1.Effects of different magnitudes of mechanical strain on proliferation and alkaline phosphatase activity in osteoblast in vitro
Lin TANG ; Zhu LIN ; Yongming LI
Medical Journal of Chinese People's Liberation Army 1981;0(06):-
Objective To investigate the effects of different magnitudes of mechanical strain on proliferation and alkaline phosphatase (ALP) activity in mouse osteoblast-like cells (MC3T3-E1). Methods MC3T3-E1 cells were subjected to 0%, 6%, 12%, 18% elongation for 24h and 48h by using multi-passage cell stress loading system respectively. MTT colorimetric method was used to assess the proliferation of the cell, ALP activity was detected by ALP assay kit. Results The proliferation of MC3T3-E1 cells was increased significantly 24h and 48h after mechanical strain treatment concomitant with increasing stretching force (P
3.Timing of headgear treatment based on the maturation of cervical vertebra
Yongming LI ; Zhu LIN ; Yinzhong DUAN
Journal of Practical Stomatology 1995;0(04):-
0.05). At stage 2 to 3, the changes of point A was the greatest. Conclusion: Timing of headgear treatment based on the morphological variation of cervical vertebra can obtain the maximum desirable orthopedic effect.
4.The effects of implant morphology on stress distribution in implant-bone interface
Zedong LAN ; Zhu LIN ; Ning LI
Journal of Practical Stomatology 2001;17(3):246-248
Objective:To investigate the effects of different shapes of implant on stress distribution in implant-bone interface and to select the most appropriate shape for orthodontic anchorage. Method:3-dimesional finite element analysis method was used to analyze the stress and strain in implant-bone interface of knife-edged threaded, square threaded and smooth type implants.Results: The first,second and third main stress (MPa) of knife-edged threaded implant were 6.67, 1.47 and 0.52 respectively with 7.72 MPa of Von Mises stress;those of square threaded 13.00,2.51,0.57 and 11.8;smooth type 10.50,2.50,0.67 and 12.60,respectively. The variables of alveolar bone at the cervix of knife-edged threaded,square threaded and smooth type implants were (0.11×10-3), (0.13×10-3) and (0.94×10-4) mm respectively. Conclusion: The stress in knife-edged threaded implant-bone interface and alveolar bone deformation at the cervix of the implants is minimal,therefore the implants are more suitable for orthodontic anchorage.
5.Establishment of three-dimensional finite element model for implant as orthodontic anchorage
Zedong LAN ; Zhu LIN ; Ning LI
Journal of Practical Stomatology 2001;17(3):243-245
Objective:To establish a 3-dimensional finite element model for implant in molar deprived region of mandible. And to lay basis for precise analysis for the biomechanic characteristics of implant anchorage system. Methods:The cross section outline drawn from the molar deprived region of mandible was input into a computer, and ANSYS 5.5 (Swanson Analysis Systems, Inc. Houston, USA) finite element analysis software was used to perform the finite element modeling of the mandible.Results:The cross section outline of the mandible,imitated by a spline curve was smooth and lifelike. This cross section outline was extruded into a three dimensional model. The three dimensional models of the implant and mandible could be smartly meshed to obtain the finite element model of mechanics. Conclusion: An effective 3-dimensional finite element biomechanical analysis model for implant as orthodontic anchorage was established.
6.Retroperitoneal laparoscopic surgery for primary aldosteronism (report of 90 cases)
Chinese Journal of Urology 2001;0(09):-
Objective To evaluate retroperitoneal laparoscopic surgery in the treatment of primary aldosteronism. Methods Retroperitoneal laparoscopic surgery was performed in 90 patients with primary aldosteronism (92 sites on either or both sides).Their clinical indicators were compared with those of 30 cases undergoing open surgery. Results Retroperitoneal laparoscopic procedures were successfully performed in 91 of the 92 sides.In these successful cases,mean operative time was 93 minutes (compared with 114 minutes in open surgery cases),mean volume of blood loss was 36 ml (compare with 87 ml),mean postoperative hospital stay was 6.8 d(compared with 11.0 d),mean time to flatus was 1.6 d (compared with 3.1 d),and mean time to walk around was 2.1 d(compared with 3.3 d), P
7.Retroperitoneal laparoscopic surgery for pheochromocytoma
Chinese Journal of Urology 2001;0(07):-
0.05).In the 16 cases,17 retroperitoneal laparoscopic excisions of pheochromocytoma were successful,only 1 was converted to open surgery due to intraoperative bleeding. The mean operative time was 85?31 (range,45 to 150) min in laparoscopic surgery group vs 155?39 (90 to 240) in open surgery group (P
8.Effects of strain force on the expression of osteoclast differentiation factor and osteoclasto-genesis inhibitory factor in human periodontal ligament cells
Feng WANG ; Zhu LIN ; Yongming LI
Journal of Practical Stomatology 2001;0(01):-
Objective:To investigate the effects of strain force on t he expression of osteoclast differentiation factor(ODF) and osteoclasto-genesis i nhibitory factor(OCIF) in human periodontal ligament cells (HPDLCs). Met hods: HPDLCs were subjected to cyclic strain force for 0, 6, 12 and 24 h ours, mRNA expression of ODF and OCIF were determined by RT-PCR. Result s:After treatment of the cells for 0,6,12 and 24 hours the ODF/?-actio n values were 0.7280?0.0261,0.6831?0.0411,0.5801?0.2230 and 0.4572?0.0373( P0.05) respectively.Conclusion:Strain force may decrease the expression of ODF and increase the expression of OCIF.
9.Subsequent laparoscopic adrenalectomy for patients with previously undergoing ipsilateral adrenal surgery or nephrectomy
Chinese Journal of Urology 2001;0(03):-
Objective To evaluate the feasibility of transperitoneal laparoscopic adrenalectomy for 3 patients with primary aldosteronism who previously underwent ipsilateral adrenal surgery or nephrectomy. Methods From October 2003 to March 2004,transperitoneal laparoscopic adrenalectomy was performed on 3 male patients with primary aldosteronism,including 2 patients (39 and 72 years,respectively) who had previously undergone ipsilateral retroperitoneal laparoscopic partial adrenalectomy for Conn’s adenoma and 1 patient (42 years) who had previously undergone ipsilateral open nephrectomy for renal tuberculosis. Results Transperitoneal laparoscopic adrenalectomy was successfully performed on all the 3 patients; no complication occurred.The mean tumor size was average 1.7 cm in greatest dimension;the mean operative time was average 93 min;the mean estimated blood loss was average 18 ml,and no one needed blood transfusion.The postoperative food intake time was average 17 h,and postoperative hospital stay was average 5.0 d. Conclusions Although scar and adhesion of previous operation may present more difficulties in the subsequent operation,it is feasible to perform transperitoneal laparoscopic adrenalectomy through different surgical access on the patients who have previously underwent ipsilateral retroperitoneal adrenal or nephric surgery.
10.Retroperitoneal laparoscopic adrenalectomy (report of 52 cases)
Chinese Journal of Urology 2001;0(07):-
Objective To evaluate retroperitoneal laparoscopic adrenalectomy. Methods From June of 1999 to January of 2001, retroperitoneal laparoscopic adrenalectomy was performed on 52 patients with adrenal diseases, including 34 cases of aldosterone-preducing adenoma,3 nodular hyperplasia bilateral in 1, 5 Cushing's syndrom,1 Cushing's disease, 3 adrenal pheochromacytoma (bila- teral in 1), 4 nonfunctional adrenal adenoma, 1 myelolipoma and 1 metastasis carcinoma. Results 54 sessions of retroperitoneal adrenalectomy have been carried out for 52 patients (2 on both sides) with success in 51 procedures. The procedure was converted to open operation in 3 occasions because of bleeding or adhesion. The mean operation time was 135 minutes (40~270 min), and the estimated blood loss 45 ml (5~150 ml) with no need of transfusion. The postoperative hospital stay was 6 d (3~14 d) and the mean analgesia consumed 8.5 mg (0~50 mg) of morphine equivalents with no need of any analgesic at all in 17 patients. Conclusions Retroperitoneal laparoscopic adrenalectomy was less traumatic to the patients, with less postoperative discomfort and quicker recovery. The procedure should be considered as the first choice of therapy for benign adrenal diseases.