Impact of grape pectic polysaccharides on anthocyanins thermostability

The impact of grape pectic polysaccharides on malvidin-3-O-β-d-glucoside thermostability was evaluated in model solutions. Pectic polysaccharides richer in homogalacturonan domains, with less neutral sidechains (chelator fraction) showed higher binding with malvidin-3-O-β-d-glucoside, by 1H NMR (Ka=505 M-1). Binding affinity with water soluble extract was estimated to be 10-fold lower, possibly due to the presence of neutral branched regions and more compacted structure, hampering the binding. Hydrophobic domains, such as rhamnogalacturonans-I domains in acid soluble polysaccharides, may participate in the formation of complexes with malvidin-3-O-β-d-glucoside. The thermostability of anthocyanin-polysaccharides complexes was evaluated at different temperatures, assessing anthocyanins degradation by HPLC-DAD. Polysaccharides showed to improve anthocyanin thermostability, with chelator and acid extract having the highest impact at lowest temperatures. Electrostatic interactions, additionally stabilized by hydrophobic effect contribute to the anthocyanin-polysaccharides binding and to the consequent thermostabilization. The protection provided by grape pectic polysaccharides foresees innovative anthocyanin food products with improved thermostability and colour features.publishe

Sarcopenia in liver transplant due to familial amyloidotic polyneuropathy (FAP): the relevance of muscle mass

Este trabalho foi financiado pelo Concurso Anual para Projetos de Investigação, Desenvolvimento, Inovação e Criação Artística (IDI&CA) 2016 do Instituto Politécnico de Lisboa. Código de referência: IPL/2016/SFQ2017_ESTeSLIntroduction: Loss of muscle mass and function is a common occurrence in liver transplant Familial Amyloidotic Polyneuropathy (FAP) patients. Sarcopenia is associated with morbidity and mortality before and after liver transplantation. However, the ability of skeletal muscle mass to recover after transplant remains questionable and thus the importance of clinical exercise prescription. Methods: Participants were 39 FAP patients aged 23-59 years, who had been submitted to a liver transplant (Tx) (22 men) between 2 and 4 months post-tx. Sarcopenia was defined according to the International Working Group on Sarcopenia and Society of Sarcopenia, Cachexia, and Wasting Disorders. Whole-body dual x-ray absorptiometry was used to measure body fat and lean-soft tissue. Skeletal Muscle Index (SMI) was calculated adjusting the value of appendicular skeletal mass to the squared height. Functional aerobic capacity was assessed using the 6 min walk test (6MWT), and handgrip strength were measured on the dominant hand using a hand dynamometer. Results: The prevalence of sarcopenia using SMI was 45.5% in men and 41.2% in women. A fat mass higher than 16% for men and 26% for women was found in 54.5% of men and 52.9% of women. Also, 27.3% of men and 17.6% of the women could be classified as having sarcopenia with low mobility (distance < 400 m). Discussion and Conclusions: Sarcopenia is common in FAP patients and a liver transplant seems to increase the prevalence, also because an aggressive medication with impact on muscle metabolism should be made longtime. More data are needed on the long-term effects of sarcopenia after transplant, especially in light of the high rate of metabolic syndrome. A clinical exercise prescription seems to be necessary for these patients but more studies are needed (e.g. longitudinal studies).info:eu-repo/semantics/publishedVersio

A Cross-Sectional Study

Publisher Copyright: © 2022 The Author(s). Published by S. Karger AG, Basel. This article is licensed under the Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC). Usage and distribution for commercial purposes requires written permission.Background: Listing patients with alcohol-associated liver disease (ALD) for liver transplant (LT) remains challenging especially due to the risk of alcohol resumption post-LT. We aimed to evaluate post-LT alcohol consumption at a Portuguese transplant center. Methods: We conducted a cross-sectional study including LT recipients from 2019 at Curry Cabral Hospital, Lisbon, Portugal. A pretested survey and a validated Portuguese translation of the Alcohol Use Disorder Identification Test (AUDIT) were applied via a telephone call. Alcohol consumption was defined by patients' self-reports or a positive AUDIT. Results: In 2019, 122 patients underwent LT, and 99 patients answered the survey (June 2021). The mean (SD) age was 57 (10) years, 70 patients (70.7%) were males, and 49 (49.5%) underwent ALD-related LT. During a median (IQR) follow-up of 24 (20-26) months post-index LT, 22 (22.2%) recipients consumed any amount of alcohol: 14 had a drink monthly or less and 8 drank 2-4 times/month. On drinking days, 18 patients usually consumed 1-2 drinks and the remainder no more than 3-4 drinks. One patient reported having drunk ≥6 drinks on one occasion. All post-LT drinking recipients were considered low risk (score <8) as per the AUDIT score (median [IQR] of 1 [1-2]). No patient reported alcohol-related problems, whether self-inflicted or toward others. Drinking recipients were younger (53 vs. 59 years, p = 0.020), had more non-ALD-related LT (72.7 vs. 44.2%, p = 0.018) and active smoking (31.8 vs. 10.4%, p = 0.037) than abstinent ones. Conclusion: In our cohort, about a quarter of LT recipients consumed alcohol early posttransplant, all with a low-risk pattern according to the AUDIT score.publishersversionepub_ahead_of_prin

A Cohort Analysis

Publisher Copyright: © 2022Background and Aims: The donor risk index (DRI) quantifies donor-related characteristics potentially associated with increased risk of early graft failure. We aimed to assess the impact of the DRI, recipient and perioperative factors on post liver transplant (LT) outcomes. Methods: This was a single-center retrospective cohort study including all adult (≥18 years) patients who underwent LT from 01/2019 to 12/2019 at Curry Cabral Hospital, Lisbon, Portugal. Primary endpoint was 1-year graft failure post LT. Associations were studied with logistic regression. Results: A total of 131 cadaveric donor LT procedures were performed in 116 recipients. Recipients' median (IQR) age was 57 (47-64) years and 101/131 (77.1%) were males. Cirrhosis was the underlying etiology in 95/131 (81.2%) transplants. Based on 8 predefined donors' characteristics, median (IQR) DRI was 1.96 (1.67-2.16). Following adjustment for MELDNa score pre LT and SOFA score (adjusted odds ratio [aOR], 95% confidence interval [CI] = 0.91 [0.56-1.47]) or lactate (aOR [95% CI] = 2.76 [0.71-10.7]) upon intensive care unit (ICU) admission post LT, DRI was not associated with 1-year graft failure. However, higher SOFA score (aOR [95% CI] = 1.20 [1.05-1.37]) or lactate (aOR [95% CI] = 1.27 [1.10-1.46]) upon ICU admission post LT were independently associated with higher odds of 1-year graft failure. Conclusions: In a recent cohort of patients who underwent LT, DRI, despite being high, was not associated with 1-year graft failure, but SOFA score or lactate upon ICU admission post LT were.publishersversionepub_ahead_of_prin

Beyond Genetic Factors in Familial Amyloidotic Polyneuropathy: Protein Glycation and the Loss of Fibrinogen's Chaperone Activity

Familial amyloidotic polyneuropathy (FAP) is a systemic conformational disease characterized by extracellular amyloid fibril formation from plasma transthyretin (TTR). This is a crippling, fatal disease for which liver transplantation is the only effective therapy. More than 80 TTR point mutations are associated with amyloidotic diseases and the most widely accepted disease model relates TTR tetramer instability with TTR point mutations. However, this model fails to explain two observations. First, native TTR also forms amyloid in systemic senile amyloidosis, a geriatric disease. Second, age at disease onset varies by decades for patients bearing the same mutation and some mutation carrier individuals are asymptomatic throughout their lives. Hence, mutations only accelerate the process and non-genetic factors must play a key role in the molecular mechanisms of disease. One of these factors is protein glycation, previously associated with conformational diseases like Alzheimer's and Parkinson's. The glycation hypothesis in FAP is supported by our previous discovery of methylglyoxal-derived glycation of amyloid fibrils in FAP patients. Here we show that plasma proteins are differentially glycated by methylglyoxal in FAP patients and that fibrinogen is the main glycation target. Moreover, we also found that fibrinogen interacts with TTR in plasma. Fibrinogen has chaperone activity which is compromised upon glycation by methylglyoxal. Hence, we propose that methylglyoxal glycation hampers the chaperone activity of fibrinogen, rendering TTR more prone to aggregation, amyloid formation and ultimately, disease

Familial amyloid polyneuropathy (FAP): clinical features, pathophysiology and treatment

In the literature, concepts of “polyneuropathy”, “peripheral neuropathy” and “neuropathy” are often mistakenly used as synonyms. Polyneuropathy is a specific term that refers to a relatively homogenous process that affects multiple peripheral nerves. Most of these tend to present as symmetric polyneuropathies that first manifest in the distal portions of the affected nerves. Many of these distal symmetric polyneuropathies are due to toxic-metabolic causes such as alcohol abuse and diabetes mellitus. Other distal symmetric polyneuropathies may result from an overproduction of substances that result in nerve pathology such as is observed in anti-MAG neuropathy and monoclonal gammopathy of undetermined significance. Other “overproduction” disorders are hereditary such as noted in the Portuguese type of familial amyloid polyneuropathy (FAP). FAP is a manifestation of a group of hereditary amyloidoses; an autosomal dominant, multisystemic disorder wherein the mutant amyloid precursor, transthyretin, is produced in excess primarily by the liver. The liver accounts for approximately 98% of all transthyretin production. FAP is confirmed by detecting a transthyretin variant with a methionine for valine substitution at position 30 [TTR (Met30)]. Familial Amyloidotic Polyneuropathy (FAP) – Portuguese type was first described by a Portuguese neurologist, Corino de Andrade in 1939 and published in 1951. Most persons with this disorder are descended from Portuguese sailors who sired offspring in various locations, primarily in Sweden, Japan and Mallorca. Their descendants emigrated worldwide such that this disorder has been reported in other countries as well. More than 2000 symptomatic cases have been reported in Portugal. FAP progresses rapidly with an average time course from symptom onset to multi-organ involvement and death between ten and twenty years. Treatments directed at removing this aberrant protein such as plasmapheresis and immunoadsorption proved to be unsuccessful. Liver transplantation has been the only effective solution as evidenced by almost 2000 liver transplants performed worldwide. A therapy for FAP with a novel agent, “Tafamidis” has shown some promise in ongoing phase III clinical trials. It is well recognized that regular physical activity of moderate intensity has a positive effect on physical fitness as gauged by body composition, aerobic capacity, muscular strength and endurance and flexibility. Physical fitness has been reported to result in the reduction of symptoms and lesser impairment when performing activities of daily living. Exercise has been advocated as part of a comprehensive approach to the treatment of chronic diseases. Therefore, this chapter concludes with a discussion of the role of exercise training on FAP

A 5-year follow-up of the benefits of an exercise training program in liver recipients transplanted due to familial amyloidotic polyneuropathy

Background: Supervised (SE) and home-based exercise (HBE) training regimes are effective on reconditioning patients with familial amyloidotic polyneuropathy (FAP) after liver transplantation, but research of the long-term retention of the benefits attained in patients with FAP has not yet been conducted. Purpose: In this 5-year follow-up study, we aimed to determine whether the exercise training gains in body composition, physical activity, and function promoted by a 24-week SE or HBE training regimes are retained in patients with FAP who resume normal activity. Methodology: Sixteen liver-transplanted patients with FAP were reassessed for body composition (dual X-ray absorptiometry), physical activity (questionnaire), and function (handgrip strength and 6-minute walk test). Results: Total body fat increased with both exercise regimes during follow-up ( P < .05; η2 = 0.432-0.625) as well as femoral neck bone density ( P = .048; η2 = 0.119). However, gains in upper limbs muscle quality during follow-up ( P < .001; η2 = 0.597) were only found in the SE group ( P = .042; η2 = 0.245). Both exercise regimes showed retaining aptitudes in walking capacity ( P < .05; η2 = 0.329-0.460) and muscle mass ( P = .05; η2 = 0.245). Still, none could retain the physical activity levels. Conclusion: Long-term resumption of normal activity following a 24-week SE or HBE regime in patients with FAP resulted in a loss of exercise-induced increases in physical activity but counterweighted postoperative losses in bone mineral density and substantially retained the benefits in walking capacity, muscle mass, and quality, in particular, in the SE group.info:eu-repo/semantics/publishedVersio

Tuberculosis in Liver Transplant Recipients: A Report of Eight Cases During a Five Year Period

Introduction: Tuberculosis incidence in Portugal ranged from 20 to 22 cases per 100 000 inhabitants between 2010 and 2014. Tuberculosis incidence in liver transplant recipients is not precisely known, but it is estimated to be higher than among the general population. Tuberculosis in liver transplant recipients is particularly challenging because of the atypical clinical presentation and side effects of the antibacillary drugs and their potential interactions with immunosuppressive therapies. Material and Methods: We retrospectively reviewed the clinical records of liver transplant recipients with post-transplant tuberculosis occurring from January 2010 to December 2014 at a liver transplantation unit in Lisbon, Portugal. Demographic data, baseline and clinical features, as well as treatment regimen, toxicities and outcomes, were analyzed. Results: Among 1005 recipients, active tuberculosis was diagnosed in eight patients between January 2010 and December 2014 (frequency = 0.8%). Late onset tuberculosis was more frequent than early tuberculosis. Mycobacterium tuberculosis complex was isolated from cultures in almost every case (7; 87.5%). Extra-pulmonary involvement and disseminated tuberculosis were frequent. Two patients developed rejection without allograft loss. Crude mortality was 37.5%, with 2 deaths being related to tuberculosis. Discussion: Despite the uncertainty regarding treatment duration in liver transplant recipients, disease severity, as well as number of active drugs against TB infection, should be taken into account. There was a need for a rifampin-free regimen and immunosuppression adjustment in patients who experienced acute graf rejection. Conclusion: Although the number of cases of tuberculosis is low, its post-transplant frequency is significant and the observed mortality rate is not to be neglected. The cases of hepatotoxicity and graft rejection seen in this case series demonstrate the challenges associated with tuberculosis diagnosis in liver transplant recipients and management of the interactions between immunosuppressors and rifampin. This study strengthens the recommendation of latent tuberculosis infection screening and treatment in liver transplant candidates or recipients

Transthyretin Amyloidosis: Chaperone Concentration Changes and Increased Proteolysis in the Pathway to Disease

<div><p>Transthyretin amyloidosis is a conformational pathology characterized by the extracellular formation of amyloid deposits and the progressive impairment of the peripheral nervous system. Point mutations in this tetrameric plasma protein decrease its stability and are linked to disease onset and progression. Since non-mutated transthyretin also forms amyloid in systemic senile amyloidosis and some mutation bearers are asymptomatic throughout their lives, non-genetic factors must also be involved in transthyretin amyloidosis. We discovered, using a differential proteomics approach, that extracellular chaperones such as fibrinogen, clusterin, haptoglobin, alpha-1-anti-trypsin and 2-macroglobulin are overrepresented in transthyretin amyloidosis. Our data shows that a complex network of extracellular chaperones are over represented in human plasma and we speculate that they act synergistically to cope with amyloid prone proteins. Proteostasis may thus be as important as point mutations in transthyretin amyloidosis.</p></div

Plasma from ATTR individuals presents a higher proteolytic activity.

<p>A- Proteolytic activity of control and ATTR plasma measured by fluorescent protease assay kit. B–Sequence coverage obtained for three spots identified as albumin with decreased molecular weight.</p