99Tcm直接法标记血管抑素

目的: 探索用99Tcm直接标记血管抑素(angiostatin, AS)的方法,并研究标记产物的体外稳定性及其生物活性. 方法:制备的AS经鉴定后,分别用2-巯基乙醇(2-ME)和氯化亚锡(SnCl2)还原法进行标记,并用正交设计筛选最佳合成条件;对标记产物用纸层析法及Sephadex G-50层析柱分离测标记率;产物中分别加入牛血清白蛋白(BSA)、生理盐水及不同摩尔比的半胱氨酸(Cys)以观察其体外稳定性;用人脐静脉内皮细胞系ECV304观察其生物活性. 结果:2-ME法最佳标记条件为AS 100 μg,PB(0.5 mol*L-1, pH 7.3) 1 mL, 2-ME 100 μg, 亚甲基二膦酸盐(MDP)(用1 mL生理盐水溶解) 10 μL,加入99TcmO4- 185 MBq,标记率可达(97.0±1.5)%; SnCl2法为AS 100 μg,硼酸缓冲液(0.1 mol*L-1, pH 9.0) 1 mL, 20 g*L-1 SnCl2 (1 mol*L-1盐酸作为溶剂) 20 μL加入MDP药盒,用去氧水稀释至1 mL, 取20 μL,加入99TcmO4- 185 MBq,标记率可达(90.0±3.0)%. 产物在体外稳定;细胞培养观察其抑制内皮细胞生物活性与AS无显著差异. 结论:用99Tcm直接法标记AS简单高效,且对AS生物活性无明显影响.     

Determination of the mean transit time for the transport of aerosolized 99mTc-DTPA across the pulmonary epithelial membrane. A plasma sample method

Summary. During the last decade it has been customary to estimate pulmonary epithelial permeability (P-P) as the pulmonary clearance of inhaled nebulized ^99mTc-DTPA from a time-activity (t-a) curve registered externally by monitoring over the chest. The t-a curve, however, is not defined by the degree of P-P alone but also by factors such as the deposition of the ^99mTc-DTPA in the lungs. To avoid these problems a plasma sample method was derived. It describes P-P by the mean transit time (t?) for the transport of ^99mTc-DTPA across the pulmonary epithelial membrane, t? (L). The calculation of t? (L) involves two steps. Following the inhalation of Tc-DTPA the plasma t-a curve is defined and used to calculate t? for the transport for ^99mTc-DTPA across the pulmonary epithelial membrane, through the E?V and until elimination by the kidneys, t? (L+ECV). Subsequently, ^99mTc-DTPA is injected as a bolus i.v. and the new t-a curve is used to calculate t? for the transport of ^99mTc-DTPA through ECV to the kidneys, t? (ECV). Finally t? (L) is calculated as t? (L) = -t? (L+ECV) t? (ECV). We applied the method in nine non-smoking individuals (median age 25–5 years, range 20–28) and compared the results to t? as calculated from the initial slope of an externally derived t-a curve. The individual t? (L) values were systematically greater than those of the external detection method (P<0·05). It is concluded that the initial slope method overestimates total PCI as measured by the plasma sample method. When choosing between the two methods, special interest should be paid to the inherent problems of the methods.     

Review of imaging techniques for the diagnosis of breast cancer: a new role of prone scintimammography using technetium-99m sestamibi

Imaging techniques currently used for the diagnosis of breast cancer are reviewed and compared. Besides mammography, magnetic resonance imaging, positron emission tomography, and thallium-201 scintimammography, a new role of technetium-99m sestamibi scintimammography is discussed. It is concluded that while mammography remains the procedure of choice in screening asymptomatic women for breast cancer, other imaging methods play an important role in detecting malignancies in symptomatic patients.^99mTc-sestamibi scintimammography has high sensitivity and improves the specificity of conventional mammography for the detection of breast cancer; with this technique, prone imaging is preferable to supine imaging.^99mTc-sestamibi scintimammography thus deserves further study as a screening technique.     

~(99m)Tc-MIBI心肌灌注断层显像监测蒽环类药物的心脏毒性

目的 :探讨99mTc-MIBI心肌灌注断层显像在蒽环类药物心脏毒性监测中的价值。方法 :2 3例接受蒽环类药物治疗的患者 ,在治疗前进行心电图、心肌酶学检查、核素心室造影测左室射血分数 (LVEF)和99mTc MIBI心肌灌注断层显像并计算相对定量值。并于每一周期治疗后重复上述检查。结果 :蒽环类药物治疗一周期后 ,2 3例患者心肌相对定量值明显下降 (P <0 .0 1)。其中 11例吡喃阿霉素、6例表阿霉素和 6例米托蒽醌治疗的患者 ,心肌相对定量值明显下降 (P <0 .0 5 ) ,心电图和心肌酶学无明显变化 (P >0 .0 5 )。蒽环类药物治疗多周期后的 10例患者心肌相对定量值较治疗前下降 (P <0 .0 5 )。 9例患者的心肌相对定量值 (最大累积剂量为 2 0 0mg/m2 )与一周期后无明显差别 (P >0 .0 5 )。10例患者治疗前及多周期治疗后LVEF均 >6 0 %,且化疗前后无明显差别 (P >0 .0 5 )。结论 :99mTC MIBI心肌灌注断层显像能监测蒽环类药物所致的心肌损害 ,且较左室射血分数敏感 ,比心电图和心肌酶学检查优越 ,有利于指导蒽环类药物的临床应用。     

99mTc-depreotide生长抑素受体显像的临床应用研究

生长抑素受体显像近年来研究较多，depreotide已成为其研究热点之一。Depreotide在诊断与鉴别诊断临床常见的孤立性肺结节方面有其独特优势；此外，^99mTc—depreotide生长抑素受体显像在乳腺癌、甲状腺癌、淋巴瘤等肿瘤及甲状腺相关性眼病等非肿瘤性疾病也有一定应用前景。     

放射性~(125)I粒子组织间植入对家兔尿道损伤的实验研究

目的:研究不同剂量的放射性125I粒子对家兔尿道的放射性损伤。方法:麻醉下将放射性125I粒子植入雄性家兔尿道旁1.0cm处。125I粒子的放射性粒子活度分别为14.8MBq(A组)、29.6MBq(B组)和44.4MBq(C组),对照组(D组)仅尿道旁种植相当于粒子大小无放射性的无菌铅管1粒。植入后4周,摄尿道片,观察粒子位置等情况;原手术切口切开,取放射粒子周围2.0cm范围内的家兔尿道组织作肉眼、光学显微镜和电子显微镜观察,进行放射性损伤的评价。结果:术后4周,肉眼及光学显微镜观察,实验组与对照组粒子周围的尿道粘膜、粘膜下及肌层所见基本一致;C组少部分电镜视野中观察到尿道上皮胞质出现较多空泡变性、空化、嵴稀疏等超微结构的损伤。光镜下尿道入射性损伤评分,A、B、C、D组分别为(2.20±0.18)、(2.23±0.15)、(2.27±0.10)、(2.10±0.17)分,A、B、C组与D组相比,差异无显著性(P>0.05)。对线粒体作FlaMeng半定量分析,A、B、C、D各组评分分别为(1.23±0.13)、(1.34±0.25)、(1.41±0.30)、(1.12±0.13)分,A、B、C各组与D组(对照组)相比,差异无显著性(P>0.05)。结论:放射性125I粒子对尿道放射性损伤随粒子的放射性活度的增加而逐渐加重,呈明显的放射性活度效应关系;正常剂量的放射性粒子对尿道的损伤是很轻微的,是安全可行的。     

局部内放疗预防肝癌切除术后复发的研究

目的了解肝内局部^32P玻璃微球（^32P-GMS）埋置对肝癌切除术后预防复发的效果。方法A组29位肝细胞性肝癌病人于肿瘤切除后局部埋置^32P-GMS，B组为同期38位肝癌病人行肝癌切除术后未埋置^32P-GMS。观察术后不同时间肝、血和尿中的放射性分布。随访统计两组病人的复发率和生存率。结果肝内局部埋置^32P-GMS的病人未发现血和尿中放射性分布。A组术后半年、1年、2年、3年及3年以上的复发率明显低于B组，存活率明显高于B组，具有统计学意义。两组手术死亡率及术后并发症发生率无明显差异。结论肝癌切除术后局部埋置^32P-GMS可以减少复发，延长病人的生存时间。     

Quantitative Analysis of the Tomographic Technetium－99m MIBI （~（99m）Tc－MIBI） Myocardial Bullseye Display： Application to Diag

ＱｕａｎｔｉｔａｔｉｖｅＡｎａｌｙｓｉｓｏｆｔｈｅＴｏｍｏｇｒａｐｈｉｃＴｅｃｈｎｅｔｉｕｍ－９９ｍＭＩＢＩ（~（９９ｍ）Ｔｃ－ＭＩＢＩ）ＭｙｏｃａｒｄｉａｌＢｕｌｌｓｅｙｅＤｉｓｐｌａｙ：ＡｐｐｌｉｃａｔｉｏｎｔｏＤｉａｇｎｏｓｉｓｏｆＣｏｒｏｎａ?..     

Localization of parathyroid enlargement: experience with technetium-99m methoxyisobutylisonitrile and thallium-201 scintigraphy,ultrasonography and computed tomography

Technetium-99m methoxyisobutylisonitrile (MIBI), like thallium-201, has recently been introduced as a myocardial perfusion agent and is now also showing very promising results in parathyroid scintigrapy. The results of ²⁰¹Tl/^99mTc-pertechnetate and ^99mTc-MIBI/^99mTc-pertechnetate subtraction scintigraphy, ultrasonography and computed tomography are presented in a series of 43 patients operated on for hyperparathyroidism. All four imaging modalities were confirmed to be reliable, scintigraphy being the most accurate. Sensitivities ranged from 81% to 95%, that of ^99mTc-MIBI being the highest. Moreover this tracer, which has more favourable physical and also biochemical properties, yielded images of superior quality. This allowed localization of the lesion by visual inspection only in as many as 86% of the patients with positive ^99mTc-MIBI/^99mTc-pertechnetate subtraction scintigraphy. We believe that the higher sensitivity, superior image quality and lower cost of ^99mTc-MIBI imaging will make ^99mTc-MIBI the new radiopharmaceutical of choice for parathyroid scintigraphy (when one takes into account the stability of labelling with large activities it is possible to perform three or four cardiac studies together with one parathyroid scintigraphic examination using one lyophililzed vial).     

Structural modification of receptor-binding technetium-99m complexes in order to improve brain uptake

Low brain uptake is a generally accepted problem in developing technetium-99m brain receptor imaging agents. For a class of potential 5-HT_2A receptorbinding agents we tried to improve the original low brain uptake of 0.4% injected dose (ID) in rats 5 min p.i. by modifying the lipophilic properties of the molecules. Because of the presence of a protonable nitrogen, which according to the pK _a value leads to ionization of the molecule at blood pH, the pK _a value was considered to be the parameter most suitable for adjustment of lipophilicity. Insertion of ether-oxygen in the molecule of five candidates lowers the apparent pK _a value from 10.0 to 8.3 and dramatically increases the brain uptake to 1.3% ID at 5 min. The direct relationship between brain uptake and apparent pK _a cannot be simply explained by the increase in the pK _a-governed proportion of the neutral species.