1.Comparison of interobserver variations in delineation of target volumes and organs-at-risk for intensity-modulated radiotherapy of nasopharyngeal carcinoma among physicians from different levels of cancer centers
Meining CHEN ; Yimei LIU ; Yinglin PENG ; Qiuying XIE ; Jinping SHI ; Rong HUANG ; Chong ZHAO ; Xiaowu DENG ; Meijuan ZHOU
Chinese Journal of Medical Physics 2024;41(3):265-272
		                        		
		                        			
		                        			Objective To assess inter-observer variations(IOV)in the delineation of target volumes and organs-at-risk(OAR)for intensity-modulated radiotherapy(IMRT)of nasopharyngeal carcinoma(NPC)among physicians from different levels of cancer centers,thereby providing a reference for quality control in multi-center clinical trials.Methods Twelve patients with NPC of different TMN stages were randomly selected.Three physicians from the same municipal cancer center manually delineated the target volume(GTVnx)and OAR for each patient.The manually modified and confirmed target volume(GTVnx)and OAR delineation structures by radiotherapy experts from the regional cancer center were used as the standard delineation.The absolute volume difference ratio(△V_diff),maximum/minimum volume ratio(MMR),coefficient of variation(CV),and Dice similarity coefficient(DSC)were used to compare the differences in organ delineation among physicians from different levels of cancer centers and among the 3 physicians from the same municipal cancer center.Furthermore,the IOV of GTVnx and OAR among physicians from different levels cancer centers were compared across different TMN stages.Results Significant differences in the delineation of GTVnx were observed among physicians from different levels of cancer centers.Among the 3 physicians,the maximum values of △V_diff,MMR,and CV were 97.23%±83.45%,2.19±0.75,and 0.31±0.14,respectively,with an average DSC of less than 0.7.Additionally,there were considerable differences in the delineation of small-volume OAR such as the left and right optic nerves,chiasm,and pituitary,with average MMR>2.8,CV>0.37,and DSC<0.51.However,relatively smaller differences were observed in the delineation of large-volume OAR such as the brainstem,spinal cord,left and right eyeballs,and left and right mandible,with average△V_diff<42%,MMR<1.55,and DSC>0.7.Compared with the differences among physicians from different levels cancer centers,the differences among the 3 physicians from the municipal cancer center were slightly reduced.Furthermore,there were also differences in the delineation of target volumes for NPC among physicians from different levels cancer centers,depending on the staging of the disease.Compared with the delineation of target volumes for earlier stage patients(stages I or II),the differences among physicians in the delineation of target volumes for advanced stage patients(stages III or IV)were smaller,with average △V_diff and DSC of 98.31%±67.36%vs 69.38%±72.61%(P<0.05)and 0.55±0.08 vs 0.72±0.12(P<0.05),respectively.Conclusion There are differences in the delineation of GTVnx and OAR in radiation therapy for NPC among physicians from different levels of cancer centers,especially in the delineation of target volume(GTVnx)and small-volume OAR for early-stage patients.To ensure the accuracy of multicenter clinical trials,it is recommended to provide unified training to physicians from different levels of cancer centers and review their delineation results to reduce the effect of differences on treatment outcomes.
		                        		
		                        		
		                        		
		                        	
2.Quality re-optimization and assessment of radiotherapy plan for rectal cancer
Lin HUANG ; Yimei LIU ; Meining CHEN ; Shaomin HUANG ; Xiaowu DENG ; Yinglin PENG ; Yu ZHANG
Chinese Journal of Medical Physics 2024;41(2):133-138
		                        		
		                        			
		                        			Objective To evaluate the quality of treatment planning(TP)and re-optimization planning(RP)of radiotherapy for rectal cancer using PlanIQ software,thereby providing methods and tools for the screening and optimization of radiotherapy plans.Methods Twenty patients with rectal cancer who received radiotherapy were selected retrospectively,with 10 cases of intensity-modulated radiotherapy(IMRT)and 10 of volumetric modulated arc therapy(VMAT).(1)TP:IMRT plan involved 5-field irradiation,and VMAT plan involved two 360°arcs.The prescription doses were 50 Gy/25 f for PTV1 and 45 Gy/25 f for PTV2.All plans underwent direct machine parameter optimization and required 95%isodose lines to cover 100%of the target volume.Organs-at-risk(OAR)were limited by reference to tolerated dose standards.After the planning was completed,the plans were reviewed and confirmed by a physician,and the treatment was implemented after dose verification.(2)RP:a physicist with 10 years of experience re-optimized the 20 TP plans,with the irradiation technique and field setting unchanged.The re-optimization involved adjusting planning conditions and parameters based on individual experience until the dose to OAR was minimized while without affecting PTV coverage.The quality of TP plans and RP plans were quantitatively evaluated using PlanIQ software.Non-parametric Wilcoxon signed rank test was performed for dose-volume histogram parameters and plan quality index between two groups.Results The dose-volume histogram parameters in RP plans were superior to those in TP plans,and the differences in the Dmax of PTV1,the V45 Gy and Dmax of small intestine,and the V45 Gy of colon were statistically significant(P<0.05).The quality scores of RP plans for IMRT group,VMAT group and all patients were significantly higher than those of TP plans(P<0.05),with plan quality index of 88.55±3.35 vs 86.61±4.63(P=0.005),89.72±3.15 vs 87.21±3.04(P=0.028),and 89.14±3.22 vs 86.91±3.22(P=0.001),respectively.Conclusion RP can further improve the quality of radiotherapy plan for rectal cancer.PlanIQ software serves as an effective tool for quality control and screening of radiotherapy planning.
		                        		
		                        		
		                        		
		                        	
3.Application of intraoperative ultrasound in robot-assisted precise resection of pancreatic tumors
Zheng LI ; Wensheng LIU ; Qifeng ZHUO ; Yihua SHI ; Shunrong JI ; Xianjun YU ; Xiaowu XU
Chinese Journal of General Surgery 2024;33(9):1368-1376
		                        		
		                        			
		                        			The incidence and detection rates of benign and low-grade malignant pancreatic tumors have risen yearly.For patients with such tumors,traditional radical resection procedures often result in excessive loss of normal pancreatic parenchyma,leading to complications such as postoperative insufficiency of both exocrine and endocrine functions.Studies have shown that functional-preserving surgeries,such as minimally invasive enucleation or partial resection surgeries,can maximize the protection of patients'pancreatic function and improve long-term quality of life.However,for some tumors deep within the pancreatic parenchyma,accurately locating the tumor and protecting the pancreatic duct pose challenges.Intraoperative ultrasound(IOUS)has become an ideal intraoperative imaging tool,often referred to as the surgeon's"third eye"because of its portability,ability to provide real-time high-resolution information,non-reliance on ionizing radiation,and the fact that it does not require special patient preparation.With advancements in technology,the application scope of IOUS has expanded beyond its initially limited diagnostic role to various surgical applications,including identifying non-palpable lesions,guiding surgical strategies,and staging tumors.In the current era of minimally invasive and precision surgery,the proficiency of surgeons in using IOUS has become an important issue.This article reviews the history of IOUS applications,summarizes the advantages and basic usage methods of robotic IOUS,and shares techniques for applying IOUS in robot-assisted precise resection of pancreatic tumors.
		                        		
		                        		
		                        		
		                        	
4.Assessment of risk factors and development and validation of an early prediction model for mortality in patients with severe traumatic liver injury
Bing LIU ; Xiaomei WANG ; Chuangye SONG ; Xiaoning LIU ; Jianjun MIAO ; Xiaowu LI ; Peizhong SHANG
Chinese Journal of Trauma 2023;39(6):528-537
		                        		
		                        			
		                        			Objective:To investigate the risk factors associated with mortality in patients with severe traumatic liver injury (TLI) and to establish and validate an early prediction model for mortality.Methods:A retrospective cohort study was conducted to analyze the clinical data of 273 patients with severe TLI admitted to the ICU from the medical information mart for the intensive care-IV (MIMIC-IV) database. The cohort consisted of 176 males and 97 females, with age ranging from 18 to 83 years [35.6 years(25.7,57.5)years]. The patients were divided into two groups based on in-hospital mortality: the survival group (253 patients, 92.7%) and the death group (20 patients, 7.3%). The two groups were compared with regards to gender, age, cause and type of injury, treatment method, massive blood transfusion, comorbidities as well as vital signs and laboratory tests measured within 24 hours of ICU admission. Univariate analysis was used to screen for risk factors associated with mortality in severe TLI patients. Independent risk factors for mortality were determined using multivariate Logistic regression analysis. Lasso regression was used to screen for predictors of mortality, and a nomogram prognostic model was then established through a multivariate Logistic regression analysis. The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the discrimination of the model, while the Hosmer-Lemeshow goodness-of-fit test and calibration curve were used to evaluate the calibration of the model. The model′s clinical applicability was evaluated through decision curve analysis (DCA). Internal validation was performed by the 200 Bootstrap samples, and external validation was performed by using 163 patients with severe TLI from the emergency ICU collaborative research database (eICU-CRD). Finally, the predictive efficacy of the nomogram model was compared to other trauma or severity scores.Results:Univariate analysis showed that the age, cause of injury, massive blood transfusion, chronic liver disease and laboratory tests measured within 24 hours of ICU admission, including temperature, systolic blood pressure, diastolic blood pressure, mean arterial pressure, shock index, platelets, red blood cell distribution width (RDW), mean red blood cell hemoglobin concentration (MCHC), blood glucose, blood urea nitrogen, creatinine, anion gap, bicarbonate, prothrombin time (PT), activated partial thromboplastin time (APTT) and international normalized ratio (INR) were associated with the mortality of severe TLI patients ( P<0.05 or 0.01). Multivariate Logistic regression analysis revealed that age ( OR=1.08, 95% CI 1.03, 1.12, P<0.01), body temperature <36 ℃ ( OR=8.00, 95% CI 2.17, 29.53, P<0.01), shock index ( OR=9.59, 95% CI 1.76, 52.18, P<0.01) and anion gap ( OR=1.32, 95% CI 1.15, 1.53, P<0.01) were significantly associated with mortality in severe TLI patients. Lasso regression analysis selected 7 predictors, including age, body temperature<36 ℃, shock index, anion gap, chronic liver disease, creatinine and APTT. Based on these 7 predictors, a nomogram prediction model was developed. The AUC of the nomogram for predicting mortality was 0.96 (95% CI 0.94, 0.99), and the Hosmer-Lemeshow goodness-of-fit test indicated a good fit ( P>0.05). The calibration curve demonstrated excellent consistency between the predicted and actual probabilities, and DCA demonstrated that the model had good clinical net benefit at all risk threshold probability ranges. Internal validation confirmed the stability of the model ( AUC=0.96, 95% CI 0.92, 0.98), and external validation demonstrated good generalization ability ( AUC=0.95, 95% CI 0.91, 0.98). Moreover, the nomogram exhibited superior predictive efficacy compared with injury severity score (ISS), revised trauma score (RTS), trauma injury severity score (TRISS), sequential organ failure score (SOFA), acute physiological score III (APS III), Logistic organ dysfunction score (LODS), Oxford acute severity of illness score (OASIS) and simplified acute physiological score II (SAPS II). Conclusions:Age, body temperature <36 ℃, shock index and anion gap are independent risk factors for mortality in severe TLI patients. A nomogram prognosis model based on 7 predictors, namely age, body temperature <36 ℃, shock index, anion gap, chronic liver disease, creatinine and APTT exhibits good predictive efficacy and robustness, and is contributive to accurately assess the risk of mortality in severe TLI patients at an early stage.
		                        		
		                        		
		                        		
		                        	
5.Minimally invasive enucleation for benign and low-grade malignant pancreatic tumors: an analysis of 60 cases
Mengqi LIU ; Wensheng LIU ; Zheng LI ; Qifeng ZHUO ; Shunrong JI ; Wenyan XU ; Yihua SHI ; Xianjun YU ; Xiaowu XU
Chinese Journal of Surgery 2022;60(7):674-679
		                        		
		                        			
		                        			Objective:To investigate the safety and feasibility of minimally invasive pancreatic tumor enucleation.Methods:The clinicopathological data of 60 patients with minimally invasive pancreatic tumor enucleation admitted to the Department of Pancreatic Surgery of Fudan University Cancer Center from November 2019 to August 2021 were retrospectively analyzed. There were 17 males and 43 females,with age of (50.0±13.2)years(range: 23 to 73 years). Tumors were located in the head of pancreas in 40 cases(66.7%),neck and tail of pancreas in 20 cases(33.3%). Patients were divided into robotic group( n=25) and laparoscopic group( n=35) according to surgical methods. The measurement data were compared by t-test or Mann-Whitney U test, and the categorical data were compared by χ 2 test or Fisher exact probability method. The influencing factors of postoperative pancreatic fistula were analyzed by univariate and multivariate Logistic regression. Results:All patients successfully completed tumor enucleation without conversion to laparotomy. The operation time was (183.5±67.3)minutes(range:90 to 410 minutes). Twelve patients(20.0%) underwent stent placement and pancreatic duct repair during operation. The removal time of abdominal drainage tube after operation was (24.7±22.9)days(range:2 to 113 days). The tumor diameter in the robotic group was larger than that in the laparoscopic group((3.5±0.9)cm vs. (2.9±0.7)cm, t=-2.825, P=0.006). The incidences of postoperative biochemical fistula and grade B pancreatic fistula were 20.0%,22.9% and 36.0%,51.4%,respectively(χ2=2.289, P=0.318). There were no grade C pancreatic fistula,lymphatic fistula,biliary fistula,delayed gastric emptying,secondary operation and perioperative death in both groups. Multivariate logistic regression analysis was performed on the occurrence of clinically related pancreatic fistula(above grade B). The results showed that the increase of body mass index( OR=1.285,95% CI:1.053 to 1.569, P=0.014),the larger diameter of the tumor( OR=3.703,95% CI:1.465 to 9.360, P=0.006) and intraoperative pancreatic duct repair( OR=7.889,95% CI:1.471 to 42.296, P=0.016) were independent risk factors,whereas robotic surgery( OR=0.168,95% CI:0.036 to 0.796, P=0.025) was a protective factor. No case of pancreatin dependent dyspepsia and new onset diabetes mellitus was observed. Conclusions:Minimally invasive tumor enucleation is feasible in the treatment of benign and low-grade pancreatic tumors. The incidence of pancreatic fistula is high in the short term after operation,but serious complications are rare. The robot assisted system can reduce the risk of postoperative pancreatic fistula and has more advantages in dealing with larger diameter tumors because of clearer surgical vision and more accurate operation.
		                        		
		                        		
		                        		
		                        	
6.Minimally invasive enucleation for benign and low-grade malignant pancreatic tumors: an analysis of 60 cases
Mengqi LIU ; Wensheng LIU ; Zheng LI ; Qifeng ZHUO ; Shunrong JI ; Wenyan XU ; Yihua SHI ; Xianjun YU ; Xiaowu XU
Chinese Journal of Surgery 2022;60(7):674-679
		                        		
		                        			
		                        			Objective:To investigate the safety and feasibility of minimally invasive pancreatic tumor enucleation.Methods:The clinicopathological data of 60 patients with minimally invasive pancreatic tumor enucleation admitted to the Department of Pancreatic Surgery of Fudan University Cancer Center from November 2019 to August 2021 were retrospectively analyzed. There were 17 males and 43 females,with age of (50.0±13.2)years(range: 23 to 73 years). Tumors were located in the head of pancreas in 40 cases(66.7%),neck and tail of pancreas in 20 cases(33.3%). Patients were divided into robotic group( n=25) and laparoscopic group( n=35) according to surgical methods. The measurement data were compared by t-test or Mann-Whitney U test, and the categorical data were compared by χ 2 test or Fisher exact probability method. The influencing factors of postoperative pancreatic fistula were analyzed by univariate and multivariate Logistic regression. Results:All patients successfully completed tumor enucleation without conversion to laparotomy. The operation time was (183.5±67.3)minutes(range:90 to 410 minutes). Twelve patients(20.0%) underwent stent placement and pancreatic duct repair during operation. The removal time of abdominal drainage tube after operation was (24.7±22.9)days(range:2 to 113 days). The tumor diameter in the robotic group was larger than that in the laparoscopic group((3.5±0.9)cm vs. (2.9±0.7)cm, t=-2.825, P=0.006). The incidences of postoperative biochemical fistula and grade B pancreatic fistula were 20.0%,22.9% and 36.0%,51.4%,respectively(χ2=2.289, P=0.318). There were no grade C pancreatic fistula,lymphatic fistula,biliary fistula,delayed gastric emptying,secondary operation and perioperative death in both groups. Multivariate logistic regression analysis was performed on the occurrence of clinically related pancreatic fistula(above grade B). The results showed that the increase of body mass index( OR=1.285,95% CI:1.053 to 1.569, P=0.014),the larger diameter of the tumor( OR=3.703,95% CI:1.465 to 9.360, P=0.006) and intraoperative pancreatic duct repair( OR=7.889,95% CI:1.471 to 42.296, P=0.016) were independent risk factors,whereas robotic surgery( OR=0.168,95% CI:0.036 to 0.796, P=0.025) was a protective factor. No case of pancreatin dependent dyspepsia and new onset diabetes mellitus was observed. Conclusions:Minimally invasive tumor enucleation is feasible in the treatment of benign and low-grade pancreatic tumors. The incidence of pancreatic fistula is high in the short term after operation,but serious complications are rare. The robot assisted system can reduce the risk of postoperative pancreatic fistula and has more advantages in dealing with larger diameter tumors because of clearer surgical vision and more accurate operation.
		                        		
		                        		
		                        		
		                        	
7.Application of 3D printing technology in the personalized surgery of right ventricular double outlet
Zhu DONG ; Ben ZHANG ; Yiqiu CAO ; Bo YANG ; Ying LIU ; Yanchun ZHENG ; Xiaowu WANG
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2021;28(04):441-446
		                        		
		                        			
		                        			Objective    To evaluate the clinical value of three-dimensional (3D) printing model in accurate and minimally invasive treatment of double outlet right ventricle (DORV). Methods    From August 2018 to August 2019, 35 patients (22 males and 13 females) with DORV aged from 5 months to 17 years were included in the study. Their mean weight was 21.35±8.48 kg. Ten patients who received operations guided by 3D printing model were allocated to a 3D printing model group, and the other 25 patients who received operations without guidance by 3D printing model were allocated to a non-3D printing model group. Preoperative transthoracic echocardiography and CT angiography were performed to observe the location and diameter of ventricular septal defect (VSD), and to confirm the relationship between VSD and double arteries. Results    The McGoon index of patients in the 3D printing model group was 1.91±0.70. There was no statistical difference in the size of VSD (13.20±4.57 mm vs. 13.40±5.04 mm, t=−0.612, P=0.555), diameter of the ascending aorta (17.10±2.92 mm vs. 16.90±3.51 mm, t=0.514, P=0.619) or diameter of pulmonary trunk (12.50± 5.23 mm vs. 12.90±4.63 mm, t=−1.246, P=0.244) between CT and 3D printing model measurements. The Pearson correlation coefficients were 0.982, 0.943 and 0.975, respectively. The operation time, endotracheal intubation time, ICU stay time and hospital stay time in the 3D printing model group were all shorter than those in the non-3D printing model group (P<0.05). Conclusion    The relationship between VSD and aorta and pulmonary artery can be observed from a 3D perspective by 3D printing technology, which can guide the preoperative surgical plans, assist physicians to make reasonable and effective decisions, shorten intraoperative exploration time and operation time, and decrease the surgery-related risks.
		                        		
		                        		
		                        		
		                        	
8.Structural changes of a bacteriophage upon DNA packaging and maturation.
Wenyuan CHEN ; Hao XIAO ; Xurong WANG ; Shuanglin SONG ; Zhen HAN ; Xiaowu LI ; Fan YANG ; Li WANG ; Jingdong SONG ; Hongrong LIU ; Lingpeng CHENG
Protein & Cell 2020;11(5):374-379
		                        		
		                        		
		                        		
		                        	
9. Interobserver variations in the delineation of planning target volume and with orgagans at risk different contouring methods in intensity-modulated radiation therapy for nasopharyngeal carcinoma
Yinglin PENG ; Wenzhao SUN ; Wanqin CHENG ; Haiqun XIA ; Jijin YAO ; Weiwei XIAO ; Guanzhu SHEN ; Lin YANG ; Shu ZHOU ; Jiaxin LI ; Ying GUAN ; Shuai LIU ; Xiaowu DENG
Chinese Journal of Radiation Oncology 2019;28(10):762-766
		                        		
		                        			 Objective:
		                        			To assess the interobserver variations in delineating the planning target volume (PTV) and organs at risk (OAR) using different contouring methods during intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC), aiming to provide references for the quality control of multi-center clinical trials.
		                        		
		                        			Methods:
		                        			The PTV and OAR of CT image of 1 NPC patient manually delineated by 10 physicians from 8 different radiation centers were defined as the " manual contour group" , and the OAR auto-contoured using the ABAS software and modified by the physicians were defined as the " auto+ manual contour group" . The maximum/minimum ratio (MMR) of the PTV and OAR volumes, and the coefficient of variation (CV) for different delineated contours were comparatively evaluated.
		                        		
		                        			Results:
		                        			Large variation was observed in the PTV and OAR volumes in the manual contour group. The MMR and CV of the PTV were 1.72-3.41 and 0.16-0.39, with the most significant variation in the PTVnd (MMR=3.41 and CV=0.39 for the PTVnd-L). The MMR and CV of the manually contoured OAR were 1.30-7.89 and 0.07-0.67. The MMR of the temporal lobe, spinal cord, temporomandibular joint, optic nerve and pituitary gland exceeded 2.0. Compared with the manual contour group, the average contouring time in the auto+ manual group was shortened by 68% and the interobserver variation of the OAR volume was reduced with an MMR of 1.04-2.44 and CV of 0.01-0.37.
		                        		
		                        			Conclusions
		                        			Large variation may occur in the PTV and OAR contours during IMRT plans for NPC delineated by different clinicians from multiple medical centers. Auto-contouring+ manually modification can reduce the interobserver variation of OAR delineation, whereas the variation in the delineation of small organs remains above 1.5 times. The consistency of the PTV and OAR delineation and the possible impact upon clinical outcomes should be reviewed and evaluated in multi-center clinical trials. 
		                        		
		                        		
		                        		
		                        	
10.Effect of adipose-derived stem cells on radiation-induced acute skin injury in rats.
Zhiyan LIU ; Zhen RAO ; Xiaowu SHENG ; Ying LONG ; Xiao ZHOU
Journal of Central South University(Medical Sciences) 2019;44(2):150-157
		                        		
		                        			
		                        			To investigate the effect of adipose-derived stem cells (ADSCs) on radiation-induced skin injury in SD rats.
 Methods: Radioactive particles 192Ir were used to irradiate the left medial thigh skin of SD rats, and the irradiation dose was at 90 Gy. Then, the rats were randomly allocated into a control group and a treatment group (each n=9). After the irradiation, the control group was injected with 60 μL PBS and the treatment group was injected with 60 μL ADSCs in irradiated skin. The progress of skin damage and healing was observed and photographed every day. Twenty-eighth days after the irradiation, the irradiated skin tissue was taken from the left thigh, and then fixed with formaldehyde fixative solution. At the same time, the skin tissue of the corresponding part of the normal group (n=9) that was not irradiated was also taken. After sampling, embedding and slicing, immunohistochemical staining was used to compare the levels of α-smooth muscle actin (α-SMA), and HE staining was used to compare pathological features of the skin.
 Results: Radioactive particle 192Ir caused the development of III or IV radioactive skin damage. The score of the treatment group was significantly lower than that of the control group. The wounds of the treatment group were basically healed at 28 days, while the ulcer of the control group was unhealed. So, the healing time was shorter in the treatment group. The expression of α-SMA in the skin of the two groups was increased after the radiotherapy. By analyzing the pathological microstructure image, we found that the thickness of epidermis in the control group was greater than that in the treatment group, while the vascular density in the treatment group was greater than that in the control group (all P<0.05).
 Conclusion: Radioactive particles 192Ir can cause skin damage, while the adipose-derived stem cells might alleviate radiation-induced skin injury and promote ulcer healing by promoting angiogenesis.
		                        		
		                        		
		                        		
		                        			Adipocytes
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		                        			Animals
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		                        			Iridium Radioisotopes
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		                        			Rats
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		                        			Rats, Sprague-Dawley
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		                        			Skin
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		                        			Stem Cells
		                        			
		                        		
		                        	
            
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