(1/3500) Variations in 35SO4 incorporation into glycosaminoglycans along canine coronary arteries. A possible index of artery wall stress.
Focal areas of accentuated wall stress along the course of canine coronary arteries may be revealed by the level of 35SO4 incorporation into glycosaminoglycans (GAG). In the anterior descending artery, 35SO4 incorporation in higher in the proximal than in the distal region and may be extraordinarily high as the vessel enters a proximally located muscle bridge and at the takeoff region of multidirectional branches. In the circumflex artery, the incorporation also is higher in the proximal than in the distal region and is high at the genu where the posterior descending artery forms. There are differences in uptake of 35SO4 in vessels even when the arteries arise from the same vascular bed.this was shown by the higher incorporation in the left coronary artery than in the right coronary artery. A general anatomical agreement exists between these sites of high 35SO4 incorporation and previously described locations of interval elastic disruption ans proliferation of intimal connective tissue in the dog. (+info)
(2/3500) Sulphated and unsulphated bile acids in serum, bile, and urine of patients with cholestasis.
Samples of serum, bile, and urine were collected simultaneously from patients with cholestasis of varying aetiology and from patients with cirrhosis; their bile acid composition was determined by gas/liquid chromatography and mass spectrometry. In cholestasis, the patterns in all three body fluids differed consistently and strikingly. In serum, cholic acid was the major bile acid and most bile acids (greater than 93%) were unsulphated, whereas, in urine, chenodeoxycholic was the major bile acid, and the majority of bile acids (greater than 60%) were sulphated. Secondary bile acids were virtually absent in bile, serum, and urine. The total amount of bile acids excreted for 24 hours correlated highly with the concentration of serum bile acids; in patients with complete obstruction, urinary excretion averaged 71-6 mg/24 h. In cirrhotic patients, serum bile acids were less raised, and chenodeoxycholic acid was the predominant acid. In healthy controls, serum bile acids were consistently richer in chenodeoxycholic acid than biliary bile acids, and no bile acids were present in urine. No unusual monohydroxy bile acids were present in patients with primary biliary cirrhosis, but, in several patients, there was a considerable amount of hyocholic acid present in the urinary bile acids. The analyses of individual bile acids in serum and urine did not appear to provide helpful information in the differential diagnosis of cholestasis. Thus, in cholestasis, conjugation of chenodeoxycholic acid with sulphate becomes a major biochemical pathway, urine becomes a major route of bile acid excretion, and abnormal bile acids are formed. (+info)
(3/3500) The sialylation of bronchial mucins secreted by patients suffering from cystic fibrosis or from chronic bronchitis is related to the severity of airway infection.
Bronchial mucins were purified from the sputum of 14 patients suffering from cystic fibrosis and 24 patients suffering from chronic bronchitis, using two CsBr density-gradient centrifugations. The presence of DNA in each secretion was used as an index to estimate the severity of infection and allowed to subdivide the mucins into four groups corresponding to infected or noninfected patients with cystic fibrosis, and to infected or noninfected patients with chronic bronchitis. All infected patients suffering from cystic fibrosis were colonized by Pseudomonas aeruginosa. As already observed, the mucins from the patients with cystic fibrosis had a higher sulfate content than the mucins from the patients with chronic bronchitis. However, there was a striking increase in the sialic acid content of the mucins secreted by severely infected patients as compared to noninfected patients. Thirty-six bronchial mucins out of 38 contained the sialyl-Lewis x epitope which was even expressed by subjects phenotyped as Lewis negative, indicating that at least one alpha1,3 fucosyltransferase different from the Lewis enzyme was involved in the biosynthesis of this epitope. Finally, the sialyl-Lewis x determinant was also overexpressed in the mucins from severely infected patients. Altogether these differences in the glycosylation process of mucins from infected and noninfected patients suggest that bacterial infection influences the expression of sialyltransferases and alpha1,3 fucosyltransferases in the human bronchial mucosa. (+info)
(4/3500) Anticoagulant heparan sulfate precursor structures in F9 embryonal carcinoma cells.
To understand the mechanisms that control anticoagulant heparan sulfate (HSact) biosynthesis, we previously showed that HSact production in the F9 system is determined by the abundance of 3-O-sulfotransferase-1 as well as the size of the HSact precursor pool. In this study, HSact precursor structures have been studied by characterizing [6-3H]GlcN metabolically labeled F9 HS tagged with 3-O-sulfates in vitro by 3'-phosphoadenosine 5'-phospho-35S and purified 3-O-sulfotransferase-1. This later in vitro labeling allows the regions of HS destined to become the antithrombin (AT)-binding sites to be tagged for subsequent structural studies. It was shown that six 3-O-sulfation sites exist per HSact precursor chain. At least five out of six 3-O-sulfate-tagged oligosaccharides in HSact precursors bind AT, whereas none of 3-O-sulfate-tagged oligosaccharides from HSinact precursors bind AT. When treated with low pH nitrous or heparitinase, 3-O-sulfate-tagged HSact and HSinact precursors exhibit clearly different structural features. 3-O-Sulfate-tagged HSact hexasaccharides were AT affinity purified and sequenced by chemical and enzymatic degradations. The 3-O-sulfate-tagged HSact hexasaccharides exhibited the following structures, DeltaUA-[6-3H]GlcNAc6S-GlcUA-[6-3H]GlcNS3(35)S+/-6S-++ +IdceA2S-[6-3H]Glc NS6S. The underlined 6- and 3-O-sulfates constitute the most critical groups for AT binding in view of the fact that the precursor hexasaccharides possess all the elements for AT binding except for the 3-O-sulfate moiety. The presence of five potential AT-binding precursor hexasaccharides in all HSact precursor chains demonstrates for the first time the processive assembly of specific sequence in HS. The difference in structures around potential 3-O-sulfate acceptor sites in HSact and HSinact precursors suggests that these precursors might be generated by different concerted assembly mechanisms in the same cell. This study permits us to understand better the nature of the HS biosynthetic pathway that leads to the generation of specific saccharide sequences. (+info)
(5/3500) Desulfocella halophila gen. nov., sp. nov., a halophilic, fatty-acid-oxidizing, sulfate-reducing bacterium isolated from sediments of the Great Salt Lake.
A new halophilic sulfate-reducing bacterium, strain GSL-But2T, was isolated from surface sediment of the Southern arm of the Great Salt Lake, UT, USA. The organism grew with a number of straight-chain fatty acids (C4-C16), 2-methylbutyrate, L-alanine and pyruvate as electron donors. Butyrate was oxidized incompletely to acetate. Sulfate, but not sulfite or thiosulfate, served as an electron acceptor. Growth was observed between 2 and 19% (w/v) NaCl with an optimum at 4-5% (w/v) NaCl. The optimal temperature and pH for growth were around 34 degrees C and pH 6.5-7.3, respectively. The generation time under optimal conditions in defined medium was around 28 h, compared to 20 h in complex medium containing yeast extract. The G+C content was 35.0 mol%. 16S rRNA gene sequence analysis revealed that strain GSL-But2T belongs to the family Desulfobacteriaceae within the delta-subclass of the Proteobacteria and suggested that strain GSL-But2T represents a member of a new genus. The name Desulfocella halophila gen. nov., sp. nov. is proposed for this organism. The type strain of D. halophila is strain GSL-But2T (= DSM 11763T = ATCC 700426T). (+info)
(6/3500) Improved antibody detection by the use of range expansion and longer filter wavelength in a low ionic strength-protamine sulphate Auto-Analyzer system.
Range expansion, achieved by insertion of a variable resistance between the colorimeter and the recorder together with the use of 550 nm colorimeter filters, has resulted in markedly improved sensitivity for antibody detection, and improved sample identification, in a low ionic strength-protamine sulphate (LISPS) system. Range expansion also permits a lower concentration of red cells to be used, thus economizing on fully typed cells. Glycerol stored frozen cells were found to be only slightly less sensitive than fresh cells in this system. (+info)
(7/3500) The localisation of 2-carboxy-D-arabinitol 1-phosphate and inhibition of Rubisco in leaves of Phaseolus vulgaris L.
A recent controversial report suggests that the nocturnal inhibitor of Rubisco, 2-carboxy-D-arabinitol 1-phosphate (CAIP), does not bind to Rubisco in vivo and therefore that CA1P has no physiological relevance to photosynthetic regulation. It is now proved that a direct rapid assay can be used to distinguish between Rubisco-bound and free CA1P, as postulated in the controversial report. Application of this direct assay demonstrates that CA1P is bound to Rubisco in vivo in dark-adapted leaves. Furthermore, CA1P is shown to be in the chloroplasts of mesophyll cells. Thus, CA1P does play a physiological role in the regulation of Rubisco. (+info)
(8/3500) Anaerobic oxidation of o-xylene, m-xylene, and homologous alkylbenzenes by new types of sulfate-reducing bacteria.
Various alkylbenzenes were depleted during growth of an anaerobic, sulfate-reducing enrichment culture with crude oil as the only source of organic substrates. From this culture, two new types of mesophilic, rod-shaped sulfate-reducing bacteria, strains oXyS1 and mXyS1, were isolated with o-xylene and m-xylene, respectively, as organic substrates. Sequence analyses of 16S rRNA genes revealed that the isolates affiliated with known completely oxidizing sulfate-reducing bacteria of the delta subclass of the class Proteobacteria. Strain oXyS1 showed the highest similarities to Desulfobacterium cetonicum and Desulfosarcina variabilis (similarity values, 98.4 and 98.7%, respectively). Strain mXyS1 was less closely related to known species, the closest relative being Desulfococcus multivorans (similarity value, 86.9%). Complete mineralization of o-xylene and m-xylene was demonstrated in quantitative growth experiments. Strain oXyS1 was able to utilize toluene, o-ethyltoluene, benzoate, and o-methylbenzoate in addition to o-xylene. Strain mXyS1 oxidized toluene, m-ethyltoluene, m-isoproyltoluene, benzoate, and m-methylbenzoate in addition to m-xylene. Strain oXyS1 did not utilize m-alkyltoluenes, whereas strain mXyS1 did not utilize o-alkyltoluenes. Like the enrichment culture, both isolates grew anaerobically on crude oil with concomitant reduction of sulfate to sulfide. (+info)