The hallmark lesions of age-related macular degeneration (AMD) are drusen and basal linear deposit which are lipid substances deposited in Bruch membrane or the compartment on the Bruch membrane. There is a prevailing hypothesis that lipid and its oxidized derivant deposited in retina may have important roles in the pathogenesis of AMD. Lipid oxidation products are toxic, may affect the adjacent cells, induce inflammation, and trigger neovascularization.7-ketocholestoral (7KCh), a naturally occurring oxidized form of cholesterol, had been found to be toxic to retinal cells and able to induce chronic inflammation, which may play a critical role in the development of AMD. However the precise mechanism remains to be elucidated. Thus we will make a brief review of 7KCh and its association with AMD.
Objective To observe the influences of depolarized arrest and hyperpolarized arrest on alternation of fluidity of myocardial cell membrane during cardiopulmonary bypass (CPB) and evaluate the protective effects on myocardium of hyperpolarized arrest. Methods Seventy-two felines were randomized into three groups, each group 24. Control group: 180 minutes of CPB was conducted without aortic and vena caval cross-clamping. Depolarized arrest group: hearts underwent 60 minutes of global ischemia after aortic cross-clamping (ACC) followed by 90 minutes of reperfusion. The cardioplegic solution consisted of St. Thomas solution (K+16mmol/L). Hyperpolarized arrest group: the protocol was the same as that in depolarized arrest group except that the cardioplegic solution consisted of St.Thomas solution with pinacidil (50 mmol/L,K+5mmol/L). Microviscosity, the reciprocal of fluidity of myocardial membrane was measured in all groups by using fluorescence polarization technique. (Results )Microvis cosity of myocardial cell in depolarized arrest group during ACC period was significantly higher than that before ACC and kept on rising during reperfusion period. Microviscosity of myocardial cell in hyperpolarized arrest group during ACC was trending up and reperfusion periods as well, but markedly lower compared to that in depolarized arrest group at corresponding time points(Plt;0.01). Conclusion Hyperpolarized arrest is more effective in protecting myocardial cells from ischemia-reperfusion injury than depolarized arrest during CPB by maintaining better fluidity of myocardial membrane.
Objective To evaluate the effects of surgical treatment for severe ocular rupture with blood staining of cornea and non-light perception , and analyze the relative factors. Methods Seven severely rup tured eyes of 7 patients with blood staining of cornea and non-light perception underwent second-stage penetrating keratoplasty combined with vitrectomy using temporary keratoprosthesis. All injured eyes had blood staining of cornea, hemorrhage in anterior chamber and vitreous, and choroidal and retinal detachment before the second-stage surgery. The average interval of the two surgical stages was 18 days (12-21 days). The preoperative visual acuity was non-light percept ion in all injured eyes with the mean intraocular pressure of 3 mm Hg (1 mm Hg =0.133 kPa) (2-5 mm Hg).The mean follow-up period was 12 months (6-30 months). Results The postoperative visual acuity was better than light perception in 5 eyes with the best corrected visual acuity of light perception to 0.06. The retina was attached in 5 eyes (5/7). The mean postoperative intraocular pressure was 12 mm Hg(5-15 mm Hg)which was significantly higher than the preoperative one (Plt;0.05). Postoperative complications mainly included temporary intraocular hypertension (1 eye), corneal neovasculariza tion (4 eyes), cornea rejection (4 eyes), and ocular atrophy (2 eyes). Conclusion Penetrating keratoplasty combined with vitrectomy using temporary keratoprosthesis is a safe and effective method in treating severe ocular rupture with blood staining of cornea and non-light perception. (Chin J Ocul Fundus Dis，2004，20：212-214)
OBJECTIVE To sum up the experience of diagnosis and treatment of intrinsic upper gastro-intestinal membrane, 13 cases in children were studied retrospectively. METHODS There were 10 boys and 3 girls, the major symptoms were vomiting and epigastric distension. Eleven cases were treated by membranectomy with intestinal plasty, and 2 cases were treated by retrocolic side to end duodenojejunostomy. RESULTS All cases had good results without severe complications. CONCLUSION The children who have typical symptom of upper digestive tract should be considered duodental and upper jejunal membrane, and should be proved by contrast radiology. The membranectomy with intestinal plasty is the better operative method.
Objective To compare the effect between vascularization osteogenesis and membrane guided osteogenesis in the bone repair by the tissue engineered bone with pedicled fascial flap packing autologous red bone marrow (ARBM), so as to provide a reference for the bone defect repair in cl inic. Methods The tissue engineered bone was constructed with ARBM and the osteoinductive absorbing recombinant human materials with recombinant human bone morphogenetic protein 2. Sixty New Zealand rabbits (aged 4-5 months, weighing 2.0-2.5 kg) were randomly divided into group A (n=16), group B (n=22), and group C (n=22). The complete periosteum defect model of 1.5 cm in length was prepared in right ulnar bone, then the tissue engineered bone was implanted in the bone defect area in group A, the tissue engineered bonewith free fascial flap in group B, and the tissue engineered bone with pedicled fascial flap in group C. At 4, 8, 12, and 16 weeks, the tissue of bone defect area was harvested from 4 rabbits of each group for the general, histological, and immunohistochemical staining observations; at 8, 12, and 16 weeks, 2 rabbits of groups B and C, respectively were selected to perform ink perfusion experiment by axillary artery. Results The general observation showed that the periosteum-l ike tissues formed in the fascial flap of groups B and C, chondroid tissues formed in group B, new bone formed in group C, and the fibrous and connective tissues in group A at 4 and 8 weeks; a few porosis was seen in group A, more new bone in group B, and bone stump formation in group C at 12 and 16 weeks. Histological observation showed that there were few new blood vessels and new bone trabeculae in groups A and B, while there were large amounts of new blood vessels and mature bone trabeculae in group C at 4 and 8 weeks. There were a few new blood vessels and new bone trabeculae in group A; more blood vessels, significantly increased mature trabeculae, and the medullary cavity formation in group B; and gradually decreased blood vessels, the mature bone structure formation, and the re-opened medullary cavity in group C at 12 and 16 weeks. The immunohistochemical staining observation showed that the levels of CD105, CD34, and factor VIII were higher in group C than in groups A and B at different time points.The bone morphometry analysis showed that the trabecular volume increased gradually with time in 3 groups after operation; the trabecular volume in group C was significantly more than those in groups A and B at different time points (P lt; 0.05); and there was significant difference between groups A and B (P lt; 0.05) except the volume at 4 weeks (P gt; 0.05). The vascular image analysis showed that the vascular regenerative area ratio in group C was significantly higher than those in groups A and B at different time points (P lt; 0.05). The ink perfusion experiment showed that the osteogenic zone had sparse ink area with no obvious change in group B, while the osteogenic zone had more intensive ink area and reached the peak at 8 weeks, then decreased in group C. Conclusion The tissue engineered bone with pedicled fascial flap packing ARBM has the vascularization osteogenesis effect at early stage, but the effect disappears at late stage gradually when the membrane guided osteogenesis is main.
Objective To analyze the correlation of foveal avascular zone (FAZ) size with visual acuity and metamorphopsia in idiopathic macular epiretinal membrane (IMEM) eyes. Methods This is a cross-sectional study, including 43 patients (43 eyes) with IMEM (IMEM group) and 35 health subjects (35 eyes) as control group. The best corrected visual acuity (BCVA) was measured using the international standard visual acuity chart, and the results were converted to the logarithm of the minimum angle of resolution (logMAR) visual acuity. The severity of metamorphopsia was measured using M-charts. The FAZ areas were estimated with optical coherence tomography angiography (OCTA) in both the superficial and deep capillary plexus layers. The central macular thickness (CMT) was assessed with spectral-domain optical coherence tomography. There was no difference of logMAR BCVA and CMT between two groups (Z=−7.379, −7.560; P＜0.001). The differences of FAZ areas between the two groups were analyzed. The correlative analysis was performed to investigate the relationship between FAZ areas and visual acuity as well as metamorphopsia. Results The FAZ area in superficial and deep capillary plexus in IMEM group were smaller than those in control group (t=−30.316, −27.606; P＜0.001). In IMEM group, the mean M-score was 0.41±0.32; the horizontal and vertical M-score were 0.49±0.40 and 0.32±0.29, respectively. The horizontal M-score was higher than vertical M-score with the significant difference (Z=−2.000, P=0.046). In IMEM group, the FAZ area in superficial capillary plexus correlated inversely with metamorphopsia (r=−0.709, P＜0.001); the FAZ area in deep capillary plexus correlated inversely with metamorphopsia and BCVA (r=−0.533, −0.838; P＜0.001). Conclusions The FAZ areas are significantly decreased in IMEM eyes compared with normal eyes. Both superficial and deep FAZ areas are correlated with metamorphopsia, and deep FAZ area is also correlated with BCVA.
Idiopathic macular membrane (iERM) is a fibrocellular membrane that forms on the inner surface of the retina. In its early stages, symptoms of iERM are usually not apparent. However, advanced iERM can cause different degrees of visual impairment and effect the quality of life of patients. Current studies suggest that iERM may be associated with posterior vitreous detachment (PVD), age, sex, race and/or ethnicity, poor lifestyle, refractive error, diabetes, hypercholesterolemia, and cardiovascular disease. The most well-established risk factors for iERM are age and PVD. The pathogenesis of iERM is extremely complex. Various cell types, such as Müller cells, Hyalocytes and myofibroblasts, nerve growth factor, interleukin-6, transforming growth factor β, vascular endothelial growth factor and other cytokines and growth factors, as well as a variety of genes and proteins are directly or indirectly involved in the formation of iERM, however, their exact role remains a mystery. In the future, further studies at the molecular level and gene level are needed to provide greater help for the clinical diagnosis and treatment of iERM.
Membrane guided tissue regeneration is new biological concept. The basic theory of this concept includes the belief that during the healing process of wound, the different cells will show different speed of cell migration and regeneration in the wound. If an appropriate membrane being placed to form a mechanical barrier, so that only the needed cells can grow into that area and prevent others from going in, thus resulting in the creation of a guided area where the needed cells can undergo proliferation and differentiation under protection in completing an ideal tissue regeneration and repair. In this article, the experimental researches on the application of membrane guided tissue regeneration in the repair of tubular bone defects, skull defects and faciomaxillary defects were reviewed from literatures, and the degradable and non-degradable materials were introduced, particularly. The pros and cons of this method and the materials were evaluated. It is believed that this technique will push forward the progress in bone biology and reconstructive surgery.
Objective To study the responsiveness change of neutrophils when experiencing the second insult after the initial temperature activation in cardiopulmonary bypass (CPB) by using an in vitro model. Methods The neutrophils were isolated from blood which was drawn from each of 60 health volunteers. The samples were divided into 5 groups including normothermia, tepid temperature, moderate hypothermia, deep hypothermia, and rewarming hyperthermia by random digital table with 12 in each group according to the change of temperature during CPB. An in vitro model for studying neutrophil responsiveness was established by using a polymerase chain reaction thermocycler. Five time points were set for each group, including T0: starting CPB, T1: starting rewarming, T2: 0.5 h after rewarming, T3: 1 h after rewarming, and T4: 1.5 h after rewarming. Platelet activating factor (PAF) was added into each group at T2, T3, and T4, and then the value of membranebound elastase (MBE) activity was measured as responsiveness of neutrophils. Analysis of covariance was applied by using SPSS 13.0 for statistic analysis. If the [CM(159mm]covariance had significant difference between main effects, Bonferroni method would be applied for pairwise comparison. Results The main effect difference of neutrophil responsiveness among different groups was statistically different (F=4.372,P=0.002). MBE value had no statistical difference between the normothermia and tepid temperature groups (81.9±4.5 ng/10.6 cells vs. 76.5±3.6 ng/106 cells, P=0.134). while the MBE values in these two groups were higher than those in the other three groups (P=0.001). MBE value in the rewarming hyperthermia group was higher than that in the deep hypothermia group (61.2±2.7 ng/106 cells vs. 50.9±3.7 ng/106 cells, P=0.005). There was no statistical difference between the moderate hypothermia group (56.4±3.2 ng/106 cells) and the rewarming hyperthermia group (P=0.167), so was it between the moderate hypothermia group and the deep hypothermia group (P=0.107). The main effects of neutrophil responsiveness at different time points was statistically different (F=3.566, P=0.03) when PAF was added. MBE value at T4 was higher thanthat at T2 (70.9±2.5 ng/106 cells vs. 59.9±2.3 ng/106 cells, P=0.027). There was no statistical difference among T3 (65.5±1.8 ng/106 cells), T2 (P=0.168), and T4 (P=0.292) in MBE value. Conclusion Normothermia， tepid temperature， and rewarming hyperthermia during CPB can enhance neutrophil responsiveness and MBE release when neutrophils suffer the second insult. There is a time window for neutrophils to be easily activated during rewarming period.
Recently, the new term "lamellar hole-associated epiretinal proliferation" was introduced to describe a specific epiretinal proliferation. Different from conventional epimacular retinal membrane, lamellar hole-associated epiretinal proliferation (LHEP) can be found around the edge of lamellar macular holes and part of full thickness macular holes. It is defined as a thick homogenous layer of yellowish material without any contractive properties on the epiretinal surface with medium reflectivity on optical coherence tomography images. Immunocytochemical analysis showed the presence of glial cells, fibroblasts, hyalocytes and collagen type Ⅱ. Electron microscopy revealed fibroblasts and hyalocytes as predominant cell types, densely packed in cell agglomerations. LHEP is a secondary event in lamellar macular hole formation and may represent a repair process after large and deep retinal defect. Further studies on its clinical features and clinical significance are still required.