Aqueous angiopoietin-like levels correlate with optical coherence tomography angiography metrics in diabetic macular edema

AIM: To quantitatively detect aqueous levels of angiopoietin-like (ANGPTL)3, ANGPTL4, and ANGPTL6 and investigate their correlation with optical coherence tomography angiography (OCTA) findings in patients with diabetic macular edema (DME). METHODS: This cross-sectional study included 23 patients (27 eyes) with type 2 diabetes and 16 control subjects (20 eyes). All patients underwent OCTA imaging and ultra-wide field fundus photography. Diabetic patients were categorized into two groups according to the presence or absence of diabetic retinopathy (DME group, 14 patients, 16 eyes); and non-diabetic retinopathy (NDR) group, 9 patients, 11 eyes, respectively. Aqueous levels of ANGPTL3, ANGPTL4, and ANGPTL6 were assessed using suspension array technology, and foveal-centered 3×3 mm2 OCTA scans were automatically graded to determine the central, inner, and full vessel density (CVD, IVD, FVD); central, inner, and full perfusion density (CPD, IPD, FPD), foveal avascular zone (FAZ) area, FAZ perimeter, and FAZ circularity index (FAZ-CI) on superficial capillary plexuses. Additionally, central subfield thickness (CST), cube volume (CV), and cube average thickness (CAT) were measured in a model of macular cube 512×128. RESULTS: Aqueous ANGPTL3 levels were not significantly different among the three groups (P>0.05). ANGPTL4 levels were significantly higher in the DME group than the control and NDR groups (P<0.0001 and P<0.001), while ANGPTL6 levels were significantly higher in the DME group than the control group (P<0.05). In the whole cohort, the aqueous ANGPTL3 levels correlated negatively with the IVD, FVD, IPD, and FPD, and positively with the CV and CAT. The aqueous ANGPTL4 levels correlated negatively with the CVD, IVD, FVD, CPD, IPD, and FPD, and positively with the FAZ perimeter, CST, CV, and CAT. The aqueous ANGPTL6 levels correlated negatively with the IVD, FVD, IPD, FPD, FAZ-CI and positively with CST, CV, CAT. CONCLUSION: ANGPTL4 and ANGPTL6 may be associated with vascular leakage in DME and may represent good targets for DME therapy. In addition, OCTA metrics may be useful for evaluating macular ischemia in DME.

Associations Between Diabetic Retinal Microvasculopathy and Neuronal Degeneration Assessed by Swept-Source OCT and OCT Angiography

Purpose: To provide clinical evidence of the associations between retinal neuronal degeneration and microvasculopathy in diabetic retinopathy (DR).Methods: This case-control study included 76 patients (76 eyes) with type 2 diabetes mellitus (DM), and refraction error between −3.0 and +3.0 D. The eyes were assigned into DM (without DR), non-proliferative DR (NPDR), and proliferative DR (PDR) groups. Age-, sex-, and refractive error-matched normal subjects were enrolled as controls. The mean retinal thickness (mRT), the relative mean thickness of the retinal nerve fiber layer (rmtRNFL, mtRNFL/mRT), ganglion cell layer (rmtGCL), ganglion cell complex (rmtGCC) layer, foveal avascular zone area (FAZa), FAZ perimeter (FAZp), FAZ circularity index (FAZ-CI), and vessel density (VD) in superficial capillary plexus (SCP) and deep capillary plexus (DCP) were assessed by swept-source optical coherence tomography (OCT) and OCT angiography (OCTA). Group comparison and Spearman's partial correlation coefficient analysis were applied to evaluate the correlation between these morphological parameters.Results: rmtRNFL, FAZa, and FAZp in SCP and DCP increased with the DR severity (prmtRNFL &lt; 0.001; pFAZa, SCP = 0.001; pFAZa, DCP = 0.005; pFAZp, SCP &lt; 0.001; pFAZp, DCP &lt; 0.001). The rmtGCL, FAZ-CI in SCP and DCP, and VD in DCP decreased with the DR severity (prmtGCL = 0.002, pFAZ−CI, SCP = 0.002; pFAZ−CI, DCP &lt; 0.001, pVD, DCP &lt; 0.001). After controlling age, sex, duration of diabetes, and hypertension, the rmtRNFL, FAZa in SCP and DCP, and FAZp in SCP and DCP were correlated with the severity of DR (p &lt; 0.05), while VD in SCP and DCP, FAZ-CI, and rmtGCL were negatively correlated with the severity of DR (p &lt; 0.05). The rmtGCL was negatively correlated with the FAZa in SCP (r = −0.34, p = 0.002) and DCP (r = −0.23, p = 0.033), and FAZp in SCP (r = −0.37, p = 0.001) and DCP (r = −0.32, p = 0.003), but positively correlated with VD in SCP (r = 0.26, p = 0.016), VD in DCP (r = 0.28, p = 0.012), and FAZ-CI in DCP (r = 0.31, p = 0.006).Conclusions: rmtRNFL, FAZ-CI in SCP and DCP, and FAZp in SCP are strong predictors of the severity of DR. The ganglion cell body loss is highly correlated with increased FAZp and FAZa, decreased FAZ-CI, and reduced VD with the severity of DR.

Delimitação e caracterização morfométrica da bacia hidrográfica do Riacho do Navio, Pernambuco, a partir de dados SRTM processados no QGIS

A bacia hidrográfica do Riacho do Navio, em Pernambuco, tem importante papel ao atender as demandas hídricas de animais, culturas agrícolas e da população local, sendo fundamental estudá-la de maneira mais específica, a fim de que sejam geradas informações que subsidiem a gestão de seus recursos ambientais. O objetivo deste estudo foi delimitar a bacia hidrográfica do Riacho do Navio e descrever suas características morfométricas (forma, rede de drenagem e relevo) a partir de dados Shuttle Radar Topography Mission (SRTM) processados no programa livre Quantum GIS (QGIS), via a ferramenta Terrain Analysis Using Digital Elevation Models (TauDEM). A bacia em questão possui 3.312,97 km2, sendo considerada de quinta ordem, com densidade de drenagem de 0,50 km km-2. Observou-se que a declividade média foi de 5,23%, sendo que mais de 86,61% da área da bacia apresentou declividades menores que 8%. O fator de forma, o coeficiente de compacidade e o índice de circularidade atingiram valores de 0,29; 2,10 e 0,22, indicando que a bacia possui formato alongado e, por conseguinte, baixa tendência a enchentes. Por outro lado, a sinuosidade e a declividade média do álveo podem favorecer a ocorrência de cheias em situações de chuvas intensas. O uso do QGIS e do TauDEM para tratamento de imagens SRTM se mostrou uma ferramenta eficiente, podendo auxiliar na gestão e no gerenciamento dos recursos hídricos da bacia do Riacho do Navio. Delimitation and morphometric characterization of the hydrographic basin of Riacho do Navio, Pernambuco, based on SRTM data processed at QGIS A B S T R A C TThe Riacho do Navio watershed, in Pernambuco, has an important role in meeting the water demands of animals, agricultural crops and the local population, and it is essential to study it more specifically, in order to generate information that supports the management of its environmental resources. The objective of this study was to delimit the Riacho do Navio watershed and describe its morphometric characteristics (shape, drainage network and relief) from Shuttle Radar Topography Mission (SRTM) data, processed in the free program Quantum GIS (QGIS), via the Terrain Analysis Using Digital Elevation Models (TauDEM) tool. The watershed in question has 3,312.97 km2, being considered of fifth order, with drainage density of 0.50 km km-2. It was observed that the average slope was 5.23%, with more than 86.61% of the watershed area showing slopes less than 8%. The shape factor, the compactness coefficient and the circularity index reached values of 0.29; 2.10 and 0.22, indicating that the watersehd has an elongated shape and, therefore, low tendency to flooding. On the other hand, the sinuosity and the average slope of the riverbed can favor the occurrence of floods in situations of intense rains. The use of QGIS and TauDEM for the treatment of SRTM images proved to be an efficient tool, which can assist in the management and administration of water resources in the Riacho do Navio watershed.Keywords: physiographic analysis, Hydrology, digital elevation model, Semiarid, TauDEM.

Post-stroke Delivery of Valproic Acid Promotes Functional Recovery and Differentially Modifies Responses of Peri-Infarct Microglia

The specific role of peri-infarct microglia and the timing of its morphological changes following ischemic stroke are not well understood. Valproic acid (VPA) can protect against ischemic damage and promote recovery. In this study, we first determined whether a single dose of VPA after stroke could decrease infarction area or improve functional recovery. Next, we investigated the number and morphological characteristic of peri-infarct microglia at different time points and elucidated the mechanism of microglial response by VPA treatment. Male Sprague-Dawley rats were subjected to distal middle cerebral artery occlusion (dMCAo) for 90 min, followed by reperfusion. Some received a single injection of VPA (200 mg/kg) 90 min after the induction of ischemia, while vehicle-treated animals underwent the same procedure with physiological saline. Infarction volume was calculated at 48 h after reperfusion, and neurological symptoms were evaluated. VPA didn’t significantly reduce infarct volume but did ameliorate neurological deficit at least partially compared with vehicle. Meanwhile, VPA reduced dMCAo-induced elevation of IL-6 at 24 h post-stroke and significantly decreased the number of CD11b-positive microglia within peri-infarct cortex at 7 days. Morphological analysis revealed that VPA therapy leads to higher fractal dimensions, smaller soma size and lower circularity index of CD11b-positive cells within peri-infarct cortex at both 2 and 7 days, suggesting that VPA has core effects on microglial morphology. The modulation of microglia morphology caused by VPA might involve HDAC inhibition-mediated suppression of galectin-3 production. Furthermore, qPCR analysis of CD11b-positive cells at 3 days post-stroke suggested that VPA could partially enhance M2 subset polarization of microglia in peri-infarct cortex. Analysis of VPA-induced changes to gene expressions at 3 days post-stroke implies that these alternations of the biomarkers and microglial responses are implicated in the upregulation of wound healing, collagen trimmer, and extracellular matrix genes within peri-infarct cortex. Our results are the first to show that a low dose of VPA promotes short-term functional recovery but does not alter infarct volume. The decreases in the expression of both IL-6 and galectin-3 might influence the morphological characteristics and transcriptional profiles of microglia and extracellular matrix remodeling, which could contribute to the improved recovery.

Investigating the Microchannel Architectures Inside the Subchondral Bone in Relation to Estimated Hip Reaction Forces on the Human Femoral Head

The interplay between articular cartilage (AC) and subchondral bone (SB) plays a pivotal role in cartilage homeostasis and functionality. As direct connective pathways between the two are poorly understood, we examined the location-dependent characteristics of the 3D microchannel network within the SB that connects the basal cartilage layer to the bone marrow (i.e. cartilage-bone marrow microchannel connectors; CMMC). 43 measuring points were defined on five human cadaveric femoral heads with no signs of osteoarthritis (OA) (age ≤ 60), and cartilage-bone cylinders with diameters of 2.00 mm were extracted for high-resolution scanning (n = 215). The micro-CT data were categorized into three groups (load-bearing region: LBR, n = 60; non-load-bearing region: NLBR, n = 60; and the peripheral rim: PR, n = 95) based on a gait analysis estimation of the joint reaction force (young, healthy cohort with no signs of OA). At the AC-SB interface, the number of CMMC in the LBR was 1.8 times and 2.2 times higher compared to the NLBR, and the PR, respectively. On the other hand, the median Feret size of the CMMC were smallest in the LBR (55.2 µm) and increased in the NLBR (73.5 µm; p = 0.043) and the PR (89.1 µm; p = 0.043). AC thickness was positively associated with SB thickness (Pearson's r = 0.48; p < 1e-13), CMMC number. (r = 0.46; p < 1e-11), and circularity index (r = 0.61; p < 1e-38). In conclusion, our data suggest that regional differences in the microchannel architecture of SB might reflect regional differences in loading.

Acircularity and Circularity Indexes of the Foveal Avascular Zone in High Myopia

We explored the association between foveal avascular zone (FAZ) parameters and high myopia using optical coherence tomography angiography (OCTA). To evaluate the specific influence of high myopia on the FAZ, we divided 106 eyes of 106 patients into quartiles based on the axial length. The upper quartile was then defined as the high myopia group (n = 27), while the lower quartile was the non-high myopia group (n = 26). The FAZ parameters of these two groups were then retrospectively compared to investigate variations in FAZ size and morphology. The mean axial length and spherical equivalent were 23.96 ± 0.94 mm and -2.27 ± 1.58 diopters in the non-high myopia group and 27.42 ± 0.36 mm and -8.12 ± 2.14 diopters in the high myopia group, respectively. The areas of superficial and deep FAZ, perimeters of deep FAZ, major axis lengths of deep FAZ, minor axis lengths of superficial and deep FAZ were significantly larger in eyes with high myopia than in eyes with non-high myopia (P < 0.05). Linear regression analyses showed that no significant correlation was observed between FAZ areas and acircularity and circularity index of FAZ in non-high myopia group, conversely, FAZ areas strongly correlated with acircularity and circularity index of FAZ in high myopia group. We found that An increase in the FAZ area in highly myopic eyes was accompanied by a significant variation in FAZ acircularity and circularity indexes. Further research should address whether these findings are associated with future disease development in highly myopic eyes.

Does a Relationship Exist Between Posterior Vitreous Detachment, Macular Thickness and Foveal Avascular Zone Dimensions in Myopic Eyes?

Background: The posterior vitreous detachment (PVD) is a separation of the posterior vitreous cortex from the internal limiting membrane of the retina. The PVD induces several potentially serious pathologic events at the vitreoretinal interface. The aim of the study is to determine if relationships exist between PVD, macular thickness (MT) and the foveal avascular zone (FAZ) in myopic eyes. Methods: This is a retrospective case study of 63 myopic subjects who underwent comprehensive eye examination including the optical coherence tomography angiography (OCTA) between January 1 and Jun 30, 2019. The spherical equivalent (SE) was calculated using the manifest refraction. The myopia grouping was based on a severity scale, namely mild, moderate, high and very high using standard refractive error classifications. The PVD classification was based on optical coherence tomography (OCT) images. The status of the PVD and MT were evaluated with Macular Cube 200 × 200 images and the FAZ was imaged with an OCTA, Angioplex. The MT and FAZ dimensions were calculated using a custom algorithm. Results: A total of 114 myopic eyes subjects had median (range) age of 26.00 (22.00 - 28.00) years. Of this cohort, females comprised 62.3 % of the dataset, and the right eyes were 50.00 %. In this population, 10 eyes had no PVD in any quadrant, and 73 eyes had incomplete PVD in all four quadrants. The inferior quadrant had the maximum number of PVD cases and the nasal quadrant had the least number of cases. High myopic eyes exhibited significantly increased low foveal volume (p = 0.000). The inferior part of para- and perimacular area showed a significant thinning in very high myopic eyes (p = <0.05). A statistically significant alteration of FAZ circularity index found in very high myopic eyes (p = 0.002). Conclusion: In high and very high myopic eyes, an increasing trend of partial PVD is seen. The most commonly involved location was the inferior quadrant. A significant alteration in foveal volume and circularity index of the FAZ is seen in high and very high myopic eyes.

Toward a global calibration for quantifying past oxygenation in oxygen minimum zones using benthic Foraminifera

Oxygen Minimum Zones (OMZs) are oceanic areas largely depleted in dissolved oxygen, nowadays considered in expansion in the face of global warming. Their ecological and economic consequences are being debated. The investigation of past OMZ conditions allows us to better understand biological and physical mechanisms responsible for their variability with regards to climate change, carbon pump and carbonate system. To investigate the relationship between OMZ expansion and global climate changes during the late Quaternary, quantitative oxygen reconstructions are needed, but are still in their early development. Here, past bottom water oxygenation (BWO) was quantitatively assessed through a new, fast, semi-automated, and taxonfree morphometric analysis of benthic foraminiferal tests, developed and calibrated using Eastern North Pacific (ENP) and the Eastern South Pacific (ESP) OMZs samples. This new approach is based on an average size and circularity index for each sample. This method, as well as two already published micropalaeontological approaches based on benthic foraminiferal assemblages variability and porosity investigation of a single species, were here calibrated based on availability of new data from 23 core tops recovered along an oxygen gradient (from 0.03 to 1.79 mL.L−1) from the ENP, ESP, AS (Arabian Sea) and WNP (Western North Pacific, including its marginal seas) OMZs. Global calibrated transfer functions are thus herein proposed for each of these methods. These micropalaeontological reconstruction approaches were then applied on a paleorecord from the ENP OMZ to examine the consistency and limits of these methods, as well as the relative influence of bottom and pore waters on these micropalaeontological tools. Both the assemblages and morphometric approaches (that is also ultimately based on the ecological response of the complete assemblage and faunal succession according to BWO) gave similar and consistent past BWO reconstructions, while the porosity approach (based on a single species and its unique response to a mixed signal of bottom and pore waters) shown ambiguous estimations.

Early results of circularity and centration of capsulotomy prepared by three different methods

AIM: To compare the difference of capsulotomy produced by precision pulse capsulotomy (PPC), manual (M-CCC), and femtosecond laser assisted capsulotomy (FLAC) in relation to intraocular lens (IOL) centration, circularity and its effect on visual outcomes. METHODS: Prospective, non-randomized comparative study conducted at LV Prasad Eye Institute, Hyderabad, India. Sixty eyes of 52 patients were grouped into 3 (FLAC, PPC and M-CCC) based on capsulotomy techniques used. Twenty consecutive eyes with uneventful phacoemulsification and with no comorbidities affecting the capsulotomy or visual outcome were included in each group. The main outcome measure was IOL centration in relation to capsulotomy and pupil. Secondary outcome measures were post-operative visual acuity, manifest refraction and aberration profile between groups. RESULTS: At 5wk the visual, refractive outcomes and endothelial cell density were comparable between the 3 groups. The median circularity index of FLAC was statistically significantly different to M-CCC or PPC (1-10) groups (P<0.01) but PPC (11-20) was comparable to FLAC. Decentration of IOL center in relation to capsulotomy was seen only between the PPC (1-10) group and FLAC group (P=0.02). The IOL was well centered in relation to the pupil in all the groups (P=0.46). The quality of vision parameters like the higher order aberrations, spherical aberration, coma, trefoil, modular transfer function, and Strehl ratio were comparable between the groups. CONCLUSION: Our study shows that despite differences in the morphology of capsulotomy produced by PPC, M-CCC, FLAC a well-centered IOL can be achieved. The measured capsular morphology parameters do not affect visual outcomes.

Tools for prioritizing Ecosystem Services provided by fragments forest in the context of cities

Forest remnants are essential in the provision of ecosystem services in cities. However, adequate ecological parameters are still needed to assess them. Because of this, the present work proposes a methodology for assessing the potential of providing ecosystem services by forest remnants in urban watershed based on the application and interpretation of landscape spatial metrics used in Landscape Ecology studies. For that, the environmental indicators (area, central area, circularity index, distance from the nearest neighbor, water springs, land use, and occupation in the surroundings) were evaluated in GIS software and to them, the Hierarchical Process Analysis Method (AHP) was applied to identify the importance of each parameter in the provision of ecosystem services and the priority in each remainder. The study was carried out in a watershed in Campinas/ SP, in which it was found that forest remnants develop, primarily, ecosystem support or habitat services, regulation services, and cultural services.