Establishment and evaluation of rat obesity model induced by electrical damage of ventromedial hypothalamic nucleus and arcuate nucleus / 中华行为医学与脑科学杂志

Objective:To construct a rat model of hypothalamic obesity by two point electrical damage to the ventromedial hypothalamus and arcuate nucleus.Methods:Twenty adult male SD rats of SPF grade were randomly divided into experimental group and sham operation group.A 25GA (0.45 mm) solid iron needle was used, the needle was coated with an insulating layer, and the tip exposed a 0.5 mm conductive area.With reference to The Rat Brain in Stereotaxic Coordinates and using the stereotactic instrument (AP: -2.6 mm, ML: ± 0.6 mm, DV: -9.6 mm) as the coordinate, 1.5 mA current was continuously applied for 25 s, the ventromedial nucleus (VMH) and arcuate nucleus (ARC) of bilateral brain in SD rats was damaged.During the experiment, the body weight(BW), food intake(FI) and water intake(WI) of the two groups were recorded regularly.The rats were sacrificed on the 28th day after the operation, and the changes of periprenal fat mass and body length were measured.The changes of liver and adipose tissue were detected by HE staining method, leptin by ELISA, leptin receptor(LEPR) by Western blot.Results:(1) The body weight of rats in the experimental group ((427.5±17.7)g) and weight gain ((208.5±14.8)g) were significantly increased compared with the rats in the control group((349.2±17.7)g), ((136.2±21.4)g)on the 28th day after operation ( t=7.661, 6.806, both P<0.001). (2) The daily food intake of rats in the experimental group ((44.2±6.6)g) on the 28th day after surgery was significantly higher than that in the control group ((23.0±3.6)g) ( t=6.918, P<0.001). There was no significant difference of the daily drinking water of rats between experimental group((37.5±12.1)ml) and the control group ((35.0±11.8)ml) ( t=0.361, P=0.726). (3) Perikidney fat mass of experimental group rats ((13.4±2.7)g) significantly increased 28 days after operation compared with control group rats((6.3±0.9)g)( t=4.250, P<0.05). The naso-anal length of experimental group((21.8±0.4)cm) was significantly decreased compared with the control group ((23.4±0.2)cm) ( t=-6.788, P<0.01). The Lee index of the experimental group (348.9±8.5) was significantly higher than that of the control group(305.5±4.3)( t=7.898, P<0.01). (4) The serum leptin content ((8 324.10±159.00)μg/L) of the experimental group rats at 28 days after surgery was significantly higher than that of the control group((2 705.31±407.10)μg/L) ( t=25.712, P<0.001). The lateral hypothalamus area (LHA) LEPR protein expression (1.3±0.1) in the experimental group was significantly higher than that in the control group (0.9±0.1) ( t=4.932, P<0.01). Conclusion:Two-point electrical damage to bilateral VMH and ARC of rats can establish hypothalamic obese rat model.

JNK/c-Jun signaling pathway mediates arginine vasopressin neuron regeneration by promoting cytoskeleton reconstruction in rats with electrical lesions of the pituitary stalk / 南方医科大学学报

OBJECTIVE@#To investigate the mechanism by which doublecortin promotes the recovery of cytoskeleton in arginine vasopressin (AVP) neurons in rats with electrical lesions of the pituitary stalk (PEL).@*METHODS@#Thirty-two SD rats were randomized into PEL group with electrical lesions of the pituitary stalk through the floor of the skull base (=25) and sham operation group (=7), and the daily water consumption (DWC), daily urine volume (DUV) and urine specific gravity (USG) of the rats were recorded. Four rats on day 1 and 7 rats on each of days 3, 7 and 14 after PEL as well as the sham-operated rats were sacrificed for detection of the expressions of β-Tubulin (Tuj1), doublecortin and caspase- 3 in the AVP neurons of the supraoptic nucleus using immunofluorescence assay and Western blotting.@*RESULTS@#After PEL, the rats exhibited a typical triphasic pattern of diabetes insipidus, with the postoperative days 1-2 as the phase one, days 3-5 as the phase two, and days 6-14 as the phase three. Immunofluorescent results indicated the repair of the AVP neurons evidenced by significantly increased doublecortin expressions in the AVP neurons following PEL; similarly, the expression of Tuj1 also increased progressively after PEL, reaching the peak level on day 7 after PEL. The apoptotic rates of the AVP neurons exhibited a reverse pattern of variation, peaking on postoperative day 3 followed by progressive reduction till day 14. Western blotting showed that the expressions of c-Jun and p-c-Jun were up-regulated significantly on day 3 ( < 0.05) and 7 ( < 0.01) after PEL, while an upregulated p-JNK expression was detected only on day 3 ( < 0.05), as was consistent with the time-courses of neuronal recovery and apoptosis after PEL.@*CONCLUSIONS@#JNK/c-Jun pathway is activated after PEL to induce apoptosis of AVP neurons in the acute phase and to promote the repair of neuronal cytoskeleton by up-regulation of doublecortin and Tuj1 expressions.

Comparison of transparent effects of six different optical clearing methods on rat brain tissues / 中国比较医学杂志

Objective To compare the transparency efficiency of six different optical clearing method on the rat brain tissues. Methods Brain tissue blocks of 14 SD rats were processed with iDISCO, SeeDB, CUBIC, SCALEVIEW-A2,CLARITY-CUBIC, Passive-CLARITY clearing method, respectively. Results The gray value of PBS group was 13.031 ± 0.586,that of iDISCO,SeeDB,CUBIC,SCALEVIEW-A2,CLARITY-CUBIC,passive-CLARITY clearing were 6.447 ± 0.574,11.690 ± 0.909,2.318 ± 0.986,8.118 ± 1.026,8.591 ± 0.384,4.198 ± 0.182, respectively. Except the SeeDB group(P=0.185),the rest groups showed significant differences compared with the PBS group(P< 0.01), and there were significant differences between CUBIC and other groups(P < 0.01). After the clearing treatment, the changes of tissue area ratio in the iDISCO, SeeDB, CUBIC, SCALEVIEW-A2, CLARITY-CUBIC, Passive-CLARITY method were(-30.02 ± 2.39)%,(19.74 ± 4.09)%,(14.7 ± 3.92)%,(10.7 ± 5.55)%,(23.01 ± 4.19)%,(66.51 ± 5.68)%,respectively. Each group showed a significant difference compared with the groups iDISCO and the Passive-CLARITY,P< 0.01. Conclusions Except the SeeDB method,all the clearing methods can achieve a transparent effect, while CUBIC is better than the other groups applied for rat brain tissues. The tissue block volume is shrunken after iDISCO clearing,and expanded after Passive-CLARITY processing.

Surface replacement of hip in the treatment of osteoarthrithis of hip / 中国基层医药

Objective To study the therapeutic effect of the hip surface replacement on osteoarthrithis of hip.Methods The clinical data of 5 cases with osteoarthrithis of hip treated by hip surface replacement were retrospectively reviewed.Results Patients were followed up for an average period of 2.1 years(6～28 months).There were no femoral neck fracture,no dislocation,no infection in all patients.The average Harris score was 85.4(48.3 scores before surgery).Postoperatively quality of life improved obviously.Conclusion The therapeutic effect on osteoarthrithis of hip treated by the hip surface replacement is satisfactory,and the quality of patient's life can be improved,espcially for the youth.

The Finite Element Modeling and Mechanical Analysis of "V"-type Atlantoaxial Reduction and Internal Fixation / 医学研究杂志

Objective To establish a three-dimensional finite element model and make mechanical analysis of "V"-type atlantoaxial reduction and internal fixation. Methods According to "V"-type atlantoaxial and internal fixation,based on screw-type Ⅱ design parameters,and using Pro/E 2001 and MSC.Patran 2005 software,we set up a finite element model and calculated the region containing the node scope of the force as the sites binding and 100N mechanics adding. Results The model looked realistic,geometric similarity.The deformation stress field mainly concentrated in the reset device V-tip arm bending and stability.The strength of its maximum stress was 4.78MPa,and the scope had 2794 nodes.V-type wing of the acute angle point of convergence of the premises to bear the stress intensity followed.It was 0.31MPa,and the scope had 1953 nodes.V-type wing by the end of edge was the smallest for the 1.22?10-3MPa,and there was the scope of 1730 nodes. Ⅱ-shaped fixed nail stress concentrated at the central parts of tooth and the art on both sides of teeth,with maximum stress intensity of 1.68?10-2MPa,and there was the scope of 1146 nodes. Conclusion The reduction and fixation devices to load at the time of recovery deformation forces and mechanical characteristics adapted to Ni-Ti shape memory alloy material functions and super-elasticity completely,which meets the clinical needs.