scholarly journals Impact of the COVID-19 Pandemic on Ophthalmic Practice. Historical Aspects and Clinical Examples

2021 ◽  
Vol 18 (2) ◽  
pp. 181-187
Author(s):  
V. N. Trubilin ◽  
E. G. Poluninа ◽  
V. V. Kurenkov ◽  
D. V. Andzhelova ◽  
E. E. Kazaryan ◽  
...  
Keyword(s):  
Process Development ◽  
Ganglion Cell Layer ◽  
Vascular System ◽  
Plexiform Layer ◽  
Pathological Process ◽  
Close Attention ◽  
Central Artery ◽  
Coronavirus Infection ◽  
Papillomacular Bundle ◽  
Visual Organ

This article presents data on clinical ophthalmological manifestations of COVID-19 described in the literature, clinical examples that we met in pandemic conditions, COVID-19 including early and late manifestations, as well as references to studies conducted decades ago and aimed to evaluate the effects of coronavirus infection on the visual organ. The purpose of the most studies was to study the effect of COVID-19 on the visual organ indicate that the most common ophthalmological manifestation of this disease is conjunctivitis, which occurs in 3–10 % of cases. Our observations showed that patients with COVID-19, when applying for an appointment with an ophthalmologist after 1–3 months, make complaints about the feeling of dryness, discomfort in the eyes, itching and redness of the eyelids. These complains arose immediately after the illness and persisted during the above terms. This phenomenon can be explained by the fact that any inflammatory process occurring on the eye surface disrupts the process of lacrimation and leads to the emergence of dry eye syndrome. It is necessary to pay close attention to complaints from the visual organ not only in patients with COVID-19 in the early stages of the disease, but also in the coming months after stopping the acute pathological process. As studies have shown, coronavirus can involve the posterior segment of the eye in the pathological process, since this virus has a retinotropic effect. This hypothesis can be confirmed by the reports of several authors who studied with optical coherence tomography (OCT) the state of the retina 11–33 days after the onset of symptoms in patients with COVID-19. OCT data indicate the presence of hyperreflexive zones at the level of the ganglion cell layer and the plexiform layer, the severity of these zones being greater in the papillomacular bundle region. In addition, cases of thromboembolic complications affecting the vascular system of the eye are described. Considering the fact that in the development of thromboembolism of the central artery and retinal vein, therapy is as effective as possible in the first hours from the beginning of this pathological process development, close attention should be paid to patients’ complaints to visual impairment occurred against the background of coronavirus infection. The data presented in this article open up a range of possibilities for conducting new scientific research that will help to preserve the vision and health of our patients as effectively as possible. 

scholarly journals New inhibitors of glucosylceramide synthase and their effect on cell fate

2014 ◽  
Vol 7 (2) ◽  
pp. 99-104 ◽  
Author(s):  
Katarína Turáková ◽  
Boris Lakatoš ◽  
Andrej Ďuriš ◽  
Daniela Moravčíková ◽  
Dušan Berkeš
Keyword(s):  
Cell Viability ◽  
Cell Fate ◽  
Calcium Transport ◽  
Large Scale ◽  
Process Development ◽  
Pharmaceutical Research ◽  
Pathological Process ◽  
Uridine Diphosphate ◽  
Induction Of Apoptosis

Abstract Glucosylceramide (GlcCer) is an essential glycosylated lipid found in organisms ranging from fungi to mammals. It is composed of a hydrophilic β-linked glucose and a hydrophobic ceramide, with a predominant content of sphingosine in mammals (d18:1). GlcCer is the precursor of a large scale of different glycosphingolipids. This cerebrozide is synthesized from uridine diphosphate-glucose and ceramide by a GlcCer synthase (UDP-glucose:ceramide glucosyltransferase; UGCG, EC 2.4.1.80). GlcCer-based sphingolipids have been identified as important mediators of a variety of cellular functions and their disequilibrium leads to pathological process development and may induce several diseases progression. Therefore, design of UGCG inhibitor represents an important topic for pharmaceutical research. In this paper, we aimed to study effects of newly synthesized derivatives of (±)-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol (PPMP, known UGCG inhibitor) on: i) activity of UGCG in vitro; ii) thymocytes viability; iii) calcium transport through plasma membrane of thymocytes; iv) induction of apoptosis and autophagy in thymocytes. Thymocytes were isolated from thymus of three to seven weeks old mice (ICR strain). The key factors influencing the effect of PPMP analogues were their concentration, chemical structure and incubation time. Derivatives were able to change Ca2+ transport already after 15 min of cultivation, but their effects on cell viability were manifested at least after 12 h of cultivation. Four from fifteen studied compounds affected UGCG activity after four hour lasting cultivation, - but without correlation with data relating to effects on calcium transport and/or cell viability. Most potent UGCG inhibitor was chosen and applied for induction of apoptosis and autophagy in thymocytes. This inhibitor induced typical DNA fragmentation and upregulation of LC3B protein as autophagy marker, after 2 h and 4 h cultivation, respectively.

GABAA receptors in neurons of the nerve fiber layer in rabbit retina

1996 ◽  
Vol 13 (5) ◽  
pp. 991-994 ◽  
Author(s):  
B. Ehinger ◽  
C. L. Zucker
Keyword(s):  
Nerve Fiber ◽  
Gabaa Receptors ◽  
Ganglion Cell Layer ◽  
Cell Layer ◽  
Plexiform Layer ◽  
Rabbit Retina ◽  
Fiber Layer ◽  
Nerve Fiber Layer ◽  
Mammalian Retina ◽  
Plexiform Layers

AbstractTwo synapse-rich layers are well recognized in the mammalian retina, the inner and outer plexiform layers. However, synapses occur also in other layers, particularly in the innermost nerve fiber layer. These synapses form a tenuous layer at times referred to as the superficial plexiform layer. We have found that staining for GABAA receptors in whole-mounted rabbit retina demonstrates this layer. It is most well developed in the region of the visual streak 2–4 mm below the center of the myelinated streak and is very sparse in other parts. Most or all of the processes in the plexus originate from cells in the ganglion cell layer.

scholarly journals The disorder of the iron metabolism as a possible mechanism for the development of neurodegeneration after new coronavirus infection of SARS-CoV-2

2021 ◽  
Vol 40 (4) ◽  
pp. 13-24
Author(s):  
Igor V. Litvinenko ◽  
Igor V. Krasakov
Keyword(s):  
Nervous System ◽  
Neurodegenerative Diseases ◽  
Iron Metabolism ◽  
Iron Homeostasis ◽  
Molecular Mechanisms ◽  
Brain Structures ◽  
Pathological Process ◽  
Parkinsons Disease ◽  
Neurodegenerative Process ◽  
Coronavirus Infection

The involvement of the nervous system in the pathological process that occurs when COVID-19 is infected is becoming more and more obvious. The question of the possibility of the debut or progression of the already developed Parkinsonism syndrome in patients who have undergone COVID-19 is regularly raised. A large number of hypotheses are put forward to explain this relationship. It is assumed that a violation of iron metabolism in the brain may underlie the development and progression of neurodegenerative diseases, including after the new coronavirus infection SARS-CoV-2. The analysis of stu dies on the possible influence of iron metabolism disorders on the occurrence and mechanism of development of neurodegenerative diseases after infection with SARS-CoV-2 has been carried out. The processes of physiological maintenance of iron homeostasis, as well as the influence of physiological aging on the accumulation of iron in the central nervous system are described. The relationship between hyperferritinemia occurring in COVID-19 and ferroptosis as the basis of the neurodegenerative process in Parkinsons disease and Alzheimers disease is discussed. The main molecular mechanisms involved in ferroptosis are described. Examples of involvement of metal homeostasis disorders in the process of altering the structure of -synuclein, synthesis of -amyloid, hyperphosphorylated tau- protein are given. The causes of excessive iron accumulation in certain brain structures are discussed. The question of the possibility of using the assessment of changes in iron metabolism as a new biomarker of the progression of Parkinsons disease is analyzed. (1 figure, bibliography: 62 refs)

Analysis of COVID-associated posterior eye segment lesions for the period from may 2020 to april 2021 in the Budgetary institution of the Chuvash Republic «Republican clinical ophthalmological hospital» of the Ministry of healthcare of the Chuvash Republic

2021 ◽  
pp. 180-183
Author(s):  
M.Y. Leonteva ◽  
◽  
D.G. Arsiutov ◽  
◽  
◽  
...  
Keyword(s):  
Inflammatory Diseases ◽  
Young Patients ◽  
Vascular Diseases ◽  
Pathological Process ◽  
Posterior Segment ◽  
Unfavorable Outcome ◽  
Laser Coagulation ◽  
Associated Lesions ◽  
Coronavirus Infection ◽  
Chuvash Republic

Purpose. To evaluate COVID-associated lesions of the posterior segment of the eye and analyze them in terms of severity. Material and methods. The study was carried out at the Republican Clinical Ophthalmological Hospital of the Ministry of Healthcare of Chuvashia, Cheboksary. For the period from May 2020 to April 2021, 58 complaints were registered from patients with a sharp deterioration in vision against the background of a confirmed coronavirus infection. All patients underwent a standard ophthalmologic examination. After the examination and verification of the diagnosis, the patients were divided into two groups. The first group: COVID - associated vascular diseases of the posterior segment of the eye, and the second group - COVID - associated inflammatory diseases of the posterior segment of the eye. Results. In the first group, when macular edema was detected using OCT, intravitreal instillation of ranibizumab (the average number of injections was 3) followed by paravasal laser coagulation of the retina. In the second group, patients received pathogenetic therapy - glucocorticosteroids, non-steroidal anti-inflammatory, desensitizing drugs both locally and systemically, cycloplegia. We noted that COVID-associated inflammatory diseases of the posterior eye segment are distinguished by the severity of the course, a tendency to relapse and, often, an unfavorable outcome. Conclusions. Coronavirus infection tends to affect the posterior segment of the eye. COVID-associated diseases of the posterior segment of the eye are distinguished by the severity of the course, a tendency to relapse and, often, an unfavorable outcome. In young patients, inflammatory manifestations of coronavirus infection in the posterior segment of the eye predominate. It can be assumed that coronavirus infection is neurotropic according to the frequent involvement of the optic nerve in the pathological process. Key words: coronavirus infection, posterior segment of the eye, COVID-associated vascular diseases of the posterior segment of the eye, COVID-associated inflammatory diseases of the posterior segment, neurotropicity.

scholarly journals Patterns of retrograde axonal degeneration in the visual system

Brain ◽  
2019 ◽  
Vol 142 (9) ◽  
pp. 2775-2786 ◽  
Author(s):  
Willemien A de Vries-Knoppert ◽  
Johannes C Baaijen ◽  
Axel Petzold
Keyword(s):  
Experimental Data ◽  
Optical Coherence Tomography ◽  
Ganglion Cell ◽  
Axonal Degeneration ◽  
Ganglion Cell Layer ◽  
Cell Layer ◽  
Region Of Interest ◽  
Plexiform Layer ◽  
Inner Plexiform Layer ◽  
Layer Region

Abstract Conclusive evidence for existence of acquired retrograde axonal degeneration that is truly trans-synaptic (RTD) has not yet been provided for the human visual system. Convincing data rely on experimental data of lesions to the posterior visual pathways. This study aimed to overcome the limitations of previous human studies, namely pathology to the anterior visual pathways and neurodegenerative co-morbidity. In this prospective, longitudinal cohort retinal optical coherence tomography scans were acquired before and after elective partial temporal lobe resection in 25 patients for intractable epilepsy. Newly developed region of interest-specific, retinotopic areas substantially improved on conventional reported early treatment diabetic retinopathy study (ETDRS) grid-based optical coherence tomography data. Significant inner retinal layer atrophy separated patients with normal visual fields from those who developed a visual field defect. Acquired RTD affected the retinal nerve fibre layer, ganglion cell and inner plexiform layer and stopped at the level of the inner nuclear layer. There were significant correlations between the resected brain tissue volume and the ganglion cell layer region of interest (R = −0.78, P < 0.0001) and ganglion cell inner plexiform layer region of interest (R = −0.65, P = 0.0007). In one patient, damage to the anterior visual pathway resulted in occurrence of microcystic macular oedema as recognized from experimental data. In the remaining 24 patients with true RTD, atrophy rates in the first 3 months were strongly correlated with time from surgery for the ganglion cell layer region of interest (R = −0.74, P < 0.0001) and the ganglion cell inner plexiform layer region of interest (R = −0.51, P < 0.0001). The different time course of atrophy rates observed relate to brain tissue volume resection and suggest that three distinct patterns of retrograde axonal degeneration exist: (i) direct retrograde axonal degeneration; (ii) rapid and self-terminating RTD; and (iii) prolonged RTD representing a ‘penumbra’, which slowly succumbs to molecularly governed spatial cellular stoichiometric relationships. We speculate that the latter could be a promising target for neuroprotection.

Morphology of human retinal ganglion cells with intraretinal axon collaterals

1998 ◽  
Vol 15 (2) ◽  
pp. 377-387 ◽  
Author(s):  
BETH B. PETERSON ◽  
DENNIS M. DACEY
Keyword(s):  
Ganglion Cell ◽  
Ganglion Cell Layer ◽  
Ganglion Cells ◽  
Cell Layer ◽  
Plexiform Layer ◽  
Wide Field ◽  
Inner Plexiform Layer ◽  
Human Retina ◽  
Cell Type ◽  
Axon Collaterals

Ganglion cells with intraretinal axon collaterals have been described in monkey (Usai et al., 1991), cat (Dacey, 1985), and turtle (Gardiner & Dacey, 1988) retina. Using intracellular injection of horseradish peroxidase and Neurobiotin in in vitro whole-mount preparations of human retina, we filled over 1000 ganglion cells, 19 of which had intraretinal axon collaterals and wide-field, spiny dendritic trees stratifying in the inner half of the inner plexiform layer. The axons were smooth and thin (∼2 μm) and gave off thin (<1 μm), bouton-studded terminal collaterals that extended vertically to terminate in the outer half of the inner plexiform layer. Terminal collaterals were typically 3–300 μm in length, though sometimes as long as 700 μm, and were present in clusters, or as single branched or unbranched varicose processes with round or somewhat flattened lobular terminal boutons 1–2 μm in diameter. Some cells had a single axon whereas other cells had a primary axon that gave rise to 2–4 axon branches. Axons were located either in the optic fiber layer or just beneath it in the ganglion cell layer, or near the border of the ganglion cell layer and the inner plexiform layer. This study shows that in the human retina, intraretinal axon collaterals are associated with a morphologically distinct ganglion cell type. The synaptic connections and functional role of these cells are not yet known. Since distinct ganglion cell types with intraretinal axon collaterals have also been found in monkey, cat, and turtle, this cell type may be common to all vertebrate retinas.

The Biophysical Modeling of the Hemodynamic in the Human Organism

2020 ◽  
Vol 7 (11) ◽  
pp. 494-502
Author(s):  
Janos Vincze ◽  
Gabriella Vincze-Tiszay ◽  
Julianna Szakacs
Keyword(s):  
Blood Flow ◽  
Vascular System ◽  
Experimental Testing ◽  
Real Life ◽  
Pathological Process ◽  
Human Organism ◽  
Main Function ◽  
Biophysical Modeling ◽  
Circulatory Apparatus ◽  
Cardio Vascular

The circulatory apparatus has as a main function the constant maintaining of the internal environment in all the regions of the organism. The blood is a liquid tissue, being formed of a fundamental substance – plasma and blood cells. Heart is the central organ of the cardiovascular apparatus. The heart muscles have numerous biophysical properties. The cardiac muscle is never tired unless it suffered a pathological process. During the diastole, blood is aspired in the heart and during the systole it is pushed in the big and small circulation. The blood amount pushed from the heart in the vascular system in a certain time represents the blood flow. The biophysical methods are next: we administer a certain substance amount, then its passing speed will depend on its concentration; to apply the calorimetric principles for the measurement of the gastric blood flow; the diagnostic of a chronic peripheral arteriopathy we use the calorimetric method is based on measuring the heat being introduced in a certain amount of water which has known temperature; one of the most often used methods for the evaluation of the use of radioisotopes in the cardio-vascular system is the compartment method. Any attempt to apply biophysics to the life systems involves three stages. First we observe the phenomena and formulate a biophysical description in the form of equations; after to solve the equations. Finally we return to the real life system and interpret this solution in terms of reality, this interpretation may requiew experimental testing.

scholarly journals ETIOLOGY AND PATHOGENESIS OF THE CONGENITAL PNEUMONIA IN NEWBORNS (LITERATURE REVIEW - PART 1)

2021 ◽  
Vol 4 (11(75)) ◽  
pp. 22-25
Author(s):  
L. Levchenko ◽  
H. Sargsyan ◽  
K. Nikoghosyan
Keyword(s):  
Premature Infants ◽  
Newborn Infants ◽  
Intrauterine Infection ◽  
Pathological Process ◽  
Close Attention ◽  
Clear Trend ◽  
Premature Babies ◽  
Causative Agents ◽  
Intrauterine Infections ◽  
Number Of Births

This article focuses on the incidence of intrauterine pneumonia among newborns, with an emphasis on premature babies. So, at the beginning of the 21st century, there is a clear trend in all countries to an increase in the number of births of premature patients. Among the variety of intrauterine infections in premature infants, intrauterine pneumonia deserves close attention. The article presents the main risk factors for preterm birth. The modern views on the etiology of intrauterine pneumonia in newborn infants are presented in detail. The main causative agents of this pathological process are given. The causes of lung lesions in newborns, especially premature babies, are indicated. Clear parallels are drawn between low gestational age and newborn’s body weight with the consequences of previous hypoxia (acute and / or chronic), as well as with the emergence and rate of development of intrauterine infection and its influence on the formation and development of the fetal immune system. The combined effect of unfavorable factors subsequently leads to the manifestation of pronounced immunosuppression in the newborn and creates the preconditions for the generalization of the pathological process.

scholarly journals Investigation of the pathophysiology of the retina and choroid in Parkinson's disease by optical coherence tomography

2021 ◽  
Author(s):  
Yasuaki Kamata ◽  
Naoto Hara ◽  
Tsukasa Satou ◽  
Takahiro Niida ◽  
Kazuo Mukuno
Keyword(s):  
Optical Coherence Tomography ◽  
Ganglion Cell ◽  
Nerve Fiber ◽  
Retinal Nerve Fiber Layer ◽  
Ganglion Cell Layer ◽  
Cell Layer ◽  
Plexiform Layer ◽  
Inner Plexiform Layer ◽  
Fiber Layer ◽  
Luminal Area

Abstract Purpose The pathology of Parkinson's disease (PD) is suspected to affect the retina and choroid. We investigated changes in the retina and choroid of patients with PD using optical coherence tomography. Methods We examined 14 patients with PD and 22 patients without PD. Patients without PD had no ophthalmic disease other than cataracts. In addition, it was also confirmed that there was no neurodegenerative disease. The retinal nerve fiber layer, ganglion cell layer + inner plexiform layer, and choroidal thickness were compared between both groups. Additionally, the choroidal image was divided into the choroid area, luminal area, and interstitial area using the binarization method, and the area of each region and the percentage of luminal area in the choroid area were analyzed. Results Patients with PD had a significantly thinner ganglion cell layer + inner plexiform layer compared to those without PD. The choroid area, luminal area, and interstitial area were significantly decreased in patients with PD compared to those without PD. Seven patients with PD who were successfully followed up showed decreased retinal nerve fiber layer and interstitial area after 3 years. Conclusion Autonomic nervous disorders and neurodegeneration in PD can cause thinning of the retina and choroid, as well as a reduction in the choroid area.

scholarly journals RISK FACTORS FOR MALIGNANCY OF PAPILLOMAS IN THE OROPHARYNGEAL MUCOUS MEMBRANE ASSOCIATED WITH HUMAN PAPILLOMAVIRUS (HPV)

2021 ◽  
Vol 11 (3) ◽  
pp. 46-49
Author(s):  
Galina Reva ◽  
Stanislav Ichenko ◽  
Igor Sementsov ◽  
Aleksandr Kim ◽  
Oksana Voskanyan ◽  
...  
Keyword(s):  
Mucous Membrane ◽  
Process Development ◽  
Basal Membrane ◽  
Growth Zone ◽  
Pathological Process ◽  
Oral Epithelium ◽  
Epithelial Layer ◽  
Third Stage ◽  
Hematoxylin And Eosin ◽  
Antigen Presenting

Analysis of the HPV positive papilloma structures at different levels of pathological process development was carried out. Classical staining of preparations with hematoxylin and eosin was used for immunohistochemical determination of Ki67-positive cells and phenotyping of CD positive cells. We found that the process of papilloma formation begins with a local increase in the proliferative activity of keratinocytes which contributes to the formation of a local epithelial convex above the surface of the oropharyngeal mucosa (OPM) in the form of papilloma. The connective tissue of the OPM adjacent to the epithelium grows at the second stage. At the same time here is a decrease in immunocytes/macrophages number of the oral epithelium not only in the growth zone of the papilloma but in the adjacent neoplasm tissue. The third stage is characterized by the destruction of the basal membrane of the OPM. Apoptotic cells in the cambial layer and forming leukocytes infiltrate the OPM lamina propria. Virus-infected keratinocytes are phagocytized by macrophages or exfoliated from the surface of the epithelial layer. The emerging in the middle layers defect of tissue of the epithelial layer and the absence of Langerhans cells indicate a relationship between the migration of antigen-presenting cells expressing CD68 with impaired differentiation and specialization of keratinocytes. The conclusion is based on the analogy of "leukemic failure" in leukemia and on the absence of differentiating epithelial cells between the cambium and the specialized surface layer in the long-existing papilloma. The disappearance from the epithelium of CD68-positive cells specific to the epithelial layer is a prognostic sign of malignization in the mucous membrane of the oropharynx.

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