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in category pathology

324 results found. For more information, click each entry to expand.

61: Evaluation of p53 Immunohistochemical Expression Using Open-Source Software for Digital Image Analysis: A Tissue Microarray Study of Penile Squamous Cell Carcinomas
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Posted to bioRxiv 26 Oct 2015

Evaluation of p53 Immunohistochemical Expression Using Open-Source Software for Digital Image Analysis: A Tissue Microarray Study of Penile Squamous Cell Carcinomas
482 downloads pathology

Alcides Chaux

The addition of molecular biomarkers is needed to increase the accuracy of pathologic factors as prognosticators of outcome in penile squamous cell carcinomas (SCC). Evaluation of these biomarkers is usually carried out by immunohistochemistry. Herein we assess p53 immunohistochemical expression on tissue samples of penile SCC using freely-available, open-source software packages for digital image analysis. We also compared the results of digital analysis with standard visual estimation. Percentages of p53 positive cells were higher by visual estimation than by digital analysis. However, correlation was high between both methods. Our study shows that evaluation of p53 immunohistochemical expression is feasible using open-source software packages for digital image analysis. Although our analysis was limited to penile SCC, the rationale should also hold for other tumor types in which evaluation of p53 immunohistochemical expression is required. This approach would reduce interobserver variability, and would provide a standardized method for reporting the results of immunohistochemical stains. As these diagnostic tools are freely-available online, researchers and practicing pathologists could incorporate them in their daily practice without increasing diagnostic costs.

62: Drosophila melanogaster infected with Wolbachia strain wMelCS prefer cooler temperatures
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Posted to bioRxiv 21 Jun 2018

Drosophila melanogaster infected with Wolbachia strain wMelCS prefer cooler temperatures
471 downloads pathology

Pieter Andrew Arnold, Samantha C Levin, Aleksej L Stevanovic, Karyn N Johnson

Temperature plays a fundamental role in host-pathogen interactions. Wolbachia is an endosymbiont that infects about 40% of arthropod species, which can affect host behaviour and reproduction. The effect of Wolbachia on host thermoregulatory behaviour is largely unknown. Here, we used a thermal gradient to test whether Drosophila melanogaster infected with Wolbachia exhibit different temperature preferences (Tp) to uninfected flies. We found that Wolbachia-infected flies preferred a cooler mean temperature (Tp = 25.06±0.25°C) than uninfected flies (Tp = 25.78±0.24°C). Our finding suggests that Wolbachia-infected hosts might seek out cooler microclimates to reduce exposure to and lessen the consequences of high temperatures.

63: Hepatocyte-specific deletion of Pparα promotes NASH in the context of obesity
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Posted to bioRxiv 06 Dec 2018

Hepatocyte-specific deletion of Pparα promotes NASH in the context of obesity
461 downloads pathology

Marion Régnier, Arnaud Polizzi, Sarra Smati, Céline Lukowicz, Anne Fougerat, Yannick Lippi, Edwin Fouché, Frédéric Lasserre, Claire Naylies, Colette Bétoulières, Valentin Barquissau, Etienne Mouisel, Justine Bertrand-Michel, Aurélie Batut, Talal Al Saati, Cécile Canlet, Marie Tremblay-Franco, Sandrine Ellero-Simatos, Dominique Langin, Catherine Postic, Walter Wahli, Nicolas Loiseau, Hervé Guillou, Alexandra Montagner

Objectives: Peroxisome proliferator activated receptor α (PPARα) acts as a fatty acid sensor to orchestrate the transcription of genes coding for rate-limiting enzymes required for lipid oxidation in hepatocytes. Mice only lacking Pparα in hepatocytes spontaneously develop steatosis without obesity in aging. Altough steatosis is a benign condition it can develop into non alcoholic steatohepatitis (NASH), which may progress to irreversible damage, such as fibrosis and hepatocarcinoma. While NASH appears as a major public health concern worldwide, it remains an unmet medical need. Several drugs are being tested in clinical trials, including pharmacological agonists for the different PPAR isotypes. In current study, we investigated the role of hepatocyte PPARα in a preclinical model of steatosis. Methods/Results: We have investigated the role of hepatocyte PPARα in a preclinical model of steatosis using High Fat Diet (HFD) feeding as a model of obesity in C57BL/6J male Wild-Type mice (WT), in whole-body (Pparα-/-) mice and in mice lacking Pparα in hepatocyte (Pparαhep-/-). We provide evidence that Pparα deletion in hepatocytes promotes NASH in mice fed an HFD. This enhanced NASH susceptibility occurs without development of glucose intolerance. Moreover, our data reveal that non-hepatocytic PPARα activity predominantly contributes to the metabolic response to HFD. Conclusion: Taken together, our data support hepatocyte PPARα as being essential to the prevention of steatosis progression to NASH and that extra-hepatocyte PPARα activity contributes to whole-body lipid homeostasis.

64: A strain of an emerging Indian pathotype of Xanthomonas oryzae pv. oryzae defeats the rice bacterial blight resistance gene xa13 without inducing a clade III SWEET gene and is nearly identical to a recent Thai isolate
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Posted to bioRxiv 06 Aug 2018

A strain of an emerging Indian pathotype of Xanthomonas oryzae pv. oryzae defeats the rice bacterial blight resistance gene xa13 without inducing a clade III SWEET gene and is nearly identical to a recent Thai isolate
461 downloads pathology

Sara C. D. Carpenter, Prashant Mishra, Chandrika Ghoshal, Prasanta Dash, Li Wang, Samriti Midha, Gouri S. Laha, Jagjeet S Lore, Wichai Kositratana, Nagendra K. Singh, Kuldeep Singh, Prabhu B Patil, Ricardo Oliva, Sujin Patarapuwadol, Adam J Bogdanove, Rhitu Rai

The rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae (Xoo) injects transcription activator-like effectors (TALEs) that bind and activate host susceptibility (S) genes important for disease. Clade III SWEET genes are major S genes for bacterial blight. The resistance genes xa5, which reduces TALE activity generally, and xa13, a SWEET11 allele not recognized by the cognate TALE, have been effectively deployed. However, strains that defeat both resistance genes individually were recently reported in India and Thailand. To gain insight into the mechanism(s), we completely sequenced the genome of one such strain from each country and examined the encoded TALEs. Strikingly, the two strains are clones, sharing nearly identical TALE repertoires, including a TALE known to activate SWEET11 strongly enough to be effective even when diminished by xa5. We next investigated SWEET gene induction by the Indian strain. The Indian strain induced no clade III SWEET in plants harbouring xa13, indicating a pathogen adaptation that relieves dependence on these genes for susceptibility. The findings open a door to mechanistic understanding of the role SWEET genes play in susceptibility and illustrate the importance of complete genome sequence-based monitoring of Xoo populations in developing varieties with effective disease resistance.

65: Outcome of radial scar/complex sclerosing lesion associated with epithelial proliferations with atypia diagnosed on breast core biopsy – Results from a multicentric UK based study
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Posted to bioRxiv 04 Feb 2019

Outcome of radial scar/complex sclerosing lesion associated with epithelial proliferations with atypia diagnosed on breast core biopsy – Results from a multicentric UK based study
456 downloads pathology

Emad Rakha, Francisco Beca, Mariangela D'Andrea, Areeg Abbas, William Petrou-Nunn, Abeer M Shaaban, Aneeshya Kandiyil, Samantha Smith, Sindhu Menon, Somaia Elsheikh, Maysa E ElSayed, Andrew H S Lee, Nisha Sharma

AIMS: The clinical significance of radial scar/complex sclerosing lesion (RS/CSL) with high risk lesions (epithelial atypia) diagnosed on needle core biopsy (NCB) is not well defined. We aimed at assessing the upgrade rate to carcinoma in-situ (DCIS) and invasive on the surgical excision specimen in a large cohort of RS/CSL associated with atypia. METHODS: 161 women with NCB diagnosis of a RS/CSL with atypia and follow-up histology were studied. Histological findings including different forms of the atypical lesions and final histological outcome in the excision specimens were retrieved and analysed and the upgrade rate for malignancy and invasive carcinoma calculated. RESULTS: 76% of the cases were associated with an atypical ductal hyperplasia (ADH) whereas lobular neoplasia was seen in 24%. On final histology 38 cases were malignant (overall upgrade rate of 25%); 12 invasive and 27 DCIS. The upgrade differed according to the type of atypia and was highest for ADH (35%). When associated with lobular neoplasia the upgrade rate was 12%. The upgrade rates variability was also considerably lower and showing less variability when considering the upgrade to invasive carcinoma alone. CONCLUSION: The upgrade rate for ADH diagnosed on NCB with RS is similar to that of ADH without RS and therefore should be managed similarly. RS associated with LN is less frequently associated with malignant outcome. Most lesions exhibiting some degree of atypia showed similar upgrade rate to invasive carcinoma. Management of RS should be based on the concurrent atypical lesion.

66: Nimodipine prevents the development of spasticity after spinal cord injury
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Posted to bioRxiv 17 May 2019

Nimodipine prevents the development of spasticity after spinal cord injury
455 downloads pathology

Maite Marcantoni, Andrea Fuchs, Peter Löw, Ole Kiehn, Carmelo Bellardita

Spasticity, one of the most frequent comorbidities of spinal cord injury (SCI), disrupts motor recovery and quality of life. Despite major progress in neurorehabilitative and pharmacological approaches, no curative treatment for spasticity exists. Here, we show in a mouse model of chronic SCI that treatment with nimodipine, an FDA-approved L-type calcium channel blocker, starting in the acute phase of SCI completely prevents the development of spasticity measured as increased muscle tone and spontaneous spasms. The aberrant muscle activities are permanently blocked even after termination of the treatment. Constitutive and conditional silencing in neuronal subtypes of Cav 1.3 channels shows that preventive effect of nimodipine on spasticity after SCI is mediated by the neuronal Cav 1.3 channels. This study identifies a potentially curative treatment protocol with a specific target for the prevention of spasticity after SCI.

67: Light Pollution Increases West Nile Virus Competence in a Ubiquitous Passerine Reservoir Species
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Posted to bioRxiv 21 Feb 2018

Light Pollution Increases West Nile Virus Competence in a Ubiquitous Passerine Reservoir Species
452 downloads pathology

M. E. Kernbach, J. M. Miller, R. J. Hall, T. R. Unnasch, N. D. Burkett-Cadena, L. B. Martin

Light pollution is a growing problem, but its impacts on infectious disease risk have not been considered. Previous research has revealed that dim light at night (dLAN) dysregulates various immune functions and biorhythms, which hints that dLAN could change the risk of disease epidemics. Here, we demonstrate that dLAN enhances infectiousness of the house sparrow (Passer domesticus), an urban-dwelling avian host of West Nile virus (WNV). Sparrows exposed to dLAN maintained viral titers above the transmission threshold to a biting vector (10^5 plaque-forming units) for two days longer than controls but did not die at higher rates. A mathematical model revealed that such effects could increase WNV outbreak potential by ~41%. dLAN likely affects other host and vector traits relevant to transmission, so additional research is needed to advise management of zoonotic diseases in light polluted areas.

68: Angiodysplasia Detection and Localization Using Deep Convolutional Neural Networks
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Posted to bioRxiv 23 Apr 2018

Angiodysplasia Detection and Localization Using Deep Convolutional Neural Networks
440 downloads pathology

Alexey Shvets, Vladimir Iglovikov, Alexander Rakhlin, Alexandr A. Kalinin

Accurate detection and localization for angiodysplasia lesions is an important problem in early stage diagnostics of gastrointestinal bleeding and anemia. Gold-standard for angiodysplasia detection and localization is performed using wireless capsule endoscopy. This pill-like device is able to produce thousand of high enough resolution images during one passage through gastrointestinal tract. In this paper we present our winning solution for MICCAI 2017 Endoscopic Vision SubChallenge: Angiodysplasia Detection and Localization its further improvements over the state-of-the-art results using several novel deep neural network architectures. It address the binary segmentation problem, where every pixel in an image is labeled as an angiodysplasia lesions or background. Then, we analyze connected component of each predicted mask. Based on the analysis we developed a classifier that predict angiodysplasia lesions (binary variable) and a detector for their localization (center of a component). In this setting, our approach outperforms other methods in every task subcategory for angiodysplasia detection and localization thereby providing state-of-the-art results for these problems. The source code for our solution is made publicly available at https://github.com/ternaus/angiodysplasia-segmentation

69: Targeting the DNM3OS / miR-199a~214 cluster for the treatment of fibroproliferative diseases
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Posted to bioRxiv 04 Jan 2018

Targeting the DNM3OS / miR-199a~214 cluster for the treatment of fibroproliferative diseases
434 downloads pathology

G. Savary, M. Buscot, E. Dewaeles, S. Diazzi, N. Nottet, E. Courcot, J. Fassy, K. Lebrigand, I. S. Henaoui, N. Martis, C. Van der Hauwaert, S. Leroy, L. Plantier, A. Paquet, C. L. Lino Cardenas, G. Vassaux, B. Crestani, B. Wallaert, R. Rezzonico, T. Brousseau, F. Glowacki, S Bellusci, M. Perrais, F. Broly, P. Barbry, C. H. Marquette, C. Cauffiez, Bernard Mari, Nicolas Pottier

Given the paucity of effective treatments for fibrotic disorders, new insights into the deleterious mechanisms controlling fibroblast activation, the key cell type driving the fibrogenic process, are essential to develop new therapeutic strategies. Here, we identified the long non-coding RNA DNM3OS as a critical downstream effector of TGF-β-induced myofibroblast activation. Mechanistically, DNM3OS regulates this process in trans by giving rise to 3 distinct profibrotic mature miRNAs (i.e. miR-199a-5p/3p and miR-214-3p), which influence both SMAD and non-SMAD components of TGF-β signaling in a multifaceted way, through two modes of action consisting of either signal amplification or mediation. Finally, we provide preclinical evidence that interfering with DNM3OS function using distinct strategies not only prevents lung and kidney fibrosis but also improves established lung fibrosis, providing thus a novel paradigm for the treatment of refractory fibrotic diseases such as idiopathic pulmonary fibrosis.

70: Profile of Molecular Subtypes of Breast Cancer Among Bangladeshi Women - Audit of Initial Experience
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Posted to bioRxiv 25 Jan 2018

Profile of Molecular Subtypes of Breast Cancer Among Bangladeshi Women - Audit of Initial Experience
433 downloads pathology

Md. Zillur Rahman, Md Anwarul Karim

Background Receptor status and molecular subtyping of breast cancer are crucial for patient management. We present here our initial experience on the status of different molecular subtypes and clinicopathological characteristics of invasive breast carcinomas in Bangladeshi population especially in Chittagong zone. Materials and methods A total of 59 histopathologically confirmed cases of invasive ductal carcinoma were selected for this study. Fifteen out of 59 cases were reported as HER2 equivalent and could not be categorized into any subtype because of the lack of availability of fluorescence in situ hybridization. The remaining 44 cases were distributed into different molecular subtypes and then the clinicopathological characteristics were compared for each molecular subtype. Results Age ranges from 24-70 years with a mean age of 43.95 years. Most of the patients were in 41-50 years age group. Among the 44 cases, most common subtype was HER2/neu amplification (13 cases, 29.55%). Luminal A, luminal B and basal like subtypes were 11 (25%), 10 (22.73%) and 10 (22.73%) respectively. The mean tumor size was 3.46 cm and the highest mean tumor size was in basal-like subtype (4.01cm). Twenty five out of 59 cases (42.37%) showed axillary lymph node metastasis. Lowest axillary lymph node metastasis was found in luminal A subtype (3/11=27.27%). Conclusion HER2/neu amplification subtype was found to be more common in this region. Luminal A subtype was found to be more favorable in comparison to the other subtypes in terms of axillary lymph node metastasis.

71: TDAG8 (GPR65) Inhibits Intestinal Inflammation in the DSS-Induced Experimental Colitis Mouse Model
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Posted to bioRxiv 13 Dec 2018

TDAG8 (GPR65) Inhibits Intestinal Inflammation in the DSS-Induced Experimental Colitis Mouse Model
429 downloads pathology

Edward J. Sanderlin, Swati Satturwar, Heng Hong, Kvin Lertpiriyapong, Mona Marie, Li V. Yang

T cell death-associated gene 8 (TDAG8, also known as GPR65) is a proton-sensing G protein-coupled receptor (GPCR) predominantly expressed in immune cells. Genome-wide association studies identify TDAG8 as a susceptibility candidate gene linked to several human inflammatory diseases including inflammatory bowel disease (IBD), asthma, spondyloarthritis, and multiple sclerosis. In this study, our results demonstrate that mice deficient of TDAG8 exhibited more severe inflammatory phenotypes than wild-type mice in a chronic dextran sulfate sodium (DSS)-induced colitis mouse model. Several disease parameters, such as diarrhea, colon shortening, fibrosis, histopathological score, and mesenteric lymph node enlargement were aggravated in TDAG8-null mice in comparison to wild-type mice treated with DSS. Increased leukocyte infiltration and myofibroblast expansion were observed in colonic tissues of DSS-treated TDAG8-null mice. These changes may represent a cellular basis of the observed exacerbation of intestinal inflammation and fibrosis in these mice. In line with high expression of TDAG8 in infiltrated leukocytes, real-time RT-PCR revealed that TDAG8 mRNA expression was increased in inflamed intestinal tissue samples of IBD patients when compared to normal intestinal tissues. Altogether, our data demonstrate that TDAG8 suppresses intestinal inflammation and fibrosis in the chronic DSS-induced colitis mouse model, suggesting potentiation of TDAG8 with agonists may have anti-inflammatory therapeutic effects in IBD.

72: Single fiber proteomics of respiratory chain defects in mitochondrial disorders
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Posted to bioRxiv 20 Sep 2018

Single fiber proteomics of respiratory chain defects in mitochondrial disorders
423 downloads pathology

Marta Murgia, Jing Tan, Philipp E. Geyer, Sophia Doll, Matthias Mann, Thomas Klopstock

Mitochondrial DNA mutations progressively compromise the respiratory chain of skeletal muscle, resulting in a mosaic of metabolically healthy and defective fibers. The single fiber investigation of this important diagnostic feature has been beyond the capability of large-scale technologies so far. We used laser capture microdissection (LCM) to excise thin sections of individual muscle fibers from frozen biopsies of patients suffering from chronic progressive external ophthalmoplegia. We then applied a highly sensitive mass spectrometry (MS)-based proteomics workflow to analyze healthy and defective muscle fibers within the same biopsy. We quantified more than 4000 proteins in each patient, covering 75% of all respiratory chain subunits, and compared their expression in metabolically healthy and defective muscle fibers. Our findings show that mitochondrial disease causes extensive proteomic rearrangements, affecting the OPA1-dependent cristae remodeling pathway and mitochondrial translation. We provide fiber type-specific information showing that increased expression of fatty acid oxidation enzymes occurs in defective slow but not fast muscle fibers. Our findings shed light on compensatory mechanisms in muscle fibers that struggle with energy shortage and metabolic stress.

73: Dietary and behavioral inferences from dental pathology and non-masticatory wear on dentitions from a British medieval town
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Posted to bioRxiv 19 Nov 2017

Dietary and behavioral inferences from dental pathology and non-masticatory wear on dentitions from a British medieval town
420 downloads pathology

Ian Towle, Carole Davenport, Joel D Irish, Isabelle De Groote

Dental pathology and wear data can provide valuable insights into diet, cultural practices, and the health of populations. In this study, various dental pathologies and types of wear were recorded for 41 individuals (914 permanent teeth), excavated from the medieval cemetery of St. Owens Church in Southgate Street, Gloucester. Teeth were studied macroscopically with a 10x hand lens to confirm the presence of specific pathologies. Relatively high rates of antemortem chipping on the anterior teeth, and the presence of maxillary central incisor notches, suggested that the Gloucester population commonly used their teeth for non-masticatory activities. Abscessing and antemortem tooth loss fell within previously reported ranges for British medieval sites (2.6% and 6% respectively). However, the sample exhibits extremely high levels of carious lesions and calculus. Nearly 24% of teeth have at least one carious lesion, and the presence of calculus was recorded in 74% of teeth within the sample. Overall caries frequency is similar to sites from later time periods. This frequency may reflect Gloucester's location as a large port town. Remains from the same area, but the earlier Roman period, also shows high rates of both caries and calculus, suggesting a continuation of consuming certain cariogenic foods is likely.

74: Differential physiological role of BIN1 isoforms in skeletal muscle development, function and regeneration
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Posted to bioRxiv 23 Nov 2018

Differential physiological role of BIN1 isoforms in skeletal muscle development, function and regeneration
416 downloads pathology

Ivana Prokic, Belinda Simone Cowling, Candice Kutchukian, Christine Kretz, Hichem Tasfaout, Josiane Hergueux, Olivia Wendling, Arnaud Ferry, Anne Toussaint, Christos Gavriilidis, Vasugi Nattarayan, Catherine Koch, Jeanne Lainné, Roy Combe, Laurent Tiret, Vincent Jacquemond, Fanny Pilot-Storck, Jocelyn Laporte

Skeletal muscle development and regeneration are tightly regulated processes. How the intracellular organization of muscle fibers is achieved during these steps is unclear. Here we focus on the cellular and physiological roles of amphiphysin 2 (BIN1), a membrane remodeling protein mutated in both congenital and adult centronuclear myopathies, that is ubiquitously expressed and has skeletal muscle-specific isoforms. We created and characterized constitutive, muscle-specific and inducible Bin1 homozygous and heterozygous knockout mice targeting either ubiquitous or muscle-specific isoforms. Constitutive Bin1 deficient mice died at birth from lack of feeding due to a skeletal muscle defect. T-tubules and other organelles were misplaced and altered, supporting a general early role of BIN1 on intracellular organization in addition to membrane remodeling. Whereas restricted deletion of Bin1 in unchallenged adult muscles had no impact, the forced switch from the muscle-specific isoforms to the ubiquitous isoforms through deletion of the in-frame muscle-specific exon delayed muscle regeneration. Thus, BIN1 ubiquitous function is necessary for muscle development and function while its muscle-specific isoforms fine-tune muscle regeneration in adulthood, supporting that BIN1 centronuclear myopathy with congenital onset are due to developmental defects while later onset may be due to regeneration defects.

75: Estrogen receptor regulates hormone-induced growth arrest in a luminal A like breast cancer model
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Posted to bioRxiv 23 Apr 2018

Estrogen receptor regulates hormone-induced growth arrest in a luminal A like breast cancer model
414 downloads pathology

Lacey Haddon, Sunny Hu, Hosna Jabbari, Brittney Loney, Zelda-Saidman Lichtensztejn, Richard Fahlman, Mary Hitt, Kirk McManus, Kelly Dabbs, John Mackey, Judith Hugh

Estrogen receptor positive (ER+) breast cancer has been divided into two subtypes, luminal A and luminal B, which differ in their ER expression and response to hormone therapy. The absence of luminal A cell lines means the extensive amount of in vitro work studying the response to hormones in ER+ breast cancers is biased for the luminal B subtype. We have developed a luminal A like cell model by increasing the ER expression in the MCF-7 cell line. Our results show that increased ER expression promotes an anti-proliferative response to estrogen through regulation of genes involved in the G1/S-phase transition of the cell cycle. Furthermore, increased ER expression increases ER-DNA binding in the absence of estrogen and regulates basal gene transcription by promoting DNA looping. These results provide novel evidence that the characteristic increased ER expression of luminal A tumors may promote a novel chromatin configuration that enables growth of these tumors in the absence of estrogen and enables gene repression in the presence of hormones.

76: 3D spatially-resolved geometrical and functional models of human liver tissue reveal new aspects of NAFLD progression
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Posted to bioRxiv 09 Mar 2019

3D spatially-resolved geometrical and functional models of human liver tissue reveal new aspects of NAFLD progression
413 downloads pathology

Fabián Segovia-Miranda, Hernan Morales-Navarrete, Michael Kücken, Vincent Moser, Sarah Seifert, Urska Repnik, Fabian Rost, Alexander Hendriks, Sebastian Hinz, Christoph Röcken, Dieter Lüthjohann, Yannis Kalaidzidis, Clemens Schafmayer, Lutz Brusch, Jochen Hampe, Marino Zerial

Early disease diagnosis is key for the effective treatment of diseases. It relies on the identification of biomarkers and morphological inspection of organs and tissues. Histopathological analysis of human biopsies is the gold standard to diagnose tissue alterations. However, this approach has low resolution and overlooks 3D structural changes that are consequence of functional alterations. Here, we applied multiphoton imaging, 3D digital reconstructions and computational simulations to generate spatially-resolved geometrical and functional models of human liver tissue at different stages of non-alcoholic fatty liver disease (NAFLD). We identified a set of new morphometric cellular parameters correlated with disease progression. Moreover, we found profound topological defects in the 3D bile canaliculi (BC) network. Personalized biliary fluid dynamic simulations predicted an increased pericentral biliary pressure and zonated cholestasis, consistent with elevated cholestatic biomarkers in patients' sera. Our spatially-resolved models of human liver tissue can contribute to high-definition medicine by identifying quantitative multi-parametric cellular and tissue signatures to define disease progression and provide new insights into NAFLD pathophysiology.

77: Hemozoin produced by mammals confers heme tolerance
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Posted to bioRxiv 16 May 2019

Hemozoin produced by mammals confers heme tolerance
408 downloads pathology

Rini H. Pek, Xiaojing Yuan, Nicole Rietzschel, Jianbing Zhang, Laurie K. Jackson, Eiji Nishibori, Ana Ribeiro, William R. Simmons, Jaya Jagadeesh, Hiroshi Sugimoto, Md. Zahidul Alam, Lisa J. Garrett, Malay Haldar, Martina Ralle, John Phillips, David Bodine, Iqbal Hamza

Free heme is cytotoxic as exemplified by hemolytic diseases and genetic deficiencies in heme recycling and detoxifying pathways. Thus, intracellular accumulation of heme has not been observed in mammalian cells to date. Here we show that mice deficient for the heme transporter HRG1 accumulate over ten-fold excess heme in reticuloendothelial macrophage lysosomes that are 10 to 100 times larger than normal. Macrophages tolerate these high concentrations of heme by polymerizing them into crystalline hemozoin, which heretofore has only been found in blood-feeding parasites. HRG1 deficiency results in impaired erythroid maturation and an inability to systemically respond to iron deficiency. Complete heme tolerance requires a fully-operational heme degradation pathway as haploinsufficiency of HMOX1 combined with HRG1 inactivation causes perinatal lethality demonstrating synthetic lethal interactions between heme transport and degradation. Our studies establish the formation of hemozoin by mammals as a previously unsuspected heme tolerance pathway.

78: Multi-task learning of a deep k-nearest neighbour network for histopathological image classification and retrieval
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Posted to bioRxiv 06 Jun 2019

Multi-task learning of a deep k-nearest neighbour network for histopathological image classification and retrieval
408 downloads pathology

Tingying Peng, Melanie Boxberg, Wilko Weichert, Nassir Navab, Carsten Marr

Deep neural networks have achieved tremendous success in image recognition, classification and object detection. However, deep learning is often criticised for its lack of transparency and general inability to rationalize its predictions. The issue of poor model interpretability becomes critical in medical applications, as a model that is not understood and trusted by physicians is unlikely to be used in daily clinical practice. In this work, we develop a novel multi-task deep learning framework for simultaneous histopathology image classification and retrieval, leveraging on the classic concept of k-nearest neighbours to improve model interpretability. For a test image, we retrieve the most similar images from our training databases. These retrieved nearest neighbours can be used to classify the test image with a confidence score, and provide a human-interpretable explanation of our classification. Our original framework can be built on top of any existing classification network (and therefore benefit from pretrained models), by (i) adding a triplet loss function with a novel triplet sampling strategy to compare distances between samples and (ii) a Cauchy hashing loss function to accelerate neighbour searching. We evaluate our method on colorectal cancer histology slides, and show that the confidence estimates are strongly correlated with model performance. The explanations provided by nearest neighbours are intuitive and useful for expert evaluation by giving insights into understanding possible model failures, and can support clinical decision making by comparing archived images and patient records with the actual case.

79: Liraglutide improves hepatic steatosis and metabolic dysfunctions in a 3-week dietary mouse model of non-alcoholic steatohepatitis
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Posted to bioRxiv 17 May 2019

Liraglutide improves hepatic steatosis and metabolic dysfunctions in a 3-week dietary mouse model of non-alcoholic steatohepatitis
407 downloads pathology

Thibaut Duparc, François Briand, Charlotte Trenteseaux, Jules Mérian, Guillaume Combes, Souad Najib, Thierry Sulpice, Laurent O. Martinez

Aim: Non-alcoholic steatohepatitis (NASH) is an emerging health problem worldwide. However, efficacious pharmacological treatment for NASH is lacking. A major issue for preclinical evaluation of potential therapeutics for NASH is the limited number of appropriate animal models, i.e., models that do not require long-term dietary intervention and adequately mimic disease progression in humans. The present study aimed to evaluate a 3-week dietary mouse model of NASH and to validate it by studying the effects of liraglutide, a compound in advanced clinical development for NASH. Methods: C57BL6/J mice were fed a diet high in fat (60%), cholesterol (1.25%) and cholic acid (0.5%) along with 2% hydroxypropyl-β-cyclodextrin in drinking water (HFCC-CDX diet). Histological and biological parameters were measured at 1 and 3 weeks. Following 1-week diet induction, liraglutide was administrated daily for 2 weeks, and then NASH-associated phenotypic aspects were evaluated in comparison with control mice. Results: Prior to treatment with liraglutide, mice fed the HFCC-CDX diet for 1 week developed liver steatosis and had increased levels of oxidative-stress markers and hepatic and systemic inflammation. For mice not treated with liraglutide, these aspects were even more pronounced after 3 weeks of the dietary period, with additional liver insulin resistance and fibrosis. Liraglutide treatment corrected the diet-induced alterations in glucose metabolism and significantly reduced hepatic steatosis and inflammation. Conclusion: This study provides a novel 3-week dietary model of mice that rapidly develop NASH features, and this model will be suitable for evaluating the therapeutic efficacy of compounds in preclinical drug development for NASH.

80: Use of human iPSCs and kidney organoids to develop a cysteamine/mTOR inhibition combination therapy to treat cystinosis
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Posted to bioRxiv 01 Apr 2019

Use of human iPSCs and kidney organoids to develop a cysteamine/mTOR inhibition combination therapy to treat cystinosis
401 downloads pathology

Jennifer A Hollywood, Aneta Przepiorski, Patrick T Harrison, Ernst J Wolvetang, Alan J. Davidson, Teresa M Holm

Cystinosis is a lysosomal storage disease caused by mutations in CTNS, encoding a cystine transporter, and in its severest form is characterized by cystine accumulation, renal proximal tubule dysfunction and kidney failure. Cystinosis is treated with the cystine-depleting drug cysteamine, however this only slows progression of the disease and there is an urgent need for better treatments. Here, we have generated and characterized the first human induced pluripotent stem cell (iPSC) and kidney organoid models of cystinosis. These models exhibit elevated cystine and cysteine levels, enlarged lysosomes and a block in basal autophagy flux. Cysteamine treatment ameliorates this phenotype except for the basal autophagy flux defect. We found that treatment with Everolimus, an inhibitor of the mTOR pathway, reduces the number of large lysosomes and activates autophagy but does not rescue the cystine/cysteine loading defect. However, dual treatment of cystinotic iPSCs or kidney organoids with cysteamine and Everolimus corrects all of the observed phenotypes indicating that a combination therapy has therapeutic potential to improve the treatment of cystinosis.

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