Application of avastin in vitrectomy for proliferative diabetic retinopathy and its mechanism / 中华实验眼科杂志

Background Researches demonstrated that avastin-assisted vitrectomy for serious proliferative diabetic retinopathy can decrease intra-operation complication and bring down difficulty of surgery.It is speculated that this is associated with suppression of avastin on neovascularization.However,the evidence of its pathology is lack.Objective The aim of this study was to evaluate the application and mechanism of avastin in vitrectomy for severe proliferative diabetic retinopathy. Methods Twenty-four eyes from consecutive 24 patients with vitrectomy for severe proliferative diabetic retinopathy were enrolled in this study.Fourteen eyes received all intravitreal injection of 0.06 ml avastin(1.5 mg)14 days prior to vitrectomy。And the other 10 eyes underwent only vitrectomy without avastin injection as controls,Preretinal membranes were collected during vitrectomy for histopathologic examination by hemotoxylin and eosin staining.The differences in the density of the neovessels and micro-neovessels between the two groups were observed by detecting the expression of CD34 in vesse]endothelial cells using immunohistochemistry.Written informed consent was obtained from each patient before surgery. Results No statistically significant differences were found in the demography and eye manifestations between only vitreetomy group and avastin+vitrectomy group(P＞0.05).The neovessels with grade three was in 10 eyes in only vitrectomy group and 1 eye in avastin+vitrectomy group(P＜0.01).More capillary-like neovascularization with single vascular endothelial cells,obvious hemorrhage and inflammatory cells infiltration were observed on preretinal membranes in vitrectomy group.However,there were less hemorrhage,ceUular components and few capillary-like neovascularization but more hyaline degeneration of fibrous tissue were observed in avastin+vitrectomy group under the light microscope.Immunochemistry revealed that CD34 was positively expressed in vascular endothelial cells on preretinal membrane in both two groups.The neovessels density and miero-neovessels density were 15.40±7.42/field and 1.88±1.70/field in avastin+vitrectomy group and those in vitreetomy group were 18.00±3.80/field and 0.45±0.56/field respectively,showing significant differences between these two groups(neovessels density:Z=-4.102,P＜0.01;micro-neovessels density:Z=-4.137,P＜0.01).Conclusion As an adjunct drug during the vitrectomy for proliferative diabetic retinopathy, avastin can improve the successful rate of surgery by inhibiting the neovascular formation and alleviating retinal edema.

Expression of stromal cell-derived factor-1 in diabetic retinopathy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Neovascularization can cause vision loss in proliferative diabetic retinopathy (PDR) and may be affected by many factors. Stromal cell-derived factor-1 (SDF-1) is a potent stimulator of angiogenesis. The study was aimed to investigate the expression of SDF-1 and its correlation with vascular endothelial growth factor (VEGF) in the eyes with diabetic retinopathy.</p><p><b>METHODS</b>The levels of SDF-1 and VEGF were measured by enzyme-linked immunosorbent assay in the vitreous of 41 eyes of 41 patients with PDR and 12 eyes of 12 patients with idiopathic macular hole (IMH). Vitreous fluid samples and fibrovascular preretinal membranes were obtained at vitrectomy. SDF-1 and VEGF were localized using immunohistochemistry.</p><p><b>RESULTS</b>The vitreous concentration of VEGF was significantly higher in eyes with PDR ((2143.7 +/- 1685.21) pg/ml) than in eyes with IMH ((142.42 +/- 72.83) pg/ml, P < 0.001). The vitreous level of SDF-1 was also significantly higher in eyes with PDR ((306.37 +/- 134.25) pg/ml) than in eyes with IMH ((86.91 +/- 55.05) pg/ml, P < 0.001). The concentrations of both VEGF and SDF-1 were higher in eyes with active PDR than in eyes with inactive PDR. Panretinal photocoagulation (PRP) could decrease the SDF-1 levels in the vitreous of PDR patients. The vitreous concentration of SDF-1 correlated with that of VEGF in eyes with PDR (r = 0.61, P < 0.001). The costaining of SDF-1 and VEGF was confined to the vascular components in preretinal membranes.</p><p><b>CONCLUSIONS</b>SDF-1 protein is highly expressed in both the vitreous and preretinal membranes of PDR patients; SDF-1 may be correlated with VEGF in angiogenesis in PDR.</p>

Caspase-dependent retinal ganglion cell apoptosis in the rat model of acute diabetes / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Neural apoptosis is generally believed to be mediated by two distinct pathways, caspase-dependant and caspase-independent pathways. This study investigated the apoptotic pathways involved in retinal ganglion cells in acute diabetes in rats.</p><p><b>METHODS</b>Diabetes was induced in male Wistar rats by a peritoneal injection of streptozotocin (STZ). Expression and localization of caspase-3 and apoptosis-inducing factor (AIF) proteins in the retina of diabetic rats was examined by Western blotting and immunohistochemistry analyses. Terminal transferase dUTP nick end labeling (TUNEL) assay and immunofluorescent staining specific for caspase-3 and AIF were applied to analyze for apoptosis of retinal ganglion cells. In addition, a caspase-3 inhibitor DEVD-CHO was injected intravitreally to further determine the apoptotic pathways of retinal ganglion cells triggered in acute diabetes.</p><p><b>RESULTS</b>Two weeks after induction of diabetes, a significant increase in caspase-3 protein expression and localization occurred in the nerve fiber layer, ganglion cell layer, and inner plexiform layer of the retina. Four weeks after the onset of diabetes, the increase in caspase-3 expression was profound eight weeks postinduction of diabetes (P < 0.05). Meanwhile, no AIF protein expression was detected in this study. In addition, intravitreal administration of the caspase-3 inhibitor DEVD-CHO reduced apoptosis of retinal ganglion cells by its direct inhibitory action on caspase-3.</p><p><b>CONCLUSION</b>Caspase-dependent apoptotic pathways may be the main stimulant of STZ-induced retinal ganglion cell apoptosis in acute diabetes.</p>

Clinical observation on treatment of gastrointestinal dysfunction by fu'an liquid for retention enema in children with critical illness / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the therapeutic effect of Fu'an Liquid (FAL) for retention enema in treating gastrointestinal (GI) dysfunction of children with critical illness.</p><p><b>METHODS</b>Eighty-nine patients were randomly divided into two groups, 52 in the treated group and 37 in the control group. Conventional therapy of western medicine was given to both groups and to the treated group FAL was given additionally. Plasma endothelin (ET) level was measured during admission, GI dysfunction occurrence and after treatment, and the therapeutic effect as well as the recovery of GI condition were observed.</p><p><b>RESULTS</b>The total effective rate of FAL in treating GI dysfunction was 84.62%, which was significantly higher than that in the control group (62.17%) (P < 0.05). In the treated group, 34 cases were treated successfully, 16 died and the other 2 abandoned, the mortality rate being 30.77%, while in the control group, the corresponding numbers were 16, 18, 3 and 48.65%. The mortality rate in the treated group was lower than that in the control group (chi 2 = 4.64, P < 0.05). Level of ET in both groups was higher than normal range during admission (P < 0.01), it further increased when GI dysfunction occurred (P < 0.01), and decreased when successfully treated, the decrease was quicker in the treated group than that in the control group (P < 0.05).</p><p><b>CONCLUSION</b>In children with critical illness, ET level would increase when the patient was complicated with GI dysfunction. FAL for retention enema could reduce the ET level effectively, promote the recovery of patients from GI dysfunction, so as to play a definite role in enhancing the successful rate of rescue.</p>