Objective To assess the dose reduction potential of adaptive statistical iterative reconstruction(ASiR)and model-based iterative reconstruction(MBIR)in pelvic CT with a standard male phantom.Methods A Fluke Biomedical RANDO standard male phantom was scanned with discovery CT750 HD using different tube currents.CT images were reconstructed with FBP,50％ASiR and MBIR.The CT value,the image noise and the contrast-to-noise ratio(CNR)for the sacral vertebra relative to muscle were measured.The volume CT dose indexes(CTDIvo1)and dose-length product(DLP)were recorded.Results Compared with FBP,using 50％ASiR and MBIR had significant reduced image noise and greater CNR.The effective minimal tube currents for displaying sacral vertebra were 250 mA(FBP),180 mA(50％ASiR),and 100 mA(MBIR).With the similar image quality using FBP,the dose was reduced by 28.0％ and 59.9％ using 50％ASiR and MBIR,respectively.Conclusions Using advanced iterative algorithms can reduce image noise,improve CNR,and reduce the radiation dose in pelvic CT examination.

Objective High-density porous polyethylene(Medpor)has been widely used in chin augmentation in recent years.The study aimed to observe the outcomes of clinical use of high-density porous polyethylene implant in chin augmentation in contour plastic surgery of low face.Methods From 2005 to 2008,149 cases of chin augmentations intraorally with Medpor implants combined with were collected.121 of them received bilateral mandibular angle osteotomy and 28 cases received bilateral mandibular angle osteotomy and bilateral malar reduction simultaneously.They wre all females aged from 17 to 46 years.The patients were followed up for 6 to 36 months(average 24 months)and photographs were taken before and after operations.Clinical outcomes were observed and analysed.Resuits 145 patients(97.3%)were satisfied with their chin and contour of low face.2 patients (1.3%)were not satisfied with the projection of their chin,and 1 of them were admitted to take out the implant and received sliding advancement genioplasty.1 patient(0.7 0A)felt the implants was too large to some extent and was admitted to modify the implant.1 patient(0.7%)received genioplasty 6months after operation because of the deviation of the implant.20 patients(13.4%)felt numbness of the lower lip which gradually disappeared 1 to 3 months postoperatively.Complications such as infection,edema and extrusion,break of the implant were not found during the following period.Conclusions Medpor is an excellent biomaterial with good biocompatibility.Simultaneously chin augmentation with Medpor combined with bilateral mandibular angle osteotomy intraorally shows a good result in contour plastic surgery of low face.

Objective To investigate the effect of intraurethral irrigation with honeysuckle water-decoction on formation of bacterial biofilm on the surface of the catheter. Methods Eighty male patients,who had no history of catheterization and no urinary infection with negative results of urine bacterial culture,were enrolled in the study. All patients were randomly divided into 4 groups with 20 cases in each: group A (patients underwent intraurethral irrigation with honeysuckle water-decoction); group B (intraurethral irrigation with 25% PVP); group C (intraurethral irrigation with normal saline ) and group D (no intraurethral irrigation). The urethral catheters were removed at the 7th day and the bacterial biofilm on the surface of the catheter was examined by scanning electron microscopy (SEM). Results SEM demonstrated uneven- distributed matrixes coated on the surface of the catheter, and bacteria adhered to the matrixes. The average thickness of biofilm in group A, B, C and D was (17.876 ±11.788)μn, (31.090±15. 006)μm,(33.716±11.927)μm, (67.762±23.588)μm, respectively. The average thickness of biofilm in group A, B, C was significantly thinner than that in group D (P<0.01), and the thickness in group A was thinner than that in group B and C (P<0.01), but there was no significance difference between group B and group C (P>0.01). Conclusions Intraurethral irrigation with honeysuckle water-decoction can effectively reduce the formation of bacterial biofilm on the surface of the catheter.

To study the effect of the osmotic stress in the microenvironment on the growth and metabolism of the encapsulated cells under aerobic condition, Osmo-sensitive yeast Y02724 and high-osmotic resistant yeast Hansel were used as models to explore the growth and metabolism state of the cells cultivated inalginate-chitosan-alginate (ACA) microcapsules. The changes of the yeast cells' specific growth rate, maximum product quantity and the secretion of ethanol and glycerol were analyzed. For Y02724, the yield of ethanol was increased in the ACA microenvironment compared to suspension cultivation. For Hansel, the maximum growth speed of microencapsulated cultivation had no obvious difference compared to the suspension cultivation. Moreover, after encapsulation, the production of glycerol was decreased for both Y02724 and Hansel compared to suspension cultivation. In conclusion, osmotic stress existed in the ACA microcapsules and affected the growth and metabolism of the cells.
Alginates ; metabolism ; Capsules ; metabolism ; Cell Culture Techniques ; methods ; Chitosan ; metabolism ; Osmosis ; physiology ; Osmotic Pressure ; Polylysine ; analogs & derivatives ; metabolism ; Saccharomyces cerevisiae ; growth & development ; metabolism ; Yeasts ; classification ; growth & development ; metabolism

Objective To investigate the MRI manifestations of pilomyxoid astrocytoma (PMA)at unusual sites and differential diagnosis in children.Methods The clinical and MRI data from 6 cases of PMA with atypical locations confirmed by surgery and pathology were analyzed retrospectively.Results 2 cases located at cerebral hemisphere,1 case at tegmentum mesencephali,1 case at medulla and 2 cases at cerebellar hemisphere.There were 4 cases of solid tumor and 2 case belonged to cystic-solid mass.5 cases were round or oval and 1 case was shallow lobulated.In addition,there were 2 cases with hemorrhage and 2 cases with peritumoral edema.T1WI showed hypointensity,isointense or slightly hyperintense while T2WI and fluid attented inversion recovery (FLAIR)exhibited isointensity or hyperintensity.After contrast administration,there were 3 cases of obvious multi-ring enhancement,of which 1 case showed astral enhancement of the mural nodules and the other 3 cases showed mild homogeneous or inhomogeneous enhancement.4 cases showed non-enhanced areas in the solid parts.No signs of leptomeningeal dissemination were found in all 6 cases.Conclusion The PMA at unuaual sites in children is primarily solid or cystic-solid,and the image manifestations of plain scan are varied.After enhancement,the tumors show obviously multi-circular enhancement and mild homogeneous or inhomogeneous enhancement could be observed,no enhancement areas are visible in the solid parts.It is noteworthy to distinguish this astrocytoma from other lesions.

Objective:To study the acute toxicity in mice and cytotoxicity of the impuritiy(3-amino-2-piperidinone hydrochloride) in ornithine. Methods:The mice were given the impurity by intravenous injection.The acute toxicity was observed and LD50in mice was calculated by Bliss method. According to the result of LD50,the mice were given the impurity respectively at high,medium and low dose. The changes of general condition and body weight were recorded,and the blood biochemical indices and histomorphology of organs and tissues were observed after 14 days. The cytotoxicity was measured on fibroblasts(L929) cells. Results:The LD50and 95% con-fidence limit of the impurity (intragastric administration) was 758.49-848.08 mg·kg-1.All the detected indices of the three groups (660,330 and 170 mg·kg-1) including general condition,weight change,biochemical indices,organ morphological and histological change were all within the normal ranges. The impurity significantly decreased the viability of L929 cells. The NOAEL value was 660 mg·kg-1in mice. Conclusion:The impurity has certain toxicity to mice and cells. The data can provide experimental basis for the quality standard establishment for ornithine and the safety improvement in clinic use.

BACKGROUND: Silk fibroin, the main component of silk fibroin biofilm, is a natural protein, but it is still a heterologous protein to the body. Its immunogenicity/toxicity is an important factor in determining the development prospects. OBJECTIVE: To evaluate the toxicity of absorbable silk fibroin biofilm and its degradation products on the rat immune system by muscle implantation experiments in rats. METHODS: Ten Wistar rats from Beijing Weitong Lihua Experimental Animal Technology Co., Ltd. were implanted with a long strip of 1 mm× 10 mm in the right gluteal muscle to observe the implant absorption and determine the implantation cycle. Seventy-two Wistar rats were assigned into control and experimental groups (n=36/group, 18 in either sexes) . A long strip of 1 mm×10 mm was implanted into the rat right gluteal muscle in the experimental group, and the control group received no implantation. Some of the rats were taken for histological examination and calculate the organ/weight ratio, at 26 weeks postoperatively. The spleen lymphocyte proliferation ability, NK cell activity, cell classification of T lymphocytes, and levels of interleukin 2 and tumor necrosis factor α were detected. Another part of the animals was taken for macrophage phagocytosis of erythrocytes cell capacity and antibody producing cell count. RESULTS AND CONCLUSION: (1) Silk fibroin biofilm was completely absorbed after implanted into the rat muscle for 26 weeks. (2) In female or male Wistar rats, the immune organs in the experimental group showed no significant changes in the appearance, weight and histological examination. There were no significant differences in the hematological indexes (hemoglobin, red blood cell count, hematocrit, blood platelet count and white blood cell count and classification) , spleen lymphocyte proliferation, NK cell activity, the ratio of T lymphocytes and their subpopulations, and the levels of interleukin 2 and tumor necrosis factor α had no significant differences between two groups (P> 0.05) . (3) In female or male Wistar rats, the macrophage phagocytosis of chicken erythrocytes cell capacity and antibody producing cell count showed no significant differences between two groups (P> 0.05) . (4) These results indicate that silk fibroin biofilm causes no immunosuppression or immunostimulation on immune organs, immune cells and immune molecules (cytokines) of rats.