Large Alterations in Ganglioside and Neutral Glycosphingolipid Patterns in Brains from Cases with Infantile Neuronal Ceroid Lipofuscinosis/Polyunsaturated Fatty Acid Lipidosis

Lipid composition was studied on cerebral tissue from nine children who had died of a progressive encephalopathy called the infantile form of neuronal ceroid lipofuscinosis (INCL) or polyunsaturated fatty acid lipidosis (PFAL). In the terminal stage of the disease, the concentrations of all lipid classes were found to be significantly reduced in the cerebral and cerebellar cortex and white matter. The concentration of gangliosides of the cerebral cortex was 15% and that of cerebrosides (galactosylceramide) in white matter 0.2-5% of the normal values for the children's ages. The reduction of gangliosides mainly affected those of the gangliotetraose series, particularly GD1a. The fatty acids of the linolenic acid series were strongly reduced in ethanolamine and serine phosphoglycerides. A very large increase up to 100-fold of oligoglycosphingolipids of the globo series and two fucose-containing lipids of the neolacto series was found in the forebrain of the three advanced cases examined. The brain tissue also contained very high concentrations of mono-, di-, and trisialogangliosides of the lacto and neolacto series, gangliosides with type 1 chain dominating. The structures of the gangliosides were tentatively identified by gas chromatography-mass spectrometry and monoclonal antibodies with carefully determined epitope specificity. The gangliosides and neutral glycosphingolipids had very similar fatty acid composition, consisting of about 40% stearic acid and 40% C24-acids.     

Inhibited growth of common enteropathogenic bacteria in lactic-fermented cereal gruels

A natural lactic fermentation of mixtures of water and whole flour of either maize or high-tannin sorghum was obtained either before or after cooking to a weaning gruel: The preparations had a final pH of about 3.8 (range 3.67 to 4.00) and a ratio of lactic acid to acetic acid of 91 (w/w). The growth of added (about 10⁷ c.f.u./g gruel) Gram-negative intestinal pathogenic bacteria, enterotoxigenicEscherichia coli, Campylobacter jejuni, Shigella flexneri andSalmonella typhimurium, was strongly inhibited in the sour gruels, and the effect could primarily be explained by the low pH caused by the formation of lactic and acetic acids during the fermentation process. Of the added Gram-positive bacteria,Bacillus cereus andStaphylococcus aureus showed similar inhibited growth up to 7h after inoculation in the sour gruels. The strain ofStaphylococcus, however, showed only a continued reduction in growth in the fermented gruel samples, which had a viable lactic bacteria culture indicating the presence of a bacteriocin. This implies that a low pH (< 4.0) alone is not sufficient to sustain the inhibition of the growth ofStaphylococcus aureus. The survival studies were carried out at optimal temperatures for each respective enteropathogen.     

A method for studies of an El Tor-associated antigen of Vibrio cholerae O1

A method for studying the biotype El Tor associated mannose-sensitive haemagglutinin (MSHA) of V. cholerae O1 has been developed. By using crude MSHA adsorbed to chicken erythrocytes as solid phase antigen in an enzyme-linked immunosorbent assay (ELISA), antisera against V. cholerae of the El Tor biotype reacted in high titre with the MSHA-coated cells, whereas antisera against vibrios of the classical biotype did not bind significantly, i.e. in higher titre than pre-immune sera. The binding of anti-MSHA serum, or a monoclonal antibody against MSHA, to the MSHA-coated erythrocytes could be efficiently inhibited by crude MSHA as well as by El Tor vibrios whereas neither V. cholerae lipopolysaccharide nor different strains of classical vibrios had any inhibitory effect. These results support the existence of an El Tor-associated immunogen. They also suggest a possibility of determining antibodies against different haemagglutinins in ELISA without having access to purified antigens.     

Binding specificity of monoclonal antibodies to ganglioside, Fuc-GM1

The binding specificity of thirteen mouse monoclonal antibodies reacting with Fuc-GM1, Fuc alpha 1-2Gal beta 1-3GalNAc beta 1-4(NeuAc alpha 2-3)-Gal beta 1-4Glc beta 1-1Cer, a ganglioside found to be associated with small cell lung carcinoma (O. Nilsson et al. (1984) Glycoconjugate J. 1, 43-49) was studied. The results are based upon radioimmunodetection of their binding to structurally related glycolipids adsorbed to microtiter plates or chromatographed on thin-layer plates. Four of thirteen antibodies reacted only with Fuc-GM1 and both the fucose and the sialic residues were necessary for binding. Optimal binding was obtained when the sialic acid was N-acetylneuraminic acid. When this sialic acid residue was substituted with N-glycoloylneuraminic acid the binding activity was reduced and up to 10-times more Fuc-GM1 was needed for detection. The ceramide composition did not influence the binding. The other nine monoclonal antibodies cross-reacted with glycolipids containing structures closely related to Fuc-GM1 and differed from the specific ones by recognizing a smaller portion of the carbohydrate moiety in Fuc-GM1. These results indicate that anticarbohydrate monoclonal antibodies, recognizing structures involving a large proportion of the sugar in the glycolipid, possess a high specificity and might be useful for detection of tumor-associated ganglioside antigen.     

Characterization of new gangliosides of the lactotetraose series in murine xenografts of a human glioma cell line

The major mono- and disialogangliosides of the extensively characterized established human glioma line D54MG were isolated and purified from subcutaneous solid xenografts grown in athymic (nu/nu) mice. Structural determination showed that they belonged to the lactotetraosylceramide series. The sialyllactotetraosylceramide contained 90% N-glycolyl- and 10% N-acetylneuraminic acid linked in an alpha 2-3 linkage (IV3NeuGc-LcOse4Cer, IV3NeuAc-LcOse4Cer). The disialogangliosides had a previously undescribed type of structure with sialic acids linked to the terminal galactose in an alpha 2-3 linkage and to N-acetylglucosamine in an alpha 2-6 linkage. Not only did species with NeuAc or NeuGc occur, but also species with mixtures of the two sialic acids, e.g. NeuAc and NeuGc. The schematic structures of the new disialogangliosides are (Formula:see text).     

Gangliosides of human thyroid gland

The ganglioside composition of adult human thyroid gland was examined in autopsy material obtained from patients who died of circulatory diseases but who showed no signs of thyroid disorders. The concentrations of phospholipids, cholesterol and gangliosides (lipid-bound sialic acid) in the whole glands were 5.2, 4.3 and 0.12 mmol/kg fresh tissue weight and, in dissected follicular material, 7.0, 3.4 and 0.24 mmol/kg tissue, respectively. The molar ratio of phospholipids/cholesterol/gangliosides in the follicular material was 1.00:0.49:0.034. Twelve molecular species of gangliosides were isolated and identified. Gangliosides GM3 and GD3 were most abundant, but GD1a, GD1b, GT1b and 3'-LM1 were also present in quantities greater than 5% of the total gangliosides. N-Acetylneuraminic acid and an alkali labile sialic acid, probably N-acetyl-9-O-acetylneuraminic acid, were found to occur in human thyroid.     

Expression of the Ganglioside GD3 in Human Meningiomas Is Associated with Monosomy of Chromosome 22

The ganglioside composition of 59 meningiomas has been compared with a molecular genetic analysis of chromosome 22 in the same specimens. Major gangliosides were GM3 (II3NeuAc-LacCer) and/or GD3 [II3(NeuAc)2-LacCer]. In specimens with no or partial deletions of chromosome 22, the GM3 ganglioside predominated, and the mean value for GM3, 61% of total sialic acid, was around four times higher than that for GD3. A loss of chromosome 22, found in 56% of the specimens, was shown to be associated with an increase in the proportion of ganglioside GD3, with the ratio between mean values of GM3 and GD3 being approximately 1:1. Logistic regression revealed that the probability of predicting monosomy of chromosome 22 by the GD3 proportion was 66%.     

A sulfated glucosylceramide from rat kidney

A novel sulfated glycosphingolipid containing a sulfated glucosyl residue was isolated from rat kidney and purified to homogeneity by column chromatographies with DEAE-Sephadex and silica beads. By compositional analyses, permethylation studies, one- and two-dimensional proton magnetic resonance spectroscopy, infrared spectroscopy, negative secondary ion mass spectrometry, solvolysis, and immunostaining on thin layer chromatogram, the structure of this glycolipid was proposed to be HSO3-3Glc beta 1-1Cer (where Cer is ceramide). The ceramide portion consisted of 4-D-hydroxysphinganine as the sole long chain base, and the fatty acid consisted of predominantly tetracosanoic acid, deduced from both composition analysis and negative secondary ion mass spectrometry. The yield of glucosyl sulfatide was about 5 nmol/g of tissue, being about three times as much as that of lactosylceramide sulfate.     

Application of a panel of antiganglioside monoclonal antibodies to cytologic specimens.

The cytologic evaluation of poorly differentiated tumors frequently poses a diagnostic dilemma as to the tissue of origin. To assess the diagnostic utility of monoclonal antibodies (MAbs) in these situations, we applied a panel of three highly purified MAbs specific for tumor-associated ganglioside epitopes to a diverse series of cytologic specimens. The panel was composed of DMAb-3, reactive with the epitope GalNAc beta 1-4 (NeuAc alpha 2-3)Gal- of GM2; DMAb-7, reactive with the epitope (NeuAc alpha 2-8NeuAc alpha 2-3)Gal beta 1-4(Glc or GlcNAc)- of GD3 and 3'8'-LD1; and DMAb-20, reactive with the epitope GalNAc beta 1-4(NeuAc alpha 2-8NeuAc alpha 2-3)Gal- of GD2. The cytologic material consisted of air-dried Cytospin preparations prepared predominantly from fine needle aspirates and stained with the ABC immunohistochemical method. Positive reactivity was recognized when greater than 5% of tumor cells stained with the antibody; lesser reactivity was called negative. DMAb-3 stained 9/14 (64%) glial tumors, 4/13 (31%) nonglial central nervous system tumors, 1/21 (5%) melanomas, 7/38 (18%) non-small cell carcinomas (NSCC), 1/15 (7%) small cell carcinomas (SCC), 0/9 (0%) lymphomas/leukemias, 2/10 (20%) sarcomas, 1/7 (14%) miscellaneous tumors and 2/2 (100%) reactive fluids. DMAb-7 recognized 14/14 (100%) glial tumors, 9/13 (69%) non-glial central nervous system tumors, 19/22 (86%) melanomas, 19/43 (44%) NSCC, 5/15 (33%) SCC, 2/9 (22%) lymphomas/leukemias, 6/10 (60%) sarcomas, 1/7 (14%) miscellaneous tumors and 4/4 (100%) reactive fluids. DMAb-20 stained 6/14 (43%) glial tumors, 2/13 (15%) nonglial central nervous system tumors, 1/21 (5%) melanomas, 4/38 (10%) NSCC, 0/15 (0%) SCC, 0/9 (0%) lymphomas/leukemias, 1/10 (10%) sarcomas, 1/7 (14%) miscellaneous tumors and 1/3 (33%) reactive fluids. The GD3-reactive DMAb-7 recognized a large portion of many tumor types and thus is not diagnostically useful alone. DMAb-3 and DMAb-20 were more selective and showed the strongest reactivity for glial tumors and minimal reactivity for melanomas, small cell carcinomas, and lymphomas or leukemias. DMAb-3 and DMAb-20 may be useful as components of a larger panel of MAbs in distinguishing between poorly differentiated tumors in samples derived from the central nervous system.     

Changes in fatty acid composition of human brain myelin lipids during maturation

Abstract— The variation with age of the fatty acid composition of the major lipids in human brain myelin was compared with that of cerebral white matter from the same region. The myelin was isolated from the semiovale centre of the cerebrum of 27 subjects neonatal to old aged. The phospholipid, cholesterol and galactolipid concentrations were determined in all the samples, as were the proportions of the major phospholipid classes. The proportions of cholesterol and especially of the galactolipids increased in myelin during the first 6 months, and in cerebral white matter up to 2 years. During this period the individual phospholipids also varied substantially. Serine phosphoglycerides and especially sphingomyelins increased, and choline phosphoglycerides decreased. The fatty acid patterns of ethanolamine phosphoglycerides (EPG) and sphingomyelins underwent the largest changes. The proportions of saturated fatty acids in EPG diminished rapidly, and there was an increase of monoenoic acids. Fatty acids of the linoleic acid series showed a peak between 4 and 12 months, after which time their proportion slowly diminished to old age. The major fatty acid of this series was docosatetraenoic acid, 22:4 (n-6), which constituted more than 25% of total fatty acids at the maximum level. The fatty acid changes were larger in cerebral white matter, but from 2 years of age the EPG fatty acid pattern in myelin was similar to that in white matter. The fatty acid changes in serine and choline phosphoglycerides of myelin with maturation were much less striking than in EPG but of a similar type. In myelin sphingomyelin the proportion of saturated long-chain fatty acids, C₁₆-C₂₂, diminished, while that of monoenoic acids increased and continued to do so up to old age. From 2 years of age the fatty acid patterns in myelin and cerebral white matter were quite similar. Also the fatty acid patterns of cerebrosides and sulphatides in cerebral white matter and myelin were the same except for the first 2 months of life. The same fatty acid changes occurred in cerebrosides and sulphatides as in the sphingomyelins, i.e. increased proportions of unsaturated (monoenoic) acids. The proportions of 24:1 and 24h:1 and of the odd-numbered fatty acids 25:1 and 23h:1 continued to increase to old age. The variations of the individual lipid fatty acid patterns were small except in the youngest age classes, in which the variations were presumably ascribable to the difficulty in determining the gestational age.