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.

Força de preensão – Análise de concordância entre dois dinamómetros: JAMAR vs E‑Link

Introdução – Avaliar a força de preensão mostrou ser de primordial importância pela sua relação com a capacidade funcional dos indivíduos, permitindo determinar níveis de risco para incapacidade futura e, assim, estabelecer estratégias de prevenção. Grande parte dos estudos utiliza o dinamómetro hidráulico JAMAR que fornece o valor da força isométrica obtida durante a execução do movimento de preensão palmar. Contudo, existem outros dinamómetros disponíveis, como é o caso do dinamómetro portátil computorizado E‑Link (Biometrics) que fornece o valor da força máxima (peak force), para além de outras variáveis, como a taxa de fadiga. Não existem, contudo, estudos que nos permitam aceitar e comparar ou não os valores obtidos com os dois equipamentos e porventura utilizá‑los indistintamente. Objetivos – Avaliar a concordância entre as medições da força de preensão (força máxima ou peak force em Kg) obtida a partir de dois equipamentos diferentes (dinamómetros portáteis): um computorizado (E‑Link, Biometrics) e outro hidráulico (JAMAR). Metodologia – Foram avaliados 29 indivíduos (13H; 16M; 22±7 anos; 23,2±3,3 kg/m2) em 2 dias consecutivos, na mesma altura do dia. A posição de teste escolhida foi a recomendada pela Associação Americana de Terapeutas Ocupacionais e foi escolhido o melhor resultado de entre 3 tentativas para a mão dominante. Realizou‑se uma análise correlacional entre os valores obtidos na variável analisada em cada equipamento (coeficiente de Spearman) e uma análise de Bland & Altman para verificar a concordância entre as duas medições. Resultados – O coeficiente de correlação entre as duas medições foi elevado (rS= 0,956; p<0,001) e, pela análise de Bland & Altman, os valores obtidos encontram‑se todos dentro do intervalo da média±2SD. Conclusões – As duas medições mostraram ser concordantes, revelando que os dinamómetros testados podem ser comparáveis ou utilizados indistintamente em diferentes estudos e populações. ABSTRACT: Introduction – Assess grip strength has proved to be of vital importance because of its relationship with functional capacity of individuals, in order to determine levels of risk for future disability and thereby establish prevention strategies. Most studies use the JAMAR Hydraulic dynamometer that provides the value of isometric force obtained during the performance of grip movement. However, there are other dynamometers available, such as portable computerized dynamometer E‑Link (Biometrics), which provides the value of maximum force (peak force) in addition to other variables as the rate of fatigue. There are no studies that allow us to accept or not and compare values obtained with both devices and perhaps use them interchangeably. Purpose – To evaluate the agreement between the measurements of grip strength (peak force or maximum force in kg) obtained from two different devices (portable dynamometers): a computerized (E‑Link, Biometrics) and a hydraulic (JAMAR). Methodology – 29 subjects (13H, 16M, 22 ± 7 years, 23.2 ± 3.3 kg/m2) were assessed on two consecutive days at the same time of day. The test position chosen was recommended by the American Association of Occupational Therapists and was considered the best result from three attempts for the dominant hand. A correlation was studied between values obtained in the variable analyzed in each equipment (Spearman coefficient) and Bland‑Altman analysis to assess the agreement between the two measurements. Results – The correlation coefficient between the two measurements was high (rs = 0,956, p <0,001) and Bland & Altman analysis of the values obtained are all within the range of mean±2SD. Conclusions – The two measurements were shown to be concordant, revealing that the tested dynamometers can be comparable or used interchangeably in different studies and populations.

Dominant set approach to ECG biometrics

Electrocardiographic (ECG) signals are emerging as a recent trend in the field of biometrics. In this paper, we propose a novel ECG biometric system that combines clustering and classification methodologies. Our approach is based on dominant-set clustering, and provides a framework for outlier removal and template selection. It enhances the typical workflows, by making them better suited to new ECG acquisition paradigms that use fingers or hand palms, which lead to signals with lower signal to noise ratio, and more prone to noise artifacts. Preliminary results show the potential of the approach, helping to further validate the highly usable setups and ECG signals as a complementary biometric modality.

An experimental study to compare the interface pressure and experience of healthy participants when lying still for 20 minutes in a supine position on two different imaging surfaces

Introduction: Pressure ulcers are a high cost, high volume issue for health and medical care providers, affecting patients’ recovery and psychological wellbeing. The current research of support surfaces on pressure as a risk factor in the development of pressure ulcers is not relevant to the specialised, controlled environment of the radiological setting. Method: 38 healthy participants aged 19-51 were placed supine on two different imaging surfaces. The XSENSOR pressure mapping system was used to measure the interface pressure. Data was acquired over a time of 20 minutes preceded by 6 minutes settling time to reduce measurement error. Qualitative information regarding participants’ opinion on pain and comfort was recorded using a questionnaire. Data analysis was performed using SPSS 22. Results: Data was collected from 30 participants aged 19 to 51 (mean 25.77, SD 7.72), BMI from 18.7 to 33.6 (mean 24.12, SD 3.29), for two surfaces, following eight participant exclusions due to technical faults. Total average pressure, average pressure for jeopardy areas (head, sacrum & heels) and peak pressure for jeopardy areas were calculated as interface pressure in mmHg. Qualitative data showed that a significant difference in experiences of comfort and pain was found in the jeopardy areas (P<0.05) between the two surfaces. Conclusion: A significant difference is seen in average pressure between the two surfaces. Pain and comfort data also show a significant difference between the surfaces, both findings support the proposal for further investigation into the effects of radiological surfaces as a risk factor for the formation of pressure ulcers.