scholarly journals Contrast-Enhanced Ultrasound in the Diagnosis of Ocular Pathology: Application Prospects

2021 ◽  
Vol 18 (2) ◽  
pp. 216-221
Author(s):  
T. N. Kiseleva ◽  
A. N. Bedretdinov
Keyword(s):  
Ganglion Cells ◽  
Inflammatory Diseases ◽  
Gene Transfection ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Abdominal Cavity ◽  
Nucleic Acid Delivery ◽  
Local Contrast ◽  
Contrast Enhanced Ultrasound ◽  
Contrast Enhanced

Contrast-enhanced ultrasound is a highly informative method for the differential diagnosis of focal changes in various organs and tissues, which allows to visualize vascular structures and obtain new previously unavailable information when using standard b-scan. At the beginning of the 21st century after the development of a new generation of contrast agents consisting of microbubbles with inert gas contrast-enhanced ultrasound became widely used to improve visual assessment of small-caliber vessels in the diagnosis of the abdominal cavity and retroperitoneal space pathology: benign and malignant liver formations, spleen pathology, inflammatory diseases and tumors of the pancreas, defects in renal perfusion, tumor and cystic lesions of the kidneys. Assessment of intraocular tumors microcirculation and diagnosis of vitreoretinal pathology are still two main directions of using contrast-enhanced ultrasound in ophthalmology. In recent years, there has been a growing interest in the use of contrast-enhanced ultrasound in the study of perfusion of different types of uveal melanoma in an animal experiment. A promising direction in the field of genetic engineering is the use of local contrast-enhanced ultrasound exposure on retinal cells (retinal ganglion cells, retinal pigment epithelium) to promote gene transfection (non-viral nucleic acid delivery into the DNA of a cell), which is an important part of gene therapy. Despite the successes achieved in the study of contrast-enhanced ultrasound effectiveness in medicine, further research is needed to increase the informative value of this method in the diagnosis of ophthalmopathology. 

scholarly journals EFSUMB Recommendations for Gastrointestinal Ultrasound Part 3: Endorectal, Endoanal and Perineal Ultrasound

2019 ◽  
Vol 05 (01) ◽  
pp. E34-E51 ◽  
Author(s):  
Dieter Nuernberg ◽  
Adrian Saftoiu ◽  
Ana Barreiros ◽  
Eike Burmester ◽  
Elena Ivan ◽  
...  
Keyword(s):  
Inflammatory Diseases ◽  
Perineal Ultrasound ◽  
Therapy Planning ◽  
Contrast Enhanced Ultrasound ◽  
Rectal Tumors ◽  
Targeted Biopsy ◽  
Contrast Enhanced ◽  
Gastrointestinal Ultrasound ◽  
Examination Techniques ◽  
Inflammatory Bowel

AbstractThis article represents part 3 of the EFSUMB Recommendations and Guidelines for Gastrointestinal Ultrasound (GIUS). It provides an overview of the examination techniques recommended by experts in the field of endorectal/endoanal ultrasound (ERUS/EAUS), as well as perineal ultrasound (PNUS). The most important indications are rectal tumors and inflammatory diseases like fistula and abscesses in patients with or without inflammatory bowel disease (IBD). PNUS sometimes is more flexible and convenient compared to ERUS. However, the technique of ERUS is quite well established, especially for the staging of rectal cancer. EAUS also gained ground in the evaluation of perianal diseases like fistulas, abscesses and incontinence. For the staging of perirectal tumors, the use of PNUS in addition to conventional ERUS could be recommended. For the staging of anal carcinomas, PNUS can be a good option because of the higher resolution. Both ERUS and PNUS are considered excellent guidance methods for invasive interventions, such as the drainage of fluids or targeted biopsy of tissue lesions. For abscess detection and evaluation, contrast-enhanced ultrasound (CEUS) also helps in therapy planning.

scholarly journals Vertebrate features revealed in the rudimentary eye of the Pacific hagfish (Eptatretus stoutii)

2020 ◽  
Author(s):  
Emily M. Dong ◽  
W. Ted Allison
Keyword(s):  
Ganglion Cells ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Photoreceptor Cells ◽  
List Type ◽  
Eye Evolution ◽  
The Pacific ◽  
Pigmented Epithelium ◽  
Cell Layers ◽  
Eptatretus Stoutii

SUMMARYHagfish eyes are markedly basic compared to the eyes of other vertebrates, lacking a pigmented epithelium, a lens, and a retinal architecture built of three cell layers – the photoreceptors, interneurons & ganglion cells. Concomitant with hagfish belonging to the earliest-branching vertebrate group (the jawless Agnathans), this lack of derived characters has prompted competing interpretations that hagfish eyes represent either a transitional form in the early evolution of vertebrate vision, or a regression from a previously elaborate organ. Here we show the hagfish retina is not extensively degenerating during its ontogeny, but instead grows throughout life via a recognizable Pax6+ ciliary marginal zone. The retina has a distinct layer of photoreceptor cells that appear to homogeneously express a single opsin of the rh1 rod opsin class. The epithelium that encompasses these photoreceptors is striking because it lacks the melanin pigment that is universally associated with animal vision; notwithstanding, we suggest this epithelium is a homolog of gnathosome Retinal Pigment Epithelium (RPE) based on its robust expression of RPE65 and its engulfment of photoreceptor outer segments. We infer that the hagfish retina is not entirely rudimentary in its wiring, despite lacking a morphologically distinct layer of interneurons: multiple populations of cells exist in the hagfish inner retina that differentially express markers of vertebrate retinal interneurons. Overall, these data clarify Agnathan retinal homologies, reveal characters that now appear to be ubiquitous across the eyes of vertebrates, and refine interpretations of early vertebrate visual system evolution.HIGHLIGHTSHagfish eyes are degenerate but not degenerating, i.e. rudimentary but growingRetinal interneurons discovered implying ancestral hagfish had derived retinas & visionDespite lacking pigment, a Retinal Pigmented Epithelium homolog functions in hagfishRevised synapomorphies illuminate the dimly lit origins of vertebrate eye evolutionGRAPHICAL ABSTRACT

scholarly journals Creatine transporter localization in developing and adult retina: importance of creatine to retinal function

2005 ◽  
Vol 289 (4) ◽  
pp. C1015-C1023 ◽  
Author(s):  
Monica L. Acosta ◽  
Michael Kalloniatis ◽  
David L. Christie
Keyword(s):  
Ganglion Cells ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Müller Cells ◽  
Nerve Fibers ◽  
Retinal Function ◽  
Mouse Retina ◽  
Muller Cells ◽  
Creatine Transporter ◽  
Subsequent Decrease

Creatine and phosphocreatine are required to maintain ATP needed for normal retinal function and development. The aim of the present study was to determine the distribution of the creatine transporter (CRT) to gain insight to how creatine is transported into the retina. An affinity-purified antibody raised against the CRT was applied to adult vertebrate retinas and to mouse retina during development. Confocal microscopy was used to identify the localization pattern as well as co-localization patterns with a range of retinal neurochemical markers. Strong labeling of the CRT was seen in the photoreceptor inner segments in all species studied and labeling of a variety of inner neuronal cells (amacrine, bipolar, and ganglion cells), the retinal nerve fibers and sites of creatine transport into the retina (retinal pigment epithelium, inner retinal blood vessels, and perivascular astrocytes). The CRT was not expressed in Müller cells of any of the species studied. The lack of labeling of Müller cells suggests that neurons are independent of this glial cell in accumulating creatine. During mouse retinal development, expression of the CRT progressively increased throughout the retina until approximately postnatal day 10, with a subsequent decrease. Comparison of the distribution patterns of the CRT in vascular and avascular vertebrate retinas and studies of the mouse retina during development indicate that creatine and phosphocreatine are important for ATP homeostasis.

Modern Imaging Techniques for Visualising Choroidal Morphology and Function

2021 ◽  
Vol 238 (09) ◽  
pp. 951-961
Author(s):  
Marion Munk ◽  
Chantal Dysli
Keyword(s):  
Inflammatory Diseases ◽  
Imaging Techniques ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Diagnostic Techniques ◽  
Age Related Macular Degeneration ◽  
Basic Knowledge ◽  
Pathologic Myopia ◽  
Age Related ◽  
And Function

AbstractThe choroid is directly adjacent to the retina and consists of a dense vascular network that supplies the outer retina. Pathologies in the choroid can lead to changes in the retinal pigment epithelium (RPE) and photoreceptors. Thus, the choroid plays a crucial role in the development of retinal diseases such as age-related macular degeneration (AMD), central serous chorioretinopathy (CSCR), pathologic myopia, and inflammatory diseases such as Vogt-Koyanagi-Harada syndrome (VKH). Basic knowledge of the structure and physiology of the choroid, as well as diagnostic options for visualizing choroidal changes, provides a better understanding of the physiology and pathology of choroidal processes. This review provides an overview of the anatomy and function of the choroid, and describes the diagnostic techniques currently available to characterize and visualize the choroid. It also includes an overview of various retinal conditions, which are associated with choroidal changes.

Pax6 induces ectopic eyes in a vertebrate

Development ◽  
1999 ◽  
Vol 126 (19) ◽  
pp. 4213-4222 ◽  
Author(s):  
R.L. Chow ◽  
C.R. Altmann ◽  
R.A. Lang ◽  
A. Hemmati-Brivanlou
Keyword(s):  
Ganglion Cells ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Ectopic Expression ◽  
Spatial Arrangement ◽  
Lineage Tracing ◽  
Dominant Negative ◽  
Retinal Pigment Epithelial Cells ◽  
Dominant Negative Form ◽  
Ectopic Eyes

We report here that misexpression of the transcription factor Pax6 in the vertebrate Xenopus laevis leads to the formation of differentiated ectopic eyes. Multiple molecular markers indicated the presence of mature lens fiber cells, ganglion cells, Muller cells, photoreceptors and retinal pigment epithelial cells in a spatial arrangement similar to that of endogenous eyes. Lineage tracing experiments showed that lens, retina and retinal pigment epithelium arose as a consequence of the cell-autonomous function of Pax6. These experiments also reveal that the cell autonomous activity of misexpressed Pax6 causes the ectopic expression of a number of genes including Rx, Otx2, Six3 and endogenous Pax6, each of which has been implicated in eye development. The formation of ectopic and endogenous eyes could be suppressed by coexpression of a dominant-negative form of Pax6. These data show that in vertebrates, as in the invertebrate Drosophila melanogaster, Pax6 is both necessary and sufficient to trigger the cascade of events required for eye formation.

scholarly journals The role of inflammation and neurodegeneration in diabetic macular edema

2021 ◽  
Vol 13 ◽  
pp. 251584142110559
Author(s):  
Vincenzo Starace ◽  
Marco Battista ◽  
Maria Brambati ◽  
Michele Cavalleri ◽  
Federico Bertuzzi ◽  
...  
Keyword(s):  
Macular Edema ◽  
Diabetic Macular Edema ◽  
Ganglion Cells ◽  
Vascular Dysfunction ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Ganglion ◽  
High Blood Glucose ◽  
Oxidation Stress ◽  
Antiangiogenic Drugs

The pathogenesis of diabetic macular edema (DME) is complex. Persistently high blood glucose activates multiple cellular pathways and induces inflammation, oxidation stress, and vascular dysfunction. Retinal ganglion cells, macroglial and microglial cells, endothelial cells, pericytes, and retinal pigment epithelium cells are involved. Neurodegeneration, characterized by dysfunction or apoptotic loss of retinal neurons, occurs early and independently from the vascular alterations. Despite the increasing knowledge on the pathways involved in DME, only limited therapeutic strategies are available. Besides antiangiogenic drugs and intravitreal corticosteroids, alternative therapeutic options tackling inflammation, oxidative stress, and neurodegeneration have been considered, but none of them has been currently approved.

Light-sensitive melatonin synthesis by Xenopus photoreceptors after destruction of the inner retina

1992 ◽  
Vol 8 (5) ◽  
pp. 487-490 ◽  
Author(s):  
Gregory M. Cahill ◽  
Joseph C. Besharse
Keyword(s):  
Ganglion Cells ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Inner Nuclear Layer ◽  
Cellular Mechanisms ◽  
Inner Retina ◽  
Melatonin Synthesis ◽  
Retinal Photoreceptors ◽  
Melatonin Production

AbstractSeveral lines of evidence indicate that retinal photoreceptors produce melatonin. However, there are other potential melatonin sources in the retina, and melatonin synthesis can be regulated by feedback from the inner retina. To analyze cellular mechanisms of melatonin regulation in retinal photoreceptors, we have developed an in vitro method for destruction of the inner retina that preserves functional photoreceptors in contact with the pigment epithelium. Eyecups, which include the neural retina, retinal pigment epithelium, choroid, and sclera were prepared. The vitreal surface of the retina in each eyecup was washed sequentially with 1% Triton X-100, water, and culture medium. This lysed the ganglion cells and neurons and glia of the inner nuclear layer, causing the retina to split apart within the inner nuclear layer. The damaged inner retina was peeled away, leaving photoreceptors attached to the pigment epithelium. The cell density of the inner nuclear layer was reduced 94% by this method, but there was little apparent damage to the photoreceptors. Lesioned eyecups produced normal melatonin levels in darkness at night, and melatonin production was inhibited by light. These results indicate that the inner retina is not necessary for melatonin production nor for regulation of photoreceptor melatonin synthesis by light. The lesion method used in this study may be useful for other physiological and biochemical studies of photoreceptors.

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