PurposeTo optimize the imaging parameters of clinical MRI scanner in rat pancreas imaging to improve the image quality and to provide better MRI image quality and more economical research method for imaging study of rat pancreas. Materials and Methods Twenty-four healthy male Wistar rats were randomly divided into the conventional sequence (CS) group, the adjustment sequence (AS) group and the optimization sequence (OS) group, with 8 rats in each group. The rats in the CS group were scanned with conventional parameters using a clinical MRI scanner. The principle of parameter adjustment was: parameters associated with T1WI or T2WI imaging quality (TR, TE, slice thickness, NEX, FOV and matrix) was set with four changes, and only one of the six parameters was changed in each scan, image quality was evaluated by two senior radiologists, the parameter corresponded the best image quality evaluated consistently by two radiologists were selected as the optimal imaging parameter, all the optimized parameters were set up step by step in this way which formed the imaging parameters in OS group. The pancreatic signal intensity and signal to noise ratio was compared between CS group and OS group after imaging.Results The optimized sequence parameters in clinical MRI scanner were listed below: T1WI sequence (M3D/FSPGR/15): TR 6 ms, TE 2.5 ms, slice thickness 2.0 mm, NEX 8, FOV 7 cm×7 cm, Matrix 120×120; T2WI sequence (FSE-XL/90): TR 4000 ms, TE 71 ms, slice thickness 2.0 mm, NEX 1, FOV 8 cm×8 cm, Matrix 192×160. The pancreatic SI in T1WI and T2WI sequence of the OS group were significantly higher than those in the CS group (t=5.16 and 3.80,P<0.01), while the pancreatic SNR in T1WI and T2WI sequence of the OS group were significantly higher than those in the CS group (t=5.65 and 3.26,P<0.01).Conclusion The optimized parameters can improve the imaging quality of rat pancreas MRI significantly, thus provide a reference for the related experimental study.

ObjectiveTo investigate the unfavorable factors of intestinal mucosa repair after the intestinal epithelial injury in vivo in a mouse model of sepsis. MethodsThe method of cecal ligature and puncture (CLP) was used to induce sepsis and then the intestinal mucosa damage, epithelial cell apoptosis and the number of transformed goblet cells were observed, and the concentrations of serum TNF-αt, IL-1 and TGF-β1 and TFF3 ( trefoil factor 3) in small intestinal mucosa were determined. All above various laboratory examinations were made by different assays including H-E staining, western blot, ELISA and immunohistochemistry respectively. The experimental mice were divided into sepsis group and sham operation control group. The mice with sepsis were separately sacrificed 6 hours ( n = 7 ), 24 hours ( n = 7) and 48 hours ( n = 7) after CLP. Results In septic mice group, the injured intestinal mucosa was found 6 hours after CLP. The damage scores in mice 24 h and 48 h after CLP were higher than those 6 h after CLP, but there was no significant difference between those 24 h and 48 h after CLP. Moreover, a few goblet cells or other epithelial cells adjacent to the injured surface migrated onto the wound to cover the denuded area. The number of goblet cells was substantially decreased in mice of sepsis group 6 hours after CLP compared with sham operation control group. Compared with sham operation control group, levels of IL-1 and TNF-α significantly increased 3-4 times in mice of sepsis group at all intervals, and the phosphorylated caspase-3 increased 4 times. Although TFF3 assayed by using Western blot showed modest increase 6 h after CLP and it declined 24 h and 48 h later. A similar change was found in TGF-β1, it modestly increased 6h after CLP, but it didn't elevate 24 h and 48 h later. ConclusionsSevere sepsis keeps on the inflammatory reaction and epithelial cell apoptosis, preventing the repair of intestinal mucosa from injury.

BACKGROUND: At present, bladder acellular matrix grafts have been successfully used for substituting animal bladder and urinary canal, and for repairing hypospadia. However, reports on bladder acellular matrix grafts for substituting albuginea penis need to be investigated. OBJECTIVE: Allogeneic bladder acellular grafts were used for substituting albuginea penis of rabbits, in order to observe repairing results. DESIGN: A randomized controlled observation. SETTING: West China Medical Laboratory Animal Center and West China Laboratory of Tissue Engineering of Sichuan University as well as Laboratory of Tissue Engineering of Guiyang Medical College. MATERIALS: Fifty male healthy New Zealand Rabbits of grade 3, weighing 2.6-3.0 kg, without phimosis and penis dysplasia, and without presence of phallocampsis after normal saline being perfused, were provided by Huaxi Laboratory Animal Center of Sichuan University. METHODS: This study was performed at the West China Laboratory Animal Center and West China Laboratory of Tissue Engineering of Sichuan University as well as Laboratory of Tissue Engineering of Guiyang Medical College between December 2005 and June 2007. Bladders were taken from 10 experimental rabbits for preparing bladder acellular matrix grafts. The other 40 New Zealand rabbits were randomly divided into the control group, and the bladder acellular matrix grafts group, with 20 in each. An area of 10 mm×5 mm of albuginea penis was resected from dorsum penis of each rabbit. Suture in situ of albuginea penis and bladder acellular matrix grafting were conducted in rabbits of the control group and bladder acellular matrix grafts group, respectively. In the 2nd, 6th, 12th and 24th weeks postoperatively, each rabbit was intracavernously perfused normal saline for inducing penile erection, separately, in order to observe phallocampsis. At above-mentioned each time point, experimental animals were sacrificed. Sample was taken from surgical region for haematoxylin-eosin (HE) staining and Masson trichrome staining, in order to observe the changes of tissue and structure of surgical region. Types Ⅰand Ⅲ collagen fiber areas were detected by Stirus red staining, and the expressions of inducible nitric oxide synthase(iNOS) and transforming growth factor-β1 (TGF-β1) were detected by immunohistochemical staining. MAIN OUTCOME MEASURES: ①Phallocampsis status. ② Changes of tissue and structure of surgical region. ③iNOS and TGF-β1 expressions. ④TypeⅠand Ⅲ collagen fiber areas.RESULTS: Forty experimental rabbits were involved in the penile surgery, two of them died from overdose anesthesia, two died from chordapsus, so the remaining thirty-six rabbits were involved in the final analysis. In the 6th week postoperatively, phallocampsis reached its highest level, and 2 rabbits in the control group and 1 rabbit in the bladder acellular matrix grafts group presented phallocampsis. In the 12th week, every rabbit presented phallocampsis. In the 24th week, 1 rabbit in the control group but none in the bladder acellular matrix grafts group presented phallocampsis. In the 2nd week, the structure of surgical regions of each rabbit was poorly clear, with remarkable inflammatory infiltration. In the bladder acellular matrix grafts group, grafting regions presented cells ingrowing the bladder acellular matrix grafts. Masson trichrome staining results showed that in the surgical region, tunica albuginea fibers were thin and poorly arranged. In the 6th week, tunica albuginea recovered its integrity, and bladder acellular matrix grafts could not be distinguished. No significant difference existed between two groups. In the 24th week, tunica albuginea was even and complete in the sugical region, and fibers restored their arrangement of circular muscle in inner layer and longitudinal muscle in outer layer, without difference from normal tunica albuginea. iNOS and TGF-β1 expressions were the strongest in the 2nd week, and they were found in the fibrocytes and vascular endothelial cells in the 6th week, but a little in the 12th and 24th weeks postoperatively. There were no remarkable differences in iNOS and TGF-β1 expressions between two groups at the same time point. In the 2nd week, typesⅠand Ⅲ collagen fibers co-existed with equivalent proportion. Then, typeⅠcollagen fibers were gradually increased, while type Ⅲ collagen fibers were on the contrary. In the 24th week, typeⅠcollagen fibers took the main place and type Ⅲ collagen fibers were unremarkable. CONCLUSION: Bladder acellular matrix grafts have no remarkable inflammatory reactions and fibrosis in repairing tunica albuginea of New Zealand rabbits, so they are very ideal grafting materials for penile surgery.

Objective:To study the quality and stability of commercial ready-to-use tryptone soya agar(TSA)after storing at 2-25 ℃ for different storage duration under dark condition in order to discuss a determination method of validity period for medium.Methods:Three consecutive batches of ready-to-use TSA medium from two manufac-turers were selected and stored at 2-25 ℃ under dark conditions for 30,90 and 180 days,respectively.The appearance,pH,medium suitability and sterility of the medium were tested.Results:The results of appearance,pH,suitability and sterility of TSA medium from two manufacturers for each batch under different storage duration all met the requirements of the Chinese Pharmacopoeia 2020 Volume IV on the quality control of medium.Conclusion:The TSA medium from two manufacturers all met the requirements when stored for 180 days at 2-25 ℃ under dark condition,indicating that the validity period of TSA medium from two manufacturers can reach 180 days.