The synthesis of a new macromolecule for the sentinel node detection: 99mTc-gly-mannosyl-dextran.

OBJECTIVE: We aimed to design and synthesize a new macromolecule for sentinel node detection to improve the imaging quality and avoid possible adverse effect. BACKGROUND: The imaging of sentinel lymph node has been an important field in the nuclear medicine. A lot of imaging agents have been developed, including Tc-sulfer colloid, Tc-labeled dextrans and the latest Tc-DTPA-mannosyl-dextran. With the technology advanced, the imaging ability of the agents has been better and better. However, there are still some drawbacks. MATERIALS AND METHODS: The new macromolecule agent was based on the dextran macromolecule backbone. Then the gly-gly-gly and mannose molecules were conjugated onto the backbone proportionally by targeting two different reaction sites. Once the new macromolecule was labelled with Tc, its imaging ability was tested by single-photon emission computed tomography scanning with Tc-sulfur colloid as the comparison. RESULTS: The average numbers of gly-gyl-gyl and mannosyl groups on the dextran backbone are determined to be ∼1: 2 per dextran. The average molecular diameter and molecular weight are measured to be 5.4±0.7 nm and 10 324 g/mol, respectively. The macromolecule is labelled by Tc with 93.2±2.4% radiochemical yield. The lymphatic imaging by single-photon emission computed tomography with the labeled compound showed no worse imaging ability but cost less time than the commercially available Tc-sulfur colloid. CONCLUSION: A new macromolecule imaging agent for sentinel node detection has been synthesized with better imaging ability and less imaging time cost.

The vial kit formulation for preparation of no-carrier-added 131 I-MIBG.

We have developed a new set of lyophilized kits, composed of 3 different kits, for the instant preparation of no-carrier-added 131 I-MIBG in the clinic. We here discussed the formulation of the kits, optimization of radiolabelling, quality control of radiolabeled 131 I-MIBG, and studies of animal biodistribution. The no-carrier-added (nca) 131 I-MIBG injection could be prepared within 30 minutes in the clinic with the help of the lyophilized kits. The radiochemical purity and specific activity (SA) could achieve above 98% and 6700 MBq/mg, respectively.

A convenient method for the preparation of radioiodinated meta-iodobenzylguanidine at a no-carrier-added level.

Radioiodinated meta-iodobenzylguanidine (MIBG) in high effective specific activity was prepared using 3-tributylstannylbenzylguanidine as the precursor. The labeling was carried out in aqueous solution with the insoluble and lyophilized precursor suspended in the solvent. Simply by filtration, the starting material and by-products were readily separated from the labeled solution. Less than 1.15 ppb tin has remained in the filtrate as determined by the atom fluorescence spectrometry. By this approach, high specific activity (3.4 GBq/µmol) [(131)I]MIBG was obtained in 72.3 ± 3% (n = 3) radiochemical yield and 97.3 ± 2% (n = 3) radiochemical purity. The whole preparation could be finished in less than 10 min. According to this method, a kit for the preparation of (123)I-MIBG and (131)I-MIBG is currently being developed.

[Pilot observation on the effect of integrated control measures against clonorchiasis in Pengjiang District of Jiangmen City].

From June to December in 2008, five villages were randomly chosen from Pengjiang District of Jiangmen city and about five hundred residents from each village were examined for clonorchiasis by Kato-Katz method (three slides per specimen). Fifty residents from each village were re-examined one month after treatment. One year later 50 treated residents were chosen from Dalin village and Sanya village for fecal examination. Questionnairing was conducted to determine the knowledge rate on clonorchiasis prevention among residents. The percentage and usage of sanitary toilets were investigated. The average infection rate of clonorchiasis from five villages was 21.5%(537/2501). 86.6%(465/537) of clonorchiasis received treatment voluntarily. One month after treatment the infection rate in four villages declined significantly. The positive rate showed no significant difference between one month and one year after treatment in Dalin and Sanya villages (P>0.05) . Questionairing indicated that 41.2%(170/413) of the clonorchiasis cases ate raw fish frequently, which was significantly higher than those non-infected people [4.2%, 8/192] (P<0.05). After health education, the knowledge awareness rate raised from 23.1% (135/584) to 84.5% (349/413) (P<0.05). The dissemination and usage of sanitary toilets were 93.2% (38 068/40 848) and 100%, respectively.