重组人白细胞介素-11和姜黄素对中子照射致小鼠肠道损伤的治疗作用

Objective To explore the therapeutic effect of recombinant human interleukin(rhIL-11) and curcumin on jejunal damage in mice after neutron irradiation.Methods 140 male BALB/c mice were randomly divided into 4 groups:20 mice in healthy control group,60 mice in mere irradiation group,30 mice in IL-11 treatment group and 30 mice in curcumin treatment group.The mere irradiation group mice were wholly exposed to 3 Gy neutron irradiation.The treatment groups mice were intraperitoneally enterocoelia once a day for 5 d after irradiation.The mortality of the mice were observed.The mice in the control and mere irradiation groups were killed 6 h,1,3,and 6 d post-irradiation,respectively,and the mice of the 2 treatment groups were killed 3 and 6 d post-irradiation,respectively and the samples of jujunum were colleted.HE staining,argyrophilic of nucleaolar organizer regions staining,Feulgen staining,and image analysis were used to observe the pathology and levels of argyrophilic proteins and DNA.Results The mice in the mere irradiation group all died at 5 d post-irradiation,while 2 mice in the IL-11 treatment group and 3 in the curcumin group survived.Large area necrosis and exfoliation were found in the intestinal epithelial mucosa of the mere irradiated group mice since 6 h to 3 d after irradiation.Crypt cell regeneration was seen occasionally found 3 days later and much more 5 days later.Crypt cell regeneration was obviously found in the intestinal epithelial mucosa and lots of new villi were observed 5 d after irradiation in both treatment groups,however,the amounts of crypt cells and new villi of the curcumin treatment group were less than those of the IL-11 treatment group.The contents of AgNOR and DNA in the intestinal epithelial cells 5 days after irradiation of the 2 treatment groups were all significantly higher than those of the mere irradiation group (F = 0.015-0.035,all P ＜ 0.05) but without significant differences between them.Conclusions Jejunal damage in mice could be induced after 3 Gy neutron irradiation.rhIL-11 and curcumin might reduce the damage and promote the regeneration and repair of the intestinal epithelium.     

X射线对人肺癌A549细胞CCR7表达影响的研究

目的 研究不同剂量X射线照射及照射后不同时间点对人肺癌A549细胞CC-趋化因子受体7(CCR7)表达的影响.方法 体外培养A549细胞,实验组采用直线加速器X射线一次性照射,细胞吸收剂量分别为2、4、6和8 Gy(源皮距100 cm;剂量率442.89 cGy/min),照射后4、12、24、48和72 h分别采用实时荧光定量PCR技术及Western blot方法分别进行CCR7 mRNA及蛋白质表达水平检测;对照组A549细胞除不接受x射线照射外,余处理同实验组.结果 A549细胞经2、4、6和8 Gy的X射线照射后,CCR7 mRNA及蛋白质在照射4 h后开始表达升高,达到高峰后相继出现下降;72 h后6和8 Gy组mRNA表达量仍高于对照组水平(t=6.75～7.26,P＜0.01),2和6 Gy组蛋白质表达量高于对照组(t=11.13～14.17,P＜0.01),而4和8 Gy组蛋白质表达量在48和72 h已降至对照组水平.结论 2、4、6和8 Gy的X射线照射A549细胞后,A549细胞CCR7mRNA及蛋白质的表达量明显增加,可能与一定剂量X射线辐射促进A549细胞增殖和转移有关.

Abstract：

Objective To study the effects of X-ray radiation on CC-chemokine receptor 7(CCR7) expression in human non-small cell lung cancer (NSCLC) cells.Methods Humanadenocarcinoma cells of the line A549 were cultured and irradiated by X-ray at the absorbed doses of 2,4,6,and 8 Gy respectively by linear accelerator (with the source skin distance of 100 cm and dose rate of 442.89 cGy/min).The relative levels of CCR7 mRNA and protein expression in the A549 cells were respectively detected by real time-PCR and Western blotting 4,12,24,48,and 72 h after radiation.Untreated A549 cells were used as control group.Results The expression levels of CCR7 mRNA and protein in the A549 cells began to increase since 4 h after radiation and then decreased gradually after they reached the peak.The CCR7 mRNA expression levels 72 h after radiation of the 6 and 8 Gy groups were still significantly higher than those of the control group (t = 6.75-7.26,both P < 0.01),and the CCR7 protein expression levels of the 2 and 6 Gy group were still significantly higher than those of the control group(t=11.13-14.17,both P <0.01).Then the CCR7 protein expression levels of the 4 and 8 Gy groups decreased to the control group level 48 and 72 h after radiation respectively.Conclusions The CCR7 mRNA and protein expression levels in the NSCLC cells increase after X-ray irradiation,which may be correlated with the promotion of proliferation and metastasis of NSCLC cells by X-ray irradiation at a certain dose.     

Intervention of Astragalus membranaceus on radioactive lung injuries and influence on TNF-α and ET expression

Objective To observe the lung protection of Astragalus membranaceus against radiotherapy to intermediate-stage and terminal thoracic neoplasm, and its influence on TNF-α and ET expression.Methods The patients with intermediate-stage and terminal thoracic neoplasm under radiotherapy were divided into a treatment group and a control group.Patients in the treatment group took 10 ml of Asragalus membranaceus twice a day.for consecutive 6 months from the beginning of radio therapy.TNF-α and ET in the plasma were measured before and after the radiotherapy.The clinical symptom,iconographic changes and lung diffusion were observed from the 15th day of radiotherapy.Results The TNF-α and ET in plasma afterthe radiotherapy were(2.48±0.75)as/ml and(69.32±23.03)pg/ml for the treatment group,and(5.12±1.01)ns/ml and(97.87±37.83)pg/ml for the control group with the statistial difference(x2=7.49,6.57,P<0.001).The decrease of CO diffusion 5 and 10 months after the radiotherapy in the treatment group was statistically different compared with that in the control group(x2=3.98,3.78,P<0.05).There was a statistical difference of the incidence of acute radiation pneumonitis and pulmonary fibrosis between these two groups(P<0.05).Conclusions Astragalus membranaceus could inhibit the excess expression of TNF-α and ET in plasma and reduce the deterioration of diffusion after radiotherapy,so that it can be used for intervention of lung injuries from radiotherapy.     

Intervention of Astragalus membranaceus on radioactive lung injuries and influence on TNF-α and ET expression

Objective To observe the lung protection of Astragalus membranaceus against radiotherapy to intermediate-stage and terminal thoracic neoplasm, and its influence on TNF-α and ET expression.Methods The patients with intermediate-stage and terminal thoracic neoplasm under radiotherapy were divided into a treatment group and a control group.Patients in the treatment group took 10 ml of Asragalus membranaceus twice a day.for consecutive 6 months from the beginning of radio therapy.TNF-α and ET in the plasma were measured before and after the radiotherapy.The clinical symptom,iconographic changes and lung diffusion were observed from the 15th day of radiotherapy.Results The TNF-α and ET in plasma afterthe radiotherapy were(2.48±0.75)as/ml and(69.32±23.03)pg/ml for the treatment group,and(5.12±1.01)ns/ml and(97.87±37.83)pg/ml for the control group with the statistial difference(x2=7.49,6.57,P<0.001).The decrease of CO diffusion 5 and 10 months after the radiotherapy in the treatment group was statistically different compared with that in the control group(x2=3.98,3.78,P<0.05).There was a statistical difference of the incidence of acute radiation pneumonitis and pulmonary fibrosis between these two groups(P<0.05).Conclusions Astragalus membranaceus could inhibit the excess expression of TNF-α and ET in plasma and reduce the deterioration of diffusion after radiotherapy,so that it can be used for intervention of lung injuries from radiotherapy.     

^18F-FLT评价食管癌照射后早期生物学响应的实验研究

目的探讨^18F—FLT在评价食管癌细胞及其动物模型经X线照射后早期生物学响应中的应用价值。方法在体外以5、10和15Gyx线分别照射人食管癌细胞Eca-109,照射前及照射后2、4和8h检测细胞对^18F—FLT摄取率的变化、细胞相对存活率和ATP的表达情况。将24只荷食管癌裸鼠按随机数字表法分成4组：对照（未照射）组;10Gy照射后1、7及15d各1组,分别行^18F—FLT PET显像并测量肿瘤对^18F—FLT的摄取值（T／NT）的变化。显像后处死各组荷瘤裸鼠,取肿瘤组织,用免疫组织化学检测照射前、后瘤组织内细胞增殖核抗原（PCNA）及Ki67抗原的表达。组间差异比较用单因素方差分析及两独立样本t检验,数据间相关性分析用Pearson直线相关分析。结果照射前细胞对^18F-FLT摄取率为（4．00±0．42）％;经5、10、15Gy照射后2h分别下降至（3．65±0．41）％、（3．17±0．45）％和（2．53±0．28）％;照射后4h分别下降至（2．84±0．35）％、（2．58±0．39）％和（1．80±0．22）％;照射后8h分别下降至（2．71±0．23）％、（1．89±0．31）％和（1．44±0．20）％。与对照组比较,5、10、15q照射后2、4、8h,细胞相对存活率差异无统计学意义（F=4．02,P〉0．05）;ATP浓度下降明显,呈剂量依赖性。细胞受照后的^18F—FLT摄取率与ATP浓度呈正相关（r=0．89,P〈0．01）。^18F—FLTPET显像示裸鼠肿瘤呈高摄取,照射前T／NT为2．24±0．06,照射后1、7和15d分别下降至1．99±0．09、1．85±0．04和1．15±0．10。瘤组织对^18F-FLT的摄取值与PCNA、Ki67表达均呈正相关（r=0．83和0．88,均P〈0．01）。结论^18F—FLT在食管癌细胞及肿瘤内摄取的变化能较好地评价其照射后早期生物学响应,^18F—FLTPET有望用于监测食管癌照射后早期疗效。     

大鼠C6胶质瘤放射治疗前后^18F—FDG摄取水平变化与多种生物学指标的相关性研究

目的探讨大鼠C6胶质瘤放疗前后^18F-FDG摄取水平变化及其与肿瘤细胞密度、Glut、细胞增殖及血管生成的关系。方法30只雄性荷C6胶质瘤SD大鼠按随机数字表法分为A、B和C3组,每组10只,均接种肿瘤细胞。2周后,A组行^18F-FDG PET／CT显像,B和C组分别于放疗后48h、1周行^18F-FDG PET／CT显像,计算肿瘤与对侧脊柱旁肌肉的SUVmax比值（TIM）,观察放疗前后肿瘤TIM的变化。显像后处死大鼠,取出肿瘤组织,观察组织病理变化,并计数肿瘤细胞密度,免疫组织化学法测定肿瘤Ki67标记指数（Ki67 LI）及微血管密度（MVD）,Western blot法检测Glut-1及VEGF的表达,采用单因素方差分析比较放疗前后T／M及各指标的变化,双变量相关分析评价T／M变化与各生物学指标间的相关性。结果（1）A、B、C3组T／M、肿瘤细胞密度、Ki67LI、MVD、Glut-1及VEGF水平总体比较组间差异均有统计学意义（F值依次为6．77,60．66,104．56,95．49,9．13和24．48,P均〈0．05）。两两比较示,B组T／M（9．23±4．56）、肿瘤细胞密度（672．70±92．98）及Ki67 LI（18．56±2．26）与A组（10．86±3．31,730．50±78．93,20．02±2．14）差异无统计学意义（P均〉0．05）,C组（5．16±2．52,355．60±72．62,7．81±1．76）与A、B2组相比下降明显,差异均有统计学意义（P均〈0．05）;B组MVD（19．50±1．96）及Glut-1水平（0．20±0．09）较A组（17．90±2．02,0．15±0．04）差异无统计学意义（P均〉0．05）,C组该两指标（8．40±1．84,0．07±0．06）显著下降,且与A、B2组间差异均有统计学意义（P均〈0．05）。B组肿瘤VEGF表达（0．42±0．13）与A组、C组（分别为0．17±0．04,0．16±0．09）相比显著增高,差异均有统计学意义（P均〈0．05）。（2）A、B组间T／M变化与肿瘤细胞密度变化呈明显正相关（r=0．81,P〈0．05）;A、C组间T／M变化与肿瘤细胞密度、Ki67 LI、MVD、Glut-1的变化呈正相关（r分别为0．83,0．71,0．68,0．62,P均〈0．05）。结论大鼠C6胶质瘤放疗后^18F—FDG摄取水平变化在放疗后48h仅与肿瘤细胞密度变化相关,而放疗后1周则能体现放疗引起的肿瘤多种生物学改变。     

AIF、Bax和Bcl-2在中子及γ射线照射致肠道损伤中的表达

目的 探讨AIF、Bax和Bcl-2在中子及7射线照射致肠道损伤中的表达变化及意义.方法 290只BALWc雄性小鼠,随机分为对照组(24只)、2.5Gy中子照射组(80只)、4.0Gy中子照射组(60只)、5.5Gy γ射线照射组(72只)及12.0Gy γ射线照射组(54只),分别采用5.5和12.0Gy γ射线以及2.5和4.0Gy的中子照射,并于照射后6h,1、2、3、5、10d活杀,取空肠组织,用免疫组织化学和图像分析技术定量分析MF、Bax及Bcl-2蛋白的表达变化.结果 对照组小鼠空肠绒毛及隐窝上皮细胞质AIF呈强阳性,Bax和Bd-2呈弱阳性.中子和γ射线照射后6h～1d,隐窝细胞核中AIF呈强阳性,表达明显增加(P<0.01);4.0Gy中子照射后Bax强阳性持续至照射后3d,表达明显增加(P<0.01).5.5、12.0Gy γ射线及2.5Gy中子照射后6h～5d,Bcl-2于上述部位呈强阳性,表达明显增加(P<0.01).4.0Gy中子照射后6h～3d,Bcl-2于上述部位呈弱阳性,表达无改变(P>0.05).结论 中子及γ射线照射后空肠隐窝上皮细胞核中AIF表达增加,参与了肠上皮细胞凋亡的过程.中子照射时的Bax表达强于γ射线照射时,γ射线照射时的Bcl-2表达强于中子照射时,二者变化规律不同,提示中子和γ射线致肠道损伤具有不同的分子机制.     

PET预测结肠癌转移潜能的实验研究

目的 评价PET在预测结肠癌转移特性中的作用。方法体外培养人结肠癌SW480、SW620细胞并分别种植裸鼠,形成移植瘤,观察肿瘤生长、转移情况以及生存期。分别于体内、体外检测肿瘤细胞对18F,脱氧葡萄糖（FDG）、18F-脱氧胸腺嘧啶核苷（FLT）的摄取。在体外分别于30,60,90和120min测定肿瘤细胞摄取18F—FDG与18F—FLT的放射性。经鼠尾静脉注射18F—FDG、18F—FLT,60min后行动物PET显像,利用感兴趣区（ROI）计算肿瘤／正常组织放射性（TINT）比值。应用免疫细胞化学染色与Westernblot法检测细胞以及肿瘤组织热休克蛋白27（HSP27）、整合素B3（Integrinβ3）、血管内皮生长因子受体2（VEGFR2）、核增殖抗原（Ki67）蛋白表达。应用独立样本t检验、Fisher精确检验以及直线回归分析研究体内外放射性摄取的差异以及放射性摄取与肿瘤标志物表达之间的关系。结果SW480移植瘤较SW620肿瘤成瘤早、生长快、生存期短、肝肺转移率高。体外摄取实验示,18F—FDG在SW480与SW620细胞中的摄取60min时分别达到（1．76±0．87）％和（1．14±0．38）％（t=-2．507,P=0．021）;18F-FLT分别达到（5．21±1．60）％和（2．90±1．82）％（t=3．497,P=0．002）。SW480较SW620细胞摄取“F—FDG、18F—FLT高,18F—FLT在细胞内的摄取高于18F—FDG。动物PET显像示,18F-FDG在SW480与SW620肿瘤中的T／NT比值分别为2．69±0．98,3．09±1．26（t=0．657,P=0．524）;18F-FLT T／NT比值分别为3．65±0．51,2．22±0．42（t=6．491,P〈0．001）;18F—FLT摄取与肿瘤组织内HSP27表达（r=0．924,P=0．004）、Integrinβ3表达（r=0．813,P=0．025）呈明显正相关。而18F-FDG的摄取与荷瘤鼠的生存期呈明显负相关（r=-0．500,P=0．017）。结论18F—FDG、18F—FLTPET在肿瘤内的摄取可反映结肠癌不同的生物学行为,18F—FLT在结肠癌内的高摄取可预测结肠癌具有高转移潜能。     

Comparison of [18F]FDG uptake and distribution with hypoxia and proliferation in FaDu human squamous cell carcinoma (hSCC) xenografts after single dose irradiation

Purpose: This study investigated the uptake of [¹⁸F]2-fluoro-2-deoxy-glucose ([¹⁸F]FDG) in the human tumour xenograft FaDu at early time points after single dose irradiation with Positron-Emission-Tomography (PET), autoradiography and functional histology.

Materials and methods: [¹⁸F]FDG-PET of FaDu hSCC xenografts on nude mice was performed before 25 Gy or 35 Gy single dose irradiation and one, seven or 11 days post irradiation (p.irr.). Before the second PET, mice were injected with pimonidazole (pimo) and bromodeoxyuridine (BrdU). After the PET tumours were excised, sliced and subjected to autoradiography and functional histology staining (pimo, BrdU, Ki67). [¹⁸F]FDG tumour uptake was quantified in the PET scans by maximal standard uptake value (SUV_max) and in the autoradiography after co-registration to the histology slices.

Results: No differences in the overall [¹⁸F]FDG uptake between the two dose groups and time points were found with PET or autoradiography. Comparing autoradiography and histology, the [¹⁸F]FDG uptake was constant in tumour necrosis over time, while it decreased in vital tumour areas and particularly in hypoxic regions. No differences in the [¹⁸F]FDG uptake between positive and negative areas of Ki67 and BrdU were found.

Conclusions: The decline of [¹⁸F]FDG uptake in vital tumour and in pimopositive areas as seen in autoradiography, was not reflected by evaluation of SUV_max determined by PET. These findings suggest that the SUV_max does not necessarily reflect changes in tumour biology after irradiation.     

Preclinical efficacy of the c-Met inhibitor CE-355621 in a U87 MG mouse xenograft model evaluated by 18F-FDG small-animal PET.

The purpose of this study was to evaluate the efficacy of CE-355621, a novel antibody against c-Met, in a subcutaneous U87 MG xenograft mouse model using (18)F-FDG small-animal PET. METHODS: CE-355621 or control vehicle was administered intraperitoneally into nude mice (drug-treated group, n = 12; control group, n = 14) with U87 MG subcutaneous tumor xenografts. Drug efficacy was evaluated over 2 wk using (18)F-FDG small-animal PET and compared with tumor volume growth curves. RESULTS: The maximum %ID/g (percentage injected dose per gram of tissue) of (18)F-FDG accumulation in mice treated with CE-355621 remained essentially unchanged over 2 wk, whereas the %ID/g of the control tumors increased 66% compared with the baseline. Significant inhibition of (18)F-FDG accumulation was seen 3 d after drug treatment, which was earlier than the inhibition of tumor volume growth seen at 7 d after drug treatment. CONCLUSION: CE-355621 is an efficacious novel antineoplastic chemotherapeutic agent that inhibits (18)F-FDG accumulation earlier than tumor volume changes in a mouse xenograft model. These results support the use of (18)F-FDG PET to assess early tumor response for CE-355621.     

Evaluation of 3'-deoxy-3'-18F-fluorothymidine for monitoring tumor response to radiotherapy and photodynamic therapy in mice.

3'-Deoxy-3'-18F-fluorothymidine (18F-FLT) has been suggested as a new PET tracer for imaging tumor proliferation. We investigated the use of 18F-FLT to monitor the response of tumors to radiotherapy and photodynamic therapy (PDT) in mice. METHODS: C3H/He mice bearing an SCCVII tumor were treated with single-dose x-ray irradiation of 20 Gy. Tumor uptake was examined for 18F-FLT, 3H-thymidine (3H-Thd), 18F-FDG, and 14C-deoxyglucose (14C-DG) at 6 h, 12 h, 24 h, 3 d, and 7 d after radiotherapy. BALB/c nu/nu mice bearing a HeLa tumor were treated with PDT. Tumor uptake was examined for the 4 tracers at 24 h after PDT. Expression of proliferating cell nuclear antigen (PCNA) was determined in untreated and treated tumors. RESULTS: In the biodistribution study, considerable uptake of 18F-FLT was observed in both tumor types. Tumor volumes decreased to 39.3% +/- 22.4% at 7 d after radiotherapy. The PCNA labeling index was reduced in x-ray-irradiated tumors (control, 53.2% +/- 8.7%; 6 h, 38.5% +/- 5.3%; 24 h after radiotherapy, 36.8% +/- 5.3%). 18F-FLT uptake in tumor expressed as the percentage of the injected dose per gram of tumor (%ID/g) decreased significantly at 6 h and remained low until 3 d after radiotherapy (control, 9.7 +/- 1.2 %ID/g; 6 h, 5.9 +/- 0.4 %ID/g; 24 h, 6.1 +/- 1.3 %ID/g; 3 d after radiotherapy, 6.4 +/- 1.1 %ID/g). 18F-FDG uptake tended to gradually decrease but a significant decrease was found only at 3 d (control, 12.1 +/- 2.7 %ID/g; 6 h, 13.3 +/- 2.3 %ID/g; 24 h, 8.6 +/- 1.8 %ID/g; 3 d after radiotherapy, 6.9 +/- 1.2 %ID/g). PDT resulted in a reduction of the PCNA labeling index (control, 82.0% +/- 8.6%; 24 h after PDT, 13.5% +/- 12.7%). Tumor uptake of 18F-FLT decreased (control, 11.1 +/- 1.3 %ID/g; 24 h after PDT, 4.0 +/- 2.2 %ID/g), whereas 18F-FDG uptake did not decrease significantly after PDT (control, 3.5 +/- 0.6 %ID/g; 24 h after PDT, 2.3 +/- 1.1 %ID/g). Changes in the uptake of 18F-FLT and 18F-FDG were similar to those of 3H-Thd and 14C-DG, respectively. CONCLUSION: In our model system, changes in 18F-FLT uptake after radiotherapy and PDT were correlated with those of 3H-Thd and the PCNA labeling index. The decrease in 18F-FLT uptake after treatments was more rapid or pronounced than that of 18F-FDG. Therefore, 18F-FLT may be a feasible PET tracer for monitoring response to therapy in oncology.     

18F-氟脱氧葡萄糖PET-CT在非小细胞肺癌临床分期及经治患者疗效评价中的应用

目的 评价18F-氟脱氧葡萄糖(18F-FDG)PET-CT在非小细胞肺癌临床分期和经治患者中的应用价值.方法 (1)比较32例初诊患者CT与PET-CT在临床分期上的差别.(2)观察肿瘤大小与最大标准化摄取值(SUVmax)相关性.(3)比较30例经治患者CT、PET-CT发现残留、新发病灶数的差异.结果 (1)PET-CT上调及下调分期各7例,分期改变率43.8%(14/32).PET-CT改变NM分期例数的差别无统计学意义.(2)SUV-与肿瘤大小呈正相关(rs=0.426,P<0.05).(3)PET-CT较CT多发现残留病灶3个(Z=0.520,P0.05),新发病灶数19个(Z=-2.871,P<0.05).结论 18F-FDG PET-CT对确定1P4,细胞肺癌临床分期具有优势;有助于对经治患者新发病灶的榆出.     

Increasing the yield of recombinant thyroid-stimulating hormone-stimulated 2-(18-fluoride)-flu-2-deoxy-D-glucose positron emission tomography-CT in patients with differentiated thyroid carcinoma

Objective The aim of this study was to assess the accuracy of recombinant thyroid-stimulating hormone (rTSH)-stimulated 2-(18-fluoride)-flu-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography (PET)-CT in detecting recurrence in patients with differentiated thyroid cancer. Methods Consecutive (18)F-FDG PET-CT scans performed with rTSH stimulation between 2007 and 2010 in patients with a history of papillary or follicular thyroid carcinoma were reviewed. PET-CT findings were correlated with thyroglobulin levels, and histological, clinical and radiological follow-up. Results 58 rTSH PET-CT scans were performed in 47 patients with a previous thyroidectomy and radioiodine ablation. The only indication for PET-CT was a raised thyroglobulin level in 46 of 58 scans, with the remainder for characterisation of equivocal radiology or staging. 25 (43%) of PET-CT scans were positive for recurrent disease. Histological correlation was available for 21 (36%) scans. The overall sensitivity, specificity, positive predictive value and negative predictive value were 69%, 76%, 72% and 73%, respectively. Median unstimulated thyroglobulin in true-positive scans was 33 μg l(-1) and 2.2 μg l(-1) in the remainder (p=0.12). 4 of 35 (11%) patients with unstimulated thyroglobulin levels <10 μg l(-1) had true-positive scans. Median stimulated thyroglobulin in true-positive scans was 320 μg l(-1), and 10 μg l(-1) in the remainder (p=0.046), with no positive scans with a stimulated thyroglobulin <8 μg l(-1). PET-CT directly influenced patient management in 17/58 (29%) scans. Conclusion rTSH PET-CT is a useful imaging technique for detecting disease recurrence in patients with iodine-resistant differentiated thyroid cancer. Low stimulated thyroglobulin levels are potentially useful in identifying patients unlikely to benefit from a PET-CT scan.     

白藜芦醇通过Akt/mTOR通路上调自噬改善辐射诱导小肠损伤

目的探讨白藜芦醇是否能够通过调节Akt/mTOR通路改善辐射诱导小肠损伤并研究其机制。方法将24只C57BL/6小鼠随机分为对照组、照射组和照射给药组(每组8只)。照射组和照射给药组小鼠接受9.0 Gy剂量的6MV-X射线全身照射,照射给药组小鼠在照射前3 d至照射后3 d每日腹腔注射白藜芦醇(50 mg·kg~(-1)·d~(-1)),对照组、单纯照射组予等量生理盐水。照射后3.5 d获取小肠组织并制作石蜡块后切片,采用HE染色及免疫组织化学染色行组织学分析;行Western blot试验检测p-Akt/Akt、p-S6RP/S6RP、LC3-Ⅱ、Beclin-1表达。采用ANOVA方差分析进行3组间比较。结果照射给药组小鼠小肠绒毛长度、小肠横断面隐窝数、单个小肠隐窝细胞总数、隐窝细胞Ki67阳性率均高于照射组(均P0.05);照射给药组较照射组小肠组织p-Akt/Akt、p-S6RP/S6RP蛋白表达下降(均P0.001),LC3-Ⅱ、Beclin-1蛋白表达升高(均P0.001)。结论白藜芦醇可能通过抑制Akt/mTOR通路促进受辐射小鼠小肠隐窝细胞自噬从而改善辐射诱导小肠损伤。