Altered signal pathway in granulocytes from patients with hypercholesterolemia.

In the present study the signal transduction of the formyl-Met-Leu-Phe receptor was studied in granulocytes obtained from control subjects and patients with elevated low density lipoprotein levels. According to our results, 10 nm formyl-Met-Leu-Phe in control cells activates phospholipase C inducing a pronounced inositol phosphate production followed by a Ca(2+) signal from intracellular pools. The pertussis toxin-sensitive O(2)(-) generation and leukotriene synthesis were moderate. In contrast, in granulocytes from hypercholesterolemic patients, formyl-Met-Leu-Phe triggered an intensive pertussis toxin-insensitive oxidative burst and leukotriene synthesis. The inositol trisphosphate and Ca(2+) signals were decreased significantly in granulocytes of hypercholesterolemic patients and seem to be dependent on the extracellular Ca(2+) content. Furthermore, in the resting granulocytes of hypercholesterolemic patients the [Ca(2+)]i and the membrane-bound protein kinase C activity were higher than in controls, the time of normalization after the low Ca(2+) signal was delayed, while the membrane fluidity was decreased. Our results suggest that in these ex vivo experiments, the high level of circulating low density lipoprotein in patients can affect the membrane composition of granulocytes leading to altered signal transduction by the formyl-Met-Leu-Phe receptor, to altered Ca(2+) pump-activity, and protein kinase C translocation.

High-3He Plume Origin and Temporal-Spatial Evolution of the Siberian Flood Basalts.

An olivine nephelinite from the lower part of a thick alkalic ultrabasic and mafic sequence of volcanic rocks of the northeastern part of the Siberian flood basalt province (SFBP) yielded a (40)Ar/(39)Ar plateau age of 253.3 +/- 2.6 million years, distinctly older than the main tholeiitic pulse of the SFBP at 250.0 million years. Olivine phenocrysts of this rock showed (3)He/(4)He ratios up to 12.7 times the atmospheric ratio; these values suggest a lower mantle plume origin. The neodymium and strontium isotopes, rare earth element concentration patterns, and cerium/lead ratios of the associated rocks were also consistent with their derivation from a near-chondritic, primitive plume. Geochemical data from the 250-million-year-old volcanic rocks higher up in the sequence indicate interaction of this high-(3)He SFBP plume with a suboceanic-type upper mantle beneath Siberia.

Early and Late Alkali Igneous Pulses and a High-3He Plume Origin for the Deccan Flood Basalts.

Several alkalic igneous complexes of nephelinite-carbonatite affinities occur in extensional zones around a region of high heat flow and positive gravity anomaly within the continental flood basalt (CFB) province of Deccan, India. Biotites from two of the complexes yield (40)Ar/(39)Ar dates of 68.53 +/- 0.16 and 68.57 +/- 0.08 million years. Biotite from a third complex, which intrudes the flood basalts, yields an (40)Ar/(39)Ar date of 64.96 +/- 0.1 1 million years. The complexes thus represent early and late magmatism with respect to the main pulse of CFB volcanism 65 million years ago. Rocks from the older complexes show a (3)He/(4)He ratio of 14.0 times the air ratio, an initial (87)Sr/(86)Sr ratio of 0.70483, and other geochemical characteristics similar to ocean island basalts; the later alkalic pulse shows isotopic evidence of crustal contamination. The data document 3.5 million years of incubation of a primitive, high-(3)He mantle plume before the rapid eruption of the Deccan CFB.

Prenatal diagnosis of cystic fibrosis by microvillar membrane enzyme analysis in amniotic fluid.

Prenatal diagnosis was performed in 92 pregnancies high-risk for cystic fibrosis during six years. Amniotic fluid samples obtained by amniocentesis were examined with regard to their microvillar membrane enzyme activity. Though trehalase, alkaline phosphatase isoenzymes and L-gamma-glutamyltransferase in the amniotic fluid are not specific markers of cystic fibrosis, their activity is significantly lower than in normal pregnancies. By measuring the three enzymes simultaneously, sensitivity, specificity and reliability of the method were found to be over 92%. It is concluded that mid-trimester amniotic fluid diagnosis is indispensable for some heterozygotic couples for cystic fibrosis even in the possession of DNA (desoxyrobonucleic acid) methods.

Discriminant analysis for assessing the value of amniotic fluid microvillar enzymes in the prenatal diagnosis of cystic fibrosis.

We have analysed the sensitivity, specificity, and reliability of biochemical diagnosis based on microvillar membrane enzyme assay and using discriminant analysis in amniotic fluid samples obtained from 54 pregnancies at high risk for cystic fibrosis and 125 normal pregnancies. Our results show that amniotic fluid trehalase, alkaline phosphatase, alkaline phosphatase isoenzymes and gamma-glutamyltransferase enzyme activities measured during 16-20 gestational weeks, in spite of their non-specificity for cystic fibrosis, have a very good predictive value for fetal cystic fibrosis or exclude the possibility of the disease. Overall enzyme activity analysis provided over 90 per cent reliability of the method.

Amniotic fluid microvillar enzyme activity in fetal malformations.

Prenatal diagnosis of cystic fibrosis based on amniotic fluid microvillar enzyme activity assay has become routine practice in the past few years. Normal (median) values of these enzymes were determined in 177 normal healthy pregnancies between 15-20 gestational weeks and were related to enzyme values measured in 50 pregnancies complicated with congenital malformations, 6 monogenic inherited diseases and 4 chromosomal aberrations. It is concluded that increased trehalase activity has diagnostic importance in detecting fetal kidney diseases, and radial-renal syndrome (with elevated GGT activity), while low enzyme activities may indicate chromosomal aberrations (with no signs of intestinal obstruction). With the collection of further data, the analysis of these enzymes might provide an opportunity to set up diagnostic procedures for the detection of other, non-CF-related cases.

[Prenatal diagnosis of cystic fibrosis by analysis of microvillar enzymes of the amniotic fluid]. / A cystikus fibrosis praenatalis diagnosztikája a magzatvíz mikrovilláris membránenzimjeinek vizsgálatával.

Prenatal diagnosis was performed in 92 pregnancies high-risk for cystic fibrosis during six years. Amniotic fluid samples obtained by amniocentesis were examined with regard to their microvillar membrane enzyme activity. However, trehalase, alkaline phosphatase isoenzymes and L-gamma-glutamyl-transferase in the amniotic fluid are not specific markers of the cystic fibrosis, their activity is significantly lower than in normal pregnancies. By measuring the three enzymes simultaneously, sensitivity, specificity and reliability of the method were found to be over 92%. It is concluded that the mid-trimester amniotic fluid diagnosis is useful for some heterozygotic couples for cystic fibrosis even in the possession of the DNA methods.

Genetic counselling and prenatal diagnosis of cystic fibrosis in Debrecen (Hungary)--prenatal diagnosis by microvillar enzyme assay from amniotic fluid.

Amniotic fluid intestinal alkaline phosphatase, gammaglutamyltransferase and trehalase activity were quantitated to assess their reliability for the prenatal diagnosis of cystic fibrosis. To obtain optimal diagnostic discrimination, the three enzyme values obtained for each sample were combined into a single linear discriminant function that proved to be a more accurate indicator of the outcome of the pregnancy. From the cases studied here, it appears that this method can be expected to give a correct prediction in 92.0% of all high risk pregnancies.

Lymphokine effect upon the erythrocyte antibody uptake by human monocytes.

Preincubation of human monocytes with different amounts of human lymphokine at 37 degrees C dose dependently increased the uptake of EA cells at both 37 degrees C and 4 degrees C. Phenylmethanesulphonyl fluoride (PMSF), an inhibitor of serine esterases, inhibited the process. It seemed that the serine esterase and not the gamma interferon component of the lymphokine played the main role in the phenomenon.

Prenatal diagnosis of cystic fibrosis by trehalase enzyme assay in amniotic fluid.

Amniocentesis and amniotic fluid trehalase enzyme assay were offered to 14 pregnant women at a 1 in 4 risk for a child with cystic fibrosis. Twelve of these pregnancies were screened at the 18th week of gestation; ten proceeded to term, seven following the finding of a normal trehalase activity and three despite the low enzyme level in amniotic fluid. In all ten cases prenatal diagnosis proved to be correct. In two cases with low enzyme activity parents opted for termination at the 19th week, and with PAS-Alcian Blue staining some slight histochemical lesions characteristic of cystic fibrosis were seen in the exocrine glands, including the pancreas and intestinal mucosa, of both fetuses. The total protein content in the meconium of these fetuses was significantly higher than in the controls. Results suggest that trehalase assay in the amniotic fluid is a potential prenatal test for cystic fibrosis and it appears that in fetuses with cystic fibrosis some histochemical and biochemical abnormalities can be observed as early as the 19th week of gestation. The role of ultrasound examination as an additional procedure for the prenatal diagnosis of cystic fibrosis is also discussed.