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81.
S H Saverymuttu A M Peters H J Hodgson V S Chadwick J P Lavender 《BMJ (Clinical research ed.)》1982,285(6337):255-257
Indium-111 autologous leucocyte scanning was compared with barium enema for assessing the extent of colonic disease in Crohn''s colitis and ulcerative colitis. Scanning was shown to be as accurate as conventional radiology in colitis, reliably distinguishing active from inactive disease. The results suggest that 111In-leucocyte scanning is an accurate, non-invasive, alternative technique for imaging the extent of disease in colitis. 相似文献
82.
The reinvestigation of the aerial parts of Wedelia trilobata afforded, in addition to known compounds, six new eudesmanolides, two ent-kaurenic acid derivatives as well as a degraded one. A corresponding hydroxy compound was present in Gnaphalium undulatum. From Aspilia parvifolia new ent-kaurenic acid epoxides were isolated. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation is discussed briefly. 相似文献
83.
K.G. Blass R.L. Briand D.S. Ng S. Harold 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1980,182(3):311-316
A miniature two-dimensional thin-layer chromatographic procedure employing silica gel impregnated glass-microfiber chromatography sheets (commercial product, ITLC-type SG sheets) has been developed for the separation of lecithin (L) and sphingomyelin (S) from a standard lipid mixture containing L, S, lysolecithin, phosphatidyl inositol (PI), phosphatidyl serine (PS), phosphatidyl ethanolamine, phosphatidyl glycerol, and diphosphatidyl glycerol. The newly developed procedure eliminates possible interference from PI and PS. Complete separation of L and S was easily achieved with chromatographic solvent migration times of approximately 3 and 2 min for the first and second dimensions, respectively. The lipids were visualized by charring and fluorescent staining techniques. The procedure has been adapted for the separation of L and S from amniotic fluid samples. 相似文献
84.
Genetic and biochemical characterization of a human surface determinant on somatic cell hybrids: the 4F2 antigen 总被引:1,自引:0,他引:1
P G Peters M E Kamarck M E Hemler J L Strominger F H Ruddle 《Somatic cell genetics》1982,8(6):825-834
We have mapped the gene which codes the species-specific determinant defined by monoclonal antibody 4F2 to human chromosome 11. All human chromosomes, except Y, were included in a group of four human-mouse hybrid lines. Hybrids heterogeneous for 4F2 antigen expression were sorted using the fluorescence-activated cell sorter (FACS) to yield populations homogeneous with respect to the presence or absence of this determinant. Isozyme analysis indicated corresponding genetic selection for or against human chromosome 11. This map assignment was confirmed using a hybrid line which contained only human chromosome 11. Immunoprecipitation of the 4F2 determinant from the 11 only hybrid resulted in a heavy subunit of molecular weight (Mr) = 100,000 and a light subunit of Mr = 41,000. This contrasts with results obtained from nonhybrid human cells of different lineages. These results demonstrate the importance of FACS techniques in the rapid mapping of genes which code human cell surface antigens. 相似文献
85.
G E Peters 《Regulatory peptides》1982,3(5-6):361-369
The mechanisms of clearance and degradation of injected [3H]somatostatin have been studied in the rat using octadecasilyl-silica extraction and HPLC separation methods.. Three apparent consecutive plasma half-lives of 1, 3 and 20 min were estimated following administration of a pharmacological dose. The initial rapid clearance was due to uptake by various tissue beds, mainly the large peripheral tissue masses muscle, skin and intestine which together accounted for 70% injected radioactivity at 1 min. By contrast the amounts taken up by liver and kidney were relatively small (less than 10%) despite the accumulation of higher concentrations. Massive degradation occurred following uptake and small fragments and amino acids were released into the circulation almost immediately. Inactivation by blood itself was negligible. A slow phase of decline observed at later times suggested a return of intact peptide from extravascular storage sites to sustain plasma concentrations. 相似文献
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88.
The primary electron transfer processes in Rhodopseudomonas sphaeroides R-26 were studied as a function of temperature by means of picosecond spectroscopy. The first chemical step of the bacterial photosynthesis involves an electron transfer from the excited state of a bacteriochlorophyll a dimer, (BChl)2, to a bacteriopheophytin (BPh) to form the radical ion pair (BChl)2+. BPh-.. The upper limit for the formation time of this ion-pair was found to be 10 ps, at temperatures in the range 300-4.2 degree K. Similarly, the second chemical step, involving electron transfer from BPh-. to an ubiquinone-iron complex (QFe), was found to have a lifetime of approximately 150 ps, also independent of temperature in the same range. We interpret the absence of temperature dependence as indicating that process 2 proceeds via a tunneling mechanism. Utilizing our results in conjunction with electron tunneling theories, we calculate the distance between BPh-. and Q(Fe) to be 9--13 A. Our results also imply a closer proximity between (BChl)2 and BPh. 相似文献
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90.
Hemolymph enzyme activities were investigated during the course of Minchinia nelsoni (MSX) disease development in Crassostrea virginica. Aspartate aminotransferase, alanine aminotransferase, and phosphohexose isomerase activities increase significantly during the gill lesion stage of MSX disease. Enzyme activities are not significantly elevated during the general infection stage of MSX disease. The alteration of hemolymph enzyme activity is discussed with respect to host metabolism and possible humoral defense mechanisms. 相似文献