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971.
目的:探讨单侧输尿管梗阻后大鼠肾间质纤维化发生过程中肝细胞生长因子(HGF)的表达及中药参附注射液对其的影响。方法:采用单侧输尿管结扎(UUO)制造梗阻性肾病模型,将56只大鼠随机分为对照组(假手术组)、手术组(UUO组)和治疗组(UUO+参附),术后7d、14d观察肾组织病理改变,应用免疫组织化学方法检测肾组织中HGF的表达。结果:与对照组相比,手术组肾间质出现了明显的纤维化,HGF的表达在术后第7天明显增加,第14天较第7天减弱,与手术组相比,治疗组肾间质纤维化明显减轻,而且HGF的表达在术后第7天明显上调,第14天较第7天上调更明显,有统计学差异(P〈0.05)。结论:参附注射液可以上调肾组织HGF的表达,减轻肾小管一间质纤维化,发挥肾保护作用。  相似文献   
972.
The present study was aimed to investigate the chemopreventive effects of Solanum trilobatum (ST) extract against diethylnitrosamine (DEN)-induced hepatocarcinogenesis promoted by Phenobarbital (PB) in Wistar rats. Hepatocarcinogenesis was initiated by a single intraperitoneal injection of DEN (200 mg/kg b.w.) and promoted with PB (0.05%) in basal diet. The experimental study extended for periods of 13 and 26 weeks. Alcoholic extract of ST was orally administered for the entire experimental period after initiation along with commencement of promotion. The chemopreventive effect of ST was assessed from the incidence of nodules, drug metabolizing phase I components such as contents of cytochrome P450, cytochrome b(5), activities of NADPH cytochrome c reductase, NADH - cytochrome b(5) reductase and phase II components such as levels of glutathione, activities of UDP-glucuronyl transferase, glutathione S-transferase and gamma-glutamyl transpeptidase in the liver. Lipid peroxidation at basal and prooxidants-induced (NADPH + ADP + Fe and Ascorbate + Fe) states was assessed in the microsomes. Animals administered with ST extract evidenced significant inhibition of tumor nodular incidence in DEN + PB + ST animals compared to DEN + PB animals, with favorable alterations in the hepatic drug-metabolizing phase I and phase II components. Administration of ST inhibited basal and pro-oxidant-induced lipid peroxidation. The present result suggests the probable mediation of chemoprevention by ST against DEN-induced carcinogenesis by the modulation of drug metabolizing components in the liver of treated animals.  相似文献   
973.
A new radioactivity solution standard of 210Pb has been developed and will be disseminated by the National Institute of Standards and Technology (NIST) as standard reference material (SRM) 4337. This new 210Pb solution standard is contained in a 5 mL flame-sealed borosilicate glass ampoule, consists of (5.133±0.002) g of a nominal 1 mol L−1 nitric acid solution, has a density of (1.028±0.002) g mL−1 at 20 °C, has carrier ion concentrations of about 11 μg Pb2+ and 21 μg Bi3+ per gram of solution, and is certified to contain a massic activity (9.037±0.22) kBq g−1 as of the reference time 1200 EST, 15 June 2006. All of the uncertainties cited above correspond to standard uncertainties multiplied by a coverage factor k=2. The standardization for the 210Pb content of the solution was based on 4πβ liquid scintillation (LS) measurements using CIEMAT/NIST 3H-standard efficiency tracing (CNET). Confirmatory determinations were also performed by high-resolution HPGe γ-ray spectrometry, by 2π spectrometry with a Si surface barrier detector of separated 210Po, and by 4πβ(LS)–γ(NaI) anticoincidence counting.  相似文献   
974.
Ultrashort echo time (UTE) imaging is a technique that can visualize tissues with sub-millisecond T(2) values that have little or no signal in conventional MRI techniques. The short-T(2) tissues, which include tendons, menisci, calcifications, and cortical bone, are often obscured by long-T(2) tissues. This paper introduces a new method of long-T(2) component suppression based on adiabatic inversion pulses that significantly improves the contrast of short-T(2) tissues. Narrow bandwidth inversion pulses are used to selectively invert only long-T(2) components. These components are then suppressed by combining images prepared with and without inversion pulses. Fat suppression can be incorporated by combining images with the pulses applied on the fat and water resonances. Scaling factors must be used in the combination to compensate for relaxation during the preparation pulses. The suppression is insensitive to RF inhomogeneities because it uses adiabatic inversion pulses. Simulations and phantom experiments demonstrate the adiabatic pulse contrast and how the scaling factors are chosen. In vivo 2D UTE images in the ankle and lower leg show excellent, robust long-T(2) suppression for visualization of cortical bone and tendons.  相似文献   
975.
We assessed the relations of visual hallucinations (VH) to cardiovascular autonomic dysfunction in patients with Parkinson's disease (PD). The subjects were 37 patients without VH (VH(-)) and 31 with VH (VH(+)). Autonomic function was evaluated on the basis of cardiac 123-radioiodinated metaiodobenzylguanidine (123I-MIBG) uptake and hemodynamic testing with Valsalva maneuver. Systolic blood pressure (SBP) and plasma norepinephrine concentrations (NE) were measured by tilt-table testing. 123I-MIBG uptake was lower in VH(+) than VH(-). Hemodynamic studies showed that VH(-) had only cardiac sympathetic and parasympathetic dysfunction, while VH(+) additionally had reduced vasomotor sympathetic functions. The fall in SBP during tilt-table testing was greater in VH(+) than VH(-). NE and its difference in the supine and upright positions were decreased in VH(+). We conclude that cardiac and vasomotor sympathetic dysfunction is more severe in VH(+) than in VH(-). Severe dysfunction in PD with VH is probably attributed to Lewy-body lesions or neuronal loss in sympathetic ganglia, the central autonomic system, or both.  相似文献   
976.
The purpose of this study was to evaluate the dose to normal tissues as a function of increasing margins around the lumpectomy cavity in accelerated partial breast irradiation (APBI) using 3D-conformal radiotherapy (3DCRT). Eight patients with Stage 0-I breast cancer underwent treatment planning for 3DCRT APBI. The clinical target volume (CTV) was defined as a 15-mm expansion around the cavity limited by the chest wall and skin. Three planning target volumes (PTV1, PTV2, PTV3) were generated for each patient using a 0, 5-, and 10-mm expansion around the CTV, for a total margin of 15, 20, and 25 mm. Three treatment plans were generated for every patient using the 3 PTVs, and dose-volume analysis was performed for each plan. For each 5-mm increase in margin, the mean PTV:total breast volume ratio increased 10% and the relative increase in the mean ipsilateral breast dose was 15%. The mean volume of ipsilateral breast tissue receiving 75%, 50%, and 25% of the prescribed dose increased 6% to 7% for every 5 mm increase in PTV margin. Compared to lesions located in the upper outer quadrant, plans for medially located tumors revealed higher mean ipsilateral breast doses and 20% to 22% more ipsilateral breast tissue encompassed by the 25% IDL. The use of 3DCRT for APBI delivers higher doses to normal breast tissue as the PTV increases around the lumpectomy cavity. Efforts should be made to minimize the overall PTV when this technique is used. Ongoing studies will be necessary to determine the clinical relevance of these findings.  相似文献   
977.
目的:探讨胃肠间质瘤(GIST)的CT表现及分子靶向药物甲磺酸伊马替尼(STI571)对胃肠间质瘤疗效的CT评价。方法:选择经手术及病理证实的胃肠间质瘤病例32例进行回顾性分析。对19例接受STI571治疗者进行定期CT检查随访,观察病灶大小、形态及密度变化,评价药物疗效。结果:32例GIST中,发生于胃部的18例,小肠11例,肠系膜1例,直肠2例。①CT特征:恶性度较高的胃肠间质瘤CT表现为:肿块相对较大,密度不均,肿瘤中央坏死及囊变多见;肿瘤边缘多不光整,可呈分叶状。增强扫描肿瘤呈不均匀强化;少数巨大肿瘤密度较低,极少数可见高密度出血及钙化灶。良性GIST体积较小,密度均匀,肿瘤坏死及囊变少见,病灶边缘光整,增强扫描多呈均匀强化;②19例接受STI571治疗者定期CT检查疗效评价为(肿瘤缩小):疗效达PR(部分缓解)者9例,占47.4%,疗效为SD(疾病稳定)者8例,占42.1%,病灶进展(PD)者2例,占10.5%。术后2年内复发及转移者19例。结论:①螺旋CT扫描是诊断胃肠间质瘤最常用和最有价值的影像检查手段,其定位诊断率达81%以上;②应用CT扫描观察测量病灶变化是评价药物(STI571)治疗胃肠间质瘤疗效最重要和最直接的方法之一;对指导临床治疗具有重要意义。  相似文献   
978.
Cytomegalovirus (CMV) infection accelerates transplant vascular sclerosis (TVS) and chronic rejection (CR) in both human and animal solid organ transplantation models. The host/viral mechanisms involved in this process are unclear. We examine the role of the rat CMV (RCMV)-encoded chemokine-receptor R33 in the development of TVS using a rat heart transplantation/CR model. F344 heart grafts were transplanted heterotopically into Lewis recipients. The ability of RCMV lacking the R33 gene (RCMV-Deltar33) to accelerate CR/TVS (neointimal index, NI) was compared to wild-type (WT) RCMV. Allograft recipients were infected with 1 x 10(5) pfu RCMV or RCMV-Deltar33 on postoperative day (POD) 1. Grafts from RCMV-Deltar33-infected recipients demonstrated an accelerated time to allograft CR compared to grafts from uninfected recipients (POD = 56 vs. 90), this was slower than that seen in grafts from WT-RCMV-infected recipients (POD = 45). Similarly, the degree of graft TVS formation at terminal rejection in RMCV-Deltar33 infected recipients was more severe than uninfected recipients (NI = 63 vs. 45), yet not as severe as in WT-RCMV infected recipients (NI = 83). In parallel, RCMV-Deltar33 failed to induce vascular smooth muscle cell (SMC) migration in vitro, whereas WT-RCMV induced substantial migration. The RCMV-encoded chemokine-receptor r33 is critical for RCMV-accelerated TVS/CR and vascular SMC migration.  相似文献   
979.
Objective: Aprotinin is widely used in heart surgery for reduction of intraoperative blood loss. But recent reports presenting results from rat aorta experiments claimed that aprotinin selectively impairs endothelium-dependent relaxation (EDR) as well as basal NO availability in concentrations similar to doses routinely used in cardiovascular surgery. An impairment of coronary EDR by aprotinin would be a great danger for any cardiothoracic intervention. We therefore tested the influence of aprotinin in the coronary arteries of a non-rodent species. Methods: Fresh coronary arteries of pigs were obtained from the local slaughterhouse and transported to our laboratory in cold oxygenated Krebs–Henseleit solution. Five-millimeter long rings were consecutively tested with or without aprotinin in concentrations of 500 KIU/ml (n = 7) or 1000 KIU/ml (n = 6) in oxygenated normothermic Krebs–Henseleit solution. PGF2 (10 μmol/l) was used for inducing contraction and substance P (10 nmol/l) for inducing EDR, which was calculated in percentage of the precontraction. Indomethacin (10 μmol/l) was added in all measurements to eliminate the influence of prostaglandins. In additional similar experiments (n = 5), the influence of 1000 KIU/ml aprotinin on the EDR caused by the endothelium-derived hyperpolarizing factor (EDHF) was tested using l-NNA (300 μmol/l) to block all NO formation. Results: The EDR of pig coronaries (82 ± 5% or 80 ± 5% of the precontraction in the control tests before and after aprotinin exposure) was not significantly changed by 500 KIU/ml aprotinin (78 ± 7%). A small, but significant reduction of less than 1/10 of the EDR was induced by 1000 KIU/ml aprotinin (74 ± 5%). After accounting for l-NNA for NO blockage, no aprotinin-related difference remained (59 ± 6% vs 60 ± 6% in controls). Conclusion: For clinically relevant concentrations of aprotinin up to 500 KIU/ml, no significant reduction of the EDR can be found in epicardial coronary arteries of the pig. For higher doses of 1000 KIU/ml, a reduction in NO production seems to be the cause of the small but significant reduction of the EDR by aprotinin. Therefore, danger for impairment of coronary EDR by aprotinin at clinical dosage levels, as suggested by studies on rat aortas, seems to be absent in coronary arteries of a large mammalian model.  相似文献   
980.
目的 观察丝素蛋白与牛骨形态发生蛋白的载体系统与骨髓间充质干细胞的体外相容性.方法 将多孔丝素蛋白修剪成20×10×5 mm长方体状物,置入6孔板中;将粉状bBMP用PBS液溶解制成2mg/ml混悬液,0.5ml无菌移液管滴定于多孔丝素蛋白上(0.5毫升/个).骨髓间充质干细胞以107/ml接种到载体系统上,复合4小时后加入生长液继续体外培养,每1、4、8天时进行碱性磷酸酶、矿化结节染色观察以及扫描电镜和激光共聚焦显微镜观察;另外同时设立单纯丝素蛋白与细胞复合培养对照组进行观察.结果 倒置显微镜、扫描电镜和共聚焦显微镜下观察到细胞在两种材料上生长形态、活性正常,体外培养24小时时细胞已贴附材料上,呈匍匐状伸展,以后逐渐融合生长,8天时大量细胞成片状攀附在材料表面,并分泌有大量的网状细胞外基质,实验组可见结节状基质生成;碱性磷酸酶、矿化结节染色观察发现实验组细胞碱性磷酸酶和矿化结节染色阳性反应,对照组阴性.结论 丝素蛋白是一种良好细胞外基质材料,也是一种良好生长因子的缓释载体.  相似文献   
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