AIM AND METHODSThe relation between AT sclerosis (loss of neurons and proliferation of astrocytes) and long-lasting epileptic susceptibility was investigated by thionine staining, GFAP immunohistochemistry and observing the behavior of rats, after scorpion venom (SV) or normal saline (NS) administrated for three week.

RESULTSCompared with NS+ NS group, both the loss of neurons and proliferation of astrocytes were very marked in KA+ NS group (epileptic susceptible rats) (P < 0.05), but those changes were not visible in KA+ NS group (epileptic nonsusceptible rats).

CONCLUSIONSIt suggested that AT sclerosis may be one of important reasons of the long-lasting epileptic susceptibility.

Animals ; Astrocytes ; pathology ; Epilepsy ; pathology ; Glial Fibrillary Acidic Protein ; metabolism ; Male ; Neurons ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley

AIMTo investigate the causative role of nitric oxide synthase (NOS) and nitric oxide (NO) in neurotoxicity of beta-amyloid (Abeta) and the pathogenesis of Alzheimer's disease (AD).

METHODSUsing behavioral and neuropathological methods, we observed the effects of Abeta(1-40) injection into hippocampi on rats learning and memory in Y maze and on the neuropathology in hippocampi. The intervention by intraperitoneal administration of aminoguanidine (AG), a selective inducible NOS (iNOS) inhibitor, and 7-nitroindazole (7-NI), a selective neuronal NOS (nNOS) inhibitor, in the neurotoxicity of Abeta(1-40) was studied then.

RESULTSThe capability of acquisition and retrieval in Y maze and local neurons in hippocampus of the rats were impaired significantly after Abeta(1-40) injection. Intraperitoneal administration of AG, but not 7-NI, could prevent the damages caused by Abeta(1-40) injection above-mentioned.

CONCLUSIONiNOS/NO participates in the mechanisms of Abeta-induced neurotoxicity and may play an important role in the pathogenesis of AD.

Alzheimer Disease ; metabolism ; pathology ; Amyloid beta-Peptides ; metabolism ; toxicity ; Animals ; Guanidines ; pharmacology ; Indazoles ; pharmacology ; Male ; Maze Learning ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; antagonists & inhibitors ; Nitric Oxide Synthase Type II ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo evaluate the effect of extraction and non-extraction decompensation to bimaxillary orthognathic surgery in skeletal class III malocclusion and the effect on postoperative.

METHODSRecords of 36 completed surgical-orthodontic treatment skeletal class III malocclusion patients were obtained from School of Stomatology, China Medical University, 18 underwent maxillary premolar extraction, the other 18 underwent non-extraction. Their post-decompensation and postsurgery cephalometric radiographs were analyzed objectively, and their profile scissors-shadows in different groups were evaluated subjectively.

RESULTSThe cephalometric index of post-presurgical orthodontics showed that there were significant deviations between the extraction and non-extraction groups including U1-SN, Overjet and Cm-Sn-UL values (P<0.05). During surgery, mandible was retruded (8.66 +/- 1.42) mm in extraction group compared with (6.21 +/- 3.06) mm in non-extraction group (P<0.05). After surgery, the extraction group achieved more normal ANB, U1-SN, NA-PA values (P>0.05).

CONCLUSIONMaxillary premolar extraction can make incisor decompensation more complete so that mandible can be retruded to more ideal position and concave face can be successfully corrected.

Bicuspid ; Cephalometry ; Face ; Humans ; Incisor ; Male ; Malocclusion, Angle Class III ; Mandible ; Orthognathic Surgery ; Treatment Outcome

Aged, 80 and over ; Cerebral Hemorrhage ; diagnosis ; physiopathology ; Heparin ; adverse effects ; Humans ; Percutaneous Coronary Intervention ; Thrombocytopenia ; chemically induced

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.

Sodium ; Wastewater ; Potassium ; Diet ; Blood Pressure ; China ; Sodium, Dietary ; Sodium Chloride, Dietary

Stress distribution of denture is an important criterion to evaluate the reasonableness of technological parameters, and the bite force derived from the antagonist is the critical load condition for the calculation of stress distribution. In order to improve the accuracy of stress distribution as much as possible, all-ceramic crown of the mandibular first molar with centric occlusion was taken as the research object, and a bite force loading method reflecting the actual occlusal situation was adopted. Firstly, raster scanning and three dimensional reconstruction of the occlusal surface of molars in the standard dental model were carried out. Meanwhile, the surface modeling of the bonding surface was carried out according to the preparation process. Secondly, the parametric occlusal analysis program was developed with the help of OFA function library, and the genetic algorithm was used to optimize the mandibular centric position. Finally, both the optimized case of the mesh model based on the results of occlusal optimization and the referenced case according to the cusp-fossa contact characteristics were designed. The stress distribution was analyzed and compared by using Abaqus software. The results showed that the genetic algorithm was suitable for solving the occlusal optimization problem. Compared with the reference case, the optimized case had smaller maximum stress and more uniform stress distribution characteristics. The proposed method further improves the stress accuracy of the prosthesis in the finite element model. Also, it provides a new idea for stress analysis of other joints in human body.
Bite Force ; Ceramics ; Crowns ; Dental Stress Analysis ; Finite Element Analysis ; Humans ; Molar ; Prostheses and Implants ; Stress, Mechanical

As a representative part of the oral system and masticatory robot system, the modeling method of the dental model is an important factor influencing the accuracy of the multi-body dynamic model. Taking the right first molars of the masticatory robot as the research object, an equivalent model, point-contact higher kinematic pair composed of v-shaped surface and sphere surface, was proposed. Firstly, the finite element method was used to analyze the occlusal dynamics of the original model in three static contact cases (intrusive contact, centric occlusion, and extrusive contact) and one dynamic chewing case, and the expected bite force was obtained. Secondly, the Hertz contact model was adopted to establish the analytical expression of the bite force of the equivalent model in three static contact cases. The normal vectors and contact stiffness in the expression were designed according to the expected bite force. Finally, the bite force performance of the equivalent model in three static contact cases and one dynamic chewing case was evaluated. The results showed that the equivalent model could achieve the equivalent bite force of 8 expected items in the static contact cases. Meanwhile, the bite force in the early and late stages of the dynamic chewing case coincides well with the original model. In the middle stage, a certain degree of impact is introduced, but it can be weakened by subsequent trajectory planning. The equivalent modeling scheme of the dental model proposed in this paper further improves the accuracy of the dynamic model of the multi-body system. It provides a new idea for the dynamic modeling of other complex human contacts.
Biomechanical Phenomena ; Bite Force ; Humans ; Mastication ; Molar

Masticatory robots have a broad application prospect in the field of denture material tests and mandible rehabilitation. Mechanism type of temporomandibular joint structure is an important factor influencing the performance of the masticatory robot. In view of the wide application of elastic components in the field of the biomimetic robot, an elastic component was adopted to simulate the buffering characteristics of the temporomandibular joint disc and formed the elastic temporomandibular joint structure on the basis of point-contact high pair. Secondly, the influences of the elastic temporomandibular joint structure (on mechanism degree, kinematics, dynamics, etc.) were discussed. The position and velocity of the temporomandibular joint were analyzed based on geometric constraints of the joint surface, and the dynamic analysis based on the Lagrange equation was carried out. Finally, the influence of the preload and stiffness of the elastic component was analyzed by the response surface method. The results showed that the elastic temporomandibular joint structure could effectively guarantee the flexible movement and stable force of the joint. The elastic joint structure proposed in this paper further improves the biomimetic behavior of masticatory robots. It provides new ideas for the biomimetic design of viscoelastic joint discs.

AIM AND METHODSUsing Strain C57/BL of COX-2 deficient mice, the effect of Cyclooxygenase-2 (COX-2) on dopaminergic neurons in substantia nigra of Parkinson's disease (PD) mice induced by intraperitoneal injections of MPTP-HCl were investigated by immunocytochemistry(ICC) .

RESULTSWe found that the mortality in COX-2 heterozygous mice is much lower than that in wild type mice (P < 0.01) after injection of MPTP (30 mg/kg/day). The result of semiquantitative immunocytochemical staining showed that the number of tyrosine hydroxylase (TH) immunoreactive neurons in the substantia nigra pars compacta (SNc) declined more significantly in MPTP-treated wild type mice than that in COX-2 heterozygotes mice (P < 0.01).

CONCLUSIONCOX-2 may be related with lesion of dopaminergic neurons in the SNc of PD.

Animals ; Cyclooxygenase 2 ; deficiency ; Male ; Mice ; Mice, Inbred C57BL ; Neurons ; pathology ; Parkinson Disease ; pathology ; Substantia Nigra ; pathology