Magnetic Resonance Imaging Features Indicative of Permanent Colon Damage in Ulcerative Colitis: An Exploratory Study.

Background And Aims: It is uncertain whether ulcerative colitis leads to accumulated bowel damage on cross-sectional image. We aimed to characterise bowel damage in patients with ulcerative colitis using magnetic resonance imaging [MRI], and to determine its relation with duration of disease and the impact on patients' quality of life.

Methods: In this prospective study, patients with ulcerative colitis [UC] in endoscopic remission underwent MRI without bowel cleansing, and completed quality-of-life questionnaires.

Diagnosis and treatment of hepatocellular carcinoma. Update of the consensus document of the AEEH, AEC, SEOM, SERAM, SERVEI, and SETH.

Hepatocellular carcinoma (HCC) is the most common primary liver neoplasm and one of the most common causes of death in patients with cirrhosis of the liver. In parallel, with recognition of the clinical relevance of this cancer, major new developments have recently appeared in its diagnosis, prognostic assessment and in particular, in its treatment. Therefore, the Spanish Association for the Study of the Liver (AEEH) has driven the need to update the clinical practice guidelines, once again inviting all the societies involved in the diagnosis and treatment of this disease to participate in the drafting and approval of the document: Spanish Society for Liver Transplantation (SETH), Spanish Society of Diagnostic Radiology (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Association of Surgeons (AEC) and Spanish Society of Medical Oncology (SEOM).

Structural organization of mammalian prions as probed by limited proteolysis.

Elucidation of the structure of PrP(Sc) continues to be one major challenge in prion research. The mechanism of propagation of these infectious agents will not be understood until their structure is solved. Given that high resolution techniques such as NMR or X-ray crystallography cannot be used, a number of lower resolution analytical approaches have been attempted.

PK-sensitive PrP is infectious and shares basic structural features with PK-resistant PrP.

One of the main characteristics of the transmissible isoform of the prion protein (PrP(Sc)) is its partial resistance to proteinase K (PK) digestion. Diagnosis of prion disease typically relies upon immunodetection of PK-digested PrP(Sc) following Western blot or ELISA. More recently, researchers determined that there is a sizeable fraction of PrP(Sc) that is sensitive to PK hydrolysis (sPrP(Sc)).

Increased oxidation, glycoxidation, and lipoxidation of brain proteins in prion disease.

The basic molecular underpinnings of the pathological changes that unfold in prion disease remain elusive. A key role of increased oxidative stress has been hypothesized. Given the transient nature of most intermediate molecules implicated, increased oxidative stress is better assessed by quantitating the damage it causes to macromolecules.

Scrapie prion protein structural constraints obtained by limited proteolysis and mass spectrometry.

Elucidation of the structure of scrapie prion protein (PrP(Sc)), essential to understand the molecular mechanism of prion transmission, continues to be one of the major challenges in prion research and is hampered by the insolubility and polymeric character of PrP(Sc). Limited proteolysis is a useful tool to obtain insight on structural features of proteins: proteolytic enzymes cleave proteins more readily at exposed sites, preferentially within loops, and rarely in beta-strands. We treated PrP(Sc) isolated from brains of hamsters infected with 263K and drowsy prions with varying concentrations of proteinase K (PK).

Fibrillar prion peptide PrP(106-126) treatment induces Dab1 phosphorylation and impairs APP processing and Abeta production in cortical neurons.

Alzheimer's disease and prion diseases (e.g., Creutzfeldt-Jakob disease) display profound neural lesions associated with aberrant protein processing and extracellular amyloid deposits.

Isolation and characterization of a proteinase K-sensitive PrPSc fraction.

Recent studies have shown that a sizable fraction of PrPSc present in prion-infected tissues is, contrary to previous conceptions, sensitive to digestion by proteinase K (PK). This finding has important implications in the context of diagnosis of prion disease, as PK has been extensively used in attempts to distinguish between PrPSc and PrPC. Even more importantly, PK-sensitive PrPSc (sPrPSc) might be essential to understand the process of conversion and aggregation of PrPC leading to infectivity.