Animals ; Evoked Potentials, Motor ; physiology ; Male ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Spinal Cord ; physiology

Objective To probe the biological degradation of composite bone cement of calcium phosphate and cancellous bone granules,as well as its biophysical and solidifying characteristics.Methods The specimens of composite bone cement were determined by its solidification,which were made of 2.5g calcium phosphate cement mixed either with10%,15%,20%,25%,30%or 35%bone granules of 0.5～1.0mm diameter.The cylindrical specimens of 10mm diameter and18mm length were used for biomechnical test.Furthermore,the bone defect of 5mm?5mm?6mm in12canines were made in L 3 and L 4 verte bral body through anterolateral lumbar vertebral body approach,and composite bone cement with20%bone granules and calcium phosphate cement were filled into the bone defects respectively.The bone formation was evaluated by X-ray and histological examination.Results The composite bone cement with less than20%cancellous bone granules displayed excellent solidifying character,while with the diameter of 0.5～1.0mm and the content of 15%to20%cancellous bone granules,the maximal load and com pressive strength of the composite bone cement were of no significant difference with calcium phosphate ce ment ;but the biomech nical characteristics would decrease if the diameter was1.0～2.0mm despite of the content 15%to20%gran ules.New bone formation were observed in the center of composite bone cement 2months later,and com posite bone cement were replaced mostly by new bone at4months;while in calcium phosphate cement group,only slight degradation occurred at the interface of implant material and host bone at2and4months.Conclusion The composite bone cement of calcium phosphate with20%content and0.5～1mm di am eter of can cellous bone granules can provide the ability of rapid degradation and bone formation.The re sults of study present the basic data of the reparative materials with the composite bone cement for verte-broplasty clinically.

Background Goldmann applanation tonometry (GAT) is a gold standard of intraocular pressure measurement.But its utilization iS limited because of its complexity and high requirement of cooperation.iCare rebound tonometer (iCare RBT) is a new type of applanation tonometry,and its accuracy and safety in clinical application need to be evaluated.Objective Present study was to investigate the reproducibility and tolerability of iCare RBT and its measurement agreement with GAT over a wide intraocular pressure (IOP) range. Methods The IOP were measured in bilateral eyes of 36 glaucoma and glaucoma suspect patients by 2 examinees with iCare RBT at the 1-minute interval to assess the interobserver reproducibility.Then the IOP of both eyes from 56 Subjeets and other 52 subjects were separately measured twice for each by two operators with iCare RBT for the evaluation of intraobserver reproducibility.Finally.IOP of 182 eyes of 92 glaucoma and glaucoma suspect patients was obtained by examiner 2 with RBT first and examiner 1 with GAT subsequently at a 2.minute interval in a masked fashion to perform an agreement evaluation of two readings by using Bland-Ahman method.The tolerance of subjects to iCare RBT measurement were surveyed.Oral informed consent was obtained prior to the IOP measurement. Results Concerning the iCare RBT readings.interobserver correlation coefficients were 0.937 in the right eye and 0.887 in the left eye.Intraobserver correlation coefficients of examiner 1 were 0.986 in the left eyes and 0.969 in the fight eyes.And those of examiner 2 were 0.990 and 0.979.Mcan values of iCare RBT readings and GAT were(18.74±8.36)mmHg and(19.33±8.20)mmHg and the mean difference values(iCare-GAT)was(-0.59 4±2.60)mmHg with the 95%confidence interval of -5.80-4.60 mmHg.The correlation coefficient between two modalities of IOP measurement WaS 0.95 1.No severe pain and discomfort were complained in all the subjects during or after measurement of iCare RBT. Conclusion iCare RBT has good interobserver and intraobserver reproducibility and good tolerance.It was proved that this is a good correlation between iCare RBT readings and GAT readings.

Objective: To study the biocompatibility of CFR/PEEK composite in bone tissue after implanted in lumbar intervertebral space and to evaluate its role in the interbody fusion compared to the allograft bone. Methods: Thirteen beagles were chosen among which 7 were implanted with the disk-like CFR/PEEK composite in the lumbar intervertebral space and the other 6 were implanted with allograft bone. X-ray, QCT and histological examination were employed at 6, 12 and 24 months postoperatively. Results: The X-ray results of fusion segment were in conformity with the QCT's as well as that of histological results. All animals obtained a complete fusion at 24 months. Histological examination revealed that the anterior soft tissue to the implant exhibited a nonspecific foreign body reaction with connective tissue embed the biomaterials. Carbon fragment were seen in the surrounding tissue and some of the debric were phagocytosed by foreign body giant cell. Histological examination of bone and material revealed that new bone grew along the hole of CFR/PEEK implant. Conclusion: CFR/PEEK has an excellent biocompatibility to bone tissue.

OBJECTIVETo compare the biomechanical performances of different wires and cable fixation devices in posterior instrumentation for atlantoaxial instability, and test the effect of different fixation strengths and fixation approaches on the surgical outcomes.

METHODSSix specimens of the atlantoaxial complex (C0-C3) were used to establish models of the normal complex, unstable complex (type II odontoid fracture) and fixed complex. On the wd-5 mechanical testing machine, the parameters including the strength and rigidity of anti-rotation, change and strength of stress, and stability were measured for the normal complex, atlantoaxial instability complex, the new type titanium cable fixation system, Atlas titanium cable, Songer titanium cable, and stainless wire.

RESULTSThe strength and rigidity of anti-rotation, change and strength of stress, stability of flexion, extension and lateral bending of the unstable atlantoaxial complex fixed by the new double locking titanium cable fixation system were superior to those of the Songer or Atlas titanium cable (P<0.05) and medical stainless wire (P<0.05). Simultaneous cable fastening on both sides resulted in better fixation effect than successive cable fastening (P<0.05). Better fixation effect was achieved by fastening the specimen following a rest (P<0.05).

CONCLUSIONSThe fixation effects can be enhanced by increased fastening strengths. The new type double locking titanium cable fixation system has better biomechanical performance than the conventional Songer and Atlas titanium cables. Fastening the unstable specimens after a rest following simultaneous fastening of the specimen on both sides produces better fixation effect.

Atlanto-Axial Joint ; physiopathology ; surgery ; Biomechanical Phenomena ; Bone Wires ; Cadaver ; Humans ; Internal Fixators ; Joint Instability ; physiopathology ; surgery ; Orthopedic Fixation Devices

Multi-drug resistance (MDR) of cancer cells is a major cause of failure in chemotherapy. To the majority of anti-cancer drugs, tumor cells are able to generate a multi-drug resistance; but there is no common views on the mechanism of MDR. This review summarizes the use of drug delivery system based on nanoparticles to overcome MDR in recent years. Three kinds including non-modified, ligand-modified and multifunctional drug delivery systems are described. Especially, the mechanism of reversing MDR based on nanoparticles is covered. Through efficiently offsetting and antagonizing the action of pumping drugs out of the tumor cells, drug delivery system based on nanoparticles can increase the concentration of the drug in tumors, while reduce the side effects on normal cells and overcome multi-drug resistance. The use of drug-loaded nanoparticles, which combines nanotechnology with the strategy of active and passive targeting administration, has shown significant prospect improving cancer therapy.
Animals ; Antineoplastic Agents ; administration & dosage ; therapeutic use ; Drug Delivery Systems ; methods ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Humans ; Nanoparticles ; therapeutic use ; Neoplasms ; drug therapy

Objective To explore the effect of hypoxic preconditioning on the activity and gene expressions of glu-cose transporters in the cultured rat hippocampal neurons and astrocytes under anoxic condition. Methods The cultured rat hippocampal neurons and astrocytes were treated for 6 days by intermittently exposing to hypoxic gas mixture (1% O_2, 10% CO_2, 89% N_2) for20 min each day. 24 h after the last hypoxic exposure, the cells were exposed to anoxic gas mixture (10% CO_2, 90% N_2) for 6 h, and the uptake rate of [~3H]-2-deoxyglucose (2-DG), the levels of glucose transporter GLUT1 and GLUT3 mRNAs and the cell survival rate were examined im-mediately after anoxic exposure. Results Neurons and astrocytes preconditioned with hypoxia showed higher 2-DG uptake rates and increased expressions of GLUT 1 mRNA in the astrocytes and GLUT 1 and GLUT 3 mRNA in the neurons. The preconditioned neurons also showed an increased tolerance to anoxia. Conclusion Hypoxic precon-ditioning up-regulates the activity and gene expressions of glucose transporters of hippocampal neurons and astro-cytes under anoxic condition.

Objective To investigate the clinical significance of generalized epilepsy with febrile seizures plus(GEFS+ ). Methods The data of one family with GEFS+ were retrospectively analyzed by studying clinical manifestations, physical examinations, electroencephalogram(EEG), 24 hours dynamic EEG monitoring, et al. Some of the patients were examined by CT. Results Ⅳ 12, her chief complaints when admitted to hospital were frequent spasm for 3 days. She began to appear febrile seizures (FS) from 8 months after birth, and frequent generalized tonic - clonic FS appeared during that time. There were 36 people in 5 generations of the family including 14 patients (8 males and 6 females) ,aged from 4 years and 5 months to 82 years. FS presented in 8 cases (Ⅱ 2, Ⅲ1, Ⅲ4, Ⅲ6, Ⅳ1, Ⅳ11, Ⅳ17, Ⅴ2),febrile seizures plus(FS +) in 4 cases ( Ⅳ2, Ⅳ12, Ⅳ13, Ⅳ14), ES + and absence seizures in 1 case ( Ⅴ1 ), uncertain type in 1 case (Ⅰ2). The results of EEG indicated that 12 cases were normal and 4 cases with FS+ and 1 case with absence seizures had epileptic discharges. Apart form Ⅳ13, Ⅳ14 who were treated with magnesium valproate, the dosage for the other patients decreased, or medicine terminated or without medicine, and all the patients had no recurrence of seizures. The intelligence, movement development and neurological examinations of the family were all normal. Head CT scan of 3 cases were normal. Conclusions GEFS+ is autosomal dominant inheritance disease with conspicuous genetic heterogeneity and phenotypic heterogeneity. The apprehension of GEFS+ plays an important role in diagnosis and differential diagnosis of epilepsy in childhood.

Background It has been clarified that topical administration of cholinomimetic drug or prostaglandin analogus can effectively low intraoeular pressure (IOP) in primary angle-closure glaueoma and angleopen glaucoma,respectively.The two eyedrops are often combined clinically to treat glaueomatous eye.But their effect mechanism on ciliary muscle is different.It is neeessarv to prove the clinical efficacy of combination of these two drugs.Objective This study attempted to compare hypotensive effect of individual and combinative use of 2％piloearpine and 0.004％ travoprost in normal rabbit eyes.Methods Thirty normal albino rabbits were randomly divided into three parallel groups.Lateral eye of each rabbit was appointed as the experimental eye and the fellow eye was used as control eye.2％ Pilocarpine eyedrop was instilled three times daily and 0.004％ travoprost eyedrops was used once per night in the pilocarpine and travoprost group.These two drugs were combined in the combination group.The normal saline solution was used in the control eyes IOP was measured bilaterally with Perkins application tonometer at 8:00 am on the day before and 1,2,4,8,14,24 days after the administration of eyedrops.The use of the animals complied with the Regulations for the Administration of Affairs Concerning Experimental Animals by State Science and Technology Commission.Results The IOP was significantly lower on 1 day after use of eyedrops than baseline IOP in the experimental eyes in the pilocarpine group,travoprost group and combination group,but no obvious change in IOP before and after use of eyedrops in the control eyes.There was no significant difference in the baseline IOP in both experimental eyes and control eyes,however,signifieant differences were seen in various time points after administration of eyedrops between experimental eyes and control eyes(P＜0.05).Compared with baseline IOP,IOP declined by 17.5％-22.0％ in pilocarpine group,23.8％-26.4％ travoprost group,27.6％-32.0％ in the combination group.For normal eye,piloearpine+travoprost showed a more power lowing IOP effect.Conclusions Hypotensive effect of combinative use of 2％ pilcoarpine and 0.004％ travoprost is strongest in comparison with individual use of pilocarpine or travoprost,but less than the statistical sum of individual use of these two drugs in a 24-day duration in normal eye of albino rabbit.

Objective To observe the expressions of bone morphogenetic protein-2(BMP-2)and bone morphogenetie protein-7(BMP-7)in the synovial tissue of fluorosis rats and its correlation with pathogenic mechanism of fluorosis arthritis.Methods Thirty-two SD rats were randomly divided into 4 groups:the control group,low,moderate and high-dose fluoride group.The control group ate commou fodder.The low,moderate and high dose fluoride group were fed with fodder composed of 25%.35%and 68%of corn(containing fluorine of 148.00 mg/kg)in chronic endemic fluorosis region in Guizhou Province.After 140 days,the expressions of BMP-2 and BMP-7 protein were determined by immunohistochemistry and assayed the absorbanee by computer image-pattern analysis system.Light microscope was used to observe the synovial tissue by Hematoxin Eosin,and calculated the pathological integral of synovium according to pathological grade standard.Results The expressions of BMP-2 (32.50±2.73)and BMP-7(38.90±2.56)in the control group was spare.Compared with the control group,the expressions of BMP-2(59.43±5.12,79.82±6.41,101.76±7.56)and BMP-7(55.10±4.82,78.42±5.61,98.46± 6.05)in the synovial tissue was up-regulated in each experimental groups(P＜0.05),especially in the moderate dose and the high-dose groups(P＜0.05).Compared with the control group(0.54±0.21).the pathological integral of synovium increased(P＜0.05)in each experimental groups(1.04±0.98,4.69±1.28,8.60±2.07).The expressions of BMP-2 and BMP-7 in the synovial tissue was found to be positively related with the pathological integral of synovium(r=0.98,0.99,P＜0.05).Conclusion The BMP-2 and BMP-7 play an important role in the development of fluorosis arthritis,probably by affecting osteogenesis.