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71.
Metastasis formation is a major clinical problem in cancer treatment, and no significant progress in the treatment of metastatic
spread has been made. This apparent lack of progress is partly caused by the absence of clinically relevant animal models
of meta stases. The binding of the lectin Helix pomatia agglutinin (HPA) has been associated with a poor prognosis in breast
and colon cancer patients. HPA-positive and -negative human breast and colon cancer cell lines were transplanted into severe
combined immunodeficient (SCID) mice. HPA-positive breast cancer cell lines (MCF-7 and T47D) metastasized in SCID mice, whereas
the HPA-negative ones (BT20, HS578T and HBL100) did not. The HPA-positive colon cancer cell line HT29 metastasized, while
the HPA-negative ones (COLO320DM, SW480 and SW620) did not. However, in two of eight SCID mice inoculated with the HPA-negative
colon cancer cell line, CACO2 metastatic deposits were found. Despite this exception, HPA binding is a good indicator of the
metastasis of human breast and colon cancer cells in SCID mice: 23 out of 26 HPA-positive cancers metastasized, as opposed
to only two out of 38 HPA-negative cancers. This experimental model is well suited for investigating the functional role of
carbohydrate residues recognized by HPA in breast and colon cancer metastasis.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
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Role of inhibition of nitric oxide production in monocrotaline-induced pulmonary hypertension 总被引:1,自引:0,他引:1
Mathew Rajamma; Gloster Elizabeth S.; Sundararajan T.; Thompson Carl I.; Zeballos Guillermo A.; Gewitz Michael H. 《Journal of applied physiology》1997,82(5):1493-1498
Mathew, Rajamma, Elizabeth S. Gloster, T. Sundararajan, Carl I. Thompson, Guillermo A. Zeballos, andMichael H. Gewitz. Role of inhibition of nitric oxide productionin monocrotaline-induced pulmonary hypertension. J. Appl. Physiol. 82(5): 1493-1498, 1997.Monocrotaline (MCT)-induced pulmonary hypertension (PH) isassociated with impaired endothelium-dependent nitric oxide(NO)-mediated relaxation. To examine the role of NO in PH,Sprague-Dawley rats were given a single subcutaneous injection ofnormal saline [control (C)], 80 mg/kg MCT, or the same doseof MCT and a continuous subcutaneous infusion of 2 mg · kg1 · day1of molsidomine, a NO prodrug (MCT+MD). Two weeks later, plasma NO3 levels, pulmonary arterialpressure (Ppa), ratio of right-to-left ventricular weights (RV/LV) toassess right ventricular hypertrophy, and pulmonary histology wereevaluated. The plasma NO3 level inthe MCT group was reduced to 9.2 ± 1.5 µM(n = 12) vs. C level of 17.7 ± 1.8 µM (n = 8; P < 0.02). In the MCT+MD group,plasma NO3 level was 12.3 ± 2.0 µM (n = 8). Ppa and RV/LV in theMCT group were increased compared with C [Ppa, 34 ± 3.4 mmHg(n = 6) vs. 19 ± 0.8 mmHg(n = 8) and 0.41 ± 0.01 (n = 9) vs. 0.25 ± 0.008 (n = 8), respectively;P < 0.001]. In the MCT+MDgroup, Ppa and RV/LV were not different when compared with C [19 ± 0.5 mmHg (n = 5) and 0.27 ± 0.01 (n = 9), respectively;P < 0.001 vs. MCT]. Medial wall thickness of lung vessels in the MCT group was increased comparedwith C [31 ± 1.5% (n = 9)vs. 13 ± 0.66% (n = 9);P < 0.001], and MDpartially prevented MCT-induced pulmonary vascular remodeling [22 ± 1.2% (n = 11);P < 0.001 vs. MCT and C].These results indicate that a defect in the availability of bioactive NO may play an important role in the pathogenesis of MCT-induced PH. 相似文献
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Production of Viscous Dextran-Containing Whey-Sucrose Broths by Leuconostoc mesenteroides ATCC 14935 下载免费PDF全文
Viscous broths were produced by growing Leuconostoc mesenteroides on a medium containing whey supplemented with sucrose. When combined with similarly produced xanthan-containing broths, a synergistic increase in viscosity was observed. 相似文献
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Summary We have used a combination of chemical labeling and detergent fractionation techniques to locate the divalent cation binding sites on the chloroplast membrane. We determined the Ca2+-binding properties of Triton X-100 subchloroplast particles. Photosystem II (TSFII) particles showed one binding site withn=8.4 moles-mg chl–1 andk
d
=20 m. Photosystem I (TSFI) particles contained two binding sites. The first had ann=1.5 moles-mg chl–1 andk
d
=4 m. The second had ann=9.6 moles-mg chl–1 andk
d
=160 m. We have previously shown (Prochaska & Gross,Biochim. Biophys. Acta
376:126, 1975) that the divalent cation binding sites could be blocked using a water-soluble carbodiimide plus a nucleophile. Chlorophylla fluorescence and lightscattering changes were affected at the same carbodiimide concentrations emphasizing the relationship between these processes. The carbodiimide-sensitive sites were found to be located on the Photosystem II particles. A direct correlation between the inhibition of calcium binding and the carbodiimide-mediated incorporation of a (14C)-nucleophile was observed upon varying such parameters as carbodiimide concentration, nucleophile concentration, pH, and time of reaction. The presence of CaCl2 during the carbodiimide plus nucleophile modification procedure decreased the incorporation of (14C)-nucleophile, emphasizing the competition of the CaCl2 and the modification reagents for some of the same sites. Sodium dodecylsulfate gel electrophoresis of chlorophyll protein aggregates suggested that the site of competition of the calcium chloride and the modification reagents was the light-harvesting chlorophylla/b protein. 相似文献