Uniform Random Sampling Research Articles

Impact of maternal diabetes type 1 on proliferative potential, differentiation and apoptotic activity in villous capillaries of term placenta

IntroductionMaternal diabetes mellitus changes morphology and impairs function of placental capillaries. Here, quantitative parameters characterizing cell proliferation using detection of Ki67, differentiation reflected by nestin expression and apoptosis in placental capillary bed with active caspase 3 as a marker were compared in normal term placentas and placentas from pregnancies complicated by Type 1 maternal diabetes mellitus. MethodsSpecimens of sixteen diabetic placentas and eight control placentas were collected by systematic uniform random sampling. Immunohistochemical detections of Ki67, nestin, and active caspase 3 were performed in histological sections of five haphazardly chosen blocks per placenta. Twenty fields of view per section, i.e. one hundred fields of view per placenta, were used for analysis of proliferation as well as of apoptosis, and in approximately 70 capillary cross-sections per placenta the nestin-positive segments of their circumference were measured. ResultsThe percentage of Ki67-positive cells counted in the capillary wall was significantly lower in diabetic group. The counts of Ki67-labelled nuclei per villous area unit were significantly lower in cytotrophoblast and capillary wall of terminal villi in diabetic placenta. The proportion of nestin-labeled segments of capillary circumference was significantly higher in placentas of diabetic group. No differences in the numbers of apoptotic cells were found between studied groups. DiscussionThe results show that the term placenta in Type 1 diabetes has lower potential to enlarge the surface area of structures involved in maternofetal transport, and that the villous capillary bed displays delayed differentiation. Those factors may participate in decreased ability of diabetic placenta to comply with fetal requirements in the final stage of pregnancy.

A Quantitative Study of Pure Parallel Processes

In this paper, we study the interleaving – or pure merge – operator that most often characterizes parallelism in concurrency theory. This operator is a principal cause of the so-called combinatorial explosion that makes the analysis of process behaviours e.g. by model-checking, very hard – at least from the point of view of computational complexity. The originality of our approach is to study this combinatorial explosion phenomenon on average, relying on advanced analytic combinatorics techniques. We study various measures that contribute to a better understanding of the process behaviours represented as plane rooted trees: the number of runs (corresponding to the width of the trees), the expected total size of the trees as well as their overall shape. Two practical outcomes of our quantitative study are also presented: (1) a linear-time algorithm to compute the probability of a concurrent run prefix, and (2) an efficient algorithm for uniform random sampling of concurrent runs. These provide interesting responses to the combinatorial explosion problem.

Estimation of volume density of interdental papilla components in patients with chronic periodontitis and interleukin-6 (-174G/C) gene polymorphisms.

The association between interleukin-6 (IL-6) (-174G/C) gene polymorphisms and level of tissue breakdown and periodontal disease progression is unknown. The present study investigated quantitative parameters of interdental papilla in chronic periodontitis (CP) patients with IL-6 (-174G/C) gene polymorphisms. Sixty gingival samples were studied. After determination of IL-6 (-174G/C) gene polymorphisms using a tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) technique, 45 gingival tissue samples of CP patients (GG and GC+CC genotypes) were considered as case groups. Fifteen control samples were also collected from healthy individuals. After tissue processing, interdental gingival tissues were exhaustively sectioned into 4 μm-thick sections. Ten to thirteen sections were sampled by systematic uniform random sampling and stained with Masson trichrome, and the volume density (Vv) of the gingival components was estimated using Cavalier's point counting method. Statistical analysis was performed by Student t-test to compare differences between groups. The significance level was set at P < 0.05. There were statistically significant differences in the Vv of epithelium, connective tissue, collagenous and non-collagenous matrix, and blood vessels between the control and CP groups (P < 0.0001). There were no statistically significant differences in the Vv of epithelium, connective tissue of gingiva, collagenous and non-collagenous matrix, and blood vessels among GG, GC, and CC genotypes in CP patients (P > 0.05). Results of the current study showed that there was no association between IL-6 (-174G/C) gene polymorphisms and quantitative parameters of interdental papilla in CP patients.

Riemannian Optimization for High-Dimensional Tensor Completion

Tensor completion aims to reconstruct a high-dimensional data set where the vast majority of entries is missing. The assumption of low-rank structure in the underlying original data allows us to cast the completion problem into an optimization problem restricted to the manifold of fixed-rank tensors. Elements of this smooth embedded submanifold can be efficiently represented in the tensor train or matrix product states format with storage complexity scaling linearly with the number of dimensions. We present a nonlinear conjugate gradient scheme within the framework of Riemannian optimization which exploits this favorable scaling. Numerical experiments and comparison to existing methods show the effectiveness of our approach for the approximation of multivariate functions. Finally, we show that our algorithm can obtain competitive reconstructions from uniform random sampling of few entries compared to adaptive sampling techniques such as cross-approximation.

Standardisation of oxygen exposure in the development of mouse models for bronchopulmonary dysplasia.

ABSTRACTProgress in developing new therapies for bronchopulmonary dysplasia (BPD) is sometimes complicated by the lack of a standardised animal model. Our objective was to develop a robust hyperoxia-based mouse model of BPD that recapitulated the pathological perturbations to lung structure noted in infants with BPD. Newborn mouse pups were exposed to a varying fraction of oxygen in the inspired air (FiO2) and a varying window of hyperoxia exposure, after which lung structure was assessed by design-based stereology with systemic uniform random sampling. The efficacy of a candidate therapeutic intervention using parenteral nutrition was evaluated to demonstrate the utility of the standardised BPD model for drug discovery. An FiO2 of 0.85 for the first 14 days of life decreased total alveoli number and concomitantly increased alveolar septal wall thickness, which are two key histopathological characteristics of BPD. A reduction in FiO2 to 0.60 or 0.40 also caused a decrease in the total alveoli number, but the septal wall thickness was not impacted. Neither a decreasing oxygen gradient (from FiO2 0.85 to 0.21 over the first 14 days of life) nor an oscillation in FiO2 (between 0.85 and 0.40 on a 24 h:24 h cycle) had an appreciable impact on lung development. The risk of missing beneficial effects of therapeutic interventions at FiO2 0.85, using parenteral nutrition as an intervention in the model, was also noted, highlighting the utility of lower FiO2 in selected studies, and underscoring the need to tailor the model employed to the experimental intervention. Thus, a state-of-the-art BPD animal model that recapitulates the two histopathological hallmark perturbations to lung architecture associated with BPD is described. The model presented here, where injurious stimuli have been systematically evaluated, provides a most promising approach for the development of new strategies to drive postnatal lung maturation in affected infants.

Retinoic acid promotes the endogenous repair of lung stem/progenitor cells in combined with simvastatin after acute lung injury: a stereological analysis.

BackgroundThe treatment of acute respiratory distress syndrome (ARDS), most commonly seen during the organ dysfunction remains unsatisfied. Presently, the stem/progenitor cell-based endogenous repair has been aroused attention enormously. This report investigated the effects of retinoic acid (RA) plus simvastatin (SS) with respect to dynamics of lung repair cells as well as to elucidate the underlying mechanism.Materials and methodsThe experimental Sprague–Dawley rats were divided randomly into normal control (control), sham operated (sham), ARDS, ARDS + vehicle and ARDS + RA + SS groups. ARDS was reproduced through hemorrhagic shock/resuscitation (shock) and subsequent intratracheal LPS (4.5 mg/kg, Escherichia coli serotype O55: B5) injection. The rats were treated by intragastric administration of RA (2 mg/kg/day) and SS (2 mg/kg/day) for 5 days in the ARDS + RA + SS group. Seven days after the first RA-SS injection, a right lower lobe of lung was sampled for histological analysis concerning systemic uniform random sampling method. Immunohistochemistry of inflation-fixed lungs for alveolar type 1 (AT1), alveolar type 2 (AT2) and Clara cells was measured by AQP5, Pro-SPC and CCSP staining respectively. The alveolar cell proliferation and apoptosis were analyzed with Ki67 staining and terminal deoxylnucleotidyl transferase mediated-dUTP nick end labeling (TUNEL) method. Meanwhile, the alveolar cell numerical and surface density (alveolar cells, AT1, AT2, Clara, proliferating and apoptotic cells) were evaluated by stereology.ResultsRA-SS compound exerted anti-inflammatory and pro-repairing effects on respiratory tracts in ARDS induced by hemorrhagic-endotoxin shock. The numerical density and surface density of alveolar cells, AT1 cell fraction, and numerical density of AT2 and Clara cells were significantly increased after treatment with RA-SS compound in ARDS. Concurrently, the Ki67+ alveolar cells were obviously increased while the TUNEL+ alveolar cells were reduced, which was correlated with the attenuation of inflammatory injury and functional repair in injured lung tissues.ConclusionsOur data convincingly indicated that the prophylactic and therapeutic treatment of RA plus SS had obvious beneficial effect on the remodeling/regeneration of injured pulmonary tissues, suggesting that the underlying mechanisms are related to the re-balance between regeneration and apoptosis in lung stem/progenitor cells.

Inference on diversity from forest inventories: a review

A number of international agreements and commitments emphasize the importance of appropriate monitoring protocols and assessments as prerequisites for sound conservation and management of the world’s forest ecosystems. Mandated periodic surveys, like forest inventories, provide a unique opportunity to identify and properly satisfy natural resource management information needs. Distinctively, there is an increasing need for detecting diversity by means of unambiguous diversity measures. Because all diversity measures are functions of tree species abundances, estimation of tree diversity indices and profiles is inevitably performed by estimating tree species abundances and then estimating indices and profiles as functions of the abundance estimates. This strategy can be readily implemented in the framework of current forest inventory approaches, where tree species abundances are routinely estimated by means of plots placed onto the surveyed area in accordance with probabilistic schemes. The purpose of this paper is to assess the effectiveness of this strategy by reviewing theoretical results from published case studies. Under uniform random sampling (URS), that is when plots are uniformly and independently located on the study region, consistency and asymptotic normality of diversity index estimators follow from standard limit theorems as the sampling effort increases. In addition, variance estimation and bias reduction are achieved using the jackknife method. Despite its theoretical simplicity, URS may lead to uneven coverage of the study region. In order to avoid unbalanced sampling, the use of tessellation stratified sampling (TSS) is suggested. TSS involves covering the study region by a polygonal grid and randomly selecting a plot in each polygon. Under TSS, the diversity index estimators are consistent, asymptotically normal and more precise than those achieved using URS. Variance estimation is possible and there is no need to reduce bias.

Staining histological lung sections with Sudan Black B or Sudan III for automated identification of alveolar epithelial type II cells

Alveolar epithelial type II (AE2) cells produce, store and secrete pulmonary surfactant and serve as progenitor cells for the alveolar epithelium. They are thus an interesting target in wide fields of pulmonary research. Stereological methods allow their quantification based on measurements on histological sections. A proper AE2 cell quantification, however, requires a method of tissue processing that results in little tissue shrinkage during processing. It was recently shown that a primary fixation with a mixture of glutaraldehyde and formaldehyde, postfixation with osmium tetroxide and uranyl acetate and embedding in glycol methacrylate fulfills this requirement. However, a proper quantification, furthermore, requires a secure identification of the cells under the microscope. Classical approaches using routine stainings, high magnifications and systematic uniform random sampling can result in a tedious counting procedure. In this article we show that Sudan Black B and Sudan III staining in combination with the previously described “low shrinkage method” of tissue processing result in good staining of lamellar bodies of AE2 cells (their storing organelles of surfactant) and thus provide a good signal of AE2 cells, which allows their easy and secure identification even at rather low magnifications. We further show that this signal enables automated detection of AE2 cells by image analysis, which should make this method a suitable staining method for the recently developed and more efficient proportionator sampling.

Colocalization error between the scanning laser ophthalmoscope infrared reflectance and optical coherence tomography images of the heidelberg spectralis.

To examine the colocalization error between the infrared reflectance (IR) scanning laser ophthalmoscope (SLO) and spectral domain optical coherence tomography (SD-OCT) images of the Heidelberg Spectralis. The IR and corresponding horizontal raster SD-OCT images were compared in 10 healthy volunteers examined with 3 Heidelberg Spectralis + OCT instruments. The center points of retinal vessels selected by random uniform sampling in scanning laser ophthalmoscope-IR images were compared with colocalizing points in corresponding SD-OCT images by two masked readers. The error of colocalization was measured in the SD-OCT image. The point positions were recorded using Cartesian coordinates measured in microns. The error of colocalization was evaluated using a fixed-effects generalized least squares regression model with location and instrument as predictor variables. A total of 1,617 points in the IR and SD-OCT images were analyzed, and the mean error of colocalization was 42.2 ± 32.4 μm. The Heidelberg Spectralis instrument used was not a significant predictor of colocalization error (P = 0.15). The colocalization errors were negatively correlated with x-coordinate position (P < 0.001). There is a mean colocalization error between the IR and SD-OCT images produced by the Heidelberg Spectralis that is on the scale of many features being evaluated in the fundus. The variability in these measurements means the confidence interval for the exact colocalization is much larger. Because of the magnitude and variability of the error, the colocalization feature of the Heidelberg Spectralis should be used as a rough guide, not an absolute determinant.

The estimation of diversity indexes by using stratified allocations of plots, points or transects

The estimation of diversity indexes is considered when species abundance is estimated by means of plots, points or transects placed onto the study region in accordance with probabilistic schemes. Under uniform random sampling–that is when plots, points or transects are uniformly and independently located on the study region–the consistency and the large‐sample normality of diversity index estimators follow from the usual limit theorems as the sampling effort increases. In addition, variance estimation and finite‐sample bias reduction are achieved by means of standard results on the jackknife method. Despite its theoretical simplicity, uniform random sampling may lead to uneven coverage of the study region. In order to avoid this shortcoming, the use of one‐per‐stratum stratified sampling is usually considered. This sampling scheme involves partitioning the study region into subsets of equal size and uniformly selecting a plot, a point or a transect in each of these subsets. The present paper aims to show the consistency and the large‐sample normality of the diversity index estimators under one‐per‐stratum stratified sampling, as well as to deal with variance estimation and bias reduction. Copyright © 2015 John Wiley &amp; Sons, Ltd.

On the Sampling of the Electromagnetic Field Radiated by Sparse Sources

The aim of this paper is to discuss the effectiveness of random sampling of the electromagnetic field in problems involving sparse radiating sources. The method adopted in this paper uses an intuitive geometrical approach based on the Johnson-Linderstrauss lemma applied to the $\epsilon$ -net of the set of the fields radiated by the sparse source. The paper shows that a proper Non Uniform Random Sampling (NURS) using some a-priori information on the problem allows a significant reduction in the cardinality of the set of the measured data compared to uniform random sampling and to random sampling from a $\lambda/2$ equispaced set of data. It is also shown that there is a limiting number of data after which random sampling is not convenient. In this case a deterministic sampling strategy, called Modified Non Uniform Sampling (MNUS), is proposed. Numerical results on linear sparse arrays confirm the effectiveness of NURS and MNUS.

AutoTag and AutoSnap: Standardized, semi-automatic capture of regions of interest from whole slide images

Tumor angiogenesis is measured by counting microvessels in tissue sections at high power magnification as a potential prognostic or predictive biomarker. Until now, regions of interest11ROI: region of interest. (ROIs) were selected by manual operations within a tumor by using a systematic uniform random sampling22SURS: systematic, uniform random sampling. (SURS) approach. Although SURS is the most reliable sampling method, it implies a high workload. However, SURS can be semi-automated and in this way contribute to the development of a validated quantification method for microvessel counting in the clinical setting. Here, we report a method to use semi-automated SURS for microvessel counting:•Whole slide imaging with Pannoramic SCAN (3DHISTECH)•Computer-assisted sampling in Pannoramic Viewer (3DHISTECH) extended by two self-written AutoHotkey applications (AutoTag and AutoSnap)•The use of digital grids in Photoshop® and Bridge® (Adobe Systems)This rapid procedure allows traceability essential for high throughput protein analysis of immunohistochemically stained tissue.

Effects of a single intravitreal injection of aflibercept and ranibizumab on glomeruli of monkeys.

PurposeIt is known that endothelial cells in the kidney are also strongly VEGF-dependent. Whether intravitreal drugs can be detected within the glomeruli or affect VEGF in glomerular podocytes is not known. Therefore, the aim of this pilot study was to investigate the effects of a single intravitreal injection of aflibercept and ranibizumab on glomeruli of monkeys.MethodsThe kidneys of eight cynomolgus monkeys, which were intravitreally injected either with 2 mg of aflibercept or with 0.5 mg of ranibizumab, were investigated one and seven days after injection. Two animals served as controls. The distribution of aflibercept, ranibizumab and VEGF was evaluated using anti-Fc- or anti-F(ab)-fragment and anti-VEGF antibodies respectively. The ratio of stained area/nuclei was calculated using a semi-quantitative computer assisted method. Glomerular endothelial cell fenestration was quantified in electron microscopy using a systematic uniform random sampling protocol and estimating the ratio of fenestrae per µm.ResultsCompared to the controls, the anti-VEGF stained area/nuclei ratio of the ranibizumab-treated animals showed no significant changes whereas the stained areas of the aflibercept-treated monkeys showed a significant decrease post-treatment. Immune reactivity (IR) against aflibercept or ranibizumab was detected in aflibercept- or ranibizumab treated animals respectively. The number of fenestrations of the glomerular endothelial cells has shown no significant differences except one day after aflibercept injection in which the number was increased.ConclusionSurprisingly, both drugs could be detected within the capillaries of the glomeruli. After a single intravitreal injection of aflibercept, VEGF IR in the podocytes was significantly reduced compared to controls. Ranibizumab injection had no significant effect on the glomeruli's VEGF level. Whether this is caused by aflibercept's higher affinity to VEGF or because it is used in a higher stoichiometric concentration compared to ranibizumab remains to be investigated.

Improved Compressive Sampling SFCW Radar by Equipartition of Energy Sampling

A Stepped-Frequency Continuous Wave (SFCW) radar performs imaging by transmitting a number of electromagnetic tones whose frequency is increased step-wisely to obtain an equivalent representation of a signal in frequency domain, then Fourier inversion is conducted to obtain a range profile. A Compressive Sampling (CS) SFCW radar reduces measurement time by randomly selecting a small number of the tones, followed by CS reconstruction. This paper shows empirically, that the knowledge of typical magnitude spectrum of the radar's signal can be used to improve the CS-SFCW radar system in term of either better reconstruction quality or less number of required samples. Instead of random selection, the knowledge of the spectrum is used to select the best set of frequencies, by applying equipartition of energy sampling (EES) principle. Three sampling schemes, i.e., Frequency Equidistant Sampling (FES), Uniform Random Sampling (URS), and the proposed EES, are used to obtain the samples of both simulated and actual A-scan data and then identical CS reconstruction methods are applied. Objective performance evaluation in term of PSNR (Peak Signal to Noise Ratio) shows that reconstructed result of URS outperforms the FES, while the EES outperforms both of them.

Calibration of nearest neighbors model for avalanche forecasting

Nearest neighbors (NN) method is very popular among avalanche forecaster world-over for data exploration and forecast guidance. The NN method based models employ snow-meteorological variables as input to search for past days with similar conditions and then analyze the events associated with past similar days to generate forecast. In order to achieve high forecast accuracy, a NN model needs to be calibrated by way of assigning distinct weights to various input variables. Thus model calibration may be treated as an optimization problem with objective to maximize the forecast accuracy. To investigate the structural characteristics of the problem, uniform random sampling method was applied on eNN10 (a NN model developed in India for avalanche forecasting). The problem has an issue of multiple optima. Population based metaheristics are suggested to handle such optimization problem better in comparison to classical analytical methods. Thus artificial bee colony algorithm, a metaheuristic inspired by the foraging behavior of honey bees, was explored to calibrate eNN10. The study was conducted for two climatologically diverse avalanche prone regions of Indian Himalaya. The results have been verified for operational forecast with significant gains in forecast accuracy in terms of Heidke skill score.

Effect of Urtica dioica extract on stereological structure of ventral prostate in streptozotocin induced diabetic rats

Diabetes mellitus is a common and important metabolic disorder that can be associated with many functional and structural complications in male sex organs and infertility. Many studies showed that Urtica dioica caused hypoglycemia and prevented diabetes undesirable side effects on the different organs. This study was done to investigate the effects of ethanol extract of Urtica dioica on ventral prostate in streptozotocin induced diabetic rats. In this study, 15 adult male wistar rats were divided into control, diabetic and treatment groups. Hyperglycemia was induced by 50 mg/kg Streptozotocin (STZ) in diabetic and treatment groups. One week after STZ injection, treatment group received 30 mg/kg/day Urtica dioica extract by oral gavage for 30 consecutive days. Finally animals were euthanized and ventral prostate were removed and fixed in 10% neutral buffered formalin. Samples of the ventral prostate were obtained according to the orientator to produce an isotropic uniform random sample. The volumes of the lumen, glandular epithelium and fibromuscular stroma were estimated by multiplying each respective volume density. This study showed that diabetes could lead to structural changes in ventral prostate. Stereological results indicated that volume of lumen and fibromuscular stroma of ventral prostate was significantly increased in diabetic rats but Urtica dioica could in hibit these changes partially. It was also revealed that volume of glandular epithelium was significantly reduced in ventral prostate of diabetic rats but it was significantly increased in treated animals compared to diabetic animals (p<0.05). It can be concluded that ad ministration of ethanolic extract of Urtica dioica a can inhibit side effect of diabetes on structure of ventral prostate and has protective effects on its histoarchitecture.

A Compression Sampling System based on Sparse AR Model

A compression sampling system based on sparse AR (auto regression) model is designed in this paper. The sparse samples are non-uniform sampled using uniform random sampling (URS) method by mono-chip computer. To guarantee the reconstruction effectiveness, a basis matrix is constructed with prior signal information to represent the received signal sparsely. Then the received signal is recovered from the samples using optimization algorithms in PC. The URS method can scale down the sampling frequency effectively. The basis matrix is constructed based on the known AR model and named sparse AR (SAR) basis in this paper. Since the SAR basis is a self-adaptive basis, better reconstruction quality at a low sampling rate can be obtained. The performance of the proposed compression sampling system is illustrated using normal vibration signal. From both simulation and experiment, the transmitted signal can be reconstructed effectively and accurately

Microvessel density of mantle cell lymphoma. A retrospective study of its prognostic role and the correlation with the Ki-67 and the mantle cell lymphoma international prognostic index in 177 cases.

The clinical course and therapy of mantle cell lymphoma (MCL) are heterogeneous and often unsatisfactory. Prognostic factors are needed to stratify the patients. Microvessel density (MVD) has prognostic significance in some malignancies. There is little information about the vasculature of MCL, although some antiangiogenic drugs are in use. We studied MVD using systematic uniform random sampling and unbiased counting frames in immunohistochemical reactions with anti-CD34 antibody in pre-therapeutic extramedullary MCL samples of 177 patients. We analyzed the relationship of MVD to overall survival (OS) and progression-free survival (PFS), as well as to proliferative activity (Ki-67), mantle cell lymphoma prognostic index (MIPI), morphological variant, pattern of growth, and localization. MVD varied widely: range 54.6-503.6 vessels/mm(2), median 158.2 vessels/mm(2). Higher MVD was associated with bone marrow infiltration at the time of diagnosis (P = 0.001). High MVD was associated with significantly worse OS (P = 0.04) only in patients treated with non-intensive (conventional) therapy. MVD correlated positively with MIPI scores but not with the proliferation, morphological variant, growth pattern, or localization. Univariate analysis identified a prognostic influence of morphological variant, MIPI, and proliferative activity on OS and PFS and a prognostic influence of bone marrow infiltration at the time of diagnosis on PFS. Multivariate analysis showed prognostic influence of MIPI and proliferative activity on OS and PFS only. In conclusion, this is the first clinicopathological study of MVD of MCL with long-term follow-up showing negative prognostic trends of high MVD in MCL and positive correlation of MVD and MIPI.

The Lack of Concordance Between Subretinal Drusenoid Deposits and Large Choroidal Blood Vessels

To evaluate the concordance between pseudodrusen as manifested by subretinal drusenoid deposits and large choroidal blood vessels using stereological analysis of spectral-domain optical coherence tomography (SD OCT) images. Retrospective, observational case series. The SD OCT images of 31 consecutive patients with the clinical appearance of pseudodrusen from a private-referral retinal clinic were retrospectively reviewed. A grid of 19 evenly spaced vertical lines was randomly superimposed on each SD OCT image using ImageJ to perform systematic uniform random sampling. The main outcome measure was the likelihood of association between subretinal drusenoid deposits and large choroidal vessels. Uniform random systematic sampling of 589 samples found the proportion of geometric probes intersecting subretinal drusenoid deposits to be 0.28, large choroidal vessel 0.65, and both 0.19. This value was nearly identical to the product of the joint probabilities and was within the 95% confidence interval (0.15-0.21) of the point estimate as calculated by the binomial theorem, indicating mutual independence. The subretinal drusenoid deposits were associated with neither large choroidal vessels nor the intervals in between. Our results demonstrate that there is no concordance between subretinal drusenoid deposits and large choroidal vessels or the stroma in between. As a consequence, hypotheses postulating that subretinal drusenoid deposits are associated with large choroidal vessels or the choroidal stromal spaces should be abandoned. Stereological techniques are powerful methods used in image evaluation in other fields of study and appear to have utility in analyzing OCT findings of the retina and choroid.

PPO.25 Novel insights from using Stereology based volume estimation of Syncytial nuclear aggregates in Diabetic placenta

IntroductionPlacental dysfunction leads to intrauterine compromise and stillbirth. Hypoxia is usually cited as the underlying mechanism in pregnancies complicated by hypertensive disorders, and syncytial deportation (inferred by the presence of...