The paper proposes and realizes a programmable wireless neural stimulation system which can be used as a solution of functional electrical stimulation to treat neural diseases. The system is composed of two parts: controller and neural stimulator. The controller can transmit pulse parameters to the stimulator wirelessly, and the stimulator can generate bidirectional pulses with charge balance. The simulator takes use of ADCs to sample on the bidirectional pulse output, which compared with preset amplitude to the DAC output voltage to realize the voltage calibration. Through the test, the whole system works stably and the output of the biphasic charge balanced circuit is definite. The stimulator output ranges from 0 to 5 V ajustably, and the frequency ranges from 1 Hz to 200 Hz ajustably, while the pulse width ranges from 500 μs to 1500 μs ajustably. The duration of the stimulation can be set from 10 s to 10 min.
Electric Stimulation ; instrumentation ; Equipment Design ; Wireless Technology

BACKGROUND: The survival rate of articular chondrocytes is low after traditional cryopreservation,and great differences existed in chondrocytes from surface layer and deep layer,which easily result in graft degeneration and lead to surgery failure.OBJECTIVE: To establish rabbit allograft models of graded frozen articular cartilages with holes made before cryopreservation and to observe the effect of holed cryopreservation on the rabbit articular cartilages.METHODS: Osteochondral plugs taken aseptically from 2 months old rabbits were randomly divided into 3 groups: the experimental group,making holes(3 mm× 3 mm)in articular cartilages and graded freezing; non-hole graded freezing group,non-making holes and graded freezing; cryopreservation group: non-making holes and rapid freezing.The grafts were thawed and transplanted into the relevant articular cartilage defects of recipient rabbits.The grafts differences were observed by gross observation,histochemistry and immunohistochemistry staining.RESULTS AND CONCLUSION: The gross observation,histochemistry and immunohistochemistry staining of the experimental group were superior to the cryopreservation group.Though there were no significant differences between the non-hole graded freezing group and the experimental group,however,the experimental group enhanced the protective effect on cartilage tissue in the middle layer.The graded cryopreservation of articular cartilage gets an advantage over rapid cryopreservation.And the articular cartilage with holes could be preserved successfully in graded cryopreservation,which assures the survival and function of chondrocytes and slows down degrading process of the articular cartilage tissue after thawed and transplanted.

BACKGROUND: Adipose-derived mesenchymal stem cells (ADMSCs) can improve the liver function of rats with liver failure, which illustrates the important research value in the field of tissue engineering and cell transplantation.OBJECTIVE: To evaluate the therapeutic potential of human ADMSCs in heart failure rats and to discuss the possible biological mechanisms involved.METHODS: Heart failure rats were randomized into model and ADMSCs groups, which were given normal saline or DAPI-labeled human ADMSCs (3.0×106) via the tail vein. At 1, 3, 7 days after transplantation, we detected the biochemical indexes for liver function in rats. At 3 days after transplantation, the serum levels of cytokines, such as tumor necrosis factor α and interleukin-10, were detected, the histomorphological changes in the liver were observed by hematoxylin-eosin staining, and the protein expression of proliferating cell nuclear antigen was detected by western blot. RESULTS AND CONCLUSION: We found that human ADMSCs could migrate to the liver and lung tissues in rats after the transplantation via the tail vein. At 1 and 3 days after transplantation, the levels of serum alanine aminotransferase and aspartate aminotransferase were significantly reduced in the ADMSCs group as compared with the model group (P< 0.05); furthermore, the secretion of tumor necrosis factor α and interleukin-10 was significantly suppressed at 3 days after cell transplantation (P < 0.05). The results of hematoxylin-eosin staining indicated a significant improvement in liver degeneration and necrosis. The expression of proliferating cell nuclear antigen protein in the ADMSCs group was significantly up-regulated compared with the model group. To conclude, human ADMSCs can inhibit the inflammatory reaction and up-regulate the expression of proliferating cell nuclear antigen, to promote the regeneration of liver cells and he recovery of liver function.

BACKGROUND:Recent studies have shown that adipose-derivedmesenchymal stem cells (ADMSCs) not only have multilineage differentiation potential, but also exert an important role in blood sugar balance and hormone production.OBJECTIVE:To observe the differentiation potential of human ADMSCs (hADMSCs) into functional islet-like cells and the therapeutic effect of hADMSCs transplantation in diabetic rats.METHODS:PDX-1 gene was transfected into hADMSCs by adenovirus. Cell differentiation and insulin secretion were identified and detected by dithizone staining and ELISA, respectively. Twenty male Sprague-Dawley rats were randomly divided into control group (n=4), diabetes group (n=8) and transplantation group (n=8). Rats in the latter two groups were subjected to making diabetic models by 65 mg/kg streptozotocin injection. Afterwards, rats in the transplantation group were given PDX-1 transfected ADMSCs via the tail vein.RESULTS AND CONCLUSION:At 15 days after transfection, the number of insulin positive cells and insulin secretion were both increased significantly (P < 0.05). Fasting glucose levels in the transplantation group decreased significantly (P < 0.05), while the body weight increased significantly (P < 0.05). In the diabetic group, the fasting glucose level still maintained at a high level, and the body weight of rats was significantly decreased. These results implicated that PDX-1 gene could induce hADMSCs differentiating into functional islet-like cells. PDX-1 transfected ADMSCs transplantation is effective in treating diabetic rats, but the mechanism needs further study.

Objective To discuss the clinical application and evaluate the effect of repairing finger injuries using the perforator flap in forearm cubital fossa.Methods From July,2012 to December,2013,8 cases of finger injuries with totaled defect area of 2.5 cm × 4.0 cm-5.5 cm × 7.0 cm were reviewed.Among them,6 cases had phalangeal fracture,7 cases had neurovascular injury and 4 cases combined with tendon injuries.Cubital fossa flaps based on the inferior cubital perforator of radial artery were transplanted to repair the defects.Results All of the 8 flaps survived.One of them experienced distal end necrosis of epidermis and 1 cm long wound dehiscence.But it was healed by dressing change.All of the 8 cases were followed up for an average of 11 months (range,6-20 months).Sensory quality of （S） + was present in all of the flaps with two-point discrimination ranging between 7.5 mm and 9.8 mm with an average of 8.5 mm.All flaps were seen with good appearance,texture and colour.Moreover,function and appearance in donor sites were satisfactory.Conclusion The perforator flap in forearm cubital fossa is a satisfying choice in repairing small skin defects in fingers and other paas in that it is fixed,easy to dissect and leaves small injuries in targeted area.

Objective To discuss the method and clinical effect of bilobed DIEP flap for repair of degloving injuries of the hand.Methods From June, 2013 to January, 2015, the bilobed DIEP flap were designed to repair 6 cases of degloving injuries of hand, of which the small leaf flap repaired separately defect of thumb, larger leaf flap repair 2nd-5th finger and palm and dorsum.The bilobed DIEP flap design were based upon anatomic study on deep inferior epigastric artery, superior epigastric artery, intercostal artery and its anastomosis.Results The largest area of main flap was 35 cm × 12 cm, and the deputy leaves of flap was 10 cm× 7 cm.All of the 6 flaps survived.One of them experienced distal end necrosis of epidermis.But it was healed by dressing changes.All of the 6 cases were followed up for average of 12 months (range, 6-20 months).All flaps were seen with good appearance, fully recovered protectve sensation and the active motion of the thumb was recovery.Moreover, the donor sites were closed directly and the appearance were satisfactory.Conclusion The bilobed DIEP flap is a satisfying choice in repairing degloving injuries of the hand in that it has reliable blood supply, can obtain the larger area of skin and leaves small injuries in targeted area.

To establish the quality standard for Zhike Xiaoyan Zhitong lotion. Methods: Phellodendri chinensis Cor-tex, Angelicae sinensis Radix and Astragali Radix in the preparation were identified by TLC. The content of berberine hydrochloride, the effective component in Phellodendri chinensis Cortex, was determined by HPLC with the chromatographic conditions as follows: an Agilent 5 TC-C18 column (250 mm × 4. 6 mm, 5 μm) was used, the mobile phase was acetonitrile-0. 05 mol·L-1 potassium dihydro-gen phosphate (30∶70) with the flow rate of 1. 0 ml·min-1 , the detection wavelength was 265 nm, and the column temperature was at 30 ℃. Results:The spots of Phellodendri chinensis Cortex, Angelicae sinensis Radix and Astragali Radix in Zhike Xiaoyan Zhitong lotion on TLC were clear with strong specificity and without any interference from the negative controls. There was a good linear rela-tionship for berberine hydrochloride within the range of 0. 029-3. 628 μg(r=0. 999 9), and the average recovery was 97. 83% (RSD=2. 05%, n=6). Conclusion:The qualitative and quantitative methods are accurate, reliable and repeatable, which can effectively control the inherent quality of Zhike Xiaoyan Zhitong lotion.

Objective To investigate the application of peroneal artery chain perforator flap in repairing skin and soft tissue defects of ankle and lower leg and the corresponding clinical effect.Methods From 2005 to 2010,19 cases of skin and soft tissue'defects of the ankle and lower leg were treated by using peroneal artery chain perforator flaps.The sites of peroneal artery branches were detected by using Doppler flowmeter before operation.Supplied by the chain form of terminal branches of the peroneal artery,the cutaneous fulcrum straightly nearest to the wound was selected as the rotation point to design the flap,with area ranging from 25 cm × 8 cm to 16 cm × 6 cm.Results The follow-up for 1.5- 42 months revealed that all cases of flap survived with satisfactory shape,except for one case suffered from distal skin flap necrosis.Conclusions The peroneal artery chain perforator flap with unsteady peduncle has no restrictions of peduncle sites and can be cut flexibly.It is a perfect method in repair of soft tissue defect of ankle and lower leg.

Objective To evaluate the application of Sigma stent in treatment for esophagn-tracheal fistula. Methods Clinical data of 22 cases of esophago-tracheal fistula treated with Sigma stent were retrospectively analyzed, including 17 cases of esophageal cancer and 5 cases of benign esophageal diseases, with length of 4 days to 2 months. One single stent was placed in 5 cases, two stents ( both in trachea and esophagus each) in 15 cases, and three stents in 2 cases, and 18 eases with tube-type trachea stent, 3 with obtuse angle L-type and 1 with Y-type. Placement of stent was by interventional method or/and endoscopy. Results Forty-one stents were successfully placed in 22 patients with no death in the procedure. And, all patients with fistula were healed successfully and could have normal eating 2 to 4 days after operation, except 1 patient who received a tracheal stent inserted first, but an esophageal stent inserted again due to incomplete seal of the fistula and another benign case who received surgical operation 1 year after stent placement due to protracted unsealed fistula, with an overall cure rate of 91% (20/22). Conclusions Placement of Sigma stent in the esophagus or/and trachea could effectively heal esophago-tracheal fistula. All the patients can eat normally after the procedure. Stent can be recycled and formation of secondary esophago-traeheal fistula can be prevented effectively with such procedure.

Objective:To evaluate the clinical effect of fibula flap in the repair of large segment of composite tissue defect in upper limb.Methods:From April, 2015 to June, 2019, 7 patients with large composite tissue defects in upper limbs were treated. All of them with various skin, vessel, nerve, tendon and other tissue defects. Repairing was well planned before surgery according to the type, location and size of defect. While in repairing of the bone and skin defect, fibula flap was taken from the shank and to repair the defects of nerve, tendon and vessels in upper limb. Regular followed-ups were made after surgery.Results:The 7 fibula flaps all survived. Postoperative follow-up ranged between 8 to 36 (averaged of 15) months. All the reconstructed limbs were in satisfactory appearance and function recovery. All the patients were able to manage their daily activities and live independently. The shape and function of donor sites were good. According to the Enneking system, the outcomes were graded as excellent in 4 cases and good in 3, with the average score was 25.9 points.Conclusion:Free grafting of vascularised fibula flap is especially feasible to be used in the repair of large bone tissue defect of upper limb. It repairs the defects of skin, vessel, nerve and tendon with the flap from a single donor site.