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Journal of Cell Science Jan 2019Epithelial tissues function as barriers that separate the organism from the environment. They usually have highly curved shapes, such as tubules or cysts. However, the...
Epithelial tissues function as barriers that separate the organism from the environment. They usually have highly curved shapes, such as tubules or cysts. However, the processes by which the geometry of the environment and the cell's mechanical properties set the epithelium shape are not yet known. In this study, we encapsulated two epithelial cell lines, MDCK and J3B1A, into hollow alginate tubes and grew them under cylindrical confinement forming a complete monolayer. MDCK monolayers detached from the alginate shell at a constant rate, whereas J3B1A monolayers detached at a low rate unless the tube radius was reduced. We showed that this detachment is driven by contractile stresses in the epithelium and can be enhanced by local curvature. This allows us to conclude that J3B1A cells exhibit smaller contractility than MDCK cells. Monolayers inside curved tubes detach at a higher rate on the outside of a curve, confirming that detachment is driven by contraction.
Topics: Alginates; Animals; Biomechanical Phenomena; Cell Adhesion; Cell Culture Techniques; Cell Line; Cell Movement; Cells, Immobilized; Collagen; Dogs; Drug Combinations; Epithelial Cells; Laminin; Madin Darby Canine Kidney Cells; Mechanotransduction, Cellular; Mice; Organ Specificity; Proteoglycans
PubMed: 30578312
DOI: 10.1242/jcs.222372 -
Cytotechnology Apr 2019Low intensity (< 2 V/cm (peak to peak voltage/cm)), high frequency (10-30 MHz), and 10 min alternating electric fields (sine wave with no DC component) induce...
Low intensity (< 2 V/cm (peak to peak voltage/cm)), high frequency (10-30 MHz), and 10 min alternating electric fields (sine wave with no DC component) induce non-contact and enzyme-free cell detachment of anchorage-dependent cells directly from commercially available cell culture flasks and stack plates. 0.25 V/cm, 20 MHz alternating electric field for 10 min at room temperature (RT) induced maximum detachment and separated 99.5 ± 0.1% (mean ± SEM, n = 6) of CHO-K1 and 99.8 ± 0.2% of BALB/3T3 cells from the culture flasks. Both vertical and lateral alternating electric field applications for 10 min at RT detach the CHO-K1 cells from 25 cm culture flasks. The alternating electric field application induced cell detachment is almost noncytotoxic, and over 90% of the detached cells remained alive. The alternating electric field applied CHO-K1 cells for 90 min showed little or no lag phase and immediately enter exponential phase in cell growth. Combination of the 20 MHz alternating electric field and enzymatic treatment for 4 min at 37 °C showed synergetic effect and quickly detached human induced pluripotent stem cells from a laminin-coated culture flask compared with the only enzymatic treatment. These results indicate that the rapid cell detachment with both the electric field application and the enzymatic treatment could be applied to subcultures of cells that are susceptible to prolonged enzymatic digestion damage for mass culture of sustainable clinical use.
PubMed: 30783819
DOI: 10.1007/s10616-019-00307-4 -
Graefe's Archive For Clinical and... Mar 2023There have been disparate outcomes in the few studies that have looked at anatomic success and visual acuity (VA) in chronic retinal rhegmatogenous detachment (RRD)...
PURPOSE
There have been disparate outcomes in the few studies that have looked at anatomic success and visual acuity (VA) in chronic retinal rhegmatogenous detachment (RRD) repair. Chronic retinal detachments (RD) without a posterior vitreous detachment (PVD) occur in young myopes often secondary to an atrophic hole. These patients are often asymptomatic, and studies report good surgical anatomic results. However, chronic RD with a PVD is symptomatic but presents late due to patient compliance. This paper aims to evaluate this lesser-studied chronic macula-off RD with PVD.
METHODS
After obtaining Institutional Review Board (IRB) approval, patients who had undergone surgical intervention for all diagnosis codes of RD were identified in the Denver Health Medical Center database. Medical records were reviewed, and patients found to have open-globe injuries, tractional RD due to proliferative diabetic retinopathy, macula-on detachments, and RD due to previous ocular surgery were excluded. Similarly, patients without PVD were also excluded. A total of 37 patients with PVD-type chronic macula-off RD were thus identified and preoperative characteristics, surgical intervention, and complications were analyzed.
RESULTS
The average patient age was 53.8 years. The length of RRD duration ranged from 30 to 365 days (mean 136.7 days). Twenty-six (70.3% patients had proliferative vitreoretinopathy (PVR) grade C or greater. Initial anatomic success-defined as re-attachment after one surgery-was 54.1%. The final attachment was 94.6%. Fifteen of 37 (40.5%) of the patients had issues with drop adherence, positioning, or missing post-operative appointments.
CONCLUSION
Chronic macula-off RD with a PVD should be identified as it is associated with much lower rates of initial re-attachment. Socioeconomic factors likely are the driving factor for patients with PVD-type chronic macula-off RD to present late, struggle with positioning, and have difficulty with follow-up and drop compliance. These extended periods without treatment then lead to high rates of PVR and poor initial anatomic success. However, repair of PVD-type chronic macula-off RD should still be pursued as final anatomic success is high.
Topics: Humans; Middle Aged; Retinal Detachment; Retina; Vitreous Body; Scleral Buckling; Vitreoretinopathy, Proliferative; Vitreous Detachment; Vitrectomy; Retrospective Studies
PubMed: 36289075
DOI: 10.1007/s00417-022-05876-3 -
Indian Journal of Ophthalmology Sep 1996Pneumatic retinopexy (PR) is an alternative to scleral buckling for the surgical repair of selected retinal detachments. A gas bubble is injected into the vitreous... (Review)
Review
Pneumatic retinopexy (PR) is an alternative to scleral buckling for the surgical repair of selected retinal detachments. A gas bubble is injected into the vitreous cavity, and the patient is positioned so that the bubble closes the retinal break (s), allowing absorption of the subretinal fluid. Cryotherapy or laser photocoagulation is applied around the retinal break(s) to form a permanent seal. The procedure can be done in an outpatient setting, and no incisions are required. A multicenter randomized controlled clinical trial has demonstrated that the anatomic success rate is comparable to scleral buckling, but the morbidity is significantly less with PR. If the macula was detached for less than two weeks, the visual results are significantly better with PR than with scleral buckling. Cataract surgery was required significantly more often following scleral buckling than following PR. Two independent reports have shown that an attempt with PR does not disadvantage the eye; such that the results of scleral buckling after failed PR are not significantly different than primary scleral buckling. A comprehensive review of the world literature on PR revealed 27 statistical series totaling 1,274 eyes. These combined series had a single-operation success rate of 80%, and 98% were cured with reoperations. Pneumatic retinopexy should be considered in cases without inferior or extensive retinal breaks and without significant proliferative vitreoretinopathy. The cost of buckling varies from 4 to 10 times that of PR.
Topics: Air; Cryosurgery; Fluorocarbons; Humans; Laser Coagulation; Retinal Detachment; Retinal Perforations; Scleral Buckling; Sulfur Hexafluoride
PubMed: 9018990
DOI: No ID Found -
Methods in Molecular Biology (Clifton,... 2018We describe a recently reported method for directly applying a known, nanonewton-scale force to the nucleus in a living, intact cell. First, a suction seal is applied on...
We describe a recently reported method for directly applying a known, nanonewton-scale force to the nucleus in a living, intact cell. First, a suction seal is applied on the nuclear surface using a micropipette. Then, the micropipette is translated away from the nucleus. The nucleus deforms and translates with the moving micropipette and then eventually detaches from the micropipette and recovers (roughly) its original shape and position. At the point of detachment, the resisting force (from the deformed nucleus and connected cytoskeleton) balances the suction force. Because the suction force is precisely known and reproducibly applied, this method therefore allows comparisons of nuclear response across disruptions to the cytoskeleton, nucleus, or cell. This method is useful for quantifying nuclear elastic properties in its native, integrated environment.
Topics: Animals; Biological Assay; Biomechanical Phenomena; Cell Nucleus; Mice
PubMed: 30141040
DOI: 10.1007/978-1-4939-8691-0_8 -
Current Ophthalmology Reports Sep 2020In this article, the current use and limitations of existing retinal tamponades are discussed. Potential novel developments that address those limitations are...
PURPOSE OF REVIEW
In this article, the current use and limitations of existing retinal tamponades are discussed. Potential novel developments that address those limitations are subsequently highlighted, along with areas of future improvements.
RECENT FINDINGS
While retinal tamponades have existed for decades and improved the treatment of retinal detachments, many problems still exist with their use, including inadequate tamponade of the inferior retina, toxicity from retained heavy liquids, glaucoma, and keratopathy, among others. New advancements in the components of heavy liquids and vitreous substitutes aim to mitigate those issues.
SUMMARY
Existing retinal tamponades, including perflurocarbon heavy liquids, fluorinated gases, and silicone oil, have specific limitations that cause potentially avoidable morbidity. New developments, such as heavy silicone oil, novel vitreous gels, and future avenues of approach, such as potentially reabsorbing heavy liquids may help increase our ability to treat retinal detachments with fewer complications.
PubMed: 33767924
DOI: 10.1007/s40135-020-00247-9 -
American Family Physician Apr 2004Retinal detachment often is a preventable cause of vision loss. There are three types of retinal detachments: exudative, tractional, and rhegmatogenous. The most common... (Review)
Review
Retinal detachment often is a preventable cause of vision loss. There are three types of retinal detachments: exudative, tractional, and rhegmatogenous. The most common type is rhegmatogenous, which results from retinal breaks caused by vitreoretinal traction. Risk factors for retinal detachment include advancing age, previous cataract surgery, myopia, and trauma. Patients typically will present with symptoms such as light flashes, floaters, peripheral visual field loss, and blurred vision. Early intervention facilitates prevention of retinal detachment after formation of retinal breaks and improves visual outcomes of retinal detachment surgery. Patients with acute onset of flashes or floaters should be referred to an ophthalmologist.
Topics: Aged; Child; Diagnosis, Differential; Eye; Humans; Middle Aged; Retinal Detachment; Risk Factors
PubMed: 15086041
DOI: No ID Found -
International Journal of Retina and... Feb 2022In primary rhegmatogenous retinal detachment (RRD), the foveal attachment is an important prognostic factors for post-operative vision. When the fovea is obscured by the...
In primary rhegmatogenous retinal detachment (RRD), the foveal attachment is an important prognostic factors for post-operative vision. When the fovea is obscured by the RRD, its attachment status is considered uncertain. Using a model of the reduced emmetropic and - 10 dioptre myopic eye and the physical properties of the detached retina, we aimed to mathematically ascertain if it is clinically possible for the fovea to be attached while it is obscured by the primary RRD. With the patient upright, a primary RRD due to a 12 o'clock break directly above the fovea was considered. Mathematically, once the trough of the RRD touches the visual axis the edge of the RRD nearest to fovea is [Formula: see text] away from fovea in emmetropic eye and [Formula: see text] in myopic eye. When the RRD reaches the fovea, its trough is [Formula: see text] below the visual axis in emmetropic eye and [Formula: see text] in myopic eye. However, in vivo the RRD makes an acute angle with the retinal pigment epithelium and the corrugation of the retina in RRD shortens the retina. When these in vivo constraints are considered, in both of the above situations the fovea will be detached. If the fovea is obscured by an RRD, the fovea is very likely to be detached. In idiomatic terms, if the fovea cannot be seen, the fovea cannot see. This is an important clinical diagnosis for appropriate triage of the patient.
PubMed: 35115051
DOI: 10.1186/s40942-022-00359-3 -
Radiology Case Reports Aug 2024Choroidal detachment (CD) is a rare and potentially vision-threatening complication of glaucoma surgery. Inflammation and prolonged ocular hypotony can promote fluid...
Choroidal detachment (CD) is a rare and potentially vision-threatening complication of glaucoma surgery. Inflammation and prolonged ocular hypotony can promote fluid accumulation between the choroid and sclera. Risk factors include trauma, advanced age, use of anticoagulant medications, systemic hypertension, atherosclerosis, and diabetes. CD ultrasound findings will show 2 layers, detaching as far anteriorly as the ciliary bodies, that protrude convexly into the vitreous without extending to the optic disc, often described as the appositional or In contrast, retinal detachments will show a distinct "V" shape due to the retina's fixation to the optic nerve head posteriorly. In the case of hemorrhagic CD, therapy should be targeted at reducing intraocular pressure. In this case, the patient was started on atropine and prednisolone drops and discontinued on all glaucoma medications in the left eye. While serous choroidal detachments are usually benign, persistent choroidal effusions may cause significant morbidity with hemorrhagic CD having a worse prognosis. Point of care ultrasound can help emergency physicians quickly distinguish between choroidal and retinal detachments and thus guide management in a safe and timely manner.
PubMed: 38737180
DOI: 10.1016/j.radcr.2024.04.017 -
International Journal of Retina and... 2019Retinoschisis and retinal detachment are distinguished based on features in clinical examination. Even to skilled examiners, some cases may be diagnostic challenges.... (Review)
Review
BACKGROUND
Retinoschisis and retinal detachment are distinguished based on features in clinical examination. Even to skilled examiners, some cases may be diagnostic challenges. Infrared and wide-angle infrared reflectance imaging are relatively new modalities that can provide additional diagnostic information. Non-contact infrared reflectance imaging (also described as near-infrared imaging) highlights sub-retinal features which may otherwise be obscured by standard retinal photography. It is non-invasive and uses the retina's ability to absorb, reflect or scatter infrared light to produce high quality images.
MAIN BODY
The aim of this review is to describe the role of wide-field infrared imaging in screening, diagnosing, and monitoring structural peripheral retinal disorders including retinoschisis, retinal detachment or combined retinoschisis rhegmatogenous detachments. Infrared imaging can also be used to monitor anterior segment inflammation. Heidelberg Wide-Field Module lens and Heidelberg Spectralis HRA + OCT machine (Heidelberg Engineering, Heidelberg, Germany) were used to obtain noncontact, wide-field infrared images on each study eye. Pseudocolor photos were captured by Optos Optomap (Optos, Inc, Massachusetts, USA).
CONCLUSION
Wide angle infrared imaging offers a quick, noncontact, and noninvasive way to help specialists accurately diagnose, monitor for progression, and educate patients about retinal detachment, retinoschisis and even anterior segment inflammation.
PubMed: 31890288
DOI: 10.1186/s40942-019-0188-5