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1.
The detection of 5-lipoxygenase and cyclo-oxygenase products in sputum of patients with chronic bronchitis and bronchiectasis 总被引:1,自引:0,他引:1
Leukotrienes (LTs) and prostanoids (Ps) were detected in sputum of patients with chronic bronchitis and/or bronchiectasis (CB/B) using selective superfusion bioassay and radioimmunoassay (RIA) techniques. Analysis of sputum extracts showed a 4-fold increase in the level of LTB4 compared to the cysteinyl-containing LTs (LTC4/LTD4). The measurement of cyclo-oxygenase products (COPs) indicated relatively greater amounts of the vasodilator prostaglandin E2 (PGE2) and prostacyclin (PGI2) compared to the vasoconstrictor prostaglandin F2 alpha (PGF2 alpha) and thromboxane A2 (TxA2) agents (70:30% of total COPs respectively). The presence of eicosanoids (LTs and Ps) in sputum of patients with CB/B suggest that these biologically active substances may act as mediators of bronchoconstriction and inflammation in these diseases. 相似文献
2.
Isolation and culture of cells derived from human cerebral microvessels 总被引:10,自引:0,他引:10
Harry V. Vinters Susan Reave Penny Costello John P. Girvin Steven A. Moore 《Cell and tissue research》1987,249(3):657-667
Summary Microvessels were isolated from non-neoplastic human cerebral cortical fragments resected for treatment of intractable seizure disorder. The microvessels were incubated in modified Lewis medium with 20 or 30% fetal bovine serum. Within 1–2 weeks, two cell populations emerged from the isolates. One type of cells had polygonal morphology, showed density-dependent contact inhibition at confluence in vitro, showed lectin-binding characteristics of endothelium (but only moderate positivity for factor VIII antigen), demonstrated induction of -glutamyl trans-peptidase when exposed to astrocyte-conditioned media, and responded to insulin by a pronounced increase in DNA synthesis. The other variety of cells grew in vitro more slowly in irregular strands separated by clear zones, showed ultrastructural features of smooth muscle, and isoelectric focusing of cell proteins revealed the presence of smooth-musclespecific -isoactin. Both types of cells could be serially subcultured. The ability to isolate and grow the two cell types, tentatively identified as human cerebral microvascular endothelium and smooth muscle, may facilitate studies of human blood-brain barrier function as well as the pathogenesis of cerebral microangiopathies unique to the human brain.Funded by Canadian Heart Foundation, Heart and Stroke Foundation of Ontario and UCLA Biomedical Research Support Grant 相似文献
3.
Citrate oxidation by rat ventral prostate was reduced by castration and increased by testosterone administration. Similarly, the mitochondrial aconitase activity was decreased by castration; whereas cytosol aconitase was unaffected. The rate of citrate oxidation is extremely low in prostate. Castration also decreased mitochondrial aspartate aminotransferase activity while having no effect on the cytosol isoenzyme. Testosterone markedly stimulated the net production of citrate from aspartate plus glutamate by prostate mitochondria. These studies support the proposal that aspartate is a major source of oxalacetate for citrate production, and that a "glutamate-aspartate-citrate" pathway may be functional in prostate mitochondria. In addition, testosterone can regulate citrate production by a specific effect on mitochondrial aspartate aminotransferase activity. Testosterone also regulates the flux of citrate through the Krebs cycle, but this represents only a small proportion of the citrate accumulated. These conditions would be consistent with the function of prostate epithelium in accumulating and secreting citrate. 相似文献
4.
5.
T E Dever C E Costello C L Owens T L Rosenberry W C Merrick 《The Journal of biological chemistry》1989,264(34):20518-20525
Amino acid sequencing of a large number of chemical and enzymatic cleavage products of elongation factor 1 alpha purified from rabbit reticulocyte has identified seven post-translationally modified residues. Five of the modifications are methylations of lysine residues yielding dimethyllysine at residues 55 and 165 and trimethyllysine at residues 36, 79, and 318. The two remaining post-translational modifications involve the addition of ethanolamine to glutamic acid residues 301 and 374, as reported previously (Rosenberry, T. L., Krall, J. A., Dever, T. E., Haas, R., Louvard, D., and Merrick, W. C. (1989) J. Biol. Chem. 264, 7096-7099). Fast atom bombardment mass spectrometry and fast atom bombardment tandem mass spectrometry have been used to analyze peptides containing these modified residues. The analyses have determined that glycerylphosphorylethanolamine has been attached to the glutamic acid residues. An analysis of the amino acid sequence surrounding each of the three types of modification has indicated no similarities. Therefore, it seems likely that the modifying enzymes do not recognize a specific amino acid sequence but rather the three-dimensional presentation of either amino or carboxyl residues in the elongation factor 1 alpha structure. 相似文献
6.
An assay is described for the determination of the radioactive purity of [14C]oxalic acid preparations and the quantity of [14C]oxalic acid in biological samples. In this method oxalate decarboxylase is used to convert oxalate to formate and CO2. The entire procedure is carried out in a scintillation vial. The 14CO2 released in the enzymic reaction is allowed to diffuse off in a fume hood following acidification. Scintillation fluid is added to reacted and unreacted vials and the radioactivity measured. The loss of radioactivity from the reacted versus the unreacted vials provides the quantity of evolved 14CO2. This value is equal to 50% of the [14C]-oxalate (dpm) present. The radioactive purity of four preparations of [U-14C]oxalic acid was 99.0% while a fifth batch had a purity of 88%. A single batch of [U-14C]oxalic acid had a radioactive purity of 99.0% following storage of an aqueous solution, at -20 degrees C for 7 years. Recovery of [14C]oxalic acid from rat fecal extracts was 101.3%. Eight replicate analyses of a [U-14C]oxalic acid preparation gave a coefficient of variation of 0.3%. Following subcutaneous infusion of [U-14C]oxalic acid to rats, 100.2 +/- 2.9%, mean +/- SD, of the 14C in fecal extracts was present as [14C]oxalic acid (n = 10). The procedure provides a rapid, sensitive, and specific method to determine [14C]oxalic acid. It avoids the time consuming and inconvenient procedure for trapping and counting the evolved 14CO2. The approach used to determine the evolved 14CO2 may find application in other radiochemical methods that require its measurement. 相似文献
7.
Subcellular localization of Aleutian mink disease parvovirus proteins and DNA during permissive infection of Crandell feline kidney cells. 总被引:3,自引:3,他引:0 下载免费PDF全文
M B Oleksiewicz F Costello M Huhtanen J B Wolfinbarger S Alexandersen M E Bloom 《Journal of virology》1996,70(5):3242-3247
Confocal microscopy allowed us to localize viral nonstructural (NS) and capsid (VP) proteins and DNA simultaneously in cells permissively infected with Aleutian mink disease parvovirus (ADV). Early after infection, NS proteins colocalized with viral DNA to form intranuclear inclusions, whereas VP proteins formed hollow intranuclear shells around the inclusions. Later, nuclei had irregular outlines and were virtually free of ADV products. In these cells, inclusions of viral DNA with or without associated NS protein were embedded in cytoplasmic VP protein. These findings implied that ADV replication within an infected cell is regulated spatially as well as temporally. 相似文献
8.
Detecting non-neutral heterogeneity across a region of DNA sequence in the ratio of polymorphism to divergence 总被引:11,自引:4,他引:7
Natural selection, in the form of balancing selection or selective sweeps,
can result in a decoupling of the amounts of molecular polymorphism and
divergence. Thus natural selection can cause some areas of DNA sequence to
have greater silent polymorphism, relative to divergence between species,
than other areas. It would be useful to have a statistical test for
heterogeneity in the polymorphism to divergence ratio across a region of
DNA sequence, one that could identify heterogeneity greater than that
expected from the neutral processes of mutation, drift, and recombination.
The only currently available test requires that a region be arbitrarily
divided into sections that are compared with each other, and the
subjectivity of this division could be problematic. Here a test is proposed
in which runs of polymorphic and fixed sites are counted, where a "run" is
a set of one or more sites of one type preceded and followed by the other
type. The number of runs is smaller than otherwise expected if
polymorphisms are clumped together. By simulating neutral evolution and
comparing the observed number of runs to the simulations, a statistical
test is possible which does not require any a priori decisions about
subdivision.
相似文献
9.
Barrera Lawrence N. Ridley P. Matthew Bermejo-Rodriguez Camino Costello Eithne Perez-Mancera Pedro A. 《Journal of physiology and biochemistry》2023,79(1):193-204
Journal of Physiology and Biochemistry - Pancreatic ductal adenocarcinoma (PDAC) is the deadliest of the common cancers. A major hallmark of PDAC is an abundant and dense fibrotic stroma, the... 相似文献
10.
R W Heaton R J Guy B J Gray P J Watkins J F Costello 《BMJ (Clinical research ed.)》1984,289(6438):149-151
To investigate the role of neural pathways in the nonasthmatic response to eucapnic hyperventilation with below freezing air five diabetic patients with severe symptomatic autonomic neuropathy were studied. Their responses were compared with those shown by five diabetic patients without autonomic neuropathy and five non-diabetic controls. After bronchial provocation testing with cold air the diabetic patients with autonomic neuropathy did not show a significant fall in specific airways conductance (mean (SE) maximum percentage fall 2.0 (3)%), whereas conductance fell in the diabetic patients without neuropathy by 30.8 (2.0)% (p less than 0.001) and in the non-diabetic controls by 22.7 (4.6)% (p less than 0.02). In subjects who do not have asthma the bronchial response to cold air is mediated largely via neural mechanisms. 相似文献