BACKGROUND: Scaffolds are an important part in bone tissue engineering. However, no perfect scaffolds have been developed for bone tissue engineering yet.OBJECTIVE: To evaluate the repair of rabbit radial defects by poly (L-lactic acid)/tricalcium phosphate(PLLA/TCP) scaffolds prepared by rapid prototyping(RP) technology so as to find a new carrier for growth factors.DESIGN: A completely randomized controlled study was conducted. SETTING: Orthopaedic institute of a military medical university.MATERIALS: The study was conducted in the General Orthopedic Institute,Fourth Military Medical University of Chinese PLA, from May 2001 to February 2002. Twenty clean New Zealand rabbits with body mass of(2.5 ±0. 5) kg for this study were obtained from the Experiment Animal Center of Fourth Military Medical University of Chinese PLA. The animals were divided into experiment group and control group with 10 rabbits in each group.INTERVETIONS: PLLA/TCP scaffolds prepared by RP technology and loaded with or without bovine bone morphogenetic protein (BMP) were used to repair the rabbit radial defects of 15 mm.MAIN OUTCOME MEASURES: Main outcomes: ① microscopic observation results of transplanted materials of the two groups; ② degradation rate of scaffolds. Secondary outcomes: ① gross observation; ② radiographic results; ③ bone density.RESULTS: At week 12, bone defect healing in experiment group was good. X-ray examination showed continuous bone callus and partial molding of different degrees. Degradation rate of scaffolds was 39.6%, and bone density in the defected part reached 70% of the normal level. All the indexes of experiment group were superior to those of control group, and no healing was found in the defected area in control group.CONCLUSION: PLLA/TCP scaffolds prepared by RP technology and loaded with bovine BMP can repair radial defects of 15mm in rabbits.

Objective To investigate the survival profile of the intradermally injected mouse autologous skin fibroblasts and the changes of the collagen fibers by using green fluorescent protein labeling and two-photon fluorescence microscopy. Methods The cultured cells were transfected by EGFP lentivirus, and then the cells were injected into the corresponding mouse skin. Biopsy was taken from the animals after 1 and 2 months. The specimens made serial frozen sections, the survival profile of the injected cells and the changes of the collagen fibers were observed by two-photon fluorescence microscopy. The collagenic area and dermal thickness were measured with image analysis software, and statistical analysis was also carried out. Results Two-photon fluorescence microscopy showed clear images of the injected cells and collagen fibers. Both the area of collagen fibers and the dermal thickness were significantly increased in injected cells after 2 months (P<0.05), however, there were no difference between injected cells and control after 1 mouth (P>0.05). Conclusions Autologous cultured fibroblasts could survive in a long time after transplantating into the skin, and collagen could be newly produced, the depth of dermis increases, which provides a possibility to treat mini-defects of the tissue.

Hela is the cell line of adenocarcinoma of the uterine cervix, and human papillomavirus (HPV) 18 shows positive. We delivered siRNA with target specifically to HPV18 E7 mRNA into nude mice Hela tumor xenografts by nanopatch to inhibit the HPV gene expression, and further to study the superiority, the best action time and concentration of siRNA of using nanopatch to transfer siRNA in vivo. We designed siRNA that target specifically to HPV18 E7 mRNA (siE7) and checked the effect of siE7 in vitro. Tumor xenografts were transfected with siE7 and GenEscort III by nanopatch. Expression of HPV18 E7 mRNA and protein were detected 0 hours, 24 hours, 48 hours, 72 hours after transfection with PT-PCR and Western blot, and the best action time was analyzed using nanopatch to thansfect siRNA in vivo. We transfected GenEscort III and siE7 of Different concentration into tumor xenografts respectively by nanopatch and intraperitoneal injection. Expression of HPV18 E7 mRNA and protein was detected 72 hours after transfection by PT-PCR and Western blot, to analyze the best action concentration of siRNA and the superiority of using nanopatch to thansfect siRNA in vivo. The results proved that SiE7was efficient to inhibit expression of HPV18 E7 mRNA and to advance Hela apoptosis in vitro. SiE7 transfected by nanopatch into xenografts could inhibit effectively expression of HPV18 E7 mRNA and protein. The best action time and concentration of siRNA of using nanopatch to thansfect siRNA in vivo are 72 hour post-transfection and 2 micromol/L siE7. To compare intraperitoneal injection in delivering siRNA in vivo, the effect of nanopatch is very predominant. It can be well concluded that Nanopatch can effectively transfer siRNA in vivo, which can effectively inhibit the HPV gene expression.
Animals ; Apoptosis ; DNA-Binding Proteins ; genetics ; Female ; Gene Expression Regulation, Viral ; HeLa Cells ; Humans ; Mice ; Mice, Nude ; Nanostructures ; administration & dosage ; Oncogene Proteins, Viral ; genetics ; Papillomaviridae ; genetics ; RNA, Small Interfering ; administration & dosage ; Transfection ; Uterine Cervical Neoplasms ; therapy ; Xenograft Model Antitumor Assays

AIM: To observe the hemostatic effect and hemostasis mechanism of XHJ (Auena fatua L.) oral Liqnid on animals. METHODS: Bleeding time (BT) and clotting time (CT) were measured by means of tail cutting and glass slide method on mice, Von willebrand factoe (vWF), prothrombin time (PT) and Kaolin partial thromboplastin time (KPTT) were observed by immunoterbidimerry and coagulase test, antithrombin Ⅲ(AT-Ⅲ) by chromophoric matrix method platelet count by tissue plasminogen activator (tPA), plasminogen activatore inactivator (PAI). CONCLUSION: The results indicate that XHJ has remarkable effect on hemostasis; Its mechanism is related to accelerating blood coagulatlon, inhibiting fibrinolytic activity, adding blood vessel endothelial cell release and improving platelet adhesiveness and aggregation.

Objective To explore the effect of Fas and caspase-3 on apoptosis in the white matter damage(WMD) neonatal rats.Methods The pups(45 in each group) were perfused at 30 min,1 h,4 h,12 h,1 d,3 d,7 d,14 d,21 d of recovery from hypoxia-ischemia(HI).Immunohistochemical technique was applied to investigate the changes in the expression of Fas and caspase-3 in periventricular white matter tissues.Apoptotic cells were detected in these tissues by TUNEL.Results Apoptosis index(AI) in the experimental group increased significantly at 4 h and reached the peak at 3 d after HI.No expression of Fas was found in the control group.The expression of Fas in the experimental group appeared at 30 min after HI,increased at 1 h,reached the peak at 12 h and lasted till 3 d.Caspase-3 in the experiment group was up-regulated,peaked at 1 d,demonstrating significant differences at 1 h,4 h,12 h,1 d,3 d and 7 d compared with the control group(P

Objective To promote the progress in varicella-zoster virus (VZV) immunoglobulin preparation,a rapid microneutralization test ( RMNt) was set up for screening plasmapheresis donations with high titers of special neutralizing antibodies to VZV.Methods With reference to the VZV immunoglobulin (VZIG) preparation standard of FDA and VZIG international unit ( IU) , a screening standard was formulated; the amount of virus was analyzed to determine the optimal conditions for RMNt;screening technology was established and the IU was introduced as quality control ;twenty samples of apheresis plasma and fifteen samples of pooled plasma were diluted at 1∶2 to 1∶256 and tested by RMNt respectively;and the sensitivity of RMNt was also analyzed by the commercial ELISA kit .Results Plasma samples that were diluted at 1∶16 and had a titer more than 0.4 U/ml could be used in the production of VZIG .1500 PFU/ml titers of virus in RMNt pro-duced readable results in plasma screening .Eight apheresis plasma samples tested met the screening standard , but none of the pooled samples tested positive .RMNt had a good linear relationship with ELISA (r=0.895 24,P<0.0001).Conclu-sion The sensitivity, throughput and operability of the established RMNt can be used in the screening of plasma donations as key techniques for the production of VZIG .

Objective To analyze the CT features of intestinal tumor obstruction, and explore its CT value.Methods CT manifestation and clinical materials of intestinal tumor obstruction proved by surgical findings or endoscopy biopsy in 35 cases were analyzed restrospectively, and compared with the results of surgery-pathology and endoscopy. Results CT findings were consistence with the results of surgery-pathology and endoscopy in 33 of 35 cases. The CT diagnostic accuracy of intestinal obstruction was 100%. And the accuracy of the cause was 94%, including colon carcinoma in 25, lyphoma in 5, gastrointestinal stromal tumor in 2, and lipoma in 3.Conclusion CT has unique advantage in examining intestinal tumor obstruction, not only for definiting the existence of the obstruction, but also locating the site of obstruction diagnosing the cause and chosing the appropriate treatment.

Objective To investigate gene polymorphisms of drug targets and mutations associated with drug resistance in Pneumocystis jiroveci (P.jiroveci) isolates.Methods Among 148 samples isolated from human immunodeficiency virus (HIV)infected patients with pneumonia in Guangdong,mitochondrid larg subunit rRNA (mtLSUrRNA) gene was amplified from 51 samples.Dihydropteroate synthase (DHPS),dihydrofolate reductase (DHFR) and Cytochrome b (CYB) genes of P.jiroveci were detected by gene sequencing,and compared with the reference sequences in GenBank to evaluate gene polymorphisms.Results P.jirovecii DHPS,DHFR and CYB genes were all successfully amplified from 51 samples.For DHPS gene,48 (94.1％) were wild-type and 3 (5.9％) had gene mutation associated with drug resistance.For DHFR gene,30 were wild-type,and 21 had a synonymous mutation at position 312,and 1 nonsynonymous mutation at position 188.There were no mutations associated with drug resistance.For CYB gene,polymorphisms of were detected at 5 sites,4 of which were synonymous mutations,1 was non-synonymous mutation.No mutation associated with drug resistance was found.Based on the gene polymorphism of CYB6,the strains can be classified into 6 genotypes,and 2 were first detected,including 25 CYB1,13 CYB2,2 CYB5,4 CYB8,as well as newly detected 4 CYB10 and 3 CYB11 strains.Conclusions The mutations associated with drug resistance in P.jiroveci isolates in Guangdong remain uncommon.CYB gene shows gene polymorphisms and can be selected as one of targeted genes for multilocus sequence typing.

AlM:To evaluate the expression of transcriptional factor lslet-1 in retina in experimental retinal neovascularization induced by oxygen.
METHODS: The murine retinal neovascularization were induced by hyperoxia exposure. The morphological observation of retinal neovascularization was performed using angiography by fluorescein dextran injection under the fluorescence microscope, and the new blood vessels were quantified after 5d in room air (17-day-old) by counting the vascular epithelial cell nuclei protruding into viteous cavity using HE stain. Realtime PCR and Western blot were used to examine retinal lslet-1 level in postnatal 7,12, 14,17 and 26d respectively.
RESULTS: A lots of new blood vessels were demonstrated in the mouse retina in hyperoxic group by fluorescein angiography and histological method. Moreover, no significant difference was found in retinal lslet-1 level in postnatal 7d between hyperoxic group and control group, but was significantly higher in postnatal 12, 14 and 17d mice compared with control mice. However, mice at postnatal 26d, expression of lslet-1 in retina decreased to normal level.
CONCLUSlON: ln processing mouse model of retinal neovascularization, sustained hypoxia retinal tissue induce retinal neovascularization by increas the expression of transcription factor lslet-1.

0.05).Conclusion The result suggests that T1 locus genetic polymorphism is weakly associated with asthma.