Search results for "Digestive System"
showing 10 items of 1747 documents
Polypoid anal melanoma. A case report and review of the literature
2016
Ano-rectal melanoma is an uncommon finding in patients complaining of rectal bleeding and/or anal mass often misinterpreted as a haemorroidal pile.A 55-years-old woman, complaining of rectal bleeding, frequent anal pain and anal mass suspected for haemorroidal thrombosis was referred for evaluation and possible treatment. A brown polypoid mass arising from the anal canal/lower rectum with a maximum diameter of 6 cm was diagnosed. The hystological examination of the neoplasm, transanally removed, revealed the presence of a polypoid melanoma partially involving the resection margin. Nor metastases nor limph-node involvement were found at the total-body CT scan and at a CT-PET. C-KIT examinati…
Caspase-8 regulates TNF-alpha induced epithelial necroptosis and terminal ileitis
2011
Two groups identify the regulation of death-receptor-induced necroptosis as an epithelial intrinsic mechanism that is important for the maintenance of immune homeostasis and the prevention of intestinal inflammation in mice. Welz et al. describe an unexpected physiological function for FADD (Fas-associated protein with death domain), an adaptor protein required for death-receptor-induced apoptosis. Mice with intestinal epithelial specific knockout of FADD develop severe colon inflammation due to increased death of FADD-deficient colonic epithelial cells. Gunther et al. report a novel and unexpected function of caspase-8 in maintaining immune homeostasis in the gut. Caspase-8 expression by g…
Hepatitis C Virus NS3/4A Protease Inhibitors.
2008
Chronic hepatitis C virus infection is a global problem worldwide due to the lack of an effective therapy (the current standard of care treatment is effective in about 40-50% of the cases), and the difficulties in developing a protective vaccine. Chronic infection progresses to end-stage liver disease and liver failure in a considerable number of infected individuals. Once liver function is compromised, the only reliable therapeutic intervention is liver transplantation. Unfortunately, re-infection of the graft is unavoidable, and a new chronic hepatitis is early established in transplant recipients, that can result in graft loss. Thus, there is an urgent need for new, specifically targeted…
Complex formation between the NS3 serine-type proteinase of the hepatitis C virus and NS4A and its importance for polyprotein maturation
1995
Processing of the hepatitis C virus polyprotein is mediated by host cell signalases and at least two virally encoded proteinases. Of these, the serine-type proteinase encompassing the amino-terminal one-third of NS3 is responsible for cleavage at the four sites carboxy terminal of NS3. The activity of this proteinase is modulated by NS4A, a 54-amino-acid polyprotein cleavage product essential for processing at the NS3/4A, NS4A/4B, and NS4B/5A sites and enhancing cleavage efficiency between NS5A and NS5B. Using the vaccinia virus-T7 hybrid system to express hepatitis C virus polypeptides in BHK-21 cells, we studied the role of NS4A in proteinase activation. We found that the NS3 proteinase a…
The production of 85 kDa N-terminal fragment of apolipoprotein B in mutant HepG2 cells generated by targeted modification of apoB gene occurs by ALLN…
2010
Abstract To study the mechanism of low levels of full length and truncated apoB in individuals heterozygous for apoB truncation, a non-sense mutation was introduced in one of the three alleles of apob gene of HepG2 cells by homologous recombination. Despite very low levels of apoB-82 (1–2%) in the media, a prominent N-terminal apoB protein of 85 kDa (apoB-15) was secreted that fractionated at d > 1.065 in density gradient ultracentrifugation. The mechanism of production of this short protein was studied by 35S-methionine pulse–chase experiment. Oleate prevented presecretory degradation of apoB-100 in the cell and resulted in increased secretion of newly synthesized apoB-100 with decreases i…
Sialotranscriptomics of the argasid tick ornithodoros moubata along the trophogonic cycle
2021
32 páginas, 8 tablas, 6 figuras
Identification of Rothia Bacteria as Gluten-Degrading Natural Colonizers of the Upper Gastro-Intestinal Tract
2011
Background Gluten proteins, prominent constituents of barley, wheat and rye, cause celiac disease in genetically predisposed subjects. Gluten is notoriously difficult to digest by mammalian proteolytic enzymes and the protease-resistant domains contain multiple immunogenic epitopes. The aim of this study was to identify novel sources of gluten-digesting microbial enzymes from the upper gastro-intestinal tract with the potential to neutralize gluten epitopes. Methodology/Principal Findings Oral microorganisms with gluten-degrading capacity were obtained by a selective plating strategy using gluten agar. Microbial speciations were carried out by 16S rDNA gene sequencing. Enzyme activities wer…
The Long and Winding Road to Useful Predictive Factors for Anti-EGFR Therapy in Metastatic Colorectal Carcinoma: The KRAS/BRAF Pathway
2010
Monoclonal antibodies targeting the epidermal growth factor receptor (EGFR) have improved outcomes for patients with metastatic colorectal carcinoma. Among patients not carrying activating mutations in the KRAS gene, only a limited number will experience tumor response to these therapeutic agents. The role of BRAF mutations in determining resistance to this treatment is emerging through preclinical and clinical studies. Standardization and validation of laboratory mutation analysis is needed to allow an optimal use of anti-EGFR therapies in the management of colorectal carcinoma. Clinical single-arm and randomized studies were conducted both in first-line and refractory settings to evaluate…
Irinotecan or oxaliplatin: Which is the first move for the mate?
2020
Objectives: The aim of the present review is to discuss the potential link between RAS, BRAF and microsatellite instability (MSI) mutational patterns and chemotherapeutic agent efficacy [Irinotecan (IRI) vs. Oxaliplatin (OXA)], and how this can potentially influence the choice of the chemotherapy backbone. Methods: Following a review of the research literature, all pertinent articles published in the core journals were selected for the study. The inclusion criteria regarded relevant clinical and pre-clinical studies on the topic of interest (Relationship of OXA and IRI to KRAS/BRAF mutations and MSI). Results: Excision repair cross complementation group 1 (ERCC1) expression is inhibited by…
Understanding the clinical behavior of relapsed colon cancers with microsatellite instability relative to BRAF mutations
2019
Background Microsatellite instable/deficient mismatch repair (MSI/dMMR) metastatic colorectal cancers have been reported to have a poor prognosis. Frequent co-occurrence of MSI/dMMR and BRAFV600E complicates the association. Patients and methods Patients with resected stage III colon cancer (CC) from seven adjuvant studies with available data for disease recurrence and MMR and BRAFV600E status were analyzed. The primary end point was survival after recurrence (SAR). Associations of markers with SAR were analyzed using Cox proportional hazards models adjusted for age, gender, performance status, T stage, N stage, primary tumor location, grade, KRAS status, and timing of recurrence. Results A…