Objective To report an acute ischemic left ventricular heart failure model of safe, simple, relatively steady, and reproducible in sheep. Methods Fourteen female sheep with a body weight of 36.80±3.43kg were used in this study. Heart failure model was induced by partial occluding the middle left circumflex coronary artery （LCX） combined with pacemaker-induced tachycardia. Hemodynamic measurement was done before and after heart failure, myocardial examination was observed. Results Heart failure model was induced successfully in 10 sheep. Cardiac output dropped from 3.74±0.48L/min to 2.02±0. 51L/min （P〈0. 01）, mean arterial pressure decreased from 116. 10± 14.15 mmHg（1kPa = 7.5mmHg） to 68. 10± 14. 72mmHg （P〈0.01）, central venous pressure rose from 7. 10±2.18mmHg to 10. 70± 3.50 mmHg （P〈0.05）, right ventricular end-diastolic pressure increased from 6.10±3.57mmHg to 9.90±4.41mmHg（P〈0.05）, left atrial pressure increased from 8.10±2.13 mmHg to 12.00± 4.57mmHg （P〈0. 01 ）, and left ventricular end-diastolic pressure increased from 8. 50± 4. 17mmHg to 13.10± 10. 64mmHg（P〉 0. 05）. The myocardial ultrastructure injuries was marked. Conclusions Acute ischemic left ventricular heart failure could be induced by partial occlusion of the middle LCX combined with pacemaker-induced taehyeardia in sheep. This model is simple, easy to manipulate, relatively steady, and reproducible . It may be used for assessing cardiac assist devices.
Objective To study the mid-facial development characteristics of the goats with cleft palate after in-utero surgical repair at different stages. Methods Twenty-four Boer hybrid female goats were selected, aged from 8 to 12 months and weighing from 35 to 55 kg. The mating day was designated for 0 day. At 30 days, pregnant was confirmed by B-ultrasound test, and the goats were divided into 5 groups (experimental groups 1, 2, 3, 4, and normal control group). Twenty pregnant goats of 4 experimental groups (n=5) were injected DL-anabasine (15 mg/day) from 31 to 42 days to establish cleft palate model of fetal lamb, 4 pregnant goats of normal control group used as controls without injection. At pregnant 65, 90, and 120 days, cleft palate was repaired in the uterus in experimental groups 1, 2, and 3, while cleft palate was not repaired in experimental group 4. After 1 month of birth, the maxillary bone width (posterior premolar morphological measurement, PPMM) and the maxillary bone length (anterior premolar morphological measurement, APMM) were measured with CT scanning. The dry skull of goats were harvested for gross observation. Results There was no significant difference in PPMM and APMM between experimental group 1 and the normal control group (P gt; 0.05), but there were significant differences between experimental groups 1 and 4 (P lt; 0.05) at 1 month after birth. Significant differences were oberved in PPMM and APMM between experimental group 2 and normal control group, experimental group 4 (P lt; 0.05). There were significant differences in PPMM between experimental group 3 and normal control group, experimental group 4 (P lt; 0.05), in APMM between experimental group 3 and normal control group (P lt; 0.05). Five goats with cleft palate in experimental group 4 died at 1-2 months after birth. Conclusion At pregnant 65 days, in-utero surgical repair of cleft palate has less influences on mid-facial development. The earlier repair is performed, the higher risk of miscarriage was.
Xenotansplantation has become a global focus because it may solve the formidable problems in allotransplantation, that is, the donor source. Hitherto clinical xenotransplantion has been in the stage of research with limited cases and unsatisfactory results. The difficulties which hinder the progress of xenotransplantation include: the ideal animal donor has not been found, it is rather difficult to control the rejections (hyperacute rejection, acute vascular rejection, perhaps acute cellular rejection and chronic rejection) after xenotransplantation compared with those after allotransplantation, some animal diseases might be transmitted to and do harm to human recipients, even the community. It is still unknown whether the functions of animal organs can substitute those of human organs permanently. Transgenic pigs on research and various measurements to suppress humoral and cellular immunity may be helpful in overcoming the problems of xenogeneic rejections. Animal diseases should be prevented, screened and treated, and animal models should be established to study the possibility of satisfactory working of animal organs in human body before clinical xenotransplantation is widely practised.
Objective To observe the effect of persistent flickering stimulus on the structure and function of retina in guinea pigs during a developmentally sensitive period.Methods Twenty-four two- week-old guinea pigs were randomly divided into flicker light (FL) group and control group, with 12 guinea pigs in each group. Animals in FL group were raised under 500 Lux illumination with a duty diurnal cycle of 50% at a flash rate of 0.5 Hz. Animals in control group were reared under steady 500 Lux illumination. Light emitting diode (LED) lamps were used for lighting under a 12-hour light/12-hour dark cycle. After the collection of fundus photographs and electroretinograms recorded at week 12, eyeballs were taken out, three dimensions were measured, and histopathological changes were examined.Results Compared to control group, tessellated fundus in FL group appeared more prevalent; implicit time of ldquo;ardquo; waves were prolonged in electroretinogram; the eyeballs were increased in horizontal, vertical, axial dimensions by (0.89plusmn;0.30), (0.69plusmn;0.20) and (0.96plusmn;0.30) mm respectively, the differences between two groups were statistically significant (t=12.7,11.9,15.8;P＜0.05). The gap of sclera collagen fiber was slightly widened.The photoreceptor layer was more likely to develop a disordered outer segment, which contained deciduous disc membranes.Conclusion Persistent flickering stimulus is attended by development of excessive ocular enlargement,which could affect the retinal structure and function of photoreceptors.
Objective To investigate the protective effect and mechanism of intravitreal injection with cyclosporin-A(CsA) on blood-retinal barrier (BRB) in diabetic rats. Methods A total of 48 Sprague-Dawley male mice at the age of 8-10 weeks were divided into normal group, diabetes mellitus (DM) group, CsA group and DMSO group, with 12 rats in each group. The rats in DM, CsA group and DMSO group were induced with streptozotocin (STZ) injection creating a diabetic retinopathy model. The same volume of citric sodium citrate buffer was injected into the rats in the normal group. Immunohistochemical staining was used to detect the BRB permeability, Western blot was used to measure the protein expression of intercellular adhesion molecule (ICAM-1). Enzyme-linked immunosorbent assay (ELISA) was used to measure the expression of vascular endothelial growth factor 72 hours after injection. Results Compared with the normal group, the BRB permeability, ICAM-1 and VEGF expression were significantly increased in DM group (F=29.350, 29.240, 9.658; P＜0.01). Compared with the DM group, the BRB permeability, ICAM-1 and VEGF expression were significantly decreased in CsA group (t=3.174, 5.000, 3.352; P＜0.05); but there was no obvious change of above indexes in DMSO group (t=0.420, 0.561, 0.312; P＞0.05). Conclusion Intravitreal injection of CsA has protective effects on BRB in diabetic rats. Down-regulated expression of ICAM-1 and VEGF may be the mechanism.
Objective To observe the effects of CXCR4 inhibitor (AMD3100) combined with anti-vascular endothelial growth factor (VEGF) antibody on experimental choroidal neovascularization. Methods Choroidal neovascularization (CNV) was induced in 48 BrownNorway (BN) rats by Krypton red laser photocoagulation, and those rats were randomly divided into AF564 group (group A), AMD3100 group (group B), combined treatment group (group C) and PBS group (group D), 12 rats in each group. Left eyes were the experimental eyes. The rats of group A-D received intravitreal injection of 5mu;l of AF564, AMD3100, AF564/AMD3100 and PBS after laser photocoagulation respectively. Fourteen days after photocoagulation, fundus fluorescein angiography (FFA), pathological section analysis and choroidal vascular wholemount were used to observe the degree of fluorescein leakage, the relative thickness and areas of CNV. Results Fourteen days after photocoagulation, the scores of fluorescein leakage in group A - D were 2.16plusmn;0.91, 2.16plusmn;0.91, 1.92plusmn;1.03, 1.39plusmn;0.93 respectively. Fluorescein leakage in group A - C was obviously reduced compared to group D (F=12.91,P＜0.001), while fluorescein leakage in group C was reduced compared to group A and B (F=9.21,P＜0.05). The CNV relative thicknesses in group A-D were 1.82plusmn;0.11, 1.90plusmn;0.22, 1.12plusmn;0.12, 2.82plusmn;0.29 respectively. Group A -C had thinner CNV compared to group D (F=5.92，P＜0.001), while group C had thinner CNV compared to group A and B (F=5.16, P＜0.05). The CNV areas in group A -D were (8204plusmn;122), (9332plusmn;211), (6533plusmn;101), and (13644plusmn;255) mu;m2 respectively. Group A -C had smaller CNV area compared to group D (F=147.50，P＜0.001), while group C had smaller CNV area compared to group A and B (F=112.60, P＜0.05). Conclusion Combined treatment with CXCR4 inhibitor and anti-VEGF antibody can inhibit laser-induced CNV significantly.
Objective To observe the concentration of vancomycin and the changes of pharmacokinetic parameters in rabbit vitreous with endophthalmitis in different pathological conditions.Methods Eighty-one adult healthy rabbits were randomly divided into endophthalmitis with lens group (group A), aphakic endophthalmitis group (group B), aphakic endophthalmitis and vitrectomy group (group C), 27 rabbits in each group. The right eyes of all rabbits received intravitreal injection of 1 ml (10 mg/ml) vancomycin. Three rabbits from each group were sacrificed at 0.5, 2.0, 4.0, 6.0, 12.0, 24.0, 48.0, 72.0, 84.0 hours after the injection. The eyes were harvested to collect the vitreous. The vitreous concentrations of vancomycin in all the groups were detected by high performance liquid chromatography (HPLC-UV). The pharmacokinetic parameters including the area under the curve (AUC) of the concentration-time graph, clearance rate (CL), half-life period (t1/2) and peak concentration (Cmax) were calculated by 3p 97 pharmacokinetic software. Results The concentrations of vancomycin in the group A were always higher than the therapeutic drug levels after injection. In the group B and C, the concentrations of vancomycin remained significantly high at 0.5, 2.0, 4.0, 6.0 and 12.0 hours after injection, decreased quickly at 24 and 48 hours after injection, below the minimal inhibitory concentrations at 72 hours after injection. The differences were statistically significant among group A, B and C (t=4.968, 5.232;P＜0.05), but not statistically significant between group B and C (t=1.279, P＞0.05). The AUC were 15 790.61,7643.94, 7443.44 mu;g/(ml?h), CL were 0.063, 0.131, 0.134 ml/h, t1/2 were 13.49, 7.15, 6.93 hours and Cmax were 711.56, 648.45, 667.74 mu;g/ml in the group A, B and C, respectively. In the group A, the CL was lower (t=2.963, 3.097; P＜0.05) and t 1/2 was longer (t=3.315, 3.481; P＜0.01) than those in the group B and C, but there was no significant difference on Cmax (t=1.687,1.214;P＞0.05). Conclusion The pharmacokinetic parameters of vancomycin in rabbit vitreous with endophthalmitis varied between different pathological conditions
Objective To observe the expression of C9 in laser-induced choroidal neovascularization (CNV) and the inhibitory effect of cobra venom factor (CVF) on CNV. Methods Thirty-six C57BL/6J mice were randomly divided into control group (n=12), laser photocoagulation group (n=12) and CVF group(n=12). The mice in control group had no interference treatment. CNV of the latter 2 groups were induced by photocoagulation. The mice of CVF group received intraperitoneal injection of CVF (0.1 mu;g/g) 2 days before and once a day after laser treatment. Six days after photocoagulation, the examination of fundus fluorescein angiography was used to confirm that CNV existed in the mice of laser the photocoagulation group. Then at 1, 3, 5, 7 days, the C9 expression was observed using SABCFITC histochemical stain and HE stain. The absorbance was measured by Image-Pro Plus 6.0 image software. Results Only in the laser group had formed CNV. At different time points, C9 expression was observed in the laser photocoagulation group but not in the CVF group. The A value showed a significant difference among 3 groups at different time points (F=146.045, P=0.000). The significant difference of A value exited in each group at different time points (F=9725, P=0.000). Conclusions There is C9 expression in laser-induced choroidal neovascularization. CVF can inhibit CNV formation by inducing complement consumption.
Objective To observe the inhibitory effect of intravitreal injection of triamcinolone acetonide (TA) on oxygen-induced retinal neovascularization, and to investigate its mechanism. Methods A total of 48 C57BL/6 mice at the age of 7 days were divided into normal group (groupA,n=6), highoxygen group (group B, n=6), TA control group (group C,n=18) and TA highoxygen group (group D,n=18). The retinal neovascularization of group B and D were induced by oxygen. One eye of each mouse of group C and D received an intravitreal injection 2 mu;l (20 mu;g /mu;l) of TA, and the same volume of BSS was injected into the other eye of the mice as BSS control group (group E) and BSS highoxygen group (group F). At postnatal day 17, the retinas were collected and the number of the endothelium cell nuclei of new vessels beyond the inner limiting membrane (ILM) was counted on HE-stained paraffin retina sections. The expression level of vascular endothelial growth factor (VEGF), stromal cellderived factor 1 (SDF-1) and CD14 were measured by immunohistochemical staining. The mRNA expression of VEGF and SDF-1 were detected by real-time RT-PCR. Results The numbers of the endothelium cell nuclei of new vessels beyond the ILM in group A - F were 0, 675, 0, 0, 110 and 688 respectively. In group A and D, it decreased than that in group B and F respectively (t=30.62, 19.532; P＜0.05). There was no difference of VEGF, SDF-1 and CD14 expression between group C and E (t=0.161, 0.284, 0.223; P＞0.05), but the differences were statistically significant between group D and F(t=-2.264, -2.358, -4.897;P＜0.05). There was no difference on mRNA level of VEGF and SDF-1 between group C and E(t=-0.497,-0.709;P＜0.05), but the differences were statistically significant between group D and F(z=-5.137,-4.411;P＜0.05). Conclusion Intravitreal injection with TA can inhibit oxygen-induced retinal neovascularization, down-regulated expression of VEGF and SDF-1 may be the mechanism.
Objective To investigate the possible effects of phosphorylated signal transduction and activator of transcription3 (STAT3) in the formation of choroidal neovascuarization (CNV) induced by photocoagulation in rats. Methods The CNV model in rats induced by photocoagulation was established, and the expression of phosphorylated STAT3 at the early stage in CNV were observed by immunofluorescence. To set up the hypoxia model, the specific inhibitor of Janus kinase 2 (JAK2), AG490 was mixed into cell culture fluid and then cultured for 0,1 hour,3,6,12,and 24 hours.Retinal pigment epithelial (RPE) cells proliferation activity were detected by flow cytometry (FCM).the expression of hypoxiainducible factor (HIF)1α and vascular endothelial grow factor (VEGF) mRNA were detected by reverse transcriptase polymerase chain reaction (RT-PCR); the expression of HIF1α protein was detected by Western blot; the content of VEGF in the supernatant of cell culture fluid was measured by enzyme linked immunosorbent assay (ELISA). Results Phosphorylated STAT3 highly expressed in CNV areas in rats 3 days after the photocoagulation. The proliferation activity of human RPE cells under hypoxia condition significantly decreased after inhibition of JAK2/STAT3 signal transduction pathway (t=1.472, 3.566,2.391,6.420; P=0.054,0.038,0.042,0.016). The expression of HIF-1α and VEGF mRNA increased gradually with increasing time of hypoxia;while the expression of HIF1α and VEGF mRNA and the activation of HIF1α protein in cultured human RPE cells with the JAK/STAT3 signal transduction pathway blocked by AG490 were suppressed obviously under hypoxia condition (t=0.07,0.02,0.01, P<0.05); the content of VEGF in RPE cells supernatant decreased significantly (t=1.330,1.106,2.828,7.742,5.610,6.894; P=0.082,0.063,0.014,0.002,0.016,0.011). Conclusion STAT3 may be involved in CNV formation, which may partly dependent on JAK2/STAT3 signal transduction pathway regulating the expression of HIF-1α and VEGF in RPE cells.