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11.
大狼毒三萜类化学成分的研究 总被引:3,自引:0,他引:3
自大戟科(Euphorbiaceae)植物大狼毒(Euphorbia nematocypha Hand—Mazz)根的乙醇提取物的苯溶解部分,经20%AgNO3硅胶层析,分离得到七个三萜类成分。根据光谱(IR,EIMS,1H—NMR和13C—NMR)和化学方法,确定其中一个化合物为新化合物,命名为大狼毒醇(nematocyphol,Ⅳa),其它化合物为已知物:印度荆芥醇乙酸酯(nepehinol acetate Ⅰ),日尔曼醇乙酸酯(germanicol acetate Ⅱ),大戟醇(euphol,Ⅲ),蒲公英醇(taraxasterol,Ⅴa),24-亚甲基环阿尔廷醇(24-methylenecycloartanol,Ⅴa)和印度荆芥醇(nepehinol,Ⅶa)。这些化合物均为首次从大狼毒中得到。 相似文献
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A 12-year-old girl with a history of fast myopia progression underwent advanced orthokeratology (ortho-k) treatment and suffered from recurrent lens binding and central corneal staining. The problem could not be fixed by lens fenestration and refitting with a less aggressive lens (three-zone ortho-k) design. After refitting with a lower target advanced ortho-k lens, these complications were no longer occurring, and the amount of power reduction was greater than expected considering the target designed for the refitted lenses. During the following 15 months of ortho-k lens wear, there was no clinically significant change to her refractive error. The patient and her parents were happy with the outcome, although the refractive error was not totally eliminated and she still needed to wear spectacles for clear vision. Possible etiologies of the complications are discussed. 相似文献
14.
Immunoglobulin mimicry by Hepatitis C Virus envelope protein E2 总被引:4,自引:0,他引:4
Hu YW Rocheleau L Larke B Chui L Lee B Ma M Liu S Omlin T Pelchat M Brown EG 《Virology》2005,332(2):538-549
Hepatitis C virus (HCV) establishes persistent infection in the majority of infected individuals. The currently accepted hypothesis of immune evasion by antigenic variation in hypervariable region 1 (HVR1) of glycoprotein E2 does not however, explain the lack of subsequent immune recognition. Here, we show that the N-terminal region of E2 is antigenically and structurally similar to human immunoglobulin (Ig) variable domains. E2 is recognized by anti-human IgG antibodies and also possesses common amino acid (aa) sequence features of the conserved v-gene framework regions of human Ig light chains in particular but also heavy chains and T cell receptors. Using a position specific scoring system, the degree of similarity of HVR1 to Ig types correlated with immune escape and persistence in humans and experimentally infected chimpanzees. We propose a unique role for threshold levels of Ig molecular mimicry in HCV biology that not only advances our concept of viral immune escape and persistent infection but also provides insight into host-dependent disease patterns. 相似文献
15.
Comparison of LightCycler-based PCR,COBAS amplicor CMV monitor,and pp65 antigenemia assays for quantitative measurement of cytomegalovirus viral load in peripheral blood specimens from patients after solid organ transplantation 总被引:2,自引:0,他引:2
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Pang XL Chui L Fenton J LeBlanc B Preiksaitis JK 《Journal of clinical microbiology》2003,41(7):3167-3174
In order to evaluate the LightCycler-based PCR (LC-PCR) as a diagnostic assay technique, a classical pp65 antigenemia assay and the commercially available COBAS Amplicor CMV Monitor (CACM) assay were compared to the LC-PCR assay for the detection and quantitation of cytomegalovirus (CMV) load in 404 parallel specimens of peripheral blood from 66 patients after solid organ transplantation. A good correlation existed among these three assays (r congruent with 0.6, P < 0.0001). The LC-PCR assay was the most sensitive (54% of specimens positive) compared to the CACM (48.6%) and the pp65 antigenemia (26%) assays. The LC-PCR assay detected all samples found positive by using both the CMV pp65 antigenemia assay and the CACM assay. The LC-PCR also had the widest dynamic range (from 250 to 10(7) DNA copies/ml of plasma). No cross-reactions were found among CMV and Epstein-Barr virus, varicella-zoster virus, or herpes simplex virus in the LC-PCR by using amplification with specifically designed primer pairs. Precision, expressed as the coefficient of variation, was <3% with standard DNA from cell cultures and between 6.55 and 14.1% with clinical specimens in repeat LC-PCR runs. One run of the LC-PCR took half of the time required for the semiautomated CACM procedure. Because of its sensitivity, specificity, cost-effectiveness, and simplicity, the LC-PCR assay could replace the pp65 antigenemia and the CACM assays as the preferred technique for the surveillance, diagnosis, and monitoring of response of CMV diseases in high-risk populations. 相似文献
16.
A single-chain antibody fragment (scFv) was constructed from a hybridoma antibody that binds to phosphorylcholine (PC) only when this hapten is presented in the form of the immunizing antigen (derived from Trichinella) but not when it is presented on other carriers (as found, for example, in pneumococcal capsules). The scFv derivative was found to lack this carrier specificity as it bound indiscriminately, but specifically, to the various PC-associated antigens, and exhibits a two-fold lower affinity (3.5x10(5)M(-1)) for nitrophenyl-PC than the native antibody. The findings suggest that the scFv combining site is different in fine structure from that of the native antibody. 相似文献
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T Osanai A Konta D Chui T Kanazawa K Onodera T Kogawa 《Archives of pathology & laboratory medicine》1990,114(8):829-831
The ultrastructural characteristics of a benign adrenal adenoma that produces deoxycorticosterone and 11-deoxycortisol were examined by transmission electron microscopy. Both large, round mitochondria with a few cristae in the peripheral portion and spherical or oval mitochondria with sacrotubular cristae were observed in adenoma cells. The development of agranular or granular endoplasmic reticulum varied from cell to cell. In some cells, many vacuoles and collagenous fibers were also seen. Thus, the adrenal tumor we examined was composed of the cells derived from the fascicular zone, which are associated with Cushing's syndrome, and the cells of the glomerular zone observed in association with primary aldosteronism. 相似文献
19.
Richard D. W. Hain David Chitayat Robert Cooper Elizabeth Bandler Barry Eng David H. K. Chui John S. Waye Melvin H. Freedman 《Human mutation》1994,3(3):239-242
We describe a normal neonate who presented at four days of age with asymptomatic cyanosis. There was no evidence of cardiac or pulmonary abnormality and an extended family history included 13 other affected family members with asymptomatic cyanosis lasting one to three months. Polymerase chain reaction (PCR) amplification and direct nucleotide sequencing of the proband's Gγ chain gene revealed the mutation at codon 92 (CAC→TAC) previously shown in haemoglobin FM-Fort Ripley (α2γ2Gγ 92 (F8) His→Tyr). This is the first family with Hb FM-Fort Ripley reported so far. It demonstrates autosomal dominant inheritance of this condition and incomplete penetrance. © 1994 Wiley-Liss, Inc. 相似文献
20.
Should we screen for globin gene mutations in blood samples with mean corpuscular volume (MCV) greater than 80 fL in areas with a high prevalence of thalassaemia? 总被引:2,自引:0,他引:2
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Chan LC Ma SK Chan AY Ha SY Waye JS Lau YL Chui DH 《Journal of clinical pathology》2001,54(4):317-320
AIMS: To investigate whether it is worthwhile, in areas where thalassaemia is common, to screen for globin gene mutations in subjects with a mean corpuscular volume (MCV) above 80 fL, especially in partners of known thalassaemia carriers. METHODS: Blood samples from 95 subjects with MCV between 80 and 85 fL were screened for the presence of alpha globin gene mutations and the haemoglobin (Hb) E mutation. RESULTS: Thirty four subjects harboured globin gene mutations. Of these, 31 had deletions of one alpha globin gene, one had Hb Constant Spring, and three had Hb E mutations. CONCLUSION: Based on the above figures and known prevalence rates of thalassaemia carriers, it would seem worthwhile to screen for globin gene mutations in partners of known thalassaemia carriers, regardless of MCV, to identify pregnancies at risk of Hb H disease or Hb E/beta thalassaemia. 相似文献