Publications by authors named "Sylvie Polak-Charcon"

Hyaline fibromatosis syndrome (HFS), resulting from mutations, is an ultra-rare disease that causes intestinal lymphangiectasia and protein-losing enteropathy (PLE). The mechanisms leading to the gastrointestinal phenotype in these patients are not well defined. We present two patients with congenital diarrhea, severe PLE and unique clinical features resulting from deleterious mutations.

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Cellular distribution and dynamics of mitochondria are regulated by several motor proteins and a microtubule network. In neurons, mitochondrial trafficking is crucial because of high energy needs and calcium ion buffering along axons to synapses during neurotransmission. The trafficking kinesin proteins (TRAKs) are well characterized for their role in lysosomal and mitochondrial trafficking in cells, especially neurons.

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Objectives: The purpose of this study was to describe the characteristics and outcomes of fetuses with a diagnosis of nonobstructive diffuse dilated bowel loops.

Methods: We conducted a retrospective study of all pregnancies with fetal diagnosis of nonobstructive diffuse dilated bowel loops over 14 years in a large tertiary referral center. Fetomaternal and neonatal characteristics and outcomes were assessed.

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We investigated the cause of situs inversus totalis (SIT) in two siblings from a consanguineous family. Genotyping and whole-exome analysis revealed a homozygous change in NME7, resulting in deletion of an exon causing an in-frame deletion of 34 amino acids located in the second NDK domain of the protein and segregated with the defective lateralization in the family. NME7 is an important developmental gene, and NME7 protein is a component of the γ-tubulin ring complex.

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Background: Familial restrictive cardiomyopathy (RCM) caused by a single gene mutation is the least common of the inherited cardiomyopathies. Only a few RCM-causing mutations have been described. Most mutations causing RCM are located in sarcomere protein genes which also cause hypertrophic cardiomyopathy (HCM).

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Purpose: To elucidate the relative role of the immune system and intestinal epithelium in the ethiopatogenesis of Celiac disease (CD).

Methods: A patient with childhood CD who underwent allogeneic bone marrow transplantation (BMT) for chronic myelogenous leukemia was followed for 5 years after resumption of gluten containing diet. Immunological memory to gliadin epitopes was assessed in the index patient and in 5 newly diagnosed CD patients by standard serology testing and by CFSE-based proliferation assays of peripheral blood CD4+ cells and of intestinal LPL towards gliadin-TTG antigens.

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Background: Neutrophils are the predominant phagocytes that provide protection against bacterial and fungal infections. Genetically determined neutrophil disorders confer a predisposition to severe infections and reveal novel mechanisms that control vesicular trafficking, hematopoiesis, and innate immunity.

Methods: We clinically evaluated seven children from five families who had neutropenia, neutrophil dysfunction, bone marrow fibrosis, and nephromegaly.

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Objective: To increase awareness to the possibility of nemaline myopathy (NM) when abnormal prenatal ultrasound findings appear together with a carrier state for the common exon 55 deletion in the nebulin gene (NEB) of an Ashkenazi Jewish parent.

Methods: We describe four unrelated pregnancies with abnormal prenatal ultrasound findings resulting in the birth of newborns with NM, where one or both parents were of Ashkenazi Jewish origin. Data was collected retrospectively from the patients' medical files.

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Compelling evidences have rendered the tumor microenvironment a crucial determinant in cancer outcome. Activating transcription factor 3 (ATF3), a stress response transcription factor, is known to have a dichotomous role in tumor cells, acting either as a tumor suppressor or an oncogene in a context-dependent manner. However, its expression and possible role in the tumor microenvironment are hitherto unknown.

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Activation of the pancreatic lineage in the liver has been suggested as a potential autologous cell replacement therapy for diabetic patients. Transcription factors-induced liver-to-pancreas reprogramming has been demonstrated in numerous species both in vivo and in vitro. However, human-derived liver cells capable of acquiring the alternate pancreatic repertoire have never been characterized.

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Background: Psoriasis is a complex disease at the cellular, genomic and genetic levels. The role of microRNAs in skin development was shown in a keratinocyte-specific Dicer knockout mouse model. Considering that two main characteristics of psoriasis are keratinocytes hyperproliferation and abnormal skin differentiation, we hypothesized that aberrant microRNA expression contributes to the psoriatic phenotype.

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Background: HER2 is an important prognostic and predictive marker in invasive breast cancer. It is currently assessed by immunohistochemistry for protein over-expression and by fluorescence in situ hybridization for gene amplification. The immunohistochemistry-equivocal cases (2+) are currently retested by FISH to determine eligibility for trastuzumab treatment.

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Distinguishing hepatocellular carcinoma from metastatic tumors in the liver is of great practical importance, with significant therapeutic and prognostic implications. This differential diagnosis can be difficult because metastatic cancers in the liver, especially adenocarcinomas, may mimic the morphology and immunoexpression of hepatocellular carcinoma. Biomarkers that are specifically expressed in either hepatocellular carcinoma or metastatic adenocarcinoma can therefore be useful diagnostic tools.

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Subtypes of renal tumors have different genetic backgrounds, prognoses, and responses to surgical and medical treatment, and their differential diagnosis is a frequent challenge for pathologists. New biomarkers can help improve the diagnosis and hence the management of renal cancer patients. We extracted RNA from 71 formalin-fixed paraffin-embedded (FFPE) renal tumor samples and measured expression of more than 900 microRNAs using custom microarrays.

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For surgical pathologists, distinguishing whether a pulmonary neoplasm is primary or metastatic can be challenging, and current biomarkers do not always aid lung tumor classification. The tissue-associated expression of microRNA likely explains the remarkable finding that many tumors can be classified based solely on their microRNA expression signature. Here we show that microRNAs can serve as biomarkers for lung tumor classification.

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Partial gain of chromosome arm 17q is an abundant aberrancy in various cancer types such as lung and prostate cancer with a prominent occurrence and prognostic significance in neuroblastoma--one of the most common embryonic tumors. The specific genetic element/s in 17q responsible for the cancer-promoting effect of these aberrancies is yet to be defined although many genes located in 17q have been proposed to play a role in malignancy. We report here the characterization of a naturally-occurring, non-reciprocal translocation der(X)t(X;17) in human lung embryonal-derived cells following continuous culturing.

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Objective: While both play a role in the transcriptional response of hypoxic endothelial cells (ECs), hypoxia-inducible factor-1alpha (HIF-1alpha) and HIF-2alpha differ in their transactivation sites, pointing at potentially different target genes. We studied the discrete and common effects of HIF-1alpha and HIF-2alpha on the cytokine expression and vasculogenic properties of ECs.

Methods And Results: H5V and bovine aortic ECs were transfected to express HIF-1alpha, HIF-2alpha or both.

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We describe a newborn infant with multiple congenital skull fractures and intracranial hemorrhage. He also had multiple skin folds suggesting a connective tissue abnormality. Electron microscopy of the skin biopsy showed collagen abnormalities with a "hieroglyphic appearance.

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The 4-nitroquinoline 1-oxide (4NQO)-induced rat tongue carcinoma, in which the carcinogen is administered systemically in drinking water, is the most comparable animal model to the development of human oral carcinoma. This is the first study to report the ultrastructural changes in this model. The most significant changes were observed in the carcinoma cells at the invasion front and included unique modifications in the basal lamina, presence of micropinocytotic vesicles (plasmalemmal caveolae), and emergence of cytoplasmic microfilaments featuring a parallel arrangement.

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Bone marrow stromal cells (BMSCs) contain progenitors capable of participating in postnatal angiogenesis. Hypoxia-inducible factors (HIFs) mediate endothelial activation by driving the expression of multiple angiogenic factors. We explored the potential of HIF-1alpha and HIF-2alpha modification in BMSCs, as a tool to improve cell-based angiogenic therapy.

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Fibroblastic polyps of the colon and intestinal perineuriomas are unusual mucosal lesions with identical clinical and histologic features, and apparent different immunohistochemical and ultrastructural characteristics. However, immunohistochemical distinction was solely based on the results obtained with epithelial membrane antigen (EMA), an antibody whose reactivity on perineuriomas is difficult to demonstrate. Likewise, accurate ultrastructural diagnosis may be flawed by sampling error, preservation artifacts, or paucity of specific diagnostic features.

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MicroRNAs (miRNAs) belong to a class of noncoding, regulatory RNAs that is involved in oncogenesis and shows remarkable tissue specificity. Their potential for tumor classification suggests they may be used in identifying the tissue in which cancers of unknown primary origin arose, a major clinical problem. We measured miRNA expression levels in 400 paraffin-embedded and fresh-frozen samples from 22 different tumor tissues and metastases.

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The present study describes a novel bacterial isolate exhibiting high ability to synthesise and secrete butyrate. The novel isolated bacterium was obtained from human faeces and grown in selective liquid intestinal microflora medium containing rumen fluid under microaerobic conditions. Its probiotic properties were demonstrated by the ability of the isolate to survive high acidity and medium containing bile acids and the ability to adhere to colon cancer cells (Caco-2) in vitro.

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Many studies have been performed on chromosomal aberrations of extranodal marginal zone lymphomas. However, only a few have been published so far on ocular adnexal marginal zone lymphomas. We studied 18 cases of orbital lymphoid cell infiltrates.

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Shortage in tissue availability from cadaver donors and the need for life-long immunosuppression severely restrict the large-scale application of cell-replacement therapy for diabetic patients. This study suggests the potential use of adult human liver as alternate tissue for autologous beta-cell-replacement therapy. By using pancreatic and duodenal homeobox gene 1 (PDX-1) and soluble factors, we induced a comprehensive developmental shift of adult human liver cells into functional insulin-producing cells.

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