Continuous administration of poloxamer 188 reduces overload-induced muscular atrophy in dysferlin-deficient SJL mice

Dysferlin-deficient SJL mice are commonly used to study dysferlinopathy. We demonstrated that poloxamer 188 (P188), a membrane sealant, is effective in reducing the loss of muscle mass in SJL mice when administered using an osmotic pump for 6 weeks. We did not observe significant changes over a 2-week administration period, suggesting that longthier observation is necessary to determine the effectiveness of P188. We also examined exercise endurance in P188-administered SJL mice using a rolling cage. Phosphorylated p38 was found to be reduced in P188-administered SJL mice; additionally, using microarray analysis, we found diminished expression of atrogin-1, an E3 ubiquitin ligase, as the effector of muscular atrophy. Chronic infusion of P188 to dysferlin-deficient SJL mice reduced muscular atrophy, and administering p38 and atrogin-1 in the gastrocnemius muscle improved its motor function. These results provide a basis for potential treatments for dysferlin-deficient skeletal muscle fibers.     

^188Re标记丙氧鸟苷白蛋白纳米微球的制备

目的制备188Re标记丙氧鸟苷（GCV）白蛋白纳米微球（^188Re-GCV-BSA-NP）。方法通过蛋白交联固化的方法制备GCV-BSA-NP,并测定GCV-BSA-NP的体外释药特性;采用预锡化直接标记法对GCV-BSA-NP进行188Re标记,同时观察188Re-GCV-BSA-NP体外稳定性。结果GCV-BSA-NP为大小不等的规则性微球,微球直径不等,但多集中在250-290nm。GCV-BSA-NP总的标记率〉90%,放化纯〉95%,放射性比活度1.85×105MBq/μmol。标记物放置于37℃的PBS（pH7.4）溶液中,在24h时放化纯为95%。结论预锡化直接标记法简便快速,能够得到较高的标记物放化纯度,稳定性好,GCV-BSA-NP具有明显的缓释功能。     

188Re-DTPA-DG治疗荷人乳腺癌裸鼠的疗效观察

~(18)F-脱氧葡萄糖(FDG)PET显像已用于多种肿瘤诊断、治疗和疗效评价,但由于费用较贵,从而限制了它的普及应用。陈跃等将DTPA连接在葡萄糖胺的氨基上,合成了DTPA-DG,并用~(99m)Tc标记DTPA-DG,放化纯度高(>99%),荷瘤鼠显像T/NT比值随时间延长而升高,显像效果满意。     

辐射致大鼠平滑肌细胞HPRT基因第7/8外显子突变分析

目的探讨辐射剂量与平滑肌细胞HPRT基因变异的关系,提供放射预防血管再狭窄的基础实验依据.方法不同剂量的放射性核素188Re内辐射平滑肌细胞后,应用6-TG筛选分离HPRT变异细胞,采用PCR-SSCP技术进行HPRT基因7/8外显子的变异分析.结果辐射后平滑肌细胞HPRT基因突变率为(5.5～13)×10-6;91株HPRT突变细胞克隆中,14.3%呈现7/8外显子缺失,16.5%呈现点突变,7/8外显子总变异率为30.8%;辐射剂量与HPRT基因突变率、第7/8外显子的总变异率及外显子缺失率呈正相关.结论辐射所致DNA分子的损伤,包括基因片段的缺失、断裂及点突变与辐射剂量呈正相关.     

Stability of biodegradable radioactive rhenium (Re-186 and Re-188) microspheres after neutron-activation

Our objective was to determine if microspheres made from the biodegradable polymer poly(lactic acid) that contained rhenium could withstand the conditions of direct neutron activation necessary to produce therapeutic amounts of radioactive rhenium. The radiation damage of the polymer produced by γ-doses of up to 1.05 MGy from Re-186 and Re-188 was examined by scanning electron microscopy and size exclusion chromatography. At a thermal neutron flux of 1.5×10¹³ n/cm²/s the microspheres melted after 3 h in the nuclear reactor, but suffered little damage after 1 h of radiation and released less than 5% of the radioactivity during incubation in buffer at 37°C. The radioactive microspheres produced in this manner have a specific activity too low for radioembolization for treatment of liver tumors, but could be injected directly into tumors or applied topically to the wound bed of partially resected tumors.     

Preparation and evaluation of the rhenium-188-labelled anti-NCA antigen monoclonal antibody BW 250/183 for radioimmunotherapy of leukaemia

Anti-NCA antigen antibody BW 250/183 (Anti-Granulocyte) localizes more than 50% of injected antibody dose to the bone marrow. Therefore, this antibody is promising for adjuvant conditioning radioimmunotherapy of bone marrow before bone marrow transplantation. To examine its potential use for radioimmunotherapy, we developed an efficient and reproducible technical protocol for labelling anti-NCA antigen antibody BW 250/183 with generator-produced rhenium-188, aiming at both high radiochemical yield and high specific activity. ¹⁸⁸Re-labelled BW 250/183 antibody was used in 12 patients with advanced leukaemia. Labelling of BW 250/183 with ¹⁸⁸Re was accomplished by the direct radiolabelling method using tris-(2-carboxyethyl) phosphine (TCEP) as the reducing agent. Twelve patients with recurrent acute or chronic leukaemia were treated with activities of 6.5–12.4 GBq of ¹⁸⁸Re-labelled BW 250/183. Standard gamma camera scintigraphy was used to evaluate the biodistribution, and a region of interest analysis together with the MIRDOSE 3.1 software was applied to determine the radiation doses to relevant tissues. The ¹⁸⁸Re-BW 250/183 antibody was labelled in high radiochemical yield, with high radiochemical purity (94%±3%) and specific activity (5.55–7.4 GBq/mg) within 1 h. The preliminary biodistribution studies showed persistent uptake of ¹⁸⁸Re-BW 250/183 in bone marrow. The radiation absorbed doses (mGy/MBq) delivered to the total body, red marrow, liver, spleen and kidneys were 0.13±0.02, 1.45±0.71, 0.43±0.21, 1.32±0.99 and 0.71±0.17, respectively. TCEP reduction enabled the direct, fast and effective labelling of the monoclonal antibody BW 250/183 with ¹⁸⁸Re. Preliminary clinical results suggest delivery of a significant radiation dose to bone marrow and thus the potential for adjuvant conditioning therapy before BMT. Received 6 January and in revised form 10 May 1999     

Dosimetry of rhenium-188 diethylene triamine penta-acetic acid for endovascular intra-balloon brachytherapy after coronary angioplasty

To examine the possibility of using rhenium-188 diethylene triamine penta-acetic acid (DTPA) for endovascular intra-balloon brachytherapy after angioplasty, dose distribution around the balloon was calculated and validated by film dosimetry. Medical internal radiation dosimetry (MIRD) was calculated assuming that the balloon had ruptured and that the contents had been released into the systemic circulation. ¹⁸⁸Re-perrhenate eluate from the ¹⁸⁸W/¹⁸⁸Re generator was concentrated using an ion column and used to label DTPA. The dose distibution around the angioplasty balloon (20 mm length, 3 mm diameter cylinder) was estimated by Monte Carlo simulation using the EGS4 code. The time required for 17.6 Gy to be absorbed at 1 mm from the balloon’s surface following application of 3700 MBq/ml of ¹⁸⁸Re was found to be 278 s. Fifty percent of the energy was deposited in the first millimetre of the vessel wall from the balloon’s surface. The calculated radiation absorbed dose agreed with that measured by film dosimetry, which was performed using a water phantom, with errors ranging from 9.4% to 17%. Upon balloon rupture the total amount of ¹⁸⁸Re-DTPA was presumed to enter the systemic circulation. The resulting radiation absorbed dose was calculated using the MIRDOSE3 program and residence times obtained from dogs and amounted to 0.0056 mGy/MBq to the whole body and 4.56 mGy/MBq to the urinary bladder. The absorbed dose of ¹⁸⁸Re-DTPA to the whole body was one-tenth of that of ¹⁸⁸Re-perrhenate. A window-based program was developed to calculate the exposure time and the radiation dose absorbed as a function of the ¹⁸⁸Re concentration and the arbitrary distance from the balloon to the surrounding tissues. We conclude that ¹⁸⁸Re-DTPA is easy to prepare, safe to use and suitable for intra-balloon brachytherapy after coronary angioplasty. Received 27 May and in revised form 7 September 1999     

Integrated analysis identifies microRNA-188-5p as a suppressor of AKT/mTOR pathway in renal cancer

Many current microRNA (miRNA) expression datasets for renal cell carcinoma (RCC) often show inconsistent analysis results, so a shift to comprehensive analysis of multiple datasets can effectively accelerate molecular screening for precision medicine and translational medicine research. MicroRNA (miR)-188-5p is a clinically noteworthy miRNA whose aberrant expression was previously observed in a variety of cancers, but its role in RCC is unclear. In this study, we undertook a comprehensive analysis of four RCC miRNA expression datasets and validated the results using The Cancer Genome Atlas (TCGA) dataset and a cohort of collected clinical samples. Fifteen miRNAs were identified as potential diagnostic markers by the analysis of four RCC miRNAs datasets. Analysis of the TCGA kidney renal clear cell carcinoma dataset showed significantly shorter survival in RCC patients with reduced miR-188-5p expression levels, and our collection of RCC clinical samples showed low miR-188-5p expression in the tumors. Overexpression of miR-188-5p in Caki-1 and 786-O cells inhibited cell growth, colony formation, invasion, and migration. In contrast, miR-188-5p inhibitors reversed these cell phenotypes. We identified a binding site for miR-188-5p in the 3′-UTR region of myristoylated alanine-rich C-kinase substrate (MARCKS) mRNA and demonstrated an interaction between these two molecules. Quantitative RT-PCR and western blot analysis revealed that miR-188-5p could regulate the AKT/mTOR signaling pathway through MARCKS. Mouse transplantation tumor assay indicated that miR-188-5p reduced the tumorigenicity of RCC in vivo. MicroRNA-188-5p could be a valuable new molecule for RCC diagnosis and prognosis.     

Evolution of Personalized Dosimetry for Radioembolization of Hepatocellular Carcinoma

Yttrium-90 transarterial radioembolization (TARE) has progressed from a salvage or palliative lobar or sequential bilobar regional liver therapy for patients with advanced disease to a versatile, potentially curative, and often highly selective local treatment for patients across Barcelona Clinic Liver Cancer stages. With this shift, radiation dosimetry has evolved to become more tailored to patients and target lesion(s), with treatment dose and distributions adapted for specific clinical goals (ie, palliation, bridging or downstaging to liver transplantation, converting to surgical resection candidacy, or ablative/curative intent). Data have confirmed that “personalizing” dosimetry yields real-world improvements in tumor response and overall survival while maintaining a favorable adverse event profile. In this review, imaging techniques used before, during, and after TARE have been reviewed. Historical algorithms and contemporary image-based dosimetry methods have been reviewed and compared. Finally, recent and upcoming developments in TARE methodologies and tools have been discussed.     

Protein–nanoparticle interactions evaluation by immunomethods: Surfactants can disturb quantitative determinations

The adsorption of proteins on nanoparticle surface is one of the first events that occur when nanoparticles enter in the blood stream, which influences nanoparticles lifetime and further biodistribution. Albumin, which is the most abundant protein in serum and which has been deeply characterized, is an interesting model protein to investigate nanoparticle–protein interactions. Therefore, the interaction of nanoparticles with serum albumin has been widely studied. Immunomethods were suggested for the investigation of adsorption isotherms because of their ease to quantify the non-adsorbed bovine serum albumin without the need of applying separation methods that could modify the balance between the adsorbed and non-adsorbed proteins. The present work revealed that this method should be applied with caution. Artifacts in the determination of free protein can be generated by the presence of surfactants such as polysorbate 80, widely used in the pharmaceutical and biomedical field, that are needed to preserve the stability of nanoparticle dispersions. It was shown that the presence of traces of polysorbate 80 in the dispersion leads to an overestimation of the amount of bovine serum albumin remaining free in the dispersion medium when determined by both radial immunodiffusion and rocket immunoelectrophoresis. However, traces of poloxamer 188 did not result in clear perturbed migrations. These methods are not appropriate to perform adsorption isotherms of proteins on nanoparticle dispersions containing traces of remaining free surfactant. They should only be applied on dispersions that are free of surfactant that is not associated with nanoparticles.