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71.
Flavonoid glycosides were metabolized to phenolic acids via aglycones by human intestinal microflora producing α-rhamnosidase, exo-β-glucosidase, endo-β-glucosidase and/or β-glucuronidase. Rutin, hesperidin, naringin and poncirin were transformed to their aglycones by the bacteria producing α-rhamnosidase and β-glucosidase or endo-β-glucosidase, and baicalin, puerarin and daidzin were transformed to their aglycones by the bacteria producing β-glucuronidase, C-glycosidase and β-glycosidase, respectively. Anti-platelet activity and cytotoxicity of the metabolites of flavonoid glycosides by human intestinal bacteria were more effective than those of the parental compounds. 3,4-Dihydroxyphenylacetic acid and 4-hydroxyl-phenylacetic acid were more effective than rutin and quercetin on anti-platelet aggregation activity. 2,4,6-Trihydroxybenzaldehyde, quercetin and ponciretin were more effective than rutin and ponciretin on the cytotoxicity for tumor cell lines. We insist that these flavonoid glycosides should be natural prodrugs.  相似文献   
72.
BCG对膀胱粘膜结构的影响及肿瘤超微病理的研究   总被引:3,自引:0,他引:3  
应用光镜,透射电镜与扫描电镜技术对20例浅表膀胱肿瘤BCG治疗前后粘膜结构,肿瘤超微结构及Hela细胞表面结构的影响作了比较研究。结果表明,BCG灌注后,膀胱粘膜的结构发生了明显的改变,粘膜层次变薄,粘膜下可见大量单个核细胞浸润,肉芽肿与非干酷淋巴细胞团形成。  相似文献   
73.
采集450例战士血清标本,分别用国家代表株甲3/济防/15/90(H3N2)和甲3/北京/32/92(H3N2)作血清血凝抑制抗体测定,青年对甲3型抗体阳性率为60%~67%,其GMT为34~45。1994~1995年两年中在军营人群中分离到3株H3N2毒株流行株,分别应用国际、国家和地方代表株作抗原性分析,证明流行株与它们之间抗原性有明显差异。本文分离到的3株流行株均上送国家流感中心鉴定,证实为H3N2亚型毒株。  相似文献   
74.
Two experiments were performed to investigate the relationship between the expression of sodium appetite and the appearance of Fos-like immunoreactivity (Fos-IR) in the brain of rats. In the first experiment, rats were depleted of sodium by treatment with furosemide 24 h prior to sacrifice and without access to either food or sodium solution. Some rats had access to distilled water, and others had no fluids available during the 24 h. All of the furosemide-treated rats showed Fos-IR in both the subfornical organ (SFO) and around the organum vasculosum laminae terminalis (OVLT). Rats with access to distilled water during the depletion period showed no Fos-IR in the supraoptic (SON) or paraventricular hypothalamic nuclei (PVN) and, in parallel behavioral studies, comparably-treated rats consumed only 0.3 M NaCl solution at the end of the 24 h. In rats that had no fluids during the deprivation period, only about one half showed Fos-IR in SON and PVN and, in parallel behavioral studies, comparably treated rats consumed both water and 0.3 M NaCI solution at the end of 24 h. In a second experiment, cerebroventricular administration of renin stimulated short latency intake of 0.3 M NaCI and water. The relative intakes of water and NaCl were comparable at a low dose of renin, but intake of water exceeded that of NaCl after higher doses. Renin induced Fos-IR in SFO, MnPO, peri-OVLT region, SON and PVN. Both Fos-IR and fluid intake were antagonized by administration of losartan, an angiotensin 11 type 1 receptor antagonist. Thus, only the circumventricular organs of the lamina terminalis showed Fos-IR during each natriorexigenic regimen in these studies. These data support the view that Ang 11 of both central and peripheral origin activates the SFO and/or peri-OVLT region and contributes to sodium appetite.  相似文献   
75.
目的:研究不同种类和强度基牙材料与瓷冠破折碎裂的内在关系.方法:选用计算机建立上颌中切牙的三维有限元模型,模拟陶瓷层、牙本质、核桩等结构.分析在天然齿基牙、钴铬合金基牙及复合树脂基牙情况下,铸造玻璃陶瓷全冠的瓷层内及残余牙本质的应力分布情况.结果:高弹性模量的钴铬合金能够降低瓷层及残余牙本质内的最大主应力和最小主应力峰值,防止瓷层破折碎裂;而弹性模量与牙本质相近的复合树脂桩降低应力峰值的作用不明显.结论:对于有牙髓活力的牙本质基牙,尽量保存牙髓活力后行全冠修复.对于行根管治疗术后的无髓牙,进行核桩冠修复时,采用高弹性模量的高熔合金,尽量避免使用弹性模量较小的复合树脂核.  相似文献   
76.
经皮穿刺氩氦刀冷冻治疗肝癌56例临床分析   总被引:11,自引:0,他引:11  
目的 探讨氩氦刀冷冻治疗肝脏恶性肿瘤的临床意义。方法  2 0 0 1年 7月~ 2 0 0 2年6月 5 6例肝脏恶性肿瘤在B型超声引导下行经皮穿刺氩氦刀冷冻治疗。术后患者定期复查血清肿瘤标记物、B型超声检查及CT或MRI。结果 患者肝功能ChildA级 5 0例 ,ChildB级 5例 ,ChildC级 1例。原发性肝癌 4 6例 ,转移性肝癌 10例。小肝癌 (直径≤ 5cm)甲胎蛋白阳性者治疗后转阴占80 % ,甲胎蛋白阴性者治疗后CT或MRI复查病灶完全坏死达 6 1.5 %。转移性肝癌治疗后瘤标降至正常或CT、MRI提示病灶完全坏死者占 6 0 %。结论 氩氦刀冷冻治疗肝脏恶性肿瘤是一种微创、安全、疗效可靠的新方法。对于不适宜行手术治疗的肝脏恶性肿瘤患者是一种有效的微创外科治疗方法。  相似文献   
77.
Measurement of spinal cord evoked potentials (SCEPs) is proposed as a means of predicting locomotion outcome in the rat spinal cord injury (SCI) model. Using 55 rats, three reproducible peak waves (waves I, II and III) were observed during stimulation at the C7 level with recording at the L1 epidural space. Hemisection at the T13 level showed three wave loss patterns: wave III loss only, loss of both wave II and III, and loss of all three waves. Defining an ideal SCI model as establishment of stable monoparesis or paraparesis, all animals in the wave II-III loss group showed favorable results. Histological data and electrophysiological properties allowed reasonable assumptions of wave origin: wave I from extrapyramidal tracts, wave II from the ventral corticospinal tract, and wave III from the dorsal corticospinal tract. Complete destruction of pyramidal tracts in both dorsal and ventral fibers was essential for long-term impairment of locomotion.  相似文献   
78.
BACKGROUND: For immunotherapeutic approaches, 'critical' amino acids (AAs) within allergenic epitopes are replaced with alternate AAs to eliminate IgE antibody binding. OBJECTIVE: To determine the critical AAs for IgE binding in beta-casein and beta-lactoglobulin (BLG). METHODS: Peptides of 10-14 AAs in length were synthesized on a derivatized cellulose membrane with single AA substitutions (alanine or glycine) at each position. Membranes were incubated with a pool of sera from 15 cow's milk-allergic patients and individual sera from six of the 15 patients. In cases where no decrease in binding occurred with a single AA substitution, peptides with two AA substitutions were generated and labelled. RESULTS: Using pooled patient sera, single AA substitutions led to complete elimination of binding to six of 11 peptides for beta-casein and to all six peptides for BLG. Substituting two AAs led to an elimination of binding to four of the remaining five beta-casein epitopes. However, in three of the 11 modified beta-casein peptides and five of the six BLG peptides, no decrease in IgE binding occurred in at least one individual patient. For these patients, critical AAs other than those defined by the patient serum pool were identified, indicating a heterogeneous pattern of IgE recognition. CONCLUSION: These results indicate that AAs critical for IgE binding are more heterogeneous than initially defined by pooled milk-allergic patient sera. For future immunotherapeutic interventions with mutated peptides, critical AAs should also be identified with individual patient sera to account for heterogeneity of IgE binding between patients.  相似文献   
79.
目的探讨下颌骨侧位摄影分别采用一倾斜角度为α的垫板及未采用时,X线中心线倾斜角度各为β、γ之间的关系,为更简捷地拍好下颌骨提供理论参数和实践依据。方法立足于教科书,运用X线摄影原则与数学几何原理进行推理演绎。结果二者之间存在着可替换的关系,即γ=α+β,可以大胆地去除垫板进行直接拍摄。结论不用垫板,只需通过增大X线中心线倾斜角度的方法,同样也能拍摄出一张好照片,且可操作性强,简便易行,实际使用价值更大。  相似文献   
80.
本文研究了小儿糜烂性口腔炎的病毒病因,用人胚肾细胞及Hep—2细胞分离病毒,26例患儿有21例阳性(80.7%),从中取五株病毒进行鉴定,细胞病变特点属疱疹病毒,且均可被抗HSV—I抗体中和,结果表明HSV—I是本病的主要病原。体外实验证明,白细胞干扰素对新分离的HSV—I有较强的抑制病变作用,2.4~2.9Iu/ml白细胞干扰素即可抑制病毒的50%CPE。临床上试用干扰素局部治疗必获得显著的疗效。  相似文献   
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