid patterns with relatively high proportions of longer-chain fatty acids, rather than the predominant C18:0 acid usually found in ceramide hexosides of the brain. Hematoside, also found in the white matter in a significant amount, similarly contained a large proportion of longer-chain fatty acids, whereas other gangliosides contained predominantly C18:0 acid. The abnormal ceramide hexoside pattern was restricted mostly to white matter except for glucocerebroside, which constituted 32 per cent of grey matter cerebroside. We postulate that the visceral type of sphingoglycolipids may be constituents of globoid cells, abundantly present in white matter and considered to be cells of mesenchymal origin.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 19 (1972), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— The contents and the fatty acid composition of cholesterol esters were analysed in developing rat brain. The total content did not exceed 20 μg/brain throughout development. Elimination of serum by adequate perfusion was essential for accurate results. Two separate events appeared to affect the levels of cholesterol esters in developing rat brain, one probably reflecting general developmental changes and the other apparently related to myelination. On either a unit weight or a whole brain basis, the curves appeared to be a superimposition of the two events. There was an underlying developmental change, which was characterized on a unit weight basis by the highest level of cholesterol esters immediately after birth and a steady decline to the adult level by 30 days of age or which on the basis of whole brain was characterized by a steady increase throughout the development. A period of transient increase was superimposed on this underlying developmental change between the ages of 7 and 27 days and corresponded to the period of active myelination. The major fatty acids of rat brain cholesterol esters were palmitic, palmitoleic, oleic and arachidonic acids. Palmitic and palmitoleic acids decreased in proportion while oleic acid increased, as the animal matured. The fatty acid composition of serum cholesterol esters was distinctly different from that of brain cholesterol esters; those from serum contained much higher proportions of linoleic and arachidonic acids and much less palmitoleic and oleic acids.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 19 (1972), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— Three enzymes of cholesterol ester metabolism, a cholesterol-esterifying enzyme which incorporates free fatty acids into cholesterol esters without participation of CoA, and two cholesterol ester hydrolases with differing pH optima, all showed distinct changes in developing rat brains. The specific activity of the esterifying enzyme was approx. 20 percent of the adult level at birth, increased gradually to the adult level by 20 days of age and remained constant thereafter. The pH 4.2 hydrolase at birth also had a specific activity of about 20 per cent of the adult level but it increased rapidly to reach a peak at 13 days, by which time the activity had increased eight-fold. The activity declined somewhat thereafter to reach the adult level by 23–30 days. In contrast, there already was 60 per cent of the adult specific activity of the pH 6.6 cholesterol ester hydrolase at birth. The activity remained constant until 12 days and then doubled during the next two weeks, reaching a broad peak, then declining slightly to reach the adult activity by 50 days. Therefore, the developmental changes of both of the hydrolases appeared to be related to the process of myelination. The period of active myelination (10–30 days) was characterized by the sharp rise in the activity of pH 6.6 cholesterol ester hydrolase and by the rapid decrease of pH 4.2 cholesterol ester hydrolase.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— Cholesterol esters were isolated from cerebral cortex and white matter of patients with Schilder's disease, GM1-gangliosidosis and Tay-Sachs disease, and the fatty acid composition was determined by gas-liquid chromatography. The fatty acid composition was similar among the three pathological conditions, but it was entirely different from that reported for cholesterol esters of normal brain. Lecithin and ethanolamine phospholipids were isolated from the same brain specimens, treated with snake venom phospholipase A, and the fatty acids at the a’and β-positions of the glycerol moiety were determined separately. The fatty acid composition of cholesterol esters was similar to that of the β-position fatty acids of lecithin of white matter in all samples, and was quite different from those of the a'-position of lecithin, or of the a’or β-position of ethanolamine phospholipids. The results indicate that the source of fatty acids for cholesterol esterification in nonspecific sudanophilic demyelination is different from that in normal brain, and that the most likely source is the β-linked fatty acids of lecithin. There are two possible enzymic mechanisms; activation of phospholipase A and subsequent esterification of the liberated β-position fatty acids to cholesterol, or direct transacylation by lecithin-cholesterol acyl transferase.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— Several sulphatases (arylsulphatases A, B and C, cholesterol sulphatase, dehydroepiandroster-one sulphatase, cerebroside sulphatase and psychosine sulphatase) were deficient in various tissues from two patients with a variant form of metachromatic leukodystrophy. Deficient activities of cerebroside sulphatase and psychosine sulphatase, using physiological substrates, in tissues from metachromatic leukodystrophy with multiple sulphatase deficiencies provided another example that these enzymes may be identical to arylsulphatase A. β-Galactosidase activity was reduced to about 30-50 per cent of normal in brain and liver. Other lysosomal enzyme activities were found to be normal or elevated five to eight times. Arylsulphatase B isolated from the liver of one patient was abnormal, with respect to pi (70) and enzyme kinetics. In mixing experiments with normal enzymes the reduced activities of arylsulphatases A. B and C, cerebroside sulphatase and steroid sulphatases were shown not to be due to the presence of endogenous inhibitors. No arylsulphatase A or B activity in the brain specimen from the patient with multiple sulphatase deficiencies could be detected on isoelectric focussing. In normal brain tissue arylsulphatase A had a pi of 4-6-4-8 while arylsulphatase B had a pi of 7-8 and 8-1. When 4-methylumbelliferyl sulphate was used as a substrate the elution patterns of normal brain and liver arylsulphatase B were more heterogeneous and showed more variation than that when p-nitrocatechol sulphate was used. Arylsulphatase C and steroid sulphatases (cholesterol sulphatase, dehydroepiandrosterone sulphatase and oes-trone sulphatase I were solubilized by the addition of lysolecithin and Triton X-100 and subjected to isoelectric focussing. The pi of cholesterol sulphatase, oestrone sulphatase and arylsulphatase C was 6-8, and the elution patterns of the activities of these enzymes were similar. The pattern of dehydroepiandrosterone sulphatase was more heterogeneous and two major peaks were observed at pi 6 5 and 70. Residual enzyme activities of arylsulphatase C and steroid sulphatases from the brain of the patient with multiple sulphatase activities were not detectable by isoelectric focussing. Simultaneous deficiencies of arylsulphatase C and steroid sulphatases plus isoelectric focussing findings in tissues suggest that these enzymes are closely related in regard to their function. The nature of the genetic defect in metachromatic leukodystrophy with multiple sulphatase deficiencies is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 20 (1973), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We Previously demonstrated two distinct cholesterol ester hydrolases in rat brain (Eto and Suzuki, 1971). One of the two hydrolases had a pH optimum of 6·6 and showed a bimodal subcellular distribution, in microsomes and myelin. A substantial activity of this enzyme was present in newborn rat brain. The activity remained relatively unchanged during the first 12 days and then increased sharply, concomitant with the period of active myelination (Eto and Suzuki, 1972a). The more recent investigation, however, clearly demonstrated that this pH 6·6 cholesterol ester hydrolase actually consists of two distinct cholesterol ester hydrolases, one primarily localized in microsomes and the other almost exclusively localized in the myelin sheath (Eto and Suzuki, 1972b, 1973). The microsomal hydrolase had a pH optimum of 6·0 and was activated by sodium taurocholate and Triton X-100, particularly by the latter. The myelin enzyme had a pH optimum of 7·2. It was activated by sodium taurocholate but slightly inhibited by Triton X-100. These new findings suggested that the previously reported developmental curve of the pH 6·6 cholesterol ester hydrolase was probably a composite of developmental changes of these two distinct cholesterol ester hydrolases. We report here the findings which confirm the above prediction and update the information regarding the developmental changes of the enzymes involved in cholesterol ester metabolism in rat brain.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0014-5793
    Keywords: Activin receptor ; Ovary ; mRNA
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Molecular Cell Research 1055 (1990), S. 278-286 
    ISSN: 0167-4889
    Keywords: (Human acute myeloid leukemia cell) ; Erythroid differentiation ; Phorbol ester
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...