Search

Amaç: Koroner arter cerrahisinde greft açık kalma süresi endotel fonksiyonuna bağlıdır. Nitrik Oksitin (NO) endotel fonksiyonuna yararlı etkisi bilinmektedir. Greftlerdeki Nitrik Oksit düzeyi ve Losartan’ın Nitrik Oksit üzerine etkisi invitro olarak araştırılmıştır. Yöntem: Çalışma 13 hasta da 78 örnek ile yapıldı. İnternaltorasik arter, radial arter ve safenvengreft örnekleri “Kontrol Grubu” ve “Losartan Grubu” olmak üzere ikiye ayrıldı. Losartan grubu örnekleri 1 x 10-5molar Losantanlı Troyde’s solüsyonu çözeltisi içinde inkübe edildi. Nitrik Oksit, Griess yöntemi kullanılarak ölçüldü. İstatistiksel değerlendirme. Kruskal Wallis Oneway ANOVA, İndependentsample T ile Tukey ve Bonferroni testleri kullanılarak yapıldı. Bulgular: Kontrol grubu bazal Nitrik Oksit değeri, internaltorasik arter greftinde anlamlı olarak yüksek bulunmuştur (p

To summarize the recent advances of clinical and preclinical studies for corneal endothelial tissue bioengineering. The challenges facing the generation of a clinical applicable corneal endothelial graft can be broadly classified into cell source selection, culture medium optimization, scaffold establishment, and the following three- and four-dimensional (4D) corneal construction. Based on the current advances in primary human corneal endothelial cell (HCEC) culture and good manufacturing practice (GMP)–compliant medium development, the first clinical trial of bioengineered HCEC injection therapy has been conducted with encouraging results. Other significant findings include the in vivo experiments of the stem cell–derived HCEC, the development of serum-, xeno-, and additive-free media, and the construction of 4D scaffold. It can be anticipated that tissue engineering–based therapy toward corneal endothelial diseases will replace the current keratoplasty method as a promising treatment option in the near future.

Although metallic stents improved the safety and efficacy of percutaneous coronary intervention (PCI), even the latest generation of drug-eluting stents (DES) is still limited by several factors. The limitations of DES are mainly related to the permanent metallic caging in vessel, chronic inflammatory response to the polymer and adverse effects of antiproliferative drug on endothelial tissue, leading to impaired physiological vasomotor response and late stent-related adverse events such as stent thrombosis and neoatherosclerosis. Bioresorbable vascular scaffold (Absorb BVS; Abbott Vascular) was designed to overcome these drawbacks of DES by disappearing from the vessel wall. Absorb BVS, however, was withdrawn from the world market because of increased incidence of scaffold thrombosis compared with DES. Importantly, only very limited long-term post-BVS implantation data are available, especially with regard to neoatherosclerosis, which can lead to very late adverse events even after resorption of the scaffold. Therefore, the goal of this review was to highlight the mid to long term clinical outcomes published to date, and to describe the features of the intimal healing process and neoatherosclerosis in the 5 years following Absorb BVS implantation, mainly based on our previous study. This may provide important information on the pathophysiology of the scaffolded vessel for clinicians, and promote identification of future bioresorbable materials for PCI that will minimize the stimulus for neoatherosclerosis.

The treatment of corneal endothelial dysfunction has experienced a revolutionary change in the past decades with the emergence of endothelial keratoplasty techniques: descemet stripping automated endothelial keratoplasty (DSAEK) and descemet membrane endothelial keratoplasty (DMEK). Recently, new treatments such as cultivated endothelial cell therapy, Rho-kinase inhibitors (ROCK inhibitors), bioengineered grafts, and gene therapy have been described. ,ese techniques represent new lines of treatment for endothelial dysfunction. ,eir advantages are to help address the shortage of quality endothelial tissue, decrease the complications associated with tissue rejection, and reduce the burden of postoperative care following transplantation. Although further randomized clinical trials are required to validate these findings and prove the long-term efficacy of the treatments, the positive outcomes in preliminary clinical studies are a stepping stone to a promising future. Our aim is to review the latest available alternatives and advancements to endothelial corneal transplant.

Submitted by Celio Junior da Costa Fernandes (celio.fernandes@unesp.br) on 2021-08-09T18:20:16Z No. of bitstreams: 1 Tese_Celio_30_March_2021.pdf: 204900028 bytes, checksum: 877d007d43b3628fe94ab22133db75a0 (MD5) Approved for entry into archive by Tais de Almeida (tais.almeida@unesp.br) on 2021-08-09T18:54:29Z (GMT) No. of bitstreams: 1 fernandes_cjc_dr_bot.pdf: 204900028 bytes, checksum: 877d007d43b3628fe94ab22133db75a0 (MD5) Made available in DSpace on 2021-08-09T18:54:29Z (GMT). No. of bitstreams: 1 fernandes_cjc_dr_bot.pdf: 204900028 bytes, checksum: 877d007d43b3628fe94ab22133db75a0 (MD5) Previous issue date: 2021-04-08 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Compreender os mecanismos envolvidos na manutenção e homeostase óssea requer elucidar o comportamento de células em seu microambiente. O objetivo deste estudo foi investigar como células ósseas (MC3t3-E1, HOEL) ou mesenquimais são moduladas através da sinalização parácrina desencadeada por fibroblastos (3t3-NIH), células endoteliais de veias (HUVEC) e de aorta (HCAEC), além de células de músculo liso (AoSMC/VSMC). Para avaliar essa capacidade de modulação de células ósseas, fibroblastos, células endoteliais e de musculatura lisa foram mantidas em cultura por 72 horas com o intuito de condicionar o meio, o qual foi coletado e utilizado para tratar MC3T3 ou HOEL ou células mesenquimais, com o intuito de fazer uso de ferramentas de biologia celular e molecular para investigar alterações de expressão gênica e fenotípica. Nossos resultados mostram que 3T3-NIH é capaz de modular a expressão de marcadores de diferenciação osteoblasto-osteócito (DMP1. SOST, RankL e OPG). Além disso, vimos que AoSMC em duas condições distintas - Estatico e Shear-Stress - são capazes de promover uma transição osteoblasto-osteócito através de vesículas extracelulares (EVs), ativando a expressão de biomarcadores moleculares deste processo (miR23-a, DMP1, SOST, FGF23 e GP38) e, neste contexto, nossos dados também mostram que o meio condicionado por HUVEC modula marcadores de diferenciação de osteoblastos (Runx2, Osterix e ALP) e genes que são traduzidos em proteínas e que atuam na homeostase dos minerais da matriz óssea (NPP1 e TNAP). Considerando que as células AoSMC e HUVEC são capazes de modular a osteocitogênese e a osteoblastogênese, respectivamente, o meio condicionado por essas células foi coletado e as vesículas foram extraídas coletadas para melhor caracterização em termos de tamanho, concentração, biomarcadores de membrana, carga elétrica de membrana e conteúdo proteico, o que revelou que o perfil AoSMC não apresentou diferença em termos de condições experimentais (estática e Shear-Stress), também vimos que as células mesenquimais que recebem o tratamento com meio de cultura condicionado por AoSMC aumentou os marcadores de osteocitogênese, enquanto os EVs isolados do meio condicionado por HUVEC modularam positivamente esses mesmos marcadores (PHEX, MEPE, MMP-14, GP-38, DMP1). Esses dados permitem concluir que o tecido endotelial e os fibroblastos contribuem para a homeostase do osso e sua remodelação dinâmica é modulada pela transição osteoblastos-osteócitos por meio de fatores tróficos e vesículas extracelulares. Understanding the mechanisms involved in bone maintenance and homeostasis requires elucidating the behavior of bone tissue in relation to communication with other adjacent tissues. The aim of this study was to investigate how bone cells (MC3t3-E1, HOEL) or mesenchymal cells are modulated through paracrine signaling triggered by fibroblasts (3t3-NIH), vein endothelial cells (HUVEC) and aortic endothelial cells (HCAEC), in addition to smooth muscle cells (AoSMC/VSMC). The cells of the tissues adjacent to the bone remained in culture for 72 hours to condition the medium, this same medium was collected and used to treat MC3t3 or HOEL or mesenchymal cells. Our results show that 3t3-NIH is capable of modulating the expression of osteoblast-osteocyte differentiation markers (DMP1. SOST, RankL and OPG). In addition, we saw that AoSMC in two different conditions: Static and Shear-Stress, are capable of promoting an osteoblast-osteocyte transition through extracellular vesicles (EVs), activating the expression of molecular biomarkers of this process (miR23-a, DMP1, SOST, FGF23 and GP38), in this context our data also show that the medium conditioned by HUVEC modulates osteoblast differentiation markers (Runx2, Osterix and ALP) and genes that are translated into proteins and that act in the homeostasis of bone matrix minerals (NPP1 and TNAP). Considering that AoSMC and HUVEC cells are capable of modulating osteocytogenesis and osteoblastogenesis, respectively, the medium conditioned by these cells was collected and the vesicles were extracted for treatment: 1. medium rich in vesicles and other trophic factors, and 2. treatment only with vesicles. EVs were characterized in terms of size, concentration, membrane biomarkers, membrane electrical charge and protein content, which revealed that the AoSMC profile showed no difference in terms of experimental conditions (static and Shear-Stress), we also saw that the mesenchymal cells receiving treatment with AoSMC-conditioned culture medium increased osteocytogenesis markers, while EVs isolated from HUVEC-conditioned medium positively modulated these same markers (PHEX, MEPE, MMP-14, GP-38, DMP1). These data allow us to conclude that the endothelial tissue and fibroblasts contribute to bone balance by modulating the osteoblast-osteocyte transition through trophic factors and extracellular vesicles. FAPESP: 2016/08888-9; 2018/10856-3; 2019/21807-6

In this study we produced a set of in vitro culture platforms to model vascular cell responses to growth factors and factor delivery vehicles. Two of the systems (whole vessel and whole lung vascular development) were supported by microfluidic systems facilitating media circulation and waste removal. We assessed vascular endothelial growth factor (VEGF) delivery by Pluronic F-127 hydrogel, 30 nm pore-sized microparticles (MPs), 60 nm pore-sized MP or a 50/50 mixture of 30 and 60 nm pore-sized MP. VEGF was delivered to porcine acellular lung vascular scaffolds (2.5 cm2 square pieces or whole 3D segments of acellular blood vessels) as well as whole acellular lung scaffolds. Scaffold-cell attachment was examined as was vascular tissue formation. We showed that a 50/50 mixture of 30 and 60 nm pore-sized silicon wafer MPs allowed for long-term release of VEGF within the scaffold vasculature and supported vascular endothelial tissue development during in vitro culture.

Active smokers are people who are smoking continuously. The population of active smokers in Central Kalimantan was 26,5% in 2013. The farmer, fish farmer, and laborer had a large proportion (44.5%) as an active smoker than another job that reported according to types of jobs. Cigarettes contain many toxic and addictive chemicals. Majority of active smokers that was living in Kelurahan Tanjung Pinang Kota Palangka Raya, especially who live in Jl. Bengaris works as a farmer, fish farmer, or laborer. Active smokers have a high risk of suffering from heart disease. Cigarette compound that harmful can cause endothelial tissue dysfunction in heart blood vessels and following by thrombus formation that due to increased platelet counts and platelet aggregation. This study aimed to describe of platelet count in active smokers in Jl. Bengaris Kelurahan Tanjung Pinang, Palangka Raya. The descriptive observational method was used in this study. The sample obtained by 48 people with purposive sampling technique with criteria such as active smokers, men, working as farmers, fish farmers, or laborers, no history of the disease, and willing to be respondent. Examination of platelet count was done by hematology analyzer. The average of respondents aged 20-30 years (35.4%) and 31-40 years (31.2%), worked as farmers (43.7%) and laborers (41.7%), duration of smoking were 1-10 year (37.5%), consumption of smoking was 11-20 cigarettes / day (41.7%), and rest periods were > 6 hours / day (64.6%). There was one person of the active smoker with a high platelet count (2.1%) and normal platelet count of 47 people (97.9%).

Passive smokers that exposure to cigarette smoke in their house has been reached 78,4%. Inhaled of cigarette smoke in the room was more dangerous than in an open place. Every puff of cigarette smoke from active smoker contains 1015 of free radicals which can cause oxidative stress. The presence of free radicals will trigger of activation of inflammatory genes, and then they can be activated of endothelial cells, dysfunction, and injury. Oxidative stress also stimulates large production of platelet (thrombogenesis) and followed by excessive formation of fibrin and thrombin. So that can cause thrombus in endothelial tissue, and it subsequently develops into atherosclerosis. This study aimed to describe thrombocytosis as a risk factor for increased of atherosclerosis in passive smokers in Kecamatan Pahandut, Kota Palangka Raya. This study used a descriptive observational method with a cross-sectional design. The sample obtained by 45 people with purposive sampling technique with criteria such as respondents were passive smokers, housewives, exposed to cigarette smoke more than five years, no history of the disease, and willing to become respondents. Examination of platelet counts was analyzed by an automatic method using Hematology Analyzer. The results showed that 6.7% of passive smokers had high platelet counts (thrombocytosis). High platelet counts in 6.7% of passive smokers caused by exposure of cigarette smoke from active smokers can endanger passive smoking, especially the risk of atherosclerosis. Therefore, a preventive and educative method for both passive and active smokers are needed to prevent the dangers of cigarette smoke to the risk of atherosclerosis

This article reports a combined technique of sutureless intrascleral fixated intraocular lens implantation and Descemet membrane endothelial keratoplasty in a patient with anterior pseudophakic bullous keratopathy. Two scleral tunnels were created, corneal incisions were made, and a foldable intraocular lens was cut and removed from the anterior chamber. After performing anterior vitrectomy, a 3-piece foldable intraocular lens was implanted into the anterior chamber. One of the intraocular lens haptics was grasped with a forceps and pulled out from the scleral tunnel. Then, the end of the haptic was cauterized. Similar maneuvers were applied for the other haptic. Next, an 8-mm-diameter donor tissue was prepared, and the recipient endothelial tissue was peeled and removed from the center of the recipient cornea. The prepared donor tissue was injected into the anterior chamber. After proper opening and placement of the donor tissue, an air bubble was injected below the tissue. There were no postoperative complications during the 1-month follow-up.

Background:Endothelial progenitor cells (EPC), involved in vasculogenesis and endothelial tissue repair, have been described as relevant players in vascular and connective tissue diseases [1-2]. In this regard, a previous study of our group disclosed that the degree of EPC frequency may help to identify the presence of interstitial lung disease (ILD) in rheumatoid arthritis patients [3]. Given that ILD is the main cause of mortality in patients with systemic sclerosis (SSc) [1, 4-6], the understanding of the role of EPC in the mechanism of SSc-ILD+ vasculopathy is crucial.Objectives:To assess the potential role of EPC on vascular dysfunction associated with the presence of ILD in patients with SSc.Methods:Peripheral venous blood was collected from a total of 39 patients with SSc, 20 with ILD (SSc-ILD+) and 19 without ILD (SSc-ILD-). All subjects were recruited from the Rheumatology and Pneumology departments of Hospital Universitario Marqués de Valdecilla, Santander, Spain. Quantification of EPC was analyzed by flow cytometry. EPC were considered as CD34+, CD45Low, CD309+ and CD133+.Results:Statistically significant differences in EPC frequency between patients with SSc-ILD+ and patients with SSc-ILD- were disclosed. Specifically, an increase of EPC frequency was observed in SSc-ILD+ patients when compared to patients with SSc-ILD- (mean ± standard deviation: 0.033 ± 0.012 versus 0.021 ± 0.017, respectively, p=0.012).Conclusion:Our results suggest a potential role of EPC on vascular damage associated with the manifestation of ILD in patients with SSc.References:[1]Eur J Rheumatol 2020;7(Suppl 3):S139-S146.[2]Arthritis Rheum 2009;60(11):3168-79.[3]J Clin Med 2020;9(12):4098.[4]Ann Rheum Dis 2007;66(7):940-4.[5]Rheumatology (Oxford) 2010;49(12):2375-80.[6]Eur Respir Rev 2015;24(135):102-14.Acknowledgements:Personal funds, VP-C: PREVAL18/01 (IDIVAL); SR-M: RD16/0012/0009 (ISCIII-ERDF); LL-G: INNVAL20/06 (IDIVAL); RP-F: START PROJECT (FOREUM); RL-M: Miguel Servet type I CP16/00033 (ISCIII-ESF).Disclosure of Interests:Verónica Pulito-Cueto: None declared, Sara Remuzgo Martinez: None declared, Fernanda Genre: None declared, Belén Atienza-Mateo: None declared, Victor Manuel Mora-Cuesta: None declared, David Iturbe-Fernández: None declared, Leticia Lera-Gómez: None declared, Raquel Pérez-Fernández: None declared, Diana Prieto-Peña: None declared, Virginia Portilla: None declared, Ricardo Blanco Speakers bureau: Abbvie, Pfizer, Roche, Bristol-Myers, Janssen and MSD, Consultant of: Abbvie, Pfizer, Roche, Bristol-Myers, Janssen and MSD, Grant/research support from: Abbvie, MSD and Roche, Alfonso Corrales: None declared, Jose Manuel Cifrián-Martínez: None declared, Raquel López-Mejías: None declared, Miguel A González-Gay Speakers bureau: Pfizer, Abbvie, MSD, Grant/research support from: Pfizer, Abbvie, MSD

Corneal endothelial disorders collectively represent a significant healthcare burden in most developed nations, and corneal transplantation is currently the only treatment available for patients with poor visual acuity and corneal blindness secondary to endothelial failure. Although vision in these patients can be restored by transplantation, the global demand for donor human corneas is far in excess of what can be provided for by eye banks around the world, and this deficit is set to increase with an ageing global population. As such, there has been a pressing need to explore novel and more sustainable options for the treatment of corneal endothelial diseases. In recent years, significant progress has been made not only in the development of corneal endothelial cell culture techniques, but also in the exploration of various translational strategies. Considered together, we are now much closer to attaining success in the treatment of corneal endothelial diseases via a cell-based, tissue-engineering approach. The aim of this review article is to provide an update of the translational issues currently facing human corneal endothelial cell therapy. Copyright © 2016 John Wiley & Sons, Ltd.

Descemet Membrane Endothelial Keratoplasty (DMEK) selectively replaces the damaged posterior part of the cornea. However, the DMEK technique relies on a manually-performed dissection that is time-consuming, requires training and presents a potential risk of endothelial graft damages leading to surgery postponement when performed by surgeons in the operative room. To validate precut corneal tissue preparation for DMEK provided by a cornea bank in order to supply a quality and security precut endothelial tissue. The protocol was a technology transfer from the Netherlands Institute for Innovative Ocular Surgery (NIIOS) to Lyon Cornea Bank, after formation in NIIOS to the DMEK "no touch" dissection technique. The technique has been validated in selected conditions (materials, microscope) and after a learning curve, cornea bank technicians prepared endothelial tissue for DMEK. Endothelial cells densities (ECD) were evaluated before and after preparation, after storage and transport to the surgery room. Microbiological and histological controls have been done. Twenty corneas were manually dissected; 18 without tears. Nineteen endothelial grafts formed a double roll. The ECD loss after cutting was 3.3 % (n = 19). After transportation 7 days later, we found an ECD loss of 25 % (n = 12). Three days after cutting and transportation, we found 2.1 % of ECD loss (n = 7). Histology found an endothelial cells monolayer lying on Descemet membrane. The mean thickness was 12 ± 2.2 µm (n = 4). No microbial contamination was found (n = 19). Endothelial roll stability has been validated at 3 days in our cornea bank. Cornea bank technicians trained can deliver to surgeons an ECD controlled, safety and ready to use endothelial tissue, for DMEK by "no touch" technique, allowing time saving, quality and security for surgeons.

PURPOSE To report the mid-term outcomes of hemi-Descemet membrane endothelial keratoplasty (hemi-DMEK) performed for Fuchs endothelial corneal dystrophy (FECD). METHODS In this prospective, interventional case series, we evaluated clinical outcomes of 10 eyes from 10 patients who underwent hemi-DMEK for FECD. Main outcome measures were best-corrected visual acuity (BCVA), endothelial cell density (ECD), central pachymetry, and postoperative complications. RESULTS At 1 year postoperatively, 7/7 eyes (excluding 2 eyes with low visual potential) reached a BCVA of ≥20/40 (≥0.5), 6/7 (86%) ≥20/25 (≥0.8), 4/7 (57%) ≥20/20 (≥1.0), and 2/7 (29%) 20/17 (≥1.2). BCVA remained stable until 2 years postoperatively (P ≥ 0.05) and further improved thereafter (P < 0.05). Mean ECD decreased from 2740 (±180) cells/mm preoperatively to 850 (±300) cells/mm (n = 9) at 1 year (P ≤ 0.05) and showed an annual decrease of on average 6% to 7% thereafter (P ≥ 0.05 between consecutive follow-ups). Pachymetry decreased from preoperatively 745 (±153) μm to 533 (±63) μm (n = 9) and 527 (±35) μm (n = 8) at 1 and 3 years postoperatively, respectively. Within the first 6 postoperative months, 4/10 eyes underwent rebubbling for visually significant graft detachment. One eye received secondary circular DMEK for persistent graft detachment 1 month postoperatively; another eye developed secondary graft failure 2.5 years postoperatively, and 1 eye was suspected for an allograft reaction 1.5 years postoperatively. CONCLUSIONS Hemi-DMEK may render visual outcomes comparable to those achieved by conventional DMEK. Despite low ECD counts by 6 months, ECD levels remain fairly stable thereafter. Hence, hemi-DMEK may become a potential alternative technique for treatment of FECD while increasing the yield of the endothelial tissue pool.

Background/aims There is a substantial shortage of donor tissue for endothelial keratoplasty worldwide. Using two endothelial grafts of one donor cornea may potentially increase the pool of suitable donor tissue for Descemet membrane endothelial keratoplasty (DMEK). This study evaluates the technical feasibility of obtaining two DMEK grafts with a different (semicircular) shape, but similar surface area as a ‘conventional’ 8–9 mm circular transplant from a single donor cornea and to evaluate the viability of these grafts stored in organ-culture medium up to 5 weeks after graft preparation. Methods Ten human corneas not suitable for transplantation were used for preparation of semicircular-shaped grafts (hemi-DMEK grafts). The viability of these hemi-DMEK grafts was measured by evaluating the endothelial cell density (ECD) with light microscopy before and immediately after preparation and during five additional weeks of organ culture. Results Hemi-DMEK preparation was successful in all cases. All grafts formed a roll. A small area denuded of cells was observed after preparation along the straight edge of the DM roll. The mean ECD was 2654 (±65) cells/mm 2 before and 2651 (±94) cells/mm 2 immediately after hemi-DMEK preparation and declined gradually from 2518 (±133) cells/mm 2 after 1 week to 1847 (±170) cells/mm 2 after 5 weeks of organ-culture storage. Discussion Preparation of two hemi-DMEK grafts from one single human donor cornea is technically feasible, and the grafts can be stored after preparation in organ-culture similar to standard circular DMEK grafts. Hemi-DMEK may have the potential to double the availability of donor endothelial tissue for DMEK.

Retained descemet’s membrane is a rare complication of penetrating keratoplasty. It can lead to graft failure by compromising the endothelial tissue of the cornea. We report a case which was diagnosed as retained descemet’s membrane post penetrating keratoplasty by anterior segment optical coherence tomogram and was managed surgically by descemetorhexis without compromising the graft integrity which led to good visual gain.

We present a characterization of chemically treated cells using atomic force microscopy (AFM) which can observe changes in morphology and elasticity of cells. Since AFM has the significant advantage that it does not require fixation of samples, the method is simple and can capture various properties of living cells. In this study, corneal epithelial and endothelial cells were examined. The topography images of the corneal cells without glutaraldehyde (GA) fixation were successfully obtained. The images showed a natural three-dimensional shape of these cells, which scanning electron microscope (SEM) images could not provide. The AFM images of GA-fixed cells were taken and compared with a SEM image reported in the literature. Our results show that longer time for GA fixation makes the surface of the corneal endothelial tissue stiffer. Also, longer treatment results in relatively large structural variation in samples. Combined with conventional histochemical methods, this approach helps us gain an overall understanding of the influence of such chemical treatment.

Corneal blindness affects over 10 million people worldwide and current treatment strategies often involve replacement of the defective layer with healthy tissue. Due to a worldwide donor cornea shortage and the absence of suitable biological scaffolds, recent research has focused on the development of tissue engineering techniques to create alternative therapies. This review will detail how we have refined the simple engineering technique of plastic compression of collagen to a process we now call Real Architecture for 3D Tissues (RAFT). The RAFT production process has been standardised, and steps have been taken to consider Good Manufacturing Practice compliance. The evolution of this process has allowed us to create biomimetic epithelial and endothelial tissue equivalents suitable for transplantation and ideal for studying cell-cell interactions in vitro.

Eye-bank preparation of endothelial tissue for keratoplasty continues to evolve. Although eye-bank personnel have become comfortable and competent at Descemet's stripping automated endothelial keratoplasty (DSAEK), tissue preparation and tissue transport, optimization of preparation methods continues. Surgeons and eye-bank personnel should be up to date on the research in the field. As surgeons transit to Descemet's membrane endothelial keratoplasty (DMEK), eye banks have risen to the challenge of preparing tissue. Eye banks are refining their DMEK preparation and transport techniques.This article covers refinements to DSAEK tissue preparation, innovations to prepare DMEK tissue, and nuances to improve donor cornea tissue quality.As eye bank-supplied corneal tissue is the main source of tissue for many corneal surgeons, it is critical to stay informed about tissue handling and preparation. Ultimately, the surgeon is responsible for the transplantation, so involvement of clinicians in eye-banking practices and advocacy for pursuing meaningful research in this area will benefit clinical patient outcomes.

Caffeic acid phenethyl ester (CAPE) is a component of honeybee hives with various beneficial properties. Tissue factor (TF), the key trigger of thrombosis, is expressed in human endothelial cells. This study was designed to investigate whether CAPE modulates TF expression in human aortic endothelial cells (HAECs). Western blots and real-time polymerase chain reactions were performed. CAPE (10(-7)-10(-5) M) inhibited tumor necrosis factor (TNF)-α induced endothelial TF protein expression by 2.1-fold at 10(-5) M (p

Background/Aims: End-stage renal disease (ESRD) is associated with a prothrombotic phenotype and substantial activation of platelets can occur in the course of hemodialysis. However, the underlying mechanisms for increased platelet reactivity remain unclear. Increased levels of oxidized albumin, termed “advanced oxidation protein products (AOPPs)” accumulate in subjects with renal disease. Methods: Platelet aggregation was assessed with platelet aggregometry. Platelet activation, formation of reactive oxygen species and tissue factor expression on the surface of platelets and endothelial cells was measured by flow cytometry. Platelet adherence was assessed under flow using the Cellix system. The oxidative status of albumin isolated from ESRD patients was determined by photometric analysis. Tissue factor levels in serum samples were determined using a commercially available ELISA kit. Results: Albumin isolated from hemodialysis patients as well as in vitro generated AOPP-albumin promoted platelet activation via CD36, dependent on the AOPP-content of albumin. AOPP-albumin mediated platelet activation was prevented by scavenging superoxide anions and inhibitors of phospholipase C and protein kinase C. Furthermore, AOPP and serum tissue factor levels were considerably increased in ESRD patients on hemodialysis and a significant correlation of AOPP and serum tissue factor was found. Conclusion: Interaction of platelet CD36 with endogenous oxidized albumin may link oxidative stress with a prothrombotic phenotype in ESRD.

In an era of increased cardiovascular disease burden in the ageing population, there is great demand for devices that come in to contact with the blood such as heart valves, stents, and bypass grafts that offer life saving treatments. Nitric oxide (NO) elution from healthy endothelial tissue that lines the vessels maintains haemostasis throughout the vasculature. Surgical devices that release NO are desirable treatment options and N-diazeniumdiolates and S-nitrosothiols are recognized as preferred donor molecules. There is a keen interest to investigate newer methods by which NO donors can be retained within biomaterials so that their release and kinetic profiles can be optimized. A range of polymeric scaffolds incorporating microparticles and nanomaterials are presenting solutions to current challenges, and have been investigated in a range of clinical applications. This review outlines the application of NO donors for cardiovascular therapy using biomaterials that release NO locally to prevent thrombosis and intimal hyperplasia (IH) and enhance endothelialization in the fabrication of next generation cardiovascular device technology.

Epithelial and endothelial tissue barriers are based on tight intercellular contacts (Tight Junctions, TJs) between neighbouring cells. TJs are multimeric complexes, located at the most apical border of the lateral membrane. So far, a plethora of proteins locating at tight intercellular contacts have been discovered, the role of which has just partly been unraveled. Yet, there is convincing evidence that many TJ proteins exert a dual role: They act as structural components at the junctional site and they are involved in signalling pathways leading to alterations of gene expression and cell behaviour (migration, proliferation). This review will shortly summarize the classical functions of TJs and TJ-related proteins and will introduce a new category, termed the "non-classical" functions of junctional proteins. A particular focus will be directed towards the nuclear targeting of junctional proteins and the downstream effects elicited by their intranuclear activities.

Aortic cross-clamping during cardiac operations may injure the vessel wall and cause tissue lesions. This experimental study analyses the influence of the intravascular and external pressure and the duration of aortic cross-clamping on endothelial tissue damage. Fresh porcine aortas (n=20) were tested with intravascular pressures from 30 to 80 mmHg. The external clamp pressure, necessary to occlude the aorta, was applied by using the second cog of a commercial aortic clamp and cross-clamping was performed for 1 and 30 min. The observed pressure curves were compared to the histological findings. For occlusion of the aorta, an external pressure of at least 10-fold higher than the intravascular pressure (max. 812 mmHg) had to be applied. After 30 min of clamping, a complete endothelial destruction was observed, irrespective of intra-aortic pressure. The aortic media remained intact. After 1 min clamping, fractions of intact endothelial cells were left, ranging from 40 to 70% at different intra-aortic pressures. These results indicate that endothelial tissue lesions due to aortic cross-clamping are not avoidable, even in moderate clamp application. The duration of aortic cross-clamping but not intravascular pressure is the pivotal factor. The integrity of the aortic media can be preserved if low-force cross-clamping is achieved.

Tight junction biology has many important applications, from improving knowledge of diseases characterized by the loss of epithelial or endothelial tissue barrier function to providing a mechanistic basis for improving non-invasive drug delivery. A variety of chemical and molecular biological tools have been developed, including high throughput cell-based screening of molecular libraries that facilitate discovery of novel peptides and lipids to modulate tight junction function safely and reversibly. Further development of novel tight junction modulating excipients necessitates consideration of physicochemical, toxicological, pharmaceutical and regulatory issues.

Cell-cell junctions are essential for epithelial and endothelial tissue formation and communication between neighboring cells. We report here that migfilin, a recently identified component of cell-extracellular matrix adhesions, is recruited to cell-cell junctions in response to cadherin-mediated cell-cell adhesions. Migfilin is detected at cell-cell junctions in both epithelial and endothelial cells. It forms detergent-resistant, discrete clusters that associate with actin bundles bridging neighboring cells. Immunoelectron microscopic analyses reveal that migfilin is closely associated with β-catenin, but not desmosomes, at cell-cell junctions. Furthermore, we show that the C-terminal LIM domains, but not its N-terminal domain, mediates migfilin localization to cell-cell junctions. The site mediating the localization of migfilin to cell-cell junctions at least partially overlaps with that mediating the localization of migfilin to cell-ECM adhesions. Finally, siRNA-mediated depletion of migfilin compromised the organization of adherens junctions and weakened cell-cell association. These results identify migfilin as a component of adherens junctions and suggest an important role for migfilin in the organization of the cell-cell adhesion structure.

In the United States, more than $16 billion annually is spent managing patients with severe sepsis and its sequelae. Insight into the inflammatory response, endothelial tissue, and the coagulation cascade suggest promising new treatment regimens that limit morbidity and mortality due to sepsis and multisystem organ failure. This article will discuss new information regarding the pathophysiology of the inflammatory response and sepsis. Current thoughts on clinical management and a promising new agent, Activated Protein C, will be presented.

In healthy blood vessels with a laminar blood flow, the endothelial cell division rate is low, only sufficient to replace apoptotic cells. The division rate significantly increases during embryonic development and under halted or turbulent flow. Cells in barrier tissue are connected and their motility is highly correlated. Here we investigate the long-range dynamics induced by cell division in an endothelial monolayer under non-flow conditions, mimicking the conditions during vessel formation or around blood clots. Cell divisions induce long-range, well-ordered vortex patterns extending several cell diameters away from the division site, in spite of the system’s low Reynolds number. Our experimental results are reproduced by a hydrodynamic continuum model simulating division as a local pressure increase corresponding to a local tension decrease. Such long-range physical communication may be crucial for embryonic development and for healing tissue, for instance around blood clots., Endothelial cell division is highly sensitive to fluid conditions and essential for blood vessel healing. Here Rossen et al. demonstrate how cell division triggers the emergence of long-range votex patterns in endothelial tissue under conditions that mimic blood vessel formation and blood clots.

A combination of experimental, theoretical, and imaging methodologies is used to examine the hierarchical structure and function of intramyocardial arteriolar trees in porcine hearts to provide a window onto a region of myocardial microvasculature which has been difficult to fully explore so far. A total of 66 microvascular trees from 6 isolated myocardial specimens were analyzed, with a cumulative number of 2438 arteriolar branches greater than or equal to 40 μm lumen diameter. The distribution of flow rates within each tree was derived from an assumed power law relationship for that tree between the diameter of vessel segments and flow rates that are consistent with that power law and subject to conservation of mass along hierarchical structure of the tree. The results indicate that the power law index increases at levels of arteriolar vasculature closer to the capillary level, consistent with a concomitant decrease in shear stress acting on endothelial tissue. These results resolve a long standing predicament which could not be resolved previously because of lack of data about the 3D, interconnected, arterioles. In the context of myocardial perfusion, the results indicate that the coefficient of variation of flow rate in pre-capillary distal arterioles is high, suggesting that heterogeneity of flow rate in these arterioles is not entirely random but may be due at least in part to active control.

Farmed pre-smolt stage Atlantic salmon developed an acute, severe haemorrhagic anaemia, termed haemorrhagic smolt syndrome. The fish were in good condition, but lethargic, and had widespread visceral and muscle petechiation and ecchymoses. The mean (sd) haematocrit of affected fish was 1.4 (0.9) per cent and histopathology revealed widespread haemorrhage in all organs, associated with endothelial tissue. No infectious agent was isolated and the condition could not be transmitted experimentally. The clinical evidence indicates that the condition is non-infectious, but its aetiology could not be fully established.

Hemangiopericytoma (HPC) may develop in every site where the endothelial tissue exits and primarily develops in the skeletal-muscular system or the skin. Adult cases of HPC generally exhibit a benign course. 20–30% of the cases may show a malign course. The tumors that show more than four mitoses, a focal area of necrosis, and increased cellularity on a magnification ×10 are considered as malign. In our paper, we presented our case who showed a lung metastasis at the end of 4 years and who developed a pathological fracture of the right humerus at the end of approximately 2 years, because hemangiopericytoma is rarely seen in the chest wall as a primary tumor.

Hemangiopericytoma (HPC) is an uncommon highly vascular neoplasm that originated from Zimmerman's pericytes which surrounds the endothelial tissue. Primary epidural HPC of the sacrum is extremely rare. We reported an unusual case of primary epidural malignant HPC of the sacrum that invaded vertebral bone and caused rectum compression in a 57-year-old male for the first time. The patient presented progressive low back pain and ribbon-like stool over 3 months. The surgical intervention involved sacrectomy and en bloc resection of the tumor. We described the clinical, radiological, and histological features of this tumor and reviewed the literature.

Arterial system dynamic approach necessarily implies the analysis of the interaction between the blood flow and the arterial wall. More precisely, the afore-mentioned relationship is mediated by endothelial cells intervention. Biological systems behavior is controlled by nonlinear reactions, and should be evaluated by means of representative methods, such as fractal geometry. In the present study, endothelial response related signals (arterial pressure and diameter) processing is proposed, by applying fractal characterization techniques, for different mean blood flow regimes and in presence and absence of endothelial tissue.

The objective of this study is elucidating the mechanisms by which the wettability of nanofibrous electrospun mats varies in polymer blends, and highlighting how this can play a pivotal role in enhancing the viability of cultured microvascular endothelial cells (EC). A functional microvascular network is essential for supplying bioengineered tissues with oxygen and nutrients while removing metabolic wastes. An in vitro pre-vascularization strategy consists of seeding EC on scaffolds, which in turn promotes cells infiltration, adhesion and functionality. We use electrospun poly-L-lactic acid (PLLA) and gelatin (Gel) as prototype materials for realizing nanofibrous scaffolds as bioartificial architectures to improve the proliferation and the functionality of human microvascular ECs (HMEC-1). HMEC-1 seeded on electrospun scaffolds adhere, remain viable, proliferate and positively express the endothelial cell marker CD31 particularly on blend PLLA/Gel fibers, which exhibit wettability enhanced with respect to both the constituent polymers, and are therefore especially promising constructs for promoting the formation of functional endothelial tissue. The wettability characteristics of the blend polymer fibrous scaffolds are modeled and discussed. These results can be valuable for the future design of pre-vascularized scaffolds with enhanced wettability properties for functional tissue engineered implants, with ECs able to form in perspective an effectively functioning vasculature upon implantation.

Zero-link Hb (OxyVita®, OXYVITA, Inc., New Windsor, New York), a new generation hemoglobin-based-oxygen-carrier (HBOC), is produced using a modified zero-linked polymerization mechanism that employs chemical activators to incorporate inter-dimerically cross-linked bovine hemoglobin tetramers into “super-polymeric” macromolecules (Average M. wt. = 17 MDa) for oxygen delivery when whole blood or packed red cells are not available. This molecular design pathway was developed to address several basic biochemical and physiological concerns associated with earlier generations of HBOCs. Observations made during pre-clinical (various animal models) and clinical studies provided evidence these earlier generation acellular HBOCs gave evidence of reduced retention times within the circulatory system, extravasation across endothelial tissue membranes due to their small molecular size leading to arterial and veinous vasoconstriction that was coupled with rapid increases in mean arterial pressure (MAP) upon infusion. Zero-link Hb’s increased molecular size and structural stability was developed in direct response to these serious concerns that accompanied the evolution of HBOC development within the past several decades. The distinct nature of the zero-linked synthetic route eliminates the need for chemical linkers within the product, eliminates side reaction concerns: such as reversibility and decomposition due to weak and non-specific chemical bonding, changes in temperature and/or pressure within the circulatory system, and residual toxicity. The incorporation of these molecular design characteristics within OxyVita Hb have been responsible for significant findings as determined by the pre-clinical studies that have been carried out by many independent investigators between 2002 to 2012. This chapter will present: (1) a short overview of previous generation HBOCs; (2) the experimental development of OxyVita Hb (liquid and powder forms); (3) the physiochemical properties and functional behavior of OxyVita Hb; and (4) the implications of the molecular design properties for pre-clinical studies that involved issues of extravasation and vasoconstriction, increases in MAP, regulation of oxygen delivery, and effects on coagulatory functions.

CME Educational Objectives 1. Recognize infantile hemangiomas that are associated with a higher risk for complications and associated anomalies. 2. Appreciate the typical timing of growth and involution of infantile hemangiomas. 3. Become familiar with recently reported treatments for infantile hemangiomas.

Objective Exclusion of the left atrial appendage is proposed to reduce the risk of stroke in patients with atrial fibrillation. The aim of this study was to evaluate the feasibility and efficacy of a fourth-generation atrial exclusion device developed for minimally invasive applications. Methods The novel atrial exclusion device consists of two polymer beams and two elastomeric bands that connect the two beams at either end. Fifteen mongrel dogs were implanted with the device at the base of the left atrial appendage through a median sternotomy and were evaluated at 30 (n = 7), 90 (n = 6), and 180 (n = 2) days after implantation by epicardial echocardiography, left atrial and coronary angiography, gross pathology, and histology. Results Left atrial appendage exclusion was completed without hemodynamic instability. Coronary angiography revealed that the left circumflex artery was patent in all cases. A new endothelial tissue layer developed, as expected, on the occluded orifice of the left atrium. Conclusions This novel atrial exclusion device achieved easy, reliable, and safe exclusion of the left atrial appendage, with favorable histological results in a canine model for up to 6 months. Clinical application could provide a new therapeutic option for reducing the risk of stroke in patients with atrial fibrillation.

Retention of the host’s Descemet’s membrane is a complication which can occur during the course of a penetrating keratoplasty and which eventually leads to loss of graft clarity by clouding or by coming into contact with the graft endothelium. The retained Descemet’s membrane can compromise endothelial tissue by contact injury or by limiting diffusion of aqueous humour nutrients. In our study we discuss the pathogenesis, diagnosis and treatment of this complication. In addition we report some our cases treated with three different approaches.

A combined cartographic and morphometric endothelium analyser has been developed by integrating the HISTO 2000 histological imaging and analysis system with a prototype human corneal endothelium analyser. The complete system allows the elaboration and analysis of cartographies of corneal endothelial tissue, and hence the in vitro study of the spatial distribution of corneal endothelial cells, according to their regional morphometric characteristics (cell size and polygonality). The global cartographic reconstruction is obtained by sequential integration of the data analysed for each microscopic field. Subsequently, the location of each microscopically analysed field is referred to its real position on the histologic preparation by means of X-Y co-ordinates; both are provided by micrometric optoelectronic sensors installed on the optical microscope stage. Some cartographies of an excised human corneal keratoconus button in vitro are also presented. These cartographic images allow a macroscopic view of endothelial cells analysed microscopically. Parametric colour images show the spatial distribution of endothelial cells, according to their specific morphometric parameters, and exhibit the variability in size and cellular shape which depend on the analysed area.

Ureteral stents represent a minimally invasive alternative to preserve urinary drainage whenever ureteral patency is deteriorated or is under a significant risk to be occluded due to extrinsic or intrinsic etiologies. The ideal stent that would combine perfect long-term efficacy with no stent-related morbidity is still lacking and stent usage is associated with several adverse effects that limit its value as a tool for long-term urinary drainage. Several new ideas on stent design, composition material and stent coating currently under evaluation, foreseen to eliminate the aforementioned drawbacks of ureteral stent usage. In this article we review the currently applied novel ideas and new designs of ureteral stents. Moreover, we evaluate potential future prospects of ureteral stent development adopted mostly by the pioneering cardiovascular stent industry, focusing, however, on the differences between ureteral and endothelial tissue.

IL-1β is a pleotropic cytokine that may mediate increased procoagulant activity and permeability in endothelial tissue during inflammatory conditions. The procoagulant effects of IL-1β are mediated through induction of tissue factor (TF) but its alterations on vascular permeability are not well characterized. We found that IL-1β induced a rapid and dose-dependent increase in TF activity in human umbilical vein endothelial cells (ECs) under routine culture conditions. However, IL-1β caused a rapid and marked increase in permeability across confluent EC monolayers using a two-compartmentin vitromodel only in the presence of factor VIII-deficient plasma that was completely abrogated by neutralizing anti-TF antibody pre-treatment.In vitropermeability was associated with loss of EC surface expression of VE-cadherin and contraction of F-actin cytoskeletal elements that resulted in EC intercellular gap formation. These data demonstrate that IL-1β induces marked changes in permeability across activated endothelium via a TF dependent mechanism and suggest that modulation of TF activity may represent a strategy to treat various acute and chronic inflammatory conditions mediated by this cytokine.