Increased activity of lysosomal glycohydrolases in glioma tissue and surrounding areas from human brain

Increased metabolic activity represented by an increase in both anabolism and catabolism in tumours, including gliomas, is a well known phenomenon and utilised in positron emission tomography imaging of tumours. In this study lysosomal enzyme activities of some glycohydrolases were investigated in glioma tissue from human brain. Tumour tissue (ten cases) and brain tissue surrounding the tumour tissue (seven cases) from patients with a histopathological diagnosis of glioblastoma multiforme or anaplastic astrocytoma were analysed for activity of the lysosomal enzymes galactosylceramidase, glucosylceramidase, beta-galactosidase, beta-N-acetyl-glucosaminidase, beta-glucuronidase and acid phosphatase. All of the investigated lysosomal enzymes except galactosylceramidase showed increased activity compared with that in normal brain tissue. Moreover, despite sparsity of tumour cells the specimens taken from surrounding areas showed elevated activities of the same enzymes. The findings indicate an upregulation of the activity not only in tumour but also in normal cells of the surrounding area.

Sulfatide is expressed in both erythrocytes and platelets of bovine origin

A novel sulfated glycosphingolipid containing a sulfated galactosyl residue was isolated from bovine erythrocyte ghosts, and purified to homogeneity by column chromatography on DEAE-Sephadex and silica beads. Structural characterization included compositional analyses, permethylation studies, proton nuclear magnetic resonance (NMR) spectroscopy, negative secondary ion mass spectrometry (SIMS), solvolysis and immunostaining on thin-layer chromatogram. As a result, the structure of this glycolipid is proposed as HSO3-Gal beta 1-1 Cer. The ceramide portion contained d18:1, d18:0 and t18:0, and the predominant fatty acid consisted of palmitate and palmitate with a hydroxy group, as deduced by both compositional analysis and negative SIMS mass spectrometry. The component of this glycosphingolipid probably originates from erythrocytes and platelets as indicated by the results of flow cytometry analysis using Sulph I monoclonal antibody. The yield of galactosyl sulfatide was about 0.37 mg/kg wet bovine erythrocyte membranes, about three times that of human kidney. Our results strongly suggest that galactosylceramide sulfate on erythroid cells may play an important biological role in cell to cell interaction and recognition.

Sulphatide and its precursor galactosylceramide influence the production of cytokines in human mononuclear cells

Sulphatide is expressed in the central and peripheral neural system, in islets of Langerhans, and in tissues affected by late diabetic complications. Autoantibodies to sulphatide are present in patients with insulin-dependent diabetes and the Guillain-Barré syndrome. Cytokines influence these disease processes, and we therefore studied whether sulphatide and its precursor galactosylceramide (gal-cer) influence the in vitro production of cytokines by blood mononuclear cells (MNC) originating from 15 healthy persons. Using lipopolysaccharide (LPS)-stimulated cells, sulphatide increased the IL-2 production (163 +/- 17% of controls without sulphatide, p = 0.02), and gal-cer increased the IL-1 alpha production (145 +/- 13%, p = 0.006), whereas neither gal-cer nor sulphatide had an effect on the production of IL-6, IL-10 or TNF alpha. When stimulating cells with phytohaemagglutinin (PHA), sulphatide decreased the production of IL-6 (88 +/- 5%, p = 0.009), IL-10 (66 +/- 3%, p = 0.000003), and TNF alpha (75 +/- 9% p = 0.02). Gal-cer, however, increased the production of IL-6 (188 +/- 13% p = 0.000006), and decreased the production of TNF beta (80 +/- 6%, p = 0.007). Neither gal-cer nor sulphatide had an effect on the production of IL-2 or IFN gamma from PHA-stimulated cells. Northern blot analysis using an IL-6 probe similarly showed an increased amount of IL-6 mRNA after gal-cer incubation (range 469%-150%, n = 3) of PHA-stimulated control. Thus, sulphatide and gal-cer influence the production of several cytokines thought to be involved in immunoinflammatory disease processes.

Activation of the complement cascade and increase of clusterin in the brain following a cortical contusion in the adult rat

The aim of the present study was to examine the glial cell response and the possible involvement of the complement cascade following a cerebral cortical contusion. The lesion was produced using a standardized weight-drop technique in adult rats. The blood-brain barrier was damaged, as demonstrated by a decrease of immunoreactivity for a tight junction protein normally expressed by endothelial cells of small vessels in the central nervous system. Increased immunoreactivity for microglial (OX42) and astroglial cells (glial fibrillary acidic protein), as well as macrophages expressing ED1-immunoreactivity (IR) were found in the vicinity of the lesion at all postoperative survival times (2-14 days). In the present study complement factor C3d- and C9-IR was found around the lesion, indicating that activation of the complement cascade had taken place. Furthermore, immunoreactivity for the putative complement inhibitor clusterin (sulfated glycoprotein-2) was found in some of the injured neurons. The contralateral hemisphere showed no evidence of the reaction found in the ipsilateral hemisphere. The balance between complement activation and complement inhibitors may have an impact on the degenerative components in the brain following traumatic injury and in particular on the events leading to nerve cell death.

Apolipoprotein E in cerebrospinal fluid from patients with Alzheimer's disease and other forms of dementia is reduced but without any correlation to the apoE4 isoform

Apolipoprotein E (apoE) has been suggested to play a role in regenerative processes in the brain after trauma, and also in the pathogenesis of Alzheimer's disease (AD). We examined cerebrospinal fluid (CSF) apoE in a material consisting of 23 patients with early-onset AD (EAD), 31 with late-onset AD (LAD), 16 with frontal-lobe dementia (FLD), 25 with vascular dementia (VAD) and 25 controls. CSF-apoE was decreased in all of EAD (1.8 +/- 1.1 mg/l; p < 0.0005), LAD (2.5 +/- 0.9 mg/l; p < 0.0005), VAD (2.3 +/- 1.4 mg/l; P < 0.0005) and FLD (3.0 +/- 1.3 mg/l; p < 0.05) compared to the control group (5.7 +/- 4.0 mg/l). Since apoE4 has been found to bind to beta/A4-amyloid, and AD patients homozygous for apoE4 to have higher number of senile plaques than apoE3 homozygotes, we also examined the relation between CSF-apoE and apoE alleles. However, CSF-apoE did not significantly differ between patients with different apoE isoforms. Our findings support that apoE is involved in the pathogenesis of dementia disorders, both degenerative and vascular, but the CSF-apoE level is not influenced by the apoE isoforms. CSF-apoE may be used as an unspecific marker for neurodegenerative disorders, but not in purpose of differential diagnostics between different dementia disorders.

In vivo growth conditions suppress the expression of ganglioside GM2 and favour that of lacto series gangliosides in the human glioma D-54MG cell line

The human glioma D-54MG cell line grown in vitro primarily expresses ganglio series gangliosides, particularly GM2. Subcutaneous injection of these cells into nude mice produced xenografts with an increased content of the human glioma-associated lacto series gangliosides, primarily 3'-isoLM1, an alteration that was dose dependent, with the highest dose (1 x 10(8)) resulting in a phenotype that was most like that of the inoculum. After one passage in vivo, the lacto series dominated and reached a proportional level that was kept throughout the 10 passages. The mRNA levels of the GM2-synthase clearly coincided with GM2 expression and was 20 times higher in cells grown in vitro than in those grown in vivo. These results support the view that ganglioside expression in human gliomas is strongly influenced by environmental factors.

Presence of sulphatide (3'-sulphogalactosylceramide) in pericytes in the choroid layer of the eye: sharing of this glycolipid autoantigen with islets of Langerhans

The aim of the study was to investigate the distribution in the eye of sulphatide, an acid glycolipid which has previously been demonstrated in islets of Langerhans, nervous tissue and in kidney glomeruli of diabetic patients, and against which antibodies have been found in patients with newly diagnosed insulin-dependent diabetes mellitus. A specific monoclonal antibody, Sulph I, was used for detection of sulphatide by thin-layer chromatography, and light and electron microscope immunohistochemistry. A distinct, patchy staining was found in the choroid layer and the ciliary processes. The antigen was confirmed to be sulphatide and its concentration in human eyes was 30 nmol sulphatide/g wet tissue. By electron microscopy, anti-sulphatide choroid labelling was demonstrated in pericytes and in smooth muscle cells surrounding vessels. No Sulph I-negative pericytes were seen. Double labelling with Sulph I and anti-smooth muscle actin revealed that only pericytes in the eye contained sulphatide and not those in heart, lung, liver, adrenal, spleen, lymph node, thymus, or pancreatic tissue. Thus, sharing of the autoantigen sulphatide has been demonstrated between islets of Langerhans and pericytes in the choroid layer of the eye.

Elevated cerebrospinal fluid sulfatide concentrations as a sign of increased metabolic turnover of myelin in HIV type I infection

Cerebrospinal fluid (CSF) sulfatide concentrations were analyzed in 18 patients with asymptomatic HIV-1 infection, in 16 patients with AIDS who were free from opportunistic infections in the central nervous system (CNS), in 12 HIV-1-infected patients with opportunistic CNS infections or lymphoma, and in 19 HIV-negative controls, by thin-layer chromatography overlay technique using an antisulfatide antibody to estimate the metabolic turnover of myelin. The majority of asymptomatic HIV-1-infected patients had normal CSF sulfatide concentrations, but the mean CSF sulfatide concentration was still elevated compared to that in HIV-negative controls (152 compared to 99 nmol/liter, p < 0.05). The CSF sulfatide concentrations in the AIDS group (mean 395 nmol/liter) were significantly increased compared to those in asymptomatic HIV-1-infected patients (p < 0.01) and in HIV-negative controls (p < 0.001), but did not differ significantly between patients with and without dementia. Increased CSF sulfatide concentrations were also found in patients with opportunistic infection or lymphoma in the CNS. In the entire study population, the sulfatide levels were associated with blood-brain barrier function, but not with intrathecal immunoglobulin production or with positive HIV isolations from CSF. Thus, signs of white matter changes, measured as increased CSF sulfatide concentrations, could be found in some asymptomatic HIV-1-infected patients, but the highest levels were seen in patients with AIDS.

Immunoglobulin M in cerebrospinal fluid: reference values derived from 111 healthy individuals 18-88 years of age

The importance of immunoglobulin M (IgM) determination in cerebrospinal fluid (CSF) has increased parallel to the need for early diagnosis of infectious and inflammatory disorders of the central nervous system. Current reference values are based on analysis of CSF from 'reference groups' consisting of patients with psychiatric and/or neurological symptoms but without positive clinical findings. Therefore, accurate reference values for CSF IgM are of utmost importance. The present study presents reference values for IgM in CSF in a large sample (n = 111) of healthy individuals with an age span of 18-88 years. The upper reference limit, calculated as the 0.95 fractile, was 0.36 mg/l for CSF IgM, 0.40 for CSF/serum IgM ratio, and 0.045 for the IgM index. These parameters showed no significant difference between sexes nor any significant correlations with age. The correlations between CSF/serum albumin ratio and CSF/S IgM ratio were linear and statistically highly significant, suggesting that the IgM index values do not depend on the blood-CSF barrier function within the normal range of the CSF/serum albumin ratio.

Detection of cerebrospinal fluid leakage by isoelectric focusing on polyacrylamide gels with silver staining using the PhastSystem

Cerebrospinal fluid (CSF) leakage, which sometimes occurs after skull trauma, is a life-threatening condition. A prompt start with antibiotics and/or prompt surgical treatment of fistulas is essential to avoid severe complications. This requires a fast and reliable method for detecting CSF leakage. This paper describes a fast (< 2 h) method based on the identification of the tau protein (beta 2-transferrin) band(s). Tau protein is a brain-specific variant of transferrin that is characteristic of CSF. The method includes iso-electric focusing (IEF) on pre-cast polyacrylamide gels and silver staining using the PhastSystem, an automated instrument for electrophoresis and staining. In the present study, this technology was applied on 200 consecutive CSF samples, 32 of which were from healthy volunteers. Tau protein was detected in all CSF samples but 5 (2.5%), all of which were from patients with blood-brain barrier (BBB) damage. In these cases, the tau protein band was indistinct when direct silver staining was used. Therefore, immunofixation with an antitransferrin antibody was performed, and after that the tau protein band was easy to detect. The specificity of the method was high, since no brain-specific tau protein band was detected in serum, tears, saliva, or nasal secretion. As IEF of CSF using the PhastSystem is increasingly used as the routine method for detection of oligoclonal bands of IgG in neurological disorders, it could readily be used in the clinical (neuro) chemical laboratory also for the less frequent cases of suspected CSF leakage.

Neonatal treatment of BB rats with sulphatide delays development of diabetes but does not change incidence

Sulphatide is a newly described autoantigen in insulin-dependent diabetes mellitus; it is present in the islets of Langerhans, and anti-sulphatide antibodies are found in diabetic patients and in spontaneously diabetic BB rats. The aim of the study was to treat neonatal BB rats with sulphatide in order to induce tolerance and thereby possibly influence later diabetes development. One hundred and twelve newborn BB rats, divided into three groups, were treated once daily during the first 6 days of life with intrathymic injections of sulphatide, galactosyl-ceramide (which is similar to sulphatide but without sulphate) or phosphate buffer alone. Although the results showed no difference in diabetes incidence among the three groups, there was a delayed onset of diabetes in the sulphatide-treated group, which developed diabetes on average at 77 +/- 1 days of age, compared to 70 +/- 2 days (p < 0.02) for the galactosyl-ceramide-treated group and 70 +/- 1 days (p < 0.01) for the buffer-treated group. The degree of insulitis and the size of islets of Langerhans were studied histologically for the diabetic animals in all three groups; there were no significant differences although the sulphatide-treated group tended to have a more normal histology. The blood glucose levels for the diabetic BB rats were similar in all three groups. Thus, neonatal treatment with the diabetic autoantigen sulphatide at the chosen dosage does not influence the incidence of diabetes, but delays the onset of disease.

Infection of vaginal and colonic epithelial cells by the human immunodeficiency virus type 1 is neutralized by antibodies raised against conserved epitopes in the envelope glycoprotein gp120

The rectal and genital tract mucosae are considered to be major sites of entry for the human immunodeficiency virus (HIV) during sexual contact. We now demonstrate that vaginal epithelial cells can be infected by HIV type 1 (HIV-1) via a mechanism similar to that described for neuroglial cells and, more recently, for colorectal epithelial cells, involving initial interaction of the HIV-1 envelope glycoprotein gp120 with a cell-surface glycosphingolipid (sulfated lactosylceramide). A hyperimmune serum against gp120 was able to neutralize HIV-1 infection of vaginal epithelial cells. Site-directed immunization was employed to identify sites on gp120 recognized by antibodies neutralizing HIV-1 infection of vaginal and colonic epithelial cells. Hyperimmune sera were raised in monkeys against a series of 40 overlapping synthetic peptides covering the entire sequence of HIV-1 (HTLV-IIIB) gp120. Antisera raised against five synthetic peptides, corresponding to three relatively conserved regions and to the hypervariable region (V3 loop), efficiently neutralized HIV-1 infection of human vaginal epithelial cells in vitro. Similar results were obtained with the colonic cells. Hyperimmune sera to all five peptides have been shown earlier to neutralize HIV-1 infectivity in CD4+ T cells. These results have obvious implications for the design of mucosal subunit vaccines against sexually transmitted HIV-1 infections.

Cerebrospinal fluid apolipoprotein E is reduced in Alzheimer's disease

Apolipoprotein E (ApoE) has been implicated in the pathogenesis of Alzheimer's disease (AD). ApoE is synthesized within the brain and has been suggested to be involved in the re-utilization of membrane lipids during neuronal repair and remyelination after injury. Spherical ApoE-containing lipoprotein particles are found in the cerebrospinal fluid (CSF). To study further the pathogenetic role of ApoE in degenerative brain disorders, we analysed ApoE in CSF. A significant (p < 0.001) reduction of CSF ApoE (1.5 +/- 1.2 ng ml-1) was found in AD compared with controls (5.0 +/- 2.7 ng ml-1). A less pronounced reduction was also found in frontal lobe dementia (3.1 +/- 1.5 ng ml-1; p < 0.05). These findings support the hypothesis that ApoE is involved in the pathogenesis of degenerative brain disorders such as AD. An increased reutilization of ApoE-lipid complexes in the brain, as part of a generalized repair process, may explain the low CSF ApoE in AD. Alternatively, the reduction of CSF ApoE may be caused by absorption of ApoE to senile plaques and neurofibrillary tangles.

Sulphatide in islets of Langerhans and in organs affected in diabetic late complications: a study in human and animal tissue

Sulphatide has been found in rat islets of Langerhans and anti-sulphatide antibodies have been demonstrated in patients with insulin-dependent diabetes mellitus. Using a specific monoclonal antibody, Sulph I, directed against sulphatide, we investigated the in situ distribution of this glycolipid immunohistochemically; furthermore, the sulphatide concentration was determined in several organs and cells by thin-layer chromatography. The islets of Langerhans in all species examined, mouse, rat, pig, and monkey were intensively stained but exocrine tissue remained unlabelled. The sulphatide concentration in human islets was 150 +/- 46 pmol/100 islets. The only glycolipid-antigen detected was sulphatide. Regarding other tissues, sulphatide was found to be located in distal tubules in the kidney, peripheral nerves, distinct scattered spot-like structures in the choreoid layer of the eye, the ovum, and peripheral granulocytes. Sulph I injection in mice showed homing to kidney tubules, Lung, heart, liver, adrenal, spleen, lymph node and thymus were not stained by Sulph I. Thus, the distribution of sulphatide shows an association with organs known to be affected in diabetes, either initially or in late complications.

Gangliosides and allied glycosphingolipids in human peripheral nerve and spinal cord

Glycosphingolipids were determined in human spinal cord, cauda equina and femoral nerve of 10 subjects aged 20-70 years and in dorsal and ventral roots of four subjects aged 17-60 years. Myelin was isolated from corresponding tissue. Axons were isolated from the four specimens of dorsal and ventral roots. The concentration (mean and standard error of mean) of gangliosides in spinal cord was 0.80 +/- 0.03 mumol sialic acid/g fresh tissue, in cauda equina 0.40 +/- 0.02 mumol/g and in femoral nerve 0.23 +/- 0.01 mumol/g. In spinal cord only trace amounts of glycosphingolipids of the lacto series were found, and the ganglioside pattern differed from that in cerebral white matter by a relatively high proportion of GD3 and a low proportion of GD1a. The ganglioside patterns were almost identical in cauda equina and femoral nerve--the major ganglioside being 3'-LM1, 0.07 and 0.04 mumol/g respectively. Another ganglioside of the lacto series, 3'-HexLM1, was 25% of 3'-LM1. Peripheral nerve also contained three acidic glycosphingolipids in addition to sulfatide--LK1 and HexLK1 belonging to the glycosphingolipid lacto series and containing glucuronyl-3-sulfate instead of sialic acid, and inositolphosphoryl galactosylceramide. The dorsal (sensory) and ventral (motor) roots had the same major membrane lipid composition but the ganglioside concentration was 30% higher in sensory than motor nerve and myelin. The patterns of gangliotetraose gangliosides were, however, the same in motor and sensory myelin and axons. The ceramide composition of the gangliosides is also reported.

Cerebrospinal fluid in the diagnosis of multiple sclerosis: a consensus report

The Committee of the European Concerted Action for Multiple Sclerosis (Charcot Foundation) organised five workshops to discuss CSF analytical standards in the diagnosis of multiple sclerosis. This consensus report from 12 European countries summarises the results of those workshops. It is hoped that neurologists will confer with their colleagues in clinical chemistry to arrange the best possible local practice. The most sensitive method for the detection of oligoclonal immunoglobulin bands is isoelectric focusing. The same amounts of IgG in parallel CSF and serum samples are used and oligoclonal bands are revealed with IgG specific antibody staining. All laboratories performing isoelectric focusing should check their technique at least annually using "blind" standards for the five different CSF and serum patterns. Quantitative measurements of IgG production in the CNS are less sensitive than isoelectric focusing. The preferred method for detection of blood-CSF barrier dysfunction is the albumin quotient. The CSF albumin or total protein concentrations are less satisfactory. These results must be interpreted with reference to the age of the patient and the local method of determination. Cells should be counted. The normal value is no more than 4 cells/microliters. Among evolving optional tests, measurement of the combined local synthesis of antibodies against measles, rubella, and/or varicella zoster could represent a significant advance if it offers higher specificity (not sensitivity) for identifying chronic rather than acute inflammation. Other tests that may have useful correlations with clinical indices include those for oligoclonal free light chains, IgM, IgA, or myelin basic protein concentrations.

A high-sensitivity immuno-chemiluminescence technique for detection of oligoclonal IgG and IgM in unconcentrated cerebrospinal fluid

A method is described for detection of oligoclonal IgG and IgM in unconcentrated cerebrospinal fluid (CSF). The proteins were separated by agarose gel electrophoresis and transferred to cellulose nitrate membranes. A double antibody technique with a peroxidase conjugated secondary antibody was used to detect the protein. Bound secondary antibody was visualized by autoradiography using chemiluminescence (ECL) reagent. The procedure presented here allows examination of oligoclonal bands of IgG and IgM in less than 6h. The detection limit for a single band was approximately 10pg and the results were in complete agreement with those achieved by isoelectric focusing (Phast System) and subsequent immunofixation. In 9 of the samples oligoclonal IgM was also detected.

Altered expression of ganglioside phenotypes of human gliomas in vivo and in vitro

A library of epitope-defined antiganglioside monoclonal antibodies has been used to analyze the ganglioside phenotype of human glioma cell lines, rodent xenografts derived from them, and a separate panel of human glioma biopsies by multiple quantitative and qualitative assays. We have shown that the ganglioside phenotypes of cultured cell lines differ from the ganglioside phenotypes in the xenografts grown from the parent lines. The lacto series gangliosides 3'-isoLM1 and 3',6'-isoLD1 are expressed in the majority of primary human central nervous system neoplasms and xenografts derived from glioma cell lines, whereas glioma cell lines themselves express 3'-isoLM1 and 3',6'-isoLD1 in only 2/15 and 0/15 cases, respectively. Examination of the ganglioside profiles of serially passaged xenografts established from the glioma cell line D-54 MG, which does not express the lacto series, revealed the appearance of these gangliosides within one to two passages in vivo. The presence of these defined gangliosides in the majority of human gliomas and their absence in normal brain supports their application in compartmental therapy of primary central nervous system tumors.

Detection of glioma-associated gangliosides GM2, GD2, GD3, 3'-isoLM1 3',6'-isoLD1 in central nervous system tumors in vitro and in vivo using epitope-defined monoclonal antibodies

In this study, MAbs to the 'conventional' gangliosides expressed by human gliomas were generated and used to detect ganglioside species previously unisolated or defined in normal adult CNS tissue. Despite the marked phenotypic and genotypic heterogeneity shown by glioma cell lines (Bigner et al., 1981), the ganglioside phenotype of these cell lines is remarkably consistent qualitatively, if not quantitatively, in the ganglioside species expressed (Table V). The majority of cell lines and tumor samples express GM2, GD2 and GD3; this does not provide a diagnostic advantage (Vick et al., 1992). Nevertheless, as the relative amounts of these gangliosides in tumor as compared with normal adult CNS tissue is considerable, such reagents might be considered in compartmental immunotherapeutic approaches. Since GD2 and GD3 have been determined to mediate tumoricidal activity with human effector cells via specific antiganglioside epitope MAbs (Thurin et al., 1987; Kushner and Cheung, 1991; Barker et al., 1991; Reisfeld, 1993), cell-mediated approaches, as well as targeted immunoglobulin therapies, are also possible. The prospect of a more targeted approach with little or no effect on normal CNS tissue is now possible via the 'oncofetal' epitopes characteristic of 3'-isoLM1 and 3',6'-isoLD1. Several factors recommend the use of these moieties for compartmental immunotherapy; the inability to detect them within the adult CNS; the relatively high frequency of expression of 3'-isoLM1 and 3',6'-isoLD1, especially in human tumor samples (50-100%, depending upon the series and assay); and the existence of specific MAbs reactive with these epitopes. Current technology is being applied to these MAbs to transfer the specific recognition capacity of existing murine MAbs into various human framework structures of any desired immunoglobulin class, and thereby, biologic function. The variety of effector functions, the stability in affinity, labeling capacity, and the exquisite sensitivity of these MAbs for these glioma-distinctive epitopes is an exciting and promising approach for immunotherapy of human CNS tumors.

Gangliosides associated with primary brain tumors and their expression in cell lines established from these tumors

Human primary brain tumors differ in their ganglioside composition when compared to adjacent tissues. One ganglioside found in all malignant glioma specimens, but not detected in normal adult brain, is 3'-isoLM1, a ganglioside of the lacto series. This ganglioside was also identified in medulloblastomas with astrocytic differentiation and in brain tissues containing benign proliferating astrocytes. The appearance of 3'-isoLM1 was seen over large regions of brain from glioma but was found mainly in areas either adjacent to the macroscopic tumor or areas corresponding to the tumor in the opposite hemisphere. A high concentration of 3'-isoLM1 was also seen in the corpus callosum, the anatomical structure along which glioma cells may migrate to the opposite brain hemisphere. Ganglioside expressed by cell lines established from primary malignant brain tumors varied widely among cell lines and within a given cell line propagated under different conditions. In in vitro-cultured glioma and medulloblastoma cell lines, gangliosides of the ganglio series dominated and the expression of the lacto series gangliosides, including 3'-isoLM1 was low if at all detectable. However, in vivo growth of solid subcutaneous tumors in nude mice or rats led to a significantly increased expression of the often dominant gangliosides of the lacto series and revealed a decreased expression of ganglio series gangliosides. In conclusion, these findings indicate that environmental factors could strongly influence the expression of gangliosides that may lead to a switch from the ganglio to the lacto series. These results also suggest that ganglioside 3'-isoLM1 is associated with proliferating astrocytes, of both neoplastic and non-neoplastic origin and that this ganglioside may be involved in cell-cell recognition and attachment during development and tumor cell migration.

Formulas for the quantitation of intrathecal IgG production. Their validity in the presence of blood-brain barrier damage and their utility in multiple sclerosis

There are several formulas for the quantitative determination of intrathecal IgG production: Reiber and Felgenhauer's formula (IgG(loc)), the Extended IgG index, Tourtellotte's formula (TOURT), Schuller and Sagar's formula (SCHULL), the IgG index, the Log IgG index, and Blennow and co-workers' formula (IGGPROD). To evaluate the utility of these formulas in the presence of blood-brain barrier (BBB) damage, we present the results from a study of serum and cerebrospinal fluid (CSF) samples from 125 healthy individuals, 18-88 years of age; 1072 consecutive patients without oligoclonal IgG bands (OCBs) in the CSF, 683 without BBB damage (CSF/S: albumin ratio < 9.8) and 389 with BBB damage (CSF/S albumin ratio 9.8-30); and 106 patients with definite multiple sclerosis (MS). The relation between the CSF/S albumin ratio and the CSF/S IgG ratio was remarkably linear in both healthy individuals (r = 0.95; P < 0.0001) and patients without oligoclonal bands in the CSF (r = 0.95; P < 0.0001). Therefore, IgG(loc) and the Extended IgG index, two formulas based on a nonlinear relation between the CSF/S albumin ratio and the CSF/S IgG ratio, yielded biased results (lower values) in the presence of BBB damage. TOURT and SCHULL also yielded biased (higher) values in the presence of BBB damage, probably because of incorrect constants in these formulas. There were no significant correlations between the CSF/S albumin ratio (i.e. the BBB function) and the IgG index or the Log IgG index, two dimensionless quotients for the detection of intrathecal IgG production, or between the CSF/S albumin ratio and IGGPROD, an empirical formula for the determination of intrathecal IgG production in mg/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Sulphatide antigen in islets of Langerhans and in diabetic glomeruli, and anti-sulphatide antibodies in type 1 diabetes mellitus

Clinical coincidence between diabetes and neurological disorders, and sharing of antigen determinants between islets of Langerhans and neural tissue, has been suggested. Sulphatide is a neural epitope which can be visualized with a monoclonal antibody Sulph I. Different tissues were examined by immunohistological methods. Sulphatide and anti-sulphatide antibodies were determined by thin-layer chromatographic techniques. IgG was isolated using protein A columns. A specific staining by Sulph I was found of rat islets, assigned to the secretory granules of both alpha and beta cells. No labelling of the exocrine tissue or other body tissues was seen, except for nerve and kidney structures. The latter showed staining of the distal tubules and, in addition, but only in the diabetic kidney, of glomeruli located in the subendothelial area in the capillary loops and the mesangial space. Sera from 38% of 40 spontaneously diabetic BB rats displayed anti-sulphatide antibodies, mainly IgG, whereas all 30 control Lewis rats were negative. Most recently we have demonstrated anti-sulphatide antibodies in 88% of 57 patients with newly diagnosed Type 1 diabetes (titres of > 1:400); all 135 healthy control persons were negative. The sulphatide antibody reactivity was present in the IgG fractions of the patients' sera. Thus, sulphatide is demonstrated in islets of Langerhans and in kidney related to the diabetic lesion, and, furthermore, anti-sulphatide antibodies exist in Type 1 diabetes mellitus.

Sulphatide and sulphatide antibodies in insulin-dependent diabetes mellitus

Insulin-dependent diabetes mellitus (IDDM) is associated with neurological disorders. Sulph I, a monoclonal antibody to sulphatide (a neural epitope), stained secretory granules in alpha and beta cells of rat islets of Langerhans, but not exocrine tissue. Sera from 88% of 57 newly diagnosed IDDM patients was anti-sulphatide positive, and 76% were positive 6 months later. All 135 healthy controls were negative. Sulphatide antibody may be an IDDM marker.

Peripheral neuropathy associated with monoclonal IgM antibody to glycolipids with a terminal glucuronyl-3-sulfate epitope

Twenty-nine patients with paraproteinaemia, 12 with neuropathy and 17 without a previous record of neurological symptoms were clinically characterized. All 12 neuropathy patients had a moderate to severe sensorimotor demyelinating neuropathy. The patients were examined with regard to serum antibodies to gangliosides, including GM1, GD1a, GD1b, GT1b, and LM1, and other acidic glycolipids, including LK1 and sulphatide, of human brain and peripheral nerve. Sera from 80 blood donors, 40 men and 40 women 20-60 years of age, were used as normal controls. The sera were analysed with an ELISA performed on thin-layer chromatography plates. At a dilution of 1/400 none of the control sera gave a detectable reaction and a titre of > or = 1:400 was considered as a positive test. In 11 of the 12 neuropathy patients the paraproteinaemia was of IgM type and 10 of them had a positive antibody titre against LK1 and Hex-LK1, acidic glycolipids with a terminal glucuronyl-3-sulphate group. The antibody titre against LK1 in 1 patient was 1:400 and varied between 1:5,000 and 1:3,200,000 in the other 9. One of the patients also had a positive titre, 1:64,000, to sulphatide. None of the sera from the 17 paraproteinaemia patients without a previous record of neurological symptoms contained antibodies to LK1 or to any glycolipid antigen examined, except for sulphatide. A positive titre (> or = 1:400) of antibodies to sulphatide was found in sera from 4 of these patients, the titres being < or = 3,200.(ABSTRACT TRUNCATED AT 250 WORDS)