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991.
I order to study the time-course of myeloperoxidase (MPO) and eosinophil cationic protein (ECP) as parameters for monitoring inflammation in cystic fibrosis (CF), we investigated ten patients during both a 14-day intravenous antibiotic treatment and a corresponding self control. Modified Shwachman-Kulczycki score improved significantly (p < 0.008), C-reactive protein (CRP) levels decreased significantly (p < 0.05) during antibiotic treatment, while in the control phase there were no significant differences. Lung function parameters did not change significantly during antibiotic treatment or control phase. Serum MPO concentration (p < 0.006) and peripheral blood neutrophil granulocyte counts (p < 0.04) decreased significantly during antibiotic treatment, but not during the control phase. Sentm ECP concentration showed a tendency to decrease during antibiotic treatment, but this failed to reach significance. In general, sputum concentrations of MPO and ECP Were 500- to 1000-fold higher than in serum. However, neither MPO nor ECP in sputum showed a significan variation over time during antibiotic treatment or control phase. From our data we conclude that: (1) measurements of MPO, neutrophils and CRP in peripheral blood do correlate with clinical parameters such as the modified Shwachman-Kulczycki score; (2) neutrophils and MPO seem to reflect inflammatory changes induced by antibiotic treatment; (3) eosinophils may play a role in CF by an enhanced 'releasability' and (4) Sputum measurements of mediators of inflammation cannot be recommended.  相似文献   
992.
Shoot regeneration after prescribed burning or following the freezing temperatures of winter was monitored for nineteen heathland species present in an Arctostaphyleto-Callunetum community in northeast Scotland. Species whose renewal buds were near the surface of the ground started to grow earlier in the spring than species with renewal buds above the surface, but grouping species according to the position of their renewal bud (i.e. their life-form) did not account for all of the interspecific variation apparent. In the case of shoot regeneration after fire, species whose renewal buds were destroyed by fire because they were above-ground started to regenerate about the same time as species with belowground buds, protected from fire, but reached their maximum frequency of occurrence later. Grouping species by life-form was of limited value as a means of interpreting this interspecific variation in the timing of shoot regeneration after fire. It would be unwise to use plant life-form as the sole basis for interpreting or predicting a species' response to temperature stress when extreme temperatures occur regularly, as they do in heathland. The possible use of other plant traits to interpret and predict interspecific variation in the regeneration rate of heathland plants is discussed.Nomenclature follows Tutin et al. (1964–1980) for vascular plants. Acknowledgements. The Nature Conservancy Council and Mr J. J. Humphries kindly allowed Dinnet Moor to be used for the work presented here. One of us (RJR) received financial support for field work from the Natural Sciences and Engineering Research Council of Canada.  相似文献   
993.
Changes of algal biomass, as carbon, cell numbers and volumewere determined for phytoplankton of Lake Constance suspendedin situ in 2 l glass bottles. Phytoplankton placed at the 6%surface penetrating light level (photosynthetically availableradiation) were close to the compensation depth for growth estimatedas total particulate carbon and total cell volumes. Cell countsof individual alga] species however, showed appreciable growthof diatoms offset by the decline of flagellates. Bottles suspendedat two shallower depths in a separate experiment showed somegrowth of all species and indicated a vertical niche separationof growth of Rhodomonas minuta Skuja and R. lens Dascher andRuttner in accordance with their vertical distribution. *This paper is the result of a study made at the Group for AquaticPrimary Productivity (GAP) First International Workshop heldat the Limnological Institute, University of Konstanz, in April1982.  相似文献   
994.
Using affinity-purified antibodies against mouse liver gap junction protein (26 K), discrete fluorescent spots were seen by indirect immunofluorescence labelling on apposed membranes of contiguous cells in several mouse and rat tissues: pancreas (exocrine part), kidney, small intestine (epithelium and circular smooth muscle), Fallopian tube, endometrium, and myometrium of delivering rats. No reaction was seen on sections of myocardium, ovaries and lens. Specific labelling of gap junction plaques was demonstrated by immunoelectron microscopy on ultrathin frozen sections through liver and the exocrine part of pancreas after treatment with gold protein A. Weak immunoreactivity was found on the endocrine part of the pancreas (i.e., Langerhans islets) after glibenclamide treatment of mice and rats, which causes an increase of insulin secretion and of the size as well as the number of gap junction plaques in cells of Langerhans islets. Furthermore, the affinity purified anti-liver 26 K antibodies were shown by immunoblot to react with proteins of similar mol. wt. in pancreas and kidney membranes. Taken together these results suggest that gap junctions from several, morphogenetically different tissues have specific antigenic sites in common. The different extent of specific immunoreactivity of anti-liver 26 K antibodies with different tissues is likely due to differences in size and number of gap junctions although structural differences cannot be excluded.  相似文献   
995.
We demonstrate that HEL, a human erythroleukemic cell line, has numerous megakaryocytic markers which were markedly enhanced following the addition of the inducers dimethyl sulfoxide or 12-O-tetradecanoylphorbol-13-acetate to the culture medium. Ultrastructural and cytochemical studies showed: (i) the presence of organelles morphologically resembling the platelet alpha-granules; and (ii) a peroxidase activity with the same characteristics as that specifically found in platelets. The platelet alpha-granule proteins (von Willebrand factor, platelet factor-4 and beta-thromboglobulin) were immunologically detected in the HEL cell cytoplasm and their amounts increased after induction. Of particular interest was the presence of platelet membrane proteins. A monoclonal antibody specific for glycoprotein Ib bound to HEL cells. Platelet membrane glycoproteins IIb and IIIa were identified on intact cells using specific antibodies in a binding assay or in cell lysates using either crossed immunoelectrophoresis or an immunoblotting procedure following SDS-polyacrylamide gel electrophoresis. Most HEL cells also expressed the platelet alloantigen PIA1. All of the platelet membrane proteins were present in higher amounts after induction. Glycophorin A, specific for the erythroid lineage, was also detected on HEL cells. Thus, while confirming the presence of erythroid markers, our studies provide evidence that the HEL cell line also expresses platelet antigens. As such, HEL cells represent a unique system with which to study the biosynthesis of platelet-specific proteins and glycoproteins.  相似文献   
996.
997.
Summary The effects of algal extract (AE) and yeast extract (YE) on the growth of Rhizobium japonicum were studied. YE concentrations above 0,1% inhibited growth. Increased concentrations of AE in growth medium increased bacterial yield up to an extract concentration of 1%. At 1% AE concentration maximum yields were achieved which were 3 times greater than those achieved with YE.  相似文献   
998.
The ultrastructural basis of endothelial cell surface functions   总被引:1,自引:0,他引:1  
U S Ryan  J W Ryan 《Biorheology》1984,21(1-2):155-170
Several enzymes, enzyme inhibitors, receptors and transport structures are situated on the luminal surface of endothelium. Some enzymes and transport systems are continuously active and, in effect, regulate the composition of blood moving downstream. Other components are latent. Their activities are not expressed in the absence of stimulus. Thus, endothelial cells injured by granulocytes or viral infection possess receptors for the Fc segment of IgG and for C3b, whereas normal endothelial cells do not. Both normal and injured endothelial cells express receptors for Clq. To visualize surface enzymes, inhibitors, receptors and transport structures, we have prepared surface replicas suitable for high resolution EM. The surface replication technique, coupled with immunocytochemical procedures, facilitates studies of the topographies of surface enzymes such as angiotensin converting enzyme (ACE) and carboxypeptidase N (CPN). In addition, the replicas provide unique views of the glycocalyx, a cell coating previously believed to be amorphous but now seen to be a highly organized carpet-work under which surface enzymes, receptors, etc are embedded. Given its content of fibronectin, the glycocalyx may be the Clq receptor. Cells treated with antibodies to ACE or CPN show disarrayed glycocalyces and bind Fc and C3b. Latency of the Fc and C3b receptors may be owing to the physical barrier provided by the glycocalyx. Apparently, damage to the glycocalyx creates conditions favoring binding of immune complexes, complement activation and intravascular coagulation with loss of gradients between blood and parenchyma. Whether some non-thrombogenic properties of endothelium require an intact glycocalyx deserves consideration as does the role of the glycocalyx in regulating microvascular permeability.  相似文献   
999.
Rat liver Golgi apparatus are shown to have a CMP-N-acetylneuraminate: N-acetylglucosaminide (alpha 2----6)-sialyltransferase which catalyzes the conversion of the human milk oligosaccharide LS-tetrasaccharide-a (NeuAc alpha 2----3Gal beta 1---- 3GlcNAc beta 1----3Gal beta 1----4Glc) to disialyllacto -N- tetraose containing the terminal sequence: (formula: see text) found in N-linked oligosaccharides of glycoproteins. The N-acetylglucosaminide (alpha 2----6)-sialyltransferase has a marked preference for the sequence NeuAc alpha 2----3-Gal beta 1---- 3GlcNAc as an acceptor substrate. Thus, the order of addition of the two sialic acids in the disialylated structure shown above is proposed to be first the terminal sialic acid in the NeuAc alpha 2----3Gal linkage followed by the internal sialic acid in the NeuAc alpha 2---- 6GlcNAc linkage. Sialylation in vitro of the type 1 branches (Gal beta 1---- 3GlcNAc -) of the N-linked oligosaccharides of asialo prothrombin to produce the same disialylated sequence is also demonstrated.  相似文献   
1000.
The uncoupling-like effect of fatty acids [ Scholz , R., Schwabe , U., and Soboll , S. (1984) Eur. J. Biochem. 141, 223-230] was further substantiated in experiments with perfused rat livers by two ways: firstly the kinetics of changes in metabolic rates (oxygen consumption, ketogenesis, fatty acid oxidation) were analysed; secondly subcellular contents of adenine nucleotides and pH gradients across the mitochondrial membrane were determined following fractionation of freeze-fixed and dried tissues in non-aqueous solvents. The following results were obtained. The relaxation kinetics of the increase in oxygen consumption following fatty acid infusion revealed two components, a rapid one with a half-time around 10 s and a slow one with a half-time of more than 100 s. The rapid component was similar to the kinetics of fatty acid oxidation (ketogenesis and 14CO2 production from labelled fatty acids) whereas the half-time of the slow component was in the range of half-times observed with the increase in oxygen consumption following addition of carbonylcyanide p-trifluoromethoxyphenylhydrazone. In the presence of fatty acids, the cytosolic ATP concentrations and ATP/ADP ratios decreased, whereas the corresponding parameters for the mitochondrial space were either increased (oleate) or decreased (octanoate). The effects of oleate were dependent on the albumin concentrations in the perfusate. The normally large difference between cytosolic and mitochondrial ATP/ADP ratios became smaller. Similar observations were obtained with uncoupling agents. The pH gradient across the mitochondrial membrane as calculated from the subcellular distribution of 5,5 dimethyl[2-14C]oxazolidine-2,4-dione was inversed following the addition of both carbonylcyanide p-trifluoromethoxyphenylhydrazone and fatty acids, i.e. the mitochondrial matrix became more acidic than the cytosol. The pH gradient was not affected when oleate was added in the presence of high albumin concentrations. The data support the hypothesis that the increase in hepatic oxygen consumption due to octanoate or oleate is, in part, caused by a mechanism similar to uncoupling of oxidative phosphorylation. This mechanism seems not to be an artifact of isolated systems; it may be of physiological importance for processes in which reducing equivalents are removed independently of the ATP demand of the hepatocyte.  相似文献   
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