~（99m）Tc标记DTPA-生物素和hIgG在正常小鼠体内分布实验

目的：探讨DTPA-生物素和hIgG的99mTc标记方法,并观察标记物在体内、外的稳定性及其在正常小鼠体内分布。方法：99mTc标记DTPA-生物素采用直接标记法,99mTc标记hIgG采用2-巯基乙醇还原法,标记率及放化纯测定采用纸层析法,并分别观察99mTc-生物素和99mTc-IgG在生理盐水（NS）中的稳定性;取24只正常小鼠,分为两组,分别经尾静脉注入99mTc-生物素和99mTc-hIgG,注入剂量为7.4MBq/100μl,于注入后1h、3h、6h、12h行SPECT显像并处死小鼠分离各脏器,测量放射性计数,计算各脏器每g组织百分注射剂量（%ID/g）。结果：99mTc标记DTPA-生物素的标记率〉80%,99mTc标记hIgG的标记率〉70%,99mTc-hIgG的放化纯〉90%;在NS中温育12h未观察到99mTc-生物素和hIgG放化纯度明显降低;体内生物分布显示99mTc-生物素肾内摄取高,主要经泌尿系统排泄;99mTc-hIgG在体内主要分布于肝、脾、肾,且在血液中存留时间较长。结论：99mTc标记DTPA-生物素和hIgG具有良好的标记率及体外稳定性,小鼠体内分布实验表明,99mTc-生物素和99mTc-hIgG体内分布的明显不同,为下一步基于亲和素-生物素系统预定位技术各组分的应用提供实验依据。     

新型~(99m)Tc-DTPA-GGGRDN-IF7靶向肿瘤血管Anxa1分子探针的制备及SPECT显像

目的制备针对肿瘤血管表面受体Annexin A1(Anxa1)分子探针~(99m)Tc-二乙三胺五乙酸(DTPA)-甘氨酸-甘氨酸-甘氨酸-精氨酸-天冬氨酸-天冬酰胺(GGGRDN)-异亮氨酸-苯丙氨酸-亮氨酸-亮氨酸-色氨酸-谷氨酰胺-精氨酸(IFLLWQR,IF7),进行体外肿瘤细胞(人脑星形胶质细胞瘤U87细胞)实验;探讨~(99m)Tc-DTPA-GGGRDN-IF7在荷瘤小鼠体内的生物学分布规律,并利用单光子发射计算机体层摄像术(SPECT)进行显像研究。方法将100μg DTPA-GGGRDN-IF7溶于10μL二甲基亚砜(DMSO)中,充入氮气保护。加入10μL 1 mg/mL氯化亚锡(SnCl2)溶液(pH 4.0),再加入约111 MBq(3 mCi)Na~(99m)TcO_4,37℃水浴反应30 min,经C_(18)柱淋洗后制备~(99m)Tc-DTPA-GGGRDN-IF7。取样注入分析型高效液相色谱(HPLC)仪分析~(99m)Tc-DTPA-GGGRDN-IF7的放射化学纯度及体外血清稳定性。将U87细胞与~(99m)Tc-DTPA-GGGRDN-IF7共同孵育后,测定放射性计数并计算摄取率。取30只4～5周龄18～20 g荷瘤裸鼠,建立U87荷瘤裸鼠模型,进行~(99m)Tc-DTPA-GGGRDN-IF7的体内分布实验及SPECT显像。结果 ~(99m)Tc-DTPA-GGGRDN-IF7标记产率大于95%,放射化学纯度大于95%。在大鼠血清中37℃保温2 h后性状稳定,放射化学纯度大于92.3%。U87细胞在体外对~(99m)Tc-DTPA-GGGRDN-IF7摄取在60 min时达峰值(6.85%±0.97%),过量的GGGRDN-IF7可以明显降低细胞的摄取。体内分布实验结果显示,药物均在血浆清除较快,肝肾摄取高,主要从肝肾排泄。SPECT显像结果表明,肿瘤部位呈明显放射性浓聚态,注射2 h后肿瘤对~(99m)Tc-DTPA-GGGRDN-IF7摄取值为(3.56±0.44)%ID/g。结论 ~(99m)Tc-DTPA-GGGRDN-IF7合成简便,放射化学纯度高,易于推广;U87细胞对~(99m)Tc-DTPA-GGGRDN-IF7具有较强亲和力;SPECT显像表明肿瘤明显浓聚~(99m)Tc-DTPA-GGGRDN-IF7,体内生物分布理想,靶向性强,有望用于肿瘤显像。     

99mTc-CPF制备及实验研究

目的探讨炎症显像剂99mTc-环丙沙星(99mTc-CPF)在小鼠体内分布的特点,评价其作为新型炎症显像剂的价值.方法制备99mTc-CPF,并测定其放化纯度和标记率.制作小白鼠炎症模型,并经尾静脉注入0.1ml99mTc-CPF,分别于0.5、1、4、6、12h处死小白鼠,取血样和部分器官组织,测量其放射性.结果 99mTc-CPE标记率>90%,室温下6h内化合物的放化纯稳定.小白鼠炎症组织与正常组织的放射性比值高,注射后1、4、6、12h,炎症组织与对侧正常组织比值分别为3.48、4.30、4.17、4.16.99mTc-CPF主要由肝脏代谢、经肾脏排泄,血液清除较快.结论 99mTc-CPE是一种灵敏度高的炎症灶显像剂,且制备方法简单、方便.     

99mTc-MDR1寡聚核苷酸DNAs的制备及质量控制

研究99mTc标记多药耐药基因(MDR1)mRNA反义DNAs寡聚核苷酸及其正义DNAs寡聚核苷酸的最佳标记方法并制备其二步法冰冻试剂盒,完成99mTc标记MDR1反义DNAs寡聚核苷酸和正义DNAs寡聚核苷酸及其二步法冰冻试剂盒的的质量控制.合成20个碱基单链的MDR1 mRNR的反义DNA寡聚核苷酸(ASON)及其正义DNA寡聚核苷酸(SON),全程硫代修饰并在5′末端附加氨基酸以修饰,分别将ASON和SON DNA 与MAG3偶联后用99mTc标记,制备了99mTc-寡聚核苷酸DNA二步法冰冻试剂盒.通过改变ASON-和SON-MAG3 DNAs、氯化亚锡及缓冲液的用量,调整反应介质的pH值条件,探讨其最佳标记方法.用高压液相色谱仪(HPLC)测定该药盒化合物的放射化学纯度、标记物的体内外稳定性、药盒的稳定性.99mTc-ASON-和SON-MAG3 DNAs标记化合物的放射化学纯度＞92%,标记物室温放置24 h后其放射化学纯度＞90%;药盒在-20℃条件下放置6个月,标记物的放射化学纯度仍＞90%.99mTc-寡聚核苷酸DNAs二步法冰冻试剂盒性能优良,标记方法简单、可行、有效,且标记物稳定性良好.     

抗人结肠癌单克隆抗体SC3A在荷瘤裸鼠体内的放射免疫定位研究

本文报道采用Iodogen法以~(131)I标记的抗人结肠癌McAbs SC3A,在荷人结肠癌裸鼠体内的生物学分布及放射免疫定位显像研究的结果。McAb SC3A腹水经protein ASepharose 4B纯化后,SDS-PAGE电泳鉴定纯度,分子量为160kD。标记结果标记率在85％以上,放化纯度在95％以上。用同法     

Tc-MDR_1寡聚核苷酸DNAs的制备及质量控制

研究99mTc标记多药耐药基因(MDR1)mRNA反义DNAs寡聚核苷酸及其正义DNAs寡聚核苷酸的最佳标记方法并制备其二步法冰冻试剂盒,完成99mTc标记MDR1反义DNAs寡聚核苷酸和正义DNAs寡聚核苷酸及其二步法冰冻试剂盒的的质量控制。合成20个碱基单链的MDR1 mRNR的反义DNA寡聚核苷酸(ASON)及其正义DNA寡聚核苷酸(SON),全程硫代修饰并在5′末端附加氨基酸以修饰,分别将ASON和SON DNA与MAG3偶联后用99mTc标记,制备了99mTc-寡聚核苷酸DNA二步法冰冻试剂盒。通过改变ASON-和SON-MAG3 DNAs、氯化亚锡及缓冲液的用量,调整反应介质的pH值条件,探讨其最佳标记方法。用高压液相色谱仪(HPLC)测定该药盒化合物的放射化学纯度、标记物的体内外稳定性、药盒的稳定性。99mTc-ASON-和SON-MAG3 DNAs标记化合物的放射化学纯度>92%,标记物室温放置24h后其放射化学纯度>90%;药盒在-20℃条件下放置6个月,标记物的放射化学纯度仍>90%。99mTc-寡聚核苷酸DNAs二步法冰冻试剂盒性能优良,标记方法简单、可行、有效,且标记物稳定性良好。     

~(125)I标记重组融合蛋白dTMP-GH在小鼠体内分布的实验研究

目的研究重组融合蛋白dTMP-GH在小鼠体内的分布情况,明确其是否具有靶向分布特点。方法实验室制备dTMP-GH重组融合蛋白;用放射性125I标记融合蛋白dTMP-GH后,按100μg/kg的标准小鼠尾静脉注射125I-dTMP-GH,分别于给药后5 min、15 min、30 min、1 h、2 h、4 h、8 h、12 h、24 h取心、肝、脾、肾、股骨、甲状腺等进行放射性计数。结果制备得到纯度大于98%的重组融合蛋白dTMP-GH;125I标记率为71.53%,放化纯度为96.53%,比活度为0.22 MBq/μl;尾静脉注射125I标记的dTMPGH后30 min股骨的放射性计数占到注射总量的10%,并随时间推移经肝脏和肾脏代谢。结论融合蛋白dTMP-GH经尾静脉注射后在小鼠体内主要分布于骨髓,具有骨髓组织偏向分布特点。     

11C-胆碱在线自动合成和生物体内分布

目的研究[11C-甲基]胆碱在线自动化合成的方法,并初步应用于临床试验.方法 11C-胆碱柱色层法在线制备.以Wistar大鼠研究动物体内生物学分布.结果柱色层制备的11C-胆碱放化纯度大于99%,合成效率为85%,合成时间11min.动物分布表明:放射性主要分布于肾、肝和肠道, 血液清除较快.结论柱色层法制备11C-胆碱时间短,效率高,操作简单.     

Chelator-Free法标记介孔二氧化硅纳米颗粒用于乳腺癌靶向PET成像

目的 使用Chelator-Free法进行⁶⁸Ga标记介孔二氧化硅纳米颗粒(MSNs)，制备新型正电子发射计算机断层显像(PET)分子探针，并检测其表征、生物安全性、放射性化学性能、体内生物分布及评估其体内乳腺癌靶向PET成像性能。方法 用模板法合成MSNs，对其进行纳米表征及生物安全性分析，明确其良好的生物安全性。并用Chelator-Free法进行⁶⁸Ga标记，制备出新型纳米PET分子探针⁶⁸Ga-MSNs，对其进行放射性化学分析，评估其在KM小鼠体内生物分布和对乳腺癌荷瘤小鼠的靶向PET成像性能。结果 MSNs平均粒径为85.03 nm，分散均匀，形貌优良。生物安全性分析显示MSNs在100μg/ml浓度下对细胞增殖无明显影响，显示出良好的生物安全性。⁶⁸Ga-MSNs的标记率大于95%，放射性化学分析显示，经纯化后⁶⁸Ga-MSNs放射性化学纯度大于98%，体外标记稳定性优良。KM小鼠体内生物分布显示⁶⁸Ga-MSNs主要分布于肝脏、脾脏和肺脏。乳...     

^99mTc-CPF制备及实验研究

目的 探讨炎症显像剂^99mTc-环丙沙星（^99mTc-CPF）在小鼠体内分布的特点，评价其作为新型炎症显像剂的价值。方法 制备^99mTc-CPF，并测定其放化纯度和标记率。制作小白鼠炎症模型。并经尾静脉注入0．1ml ^99mTc-CPF，分别于0．5、1、4、6、12h处死小白鼠，取血样和部分器官组织。测量其放射性。结果 ^99mTc-CPE标记率〉90％。室温下6h内化合物的放化纯稳定。小白鼠炎症组织与正常组织的放射性比值高，注射后1、4、6、12h，炎症组织与对侧正常组织比值分别为3．48、4．30、4．17、4．16．^99mTc-CPF主要由肝脏代谢、经肾脏排泄。血液清除较快。结论 ^99mTc-CPE是一种灵敏度高的炎症灶显像剂。且制备方法简单、方便。     

An experimental model to study the effects of a senna extract on the blood constituent labeling and biodistribution of a radiopharmaceutical in rats

ABSTRACT Cassia angustifolia Vahl (senna) is a natural product that contains sennosides, which are active components that affect the intestinal tract and induce diarrhea. Authors have shown that senna produces DNA (deoxyribonucleic acid) lesions in Escherichia coli cultures and can act as an antifungal agent. Natural drugs can alter the labeling of blood constituents with technetium-99m (^99mTc) and can affect the biodistribution of radiopharmaceuticals. In this work, we have evaluated the influence of a senna extract on the radiolabeling of blood constituents and on the biodistribution of the radiopharmaceutical sodium pertechnetate (Na^99mTcO₄) in Wistar rats. Twelve animals were treated with senna extract for 7 days. Blood samples were withdrawn from the animals and the radiolabeling procedure was carried out. The senna extract did not modify the radiolabeling of the blood constituents. A biodistributional assay was performed by administering Na^99mTcO₄ and determining its activity in different organs and in blood. The senna extract altered the biodistribution of Na^99mTcO₄ in the thyroid, liver, pancreas, lungs and blood. These results are associated with properties of the chemical substances present in the aqueous senna extract. Although these assays were performed in animals, our findings suggest that caution should be exercised when nuclear medicine examinations using Na^99mTcO₄ are conducted in patients who are using senna extract.     

^99mTcN—NOEt的生物分布研究

研究＾９９ｍＴｃＮ－ＮＯＥｔ的生物分布特征,材料与方法：新西兰兔９只及家狗３只,静脉注射显像剂后进行动态平面伽玛显像,利用感兴趣区技术计算器官放射性活度的主烨,结果与结论：心肌对＾９９ｍＴｃＮ－ＮＯＥｔ摄取较高心／值渐高而心／肝比渐下降;尽管肝脏明显浓像剂,但未见明显的清除,膀胱的放射性渐增多,提示泌尿系也是＾９９ｍＴｃＮ－ＮＯＥｔ生物清除的途径之一。     

Cumulated activities determined from biodistribution data in pregnant rats ranging from 13 to 21 days gestation. I. Tc-99m pertechnetate

Cumulated activity estimates for Tc-99m pertechnetate were determined using biodistribution data from pregnant and nonpregnant rats. The pregnant rats were studied at 13, 15, 17, 19, and 21 days gestation. The results indicate that maternal organ cumulated activities are not a simple function of gestational age. The organs into which Tc-99m pertechnetate enters through passive diffusion follow the pattern established by the blood, generally resulting in an increase from the 13th through the 17th day with a decrease on the 19th and 21st day. The organs dominated by active transport follow unique and different patterns. The fetal cumulated activity estimates increased exponentially with gestational age and the placental estimates increased linearly.     

cRGD肽二聚体对B16黑色素瘤细胞的体外抑制作用及在荷瘤鼠体内分布及显像研究

目的 探讨cRGD肽二聚体对B16黑色素瘤细胞的体外抑制作用及其在荷B16黑色素瘤细胞小鼠动物模型体内的分布及显像研究.方法 用MTT法检测不同浓度及作用时间cRGD肽二聚体对B16黑色素瘤细胞体外增殖能力的影响.采用直接标记法标记99 Tcm-c(RGD)2.建立荷B16黑色素瘤株动物模型,待肿瘤体积为1.0 ～ 1.5cm3左右时,分别于30min、1h、2h、3h、4h、5h及6h时,进行荷瘤鼠体内生物分布及动态显像研究.结果 cRGD肽二聚体浓度为500mg/L、作用48h时,对B16黑色素瘤细胞的增殖具有明显的抑制作用.室温下、ρ(SnCl2·2H20)=1 g/L、反应时间为30 min时,99Tcm-c(RGD)2的标记率可达(87.42±3.21)％,标记产物经Sephadex G10分离纯化后放射化学纯度大于95％;静脉注射后30min行小鼠全身SPECT显像,肿瘤部位可见明显显像剂聚集,但肿瘤与周围组织的对比度较低;延迟至6小时肿瘤仍清晰可见,且随时间延迟肿瘤与周围组织的对比度增高,此时肿瘤/血液为2.15±0.24,肿瘤/肌肉为5.07 ±0.03.结论 该结构cRGD肽二聚体对B16黑色素瘤细胞株具有一定的体外抑制作用,且动物体内肿瘤组织摄取率高,显像清晰,证明其可进一步应用于聚合物多肽靶向药物的研发.     

SHNH法和NHS-MAG3法标记的99mTc-寡聚核苷酸的比较

比较研究采用联肼尼克酰胺(Hydrazino Nicotinamide Derivative, SHNH)法和N-羟基琥珀酰胺基S-乙酰巯基乙酰三氨基乙酸(N-hydroxysuccinimidyl S-acetylmercaptoacetyltriglycline,NHS-MAG3)法以99mTc标记反义寡聚核苷酸(Antisense Oligonucleotide,ASON)的标记物的放射化学和生物学特性.合成SHNH和NHS-MAG3后,分别以SHNH和NHS-MAG3为双功能络(螯)合剂,用99mTc标记ASON;比较标记物99mTc-SHNH-ASON和99mTc-MAG3-ASON的体内外稳定性、兔血浆蛋白结合、正常BALB/C小鼠体内分布及结肠腺癌HT29细胞摄取的情况.结果显示,采用NHS-MAG3法标记的标记物99mTc-MAG3-ASON的标记率和稳定性明显高于SHNH法标记的标记物99mTc-SHNH-ASON(P＜0.05)、血浆蛋白结合率显著低于99mTc-SHNH-ASON(P＜0.05);99mTc-MAG3-ASON在血液、心脏、胃、肠的分布显著低于99mTc-SHNH-ASON(P＜0.05),而在肝、脾的分布略低于99mTc-SHNH-ASON(P＞0.05),但在肾的分布显著高于99mTc-SHNH-ASON(P＜0.05);99mTc-MAG3-ASON的HT29细胞摄取率显著高于99mTc-SHNH-ASON(P＜0.05).因此,采用NHS-MAG3法的标记物99mTc-MAG3-ASON的放射化学和生物学特性明显优于SHNH法的标记物99mTc-SHNH-ASON.     

Technetium-99m-labeled monoclonal antibodies for immunoscintigraphy. Simplified preparation and evaluation

Ascorbic acid incubated with monoclonal antibodies (22 degrees C, 60 min, pH 6.5) at a molar ratio of 3500:1, reduced 2.7 +/- 0.2% of the available disulfides to sulfhydryl groups that strongly bind 99mTc, and provided greater than 95% labeling efficiency for several IgM, IgG and F(ab')2 antibodies. The colloid formation was consistently less than 3% and the stability of the tracer when challenged with DTPA and cysteine was excellent. The immunospecificity of labeled antibodies as determined by immobilized specific antigen assay was 84 +/- 1% for IgM and 82.6 +/- 1.1% for IgG antibodies. For in vivo evaluation in mice bearing experimental abscesses and tumors, corresponding 125I-labeled antibodies served as controls. The liver uptake was similar (P = 0.76 and P = 0.12) for 99mTc or 125I labeled antinuclear antibody TNT-1 in mice bearing abscesses as well as for 99mTc-TNT-1-F(ab')2 and 125I-TNT-1-F(ab')2 in mice bearing tumors. Higher but statistically insignificant (P = 0.08, 0.18, and 0.73) urinary excretion was noted for 99mTc-antibodies. For corresponding 99mTc- and 125I-labeled antibodies, the abscess to muscle ratios (3.3 +/- 0.5 vs. 3.4 +/- 0.8) and tumor to muscle ratios (10.04 +/- 4.4 vs. 10.54 +/- 3.0) were similar. The high 99mTc-TNT-1-F(ab')2 uptake permitted excellent scintigraphic visualization of tumors whereas the nonspecific 99mTc-HSA did not (tumor/muscle ratio: 2.4 +/- 0.3). This method is simple, reliable, and adaptable to an instant labeling technique.     

An Ehrlichia strain from a llama (Lama glama) and Llama-associated ticks (Ixodes pacificus).

An ehrlichia was identified in the blood of a diseased llama (lama glama). Sequencing of its 16S rRNA gene showed the ehrlichia to be closely related to members of the Ehrlichia phagocytophila genogroup. The agent was also found in a pool of ticks (Ixodes pacificus) collected at the llama site.     

The combined oxacillin resistance and coagulase (CORC) test for rapid identification and prediction of oxacillin resistance in Staphylococcus species directly from blood culture

The combined oxacillin resistance and coagulase (CORC) protocol for rapid identification and determination of oxacillin-susceptibility in Staphylococcus spp from blood culture is described. It incorporates a modified direct tube coagulase test (TCT) and a novel 4-hour multiplication-induction step, which increases the expression of staphylococcal PBP2a if present, facilitating detection by a commercial PBP2a latex agglutination kit. The protocol shows excellent sensitivity and specificity for determination of coagulase-positivity in staphylococci from patient blood cultures (96.8% (95% CI 81.5 to 99.8) and 100% (95% CI 75.9 to 100), respectively, n = 47), and for prediction of oxacillin resistance in S aureus directly from patient blood cultures (100% (95% CI 59.8 to 100) and 100% (95% CI 82.2 to 100), respectively (100% accuracy), n = 31) within 5 hours of blood culture positivity.     

Effects of AZD2171 and vandetanib (ZD6474, Zactima) on haemodynamic variables in an SW620 human colon tumour model: an investigation using dynamic contrast-enhanced MRI and the rapid clearance blood pool contrast agent, P792 (gadomelitol)

The effect of two novel therapeutic agents on tumour haemodynamics was investigated using a fast dynamic contrast-enhanced (DCE)-MRI protocol (0.5 s/image) sensitive to signal changes in both the vascular input function and tumour during the administration of the macromolecular rapid clearance blood pool agent (MM-RCBPA), gadomelitol (P792, Vistarem). This enabled simultaneous measurement of the tumour blood flow per unit volume of tissue (F/V(T), mL/s/mL), the fractional plasma volume (V(p), %), and the permeability surface area product per unit volume of tissue (PSrho, s(-1)) in subcutaneous SW620 human colorectal tumour xenografts grown in nude rats before and after (at 0 and 22 h; imaging at 24 h) acute treatment with AZD2171 (3 mg/kg) and vandetanib (ZD6474, Zactima; 50 mg/kg), which have inhibitory activity against vascular endothelial growth factor receptor-2 (VEGFR-2) tyrosine kinase. MRI was performed at 4.7 T using a single-slice, modified, T(1)-weighted, spoiled gradient-echo technique. Both compounds reduced gadomelitol uptake into the tumour. AZD2171 and vandetanib, respectively, (a) greatly reduced PSrho to 19.7 +/- 9.5% and 28.9 +/- 14.1% of baseline (P = 0.007 and P = 0.02), (b) markedly reduced V(p) to 31.2 +/- 19.1% and 54.8 +/- 21.2% of baseline (P = 0.015 and P = 0.09), and (c) had no significant effect on F/V(T). There was no significant difference between groups treated with AZD2171 and vandetanib when each variable was compared. The reductions in PSrho and V(p) are consistent with inhibition of VEGF signalling. AZD2171 (3 mg/kg) and vandetanib (50 mg/kg) were also found to produce a comparable chronic inhibition of SW620 tumour growth (89% for both). This study shows that DCE-MRI using an MM-RCPBA can be used to distinguish tumour vascular flow, volume, and permeability surface area product in a tumour model, and enables the acute effects of VEGF signalling inhibition to be examined in detail.