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1.
Summary Three acidic polysaccharide (AP) fractions and the prostaglandin-like substances (PLS) isolated fromP. acnes were investigated regarding their chemotactic activities on polymorphonuclear leukocytes. Both AP's and PLS induced a significant chemotactic response, which suggests their involvement in inflammatory acne vulgaris.  相似文献   

2.
Summary The prostaglandin-like substances (PLS) isolated fromP. acnes were investigated by reversed phase chromatography and gas chromatography-mass spectrometry. These analyses demonstrated that PLS were not identical with PGE2, which supports a concept of PLS as a potential mediator of the inflammatory process in acne vulgaris.  相似文献   

3.
Summary The activity spectrum of prostaglandin-like substances (PLS) fromP. acnes was investigated with cascade superfusion technique and by platelet aggregation assay. The biological activity of PLS resembles that of PGI2: both relax bovine coronary artery, rabbit mesentric and coeliac arteries; both contract the rat stomach strip as well as both typically inhibit spontaneous movements of isolated guinea pig ileum. Also, similarly to PGI2, PLS inhibits platelet aggregation regardless the inducer used. However, PLS possesses a specific antiaggregatory pattern on platelet, which indicates that these compounds are not indentical with primary prostaglandins or PGI2.  相似文献   

4.
The prostaglandin-like substances (PLS) from Propionibacterium acnes increased the ovarian tissue levels of cyclic AMP (cAMP) approximately 2-fold. The lipid material extracted from P. acnes thus behaved like PG's of the E-type, and since it is unlikely that other known stimulators of the ovarian cAMP system can be present in the bacterial lipid fraction, these experiments give further evidence in favour of the occurrence of PLS in P. acnes.  相似文献   

5.
Summary The present study demonstrates a powerful vasoconstrictor activity of prostaglandin-like substances (PLS), extracted fromP. acnes, on human blood vessels. PLS is about equipotent to PGE2 in its effect on human umbilical vessels, but the contractile response pattern is different. PLS therefore seems to have specific and different physiological characteristics.  相似文献   

6.
The biological activity of a lipid fraction extracted from P. acnes was tested on isolated smooth muscle strips from the human utero-tubal junction. The bioassay experiments support the concept that prostaglandin-like substances (PLS) occur in P. acnes. However, in the bioassay system used, the effect of PLS was different from that of PGF2 alpha and PGI2 but similar, although not identical, to that of arachidonic acid and PGE2.  相似文献   

7.
Summary The prostaglandin-like substances (PLS) fromPropionibacterium acnes increased the ovarian tissue levels of cyclic AMP (cAMP) approximately 2-fold. The lipid material extracted fromP. acnes thus behaved like PG's of the E-type, and since it is unlikely that other known stimulators of the ovarian cAMP system can be present in the bacterial lipid fraction, these experiments give further evidence in favour of the occurrence of PLS inP. acnes.  相似文献   

8.
Mutations in the human TMEM16E (ANO5) gene are associated both with the bone disease gnathodiaphyseal dysplasia (GDD; OMIM: 166260) and muscle dystrophies (OMIM: 611307, 613319). However, the physiological function of TMEM16E has remained unclear. We show here that human TMEM16E, when overexpressed in mammalian cell lines, displayed partial plasma membrane localization and gave rise to phospholipid scrambling (PLS) as well as non-selective ionic currents with slow time-dependent activation at highly depolarized membrane potentials. While the activity of wild-type TMEM16E depended on elevated cytosolic Ca2+ levels, a mutant form carrying the GDD-causing T513I substitution showed PLS and large time-dependent ion currents even at low cytosolic Ca2+ concentrations. Contrarily, mutation of the homologous position in the Ca2+-activated Cl? channel TMEM16B paralog hardly affected its function. In summary, these data provide the first direct demonstration of Ca2+-dependent PLS activity for TMEM16E and suggest a gain-of-function phenotype related to a GDD mutation.  相似文献   

9.
应用可见/近红外光谱技术对土壤有机质含量进行了定量分析和预测,为土壤肥力快速测定和评价提供依据.利用ASD FieldSpec 3 Hi-Res光谱仪对116份不同有机质含量的土壤样本进行光谱测量,系统分析了土壤有机质含量与350~2500 nm波段范围光谱反射率之间的关系.利用PLS和小波-BP神经网络对350~2500 nm整个波段范围和剔除水波段的光谱数据进行分析.两种建模方法的结果均表明剔除水波段的预测效果较好,其中,PLS模型预测的相关系数R为0.8416,均方根误差RMSEP为0.2848,相对分析误差RPD为1.7768,WT-BP神经网络模型预测的R为0.9167,RMSEP为0.2196,RPD为2.3043.预测结果表明,PLS模型可以对土壤有机质含量进行粗略估测,而BP神经网络可实现较精确的预测.  相似文献   

10.
Egg lipovitellins of Orchestia gammarella tested by electrophoresis on gels of different acrylamide concentrations, following the procedure of Hedrick and Smith (1968), display a migration pattern identical to that of proteins with molecular weights of congruent to 3.2 x 10(5) (lipovitellin I) and congruent to 5.5 x 10(5) (lipovitellin II) respectively. Since their molecular weight remains constant during embryogenesis, the changes of their relative mobility in disc gels indicates alterations in their ionic charges.  相似文献   

11.
The 4-amino 5-alkyl-sulfone substituted orthoanisamides can be distinguished from their non-aminated homologues (sultopride) or sulfamoyl homologues (sulpride) mainly by the intensity of their anti-emetic effects with regard to apomorphine and their mode of action, either on hippocampic rhythms or on locomotor rhythms in the Cat.  相似文献   

12.
A significant antitumor activity of oridonin (1) and lasiokaurin (2), the kaurene-type diterpenoids of Isodon species, was shown by their i.p. injection to the test mice inoculated by Ehrlich ascites carcinoma. Enmein (8), compounds 9 and 3 were also active under larger dose. Subsequently, the relationship between their chemical structure and antitumor activity was investigated, and the activity of oridonin (1) and lasiokaurin (2) was rationalized in terms of their structural feature.  相似文献   

13.
14.
The technological sciences have at least six defining characteristics that distinguish them from the other sciences. They (1) have human-made rather than natural objects as their (ultimate) study objects, (2) include the practice of engineering design, (3) define their study objects in functional terms, (4) evaluate these study objects with category-specified value statements, (5) employ less far-reaching idealizations than the natural sciences, and (6) do not need an exact mathematical solution when a sufficiently close approximation is available. In combination, the six characteristics are sufficient to show that the technological sciences are neither branches nor applications of the natural sciences, but form a different group of sciences with specific characteristics of their own.  相似文献   

15.
M Sasaki  M Ono  S Asada  T Yoshida 《Experientia》1991,47(11-12):1229-1231
The discovery that drones of the Japanese honeybee (Apis cerana japonica) pollinate the oriental orchid (Cymbidium pumilum) is reported. Drones are attracted to the orchid flower aroma mainly during their mating flights in April through May. Some drones cluster on the flower racemes and others insert their heads deep into the flowers. Drones with pollinia on their scutellum visit other orchids, which facilitates pollination. Individual workers and swarming colonies are also strongly attracted by the flower aroma, but the allopatric western honeybee (Apis mellifera) is not attracted.  相似文献   

16.
In contrast with other antibacterial agents produced by bacteria, the bacteriocins of Gram -- bacteria (briefly: cins G--) are characterized by their primary lethal action, their inactivation by trypsin, their resistance to pH 2 (in the crude state) and insensitivity to DNase I after treatment with 7 M urea. Only 4 among 26 studied cins G + have the 4 above-cited properties and share most properties of cines G--.  相似文献   

17.
Two-component regulation systems (TCRSs) are the dominant type of signal transduction system in prokaryotes that are used to inform the cellular trancriptional machinery (and additional targets for regulation, like the motility apparatus) about actual changes in the extracellular physicochemical conditions. We now review their molecular structure and enzymatic characteristics, their mutual interactions and its implications, and their role in cellular physiology. Specific emphasis is placed on the ArcB/A system, a representative of the phosphorelay type of TCRS, and a key player in the adjustment of the cellular make-up of enterobacteria in response to alterations in the oxygen availability. Also some applied aspects of the TCRSs are discussed, i.e. their role as a target to develop new anti-bacterials and their application in biotechnology (or: 'synthetic biology').  相似文献   

18.
The so-called reactive oxygen species (ROS) are defined as oxygen-containing species that are more reactive than O(2) itself, which include hydrogen peroxide and superoxide. Although these are quite stable, they may be converted in the presence of transition metal ions, such as Fe(II), to the highly reactive oxygen species (hROS). hROS may exist as free hydroxyl radicals (HO·), as bound ("crypto") radicals or as Fe(IV)-oxo (ferryl) species and the somewhat less reactive, non-radical species, singlet oxygen. This review outlines the processes by which hROS may be formed, their damaging potential, and the evidence that they might have signaling functions. Since our understanding of the formation and actions of hROS depends on reliable procedures for their detection, particular attention is given to procedures for hROS detection and quantitation and their applicability to in vivo studies.  相似文献   

19.
Summary The capsular (K) and somatic (O) antigens of 72 Klebsiella-type strains were isolated and investigated with respect to their chemical composition and their serological behaviour. The K antigens were found to be acidic heteropolysaccharides carrying serological K specificity. The O antigens are lipopolysaccharides which are O group-specific.  相似文献   

20.
The complexity of mitogen-activated protein kinases (MAPKs) made simple   总被引:4,自引:0,他引:4  
The mitogen-activated protein kinase (MAPK) pathways are known to be involved in various processes of growth, differentiation and cell death. In spite of their ubiquitous presence and seemingly enormous cross-talk with each other, their action is very specific. This review deals with various aspects of the three different MAPK pathways (ERK, p38 and JNK) and how their specificity is brought about. Received 1 April 2008; received after revision 18 June 2008; accepted 18 June 2008  相似文献   

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