To explore the feasibility of applying magnetic stimulation technology to the movement control of animal robots, the influence of coil radius, number of turns and other factors on the intensity, depth and focus of magnetic stimulation was simulated and analyzed for robot pigeons. The coil design scheme was proposed. The coil was placed on the head and one of the legs of the pigeon, and the leg electromyography (EMG) was recorded when magnetic stimulation was performed. Results showed that the EMG was significantly strengthened during magnetic stimulation. With the reduction of the output frequency of the magnetic stimulation system, the output current was increased and the EMG was enhanced accordingly. Compared with the brain magnetic stimulation, sciatic nerve stimulation produced a more significant EMG enhancement response. This indicated that the magnetic stimulation system could effectively modulate the functions of brain and peripheral nerves by driving the coil. This study provides theoretical and experimental guidance for the subsequent optimization and improvement of practical coils, and lays a preliminary theoretical and experimental foundation for the implementation of magnetic stimulation motion control of animal robots.
Objective To monitor the release of amino acids of the whole retina during and after experimental glaucoma by increasing the intraocular pressure （IOP）． Methods Experimental glaucoma was induced in one of the two eyes of rabbits by increasing IOP at 120 mm Hg for 45 min under infusion of saline in anterior chamber；then the pressure was released and the needle inserted into the anterior chamber was removed，this state was maintained for another 45 min．Every 15 min during the experiment 5 rabbits were killed and experimental eyes were enucleated．Aliquots（20 μl）of the retinal extracts（see below）were mixed with ophthaldialdehyde reagent and analysed for amino acid content by the HPLC method of Wangwei，using a 150 mm×4.6 mm,5 μm C18 column． Results A large increase in the release of glutamate，but not of the other three amino acids monitored，occurred during initial experimental ocular hypertension．It reached peak value of（111.73±17.46）10-5 mmol/g at 15 min of hypertension．15 min after release of intraocular pressure，again，immediately large and specific increase in the concentration of glutamate was reached to（102.96±51.91）10-5 mmol/g．In eyes subjected to paracentesis of anterior chamber，no difference was found between experimental eyes and controls. Conclusion These results suggest that glutamate is triggered by increasing the IOP，and it releases not only during the period of experimental ocular hypertension，but also afterwards. (Chin J Ocul Fundus Dis, 2002, 18: 146-148)
Objective To investigate the effect of bromocriptine on rats with experimental autoimmune uveoretinitis.Methods Tweenty-four Wistar rats were immunized by bovine soluble antigen and randomly divided into treatment and control group. The rats in treatment group took bromocriptine orally with the dosage of 5 mg/(kg·d), which could inhibit prolactin (PRL) deliverance, while the rats in control group took glucose solution orally with the dosage of 50 g/(L·d). The clinical changes of all the rats and the delayed type hypersensitivity (DTH) response were detected. The rats were anesthetized and killed after im munized for 21 days, and the eyes were removed and examined histologically.Results The occurrence of EAU and histology scores of rats in treatment group were lower than the controls (P＜0.05,P＜0.001). The DTH response of two groups had no statistic difference (P＞0.05). Conclusions Bromocriptine can generally inhibit PRL deliverance, and may also inhibit the occurrence of EAU in rats through neuroendocrine-immune regulating network. (Chin J Ocul Fundus Dis，2003，19：34-37)
Objectives To investigate the expression of pax-6 in ret ina of in fant monkeys with myopia induced by optical defocus, and to determine the role of pax-6 would play or not in onset and development of myopia and emmetropization.Methods Nine healthy infant rhesus monkeys, aged from 1 to 3 months, were selected and wore spectacle lenses or underwent photorefractive keratectomy (PRK).Transcription polymerase chain reaction method and quantitative analysis were used to determine the expression of pax-6 in the retina with myopia induced by optical defocus in different time, and the result was compared with that in retina without myopia.Results The myopia caused by hyperopic defocus was found. The expression of pax-6 in the retina with myopia induced by optical defocus was significantly higher than that in the retina without myopia（t=3.480，P=0.004）.Conclusions The expression of pax-6 is enhanced by hyperopic defocus in the infant monkey retina, which suggests that pax-6 may be involved in vision-dependent eye growth and emmetropization. (Chin J Ocul Fundus Dis，2003，19：201-268)
Objective To investigate the effect of micropulse di ode laser treatment on the retina in Brown-Norway rats (BN Rats). Methods 130 eyes of BN rats received irradiance of different powers of micr opulse diode laser with 810nm wavelength through a contact lens. Fundus color photography and fundus fluorescein angiography (FFA) were performed on day 1, 3, 7, 14 and 28 days after treatment. Animals were sacrificed on 1, 3, 7, 14 and 28 days separately for historical study. The expression of heat shock protein-70 (HSP-70) in the retina was observed with immunohistochemistry. Cell apoptosis of retina tissue was examined by TdT mediated dUTP nick end labeling (TUNEL). Results (1) No change was found in no visible reaction laser spots by light microscope. High duty cycles with threshold and suprathreshold en ergies can produce severe damage even to the inner nuclear layer. (2) HSP-70 ex pression was markedly increased in the inner nuclear layer at 1d after micropulse diode laser. This increase in HSP-70 expression peaked at day 3 whereafter a decline near to normal at 2 weeks was detected. (3) Apoptosis was detected mainl y in retinal pigment epithelium, outer nuclear layer, inner nuclear layer and ev en choroid by TUNEL after micropulse diode laser treatment. The TUNEL-positive cells increased with the laser power. Maximum TUNEL-positive cells could be seen at day 3 after treatment. Conclusions The retinal injury has positive relationship with laser energy. The thermal damage is confined to the RPE and spare the neurosensory retina when using threshold power (50mW) with 50% duty-cycle and supra-threshold power with high duty-cycle (100mW，5%～15%). The hyper expression of HSP-70 and apoptosis mechanism may play an important role in the tissue repair process. (Chin J Ocul Fundus Dis,2008,24:122-126)
Objective To observe the histopathologic features and expression patterns of tumor necrosis factor-alpha; （TNF-alpha;）, interleukin-1beta;（IL-1beta;） and Escherichia coli lipopolysaccharide (LPS) in the rat vitreous with LPS inducedendophthalmitis. Methods Wistar rats were randomly divided into saline control group (SC,136 rats）,endophthalmitis group （EO, 168 rats）and blank control group （BC,12 rats）.EO group received an intravitreal injection of 5 mu;l LPS; SC group received 5 mu;l sterile saline and no intervention for BC group.Six,12,24,48, and 72 hours,5 and 7 days after injection, intraocular inflammation were observed and the eyes and vitreous were collected for histopathological examination and measurement of TNF-alpha;, IL-1beta; and LPS expression. Results Severe inflammatory responses in the eyes were observed in EO group between six and 72 hours after LPS injection，ocular inflammation subsided seven days after LPS injection. In the vitreous, a peak neutrophil count was observed at 24 hours （1224.64plusmn;132.2） cells/eye that rapidly declined at 72 hours （342.25plusmn;47.7） cells/eye. The levels of TNF-alpha; and IL-1beta; in EO group were peaked at 24 hours with （996.18plusmn;89.45） and（5556plusmn;1440）pg/ L, respectively；Persisted at 48 hours and began to decline rapidly thereafter. Seven days after LPS injection, levels of TNF-alpha; and IL-1beta; returned to baseline with （22.16plusmn;5.84）and （73.7plusmn;18.7） pg/L, respectively. LPS concentration in EO group decrease rapidly at 72 hours with （11.03plusmn;3.41） ng and disappear on days 7 with (0.22plusmn;0.08) ng after LPS injection.Conclusions Massive neutrophils infiltration, high levels expression of TNF-alpha; and IL-1beta; and spontaneous elimination of bacterial elements in vitreous cavity were major pathologic characteristics in this experimental model. The expression patterns of TNF-alpha;,IL-1beta; were in accord with LPS clearance process.
Objective To observe the pathological and functional changes of retinal photochemical damages exposed to green flurescent light. Methods The Sprague Dawley rats were continually exposed to green fluorescent light with an illuminancem level of (1 900plusmn;106.9) Lx for 24 hours.The changes of retinal morphology and morphometrics and flash electroretinogram were studied before light exposure and at the 6th hour,6th day and 14th day after light exposure. Results At the 6th hours after light exposure,the outer nuclear layer(ONL)of retina becoma thinner compared with that bfore light exposure.The thickness of ONL decreased by 23.91% and the inner and outer segments appeared disorderly arranged.At the 6th day after light exposure the thickness of ONL is thinner than that at the6th hour,i.e.decreased by 46.6%. At the 14th day after light exposure the thickness of ONL decreased by 42.40%.Flash electroretinogram showed that the amplitudes of a and b wave decreased continuously at the 6th hour and 6th day and unrecovered at the 14th day after light exposure. Conclusion This model might be an ideal one for research on retinal photochemical damage. (Chin J Ocul Fundus Dis,1998,14:101-103)