Preoperative detecting metastases of cervical cancer in pelvic and para-aortic lymph nodes：comparison of integrated ~（18）F-FDG PET/CT with or without contrast enhancement

Purpose: Compared the performance of contrast-enhanced PET/CT and non-enhanced PET/CT for preoperatively detecting pelvic and para-aortic lymph node metastases in patients with cervical cancer. Methods: This prospective study included 72 patients with clinically M0 cervical cancer. They underwent surgery within two weeks of PET/CT imaging. Imaging consisted of a whole-body PET/CT protocol without intravenous contrast, followed by abdominal and pelvic PET/CT protocol including contrast-enhanced CT. We compared the diagnostic efficiency between the methods on per-patient and per-lesion basis. Results: Patient-based analysis showed that the sensitivity, specificity, and accuracy of contrast-enhanced PET/CT were 63.6% (14/22), 94.0% (47/50), and 84.7%(61/72), respectively, whereas those of non-enhanced PET/CT were 54.5% (12/22), 88.0% (44/50), and 77.8% (56/72), respectively, and those of enhanced CT alone were 36.4% (8/22), 80.0% (40/50), and 66.7% (48/72), respectively. Lesion-based analysis showed that the sensitivity, specificity, and accuracy of contrast-enhanced PET/CT were 77.7% (87/112), 98.7%(938/950), and 96.5% (1025/1062), respectively, whereas those of non-enhanced PET/CT were 69.6% (78/112), 97.5% (926/950), and 94.5% (1004/1062), respectively, and those of enhanced CT were 54.4% (61/112), 96.1% (913/950), and 91.7% (974/1062), respectively. Contrast-enhanced PET/CT had the best sensitivity, specificity and accuracy. Although patient-based analysis showed no significant difference between contrast-enhanced PET/CT and non-enhanced PET/CT (p =0.540, 0.295 and 0.286), the specificity and accuracy of these two methods were significantly different on lesion-based analysis (p =0.043 and 0.027).     

Quantification of the impact of TOF and PSF on PET images using the noise-matching concept:clinical and phantom study

This study was to assess quantitatively the accuracy of ~(18)F-FDG PET/CT images reconstructed by TOF+PSF and TOF only, considering the noise-matching concept to minimize probable bias in evaluating algorithm performance caused by noise. PET images of similar noise level were considered. Measurements were made on an inhouse phantom with hot inserts of Φ10–37 mm, and oncological images of 14 patients were analyzed. The PET images were reconstructed using the OSEM, OSEM+TOF and OSEM+TOF+PSF algorithms. Optimal reconstruction parameters including iteration, subset, and FWHM of post-smoothing filter were chosen for both the phantom and patient data. In terms of quantitative accuracy, the recovery coefficient(RC) was calculated for the phantom PET images. The signal-to-noise ratio(SNR),lesion-to-background ratio(LBR), and SUV_(max)were evaluated from the phantom and clinical data. The smallest hot insert(Ф10 mm) with 2:1 activity concentration ratio could be detected in the PET image reconstructed using the TOF and TOF+PSF algorithms, but not the OSEM algorithm. The relative difference for SNR between the TOF+PSF and OSEM showed significantly higher values for smaller sizes, while SNR change was smaller for Ф22–37 mm inserts both 2:1 and 4:1 activity concentration ratio. In the clinical study, SNR gains were 1.6 ± 0.53 and 2.7 ± 0.74 for the TOF and TOF+PSF, while the relative difference of contrast was 17 ± 1.05 and 41.5 ± 1.85% for the TOF only and TOF+PSF, respectively. The impact of TOF+PSF is more significant than that of TOF reconstruction, in smaller inserts with low activity concentration ratio. In the clinical PET/CT images, the use of the TOF+PSF algorithm resulted in better SNR and contrast for lesions, and the highest SUV_(max)was also seen for images reconstructed with the TOF+PSF algorithm.     

Prognostic significance of interim ~(18)F-FDG PET/CT SUV reduction associated with Ki67 in patients with diffuse large B-cell lymphoma

To detect the prognostic significance of interim F-FDG PET/CT SUV(standard uptake value) reduction(△SUV_(max)) associated with Ki67 in patients with diffuse large B cell lymphoma(DLBCL).47 DLBCL patients underwent PET/CT before initiation and after 2-4 cycles of chemotherapy were included.The SUV_(max)of the dominant lesions were calculated.Ki67 positive indices were provided by enzyme-labeled immunohistochemistry.SPSS17.0 was used for statistical analysis.ASUV_(max) of different groups were compared by t test.Receiver-operator characteristic analysis was performed to determine the optimal cutoff values.KaplanMeier analyses of PFS(Progression-free survival) were compared using log-rank test.The average of △SUV_(max)and △SUV_(max)%were 11.53 and 69.10%,respectively.The optimal cutoff values of △SUV_(max)x and △SUV_(max)%were 11.45 and 82.92%,respectively.Higher △SUV_(max) and △SUV_(max)%indicated longer PFS(p 0.001).The optimal cutoff value of Ki67 was 55%.Ki6755%was revealed to be an indicator of shorter PFS(p = 0.019).Either △SUV_(max)≤11.45 or Ki6755%was defined as an indicator to poor outcome and scored 1 point.The PFS rate was 100%in patients scored 0 point,yet 0%in patients scored 2 points.PFS tended to be shorter along with the score getting higher(p = 0.006).△SUV_(max) and Ki67 positive index were both of significance in DLBCL prognosis.The prognostic value may be confirmed when △SUV_(max) was accordant with Ki67.     

Improving the detecting efficiency of suspected gastrointestinal tumors with dual-time-point ~(18)F-FDG PET/CT

We conducted a retrospective analysis of 221 subjects with 256 suspected gastrointestinal lesions from2007 to 2015 to explore the detecting efficiency of dualtime-point fluorine-18 fludeoxyglucose(~(18)F-FDG) positron emission tomography/computed tomography(PET/CT)and pathology examination. The abdominal delayed PET/CT was performed within 45 min of the conventional scan.The change in maximum standardized uptake value(ASUV_(max)) and morphological features of the suspected lesions between the conventional and dual-time-point PET/CT were compared. The sensitivity, specificity, positive predictive value, and negative predictive value(NPV) of conventional PET/CT were 81.6%(84/103), 56.2%(86/153), 55.6%(84/151), and 81.9%(86/105), respectively.Those of dual-time-point PET/CT were 94.1%(97/103),78.4%(120/153), 74.6%(97/130), and 95.2%(120/126),respectively. There was a significant difference between the conventional and dual-time-point PET/CT(P 0.005).The SUV_(early) and the %△SUV_(max) could not present more information in differential diagnoses, but the rate of tumors with increased SUVdelay accounted for 79.6%(82/103) and more than that of nonneoplastic lesions(15.5%, 29/187)(x~2= 115.5, P 0.01). Therefore, the dual-time-point~(18)F-FDG PET/CT had a higher sensitivity and NPV than the conventional PET/CT to detect gastrointestinal tumors.The constant morphology and increased SUV_(delay) help to detect the tumors and adding delayed imaging on the locality will be an effective method when we accidentally find a suspected gastrointestinal tumor on the conventional PET/CT images.     

Extrapulmonary benign and malignant lesions avid for 18F-fluoro- deoxyglucose by multivariate regression model identification

Whether extrapulmonary lesions are avid for18F-fluorodeoxyglucose（18F-FDG） could help to differentiate the benign or malignant lung lesions.In this trial,the 199 consecutive patients with newly diagnosed lung lesions（169 malignant and 36 benign lesions） were imaged by whole body18F-FDG PET/CT.Histopathology and clinic results served as the reference standard.The malignancy likelihood were conducted by CTscores;the maximum standardized uptake value（SUVmax） of lung lesions,and PET on FDG negative or positive,as well as metastasis index（MI）,by PET combined with CT findings.The data were analyzed by stepwise logistic regression and receiver-operatingcharacteristic.The malignancy predictive probability（P） was obtained by P =ex/（1＋ex）,where x= –1.16＋0.87（CTscore） ＋0.15（SUVmax）＋0.27（MI）.The area under curve（AUC） for the fitted logistic model was 0.82±0.04,this was superior and significantly different from SUVmax（AUC,0.73±0.05） and CTscores（AUC,0.71±0.05）.The fitted logistic model could improve the diagnostic performance.The MI could help for differential diagnosis.     

Image fusion using MIM software via picture archiving and communication system

The preliminary studies of the multimodality image registration and fusion were performed using an image fusion software and a picture archiving and communication system (PACS) to explore the methology,Original image voluminal data were acquired with a CT scanner,MR and dual-head coincidence SPECT,respectively.The data sets from all imaging devices were queried,retrieved,transferred and accessed via DICOM PACS.The image fusion was performed at the SPECT ICON work-station,where the MIM(Medical Image Merge)fusion software was installed.The images were created by reslicing original volume on nthe fly.The image volumes were aligned by translation and rotation of these view ports with respect to the original volume orientation.The transparency factor and contrast were adjusted in order that both volumes can be visualized in the merged images.The image volume data of CT,MR and nuclear medicine were transferred.accessed and loaded ia PACS successfully.The perfect fused images of chest CT/^18F-FDG and brain MR/SPECT were obtained.These results showed that image fusion technique using PACS was feasible and practical,Further experimentation and larger validation studies were needed to explore the full potential of the clinical use.     

^99mTc—ECD brain SPECT imaging in patients with acquired immunodeficiency syndromes

In order to investigate the changes of regional cerebral blood flow (rCBF) in patients with acquired immunodeficiency syndromes (AIDS), 99mTc-ECD brain SPECT imaging was performed in 5 patients with AIDS and 16 sex and age matched normal controls, and the rCBF percentages compared to the cerebellum were calculated using a semi-quantitative processing software. Hypoperfusions in the right and left frontal, temporal, porietal lobe, basal ganglia and left thalamus were seen in 1 patient with dementia. Hypoperfusions in the right and left frontal and temporal lobe were seen in 4 asymptomatic patients. The rCBF in the right and left frontal, temporal, porietal lobe, basal ganglia and thalamus, front and pons were decreased significantly in patients with AIDS than those of the control subjects (p <0.005). It is concluded that there exists reduced cortico-subcortical rCBF in AIDS patients.     

Evaluation of suspected local recurrence in lung cancer and head ＆ neck cancer： A comparison between ^99mTc-HL91 SPECT and CT for biopsy proven lesions

CT has rather low accuracy for the follow-up of tumors after therapy. This study was to determine whether the diagnostic accuracy can be improved with ^99mTc-HL91 SPECT in comparison with parallel results of CT imaging. Thirty patients of lung cancer or head ＆ neck cancer, suspected of recurrences on clinical symptoms and CT during clinical follow-up after therapy, underwent ^99mTc-HL91 SPECT. The radioactivity ratios of tumor to normal tissues （T/NT） were calculated using the region of interest technique. Results of ^99mTc-HL91 SPECT were verified by histopathology. The ^99mTc-HL91 average uptake ratios of T/NT in the group of recurrent lesions and non-recurrent lesions were 1.58±0.16 and 1.18±0.14, respectively. A significant difference was found between T/NT data of the two phases （t=4.87, P〈0.001）. The ^99mTc-HL91 SPECT shows sensitivity of 72.73%, specificity of 89.47% and accuracy of 83.83% for differentiating recurrent lesion, while the CT shows sensitivity of 63.63%, specificity of 84.21% and accuracy of 76.67%. A combination of ^99mTc-HL91 SPECT and CT for 21 patients with lung cancers or head ＆ neck cancers with congruent results shows sensitivity of 100%, specificity of 94.12% and accuracy of 95.23%. It is concluded that ^99mTc-HL91 SPECT may play a role in differentiating recurrent lesions in patients with lung cancer and head ＆ neck cancer. Furthermore, the combination of CT and ^99mTc-HL91 SPECT is a more effective method for diagnosing recurrence of lung cancer and head ＆ neck cancer.     

The ^18F—FDG uptake in non small cell lung carcinoma correlates with the DNA—grading of malignancy

In order to evaluate correlation of glucose metabolism and DNA Ploidity of tumors,the uptake of ^18F-Deoxyglucose(FDG) by PET prior to surgery and the DNA cotent and DNA-grading of malignancy (DNA-MG) of Schiff-Stained nuclei obtained from fresh tumor fragments by means of image cytometry were studied,and thereafter the correlation between standardized uptake value(SUV) and (DNA-MG) was analysed in forty-nine patients with histologically proven non-small cell lung carcinoma(NSCLC),As a result of the DNA higtograms of these 49 patients,46(93.88%) wrer aneuploid and only 3(6.12%) were tetraploid.A linear correlation of the SUV versus the (DNA-MG)(r=0.336,p=0.024)was found demonstrating that ^18F-FDG PET as a non-invasive metabolic imaging technique,may also provide information correlated to malignant DNA patterns which may be valuable in malignant differentiation and prognostic prediction.     

Proportion of viable myocardium is more reliable than semi-quantitative score in predicting functional recovery： a pilot study of PET myocardial viability imaging

PET myocardial viability imaging is the"gold standard"for the non-invasive assessment of myocardial viability.The research aims to find out the best methods of imaging interpretation in predicting the postoperative functional recovery.Twenty-one CAD patients with multi-vessel involvement Were recruited.All pailents underwent gated myocardial perfusion imaging(G-MPI) and FDG PET myocardial imaging within 2 weeks before coronary artery bypass grafting.The postoperative G-MPI was performed in all patients 3 months after the surgery.Out of the total 420 segments,164 segments of ischemic myocardium were detected by preoperative G-MPI.Among them,93ischemic segments were identified as non-viable(difference score≥0)and the rest 71 segments Were identified as viable(difference score＜0).The proportion of viable segments(the ratio of viabl esegments versus iscbemic segments)and summed difference score of metabolism to perfusion were calculated.The patients were further divided into 2 groups according to the proportion of viable myocardium:group Ⅰ(the proportion≥50%,12 cases)and group Ⅱ(the proportion＜50%,9 cases)while another division was made according to SDS:group A(SDSE≥0),group B(-5≤SDS＜0)and group C(SDS＜-5).The diagnostic accuracy of proportion of viable segments and SDS in predicting the post-revascularization improvement in the left ventricular ejection fraction by at least 5 or more ejection fraction units was 88.89%(8/9)and 55.56%(5/9)respectively.It is concluded that both approaches allow accurate evaluation of myocardial viability.Furthermore,the proportion of viable myocardium is more reliable in predicting the postoperative functional recovery.     

~(18)F-PBR06 PET/CT imaging of inflammation and differentiation of lung cancer in mice

The present study explored the 18-kDa translocator protein radioligand ~(18)F-PBR06 as a PET imaging biomarker for diagnosis of inflammation and compared it with ~(18)F-FDG for differentiation of inflammation and lung tumors in animals.~(18)F-PBR06 was synthesized with an average decay-corrected radiochemical yield of 30–40%(end of synthesis, EOS), and the radiochemical purity was greater than 99%. The inflammation-to-blood ratio of ~(18)FPBR06(3.53 ± 0.26) was higher than the tumor-to-blood ratio(1.77 ± 0.35)(P \ 0.001). The inflammation-tomuscle ratio of ~(18)F-PBR06(2.33 ± 0.64) was also higher than the tumor-to-muscle ratio(1.45 ± 0.14)(P = 0.036).Micro-PET/CT images showed high uptake of ~(18)F-FDG in both inflamed muscles and lung tumor tissues. However,~(18)F-PBR06 uptake in inflamed muscles remained higher than that in the lung tumor tissues, following 90 min of dynamic Micro-PET/CT imaging. Further, macrophages in the inflammatory regions showed a higher fluorescence signal than in lung tumor tissues. Results of the study confirmed that ~(18)F-PBR06 PET/CT imaging allowed for diagnosis of inflammation. Moreover,~(18)F-PBR06 uptake in the inflammatory regions was significantly higher than in lung tumor tissues, suggesting that ~(18)F-PBR06 PET/CT imaging has potential to differentiate between peripheral lung cancer and inflammation nodules.     

LIVER SCINTIGRAPHY AND ULTRASONOGRAPHY FOR THE DIAGNOSIS OF FOCAL AND DIFFUSE DISEASES

The scintiphotos and ultrasonophotos of 186 patients with focal and diffuse diseases of liver were collected and analysed. All the data were get from the in-patients of China-Japan Friendship Hospital. The Sigma 438 typedγ camera (USA) was used. Fifteen min after 99mTc-phytate were injected i.v., If any defect region was found, it was recorded as a SOL; the SSA 90A, SAL 77A and SAL 50A US scanners (Japan) were used, if any abnormal echo pattern was found, it was a SOL. Of 134 patients have done both examinations during 7 days, 122 patients had coincident results occupied 91.0%. For detection of SOL, the sensitivity of scintigraphy is 94.1%, specificity is 94.2%, accuracy is 94.8%; the sensitivity of US is 100%, specificity is 89.7%, the accuracy is 95.6%. The hepatic blood flow and blood pool study showed that 104 from 115 patients were coincident (90.4%). The spleen and liver accumulation ratio determination showed that 51 from 64 subjects were coincident (80.0%). The characteristic features of scintigraphy and US graphy were described in hepatoma, hemangioma, cyst abscess and cirrhosis. The advantages of these examinations were discussed and concluded that their procedures are valuable and widely available.     

Studies of Al metabolism in animal by accelerator mass spectrometry

The correlation between Al metabolism and senile dementia in animal has been studied by AMS(accelerator mass spectrometry).Three groups of laboratory rats were fed with normal food.food with high Al content,and with enriched Ca and Mg together with high Al,respectively for six to eight months.Mapping test was made to recored th degree of wisdom degeneration.Half of the rats were sacrificed and Al contents in various organs were measured by atomic absorption spectroscopy.The rest were injected with ^26Al,killed after 5,10,15,25,and 35d and ^26Al contents measured by AMS.The distribution of Al as well as the correlation among the accumulation of ^26Al,and the existed Al content and dementia was studied.     

The preclinical pharmacological study of dopamine transporter imaging agent ^18F-FP-β-CIT

The paper is to study pharmacologic characteristics of 18F-FP-β-CIT (18F-N-(3-fluoropropyl)-2β-carbomethoxy-3β- (4-iodophenyl)nortropane) as an imaging agent for dopamine transporter. The radiochemical purity of 18F-FP-β-CIT in aqueous solution was over 95% after standing at room temperature for 4h. Biodistribution displayed rapid uptake in rat brain (1.375 %ID/organ at 5min and 0.100 %ID/organ at 180 min) and the striatal uptake was 1.444, 0.731, 0.397, 0.230 and 0.146 %ID/g at 5, 30, 60, 120 and 180 min, respectively. The values of striatum/cerebellum, striatum /frontal cortex and striatum / hippocampus in rat's brain at 30 min were 3.38, 2.17 and 2.40 respectively. The uptake in striatum can be blocked by β-CFT, suggesting that 18F-FP-β-CIT binds to DAT peculiarly. The compound was rapidly cleared from monkey's blood. The striatal uptake was bilaterally decreased in the left-sided lesioned PD rats, compared with normal control. Brain PET imaging studies in normal monkey showed that 18F-FP-β-CIT was concentrated in striatum. The test of undue toxicity showed that the dose received by mice was 1250 times as by human, which indicates that 18F-FP-β-CIT is very safe. So 18F-FP-β-CIT is a promising PET imaging agent for DAT with safety and validity.     

Assessment of biological changes in wheat seedlings induced by ^12C^6＋-ion irradiation

The present study was designed to evaluate the effect of 12C6 ion beam (10～80 Gy) on biological changes of wheat seedlings. Reactive oxygen species (ROS)-related biomarkers and the quantification of plant survival and growth were examined at 10 day after carbon ions irradiation (LET 30.8keV/μm). The results showed that heavy ions obviously enhanced ROSs reflected by the production of O2 and H2O2 as well as TBARS, and treatment with 20 Gy achieved the peak value, suggesting that higher mutagenic potential may occur at 20 Gy. Simultaneously, increase of SOD activity was induced by heavy ions to counteract ROS accumulation. On the other hand, higher doses at 40 and 80 Gy inhibited wheat growth and survival in comparison with the control, and reversely lower doses at 10 or 20 Gy stimulated wheat growth and survival. In conclusion, the above observations imply that a dose range of 20～40 Gy is likely promised for wheat mutation breeding.     

Biological distribution of 131I-labeled anti-nucleus antigen monoclonal antibody chTNT in patients with pulmonary metastases from differentiated thyroid carcinoma

This work is to study the in vivo biological distribution of 131I-labeled mouse/human chimeric monoclonal antibody (131I-chTNT) in patients with pulmonary metastases from differentiated thyroid carcinoma.Ten patients with differentiated thyroid carcinoma were injected intravenously with a single dose of 131I-chTNT (5 MBq.kg-1 body weight).Radioactivity of blood and urine samples was measured at different time points.The in vivo stability and the metabolic status of 131I-chTNT were detected with supersaturated trichloroacetic acid.Continuous imaging was performed to outline the region of interest (ROD and estimate the intake level on the whole body,major organs and tumor lesions at different time points.The serum time-radioactivity curve of 131I-ehTNT accorded with the two-compartment model after a single intravenous injection:T1/2(h)=65.28±14.83,AUC0-t(MBq.h.mL-1)=8.93±1.32,AUC0-∞(MBq-h-mL-1)=10.58±2.19,and CL(mL.min-1.kg-1)=1635±359.The time-radioactivity percentage curve of 131I-chTNT urine excretion accorded with the one-compartment model after a single intravenous injection:T1/2(h)=99±10,and accumulative (31±9) % radioactivity of the injected dose was excreted in urine in one week.The percentages of serum 131I-ehTNT in radioactive components at 24,48 and 72 h were over 95% and it was still (88±7)% at 168 h.As for chemical composition of radioactive substances in urine,radioactivity in urine samples originated from free 131I by 100%.Radioactivity of 131I-chTNT after intravenous administration was mainly concentrated in the lung and liver,least in the brain.Radioactivity of tumor tissues reached the maximum at 24 h and the tumor/normal tissue (T/N) ratio reached the maximum (1.28～3.83) during 3～7 d.The characteristics of in vivo biological distribution of 131I-chTNT in patients with pulmonary metastases from differentiated thyroid carcinoma are favorable for its therapeutic application for the metastasis tumors.     

^99mTc-3P4 -RGD2 radiotracers for SPECT/CT of esophageal tumor

In recent years,several RGD（Arg-Gly-Asp）-based radiotracers have already been successfully tested in human for the visualization of integrin αvβ3,demonstrating its feasibility in tumor diagnosis.In this paper,we evaluated the 99mTc-3P4-RGD2 single photon emission computed tomography/computerized tomography（SPECT/CT）in patients suffering from space occupying disease of esophagus.40 patients（34 males and 6 female;mean age： 58.3 years） with a suspected space occupying lesion of esophagus were included,thus finally obtaining their definite pathologic diagnosis（malignant,n=32;benign,n=8）.All patients underwent endoscopic,barium esophagography and SPECT/CT imaging preoperatively.The chest SPECT was performed at 4 h after administration of99mTc-3P4-RGD2 with a dose of 939±118 MBq.The diagnosis precision,sensitivity and specificity among these methods were compared.The relationship between radioactive uptake and clinical pathological stage of esophageal carcinoma was discussed by calculating the tumor to normal esophagus（T/N）.Meanwhile,the integrin αvβ3 expression was assessed immunohistochemically in postoperative esophageal tissues.31 patients were diagnosed as esophageal carcinoma;and 1,leiomyosarcoma;and 6.leimyoma;and 2,esophageal tuberculosis.The accuracy,sensitivity and specificity of barium esophagography,endoscopic and SPECT/CT imaging are 92.5/93.8/87.5%,97.5/96.9/100%,and 90/90.6/87.5%,respectively.Abnormal accumulation of radiotracer in 29 malignant lesions is observed.The SPECT/CT imaging displayed the region of radioactive uptake and lesions matched extremely with the T/N ratio from 1.31 to 2.79（mean 2.04）.A case with pulmonary metastases and a case with mediastinal lymph node metastases were found which were missed by barium esophagography and endoscopic.The99mTc-3P4-RGD2 uptake of the esophageal carcinoma masses had no relevance to the tumor pathologic classification（P〉0.05）.There was a significant positive correlation between T/N ratio and positive cell percentage of integrin αvβ3（r=0.976）,demonstrating the certain clinical potential in the diagnosis of esophageal carcinoma.     

Effect of humic acid contact time on the diffusion of Re(Ⅶ) in GMZ bentonite

The effect of humic acid(HA) on the diffusion of Re(Ⅶ) was investigated in compacted Gaomiaozi(GMZ)bentonite by the through- and out- diffusion method. The effective diffusion coefficient, D e, and accessible porosity, εacc, were measured in order to evaluate the impact of humic acid on Re(Ⅶ) diffusion. The D e value was in the range of(5.2–8.3)×10-12m2/s. The diffusion of Re(Ⅶ) was enhanced in the presence of HA, and the D e value increased with the increase of ageing time, indicating that the formation of HA-Re complexes was slow. Moreover, the εacc was in the range of(0.06– 0.16), which is less than the total porosity. It implies that the HA-Re complexes are anions.     

The preclinical pharmacological study of dopamine transporter imaging agent 18F-FP-β-CIT

The paper is to study pharmacologic characteristics of 18F-FP-β-CIT (18F-N-(3-fluoropropyl)-2β- carbomethoxy-3β- (4-iodophenyl)nortropane) as an imaging agent for dopamine transporter. The radiochemical purity of 18F-FP-β-CIT in aqueous solution was over 95% after standing at room temperature for 4h. Biodistribution displayed rapid uptake in rat brain (1.375 %ID/organ at 5min and 0.100 %ID/organ at 180 min) and the striatal uptake was 1.444,0.731, 0.397, 0.230 and 0.146 %ID/g at 5, 30, 60, 120 and 180 min, respectively. The values of striatum/cerebellum,striatum/frontal cortex and striatum / hippocampus in rat's brain at 30 min were 3.38, 2.17 and 2.40 respectively. The uptake in striatum can be blocked by β-CFT, suggesting that 18F-FP-β-CIT binds to DAT peculiarly. The compound was rapidly cleared from monkey's blood. The striatal uptake was bilaterally decreased in the left-sided lesioned PD rats, compared with normal control. Brain PET imaging studies in normal monkey showed that 18F-FP-β-CIT was concentrated in striatum. The test of undue toxicity showed that the dose received by mice was 1250 times as by human, which indicates that 18F-FP-β-CIT is very safe. So 18F-FP-β-CIT is a promising PET imaging agent for DAT with safety and validity.     

Clinical significance of combined determination of serum PG I ,PGⅡ and GAS for diagnosis of gastric cancer

To evaluate the clinical value of combined determination of serum PG I, PG Ⅱ and GAS for early diagnosis of gastric cancer, the serum levels of PG I, PG Ⅱ and GAS in 190 healthy controls and 129 patients with gastric disorders were measured by RIA. The 129 patients include 68 cases of gastric cancer. The results showed that the serum levels of PG I and PG I/PG Ⅱ ratio in gastric cancer patients were obviously lower than those in healthy controls, while comparing with controls, the serum GAS levels were significantly higher. The diagnostic accuracy of the determinations for gastric cancer was evaluated by receiver operating characteristic （ROC） curve analysis. The area under the curve （AUC） levels of serum PG I, PG I/PG Ⅱ ratio and GAS were 0.833, 0.842 and 0.851, respectively. As serum PG I or PG I/PG II ratio or GAS were combined, the sensitivity and specificity of determination for gastric cancer diagnosis were 94.2% and 73.4%, respectively. All these results indicated that the combined determination of serum PG I, PG Ⅱ and GAS levels may be used as a tool for primary screening of gastric cancer.