Publications by authors named "Valeer Desmet"

Hepatic ciliated foregut remnants or cysts are congenital abnormalities resulting from retention of embryonic ciliated foregut within the liver. These structures are rarely reported in the human medical literature and have not been reported in the veterinary literature previously, to our knowledge. We describe here a case of an 8-wk-old male French Bulldog with a congenital patent hepatic ciliated foregut remnant resulting in an umbilicobiliary sinus tract.

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The revolutionary evolution in science and technology over the last few decades has made it possible to face more adequately three main challenges of modern medicine: changes in old diseases, the appearance of new diseases, and diseases that are unknown (mostly genetic), despite research efforts. In this paper we review the road travelled by pathologists in search of a method based upon the use of routine instruments and techniques which once were available for research only. The application to tissue studies of techniques from immunology, molecular biology, and genetics has allowed dynamic interpretations of biological phenomena with special regard to gene regulation and expression.

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Professional societies play a major role in medicine and science. The societies tend to be large with well-developed administrative structures. An additional model, however, is based on small groups of experts who meet regularly in an egalitarian model in order to discuss disease-specific scientific and medical problems.

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Background: Alpha-1-antitrypsin (AAT) deficiency (AATD) of Z, Mmalton, Siiyama type is associated with liver storage of the mutant proteins and liver disease. The Z variant can be diagnosed on isoelectric focusing (IEF) while Mmalton and Siiyama may be missed or misdiagnosed with this technique. Therefore, molecular analysis is mandatory for their characterization.

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Background: Blau syndrome (BS) and Crohn disease (CD) are both characterized by granulomatous inflammation and related to nucleotide oligomerization domain 2 (NOD2) mutations.

Objective: This study aimed to define the morphologic and immunohistochemical characteristics of granulomas in patients with NOD2-related BS and CD.

Methods: Granuloma-containing biopsy specimens from 6 patients with BS and 7 pediatric patients with CD carrying NOD2 mutations or single nucleotide polymorphisms were studied for morphology, cellular composition, and cytokine expression by using hematoxylin and eosin staining and immunohistochemistry.

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This article discusses on the basis of the ductal plate hypothesis the implication of the concept for several liver abnormalities. The occurrence of ductal plates (DP) during liver growth in childhood would explain the paraportal and parenchymal localizations of von Meyenburg complexes in postnatally developed parts of the liver, and their higher incidence in adulthood versus childhood. It partly clarifies the lack of postnatal intrahepatic bile duct development in Alagille syndrome and the reduced number of portal tracts in this disease.

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This article discusses the processes of bile duct growth and new lobule formation in the liver during childhood in the light of the ductal plate (DP) hypothesis. Unlike in other organs in which tubular elongation and branching ends with the creation of the organ-specific terminal differentiation products, in the liver a steadily enlarging parenchymal mass needs to establish continuity of its canalicular network with the existing bile duct system. The hypothesis suggests that this occurs by DP formation, like in the embryonic liver, and further assumes that pathological ductular reactions (DRs) induced by cholestasis or hypoxia are amplified equivalents of similar mechanisms operating at low level during liver growth.

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This article focuses on the observation that most hepatic ductular reactions (DRs) have ductal plate (DP)-like patterns. Considering old and recent data, it hypothesizes that in DR, dedifferentiation of hepatocytes in ductular metaplasia may lead to the de novo development of liver stem/progenitor cells (LPCs). The three recognized types of DR are reconsidered, and an additional fourth type, DR type 2B, is added.

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Secondary amyloidosis may complicate chronic inflammatory conditions and mostly presents as a renal disease with nephrotic syndrome or renal insufficiency. Its prognosis is largely affected by control of the underlying disease. We report a patient with primary sclerosing cholangitis, who developed cirrhosis over a 4-year period.

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Background: The expression of Keratin 19 (K19) was reported in a subset of hepatocellular carcinomas (HCCs). K19 positive HCCs are associated with an increased malignancy compared to K19 negative HCCs. No suitable mouse models exist for this subtype of HCC, nor is the incidence of K19 expression in hepatocellular neoplasia in model animals known.

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An informal review is presented by the author of his 50 years of involvement in practice and research in hepatopathology. Some background for the author's attitude and meandering pathway into his professional career serves as introduction to a short discussion of the main topics of his interest and expertise. Histogenesis of liver cancer was the theme of early work for a Ph.

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Unlabelled: Cholangiolocellular carcinoma (CLC), a subtype of cholangiocellular carcinoma (CC), is thought to originate from the ductules/canals of Hering, where hepatic progenitor cells (HPCs) are located. We investigated the clinicopathological features of 30 CLCs and their relationship to HPCs. We evaluated the expression of hepatocytic markers (hepatocyte paraffin-1, canalicular polyclonal carcinoembryonic antigen, and CD10), biliary/HPC markers (keratin [K]7, K19, and neural cell adhesion molecule), the adenosine triphosphate binding cassette transporters: multidrug resistance protein 1, multidrug resistance-associated protein (MRP)1, MRP3, and breast cancer resistance protein, using immunohistochemistry and electron microscopy.

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Cystic diseases of the liver which are in most cases hereditary, are related to an embryonic disorder know as ductal plate malformation. These diseases correspond to partial or total arrest of remodeling of the ductal plate, leading to more or less complete persistence of the excess of embryonic biliary structures. The ductal plate malformation may concern different segments of the intrahepatic biliary tree (segmental bile ducts, interlobular bile ducts and the smallest bile duct ramifications) leading to various pathoclinical entities.

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Hepatocellular adenoma and focal nodular hyperplasia (FNH) are benign liver tumours. The differential diagnosis of these lesions and of well- to moderately differentiated hepatocellular carcinomas is often difficult but is very important in view of their different treatment. Although neither type of lesion is connected to the biliary tree, FNHs are cholestatic, whereas this is rarely the case for hepatocellular adenomas.

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The early stages of hepatocarcinogenesis in human chronic liver diseases are characterized by the emergence of preneoplastic lesions of which some will eventually develop into hepatocellular carcinoma (HCC). Basic studies on the genetic and epigenetic alterations of these preneoplastic lesions may eventually lead to new therapeutic strategies. Clinicopathological studies are also important in order to determine optimal management of patients with a preneoplastic lesion.

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Background & Aims: Little is known about the long-term effects of interferon alpha on clinical outcome and survival of patients with chronic hepatitis D.

Methods: Thirty-six patients with chronic hepatitis D who participated in a randomized controlled trial of a 48-week course of high (9 million units) or low (3 million units) doses of interferon alpha or no treatment were followed for an additional 2 to 14 years.

Results: Long-term survival was significantly longer in the high-dose group than in untreated controls (P = 0.

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The work of liver stem cell biologists, largely carried out in rodent models, has now started to manifest in human investigations and applications. We can now recognize complex regenerative processes in tissue specimens that had only been suspected for decades, but we also struggle to describe what we see in human tissues in a way that takes into account the findings from the animal investigations, using a language derived from species not, in fact, so much like our own. This international group of liver pathologists and hepatologists, most of whom are actively engaged in both clinical work and scientific research, seeks to arrive at a consensus on nomenclature for normal human livers and human reactive lesions that can facilitate more rapid advancement of our field.

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Hepatic progenitor cells are immature epithelial cells that reside in the smallest ramifications of the biliary tree in human liver. These cells are capable of differentiating toward the biliary and the hepatocytic lineages and represent the human counterpart of the oval cells in murine liver. An increased number of progenitor cells (referred to as "activation") and differentiation of the same toward hepatocytes or bile duct epithelial cells, or both, is a component of virtually all human liver diseases.

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New treatments are needed for chronic hepatitis C patients in whom viral clearance cannot be achieved. Thirty-five chronic hepatitis C patients (genotype 1) were randomized to receive 20 mug of recombinant HCV E1 (E1) (n = 26) or placebo (n = 9) intramuscularly at weeks 0, 4, 8, 12, and 24. Thirty-four then received open-label E1 vaccine at weeks 50, 53, 56, 59, 62, and 65.

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Background/aims: A simple and reproducible hepatic immunohistochemical staining (IHS) for hepatitis C virus (HCV) is not available. We aimed to validate hepatic IHS with monoclonal antibody (Mab) IG222, directed against the HCV-envelope 2 (E2) protein.

Methods: A three-step indirect immunoperoxidase method was used for frozen sections and a two-step indirect EnVision technique was used for paraffin-embedded sections.

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Synopsis of recent research by authors named "Valeer Desmet"

  • - Valeer Desmet's recent research primarily focuses on liver pathology, exploring congenital and acquired liver conditions, with a notable case study on a congenital hepatic ciliated foregut remnant in a French Bulldog that highlights previously undocumented veterinary pathology.
  • - His work broadly examines the impact of advances in technology and pathology in understanding complex diseases, including the evolution of diagnostic techniques for disorders like Alpha-1-antitrypsin deficiency and Endoplasmic Reticulum Storage Disease, showcasing a blend of traditional and modern methodologies.
  • - Desmet also investigates the implications of ductal plate formation in liver pathology, providing hypotheses on embryonic liver development and its correlation with various liver diseases, reflecting on the significance of small expert groups in advancing medical science through collaborative exploration.