2.The influence of different inclination of cusp on the stress of an implant supported denture
Journal of Practical Stomatology 1996;0(02):-
Objective: To analyze the influence of different inclination of cusp on the stress of an implant supported denture. Methods: A spiral CT was used to scan a corpus' head.The model of mandible,teeth and implant was established by ANSYS 6.1 software. The superstructure of the denture had three different inclination of cusp.The stress distribution of the models under loading was analyzed. Results: When bearing non central loading, the maximum equivalent stress (max EQV) of the abutment was situated at the first screw of the abutment.When bearing central loading, the maximum equivalent stress(max EQV) of the abutment was situated at the cervix. Under all loading, the max EQV of the implant was situated at the cervix, the max EQV of mandible was situated at the upper cortical layer around the cervix of the implant. Higher inclination of cusp and non central loading lead to higher stress. Conclusion: The location of the max EQV of the abutment is consistent with the location of the abutment fracture; lower inclination of cusp and flatsurface teeth are benefit to the stress distribution of the implantation.
3.Experiment study on abutment displacement of bilateral distal-extension dentures with various retainers
Dongwei HAN ; Tao YANG ; Ping ZHOU
Journal of Practical Stomatology 1996;0(02):-
Objective: To study the influence on the displacement of abutment with various retainer designs for bilateral distal-extension removable partial dentures(RPDs). Methods: Combined clasp, extension clasp and telescopic crown were used to retain RPDs. When food chip was masticated between the upper and lower dentition on one side, the displacement of abutment on both sides was measured by a high sensitive laser traneferring-detector and the data were statistically analyzed. Results: Inclination, torsion and vertical translocation of all abutment teeth were observed. Significant statistical difference ( P
4.Significance of inter-burst interval in the induction of long-term potentiation
Dongwei YANG ; Bin PAN ; Taizhen HAN
Journal of Xi'an Jiaotong University(Medical Sciences) 1982;0(01):-
Objective To compare the different effects of different titanic parameters on the expression of long-term potentiation (LTP) and to determine the optimal patterns of tetanizing stimulation in hippocampal CA1 area in adult male rats. Methods Four tetanic parameters of 100Hz were used in the experiment. Tetanus 1 was a short burst of stimulus composed of 60 pulses, which were divided into 5 sets, each set including 4-pulses-bursts. The inter-burst intervals are lengthened gradually, 1s, 5s, 30s, 10min in sequence. Tetanus 2 was a long burst of stimulus composed of 300 pulses in all, each burst including 20 pulses. The inter-burst interval is 2s, and tetanus 3 is also a short burst of stimulus composed of 15 bursts, each burst including 4 pulses. The inter-burst interval is 2s and tetanus 4 is a single train of burst composed of 60 pulses. The field excitatory post-synaptic potentials (fEPSPs) in hippocampal CA1 area were evoked by stimulating the Schaffer collateral fibers in the stratum radiatum and the expressions of LTP induced by the four parameters were evaluated. Results The amplitude and incidence of LTP induced by tetanus 1 were higher than those induced by the other three parameters. There was no statistical significance between the responses induced by the other three parameters. Both tetanus 1 and tetanus 3 could lead to long-lasting-LTP (LL-LTP, over 3h). Conclusion A high frequency stimulus with 200ms-inter-burst interval (theta frequency) is better in the induction of LTP in hippocampal CA1 area. A short burst of stimulus with 100Hz can evoke the expression of LL-LTP in hippocampal CA1 area.
5.Effects of Functional Point Injection on Upper Limbs Disorder in Cerebral Palsy Infants
Hongyin ZHAI ; Dongwei HAN ; Chunya SU
Chinese Journal of Rehabilitation Theory and Practice 2010;16(5):461-462
ObjectiveTo investigate the effects of functional point injection on upper limbs disorder in cerebral palsy infants. Methods120 cases were divided into 2 groups and each with 60 cases. The treatment group was given rehabilitation and functional point injection (injecting VitB1>, VitB12 in the acu-points selected at the disorder muscles) and the control group was given rehabilitation alone. All the cases were assessed with Peabody Developmental Motor Scale Fine Motor (PDMS-FM) and Modified Ashworth Scale (MAS). ResultsThe scores of both PDMS-FM and MAS improved in the treatment group compared with the control group (P<0.05). ConclusionFunctional point injection can improve the recovery of upper limbs disorder in cerebral palsy infants.
6.Changes of field potentials during development and after long-term potentiation in developing rat visual cortical slices
Bin PAN ; Wen XIE ; Dongwei YANG ; Taizhen HAN
Journal of Xi'an Jiaotong University(Medical Sciences) 2003;0(06):-
Objective To study the changes of field potentials (FPs) during development and after long-term potentiation (LTP) induction in rat visual cortical slices. Methods Field potentials recorded from layer Ⅱ/Ⅲ induced by layer Ⅳ in the rat visual cortical slices were examined. The developing changes of FPs from postnatal days 8-13,15-21 and 29-35 were observed. Amplitudes, peak latencies and slopes of FPs before and after LTP induction were compared. Results Field potentials changed with the development, and the stimulating threshold at p15-21 was lower than that of the other two groups. The increase of FP amplitude was positively correlated with increase of its slope. The shortening of FP latency was positively correlated with the difference between changes of slope and amplitude. Conclusion Developing changes of field potentials reflect the development of visual cortex. The changes of FP slope follow the changes of its amplitude and latency, and thereby the slope is a proper parameter used as an index to evaluate LTP in visual cortex.
7.Changes of HO/CO pathway in renal hypertension of two-kidney one-clip hypertensive rats
Dongwei PANG ; Li HAN ; Junchang LIU ; Tiemin MA ; Hai XU
Chinese Journal of Pathophysiology 1986;0(04):-
AIM: To investigate the effect of heme oxygenase /carbon monoxide(HO/CO) system on the pathogenesis of hypertension and effect of Heme-L- Lysinate(HLL), Zine protoporphyrin-IX(ZnPPIX) on vascular tension in a two kidney one-clip model. METHODS: The changes in mean arterial pressure and heart rate as well as phenylephrine(PHE)-induced contraction in isolated aortic rings of HLL, ZnPPIX- treated rats were examined after intraperitoneal administration of HLL and carbon monoxide( CO). RESULTS: (1) Injection of exogenous CO resulted in a significant decrease in mean arterial pressure in Sham and 2K1C groups(P
8.Effect of heme oxygenase on vascular remodeling in renal hypertension
Li HAN ; Dongwei PANG ; Tiemin MA ; Hai XU ; Lilin WU
Chinese Journal of Pathophysiology 1986;0(03):-
AIM: To investigate the effect of heme oxygenase on vascular remodeling in renal hypertension. METHODS: Male Wistar rats were randomly divided into sham-operated, 2K1C (two-kidney one-clip) and hemin-induced groups. Four weeks after the treatments, the thickness of aortic media and HO enzymatic activity of the aorta were determined. Immunohistochemical staining was carried out to detect protein of HO-1 in the aorta. RESULTS: The blood pressure in 2K1C renal hypertension rats started to increase two weeks after the surgery and stabled at a high level at the 4th week. Hemin, an inducer of HO-1, markedly inhibited the increase in blood pressure. Aortic medium thickness of the 2K1C rats at 4th week was 27 5% thicker than that in the sham-operated rats. The thickness of aortic medium of the hemin-induced rats was 16 1% less than that in 2K1C group. At the 4th week after operation, protein level and enzymatic activity of HO-1 in aorta were higher than that in 2K1C group compared to those in the sham-operated group. CONCLUSION: Renal hypertension caused vascular remodeling and the activation of HO-1. HO-1 induction decreased the blood pressure of renal hypertension and reduced vascular remodeling.
9.Heme oxygenase decreases the generation of ROS in AngⅡ induced proliferation and hypertrophy of cultured vascular smooth muscle cells
Dongwei PANG ; Li HAN ; Jie LIU ; Tiemin MA ; Hai XU
Chinese Journal of Pathophysiology 1986;0(03):-
AIM:To investigate the role of heme oxygenase (HO) in AngⅡ induced proliferation and hypertrophy of cultured vascular smooth muscle cells. METHODS:(1) Western blotting analysis was carried out to detect protein level of HO-1 in the tissues. (2) [3H]-TdR,[3H]-leucine incorporation was measured in cultured vascular smooth muscle cells. (3) 2',7'-dichlorofluorescin diacetate (DCFH-DA) as an index was used to determine the cellular reactive oxygen species (ROS) level. RESULTS:(1) No significant difference in HO-1 protein expression level between AngⅡ-stimulated and control groups was observed,but HO-1 protein level in Hemin-induced group was higher than that in other two groups (P
10.Effects of GABA on the induction of LTP in developing rat visual cortical slices
Bin PAN ; Dongwei YANG ; Taizhen HAN ; Wen XIE
Journal of Xi'an Jiaotong University(Medical Sciences) 1982;0(04):-
Objective To study the effects of gamma-aminobutyric acid (GABA) on the induction of long-term potentiation (LTP) in developing rat visual cortical slices. Methods Field potentials recorded from layer Ⅱ/Ⅲ induced by layer Ⅳ stimulation in rat visual cortical slices were examined. LTP was induced by tetanus in the slices on the postnatal 2, 3 and 5-week rats. The LTP incidences and the effects of GABA on them in different developmental stages were compared. Results LTP incidence at postnatal week 5 was significantly lower than that in other two groups. GABA A receptor antagonist picrotoxin could reverse this tendency, but had no effects on the LTP induction at the early postnatal age. Conclusion In visual cortex, GABA has inhibitory effects on the LTP induction only after the end of critical period and has no any facilitatory effects on the LTP induction before the developmental critical period.