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Objective To investigate the added value of CTAC for improving image quality and diagnostic efficiency of bone imaging in SPECT/CT.Methods Seventy-five patients (47 males,28 females,(56.6± 12.8) years) with abnormal uptake in planar whole-body bone scintigraphy underwent SPECT/CTfor differentiation of malignant from benign spinal lesions.NAC and CTAC SPECT images were classified based on 5-point scale (5:excellent,4:good,3:adequate,2:suboptimal,1:inadequate).The diagnostic confidence for both NAC and CTAC SPECT images were classified based on 4-point scale (4:definite,3:certain,2:equivocal,1:uninterpretable).The pathological results after surgery were used as gold standard to evaluate the added diagnostic value of CTAC for spinal lesions.Wilcoxon-signed rank sum test was used for data analysis.Results CTAC improved the image quality in 37.3％ (28/75) of patients,and downgraded in 2.7％ (2/75) of patients.The remaining 45 patients were unchanged (60.0％,45/75).SPECT with CTAC could significantly improve the image quality (z=-4.747,P＜0.001),but the overall diagnostic confidence was not increased (z=-1.000,P＞0.05).Conclusion CTAC can improve the image quality of spinal SPECT,especially useful in imaging with poorer quality,but it has no significant incremental value in diagnostic confidence.
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<p><b>OBJECTIVE</b>This study aimed to investigate the effect of a lactoperoxidase-peroxidase-thiocyanate (LPO-H2O-SCN-) system with different concentrations of iodine (I-) on Streptococcus mutans (S. mutans), particularly on various parameters, including growth, adhesion, glucosyltransferase (GTF) enzyme activity, and insoluble exopolysaccharide synthesis.</p><p><b>METHODS</b>S. mutans ATCC 25175 was used as experimental species. Clonal formation unit (CFU) were counted to investigate the inhibitory effect on bacterial growth. The inhibition rate of bacterial adherence was calculated to analyze the effect on adhesion. Anthrone method was used to determine the content of insoluble exopolysaccharides and the amount of reducing saccharides. GTF activity and enzyme activity were then determined.</p><p><b>RESULTS</b>The inhibitory ability of the LPO-H2O2-SCN- system with I- on the cariogenicinity of S. mutans was strengthened as I- concentration was increased. At I- concentration > or = 100 micromol x L(-1) the antibacterial effects were significantly increased compared with those of the control group (P < 0.05). At I- concentration > or = 1,000 micromol x L(-1), the antibacterial effects were significantly improved compared with those of the group with SCN-only (P < 0.05). At I- concentration > or = 100 micromol x L(-1), the inhibition rate of bacterial adherence was > 50%; insoluble exopolysaccharide synthesis and GTF enzyme activity were reduced (P < 0.05).</p><p><b>CONCLUSION</b>The antibacterial effects of the LPO-H2O2-I- system were enhanced by adding I- to overcome the antagonistic effect of physiological SCN- concentration. LPO-H2O2-SCN- system with different concentrations of I- showed statistically significant inhibitory effects on growth, adhesion, insoluble exopolysaccharide synthesis, and GTF enzyme activity.</p>
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Antibacterianos , Aderência Bacteriana , Peróxido de Hidrogênio , Técnicas In Vitro , Iodo , Lactoperoxidase , Oxirredução , Streptococcus mutans , TiocianatosRESUMO
Objective To investigate the biodistribution of intratumoral administerd~(131)Ⅰ-labeled human-mouse chimeric monoclonal antibody (chTNT) in patients with advanced lung carcinoma. Methods Eleven patients enrolled had cytological and histological confirmed diagnoses of either stage Ⅲ b or stage Ⅳ inoperable lung carcinoma. Intratumoral injection was directed by thoracic CT-guided catheter using a multi-holed needle. The dose for each patient was 18.5 - 37 MBq/cm~3 tumor mass. Blood samples were drawn at different time intervals for up to 13 days, and urine samples were collected for up to 11 days after injection for pharmacokinetic studies. In vivo stability was examined by HPLC by analyzing serum and urine, which were found to contain~(131)Ⅰ-chTNT. Whole body images were taken for quantitative organ and tumor biodistribution studies. Results In all 11 patients,~(131)Ⅰ-chTNT was the major component of the radiolabel in serum. Within 96 hours after administration, it was 100% stable. Plasma disappearance curves of ~(131)Ⅰ-chTNT were best fit by a two-exponential model in all patients with T_(1/2kα) of (0. 89±0. 17) h and T_(1/2β) of (86.88 ± 25.97)h. Free Ⅰ was the only metabolite of Ⅰ-chTNT that appeared in urine. A biodistribution study demonstrated excellent localization of the radioactivity in tumors. The accumulated radioactivity in urine at 264 h was (58.37 △Corresponding author E-mail:chen. shaoliang@zs-hospital. sh. cn±17.45) % of the injection dose. There was (51.05±8.41)%ID ,~(131)Ⅰ-chTNT in the tumor at 30 min after injection, and the tumor/lung (T/N) ratio was 63.87 ± 25.71. It remained (3.47 ± 3.27) %ID at 264 h,and the T/N ratio was 9. 61 ± 11.00. Among the main target organs, accumulation of the radiolabeled antibody was mainly found in lungs, liver, heart, kidneys, spleen and thyroid.Conclusions Pharmacokinietics of ~(131)Ⅰ-chTNT follows a two-exponential model. According to its long preservation in tumor tissue, intratumoral injection of~(131)Ⅰ-chTNT is good for tumor therapy.