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Biomedical subjects

C Luley

Publications and source records attributed to C Luley.

At least 73 records · Page 4Linked to original sources
PubMed1990

[Comparative effect of oral fat loads with saturated, omega-6 and omega-3 fatty acids before and after fish oil capsule therapy in healthy probands].

To evaluate digestion, absorption and postprandial lipemia of diverse fats before and after fish oil capsule therapy (with ethylester) 20 healthy volunteers were recruited. A significant increase (p less than 0.001) in fecal fat excretion after fish oil capsule therapy, as well as serious diarrhoea after fat loads with 100 g of fish oil was noted. It was found, that under fish oil fat loads the total triglyceride content of the mucosa was significantly (p less than 0.001) lower compared to butter fat loads. Decrease digestion and absorption of omega-3 fatty acids was postulated.

Adult↗
PubMed1989

Heterogeneous response to differentiation induction in different clonal subpopulations of a rat rhabdomyosarcoma cell line (BA-HAN-1).

Three clonal subpopulations (A, B, C) isolated from the same rhabdomyosarcoma of the rat were tested and compared for their susceptibility to differentiation induction using retinoic acid (RA), dimethylformamide (DMF), and N-monomethylformamide (NMF). These subpopulations differ in that a block to spontaneous differentiation is imposed at different stages which are characteristic for each subpopulation. Whereas tumor cell proliferation was significantly inhibited (P less than 0.001) in all three subpopulations, the effects of RA, DMF, and NMF on tumor cell differentiation were strikingly heterogeneous. The response was most marked in subpopulation C, as evidenced by a significant increase in the number of terminally differentiated myotube-like giant cells (P less than 0.001) and in biochemical differentiation, as indicated by the creatine kinase activity (P less than 0.05). Between 5% (DMF and NMF) and 30% (RA) of the mononuclear cells in subpopulation C exhibited thick and thin myofilaments, which were never observed in the mononuclear cells of the control. In contrast, subpopulation A and B responded to RA, DMF, and NMF quite heterogeneously with an increase in biochemical differentiation, whereas terminally differentiated myotube-like giant cells were never observed. These results demonstrate that the therapeutic potential of differentiation induction in malignant tumors may be impaired by tumor heterogeneity.

Animals↗
PubMed1989

[Contaminating substances in 22 over-the-counter fish oil and cod liver oil preparations: cholesterol, heavy metals and vitamin A].

Fish oil capsules are increasingly used by self-medicating patients. We studied 22 commercial fish oil and menhaden oil preparations in respect to accompanying substances that could be harmful. The substances measured were: cholesterol as determined by gas liquid chromatography, heavy metals measured by atomic absorption, and vitamin A as determined by high-performance liquid chromatography (HPLC). The contents of cholesterol and heavy metals were in ranges which can be regarded as negligible; the content of vitamin A in menhaden oils, however, was found in amounts which warrant that pregnant women do not exceed the dosage as recommended by the manufacturers.

Animals↗
PubMed1989

Fetal calf serum and retinoic acid affect proliferation and terminal differentiation of a rat rhabdomyosarcoma cell line (BA-HAN-1C).

We report on the establishment of a model for differentiation induction in sarcomas, using the clonal rhabdomyosarcoma cell line BA-HAN-1C. This rhabdomyosarcoma cell line is composed of morphologically undifferentiated mononuclear stem cells, some of which spontaneously fuse to form terminally differentiated multinuclear myotube-like giant cells. The deprivation of fetal calf serum (FCS) or the exposure to retinoic acid, respectively, resulted in a significant inhibition of proliferation (P less than 0.001) and a marked increase in cellular differentiation as shown by a significant increase in the number of myotube-like giant cells (P less than 0.001) and in the creatine kinase activity (P less than 0.05) used as a biochemical marker of differentiation. Furthermore, after exposure to retinoic acid about 30% of the mononuclear tumour cells exhibited morphological features of rhabdomyogenic differentiation, such as bundles of thick and thin myofilaments, which had never been observed in the mononuclear cells of untreated cultures. These results confirm that the inverse linkage between proliferation and differentiation known from embryonic myogenesis is preserved in our rhabdomyosarcoma cell line. The failure to induce terminal differentiation by exposure to retinoic acid in all the cells of our clonal cell line indicates that some tumour cells might epigenetically be blocked from responding to retinoic acid. The temporary growth retardation observed after FCS-deprivation suggests that autocrine stimulation of proliferation may be operating in our cell line, too.

Animals↗
PubMed1989

Heterogeneous response to differentiation induction with different polar compounds in a clonal rat rhabdomyosarcoma cell line (BA-HAN-1C).

The clonal rat rhabdomyosarcoma cell line BA-HAN-1C was tested for its susceptibility to differentiation induction with different polar compounds. This cell line is composed of proliferating mononuclear tumour cells, some of which spontaneously fuse to form terminally differentiated postmitotic myotube-like giant cells. Exposure of BA-HAN-1C cells to dimethylsulphoxide (DMSO), hexamethylene bisacetamide (HMBA), sodium butyrate (NaBut) and N-monomethylformamide (NMF) resulted in a significant inhibition of proliferation (P less than 0.001) and in a simultaneous increase in differentiation. The response was most pronounced after exposure to NMF as evidenced by a marked increase in the creatine kinase activity used as a biochemical marker of differentiation (P less than 0.05) and the number of terminally differentiated myotube-like giant cells (P less than 0.001). Furthermore, about 5% of the mononuclear cells exhibited thick and thin myofilaments which were never observed in the mononuclear cells of the control. In contrast, the effects of DMSO, HMBA and NaBut were exclusively confined to a significant increase in biochemical differentiation (P less than 0.05), whereas no increase in morphological differentiation was observed and the number of myotube-like giant cells even significantly (P less than 0.001) decreased. This heterogeneous response to differentiation induction with different polar compounds probably indicates different mechanisms of action and suggests that the induction of biochemical differentiation might be independently regulated from events leading to cell fusion and terminal differentiation.

Acetamides↗
PubMed1989

Immunonephelometric determination of the apolipoprotein A-II.

A fully mechanized immunonephelometric method is described for the rapid and specific determination of apolipoprotein A-II in serum. The method utilizes commercially available sheep antiserum against human apolipoprotein A-II. Nephelometry was performed with the Behring Nephelometer Analyzer (BNA). A single determination can be performed in 12 minutes, requiring 10 microliters sample volume. The measuring range is about 0.08 to 1.25 g/l apolipoprotein A-II. Precision is characterized by intra-assay coefficients of variation of 3.37%, 3.93% and 4.49% for apolipoprotein A-II concentrations of 1.22 g/l, 0.376 g/l and 0.185 g/l, and inter-assay coefficients of variation of 4.27% for an apolipoprotein A-II concentration of 0.404 g/l, respectively. Accuracy of the method is shown by the close correlation of results with those from radial immunodiffusion (r = 0.913, y = 1.091 x -0.033, n = 75).

Apolipoprotein A-II↗
PubMed1988

Terminal differentiation and growth inhibition of a rat rhabdomyosarcoma cell line (BA-HAN-1C) in vitro after exposure to retinoic acid.

BA-HAN-1C is a clonal rat rhabdomyosarcoma cell line composed of proliferating mononuclear cells, which partly fuse to terminally differentiated postmitotic myotube-like giant cells. The exposure to retinoic acid in vitro resulted in time- and dose-dependent changes of both cell differentiation and cell growth. The mononuclear cells revealed bundles of newly formed thick and thin myofilaments, never observed in untreated cultures, and exhibited signs of contact inhibition. In addition, there was a statistically significant increase (P less than 0.001) in the number of terminally differentiated postmitotic myotube-like giant cells and in the creatine kinase activity (P less than 0.05) which was used as a biochemical differentiation marker. At the same time cell growth was significantly inhibited (P less than 0.001) in vitro and a decrease in plating efficiency, as well as in saturation density, was observed. These data demonstrate that retinoic acid can suppress cell growth and simultaneously initiate differentiation in a malignant mesenchymal tumor cell line. However, despite the clonal nature of BA-HAN-1C, the complete status of terminal differentiation was not achieved by all tumor cells. The reason why not all tumor cells responded to retinoic acid is unknown at the present time and will have to be the subject of further studies.

Animals↗
PubMed1988

[Fatty acid composition and degree of peroxidation in fish oil and cod liver oil preparations].

Omega-3-fatty acids are increasingly used by the selfmedicating patient. Since fish oils in capsules are regarded as dietary food, there are neither official regulations in the Federal Republic of Germany concerning a minimum content of omega-3-fatty acids nor detailed rules for the limitation of autoxidation of these highly reactive substances. Both fatty acid composition and the degree of lipid peroxidation were measured in this study in 23 OTC fish oil preparations. The proportion of omega-3-fatty acids was in most fish oils about 30%; exceptions were the only ethyl ester among the preparations with 59% and the cod liver oils (13% to 22%). Regarding the peroxide value considerable differences were found: the lowest was 2 and the highest was 44.7. Since lipid peroxides and their degradation products are basically toxic, a limitation of the allowed degree of lipid peroxidation in fish oils is strongly recommended.

Animals↗
PubMed1987

Determination of apolipoprotein variants by isoelectric focusing in agarose.

Isoelectric focusing (IEF) of apolipoproteins is an important procedure for the isolation of apolipoprotein isoforms. In this paper we describe the use of agarose/urea as a focusing medium for IEF of apolipoproteins. This technique, which offers several advantages over the traditional polyacrylamide gel focusing, yields a further microheterogeneity of the known isoforms of apolipoproteins A-I and E. In addition, by subsequent immunoprecipitation, both specificity and sensitivity are enhanced. Using a monospecific antiserum against Apo A-I, a new minor isoform was detected at the basic end of the Apo A-I spectrum (pI 6.02) which has not yet been observed in normal plasma samples. Another advantage of this technique in combination with immunoprecipitation is the specific detection of Apo E phenotypes which is essential for the diagnosis of hyperlipoproteinemia type III.

Apolipoproteins↗
PubMed1987

Comparison of four procedures for separating apolipoprotein A- and apolipoprotein B-containing lipoproteins in plasma.

Because lipoproteins containing apolipoprotein A (ApoA-I + ApoA-II) or apolipoprotein B (ApoB) seem to exert opposite effects as risk factors for coronary heart disease, we decided to determine the separability of these two major plasma lipoproteins by procedures originally designed to separate high-density from low- and very-low-density lipoproteins. The presumably ApoB-free lipoproteins isolated from normal plasma by (a) ultracentrifugation at d = 1.063; precipitation with (b) heparin-Mn2+ or (c) phosphotungstate-Mg2+; or (d) immunoprecipitation with antibodies to ApoB were characterized by quantifying cholesterol and apolipoproteins A-I, A-II, B, C-II, C-III, D, E, F, and Lp(a). ApoA- and ApoB-containing lipoproteins were completely separated only by immunoprecipitation with antibodies to ApoB. The ApoB-containing lipoproteins isolated by other procedures always contained 4% to 20% of total plasma ApoA-I and differed substantially from one another with respect to the content of some of the minor apolipoproteins. Measuring apolipoproteins was more reliable than measuring cholesterol for monitoring this separation and for expressing the concentrations of ApoA- and ApoB-containing lipoproteins.

Adult↗
PubMed1986

Lack of efficacy of dried garlic in patients with hyperlipoproteinemia.

The effects of dried garlic on blood lipids, apolipoproteins and blood coagulation parameters in hyperlipemic patients were studies in two controlled, randomized, double-blind studies. Both studies comprised placebo and therapy periods of 6 weeks each. The doses administered were 3 X 198 mg in Study I (34 patients) and 3 X 450 mg in Study II (51 patients). In both studies, the following serum parameters were measured every 3 weeks: total cholesterol, HDL (high density lipoprotein)- and LDL (low density lipoprotein)-cholesterol, triglycerides and several safety parameters. In addition, apolipoproteins A and B, euglobulin lysis time, fibrin split products, prothrombin time, whole blood coagulation time and fibrinogen levels were determined in the second study only. The results indicated that neither dosage of dried garlic showed any significant effect on any of the parameters measured. It is therefore concluded that, if there is any effect of garlic on the parameters measured, it is not apparent when using a dried preparation in the dosage studied.

Apoproteins↗