Lipid-bound Sialic Acid Concentrations Research Articles

Serum Sialic Acid as a Marker of Pancreatic Cancers

The carbohydrate alterations in sialoglycoproteins and sialoglycolipids cause the high serum concentration of sialic acid in many types of cancers. The aim of this study was to evaluate the diagnostic accuracy of total sialic acid (TSA), lipid-bound sialic acid (LSA), and free sialic acid (FSA) in patients with primary pancreatic cancers. TSA and LSA concentrations in the sera of 42 patients were measured by the enzymatic and FSA by the thiobarbituric method. The mean levels of TSA, LSA, and FSA in the sera of patients with pancreatic cancers were significantly higher than in controls. Taking into consideration the size and the location of the tumors, regional lymph node and distant metastases, there were no differences in TSA, FSA, and CA 19-9 levels. However, the location of tumors in the pancreas affects LSA levels. The sialic acids, contrary to CA 19-9, are not useful tools in the differential diagnosis of tumors and non-malignant diseases of the pancreas. LSA has the highest sensitivity, negative predictive value, accuracy, and the ability to discriminate cancer patients from healthy controls. The diagnostic power of LSA is similar to CA 19-9. We suggest that LSA can be useful in the diagnosis and evaluation of the tumor location in patients with primary pancreatic cancers.

Lipid-bound sialic acid (LSA) in liver diseases of different etiologies

Objective. There are evidences that the changes in glycosylation and sialylation of proteins and lipids play an important role in the pathogenesis and progression of various liver diseases. The aim of this study was to evaluate the changes in the sialylation of serum lipids measured by the level of lipid-bound sialic acid (LSA) in liver diseases of different etiologies.Materials and methods. Tested group consisted of 303 patients suffering from liver diseases: alcoholic and non-alcoholic cirrhosis, chronic non-viral hepatitis, toxic hepatitis, chronic viral C and B hepatitis, autoimmune hepatitis, primary liver cancer, liver cancer and cirrhosis (mixed group), acute hepatitis B, primary biliary cirrhosis and fatty liver. LSA was determined by the method of Katopodis and co-workers.Results. There were significant differences in the serum LSA concentrations between liver diseases of different etiologies. The level of LSA in liver tumors was higher than that in both types of cirrhosis: alcoholic and non-alcoholic. In turn, LSA level in non-alcoholic cirrhosis was lower than in toxic hepatitis and mixed group. There was no difference in LSA concentration between tumor and mixed group. Similarly to LSA, AFP level in tumor group was also higher than that in both cirrhotic groups, but there was no difference in AFP concentration between tumor and mixed group.Conclusions. The sialylation of serum lipids alters in liver diseases of different etiologies. Given the importance of glycans in biological systems we can speculate that the changes in lipids sialylation play an important role in liver pathology, especially in primary cancer, cirrhosis and toxic hepatitis.

Serum lipid-bound sialic acid as a marker in lung cancer patients

To evaluate the usefulness of serum lipid-bound sialic acid (LSA) as a tumor marker in patients with lung cancer, its serum levels were determined in 85 patients with primary lung cancer, 42 patients with benign pulmonary diseases and 22 healthy controls by the method developed by Katopodis and Stock. The mean serum LSA concentration was significantly higher in the patients with primary lung cancer [32.4 +/- 16.4 (SD) mg/dl] than that in the patients with benign pulmonary diseases (22.4 +/- 12.4 mg/dl) or in healthy controls (17.2 +/- 4.5 mg/dl). The serum LSA level was elevated above the mean value plus 2 SD for the healthy controls (26.0 mg/dl) in 60% of all cases with primary lung cancer including 1 of 9 (11.1%) in stages I and II and 50 of 76 (65.8%) in stages III and IV and 35.4% of the patients with benign pulmonary diseases. No significant difference was observed in serum LSA concentration among each cell type of lung cancer. Serum carcinoembryonic antigen (CEA) was elevated (greater than 5.0 ng/ml) in 39.8% of the patients with lung cancer. As there was poor correlation between serum LSA and CEA levels, when these two markers were used in combination, 71.1% of the cases with lung cancer in this study showed elevated levels of either serum LSA or CEA, or both. Moreover, in the patients with small cell lung cancer followed up during intensive chemotherapy, serum LSA levels changed almost parallel with the clinical course. These results indicate that serum LSA may be a useful biochemical marker in lung cancer patients.

Assessment of total sialic acid and lipid-bound sialic acid in management of brain tumors.

Background:Glycoconjugate molecules expressed at the plasma membrane of mammalian cells have been reported to be associated with tumor progression. The measurement of total sialic acid (TSA) and lipid-bound sialic acid (LBSA) in the cerebrospinal fluid (CSF) is suggested to be useful for the diagnosis of brain tumors. But there are very few reports available on the serum glycoconjugate levels in patients with brain tumors.Objective:The objective of this study is to check the feasibility of using serum glycoconjugates such as TSA and LBSA as tumor markers in brain tumor patients.Materials and Methods:Colorimetric estimation of TSA using diphenylamine was done on 100 patients with intracranial tumors; follow-up study was carried out in 24 cases. The LBSA fraction was isolated from the serum of 68 brain tumor patients and evaluated using phosphotungstic acid and resorcinol; follow-up study was done on 23 patients. The various types of brain tumors included in this study were glioma, meningioma, and acoustic neurinoma as well as some other types such as medulloblastoma, secondary tumors, and craniopharyngioma.Results:There was no significant difference between the TSA and LBSA concentrations seen in pretreatment or post-treatment cases and that seen in control subjects.Discussion:TSA and LBSA do not have the ability to discriminate between benign and malignant brain tumors. TSA and LBSA appear to be tumor markers of very limited value in patients with brain tumors.

Serum Selenium, Vitamin E, and Sialic Acids Concentrations in Lambs with White Muscle Disease

The aim of this study was to determine the serum concentrations of selenium, vitamin E, and total- and lipid-bound sialic acid (LBSA) in lambs with white muscle disease (WMD) before and after treatment with a commercial preparation containing selenite and vitamin E. Fifteen lambs with WMD and ten control animals were used as research materials. Blood samples were collected from both groups before- and 1 month after treatment for Se analysis by fluorimetry, whereas vitamin E and sialic acid were measured by HPLC and spectrophotometry, respectively. Compared to controls, in the diseased animals, there was a significant increase of serum total sialic acid (TSA) and LBSA, together with significant decreases of serum Se and vitamin E concentrations (p < 0.001). One month after treatment, a reversal of trend was observed with decreases of TSA and LBSA and increases of Se and vitamin E concentrations. The TSA and LBSA levels, however, remained significantly higher than those of the controls, p < 0.05 and 0.001, respectively. The Se and vitamin E concentrations of the treated animals were the same as those of controls. This is the first study on total and LBSA concentrations in lambs with WMD, showing that these markers can be used in the prognosis of the disease.

Serum Total and Lipid-Bound Sialic Acid Concentrations in Sheep with Natural Babesiosis

The aim of this study was to determine the serum concentrations of total and lipid-bound sialic acid in sheep naturally infected with Babesia ovis before and after treatment. Thirty diseased sheep and ten control animals were used. Babesia infection was confirmed with Giemsa's staining of blood smears. Compared to the control animals (1.351 ± 0.100 mmol l-1; 0.385 ± 0.001 mmol l-1), a marked increase of serum total and lipid bound sialic acid concentrations (1.929 ± 0.101 mmol l-1; 0.479 ± 0.004 mmol l-1, respectively) was obtained in infected sheep (p &lt; 0.05). One week after treatment, serum total and lipid bound sialic acid concentrations significantly decreased (1.554 ± 0.005 mmol l-1; 0.411 ± 0.02 mmol l-1, respectively) (p &lt; 0.05). Despite this decline, total and lipid bound sialic acid concentrations of treated animals were still signifi cantly increased in sera compared to the control animals (p &lt; 0.05). When the infected animals were treated with an antiparasitic drug (diminazene aceturate), the serum total and lipid bound sialic acid levels had a tendency to decrease to the normal ranges. It can be concluded that Babesia ovis infection induced marked and persistent elevations of serum total and lipid-bound sialic acid concentrations, suggesting that these indicators would indirectly promote the invasion and presence of the parasite in the host.

Association between serum total and lipid-bound sialic acid concentration and the severity of coronary atherosclerosis

Serum total sialic acid has recently been shown to be a cardiovascular risk factor. Increased levels of this substance are associated with higher cardiovascular mortality and with cerebrovascular disease. It has also been shown that serum concentrations of total and lipid-associated sialic acid are significantly increased in hypertriglyceridemia. On the other hand, several circulating lipoproteins have been suggested to be related to the severity of coronary atherosclerosis, but contradictory results have been reported in the possible relationship between the concentrations of sialic acid and the severity of coronary lesions in patients with coronary heart disease. The purpose of this study was to investigate the possible relationship between serum total sialic acid concentration, recently shown to be a cardiovascular risk factor, and serum lipid-bound sialic acid concentration and the severity of coronary lesions. The study comprised 90 subjects, divided into three subgroups according to angiography results: 30 patients with no vessel disease, 30 patients with single-vessel disease, and 30 patients with double/triple-vessel disease. Serum total sialic acid determination was carried out with the thiobarbituric acid method of Warren; lipid-associated sialic acid was assayed with the method of Katopodis. Mean serum total sialic acid levels in patients with single-vessel disease (P <.05) and patients with double/triple-vessel disease (P <.001) were found to be significantly increased compared with that in patients with no vessel disease, whereas mean serum lipid-bound sialic acid levels were found to be significantly different between patients with double- or triple-vessel disease and patients with no vessel disease (P <.001). We also noted a significant difference between the levels of serum total sialic acid (P <.001) and lipid-bound sialic acid (P <.001) in patients with single-vessel disease and patients with double/triple-vessel disease. We found a significant correlation only between serum lipid-bound sialic acid and coronary angiographic score in patients with double/triple-vessel disease (r = 0.425, P <.05). Although the concentration of serum total sialic acid is increased proportionally with the number of diseased coronary arteries, only the concentration of serum lipid-bound sialic acid is related to the severity of coronary atherosclerosis, especially in patients with double/triple-vessel disease. (J Lab Clin Med 2002;140:110-8)

Association between serum total and lipid-bound sialic acid concentration and the severity of coronary atherosclerosis

Association between serum total and lipid-bound sialic acid concentration and the severity of coronary atherosclerosis

Immunostimulatory effect of natural clinoptilolite as a possible mechanism of its antimetastatic ability.

Many biochemical processes are closely related to ion exchange, adsorption, and catalysis. Zeolites reversibly bind small molecules such as oxygen or nitric oxide; they possess size and shape selectivity, the possibility of metalloenzyme mimicry, and immunomodulatory activity. These properties make them interesting for pharmaceutical industry and medicine. The experiments were performed on mice. Different biochemical and molecular methods were used. Micronized zeolite (MZ) administered by gastric intubation to mice injected with melanoma cells significantly reduced the number of melanoma metastases. In mice fed MZ for 28 days, concentration of lipid-bound sialic acid (LSA) in serum increased, but lipid peroxidation in liver decreased. The lymphocytes from lymph nodes of these mice provoked a significantly higher alogeneic graft-versus-host (GVH) reaction than cells of control mice. After i.p. application of MZ, the number of peritoneal macrophages, as well as their production of superoxide anion, increased. However, NO generation was totally abolished. At the same time, translocation of p65 (NFkappaB subunit) to the nucleus of splenic cells was observed. Here we report antimetastatic and immunostimulatory effect of MZ and we propose a possible mechanism of its action.

Lipid bound sialic acid concentration in mice with myeloid leukemia and alloxan diabetes.

Lipid bound sialic acid concentration in mice with myeloid leukemia and alloxan diabetes.

Characterization of gangliosides from normal and osteoarthritic human articular cartilage.

Glycosphingolipids (GSLs) are biologically active molecules in the physiology and pathology of cells. Since changes in GSLs might be associated with the impaired metabolism of articular cartilage in osteoarthritis (OA), we investigated gangliosides from normal and OA human cartilage. OA and control cartilage was obtained from patients with hip OA and femoral neck fracture, respectively. Gangliosides were extracted and quantified by determining their lipid-bound sialic acid concentration. Major gangliosides were identified by immuno-detection on thin-layer plates, purified by high performance liquid chromatography, and analyzed for their carbohydrate, fatty acid, and long-chain base composition. The total ganglioside content of OA cartilage was decreased by 40% (per mg of DNA). Major gangliosides, GM3 and GD3, separated into 3 on thin-layer chromatography bands. All were decreased except for the lowest migrating band of GM3, which was increased 5-fold. This ganglioside had the same carbohydrate moiety and fatty acids as the other two, but differed by a long-chain base composed mainly of C20-sphingosine. OA cartilage is characterized by a decrease in all gangliosides except GM3, which demonstrates a large increase in the lowest band. These results indicate that there are changes in the biochemical composition of chondrocyte membranes in OA. The causes and roles of these changes remain to be determined.

Lipid-bound sialic acid, prostaglandin e and histamine in head and neck cancer

Blood concentration of lipid-bound sialic acid (LBSA), prostaglandin E (PGE) and histamine were determined in 37 patients with carcinoma of hypopharynx and larynx (supraglottic and glottic), in 12 non-cancer patients and in 10 healthy subjects. The concentration of LBSA was significantly increased in 94.4% cancer patients preoperatively and fell to somewhat lower levels within 1 month after tumour resection. In patients with complete tumour resection and no tumour recurrences within 2 years, it steadily decreased thereafter, reaching normal levels within 6-24 months after surgery, whereas in patients with tumour recurrences or incomplete tumour resection it rose again within 6 months after tumour resection. Similarly, the concentration of PGE was significantly increased in about two thirds of cancer patients (67.6%) preoperatively, dropped significantly within 1 month after tumour resection and rose again in patients with tumour recurrences. Preoperative histamine concentration was decreased in 24.3% of cancer patients and postoperatively it rose both in patients with or without tumour recurrences.

Total and lipid-bound serum sialic acid as markers for carcinoma of the uterine cervix

Concentrations of total sialic acid (TSA) and lipid-bound sialic acid (LSA) were determined in serum samples from 88 patients with squamous cell carcinoma of the cervix, 26 normal subjects, and 44 patients with benign uterine or ovarian disease. TSA concentrations in patients with cervical cancer were found to correlate with advanced-stage disease. LSA concentrations were only increased in stage IV of the disease. Sensitivity of the test for stage IB was zero for TSA and 27% for LSA. The specificity of both markers was about 80% due to a low incidence of false-positive values in the pathologic control group. Measurements of TSA or LSA appear to be of no value for the early detection of cervical cancer or to complement the clinical staging of this tumor.

Use and limitations of serum total and lipid-bound sialic acid concentrations as markers for colorectal cancer.

Concentrations of total serum N-acetyl-neuraminic acid (NANA) by high-performance liquid chromatography (HPLC) and lipid-bound sialic acid (LSA) by resorcinol procedure were evaluated and compared to carcinoembryonic antigen (CEA) as markers for colorectal carcinoma. Elevated concentrations of NANA were found in 32% of patients with nonmalignant disorders, 28% of patients with localized cancer, and 87% of patients with metastatic cancer. All three markers correlated with the extent of metastasis of colorectal carcinoma. Strong correlation was found between NANA and LSA measurements, whereas measurement of the sialic acid markers provide information that can not be derived from the measurement of CEA. NANA and LSA show promise as supplemental markers for staging and monitoring colorectal cancer, but they are neither sensitive nor specific enough for cancer screening.

Ganglioside Profiles during Neural Tissue Development

The accumulation and species distribution of gangliosides in cultured cerebral cells and in the late prenatal stage of the developing rat brain were examined as a function of their growth state. The concentration of lipid-bound sialic acid in cerebral cells rises from a value of about 5 nmol/mg protein at day 1 to a peak level of 16.2 nmol/mg protein by 12 days, followed by a substantial decrease after 25 days in culture. When expressed per cell DNA, a linear increase of about 10-fold, notably after 10 days in culture, in the amount of sialic acid is seen. The most significant change in the species distribution is an apparent accumulation of disialo ganglioside (GD1a) trisialo ganglioside (GT) and tetrasialo ganglioside (GQ), whereas a marked reduction of GD3 is evident. The accumulation of sialic acid and the developmental patterns of the ganglioside species in vitro reasonably agree with the developing prenatal brain. Thus, by birth, both GT and GQ account for about 36% of the total brain gangliosides as compared to 40% in the mature cerebral cultures. Since in the newborn rat brain synaptogenesis is not prominent the increase in the ganglioside complexity could be associated with neuritic sprouting and establishment of nonsynaptic interneuronal connections. Rabbit antiserum raised against pure GD1a reacted preferentially with the neuronal cell bodies and neurite extensions as observed by an indirect immunofluorescence technique. A progressive increase in immunofluorescence labeling paralleled accumulation of polysialo-gangliosides and culture maturation. In this context, the dissociated cerebral cells provide a powerful tool for investigating aspects of neuronal development because of the possibility of correlating neurochemical data with ultrastructure and cell-surface-related events.