Biomedical subjects

H Wiegandt

Publications and source records attributed to H Wiegandt.

At least 37 records · Page 2Linked to original sources

PubMed1992

Insect glial cells show differential expression of a glycolipid-derived, glucuronic acid-containing epitope throughout neurogenesis: detection during postembryogenesis and regeneration in the central nervous system of Tenebrio molitor L.

The monoclonal antibody CAF-1 recognises a glucuronic acid-containing epitope present on insect acidic glycolipids. Immunohistochemical analysis of the CAF-1 epitope has revealed its differential, temporal and spatial expression during postembryogenesis of the midbrain of Tenebrio molitor. Electron microscopic resolution demonstrated, that the CAF-1 epitope is expressed on glial cells that ensheath the glomeruli of the central body. Concomitantly, a differential pattern of expression was observed in the ventral nerve cord, exhibiting a serially homologous display on glial cells that ensheath neuronal somata in the cell body layer of the thoracic ganglia and ventral associative neuropil. Prominent, topologically restricted CAF-1 immunoreactivity was monitored in termination areas of sensory neurons in the ventral associative neuropil and corresponding nerves 6-48 h after extirpation of the respective sensory neuron somata. CAF-1 expression is correlated with structural reorganisation in postembryonic nervous tissue of T. molitor.

Animals↗

PubMed1992

Glycosphingolipids in cestodes. Chemical structures of ceramide monosaccharide, disaccharide, trisaccharide and tetrasaccharide from metacestodes of the fox tapeworm, Taenia crassiceps (Cestoda: Cyclophyllidea).

The presence of glycosphingolipids in the metacestodes of the fox tapeworm, Taenia crassiceps, has been established. The normal-phase TLC pattern of the neutral-fraction glycolipids revealed groups of bands corresponding to homologous components of increasing sugar chain length. The three simplest glycolipid components have been isolated and their chemical constitution determined as being of the neogala series: Gal beta 1Cer, Gal beta 6Gal beta 1Cer and Gal beta 6Gal beta 6Gal beta 1Cer. The ceramide tetrasaccharide fraction has been found to consist of a mixture of neogalatetraosylceramide, as an elongation of the neogala series, Gal beta 6Gal beta 6Gal beta 6Gal beta 1Cer and the component Gal alpha 4Gal beta 6Gal beta 6Gal beta 1Cer (both occurring in approximately equimolar proportions). The long-chain bases of the ceramide monogalactoside, digalactoside, trigalactoside and tetragalactosides contain, as well as small amounts of sphingosine, predominantly dihydrosphingosine/phytosphingosine in the approximate ratios 1.7:1, 1.4:1, 1:1 and 2.3:1, respectively. The major ceramide fatty acids have particularly long chains, with hexacosanoic and octacosanoic acids predominating. Upon reverse-phase TCL, the glycolipid components ceramide monogalactoside, digalactoside and trigalactoside were each separable into five component bands. Parent glycolipid components therefore show component band distributions comparable to one another in being governed by similar ceramide constitutions.

Animals↗

PubMed1992

Insect glycolipids.

Systematic elucidations of the chemical structures of glycosphingolipids from members of the phyla Arthropoda (class:insecta) of the Protostomia have shown several characteristic differences to those of the Deuterostomia, e.g., the Vertebrata. The ceramide constituents of the arthropod sphingolipids are C14:1- and C16:1-sphingoid and a majority of saturated C18-, C20-, C22- and C24-fatty acids. The GSL of the dipteran insects, L. caesar and C. vicina, consist of a series of homologous compounds of increasing sugar chain length. The carbohydrate moieties of these arthropod GSL are all derived from one unique neutral sugar core sequence, the arthro-series. The longest member known, an arthrononaosylceramide has the structure Gal beta,3GalNAc beta,3GlcNAc beta,3Gal beta,3GalNAc alpha,4GalNAc beta,4GlcNAc beta,3Man beta,4Glc beta Cer. Three pentahexosylceramides have been characterized that differ in their nonreducing terminus, i.e., IV4GalNAc alpha-Ap4Cer, IV3Gal alpha-Ap4Cer and IV3Gal beta-Ap4Cer. A large repertoire of structural variations of the arthro-series GSL is created by two types of derivatisations of the neutral carbohydrate core: addition of a zwitterionic 2-aminoethylphosphate group in phosphodiester linkage to the 6-position of the III-N-acetylglucosamine of the arthrotriaosylceramide core and/or substitution of a terminal galactose in 3-position by a glucuronic acid residue. The latter acidic arthro-series GSL were given the name arthrosides. Preliminary results have indicated that the blowfly GSL component distribution is strongly organ specific. GSL of various larval organs are distinguished by the length of their neutral core carbohydrate chain, as well as, the degree of PEtn- and GlcA-substitutions. Normal human sera contain antibodies that recognize epitopes on arthro-series GSL. Thereby, sites of the neutral carbohydrate chain, as well as, the zwitterionic and acidic epitopes are involved in the immune recognition. In a pathological condition, a M-protein of patients with autoallergic demyelinating peripheral neuropathy was found to react strongly with a glucuronic acid-containing molecular structure on arthrosides. Some indication was obtained for a possible functional role of glucuronic acid in dipteran-cell adhesion by using a mouse monoclonal antibody, mAb CAF-I. This antibody, directed against an arthroside epitope involving glucuronic acid, could induce an in vitro detachment of insect cells from one another or from their substratum. Obviously, present research on the GSL of insects is only at an early stage. Nevertheless, from the results available so far it was become increasingly apparent that a new chapter in our knowledge of GSL structures has been opened.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1992

Gangliosides in meningiomas: correlation of Glac2 to intermediary filament.

Human meninges and 29 meningiomas were analyzed as to their glycosphingolipid composition. In the neutral fraction GSL, a mostly even distribution of mono-, di-, tri-and tetrahexoside was demonstrated. In the group of the gangliosides, Glac1 in one broad band in chromatograms occurred in almost all meningiomas; Glac2 was present in 84% of tumours. Members of the Gtn-family were only found in a small minority of tumours while various Gtet-gangliosides were detectable in nearly half of them. No constant pattern or patterns emerged and no correlation to either morphological subtype or malignancy grade could be established. Immunohistochemistry revealed focal presence of Glac2 in a pattern similar to that of vimentin expression. Semiquantitative evaluation showed good correlation between both parameters.

Biomarkers, Tumor↗

PubMed1992

Comparative serological reactivity of Taenia crassiceps, Taenia solium and Taenia saginata metacestode neutral glycolipids to infection serum from Taenia crassiceps-infected mice.

A comparative survey was undertaken of the neutral fraction glycolipids from the metacestodes of 3 taeniid species, Taenia crassiceps, Taenia solium and Taenia saginata, to determine their chemical and serological staining patterns on separation by thin-layer chromatography. The orcinol-positive patterns of T. solium and T. saginata metacestodes exhibited a closer superficial resemblance to each other than to T. crassiceps or T. saginata adults. A comparison of component migration properties against standards of known structure indicated the main oligosaccharide chains to be mono-, di-, tri- and tetrasaccharides; however, in T. solium this was extended to at least a heptasaccharide. The multiple banding characteristic of each component is a consequence of lipid moiety heterogeneity. Serologically, the patterns of the 3 taeniid species neutral fraction glycolipids showed virtually the same immunological reactivity towards mouse normal serum, infection serum and a monospecific, polyclonal antibody directed against the trisaccharide component of T. crassiceps. The latter antibody was isolated from mouse infection serum by affinity chromatography on a column of glycolipid-bound octyl-Sepharose CL-4B. Immunochemically, the major common epitope expressed by the neutral fraction glycolipids of the 3 taeniid species is the same or very similar to the glycosphingolipid, neogalatriaosyl ceramide derived from the marine mollusc Turbo cornutus (Gal(beta 1-6) Gal(beta 1-6) Gal(beta 1-1)Cer). Host tissue neutral fraction glycolipids, porcine muscle and bovine muscle, as well as human spleen, were not immunoreactive.

Animals↗

PubMed1992

Expression of GD2-epitopes in human intracranial tumors and normal brain.

Two monoclonal antibodies (mabs) were raised against ganglioside GD2 (Gtri2) and tested on human intracranial tumors and normal brain by immunohistochemical methods both in frozen and paraffin embedded sections. In normal brain structures, astrocytes were visualized with both mabs (BW 625 and BW 704) almost exclusively in the subventricular and subpial layer. A minor amount of myelin sheaths in well defined localisation was only recognized in frozen sections. Consequently in astrocytic tumors of different grades of malignancy (WHO I-IV), astrocytes were depicted in their characteristic shape and arrangement around vessels. In addition, staining was observed in meningiomas and schwannomas, but not in pituitary adenomas or metastatic carcinomas. In meningioma und schwannoma the staining was restricted to the cellular periphery and was again present in frozen section material and absent in paraffin embedded tissue. In astrocytes, reactive and neoplastic, obviously fibrous processes and cytoplasm were distinctly stained both in frozen and paraffin embedded sections. It is concluded that some neuroectodermal derived cells as well as myelin of defined localisation express GD2 on the membrane surfaces and in the cytoplasm. The latter may primarily be the case in fibrous astrocytes, which were stained in reactive and pathologic conditions. The reaction can be used as diagnostic tool in astrocytic tumors; its positive therapeutic significance is hampered by the fact that (1) not all cells in heterogeneous tumor populations express the epitope and (2) there are normal structures which do so.

Antibodies, Monoclonal↗

PubMed1992

Chemical distribution of glycosphingolipids in third-instar larval organs of the blowfly, Calliphora vicina (Insecta: Diptera).

As a first approach to testing the working hypothesis that glycosphingolipids are functionally involved in the ontogeny of insects, their chemical distribution in larval organs was determined and any stadium-correlated differences documented. Selected organs, i.e., the fatbody, striated muscle, intestinal tract, salivary glands, imaginal discs, and central nervous system, were dissected from seven-day-old larvae of the blowfly, Calliphora vicina, and their glycolipids isolated. Two-dimensional, high-performance thin-layer chromatography was used to separate the neutral and acidic glycolipids of each organ. Significantly different total glycolipid component-patterns were obtained for the individual organs, whereby, except for a number of additional uncharacterized components in the intestinal tract, the neutral glycolipids of all organs were found to be qualitatively similar. However, major quantitative differences between the selected organs were found in their total glycolipid-carbohydrate contents, as well as the respective quantitative neutral glycosphingolipid-component distributions. The acidic glycolipids showed pronounced qualitative as well as quantitative organ-dependent variations. Whereas the highest proportion of uncharged glycolipids was characteristic of the fatbody, a high proportion of zwitterionic glycolipid-components was observed to be typical of the central nervous system and imaginal discs, i.e., of organs persisting during larval life and throughout metamorphosis. Imaginal disc glycolipids were distinguished by their high content of acidic glycolipids, a putative reflection of the functional role of these glycoconjugates in regulated cell reorganization during metamorphosis.

Animals↗

PubMed1992

Immunohistochemical localisation of monoclonal antibody R 24-recognized ganglioside Glac2 in early chick embryos.

The spatio-temporal cellular expression and biosynthesis of ganglioside Glac2 was investigated in early chick embryogenesis. For demonstration of embryonic Glac2-biosynthesis, chick embryos of stage 0 and of stages 4-5 were incubated in vitro in the presence of radioactive sugar precursors. It was found that chick embryos synthesize Glac2 as early as at the blastula stage as well as at the gastrula stage, both within the area pellucida and the area opaca. In contrast to the biosynthetical findings immunohistochemical staining of the chick embryos at various stages by aid of the mouse monoclonal antibody (mAb) R 24, specific for the immunoepitope NeuAc alpha, 8NeuAc alpha, 3Gal beta less than, as present on the ganglioside Glac2, revealed a spatio-temporal cellular pattern of expression of this ganglioside in early chick embryos. Immunohistochemical staining of the chick embryo at stage 0 shows that all cells of the embryo, the extraembryonic epiblast and the yolk endoderm included, are mAb R 24-positive. At the intermediate streak stage (stage 3), the cranial part of the deep layer, the so-called endophyll, is strongly mAb R 24-positive, whereas at the end of gastrulation (stage 5), mAb R 24-recognized epitopes appear to be restricted to a narrow band of deep-layer cells in the endophyllic crescent and to the yolk endoderm of the area opaca. At this stage, no labelling by the antibody is observed in cell layers of the future embryo. The beginning of neurulation (stage 7) is characterized by the expression of the mAb R 24-recognized epitope in the notochord, whilst the deep layer in the cranial part of the neural fold still expresses this epitope. No ecto- or mesodermal structures are stained by the antibody at this developmental stage. During further development (stage 12 and 13), mAb R 24-reactivity is restricted to the cranial part of the embryo with a preferential staining of cells of endodermal origin. At these stages, the notochord expresses mAb R 24 binding sites only in its cranial region. The spatial and temporal correlation between the presence of mAb R 24-recognized epitopes and the morphogenetic positioning of tissues may be indicative for a possible role of the ganglioside Glac2 in corresponding cellular interactions.

Animals↗

PubMed1991

Analyses of the effect of monensin on glycosphingolipid metabolism.

The effect of monensin on glycosphingolipid metabolism was reinvestigated. It was found that monensin increased the uptake of [3H]galactose by human fibroblasts, causing an enhanced metabolic labelling of glycosphingolipids. The preferential incorporation of radioactivity into ceramide monosaccharide in the presence of monensin was accompanied by an equally increased rate of degradation. However, using radiolabelled precursors of the ceramide moiety, a generally diminished uptake of radioactivity into all glycosphingolipids was observed under the influence of monensin, with the exception of mono- and di-hexosylceramide. The enhanced incorporation of radiolabel by these two glycolipids, as well as their increased cellular chemical content, may reflect early synthesis in a monensin-insensitive pre-Golgi compartment after disruption of the cellular Golgi transport system by monensin.

Cells, Cultured↗

PubMed1991

Glycosphingolipids in insects. The amphoteric moiety, N-acetylglucosamine-linked phosphoethanolamine, distinguishes a group of ceramide oligosaccharides from the pupae of Calliphora vicina (Insecta: Diptera).

A group of Calliphora vicina pupal glycolipids could be segregated from the neutral glycosphingolipids, according to their two-dimensional TLC migration properties and positive reactions toward ninhydrin and fluorescamine spray reagents. These classified zwitterionic glycolipids were isolated by silica-gel column chromatography and characterized by the presence of a N-acetyl-glucosamine-bound phosphoethanolamine residue. The structural elucidation of the oligosaccharide moieties was performed by the determination of constituent carbohydrates as alditol acetates, linkage analysis by permethylation, exoglycosidase cleavage, fast-atom-bombardment mass spectrometry and NMR spectroscopy. The dominant fatty acid and sphingoid base species of the ceramide moieties were C20:0 (arachidic acid) and C14:1 (tetradecasphing-4-enine), respectively. The chemical structures of the zwitterionic, biogenetic glycosphingolipid series were determined as: (PEtn-6')GlcNAc(beta 1-3)Man(beta 1-4)Glc beta Cer; GalNAc(beta 1-4)(PEtn-6')GlcNAc(beta 1-3)Man(beta 1-4)Glc beta Cer; GalNAc(alpha 1-4)GalNAc(beta 1-4)(PEtn-6')GlcNAc(beta 1-3)Man(beta 1- 4)Glc beta Cer; Gal(beta 1-3)GalNAc(beta 1-4)(PEtn-6')GlcNAc(beta 1-3)Man(beta 1-4)Glc beta Cer; Gal(beta 1-3)GalNAc(alpha 1-4)GalNAc(beta 1-4)(PEtn-6')GlcNAc(beta 1- 3)Man(beta 1-4)Glc beta Cer; GlcNAc(beta 1-3)Gal(beta 1-3)GalNAc(alpha 1-4)GalNAc(beta 1-4)(PEtn- 6')GlcNAc(beta 1-3)Man(beta 1-4)Glc beta Cer.

Acetylglucosamine↗

PubMed1991

Immunological recognition of larval Taenia crassiceps glycolipids by sera from parasite-infected mice.

The isolation and purification of a neutral glycolipid fraction from Taenia crassiceps metacestodes (KBS strain), harvested from both male and female NMRI mice at 70-80 days following intraperitoneal infection, revealed 24 thin-layer chromatography-designated glycolipid bands. The glycolipids were defined as ceramide mono- (n = 3), di- (n = 3), tri- (n = 4), tetra- (n = 5), and greater than tetrasaccharides (n = 9) according to their running properties as defined by thin-layer chromatography against standards of known structure. The defined glycolipids were tested for immunoreactivity with sera from noninfected and T. crassiceps-infected NMRI mice (intraperitoneal injection or implantation of 15 larvae/animal) using the enzyme-linked immunosorbent assay (ELISA) until day 33 p.i. (IgM and IgG reaction) and high-performance thin-layer chromatography (HPTLC) combined with immunostaining (IgG reaction) until day 7 p.i. ELISA-determined IgM and IgG titres were significantly elevated from day 5 p.i. Immunostaining revealed early reactivity for certain ceramide tetra- and greater than tetrasaccharides (n = 6) on day 3 p.i. From day 5 p.i. onwards, nearly all glycolipids, including ceramide mono- and disaccharides, were recognized by the sera from metacestode-challenged mice. On day 7 p.i., a total of 22 bands were serologically active; of these, a considerable number (n = 10) showed increased staining intensity. Remarkably, in many cases (10 of 20), 3 glycolipids (tetra- and greater than tetrasaccharides) were weakly recognized by mouse sera taken before infection.

Animals↗

PubMed1991

Tissue architecture and glycosphingolipid content in human gliomas II-IV.

Contradictory results have been reported claiming either none, partial or almost complete correlation between the complexity of GSL compound profiles and the assumed glial tumor differentiation. Therefore an attempt was made to compare GSL patterns with both the general (final) tumor diagnosis and malignancy grade (WHO) as well as the regional evaluation of the histology and the grading in the tumor tissue pieces directly subjected to biochemical analysis. Regional and general (final) diagnosis did not always correspond, especially when more than one tissue sample of a given tumor was analyzed. Four GSL component patterns were identified by TLC: GSL-type I with gangliosides primarily of the simple Glac-family lacking sulfatide and the more complex Gtri- and Gtet-gangliosides, GSL-type II with ganglioside of the Glac- and Gtri-families, also without sulfatide, and GSL-type III, with more complex gangliosides of the Gtri- and Gtet-families in addition to Glac-gangliosides and sulfatide, similar to the normal brain pattern, and the pattern of normal brain. There was only insufficient correlation between these GSL-type patterns and final diagnoses. However, between regional diagnosis of astrocytoma II and GSL-type III on the one hand and glioblastoma multiforme IV and GSL-type I on the other hand, a coincidence of more than 85% was found. In only 50% the intermediate GSL-type II and glioma III were associated. There was no relation between GFAP or vimentin expression and histology or GSL-type both with regard to final and regional diagnoses. Regional astrocytoma architectures exhibiting GSL-type III were mostly fibrillary, whilst glioblastomas with GSL component pattern I had often a giant cell make up.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Differentiation↗

PubMed1991

Human heterophile antibodies recognizing epitopes present on insect glycolipids.

As a consequence of detecting an IgM M-protein (naturally occurring diseased-state monoclonal antibody) immunoreactive to insect acidic glycolipids in a patient with demyelinating peripheral neuropathy, normal human sera were examined for the occurrence of heterophile antibodies directed against carbohydrate epitopes present on glycosphingolipids of Calliphora vicina (Insecta: Diptera). The insect glycolipids can be separated into neutral, zwitterionic, and acidic types, according to whether the oligosaccharide chains consist of neutral monosaccharides only, or carry an additional phospho-ethanolamine side chain and/or a beta-glucuronic acid residue, respectively. Natural antibody activity to these three classes of insect glycosphingolipids was detected in all normal human sera examined. The antibody activities were separated by sequential chromatography on affinity columns of octyl-Sepharose 4B-bound neutral and zwitterionic glycolipids into three populations with differing epitope-type specificities. As expected for heterophile antibodies, they are mainly of the IgM class. Population I recognized epitopes present on the three types of insect glycolipids, i.e., the neutral oligosaccharide chain backbone, the main determinant of which contains a terminal N-acetylhexosamine. Immunoreactivity is separable into at least four subpopulations of differing carbohydrate epitope specificity. Population II recognized epitopes containing phosphoethanolamine in zwitterionic and some acidic insect glycolipids. There are two subpopulations, the majority of which require the free amino group of phosphoethanolamine for immunoreactivity. Population III antibodies showed immunoreactivity to terminal beta-glucuronic acid-containing epitopes present only on acidic insect glycolipids.

Animals↗

PubMed1991

Gangliosides: the relevance of current research to neurosurgery.

Gangliosides are complex glycolipids found on the outer surface of most cell membranes: they are particularly concentrated in tissues of the nervous system. Gangliosides form part of the immunological identity of mammalian cells and are involved in a variety of cell-surface phenomena such as cell-substrate binding and receptor functions. In tumorous tissue, the ganglioside composition is altered, sometimes in direct proportion to the degree of malignancy. The literature on the glycosphingolipid composition and immunology of intracranial tumors is reviewed. Some gangliosides induce neuritogenesis and exhibit a trophic effect on nerve cells grown in vitro. In vivo, a particular ganglioside, GM1, reduces cerebral edema and accelerates recovery from injury (traumatic and ischemic) to the peripheral and central nervous systems of laboratory animals. Preliminary clinical studies have shown that treatment with gangliosides may have corresponding effects on lesions of the human peripheral nervous system. Gangliosides have not been tested in human subjects with brain injury.

Animals↗

PubMed1990

Glycosphingolipids of human gliomas.

Histologically characterized human gliomas of various grades of malignancy obtained during surgery were extracted, and their glycolipids were isolated and partially identified. Among the gliomas analyzed, three types of glycolipid component distribution could be identified. The glycosphingolipid (GSL) type I pattern correlated closely with that of the most malignant gliomas (Grade IV). Its neutral GSLs consisted of glucosyl- and, as a major component, dihexosylceramide, in addition to globo- and neolactotetraosylceramide. Galactosylceramide and sulfatide were absent. The gangliosides of GSL type I were almost exclusively of the GLac family, aside from small amounts of neolacto-series-derived species. The neutral components of GSL type II were similar to those of GSL type I. The acidic compounds of GSL type II were gangliosides of the Gtri family and trace amounts of neolacto-series sialoglycolipids, in addition to GLac1 and GLac2. GSL type II contained no Gtet gangliosides and no sulfatide. The GSL type III pattern was that of the most benign gliomas, with all glycolipids present that are found in normal brain and, in addition, those of the GSL type II.

Astrocytoma↗

PubMed1990

Glycosphingolipids in insects. Chemical structures of two variants of a glucuronic-acid-containing ceramide hexasaccharide from a pupae of Calliphora vicina (Insecta: Diptera), distinguished by a N-acetylglucosamine-bound phosphoethanolamine sidechain.

The two major components of the acidic glycolipid fraction from the pupae of Calliphora vicina were isolated using high-performance liquid chromatography. The acidic moiety was identified as glucuronic acid by beta-glucuronidase cleavage and gas chromatographic analysis as the pentafluoropropionyl derivative. The structures of the carbohydrate moiety were elucidated by peracetylation, methylation, exoglycosidase cleavage, fast-atom-bombardment mass spectrometric and 1H-nuclear magnetic resonance spectroscopic analysis. The only difference between the two hexasaccharide variants was the presence, in one of them, of a between the two hexasaccharide variants was the presence, in one of them, of a phosphoethanolamine (AeP) sidechain on the third sugar of the sequence, i.e. N-acetylglucosamine. The composition of the ceramide moiety was dominated by a C20:0 fatty acid (arachidic acid) and a C14:1 sphingoid base (tetradecasphing-4-enine). The chemical structures of the two insect acidic glycosphingolipids were determined to be: GlcA(beta 1-3)Gal-(beta 1-3)GalNAc(beta 1-4)GlcNAc(beta 1-3)Man (beta 1-4)Glc(beta 1-1)Cer; GlcA(beta 1-3)Gal(beta 1-3)GalNAc(beta 1-4)[2AeP-6]-GlcNAc(beta 1-3) Man(beta 1-4)Glc(beta 1-1)Cer. Such glucuronic-acid-containing insect glycosphingolipids have been given the generic name arthrosides, with the implied synonymity to the gangliosides.

Acetylglucosamine↗

PubMed1990

Novel phosphorus-containing glycosphingolipids from the blowfly Calliphora vicina Meigen. Structural analysis by 1H and 1H[31P]-edited NMR spectroscopy at 600 and 500 megahertz.

Two novel phosphorus-containing neutral glycosphingolipids of the arthro series were isolated from the blowfly Calliphora vicina Meigen: GalNAc alpha 1----4GalNAc beta 1----(X---- 6)4GlcNAc beta 1----3Man beta 1----4Glc beta 1----1-ceramide and GalNAc beta 1----(X----6)4GlcNAc beta 1----3Man beta 1----4Glc beta 1----1- ceramide (X = -O-P(O)(O-)-OC-H2CH2NH3+). The primary structure of the ceramide pentasaccharide was elucidated de novo using two-dimensional 1H NMR correlation spectroscopy at 500 MHz and multistep relayed coherence transfer spectroscopy at 600 MHz. Localization of the 2'-aminoethyl phosphate substituent was established with the aid of 1H-detected, 31P-edited NMR spectroscopy at 500/202 MHz.

Animals↗

PubMed1990

Evidence for the expression of a glucuronic acid-containing epitope in the central nervous system of two insects (Calliphora vicina, Diptera; Tenebrio molitor, Coleoptera).

The monoclonal antibody CAF-I recognises a glucuronic acid-containing epitope present on various acidic glycosphingolipids of Calliphora vicina. Immunohistochemistry was performed on CAF-I-labelled whole-mount preparations of the central nervous system, visualised by peroxidase-conjugated second antibody. A differential, temporal and spatial expression of this epitope in metamorphosing nervous tissue was outlined, that apparently characterises homologous neuronal populations in two phylogenetically distinct holometabolous insects, i.e. Calliphora vicina and Tenebrio molitor. Implications for a functional interpretation of insect glyco(sphingo)lipids in tissue development are discussed.

Animals↗