Binding of inositol phosphates and induction of Ca2+ release from pituitary microsomal fractions.

Bovine anterior-pituitary microsomal fractions exhibit high-affinity, saturable and reversible binding of inositol 1,4,5-[32P]trisphosphate; 50% of the labelled ligand is displaced by 3.5 nM-inositol 1,4,5-trisphosphate. 0.

Structure of cervinomycin, a novel xantone antibiotic active against anaerobe and mycoplasma.

The structures of cervinomycins A1 (1) and A2 (2), a potent anti-anaerobic and anti-mycoplasmal antibiotic were investigated by means of recent NMR techniques of O-methyl ether (3) and C,O-dimethyl ether (4) obtained by methylation of 2 with CH3I in the presence of Ag2O. The antibiotic 2 posesses a polycyclic structure involving a xanthone skeleton. The structure of 1 was confirmed to be a hydroquinone of 2 from the evidences that oxidation of 1 with Ag2O and acetylation of 1 with (CH3CO)2O in pyridine afforded quantitatively 2 and triacetylcervinomycin A1 (7), respectively.

(+)-Cyanidanol-3 prevents the functional deterioration of rat liver mitochondria induced by Fe2+ ions.

The clinically effective hepatoprotective flavonoid, (+)-Cyanidanol-3, prevented the Fe2+-induced functional deterioration of rat liver mitochondria. Fe2+ treatment of mitochondria resulted in increased lipid peroxidation (MDA-formation), decreased mitochondrial membrane potential, impaired Ca2+ uptake capacity and caused large amplitude swelling of mitochondria. All of the consequences of Fe2+ treatment were inhibited by (+)-Cyanidanol-3 in a concentration dependent manner.

The Ba2+ sensitivity of the Na+-induced Ca2+ efflux in heart mitochondria: the site of inhibitory action.

The Na+-induced Ca2+ release from rat heart mitochondria was measured in the presence of Ruthenium red. Ba2+ effectively inhibited the Na+-induced Ca2+ release. At 10 mM Na+ 50% inhibition was reached by 1.

Oxygen-17 relaxation times in the blood sera of rats with various cancers. Can a systemic effect be detected?

17O NMR relaxation times of water in the serum of rats with various cancers were measured. No systemic effect could be detected at 4.7 and 8.

Ba2+ ions inhibit the release of Ca2+ ions from rat liver mitochondria.

The release of Ca2+ from respiring rat liver mitochondria following the addition of either ruthenium red or an uncoupler was measured by a Ca2+-selective electrode or by 45Ca2+ technique. Ba2+ ions are asymmetric inhibitors of both Ca2+ release processes. Ba2+ ions in a concentration of 75 microM inhibited the ruthenium red and the uncoupler induced Ca2+ release by 80% and 50%, respectively.

Synthesis and antitumor activity of 3'-C-methyl-daunorubicin.

Reaction of 1,5-anhydro-4-O-benzoyl-2,3,6-trideoxy-3-C-methyl-3-trifluoro-acetami no-L-lyxo-hex-1-enitol with daunomycinone in the presence of anhydrous toluene-p-sulfonic acid in benzene, followed by removal of the N- and O-protecting groups under mild conditions, gave 3'-C-methyldaunorubicin. The antitumor activity of the new anthracycline glycoside has been evaluated.

Phosphate transport, membrane potential, and movements of calcium in rat liver mitochondria.

The membrane potential and calcium accumulation of mitochondria were followed by ion-specific electrodes in the presence of the proton-donor anions phosphate, acetate, glutamate, and beta-hydroxybutyrate. Phosphate was the only anion which allowed rapid and complete restoration of both the membrane potential and the steady-state extramitochondrial calcium concentration after the uptake of 100-200 nmol calcium per mg protein. If there was no influx of any proton-donor anion, the extent of calcium uptake depended on the intramitochondrial phosphate content.

Correlation of malignancy with the intracellular Na+:K+ ratio in human thyroid tumors.

Energy-dispersive X-ray microanalysis was applied on human intraoperative biopsy materials of different thyroid tumors. To ensure suitability of these tissue pieces for quantitative microanalysis in freeze-fractured, freeze-dried bulk specimens, sampling was carried out with strictly defined criteria. Benign adenomas and differentiated and anaplastic carcinomas were selected for the studies on the basis of pathohistological investigations of the same specimen.

Microfluorimetric and X-ray microanalytic studies on the DNA content and Na+:K+ ratios of the cell nuclei in various types of thyroid tumors.

Parallel studies were performed using microfluorimetric DNA determination and X-ray microanalysis on the same thyroid biopsy material to compare the intranuclear DNA and monovalent electrolyte contents (Na+, K+, Cl-). Samples were taken from apparently healthy, adenomatous, and cancerous parts of human thyroid glands removed surgically. The time interval was less than 1 min.

The validity of some morphologic methods in the diagnosis of thyroid malignancy.

The diagnostic accuracy of intraoperative frozen section and imprint cytology in thyroid conditions was analyzed along with that of cytofluorimetric nuclear DNA determination. Of 149 frozen sections in a four-year period, 90% gave a correct diagnosis, while four results were false-positive and one was false-negative. The intraoperative accuracy of imprint cytology was 95% in 309 examinations, with 12 false-positive and four false-negative results.

[Preclinical and manifest hypothyroidism following thyroid gland operation].

62 patients who were strumectomized on account of carcinoma of the thyroid gland, hyperthyroidism and thyroiditis underwent an after-examination on an average 6 years after operation. In preclinical hypothyroidism which cannot be differed from euthyroidism on the basis of the thyroid hormone concentrations, or only by means of the TRH-tolerance test, an increased TSH-response after TRH-tolerance and a T3-preference in comparison to T4 were observed. In manifest hypothyroidism the compensatory mechanisms exhausted and despite the increased TSH-concentration in the serum the ability for TRH-stimulation and the concentrations of the thyroid hormone are reduced.

Proton cycling through the mitochondrial phosphate transporter in energy transduction.

The molecular structure of the phosphate carrier of mitochondria is probably controlled by the H+ ion concentration within the matrix. It is supposed that changes in molecular structure affect the H+- and H2PO4- ion transporting function and may be part of the "gating" mechanism in phosphate transport.

Simultaneous occurrence of Graves' disease with endocrine ophthalmopathy. Thyroiditis and thyroid carcinoma.

The simultaneous occurrence of Graves' disease with ophthalmopathy lymphocytic and subacute de Quervains' thyroiditis has been observed in two male patients suffering from follicular-type thyroid carcinoma. In one of them Sjögren syndrome and a mild form of diabetes were also diagnosed. It is assumed, on the basis of indirect evidence, that the humoral and cellular lesions determined by genetic factors and influenced by prolonged thyrostatic and steroid treatment are jointly responsible for tumour genesis.

Modification of the cytoprotective effect of prostacyclin on gastric epithelial cells of rats by colchicine.

The effect of prostacyclin (PGI2) and colchicine on fundic gastric mucosa of sexually mature female Wistar rats was investigated histochemically after restraint stress. Under PGI2 treatment the ulcer index decreased significantly; this effect was moderately inhibited by colchicine. The mucus content of epithelial cells was decreased during restraint and was increased by PGI2 treatment.