The major objective was to explore the effect of early hyperbaric oxygen (HBO) therapy on the tissue structure, apoptosis, and metalloproteinases of kidney cells in Goto-Kakizaki (GK) rats with type 2 diabetes mellitus. GK rats (n = 24) were divided randomly and evenly into model, metformin hydrochloride (MH), and hyperbaric oxygen (HBO) groups, while healthy Wistar rats (n = 8) were used as normal control group. The healthy rats in the normal control group and the GK rats in the model group were both intragastrically administered with purified water (5 mL/kg) once per day. Meanwhile, the rats in the MH group received intragastric administration of MH (250 mg/kg) once daily, while the rats in the HBO group inhaled pure oxygen under a constant pressure (0.15 MPa) for 30 min. After 3 weeks of treatment, the body weight of each rat was measured, and the blood samples were collected from tails. Subsequently, the kidneys of all rats were excised for weighing mass and further examination. For each renal sample, the sections were firstly embedded with paraffin and sliced to prepare histopathologic sections stained using HE, PAS and Masson, respectively, for subsequent observation with optical microscopy. Later, the apoptosis of kidney cells was examined using the TUNEL method by computing the apoptotic index. Furthermore, the histopathologic sections were also examined using the immunohistochemistry approach with Caspase-3, MMP-2, and TIMP-2 antibodies, respectively. At the same time, the plasma concentration of TGF-β1 of the rats in each group was detected using ELISA method. These resultant data showed that the pathological changes of the HBO group were less than those of the model group with respect to increased glomerular volume density of mesangial cells, broadening mesangial matrix and thickening basement membrane as well as swelling renal tubular epithelial cells. The index of cell apoptosis and Caspase-3 expression in the HBO group showed no significant differences (P > 0.05) compared with those in the normal control and MH groups respectively, but demonstrated significant decrease compared with that in the model group (P < 0.01). Meanwhile, the MMP-2 and TIMP-2 expressions of the HBO group were stronger than those in the model and MH groups, but weaker than those in the normal control group (P < 0.05). Although the plasma concentration of TGF-β1 in HBO, MH and model groups was greater than that in the normal control group, no significant statistical difference was distinguished among these four groups (P > 0.05). These results indicate that the HBO treatment can inhibit the apoptosis and Caspase-3 expression of renal cells of GK rats, adjust the activity of MMP-2 and its inhibitors, and reduce the accumulation of extracellular matrix. This implies that the HBO treatment might protect renal tissues, thus delaying occurrence and retaining development of diabetic nephropathy.
Animals ; Apoptosis ; Caspase 3 ; metabolism ; Diabetes Mellitus, Experimental ; physiopathology ; Diabetes Mellitus, Type 2 ; physiopathology ; Diabetic Nephropathies ; therapy ; Hyperbaric Oxygenation ; Kidney ; cytology ; Matrix Metalloproteinase 2 ; metabolism ; Oxygen ; administration & dosage ; Rats ; Rats, Wistar ; Tissue Inhibitor of Metalloproteinase-2 ; metabolism ; Transforming Growth Factor beta1

The performance of intelligent prosthetic knee has an important effect on the realization of physiological gait of transfemoral amputees. A new type of single axis hydraulic damping knee prosthesis was designed based on the analysis of physiological gait. The training methods of the stance and swing phase were proposed. Knee prosthesis test was done through simulation and measurement device. The control target of peak flexion angle during swing of knee prosthesis is chosen to be 60-70°. When the damper valve closure was 0%, maximum swing-phase knee flexion angle of knee prosthesis were (86±2)°, (91±3)° and (97±3)° with the speed of 0.8 m/s, 1.2 m/s and 1.8 m/s, respectively. Once the valve closure was changed, maximum swing-phase knee flexion angle with different speeds could be adjusted between 60° and 70° and the required valve closure percentage were separately 25%, 40% and 70%. The damping adjustment law of intelligent knee prosthesis to achieve physiological gait was revealed.

A software and hardware platform for gait simulation and system evaluation for lower limb intelligent prosthesis is proposed and designed, in order that the wearable symmetry effect of the intelligent knee prosthesis can be quantitatively analyzed by machine test instead of human wear test. The whole-body three-dimensional gait and motion analysis system instrument, a device to collect gait data such as joint angle and stride of adults, was used for extracting simulated gait characteristic curve. Then, the gait curve was fitted based on the corresponding joint to verify the feasibility of the test platform in the experiment. Finally, the developed artificial knee prosthesis was worn on the prosthetic evaluation system to quantitatively analyze the gait symmetry effect. The results showed that there was no significant difference in gait symmetry between the developed knee joints at different speeds, which could reach more than 88%. The simulation and evaluation of the prosthetic gait have good effects on the functional simulation and evaluation of the lower limb intelligent prosthesis.
Adult ; Artificial Limbs ; Biomechanical Phenomena ; Gait ; Humans ; Knee Joint ; Knee Prosthesis ; Prosthesis Design

Objective To carry out a research of terrain recognition on intelligent knee joint from the perspective of pure visual information.Methods The whole experimental environment was illuminated by halogen lamp, which made the brightness and color temperature of the set scene change less. The machine vision module was embedded in the intelligent knee joint control system. The road image data was collected by the camera in real time, and the captured image was processed in grayscale. The normalized cross correlation algorithm (NCC) was used to match the image pattern to identify the corresponding road conditions.Results The accuracy rates of the road vision, up/down hill, and up/down stairs recognized by the machine vision module were 88.6%, 85.3%, 78.4%, 87.5%, and 77.9%, respectively. The recognition effect was good, and the recognition time was within one second, real-time performance was strong.Conclusion The effectiveness and feasibility of intelligent knee joint prosthetic road condition recognition based on pure visual information is proved.