Nanoparticle-Aided Detection of Colorectal Cancer-Associated Glycoconjugates of Extracellular Vesicles in Human Serum

Extracellular vesicles (EVs) are found in all biological fluids, providing potential for the identification of disease biomarkers such as colorectal cancer (CRC). EVs are heavily glycosylated with specific glycoconjugates such as tetraspanins, integrins, and mucins, reflecting the characteristics of the original cell offering valuable targets for detection of CRC. We report here on europium-nanoparticle (EuNP)-based assay to detect and characterize different surface glycoconjugates of EVs without extensive purification steps from five different CRC and the HEK 293 cell lines. The promising EVs candidates from cell culture were clinically evaluated on small panel of serum samples including early-stage (n = 11) and late-stage (n = 11) CRC patients, benign condition (n = 11), and healthy control (n = 10). The majority of CRC cell lines expressed tetraspanin sub-population and glycovariants of integrins and conventional tumor markers. The subpopulation of CD151 having CD63 expression (CD151^CD63) was significantly (p = 0.001) elevated in early-stage CRC (8 out of 11) without detecting any benign and late-stage samples, while conventional CEA detected mostly late-stage CRC (p = 0.045) and with only four early-stage cases. The other glycovariant assays such as CEA^Con-A, CA125^WGA, CA 19.9^Ma696, and CA 19.9^Con-A further provided some complementation to the CD151^CD63 assay. These results indicate the potential application of CD151^CD63 assay for early detection of CRC patients in human serum.

FUT3 and FUT2 genotyping and glycoconjugate profile Lewisb as a protective factor to Toxoplasma gondii infection

The interaction between the ABO, FUT2 and FUT3 genes results in the synthesis of different glycoconjugates profiles expressed in gastrointestinal tract. Moreover, the protozoan Toxoplasma gondii, which causes toxoplasmosis, utilizes this organ as an infection route. We analyzed the frequencies of the different glycoconjugate profiles which were determined by phenotyping ABO and genotyping the status secretor (FUT2; substitution G428A) and Lewis (FUT3; substitution T202C and C314T) histo-blood systems, assessed by PCR-RFLP and PCR-SSP, respectively. A total of 244 pregnant women (G1: Seropositive; G2: Seronegative) for IgG T. gondii antibodies were enrolled. IgG anti-T. gondii antibodies were determined by ELISA. G1 was composed of 158 (64.8%) sample and G2 by 86 (36.2%). The glycoconjugate profile was accessed in 151 seropositive and 85 seronegative samples by the combination of ABO and Lewis phenotyping as well as FUT2 and FUT3 genotyping. In G1, 36 (22.8%) presented the glycoconjugate profile ALeb, 5 (3.3%) A, 13 (8.6) BLeb, 1 (0.6%) B, 41 (27.1%) Leb, 13(8.6%) H, 38(25.2%) Lea and 4 (2.6%) Lec. G2 was composed of 13 (15.3%) of ALeb, 15 (17.6%) BLeb, 1 (1.2%) B, 42 (49,4%) Leb and 14 (16.5) Lea. H and Lec glycoconjugate profiles were not found in G2. The frequencies of the glycoconjugates profiles Leb (p = 0.001) and H (p = 0.005) were significantly different compared between G1 and G2. The glycoconjugate profile H inferred from the ABO phenotyping and FUT3 and FUT2 genotyping is associated with infection by T. gondii in pregnant women and the Leb profile appears to protect the infection by this parasite.

Serum Glycoconjugates in Patients with Anemia and Myeloid Leukemia

Because of carbohydrate alterations in malignant cells, serum glycoproteins have drawn considerable attention. In the current investigation we determined total sialic acid (TSA), lipid bound sialic acid (LSA), protein bound hexoses (galactose+mannose), fucose, hexosamines (galactosamine+glucosamine) and mucoid protein concentrations in the serum of patients with anemia and myeloid leukemia. The results were compared with those obtained in healthy individuals. In the leukemia patients we observed significant increases in glycoconjugates compared with the controls (P < 0.001), and in TSA and fucose levels compared with the anemia patients (P < 0.001). LSA and hexosamine levels were significantly lower in anemia patients with respect to the leukemia patients (P < 0.01 and P < 0.05 respectively), whereas levels of mucoid proteins and hexoses did not show significant differences. Except for hexosamines, all the markers tested were significantly elevated in the anemia patients compared with the controls. The present study suggests that the glycoconjugates investigated might be useful biochemical markers for differentiating anemic from leukemic conditions.

Serum glycomarkers of endoplasmic reticulum and lysosomal-endosomal system stress in human healthy aging and diseases

To verify the idea that extracellular free oligosaccharides might be able to reflect the functional status of the endoplasmic reticulum (ER) and lysosomal-endosomal system, HPLC-profiles of serum-derived free oligosaccharides (FOS) in human healthy aging, acute myeloproliferative neoplasms, and cardiovascular pathologies were compared with intracellular glycans. After plasma deproteinization and FOS purification the oligosaccharides were labelled with anthranilic acid, separated into the neutral and charged with QAE Sephadex (Q25-120) chromatography and analysed using high-performance liquid chromatography (HPLC). The charged FOS were digested with a sialidase and compared with free oligosaccharides from transferrin for structural decoding. HPLC-profiles of serum-derived FOS revealed mild delay of the dolichol phosphate cycle in ER, moderate intensification of ER-associated degradation (ERAD) and degradation in endosomal-lysosomal system with aging; an inhibition of the dolichol phosphate cycle, intensification of ERAD and increasing of lysosomal exocytosis in acute myeloproliferative neoplasms; intensification of ERAD and glycocojugate degradation with endosomal-lysosomal system in cardiovascular diseases. As serum free oligosaccharides are able to reflect specifically perturbations in ER and endosomal-lysosomal system under wide range of stressors they can serve as extracellular markers of functionality of these organelles.

Serum total gangliosides level: clinical prognostic implication

PURPOSE

The gangliosides overexpression contributes to the development of skin melanoma. The purpose of this study was to determine if the total gangliosides serum levels might predict the tumor growth in patients with melanoma or if the transfer of shed cell gangliosides reflects the implication in the clinical prognostic of these patients.

PATIENTS AND METHODS

Total gangliosides serum levels were measured in the cryopreserved serum by estimating lipid-associated sialic acid in 761 patients before surgical resection of melanoma, in 406 patients with precancerous pigmentary lesions, and in 410 healthy individuals. This study was performed at the Dermatovenereological Research Center, Bucharest, Romania, during 1991-2010. All sera obtained after surgical resection of melanocytic tumors were analyzed to see if adjuvant therapy (chemo-, immuno-, immunochemo-therapy) induced gangliosides changes in melanoma patients and if the responses were correlated with survival.

RESULTS

Total gangliosides serum levels were higher in melanoma patients than in precancerous melanocytic lesions patients or in healthy individuals. Larger tumors in Breslow index and more advanced stage of disease were correlated with higher total gangliosides serum values. Augmented total gangliosides serum levels after melanoma adjuvant treatment were predictive for decreased overall survival, whereas decreased total gangliosides serum levels were predictable for improved overall survival.

CONCLUSIONS

A marker for early melanoma complications and survival may be the total gangliosides serum level.

Genistein and daidzein, in combination, protect cellular integrity during 7,12-dimethylbenz[a]anthracene (DMBA) induced mammary carcinogenesis in Sprague-Dawley rats

The status of glycoconjugates (protein bound hexose, hexosamine, sialic acid and fucose) in plasma or serum serve as potential biomarkers for assessing tumor progression and therapeutic interventions. Aim of the present study was to investigate the protective effect of two major soy isoflavones, genistein and daidzein, in combination on the status of glycoconjugates in plasma, erythrocyte membrane and mammary tissues during 7,12-dimethylbenz[a]anthracene (DMBA) induced mammary carcinogenesis in female Sprague-Dawley rats. A single subcutaneous injection of DMBA (25 mg rat(-1)) in the mammary gland developed mammary carcinoma in female Sprague-Dawley rats. Elevated levels of plasma and mammary tissue glycoconjugates accompanied by reduction in erythrocyte membrane glycoconjugates were observed in rats bearing mammary tumors. Oral administration of genistein + daidzein (20 mg + 20 mg kg(-1) bw/day) to DMBA treated rats significantly (p< 0.05) brought back the status of glycoconjugates to near normal range. The present study thus demonstrated that genistein and daidzein in combination protected the structural integrity of the cell surface and membranes during DMBA-induced mammary carcinogenesis.

HYPOTHALAMIC DIGOXIN, HEMISPHERIC CHEMICAL DOMINANCE, AND ONCOGENESIS: EVIDENCE FROM MULTIPLE MYELOMA

This study assessed the changes in the isoprenoid pathway and its metabolites digoxin, dolichol, and ubiquinone in multiple myeloma. The isoprenoid pathway and digoxin status were also studied for comparison in individuals of differing hemispheric dominance to find out the rote of cerebral dominance in the genesis of multiple myeloma and neoplasms. The following parameters were assessed: isoprenoid pathway metabolites, tyrosine and tryptophan catabolites, glycoconjugate metabolism, RBC membrane composition, and free radical metabolism--in multiple myeloma, as well as in individuals of differing hemispheric dominance. There was elevation in plasma HMG CoA reductase activity, serum digoxin, and dolichol, and a reduction in RBC membrane Na(+)-K+ ATPase activity, serum ubiquinone, and magnesium levels. Serum tryptophan, serotonin, nicotine, strychnine, and quinolinic acid were elevated, while tyrosine, dopamine, noradrenaline, and morphine were decreased. The total serum glycosaminoglycans and glycosaminoglycan fractions, the activity of GAG degrading enzymes and glycohydrolases, carbohydrate residues of glycoproteins, and serum glycolipids were elevated. The RBC membrane glycosaminoglycans, hexose, and fucose residues of glycoproteins, cholesterol, and phospholipids were reduced. The activity of all free-radical scavenging enzymes, concentration of glutathione, iron binding capacity, and ceruloplasmin decreased significantly, while the concentration of lipid peroxidation products and nitric oxide increased. Hyperdigoxinemia-related altered intracellular Ca++/Mg++ ratios mediated oncogene activation, dolichol-induced altered glycoconjugate metabolism, and ubiquinone deficiency-related mitochondrial dysfunction can contribute to the pathogenesis of multiple myeloma. The biochemical patterns obtained in multiple myeloma are similar to those obtained in left-handed/right hemispheric chemically dominant individuals by the dichotic listening test. But all the patients with multiple myeloma were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Multiple myeloma occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function.

Abnormalities of erythrocyte glycoconjugates are identical in two families with congenital dyserythropoietic anemia type II with different chromosomal localizations of the disease gene

We analyzed erythrocyte glycoconjugates in two families with congenital dyserythropoietic anemia type II (CDA-II): family 2 with the typical localization of the disease gene to chromosome 20q11.2 and family 1 in which this localization was excluded. Despite the different genetics, the erythrocyte glycoconjugate abnormalities in the two families were identical suggesting a complex inheritance of CDA-II. We also found that erythrocyte anion exchanger 1 protein is decreased in CDA-II homozygotes and obligate carriers alike.

The asialoglycoprotein receptor clears glycoconjugates terminating with sialic acid alpha 2,6GalNAc

Endogenous ligands have not, to date, been identified for the asialoglycoprotein receptor (ASGP-R), which is abundantly expressed by parenchymal cells in the liver of mammals. On the basis of the rapid clearance of BSA bearing multiple chemically coupled sialic acid (Sia)alpha2,6GalNAcbeta1,4GlcNAcbeta1,2Man tetrasaccharides (SiaGGnM-BSA) from the circulation, and the ability of the ASGP-R hepatic lectin-1 subunit to bind SiaGGnM-BSA, we previously proposed that glycoproteins modified with structures terminating with Siaalpha2,6GalNAc may represent previously unrecognized examples of endogenous ligands for this receptor. Here, we have taken a genetic approach using wild-type and ASGP-R-deficient mice to determine that the ASGP-R in vivo does indeed account for the rapid clearance of glycoconjugates terminating with Siaalpha2,6GalNAc. We have also determined that the ASGP-R is able to bind core-substituted oligosaccharides with the terminal sequence Siaalpha2,6Galbeta1,4GlcNAc but not those with the terminal Siaalpha2,3Galbeta1,4GlcNAc. We propose that glycoproteins bearing terminals Siaalpha2,6GalNAc and Siaalpha2,6Gal are endogenous ligands for the ASGP-R, and that the ASGP-R helps to regulate the relative concentration of serum glycoproteins bearing alpha2,6-linked Sia.

Clinical significance of total and lipid bound sialic acid levels in oral pre-cancerous conditions and oral cancer

BACKGROUND

Altered glycosylation of glycoconjugates is among the important molecular changes that accompany malignant transformation. The purpose of our study was to investigate clinical usefulness of circulatory levels of total and lipid bound sialic acid for early diagnosis and management of oral cavity cancer patients.

METHODS

Blood samples were collected from 41 untreated oral cancer patients, 20 patients with oral pre-cancerous conditions (OPC) and 20 healthy subjects. Serum sialic acid (total and lipid bound) levels were measured spectrophotometrically.

RESULTS

Serum levels of total and lipid bound sialic acid were significantly elevated (P < 0.001) in untreated oral cancer patients as compared to healthy individuals as well as patients with OPC. Multivariate analysis documented that the progressive rise in total and lipid bound sialic acid was significantly associated (P = 0.0001 and 0.039, respectively) with stage of malignant disease.

CONCLUSION

The data revealed significant elevations in sialic acid levels in oral cancer patients and suggested potential utility of these parameters in diagnosis as well as determining clinical stage of the malignant disease.

Detection of immune-complexed 9-O-acetylated sialoglycoconjugates in the sera of patients with pediatric acute lymphoblastic leukemia

Although childhood acute lymphoblastic leukemia (ALL) is highly responsive to chemotherapy, reliable techniques are needed to determine treatment outcome. Over expression of 9-O-acetylated sialoglycoconjugates (9-OAcSGs) on lymphoblasts and concomitant anti-9-OAcSGs was found to have a diagnostic and prognostic potential. However, the presence of circulatory immune-complexed antigens remains unknown. The present study was aimed to evaluate whether immune-complexed 9-OAcSGs can be harnessed for better disease management. Immune-complexed antigens were evaluated in ALL sera (n=262) by a Dot-blot using a 9-OAcSAalpha2-6GalNAc-specific lectin, Achatinin-H. Using three serum samples, the inter- and intra-assay imprecision was evaluated as 11-13% and 7-11%, respectively. The recovery of spiked 9-OAcSGs was 84.2-95.4%. The central 95% reference interval for immune-complexed 9-OAcSGs in normal human sera (NHS, n=144) was 2.9-3.4 mug/ml irrespective of sex and age. At disease presentation, the immune-complexed 9-OAcSGs were fivefold higher than NHS, decreased with remission induction and importantly, reappeared with clinical relapse. Sera from patients with other hematological disorders (n=86) showed negligible levels. The Dot-blot demonstrated the potential application of immune-complexed antigen as a disease-specific marker and its efficacy as a sensitive and specific method that could serve as an economical yet effective index for monitoring disease status.

Analysis of glycoconjugates in patients with oral squamous cell carcinoma

BACKGROUND

Our aim was to examine the levels of glycoconjugates in plasma, erythrocyte membranes and buccal mucosa of healthy subjects and oral cancer patients.

SUBJECTS AND METHODS

This study was conducted on 48 adult male oral cancer patients with various clinical stages (stage II to stage IV; 16 of each) and 16 disease-free healthy subjects who underwent surgical removal of impacted teeth or vestibuloplasty without inflammation.

RESULTS

The plasma and tumor tissues glycoconjugates levels were significantly increased, whereas the erythrocyte membranes glycoconjugates were significantly decreased in oral cancer patients as compared to healthy subjects. The levels of glycoconjugates were gradually increased from stage II to stage IV in plasma and tumor tissues and decreased in erythrocyte membranes from stage II to stage IV of oral cancer patients.

CONCLUSION

The increased plasma glycoconjugates can be due to the expense of erythrocyte membrane glycoconjugates or tumor tissue itself.

Hypothalamic digoxin, hemispheric chemical dominance, and mesenteric artery occlusion

The role of the isoprenoid pathway in vascular thrombosis, especially mesenteric artery occlusion and its relation to hemispheric dominance, was assessed in this study. The following parameters were measured in patients with mesenteric artery occlusion and individuals with right hemispheric, left hemispheric, and bihemispheric dominance: (1) plasma HMG CoA reductase, digoxin, dolichol, ubiquinone, and magnesium levels; (2) tryptophan/tyrosine catabolic patterns; (3) free radical metabolism; (4) glycoconjugate metabolism; and (5) membrane composition. In patients with mesenteric artery occlusion there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, low ubiquinone, and elevated free radical levels. The RBC membrane Na(+)-K+ ATPase activity and serum magnesium were decreased. There was also an increase in tryptophan catabolites and reduction in tyrosine catabolites in the serum. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in these patients. The biochemical patterns obtained in mesenteric artery occlusion is similar to those obtained in left-handed/right hemispheric dominant individuals by the dichotic listening test. But all the patients with mesenteric artery occlusion were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Mesenteric artery occlusion occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function. Hemispheric chemical dominance may thus control the risk for developing vascular thrombosis in individuals.

Hypothalamic digoxin, hemispheric chemical dominance, and the tridosha theory

Ayurveda, the traditional Indian System of Medicine, deals with the theory of the three tridosha states (both physical and psychological): Vata, Pitta, and Kapha. They are the three major human constitutional types that both depend on psychological and physical characteristics. The Pitta state is described as a critical, discriminative, and rational psychological state of mind, while the Kapha state is described as being dominant for emotional stimuli. The Vata state is an intermediate unstable shifting state. The Pitta types are of average height and built with well developed musculature. The Vata types are thin individuals with low body mass index. The Kapha types are short stocky individuals that tend toward obesity, and who are sedentary. The study assessed the biochemical differences between right hemispheric dominant, bihemispheric dominant, and left hemispheric dominant individuals, and then compared this with the patterns obtained in the Vata, Pitta, and Kapha states. The isoprenoid metabolites (digoxin, dolichol, and ubiquinone), glycoconjugate metabolism, free radical metabolism, and the RBC membrane composition were studied. The hemispheric chemical dominance in various systemic diseases and psychological states was also investigated. The results showed that right hemispheric chemically dominant/Kapha state had elevated digoxin levels, increased free radical production and reduced scavenging, increased tryptophan catabolites and reduced tyrosine catabolites, increased glycoconjugate levels and increased cholesterol: phospholipid ratio of RBC membranes. Left hemispheric chemically dominant/Pitta states had the opposite biochemical patterns. The patterns were normal or intermediate in the bihemispheric chemically dominant/Vata state. This pattern could be correlated with various systemic and neuropsychiatric diseases and personality traits. Right hemispheric chemical dominance/Kapha state represents a hyperdigoxinemic state with membrane sodium-potassium ATPase inhibition. Left hemispheric chemical dominance/Pitta state represents the reverse pattern with hypodigoxinemia and membrane sodium-potassium ATPase stimulation. The Vata state is the intermediate bihemispheric chemical dominant state. Ninety-five percent of the patients/individuals in the tridosha, pathological, and psychological groups were right-handed/left hemispheric dominant, however, their biochemical patterns were different--either left hemispheric chemical dominant or right hemispheric chemical dominant. Hemispheric chemical dominance/tridosha states had no correlation with cerebral dominance detected by handedness/dichotic listening test.

Hypothalamic digoxin and isoprenoid pathway dysfunction relation to alcoholic addiction, alcoholic cirrhosis, and acquired hepatocerebral degeneration--relation to hemispheric chemical dominance

The isoprenoid pathway produces three key metabolites--endogenous digoxin (modulate tryptophan/tyrosine transport), dolichol (important in N-glycosylation of proteins), and ubiquinone (free radical scavenger). It was considered pertinent to assess the pathway in alcoholic addiction, alcoholic cirrhosis, and acquired hepatocerebral degeneration. Since endogenous digoxin can regulate neurotransmitter transport, the pathway and the related cascade were also assessed in individuals with differing hemispheric dominance to find out the role of hemispheric dominance in its pathogenesis. In the patient group there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites, as well as reduced endogenous morphine synthesis from tyrosine. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in these groups of patients. Alcoholic cirrhosis, alcoholic addiction, and acquired hepatocerebral degeneration are associated with an upregulated isoprenoid pathway and elevated digoxin secretion from the hypothalamus. This can contribute to NMDA excitotoxicity and altered connective tissue/lipid metabolism important in its pathogenesis. Endogenous morphine deficiency plays a role in alcoholic addiction. The same biochemical patterns were obtained in those with right hemispheric chemical dominance. Alcoholic addiction, alcoholic cirrhosis, and acquired hepatocerebral degeneration occur in right hemispheric, chemically dominant individuals.

Hypothalamic digoxin-mediated model for Parkinson's disease

The isoprenoid pathway produces four key metabolites important in cellular function--digoxin (endogenous membrane Na(+)-K+ ATPase inhibitor), dolichol (important in N-glycosylation of proteins), ubiquinone (free-radical scavenger), and cholesterol (component of cellular membranes). This study assessed the changes in the isoprenoid pathway and the consequences of its dysfunction in Parkinson's disease (PD). There was an elevation in plasma HMG CoA reductase activity, serum digoxin and dolichol levels, and a reduction in serum magnesium, RBC membrane Na(+)-K+ ATPase activity, and serum ubiquinone levels. Serum tryptophan, serotonin, strychnine, nicotine, and quinolinic acid were elevated, while tyrosine, morphine, dopamine, and noradrenaline were decreased. The total serum glycosaminoglycans (GAG) and glycosaminoglycan fractions (except chondroitin sulphates and hyaluronic acid), the activity of GAG degrading enzymes, carbohydrate residues of serum glycoproteins, the activity of glycohydrolase-beta galactosidase, and serum glycolipids were elevated. HDL cholesterol was reduced and free fatty acids increased. The RBC membrane glycosaminoglycans, hexose and fucose residues of glycoproteins and cholesterol were reduced, while phospholipid was increased. The activity of all serum free-radical scavenging enzymes, concentration of glutathione, alpha tocopherol, iron binding capacity, and ceruloplasmin decreased significantly in PD, while the concentration of serum lipid peroxidation products and nitric oxide increased. A dysfunctional isoprenoid pathway and related cascade are important in the pathogenesis of Parkinson's disease. A hypothalamic digoxin mediated model for Parkinson's disease is also postulated.

Hypothalamic digoxin and hemispheric chemical dominance--relation to the pathogenesis of senile osteoporosis, degenerative osteoarthritis, and spondylosis

The isoprenoid pathway produces three key metabolites: i) digoxin (a membrane sodium-potassium ATPase inhibitor which can regulate intracellular calcium/magnesium ratios), ii) dolichol (which regulates N-glycosylation of proteins), and iii) ubiquinone (a free radical scavenger), all of which are important in bone and joint metabolism. The pathway was assessed in senile osteoporosis, spondylosis, and osteoarthritis. Digoxin could possibly play a role in the genesis of cerebral dominance because it can regulate multiple neurotransmitter systems. The pathway was also assessed in individuals of differing hemispheric dominance for comparison and to find out the role of cerebral dominance in the pathogenesis of these diseases. The plasma/serum-activity of HMG CoA reductase, magnesium, digoxin, dolichol, ubiquinone, and tryptophan/tyrosine catabolic patterns, as well as RBC Na(+)-K+ ATPase activity, were measured in the above mentioned groups. The glycoconjugate metabolism, free radical metabolism, and membrane composition were also studied. The pathway was upregulated with increased digoxin synthesis in patients with spondylosis and osteoarthritis. In this group of patients, the glycoconjugate levels and dolichol levels were increased and lysosomal stability reduced. The ubiquinone levels were low and free radicals increased in spondylosis and osteoarthritis. On the other hand, in senile osteoporosis, the isoprenoid pathway was downregulated and digoxin synthesis reduced. The glycoconjugate and dolichol levels were low and lysosomal stability increased. The ubiquinone levels were increased and free radical production increased in senile osteoporosis. The significance of these changes in the pathogenesis of osteoarthritis, spondylosis, and osteoporosis is discussed. The hyperdigoxinemic state is seen in osteoarthritis and spondylosis and in right hemispheric dominance. The hypodigoxinemic state is seen in left hemispheric dominance and senile osteoporosis. Hemispheric dominance plays a crucial role in deciding the predisposition to bone and joint diseases. Right hemispheric chemical dominance predisposes to spondylosis and osteoarthritis. Left hemispheric chemical dominance predisposes to osteoporosis.

Heterozygosity of CDAN II (HEMPAS) gene may be detected by the analysis of erythrocyte membrane glycoconjugates from healthy carriers

BACKGROUND AND OBJECTIVES

Congenital dyserythropoietic anemia (CDA) type I, II, and III, is associated with abnormalities of erythrocyte membrane glycoconjugates that are most pronounced in type II CDA or hereditary erythroblastic multinuclearity with a positive acidified-serum test (HEMPAS). The abnormalities consist in hypoglycosylation of polylactoaminoglycans linked to proteins (as in band 3 glycoprotein) and ceramides (known under the name of polyglycosylceramides) as well as in accumulation of some oligoglycosylceramides: lactotriaosylceramide, neolactotetraosylceramide, and sometimes globotetraosylceramide. Glycophorin A is partially unglycosylated with respect to O-linked glycans. Types I and II of the disease are inherited in an autosomal recessive fashion. The aim of the present study was to investigate a possibility that heterozygosity with respect to CDAN2 gene in healthy carriers could be detected by analysis of erythrocyte membrane glycoconjugates.

DESIGN AND METHODS

We examined a family which consisted of heterozygous parents and their two sons, one of whom was afflicted with CDA II (proband) while the other was healthy. In all family members the glycosylation status of band 3 glycoprotein, polyglycosylceramides and glycophorin A was evaluated from their carbohydrate molar composition. In addition we determined erythrocyte membrane contents of oligo- and polyglycosylceramides, and agglutinability of erythrocytes by anti-i antibody.

RESULTS

We found that the heterozygous parents showed, but about 50% less pronounced, most of the typical abnormalities of erythrocyte membrane glycoconjugates that were present in the proband. These abnormalities included: hypoglycosylation of band 3, accumulation and hypoglycosylation of polyglycosylceramides, and accumulation of lactotriaosylceramide. The level of neolactotetraosylceramide in the erythrocyte membranes of the parents was, however, normal. Globotetraosylceramide content was elevated in erythrocytes from the proband and, surprisingly, even more so in the parents. Glycophorin A in the proband was only slightly abnormal. Erythrocytes from both the parents and the proband expressed increased agglutinability with anti-i antibody. All glycoconjugates examined were normal in erythrocytes from the healthy son.

INTERPRETATION AND CONCLUSIONS

Individuals heterozygous with respect to CDAN2 gene can be identified through determination of the carbohydrate molar composition of band 3 and polyglycosylceramides as well as by an elevated erythrocyte content of polyglycosylceramides. In the parents these abnormalities show dosage effects. Determination of the carbohydrate molar composition of glycophorin A and of oligoglycosylceramides seems to be less promising. These findings indicate that the analysis of erythrocyte membrane glycoconjugates may be a valuable addition to the repertoire of methods used in studies on the genetics of CDA.

Serum and tissue glycoconjugates, digoxin and magnesium levels in chronic calcific pancreatitis

BACKGROUND

Endogenous or exogenous digoxin can lead to membrane Na+,K+-ATPase inhibition and hypomagnesemia. Low magnesium levels can lead to increased glycosaminoglycans (GAG) concentration in many organs.

AIM

To measure the serum levels of pancreatic GAG and glycoproteins, two major components of the extracellular matrix, in patients with chronic calcific pancreatitis (CCP). Serum levels of magnesium and digoxin were also assessed.

METHODS

Patients with CCP and age- and sex-matched healthy control subjects (15 each) were studied. Serum GAG, Mg and digoxin levels were measured. RBC membrane Na+,K+-ATPase activity was also assessed. Pancreatic tissue obtained at autopsy from seven patients with CCP and sex- and age-matched healthy subjects who had died in accidents were also tested for GAG and glycoproteins.

RESULTS

Total GAG levels were significantly increased in the serum and pancreas of patients with CCP. This was associated with lower serum Mg levels, increased serum digoxin levels and decreased RBC membrane Na+,K+-ATPase activity.

CONCLUSION

Exogenous or endogenous digoxin-induced hypomagnesemia and the consequent altered glycoconjugate metabolism may be important in the pathogenesis of CCP.

Electrospray ionization-tandem mass spectrometry for the analysis of tryptophan derivatives in food

Our knowledge about bioactive tryptophan derivatives in the diet is rather limited. Consequently, our attention was focused on the efficient profiling, i.e. the structure specific detection, of novel tetrahydro-beta-carbolines and tryptophan glycoconjugates in food samples. Applying HPLC-MS/MS for screening and structural characterization, numerous products derived from the reaction of tryptophan with alpha-oxo acids and carbohydrates could be identified by means of neutral loss scanning. Subsequently, product ion experiments followed by the synthesis of the respective reference compounds accomplished structure elucidation of tryptophan derivatives.

Immunochemical quantification of glycoconjugates in serum and cerebrospinal fluid of amyotrophic lateral sclerosis patients

Glycoconjugates in the serum of 73 patients with amyotrophic lateral sclerosis (ALS), 21 cases of other motor neuron diseases and 20 healthy controls were determined. Cerebrospinal fluid (CSF) was studied in 64, 7 and 10 of these subjects, respectively. The level of sialic acid containing glycoconjugates, detected by Maakia amurensis agglutinin (MAA), was decreased in the serum of 61.6% of the ALS patients, while in the CSF it was decreased, on average, in 75% of these cases. Only in single ALS cases was the concentration of these glycoconjugates increased. There was no correlation between the content of MAA-labelled glycoconjugates both in serum and CSF and the titre of sialic acid containing anti-GM1 gangliosides. The glycoconjugates, detected by peanut agglutinin (PNA) which recognizes the disaccharide galactose beta(1-3)N- acetylgalactosamine (GGN), were decreased in the serum of 78.1% of ALS patients, while in CSF they were increased in 54.7% of these cases. There was no correlation between the concentration of PNA-labelled glycoconjugates both in serum and CSF as well as the titre of antibodies against GGN-containing anti-GM1 and anti- AGM1 gangliosides. Changes in the level of the MAA- and PNA- labelled glycoconjugates, as well as the titre of anti-GM1 and anti-AGM1 gangliosides antibodies were not specific for ALS. They were also observed in some cases of other motor neuron diseases. The low level of the lectin-labelled glycoconjugates in serum and partly in CSF of the majority of ALS patients is possibly the consequence of their accelerated clearance and/or specific inactivation by the formation of immune complexes or epitope binding. Degeneration of neurons and muscle cells could also be responsible. The relatively low incidence of high anti- glycolipids antibodies titre may be, at least partly, connected with the low concentration of the appropriate antigens. The increased content of PNA-labelled glycoconjugates in the CSF of the majority of ALS patients, together with the low incidence of high titre of antibodies against the appropriate glycolipids, could indicate that in CSF this lectin binds to the GGN epitope of glycoproteins rather than to the GGN epitope of glycolipids.

Isolation and characterization of lectin from Thai marine crab (Scylla serrata) with binding specificity to sialoglycoconjugates and its application

A lectin from Thai marine carb (Scylla serrata) hemolymph has been isolated and purified by affinity column chromatography and preparative electrophoresis. The amino acid composition and 10 amino-terminal residues have been deduced, and its reactivities have been studied using a biotin labeling technique. A method for the determination of sialoglycoconjugates in human serum is described using this lectin. The principle is based on the reaction between the sialoglycoconjugates and biotinylated lectin. The bovine submaxillary mucin (BSM) is immobilized on polystyrene microplate. The unknown sample or sialoglycoconjugate (BSM equivalent) standards, together with excess biotinylated purified lectin (B-lectin), are then added. The B-lectin that binds to the immobilized BSM is then incubated with the peroxidase-conjugated monoclonal antibiotin antibody, and the color that develops after the addition of enzyme substrate is determined by light absorption using a microplate reader. The assay is not only convenient and reliable, but also capable of measuring sialoglycoconjugates in solution at the submicrogram level. It was used in determining the sialoglycoconjugates in human serum from normal subjects and samples positive for carcinoembryonic antigen.

Glycoconjugate profile in plasma and erythrocytes of gastric cancer patients

The present study has examined the glycoconjugate profile in plasma and erythrocyte membranes of 24 adult male gastric cancer patients and an equal number of age and sex-matched controls. Protein-bound hexose, hexosamine and sialic acid were significantly increased in plasma and erythrocytes of gastric cancer patients compared to controls. Elevation of glycoconjugates in circulation is suggested to be a result of increased shedding by the tumor cells or increased synthesis by liver, due to acute phase response.

[ELISA of IgM antibodies to Thomsen-Friedenreich (TF) hapten in cancer diagnostics: comparison of data obtained with four TF-glycoconjugates]

The level of IgM antibodies to the Thomsen-Friedenreich hapten (TF) relative to the total IgM level in the blood sera of gastric and breast carcinoma patients and healthy persons was determined using enzyme-linked immunosorbent assay. The following TF glycoconjugates were tested: TF-polyacrylamide (PAA)(with 10 mol.% of TF hapten Gal beta 1-3GalNAc alpha 1-O(CH2)3NH per number of monomeric units in the polyacrylamide), TF-human serum albumin (HSA)(Gal beta 1-3GalNAc alpha 1-O-p-C6H4-HSA containing approximately 15 carbohydrate residues per HSA molecule), asialo-kappa-caseinoglycopeptide, and asialoglycophorin. The total IgM level was determined using antibodies to the mu-chain of human IgM. The statistically significant difference between cancer patients and healthy donors was revealed with two conjugates: TF-PAA and TF-HSA. In the case of TF-PPA, the sensitivity of the assay was 75-83%, and the specificity was 77%. Thus, TF-PAA is the most suitable conjugate for measuring the level of serum anti-TF-IgM antibodies.

Recognition of glycoconjugates by Helicobacter pylori. Comparison of two sialic acid-dependent specificities based on haemagglutination and binding to human erythrocyte glycoconjugates

Helicobacter pylori expresses separate binding characteristics depending on growth conditions, as documented by binding to human erythrocyte glycoconjugates. Cells grown in Ham's F12 liquid medium exhibited a selective sialic acid-dependent binding to polyglycosylceramides, PGCs (Miller-Podraza et al.(1996) Glycoconjugate J13:453-60). There was no binding to traditional sialylated glycoconjugates like shorter-chain gangliosides, glycophorin or fetuin. However, cells grown on Brucella agar bound both to PGCs and other sialylated glycoconjugates. Fetuin was an effective inhibitor of haemagglutination caused by agar-grown cells, but had no or a very weak inhibitory effect on haemagglutination by F12-grown bacteria. PGCs were strong inhibitors in both cases, while asialofetuin was completely ineffective. The results indicate that H. pylori is able to express two separate sialic acid-dependent specificities, one represented by binding to fetuin, as described before, and another represented by a selective binding to PGCs.

Carbohydrate composition of protein and lipid components in sialic acid-rich and -poor low density lipoproteins from subjects with and without coronary artery disease

Low density lipoprotein (LDL) from patients with coronary heart disease (CHD) caused 78-286% increase in accumulation of cholesterol in human aortic subendothelial cells compared to 2-17% caused by LDL from normal subjects. Ricin-Sepharose affinity chromatography was used to separate LDL into two subfractions, one sialic acid-rich (SAR) and the other sialic acid-poor (SAP). SAP-LDL from CHD patients caused 156-307% increase in accumulation of cellular cholesterol, whereas SAR-LDL from these patients caused only 14-21% increase. SAP-LDL from normal healthy subjects caused 50-86% increased accumulation, whereas their SAR-LDL induced only 2-12% increase. Carbohydrate analysis of SAP-LDL protein isolated from four CHD patients revealed mean values of 59, 25, 61, and 11 nmoles of N-acetyl glucosamine, galactose, mannose, and sialic acid per mg protein, respectively. Mean values for SAR-LDL protein from these patients were 59, 31, 77, and 24 nmol/mg protein, respectively. Analysis of SAP-LDL protein from four normal healthy subjects indicated respective mean values of 58, 29, 72, and 22 nmol/mg, whereas SAR-LDL protein from normals contained 59, 29, 72, and 29 nmol/mg. The carbohydrate content of LDL lipids represents about 25% of the total carbohydrate present in the lipoprotein. The mean values for SAP-LDL lipids from four CHD patients were about 2, 2, 18, 18, and 2 nmol/mg protein for N-acetyl galactosamine, N-acetyl glucosamine, galactose, glucose, and sialic acid, respectively. The mean values for SAR-LDL lipids from these patients were 3, 4, 34, 41, and 5 nmol/mg, respectively. Analysis of SAP-LDL lipids from four normal healthy subjects indicated respective mean values of 4, 6, 30, 31, and 3 nmol/mg, whereas SAR-LDL lipids from these subjects contained 6, 9, 41, 46, and 7 nmol/mg. These results suggest that the different biological properties of SAR-LDL and SAP-LDL are related to their different carbohydrate compositions.

Galaptin and galaptin-binding glycoconjugates in serum and effusions of carcinoma patients

The objectives of this study were (1) to quantify galaptin, an endogenous lectin, and galaptin-binding glycoconjugates present in normal serum, (2) to determine if these components were altered in the serum and effusions of carcinoma patients with advanced disease, and (3) to determine if ovarian carcinoma cells synthesize and release soluble galaptin inhibitors. Serum from healthy females (n = 10) had a mean galaptin content of 96 +/- 40 ng/ml. Galaptin levels in carcinoma patient serum (n = 29) were depressed (mean 21 +/- 23 ng/ml; p < 0.0001). Galaptin was not detected in 6 of 8 ovarian carcinoma patient sera. Effusions (n = 17) had a mean galaptin content of 358 +/- 326 ng/ml. Assays involving inhibition of binding of galaptin-peroxidase conjugates to asialofetuin were carried out to evaluate the levels of galaptin-binding glycoconjugates in serum and effusions. The mean inhibition titer of normal serum (n = 12) was 75 +/- 38. Patient serum (n = 28) had an elevated inhibitor content (mean titer = 304 +/- 155; p < 0.0001). Effusions (n = 17) also had a higher inhibitor content relative to normal serum (mean titer = 247 +/- 202; p = 0.0037). Ovarian carcinoma cells isolated from effusions and cultured in vitro were shown to synthesize and release into the medium galaptin-binding glycoconjugates of molecular mass 100-200 kD. An ovarian carcinoma cell line, A121, released galaptin-binding glycoconjugates of molecular mass > or = 200 kD into the medium. The data presented show that the levels of soluble galaptin and galaptin-binding glycoconjugates in the serum of advanced cancer patients are perturbed relative to normal female serum.

The conversion of group B red blood cells into group O by an alpha-D-galactosidase from taro (Colocasia esculenta)

An alpha-D-galactosidase (EC 3.2.1.21), capable of converting group B into group O red cells, was isolated from the stem portion of taro. It was purified about 3000 fold by gel filtration and ion-exchange chromatography. The blood group-converting activity was demonstrated by hemolysis and hemagglutination studies. This activity is comparable to that of alpha-D-galactosidase isolated from coffee beans. Taro alpha-D-galactosidase also hydrolyzes (1----4)- and (1----6)-linked alpha-D-galactopyranosyl groups from D-galactose-containing glycoconjugates. Taro alpha-D-galactosidase has a low Km value (0.28mM), a low molecular weight (40,000), and a neutral optimal pH (6.0). At a final enzyme concentration of 30 units/mL in the incubation mixture, the conversion of group B into group O activity was completed within two hours, without apparent changes in the shape of the red cells.

Biophysical and biochemical alterations in erythrocyte membranes from chronic alcoholics

Erythrocyte membranes from healthy controls and alcoholic patients, examined within 24 h of abstinence, were studied for basal membrane fluidity and membrane sensitivity to ethanol by fluorescence polarization of the apolar probe 1,6-diphenyl-1, 3,5-hexatriene (DPH) and its cationic derivative 1,4(trimethylammonium phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). The membrane partition (Kp) of ethanol and phenobarbital, and the concentrations of membrane-bound sialic acid and galactose, were also determined. The apolar hydrocarbon region of the membrane (DPH) was less fluid, in the alcoholics than in the controls (p less than 0.005). In the patients this membrane layer, as well as the polar lipid head group region (TMA-DPH), showed reduced fluidizing effect of ethanol (p less than 0.01). This resistance or tolerance to ethanol correlated with a markedly impaired (-59%, p less than 0.025) partition of ethanol into the membrane. The low Kp of ethanol in turn was partly related to reduced concentrations of polar carbohydrates such as sialic acid and galactose (p less than 0.01) at the membrane surface. The Kp of phenobarbital was reduced in the patients (-59%, p less than 0.005) but, apparently unrelated to the carbohydrate changes. These results indicate that in man, chronic alcohol abuse is associated with complex changes of membrane properties at different membrane levels e.g. at the charged surface, in the polar lipid head group region and in the hydrocarbon core. A partial basis for biophysical membrane tolerance to ethanol is suggested, implying that apart from phospholipid alterations, structural changes in membrane-bound glycoconjugates participate in this adaptive process.

Preliminary studies of serum glycoconjugates in patients with cancer using the enzyme-linked lectin assay

After primary analyses on the serum glycoconjugates of lung cancer and normal individual using the enzyme-linked lectin assay (ELLA) with 12 kinds of lectins, PHA and LCA were selected for further study in the sera of 8 kinds of cancers, 4 kinds of non-malignant diseases and a kind of postoperative cancer. It was found that the test values of 7 kinds of cancers with PHA or LCA were significantly higher than those of the normal (P less than 0.01); the values of 4 kinds of non-malignant diseases with PHA were not higher (P greater than 0.05); the values of the postoperative cancer with PHA were obviously lower than those of the preoperative (P less than 0.02). The results showed that the serum glycoconjugates which can bind to PHA seemed related to the cancerous existence in human bodies. The significance of the findings was discussed.

Localization of fucosyl glycoconjugates in human oocytes following insemination for in vitro fertilization

Human oocytes that failed to cleave after insemination were examined for the presence of fucosyl glycoconjugates in the perivitelline space by staining with Ulex europeaus lectin conjugated to fluorescein isothiocynate. Oocytes that formed two or three pronuclei following first insemination always exhibited positive lectin staining similar to that observed with in vitro fertilized mouse oocytes. Among those oocytes that failed to form any pronuclei after the first insemination attempt, only 5% contained lectin positive substances in the perivitelline space. Upon reinsemination, a higher percentage of those oocytes produced lectin-positive materials, although pronuclei were still absent. The appearance of fucosyl glycoconjugates in these oocytes might be the result of the release of cortical granules triggered by sperm penetration or, more likely, due to spontaneous granule discharge in senescent oocytes.

High-performance liquid chromatographic determination of tauro- and glyco-conjugated bile acids in human serum

A method for the identification and individual determination of the ten tauro- and glyco-conjugated bile acids is described. It consists in a specific three-step extraction from small serum samples (500 microliters), high-performance liquid chromatographic separation and direct spectrophotometric detection at 119 nm. Extraction can be checked by the use of an internal standard. The reproducibility, recovery and separation of fractions were satisfactory.

Regulation of the lateral diffusion of WGA-labeled glycoconjugates in human leukocytes. Comparison between adult granulocytes and differentiating promyelocytic HL60 cells

The regulation of the membrane mobility of glycoconjugates in human polymorphonuclear leukocytes (PMNL) was studied by comparing adult PMNL with promyelocytic HL60 cells before and after stimulation of differentiation in HL60 cells with phorbol-myristate acetate (PMA) with respect to lateral diffusion of wheat germ agglutinin (WGA)-labeled glycoconjugates. For this purpose we developed a novel variant of microscope equipment for the study of fluorescence recovery after photobleaching (FRAP) and continuous fluorescence microphotolysis (CFM) using a mini-computer for handling of shutters, data acquisition, and calculations. This equipment is presented in the report. We found that PMA-induced differentiation in HL60 cells reduced the lateral diffusion coefficient (D) of WGA-labeled membrane entities from about 1.5 to 1.0 x 10(-10) cm2/s, which was close to that found for adult blood PMNL, i.e., 1-1.2 x 10(-10) cm2/s. The lateral mobility (D x 10(10)) of succinylated WGA (S-WGA) was 2.3 and 1.7 cm2/s in undifferentiated and PMA-differentiated HL60 cells, respectively, indicating that WGA might have cross-linked membrane receptors, resulting in the slower diffusion. The results are discussed in relation to the effect of phagocyte maturation on the mobility of membrane components.

Glucuronoconjugates in chronic renal failure. Comparative determination with values in healthy adult

We have isolated substances of molecular weight ranging between 350 and 2,000 daltons from ultrafiltrates of patients traited by maintenance haemodialysis for chronic renal failure (CRF). Such substances might have a role in the genesis of uremic toxicity. They were found to be glucuronoconjugates. We have studied 22 patients with CRF and 16 with end stage renal failure, 8 of them were traited by peritoneal dialysis, 8 by haemodialysis. We have evaluated the concentration of glucuronic acid in the serum, the urine and dialysis fluid. The patients with chronic renal failure have plasma levels of free and conjugate glucuronic acid higher than normal subjects. Urinary elimination is very lower in patient with CRF. Nevertheless the glucuronoconjugates are removed to a large extend by haemodialysis and peritoneal dialysis.