Clin Chim Acta

A novel Glu421Lys substitution in the lipoprotein lipase gene in pregnancy-induced hypertriglyceridemic pancreatitis.

Year 1998
Henderson H. Leisegang F. Hassan F. Hayden M. Marais D.
Department of Chemical Pathology, University of Cape Town, South Africa. henders@ulam.generes.ca
Severe hypertriglyceridemia is an uncommon pathological finding in pregnant women if there is no prior history of hyperlipidemia. A partial reduction in lipoprotein lipase (LPL) activity due to a mutation in the LPL gene, is often an associating factor. Here we report a novel LPL gene mutation (Glu421Lys), in a previously healthy primigravid woman who died from hypertriglyceridemia-induced pancreatitis during the last trimester of pregnancy. The patient was heterozygous for this mutation which a charge inversion in the C-terminal domain of LPL resulting in a moderate reduction in catalytic activity, both in vivo and in vitro. These data support the role of partial LPL deficiency in the pathogenesis of severe gestational hypertriglyceridemia.

An ultrasensitive, nonisotopic immunoassay for hyaluronan using the streptavidin-biotin system.

Year 1998
Rossler A.
Department of Physiology, School of Medicine, Karl-Franzens University, Graz, Austria. roessler@balu.kfunigraz.ac.at
A time-resolved fluoroimmunoassay for measuring hyaluronan concentrations in plasma and several biological fluids is described. The solid-phase immunoassay is based on the competition between aggregation of hyaluronan with the cartilage proteoglycan monomer, followed by binding of a monoclonal antibody to keratan sulfate of the proteoglycan and a biotinylated anti-mouse IgG. Fluorescence can be measured by a time-resolved fluorometer after binding of Eu(3+)-labelled streptavidin to the biotinylated IgG. The assay is precise and correlates well (r = 0.986) with the only established radioimmunoassay known. The results show that it is essential to perform a blank run without addition of proteoglycan, as endogenous proteoglycan disturbs the measurement and causes underestimation of plasma hyaluronan. The distinguishing feature of this assay is its extreme sensitivity (< 0.24 microgram/l of plasma). The mean analytical recovery after serial dilutions and addition was 100.3 and 101.3%, the within-assay and between-assay coefficients of variation were 3.67% and 7.02%, respectively.

Erythrocyte membrane lipids and serum selenium in post-viral and alcoholic cirrhosis.

Year 1998
Guarini P. Stanzial AM. Olivieri O. Casaril M. Galvani S. Pantalena M. Corrocher R.
Istituto di Patologia Medica, Universita di Verona, Italy.
Erythrocyte-membrane fatty acid composition and cholesterol content were evaluated along with serum selenium in 33 patients with liver cirrhosis and in 40 normal subjects. Thirteen patients were suffering from post-viral (group V) and 20 from alcoholic (group A) cirrhosis. The aim of the study was to elucidate whether membrane lipid abnormalities in cirrhosis were linked to the aetiology of the disease or whether they were the results of the cirrhotic process itself. The patients presented a significant increase in membrane cholesterol, palmitic acid (C16:0) and saturated fatty acids (SFA), and a decrease in polyunsaturated fatty acids (PUFA) and polyunsaturated/saturated fatty acids ratio (P/S) compared with the control group. Serum selenium levels were significantly reduced. When patients were subdivided according to aetiology, the alcoholic patients showed greater lipid composition abnormalities than the viral cirrhotics (higher levels of SFA and lower PUFA and P/S), while pathologic palmitic acid, membrane cholesterol and serum selenium values were confirmed in both groups of patients. In conclusion, low serum selenium and a series of erythrocytes membrane lipid composition abnormalities would appear to be features peculiar to cirrhosis. Alcoholic cirrhotics, on the other hand, show a more deranged erythrocyte membrane lipid profile.

Specific interaction of food proteins with apical membranes of the human intestinal cell lines Caco-2 and T84.

Year 1998
Bolte G. Wolburg H. Beuermann K. Stocker S. Stern M.
University Children's Hospital, Germany.
A comparison between the intestinal epithelial cell lines Caco-2 and T84 was made to assess the influence of enterocytic differentiation on food protein binding capacities of the brush border membrane. Cell morphology and expression of brush border-associated enzymes were studied as differentiation markers. Food protein binding to isolated brush border membranes was measured with a dot blot chemiluminescence assay. Early at confluence, Caco-2 cells exhibited a more differentiated state compared to T84 cells. Brush border membranes of both cell lines bound gliadin peptides, beta-lactoglobulin and ovalbumin specifically. Binding capacities increased from gliadin peptides to ovalbumin to beta-lactoglobulin. There was correlation of membrane binding capacity with degree of cell differentiation. Due to their similarity to small intestinal epithelial cells, the colon carcinoma cell lines Caco-2 and T84 represent models for studying food protein-enterocytic brush border membrane interactions in relation to varying degrees of cell differentiation.

Serum activities of classes I and II alcohol dehydrogenases in toxic liver damage.

Year 1998
Chrostek L. Szmitkowski M.
Department of Biochemical Diagnostics, Medical University, Bialystok, Poland.
The activities of classes I and II alcohol dehydrogenase isoenzymes were determined in the sera of patients with toxic hepatitis using class-specific fluorogenic substrates. The activities of total alcohol dehydrogenase and enzymes indicative of liver damage were also measured. We found a statistically significant increase of class I alcohol dehydrogenase isoenzymes. The increase in class I (two-fold) was similar to the increase of alkaline phosphatase. In a correlated study, we observed a good correlation of the activity of class II isoenzymes with alanine aminotransferase. The total alcohol dehydrogenase activity was enhanced and correlated with lactate dehydrogenase. These results demonstrated that the alcohol dehydrogenase and class I isoenzymes are indicatory enzymes of liver cell damage, and may be diagnostically useful in toxic hepatitis.

Correlation between serum cytokeratin 19 fragment and tissue polypeptide antigen levels in patients with non-malignant diseases.

Year 1998
Kashiwabara K. Nakamura H. Kiguchi T. Matsuoka T.
Fifth Department of Internal Medicine, Tokyo Medical College, Ibaraki, Japan.
It has been reported that cytokeratin 19 fragment (CYFRA 21-1) is superior to tissue polypeptide antigen (TPA) as a tumor marker, although there is a high correlation between CYFRA 21-1 and TPA levels in patients with lung cancer. We investigated correlations between these tumor markers in patients with non-malignant diseases. Marked correlations were found between CYFRA 21-1 and TPA levels in healthy subjects (n = 31), non-insulin-dependent diabetes mellitus (n = 160) and hemodialysis patients (n = 83) (range of r-value = 0.90-0.93, P < 0.0001). However in liver cirrhosis patients (n = 36), only a weak correlation was found (r = 0.39, P < 0.0001) and there were correlations between only TPA and both aspartate aminotransferase and alanine aminotransferase levels (r2 = 0.48 and 0.36, P < 0.0001). The elevated TPA levels in liver cirrhosis patients may be related to the decreased specificity of TPA as a tumor marker.