Inactivation of SARS-CoV-2 on salt-coated surfaces: an in vitro study.

In the COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), face masks have become a very important safety measure against the main route of transmission of the virus: droplets and aerosols. Concerns that masks contaminated with SARS-CoV-2 infectious particles could be a risk for self-contamination have emerged early in the pandemic as well as solutions to mitigate this risk. The coating of masks with sodium chloride, an antiviral and non-hazardous to health chemical, could be an option for reusable masks. To assess the antiviral properties of salt coatings deposited onto common fabrics by spraying and dipping, the present study established an in vitro bioassay using three-dimensional airway epithelial cell cultures and SARS-CoV-2 virus. Virus particles were given directly on salt-coated material, collected, and added to the cell cultures. Infectious virus particles were measured by plaque forming unit assay and in parallel viral genome copies were quantified over time. Relative to noncoated material, the sodium chloride coating significantly reduced virus replication, confirming the effectiveness of the method to prevent fomite contamination with SARS-CoV-2. In addition, the lung epithelia bioassay proved to be suitable for future evaluation of novel antiviral coatings.

The Role of the Outer Lamellar Macular Hole in the Surgical Management of Myopic Traction Maculopathy.

PURPOSE: To evaluate the anatomical and functional surgical outcomes of eyes affected by myopic traction maculopathy (MTM) with and without an outer lamellar macular hole (O-LMH). METHODS: Forty-eight eyes affected by MTM were included: a study group of 24 eyes with an O-LMH and a control group of 24 eyes without an O-LMH. All patients underwent spectral-domain optical coherence tomography (SD-OCT) and were staged according to the MTM staging system. The surgical techniques applied were pars plana vitrectomy (PPV), macular buckle (MB), or combined surgery. The follow-up visit was 12 months after the latest intervention. RESULTS: Best-corrected visual acuity (BCVA) improved significantly in both groups after surgery (p < 0.05). A successful surgical result was obtained in both groups at the final follow-up. In the study group, 3 eyes underwent PPV, 14 eyes underwent MB, and 7 underwent a combined surgery. Six patients developed an iatrogenic full-thickness macular hole (FTMH). In the control group, 5 eyes underwent PPV, 16 underwent MB, and 3 had combined surgery. Four patients developed a FTMH. In both groups, all the eyes with an iatrogenic FTMH received PPV as first surgery (alone or combined). A topographical correspondence between the interruption of the ellipsoid zone (EZ) and the backscattering phenomenon was found on OCT. CONCLUSION: The O-LMH is an OCT sign that may occur in eyes affected by MTM. Its presence is correlated with a higher risk of developing an iatrogenic FTMH after PPV (alone or combined) probably due to the thinner residual retinal tissue. Postoperative BCVA is not limited in eyes with an O-LMH and this may be explained by the restoration of the EZ after surgery.

PHOTORECEPTOR DAMAGE IN DIABETIC CHOROIDOPATHY.

PURPOSE: To investigate the relationship between choriocapillaris (CC) hypoperfusion and photoreceptor alterations in eyes with nonproliferative diabetic retinopathy (NPDR). METHODS: In this prospective, observational, case-control study, 30 eyes (30 patients) with NPDR and 30 healthy eyes from 30 controls were enrolled at the University G. d'Annunzio, Chieti-Pescara, Italy. This study cohort underwent an ophthalmologic examination, including optical coherence tomography and optical coherence tomography angiography. The main outcome measures were as follows: 1) "normalized" reflectivity of en face image segmented at the ellipsoid zone level, which was calculated to quantify the photoreceptor damage, and 2) CC perfusion density. Secondary outcome measures were as follows: 1) superficial retinal capillary plexus (SCP), intermediate retinal capillary plexus (ICP), and deep retinal capillary plexus (DCP) perfusion density (based on the area of vessels); 2) SCP, ICP, and DCP vessel length density (based on a map with vessels of 1-pixel width); and 3) SCP, ICP, and DCP vessel diameter. RESULTS: Mean ± SD age was 58.9 ± 11.1 years (range 38-79 years) in the NPDR group and 61.7 ± 11.3 years (range 39-87 years) in the control group (P > 0.05 for all the comparisons). Compared with controls, NPDR eyes displayed a lower "normalized" reflectivity (0.96 ± 0.25 in controls and 0.73 ± 0.19 in the NPDR group, P < 0.0001). Moreover, the NPDR group was characterized by an impaired perfusion in both the retinal and choroidal vasculature. In multiple regression analysis, ellipsoid zone "normalized" reflectivity displayed a significant direct association with CC perfusion density in patients with NPDR (P = 0.025 and P = 0.476, in NPDR and controls, respectively). CONCLUSION: Eyes with NPDR are affected by macular hypoperfusion and photoreceptor damage, the latter investigated as ellipsoid zone "normalized" reflectivity. The diabetic choroidopathy seems to be strongly associated with photoreceptor damage.

Intraoperative optical coherence tomography in the full-thickness macular hole surgery with internal limiting membrane inverted flap placement.

PURPOSE: To describe the helpfulness of using intraoperative optical coherence tomography (OCT) during surgery for full-thickness macular hole (FTMH). OBSERVATIONS: This observational case series identifies three patients with FTMH who were treated with vitrectomy, internal limiting membrane (ILM) peel with inverted ILM flap, which was tucked into the MH, and air with 18% Sulfur Hexafluoride (SF6) gas tamponade. Intraoperative OCT was used to confirm positioning of the ILM flap, even after complete air-fluid exchange. The patients were followed for three months after surgery and all reached a good morphological and functional outcome. CONCLUSIONS: If confirmed by a prospective longitudinal study, the intraoperative OCT might become an important tool in assisting FTMH surgery.

Green Light-Triggerable Chemo-Photothermal Activity of Cytarabine-Loaded Polymer Carbon Dots: Mechanism and Preliminary In Vitro Evaluation.

Carbon-based nanostructures are attracting a lot of attention because of their very low toxicity, excellent visible light-triggered optical and photothermal properties, and intriguing applications. Currently, the development of multifunctional carbon-based nanostructures for a synergistic chemo-photothermal approach is a challenging topic for the advancement of cancer treatment. Here, we report an unprecedented example of photoresponsive carbon-based polymer dots (CPDs-PNM) obtained by a one-pot thermal process from poly(N-isopropylacrylamide) (PNIPAM) without using organic solvent and additional reagents. The CPDs-PNM nanostructures were characterized by spectroscopic techniques, transmission electron microscopy, and atomic force microscopy. The CPDs-PNM exhibited high photothermal conversion efficiency, lower critical solution temperature (LCST) behavior, and good cytarabine (arabinosyl cytosine, AraC) loading capacity (62.3%). The formation of a CPDs-PNM/AraC adduct and photothermal-controlled drug release, triggered by green light excitation, were demonstrated by spectroscopic techniques, and the drug-polymer interaction and drug release mechanism were well supported by modeling simulation calculations. The cellular uptake of empty and AraC-loaded CPDs-PNM was imaged by confocal laser scanning microscopy. In vitro experiments evidenced that CPDs-PNM did not affect the viability of neuroblastoma cells, while the CPDs-PNM/AraC adduct under light irradiation exhibited significantly higher toxicity than AraC alone by a combined chemo-photothermal effect.

A novel protein from the serum of Python sebae, structurally homologous with type-γ phospholipase A(2) inhibitor, displays antitumour activity.

Cytotoxic and antitumour factors have been documented in the venom of snakes, although little information is available on the identification of cytotoxic products in snake serum. In the present study, we purified and characterized a new cytotoxic factor from serum of the non-venomous African rock python (Python sebae), endowed with antitumour activity. PSS (P. sebae serum) exerted a cytotoxic activity and reduced dose-dependently the viability of several different tumour cell lines. In a model of human squamous cell carcinoma xenograft (A431), subcutaneous injection of PSS in proximity of the tumour mass reduced the tumour volume by 20%. Fractionation of PSS by ion-exchange chromatography yielded an active protein fraction, F5, which significantly reduced tumour cell viability in vitro and, strikingly, tumour growth in vivo. F5 is composed of P1 (peak 1) and P2 subunits interacting in a 1:1 stoichiometric ratio to form a heterotetramer in equilibrium with a hexameric form, which retained biological activity only when assembled. The two peptides share sequence similarity with PIP {PLI-γ [type-γ PLA(2) (phospholipase A(2)) inhibitor] from Python reticulatus}, existing as a homohexamer. More importantly, although PIP inhibits the hydrolytic activity of PLA(2), the anti-PLA(2) function of F5 is negligible. Using high-resolution MS, we covered 87 and 97% of the sequences of P1 and P2 respectively. In conclusion, in the present study we have identified and thoroughly characterized a novel protein displaying high sequence similarity to PLI-γ and possessing remarkable cytotoxic and antitumour effects that can be exploited for potential pharmacological applications.

Inter-observer and intra-observer reliability of the myopic traction maculopathy staging system.

AIM: The aim of this study is to evaluate the inter-observer and intra-observer agreement of the myopic traction maculopathy (MTM) staging system (MSS). METHODS: The agreement test for MSS was based on the evaluation of 104 optical coherence tomography (OCT) scans from 104 myopic eyes. According to the MSS, six observers were asked to identify, in each image, one among four retinal patterns and one among three foveal patterns of MTM, the presence of an outer lamellar macular hole (OLMH) and an epiretinal membrane (ERM). Each observer repeated the agreement test after a 60 days interval. RESULTS: Inter-observer reliability: the agreement of the test for the retina pattern was substantial (0.724), for the fovea pattern was 0.821, for the OLMH was 0.656, and for the ERM was 0.463. When all the criteria are included in the validation test the agreement was 0.657. Regarding the weighted statistics (Gwet's AC2, 95% CI), the validation test was statistically significant both when the variables were considered one by one, with an excellent agreement, respectively for the retina pattern (0.955) and the fovea pattern (0.963) and when all the variables were included in the tests (0.930). Intra-observer repeatability: all observers rerun the test after 2 months with a statistically significant percentage of confirmation of the previous test. CONCLUSION: The MSS offers in one Table information on diagnosis, natural history, function, prognosis, and management of MTM. The MSS is user-friendly and highly reproducible.

In vitro testing of salt coating of fabrics as a potential antiviral agent in reusable face masks.

During the coronavirus disease (COVID-19) pandemic, wearing face masks in public spaces became mandatory in most countries. The risk of self-contamination when handling face masks, which was one of the earliest concerns, can be mitigated by adding antiviral coatings to the masks. In the present study, we evaluated the antiviral effectiveness of sodium chloride deposited on a fabric suitable for the manufacturing of reusable cloth masks using techniques adapted to the home environment. We tested eight coating conditions, involving both spraying and dipping methods and three salt dilutions. Influenza A H3N2 virus particles were incubated directly on the salt-coated materials, collected, and added to human 3D airway epithelial cultures. Live virus replication in the epithelia was quantified over time in collected apical washes. Relative to the non-coated material, salt deposits at or above 4.3 mg/cm2 markedly reduced viral replication. However, even for larger quantities of salt, the effectiveness of the coating remained dependent on the crystal size and distribution, which in turn depended on the coating technique. These findings confirm the suitability of salt coating as antiviral protection on cloth masks, but also emphasize that particular attention should be paid to the coating protocol when developing consumer solutions.

Proposal for the management of myopic traction maculopathy based on the new MTM staging system.

PURPOSE: To propose the Myopic Traction Maculopathy (MTM) management Table, based on the MTM Staging System (MSS). METHODS: A retrospective review of 157 eyes affected by MTM, operated with pars plana vitrectomy (PPV), or macular buckle (MB) or combined surgery (MB + PPV). Each case was classified according to the MSS. Anatomical results were evaluated with OCT at an intermediate follow-up (3-6 months) and at a final follow-up (2-8 years), considering changes both in the foveal and in the retinal pattern. The number and type of operations needed were noted. The surgical complications were reported. RESULTS: Primary surgery was MB for 83 eyes (52%), PPV for 36 (23%) and MB + PPV for 38 (24%). At intermediate follow-up, the retinal pattern was restored in 55.41% and foveal in 42.68%.Further surgery was indicated as PPV in 25.48%, MB in 14.65%. At the final follow-up, the retinal pattern was restored in 96.16% and the foveal pattern in 87.90%.BCVA improved at the final follow-up (p < 0.05). The complications of MB were not sight-threatening. The complications of PPV were FTMH in 67% cases in stages 2, 3, and 4. Cataract developed in 60% of phakic eyes. The complications of combined MB+PPV were cataract (56%) and PVR (5%). CONCLUSIONS: Both PPV and MB may be used to treat MTM. PPV addresses the changes in the foveal pattern while MB addresses the changes in the retinal pattern. The MTM management table offers a proposal for the choice of type and timing of treatment customized per each stage of MTM.

Myopic Traction Maculopathy: A New Perspective on Classification and Management.

ABSTRACT: Myopic traction maculopathy (MTM) is a complex disease affecting approximately 30% of eyes with pathologic myopia. A review of the history of treatment of MTM with success rates and limitations of different surgical techniques are reported.The pathogenesis, the definition and the management were clarified in a recent study(cit). The MTM Staging System (MSS) table summarizes all the stages of MTM offering insights on the pathogenesis and natural evolution of the disease.Guidelines of management of MTM were therefore proposed, but customized for each stage.Initial stages 1a and 2a, which define maculoschisis in the inner or inner-outer or only outer layers of the retina, should be observed. Stages 3a and 4a, defining macular detachment with and without associated schisis, should be treated with a macular buckle (MB).Stage 1b, which is a lamellar macular hole in a myopic eye, should be treated with pars plana vitrectomy (PPV) only in symptomatic cases. Stages 2b, 3b, and 4b should be treated with a MB and PPV should be added in a second step only if the presence of a lamellar macular hole requires intervention to improve visual function.Stage 1c, which is a full thickness macular hole in a myopic eye, should be treated with PPV. Stages 2c, 3c and 4c should be treated with a combination of simultaneous MB + PPV to treat both the retinal pattern of schisis or detachment and the full thickness macular hole.

The new Myopic Traction Maculopathy Staging System.

PURPOSE: To describe a comprehensive OCT-based classification of myopic traction maculopathy (MTM). METHODS: Two hundred eighty-one eyes with MTM (visited from 2006 to 2018), were retrospectively reviewed for age, best-corrected-visual-acuity (BCVA), axial length (AL), optical coherence tomography (OCT), and wide-field color fundus-photographs. The study was divided in two Phases. Phase 1: MTM types were categorized with OCT and correlated with age and BCVA. The type of staphyloma was described. Phase 2: the evolution of MTM was studied evaluating at least three OCT exams of each eye taken at different timings (interval between each exam: 1-10 years). RESULTS: Phase 1: We identified, four MTM retinal stages (1. Inner/Outer Maculoschisis; 2. Predominantly outer Maculoschisis; 3. Maculoschisis-Macular Detachment; 4. Macular Detachment) and three foveal stages (a. Normal fovea; b. Inner Lamellar-Macular-Hole; c. Full-Thickness-Macular-Hole). Outer-Lamellar-Macular-Holes and epiretinal abnormalities were associated findings. Stages 1 to 2 were younger than stages 3 to 4 (p < 0.05). BCVA in stages 1, 2 was similar, and higher than stages 3, 4 (p < 0.02). About 14% of eyes had no staphyloma, 73% of eyes had staphyloma type 1 or 2. MTM stages were not correlated with AL. Phase 2: The retina could change in time from stage 1 to 4, or the fovea could change from stage a to c. Mean evolution time from stage 1 to 2, stage 2 to 3, and 3 to 4 were 20, 12, 3 months, respectively. BCVA decreased over time as stages increased (p = 0.47). CONCLUSION: The MSS Table displays a new classification, the natural evolution, and practical insights for the management of MTM.

Myopic Traction Maculopathy: Diagnostic and Management Strategies.

Pathologic myopia (PM) is an ocular disorder characterized by a spherical equivalent (SE) of more than - 6.0 diopters (D) or by an axial length (AL) of more than 26.5 millimeters (mm). PM is associated with myopic maculopathy (MM). The ATN classification describes all the aspects of MM which regroups atrophic, tractional and neovascular consequences to the sclera, choroid and retina of highly myopic eyes. The advent of OCT allowed to define the ultrastructural characteristics of the tractional changes in MM, described by the term myopic traction maculopathy (MTM). They include foveoschisis/maculoschisis/retinoschisis (FS/MS/RS), retinal/foveal detachment (RD/FD), lamellar macular holes (LMH) and full-thickness macular holes (FTMH) with or without RD (MHRD). The MTM staging system (MSS) describes all foveal and retinal changes related to MTM and their natural history interpreting them as different stages of a single progressive disorder. The management of MTM can be just observation for the earliest cases with good vision or surgery for the severe stages with vision loss. There are two possible surgical approaches: ab externo, that acts on the alteration of the scleral shape and includes posterior scleral reinforcement and macular buckle. Ab interno, that targets the alteration of the foveal profile and consists in pars plana vitrectomy with removal of all the epiretinal tractions, maneuvers on the internal limiting membrane, and the use of intravitreal tamponade and laser. As they target two different sides of the same pathology, the two techniques have to be selected on the base of the MTM stage, single or combined.

Widefield topographical analysis of the retinal perfusion and neuroretinal thickness in healthy eyes: a pilot study.

PURPOSE: In this pilot study we reported variation of superficial (SCP) and deep (DCP) capillary plexuses flow in macular and near/mid periphery regions in healthy subjects using widefield swept source-optical coherence tomography angiography (SS-OCTA). METHODS: In this prospective, cross-sectional study, enroled subjects were imaged with an SS-OCTA system (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). OCTA scans were taken in primary and extremes of gaze and a montage was automatically created. Quantitative analysis was performed in the macular and peripheral regions. In addition, SCP and DCP variables were further investigated in distinct fields within these three different regions. RESULTS: Fifty-five young healthy subjects (55 eyes) were enroled. The retinal periphery displayed a higher SCP perfusion density (39.6 ± 1.7% and 40.7 ± 1.4%, P < 0.0001) and SCP vessel diameter index (3.5 ± 0.2 and 3.6 ± 0.2, P < 0.0001), in comparison with the macular region. At the DCP level, the retinal periphery was characterized by a lower perfusion density (41.6 ± 3.7% and 37.9 ± 2.9%, P < 0.0001) and vessel length density (14.6 ± 6.0% and 9.9 ± 2.6%, P < 0.0001). In the analysis investigating the DCP in the retinal periphery, the temporal sector was characterized by a reduction in perfusion density, vessel length density, and vessel diameter index. In univariate analysis, the retinal thickness was found to have a significant direct relationship with DCP perfusion density (P < 0.0001), but not with SCP perfusion density (P = 0.712). CONCLUSIONS: We report quantitative mapping of the SCP and DCP in healthy individuals. The DCP perfusion appears to have a wide topographical variation, which is strictly dependent on the retinal thickness.

Impact of Choriocapillaris Flow on Multifocal Electroretinography in Intermediate Age-Related Macular Degeneration Eyes.

Purpose: To investigate the relationship between perfusion of the choriocapillaris (CC) and macular function in eyes with intermediate age-related macular degeneration. Methods: In this prospective, observational, cross-sectional study, macular optical coherence tomography angiography images and multifocal electroretinograms were obtained in 20 eyes with intermediate age-related macular degeneration from 20 patients. The main outcome measures were (1) the percent nonperfused choriocapillaris area (PNPCA), which represents a measure of the total area of CC vascular dropout, and (2) the average size of the CC signal voids, which represent contiguous regions of CC dropout. Furthermore, amplitude and implicit time of multifocal electroretinograms N1 and P1 waves in the two central rings (R1 and R2) were included in the analysis. Results: Of the 20 patients enrolled, only 17 eyes from 17 patients (13 women) were included in this analysis. Three patients were excluded because of poor scan quality. Mean ± SD age was 75.1 ± 7.9 years (range, 62-89 years). The best corrected visual acuity was 0.17 ± 0.13 logarithm of the minimum angle of resolution. In univariate analysis, both the PNPCA and average signal void size were found to have a significant direct relationship with N1 implicit time in the R2 ring (P = 0.006 and P = 0.035, respectively). Neither PNPCA nor the average signal void size was associated with P1 or N1 implicit times in R1. Conclusions: In intermediate age-related macular degeneration eyes, PNPCA and average signal void size are related to N1 multifocal electroretinogram implicit times, which suggests an association between CC perfusion and photoreceptor function.

Radial Peripapillary Capillary Network in Patients with Retinitis Pigmentosa: An Optical Coherence Tomography Angiography Study.

PURPOSE: To investigate radial peripapillary capillary (RPC) network in patients affected by retinitis pigmentosa (RP). METHODS: Eleven patients (22 eyes) with previous diagnosis of RP and 16 age-matched healthy subjects (16 eyes) were enrolled. The diagnosis of RP was made based on both clinical features and electrophysiological examination. All patients underwent a complete ophthalmologic examination, including optical coherence tomography angiography and visual field (VF). The primary outcomes were the RPC vessel density in the peripapillary and disk areas; the secondary outcomes were the peripapillary retinal nerve fiber layer (RNFL) thickness and the mean defect at VF. RESULTS: A total of 19 eyes of 11 RP patients (5 males, 6 females) and 16 eyes of 16 healthy subjects (10 males, 6 females) were included for the analysis. RPC vessel density in the disk area was 46.5 ± 7.1% in the RP group and 45.4 ± 10.6% in the control group (p = 0.754). RPC vessel density in the peripapillary area was significantly reduced in the RP group after the comparison with the control group (52.5 ± 5.0 and 57.2 ± 5.1%, respectively, p = 0.011). RNFL thickness was 85.9 ± 20.4 µm in the RP group and 104.0 ± 6.4 µm in the control group (p = 0.002). RPC vessel density was significantly correlated with RNFL thickness values in RP patients, both in the disk and in the peripapillary area (Rho = 0.599 and p = 0.007 in the disk area, Rho = 0.665 and p = 0.002 in the peripapillary area, respectively). CONCLUSION: We showed that density of RPC is reduced in these patients in the peripapillary area. Moreover, the RPC vessel density correlates with the RNFL thickness.

Polymerase chain reaction of 2-kb cyanobacterial gene and human anti-alpha1-chymotrypsin gene from genomic DNA on the In-Check single-use microfabricated silicon chip.

The microfabricated chip is a promising format for automating and miniaturizing the multiple steps of genotyping. We tested an innovative silicon biochip (In-Check Lab-on-Chip; STMicroelectronics, Agrate Brianza, Italy) designed for polymerase chain reaction (PCR) analysis of complex biological samples. The chip is mounted on a 1x3-in(2). plastic slide that provides the necessary mechanical, thermal, electrical, and fluidic connections. A temperature control system drives the chip to the desired temperatures, and a graphical user interface allows experimenters to define cycling conditions and monitor reactions in real time. During thermal cycling, we recorded a cooling rate of 3.2 degrees C/s and a heating rate of 11 degrees C/s. The temperature maintained at each thermal plateau was within 0.13 degrees C of the programmed temperature at three sensors. From 0.5 ng/microl genomic DNA, the In-Check device successfully amplified the 2060-bp cyanobacterial 16S rRNA gene and the 330-bp human anti-alpha(1)-chymotrypsin gene. The shortest PCR protocol that produced an amplicon by capillary electrophoresis comprised 30 cycles and was 22.5 min long. These thermal cycling characteristics suggest that the In-Check device will permit future development of a genotyping lab-on-a-chip device, yielding results in a short time from a limited amount of biological starting material.