High-performance thin-layer chromatography and densitometric determination of brain ganglioside compositions of several species

Diagnosis and prevention of lysosomal storage diseases in Russia

A special programme for the diagnosis and prevention of lysosomal storage diseases (LSD) was developed in the former USSR. All the patients from 814 families at risk were investigated using biochemical techniques. In total, 363 patients with mucopolysaccharidoses (MPS), mucolipidoses, glycoproteinoses, sphingolipidoses and other LSD were diagnosed; 55 families at risk sought prenatal diagnosis and 67 fetuses were investigated for MPS (types I, II, IIIA and IIIB, VI), Tay-Sachs disease, Sandhoff disease, GM1-gangliosidosis, metachromatic leukodystrophy, mannosidosis, Gaucher disease and multiple sulphatidosis; 17 affected fetuses were diagnosed and aborted. There was an ethnic distribution of different lysosomal storage diseases in the former USSR.

Characterization of a monoclonal antibody reactive with a glycolipid antigen expressed by tumorigenic and certain immortalized, non-tumorigenic rat esophageal epithelial cell lines

A monoclonal antibody (mAb 5G) was produced against a tumorigenic rat esophageal epithelial cell line, designated B2T. Using an enzyme-linked immunosorbent assay, immunofluorescence assay (IFA), thin-layer chromatography (TLC) and immunoperoxidase staining, it was found that mAb 5G reacted specifically with a glycolipid antigen expressed by three tumorigenic rat esophageal epithelial cell lines, and two out of the three non-tumorigenic, immortalized rat esophageal epithelial cell lines tested; but did not react with primary cultures of normal rat esophageal epithelial cells or fibroblasts. mAb 5G did not bind to rat respiratory tract carcinoma cell lines, to immortalized rat tracheal epithelial cell lines, or to primary cultures of normal rat tracheal epithelial cells. In addition, mAb 5G did not react with any of the human or mouse cell lines tested. In IFA experiments, mAb 5G stained imprints prepared from in vivo propagated B2T tumor tissues, but did not react with normal rat esophageal, tracheal, lung, liver, and kidney tissues. The antigen was identified by TLC as a neutral glycolipid, consisting of two bands, with RF = 0.45 and 0.41, which migrated in proximity to the ceramide trihexoside standard on TLC plates. Densitometric scanning of the antigen bands indicated that the tumorigenic rat esophageal cell lines possessed 50%-90% more mAb-5G-reactive antigen than the non-tumorigenic esophageal cell lines. The results show that mAb 5G reacts specifically with a glycolipid antigen expressed by tumorigenic and certain non-tumorigenic, immortalized rat esophageal epithelial cell lines that might be at the late stages of transformation and early malignancy.

Variations in the ganglioside profile of uveal melanoma correlate with cytologic heterogeneity

Gangliosides may play an important role in the proliferation and spread of human malignant melanoma. Because the frequency of metastases in uveal and cutaneous melanoma differs, it is possible that they may express different gangliosides. We analyzed the ganglioside profiles of primary uveal melanoma in 14 cases and of cutaneous melanoma metastasis in 19 cases. In cutaneous melanoma, GM3 ranged from 4.2% to 74.6% and GD3 from 22.1% to 91.8% of total lipid-bound sialic acid. GM2 (found in 13 of 19 cases, ranging from 0.5% to 11.7%), GD2 (11/19, 0.5%-22.0%) and 9-O-acetyl-GD3 (13/19, 0.5%-12.6%) were also frequently observed. By contrast, in 11 cases of uveal melanoma, GM3 was > 90%, GD3 was < 10%, GM2 was < 1.1%; neither GD2 nor 9-O-acetyl-GD3 were detected. The ganglioside profiles of these uveal melanomas were virtually identical to those of normal melanocytes obtained from foreskins. Histological examination of these 11 biopsies showed a monomorphous cell composition, but neither infiltration of lymphocytes or melanophages nor cell necrosis was observed. In 3 other cases, GD3 was increased to 19.5%-46.0%. Histological examination of these 3 biopsy specimens showed at least 2 populations of tumor cells that were separable based on morphological grounds, and mononuclear inflammatory cells interspersed among the tumor cells. An increase in GD3 appears to be related to tumor polyclonality and infiltration of the tumor by lymphocytes and macrophages. These results suggest that ganglioside expression of uveal melanoma is associated with host immune responses to the tumor. Furthermore, the low metastatic capacity of uveal melanoma, in contrast to the high metastatic rate of cutaneous melanoma, may be a result of its differentiated ganglioside expression, which is strikingly similar to that of normal melanocytes.

Isolated bovine spinal motoneurons have specific ganglioside antigens recognized by sera from patients with motor neuron disease and motor neuropathy

The gangliosides GM1 and GD1b have recently been reported to be potential target antigens in human motor neuron disease (MND) or motor neuropathy. The mechanism for selective motoneuron and motor nerve impairment by the antibodies directed against these gangliosides, however, is not fully understood. We recently investigated the ganglioside composition of isolated bovine spinal motoneurons and found that the ganglioside pattern of the isolated motoneurons was extremely complex. GM1, GD1a, GD1b, and GT1b, which are major ganglioside components of CNS tissues, were only minor species in motoneurons. Among the various ganglioside species in motoneurons, several were immunoreactive to sera from patients with MND and motor neuropathy. One of these gangliosides was purified from bovine spinal cord and characterized as N-glycolylneuraminic acid-containing GM1 [GM1(NeuGc)] by compositional analysis, fast atom bombardment mass spectra, and the use of specific antibodies. Among seven sera with anti-GM1 antibody activities, five sera reacted with GM1(NeuGc) and two did not. Two other gangliosides, which were recognized by another patient's serum, appeared to be specific for motoneurons. We conclude that motoneurons contained, in addition to the known ganglioside antigens GM1 and GD1b, other specific ganglioside antigens that could be recognized by sera from patients with MND and motor neuropathy.

Accumulation of lysosphingolipids in tissues from patients with GM1 and GM2 gangliosidoses

By using a sensitive method, we assayed lysocompounds of gangliosides and asialogangliosides in tissues from four patients with GM2 gangliosidosis (one with Sandhoff disease and three with Tay-Sachs disease) and from three patients with GM1 gangliosidosis [one with infantile type (fetus), one with late-infantile, and one with adult type]. In the brain and spinal cord of all the patients except for an adult GM1 gangliosidosis patient, abnormal accumulation of the lipids was observed, though the concentration in the fetal tissue was low. In GM2 gangliosidosis, the amounts of lyso GM2 ganglioside accumulated in the brain were similar among the patient with Sandhoff disease and the patients with Tay-Sachs disease, whereas the concentration of asialo lyso GM2 ganglioside in the brain was higher in the former patient than in the latter patients. By comparing the sphingoid bases of neutral sphingolipids, gangliosides, and lysosphingolipids, it was suggested that lysosphingolipids in the diseased tissue are synthesized by sequential glycosylation from free sphingoid bases, but not by deacylation of the sphingolipids. Because lysosphingolipids are known to be cytotoxic, the abnormally accumulated lysophingolipids may well be the pathogenetic agent for the neuronal degeneration in gangliosidoses.

Ganglioside distribution in murine neural tumors

The ganglioside composition of seven experimental brain tumors was examined in C57BL/6J mice. The tumors were produced from 20-methylcholanthrene (20-MC) implantation into either the cerebrum or cerebellum and were maintained in serial transplants through many generations. The tumors studied were grown subcutaneously as solid tumors, and cells from two of the tumors were also studied in culture. Histologically, all of the tumors were similar and could be broadly classified as highly malignant, poorly differentiated anaplastic astrocytomas. The total ganglioside sialic acid content of the solid tumors was markedly lower than that in adult mouse brain. In addition to N-acetylneuraminic acid (NeuAc), the gangliosides in the solid tumors contained significant amounts of N-glycolylneuraminic acid (NeuGc). The seven solid tumors fell into two general groups with respect to ganglioside composition. Furthermore, the differences in ganglioside composition between the two tumor groups were strongly associated with differences in tumor cell cohesion. The tumors in one group had high levels of GM3 hematosides, low levels of oligosialogangliosides, and grew as firm cohesive tissues. The tumors in the other group, however, had lower levels of GM3 hematosides, noticeable amounts of oligosialogangliosides and grew as soft noncohesive tissues. In culture, clonal cells from one of the tumors in the first group grew as clumps or islands and contained GM3 as the only major ganglioside, whereas clonal cells from a tumor in the second group grew as sheets or monolayers and contained little GM3, but expressed several gangliosides with complex structures. In marked contrast to the gangliosides in the solid tumors, the gangliosides in the cultured tumor cells contained trace amounts of NeuGc. Since NeuGc containing gangliosides are abundant in mouse nonneural tissues, the high content of NeuGc gangliosides in the solid tumors may arise from infiltration of nonneural tissue elements, e.g., macrophages, lymphocytes, and endothelial cells.

Altered ganglioside composition in virally transformed rat embryo fibroblasts

The composition of gangliosides was examined in a normal rat embryo fibroblast cell line (REF52) and in two viral transformants: a polyoma transformant (REF52-PyMLV) and a simian viral 40 transformant (REF52-SV40). The distribution of gangliosides in the cell lines was determined using gas-liquid chromatography and high-performance thin-layer chromatography. N-acetylneuraminic acid was the predominant sialic acid species detected in the three cell lines. The total ganglioside concentration (microgram/100 mg dry weight of cells) in the normal, PyMLV, and SV40 lines was 144.7 +/- 10.4, 153.8 +/- 9.2, and 86.1 +/- 6.8, respectively. Gangliosides GM3, GM2, GM1, and GD1a were the major species in the normal and transformed lines. The distribution of these gangliosides, however, differed markedly between the normal and the transformed lines and also between the transformed lines themselves. The transformed cells also differed from the normal cells in growth rate, morphology, and social behavior. The cell line with highest GM3 content (PyMLV) formed islands, whereas the normal and SV40 cell lines, which had lower GM3 levels, grew as monolayers. The findings suggest that PyMLV and SV40 transformation can have multiple and different effects on cellular ganglioside distribution and growth behavior.

Ceramide glycanase from the earthworm, Lumbricus terrestris

Ceramide glycanase (CGase) is an enzyme that cleaves the linkage between the sugar chain and the ceramide. To make this enzyme readily available, we have developed a simple method for preparing it from the earthworm, Lumbricus terrestris. The method involves Bio-Gel A-0.5m, octyl-Sepharose and p-aminophenylthiogalactoside-agarose column chromatography. By gel filtration, the molecular mass of earthworm CGase was found to be 43.7 kDa. With ganglioside GM1 as substrate, the optimal pH of this enzyme was found to be between pH 3.5 and 4.0. Earthworm CGase hydrolyses glycolipids only in the presence of a detergent. Among various bile salts tested, sodium cholate was found to be the most effective in stimulating the hydrolysis of GM1 by this enzyme. Earthworm CGase released intact glycan chains from various glycosphingolipids in which the glycan chain is linked to the ceramide through a beta-glucosyl linkage. It also detached glycan chains from lactosyldialkylglycerol and alkyl-beta-lactosides.

Chromatography and spectrofluorometry of brain fluorophores in neuronal ceroid lipofuscinosis (NCL)

The aim of the present work was to develop a chromatographic system for the separation of individual fluorophores extracted from neuronal ceroid lipofuscinosis (NCL) brain and isolated storage bodies. Extracts from gray matter were best resolved on silica-gel HPTLC plates using a mixture of chloroform/methanol/water (55:45:10 by vol.). Two other chromatographic systems were tested which gave poorer separation. Corrected fluorescence spectra were obtained on the original extract and fluorescence intensity, especially at longer wavelengths was increased in both samples. Yellow and blue fluorophores were detected on HPTLC plates using a primary violet and secondary yellow filter with cut-off levels of 400 and 520 nm, respectively. Plates were photographed at 20 min, 2 h and 1 week after chromatography. With this filter system, up to 12 yellow bands of differing intensity were observed at 20 min but with time, some of these changed to blue as a result of autoxidation. NCL tissues emit yellow fluorescence when viewed under light microscopy, however extracted material did not demonstrate a distinct peak in this region of the spectrum which should be around 575 nm. HPTLC confirmed this observation and time studies revealed that autoxidation changes occur and must be carefully controlled to reduce artifacts. The discrepancy between extracted and non-extracted observations may be the result of superposition of multiple fluorophores with differing maxima and/or a self-absorption phenomenon. The combination of chromatographic separation and spectral analysis as described in this study, may be a valuable technique to further clarify the characteristics of compound fluorescent lipopigments. It is suggested that NCL fluorophores of human brain differ in their properties from other models.

Effects of postnatal ganglioside administration and hypoxia-exposure on the dopamine release from striatal slices, the behaviour and the ganglioside pattern of 2-3 months old rats

Neonatal rats were injected with a mixture of bovine brain gangliosides (30 mg/kg body weight, s.c.) immediately before the exposure to hypoxia (pO2 = 10 kPa, 10 hrs daily) from the 2nd to the 11th day of life. At the age of 2-3 months the potential protective or restitutive effect of gangliosides on the radiolabelled dopamine release from striatal slices and on the conditioned avoidance learning was studied. No change in the content and the pattern of gangliosides of the rat striata was found after exposure to hypoxia and ganglioside administration, respectively. Both hypoxia exposure and ganglioside treatment of controls increased the dopamine release whereas hypoxic animals treated with gangliosides showed a diminished release. Hypoxia-induced impaired conditioned avoidance learning was improved by ganglioside treatment. The changed release of dopamine and the altered behavioural performance after ganglioside treatment alone indicate the necessity of a very cautious application of gangliosides to the developing brain.

Ataxic polyneuropathy and anti-Pr2 IgM kappa M proteinemia

A case of ataxic neuropathy associated with IgM kappa M proteinemia is reported. Double filtration plasmapheresis effectively treated the neuropathy. The IgM kappa antibody had anti-Pr2 cold agglutinin activity. We demonstrated reactivities of the IgM kappa antibody to sialosyl paragloboside, sialosyl lactosaminyl paragloboside, GT1b, GD1a, GD1b, GM3 and GD3 on high-performance thin-layer chromatography immunostaining and enzyme-linked immunosorbent assay, which is previously unreported antigenic specificity of the M proteins in cases of paraproteinemic neuropathy. IgM M protein with anti-Pr2 cold agglutinin activity may play a pathogenetic role in peripheral nerve demyelination, because the target antigens of the M protein are present in myelin and possibly in endothelial cells of the peripheral nervous system.

Biochemical correlates of epilepsy in the E1 mouse: analysis of glial fibrillary acidic protein and gangliosides

The E1 (epileptic) mouse is considered a model for complex partial seizures in humans. Seizures in E1 mice begin around 7-8 weeks of age and persist throughout life. To determine if astrocytic gliosis was present in adult seizing E1 mice, the distribution of glial fibrillary acidic protein (GFAP) was studied in the hippocampus using an antibody to GFAP. The mean number of GFAP-positive cells per square millimeter of hippocampus was approximately 15- to 40-fold higher in adult E1 mice than in nonseizing control C57BL/6J (B6) mice or in young nonseizing E1 mice. Relative GFAP concentration (expressed per milligram of total tissue protein) in hippocampus and cerebellum was estimated by densitometric scanning of peroxidase-stained western blots. GFAP concentration was 2.7-fold greater in hippocampus of adult seizing E1 mice than in the control B6 mice. No differences in GFAP content were detected between the strains in the cerebellum. Because gangliosides can serve as cell surface markers for changes in neuronal cytoarchitecture, they were analyzed to determine if the gliotic response in E1 mice was associated with changes in neural composition. Although the total ganglioside concentration of hippocampus, cerebral cortex, and cerebellum was similar in adult E1 and control B6 mice, a synaptic membrane enriched ganglioside, GD1a, was elevated in the adult E1 cerebral cortex and hippocampus. The findings indicate that E1 mice express a type of gliosis that is not accompanied by obvious neuronal loss.

Role of myelin-associated neuraminidase in the ganglioside metabolism of rat brain myelin

The role of myelin-associated neuraminidase in ganglioside metabolism was examined using rats of ages ranging from 17 to 97 days. The neuraminidase activity directed toward the ganglioside GM3 in the total myelin fraction was high during the period of active myelination and, thereafter, decreased rapidly to the adult level. The ganglioside composition became simpler during development with an increasing amount of GM1 and decreasing percentages of di- and polysialogangliosides. The decrease in the proportion of GD1a was most prominent, whereas relative amounts of GD1b and GT1b increased transiently before reducing to the adult levels. The heavy myelin subfraction contained higher percentages of di- and polysialo-species compared to the light myelin fraction at young and adult ages. The in vitro incubation of myelin of young rats under an optimal condition for neuraminidase action produced a profile of ganglioside changes similar to that observed in in vivo development. These results strongly suggest that myelin-associated neuraminidase may play a pivotal role in the developmental changes in the ganglioside composition of rat brain myelin.

Identification of glycoconjugates which are targets for anti-Gal(beta 1-3)GalNAc autoantibodies in spinal motor neurons

Human IgM anti-Gal(beta 1-3)GalNAc antibodies which bind to GM1 and GD1b, are implicated in the pathogenesis of predominantly motor neuropathy or motor neuron disease. By immunofluorescence microscopy, the human antibodies immunostain the surface of motor neurons from bovine spinal cord. The motor neurons are also immunostained by cholera toxin (CT), which is specific for GM1. Glycolipid analysis using thin-layer chromatography (TLC) and immunostaining reveals that the relative concentration of GM1 and GD1b in motor neurons is greatly reduced in comparison to whole spinal cord, and that other motor neuron gangliosides are unreactive with the anti-Gal(beta 1-3)GalNAc antibodies. By Western blot analysis, the antibodies react with several protein bands in motor neuron extracts, and many of the same proteins are also recognized by PNA. These data suggest that both glycoproteins and glycolipids might be targets for anti-Gal(beta 1-3)GalNAc antibodies in spinal motor neurons.

Gangliosides of human cerebrospinal fluid in various neurologic diseases

Simultaneous profile determination and quantification of human cerebrospinal fluid (CSF) gangliosides in various neurologic diseases (n = 71) was examined. Gangliosides were extracted with methanol/chloroform from clinically available amounts of CSF (4-5 ml), then separated and quantified by high-performance thin-layer chromatography (HPTLC) and direct densitometry. Based on chromatographic comparison with standards, the percentage of lipid-bound NeuAc positive fractions in 'normal' CSF samples were: GM1 (II3 NeuAc-GgOse4Cer) (3%); GD3 (II3 NeuAc2-Lac-Cer) (4%); GD1a (IV3 NeuAc, II3 NeuAc-GgOse4 Cer) (15%); X1 (3%); GD1b (II3(NeuAc)2-GgOse4 Cer) (16%); X2 (4%); GT1b (IV3 NeuAc, II3(NeuAc)2-GgOse4-Cer) (40%); and GQ1b (IV3(NeuAc)2, II3(NeuAc)2-GgOse4-Cer (15%). Similarity between CSF and CSF and human cerebellar cortex, particularly in proportion of "b" series gangliosides (GQ1b, GT1b, GD1b), could be observed. A higher proportion of GD1a ganglioside, with decreased GQ1b was found in infancy. The total ganglioside content (mean +/- 2 SD) varied between 645-894 micrograms/l. Significant alterations of the CSF ganglioside profile, with an increase in less polar gangliosides, GM3 and GD3, correlated with the blood-brain barrier dysfunction (CSF hemorrhages, compressive syndrome), or some malignant processes (metastatic brain melanoma). A statistically significant increase in the content of total CSF gangliosides was found in the following groups of patients as compared to controls: (1) ischemic cerebrovascular accident (CVI) with good outcome (P less than 0.02); (2) peripheral neuropathy and polyneuropathy (P less than 0.001) and (3) intravertebral discopathy (P less than 0.05). A significant decrease in the content of total CSF gangliosides was found in CVI group with lethal outcome (P less than 0.05).

Glycolipid changes in murine myelogenous leukemias: neutral glycolipids as markers for specific populations of leukemias

We have studied the glycolipid composition of six different murine myelogenous leukemias as well as that of T-cell leukemias and normal spleen cells. Neutral and acidic lipid fractions were isolated by column chromatography on DEAE-Sephadex and analyzed by high-performance thin-layer chromatography (HPTLC) and an HPTLC overlay method. Murine myelogenous leukemias were found to contain globo- and ganglio-series neutral glycolipids, e.g., glucosylceramide (Glc-cer), lactosylceramide (Lac-cer), globotriaosylceramide (Gb3), globoside (Gb4), Forssman glycolipid (Gb5), and asialo-GM1 (GA1). Monoblastic leukemia cells contained increased proportions of Gb3, Gb4, Gb5, and GA1. Monocytic and myelomonocytic leukemia cells contained increased proportions of Glc-cer and Lac-cer. Especially, Glc-cer accounted for approximately 60% of the total neutral glycolipids in monocytic leukemia cells. Gb3 was the major neutral glycolipid in reticulum cell neoplasm type A, and it accounted for approximately 75% of the neutral glycolipids. GA1 was the major neutral glycolipid in myeloblastic and granulocytic leukemia cells as well as T-cell leukemias. Especially, granulocytic leukemia cells contained predominantly GA1, and it accounted for approximately 80% of the total neutral glycolipids. The pattern of gangliosides in myelogenous leukemias was more complex when compared with that of the neutral glycolipids; murine myelogenous leukemias contained at least 13 gangliosides, including such major gangliosides as GM1, GM1b containing N-acetyl neuraminic acid and N-glycolyl neuraminic acid, and Ga1NAc-GM1b. Alterations of glycolipid composition in murine myeloid leukemias may be associated with cellular differentiation and maturation, and therefore these characteristic glycolipid species may be regarded as markers for specific populations of leukemia cells.

Disialoganglioside GD2 in human neuroectodermal tumor cell lines and gliomas

Monoclonal antibodies (mAbs) recognizing the disialoganglioside II3(NeuAc)2GgOse3Cer (GD2) were produced by immunizing mice with the GD2-expressing neuroblastoma cell line LAN-1 and a prefusion boost with purified GD2 coupled to Salmonella minnesota. Two IgM mAbs were isolated which demonstrated high levels of reactivity (binding ratios in excess of 100) with GD2 by solid-phase radioimmunoassay and positivity in high-performance thin-layer chromatography (HPTLC) immunostain; only one (DMAb-20) was subsequently shown by analysis with a panel of defined ganglioside species to be specific for the minimum epitope of GD2 GalNAc beta 1-4(NeuAc alpha 2-8-NeuAc alpha 2-3)Gal-, DMAb-20 was used to evaluate the expression of GD2 by malignant glioma and medulloblastoma cell lines using cell surface radioimmunoassay. indirect membrane immunofluorescence. HPTLC immunostain, and densitometric analysis of extracted gangliosides from selected cell lines. Sixteen of 20 (80%) malignant glioma and 5 of 5 medulloblastoma cell lines reacted with DMAb-20; in agreement with previous studies, 5 of 5 neuroblastoma and 2 of 3 melanoma cell lines also reacted with DMAb-20, GD2 was proportionally increased in the glioma and medulloblastoma cell lines relative to levels in normal brain, as determined by densitometric analysis. In a phenotypic survey of malignant glioma biopsies, tumor cells in 24 of 30 (80%) cases stained positively with DMAb-20. Reactive astrocytes, both within the adjacent to tumors, were frequently intensely stained. Among the morphological variants of glioblastoma examined, the most intense staining with DMAb-20 was observed in neoplastic gemistocytes, with the weakest or absent staining in small cell glioblastomas. As GD2 is a commonly expressed surface antigen of gliomas and medulloblastomas, expression of which is retained in tissue culture. DMAb-20 will be useful in determining the functional role of GD2 in cell-cell interaction, adhesion, and invasion, and in defining altered growth control mechanisms of central nervous system neoplasms in in vitro models.

Focal segmental glomerulosclerosis associated with infantile spasms in five mentally retarded children: a morphological analysis on mesangiolysis

We report five cases of nephrotic syndrome due to focal segmental glomerulosclerosis (FSGS) in mentally retarded children with severe infantile spasms. Four of the five children diagnosed as West syndrome, Lennox syndrome, or petit mal epilepsy also had cerebral palsy and microcephaly. The other patient had petit mal epilepsy without cerebral palsy and microcephaly. All patients first developed infantile spasms, with the time of onset ranging from 1 week to 2 years of age, and subsequently developed proteinuria, followed by the nephrotic syndrome at 3 to 14 years of age. Four of the five developed terminal renal failure between 7 and 11 years of age. Three subsequently died, but the other underwent kidney transplantation and is still living without further complications. The light, electron microscopic, and immunohistochemical studies performed on the renal biopsies from all the patients and on the autopsy specimens from two cases exhibited FSGS-like lesions. Besides segmental hyalinosis, differing degrees of mesangiolysis were seen, which sometimes developed into dissecting microaneurysms of the glomerular capillary loops. The clinical picture described can be differentiated from congenital nephrotic syndrome (CNS) or infantile nephrotic syndrome (INS) with respect to the age of onset, outcome, and morphological appearance. We reviewed the previous literature and extended earlier observations about an unusual association between the nephrotic syndrome due to FSGS-like lesion, mental retardation, infantile spasms, and/or microcephaly in children.

Rabies virus infection in Aedes pseudoscutellaris cells: a study on receptorial structures

Rabies virus is able to infect in vitro a wide range of homeothermic and poikilothermic cells but little is known about its multiplication in arthropod cells. In this research the infection of rabies virus in Aedes pseudoscutellaris cells, a mosquito cell line susceptible to mosquito-borne viruses, was studied. After 60 days of incubation at 26 degrees C up to 70% of infected cells showed the synthesis of both viral nucleocapsid and envelope antigens, although viral yield and cell damage could not be detected. Research performed in order to investigate the role of membrane carbohydrate moieties in rabies virus-mosquito cell interaction suggested the participation of galactose and N-acetylglucosamine whereas sialic acid, known to be a rabies binding site in many homeothermic cell lines, was not involved.

Changes of endogenous ganglioside composition in mouse cerebrum primary cultures following long-term exposure to phorbol ester

Changes in endogenous gangliosides caused by phorbol 12-myristate 13-acetate (PMA, 162 nM) were examined using mouse cerebrum primary cultures. The total ganglioside content was significantly decreased by 25% and 40% in PMA-treated cultures compared to control cultures on days 1 and 8, respectively. In addition, changes in the pattern of ganglioside composition were also observed in which the percentage of GM1 and GD3 in total gangliosides was significantly increased and, in contrast, the percentage of GD1a and GT1b was reduced. Treatment of neurons with PMA induced the change of morphology. These results suggest that the decrease in the total ganglioside content and changes in ganglioside composition produced by long-term exposure to PMA are related to the appearance of neuronal cell aggregation and neurite fasciculation.

Developmental change in ganglioside expression in primary culture of rat neurons

Developmental changes in ganglioside levels and patterns were investigated in neuronal cells dissociated from 17-day-old fetal rat hemispheres for up to 7 days of culture. Increases in ganglioside contents and the onset of GM3 synthesis, which is associated with proliferation of glial cells, were observed as the neuronal network was established in cell cultures. The distribution of gangliosides in developing neurons was monitored by the indirect immunofluorescent technique using three anti-ganglioside antibodies. Anti-GM1 antibody showed immunofluorescence only on the cell soma 1 and 3 days after plating and additional binding between cell aggregates by 7 days in culture. GD3 ganglioside, the predominant species in embryonic neurons, was not detected on the neuronal cell surface, whereas the number of positively stained non-neuronal cells was increased at 7 days. Monoclonal A2B5 antibody suggested that polysialogangliosides play a role in neuronal network formation. In 1-day-old culture, however, all antibodies bound poorly to cell surface antigens and strongly to cells, the membranes of which were permeabilized with acetone. These results suggest that a substantial amount of gangliosides are retained, transformed within the cell to more complex gangliosides, and translocated to the cell surface following neurite outgrowth and morphological changes.

Glycolipids in rat cochlea

In recent years, the functions of glycolipids have been intensively studied. Before the research of the roles of glycolipids in the inner ear, it seemed to be necessary to demonstrate the composition of glycolipids at first. Therefore, rat cochlea has been examined for glycolipid composition in the present study. Glycolipids extracted from 200 cochlea samples were separated into neutral and acidic glycolipid fractions. Each fraction was analyzed by thin-layer chromatography. The neutral glycolipid was almost exclusively galactosylceramide (cerebroside) with trace amounts of globoside and unidentified glycolipids. In acidic glycolipids, sulfated galactosylceramide (cerebroside sulfate) was most abundant. Of the gangliosides (sialic acid-containing glycolipids), ganglioside GM3 (51.8%) was the predominant component, and GM2 (6.0%), GM1 (8.8%), GD3 (10.7%), GD1a (8.7%), GD1b (5.9%), and GT1b (3.6%) were also detected. In addition to these, rat cochlea also contained several, minor, unidentified gangliosides. This pattern of the cochlear acidic glycolipids is very similar to that of the renal acidic glycolipids. This finding seems to be very interesting when considering that the toxic side effects of aminoglycosides occur only in the kidney and the inner ear.

Glycosphingolipids in the cerebrospinal fluid of patients with multiple sclerosis

Glycosphingolipids in cerebrospinal fluid (CSF) of individual patients with multiple sclerosis (MS) were analyzed using a glycolipid-overlay technique. The ganglioside composition of CSF of non-MS patients was characterized by an abundance of polysialo species, including GT1b and GQ1b. This pattern is completely different from that of human white or gray matter, in which mono- and disialogangliosides predominate. Increased levels of GM1, either associated with or without increases of other gangliosides, such as GD1a, were observed in 16% of the patients with MS (6 of 37 cases: 1 of 15 progressive progressive stage, 4 of 16 progressive stationary stage, and 1 of 6 relapsing stage). The concentration of GD3 was increased in 23% (3 of 13 cases), whereas 1 of 13 cases (8%) showed a dramatic increase of sulfoglucuronyl paragloboside (SGPG) associated with a high level of GD3. These changes may reflect the cellular changes associated with the known pathological lesions in MS, which are characterized by demyelination, gliosis, and/or remyelination with oligodendrocytic proliferation.

Purification and characterization of CMP-NeuAc:GM1 (Gal beta 1-4GalNAc) alpha 2-3 sialyltransferase from rat brain

A CMP-NeuAc:GM1 alpha 2-3 sialyltransferase (GD1a synthase, 2.4.99.2) has been purified from the Triton extract of rat brain. The enzyme was purified and resolved by affinity chromatography on CDP-Sepharose column by a linear NaCl gradient elution. Final purification was achieved by elution from a 'GM1-acid'-Sepharose column. SDS-PAGE of the enzyme revealed a single protein band with an apparent Mr 44 kDa. It catalyzed specifically the sialylation of GD1b, GM1 and asialo-GM1. Enzyme products were identified by TLC in three different solvent systems. The Km value for GM1 was 7.5 x 10(-2) M, and for CMP-NeuAc it was 6.5 x 10(-5) M.

Determination of gangliosides in human cerebrospinal fluid by high-performance thin-layer chromatography and direct densitometry

A method for the separation and quantification of a complex ganglioside mixture from a clinically available amount (5 ml) of human cerebrospinal fluid (CSF) is described. After reduction of the CSF volume by ultrafiltration, gangliosides are extracted with methanol/chloroform, then separated and quantified by high performance thin layer chromatography (HPTLC) and direct densitometry. For purification of crude ganglioside extract, the method of choice was microdialysis against water. Recovery for the present method including all methodological steps was 78%. No delective loss of gangliosides was demonstrated. The CSF ganglioside pattern from 'normal' CSF samples resembles that of brain gangliosides, particularly cerebellum gangliosides. Based on chromatographic comparison with standards, the percentages of lipid-bound NeuAc-positive fractions were: GM1 = II3NeuAc-GgOse4Cer (3%), GD3 = II3NeuAc2-Lac-Cer (3%), GD1a = IV3NeuAc,II3NeuAc-GgOse4Cer (15%), X1 (3%), GD1b = II3(NeuAc)2-GgOse4Cer (16%), X2 (3%), GT1b = IV3NeuAc,II3NeuAc2-GgOse4-Cer (41%), and GQ1b = IV3NeuAc2-,II3NeuAc2-GgOse4-Cer (16%). The total ganglioside content varied between 616-944 micrograms/l. Within-run and between-run assay precision (relative standard deviation) for 'normal' pooled CSF ranged from 0.04 to 0.12 for the predominant CSF ganglioside fractions (GD1a, GD1b, GT1b, GQ1b), and from 0.13 to 0.23 for the less pronounced fractions (GM1, GD3).

Regional differences in the appearance of adult-type glycosphingolipids in the small intestine of inbred rats at weaning time

The small intestine of 15- to 33-day-old rats was cut into four segments: duodenum, proximal jejunum, distal jejunum, and ileum. Neutral glycosphingolipids and gangliosides were purified from each segment and analyzed by thin-layer chromatography in order to study the developmental appearance of adult-type glycolipids at each level of the small intestine. Type 1 A-6 glycolipid was first detected in the ileum at 15 days and subsequently in the jejunum and duodenum at 19 days of age. N-Glycolylneuraminic acid was expressed first in the ileum at 17 days, then in the proximal jejunum at 21 days, but only after 29 days in the duodenum. In each region, 6-8 days were required between first detection and full expression of N-glycolylneuraminic acid. The presence of 2-hydroxylated fatty acids in glucosylceramide was found first in the ileum at 19 days, 2-3 days before appearing in the duodenum and proximal jejunum. A period of 2-3 days was necessary to reach full adult-type level of 2-hydroxylated fatty acids in glucosylceramide. These results show that adult-type glycolipids appear earlier in the distal than in the proximal region of the rat small intestine, and that different glycolipids appear at different times and at different rates. The finding that the biochemical differentiation of the whole small intestine expands over a period of 3 days to 2 weeks, depending on the region and the glycolipid, before being fully completed indicates that, in addition to the time lag observed between the distal and the proximal region, the new cells arising from the crypt of Lieberkhün after 15 days of age are not at once fully differentiated.

Involvement of gangliosides in the interaction between BK virus and Vero cells

BK virus infectivity was inhibited by gangliosides extracted from Vero cells and by standard preparations of different gangliosides. Gangliosides were also able to restore the susceptibility of glycosidase-treated Vero cells to BK virus infection.

Effects of various lysosphingolipids on cell growth, morphology and lipid composition in three neuroblastoma cell lines

The cell numbers of three mouse neuroblastoma cell lines were decreased upon incubation with lysosphingolipids in the following order of effectiveness: lysosulfatide (lysoCS) greater than psychosine (Ps) greater than sphingosylphosphocholine (SPC). The different cell lines showed characteristic sensitivities to various concentrations of lysolipids less than 150 microM. Interestingly, only SPC induced neurite outgrowth and changed the lipid composition, modifying the amounts of cholesterol, sphingomyelin (SM) and ganglioside GM3 in all cell lines. The effect of SPC on these cell lines was comparable to the effect of N-acetyl SPC (NAcSPC) rather than that of SM.

Abnormal glycosphingolipid metabolism in the nervous system of galactosialidosis

In an autopsy case of galactosialidosis, GM3, GM2, GM1, and GD1a were accumulated in sympathetic and spinal ganglia and grey matter of the spinal cord. Especially, the accumulations of GM3 and GM2 amounted to 41- and 86-fold increases in sympathetic ganglia, respectively, as compared to normal controls. In addition LacCer, GA2 and GA1 were accumulated in sympathetic and spinal ganglia. The accumulations of GM3 and GD1a are considered to be the result of defective lysosomal sialidase activity and the accumulation of GM1, LacCer and GA1 is also considered to be due to decreased beta-galactosidase activity in this disorder. To better understand the possible mechanism of GM2 accumulation, we determined the activity of GM2 synthesizing enzyme (GM3:UDP-GalNAc transferase), as well as hexosaminidase activity, in sympathetic ganglia, but they did not change. Abnormal ganglioside and neutral glycosphingolipid metabolism, as well as sialyloligosaccharide and sialylglycoprotein metabolism, may be involved in the pathogenesis of this disorder.

Cerebellar ganglioside abnormalities in pcd mutant mice

The distribution of cerebellar gangliosides was studied in Purkinje cell degeneration (pcd/pcd) mutant mice at postnatal days 25, 30, 50, and 150. These mutants lose the majority of Purkinje cells between 18 and 50 days of age. A reactive gliosis accompanies Purkinje cell loss and a partial loss of granule cells occurs in pcd/pcd mice older than p50. Purkinje cell loss is associated with significant reductions in cerebellar weight and ganglioside concentration. This neuronal loss was also developmentally correlated with reductions of gangliosides (GT1a/LD1 and GT1b and with elevations of GD3. These results agree with previous findings in other cerebellar mutants that GT1a/LD1 and GT1b are concentrated in Purkinje cells and that GD3 is enriched in reactive glial cells. A slight, but significant, reduction in GD1a concentration occurred only in older pcd/pcd mice, consistent with previous findings in weaver and staggerer mice that GD1a is enriched in mature granule cells. The findings with pcd/pcd and other neurological mutants indicate that certain gangliosides can serve as cell-surface markers for monitoring changes in cerebellar cytoarchitecture that accompany development or disease.

Hydrolysis of fucosyl-GM1 ganglioside by purified pellet-associated human brain and human liver alpha-L-fucosidases without activator proteins or detergents

Pellet-associated human brain alpha-L-fucosidase was solubilized with 0.5% (w/v) Triton X-100 and purified by affinity chromatography on agarose-6-aminohexanoyl-fucosamine resin. The procedure resulted in a 290,000-fold purification, a 58% yield and a final specific activity of 11,500 nmol/min per mg of protein. Isoelectric focusing indicated that all six major isoforms (with pI values between 4.1 and 5.3) present in crude brain pellet preparations were purified by the affinity technique. SDS/PAGE indicated the presence of one subunit (54 kDa) and a minor protein band at 67 kDa, which presumably is a contaminant since it was not immunoreactive on Western blotting. The pH optimum of the brain enzyme and its apparent Km for the synthetic substrate 4-methylumbelliferyl alpha-L-fucopyranoside were 5.5 and 0.07 mM respectively. Pellet-associated human brain and liver alpha-L-fucosidases were both capable of hydrolysing fucosyl-GM1 ganglioside without activator proteins or detergents. Linear hydrolysis rates were found only for short incubation times (1-5 min). Optimal enzymic activity at 37 degrees C was found at pH 3.4 for both alpha-L-fucosidases, with no activity at pH values above 4.0.

Mitogenic response of near-diploid mouse cell line m5S/1M induced by epidermal growth factor

A nonmalignant near-diploid cell line m5s/1M, established by Sasaki and Kodama (J. Cell. Res., 131:114-122, 1987), was shown to respond to the epidermal growth factor (EGF). The m5s/1M cells showed high sensitivity to post-confluence inhibition of cell division and formed a uniform monolayer after the cells had become confluent. The addition of EGF resulted in loss of contact-dependent inhibition of growth and caused a massive piling up of a multilayered array of cells after they had become confluent. When EGF was removed from the medium, the cell number decreased rapidly, and the cells formed a uniform monolayer at the density observed in the absence of EGF. m5S/1M cells have high- and low-affinity receptors for EGF (approximately 40,000 receptors per cell), and the apparent dissociation constants of the EGF-binding reactions were 3.3 nM and 0.15 nM, respectively. The effect of EGF on the intracellular mobilization of Ca2+ and the formation of inositol phosphates was studied by using the calcium-sensitive fluorescent indicator fura 2 and [3H]inositol. EGF had no effect either on the mobilization of cytosolic free calcium [( Ca2+]i) or on the formation of inositol phosphates in m5s/1M cells, whereas bradykinin induced a rapid increase in both [Ca2+]i and inositol phosphates. Analysis of the glycosphingolipid (GSL) composition of m5S/1M cells showed that globotriaosylceramide (Gb3Cer), which is known to be a Burkitt lymphoma-associated antigen, is specifically expressed in the EGF-treated cells. The expression of Gb3Cer is dependent on the presence of EGF, with a reversible shift in GSL composition being observed in the presence or absence of EGF.

Glycosphingolipids of Echinococcus multilocularis metacestodes

Neutral and acid glycosphingolipids of Echinococcus multilocularis metacestodes that were obtained after intraperitoneal infection of Meriones unguiculatus have been analyzed by thin layer chromatography. Neutral and acid glycosphingolipids accounted for 95% and 5% of total glycosphingolipids, respectively. 12 different fractions were observed in the neutral glycosphingolipids extracts of the parasite. The most important was a monohexosylceramide fraction accounting for 56.4% of neutral glycosphingolipids. 9 different fractions were detected in gangliosides (acid glycosphingolipids). The fact that these glycosphingolipids were specific to the parasite was established by the analysis of different cell populations of the host. Glycosphingolipids were purified from control and parasite-infected gerbil blood cells as well as from peritoneal exudate cells of healthy gerbils after a non-specific immunostimulation. The chromatograms obtained with these extracts were totally different from the parasite. In addition, parasitosis was found to have no effect on the host blood cell glycosphingolipids.

Age-dependent changes in monkey lenticular gangliosides

The content, composition, and distribution of gangliosides were examined in the lenses of normal rhesus monkeys aged 6-16 years. Gangliosides were isolated by organic solvent extraction. DEAE-Sephadex ion-exchange column chromatography, and thin-layer chromatography (TLC). Ganglioside contents determined by the thiobarbituric acid method increased in the lens with aging. TLC analysis of gangliosides showed a much more complex pattern with aging, and the predominant gangliosides were tentatively identified as GM3, GM1, and GD1a. Individual lenticular gangliosides were identified by TLC-immunostaining procedures using anti-GM1 and anti-asialoGM1 antisera.

Ganglioside composition of human melanoma and response to antitumor treatment

Ganglioside composition of human melanoma was correlated with sensitivity of melanoma to antitumor treatment with chemotherapeutic agents and radiation. The cytotoxic effect of each treatment was evaluated on 16 melanoma cell lines using the human tumor colony-forming assay. Ganglioside fractions were extracted and purified from each cell line and analyzed for the four major gangliosides in melanoma (GM3, GM2, GD3, and GD2) by thin-layer chromatography (TLC) and TLC scanner. GD2 content positively correlated with sensitivity to radiation (r = 0.753, p less than 0.001) and vincristine (r = 0.779, p less than 0.001). In contrast, GM3 content inversely correlated with sensitivity to radiation (r = -0.658, p less than 0.01) and vincristine (r = -0.692, less than 0.01). The gangliosides GD3 and GM2 were shown to have no significant correlation with any of these treatments.

Differences in lipid composition between isolated growth cones from the forebrain and those from the brainstem in the fetal rat

The lipid composition of nerve growth cone membranes isolated from rat fetal forebrain or brainstem by the sucrose density gradient method was analyzed biochemically and immunochemically. In the forebrain, growth cone membrane (GCM) contained lower levels of gangliosides than those from other heavier fractions, but it was not the case in the fetal brainstem at the same developmental stage. The distinctive features in the ganglioside composition of GCM are the predominance of GD3 and the presence of c-series gangliosides that are due to fetal expression in mammals. A unique acidic glycolipid, sulfoglucuronylparagloboside (SGPG), which is not present in adult brains, was first detected in both forebrain and brainstem GCM. Including such minor species, the ganglioside composition in forebrain or brainstem GCM was almost identical to other membrane fractions from the forebrain or brainstem. The compositional ratios of the major lipid classes in membranes, cholesterol and phospholipids, seemed to be common to forebrain GCM and brainstem GCM, as indicated by the identical values of phospholipid-to-protein (PL/Pr), cholesterol-to-protein (Ch/Pr), and cholesterol-to-phospholipid (Ch/PL) ratios for both. This study has revealed that GCM isolated from forebrain which is supposed to be at an earlier stage of neuronal differentiation than brainstem has less amounts of total gangliosides, high proportion of GD3 to GD1a and enriched c-series gangliosides as compared to brainstem GCM.

Gangliosides in the brain in adult Down's syndrome and Alzheimer's disease

Quantitative analysis of total gangliosides and of ganglioside composition by HPTLC has been carried out on the gray matter of frontal cerebral cortex of six brains from Down's syndrome (DS) adults, six age-matched controls, six Alzheimer's disease (AD) adults, and six controls matched for age with the AD brains, as well as on three DS and six control cerebellum specimens. In addition, the analyses were carried out on specimens of corpus callosum of five adult DS and five control brains. No abnormalities were found in the gangliosides of DS corpus callosum. In DS frontal cortex, the concentration of total gangliosides was reduced, and there was a decrease in the fraction of GT1b and GD1b, and an increase in those of GT1a, GD3, GM1 and GM2; the ratio of total b-series to a-series gangliosides was decreased. Very similar abnormalities were found in the gangliosides of DS cerebellum. In AD frontal cortex, by contrast, the total gangliosides and their composition were normal by comparison with age-matched controls, with the minor exception of reductions in the fractions of GQ1b and GT1L. It is concluded that abnormalities in gangliosides exist in the brain in DS that are unrelated to AD-type pathology and may reflect developmental disturbances.

Planar chromatographic techniques in biomedicine: current status

In planar chromatography (PLC), the solvent flows through a layer either by means of capillary forces [conventional thin-layer chromatography (TLC)] or by a forced-flow system (over-pressured layer chromatography). Phases and instrumentation currently available are briefly examined. The main applications in biomedicine are reviewed. Although silica gel TLC plates still predominate, interest in other phases is increasing. Unique detection features such as immunostaining are emphasized. Although gas chromatography and high-performance liquid chromatography have superseded TLC in the analysis of carbohydrates, amino acids and indole derivatives, interest in PLC continues to be high in lipid analysis.

Ganglioside content and composition of cells from normal and atherosclerotic human aorta

The ganglioside content and composition of cells obtained by enzyme digestion of 2 layers of human aortic intima were investigated. Five gangliosides were identified in cells isolated from the external musculo-elastic intimal layer adjacent to the media: GM3, GM1, GD3, GD1a, and GT1b. The same gangliosides plus ganglioside Gx, the chromatographic mobility of which corresponded to the mobility of ganglioside GD1b from human brain, were found in cells from the internal elastic-hyperplastic intimal layer adjacent to the vessel lumen. In both layers, the major cellular ganglioside was GM3 which represented 60% of the total cellular ganglioside content. The ganglioside content was lower in cells obtained from fatty streaks compared to cells isolated from unaffected intima. The amount of di- and trisialogangliosides in atherosclerotic plaque cells was lower, and that of monosialogangliosides higher than in cells isolated from unaffected intima. The amount of GM3 was mainly responsible for the difference in the total ganglioside content of cells obtained from different lesion types. On the whole, cells from fatty streaks contained smaller amounts of total gangliosides, whereas cells from plaques had greater total ganglioside content, than cells from unaffected intima.

Ganglioside and lipid composition of bulk-isolated rat and bovine oligodendroglia

We have examined the ganglioside composition of 30-day and 60-day postnatal rat oligodendroglia, adult bovine oligodendroglia, gray matter, white matter, and myelin and also the total lipid composition of the oligodendroglial preparations. The ganglioside patterns of rat and bovine oligodendroglia, as previously found for human oligodendroglia, were more complex than those of myelin. These data indicate that oligodendroglial perikarya can synthesize many brain type gangliosides, not all of which are incorporated into the compact myelin. Alternatively, the ganglioside composition of myelin may be altered in situ by the myelin-associated neuraminidase. In these two species, as in human, GM4 appears specific to oligodendroglia and myelin, while GD3 and GM3 are enriched in oligodendroglia but not myelin. In bovine oligodendrocytes GD3 is the major ganglioside. The total lipid concentration, as well as the percentage of cholesterol, sphingomyelin, phosphatidylinositol, and phosphatidylserine, differ for 30- and 60-day-old rat oligodendroglia and may be developmentally correlated with changes in myelin composition during myelinogenesis. There are also marked differences in the lipid composition of bovine oligodendroglia compared to rat oligodendroglia, with the former having more galactolipid and less ethanolamine phosphoglycerides.

High-performance liquid chromatography of sialooligosaccharides and gangliosides

Glycans were cleaved from gangliosides and separated by high-performance liquid chromatography (HPLC). The columns were packed with bonded stationary phases made of microparticulate, macroporous silica with serotonin, phenylpropanolamine or tryptamine as the biogenic amine ligate. The ganglioside oligosaccharides were eluted in the order of increasing number of sialic acid residues in the molecule and their retention decreased with the ionic strength of the mobile phase. Best selectivity was obtained in the pH range from 3.0 to 4.0. The two major sialic acids, N-acetylneuraminic and N-glycolylneuraminic acids, were separated by lectin affinity chromatography using an HPLC column packed with silica-bound wheat germ agglutinin and 10 mM phosphate buffer, pH 4.0, as the eluent. Throughout this study, isocratic elution was used and the column effluent was monitored at 195 nm.

Gangliosides of human melanoma

Human melanoma synthesizes a large quantity of gangliosides, glycosphingolipids containing sialic acid. The authors previously have demonstrated that the ganglioside profile differs among individual melanomas and is widely heterogeneous. In the current study, a retrospective study was performed to compare the relationship between the quantity of five major gangliosides of human melanoma (GM3, GM2, GD3, GD2, and alkali-labile ganglioside) and nine clinical factors (sex, age, site, stage, tumor size, pigmentation, histopathologic type of primary tumor, chemosensitivity, and prognosis). Melanoma specimens studied were obtained from patients of our clinic and included 52 biopsy specimens and 28 cultured cell lines. Analysis of melanoma biopsy specimens have shown a differential ganglioside expression among different sites of tumor, pigmentation, and histopathologic types. Results of cultured melanoma cell lines differed from those of biopsy specimens, but ganglioside expression also differed among the site of tumor, tumor size, histopathologic types, and chemosensitivity. GM3 positively correlated with a good prognosis in both biopsy and cultured melanomas.