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Aerosol bolus inspirations were used to assess lung injury in 15 isolated dog lungs exposed to low (0-375 units) or high doses (600-1,200 units) of papain. Effective air space size (EAD) was determined from aerosol deposition during a 5-s breath hold. Convective mixing was assessed by the spreading of the expired bolus with respect to expired volume, quantified by a coefficient of dispersion (CD) equal to the square root of the difference in the variances of the expired and inspired boluses divided by the volumetric penetration of the bolus. After exposure, CD measured with deeply penetrating boluses increased by an average of 2.5% in the low-exposure group (P greater than 0.05) and 28.0% in the high-exposure group (P less than 0.0001). CD measured with shallowly penetrating boluses decreased by 4.3% (P less than 0.0001) in the low-exposure group and increased by an average of 18.3% in the high-exposure group (P less than 0.05). Papain exposure caused EAD to increase in some lungs and decrease in others. For deep bolus penetrations, EAD changed by an average of -0.8% in the low-exposure group (P greater than 0.05) and +21.1% in the high-exposure group (P greater than 0.05). Both EAD and CD appeared to be sensitive to lung injury. However, changes in EAD were less consistent than those in CD, possibly due to changes caused by lung injury in the regional distribution of inspired aerosol.  相似文献   
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Summary A cell line derived from a human ovarian carcinosarcoma was established in tissue culture and in nude mice. Two sublines, LDF and HDF, separated by discontinuous density centrifugation were also established from the parent line JoN. The cloning efficiency of the JoN line was 21%. Morphologic features of adenocarcinoma cells characteristic of the parent JoN cells were retained in the sublines and clones; all lines showed the same karyotype and DNA content (pseudodiploid and pseudotetraploid). Keratin, as demonstrated immunohistochemically, was strongly expressed in the parent line JoN and the xenograft tumor, but not at all in the LDF sublines and only moderately in the HDF sublines. Vimentin, however, was expressed in neither the parent line JoN nor the xenograft tumor, but was present in both sublines. Transglutaminase and plasminogen activator activity was high in the parent line JoN. Neither, sublines nor clones showed the same high enzyme activity as the parent line. It is concluded that this human tumor line JoN is comprised of epithelial cells, capable of multidirectional differentiation.  相似文献   
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It has long been known that rates of synonymous substitutions are unusually low in mitochondrial genes of flowering and other land plants. Although two dramatic exceptions to this pattern have recently been reported, it is unclear how often major increases in substitution rates occur during plant mitochondrial evolution and what the overall magnitude of substitution rate variation is across plants.  相似文献   
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