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971.
By binding SIRPalpha or calreticulin/CD91, lung collectins act as dual function surveillance molecules to suppress or enhance inflammation 总被引:24,自引:0,他引:24
Surfactant proteins A and D (SP-A and SP-D) are lung collectins composed of two regions, a globular head domain that binds PAMPs and a collagenous tail domain that initiates phagocytosis. We provide evidence that SP-A and SP-D act in a dual manner, to enhance or suppress inflammatory mediator production depending on binding orientation. SP-A and SP-D bind SIRPalpha through their globular heads to initiate a signaling pathway that blocks proinflammatory mediator production. In contrast, their collagenous tails stimulate proinflammatory mediator production through binding to calreticulin/CD91. Together a model is implied in which SP-A and SP-D help maintain a non/anti-inflammatory lung environment by stimulating SIRPalpha on resident cells through their globular heads. However, interaction of these heads with PAMPs on foreign organisms or damaged cells and presentation of the collagenous tails in an aggregated state to calreticulin/CD91, stimulates phagocytosis and proinflammatory responses. 相似文献
972.
Ryan U Xiao L Read C Zhou L Lal AA Pavlasek I 《Applied and environmental microbiology》2003,69(7):4302-4307
Isolates of Cryptosporidium from the Czech Republic were characterized from a variety of different hosts using sequence and phylogenetic analysis of the 18S ribosomal DNA and the heat-shock (HSP-70) gene. Analysis expanded the host range of accepted species and identified several novel genotypes, including horse, Eurasian woodcock, rabbit, and cervid genotypes. 相似文献
973.
Habitat Degradation of Rhinopithecus bieti in Yunnan, China 总被引:3,自引:0,他引:3
Wen Xiao Wei Ding Liang-Wei Cui Ru-Liang Zhou Qi-Kun Zhao 《International journal of primatology》2003,24(2):389-398
Black-and-white snub-nosed monkeys (Rhinopithecus bieti) are endemic to the Trans-Himalayas in Northwest Yunnan and Southeast Tibet between the upper Yangtze and Mekong Rivers. Based on field surveys and previous reports, we identified the dark-coniferous forest, the mixed coniferous and broadleaf forest, and oak patches as suitable habitats (SH) for the monkeys. Summer grazing lands (SGL), which were made by local people cutting and burning the dark-coniferous forest at the high altitude belt, replaced SH. To have a general view of the status of the SH in Yunnan, we estimated the areas of SH and SGL from satellite images in 1997, and compared with areas estimated from aerial photo-based maps (ca. 1958). The work resulted in: 1) the area of SH was 4,169 km2 in 1997; 2) SGL was 1,923 km2; 3) during the past 40 years, the area of SH decreased by 31% (1,887 km2), and SGL increased by 204% (1,291 km2); and 4) the mean size of forest patches decreased from 15.6 to 5.4 km2. In addition, the area of SGL is positively correlated to local human population (R2 0.53), implying that the reduction and fragmentation of habitat for Rhinopithecus bieti is a result of population growth of humans, who mostly employ traditional modes of production. Only 11 monkey groups remained in the changing habitat. Considering that forests at lower elevation were also encroached upon by farmlands in a similar way, the forest ecosystem is highly threatened. The destruction will continue unless there is a change in the mode of production in the region. 相似文献
974.
Teng XW Wang SW Davies NM 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2003,796(2):225-231
A simple, rapid and sensitive high-performance liquid chromatographic method was developed for determination of ibuprofen, (+/-)-(R, S)-2-(4-isobutylphenyl)-propionic acid, enantiomers in rat serum. Serum (0.1 ml) was extracted with 2,2,4-trimethylpentane/isopropanol (95:5, v/v) after addition of the internal standard, (S)-naproxen, and acidification with H(2)SO(4). Enantiomeric resolution of ibuprofen was achieved on ChiralPak AD-RH column with ultraviolet (UV) detection at 220 nm without interference from endogenous co-extracted solutes. The calibration curve demonstrated excellent linearity between 0.1 and 50 microg/ml for each enantiomer. The mean extraction efficiency was >92%. Precision of the assay was within 11% (relative standard deviation (R.S.D.)) and bias of the assay was lower than 15% at the limit of quantitation (0.1 microg/ml). The assay was applied successfully to an oral pharmacokinetic study of ibuprofen in rats. 相似文献
975.
Determination of vertilmicin in rat serum by high-performance liquid chromatography using 1-fluoro-2,4-dinitrobenzene derivatization 总被引:2,自引:0,他引:2
Zhou M Wei G Liu Y Sun Y Xiao S Lu L Liu C Zhong D 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2003,798(1):43-48
A procedure for the high-performance liquid chromatographic determination of vertilmicin in rat serum was described using pre-column derivatization. The serum proteins were precipitated with acetonitrile and vertilmicin in the supernatant was derivatized with 1-fluoro-2,4-dinitrobenzene. Etimicin was selected as the internal standard. The mobile phase consisted of methanol--20mM ammonium acetate (80:20, v/v), and flow-rate was 0.9 ml/min. Ultraviolet detection was set at 365 nm. The reaction products were chromatographed on a C(18) column kept at 40 degrees C. A good linearity was found in the range of 0.5-250 microg/ml. Both intra- and inter-day precisions of vertilmicin, expressed as the relative standard deviation, were less than 7.4%. Accuracy, expressed as the relative error, ranged from -0.1 to 3.6%. The mean absolute recovery of vertilmicin at three different concentrations was 92.5%. Serum volumes of 50 microl were sufficient for the determination of vertilmicin. The method was proved suitable for the pharmacokinetic study of vertilmicin in rats. 相似文献
976.
An on-line and continuous technique based on electric cell-substrate impedance sensing (ECIS) was developed for measuring the concentration and time response function of fibroblastic V79 cells exposed to mercury chloride and 1,3,5-trinitrobenzene (TNB). Attachment, spreading and proliferation of V79 fibroblastic cells cultured on a microarray of small gold electrodes precoated with fibronectin were detected as resistance changes. The response function was derived to reflect the resistance change as a result of cell attachment, spreading, mitosis and cytotoxicity effect. Exposure of V79 cells to mercury chloride or TNB led to alterations in cell behavior, and therefore, chemical cytotoxicity was easily screened by measuring the response function of the attached and spread cells in the presence of inhibitor. The half inhibition concentration, the required concentration to achieve 50% inhibition, was obtained from the response function to provide information about cytotoxicity during the course of the assay. A simple mathematical model was developed to describe the responses of ECIS that were related to the attachment, spreading, and proliferation of V79 fibroblastic cells. The novel results of this paper are mainly characterized by the systematic study of several parameters including the cell number, detection limit, sensor sensitivity, and cytotoxicity, and they may motivate further research and study of ECIS sensors. 相似文献
977.
Yulan?Xiao Yee?Hin?Lok Toyoki?KozaiEmail author 《In vitro cellular & developmental biology. Plant》2003,39(2):186-192
Summary Explants of sugarcane, a C4 plant, were cultured in vitro for 18d on Floridalite (a solid cube consisting of vermiculite and cellulose fibers) used as supporting material with sugar-free
Murashige and Skoog liquid medium with double-strength KH2PO4, MgSO4, FeSO4, and Na2-EDTA in the vessel with enhanced natural ventilation. CO2 concentration in the culture room was kept at 1500 μmol mol−1 (four times the atmospheric CO2 concentration) during the photoperiod. A factorial experiment was designed with two levels of photosynthetic photon flux
(PPF) and three levels of N (number of air exchanges of the vessel). The results were compared with those in the control treatment (photomixotrophic
culture using sugar-containing agar medium under low PPF and low N). PPF and N showed significant positive effects on the growth of sugarcane plantlets in vitro. In the photoautotrophic (using sugar-free medium) treatments with relatively high PPF (200–400 μmol m−2 s−1) and high N (2–10 h−1), the growth of plantlets was four to seven times greater than that in the control. Also, the culture period for multiplication
and rooting was shortened from 30 d in the control to 18 d or less in the photoautotrophic, high PPF, and high N treatments. Use of porous supporting material in photoautotrophic treatments promoted rooting and plantlet growth significantly. 相似文献
978.
Guarino MP Xiao ZL Biancani P Behar J 《American journal of physiology. Gastrointestinal and liver physiology》2003,285(6):G1189-G1197
H2O2 stimulates gallbladder muscle contraction and scavengers of free radicals through the generation of PGE2. Oxidative stress causes lipid peroxidation and generation of platelet-activating factor (PAF) or PAF-like lipids. The present studies therefore were aimed at determining whether either one induced by H2O2 mediates the increased generation of PGE2. Dissociated muscle cells of guinea pig gallbladder were obtained by enzymatic digestion. Both PAF-like lipids and PAF-induced muscle contraction was blocked by the PAF receptor antagonist CV-3988. This antagonist also blocked the increased PGE2 production caused by PAF-like lipids or PAF. Actions of PAF-like lipids were completely inhibited by indomethacin, but those of PAF were only partially reduced by indomethacin or by nordihydroguaiaretic acid and completely blocked by their combination. PAF-like lipids-induced contraction was inhibited by AACOCF3 (cystolic phospholipase A2 inhibitor), whereas the actions of PAF were blocked by MJ33 (secretory phospholipase A2 inhibitor). Receptor protection studies showed that pretreatment with PAF-like lipids before N-ethylmaleimide protected the contraction induced by a second dose of PAF-like lipids or PGE2 but not by PAF. In contrast, pretreatment with PAF protected the actions of PAF and PGE2 but not that of PAF-like lipids. Both PAF-like lipids and PAF-induced contractions were inhibited by anti-Galphaq/11 antibody and by inhibitors of MAPK and PKC. In conclusion, PAF-like lipids seem to activate a pathway different from that of PAF probably by stimulating a different PAF receptor subtype. 相似文献
979.
Preferential expression of cystein-rich secretory protein-3 (CRISP-3) in chronic pancreatitis 总被引:1,自引:0,他引:1
Liao Q Kleeff J Xiao Y Guweidhi A Schambony A Töpfer-Petersen E Zimmermann A Büchler MW Friess H 《Histology and histopathology》2003,18(2):425-433
BACKGROUND: Chronic pancreatitis (CP) is a progressive inflammatory process resulting in exocrine and endocrine pancreatic insufficiency in advanced stages. Cysteine-rich secretory protein (CRISP-3) has been identified as a defense-associated molecule with predominant expression in the salivary gland, pancreas and prostate. AIMS: In this study, we investigated CRISP-3 expression in normal pancreatic tissues, chronic pancreatitis tissues, pancreatic cancer tissues and pancreatic cancer cell lines, as well as in other gastrointestinal organs. MATERIALS AND METHODS: 15 normal pancreatic tissues, 14 chronic pancreatitis tissues and 14 pancreatic cancer tissues as well as three pancreatic cancer cell lines were analyzed. Moreover, hepatocellular carcinoma and esophageal, stomach and colon cancers were also analyzed together with the corresponding normal controls. RESULTS: CRISP-3 was expressed at moderate to high levels in chronic pancreatitis tissues and at moderate levels in pancreatic cancer tissues but at low levels in normal pancreatic tissues, and was absent in three pancreatic cancer cell lines. CRISP-3 expression was below the level of detection in all cancerous gastrointestinal tissues and in all normal tissues except 2 of 16 colon tissue samples. CRISP-3 mRNA signals and immunoreactivity were strongly present in the cytoplasm of degenerating acinar cells and in small proliferating ductal cells in CP tissues and CP-like lesions in pancreatic cancer tissues. In contrast, CRISP-3 expression was weak to absent in the cytoplasm of cancer cells as well as in acinar cells and ductal cells in pancreatic cancer tissues and normal pancreatic tissues. CONCLUSION: These results reveal that the distribution of CRISP-3 in gastrointestinal tissues is predominantly in the pancreas. High levels of CRISP-3 in acinar cells dedifferentiating into small proliferating ductal cells in CP and CP-like lesions in pancreatic cancer suggests a role of this molecule in the pathophysiology of CP. 相似文献
980.
Vinores SA Xiao WH Zimmerman R Whitcup SM Wawrousek EF 《Histology and histopathology》2003,18(3):797-810
IL-1beta is a pro-inflammatory agent associated with angiogenesis and increased vascular permeability. To determine whether IL-1beta elicits these responses through an upregulation of VEGF, transgenic mice that overexpress IL-1beta in the lens were evaluated at various time points for the localization of VEGF, the location and extent of blood-retinal barrier (BRB) breakdown, and the origin and extent of neovascularization (NV). In homozygous and heterozygous transgenic mice, but not controls, intense VEGF immunoreactivity was scattered throughout the retina at postnatal days 5-7 (P5-7), just after the onset of inflammatory cell infiltration. VEGF staining in the retina remained widespread, but weak from P9-15. Beginning at P15, the intensity of VEGF immunoreactivity achieved a second peak, which it maintained through adulthood. This peak coincided with significant retinal destruction due to massive inflammation. The onset of BRB breakdown coincided with the upregulation of VEGF (P5-7) and widespread BRB breakdown was demonstrated from about P9. From P9-12, aggregates of cells positive for Griffonia simplicifolia isolectin-B4, a marker for vascular endothelial cells, formed on the retinal surface. These cells migrated into the retina at P12-15 with the more superficial cells forming a network of vessels and the deeper cells remaining in small clusters, thus demonstrating that NV occurs much later than BRB breakdown. Non-transgenic FVB/N mice, which undergo retinal degeneration beginning at about P9, also demonstrate the latter peak of VEGF upregulation and the accompanying BRB breakdown, but not the early upregulation. VEGF immunostaining of transgenic and non-transgenic mouse retinas was eliminated by pre-incubation of the VEGF antibodies with VEGF peptide. The data suggest that the early peak of VEGF upregulation (P5-7) and its accompanying BRB breakdown is due to IL-1beta expression and is likely to be dependent on inflammatory cell infiltration. The latter peak appears to be related to retinal destruction. 相似文献