188Re-Herceptin-磁性纳米微粒的体外抗肿瘤作用

目的探讨^188Re—Herceptin-磁性纳米微粒在外置磁场下对HER-2／neu癌基因高表达的SKBR-3乳腺癌细胞的靶向结合性及抗癌作用。方法采用戊二醛交联法使人源性单克隆抗体Her—ceptin与磁性纳米微粒交联，用直接标记法制备^188Re—Herceptin及^188Re—Herceptin-磁性纳米微粒，用羰基铼标记法制备^188Re-磁性纳米微粒。肿瘤细胞体外抑制实验设4个组：^188Re—Herceptin-磁性纳米微粒组、^188Re—Herceptin组、^188Re-磁性纳米微粒组和^188ReO4^-组，各组均设3．7×10^4、18．5×10^4、37×10^4、55．5×10^4、74×10^4Bq／ml5个放射性剂量级别；另设生理盐水对照组。采用四甲基偶氮唑蓝（MTT）法测定各组的抑瘤效应，计算相对抑制率，采用半数抑制放射性浓度（IC50）对各组抑瘤作用进行比较和评价。结果^188Re—Herceptin-磁性纳米微粒和^188Re—Herceptin组对SKBR-3细胞均有较强杀伤作用，且呈剂量依赖性；而^188Re-磁性纳米微粒和^188Re04组的杀伤作用较弱0188Re—Herceptin-磁性纳米微粒组的IC50（53．1×10^4Bq／L）明显低于^188Re—Herceptin组（76．1×10^4Bq／L）；^188Re一磁性纳米微粒组和^188ReO4组的IC50分别为169×10^4和175×10^4Bq／L，明显高于前2组。结论^188Re—Herceptin-磁性纳米微粒和^188Re—Herceptin均可明显抑制体外培养的SKBR-3乳腺癌细胞增殖，且前者的抑制作用较后者强。     

Brain perfusion territory imaging applying oblique-plane arterial spin labeling with a standard send/receive head coil.

A new method for the selective spin labeling of left- or right-sided supplying arteries of the brain without the need for additional RF coils is demonstrated. A clinical 1.5 T scanner was used. The spatial selectivity of the labeling process is based on the limited coverage of the excitation field of a standard send/receive head coil together with an oblique positioning of the labeling plane. A computer simulation was used to optimize key labeling parameters under the condition of laminar flow. The validity of the computer model results was confirmed by MRI measurements with a flow model. For human studies, a double-inversion continuous arterial spin labeling (CASL) sequence was modified to allow for arbitrary positioning of the labeling plane. The obtained perfusion-weighted images showed a clear delineation of the perfusion territories of the selected arteries in the anterior circulation of the brain and good gray/white matter contrast.     

Magnetically-labeled sensitized splenocytes to identify glioma by MRI: a preliminary study.

This study investigated the feasibility of imaging the migration and incorporation of magnetically-labeled sensitized splenocytes in an experimental 9L glioma brain tumor model. Splenocytes collected from tumor-bearing (sensitized splenocytes) or control (nonsensitized splenocytes) host rats were analyzed to determine the population of different cells, labeled with ferumoxides-protamine sulfate (FePro) and injected intravenously to recipient rats (N=4, for each group) bearing intracranial 9L tumors. Day 3 postinjection of splenocytes multiecho T2*-weighted and three-dimensional (3D) gradient echo MRI were obtained using a 7 Tesla MR system. R2* (1/T2*) maps were created from the T2*-weighted images. Signal intensities (SIs) and R2* values in the tumors and contralateral brain were determined by hand drawn regions of interest (ROIs). Brain sections were stained for the evidence of administered cells. Both 3D and T2*-weighted MRI showed low signal intensity areas in and around the tumors in rats that received labeled sensitized splenocytes. Prussian blue (PB), CD45- and CD8-positive cells were present in areas at the corresponding sites of low signal intensities seen on MRI. Rats that received labeled nonsensitized splenocytes did not show low signal intensity areas or PB positive cells in or around the implanted tumors. In conclusion, the immunogenic reaction can be exploited to delineate recurrent glioma using MRI following systemically delivered magnetically labeled sensitized splenocytes or T-cells.     

Synthesis of [3H] vardenafil,Levitra®, using a new labeling technique

Tritium was introduced into the new orally active, selective phosphodiesterase type V (PDE V) inhibitor vardenafil (Levitra^®), by reduction of a suitable amide precursor with freshly prepared lithium aluminum tritide. A specific activity of 52.7 Ci/mmol (1.95 TBq/mmol) was achieved. In order to overcome the usual technical difficulties during the preparation of complex tritides a new and easy labeling technique which has considerable potential for various tritia‐tion procedures, was developed. Copyright © 2003 John Wiley & Sons, Ltd.     

Thymidine labeling index in breast tumors

The relationship between primary tumor proliferative activity and clinical and pathologic characteristics was analyzed in relation to menopausal status in 32 patients with malignant or benign breast disease. The thymidine labeling index (TLI) showed significantly higher median values in the cancer patients (3.48 per cent) than in the patients with benign diseases (1.02 per cent). TLI was not significantly affected by delayed incubation at room temperature for about 1 hour. In the breast cancer patients, TLI did not significantly correlate to tumor size, the presence of axillary lymph node metastasis or pathologic nuclear grading. The only significant difference was limited to the breast cancer patients without axillary lymph node metastasis in relation to menopausal status; the TLI in the premenopausal patients (5.10 per cent) was significantly higher (p<0.05) than that in the postmenopausal patients (2.28 per cent). These data thus suggest that among premenopausal patients without axillary lymph node metastasis, those with a high TLI could be potential candidates for adjuvant chemotherapy.     

Comparison of the photochemical behavior of four different photoactivatable probes

The most commonly used photoaffinity labeling probes are compared, which are aryl azides, aryl diazirines, α-diazocarbonyls and benzophenone-derivatives. The compounds were used under identical conditions and crosslinking efficiency, influence of water, irradiation requirements, and by-products were investigated. Using the pentapeptide thymopentin (TP5) as a model system, we synthesized four analogues by solid-phase peptide synthesis and partially N-terminal modification to obtain [p-(3-trifluoromethyl)diazirinophenylalanine⁵] TP5, [p-benzoylphenylalanine⁵] TP5, 4-azidobenzoyl-TP5 and 2-diazo-3, 3, 3-trifluoropropionyl-TP5. The peptides were characterized by HPLC and ion-spray mass spectroscopy. Irradiation of the peptides with two different ultraviolet sources was carried out in water, n-propanol and water/n-propanol to imitate both hydrophobic and hydrophilic peptide/protein-interactions as well as the influence of the aqueous environment. Analysis of the products with HPLC, ion-spray MS, HPLC-MS and HPLC-CID-MS revealed that (Tmd)Phe is a highly potent carbene-precursor, which can be transformed easily into uniform crosslinking products by smooth photolysis. However, the electrophilic nature of the intermediate causes a high tendency to react with water molecules. The 4-azidobenzoyl group showed comparable crosslinking efficiency, but the probability to create non-uniform irradiation products (e.g. through rearrangement) is higher, whereas the reaction with water is less dominant. In contrast, Bpa was found to have an extremely low affinity to react with water, whereas prolonged UV irradiation is needed to get complete rearrangement into a variety of products. As the absorption band of α-diazocarbonyls at around 350 nm possesses a low extinction coefficient, 2-diazo-3, 3, 3-trifluoropropionyl-TP5 could not be activated at all with the optimized irradiation conditions that we have chosen for our comparative studies. © Munksgaard 1997.     

Location of motoneurones projecting to the cat distal forelimb. II. Median and ulnar motornuclei

The position of the motornuclei projecting through the median (Mn) and ulnar (Ul) nerves to the cat distal forelimb has been investigated. Horseradish peroxidase (HRP) and fluorescent (Fl) compounds have been used as retrograde tracers. They were either injected into forelimb muscles or applied to the proximal end of transected forelimb nerves. Limb muscles that were not investigated were carefully denervated. The position and the architecture of the individual motornuclei were traced with HRP. The topographical relations between the nuclei were established with application of up to three different Fl compounds in the same animal. The Mn motoneurones had a bimodal distribution in the brachial spinal cord. The motoneurones to the pronator teres and flexor carpi radialis muscles were located in C7 and the other Mn motoneurones were located in C8 and Th1. In C7 the Mn motoneurones occupied a single representation area, which is located some distance medially of the lateral funiculus. In C8 and Th1 two Mn representation areas were found: A dorsal one that contacts the lateral funiculus and is located at the level of the central canal; a ventral one that is located ventrally in the ventral horn. The dorsal area is occupied by the motornuclei projecting to the intrinsic hand muscles and the ventral one by the nuclei projecting to the limb. The Ul motoneurones extend with an unimodal distribution from the caudal C7 to the caudal Th1 segments. They occupy a single, broad representation area. The dorsal part, which contacts the lateral funiculus, is located at the level of the central canal and harbours the nuclei to the intrinsic hand muscles. The other Ul nuclei are located ventromedially deep in the ventral horn. These results, together with those from the companion paper on the location of the deep radial motornuclei, provide important anatomical information for the investigation of the cat brachial enlargement.     

99Tcm直接标记αvβ3受体拮抗剂环形RGD多肽

目的探讨^99Tc^m直接标记αvβ3受体配体——含2个二硫键的精氨酸-甘氨酸-天冬氨酸（RGD）-九肽（RGD-4CK）的可行性和不同标记条件对标记率的影响。方法采用预锡化法^99Tc^m直接标记RGD-4CK，3MM色谱纸层析测定^99Tc^m-RGD-4CK的雕值，计算标记率与比活度。研究各种标记条件对^99Tc^m-RGD-4CK标记率的影响。通过高效液相色谱仪（HPLC）分析，Sep-Pak C18柱层析，进行体外稳定性实验、半胱氨酸置换实验以及血清蛋白结合实验，评价^99Tc^m-RGD-4CK的放射化学性质。结果^99Tc^m-RGD-4CK在以丙酮和V（氨水）：V（乙醇）：V（水）=1：2：5为流动相中的雕值分别为0与0．8～0．9，标记率为（97．8±0．4）％，基础标记条件下的比活度为（11．90±0．05）TBq／mmol。在以下条件下放化纯均〉95％：（1）酒石酸亚锡为150～300μg；（2）预锡化反应pH值为2．0～3．5，温度60℃，保温时间6h以上；（3）^99Tc^mO4^-活度为37～185MBq，体积在200μl内；（4）标记温度为95℃，标记时间30min.^99Tc^m-RGD-4CKHPLC的保留时间与其洗脱液的放射峰基本一致；^99Tc^m-RGD-4CK室温放置6h，放化纯仍〉95％；Sep—Pak C18柱层析测定的^99Tc^m O4^-峰仅比3MM纸层析高0．5％；标记物与300mmol／L半胱氨酸37℃保温1h，^99Tc^m O4^-峰仅增加1．88％；^99Tc^m-RGD-4CK与血清蛋白无明显结合。结论预锡化法^99Tc^m直接标记RGD-4CK方法简便、标记率高，无需分离纯化即可直接应用，还可用于制备冻干品药盒。标记产物^99Tc^m-RGD-4CK具有良好的放射化学性质。     

TrKA和p75神经营养因子受体在嗅神经母细胞瘤的表达

目的 :探讨TrKA和p75神经营养因子受体在嗅神经母细胞瘤的表达及其临床意义。方法 :应用免疫组化和双荧光标记法对 10例鼻腔嗅神经母细胞瘤及 5例正常鼻腔嗅黏膜及 5例鼻咽癌组织进行TrKA和p75神经营养因子受体检测。结果 :免疫组化检测发现 10例鼻腔嗅神经母细胞瘤TrKA和p75蛋白均呈阳性表达 ,5例正常鼻腔嗅黏膜及 5例鼻咽癌组织均为阴性表达 ;双荧光标记显示所有肿瘤组织中TrKA和p75蛋白均在同一细胞表达。结论 :TrKA和p75神经营养因子受体的过度表达可能与嗅神经母细胞瘤的发生和发展有关 ;TrKA和p75神经营养因子受体检测可作为嗅神经母细胞瘤的一种辅助诊断方法     

Use of a synthetic peptide-based elisa for the diagnosis of infectious mononucleosis and other diseases

A simple enzyme immunoassay has been developed based on measuring antibodies to synthetic peptides corresponding to sequences in the Epstein-Barr nuclear antigen (EBNA). This assay, which is reproducible, quantitative, and simple to perform and interpret, can be an effective tool to aid in the diagnosis of infectious mononucleosis and nasopharyngeal carcinoma.