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51.
Use of a New Buffer System with Formalinized Sheep Erythrocytes in the Rubella Hemagglutination-Inhibition Test 总被引:4,自引:1,他引:3 下载免费PDF全文
The increased sensitivity and improved agglutination and settling patterns of formalinized sheep erythrocytes in a new buffer, HEPES (N-2-hydroxyethylpiperazine N'-2'-ethanesulfonic acid), make this system more suitable for use in the rubella hemagglutination-inhibition test. 相似文献
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The 0.5M KCl wash of rabbit reticulocyte ribosomes (I fraction) catalyzes the deacylation of Met-tRNAfMet. Upon DEAE-cellulose column chromatography, the deacylase activity elutes with the 0.1M KCl wash of the column (f1) and is well-resolved from the peptide chain initiation factors (1–3). The deacylase activity is specific for Met-tRNAfMet (retic., ). Other aminoacyl tRNAs tested including fMet-tRNAfMet (retic., ), Phe-tRNA (), Val-tRNA (retic.), and Arg-tRNA (retic.) are completely resistant to the action of the deacylase. In the presence of the peptide chain initiation factor (IF1) and GTP, retic. Met-tRNAfMet forms the initiation complex Met-tRNAfMet:IF1:GTP (2), and in this ternary complex Met-tRNAfMet is not degraded by the deacylase. Met-tRNAfMet binds to IF1 independent of GTP, and in this complex, this Met-tRNAfMet is degraded by the deacylase.Prior incubation of f1 with Met-tRNAfMet (retic.) strongly inhibited protein synthesis initiation, presumably due to deacylation of the initiator tRNA. This inhibition by f1 was completely prevented when Met-tRNAfMet (retic.) was pre-incubated with peptide chain initiation factors. 相似文献
54.
Mass spectra of nucleoside components of tRNA 总被引:2,自引:0,他引:2
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Nocardiosis: A review 总被引:2,自引:0,他引:2
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The features of the Laboratory Accreditation Program of the American Society of Cytology that pertain to quality assurance in cytopathology are reviewed. The areas considered include: (1) specimen procurement and cytopreparation, (2) the role of the cytotechnologist in cytoscreening, evaluation and reporting, (3) the role of the cytopathologist and (4) quality control measures. Attention to the issues raised in these areas is essential to achieving the best possible cytopathology practice in the most efficient and economical manner. 相似文献
58.
The effects of denervation and hindlimb suspension induced disuse on concentrations of ATP, phosphocreatine (PC), and fiber type profile were investigated in slow twitch soleus and fast twitch extensor digitorum longus (EDL) muscles. The results show that the soleus and EDL muscles differ in their dependency on loadbearing as a stimulus for maintaining normal energy metabolism and the biochemical and morphological characteristics of muscle fibers. As determined by R-P methodology, suspension reduced ATP and PC concentrations of the soleus to 26% and 56%, respectively, while, in EDL only, PC is reduced to 71% of control with no change in ATP. Both muscles, however, show identical losses in ATP and PC following denervation. The energy charge, an indicator of Pi availability in muscle was reduced significantly in both denervated muscles to 82% and 85% in soleus and EDL, respectively. No significant reduction of the energy charge was seen in the muscles from suspended rats. Thus, in parallel with the indirect regulation through muscle loadbearing, the nerve can effectively modulate the levels of high-energy phosphates more directly by some regulatory mechanisms independent of muscle type. Denervation and suspension disuse increased the proportion of type 2 fibers in the soleus with a concomitant decrease in type 1 fibers and a relative rise in the number of very small diameter fibers. The EDL showed only variation in fiber size. 相似文献
59.
Changes in the cell surface of vaginal epithelial cells were studied by scanning microscopy and fluorescence spectroscopy. Microvilli which are prominent features of the vaginal epithelial cells in proestrus and diestrus are replaced by sheet-like structures in the estrus phase. Surface morphology of vaginal epithelial cells of estradiol primed rat resembles the vaginal cells from estrus phase rats whereas vaginal cells from control rats resembles the diestrus phase. Measurement of the fluidity of the membranes indicated that the vaginal epithelial cell membrane of estrus rats is more fluid compared to proestrus and diestrus. Similarly, estradiol primed immature rat vaginal epithelial cell membrane was observed to be more fluid than the corresponding control. 相似文献
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Magnetically controlled targeted micro-carrier systems 总被引:11,自引:0,他引:11
Magnetically controlled targeted drug delivery systems are aimed at concentrating drugs at a defined target site, with the aid of a magnetic field. This technique has been developed specifically for directing drugs away from the reticuloendothelial system (RES). Literature on this topic suggests that these delivery systems are capable of altering the distribution of chemotherapeutic agents in the body. Hence these delivery devices offer the possibility of improving the therapeutic efficacy of the associated drugs. This paper reviews the work done to date towards the development and evaluation of biodegradable and non-biodegradable magnetic targeted drug delivery systems and outlines their future prospects and limitations in cancer chemotherapy. 相似文献