The effects of varying hydration conditions on the estimation of body composition by bioelectrical impedance analysis, near infrared interactance, and dual-energy x-ray absorptiometry

The purpose of this study was to examine the effects of hydration status on the prediction of body composition using BIA, NIR, and DEXA. Twenty healthy males and females ages 18 to 28 were recruited for this study. The subjects were dehydrated in the climate control chamber and engaged in physical exercise, until they lost approximately 1%, 2%, and 3% of their pre-exercise body weight. Percent body fat (%BF), body weight, and urinalysis measures were taken initially on day 1, on day 4 at euhydration, following 1%, 2%, and 3% dehydration, and upon rehydration during day 5. The results indicated that there were significant decreases for %BFBIA and %BFNIR between euhydration and 1%, 2%, and 3% dehydration. %BFDExA did not significantly change.There were also significant differences in the response to dehydration between each technique. Proper hydration should be ensured before %BF is estimated with BIA and NIR.School of Physical EducationThesis (M.S.

A fuzzy kernel motion classifier for autonomous stroke rehabilitation

Autonomous post-stroke rehabilitation systems which can be deployed outside hospital with no or reduced supervision have attracted increasing amount of research attentions due to the high expenditure associated with the current inpatient stroke rehabilitation systems. To realize an autonomous systems, a reliable patient monitoring technique which can automatically record and classify patient's motion during training sessions is essential. In order to minimize the cost and operational complexity, the combination of non-visual based inertia sensing devices and pattern recognition algorithms are often considered more suitable in such applications. However, the high motion irregularity due to stroke patients' body function impairment has significantly increased the classification difficulty. A novel fuzzy kernel motion classifier specifically designed for stroke patient's rehabilitation training motion classification is presented in this paper. The proposed classifier utilizes geometrically unconstrained fuzzy membership functions to address the motion class overlapping issue and thus it can achieve highly accurate motion classification even with poorly performed motion samples. In order to validate the performance of the classifier, experiments have been conducted using real motion data sampled from stroke patients with a wide range of impairment level and the results have demonstrated that the proposed classifier is superior in terms of error rate compared to other popular algorithms

Thyroid autoimmunity and environment

Autoimmune thyroid disorders (AITDs) are the result of a complex interplay between genetic and environmental factors, the former account for about 70-80% of liability to develop AITDs. However, at least 20-30% is contributed by environmental factors, which include certainly smoking (at least for Graves' disease and orbitopathy), probably stress, iodine and selenium intake, several drugs, irradiation, pollutants, viral and bacterial infections, allergy, pregnancy, and post-partum. Evidence for the intervention of these factors is often limited, and the mechanisms whereby environmental factors may concur to the onset of AITDs are in many instances unclear. Nevertheless, gene-environment interaction seems a fundamental process for the occurrence of AITDs

Insights into penicillin-induced Chlamydia trachomatis persistence

Chlamydia persistence is a viable, but non-cultivable, growth stage, resulting in a long-term relationship with the infected host cell. In vitro, this condition can be induced by different stressor agents, including beta-lactam antibiotics, as penicillin. The aim of this study was to get new insights into the interactions between Chlamydia trachomatis (serovars D and L2) and the epithelial host cells (HeLa) during persistence condition. In particular, we evaluated the following aspects, by comparing the normal chlamydial development cycle with penicillin-induced persistence: (i) cell survival/death, (ii) externalization of phosphatidylserine, (iii) caspase 1 and caspase 3/7 activation, and (iv) reactive oxygen species (ROS) production by the infected cells. At 72 h post-infection, the cytotoxic effect displayed by CT was completely abolished for both serovars and for all levels of multiplicity of infection only in the cells with aberrant CT inclusions. At the same time, CT was able to switch off the exposure of the lipid phosphatidylserine on the surface of epithelial cells and to strongly inhibit the activation of caspase 1 and caspase 3/7 only in penicillin-treated cells. Forty-eight hours post-infection, CT elicited a significant ROS expression both in case of a normal cycle and in case of persistence. However, serovar L and penicillin-free infection activated a higher ROS production compared to serovar D and to penicillin-induced persistence, respectively. In conclusion, we added knowledge to the cellular dynamics taking place during chlamydial persistence, demonstrating that CT creates a suitable niche to survive, switching off signals able to activate phagocytes/leukocytes recruitment. Nevertheless, persistent CT elicits ROS production by the infected cells, potentially contributing to the onset of chronic inflammation and tissue damages

Diagnosis and management of amiodarone-induced thyrotoxicosis: similarities and differences between North American and European Endocrinologists

Objective To investigate how North American thyroidologists assess and treat amiodarone-induced thyrotoxicosis (AIT) and to compare the results with those of the same questionnaire-based survey previously carried out among European thyroidologists. Design Members of the American Thyroid Association (ATA) with clinical interests were sent by e-mail a questionnaire on the diagnosis and management of AIT, 115 responses were received from the United States and Canada, representing about one-third of ATA members with clinical interests. Results The majority of respondents (91% vs. 68% in Europe, P < 0.05) see < 10 new cases of AIT per year, and AIT seems less frequent than amiodarone-induced hypothyroidism (AIH) in North America (34% and 66% of amiodarone-induced thyroid dysfunction, respectively, vs. 75% and 25%, respectively, in Europe, P < 0.001). When AIT is suspected, in North America hormonal assessment is mostly based on serum free T4 (FT4) and TSH measurements, while serum free T3 (FT3) determination is requested less frequently than in Europe; thyroid autoimmunity is included in the initial assessment less than in Europe. Most commonly used additional diagnostic procedures include, as in Europe, thyroid colour-flow Doppler sonography, and to a lesser extent, thyroid radioactive iodine uptake and scan, but Europeans tend to request multiple tests more than North Americans. Withdrawal of amiodarone is more often considered unnecessary by North American thyroidologists (21% vs. 10% in Europe in type 1 AIT, P < 0.05, 34% vs. 20% in type 2 AIT, P < 0.05). In type 1 AIT thionamides represent the treatment of choice for North Americans as well as for Europeans, but the former use them as monotherapy in 65% vs. 51% of Europeans ( P < 0.05) who more often consider potassium perchlorate as an useful addition (31% vs. 15% of North Americans, P < 0.01). Glucocorticoids are the selected treatment for type 2 AIT, alone (62% vs. 46% in Europe, P < 0.05) or in association with thionamides (16% vs. 25% in Europe, P = NS). After restoration of euthyroidism, thyroid ablation in the absence of recurrent thyrotoxicosis is recommended in type 1 AIT less frequently by North Americans. If amiodarone therapy needs to be reinstituted, prophylactic thyroid ablation is advised by 76% in type 1 AIT, while a 'wait-and-see' strategy is adopted by 61% in type 2 AIT, similar to behaviour of European thyroidologists. Conclusion Similarities and differences exist between expert North American and European thyroidologists concerning the diagnosis and management of AIT. While differences reflect the frequent uncertainty of the underlying mechanism leading to AIT, similarities may represent the basis to refine the diagnostic criteria and to improve the therapeutic outcomes of this challenging clinical situation