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741.
742.
Recovery of DNA fragments inserted by the "tailing" method: regeneration of PstI restriction sites 总被引:12,自引:0,他引:12
A general method has been developed for the recovery of any DNA fragment inserted into a cloning vehicle containing a single endonuclease PstI site. Endonuclease PstI sites are regenerated by the addition of one or more deoxyguanosine residues to the 3' termini of the PstI-cleaved vehicle by terminal deoxynucleotidyl transferase. Chain elongation by terminal deoxynucleotidyl transferase is then continued with dITP, dATP or dGTP. A plasmid vehicle, pAO1, containing a single PstI site has been constructed. Insertional (foreign) DNA fragments that were "tailed" with dCTP have been annealed to PstI-cleaved pAO1 that was "tailed" with dGTP. When the annealed fragments were used to transform competent Escherichia coli cells, the single-stranded DNA gaps in the recombinant plasmids were repaired. Plasmids recovered from transformed bacteria could be cleaved by PstI into the insertional DNA with dG:dC tracts and linear pAO1 molecules. 相似文献
743.
Characterization of ferritin from human placenta. Implications for analysis of tissue specificity and microheterogeneity of ferritins 总被引:1,自引:0,他引:1
Mammalian ferritins can be resolved into multiple components by isoelectric focusing, and each tissue contains a characteristic subset of isoferritins. Ferritin isolated from human liver was compared to acidic ferritin isolated from mid-gestational human placenta to define a structural basis for ferritin heterogeneity. Placenta ferritin contained several major bands with isoelectric points in the range of pI = 4.7-5.0 which were more acidic than the predominant isoferritins of human liver. Ferritin from each tissue was resistant to denaturation by 10 M urea and appeared to be identical by electron microscopy. Circular dichroism measurements revealed that placenta ferritin had substantially less ordered secondary structure than liver ferritin. Both types of ferritin contained only two subunits when analyzed by electrophoresis in sodium dodecyl sulfate gels, but isoelectric focusing of dissociated subunits in urea revealed 6-7 different components. In this system, placenta ferritin was enriched in the more acidic subunits and it completely lacked the most basic subunits noted in liver ferritin; placental ferritin had no unique components. Differences in isoelectric points among assembled ferritins from these two tissues appear to result from different proportions of these acidic and basic subunits. 相似文献
744.
Daisuke Kametaka Masaya Iwamuro Takahide Takahashi Araki Hirabata Kenta Hamada Yoshiyasu Kono Hiromitsu Kanzaki Seiji Kawano Takehiro Tanaka Fumio Otsuka Yoshiro Kawahara Hiroyuki Okada 《Current issues in molecular biology》2022,44(6):2443
Data regarding the in-depth surface marker profiles of gastric tissue-resident lymphocytes in autoimmune and Helicobacter pylori-associated gastritis are lacking. In this study, we investigated potential differences in lymphocyte composition between these profiles. We enrolled patients with autoimmune (n = 14), active (current infection of H. pylori in the stomach; n = 10), and inactive gastritis (post-eradication of H. pylori; n = 20). Lymphocytes were isolated from the greater curvature of the stomach and lesser curvature of the body and analyzed using flow cytometry. The CD8+/CD3+ and CD4+/CD3+ ratios differed between the samples. Body CD4+/antrum CD4+, which is calculated by dividing the CD4+/CD3+ ratio in the body by that in the antrum, was significantly higher in autoimmune gastritis (3.54 ± 3.13) than in active (1.47 ± 0.41) and inactive gastritis (1.42 ± 0.77). Antrum CD8+/CD4+ in autoimmune gastritis (7.86 ± 7.23) was also higher than that in active (1.49 ± 0.58) and inactive gastritis (2.84 ± 2.17). The area under the receiver operating characteristic curve of antrum CD8+/CD4+ was 0.842, and the corresponding optimal cutoff point was 4.0, with a sensitivity of 71.4% and a specificity of 93.3%. We propose that an antrum CD8+/CD4+ ratio > 4.0 is a potential diagnostic marker for autoimmune gastritis. 相似文献
745.
746.
The toxic effect of spermidine on normal and transformed cells 总被引:2,自引:0,他引:2
H Otsuka 《Journal of cell science》1971,9(1):71-84
747.
Effect of granulocyte-macrophage colony-stimulating factor on chemiluminescence of human neutrophils 总被引:2,自引:0,他引:2
We investigated the capacity of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) to enhance the function of neutrophils. Neutrophil function was measured in terms of N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced luminol-dependent chemiluminescence (LDCL). LDCL of fMLP-stimulated neutrophils was enhanced up to 4.5 fold following preincubation with rhGM-CSF. This enhancement depended on the length of preincubation, reaching an optimal level at 120 min. The dose-response relationship for fMLP-induced LDCL of neutrophils preincubated with rhGM-CSF revealed that half-maximum enhancement was achieved at an approximately 20-fold higher concentration than that of colony-forming units in culture-derived colony formation. These results suggest that differences in dose dependency may be explained by differences in the distribution of receptor(s) for GM-CSF. This may also enable GM-CSF to affect the hematopoietic system, which contains cells at various levels of differentiation, thus mediating the host-defense mechanism. 相似文献
748.
749.
MEASUREMENT OF γ-AMINOBUTYRIC ACID IN ISOLATED NERVE CELLS OF CAT CENTRAL NERVOUS SYSTEM 总被引:6,自引:3,他引:3
Abstract— A sensitive method for measuring γ-aminobutyric acid (GABA) has been developed. This method consists of a combination of the enzymic GABA assay of J akoby and S cott (1959) with the enzymic cycling technique of L owry , P assonneau , S chulz and R ock (1961) and permits the measurement of as little as 2 × 10−14 mol of GABA. Using this method, GABA analyses were made on single isolated nerve cell bodies of different types from the CNS of the cat. Average GABA concentrations in these cell bodies were: spinal ganglion cells, 0.2 m m ; spinal mononeurons, 0.9 m m ; large cells of the ventral part of Deiters' nucleus, 2.7 m m ; large cells of the dorsal part of Deiters' nucleus, 6.3 m m ; cerebellar nuclei cells, 6.0 m m ; cerebellar Purkinje cells, 6.6mM; cerebral Betz cells, 2.5 m m .
The GABA concentrations in the isolated dorsal Deiters' cells were greatly reduced (1.7 m m ) after the removal of the cerebellar vermis while those of the ventral Deiters' cells were unaffected by the denervation. These results suggest that GABA is concentrated within axon terminals, probably of Purkinje neurons, synapsing with the dorsal Deiters' cells. The results of GABA analyses on isolated nerve cells are discussed in relation to the relevant neuronal functions and the possible role of GABA as an inhibitory transmitter. 相似文献
The GABA concentrations in the isolated dorsal Deiters' cells were greatly reduced (1.7 m m ) after the removal of the cerebellar vermis while those of the ventral Deiters' cells were unaffected by the denervation. These results suggest that GABA is concentrated within axon terminals, probably of Purkinje neurons, synapsing with the dorsal Deiters' cells. The results of GABA analyses on isolated nerve cells are discussed in relation to the relevant neuronal functions and the possible role of GABA as an inhibitory transmitter. 相似文献
750.
Shuyi Tang Moeko Tezuka Hinata Otsuka Ryoichi Sato 《Archives of insect biochemistry and physiology》2023,112(1):e21975
The existence of an extracellular signaling pathway that mediates nodule formation, a cell-mediated immune response, has been reported in Bombyx mori larvae. In this pathway, C-type lectins and the hemolymph serine proteinase BmHP-8 function in pathogen associated molecular pattern (PAMPs) recognition and signaling transduction. However, which molecule elicits the cellular response at the end of the pathway is unknown. In this study, the Toll ligand Bombyx mori Spätzel1 was shown to be involved in the pathway by applying anit-Spätzel1 antiserum in an in vitro nodule-like aggregate formation assay and an in vivo nodule formation assay. 相似文献