The paper is to report the preparation of realgar bioleaching solution (RBS) by bacteria and the comparison of pharmacokinetics of RBS and H3AsO3 (ATO), and the study of its possible change of absorption and distribution of soluble arsenic in rat. The experiment was carried out on Wistar rats given peritoneal injection of RBS at a dose of 0.3 mg x kg(-1) (soluble arsenic content, 0.3 mg x kg(-1)), and rats given ATO at the dose of 0.3 mg x kg(-1) (soluble arsenic content, 0.3 mg x kg(-1)). The arsenic concentrations in many tissues including heart, liver, spleen, lung, renal and brain were determined. The changes of pharmacokinetic parameters and arsenic distribution in different tissues were detected and compared in these two groups of rats. The pharmacokinetic parameters of RBS and ATO are very similar. There is very few distribution of arsenic in the tissues in RBS group, compared with the ATO group. There is significant difference in the content of arsenic between two groups statistically (P < 0.01). It is feasible that we select the bacteria bioleaching solution as a candidate drug, which may be employed for primary change of arsenic compounds including dissolved inorganic arsenic and organic arsenic, in order to improve bioavailability and decrease the amount of arsenic accumulation in animal tissues. In addition, there is significant difference in the change of arsenic compounds between two groups. It can be concluded that, the investigation on application of microbial technology may provide a basis for exploratory research of realgar.

Objective To compare the dose distribution of postoperative plans with preoperative plans for 3D printing guide template assist radioactive seeds implantations,and explore the accuracy of treatment at dosimetry level.Methods A total of fourteen patients registered from Dec 2015 to Mar 2016 who were applied with 3D printing guide template assisted radioactive seed implantations in the hospital were included in this study.The preoperative planning design and 3D printing template production were performed for all patients.The dose related parameters including D90％,minimum peripheral dose (MPD),V100％,V150％,V200％,conformal index (CI),external index (EI),and homogeneity index (HI) were compared between pre-and post-operation.The paired t-test was used to perform the statistical analysis.Results A total of fourteen 3D printing individual templates were produced which included 16 treatment areas.Compared with preoperative plans,the mean value of V100％,Dg0％ and V150％ decreased while the mean value of V200％ and MPD increased in postoperative plans.However,there was no significant difference between the two groups except for V100％ (t =2.451,P ＜0.05).The differences of CI,EI,HI between two groups were not statistically significant (P ＞ 0.05).Conclusions The validation of actual dose distribution in postoperation assistied by 3D printing template in seed implantation shows that most of parameters could meet the expectation of preoperative plans,which indicates the improvement in accuracy for this new type of treatment.

Objective The renin-angiotensin system ( RAS) is involved in myocardial anoxic injury .This study aimed to in-vestigate the expressions of AT 1-R, AT2-R, and angiotensin-converting enzyme ( ACE ) in bone marrow mesenchymal stem cells (MSCs) under hypoxia. Methods Rat MSCs were isolated, cultured, and identified with CD29 and CD11b/c antibodies.The is-chemic injury model was established by exposing the MSCs to hypoxia and serum deprivation ( Hypoxia/SD) for 24 hours, while the control cells were cultured in L-DMEM with 10%FBS.The vitality and apoptosis of the cells were detected by trypan blue staining , CCK8 assay, and Annexin V-FITC staining.The mRNA and protein expressions of AT 1-R, AT2-R, and ACE were determined by real-time quantitative PCR and Western blot , respectively. Results The positive rate of CD29 was >97%and that of CD11b/c was <1% in the MSCs.Compared with the control group, Hypoxia/SD significantly increased the rate of cell apoptosis ([6.73 ±0.78]%vs [19.93 ±4.92]%, P<0.01), decreased the rate of cell viability ([78.49 ±4.94]%vs [37.33 ±2.91]%, P<0.01), and up-regulated the mRNA and protein expressions of AT 1-R, AT2-R, and ACE. Conclusion Hypoxia/SD activates the RAS in MSCs and improves the protective function of the cells against myocardial anoxic injury .

Objective To compare the preoperative and postoperative dosimetric results of radioactive seed implantation assisted by 3D printing template in the treatment of chest malignant tumor, and to examine the effect this technique on the precision of radioactive seed implantation.Methods A total of 21 patients who received 3D printing template-assisted CT-guided 125I seed implantation for chest tumors in 2016 were included in the study.The prescribed dose of the treatment was 110-180 Gy.Preoperative planning, individual template production, and puncture and seed implantation were performed in all patients, and the postoperative dosimetric results were then compared with the preoperative plan by assessing various dosimetric parameters including D90, MPD, V100, V150, CI, EI, and HI of gross tumor volume (GTV), D2cc of the spinal cord and aorta, and Dmean and V20 of the affected side of the lung.Statistical analysis was performed using the Wilcoxon non-parametric test.Results A total of 21 3D printing templates were designed and produced.The mean GTV volume (preoperative) of all patients was 77.1 cm3, and the mean number of implanted seeds was 68.In addition, the mean D90 of the postoperative GTV was 147.3 Gy.There were slight changes in the dosimetric parameters after treatment (P>0.05).Conclusions 3D printing template allows for accurate positioning and implantation of radioactive seeds during the treatment of chest tumor.Postoperative dosimetric parameters were consistent with those in the preoperative planning, indicating that the 3D printing template provides high precision for the treatment of chest tumor.

Objective To compare the pre-and post-operative tumor target volume and to examine the consistency in physical dosimetric parameters of organs at risk (OAR) following 3D-printed coplanar template (3D-PCT)-assisted and CT-guided radioactive seed implantation.Methods The 3D-printed coplanar template was designed using a computer software, and the coordinate system was established where the center was used as the basis for setting the x axis and y axis.Crosses defining the center of treatment were drawn on the patient''s body and matched with the corresponding central point, x axis, and y axis of the coplanar template.3D-PCT-assisted and CT-guided radioactive seed implantation was performed based on the pre-operative plan, and the pre-operative, operative, and post-operative plans were designed to evaluate the target tumor volume and the normal dose received by the tissues.In addition, dosimetric parameters, including D90(minimum dose received by 90% of the gross target volume), V100, V150, V200(percentage of GTV that received 100%, 150%, and 200% of the prescribed dose, respectively), minimum peripheral dose (MPD), conformal index (CI), external index (EI), and homogeneity index (HI) in the pre-operative and post-operative plans were also assessed and compared using the Wilcoxon test. Results Fourteen patients treated in our institution from August to October, 2016 were included in this study. The median age of the patients was 61.5 years, and the median Karnofsky Performance Scale score was 80. A total of 14 lesions from the 14 patients were treated by seed implantation in the neck (n=4), chest (n=3), abdomen (n=5), and pelvis (n=2). Of the 14 patients that underwent implantation, 8 had previously received radiation therapy, and 6 had not received radiation therapy. Dosage optimization was performed for all patients during the operation. The median activity of the implanted seeds was 0.625 mCi (0.55-0.75 mCi,1 Ci=3.7×1010 Bq), and the preoperatively planned median number of needling and implanted seeds were 9(4-34) and 45.5(10-162), respectively. However, the actual median number of needling and implanted seeds were 9.5(4-34) and 45.5(10-162), respectively. Dosimetric analysis showed that there were no significant changes in tumor volume (P=0.135), D90(P=0.208), MPD (P=0.104), V100(P=0.542), V150(P=0.754), V200(P=0.583), CI (P=0.426), EI (P=0.326), and HI (P=0.952) after implantation. Conclusions 3D-PCT guidance and dosage optimization can result in good consistency between pre-and post-operative plans for radioactive seed implantation. 3D-PCT is a convenient and cheap technique suitable for large-scale clinical application.

Objective:To verify the accuracy and feasibility of radioactive 125I seed implantation assisted by an optical navigation system and a 3D-printing non-coplanar template in the treatment of recurrent head and neck cancers. Methods:A total of 12 patients with recurrent head and neck cancer treated with radioactive 125I seed implantation assisted by an optical navigation system and 3D-printing non-coplanar template were enrolled from Dec 2018 to Dec 2019.The pre-plan and post-implant implantation needle number and implanted seed number were recorded.Meanwhile, their dosimetric parameters were compared, including D90, minimum peripheral dose (MPD), V100, V150, V200, conformity index (CI), external index (EI), and the homogeneity index (HI) of the target volume. Results:The median lesion volume was 31.5 cm 3, the median number of seeds was 61.5, and the median prescription dose was 130 Gy.The means of the pre-plan D90, MPD, V100, V150 and V200 were 134.2, 64.6, 93.3, 75.3 and 39.3 Gy, respectively, while those of post-implant D90, MPD, V100, V150, and V200 were 146.7, 68.94, 97.47, 80.40 and 48.30 Gy, respectively, with no statistically significant difference ( P>0.05). Meanwhile, there was no statistically significant difference between the pre-plan and post-implantation needle number, implanted seed number, CI, HI, and EI ( P>0.05). In terms of postoperative dose quality assessment, eight cases were rated excellent (66.6%) and four cases were rated good (33.3%). Conclusions:Radioactive 125I seed implantation assisted by an optical navigation system and 3D-printing non-coplanar template can be accurately performed in the treatment of recurrent head and neck cancer, with good consistency between pre-plan and post-implant dosimetric parameters and thus of prospective potential in clinical application.

Objective:To compare preoperative planning parameters between non-coplanar and coplanar template-assisted radioactive seed implantation in the treatment of pancreatic cancers, in order to guide clinical application.Methods:Patients with pancreatic cancers who received external irradiation in the Peking University Third Hospital from Jan 2017 to May 2019 were selected.Their image information was imported into the brachytherapy planning system, and the non-coplanar plan and coplanar plan were designed individually.Each patient′s prescription dose was set to 110 Gy, and the activity of the radioactive seeds were 0.4 mCi(1 Ci=3.7×10 10Bq), respectively.For the two plans, the dose distribution was optimized and dosimetric parameters were compared, including the implantation needle number, the implanted seed number, the minimum prescription doses delivered to 90% and 100% of the target volume ( D90 and D100), mean percentages of volume receiving 100%, 150% and 200% of the prescription doses ( V100, V150 and V200), conformity index (CI), external index (EI), and homogeneity index (HI) of the target volume, as well as the doses of 2 cm 3 and 5 cm 3 ( D2 cm 3 and D5 cm 3) of the surrounding normal organs such as the small intestines, colon, duodenum, stomach, and spinal cord. Results:The implantation needle number in the coplanar plan was slightly higher than that in the non-coplanar plan, namely 18.63 vs. 16.45 ( t=-3.239, P <0.05). The implanted seed number was equivalent, namely 90.2 vs. 91.01, with no statistical difference ( P>0.05). There was no significant difference between D90, D100, V100, V150, V200, CI, EI, and HI in the target area of the two plans ( P>0.05). Meanwhile, there was no obvious difference in D2 cm 3 and D5 cm 3 of normal organs including the small intestines, colon, duodenum, stomach, and spinal cord ( P>0.05). Conclusions:With both the coplanar plan and the non-coplanar plan, the prescription doses can be achieved and meanwhile, there are very small differences in the doses of normal organs.Given that 3D-printing non-coplanar and coplanar templates have their own characteristics, it is necessary to choose them according to specific situations.

Objective To investigate the acute side effect of 3D printing individual non-coplanar template for 125I seed implantation in head and neck recurrent/ metastatic carcinoma.Methods Between January 2016 and December 2016,42 patients of local recurrent malignant tumor of head and neck received 3D printing guide plate assist radioactive seeds implantations,and included in the study.The tumor volume ranged from 2.4 to 102.8 cm3 (median 28.6 cm3).The prescribed dose is 110-160 Gy,and the seeds activity were 0.34 to 0.70 mCi (1 Ci =3.7 × 1010 Bq).All patients carried out preoperative planning design,individual guide plate production,seed implantation,postoperative dose assessment,and followup.The side effects of skin,mucous membrane,blood and spinal cord were statistically analyzed.Results All patients were operated successfully.The follow-up time was 4-14 months (median 8.5 months).There were no adverse reactions at grade three or above.Three patients had grade one skin reaction.One patient experienced grade one mucosal reaction,two experienced grade two mucosal reactions.The skin response was correlated with the dose of the skin (x2 =7.067,P =0.032).No hematologic toxicity or radiation myelopathy was observed and no seed displacement was found.Conclusions 3D-printing guide plate can provide good accuracy for positioning and direction.For local recurrent malignant tumor of head and neck,there were no obvious adverse reactions and the operation was simple and the dosage was accurate.

Objective To investigate the accuracy of 3D-printing non-coplanar template (3D-PNCT) assisted 125I seed implantation with CT guidance in the pelvic recurrent cervical between the preplan and post-plan dosimetric parameters.Methods Nine patients with pelvic recurrent cervical cancer received 125I seed implantation under CT guidance assisted with 3D-PNCT.A pre-plan based brachytherapy treatment planning system (B-TPS) assisted with 3D-PNCT for seed needle depth,direction and angle was designed.The dosimetry parameters including homogeneity index (HI),dose of 90％ target volume (Dg0),mPD,volume percent of 100％,150％ and 200％ prescribed dose V100,V150 and V200 and organ at risk between the pre-plan and post-plan were compared.Results Total seeds number was 675 (median 44,25-114) according to pre-plan,and 669 (median 47,25-113) seeds were implanted actually.138 needles need implant according to preplan,and 132 needles was implanted actually.The median angle deviation was 1.99 ° ± 2.94°(0 °-13 °).There was no significant difference of HI,EI and CI between perand post-plan.The differences of D90,MPD,V100,V150 and V200 between pre-and post-plan were not significant.Conclusions The confidence of pre-plan and post-plan for 3D-PNCT assisted 125I seed implantation in the pelvic recurrent cervical cancer could be accurately performed under CT guidance.

Objective To compare the dosimetric data between preoperative plans and postoperative verification in computed tomography (CT)-guided and 3D-printing non-coplanar templateassisted 125I seed implantation for pelvic tumor,and to explore the feasibility and accuracy of the personalized template designmethod.Methods A total of 51 patients registered from Dec 2015 to Dec 2016 who were applied with 3D-printing guided template assisted radioactive seed implantations in the hospital were included in this study.A prescribed dose of 110-160 Gy was adopted.3D-printing templates were designed and produced for 51 cases.The dosimetric parameters:Dg0,minimum peripheral dose (mPD),V100,V150,V200,conformal index (CI),external index (EI),and homogeneity index (HI) were compared between pre-and post-plans.Results 51 cases' templates were in place well during the operations.Compared with the preoperative planning,the postoperative D90,V100,V150,V200,CI,EI and HI differences had no statistical difference (P ＞ 0.05);mPD is larger than before (t =-2.96,P ＜ 0.05).Conclusions The main dosimetric parameters of postoperative verification were consistent well with the preoperative planning and have good accuracy,which could meet the clinical requirements.