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1.
A neutral metalloprotease with marked specificity for an O-sialoglycoprotein has been isolated from culture supernatants of Pasteurella haemolytica A1. The 35-kDa enzyme cleaves human erythrocyte glycophorin A, which is O glycosylated, but does not cleave N-glycosylated proteins or nonglycosylated proteins. Glycophorin A was cleaved when it was present in situ in erythrocyte ghost plasma membranes or when it was free in solution. The glycoprotease did not hydrolyze glycophorin A from which sialate residues had been removed by neuraminidase treatment. An immobilized preparation of the enzyme cleaved glycophorin A at several positions, with a major site of cleavage at Arg-31-Asp-32. The glycoprotease is inhibited by EDTA, citrate, and ascorbate, but inhibition appears to be due to the masking of metal ion activators rather than to their removal. The enzyme is not inhibited by phosphoramidon, an inhibitor of other bacterial neutral metalloproteases.  相似文献   
2.
In this study, we examined the corrosion behaviors of pure titanium, the alloys Ti-6Al-4V and Ti-6Al-7Nb, and the new experimental alloys Ti-Pt and Ti-Pd using anodic polarization and corrosion potential measurements in an environment containing fluoride. Before and after immersion in the test solutions, we made observations using a scanning electron microscope. The test solutions included an artificial saliva containing 0.2% NaF (corresponding to 905 ppm F) and an artificial saliva with a low concentration of oxygen. Although the surfaces of the Ti-Pt and Ti-Pd alloys were not affected by an acidic environment containing fluoride, the surfaces of the pure titanium, the Ti-6Al-4V alloy, and the Ti-6Al-7Nb alloy were markedly roughened by corrosion. The surfaces of the pure titanium, the Ti-6Al-4V alloy, and the Ti-6Al-7Nb alloy were microscopically damaged by corrosion when they were immersed in the solution containing a low concentration of dissolved oxygen, even with a fluoride concentration included in the commercial dentifrices. In this situation, however, the surfaces of the new Ti-Pt and Ti-Pd alloys were not affected. These alloys are expected to be of use in dental work as new titanium alloys with high corrosion resistances.  相似文献   
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Extracts of the leaf and seed of Piper guineense were separately prepared and their pharmacological effects screened using smooth muscle of the gastrointestinal tract and uterus. The leaf extract enhanced both the frequency and tone of spontaneous contractions of rabbit jejunum and induced contraction of guinea-pig ileum, which were blocked by atropine. The seed extract had the opposite effect on rabbit jejunum, an inhibition which was antagonized by prazocin, and little or no effect on guinea-pig ileum. Both extracts had a stimulant effect on rat uterine muscle, the seed extract to a lesser extent.  相似文献   
5.
We describe the case of a 40‐year‐old woman who presented with a pararenal hyaline‐vascular type Castleman’s disease that had an arterial supply from the renal artery and a draining vein as showed by multidetector CT. Identification of the renal artery relationship to the feeding vessel of the mass is critical to prevent potential surgical complications.  相似文献   
6.
目的探讨总结肝癌自发性破裂出血的诊治经验。方法回顾性分析海口市人民医院自1992年1月~2004年5月收治26例原发性肝癌破裂出血的临床资料。结果该组原发性肝癌自发性破裂出血病例中,行肝癌切除术者,生存时间长。结论原发性肝癌破裂出血行肝叶切除和肝局部切除不但可以彻底有效地止血,而且可以达到切除肿瘤的目的,是首选的方法,是一种安全、可行的方法.如果病人情况不允许,可先行保守治疗或介入治疗(TAE),争取行Ⅱ期或延期肝切除术。而肝动脉结扎加胃网膜右静脉插管化疗,注入无水酒精等癌灶综合治疗为一种有效的辅助措施。  相似文献   
7.
Bridging bronchus: a rare airway anomaly   总被引:1,自引:0,他引:1  
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The stem bark and leaves of Daniellia oliveri were screened phytochemically and the effects of their respective methanol extracts on the skeletal muscle of rats were investigated using the isolated phrenic nerve hemidiaphragm muscle preparation. Both were found to contain tannins, cardiac and saponin glycosides. In addition, the bark, but not leaves, contained cyanogenetic glycosides. The methanol extracts were found to possess neuromuscular blocking properties. The leaf extract appeared to act primarily by inhibiting the influx of extracellular Ca(2+) principally by inhibiting K(+) channels. The inhibitory action of the bark extract appeared to be mediated by interference with transmitter release and an action on multiple sites.  相似文献   
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