Search results for "AMYLOIDOSIS"

Lymphonodal amyloidosis: case report

2009

Valorization of apple peels through the study of the effects on the amyloid aggregation process of ?-casein

2021

Waste valorization represents one of the main social challenges when promoting a circular economy and environmental sustainability. Here, we evaluated the effect of the polyphenols extracted from apple peels, normally disposed of as waste, on the amyloid aggregation process of ?-casein from bovine milk, a well-used amyloidogenic model system. The effect of the apple peel extract on protein aggregation was examined using a thioflavin T fluorescence assay, Congo red binding assay, circular dichroism, light scattering, and atomic force microscopy. We found that the phenolic extract from the peel of apples of the cultivar "Fuji", cultivated in Sicily (Caltavuturo, Italy), inhibited ?-casein fib…

Interacting processes in protein coagulation

1999

A strong interest is currently focused on protein self-association and deposit. This usually involves conformational changes of the entire protein or of a fragment. It can occur even at low concentrations and is responsible for pathologies such as systemic amyloidosis, Alzheimer's and Prion diseases, and other neurodegenerative pathologies. Readily available proteins, exhibiting at low concentration self-association properties related to conformational changes, offer very convenient model systems capable of providing insight into this class of problems. Here we report experiments on bovine serum albumin, showing that the process of conformational change of this protein towards an intermedia…

Diabetes and cognitive decline

2022

Epidemiologic studies have documented an association between diabetes and increased risk of cognitive decline in the elderly. Based on animal model studies, several mechanisms have been proposed to explain such an association, including central insulin signaling, neurodegeneration, brain amyloidosis, and neuroinflammation. Nevertheless, the exact mechanisms in humans remain poorly defined. It is reasonable, however, that many pathways may be involved in these patients leading to cognitive impairment. A major aim of clinicians is identifying early onset of neurologic signs and symptoms in elderly diabetics to improve quality of life of those with cognitive impairment and reduce costs associa…

Polymer-doxycycline conjugates as fibril disrupters: an approach towards the treatment of a rare amyloidotic disease.

2014

The term amyloidosis describes neurological diseases where an abnormal protein is misfolded and accumulated as deposits in organs and tissues, known as amyloid, disrupting their normal function. In the most common familial amyloid polyneuropathy (FAP), transthyretin (TTR) displays this role primarily affecting the peripheral nervous system (PNS). Advanced stages of this inherited rare amyloidosis, present as fibril deposits that are responsible for disease progression. In order to stop disease progression, herein we designed an efficient family of nanoconjugates as fibril disrupters. These polymer conjugates are based on doxycycline (doxy), already in phase II trials for Alzheimer's disease…

Probing ensemble polymorphism and single aggregate structural heterogeneity in insulin amyloid self-assembly.

2020

Ensembles of protein aggregates are characterized by a nano- and micro-scale heterogeneity of the species. This diversity translates into a variety of effects that protein aggregates may have in biological systems, both in connection to neurodegenerative diseases and immunogenic risk of protein drug products. Moreover, this naturally occurring variety offers unique opportunities in the field of protein-based biomaterials. In the above-mentioned fields, the isolation and structural analysis of the different amyloid types within the same ensemble remain a priority, still representing a significant experimental challenge. Here we address such complexity in the case of insulin for its relevance…

Myocardial contrast echocardiography in biopsy-proven primary cardiac amyloidosis.

2008

Abstract Cardiac vasculature is affected in 88-90% of patients with primary cardiac amyloidosis (CA). Myocardial contrast echocardiography (MCE) relies on the ultrasound detection of microbubble contrast agents that are solely confined to the intravascular space, and are therefore useful in the evaluation of flow in the microvasculature. This is the first case report describing the use of MCE during vasodilator stress to evaluate coronary flow reserve in a patient with biopsy-proven primary CA and angiographically normal coronaries. Qualitative MCE demonstrated delayed replenishment of microbubbles during peak stress; quantitative analysis was consistent with a reduction in total myocardial…

Role of Cardiac Magnetic Resonance Imaging in the Detection of Cardiac Amyloidosis

2010

Objectives Our aim was to evaluate the role and mechanism of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) in identifying cardiac amyloidosis (CA) and to investigate associations between LGE and clinical, morphologic, functional, and biochemical features. Background CA can be challenging to diagnose by echocardiography. Recent studies have demonstrated an emerging role for LGE-CMR. Methods LGE-CMR was performed in 120 patients with amyloidosis. Cardiac histology was available in 35 patients. The remaining 85 patients were divided into those with and without echocardiographic evidence of CA. Results Of the 35 patients with histologically verified CA, abnormal LGE was pre…

Benign and malignant mimickers of infiltrative hepatocellular carcinoma: tips and tricks for differential diagnosis on CT and MRI

2021

Hepatocellular carcinoma (HCC) may have an infiltrative appearance in about 8-20% of cases. Infiltrative HCC can be a challenging diagnosis and it is associated with the worst overall survival among HCC patients. Infiltrative HCC is characterized by the spread of multiple minute nodules throughout the liver, without a dominant one, ultimately resulting into macrovascular invasion. On CT and MRI, infiltrative HCC appears as an ill-defined, large mass, with variable degree of enhancement, and satellite neoplastic nodules in up to 52% of patients. On MRI, it may show restriction on diffusion weighted imaging, hyperintensity on T2- and hypointensity on T1-weighted images, and, if hepatobiliary …

A disintegrin-metalloproteinase prevents amyloid plaque formation and hippocampal defects in an Alzheimer disease mouse model

2004

Alzheimer disease (AD) is characterized by excessive deposition of amyloid beta-peptides (A beta peptides) in the brain. In the nonamyloidogenic pathway, the amyloid precursor protein (APP) is cleaved by the alpha-secretase within the A beta peptide sequence. Proteinases of the ADAM family (adisintegrin and metalloproteinase) are the main candidates as physiologically relevant alpha-secretases, but early lethality of knockout animals prevented a detailed analysis in neuronal cells. To overcome this restriction, we have generated transgenic mice that overexpress either ADAM10 or a catalytically inactive ADAM10 mutant. In this report we show that a moderate neuronal overexpression of ADAM10 i…