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Amniotic Membrane (amniotic + membrane)
Terms modified by Amniotic Membrane Selected AbstractsFabrication of Myomucosal Flap Using Tissue-engineered Bioartificial Mucosa Constructed With Oral Keratinocytes Cultured on Amniotic MembraneARTIFICIAL ORGANS, Issue 6 2006Kang-Min Ahn Abstract:, The purpose of this study was to fabricate bioartificial mucosa using cultured oral keratinocytes (OKCs) on an amniotic membrane (AM), and to evaluate the possibility of developing a prelaminated myomucosal flap using the fabricated bioartificial mucosa and local muscle flap. Buccal mucosa was harvested from male New Zealand rabbits (n = 40, 2.5,3.0 kg) and primary cultivation was performed. The cultured OKCs were seeded on the AM and a submerged culture was performed. Prelamination of the bioartificial mucosa was performed on the latissimus dorsi (LD) muscle of rabbits. Survival rate, layer of OKCs, and Cinamon's score (CS) based on macroscopic and microscopic examinations were evaluated 7, 10, 14, and 21 days after prelamination (n = 10 per day). The OKCs cultured on AM showed multiple layers (3.85 ± 1.32) and cells were tightly adhered with desmosomes. Basal layer cells adhered to the AM with hemidesmosomes. In addition, the AM played an excellent role as a substrate for the OKCs and simplified handling during prelamination. A myomucosal flap with OKCs cultured on AM was fabricated within 2 weeks (CS: 11.05 ± 2.63). The basement component of laminin was observed 2 weeks after prelamination and showed enough strength to adhere to the underlying fascia. A myomucosal flap was successfully developed using prelamination of bioartificial mucosa on the LD muscle between 10 and 14 days. [source] Donor age and gestational age influence on growth factor levels in human amniotic membraneACTA OPHTHALMOLOGICA, Issue 6 2010Maria J. López-Valladares Acta Ophthalmol. 2010: 88: e211,e216 Abstract. Purpose:, Amniotic membrane (AM) is used as a biomaterial for reconstruction in ocular surface surgery. This study investigated the influence of interdonor variations and processing and preservation procedures applied to the AM on growth factors and protein levels. Methods:, Samples of human AM from thirteen donors were analysed. Collected donor data were age, parity and gestational age. Total protein amount was measured in extracts of intact AM nonpreserved, lyophilized and cryopreserved, at ,80°C and in liquid nitrogen. An enzyme-linked immunosorbent assay (ELISA) was used to assay growth factors protein levels for epidermal growth factor, basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), keratinocyte growth factor (KGF), transforming growth factor beta1 (TFG-,1) and nerve growth factor (NGF). Univariate and multivariate statistical analyses were used to study the influence of the preservation method applied and interdonor variations on growth factors levels. Results:, We detected important variations in growth factors and protein concentrations between samples from different donors. Total protein amount, bFGF, HGF, KGF and TGF-,1 showed lower levels in samples from donors with higher gestational ages and donor ages, for all groups. Conclusion:, The variability in the biochemical composition of AM from different donors is considerable, and it is related with donor factors as donor age and gestational age. As AM biochemical composition has a role in its therapeutic effects, these variations could affect the clinical results of amniotic membrane transplantation and must be taken into account in donor selection processes. [source] Amniotic membrane grafting in the surgical management of primary pterygiumCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 5 2004Rohan W Essex FRANZCO Abstract Background:,To evaluate the efficacy of amniotic membrane transplantation in primary pterygium surgery. Methods:,Patients presenting to the outpatient clinic of the Royal Victorian Eye and Ear Hospital with primary pterygium requiring surgical management were included in this study. The pterygia were excised to bare sclera and the conjunctival defects were closed with amniotic membrane grafts. The primary outcome was pterygium recurrence. Results:,Twenty-eight pterygia of 26 patients were included. Twenty-three patients (88%, 25 eyes) completed 12 months follow up. By 12 months postoperatively 16 of these eyes (64%) had developed corneal recurrence and a further two had developed a limbal recurrence (9%). Five required repeat surgery during the 12 month follow-up period. No association was found between pterygium recurrence and pterygium size (P = 0.33), amniotic membrane graft dimension (P = 0.12), patient age (P = 0.53) or patient sex (P = 0.63). Conclusion:,Amniotic membrane grafting for primary pterygium was associated with an unacceptably high recurrence rate in this population. [source] A decreased positivity for CD90 on human mesenchymal stromal cells (MSCs) is associated with a loss of immunosuppressive activity by MSCs,CYTOMETRY, Issue 3 2009Diana Campioni Abstract Biologic and clinical interest in human mesenchymal stromal cells (hMSC) has risen over the last years, mainly due to their immunosuppressive properties. In this study, we investigated the basis of immunomodulant possible variability using hMSC from different sources (amniotic membrane, chorion, and bone marrow from either healthy subjects or patients with hematological malignancies, HM) and having discordant positivity for several immunological markers. The CD90+ hMSC reduced lymphoproliferative response in phytohemagglutinin (PHA) activated peripheral blood mononuclear cells (PBMC) via sHLA-G and IL-10 up-modulation. On the contrary, hMSC showing a significantly lower expression for CD90 antigen, elicited a lymphoproliferative allogeneic response in PHA/PBMCs without any increase in soluble HLA-G and IL-10 levels. These data seems to suggest that CD90 molecule may be considered a novel predictive marker for hMSC inhibitory ability, and might cooperate with HLA-G molecule in regulating suppressive versus stimulatory properties of hMSC. These results may have clinical implication in either transplantation or in regenerative medicine fields. © 2008 Clinical Cytometry Society [source] Fabrication of Myomucosal Flap Using Tissue-engineered Bioartificial Mucosa Constructed With Oral Keratinocytes Cultured on Amniotic MembraneARTIFICIAL ORGANS, Issue 6 2006Kang-Min Ahn Abstract:, The purpose of this study was to fabricate bioartificial mucosa using cultured oral keratinocytes (OKCs) on an amniotic membrane (AM), and to evaluate the possibility of developing a prelaminated myomucosal flap using the fabricated bioartificial mucosa and local muscle flap. Buccal mucosa was harvested from male New Zealand rabbits (n = 40, 2.5,3.0 kg) and primary cultivation was performed. The cultured OKCs were seeded on the AM and a submerged culture was performed. Prelamination of the bioartificial mucosa was performed on the latissimus dorsi (LD) muscle of rabbits. Survival rate, layer of OKCs, and Cinamon's score (CS) based on macroscopic and microscopic examinations were evaluated 7, 10, 14, and 21 days after prelamination (n = 10 per day). The OKCs cultured on AM showed multiple layers (3.85 ± 1.32) and cells were tightly adhered with desmosomes. Basal layer cells adhered to the AM with hemidesmosomes. In addition, the AM played an excellent role as a substrate for the OKCs and simplified handling during prelamination. A myomucosal flap with OKCs cultured on AM was fabricated within 2 weeks (CS: 11.05 ± 2.63). The basement component of laminin was observed 2 weeks after prelamination and showed enough strength to adhere to the underlying fascia. A myomucosal flap was successfully developed using prelamination of bioartificial mucosa on the LD muscle between 10 and 14 days. [source] The quality and size of yolk sac in early pregnancy lossAUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 5 2006Fu-Nan CHO Abstract Background:, Accurate differentiation between normal pregnancy and pregnancy loss in early gestation remains a clinical challenge. Aims:, To determine whether ultrasound findings of yolk sac size and morphology are valuable in relation to pregnancy loss at six to ten weeks gestation. Methods:, Transvaginal ultrasonography was performed in 111 normal singleton pregnancies, 25 anembryonic gestations, and 18 missed abortions. Mean diameters of gestational sac and yolk sac were measured. The relationship between yolk sacs and gestational sacs in normal pregnancies was depicted. The yolk sacs ultrasound findings in cases of pregnancy loss were recorded. Results:, In normal pregnancies with embryonic heartbeats, a deformed or an absent yolk sac was never detected. Sequential appearance of yolk sac, embryonic heartbeats and amniotic membrane was essential for normal pregnancy. The largest yolk sac in viable pregnancies was 8.1 mm. Findings in anembryonic gestations included an absent yolk sac, an irregular-shaped yolk sac and a relatively large yolk sac (> 95% upper confidence limits, in 11 cases). In cases of missed abortion with prior existing embryonic heartbeats, abnormal findings included a relatively large, a progressively regressing, a relatively small, and a deformed yolk sac (an irregular-shaped yolk sac, an echogenic spot, or a band). Conclusion:, A very large yolk sac may exist in normal pregnancy. When embryonic heartbeats exist, the poor quality and early regression of a yolk sac are more specific than the large size of a yolk sac in predicting pregnancy loss. When an embryo is undetectable, a relatively large yolk sac, even of normal shape, may be an indicator of miscarriage. [source] Human immature dental pulp stem cells share key characteristic features with limbal stem cellsCELL PROLIFERATION, Issue 5 2009B. G. Monteiro Objectives:, Limbal stem cells (LSC) are self-renewing, highly proliferative cells in vitro, which express a set of specific markers and in vivo have the capacity to reconstruct the entire corneal epithelium in cases of ocular surface injury. Currently, LSC transplantation is a commonly used procedure in patients with either uni- or bilateral total limbal stem cells deficiency (TLSCD). Although LSC transplantation holds great promise for patients, several problems need to be overcome. In order to find an alternative source of cells that can partially substitute LSC in cornea epithelium reconstruction, we aimed at investigating whether human immature dental pulp stem cells (hIDPSC) would present similar key characteristics as LSC and whether they could be used for corneal surface reconstruction in a rabbit TLSCD model. Materials:, We used hIDPSC, which co-express mesenchymal and embryonic stem cell markers and present the capacity to differentiate into derivative cells of the three germinal layers. TLSCD was induced by chemical burn in one eye of rabbits. After 30 days, the opaque tissue formed was removed by superficial keratectomy. Experimental group received undifferentiated hIDPSC, while control group only received amniotic membrane (AM). Both groups were sacrificed after 3 months. Results and conclusions:, We have demonstrated, using immunohistochemistry and reverse transcription,polymerase chain reaction, that hIDPSCs express markers in common with LSC, such as ABCG2, integrin ,1, vimentin, p63, connexin 43 and cytokeratins 3/12. They were also capable of reconstructing the eye surface after induction of unilateral TLSCD in rabbits, as shown by morphological and immunohistochemical analysis using human-specific antibodies against limbal and corneal epithelium. Our data suggest that hIDPSCs share similar characteristics with LSC and might be used as a potential alternative source of cells for corneal reconstruction. [source] Donor age and gestational age influence on growth factor levels in human amniotic membraneACTA OPHTHALMOLOGICA, Issue 6 2010Maria J. López-Valladares Acta Ophthalmol. 2010: 88: e211,e216 Abstract. Purpose:, Amniotic membrane (AM) is used as a biomaterial for reconstruction in ocular surface surgery. This study investigated the influence of interdonor variations and processing and preservation procedures applied to the AM on growth factors and protein levels. Methods:, Samples of human AM from thirteen donors were analysed. Collected donor data were age, parity and gestational age. Total protein amount was measured in extracts of intact AM nonpreserved, lyophilized and cryopreserved, at ,80°C and in liquid nitrogen. An enzyme-linked immunosorbent assay (ELISA) was used to assay growth factors protein levels for epidermal growth factor, basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), keratinocyte growth factor (KGF), transforming growth factor beta1 (TFG-,1) and nerve growth factor (NGF). Univariate and multivariate statistical analyses were used to study the influence of the preservation method applied and interdonor variations on growth factors levels. Results:, We detected important variations in growth factors and protein concentrations between samples from different donors. Total protein amount, bFGF, HGF, KGF and TGF-,1 showed lower levels in samples from donors with higher gestational ages and donor ages, for all groups. Conclusion:, The variability in the biochemical composition of AM from different donors is considerable, and it is related with donor factors as donor age and gestational age. As AM biochemical composition has a role in its therapeutic effects, these variations could affect the clinical results of amniotic membrane transplantation and must be taken into account in donor selection processes. [source] 3235: Application of autologous cultivated corneal epithelium for restoring of corneal surfaceACTA OPHTHALMOLOGICA, Issue 2010D DOBROWOLSKI Purpose To present results of transplantations of cultured corneal epithelium in limbal stem cell insufficiency. Methods 26 patients were donors of limbal epithelium for corneal epithelial culture. Patients suffered from limbal deficiency in one eye after chemical or thermal burn. Limbal cells from 2 mm2 biopsy were seeded on amniotic membrane. Cultures were carried in standard conditions in supplememted DMEM in presence of 3T3 fibroblasts. After superficial keratectomy amniotic carries with epithelial cells were transplanted on denuded corneas. Stabilisation of corneal surface was evaluated. Results 3 months after surgery 61,5% of eyes showed stabile epithelium with corneal slight haze caused by the amnion. In 50,0% of eyes there was no recurrent conjuntival neovascularisation. 38,4% of eyes remained cloudy due to stromal revascularization. In 4 eyes total conjuctival pannus developed again. Visual acuity ranged from counting fingers to 0,5. Conclusion Grafting of cultured epithelium is a promising method in treatment of limbal stem cell insufficiency in burns. [source] Clinical decision paths in KPro SurgeryACTA OPHTHALMOLOGICA, Issue 2009G GRABNER Purpose To analyse the currently available methods for treating very severe anterior segment disease, such as stem cell transplantation with amniotic membrane transplantation, lamellar and penetrating keratoplasty techniques, and the different Kpro´s currently available, in regard to the initial clinical findings, the potential complications encountered and the surgical requirements needed for the different techniques. Factors considered are: uni- or bilaterality, limbal stem cell status, dry eye status and availability of healthy teeth. Methods A systematic analysis of surgical options available for different stages of a variety of anterior segment diseases and currently published results of VA and complications Results With a systematic approach it becomes clear that some popular reconstructive surgical techniques should be avoided in cases where a very low chance of success is to be expected (e.g. amniotic membrane and stem cell transplantation and /or PKP in very dry eyes ,> these would have to be treated with OOKP). Conclusion Following a simple the clinical decision path the anterior segment surgeon will be presented with standardized guidelines for treating those patients where conventional surgical procedures have to be avoided and replaced by rather rarely performed KPro techniques. [source] Effects of lyophilization on human amniotic membraneACTA OPHTHALMOLOGICA, Issue 4 2009M. Teresa Rodríguez-Ares Abstract. Purpose:, This study aimed to evaluate the effects of lyophilization and cryopreservation on human amniotic membrane (HAM) in terms of histological characteristics and growth factor levels. Methods:, Non-preserved, lyophilized and cryopreserved HAM samples from 13 placentas were investigated. The morphological characteristics of HAM were evaluated using light and electron microscopy. Immunohistochemical methods were also applied to assess the distribution of collagen IV in the basement membrane. Total protein amounts were measured in extracts of intact amniotic membrane from non-preserved, lyophilized and cryopreserved samples. An enzyme-linked immunosorbent assay (ELISA) was used to assay growth factor protein levels for epidermal growth factor, fibroblast growth factor basic, hepatocyte growth factor, keratinocyte growth factor, transforming growth factor-,1 and nerve growth factor. Results:, Histological examination of lyophilized and cryopreserved human amniotic membrane showed similar results. Immunohistochemistry showed presence of collagen IV throughout the basement membrane, both in cryopreserved and lyophilized samples. Total protein amount was higher in cryopreserved samples, without statistical significance. Growth factors ELISA did not show statistically significant differences except for fibroblast growth factor basic, with higher levels in cryopreserved amniotic membrane. Conclusions:, Lyophilization maintains the histological structure of HAM, but seems to cause greater reductions in total protein amount and growth factor concentration than cryopreservation. [source] 2333: Cultivation of limbal stem cells-derived corneal epithelium on different biologic materials for clinical transplantationACTA OPHTHALMOLOGICA, Issue 2010G PETROVSKI Purpose To develop simple, reproducible, animal-materials free method for cultivating limbal stem-cells and differentiating them into corneal epithelium on different human biologic materials for clinical transplantation. Methods The limbal tissues (2x2mm) were harvested from cadavers not more than 8 hours after death and proliferated in vitro on cell culture tissue plates, human amniotic membranes (HAM) or human lens capsules in medium containing human AB serum. Cell viability was tested using the MTT assay and annexin-FITC/Propidium Iodide positivity methods. Molecular gene and immunofluorescent marker studies for stemness, proliferation and differentiation were used for the analysis. Results Over a period of one year, 50 limbal tissue explants were cultivated. Emergence of cells at one edge of the explants occurred within 24 hours from culturing and formed monolayer within 14 days. Although the speed of cell growth varied among donors and types of media for growth, inadequate growth at two weeks was never recorded. The viability of the cells at 7 and 14 days of cultivation was higher than 96% except in case of HAM use where viability was below 80%. The growing cells were characterized for their positivity for stemness (P63, ABCG2), proliferation (ki67) and epithelial cell markers CK 3, 8, 12, 14, 18 and 19. Conclusion We demonstrate a simple, animal-materials free technique for generating corneal epithelium from cadavers or alternatively from autologous donors for viable cell growth on different biologic materials for transplantation. The growth of corneal epithelium on lens capsules proved to be superior compared to the other cultivation techiques. [source] | |||||||||||||