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481.
482.
483.
Studies on the anti-tumor efficacy of systemically administered recombinant tumor necrosis factor against several murine tumors in vivo 总被引:12,自引:0,他引:12
A Asher J J Mulé C M Reichert E Shiloni S A Rosenberg 《Journal of immunology (Baltimore, Md. : 1950)》1987,138(3):963-974
The anti-tumor activity of recombinant human tumor necrosis factor (rHTNF) was examined against four newly induced murine sarcomas (MCA-101, -102, -105, and -106) and a murine adenocarcinoma (MCA-38) transplanted s.c. into C57BL/6 mice. The serum half-life after a single i.v. injection of rHTNF was determined to be 30 +/- 2 min. Tumor-bearing mice were more susceptible to the toxic side effects of rHTNF than were normal mice. Forty-eight percent (41/86) of tumor bearing animals that received 10 micrograms rHTNF died within 48 hr after treatment compared with no deaths in 28 normal animals receiving this dose. Treatment of mice bearing either the MCA-101, -102, -105, or -106 sarcoma or the MCA-38 adenocarcinoma with rHTNF resulted in a marked necrosis of the central portion of each tumor within 24 hr. Animals bearing the weakly immunogenic tumors MCA-105, -106, and -38 experienced a reduction in average tumor area of 47% +/- 5, 46% +/- 6, and 37% +/- 11, respectively, by 3 to 4 days after treatment with rHTNF compared with pre-treatment values (p less than 0.001); increases of 79% +/- 11, 74% +/- 10, and 41% +/- 6 were seen in excipient-treated control animals over the same period. In contrast, animals bearing the non-immunogenic tumors MCA-101 and -102 experienced little if any decrease in tumor area at the doses of rHTNF used. rHTNF failed to mediate cures in animals bearing MCA-38, -101, or -102. In contrast, 67 and 28% of animals bearing MCA-105 and -106, respectively, which received 6 to 10 micrograms rHTNF were cured. Likewise, animals bearing MCA-105 and -106 sarcomas treated with 6 to 10 micrograms rHTNF had significantly increased survival compared with excipient-treated control animals. In contrast, no significant difference in mean survival was observed between excipient and rHTNF treated animals bearing MCA-38, -101, or -102. Histologically, the necrotic response of immunogenic MCA-106 and non-immunogenic MCA-102 tumors to systemically administered rHTNF was very similar. These two tumors differed morphologically, however, by the greater degree of chronic inflammation that was present at the periphery of the MCA-106 tumor in comparison with the MCA-102. By 72 hr after rHTNF administration, the sites of regressed MCA-106 tumors were replaced by a heterogeneous population of inflammatory cells and tumor cell "ghosts".(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
484.
Summary Reduced productivity due to soil acidity has been demonstrated with subterranean clover and wheat in many parts of Australia.
Nodulation in clover appears to be more sensitive to low pH than growth of the host plant in the presence of adequate mineral
nitrogen. Low pH is associated with aluminium toxicity in a number of species and nodulation in clover is more sensitive than
growth of the host plant to Al. Decrease in soil pH is associated with significant increases in exchangeable Al. The breeding
of Al tolerant wheats in Australia involves a backcross programme utilizing the transfer of tolerance from the Brazilian cultivar
Carazinho. 相似文献
485.
W. Powell E. M. Borrino M. J. Allison D. W. Griffiths M. J. C. Asher J. M. Dunwell 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1986,72(5):619-626
Summary From an F1 hybrid between the two barley (Hordeum vulgare L.) cultivars Golden Promise and Mazurka a series of doubled haploid (DH) lines were generated both from microspores by anther culture and from immature zygotic embryos after hybridization withH. bulbosum. The DH lines from both sources were used to monitor the segregation of the five major genes, rachilla hair length, DDT susceptibility, height, C hordein polymorphism and mildew resistance. Whereas the microspore-derived samples showed significant departures from the expected 11 ratio for three of the five genes, theH. bulbosum lines showed deviation for only one gene. Analysis of linkage data also showed differences between the two series of DH lines. Cytogenetic analysis revealed a mean chiasma frequency in theH. bulbosum lines which was very similar to the F1 hybrid. In contrast, four of the ten microspore derived lines examined showed a reduced chiasma frequency. One showed evidence of translocation heterozygosity. 相似文献
486.
Summary Two fertilizer experiments were conducted in the field at Beerwah, South-East Queensland. In the first experiment leaf nitrogen concentrations, and the yield of ginger shoots and rhizomes at early and late harvests increased both with the total amount of nitrogen applied up to the highest level studied (336 kg N/ha as ammonium nitrate) and with the number of applications making up the total. At all levels of nitrogen application the apparent recovery of fertilizer nitrogen increased in the order 1 application <2 applications <4 applications. At 33.6 kg N/ha there appeared to be no advantage in dividing the total N applied into more than 4 applications but the data suggested higher recoveries of nitrogen with 8 applications at 112 kg N/ha and 336 kg N/ha. In the second experiment, ammonium nitrate, urea, and ammonium sulphate were found to be equally effective as nitrogen fertilizers for ginger when applied at equal rates of nitrogen per hectare. However, in terms of cost effectiveness they rated in the order urea > ammonium nitrate > ammonium sulphate.All three nitrogen sources acidified the soil, the decrease in soil pH during the growing season increasing with increasing rate of application. In Experiment 1 split applications, which increased the recovery of applied nitrogen in the crop, also increased the extent of acidification. In Experiment 2 ammonium sulphate tended to be more strongly acidifying than the other fertilizers but the difference was statistically significant only at the highest rate of nitrogen application. Because of the strong effects of nitrogen supply on both yield and soil pH, the highest yields were associated with end-of-season pH values below 5.0. 相似文献
487.
488.
Role of Sulfate Reduction Versus Methanogenesis in Terminal Carbon Flow in Polluted Intertidal Sediment of Waimea Inlet, Nelson, New Zealand 总被引:9,自引:9,他引:0
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An investigation of the terminal anaerobic processes occurring in polluted intertidal sediments indicated that terminal carbon flow was mainly mediated by sulfate-reducing organisms in sediments with high sulfate concentrations (>10 mM in the interstitial water) exposed to low loadings of nutrient (equivalent to <102 kg of N · day−1) and biochemical oxygen demand (<0.7 × 103 kg · day−1) in effluents from different pollution sources. However, in sediments exposed to high loadings of nutrient (>102 kg of N · day−1) and biochemical oxygen demand (>0.7 × 103 kg · day−1), methanogenesis was the major process in the mediation of terminal carbon flow, and sulfate concentrations were low (≤2 mM). The respiratory index [14CO2/(14CO2 + 14CH4)] for [2-14C]acetate catabolism, a measure of terminal carbon flow, was ≥0.96 for sediment with high sulfate, but in sediments with sulfate as little as 10 μM in the interstitial water, respiratory index values of ≤0.22 were obtained. In the latter sediment, methane production rates as high as 3 μmol · g−1 (dry weight) · h−1 were obtained, and there was a potential for active sulfate reduction. 相似文献
489.
Carbon and Electron Flow in Mud and Sandflat Intertidal Sediments at Delaware Inlet, Nelson, New Zealand 总被引:26,自引:22,他引:4
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Douglas O. Mountfort Rodney A. Asher Edward L. Mays James M. Tiedje 《Applied microbiology》1980,39(4):686-694
An investigation of carbon and electron flow in mud and sandflat intertidal sediments showed that the terminal electron acceptor was principally sulfate and that the carbon flow was mainly to CO2. Studies with thin layers of sediment exposed to H2 showed that methane production accounted for virtually none of the H2 utilized, whereas sulfate reduction accounted for a major proportion of the gas uptake. At all sampling sites except one (site B7), rates of methanogenesis were low but sulfate concentrations in the interstitial water were high (>18 mM). At site B7, the sulfate concentrations declined with depth from 32 mM at 2 cm to <1 mM at 10 cm or below, and active methanogenesis occurred in the low-sulfate zone. Sulfate-reducing activity at this site initially decreased and then increased with depth so that elevated rates occurred in both the active and nonactive methanogenic zones. The respiratory index (RI) [RI = 14CO2/(14CO2 + 14CH4)] for [2-14C]acetate catabolism at site B7 ranged from 0.98 to 0.2 in the depth range of 2 to 14 cm. Addition of sulfate to sediment from the low-sulfate zone resulted in an increase in RI and a decrease in methanogenesis. At all other sites examined, RI ranged from 0.97 to 0.99 and was constant with depth. The results suggested that although methanogenesis was inhibited by sulfate (presumably through the activity of sulfate-reducing bacteria), it was not always limited by sulfate reduction. 相似文献
490.
Seven isolates of tobacco ringspot virus (TRSV) from grape, cherry, two cultivars of blueberry, tobacco, soybean and watermelon were compared in this study. The most virulent isolate was from‘Jersey’blueberry and the least virulent isolate was from soybean. The‘Jersey’blueberry isolate and the watermelon isolate could be distinguished serologically from all other isolates. The‘Jersey’blueberry isolate was different in electrophoretic mobility from the soybean and tobacco isolates. A unique technique for comparing the in vitro translation products of three of the TRSV isolates is described. 相似文献