Cryosectioning the intestinal crypt-villus axis: An ex vivo method to study the dynamics of epigenetic modifications from stem cells to differentiated cells

AbstractThe intestinal epithelium is a particularly attractive biological adult model to study epigenetic mechanisms driving adult stem cell renewal and cell differentiation. Since epigenetic modifications are dynamic, we have developed an original ex vivo approach to study the expression and epigenetic profiles of key genes associated with either intestinal cell pluripotency or differentiation by isolating cryosections of the intestinal crypt-villus axis. Gene expression, DNA methylation and histone modifications were studied by qRT-PCR, methylation-specific PCR and micro-chromatin immunoprecipitation, respectively. Using this approach, it was possible to identify segment-specific methylation and chromatin profiles. We show that (i) expression of intestinal stem cell markers (Lgr5, Ascl2) exclusively in the crypt is associated with active histone marks, (ii) promoters of all pluripotency genes studied and transcription factors involved in intestinal cell fate (Cdx2) harbour a bivalent chromatin pattern in the crypts and (iii) expression of differentiation markers (Muc2, Sox9) along the crypt-villus axis is associated with DNA methylation. Hence, using an original model of cryosectioning along the crypt-villus axis that allows in situ detection of dynamic epigenetic modifications, we demonstrate that regulation of pluripotency and differentiation markers in healthy intestinal mucosa involves different and specific epigenetic mechanisms

A vision transformer-based framework for knowledge transfer from multi-modal to mono-modal lymphoma subtyping models

Determining lymphoma subtypes is a crucial step for better patients treatment targeting to potentially increase their survival chances. In this context, the existing gold standard diagnosis method, which is based on gene expression technology, is highly expensive and time-consuming making difficult its accessibility. Although alternative diagnosis methods based on IHC (immunohistochemistry) technologies exist (recommended by the WHO), they still suffer from similar limitations and are less accurate. WSI (Whole Slide Image) analysis by deep learning models showed promising new directions for cancer diagnosis that would be cheaper and faster than existing alternative methods. In this work, we propose a vision transformer-based framework for distinguishing DLBCL (Diffuse Large B-Cell Lymphoma) cancer subtypes from high-resolution WSIs. To this end, we propose a multi-modal architecture to train a classifier model from various WSI modalities. We then exploit this model through a knowledge distillation mechanism for efficiently driving the learning of a mono-modal classifier. Our experimental study conducted on a dataset of 157 patients shows the promising performance of our mono-modal classification model, outperforming six recent methods from the state-of-the-art dedicated for cancer classification. Moreover, the power-law curve, estimated on our experimental data, shows that our classification model requires a reasonable number of additional patients for its training to potentially reach identical diagnosis accuracy as IHC technologies

Tumour biology of colorectal liver metastasis is a more important factor in survival than surgical margin clearance in the era of modern chemotherapy regimens

AbstractBackgroundThe aim of the authors was to reassess the impact of a positive surgical margin (R1) after a liver resection for colorectal liver metastases (CLMs) on survival in the era of modern chemotherapy, through their own experience and a literature review.MethodsInclusion criteria were: R1 or R0 resection with no local treatment modalities, extra‐hepatic metastases or other cancer.ResultsAmong 337 patients operated between 2000 and 2010, 273 patients were eligible (214 R0/59 R1). The mean follow‐up was 43 ± 29 months. Compared with a R0 resection, a R1 resection offered a lower 5‐year overall (39.1% versus 54.2%, P = 0.010), disease‐free (15.2% versus 31.1%, P = 0.021) and progression‐free (i.e. time to the first non‐curable recurrence; 33.1% versus 47.3%, P = 0.033) survival rates. Metastases in the R1 group were more numerous, larger and more frequently synchronous. Independent factors of poor survival were: number, size and short‐time interval of CLM occurrence, N status, rectal primary, absence of adjuvant chemotherapy, but not a R1 resection. With the more‐systematic administration of chemotherapy since 2005, the intergroup difference in progression‐free survival disappeared (P = 0.264).ConclusionA R1 resection had no prognostic value per se but reflected a more severe disease. The recent change in the prognostic value of a R1 resection may be linked to the beneficial effect of chemotherapy

Galectin-4 and sulfatides in apical membrane trafficking in enterocyte-like cells

We have previously reported that 1-benzyl-2-acetamido-2-deoxy-α-d-galactopyranoside (GalNAcα-O-bn), an inhibitor of glycosylation, perturbed apical biosynthetic trafficking in polarized HT-29 cells suggesting an involvement of a lectin-based mechanism. Here, we have identified galectin-4 as one of the major components of detergent-resistant membranes (DRMs) isolated from HT-29 5M12 cells. Galectin-4 was also found in post-Golgi carrier vesicles. The functional role of galectin-4 in polarized trafficking in HT-29 5M12 cells was studied by using a retrovirus-mediated RNA interference. In galectin-4–depleted HT-29 5M12 cells apical membrane markers accumulated intracellularly. In contrast, basolateral membrane markers were not affected. Moreover, galectin-4 depletion altered the DRM association characteristics of apical proteins. Sulfatides with long chain-hydroxylated fatty acids, which were also enriched in DRMs, were identified as high-affinity ligands for galectin-4. Together, our data propose that interaction between galectin-4 and sulfatides plays a functional role in the clustering of lipid rafts for apical delivery

Diagnosing nodular regenerative hyperplasia of the liver is thwarted by low interobserver agreement

Background and Aims: Nodular regenerative hyperplasia (NRH) of the liver is associated with several diseases and drugs. Clinical symptoms of NRH may vary from absence of symptoms to full-blown (noncirrhotic) portal hypertension. However, diagnosing NRH is challenging. The objective of this study was to determine inter- and intraobserver agreement on the histopathologic diagnosis of NRH. Methods: Liver specimens (n=48) previously diagnosed as NRH, were reviewed for the presence of NRH by seven pathologists without prior knowledge of the original diagnosis or clinical background. The majority of the liver specimens were from thiopurine using inflammatory bowel disease patients. Histopathologic features contributing to NRH were also assessed. Criteria for NRH were modified by consensus and subsequently validated. Interobserver agreement was evaluated by using the standard kappa index. Results: After review, definite NRH, inconclusive NRH and no NRH were found in 35% (23-40%), 21% (13-27%) and 44% (38-56%), respectively (median, IQR). The median interobserver agreement for NRH was poor (κ = 0.20, IQR 0.14-0.28). The intraobserver variability on NRH ranged between 14% and 71%. After modification of the criteria and exclusion of biopsies with technical shortcomings, the interobserver agreement on the diagnosis NRH was fair (κ = 0.45). Conclusions: The interobserver agreement on the histopathologic diagnosis of NRH was poor, even when assessed by well-experienced liver pathologists. Modification of the criteria of NRH based on consensus effort and exclusion of biopsies of poor quality led to a fairly increased interobserver agreement. The main conclusion of this study is that NRH is a clinicopathologic diagnosis that cannot reliably be based on histopathology alone

A histologic scoring system for prognosis of patients with Alcoholic hepatitis

BACKGROUND & AIMS: There is no histologic classification system to determine prognoses of patients with alcoholic hepatitis (AH). We identified histologic features associated with disease severity and created a histologic scoring system to predict short-term (90-day) mortality. METHODS: We analyzed data from 121 patients admitted to the Liver Unit (Hospital Clinic, Barcelona, Spain) from January 2000 to January 2008 with features of AH and developed a histologic scoring system to determine the risk of death using logistic regression. The system was tested and updated in a test set of 96 patients from 5 academic centers in the United States and Europe, and a semiquantitative scoring system called the Alcoholic Hepatitis Histologic Score (AHHS) was developed. The system was validated in an independent set of 109 patients. Interobserver agreement was evaluated by weighted κ statistical analysis. RESULTS: The degree of fibrosis, degree of neutrophil infiltration, type of bilirubinostasis, and presence of megamitochondria were independently associated with 90-day mortality. We used these 4 parameters to develop the AHHS to identify patients with a low (0-3 points), moderate (4-5 points), or high (6-9 points) risk of death within 90 days (3%, 19%, and 51%, respectively; P < .0001). The AHHS estimated 90-day mortality in the training and test sets with an area under the receiver operating characteristic value of 0.77 (95% confidence interval, 0.71-0.83). Interrater agreement values were 0.65 for fibrosis, 0.86 for bilirubinostasis, 0.60 for neutrophil infiltration, and 0.46 for megamitochondria. Interestingly, the type of bilirubinostasis predicted the development of bacterial infections. CONCLUSIONS: We identified histologic features associated with the severity of AH and developed a patient classification system that might be used in clinical decision making

A Histologic Scoring System for Prognosis of Patients With Alcoholic Hepatitis

There is no histologic classification system to determine prognoses of patients with alcoholic hepatitis (AH). We identified histologic features associated with disease severity and created a histologic scoring system to predict short-term (90 day) mortality

CINQUANTE TUMEURS CORTICOSURRENALIENNES (EVALUATION DU SYSTEME DE WEISS ET ETUDE EN IMMUNOHISTOCHIMIE DE KI-67, P27 ET P21)

LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

La classification de Bethesda en cytologie thyroïdienne (bilan et perspectives d'évolution après une année d'utilisation au CHR-U de Lille)

LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF

Caractérisation clinique, morphologique, immunohistochimique et moléculaire des carcinomes papillaires et adénomes folliculaires thyroïdiens (à propos d'une série de 190 patients)

Contexte Notre équipe a précédemment proposé un score microscopique pour évaluer notre pratique du diagnostic différentiel entre carcinome papillaire (CPT) et adénome folliculaire (AF). Il existait des tumeurs dont le résultat du score était situé dans une zone intermédiaire , attestant de la subjectivité du diagnostic de malignité pour certaines tumeurs thyroïdiennes bien différenciées et encapsulées. Cette série constituait une base objective pour poursuivre la caractérisation des tumeurs, à la recherche de marqueurs diagnostiques et/ou pronostiques du CPT et afin de classer les tumeurs de la zone intermédiaire . Méthode L étude incluait 95 CPT et 95 AF caractérisés par une valeur du score. Un tissuemicroarray était construit pour étudier l expression en immunohistochimie de HBME-1, CK19, TPO, MUC1, Gal-1, Gal-3 et b-caténine. Les mutations B-RAF et RAS (N-,H-,K-) étaient recherchées par pyroséquençage. Le suivi clinique était de 96 à 144 mois. Les statistiques étaient réalisées en modes uni et multivariés. Résultats La variante folliculaire du CPT (VFCPT) était associée à un profil immunohistochimique spécifique HBME-1+ et/ou CK19+ et TPO+ (p<0,0001). MUC1 était associée aux CPT avec caractéristiques histologiques agressives (p<0,0001). La mutation BRAF était identifiée dans 40% des CPT, dont elle était exclusive. Les mutations RAS étaient détectées dans 29% des CPT et 12% des AF. En analyse multivariée, H-RAS était associé à la malignité (OR : 23 et IC95% [3-189]) et MUC1 à B-RAF (OR : 23 et IC95% [4-130]). TPO était associée à N-RAS dans les tumeurs d architecture folliculaire (p<0,001). La comparaison des différents marqueurs montrait une supériorité des critères microscopiques par rapport à l immunohistochimie et à la biologie moléculaire pour le diagnostic de malignité des tumeurs intermédiaires . MUC1 et B-RAF étaient associés à une moins bonne survie sans progression (p=0,0002 et p=0,0009). Conclusion Les tumeurs thyroïdiennes bien différenciées de morphologie ambiguë avaient un phénotype et un génotype non spécifiques et une excellente évolution. Nous identifions un intérêt diagnostique de malignité pour H-RAS, diagnostique de VFCPT pour TPO, et pronostique pour MUC1, qui était fortement associé à B-RAF.LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF