Human granzyme B mediates cartilage proteoglycan degradation and is expressed at the invasive front of the synovium in rheumatoid arthritis

Objective. To investigate the cartilage-degrading capacity of granzyme B and the presence of granzyme B-positive cells at sites of erosion in the rheumatoid synovium. Methods. Granzyme B was added to [3H]proline/[35S]sulphate-labelled cartilage matrices and to cartilage explants. Proteoglycan degradation was assessed by the release of 35S and...

Apolipoprotein E participates in the regulation of very low density lipoprotein-triglyceride secretion by the liver

ApoE-deficient mice on low fat diet show hepatic triglyceride accumulation and a reduced very low density lipoprotein (VLDL) triglyceride production rate. To establish the role of apoE in the regulation of hepatic VLDL production, the human APOE3 gene was introduced into apoE-deficient mice by cross-breeding with APOE3 transgenics (APOE3/apoe-/-...

In vitro measurement of beta-carotene cleavage activity: Methodological considerations and the effect of other carotenoids on beta-carotene cleavage

In view of controversies about assessment of the β-carotene cleavage activity, methodological aspects and problems of the dioxygenase assay are described. Using rat and hamster intestinal preparations the method was optimized on retinal formation, the only cleavage product we could demonstrate. It appeared that the cell fraction with the highest...

Transport and metabolism of glutathione conjugates of menadione and ethacrynic acid in confluent monolayers of rat renal proximal tubular cells

Confluent monolayers of primary rat renal proximal tubular (RPT) cells were used to compare transepithelial transport and concomitant metabolism of two different glutathione (GSH) S-conjugates. For the GSH-conjugated quinone compound, [35S]GSH-conjugated menadione (MGNQ), no specific transepithelial transport was observed. Most likely, [35S]MGNQ...

Maximal epidermal growth-factor-induced cytosolic phospholipase A2 activation in vivo requires phosphorylation followed by an increased intracellular calcium concentration

The 85 kDa cytosolic phospholipase A2 (cPLA2) preferentially catalyses the hydrolysis of arachidonic acid from the sn-2 position of phospholipids. cPLA2 can be activated by extracellular stimuli such as thrombin, platelet-derived growth factor and epidermal growth factor (EGF). A full activation of cPLA2 requires an increase of intracellular Ca2...

Effect of wheat bran on excretion of radioactively labeled estradiol-17 Beta and estrone-glucuronide injected intravenously in male rats

Urinary and fecal estrogen excretion were studied in male rats fed a non-fiber wheat starch diet (dietary fiber < 1%; NF group; n = 4), a low-fiber wheat flour diet (dietary fiber 2%; LF group; n = 4) or a high-fiber wheat bran diet (dietary fiber 11.6%; HF group; n = 3). Short-term effects of the experimental diet on estrogen excretion were...

Bile acids and lipids in isolated rat hepatocytes. II. Source of cholesterol used for bile acid formation, estimated by incorporation of tritium from tritiated water, and by the effect of ML-236B

Chemicals/CAS: cholesterol, 57-88-5; cholic acid, 32500-01-9, 361-09-1, 81-25-4; colestyramine, 11041-12-6, 58391-37-0; compactin, 73573-88-3; lipid, 66455-18-3; tritium oxide, 14940-65-9; Bile Acids and Salts; Cholesterol, 57-88-5; Cholestyramine, 11041-12-6; compactin, 73573-88-3; Lipids; Naphthalenes; Tritium, 10028-17-8

Pitfalls in determination of acetylcholine from brain by pyrolysis gas chromatography/mass spectrometry

Demethylation by sodium benzenethiolate has been used to analyse mixtures of isotopic variants of acetylcholine (ACh) by gas chromatography/mass spectrometry (GC/MS). The present experiments show that demethylation by pyrolysis is also suitable for the simultaneous determination of deuterium labelled variants of ACh by means of GC/MS. However,...

Subcellular localization of newly formed [3H]acetylcholine in rat cerebral cortex in vitro

Slices from rat brain cortex were incubated for either 5 or 60 min in a medium containing [3H]choline and 4.7 or 25 mM KCl. Bioassayable ACh and labelled ACh were determined in the incubation medium, in the total tissue homogenate and in subcellular fractions. Raising the KCl concentration from 4.7 to 25 mM stimulated the release and synthesis...

Early increase of amino acid transport in stimulated lymphocytes

Chemicals/CAS: 2 amino 2 methylpropionic acid, 62-57-7; carbon, 7440-44-0; thymidine, 50-89-5; tritium, 10028-17-8; Aminoisobutyric Acids; Carbon Isotopes; Lectins; Thymidine, 50-89-5; Tritium, 10028-17-8

Repair of X-ray damage in DNA of cultivated cells from patients having xeroderma pigmentosum

Repair replication and rejoining of single-strand breaks after X-irradiation in human-skin fibroblasts from normal donors and several patients with xeroderma pigmentosum have been compared. The xeroderma strains showed different levels of repair replication following UV exposure. Repair replication and rejoining of breaks, which are considered...

The regulation of cell proliferation and differentiation in intestinal epithelium. II. A quantitative histochemical and autoradiographic study after low doses of X-irradiation

To investigate the biochemical mechanisms involved in the regulation of cell proliferation and differentiation the intestinal epithelium has been chosen because of the regular distribution of proliferative-, non-dividing maturing- and functional cells along the crypt and villus. The effect of low doses of irradiation (50-400 R) which selectively...

Synchronization of mammalian cells in vitro by inhibition of the DNA synthesis. II. Population dynamics

Some aspects of the population dynamics before, during and after the double thymidine treatment synchronization procedure were analysed. The mitotic index in the synchronized populations rose from 0.0 per cent at 1 hr after the end of the second treatment to 20.8 per cent at 9.7 hr, dropped to 0.1 per cent at about 22 hr and increased again to a...

Synchronization of mammalian cells in vitro by inhibition of the DNA synthesis. I. Optimal conditions

An optimal procedure to synchronize the life cycles of the individuals in a population of human cells, cultured in vitro, by repeated temporary inhibition of the DNA synthesis was elaborated. Cultures in the logarithmic growth phase were treated three times with 7.5 mM thymidine dissolved in medium. Each treatment was terminated after 24 hr by...