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Clinical & Experimental Optometry Mar 2019Choroidal detachments occur when there is an accumulation of fluid or blood in the suprachoroidal space, a potential space situated between the choroid and the sclera.... (Review)
Review
Choroidal detachments occur when there is an accumulation of fluid or blood in the suprachoroidal space, a potential space situated between the choroid and the sclera. They are an uncommon ocular pathology. The most common cause of choroidal detachment is secondary to trabeculectomy; however, there are other causes such as trauma and inflammation. Clinically, choroidal detachments may vary in presentation from asymptomatic, to very poor vision, severe ocular pain, vomiting and nausea. Ocular findings associated with choroidal detachments include serous retinal detachment, secondary angle closure, and a very shallow anterior chamber. Optometrists, as primary eye care providers, need to be aware of the clinical signs and symptoms associated with choroidal detachments and ensure that appropriate and timely management, with a referral to an ophthalmologist, is instigated for optimal visual outcomes. In this review, the pathophysiology, detection, and associated risk factors for choroidal detachments are discussed, and evidence-based management recommendations in an optometric context are provided. The characteristics and management of uveal effusion syndrome are also reviewed, as this can cause idiopathic exudative choroidal detachments distinct from classical choroidal detachment.
Topics: Antihypertensive Agents; Choroid; Choroidal Effusions; Diagnosis, Differential; Global Health; Humans; Incidence; Multimodal Imaging; Risk Factors; Tomography, Optical Coherence; Trabeculectomy; Ultrasonography
PubMed: 29971817
DOI: 10.1111/cxo.12807 -
Indian Journal of Ophthalmology Dec 2018Twenty-five percent of diabetes-related vision loss stems from complications of proliferative diabetic retinopathy (PDR). Panretinal photocoagulation has been the... (Review)
Review
Twenty-five percent of diabetes-related vision loss stems from complications of proliferative diabetic retinopathy (PDR). Panretinal photocoagulation has been the preferred treatment of high-risk PDR for decades and more recently intravitreal injections of drugs that inhibit the actions of vascular endothelial growth factor have become popular. But despite these treatments PDR may progress uncontrollably to advanced pathologies such as traction retinal detachments (TRDs), combined traction/rhegmatogenous retinal detachments (TRD/RRDs), vitreous hemorrhages, rubeosis iridis, and traction maculopathies, which produce mild-to-severe loss of vision. TDR have long been the most common indication for PDR-related vitreoretinal surgery. Vitrectomy surgery is indicated for recent (<6 months duration) TRD involving the macula, progressive TRD that threatens the macula, and recent data suggest that chronic macula-involving TRDs (>6 months duration) may also benefit. Combined TRD/RRD represents a particularly challenging surgical condition but advances in surgical instrumentation, dissection techniques, and post-operative tamponade have produced excellent success rates. The recent development of small-gauge vitrectomy systems has persuaded most surgeons to switch platforms since these appear to produce shorter surgical times and quicker post-operative recoveries. Pre-operative injections of bevacizumab are frequently administered for persistent neovascularization to facilitate surgical dissection of pre-retinal fibrosis and reduce the incidence of post-operative hemorrhages. Recent trends toward earlier surgical intervention and expanded indications are likely to continue as surgical instrumentation and techniques are further developed.
Topics: Angiogenesis Inhibitors; Diabetic Retinopathy; Disease Management; Fluorescein Angiography; Fundus Oculi; Humans; Intravitreal Injections; Retinal Detachment; Tomography, Optical Coherence; Vascular Endothelial Growth Factor A; Visual Acuity; Vitrectomy
PubMed: 30451175
DOI: 10.4103/ijo.IJO_1217_18 -
Frontiers in Cell and Developmental... 2023Detachment from the extracellular matrix (ECM) is the first step of the metastatic cascade. It is a regulated process involving interaction between tumor cells and...
Detachment from the extracellular matrix (ECM) is the first step of the metastatic cascade. It is a regulated process involving interaction between tumor cells and tumor microenvironment (TME). Iron is a key micronutrient within the TME. Here, we explored the role of iron in the ability of ovarian cancer cells to successfully detach from the ECM. HEY and PEO1 ovarian cancer cells were grown in 3D conditions. To mimic an iron rich TME, culture media were supplemented with 100 μM Fe. Cell mortality was evaluated by cytofluorimetric assay. The invasive potential of tumor spheroids was performed in Matrigel and documented with images and time-lapses. Iron metabolism was assessed by analyzing the expression of CD71 and FtH1, and by quantifying the intracellular labile iron pool (LIP) through Calcein-AM cytofluorimetric assay. Ferroptosis was assessed by quantifying mitochondrial reactive oxygen species (ROS) and lipid peroxidation through MitoSOX and BODIPY-C11 cytofluorimetric assays, respectively. Ferroptosis markers GPX4 and VDAC2 were measured by Western blot. knockdown was performed by using siRNA. To generate spheroids, HEY and PEO1 cells prevent LIP accumulation by upregulating FtH1. 3D HEY moderately increases FtH1, and LIP is only slightly reduced. 3D PEO1upregulate FtH1 and LIP results significantly diminished. HEY tumor spheroids prevent iron import downregulating CD71, while PEO1 cells strongly enhance it. Intracellular ROS drop down during the 2D to 3D transition in both cell lines, but more significantly in PEO1 cells. Upon iron supplementation, PEO1 cells continue to enhance CD71 and FtH1 without accumulating the LIP and ROS and do not undergo ferroptosis. HEY, instead, accumulate LIP, undergo ferroptosis and attenuate their sphere-forming ability and invasiveness. knockdown significantly reduces the generation of PEO1 tumor spheroids, although without sensitizing them to ferroptosis. Iron metabolism reprogramming is a key event in the tumor spheroid generation of ovarian cancer cells. An iron-rich environment impairs the sphere-forming ability and causes cell death only in ferroptosis sensitive cells. A better understanding of ferroptosis sensitivity could be useful to develop effective treatments to kill ECM-detached ovarian cancer cells.
PubMed: 38033861
DOI: 10.3389/fcell.2023.1272667 -
MBio May 2021Gram-negative bacteria have a unique cell envelope with a lipopolysaccharide-containing outer membrane that is tightly connected to a thin layer of peptidoglycan. The...
Gram-negative bacteria have a unique cell envelope with a lipopolysaccharide-containing outer membrane that is tightly connected to a thin layer of peptidoglycan. The tight connection between the outer membrane and peptidoglycan is needed to maintain the outer membrane as an impermeable barrier for many toxic molecules and antibiotics. such as covalently attach the abundant outer membrane-anchored lipoprotein Lpp (Braun's lipoprotein) to tripeptides in peptidoglycan, mediated by the transpeptidases LdtA, LdtB, and LdtC. LdtD and LdtE are members of the same family of ld-transpeptidases but they catalyze a different reaction, the formation of 3-3 cross-links in the peptidoglycan. The function of the sixth homologue in , LdtF, remains unclear, although it has been shown to become essential in cells with inhibited lipopolysaccharide export to the outer membrane. We now show that LdtF hydrolyzes the Lpp-peptidoglycan linkage, detaching Lpp from peptidoglycan, and have renamed LdtF to peptidoglycan -iaminopimelic acid rotein midase (DpaA). We show that the detachment of Lpp from peptidoglycan is beneficial for the cell under certain stress conditions and that the deletion of allows frequent transposon inactivation in the () gene, whose product downregulates lipopolysaccharide biosynthesis. DpaA-like proteins have characteristic sequence motifs and are present in many Gram-negative bacteria, of which some have no Lpp, raising the possibility that DpaA has other substrates in these species. Overall, our data show that the Lpp-peptidoglycan linkage in is more dynamic than previously appreciated. Gram-negative bacteria have a complex cell envelope with two membranes and a periplasm containing the peptidoglycan layer. The outer membrane is firmly connected to the peptidoglycan by highly abundant proteins. The outer membrane-anchored Braun's lipoprotein (Lpp) is the most abundant protein in , and about one-third of the Lpp molecules become covalently attached to tripeptides in peptidoglycan. The attachment of Lpp to peptidoglycan stabilizes the cell envelope and is crucial for the outer membrane to function as a permeability barrier for a range of toxic molecules and antibiotics. So far, the attachment of Lpp to peptidoglycan has been considered to be irreversible. We have now identified an amidase, DpaA, which is capable of detaching Lpp from peptidoglycan, and we show that the detachment of Lpp is important under certain stress conditions. DpaA-like proteins are present in many Gram-negative bacteria and may have different substrates in these species.
Topics: Amidohydrolases; Diaminopimelic Acid; Escherichia coli; Escherichia coli Proteins; Lipoproteins; Peptidoglycan
PubMed: 33947763
DOI: 10.1128/mBio.00836-21 -
The Journal of Analytical Psychology Jun 2021This paper attempts to read the psychological and emotional impact of the COVID-19 pandemic through the archetypal images contained in patients' dreams. In these dreams,...
This paper attempts to read the psychological and emotional impact of the COVID-19 pandemic through the archetypal images contained in patients' dreams. In these dreams, symbols related to the power of nature and to extreme danger are paired with feelings of detachment that seem to point to a traumatic dissociation, due to the archetypal experience that erupts in familiar surroundings. Through the humanization of the ineffable experience, dissociation, which in the beginning of the pandemic showed in high levels of anxiety, panic attacks and depersonalization, can be transformed into the overview needed for the search for meaning. The container for this process of transformation is the analyst, the real, virtual or imagined one, and his or her ability to relate and feel.
Topics: Adult; COVID-19; Dreams; Humans; Professional-Patient Relations; Psychoanalytic Interpretation; Psychoanalytic Therapy; Psychotherapeutic Processes
PubMed: 34231897
DOI: 10.1111/1468-5922.12676 -
Nature Communications Oct 2023Crystal dissolution, which is a fundamental process in both natural and technological settings, has been predominately viewed as a process of ion-by-ion detachment into...
Crystal dissolution, which is a fundamental process in both natural and technological settings, has been predominately viewed as a process of ion-by-ion detachment into a surrounding solvent. Here we report a mechanism of dissolution by particle detachment (DPD) that dominates in mesocrystals formed via crystallization by particle attachment (CPA). Using liquid phase electron microscopy to directly observe dissolution of hematite crystals - both compact rhombohedra and mesocrystals of coaligned nanoparticles - we find that the mesocrystals evolve into branched structures, which disintegrate as individual sub-particles detach. The resulting dissolution rates far exceed those for equivalent masses of compact single crystals. Applying a numerical generalization of the Gibbs-Thomson effect, we show that the physical drivers of DPD are curvature and strain inherently tied to the original CPA process. Based on the generality of the model, we anticipate that DPD is widespread for both natural minerals and synthetic crystals formed via CPA.
PubMed: 37813861
DOI: 10.1038/s41467-023-41443-y -
Medical Hypotheses Nov 2020The limiting step in cancer prevention is a lack of understanding of cancer biology. This limitation is exacerbated by a focus on the dominant somatic mutation theory...
The limiting step in cancer prevention is a lack of understanding of cancer biology. This limitation is exacerbated by a focus on the dominant somatic mutation theory (that driver mutations cause cancer) with little consideration of alternative theories of carcinogenesis. The recently proposed detached pericyte hypothesis explains many puzzling phenomena in cancer biology for which the somatic mutation theory offers no obvious explanation. These puzzling phenomena include foreign-body tumorigenesis, the link between denervation and cancer, tumors in transgenic mice that lack the inducing mutation, and non-genotoxic carcinogens. The detached pericyte hypothesis postulates that (1) a carcinogen or chronic inflammation causes pericytes to detach from blood cell walls, (2) some detached pericytes develop into myofibroblasts which alter the extracellular matrix (3) some detached pericytes develop into mesenchymal stem cells, (4) some of the mesenchymal stem cells adhere to the altered extracellular matrix (5) the altered extracellular matrix disrupts regulatory controls, causing the adjacent mesenchymal stem cells to develop into tumors. Results from experimental studies support the detached pericyte hypothesis. If the detached pericyte hypothesis is correct, pericytes should play a key role in metastasis - a testable prediction. Recent experimental results confirm this prediction and motivate a proposed experiment to partially test the detached pericyte hypothesis. If the detached pericyte hypothesis is correct, it could lead to new strategies for cancer prevention.
Topics: Animals; Carcinogenesis; Mesenchymal Stem Cells; Mice; Mice, Transgenic; Myofibroblasts; Pericytes
PubMed: 32758893
DOI: 10.1016/j.mehy.2020.110056 -
Ophthalmic Surgery, Lasers & Imaging... Sep 2022
Topics: Arthritis; Connective Tissue Diseases; Eye Diseases, Hereditary; Hearing Loss, Sensorineural; Humans; Retinal Detachment
PubMed: 36107624
DOI: 10.3928/23258160-20220815-03 -
RSC Advances Jan 2023Polytetrafluoroethylene (PTFE) has high-frequency characteristics and low transmission loss, and is expected to be used as a substrate material of printed wiring board...
Polytetrafluoroethylene (PTFE) has high-frequency characteristics and low transmission loss, and is expected to be used as a substrate material of printed wiring board for high-frequency applications. Meanwhile, silicone gel has superior properties such as attaching/detaching, weather resistance, and human safety. If the PTFE and silicone gel can be strongly adhered to, they can be applied to internet of things (IoT) devices that can be attached and detached freely. However, adhesion between PTFE, which has poor adhesion, and silicone gel, which has low mechanical strength, is difficult and has not been reported. In this study, PTFE was modified with heat-assisted plasma treatment, and silicone gel was treated with oleophilic SiO powder to improve elastic modulus and modified with plasma jet treatment, and then bonded without adhesive. The adhesion strength of PTFE/silicone gel assembly was 1.13 N mm when treated moderately, but only 0.01 N mm when untreated and treated excessively. To investigate the factors causing the difference in the adhesion strength, the surface of silicone gel was evaluated by water contact angle measurement, Fourier transform infrared spectroscopy, and confocal laser scanning microscopy. When treated moderately, hydrophilic functional groups and cross-linking were most frequently increased. Furthermore, when treated excessively, surface degradation was observed, which was expected to lower the adhesion strength. The adhesive-free bonding between PTFE and silicone gel can open a new path for developing IoT devices that can be freely attached and detached.
PubMed: 36712624
DOI: 10.1039/d2ra05749b -
Journal of Ophthalmology 2018Intraocular gases have been used in vitreoretinal surgery for over 40 years. The aim of this study was to review the complications related to the use of expandable gases... (Review)
Review
Intraocular gases have been used in vitreoretinal surgery for over 40 years. The aim of this study was to review the complications related to the use of expandable gases in vitrectomy and their management. A PubMed, Cochrane Library, and Embase search was conducted using the terms "intraocular gas" and "vitrectomy for retinal detachment." Of the articles retrieved by this method, all publications in English and abstracts of non-English publications were reviewed. Intraocular pressure elevation was reported in up to 58.9% patients after vitrectomy with expandable gas administration for retinal detachment. Vitreoretinal surgery is known to induce cataract development. With that, cataract progression is associated with lens exposure to intraocular gas, the duration of such exposure, patient's age, and the magnitude of vitreous removal. With intraocular gas, the posterior surface of the lens becomes a strongly refractive factor, resulting in high myopia and temporary vision impairment. Other complications related to the use of expandable gases include anterior chamber and subconjunctival gas displacement. Single reports on subretinal and cranial gas migration were published. In vitrectomy for uncomplicated retinal detachments, attempts to shift from expandable gases towards air are observed. Nevertheless, gas tamponade remains a reasonable choice for patients suffering from retinal detachment.
PubMed: 30581605
DOI: 10.1155/2018/8606494