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1.
Selective diapedesis of Th1 cells induced by endothelial cell RANTES.   总被引:16,自引:0,他引:16  
Differentiated CD4 T cells can be divided into Th1 and Th2 types based on the cytokines they produce. Differential expression of chemokine receptors on either the Th1-type or the Th2-type cell suggests that Th1-type and Th2-type cells differ not only in cytokine production but also in their migratory capacity. Stimulation of endothelial cells with IFN-gamma selectively enhanced transmigration of Th1-type cells, but not Th2-type cells, in a transendothelial migration assay. Enhanced transmigration of Th1-type cells was dependent on the chemokine RANTES produced by endothelial cells, as indicated by the findings that Ab neutralizing RANTES, or Ab to its receptor CCR5, inhibited transmigration. Neutralizing Ab to chemokines macrophage-inflammatory protein-1alpha or monocyte chemotactic protein-1 did not inhibit Th1 selective migration. Whereas anti-CD18 and anti-CD54 blocked basal levels of Th1-type cell adherence to endothelial cells and also inhibited transmigration, anti-RANTES blocked only transmigration, indicating that RANTES appeared to induce transmigration of adherent T cells. RANTES seemed to promote diapedesis of adherent Th1-type cells by augmenting pseudopod formation in conjunction with actin rearrangement by a pathway that was sensitive to the phosphoinositol 3-kinase inhibitor wortmannin and to the Rho GTP-binding protein inhibitor, epidermal cell differentiation inhibitor. Thus, enhancement of Th1-type selective migration appeared to be responsible for the diapedesis induced by interaction between CCR5 on Th1-type cells and RANTES produced by endothelial cells. Further evidence that CCR5 and RANTES play a modulatory role in Th1-type selective migration derives from the abrogation of this migration by anti-RANTES and anti-CCR5 Abs.  相似文献   
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Localization of carbonic anhydrase in the rat lung   总被引:4,自引:0,他引:4  
Summary The localization of carbonic anhydrase in the rat lung has been demonstrated, at light and electron microscopic levels, by the cobalt bicarbonate histochemical method of Hansson. Focal deposits of the cobalt sulfide reaction product were found not only in the capillary endothelium of the alveolar walls, but also in the small and large alveolar cells. The histochemical reaction was abolished by two potent inhibitors, acetazolamide (10–5 to 10–6 M) and KCNO (5×10–3 to 10×10–3 M). Physiological assay with Maren's method indicated that values for carbonic anhydrase activity in rat lung are 4.4±0.8 UA/mg of protein, 25.0±5.5 UA/mg of nitrogen, and 369±86 UA/g of wet weight. In addition, it was calculated that after fixation in glutaraldehyde-formaldehyde-picric acid about 9% activity is retained.  相似文献   
4.
Using Toyopearl and cyclohexane: cyclohexanol solvent, fourCl-containing Chls were separated from 36Cl-labeled cells ofthe blue-green, Plectonema boryanum. In normally grown cells,all four Cl-containing chlorophylls amounted to less than 1/2,000of the total Chi and about 1/50 of P700, values much lower thanpreviously reportedcontents of Chi RC I, and varied from algato alga. The level of Cl-containing Chi was markedly enhancedwhen the cells were poisoned with methyl viologen. These resultssuggests that these Cl-containing Chls are not related to thereaction center of PS I. (Received June 23, 1987; Accepted September 17, 1987)  相似文献   
5.
The calcium-binding property of equine lysozyme   总被引:2,自引:0,他引:2  
K Nitta  H Tsuge  S Sugai  K Shimazaki 《FEBS letters》1987,223(2):405-408
It was found that equine lysozyme binds one Ca2+. It was eluted with equimolar Ca2+ from a Bio-Gel P-4 column. Human lysozyme did not behave similarly. Equine lysozyme is concluded to be a calcium metallo-protein like alpha-lactalbumin, which is a homologue of hen egg white lysozyme.  相似文献   
6.
Protoplasts isolated enzymatically from juvenile leaflets of sporophytes in fern Lyqodium japonicum were inoculated in a MS medium containing NAA 2.7 m, BAP 2.2 m, 0.6 M mannitol, and 0.05 M sucrose. Cell division took place within 8 days of culture initiation, and after 30 days cell-clusters with 10–15 cells were observed. When the cell-clusters were transferred into fresh hormone-free medium containing no mannitol, they developed rhizoids and protonema-like regenerants. About 2 months later, cordate prothallia developed bearing both antheridia and archegonia.Abbreviations MS Murashige and Skoog (1962) - NAA naphthalene acetic acid - BAP 6-benzylaminopurine  相似文献   
7.
The fertility plasmid F'gal was not stably maintained in a hupA-hupB double mutant of Escherichia coli. Moreover, mini-F plasmids pFZY1, pFTC1 and pFTC2 were unable to transform the double mutant, though these plasmids efficiently transformed cells harboring a hupA or hupB single mutation. The composite plasmid pFHS1, which consists of the f5 DNA fragment of F plasmid and the whole DNA of a pSC101 derivative that carries a temperature-sensitive mutation for DNA replication, was not stably maintained in the hup double mutant at 42°C. These findings strongly suggest that HU protein is required for ori2-dependent replication of the F plasmid.  相似文献   
8.
H. Kuroiwa  M. Sugai  T. Kuroiwa 《Protoplasma》1988,146(2-3):89-100
Summary The fate of the chloroplasts and chloroplast nuclei (cp-nuclei) was followed during spermatogenesis in the fernPteris vittata L. by epifluorescence microscopy after staining with 4-6-diamidino-2-phenylindole (DAPI) and by quantitation of chloroplast DNA (cp-DNA) by fluorimetry using a video intensified microscope photon counting system (VIMPICS). The spores were grown on solid medium that contained antheridiogen (Anptd), and formed an antheridium initial on the protonema cell. The antheridium initial divided and produced 16 spermatocytes and 3 surrounding cells. The chloroplasts in the spermatocytes decreased in volume as cell division was repeated, until finally the volume of each chloroplast was 1/15 of that of the primary chloroplasts. The DNA content of the chloroplasts was also reduced to 1/5 of the original value and when the sperm matured, the fluorescence of cp-DNA disappeared. In the 16-cell spermatocyte, the recognition of the fluorescence of chlorophyll in the chloroplasts with a green excitation filter became difficult. But, the plastids could be observed until the final stage of the sperm. From these observations, it appears that there are two steps in the metamorphosis of chloroplasts during spermatogenesis in the fern. The first step involves the decrease in the volume of chloroplasts, accompanied by reduction of the DNA content, and the second step involves the change of the physical state of chloroplasts to amyloplasts and the disappearance of the cp-DNA from the amyloplasts.  相似文献   
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Considerable inherent variations in the relation between macropterous and brachypterous wing forms, and nymphal density were found in field populations of the brown planthopper, Nilaparvata lugens Stål (Homoptera: Delphacidae), collected from various locations in Japan. When compared under uniform laboratory rearing conditions, most of the female populations exhibited higher ratios of macropters with increasing nymphal density, but some showed extremely high proportion of brachypters and the others were highly macropterous, over broad ranges of density. These results indicate the possibility that the planthoppers in Japan, which are known not to persist in winter, are derived from different migration sources.About ten generations of successive selection for brachyptery from a population showing usual density-dependent wing morphism generated populations similar to highly brachypterous ones mentioned above. Genetic analysis of the inheritance of wing morphism revealed that brachyptery in the females was controlled by a single pair of dominant alleles. However, in the males wing forms did not segregate so clearly in the crossing experiments. This suggests that wing morphism in N. lugens in under sex-limited inheritance.
Einwanderung von Nilaparvata lugens mit unterscheidlicher Reaktion auf Populationsdischte bei der Flügelausbildung
Zusammenfassung In Feldpopulationen von Nilaparvata lugens Stål., welche in verschiedenen Regionen Japans gesammelt wurden, bestand in der Beziehung zwischen makropteren bzw. brachypteren Flügelformen und der Larvendichte eine beträchtliche Variation. Unter einheitlichen Zuchtbedingungen im Laboratorium stieg der Makropterenanteil bei den meisten Weibchenpopulationen mit steigender Temperatur; bei einigen Populationen hingegen war entweder der Brachypterenanteil oder der Makropterenanteil extrem hoch und zwar über weite Dichtebereiche. Dies deutet auf die Möglichkeit hin, dass die Zikade in Japan, wo sie bekanntlich nicht überwintert, jeweils aus verschiedenen Quellen einwandert.Wenn eine Population mit der üblichen dichteabhängigen Flügelausbildung 10 Generationen lang auf Brachypterie selektioniert wurde, entstanden Populationen, die den erwähnten hochbrachypteren Populationen aus dem Feld glichen. Die genetische Analyse der Vererbung der Brachypterie ergab, dass bei Weibchen ein einzelnes dominantes Allel verantwortlich ist. Bei Männchen dagegen trennten sich bei Kreuzungsexperimenten die Flügelformen nicht so klar. Dies deuted auf Unterschiede zwischen den Geschlechtern bei der Vererbung der Flügelformen.
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