scholarly journals Transplantation of Amniotic Membrane to the Subretinal Space in Pigs

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Jens Folke Kiilgaard ◽  
Erik Scherfig ◽  
Jan Ulrik Prause ◽  
Morten la Cour
Keyword(s):  
Wound Healing ◽  
Amniotic Membrane ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Mechanical Damage ◽  
Choroidal Neovascularisation ◽  
Subretinal Space ◽  
Control Group ◽  
Surgical Removal ◽  
Complete Coverage

Purpose. To investigate the effect of transplanted amniotic membrane (AM) on subretinal wound healing.Methods. Nine Danish Landrace pigs had surgical removal of retinal pigment epithelium (RPE) and mechanical damage of Bruch’s membrane (BM) and served as a control group. 15 pigs additionally had AM transplanted to the subretinal space.Results. AM significantly reduces choroidal neovascularisation when complete coverage of the induced defect is obtained (7 pigs) (P<0.05). In cases where AM did not cover the rupture in BM choroidal tissue covered the transplanted membrane (8 pigs). AM is well tolerated in the subretinal space, causes only limited inflammation, and is covered with a monolayer of pigmented cells when in contact with the host RPE.Conclusions. AM modifies choroidal neovascularisation after BM damage and may serve as a basement membrane substitute for the RPE.

PENGGUNAAN SELAPUT AMNION SEGAR PADA INSISI LUKA OPERASI SEKSIO SESAREA

2019 ◽  
Vol 1 (2) ◽  
pp. 47-55
Author(s):  
Syahredi Syaiful Adnani ◽  
Hafni Bachtiar
Keyword(s):  
Wound Healing ◽  
Caesarean Section ◽  
Amniotic Membrane ◽  
Healing Time ◽  
Cost Of Care ◽  
Control Group ◽  
P Value ◽  
Control Groups ◽  
And Control ◽  
Wound Healing Time

In the last few decades, the incidence of caesarean section is increasing in the world, especially in Indonesia. One of the way to treat tissue scar is through biologic and synthetic dressing where nowadays, amnion has been used as biologic dressing frequently. This study was conducted to determine the effect of the use of fresh amniotic membrane on wound incision Caesarean section compared with Caesarean section incision wound covered using regular gauze bandages and fixated with plaster in RS. Dr. Reksodiwiryo Padang. The design of this study is an experimen-tal study with Post test design with control group design. Sampling was done using a formula consecutive sampling two different test samples obtained an average of 72 people for each group. The analysis used include univariate and bivariate analyzes. The average wound healing time the difference was statistically significant (p value <0.05) in the treatment and control groups. There was highly significant difference in the proportion of local infection on day 3 between the treatment and control groups (p value <0.05). There were very significant differences in the proportion of local allergic reactions at day 3, and 5 between the treatment and control group (p <0.05). There are significant differences in terms of the cost of care per day between treatment and control groups (p <0.05). From this study, the average wound healing time has a very significant difference.Keywords: Fresh Amniotic Membrane, Wound Cesarean Section, Wound Healing

scholarly journals The Role of Imaging in Planning Treatment for Central Serous Chorioretinopathy

2021 ◽  
Vol 14 (2) ◽  
pp. 105
Author(s):  
Stefano Da Pozzo ◽  
Pierluigi Iacono ◽  
Alessandro Arrigo ◽  
Maurizio Battaglia Parodi
Keyword(s):  
Central Serous Chorioretinopathy ◽  
Therapeutic Strategy ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Subretinal Fluid ◽  
Subretinal Space ◽  
Planning Treatment ◽  
Multiple Biomarkers ◽  
Effective Procedures

Central serous chorioretinopathy (CSC) is a controversial disease both in terms of clinical classification and choice of therapeutic strategy. Choroidal layers, retinal pigment epithelium (RPE), photoreceptors, and retina are involved to varying degrees. Beyond well-known symptoms raising the clinical suspect of CSC and slit-lamp fundus examination, multimodal imaging plays a key role in assessing the extent of chorioretinal structural involvement. Subretinal fluid (SRF) originating from the choroid leaks through one or multiple RPE defects and spreads into the subretinal space. Spontaneous fluid reabsorption is quite common, but in some eyes, resolution can be obtained only after treatment. Multiple therapeutic strategies are available, and extensive research identified the most effective procedures. Imaging has carved a significant role in guiding the choice of the most appropriate strategy for each single CSC eye. Multiple biomarkers have been identified, and all of them represent a diagnostic and prognostic reference point. This review aims to provide an updated and comprehensive analysis of the current scientific knowledge about the role of imaging in planning the treatment in eyes affected by CSC.

scholarly journals OCT imaging of rod mitochondrial respiration in vivo

2021 ◽  
pp. 153537022110137
Author(s):  
Bruce A Berkowitz ◽  
Haohua Qian
Keyword(s):  
Signaling Pathway ◽  
Mitochondrial Respiration ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
The Body ◽  
Subretinal Space ◽  
Outer Retina ◽  
Water Efflux ◽  
Resolution Imaging

There remains a need for high spatial resolution imaging indices of mitochondrial respiration in the outer retina that probe normal physiology and measure pathogenic and reversible conditions underlying loss of vision. Mitochondria are involved in a critical, but somewhat underappreciated, support system that maintains the health of the outer retina involving stimulus-evoked changes in subretinal space hydration. The subretinal space hydration light–dark response is important because it controls the distribution of vision-critical interphotoreceptor matrix components, including anti-oxidants, pro-survival factors, ions, and metabolites. The underlying signaling pathway controlling subretinal space water management has been worked out over the past 30 years and involves cGMP/mitochondria respiration/pH/RPE water efflux. This signaling pathway has also been shown to be modified by disease-generating conditions, such as hypoxia or oxidative stress. Here, we review recent advances in MRI and commercially available OCT technologies that can measure stimulus-evoked changes in subretinal space water content based on changes in the external limiting membrane-retinal pigment epithelium region. Each step within the above signaling pathway can also be interrogated with FDA-approved pharmaceuticals. A highlight of these studies is the demonstration of first-in-kind in vivo imaging of mitochondria respiration of any cell in the body. Future examinations of subretinal space hydration are expected to be useful for diagnosing threats to sight in aging and disease, and improving the success rate when translating treatments from bench-to-bedside.

Calcium gradients and light-evoked calcium changes outside rods in the intact cat retina

1994 ◽  
Vol 11 (4) ◽  
pp. 753-761 ◽  
Author(s):  
Ron P. Gallemore ◽  
Jian-Dong Li ◽  
Victor I. Govardovskii ◽  
Roy H. Steinberg
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Plexiform Layer ◽  
Rapid Onset ◽  
Subretinal Space ◽  
Inner Plexiform Layer ◽  
Rod Outer Segments ◽  
Volume Increase ◽  
Cat Retina ◽  
Dependent Sources

AbstractWe have studied light-evoked changes in extracellular Ca2+ concentration in the intact cat eye using ion-sensitive double-barreled microelectrodes. Two prominent changes in Ca2+ concentration were observed that differed in retinal location. There was a light-evoked increase in accompanied by brief ON and OFF transients, which was maximal in the inner plexiform layer and was not further studied. There was an unexpected sustained light-evoked decrease in of relatively rapid onset and offset, which was maximal in the distalmost region of the subretinal space (SRS). in the SRS was 1.0 mM higher than in the vitreous humor during dark adaptation and this transretinal gradient disappeared during rod-saturating illumination. After correcting for the light-evoked increase in the volume of the SRS, an increase in the total Ca2+ content of the SRS during illumination was revealed, which presumably represents the Ca2+ released by rods. To explain the light-evoked changes, we used the diffusion model described in the accompanying paper (Li et al., 1994b), with the addition of light-dependent sources of Ca2+ at the retina/retinal pigment epithelium (RPE) border and rod outer segments. We conclude that a drop in around photoreceptors, which persists during illumination and reduces a transretinal Ca2+ gradient, is the combined effect of the light-evoked SRS volume increase, Ca2+ release from photoreceptors, and an unidentified mechanism(s), which is presumably Ca2+ transport by the RPE. The relatively rapid onset and offset of the decrease remains unexplained. These steady-state shifts in should have significant effects on photoreceptor function, especially adaptation.

scholarly journals Association of Thiol–disulfide Homeostasis with Retinal Layer Thickness in Patients with Diabetes Mellitus

2021 ◽  
Author(s):  
Muhammet Cuneyt Bilginer ◽  
Abbas Ali Tam ◽  
Berna Evranos Ogmen ◽  
Bagdagul Yuksel Guler ◽  
Nagihan Ugurlu ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Diabetic Retinopathy ◽  
Layer Thickness ◽  
Disease Duration ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Control Group ◽  
Retinal Layer ◽  
Healthy Controls ◽  
Total Thiol

Abstract Background: This study aimed to investigate the relationship between early changes in retinal layer thickness and thiol–disulfide homeostasis in patients with type II diabetes mellitus (T2DM).Materials-Methods: There were 69 patients with T2DM (61 patients without retinopathy, 8 patients with retinopathy) and 21 healthy controls. In patients without retinopathy, 31 of the patients had a disease duration under 10 years, 30 of the patients had a disease duration over 10 years. Retinal layer thickness of the right eye was measured using Spectral Domain Optical Coherence Tomography. Results: Patients with T2DM and healthy controls had mean ages of 48.40 ± 8.25 years and 45.94 ± 7.32 years, respectively. The ganglion cell layer and retinal pigment epithelium thicknesses were significantly lesser in patients without diabetic retinopathy than those in the control group. In patients without diabetic retinopathy and with a disease duration of under 10 years, there was a negative correlation between the retinal nerve fiber layer thickness (µm) and disulphide/total thiol ratio, between the inner nuclear layer thickness (µm) and disulphide/native thiol ratio as well as disulphide/total thiol ratio (r= −0.376, p= 0.037; r= −0.356, p= 0.050; r= −0.380, p= 0.035, respectively) and positive correlation between the INL thickness (µm) and native thiol/total thiol ratio (r= 0.359, p= 0.047).Conclusion: Early changes in retinal layers in patients with DM were associated with thiol–disulfide homeostasis. Administration of therapeutic supplements may aid in the management of low thiol concentrations; this increases the importance of the study findings.

Degradation of extracellular ATP by the retinal pigment epithelium

2005 ◽  
Vol 289 (3) ◽  
pp. C617-C624 ◽  
Author(s):  
David Reigada ◽  
Wennan Lu ◽  
Xiulan Zhang ◽  
Constantin Friedman ◽  
Klara Pendrak ◽  
...  
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Adenosine Diphosphate ◽  
Cell Types ◽  
P2y Receptors ◽  
Extracellular Atp ◽  
Pcr Analysis ◽  
Subretinal Space ◽  
Rpe Cells ◽  
Mrs 2179

Stimulation of ATP or adenosine receptors causes important physiological changes in retinal pigment epithelial (RPE) cells that may influence their relationship to the adjacent photoreceptors. While RPE cells have been shown to release ATP, the regulation of extracellular ATP levels and the production of dephosphorylated purines is not clear. This study examined the degradation of ATP by RPE cells and the physiological effects of the adenosine diphosphate (ADP) that result. ATP was readily broken down by both cultured human ARPE-19 cells and the apical membrane of fresh bovine RPE cells. The compounds ARL67156 and βγ-mATP inhibited this degradation in both cell types. RT-PCR analysis of ARPE-19 cells found mRNA message for multiple extracellular degradative enzymes; ectonucleotide pyrophosphatase/phosphodiesterase eNPP1, eNPP2, and eNPP3; the ectoATPase ectonucleoside triphosphate diphosphohydrolase NTPDase2, NTPDase3, and some message for NTPDase1. Considerable levels of ADP bathed RPE cells, consistent with a role for NTPDase2. ADP and ATP increased levels of intracellular Ca2+. Both responses were inhibited by thapsigargin and P2Y1 receptor inhibitor MRS 2179. Message for both P2Y1 and P2Y12 receptors was detected in ARPE-19 cells. These results suggest that extracellular degradation of ATP in subretinal space can result in the production of ADP. This ADP can stimulate P2Y receptors and augment Ca2+ signaling in the RPE.

scholarly journals Human acellular amniotic membrane implantation for lower third nasal reconstruction: a promising therapy to promote wound healing

2018 ◽  
Vol 6 ◽  
Author(s):  
Si-Liang Xue ◽  
Kai Liu ◽  
Ornella Parolini ◽  
Yue Wang ◽  
Li Deng ◽  
...  
Keyword(s):  
Wound Healing ◽  
Amniotic Membrane ◽  
Skin Lesions ◽  
Control Group ◽  
Nasal Reconstruction ◽  
Nasal Tissue ◽  
Alternative Approach ◽  
The Face ◽  
Duration Of Operation ◽  
Reconstructive Techniques

Abstract Background The lower third of the nose is one of the most important cosmetic units of the face, and its reconstructive techniques remain a big challenge. As an alternative approach to repair or regenerate the nasal tissue, the biomaterial-based strategy has been extensively investigated. The aim of this study is to determine the safety and efficacy of human acellular amniotic membrane (HAAM) to repair the full-thickness defects in the lower third of the nose in humans. Methods In this study, 180 patients who underwent excision of skin lesions of the lower third of the nose from 2012 to 2016 were included; of the patients, 92 received HAAM and Vaseline gauze treatments, and the other 88 patients received Vaseline gauze treatment only. The haemostasis time and the duration of operation were recorded during surgery; after surgery, the time to pain disappearance, scab formation and wound healing, and the wound healing rate were measured. Results Immediately after the HAAM implantation, a reduction of the haemostasis time and an accelerated disappearance of pain were observed. Compared with the control group, the formation and detachment of scab in patients who received the HAAM implantation were notably accelerated, postoperatively. When the diameter of the lesion exceeded 5 mm, the HAAM implantation was found to enhance the wound healing, although this enhancement was not seen when the diameter was less than 5 mm. Additionally, the HAAM implantation significantly reduced bleeding, wound infection and scar formation, postoperatively. Conclusions HAAM-assisted healing is a promising therapy for lower third nasal reconstruction leading to rapid wound healing and fewer complications and thus has considerable potential for extensive clinical application in repairing skin wounds. Trial registration ChiCTR1800017618, retrospectively registered on July 08, 2018.

Biological effects of amniotic membrane on diabetic foot wounds: a systematic review

2018 ◽  
Vol 27 (Sup2) ◽  
pp. S19-S25 ◽  
Author(s):  
André Oliveira Paggiaro ◽  
Andriws Garcia Menezes ◽  
Alexandra Donizetti Ferrassi ◽  
Viviane Fernandes De Carvalho ◽  
Rolf Gemperli
Keyword(s):  
Systematic Review ◽  
Wound Healing ◽  
Amniotic Membrane ◽  
Diabetic Foot ◽  
Biological Effects ◽  
Meta Analysis ◽  
Healing Process ◽  
Intervention Group ◽  
Risk Of Bias ◽  
Control Group

Objective: The amniotic membrane has biological properties that are beneficial to the wound healing process of diabetic foot ulcers (DFU). Our aim is to analyse the scientific evidence found in literature on the use of the amniotic membrane to stimulate DFU healing. Method: A systematic review of amniotic membrane's influence was undertaken, using the search terms ‘placenta’ ‘diabetic foot’ ‘amnion’ and biological dressing’, assessing the outcomes ‘wound healing’ and ‘wound healing time’, in DFU. Following the inclusion and exclusion criteria, randomised controlled trials (RCT) were identified, and the risk of bias was analysed according to the Cochrane risk of bias tool. We conducted a meta-analysis of the two outcomes to evaluate the level of evidence. Results: We identified six clinical trials, with a total of 331 patients. The most common risks of bias in the studies were selection, attrition, and detection biases. From the meta-analysis, the difference of the intervention group (amnion) in relation to the control group was statistically significant. We found that wound healing in the group treated with amniotic membrane occurs 2.32 times more often and is 32 days faster in comparison with the group that used conventional dressings. Conclusion: There is statistical evidence to support the effectiveness of amniotic membrane in comparison with other conventional dressings. In addition, there is a clear tendency for the use of amniotic membrane treatment to result in a larger number of DFUs healing at a quicker rate.

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