Changes In Blood Vessels Research Articles

Obesity during pregnancy results in maternal intestinal inflammation, placental hypoxia, and alters fetal glucose metabolism at mid-gestation

We investigated whether diet-induced changes in the maternal intestinal microbiota were associated with changes in bacterial metabolites and their receptors, intestinal inflammation, and placental inflammation at mid-gestation (E14.5) in female mice fed a control (17% kcal fat, n = 7) or a high-fat diet (HFD 60% kcal fat, n = 9; ad libitum) before and during pregnancy. Maternal diet-induced obesity (mDIO) resulted in a reduction in maternal fecal short-chain fatty acid producing Lachnospiraceae, lower cecal butyrate, intestinal antimicrobial peptide levels, and intestinal SCFA receptor Ffar3, Ffar2 and Hcar2 transcript levels. mDIO increased maternal intestinal pro-inflammatory NFκB activity, colonic CD3+ T cell number, and placental inflammation. Maternal obesity was associated with placental hypoxia, increased angiogenesis, and increased transcript levels of glucose and amino acid transporters. Maternal and fetal markers of gluconeogenic capacity were decreased in pregnancies complicated by obesity. We show that mDIO impairs bacterial metabolite signaling pathways in the mother at mid-gestation, which was associated with significant structural changes in placental blood vessels, likely as a result of placental hypoxia. It is likely that maternal intestinal changes contribute to adverse maternal and placental adaptations that, via alterations in fetal hepatic glucose handling, may impart increased risk of metabolic dysfunction in offspring.

Artery/vein classification of retinal vessels using classifiers fusion.

The morphological changes in retinal blood vessels indicate cardiovascular diseases and consequently those diseases lead to ocular complications such as Hypertensive Retinopathy. One of the significant clinical findings related to this ocular abnormality is alteration of width of vessel. The classification of retinal vessels into arteries and veins in eye fundus images is a relevant task for the automatic assessment of vascular changes. This paper presents an important approach to solve this problem by means of feature ranking strategies and multiple classifiers decision-combination scheme that is specifically adapted for artery/vein classification. For this, three databases are used with a local dataset of 44 images and two publically available databases, INSPIRE-AVR containing 40 images and VICAVR containing 58 images. The local database also contains images with pathologically diseased structures. The performance of the proposed system is assessed by comparing the experimental results with the gold standard estimations as well as with the results of previous methodologies, achieving promising classification performance, with an over all accuracy of 90.45%, 93.90% and 87.82%, in retinal blood vessel separation for Local, INSPIRE-AVR and VICAVR dataset, respectively.

Selective Priming of Tumor Blood Vessels by Radiation Therapy Enhances Nanodrug Delivery

Effective drug delivery is restricted by pathophysiological barriers in solid tumors. In human pancreatic adenocarcinoma, poorly-permeable blood vessels limit the intratumoral permeation and penetration of chemo or nanotherapeutic drugs. New and clinically viable strategies are urgently sought to breach the neoplastic barriers that prevent effective drug delivery. Here, we present an original idea to boost drug delivery by selectively knocking down the tumor vascular barrier in a human pancreatic cancer model. Clinical radiation activates the tumor endothelial-targeted gold nanoparticles to induce a physical vascular damage due to the high photoelectric interactions. Active modulation of these tumor neovessels lead to distinct changes in tumor vascular permeability. Noninvasive MRI and fluorescence studies, using a short-circulating nanocarrier with MR-sensitive gadolinium and a long-circulating nanocarrier with fluorescence-sensitive nearinfrared dye, demonstrate more than two-fold increase in nanodrug delivery, post tumor vascular modulation. Functional changes in altered tumor blood vessels and its downstream parameters, particularly, changes in Ktrans (permeability), Kep (flux rate), and Ve (extracellular interstitial volume), reflect changes that relate to augmented drug delivery. The proposed dual-targeted therapy effectively invades the tumor vascular barrier and improve nanodrug delivery in a human pancreatic tumor model and it may also be applied to other nonresectable, intransigent tumors that barely respond to standard drug therapies.

Differences in Expression of Genes Involved in Bone Development and Morphogenesis in the Walls of Internal Thoracic Artery and Saphenous Vein Conduits May Provide Markers Useful for Evaluation Graft Patency.

Coronary artery bypass grafting (CABG) is one of the most efficient procedures for patients with advanced coronary artery disease. From all the blood vessels with the potential to be used in this procedure, the internal thoracic artery (ITA) and the saphenous vein (SV) are the most commonly applied as aortocoronary conduits. Nevertheless, in order to evaluate the graft patency and efficiency effectively, basic knowledge should be constantly expanding at the molecular level as well, as the understanding of predictive factors is still limited. In this study, we have employed the expressive microarray approach, validated with Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR), to analyze the transcriptome of both venous and arterial grafts. Searching for potential molecular factors, we analyzed differentially expressed gene ontologies involved in bone development and morphogenesis, for the possibility of discovery of new markers for the evaluation of ITA and SV segment quality. Among three ontological groups of interest—“endochondral bone morphogenesis”, “ossification”, and “skeletal system development”—we found six genes common to all of them. BMP6, SHOX2, COL13A1, CSGALNACT1, RUNX2, and STC1 showed differential expression patterns in both analyzed vessels. STC1 and COL13A1 were upregulated in ITA samples, whereas others were upregulated in SV. With regard to the Runx2 protein function in osteogenic phenotype regulation, the RUNX2 gene seems to be of paramount importance in assessing the potential of ITA, SV, and other vessels used in the CABG procedure. Overall, the presented study provided valuable insight into the molecular background of conduit characterization, and thus indicated genes that may be the target of subsequent studies, also at the protein level. Moreover, it has been suggested that RUNX2 may be recognized as a molecular marker of osteogenic changes in human blood vessels.

Features of microscopic changes in lung structure of young rats under conditions of hyperhomocysteinemia

Hyperhomocysteinemia is a risk factor for many diseases, including pathologies of the respiratory system. The pathogenesis of lung tissue damage is complex and multifactorial, however, it has now been found that homocysteine has a toxic effect on the vascular system and parenchyma of the organ. The purpose of the study is to identify the features of microscopic changes in the structure of the lungs of young rats under conditions of hyperhomocysteinemia. The experimental study was performed on 22 white non-linear young (1-2 months) male rats. During the experiment, the animals were divided into two groups – control and experimental. Simulation of persistent hyperhomocysteinemia was achieved by administering to rats of the experimental group thiolactone homocysteine at a dose of 200 mg/kg body weight intragastrically for 60 days. Histological specimens were examined using an SEO SCAN light microscope and photo-documented using a Vision CCD Camera with the system output images of histological preparations. It was found that the introduction of thiolactone homocysteine to young rats at a dose of 200 mg/kg led to the development of destructive changes in blood vessels, bronchi, components of the respiratory department with signs of atelectasis. Hemodynamic disorders and increased vascular permeability led to perivascular, peribronchial, interstitial, intra-alveolar edema, histo-leukocyte infiltration. The detected changes are reversible and have a compensatory nature.

Maladaptive neuropathological syndrome of blood vessel aging

This article discusses the relationship between maladaptation and blood vessel aging. The work shows that upright posture created an additional load on the circulatory system, and the lifestyle of a modern human is an additional risk factor of cardiovascular diseases. It has been suggested that a disorder of the nervous regulation of vascular tone is the main etiopathogenetic mechanism of morphofunctional changes in blood vessels and their aging. We discussed the statute that vascular reactions in humans is based on the formation of a maladaptive circuit in the cerebral cortex, consisting of a matrix of motor, sensory and associative cortical neurons involved in the maladaptive process. This hypothesis is based on the fact that any irritations entering the cerebral cortex from the periphery (thermal, pain, and others) cause cortical-vascular reflex reactions that change their tonic activity. Based on this principle, a model of vascular aging is further constructed, which is based on the maladaptive damage to all layers of the vascular wall (intima, media and adventitia). The opinion is expressed about the need for early diagnosis and prevention of vascular disorders to maintain human health. In conclusion, it is concluded that if the age of a person is really determined by the age of his blood vessels, then in order to achieve active longevity it is necessary to normalize the relationship in the adaptation-maladaptation-environment. Detailed study of hypertrophy and calcification of blood vessels is needed, since aging always reveals vascular wall thickening and stiffness increase.

IL-6 trans-signaling in the brain influences the behavioral and physio-pathological phenotype of the Tg2576 and 3xTgAD mouse models of Alzheimer’s disease

Alzheimer’s disease (AD) is the most commonly diagnosed dementia but its underlying pathological mechanisms still unclear. Neuroinflammation and secretion of cytokines such as interleukin-6 (IL-6) accompany the main hallmarks of the disease: amyloid plaques and neurofibrillary tangles. In this study, we analyzed the role of IL-6 trans-signaling in two mouse models of AD, Tg2576 and 3xTg-AD mice. The inhibition of IL-6 trans-signaling partially rescued the AD-induced mortality in females of both models. Before amyloid plaques deposition, it reversed AD-induced changes in exploration and anxiety (but did not affect locomotion) in Tg2576 female mice. However, after plaque deposition the only behavioral trait affected by the inhibition of IL-6 trans-signaling was locomotion. Results in the Morris water maze suggest that cognitive flexibility was reduced by the blocking of the IL-6 trans-signaling in young and old Tg2576 female mice. The inhibition of IL-6 trans-signaling also decreased amyloid plaque burden in cortex and hippocampus, and Aβ40 and Aβ42 levels in the cortex, of Tg2576 female mice. The aforementioned changes might be correlated with changes in blood vessels and matrix structure and organization rather than changes in neuroinflammation. 3xTgAD mice showed a very mild phenotype regarding amyloid cascade, but results were in accordance with those of Tg2576 mice. These results strongly suggest that the inhibition of the IL-6 trans-signaling could represent a powerful therapeutic target in AD.

Effect of Different Classes of Antihypertensive Drugs on Endothelial Function and Inflammation.

Hypertension is characterized by structural and functional changes in blood vessels that travel with increased arterial stiffness, vascular inflammation, and endothelial dysfunction. Some antihypertensive drugs have been shown to improve endothelial function and reduce levels of inflammatory markers regardless of the effect of blood pressure lowering. Third-generation β-blockers, such as nebivolol and carvedilol, because they have additional properties, have been shown to improve endothelial function in patients with hypertension. Calcium channel antagonists, because they have antioxidant effects, may improve endothelial function and vascular inflammation.The Angiotensin Receptor Blocker (ARBs) are able to improve endothelial dysfunction and vascular inflammation in patients with hypertension and other cardiovascular diseases. Angiotensin converting enzyme (ACE) inhibitors have shown beneficial effects on endothelial function in patients with hypertension and other cardiovascular diseases, however there are few studies evaluating the effect of treatment with this class on the reduction of C-reactive protein (CRP) levels. Further studies are needed to assess whether treatment of endothelial dysfunction and vascular inflammation may improve the prognosis of patients with essential hypertension.

Robust intensity variation and inverse surface adaptive thresholding techniques for detection of optic disc and exudates in retinal fundus images

Diabetic Retinopathy (DR) is an adverse change in retinal blood vessels leads to blindness for diabetic patients without any symptoms. Diabetes is characterized by imbalance level of glucose in the human body. The optic disc (OD) is the major retinal landmark. Localization of OD is an important step in fundus image analysis and to develop Computer Aided Diagnosis tool for DR. OD center detection is necessary to reduce false positive rate in the detection of exudates (EXs). EXs is the white lesion present in the retina which is the early symptom for the diagnosis of DR. OD is detected using intensity variation algorithm and EXs is segmented using inverse surface adaptive thresholding algorithm. This algorithm achieves better result in localizing OD and segmenting EXs when compared to literature-reviewed methods. The maximum intensity variance method is used to locate OD with average ACC of 96.54%, 98.65%, 98.12%, 99.23%, 99.81% and 98.47% in DIARETDB0, DIARETDB1, MESSIDOR, DRIVE, STARE and Bejan Singh Eye Hospital databases with less computation time of 102ms, 108ms, 120ms, 93ms, 110ms and 131ms. The inverse surface adaptive thresholding method has achieved an SE of 97.43%, 98.87%, 99.12%, 97.21%, 98.72%, and 96.63%, a SPE of 91.56%, 92.31%, 90.21%, 90.14%, 89.58%, 92.56% and an ACC of 99.34%, 99.67%, 98.34%, 98.87%, 99.13%, 98.34% for DIARETDB0, DIARETDB1, MESSIDOR, DRIVE, STARE and Bejan Singh Eye Hospital databases respectively.

Anti‐C1q antibodies in scleroderma

Systemic sclerosis (SSc) is an autoimmune condition which means that the body's immune system, which usually fights off disease, wrongly targets healthy parts of the body, and SSc patients produce antibodies to their own tissues (‘autoantibodies’). Extensive thickening and scarring of tissues (fibrosis) is the main feature of the condition and is due to over‐production of collagen. Changes in small blood vessels also occur. When fibrosis occurs in the lungs (pulmonary fibrosis) it can lead to high blood pressure in the arteries going to the lungs, and this may be life‐threatening. The condition is commoner in women. SSc can be localised or disseminated (generalised), depending on the extent of skin involvement. Although the cause of SSc has not been fully worked out, many of the autoantibodies associated with the condition are believed to be involved in one way or another. Autoantibodies called ‘anti‐C1q’ are certainly found in another autoimmune condition called systemic lupus erythematosus, so the aim of this study from Greece and the USA was to see if they were also present in SSc. Anti‐C1q autoantibodies were found in 16.1% of the 124 SSc patients in the study, occurring as often as the third most frequently found autoantibody, known as anti‐RNA polymerase III. They were found particularly in men and in patients with disseminated SSc. Presence of anti‐C1q antibodies was associated with pulmonary fibrosis but not with any of the other features of SSc. The authors therefore suggest that anti‐C1q autoantibodies could be looked at as a marker for (sign of) pulmonary fibrosis in SSc patients.

TREATMENT WITH THE DIRECT THROMBIN INHIBITOR DABIGATRAN ETEXILATE REDUCES OXIDATIVE STRESS IN VIVO IN A MOUSE MODEL OF ALZHEIMER’S DISEASE

The coagulation factor thrombin is a multifunctional serine protease that contributes to oxidative stress and inflammation. Thrombin has been shown to be neurotoxic and is elevated in the brain and cerebrovasculature in Alzheimer's disease (AD). We have identified thrombin as a key mediator of cerebrovascular activation in AD and have data demonstrating that thrombin inhibition diminishes vascular activation in an animal model of AD. Transgenic Tg4510 AD mice overexpress tau with the P301L familial frontotemporal dementia mutation and exhibit profound tau-related pathology in the hippocampus and cortex. These mice also show blood vessel abnormalities and changes in both oxidative stress and inflammatory markers. Here, we hypothesize that thrombin inhibition will reduce oxidative stress and inflammation related to tau pathology in vivo. 15-month-old Tg4510 mice were treated with 100 mg/kg once a day for 7 days with the direct thrombin inhibitor dabigatran etexilate or vehicle control via oral gavage. 24 hours after the final drug dose, mice were sacrificed and brains were collected. The cerebellum was removed and the brain was homogenized and Western analysis performed. Blots were probed and quantified for oxidative stress-related proteins, inducible nitric oxide synthase (iNOS), endothelial NOS (eNOS), NAPDH oxidase 4 (NOX4); antioxidant proteins SOD1 and SOD2 as well as the inflammatory cytokine interleukin 1beta (IL-1β). Treatment of mice with dabigatran for 7 days reduced thrombin expression and activity in the brain, shown by significantly decreased prothrombin and fibrin expression. Tg4510 mice that received dabigatran showed significant reduction in the expression of oxidative stress proteins (iNOS, eNOS, NOX4) as well as a concomitant increase in antioxidant SOD1 and SOD2. In addition, dabigatran treatment also lowered expression of IL-1β. Taken together, these data indicate that short-term treatment with a direct thrombin inhibitor was effective at lowering oxidative stress in the brains of aged Tg4510 mice. This finding supports our hypothesis that targeting thrombin, a key mediator of vascular activation and neurotoxicity, may be effective in reducing AD-related pathology. Further studies are needed to better understand the mechanisms of action and possible neuroprotective benefits of the thrombin inhibitor dabigatran.

Label-Free Imaging of Blood Vessels in Human Normal Breast and Breast Tumor Tissue Using Multiphoton Microscopy.

Blood vessels are the important components of the circulatory systems that transport blood throughout the human body and maintain the homeostasis of physiological tissues. Pathologically, blood vessels are often affected by diseases, leading to the formation of unstable, irregular, and hyperpermeable blood vessels. In the tumor microenvironment, abnormal leakage of tumor blood vessels is related to the histological grade and malignant potential of tumors and may also facilitate metastasis of cancer. Visual diagnosis of blood vessels is very important for us to understand the occurrence and development of diseases. Multiphoton microscopy (MPM) is a potential label-free diagnostic tool based on second harmonic generation (SHG) and two-photon excited fluorescence (TPEF). MPM can effectively observe the morphological changes of biological tissues at the molecular and cellular levels. In this work, we demonstrate that label-free MPM can be used to visualize the microstructure of blood vessels in human normal breast and breast tumor tissue. Moreover, MPM can monitor the changes of blood vessels in tumor microenvironment. These results show that the MPM will become a promising technique for clinicians to study the properties of the microstructure of the blood vessels.

Systemic effects of IL-17 in inflammatory arthritis.

Inflammatory arthritis occurs in many diseases and is characterized by joint inflammation and damage. However, the inflammatory state in arthritis is commonly associated with systemic manifestations, which are generally linked to a poor prognosis. The pro-inflammatory cytokine IL-17 functions within a complex network of cytokines and contributes to the pathogenesis of various inflammatory diseases. Three IL-17 inhibitors have already been approved for the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis. After a brief description of IL-17 and its local effects on joints, this Review focuses on the systemic effects of IL-17 in inflammatory arthritis. Increased circulating concentrations of bioactive IL-17 mediate changes in blood vessels, liver and cardiac and skeletal muscles. The effects of IL-17 on vascular and cardiac cells might contribute to the increased risk of cardiovascular events that occurs in all patients with inflammatory disorders. In the liver, IL-17 contributes to the high circulating concentrations of acute-phase proteins, such as C-reactive protein, and the appearance of liver lesions. In skeletal muscle, IL-17 contributes to muscle contractibility defects and weakness. Thus, targeting IL-17 might have beneficial effects at both local and systemic levels, and could also be proposed for the treatment of a wider range of inflammatory diseases.

Vascular Pathology and Osteoarthritis: A Systematic Review.

Vascular pathology (changes in blood vessels) and osteoarthritis (OA) are both common chronic conditions associated with aging and obesity, but whether vascular pathology is a risk factor for OA is unclear. The aim of this study was to systematically review the evidence for an association between vascular pathology and risk of joint-specific OA. Scopus, Ovid Medline, and EMBASE were searched from inception to February 2019. MeSH terms and keywords were used to identify studies examining the association between vascular pathology and OA. Two reviewers independently extracted the data and assessed the methodological quality. Qualitative evidence synthesis was performed. Fifteen studies with high (n = 3), fair (n = 3), or low (n = 9) quality were included. Features of vascular pathology included atherosclerosis, vascular stiffness, and endothelial dysfunction in different vascular beds. There was evidence for an association between vascular pathology and risk of hand OA in women but not men, and between vascular pathology and risk of knee OA in both men and women. Only 2 studies examined hip OA showing no association between vascular pathology and risk of hip OA. There is evidence suggesting an association between vascular pathology and risk of hand and knee OA, with a potential causal relationship for knee OA. Based on the limited evidence, it is hard to conclude an association for hip OA. Further stronger evidence is needed to determine whether there is a causal relationship.

The Gray Degeneration of the Brain and Spinal Cord: A Story of the Once Favored Diagnosis With Subsequent Vessel-Based Etiopathological Studies in Multiple Sclerosis.

In 1857, French-Austrian psychiatrist Bénédict Augustin Morel (1809-1873) published his infamous though highly successful Traité des dégénérescences physiques, intellectuelles et morales de l'espèce humaine, which was fully dedicated to the social problem of "degeneration" and its psychiatric and neurological underpinnings. European psychiatrists, neurologists, and pathologists integrated Morel's approach into their neuropsychiatric theories and searched for the somatic and morphological alterations in the human brain, as did the versatile pupil of Rudolph Virchow (1821-1902), Georg Eduard von Rindfleisch (1836-1908), in his Lehrbuch der pathologischen Gewebelehre (1867). This can be seen as a starting point of research into the vascular genesis of "multiple sclerosis" by observing that the changes of blood vessels and nerve elements could be the result of inflammation and increased blood flow. We examine the waxing and waning of a 19th century diagnostic condition, which fell out of favor and resurfaced during the 20th century.

Insights from outside BJOG

Insights from outside BJOG

A Discriminative Colour-to-Grayscale Representation for Retinal Vessel Segmentation

Structural changes in retinal blood vessels are important indicators for many ocular diseases including diabetic retinopathy (DR), glaucoma, and hypertension. An automated vessel segmentation process almost always begins with acquired color fundus image, containing three layers of images (red, green and blue), and then quickly converted them to a single grayscale image. However, grayscale conversion is not unique and more than one grayscale representation can be obtained for a given color image. For the many currently existing automated vessel extraction methods, the green channel of the RGB color fundus image is routinely used as an input grey-scale representation to a pipeline of the segmentation process for the reason that it provides the best contrast among all three channels, namely red, green and blue. We hypothesize that vessel information contained in dropped channels, red and blue, will add to result in improved segmentation performance. In this paper, we propose a linear combination framework to utilize all three channels of the color fundus image based on their importance level rather than completely discarding some channels. We devised a Principal Component Analysis (PCA) method that provides appropriate weights for each color channel to realize a more discriminative grey-scale representation. The added information made available through PCA-based grayscale representation results in improved performance for Modautomated vessel segmentation algorithms. The performance of the framework is analyzed on two publically available databases (DRIVE, STARE) of fundus images quantifying improvements in all three aspects called accuracy, sensitivity, and specificity.

Dual-Element Intravascular Ultrasound Transducer for Tissue Harmonic Imaging and Frequency Compounding: Development and Imaging Performance Assessment.

For accurate diagnosis of atherosclerosis, the high spatial and contrast resolutions of intravascular ultrasound (IVUS) images are a key requirement. Increasing the center frequency of IVUS is a simple solution to meet this requirement. However, this leads to a reduction in imaging depth due to the frequency-dependent attenuation of ultrasound. Here, we report a recently developed dual-element IVUS transducer for tissue harmonic imaging (THI) and frequency compounding to increase the spatial and contrast resolutions of IVUS images, while maintaining the imaging depth to assess the overall morphological change of blood vessels. One 35-MHz element is used for producing general IVUS images and the other 70-MHz element is for receiving the second harmonic signals induced by the 35-MHz ultrasound. The fundamental and second harmonic signals can also be used for frequency compound imaging to further improve contrast resolution. The spatial and contrast resolutions achieved by the developed transducer were evaluated through wire and tissue-mimicking phantom imaging tests. Additionally, the images of a stent deployed in a tissue-mimicking phantom and an excised pig artery were acquired to assess clinical usefulness of the transducer. The results demonstrated that the developed IVUS transducer enables us to simultaneously examine the overall morphological change of blood vessels by the 35-MHz ultrasound images and the near vessel layers such as the intima, the media, and the adventitia by either THI or compound images with high spatial and contrast resolutions. In addition, the developed transducer facilitates the simultaneous acquisition of 35- and 70-MHz fundamental images when needed. The developed dual-element IVUS transducer makes it possible to fully realize the potential benefits of IVUS in the diagnosis of atherosclerosis.

Joint segmentation and classification of retinal arteries/veins from fundus images.

Automatic artery/vein (A/V) segmentation from fundus images is required to track blood vessel changes occurring with many pathologies including retinopathy and cardiovascular pathologies. One of the clinical measures that quantifies vessel changes is the arterio-venous ratio (AVR) which represents the ratio between artery and vein diameters. This measure significantly depends on the accuracy of vessel segmentation and classification into arteries and veins. This paper proposes a fast, novel method for semantic A/V segmentation combining deep learning and graph propagation. A convolutional neural network (CNN) is proposed to jointly segment and classify vessels into arteries and veins. The initial CNN labeling is propagated through a graph representation of the retinal vasculature, whose nodes are defined as the vessel branches and edges are weighted by the cost of linking pairs of branches. To efficiently propagate the labels, the graph is simplified into its minimum spanning tree. The method achieves an accuracy of 94.8% for vessels segmentation. The A/V classification achieves a specificity of 92.9% with a sensitivity of 93.7% on the CT-DRIVE database compared to the state-of-the-art-specificity and sensitivity, both of 91.7%. The results show that our method outperforms the leading previous works on a public dataset for A/V classification and is by far the fastest. The proposed global AVR calculated on the whole fundus image using our automatic A/V segmentation method can better track vessel changes associated to diabetic retinopathy than the standard local AVR calculated only around the optic disc.

Morphological analysis of melasma lesions at different clinical stages by using three different skin imaging techniques

Objective To investigate morphological characteristics of female melasma lesions at different clinical stages by using three skin imaging techniques. Methods A total of 253 female outpatients with melasma were enrolled from the Third Affiliated Hospital of Zhejiang Chinese Medicine University between June 2017 and January 2018. According to the clinical staging criteria, melasma lesions at different clinical stages were observed with reflectance confocal microscopy (RCM) , VISIA skin imaging detector and dermoscopy, and correlations of clinical staging with dendritic melanocytes, subclinical melasma and morphological changes of blood vessels were analyzed. Statistical analysis was carried out with SPSS19.0 software by using chi-square test and Mann-Whitney U test for the comparison of enumeration data. Results Of 253 patients with melasma, 100 were with progressive melasma, and 153 with stable melasma. RCM showed that dendritic melanocytes were observed in 78 (78%) patients with progressive melasma, as well as in 22 (14.4%) patients with stable melasma, and there was a significant difference between the 2 groups (χ2 = 102.40, P < 0.01) . VISIA skin imaging detector showed that subclinical melasma was observed in 78 (78%) patients with progressive melasma, as well as in 25 (16.3%) patients with stable melasma, and the prevalance of subclinical melasma was significantly higher in the patients with progressive melasma than in those with stable melasma (χ2 = 95.26, P < 0.01) . Dermoscopy showed that the frequency of morphological changes in blood vessels did not differ between the patients with progressive melasma (74%, 74/100) and those with stable melasma (68.6%, 105/153; χ2 = 0.84, P = 0.39) . Conclusion The dendritic melanocytes and subclinical manifestations under RCM and VISIA skin imaging detector can serve as reference indices for clinical staging of melasma. Key words: Chloasma; Melanocytes; Microscopy, confocal; Dermoscopy; Clinical stages; Skin imaging detector