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Nerve growth factor promotes corneal epithelial migration by enhancing expression of matrix metalloprotease-9.
No full textPURPOSE. Nerve growth factor (NGF) is a neuropeptide essential for the development, survival,
growth, and differentiation of corneal cells. Its effects are mediated by both TrkA and p75
receptors. Clinically relevant use of NGF was introduced to treat neurotrophic ulcerations in
patients. Herein, we examine the mechanisms by which NGF enhances epithelial wound
healing both in vivo and in vitro.
METHODS. An animal model using adult hens was implemented for the in vivo experiments.
Laser ablation keratectomy was performed and animals were observed for up to 7 days.
Epithelial healing was measured with fluorescein. In addition, proliferation was measured
using BrdU incorporation and both TrkA and matrix metalloprotease-9 (MMP-9) expression
were measured by immunohistochemistry (IHC) and Western blot (WB). In vitro experiments
were carried out with telomerase-immortalized human corneal epithelial cells (HCLE). The
rate of proliferation was measured using a colorimetric assay and BrdU incorporation. Realtime
migration was evaluated with an inverted microscope. MMP-9 expression was evaluated
by immunocytochemistry (ICC), WB, zymography, and RT-PCR. Finally, beta-4 integrin (b4)
expression was assessed by ICC and WB.
RESULTS. Faster epithelial healing was observed in NGF-treated corneas compared with
controls (P < 0.01). These corneas showed increased proliferation, TrkA upregulation, and
enhanced MMP-9 presence (P < 0.01). In vitro, faster spreading and migration were observed
in response to NGF (P < 0.01). Enhanced proliferation, as well as enhanced TrkA and MMP-9
expression, and decreased b4 levels were observed after adding NGF (P < 0.01).
CONCLUSIONS. NGF plays a major role during the epithelial healing process by promoting
migration, a process that is accelerated by cell spreading. This effect is mediated by both the
upregulation of MMP-9 and cleavage of b4 integrin
TFOS lifestyle: Impact of lifestyle challenges on the ocular surface
No full textThe authors would like to add new affiliations for Dr. Giulio Ferrari as follows. 1. IRCCS San Raffaele Scientific Institute, Division of Neuroscience, Cornea and Ocular Surface Disease Unit, Eye Repair Lab, Milan, Italy2. Vita-Salute San Raffaele University, Dept. Of Ophthalmology, Milan, Italy The authors would like to apologize for any inconvenience caused
Eye bank versus surgeon prepared DMEK tissues: influence on adhesion and re-bubbling rate
No full textAim: To investigate the difference in adhesion and rebubbling rate between eye bank and surgeon prepared Descemet membrane endothelial keratoplasty (DMEK) tissues. Methods: Laboratory and clinical retrospective comparative interventional case series. Research corneal tissues were obtained for laboratory investigation. The clinical study involved patients with endothelial dysfunction who underwent DMEK surgery and tamponade with air. Tissues were stripped using a standard DMEK stripping technique (SCUBA) and shipped as prestripped or loaded in a 2.2 intra-ocular lens cartridge with endothelium facing inwards (preloaded) before transporting from the eye bank to the surgeon. For surgeon prepared tissues, all the grafts were stripped in the theatre and transplanted or stripped in the laboratory and tested immediately. Adhesion force and elastic modulus were measured in the centre and mid-periphery in a laboratory ex vivo investigation using atomic force microscopy, while rebubbling rates were recorded in the clinical study. Results: There was no difference in endothelial cell viability between surgeon or eye bank prepared tissue. Surgeon-stripped DMEK grafts in the laboratory investigation showed significantly higher elastic modulus and adhesion force compared to prestripped and preloaded tissues (p<0.0001). In the clinical data, rebubbling rates of 48%, 40% and 15% were observed in preloaded, prestripped and surgeon-stripped DMEK grafts, respectively. Rebubbling rates were significantly associated with combined cataract surgery (p=0.009) and with time from harvesting the graft to the surgery (p=0.02). Conclusions: Decreased adhesion forces and elastic modulus in eye bank prepared tissues may contribute to increased rebubbling rates
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
TFOS Lifestyle: Impact of lifestyle challenges on the ocular surface
No full textMany factors in the domains of mental, physical, and social health have been associated with various ocular surface diseases, with most of the focus centered on aspects of dry eye disease (DED). Regarding mental health factors, several cross-sectional studies have noted associations between depression and anxiety, and medications used to treat these disorders, and DED symptoms. Sleep disorders (both involving quality and quantity of sleep) have also been associated with DED symptoms. Under the domain of physical health, several factors have been linked to meibomian gland abnormalities, including obesity and face mask wear. Cross-sectional studies have also linked chronic pain conditions, specifically migraine, chronic pain syndrome and fibromyalgia, to DED, principally focusing on DED symptoms. A systematic review and meta-analysis reviewed available data and concluded that various chronic pain conditions increased the risk of DED (variably defined), with odds ratios ranging from 1.60 to 2.16. However, heterogeneity was noted, highlighting the need for additional studies examining the impact of chronic pain on DED signs and subtype (evaporative versus aqueous deficient). With respect to societal factors, tobacco use has been most closely linked to tear instability, cocaine to decreased corneal sensitivity, and alcohol to tear film disturbances and DED symptoms
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
The ocular microbiome and microbiota and their effects on ocular surface pathophysiology and disorders
Get PDFThe ocular surface flora perform an important role in the defense mechanisms of the ocular surface system. Its regulation of the immunological activity and the barrier effect against pathogen invasion are remarkable. Composition of the flora differs according to the methods of investigation, because the microbiome, composed of the genetic material of bacteria, fungi, viruses, protozoa, and eukaryotes on the ocular surface, differs from the microbiota, which are the community of microorganisms that colonize the ocular surface. The observed composition of the ocular surface flora depends on harvesting and examining methods, whether with traditional culture or with more refined genetic analysis based on rRNA and DNA sequencing. Environment, diet, sex, and age influence the microbial flora composition, thus complicating the analysis of the baseline status. Moreover, potentially pathogenic organisms can affect its composition, as do various disorders, including chronic inflammation, and therapies applied to the ocular surface. A better understanding of the composition and function of microbial communities at the ocular surface could bring new insights and clarify the epidemiology and pathology of ocular surface dynamics in health and disease. The purpose of this review is to provide an up-to-date overview of knowledge about this topic
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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