Background To establish the ideal animal model of retinitis pigmentosa (RP) is very important for onward relevant study.Previous research determined that N-methyl-N-nitrosourea (MNU) can selectively damage photoreceptors via intravenous injection in mammal.However,whether MNU can be used to create an RP model needs to be investigated.Objective This experiment was designed to evaluate the toxic effect of MNU on photoreceptor cells of cats.Methods MNU was injected into 20 2-year-old cats via femoral vein and randomized into 20mg/kg, 25mg/kg, 30mg/kg, 35mg/kg and 40mg/kg MNU groups,and equal amount of normal saline solution was used in the same way in 4 normal cats as the control group.The activity,pupil size and light reflex were observed after injection of MNU.The cats were sacrificed and eyeballs were enucleated for histological examination to evaluate the structural and morphological changes of photoreceptors at 24 hours,72 hours,7 days and 14 days after the administration of MNU.This experimental study complied with the Statement for the Use of Animals in Ophthalmic and Vision Research.Results Dilated pupil and inertia of light reaction were found in experimental cats on the 7th days in the various groups.In 24 hours after MNU injection,the damage of photoreceptors was primarily characterized by pyknosis and disorder.In 72 hours after MNU injection,attenuation of the outer nuclear layer and disruption of cells were seen.Loss of photoreceptors and disappearance of the outer nuclear layer were observed on the 7th and 14th day.The extent of retinal photoreceptor cell damage was dependent on the dose of MNU.Conclusion MNU can selectively induce serious damage of the photoreceptor cells in cats retina in a time- and dose-dependent manner.

Objective To evaluate the safety,biocompatibility and efficacy of transcatheter closure of atrial septal defect(ASD)with no stainless-steel-screw occluder in canine model.Methods The device was constructed from superelastic Nitinol wires tightly woven into two flat disks and sewed with polyester fibers inside,with a pliable loop on the right-atrial-disk of the device,connecting to the delivery cable.ASD was created by transcatheter puncture and balloon dilatation and then closed by occluder under fluoroscopy in the catheterization laboratory.The location and the influence of the implanted device on function of tricuspid valve and mitral valve were evaluated by echocardiography.At 1,2,3 and 6 months after the operation,the animals were killed and autopsy was conducted.Results Eight dogs with puncture-produced ASD underwent ASD closing procedure successfully.The occluder showed no influence on the function of MV and AV demonstrated by echocardiogram.The two disks of the implanted device were covered with a smooth intact neogenesis layer in all dogs.Endocardial cells fully covered the surface of the two disk without inflammating reaction 3 months later. There was no evidence of corrosion on the surface of the nitinol wire removed from the dog after 6 months.Light microscopic examination of the liver,kidney,lung and spleen showed no evidence of embolization and inflammation.Conclusion Transcatheter ASD occlusion with new-type occluder is safe,feasible,effective and good biocompatibility with a good prospective clinical application.

Objective To establish a method for rapidly detecting the G-protein ?3 subunit (GNB3) 825 site single nucleotide polymorphism (SNP) and to analyse the relationship between GNB3 825 site gene SNP and obesity. Methods The real-time fluorescent PCR was employed to analyse the GNB3 825 site gene SNP of 420 samples from 21 provinces and the the frequencies of genotypes were compared with those detected by gene sequencing. GNB3 825 site genotype, body weight, body mass index (BMI) and fat content were examined from 207 subjects and the correlation between GNB3 825 site gene SNP and obesity was analysed. Results The result by real-time fluorescent PCR showed that the frequencies of 825T and 825C haploid were 46.90% and 53.10%, respectively, and the frequencies of 825TT, 825TC and 825CC genotype were 22.38%, 51.42% and 28.10%, respectively, with no other genotype detected, which was consistent with the result by gene sequencing. BMI and fat content were significantly higher in subjects with GNB3 825TT than in subjects with other genotypes. Body weight was much higher in subjects with GNB3 825TT genotype than in subjects with 825CC genotype, but not significantly different with 825CT genotype. Conclusion A new rapid method for the detection of GNB3 825 site SNP has been successfully established. There existed significant correlation between GNB3 825TT genotype and obesity.

Background Bevacizumab is primarily aimed at pathologic angiogenesis for off-label uses such as the treatment of ocular neovascular disorders.However,as a new anti-fibrotic and anti-angiogenic agent following trabeculectomy,the safety and efficacy of bevacizumab by multiple-time and high-dose subconjunctival injection are still under study.Objective This study was to assess the safety and efficacy of bevacizumab after multiple-time and high-dose subconjunctival injections.Methods Regular trabeculectomy filtration surgery was performed on both eyes of 18 clean New Zealand White rabbits 0.1ml of bevacizumab(25g/L) was subconjunctivally injected intraoperatively and 3,5,7 days postoperatively in the left eyes of rabbits,and no any intervene in the right eyes were as normal controls.Bleb morphology was examined every 2 days and graded based on Moorefield's criteria and compared between the bevacizumab-treated eyes and normal saline(NS) eyes.The animals were sacrificed at 10,20 and 30 days after surgery respectively.The histopathological changes of the blebs were detected by hematoxylin and eosin stain to evaluate the cellular element around the bleb,and Masson stain was used to assess the degree of fibroblast proliferation.The degree of vascularity of bleb was identified by anti-vWf stain.Approval of this protocol was obtained and permitted from People's Hospital Institutional Animal Care and Use Committee of Peking University.The use of experimental animals complied with the Regulation for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.Results Compared to the NS-treated eyes,bevacizumab-treated eyes showed the larger and more diffusely elevated blebs with the significant difference(2.48±0.22cm2 versus 1.73±0.27cm2,t=5.194,P＜0.05).The survival time of the filtration bleb in bevacizumab panel was longer in bevacizumab-treated eyes compared to control eyes,showing a significantly difference between them(21.0±1.56 days versus 12.5±1.97 days,t=3.830,P=0.005).Histological and immunohistochemical analysis confirmed that bleb and adjacent conjunctiva vascularity(A value) was significantly less in bevacizumab-treated eyes than that in control eyes at 20 days after surgery with the difference value 14320.7±4134.9(t=12.275,P＜0.05),and fibroblast deposition value was evidently diminished after bevacizumab treatment at 30 days following surgery in comparison with control eyes with the mean difference 0.27±0.03(t=15.980,P＜0.05＝.Conclusion Repeated subconjunctival injection of bevacizumab can effectively prolong the survival time of bleb in a rabbit model of trabeculectomy and limit the degree and area of vascularization in 30 days following surgery.Bevacizumab inhibit fibroblast-meditated tissue formation significantly in the later phase of vascularization after trabeculectomy.

OBJECTIVE: To establish the diagnosis of amniotic fluid embolism with blood samples by liquid-based cytology technique and to study the validity of method. METHODS: The blood samples were collected from patients who suffered from amniotic fluid embolism. The components of amniotic fluid in blood samples were examined with blood smear by two direct smear methods (supernatant smear, sediment smear) and two liquid-based cytology methods (automatic smear, manual smear). The positive detection rate of each method was calculated. RESULTS: The positive detection rates of two liquid-based cytology methods (84.6% and 92.3%, respectively) were much higher than those of two direct methods (53.8% and 61.5%, respectively). CONCLUSION The liquid-based cytology technique could improve the positive detection rate of amniotic fluid embolism.
Amniotic Fluid ; Cytological Techniques/methods* ; Embolism, Amniotic Fluid/diagnosis* ; Female ; Humans ; Pregnancy

OBJECTIVETo observe the dynamic immunity of the porcine cancellous bone scaffold(PCBS) after transplantation and provide experimental evidences for amending and clinical use.

METHODSThe PCBS was gained through physical and chemical disposals to porcine cancellous bone and was implanted subcutaneously in rabbit. The histological investigation and the expression of Th1 (such as IL-2, IFN-gamma) and Th2 (such as IL-4, IL-10) mRNA were measured by HE, RT-PCR respectively in 1,2,4,8,12 week postoperation.

RESULTSHE revealed: Inflammation cells (lymphocytes and monocytes) were shown abundantly in the surrounding tissue in 1 week and were decreased gradually since 2 week. At 12 week, there were few inflammation cells in the surrounding tissue. RT-PCR revealed: The mRNA expression level of Th1 cytokines such as IL-2, IFN-gamma was high in 1 week and began to fall since 2 week. At 12 week, the mRNA expression level of Th1 cytokines was low; The mRNA expression level of Th2 cytokines such as IL-4, IL-10 was low in 1 week, rose gradually since 2 week and reached tiptop in 8 week. At 12 week, the mRNA of Th2 cytokines maintained high level expression.

CONCLUSIONSThe porcine cancellous bone scaffold excitate immunoreaction was transitory inflammation after implantation.

Animals ; Bone Transplantation ; immunology ; Cytokines ; metabolism ; RNA, Messenger ; genetics ; Rabbits ; Swine ; Th1 Cells ; metabolism ; Th2 Cells ; metabolism ; Tissue Scaffolds ; Transplantation, Heterologous

For medical image volume rendering, it is very difficult to simultaneously visualize interior and exterior structures while preserving clear shape cues. Highly transparent transfer functions produce cluttered images with many overlapping structures, while clipping techniques completely remove possibly important contextual information. To address this issue, A gradient adaptive shading based illumination model is proposed and implemented in CUDA architecture. The coefficients of ambient, diffuse and specular lighting are tuned adaptively according to gradient. The experiments show that our method is capable of preserving 3-D contextual information in medical image dataset while still show clear boundaries with real-time interactive speed.
Algorithms ; Artifacts ; Computer Graphics ; Computer Simulation ; Humans ; Image Enhancement ; methods ; Image Interpretation, Computer-Assisted ; methods ; Imaging, Three-Dimensional ; Models, Theoretical ; Pattern Recognition, Automated ; methods

Objective To investigate the prevention of glucocorticoid-induced osteoporosis or bone loss in systemic lupus erythematosus (SLE) patients by Bugu capsules.Methods Sixty-six patients with SLE were randomly divided into A and B groups:34 patients in Group A were treated by glucocorticoid and Bugu capsules,and 32 patients in Group B by glucocorticoid alone.All patients were measured for bone mineral density (BMD) in Wards triangle,and for related biochemical parameters such as serum calcium, phosphonium,alkaline phosphatase,parathyroid hormone (PTH) and interleukin-6 (IL-6) before and after the treatment.As the control group,thirty healthy subjects were measured for the above parameters.Results There was significant difference in the serum level of IL-6,calcium and PTH between the Group B and con- trol group (P＜0.01).The occurrence rate of osteoporosis or bone loss in group A was significant lower than that in group B [2/34 (5.88%) vs 9/32 (28.13%),P=0.0364].Conclusion Bugu capsules can prevent glucocorticoid-induced osteoporosis or bone loss in SLE patients,possibly by restoring the balance among serum IL-6,calcium and PTH.

OBJECTIVETo investigate the role of CD40 ligand (CD40L) in dendritic cells (DC) of CEA transgenic mice and to evaluate the specific cellular immunity induced by activated DC.

METHODSBone marrow cells of the CEA transgenic mice were used to generate immature dendritic cells under the condition of GM-CSF and IL-4. CD40L was added to activate dendritic cells into mature phenotype. Dendritic cells cancer vaccine was pulsed with CEA526-533 peptide which made the vaccine specific for cancer immunity. The immunophenotype molecules were identified by flow cytometry. The cytokines produced by cells were determined by ELISA. T cells proliferation was measured by (3)H-thymidine essays.

RESULTSImmunophenotype molecules expressions of CD40L-activated dendritic cells were significantly higher than those in control group. IL-12 secretion by CD40L-activated dendritic cells was (937.81+/-51.99) pg/10(6) DC, significantly higher than that in control group [(83.06+/-8.58) pg/10(6) DC, P<0.01]. CD8(+) T cells proliferation induced by CD40 L-activated dendritic cells was stronger as compared to control group (P<0.05), and the secretion of IFN-gamma was(33.900+/-4.550) ng/L, significantly higher than that in control group [(5.226+/-0.460) ng/L, P<0.01]. Splenocytes proliferation induced by CD40 L-activated dendritic cells was stronger as compared to control group (P<0.01), and the secretion of IFN-gamma was (69.802+/-11.407) ng/L, significantly higher than that in control group [(2.912+/-0.562) ng/L, P<0.01].

CONCLUSIONThe method of using CD40L to stimulate bone marrow-delivered dendritic cells promotes the maturation and activation of dendritic cells, which enhances the cellular immunity in CEA transgenic mice.

Animals ; CD40 Ligand ; immunology ; physiology ; Dendritic Cells ; cytology ; immunology ; metabolism ; Immunity, Cellular ; immunology ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic

Objective To discuss the characteristic of brachial plexus root avulsion injury of high resolution MR imaging and the value in diagnosing of brachial plexus root avulsion injury early.Methods Fourty-five cases of brachial plexus root avulsion injury patients had being used for investigation to find the characteristic and diagnostic value of MR image of brachial plexus root avulsion injury,which all have pre-operative MR imaging and were diagnosed brachial plexus root avulsion injury by intra-operative exploration and electrophysiology form February 2006 to February 2011.Results Post-traumatic spinalmeningolceles were seen in 42 cases,the frequency was 93.3％; Displacement of spinal cord was seen in 25 cases,the frequency was 55.6％; Absence of anterior and posterior root of spinal nerve was seen in 8 eases,the frequency was 17.8％;Black line sign was seen in 18 cases,the frequency was 40.0％.The sensitivity,specificity,and accuracy of MRI in diagnosing brachial plexus root injury were 95.7％,77.8％ and 94.6％ respectively.Conclusion Posttraumatic spinalmeningolceles are most often seen in MR of brachial plexus root avulsion injury,this sign can play an important role in diagnosing and treatment of brachial plexus root avulsion injury.