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[Surgical management of nontraumatic corneal perforations: an 8-year retrospective study]
[Article in French]
Service d'Ophtalmologie, Hopital Charles Nicolle, Rouen.
PURPOSE: Treatment of nontraumatic corneal perforation is a difficult task. The aim of our study was to retrospectively analyze predisposing conditions leading to perforation, surgical treatments, and visual outcomes. METHODS: Fifty-six patients were admitted in our department for a nontraumatic corneal perforation between 1997 and 2004. Mean patient age was 69 years (range, 16-95 years) and the mean follow-up was 20.5 months (range, 6-96 months). RESULTS: The diseases associated with perforations were neurotrophic ulcer in 24 cases (43%), peripheral immunologic ulcer in ten cases (18%), dry eye in six cases (11%), and infectious keratitis in seven cases (13%). All patients had specific adapted medical treatment before surgery. As a first procedure, we used cyanoacrylate glue in 14 cases (50% anatomic success), multilayer amniotic membrane transplantation in 23 cases (100% anatomic success), conjunctival flap in six cases, peripheral lamellar graft in three cases (33% anatomic success), emergency penetrating keratoplasty in 13 cases (31% anatomic success), and one patient's eye had to be eviscerated. Several surgical procedures were necessary in 16 cases (28%), nine patients needing total conjunctival flap at the end. We were able to achieve tectonic stability in 91% of eyes and 32% of patients recovered useful visual acuity between 20/400 and 20/50. CONCLUSION: Amniotic membrane transplantation is an effective method for managing corneal perforations and usually does not need a further reconstructive procedure. Visual outcome is poor when peripheral or central keratoplasty are needed. We recommend a conjunctival flap when descemetocele or perforation recurs despite previous surgical management.
PMID: 16988625 [PubMed - in process]
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Enhanced regeneration in injured sciatic nerve by human amniotic mesenchymal stem cell.
Department of Medical Research, Taichung Veterans General Hospital, Taichung, (40705), Taiwan, ROC.
OBJECTIVE: Amniotic fluid mesenchymal stem cells (MSCs) have the potential to differentiate into neuronal stem cells in vitro. We evaluated using amniotic fluid MSCs to support or enhance the ability of the injured sciatic nerve to cross a nerve gap. MATERIALS AND METHODS: We created a 5 mm nerve defect in Sprague Dawley rats. One group received therapy with MSCs embedded into woven oxidised regenerated cellulose gauze (Surgical; Ethicon, Somerville, NJ) and fibrin glue, while a control group received woven Surgicel and fibrin glue only. Evaluation methods included behavioural, electrophysiological and immunohistochemical studies. RESULTS: In gait analysis, the angle of the ankles in the treatment and control group were 46.4 degrees (standard deviation [SD]=15 degrees) and 36 degrees (SD=8.2 degrees), respectively, which was statistically significant (p=0.045). Five of 10 treated rats (50%) demonstrated partial foot movement, while none of the control group had any movement. The percentage amplitude of muscle compound action potential in the experimental group was 43% (SD=12.5%) compared to 29% (SD=8.8%) in the control group (p=0.038). The conduction latencies in the control and experimental groups was 2.5 ms (SD=0.45) and 1.7 ms (SD=0.47), respectively (p=0.005). Histological examination demonstrated that 70% of the treatment group achieved a maximum axon diameter percentage across the nerve gap of greater than 50%, compared with 0% in the control group. There were no differences in direction of fibre growth and fibrotic reaction between the two groups. CONCLUSION: Amniotic fluid MSC can augment growth of injured nerve across a nerve gap. This effect may be due to neurotrophic or induction effects of the MSC interacting with Schwann cells. Further study is required to determine the underlying mechanism of this effect.
PMID: 16769515 [PubMed - indexed for MEDLINE]
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Combination of serum eye drops with hydrogel bandage contact lenses in the treatment of persistent epithelial defects.
Department of Ophthalmology, UK-SH Campus Lubeck, Klinik fur Augenheilkunde, Ratzeburger Allee 160, 23538, Lubeck, Germany. mail@stefanschrader.de
BACKGROUND: The treatment of persistent epithelial defects (PED) with autologous serum eye drops is often combined with conventional medication such as artificial tears and topical antibiotics, but until now no report exists on the use of a bandage contact lens (BCL) in combination with autologous serum eye drops in the treatment of PEDs. We report six eyes (five patients) which were all treated with autologous serum eye drops in combination with an FDA group IV hydrogel contact lens. METHODS: Five patients aged 36-88 years, were suffering from six PEDs for 73.5+/-46.9 days due to rheumatoid sterile corneal ulcer (n=1), neurotrophic keratopathy (n=3) or partial limbal stem cell deficiency (n=1). All patients had been unsuccessfully treated with conventional therapy before. Three of them had already had an amniotic membrane transplantation and two had undergone a keratoplasty; however, the epithelial defect persisted or recurred. In all cases, an FDA group IV hydrogel contact lens (Biomedics 55, ocufilcon D, 55% water content) was fitted and serum eye drops applied 8 times a day. RESULTS: The PED healed in five of six eyes after a treatment period of 14.2+/-8.9 days. In one eye the PED became smaller, but it took 90 days until the lesion healed completely. In three eyes (two patients) white deposits appeared on the surface of the BCL during the treatment after 12.3+/-5.1 days. Because no signs of inflammation were observed and since the epithelial defect improved, a new identical lens was applied and the medication continued unaltered. The surface of contaminated and non-contaminated BCLs were analyzed by scanning electron microscopy and SDS gel-electrophoresis. The scanning electron microscopic examination presented a coating of amorphous material with a wrinkled appearance and many corpuscular deposits. There was no indication of bacterial colonisation. The SDS gel-electrophoresis showed a small band at 65 kDa, probably albumin. CONCLUSION: These findings suggest that the combination of a therapeutic contact lens and serum eye drops can be successfully used in the treatment of persistent epithelial defects. Deposition of albumin may occur on the surface of the contact lenses, which, in the small group presented here, caused no unwanted effects.
PMID: 16544115 [PubMed - in process]
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Ocular surface restoration using non-surgical transplantation of tissue-cultured human amniotic epithelial cells.
Division of Cornea, External Disease and Refractive Surgery, Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas.
PURPOSE: To assess the effect of tissue-cultured human amniotic epithelial cells (AECs) in restoring the ocular surface, transplanted using a collagen shield seeded with AECs supported by a soft contact lens. DESIGN: Prospective interventional single-institutional case series with crossover controls. METHODS: Three eyes in three patients were identified with persistent corneal epithelial defects (PEDs) refractory to medical therapy. Two cases were secondary to neurotrophic keratopathy, while one case was attributable to longstanding alkali injury. AECs were isolated from serologically screened donor human placenta, seeded onto collagen corneal shields, and incubated in tissue culture medium for 7 days. These collagen shields were placed over the PED and supported by an overlying soft contact lens. The collagen shields dissolved by 72 hours, and the contact lenses were removed after this time. This cycle was repeated every week until healing was achieved. As a crossover control, collagen shields without AECs were placed in the same eye 1 week before placing collagen shields containing AECs. The PED was assessed by vital staining and slit-lamp color photography. RESULTS: The PEDs had a mean duration of 4 months and involved 20% to 37% of the corneal surface area, one case secondary to longstanding alkali injury and two cases attributable to neurotrophic keratopathy. No change in PED size was observed in those control eyes receiving collagen shields without AECs. Complete resolution of the PED was seen after two cycles of AEC-seeded collagen shield in one case, and four cycles in two cases, from 7 to 12 weeks following treatment in all patients. No loss of visual acuity was seen and clinical improvement was maintained in all cases, with a mean follow-up of 6.3 months. CONCLUSIONS: Nonsurgical transplantation of tissue-cultured AECs on a collagen shield provides a promising approach to restoring the ocular surface in cases of PED.
PMID: 16458684 [PubMed - indexed for MEDLINE]
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Amniotic membrane transplantation in refractory neurotrophic corneal ulcers: a randomized, controlled clinical trial.
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, India.
PURPOSE: This study was designed to compare and evaluate the efficacy of amniotic membrane transplantation with the conventional management (tarsorrhaphy and bandage contact lens) in eyes with refractory neurotrophic corneal ulcers. METHODS: Thirty eyes of 30 patients (14 females and 16 males) with neurotrophic corneal ulcers refractory to medical management were included and divided randomly into group 1 (n = 15), who received conventional management with a tarsorrhaphy (n = 11) or bandage contact lens (n = 4), and group 2 (n = 15), who underwent Amniotic Membrane Transplantation. The outcome parameters evaluated were epithelialization time, duration of healing of corneal ulcers, and improvement in best corrected visual acuity. RESULTS: The mean age in our study was 37 +/- 14.71 years. At the end of 3 months follow-up, 10 of 15 patients (66.67%) in group 1 showed complete epithelialization and subsequent healing and 11 of 15 patients (73.33%) in group 2 showed complete epithelialization and healing (P > 0.05). The median time for complete epithelialization was 21 days in both groups. Both groups showed an improvement in the best-corrected visual acuity. CONCLUSIONS: Both amniotic membrane transplantation and conventional management (tarsorrhaphy or bandage contact lens) are effective treatment modalities for refractory neurotrophic corneal ulcers.
PMID: 16015082 [PubMed - indexed for MEDLINE]
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Suspension made with amniotic membrane: clinical trial.
Department of Ophthalmology, Eye Bank, S. Maria della Scaletta Hospital, Imola (BO) - Italy.
PURPOSE: To investigate if a suspension made with amniotic membrane could have a beneficial effect on ocular surface diseases. METHODS: In the Imola branch of the Eye Bank of Emilia Romagna, the authors prepared a suspension containing homogenized amniotic membrane previously conserved at -80 degrees Celsius. Subsequently, the authors gave this preparation to 21 patients: 8 had undergone lamellar keratoplasty, 4 had undergone penetrating keratoplasty, 2 had undergone photorefractive keratectomy with a delay of epithelialization, 3 had neurotrophic corneal ulcers, 2 had corneal burning, 1 had torpid corneal ulcer, and 1 had Sjogren syndrome. Each patient had been treated with conventional therapy for at least, 4 months without any clinical improvement. In this sample of eyes the authors evaluated the transparency and integrity of epithelium before and after the therapy by means of a fluorescein staining test, examining the area of epithelial defect as well as the phlogistic situation and the symptoms referred by patients. Nine eyes from this group of patients were studied by impression cytology before and after 3 months of use of suspension. The follow-up was 5 months of once-weekly visits. RESULTS: In all patients, after 15 to 30 days the corneas became negative to fluorescein staining test and the epithelium seemed more complete and regular, there was an evident decrease of phlogistic situation in the conjunctiva, and an improvement of symptoms was referred by patients. The situation was stable during the whole follow-up. No side effects were noted. The impression cytology repeated 3 months after the treatment showed a significant corneal recovery of the cytologic situation with an important decrease of CK19+ cells on the corneal surface. CONCLUSIONS: This new therapy, which is less traumatic than an implant of amniotic membrane, is safe, and can be repeated for a long period, could help patients with corneal superficial defects.
PMID: 16001374 [PubMed - indexed for MEDLINE]
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Amniotic membrane transplantation and fibrin glue in the management of corneal ulcers and perforations: a review of 33 cases.
Department of Ophthalmology, University of Liege, Belgium.
PURPOSE: To evaluate the efficacy of amniotic membrane in corneal ulcers refractive to conventional treatment and amniotic membrane with fibrin glue in corneal perforations. METHODS: Amniotic membrane transplantation (AMT) was performed in 33 eyes from 32 patients for corneal ulcers refractive to conventional treatment. Fourteen ulcers were perforated and received fibrin glue and amniotic membrane. Ulcers were divided into 3 groups: neurotrophic or exposure, autoimmune, and other etiology. RESULTS: Overall success was observed in 80% (27/33 eyes) of the cases, with success rates of 87.5% (14/16 eyes), 70% (7/10 eyes), 85.7% (6/7 eyes) in groups 1, 2, and 3, respectively. The ulcers healed in a mean time of 3.6 +/- 1.6 weeks and the follow-up was 14.8 +/- 9.9 months. Failure was noted in 6 eyes with severe neurotrophic keratitis, Stevens-Johnson syndrome, ocular cicatricial pemphigoid, and Acanthamoeba keratitis. Grafts with fibrin sealant showed a success rate of 92.9 % (13/14 eyes) compared to 73.7% (14/19 eyes) for amniotic grafts alone. In patients with severe limbal damage, a success rate of only 20% (1/5) was observed. CONCLUSIONS: AMT is a viable option in the treatment of nonhealing corneal ulcers of various depth and etiologies. Perforations up to 3 mm can be safely managed by fibrin glue and AMT. These techniques lead to rapid reconstruction of the corneal surface and can give a good final functional result or allow keratoplasty to be done in more favorable conditions.
PMID: 15829790 [PubMed - indexed for MEDLINE]
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The effects of amniotic membrane on retinal pigment epithelial cell differentiation.
Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University, Tokyo, Japan.
PURPOSE: To examine the characteristics of retinal pigment epithelial (RPE) cells cultured on amniotic membrane (AM). The present study examined how AM modulates RPE cell differentiation. METHODS: Human RPE cells were cultured on the basement membrane side of dispase treated AM. After one week of cellular confluence, cultures were terminated, conditioned medium was collected, and total RNA was extracted. The expression pattern of several genes considered to participate in the function of differentiated RPE was evaluated. Ultrastructural changes were evaluated by transmission electron microscopy. RESULTS: Morphologically, RPE cells cultured on AM exhibited ultrastructural epithelial features such as microvilli of the apical membrane and intercellular junctions. Gene expression of RPE65, CRALBP, bestrophin, and tyrosinase related protein (TRP)-2 was upregulated in RPE cells cultured on AM compared to cells cultured on plastic. In addition, protein production of vascular endothelial growth factor, thrombospondin-1, and pigment epithelium derived factor was markedly increased in cells cultivated on AM. Gene expression of cathepsin D, brain derived neurotrophic factor, and basic fibroblast growth factor, however, did not differ between RPE cells cultured on plastic or AM. CONCLUSIONS: RPE cells cultured on AM demonstrated an epithelial phenotype morphologically and several growth factors important for maintaining retinal homeostasis were upregulated. AM might be a useful matrix substrate to retain the differentiated and epithelial phenotype of RPE for subretinal transplantation.
PMID: 15660020 [PubMed - indexed for MEDLINE]
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[Conservative and surgical treatment of neurotrophic keratopathy]
[Article in German]
Augenklinik mit Poliklinik, Universitat Erlangen-Nurnberg, Erlangen. berthold.seitz@augen.imed.uni-erlangen.de
Neurotrophic keratopathy is one of the most challenging conditions among the disorders of wound healing of the ocular surface. In addition to bilateral assessment of corneal sensitivity, tear status and lid function must be analyzed and treated by unpreserved artificial tears and adequate lid surgery. Further conservative treatment options include hyaluronic acid and dexpanthenol as well as autologous serum. Application of recombinant growth factors (especially NGF) represents an interesting perspective. Concerning surgical interventions, temporary or permanent occlusion of the lacrimal punctum may be accompanied by lateral tarsorrhaphy which is easy to perform, potentially reversible, and in most cases successful. Depending on the type of wound healing disorder amniotic membrane transplantation may be helpful either as basal membrane transplant (graft) or as a patch, or in combination (sandwich). A tectonic keratoplasty a chaud should typically be combined with a simultaneous amniotic membrane patch and/or a lateral tarsorrhaphy to avoid persistent epithelial defects.
PMID: 15622497 [PubMed - indexed for MEDLINE]
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[Neurotrophic keratitis. Problem child among corneal diseases]
[Article in German]
Augenklinik mit Poliklinik, Universitat Erlangen-Nurnberg, Erlangen.
PMID: 15616815 [PubMed - indexed for MEDLINE]
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- Erratum in:
- J Neurosci Res. 2005 Mar 1;79(5):725.
Human amnion mesenchyme cells express phenotypes of neuroglial progenitor cells.
Department of Regenerative Medicine, Toho University School of Medicine, Sagamihara, Kanagawa, Japan. sakuraga@sea.plala.or.jp
Previous studies from our laboratory showed that human amnion epithelial cells (AECs) have multiple functions, such as synthesis and release of catecholamines, acetylcholine, neurotrophic factors, activin, and noggin. In this study, we investigated the identity of neural progenitor cells in human amnion mesenchyme cells (AMCs), which lie immediately adjacent to the AECs. Cryostat sections revealed that vimentin expression was detected in the AMCs and CK19 in AECs. Vimentin-positive cells made up 97.5% of total cells tested in cultured AMCs. Interestingly, 3.6% of total AMCs expressed the phenotype CK19+/vimentin+, indicating coexpression of epithelial and mesenchyme cell markers. In culturing with bromodeoxyuridine (BrdU) for 24 hr, 66-82% of cells were found to be BrdU positive, suggesting that they have proliferating potency. By using RT-PCR, AMCs express mRNA of nestin and Musashi1. With a neural cell differentiating protocol, cell bodies extended long bipolar or complex multipolar processes. Nestin (87.7% of total cells tested) and Musashi1 (93.1%) were expressed in undifferentiated cells, and their positively stained cells increased in number slightly after induction. Undifferentiated cells were stained by anti-Tuj1 and NF-M, and their positively stained cells increased significantly in number after induction, to 72.8% and 46.0%, respectively. Meanwhile, glial fibrillary acidic protein-positive cells increased from 25.4% to 43.2% after induction. These studies demonstrate that AMCs have phenotypes of neuroglial progenitor cells and can be differentiated into neuroglial phenotypes by optimal differentiation protocol. Eventually, AMC-derived stem cells may be a favorable cell vehicle in regenerative medicine. Copyright 2004 Wiley-Liss, Inc.
PMID: 15378611 [PubMed - indexed for MEDLINE]
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Multilayer amniotic membrane transplantation in the treatment of corneal perforations.
Anterior Segment Unit, Department of Ophthalmology, Hospital de Conxo-Complejo Hospitalario Universitario de Santiago, Universidad de Santiago de Compostela, Spain. trares@usc.es
PURPOSE: To determine if multilayer amniotic membrane transplantation (AMT) is useful in the treatment of corneal perforations, and in particular to assess to what extent efficacy is affected by perforation size. METHODS: Fifteen patients (15 eyes) with corneal perforations of different sizes were divided into 3 groups: group A (microperforation, 6 eyes), group B (0.5-1.5 mm, 4 eyes), and group C (>1.5 mm, 5 eyes). The corneal perforation was caused by autoimmunity-related ulcer (3 eyes), neurotrophic ulcer (9 eyes), infectious keratitis (1 eye), or postkeratoplasty ulcer (2 eyes). Two layers of AM (for microperforations) or 3-4 layers (for the other groups) were trimmed to the size of the ulcer and sutured in place with interrupted 10-0 nylon sutures. In all cases, a bandage contact lens was then applied. RESULTS: Mean epithelialization time was 3.7 weeks (range 2-6). Mean time to recovery of corneal stroma thickness was 10.1 weeks (range 7-15). In all cases, ocular inflammation subsided within 2-5 weeks. The treatment was judged successful in 73% (11/15) of eyes. Three of the 4 unsuccessful treatments were of perforations 3 mm or more in diameter; of the 5 eyes with perforations of more than 1.5 mm in diameter, only 2 were treated successfully. CONCLUSIONS: These results suggest that multilayer AMT is effective for treating corneal perforations with diameter less than 1.5 mm. The technique may be a good alternative to penetrating keratoplasty, especially in acute cases in which graft rejection risk is high.
PMID: 15256996 [PubMed - indexed for MEDLINE]
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Implantation of human amniotic epithelial cells prevents the degeneration of nigral dopamine neurons in rats with 6-hydroxydopamine lesions.
Department of Neurological Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama 641-0012, Japan.
We recently found that human amniotic epithelial (HAE) cells secrete biologically active neurotrophins such as brain-derived neurotrophic factor and neurotrophin-3, both of which exhibit trophic activities on dopamine (DA) neurons. The present study explored whether implantation of HAE cells can be a possible means to deliver trophic factors into the brain to prevent the death of DA neurons in a rat model of Parkinson's disease. We first investigated the ability of HAE cells to produce factors capable of promoting DA cell survival in vitro, and then tested whether HAE cell grafts survive and prevent the death of nigral DA neurons in rats with 6-hydroxydopamine lesions. A treatment with conditioned medium derived from HAE cell cultures enhanced the survival of tyrosine hydroxylase (TH)-immunopositive DA cells in serum-free cultures. The conditioned medium also protected the morphological integrity of TH-positive neurons against toxic insult with 6-hydroxydopamine. HAE cells were grafted into the midbrain of immunosuppressed rats. The rats were then subjected to a unilateral nigrostriatal lesion induced by intrastriatal infusions of 6-hydroxydopamine. HAE cell transplants were found to survive without evidence for overgrowth 2 weeks postgrafting. The number of nigral DA cells, detected with either TH-immunohistochemistry or retrograde labelling with fluorogold, was significantly increased in rats given the grafts as compared to that in control animals without the grafts. The results indicate that HAE cells produce diffusible molecules that can enhance the survival of DA neurons. Although the factors that contribute to the currently observed effects remain to be fully determined, implantation of HAE cells could be a viable strategy to counteract the loss of DA neurons in Parkinson's disease.
PMID: 12865158 [PubMed - indexed for MEDLINE]
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Factors secreted by human amniotic epithelial cells promote the survival of rat retinal ganglion cells.
Department of Ophthalmology, Tokyo University School of Medicine, Tokyo 113-8655, Japan.
We evaluated whether factors secreted by human amniotic epithelial cells (HAECs) have the neuroprotective effect on rat retinal ganglion cells (RGCs) purified by immunopanning. After culture in B27 complete medium containing B27 supplement, brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF) and forskolin, the medium was changed to: (1). medium containing N2 supplement and forskolin (N2 basal medium); (2). medium conditioned by HAECs containing N2 supplement and forskolin (HAEC-CM); and (3). N2 basal medium containing several neurotrophic factors. HAEC-CM promoted the RGC survival compared to N2 basal medium. The effect of HAEC-CM was significantly higher than that of BDNF, neurotrophin-3 and CNTF. These results suggest that HAECs may produce unknown neuroprotective factors, suggesting its potential for the treatment of RGC degenerative diseases.
PMID: 12676329 [PubMed - indexed for MEDLINE]
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Role of human amniotic epithelial cell transplantation in spinal cord injury repair research.
Department of Anatomy, Dr. Arcot Lakshmanaswamy Mudaliar Postgraduate Institute of Basic Medical Sciences, Taramani Campus, University of Madras, 600 113, Chennai, India. venkatsankar@yahoo.com
Human amniotic epithelial cells (HAEC) possess certain properties similar to that of neural and glial cells. In the present work, the potential of HAEC as stem cells for spinal cord injury repair was tested. HAEC obtained from human placenta were labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethyllindocarbocyanine perchlorate (Dil) in the culture medium. These labeled cells were transplanted into the transection cavities in the spinal cord of bonnet monkeys. Results were analyzed after 15 and 60 days of post-transplantation. HAEC cells survived in the monkey spinal cord for up to the maximum period of observation in the present study, i.e. 60 days. HAEC graft was penetrated by the host axons. There was no glial scar at the transection lesion site. Some of the host spinal neurons and axons were labeled with Dil (used to label HAEC) whereas in lesion control group, there was no such host-neuron labeling. This may be either due to the prevention of death in the axotomized neuron's ensuing lesion or due to the neurotrophic effect exhibited by the transplanted HAEC. Further studies would be required to verify these speculations. Therefore from this pilot study it appears that HAEC survive in the transplanted environment, support the growth of host axons through them, prevent the formation of glial scar at the cut ends and may prevent death in axotomized cells or attract the growth of new collateral sprouting. The abovementioned properties, i.e. serving as a suitable milieu for the host axons to grow, preventing glial scar at the lesion site and rescuing axotomized neurons from death were previously reported in the case of neural transplantation studies. Thus it is speculated that HAEC may be having certain properties equal to the beneficial effects of neural tissue in repairing spinal cord injury. Apart from this speculation, there are two more reasons for why HAEC transplantation studies are warranted to understand the long-term effects of such transplantations. First, there was no evidence of immunological rejection probably due to the non-antigenic nature of the HAEC. Second, unlike neural tissue, procurement of HAEC does not involve many legal or ethical problems.
PMID: 12676132 [PubMed - indexed for MEDLINE]
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Expression of angiogenic and neurotrophic factors in the human amnion and choriodecidua.
Liggins Institute and the Division of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, New Zealand. k.marvin@auckland.ac.nz
OBJECTIVE: Our objective was to identify the novel or differential expression of growth or development associated genes in the human gestational membranes that might play roles in pregnancy or in term or preterm parturition. STUDY DESIGN: Complementary DNA arrays were probed with [alpha(33)P]dCTP-labeled-complementary DNA that was prepared from the RNA of reflected amnion and choriodecidua that represent term not-in-labor, term spontaneous labor, and preterm labor with and without chorioamnionitis (n = 4 per group). Differential expression (term not-in-labor vs term spontaneous labor or preterm labor with chorioamnionitis vs preterm labor without chorioamnionitis) was evaluated by Wilcoxon tests. RESULTS: All 16 amnion samples expressed angiogenic factors (endothelin-2 and -3, vascular endothelial growth factor, and vascular endothelial growth factor-B) and neurotrophic factors (ephrin-A2, ephrin receptors-A2, -B1, -B3, -B4, and -B5, neuropilin-2, p75/nerve growth factor receptor and semaphorin-F). In both amnion and choriodecidua, the expression of vascular endothelial growth factor and the angiopoietin receptor, Tie-2, were greater with term spontaneous labor than with term not-in-labor (P <.05); increased VEGF receptor-2 (flk-1) expression was observed in term spontaneous labor choriodecidua (P <.05) but not amnion. Ephrin-A1 expression increased with term spontaneous labor in both tissues (P <.05). Semaphorin-F expression decreased with preterm labor with chorioamnionitis in choriodecidua (P <.05), although the trend was not significant in amnion (P =.1). CONCLUSION: Neurotrophic and angiogenic factor genes are expressed in amnion and choriodecidual membranes. Several of the genes exhibit differential expression with labor at term or in association with infection preterm, which suggests roles in or associated with these processes.
PMID: 12237655 [PubMed - indexed for MEDLINE]
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Amniotic membrane transplantation for ocular surface reconstruction in neurotrophic corneal ulcera.
Department of Ophthalmology, University Hospital Sestre Milosrdnice, Zagreb, Croatia.
The purpose of this study is to analyze clinical experience about the effects of human amniotic membrane transplantation in eyes with neurotrophic ulcers. In 11 eyes the application of amniotic membrane was performed since January 1999 because of neurotrophic ulcers. The follow up period was longer than 12 months: 19.7+/-6.0 months. The average healing period after the surgery was 1.6+/-0.6 weeks. All corneas were fluorescein negative even 12 months after operation. Visual acuity after the transplantation was similar to the one before the surgery in 8 eyes. In 3 eyes the visual acuity after the surgery was better than before. Amniotic membrane transplantation can be considered an effective alternative for treating persistent epithelial defects such as neurotrophic ulcers. It has some advantages over corneal transplantation: a relatively simple procedure, no allograft rejection and it could be particularly beneficial in countries where cornea shortage is apparent.
PMID: 12137322 [PubMed - indexed for MEDLINE]
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Amniotic membrane grafts for nontraumatic corneal perforations, descemetoceles, and deep ulcers.
Department of Ophthalmology, Bascom Palmer Eye Institute, Miami, Florida, USA.
PURPOSE: To describe the clinical outcome of amniotic membrane transplantation (AMT) for nontraumatic corneal perforations, descemetoceles, and deep ulcers. DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: Thirty-four eyes of 33 consecutive patients operated on for nontraumatic corneal perforations or descemetoceles at four academic departments of ophthalmology. Associated autoimmune disorders included rheumatoid arthritis (n = 6), Stevens-Johnson syndrome (n = 3), ocular cicatricial pemphigoid (n = 2), systemic lupus erythematosus (n = 1), and one eye with Mooren's ulcer, as well as neurotrophic, or exposure keratopathy (n = 10), postinfectious nonhealing ulcers (n = 6), and postsurgery (n = 5). INTERVENTION: Three or four layers of amniotic membrane (AM) were applied over the ulcer bed and anchored with 10-0 nylon interrupted or running sutures. A large AM piece was used as a patch to cover the entire corneal surface. MAIN OUTCOME MEASURES: Formation of anterior chamber depth, epithelialization of the AM grafts, and stability of the corneal stromal thickness. RESULTS: The mean follow-up period was 8.1 +/- 5.7 (ranging from 2-23) months. A successful result was observed in 28 of 34 eyes (82.3%). Of the successful cases, 23 eyes needed one AMT procedure, whereas 5 eyes needed two procedures to achieve a successful result. In five eyes, a subsequent definitive surgical procedure such as penetrating keratoplasty or lid surgery was needed. Failure was observed in six eyes with rheumatoid arthritis, neurotrophic keratopathy, or graft melting. CONCLUSIONS: AMT is an effective method for managing nontraumatic corneal perforations and descemetoceles. It can serve as either a permanent therapy or as a temporizing measure until the inflammation has subsided and a definitive reconstructive procedure can be performed. This treatment option is also beneficial in those countries where corneal tissue availability is limited.
PMID: 11927426 [PubMed - indexed for MEDLINE]
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The role of NGF signaling in human limbal epithelium expanded by amniotic membrane culture.
Department of Ophthalmology, Bascom Palmer Eye Institute, Miami, Florida, USA.
PURPOSE: Amniotic membrane (AM) transplantation facilitates rapid epithelialization in severe neurotrophic corneal ulcers. To elucidate its action mechanism, we investigated the expression of ligands and receptors of the neurotrophin family by human limbal epithelial (HLE) cells expanded on AM cultures. METHODS: Expression of nerve growth factor (NGF); neurotrophins (NT)3 and NT4; brain-derived neurotrophic factor (BDNF); tyrosine kinase-transducing receptors TrkA, TrkB, and TrkC; and a pan-NT low-affinity receptor (p75(NTR)) was examined by immunostaining in the normal human corneolimbus, HLE grown on intact epithelially denuded AM, and stratified HLE, after subcutaneous implantation in NIH-bg-nu-xid BR mice. NGF protein level was assayed by an ELISA in extracts of intact and epithelially denuded AM. K252a, a specific inhibitor of TrkA autophosphorylation, was added to test whether it would inhibit HLE expansion on AM culture. RESULTS: Strong positive TrkA staining was confined to the basal epithelial cell layer of normal corneal and limbal epithelia, with the highest intensity noted in the limbus. TrkA staining was also strongly positive in the basal layer of HLE cells cultured on intact and epithelially denuded AM and in basal and some suprabasal layers of stratified HLE transplanted in nude mice. Positive staining of p75(NTR) was noted in the full-thickness of the corneal epithelium but was limited to the superficial layers of the limbus and in HLE cells cultured on intact and epithelially denuded AM, but was weak in HLE transplanted to nude mice. Weak staining of NT3 and TrkC was noted in the suprabasal layers of corneal and limbal epithelia but was negative in the stratified HLE in nude mice. Negative staining of NGF, NT4, BDNF, and TrkB was noted in all specimens tested. The NGF protein level was readily measured as 35.6 +/- 9.1 and 41 +/- 12.5 pg/mg protein in the homogenate of the intact and epithelially denuded AM, respectively (P = 0.0256). K252a significantly inhibited the HLE outgrowth on intact AM culture (P = 0.024). CONCLUSIONS: The strong expression of TrkA but not p75(NTR) in the limbal basal epithelial cells in vivo suggests that NGF signaling favors limbal epithelial stem cell survival. Such a phenotype is preserved in HLE cells on AM. Blocking NGF signaling significantly retarded HLE expansion on AM, supporting the notion that NGF is important in expansion of limbal epithelial progenitor cells. Furthermore, a high and therapeutic level of NGF was present in AM. Collectively, these findings indicate that denervated neurotrophic ulcers are associated with poor epithelial stem cell function at the limbus. Future studies are needed to determine whether AM transplantation to heal such ulcers may include the promotion of nerve regeneration and survival of epithelial progenitor cells.
PMID: 11923238 [PubMed - indexed for MEDLINE]
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Histologic findings after amniotic membrane graft in the human cornea.
Instituto de Microcirugia Ocular (IMO), Universitat Autonoma de Barcelona, Munner 10, 08022 Barcelona, Spain.
OBJECTIVE: To describe the histopathologic findings in the human cornea several months after a stromal amniotic membrane graft. To show the clinicopathologic correlation after the graft in two cases with different follow-up times. DESIGN: Two interventional case reports with clinicopathologic correlation. PARTICIPANTS: Two patients with neurotrophic corneal ulcer unresponsive to medical treatment (one with stromal vascularization and the other without stromal vascularization). INTERVENTION: Amniotic membrane graft was performed in both patients to treat the neurotrophic ulcer. Three and 7 months after amniotic membrane grafting, a penetrating keratoplasty was needed, and the removed corneas were analyzed. MAIN OUTCOME MEASURES: Clinical and histopathologic examinations, including routine histopathologic and immunohistochemical studies. RESULTS: Complete epithelialization was observed on histologic examination over the basement membrane of the amniotic membrane graft. The amniotic membrane was slowly reabsorbed in the cornea without stromal vascularization with no inflammatory reaction produced. In the cornea that had stromal vascularization the amniotic membrane was rapidly reabsorbed because of the presence of abundant inflammatory cells. Once reabsorbed, the amniotic membrane was replaced by new fibrotic stroma, that was different from that found in the rest of the cornea but that helped to maintain corneal thickness. CONCLUSIONS: The amniotic membrane graft allows for correct epithelialization in cases of neurotrophic corneal ulcer. Once the amniotic membrane is reabsorbed, it is replaced by a new fibrotic stroma, which can reduce corneal transparency. In corneas that have no stromal vascularization, the graft may remain in the stroma for many months, compromising corneal transparency during this period.
PMID: 11874752 [PubMed - indexed for MEDLINE]
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Multilayer vs. monolayer amniotic membrane transplantation for deep corneal ulcer treatment.
Lions Croatian Eye Bank, Department of Ophthalmology, General Hospital Sveti Duh, Zagreb, Croatia.
The purpose of the study was to evaluate the efficacy of multilayer amniotic transplantation (AMT) for reconstruction of corneal stroma and epithelium. Corneal ulcer (28) was a consequence of a previous infectious or neurotrophic keratitis. In the first group (17) ulcer was covered with monolayer AM, while in the other group (11) there were two or more layers of AM situated in the ulcer and the whole cornea was covered with AM sheet. Monolayer AMT was successful in 64% while the multilayer AMT success rate was 72%. AM gradually dissolved within 3-6 postoperative weeks. AM transplantation facilitates rapid healing of corneal epithelium, reduces inflammation and stimulates epithelial cell regrowth. In eyes with deep corneal ulcer multilayer technique proved to be better then monolayer procedure.
PMID: 11817009 [PubMed - indexed for MEDLINE]
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- Br J Ophthalmol. 2001 Dec;85(12):1400-1.
Single and multilayer amniotic membrane transplantation for persistent corneal epithelial defect with and without stromal thinning and perforation.
Department of Ophthalmology, Faculty of Medicine, Siriraj Hospital Mahidol University, Bangkok, Thailand. sippb@mahidol.ac.th
AIMS: To evaluate the efficacy of amniotic membrane transplantation (AMT) in persistent corneal epithelial defect with or without stromal thinning and corneal perforation. METHODS: 28 patients (28 eyes) with persistent corneal epithelial defect unresponsive to medical treatment were given preserved human amniotic membrane transplants. The patients were divided into three groups: group A, persistent corneal epithelial defect 10 eyes; group B, epithelial defect with stromal thinning 13 eyes; and group C, corneal perforation five eyes. AMT was performed using one layer in group A and multilayers in group B and C. The causes of persistent epithelial defect were neurotrophic keratopathy (24 eyes), limbal deficiency (six eyes), exposure keratopathy (four eyes), and Mooren's ulcer (one eye). RESULTS: Success was noted in 82.1% (23/28 eyes) in all groups, with 80% (8/10 eyes), 84.6% (11/13 eyes), and 80% (4/5 eyes) in groups A, B, and C respectively, with a mean follow up of 10.9 months (1-30 months). The mean epithelialisation time after AMT was 2.1 weeks. The healing times of groups B and C are also significantly shorter than group A (p=0.017 and 0.018, respectively). Corneal stromal thickness was significantly increased in all cases in groups B and C (p=0.006). Those with corneal perforation in group C were completely healed by multilayer AMT. There was no difference in the epithelialisation time between successful cases treated by a single operation (17 eyes) or repeated operation (six eyes). Vision improved in 18.9% (8/28 eyes) and worsened as a result of cataract formation in 2.3% (1/28 eyes). Failure was noted in 17.9% (5/28 eyes), because of corneal infection (two eyes), neurotrophic keratopathy with and without limbal deficiency (two eyes), and intractable corneal perforation (one eye). No patient developed major immediate postoperative complications or graft rejection. CONCLUSION: Amniotic membrane can successfully treat refractory corneal epithelial defect by promoting epithelial healing and thus prevent corneal perforation. It can be used as a treatment for corneal perforation by restoring corneal stromal thickness so that emergency penetrating keratoplasty can be avoided.
PMID: 11734521 [PubMed - indexed for MEDLINE]
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Amniotic membrane transplantation for severe neurotrophic corneal ulcers. Chen H-J, Pires RTF, Tseng SCG*(1). Br J Ophthalmol 2000;84:826-833.
PMID: 11341884 [PubMed - as supplied by publisher]
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Non-neuronal neurotransmitters and neurotrophic factors in amniotic epithelial cells: expression and function in humans and monkey.
Department of Inherited Metabolic Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan. sakuraga@ncnp.go.jp
Human amniotic epithelial cells (HAEC) are formed from epiblasts on the 8th day after fertilization. Because they lack major histocompatibility complex (MHC) antigen, human amniotic tissue transplantation has been used for allotranplantation to treat patients with lysosomal diseases. We have provided evidence that HAEC have multiple functions such as synthesis and release of acetylcholine (ACh) and catecholamine (CA) as well as expressing mRNA coding for dopamine receptors and dopamine (DA) transporter (DAT). On the other hand, we showed that monkey amniotic epithelial cells (MAEC) synthesize and release CA and posses DA receptors and DAT. Detection of muscarinic actylcholine receptors indicates the presence of an autocrine mechanism in HAEC. Recently, we found that HAEC have neurotrophic function in conditioned medium from HAEC, indicating the presence of a novel neurotrohpic factor that is synthesized and released from HAEC. The amniotic membrane may have a significant role in supplying neurotrophic factors as well as neurotransmitters to the amniotic fluid, suggesting an important function in the early stages of neural development of the embryo. This review will focus on the neuropharmacological aspects of HAEC and MAEC in relation to the physiology of amniotic membrane.
PMID: 11243569 [PubMed - indexed for MEDLINE]
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Neurotrophic function of conditioned medium from human amniotic epithelial cells.
Department of Inherited Metabolic Disease, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan.
Human amniotic epithelial cells (HAEC) may have pluripotent function because they are formed from the epiblast cells at the 8th day of fertilization. Previously, we reported that HAEC have the capacity to synthesize and release acetylcholine and catecholamine associated with the binding sites of catecholamine receptors. We show the neurotrophic function of a conditioned medium from HAEC using cultured cortical neurons of E18 rats. Extensive analyses with various techniques demonstrated that HAEC and immortalized HAEC synthesize and release brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and nerve growth factor (NGF). Other neurotrophic factors were not detected in a cultured medium of HAEC by enzyme immunoassay. Various neurotrophic factors or growth factors did not show neurotrophic effects on E18 rat neuron except for EGF. Because EGF was not detected in the conditioned medium of HAEC, these data indicate an unidentified neurotrophic factor presently that is synthesized and released from HAEC. The amniotic membrane may have a significant role in supplying neurotrophic factors to the amniotic fluid as well as neurotransmitters, suggesting an important function to the early stages of neural development in the embryo. Copyright 2000 Wiley-Liss, Inc.
PMID: 11070502 [PubMed - indexed for MEDLINE]
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Amniotic membrane transplantation for severe neurotrophic corneal ulcers.
Ocular Surface and Tear Center, Department of Ophthalmology, Bascom Palmer Eye Institute, Miami, Florida, USA.
AIMS: To evaluate whether amniotic membrane transplantation can be an effective alternative treatment for neurotrophic corneal ulcers. METHODS: Amniotic membrane transplantation was performed in 16 eyes of 15 patients with neurotrophic corneal ulcers and vision equal to or worse than 20/200. The neurotrophic state was developed following keratoplasty (four eyes), herpes zoster ophthalmicus (four eyes), diabetes mellitus (four eyes), radiation (two eyes), removal of acoustic neuroma with neuroparalysis (one eye), and herpes simplex keratitis (one eye). RESULTS: During a mean follow up period of 18.8 (SD 13.0) months, one to three layers of amniotic membrane with or without additional membrane as a patch were used for 17 procedures in 16 eyes for persistent neurotrophic corneal ulcers. All but four (76.4%) instances of amniotic membrane transplantation achieved rapid epithelialisation in 16.6 (9.0) days. Of the four eyes showing delayed healing, three eyes healed by tarsorrhaphy, and the remaining one eye with corneal perforation required penetrating keratoplasty and tarsorrhaphy. Two eyes gained vision better than 20/200. The healed corneal surface was accompanied by reduced inflammation. CONCLUSION: Amniotic membrane transplantation can be considered an effective alternative for treating severe neurotrophic corneal ulcers.
PMID: 10906085 [PubMed - indexed for MEDLINE]
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Application of the amniotic membrane in ocular surface pathology.
Department of Ophthalmology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
The amnion is a fine semi-transparent membrane that has been used in clinical practice to encourage epithelization in burns, in skin ulcers, or as a skin graft. Application in ocular surface disorders first took place in 1940. We carried out the membrane amniotic implantation on 11 patients with different pathologies: three cases of limbal stem cell deficiency (caustication with failure of prior keratoplasty, congenital aniridia and post-radiotherapy keratopathy), one case with persistent neurotrophic corneal ulcer after prior keratoplasty, four cases with epithelial defect of long evolution, one case of extensive Salzmann's degeneration of the cornea, and two cases after the resection of conjunctival tumour. The follow-up period varied between 2 and 6.5 months (mean = 4 months). Amniotic membrane was obtained by elective Caesarean, and it was preserved at -80 degrees C. In all transplanted patients the reabsorption of the amniotic membrane took place between the third and the fifth week. In the cases of resection of conjunctival tumour the epithelialization was completed between the first and the second post-operative week, with minimal residual scarring. In the other cases, with affliction of the corneal epithelium, the complete epithelialization, together with a marked reduction in the inflammatory response, occurred in all except 2 cases. In conclusion, the implantation of preserved human amniotic membrane can favour the recovery of a normal ocular surface in different pathologies, both in corneal and conjunctival lesions.
PMID: 10853789 [PubMed - indexed for MEDLINE]
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- Comment in:
- Ann Plast Surg. 2000 Nov;45(5):569.
Increased axonal regeneration through a biodegradable amnionic tube nerve conduit: effect of local delivery and incorporation of nerve growth factor/hyaluronic acid media.
Microsurgery Research Laboratory, Baylor College of Medicine, Houston, TX, USA.
The authors emphasize the possible pharmacological enhancement of axonal regeneration using a specific growth factor/ extracellular media incorporated in a biodegradable nonneural nerve conduit material. They investigated the early effects on nerve regeneration of continuous local delivery of nerve growth factor (NGF) and the local incorporation of hyaluronic acid (HA) inside a newly manufactured nerve conduit material from fresh human amnionic membrane. Human amnionic membrane contains important biochemical factors that play a major neurotrophic role in the nerve regeneration process. The process of manufacturing a nerve conduit from fresh human amnionic membrane is described. This nerve conduit system was used in rabbits to bridge a 25-mm nerve gap over 3 months. NGF was released locally, over 28 days, at the distal end of the tube via a system of slow release, and HA was incorporated inside the lumen of the tube at the time of surgery. NGF/HA treatment promoted axonal regeneration across the amnionic tube nerve conduit (8,962 +/- 383 myelinated axons) 45% better than the nontreated amnionic tube group (6,180 +/- 353 myelinated axons). The authors demonstrate that NGF/HA media enhances additional axonal regeneration in the amnionic tube nerve conduit. This result is secondary to the effect of the amnion promoting biochemical factors, in combination with the NGF/HA effect on facilitating early events in the nerve regeneration process.
PMID: 10651367 [PubMed - indexed for MEDLINE]
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Multilayer amniotic membrane transplantation for reconstruction of deep corneal ulcers.
Department of Ophthalmology, University of Heidelberg, Germany. Friedrich_Kruse@ukl.uni-heidelberg.de
PURPOSE: To evaluate the efficacy of multilayer amniotic membrane transplantation for reconstruction of corneal epithelium and stroma in the context of deep corneal ulcers. DESIGN: Prospective, noncomparative, interventional case series. PARTICIPANTS: Eleven consecutive patients with deep corneal ulcers refractory to conventional treatment; six patients had herpetic keratitis and five had other forms of neurotrophic keratitis. INTERVENTION: Multilayer amniotic membrane transplantation with kryopreserved human amniotic membrane. MAIN OUTCOME MEASURES: Integrity of corneal epithelium and stroma, opacification, and appearance of grafted membrane during 12 months follow-up. RESULTS: Amniotic membrane transplantation markedly reduced ocular inflammation in all patients. Epithelium healed above all corneal ulcers within 4 weeks and remained stable in 9 of 11 patients for 1 year. Two patients with recurrent epithelial defect suffered from severe neurotrophic keratitis. Following transplantation the amniotic membranes gradually dissolved over a period of 12 months, but stromal thickness remained stable. CONCLUSION: Amniotic membrane transplantation allows corneal surface reconstruction in patients with persistent epithelial defects. The multilayer technique is useful for treating deep corneal ulcers and even descemetoceles. Because the procedure results in stability of the ocular surface over a period of more than 12 months in most patients, it may be considered an alternative to conventional surgical techniques for ocular surface reconstruction.
PMID: 10442895 [PubMed - indexed for MEDLINE]
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Neurotrophic effects of amnion explants co-cultured with rat mesencephalon.
Department of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, NY 14642.
We investigated amnion-derived neurotrophic effects on embryonic day 14 rat mesencephalic (E14M) explants in co-culture. E14M explants showed extensive neurite outgrowth directed toward amnion tissue. Tyrosine hydroxylase immunocytochemistry, western immunoblot and [3H]dopamine uptake studies revealed significant neurotrophic effects on E14M dopaminergic neurons over 14 days in culture. Thus, amnion tissue appears to have potent neurotrophic effects for embryonic mesencephalic dopaminergic neurons in vitro.
PMID: 7907534 [PubMed - indexed for MEDLINE]
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