[en] Objective: The aim of this study was to evaluate the clinical role of ¹⁸F-fluorodeoxyglucose (FDG) PET/CT in detection of malignant melanoma. Methods: The whole body ¹⁸F-FDG PET/CT scans were performed on 61 patients with malignant melanoma. All PET and CT images of one patient were fused by the specific software on workstation. PET images, CT images and PET/CT fused images were analyzed by frame to frame. All patients were followed up for at least six months or last to the patient death. The final diagnosis was obtained by pathologic finding horn surgery or biopsy, and (or) multi-modalities of imaging and clinical follow-up. Results: The overall sensitivity, specificity and accuracy of ¹⁸F-FDG PET/ CT for detecting primary malignant melanoma was 90.9% (40/44), 88.2% (15/17) and 90.2% (55/61), respectively. In 9 patients post local surgery and proven histologically malignant melanoma, ¹⁸F-FDG PET/ CT detected the residual and metastatic tumor in 3/5 and 4/4 eases, respectively. In 7 patients with metastastic melanoma, ¹⁸F-FDG PET/CT found primary tumors in 2 eases and metastatic foci in 4 eases. In 33 patients after the radical operation, the sensitivity, specificity and accuracy of ¹⁸F-FDG PET/CT for detecting recurrence or metastasis was 100.0% (19/19), 85.7% (12/14) and 93.9% (31/33), respectively. Of these 33 patients, 16 (48.5%) were up-staged and 7 (21.2%) were down-staged by ¹⁸F-FDG PET/ CT. Conclusion: ¹⁸F-FDG PET/CT is a valuable imaging tool to detect the residual, recurrent and metastatic tumor in patients with malignant melanoma. (authors)

[en] Objective: To assess the value of ¹¹C-methionine (MET) PET/CT for the diagnosis of residual or recurrent glioma in comparison to ¹⁸F-FDG PET/CT. Methods: Forty-six patients suspected of residual or recurrent glioma underwent both ¹¹C-MET and ¹⁸F-FDG PET/CT within 5-day interval. The glioma was considered as positive on PET/CT images based on (1) visual judgment of higher tracer uptake compared with the normal gray matter; (2) semiquantitative analysis of tumor to contralateral normal gray matter (T/G) and contralateral normal white matter (T/W) ratios. The diagnosis was confirmed by stereotactic biopsy or radiological findings of MRI or CT and clinical follow-up (>6 months). The Chi-square test and paired t test were used for statistical analysis. Results: Residual or recurrent glioma was confirmed in 36 patients. The sensitivity, specificity, accuracy of ¹¹C-MET and ¹⁸F-FDG PET/CT were 94.4% (34/36) vs 47.2% (17/36), 90.0% (9/10) vs 100% (10/10), 93.5% (43/46) va 58.7% (27/46) (χ²=19.429, 1.053, 15.294, P<0.001, >0.05,<0.001), respectively. The T/G and T/W ratios of residual/recurrent glioma by ¹¹C-MET were significantly higher than those by ¹⁸F-FDG (T/G ratio: 1.68 ± 0.23 vs 1.13 ±0.51, t=5.877, P<0.001; T/W ratio: 2.52 ± 0.28 vs 1.42 ± 0.57, t=10.470, P<0.001). Conclusion: ¹¹C-MET PET/CT is more sensitive and accurate than ¹⁸F-FDG PET/CT for the detection of residual or recurrent glioma. (authors)

[en] Radiopharmaceutical of ¹⁸F-FHBG was synthesized and recombinant expression plasmid pLXSN-tk was constructed. The nude mice sub-skin model transplanted with human liver cancer was constructed by subcutaneous implantation of cultured the BEL-7402 liver carcinoma cell lines into the two sides axillary fossa nude mice. The left tumors were used as the control, while the right tumors were used as the experiment group, with the cancer cell being transfected by the pLXSN-tk. PET images were taken at 10, 30, 50, 70, 90, 110, 130, 150, 170, 190 and 210 min after ¹⁸F-FHBG injection via the tail veins. The results show that the uncorrected radiochemical yield of ¹⁸F-FHBG was 4%-10% and the radiochemical purity was over 95%. The ¹⁸F-FHBG PET images indicated that ¹⁸F-FHBG uptake of the control did not increase obviously, whereas high activity was observed in the experiment group 50-210 min after ¹⁸F-FHBG injection. ¹⁸F-FHBG uptake of the experiment group increased gradually to 19.772 kBq·mL^-1 150 min after ¹⁸F-FHBG injection, where the experiment/control tumor ratio was peaked at 4.99. The results indicated that ¹⁸F-FHBG PET imaging of HSV1-tk expression in tumors can be used to monitor, in living animals, and expression of theoretical gene. (authors)

[en] In this paper, we investigate the diagnostic value of ¹¹C-methionine (MET) positron emission tomography/computed tomography (PET/CT) for brain gliomas, and compare the results to ¹⁸F-fluorodeoxyglucose. Forty-four patients with suspected gliomas were examined with ¹¹C-MET and ¹⁸F-FDG PET/CT. ¹⁸F-FDG and ¹¹C-MET PET/CT images were compared and evaluated by visual and semiquantitative analysis. The accuracy of ¹¹C-MET and ¹⁸F-FDG PET/CT for detecting gliomas were 88.6% and 65.9%, respectively. Semiquantitative analysis showed that the 26 gliomas had higher mean ± SD T/NG_max ratio on ¹¹C-MET PET/CT than on ¹⁸F-FDG PET/CT(1.95±0.52 vs. 0.90±0.27, t=9.101, P<0.001). ¹¹C-MET had a higher sensitivity than ¹⁸F-FDG (83.3% vs.33.3%, χ² =4.16, P<0.05) for low-grade gliomas, but it did not differ significantly from ¹⁸F-FDG in the sensitivity for high-grade gliomas(100% vs. 64.3%, χ²=3.20, P>0.05). The difference was no significant, too, between high-and low-grade gliomas, compared by ¹¹C-MET T/NG_max ratio (2.07±0.51 vs. 1.81±0.52, t=1.302, P=0.205). ¹⁸F-FDG T/NG_max ratio in high-grade gliomas was significantly higher than that in low-grade gliomas (1.03±0.30 vs. 0.75±0.11, t=3.198, P=0.004). It is concluded that ¹¹C-MET PET/CT is more accurate than ¹⁸F-FDG PET/CT for detecting and delineating gliomas, especially for low-grade gliomas, and it can play a complement role to ¹⁸F-FDG in tumor grading. (authors)

[en] Highlights: • The interaction of Sb(III) with FeS was strongly pH dependent. • At pH 9 Sb(III) adsorption was the dominant process. • Kinetic decrease of Sb(III) and concurrent dissolution of FeS were observed. • Replacement of FeS by Sb₂S₃ was more significant as pH decreased. • Replacement of FeS by Sb₂S₃ was a relatively slow process. Ferrous sulfide (FeS) is an important carrier for metal(loid)s in anoxic environments, but the effect of FeS on the behavior of Sb is poorly understood. This work investigated the interaction of Sb(III) with FeS under anoxic condition. FeS was synthesized and both equilibrium and kinetic experiments on the interaction of Sb(III) with synthesized FeS were conducted at various pH values. The final solid phases were examined by SEM, XRD, TEM, and XPS. The results showed that the uptake of Sb(III) by FeS increased as pH decreased. The kinetic experiment at pH 5 obviously showed that the temporal decrease of Sb(III)_aq coincide with the partial dissolution of FeS. In contrast, both the concentrations of Sb(III)_aq and FeS in the kinetic experiment at pH 9 did not vary with time. The examination of the solid phases revealed the formation of amorphous Sb₂S₃ in the experiments at pH 5 and 7.5. Different mechanisms were suggested to affect the interaction of Sb(III) with FeS under acidic and alkaline conditions. At pH 9, adsorption dominated in the interaction. The decrease of Sb(III)_aq and the concomitant partial dissolution of FeS at pH 5 indicated the replacement of FeS by Sb₂S₃, which was more significant at lower pH. The replacement of FeS by Sb₂S₃ was a relatively slow process compared to the acidic dissolution of FeS. The result of this study helps understand the mobility of Sb in anoxic environments and may favor the remediation of Sb contamination by the use of FeS.

[en] The molecular of scaffold of thiazole orange has a number of merits for being as a fluorescent dye with tailor-made structure advancement for many useful applications. Structural modification based on 1-methylquinolinium moiety of thiazole orange is able to induce critical effects on fluorescent signal discrimination ability towards certain secondary or tertiary DNA structures. The electronic effect of the substituent on both molecular signaling and binding preference were investigated in the present study. We systematically compared the structural influence on the fluorescence signaling and binding preference towards nucleic acids in vitro through the addition of a number of substituent groups including p-methylstrylyl, p-hydroxylstyryl, p-chlorostyryl, p-bromostyryl, p-fluorostyryl, and (p-fluorobenzyl)-1,3-butadien-1-yl. The dyes synthesized were investigated with 19 nucleic acids for their interaction kinetics and fluorescent signal response with fluorescence titration experiments. The experimental results indicate that both the electronic effect and the molecular size of the dyes show significant influence on achieving higher binding affinity and fluorescent signal discrimination for G-quadruplex DNA. In addition, the dye with the introduction of a p-fluorostyryl substituent exhibits excellent linear relationship of the enhanced signal with respect to the concentration of telo21 DNA in vitro. The limit of detection (LOD) obtained was found to be 9 nM, which is much better than other analogues under the same conditions.