截止至2002年5月,現有早產治療的臨床證據如下: (1) 高危早產:在一些國家實施的RCT發現,在降低早產危險方面,加強產前保健與普通產前保健沒有明顯差異.包括5個RCT的1個系統評價發現,對有宮頸改變的婦女行宮頸環扎術有不同的結果,沒有明確的結論.1個大樣本的RCT發現,孕9～29周宮頸功能可能不全的婦女進行預防性宮頸環扎手術與不環扎相比,能明顯降低早產(＜33孕周),但也會明顯增加產褥感染的危險.另外4篇較小樣本的RCT發現,孕10～30周、具各種早產高危因素的婦女,進行預防性宮頸環扎手術與不環扎相比,并不能降低早產(＜34孕周).1篇系統評價的2個RCT報告,對有宮頸改變的婦女進行環扎術有不同的結果,其中1個RCT發現其并不能明顯降低早產(＜34孕周),而另外1個較小樣本的RCT卻發現宮頸環扎手術加臥床休息與單純臥床休息比較,能明顯降低34周前的早產.沒有1個RCT證實行環扎術加臥床休息與單純臥床休息相比,能降低圍生兒死亡率. (2) 胎膜早破:1個系統評價發現,對胎膜早破的婦女,抗生素較安慰劑能明顯延長孕周、降低新生兒發病率的危險,如新生兒感染、出生后氧療、腦部超聲異常等.阿莫西林加克拉維酸治療與新生兒壞死性小腸結腸炎的發生率明顯增加有關.一個基于1個RCT的系統評價發現,沒有充足的證據證實羊膜腔灌注與不灌注比較能改善胎膜早破后的新生兒結局. (3) 先兆早產的治療:①β-腎上腺素興奮劑:1個系統評價發現,β-腎上腺素興奮劑與安慰劑或不治療相比,并不能明顯降低圍生兒死亡率、呼吸窘迫綜合征及低體重兒(＜2 500 g)發生率,且與與安慰劑或不治療相比,β-腎上腺素興奮劑增加孕母副反應,如胸痛、心悸、呼吸困難、震顫、惡心、嘔吐、頭痛、高血糖、低鉀血癥.②鈣離子通道拮抗劑: 沒有關于鈣離子通道拮抗劑與安慰劑比較的系統評價或RCT.1個系統評價發現,鈣離子通道抑制劑與其它保胎藥(主要是β-腎上腺受體興奮劑)比較,能顯著降低48 h內的早產分娩,減少因孕母副反應退出治療和新生兒發病率.③硫酸鎂:1個系統評價發現,硫酸鎂與安慰劑比較,并不能明顯降低孕36周前的早產率、圍生兒死亡率、呼吸窘迫綜合征的發生率.另一個系統評價發現,硫酸鎂和其他宮縮抑制劑(β-腎上腺素興奮劑、鈣離子通道拮抗劑、前列腺素合成抑制劑、硝化甘油、酒精和葡萄糖注射劑)比較,并不能明顯降低48 h內早產率(盡管結果沒有差異).④垂體受體拮抗劑(阿托西班):1個系統評價納入 2個RCT,對阿托西班和安慰劑治療早產進行比較有不同的結果.較大樣本的RCT發現,阿托西班較安慰劑能延長孕周,但阿托西班增加了孕28周以下的胎兒死亡率.另一個RCT發現,阿托西班增加了48 h內的早產.⑤前列腺素抑制劑(消炎痛):1個系統評價發現,消炎痛與安慰劑比較,能明顯降低孕37周前的48 h和7天的早產率的證據有限.然而,同時發現消炎痛與安慰劑或不治療相比,并不能明顯降低圍生兒死亡率、新生兒呼吸窘迫綜合征、肺支氣管發育不良、壞死性小腸結腸炎、新生兒敗血癥或低體重兒.但這個系統評價樣本太小,尚不能發現有臨床意義的差異. (4) 擇期或非擇期剖宮產對早產婦女治療效果:1個系統評價結果發現,擇期剖宮產較非擇期剖宮產會增加孕母的發病率,卻不能降低新生兒的發病率和死亡率.但尚不能證明此效果是否對新生兒有臨床意義. (5) 改善早產妊娠結局的干預措施:①對早產者采用皮質類固醇:1個系統評價認為,對可能發生早產的婦女使用皮質激素較安慰劑或不處理能明顯降低早產兒出生后呼吸窘迫綜合征、新生兒死亡率和顱內出血的發生.②促甲狀腺激素釋放激素在早產中的運用:1個系統評價發現,在早產的高危婦女中,促甲狀腺激素釋放激素和類固醇激素聯合應用與單用皮質類固醇激素比較,對新生兒結局的影響無明顯差異,但會明顯增加孕母和胎兒的不良反應.③抗生素:1個系統評價發現,抗生素與安慰劑比較,不能延長孕周、降低新生兒死亡率,但可降低孕母感染率.
Objective To observe clinical effects of burn wounds treatment with bovine amnion and to screen the best method of preparing and storing of bovine amnion. Methods From January 2004 to January 2005,We selected randomly 58 patients with superficial Ⅱ° wound, deepⅡ° wound, autografting area for removal of eschars and tangential excision, fetching skin area or residual burn wound . Using auto-control, every burn wound was divided into 3 parts and was treated with 3 dressings: bovine amnion dealt with by 0.1% chlorhexidine（group A）, bovine amnion dealt with by 0.4% glutaraldehyde（group B） and vaseline gauze dressing（group C as control）. The clinical effects were compared between different groupsand the method of preparing and storing bovine amnion was evaluated. Results The dressing texture of group A was softer than that of group B, and its flexibility was fine. The pretreatment was not necessary for dressing in group A. When the dressing was used on burn wounds in groups A and B, painwas slight, but pain was obvious in group C; healing time in groups A and B was much less than that in group C, showing statistically significant difference(P＜0.01). There was no statistically significant difference in healing time between groups A and B (P＞0.05). The infection ratio of burn wound in deepⅡ° wound and residual burn wound of groups A and B is much lower than that of group C, showing statistically significant difference (P＜0.05); in theother burn wounds there was no significant difference (P＞0.05). There was no statistically significant difference between groups A and B (P＞0.05). Conclusion Bovine amnion could make benefit on burn wounds healing, reduce infection ratio of burn wounds, could be used on different kinds of burn wounds. The clinical effect between bovine amnion dealt with by glutaraldehyde and by chlorhexidine is similar. Whereas the latter is more easy to be popularized.
Objective To compare the effects of the denudedfreeze-dried-amniotic-membrane and the denuded freeze-dried bovine corneal stroma when they were explanted to repair the corneal defect of rabbits. Methods The amnia from healthy human placentae were prepared with the method reported by LUO Jingcong, which were freeze-dried and sterilized. The bovine cornea was also denuded by typsin, rinsed, freeze-dried, and sterilized. Twenty Japan rabbits weredivided into group A(the amniontic group) and group B(the bovine-corneal-stroma group) at random. The defect was made, which was 7.5 mm in diameter and 1/3 ofthe thickness of the cornea, and the two kinds of materials were explanted to repair the defect. The vascularization and the changes of the operated eye were observed. The samples were taken at 2, 4 and 8 weeks for histologicalexamination. Results The explanted materials were not melted or excluded. There were visible neovessels in both groups, yet there was no significant difference between them. According to the histological observation, there was severe inflammation in both groups 2 weeks after operation, the fibroblasts were proliferated, and the collagen fibers were disorganized; however,the reactions became milder from 4 weeks after operations,andthe neovessles could be seen in groups A and B; at 8 weeks, the collagen fibers were more organized in groups A and B; however,there was still a small area of disorganized fibers left. Conclusion The two materials can lead to rejection to some extent, and so they need to be improved.
ObjectiveUnder hypoxic conditions, the survival and apoptosis of human amniotic mesenchymal stem cells (hAMSCs) were observed by transient transfection of hypoxia-inducible factor 1α (HIF-1α) gene, to investigate the effect of HIF-1α on hypoxic tolerance of hAMSCs.MethodsThe hAMSCs were isolated and cultured from amniotic membrane tissue from voluntary donors who were treated with cesarean section. And the morphological observation by inverted phase contrast microscope and immunofluorescence detection of the expressions of stem cell markers OCT-4 and NANOG were performed to identify the cultured cells. The third generation hAMSCs were treated with 200 μmol/L CoCl2, and transient transfection of plasmids were added according to the following grouping: group A was hAMSCs blank group; group B was pcDNA3.1 negative control group; group C was short hairpin RNA (shRNA) negative control group; group D was shRNA-HIF-1α interference group; group E was pcDNA3.1-HIF-1α over expression group. Cell survival rate of each group was measured by cell counting kit 8 (CCK-8) at 12, 24, 48 hours after hypoxia treatment. Flow cytometry was used to detect apoptosis rate of each group at 24 hours after hypoxia treatment. The expression levels of HIF-1α, vascular endothelial growth factor (VEGF), B-cell lymphoma 2 (Bcl-2), Bax, and cleaved Caspase-3 (C-Caspase-3) proteins were detected by Western blot at 24 hours after hypoxia treatment.ResultsCCK-8 assay showed that the cell survival rate of group D was significantly lower than those of groups A and C at all time points after hypoxia treatment; while the cell survival rate in group E was significantly increased than those in groups A and B, and the diffrences at 24 hours were significant (P<0.05). In group E, the cell survival rate at 24 hours was significantly higher than those at 12 and 48 hours (P<0.05). The results of flow cytometry showed that the apoptosis rate in group D was significantly higher than those in groups A and C (P<0.05), and the apoptosis rate in group E was significantly lower than those in groups A and B (P<0.05). Western blot showed that the expressions of HIF-1α, VEGF, and Bcl-2 proteins in group D were significantly decreased when compared with those in groups A and C, and the expressions of Bax and C-Caspase-3 proteins were significantly increased (P<0.05). On the contrary, the expressions of HIF-1α, VEGF, and Bcl-2 proteins in group E were significantly higher than those in groups A and B, and the expressions of Bax and C-Caspase-3 proteins were significantly decreased (P<0.05).ConclusionOverexpression of HIF-1α gene can significantly improve hAMSCs tolerance to hypoxia, the mechanism may be related to up-regulation of VEGF and Bcl-2 expressions, and down-regulation of Bax and C-Caspase-3 expressions.
Objective To observe the effect of amniotic homogenate on closing holes in experimental rhegmatogenous retinal detachment and investigate its mechanism. Methods Forty rabbits were randomly divided into group A, B, C and D with 10 rabbits in each group. Group A and C were the treatment groups, and group B and D were the control groups. All eyes of rabbits underwent pars plana vitrectomy, retinectomy, and fluidair exchange. The surface of the breaks was treated with 01 ml amniotic homogenate in experimental groups and 0.1 ml PBS in control groups. At the end of operation, 20% SF6 was tamponaded and the retina reattaced. The animals were executed 14 (group A and B) and 28 days (group C and D) after the surgery. The tissue sections were observed by light microscope, electron microscope and immunocytochemistry method. Results Fourteen days after the surgery, the retina reattached in 6 eyes in group A (60%) and 2 eyes in group B (20%) （P=0.021）. Twenty-eight days after the surgery, the retina reattached in 8 eyes in group C (80%) and 3 eyes in group D (30%) (P=0.046). The difference of the rate of retinal reattachment among the 4 groups were statistical significant (Plt;0.05). Light postoperative inflammation of ocular anterior segment was observed, which was controlled 3-5 days after treated with topical steroids. The result of light microscopy showed that the eyes in treatment groups had multilayer of fibroblastlike cells around the retinal breaks, adhering to the choroid and retinal pigment epithelial cells. The proliferative cells around the retinal breaks obvious less in control groups than that in the treatment groups, and the retina could not adhere to the choroid. The results of electron microscopy were the same as that of light microscopy. Immunohistochemistry staining of the fibroblastlike cells revealed positve glial fibrillary acidic protein, which suggested that the proliferative cells around the retinal breaks were retinal glial cells. Conclusions Amniotic homogenate helps to seal retinal breaks and promote retinal reattachment by stimulating the proliferation of retinal glial cells around the breaks.
Objective To review the latest development of amniotic membrane andits application. Methods Related literatures on the development of amniotic membrane and its application were extensively reviewed and summarized. Results There were amniotic epithelial cells and many growth factors in the outer layer of amniotic membrane and there were many kinds of collagen in the basement. The special structure promoted the growth of many kinds of cells. It was widely used in ophthalmology. Conclusion As it is easily available, compatible, cheap in price, low in antigenicity, and able to promote the growth of many kinds of cells, with few ethical problems involved, amniotic membrane will be more and more widely applied.
Objective To explore an effective method to culture and purify porcine keratinocytes, to observe the morphological characteristics of porcine keratinocytes growing on acellular amnion and to offer the experimental basis for that the amnion is used for tissue engineering. Methods The primary porcine keratinocytes were cultivated with DKSFM(Defined keratinocyteSFM) containing 10% fetal bovine serum (FBS). The second passage porcine keratinocytes were cultivated with the medium of DKSFM containing different concentrations of FBS. Because of the speciality that keratinocytes stick to flask fast, we purified the keratinocytes by 0.02% EDTA and 005% trypsin step by step. The second passage keratinocytes were seeded on amnion, the keratinocytes/amnion composites were observed by dye directly, histopathology and immunohistochemical staining. Results The proliferation of the primry porcine keratinocytes cultured with the medium ofDKSFM containing 10% FBS was fast and the morphological characteristics were good. The cultivated porcine keratinocytes expanded to 60%70% of the total area of the bottle of the flask after 5 days. The proliferation of the second passage porcine keratinocytes cultivated with the medium that DKSFM containing 5% FBS was faster than the second porcine keratinocytes cultured with the medium of DKSFMcontaining 10% FBS, or DKSFM without FBS. The proliferation of the second passage porcine keratinocytes cultivated with DKSFM without FBS was the slowest one among the 3 medium. The porcine keratinocytes that were purified by 0.02% EDTA and 005% trypsin step by step were got with high pure. After the keratinocytes were cultivated on the surface of amnion 12 days, the keratinocytes form a single layer on the surface of amnion and the cells were polygong and arranged like slabstone. After 14 and 16 days,the cells contacted more closely. But at 16 days after the cells were seeded, some of the cells got aging. Conclusion To culture primary porcine keratinocytes with the medium that DKSFMcontaining 10% FBS and to cultivate the second passage with the medium containing 5% FBS, the proliferation of porcine keratinocytes are faster. The method that purify the porcine keratinocytes is effective. Acellular amnion offers excellent bioscafold to support keratinocytes to adhere and grow. After the porcine keratinocytes are cultivated on the surface of the acellular amnion 12 days, the morphologic characteristics are better than that of other groups.
OBJECTIVE: To evaluate the therapeutic effect of amniotic membrane transplantation(AMT) for ocular burn. METHODS: Twenty patients with ocular burn(28 eyes) were treated with amniotic membrane transplantation. Of them, there were 6 cases of severe alkali burn(10 eyes), 8 cases of severe acid burn(10 eyes), and 6 cases of thermal burn(8 eyes). RESULTS: In 28 eyes, ocular inflammation was controlled after 3-7 days of surgery; no continued dissolution, perforation and iris atrophy were found. There were corneal transparency in 16 eyes, keratoleukoma in 4 eyes, and total corneal opacity in 8 eyes. All eyeballs were saved and had stable ocular surface. There was no allograft immune rejection and secondary infection. CONCLUSION: Amnitic membrane transplantation can relieve the inflammatory reaction, reduce the growth of blood vessel and restrain the proliferation of fibrous tissue. It is an effect surgical method for ocular burn in reconstruction of ocular surface and salvage of eyeball.
目的:觀察新鮮羊膜移植聯合絲裂霉素C治療復發性翼狀胬肉的臨床療效。方法:對32例(38眼)復發性翼狀胬肉行翼狀胬肉切除聯合新鮮羊膜移植加絲裂霉素C治療,觀察術后角膜上皮愈合、胬肉復發情況。結果:術后隨訪3～24個月,有2眼復發,復發率為5.26%。結論:新鮮羊膜移植聯合絲裂霉素Ｃ治療復發性翼狀胬肉降低了復發率,無嚴重手術并發癥,是一種安全有效的手術方法。