Automated analysis of histological images by computational algorithms

The study of cellular tissues provides an incontestable source of information and comprehension about thehuman body and the surrounding environment. Accessing this information is, therefore, crucial to determineand diagnose a wide variety of pathologies detectable only at a microscopic scale. Hence, histology plays animportant role in the clinical diagnosis of pathologies involving abnormal cellular conformation. Inhistological images, semi- or automated segmentation algorithms are able to separate and identify cellularstructures according to morphological differences. The segmentation is usually the first task incomputational vision systems and, concerning histopathology, for the automated analysis of histologicalimages. Since the histological samples are thin, the volumetric features are almost unnoticeable,corresponding to losses of valuable information, mainly topographical and volumetric data, critical for acorrect analysis. Hence, the combination of segmentation and 3D reconstruction algorithms applied tohistological image datasets provides more information about the analyzed pathology and microscopicstructures, highlighting abnormal areas [1].In order to provide insights on pathological volumetric data, the present work focused on developing anautomatic computational solution for performing the 3D surface reconstruction of relevant tissue structurespresented in 2D histological slices. A state of the art technique, called stain deconvolution, was implementedto achieve color image segmentation providing an accurate segmentation of two different stains present inthe histological data: Hematoxylin and Eosin tissues. To register, i.e. align, the image slices presented in theinput datasets, an intensity based registration method was implemented, being the alignment performedbetween each slice in the input dataset and the reference slice (middle slice of the dataset). The datasetchosen for the previous alignment operation was the set of images obtained through the stain deconvolutionmethod for the hematoxylin stain. The transformation matrix obtained for each slice was then applied to theeosin stained images. The 3D reconstruction was implemented based on the Marching Cubes algorithm.Thus, combining algorithms of image segmentation and registration with of 3D surface reconstruction, itwas possible to obtain a volumetric representation of the pertinent tissue structures from the input imagedatasets. The experiments conducted revealed accurate and fast surface reconstructions of the differentstained tissues under study, highlighting the interesting structures and their volumetric interactions with thesurrounding healthy tissue

Implantation of a Dual-Chamber Pacemaker in a Patient With Situs Inversus and Dextrocardia Using a Novel Ultrasound Technique

Acesso ao texto integral: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6829762/We report a case of a 43-year-old man with situs inversus and dextrocardia who was admitted with syncope in the setting of complete atrioventricular block. The complex anatomy poses a considerable challenge to transvenous permanent pacemaker implantation. We employed a novel technique using vascular ultrasound and agitated saline solution to assist with lead positioning. This technique could be useful in pediatric populations or younger patients, in whom the use of ionizing radiation is an important issue.info:eu-repo/semantics/publishedVersio

GASTRIC CARCINOMA WITH OSSEOUS METAPLASIA IN A DOG

This report describes an unprecedented case of a gastric carcinoma with osseous metaplasia in a 8-year-old male standard poodle. An exploratory laparotomy revealed a firm yellowish nodular mass in the pyloric region. The lesion was surgically removed and submitted for current histological examination. Immunohistochemistry was performed employing monoclonal antibodies for pan-cytokeratin, vimentin, smooth muscular a-actin and BMP-2/4. The mass consisted in neoplastic proliferation of epithelial cells, arranged in a tubular or acinar pattern and supported by scirrhous stroma, with mucin production and multiple foci of heterotopic ossification. Neoplastic epithelial cells showed strong positive immunostaining for AE1/AE3 and BMP-2/4, although they were negative for both vimentin and a-actin. Histopathological findings suggested that the bone tissue may be primarily originated from neoplastic epithelial cells which directly circumscribe the osseous metaplasia foci

Segmentation and 3D reconstruction of animal tissues in histological images

Histology is considered the "gold standard" to access anatomical informationat a cellular level. In histological studies, tissue samples are cut into very thinsections, stained, and observed under a microscope by a specialist. Such studies,mainly concerning tissue structures, cellular components and their interactions, canbe useful to detect and diagnose certain pathologies. Thus, to find new techniquesand computational solutions to assist this diagnosis, such as the 3D image basedtissue reconstruction, is extremely interesting. In this chapter, a methodology tobuild 3D models from histological images is proposed, and the results obtained usingthis methodology in four experimental cases are presented and discussed based onquantitative and qualitative metrics

The usefulness of mesocosms for ecotoxicity testing with lacertid lizards

Mesocosms (i.e., outdoor, man-made representations of natural ecosystems) have seldom been used to study the impact of contaminants on terrestrial ecosystems. However, mesocosms can be a useful tool to provide a link between field and laboratory studies. We exposed juvenile lacertid lizards for a period of over one year to pesticides (herbicides and insecticides) in mesocosm enclosures with the intention of validating field observations obtained in a previous study that examined the effects of corn pesticides in Podarcis bocagei. Our treatments replicated field conditions and consisted of a control, an herbicides only treatment (alachlor, terbuthylazine, mesotrione and glyphosate) and an herbicides and insecticide treatment (including chlorpyrifos). We used a multi-biomarker approach that examined parameters at an individual and sub-individual level, including growth, locomotor performance, standard metabolic rate, biomarkers of oxidative stress, esterases and liver histopathologies. Although mortality over the course of the exposures was high (over 60%), surviving individuals prospered relatively well in the mesocosms and displayed a broad range of natural behaviours. The low numbers of replicate animals compromised many of the statistical comparisons, but in general, surviving lizards exposed to pesticides in mesocosm enclosures for over one year, thrived, and displayed few effects of pesticide exposure. Despite the difficulties, this work acts as an important stepping-stone for future ecotoxicology studies using lizards.publishe

Early peripheral endothelial dysfunction predicts myocardial infarct extension and microvascular obstruction in patients with ST-elevation myocardial infarction.

INTRODUCTION AND OBJECTIVES: The role of endothelial dysfunction (ED) in patients with ST-elevation myocardial infarction (STEMI) is poorly understood. Peripheral arterial tonometry (PAT) allows non-invasive evaluation of ED, but has never been used for this purpose early after primary percutaneous coronary intervention (P-PCI). Our purpose was to analyze the relation between ED assessed by PAT and both the presence of microvascular obstruction (MVO) and infarct extension in STEMI patients. METHODS: ED was assessed by the reactive hyperemia index (RHI), measured by PAT and defined as RHI <1.67. Infarct extension was assessed by troponin I (TnI) release and contrast-enhanced cardiac magnetic resonance (ceCMR). MVO was assessed by ceCMR and by indirect angiographic and ECG indicators. An echocardiogram was also performed in the first 12 h. RESULTS: We included 38 patients (mean age 60.0±13.7 years, 29 male). Mean RHI was 1.87±0.60 and 16 patients (42.1%) had ED. Peak TnI (median 118 mg/dl, IQR 186 vs. 67/81, p=0.024) and AUC of TnI (median 2305, IQR 2486 vs. 1076/1042, p=0.012) were significantly higher in patients with ED, who also showed a trend for more transmural infarcts (63.6% vs. 22.2%, p=0.06) and larger infarct mass on ceCMR (median 17.5%, IQR 15.4 vs. 10.1/10.3, p=0.08). Left ventricular ejection fraction (LVEF) was lower and wall motion score index (WMSI) was higher on both echocardiogram and ceCMR in patients with ED. On ceCMR, MVO was more frequent in patients with RHI <1.67 (54.5% vs. 11.1%, p=0.03). ECG and angiographic indicators of MVO all showed a trend toward worse results in these patients. CONCLUSIONS: The presence of ED assessed by PAT 24 h after P-PCI in patients with STEMI is associated with larger infarcts, lower LVEF, higher WMSI and higher prevalence of MVO.info:eu-repo/semantics/publishedVersio

Discovery of thiazolo [5,4-c] isoquinoline based compounds as acetylcholinesterase inhibitors through computational target prediction, molecular docking and bioassay

We thank Nathalie Reichmann and Leendert Hamoen (University of Amsterdam) for critical reading of the manuscript, Ana Velic (Proteome Center Tübingen) for help with proteome analysis and Mike VanNieuwenhze (Indiana University) for the generous gift of HADA. This study was funded by the European Research Council through grant ERC‐2017‐CoG‐771709 (to MGP), by national funds through FCT– Fundação para a Ciência e a Tecnologia, PTDC/BIA‐MIC/6982/2020 (to HV); PTDC/BIA‐PLA/3432/2012 (to SRF); FCT through MOSTMICRO‐ITQB R&D Unit (UIDB/04612/2020, UIDP/04612/2020) and LS4FUTURE Associated Laboratory (LA/P/0087/2020) and FCT fellowship SFRH/BD/147052/2019 (to BMS); by the Swiss National National Foundation through P300P3_155346 (to AJ); by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska‐Curie grant agreement No 839596 (to SS) and by the European Molecular Biology Organization through award ALTF 673‐2018 (to SS). Figure 6D and Appendix Fig S7 were created with Biorender.com .A computer-aided drug design (CADD) approach was developed for a focused chemical library comprising a series of sixteen thiazolo[5,4-c]isoquinoline derivatives. Little is known about this group of heteroaromatic compounds, both from the point of view of their synthesis and their biological properties. First, our CADD approach included target prediction by Mondrian conformal prediction with the ChEMBL database. The acetylcholinesterase (AChE) was identified as having a high probability of thiazolo[5,4-c]isoquinolines being active against it. Secondly, the molecular docking predictions revealed four promising thiazoloisoquinolines (2, 7, 13 and 14) according to their prominent ligand-protein energy scores and relevant binding affinities with the AChE pocket residues. The subsequent in vitro evaluation of promising hits and related ones revealed a set of novel AChE inhibitors. Therefore, the findings reported herein may provide a new strategy for discovering novel AChE inhibitors.publishersversionpublishe

Osteoporosis management during the COVID-19 pandemic - Position paper

verCOVID-19 pandemic significantly increased the already large number of victims of osteoporosis in Portugal. Osteoporosis outpatient clinics were either closed or had limited presential appointments. Many hospitals reduced orthopaedic services to make space for patients with COVID-19. In addition, the volunteer or forced sedentarism, as imposed by the pandemic, increased the risk of falls and fractures drastically. It urges to intensify the current efforts to improve the management of bone health and to prioritize fragility fracture care and prevention. This paper addresses the challenges in osteoporosis management during the COVID-19 pandemic and provides guidance on osteoporosis management. This position paper is a joint initiative of several health professionals and patients dedicated to osteoporosis.publishersversionpublishe