Clinical assessment of HIV-associated lipodystrophy syndrome: bioelectrical impedance analysis, anthropometry and clinical scores

Background Diagnosis of the HIV-associated lipodystrophy syndrome is based on clinical assessment, in lack of a consensus about case definition and reference methods. Three bedside methods were compared in their diagnostic value for lipodystrophy. Patients and Methods. Consecutive HIV-infected outpatients (n = 278) were investigated, 128 of which also had data from 1997 available. Segmental bioelectrical impedance analysis (BIA) and waist, hip and thigh circumferences were performed. Changes in seven body regions were rated by physicians and patients using linear analogue scale assessment (LASA). Diagnostic cut-off values were searched by receiver operator characteristics. Results. Lipodystrophy was diagnosed in 85 patients (31%). BIA demonstrated higher fat-free mass in patients with lipodystrophy but not after controlling for body mass index and sex. Segmental BIA was not superior to whole body BIA in detecting lipodystrophy. Fat-free mass increased from 1997 to 1999 independent from lipodystrophy. Waist-hip and waist-thigh ratios were higher in patients with lipodystrophy. BIA, anthropometry and LASA did not provide sufficient diagnostic cut-off values for lipodystrophy. Agreement between methods, and between patient and physician rating, was poor. Conclusion: These methods do not fulfil the urgent need for quantitative diagnostic tools for lipodystrophy. BIA estimates of fat free mass may be biased by lipodystrophy, indicating a need for re-calibration in HIV infected populations. (C) 2001 Harcourt Publishers Ltd.

A new technique for the quantification of peripheral edema with application in both unilateral and bilateral cases

Current noninvasive techniques for the routine and frequent quantification of peripheral lymphedema in patients are total limb volume measurement (by water immersion or by circumferential measurements) and bioelectrical impedance analysis (BIA). However both of these techniques require standardizing the measurement using a contralateral measurement from the unaffected limb, Hence these techniques are essentially restricted to unilateral lymphedema. This paper describes the results from a preliminary study to investigate an alternative approach to the analysis of the data from multiple frequency BIA to produce an index of lymphedema without the need for normalization to another body segment. Twenty patients receiving surgical treatment for breast cancer were monitored prior to surgery and again after diagnosis with unilateral lymphedema. The data recorded were total limb volume, by circumferential measurements; and BIA measurements of both limbs. From these measurements total limb volumes and extracellular fluid volumes were calculated and expressed as ratios of the affected limb to that of the unaffected limb. An index of the ratio of the extracellular fluid volume to the intracellular fluid volume was determined. This ECW/ICW index was calculated for both the affected and unaffected limbs at both measurement times. Results confirmed that the established techniques of total limb volume and extracellular fluid volume normalized to the unaffected contralateral limb were accurate in the detection of lymphedema (p < 10(-6)). Comparison of the ECW/ICW index from the affected limb after diagnosis with that from the pre-surgery measurement revealed a significant (p< 10(-6)) and considerable (75%) increase. The results of this pilot study suggest that by using multiple frequency bioelectrical impedance analysis, an index of the ECW/ICW ratio can be obtained and this index appears to have an equal, or better, sensitivity, than the other techniques in detecting lymphedema. More importantly, this index does not require normalization to another body segment and can be used to detect all types of peripheral edema including both unilateral and bilateral lymphedema.

Estimation of total body water from bioelectrical impedance analysis in patients with pancreatic cancer - agreement between three methods of prediction

Introduction Bioelectrical impedance analysis (BIA) is a useful field measure to estimate total body water (TBW). No prediction formulae have been developed or validated against a reference method in patients with pancreatic cancer. The aim of this study was to assess the agreement between three prediction equations for the estimation of TBW in cachectic patients with pancreatic cancer. Methods Resistance was measured at frequencies of 50 and 200 kHz in 18 outpatients (10 males and eight females, age 70.2 +/- 11.8 years) with pancreatic cancer from two tertiary Australian hospitals. Three published prediction formulae were used to calculate TBW - TBWs developed in surgical patients, TBWca-uw and TBWca-nw developed in underweight and normal weight patients with end-stage cancer. Results There was no significant difference in the TBW estimated by the three prediction equations - TBWs 32.9 +/- 8.3 L, TBWca-nw 36.3 +/- 7.4 L, TBWca-uw 34.6 +/- 7.6 L. At a population level, there is agreement between prediction of TBW in patients with pancreatic cancer estimated from the three equations. The best combination of low bias and narrow limits of agreement was observed when TBW was estimated from the equation developed in the underweight cancer patients relative to the normal weight cancer patients. When no established BIA prediction equation exists, practitioners should utilize an equation developed in a population with similar critical characteristics such as diagnosis, weight loss, body mass index and/or age. Conclusions Further research is required to determine the accuracy of the BIA prediction technique against a reference method in patients with pancreatic cancer.

Body proportions in three Nigerian tribes

Prediction equations of body composition based on measurements of whole-body bioelectrical impedance analysis (BIA) have been found to be population-specific. It was hypothesised that this may be, in part, due to differences in proportional limb lengths between ethnic or racial groups. As a preliminary to a survey of body composition in urban Nigerians using BIA, the relative limb lengths of the three major tribal groups (Hausa, Yoruba and Ibo) were determined. We found small (5-9%) but significantly longer limb lengths in Nigerians compared to a Caucasian population, but no significant differences between tribes. This implies that BIA prediction equations generated in a Caucasian population are inappropriate for use in a Nigerian population.

Assessment of bioelectrical impedance analysis for the prediction of total body water in cystic fibrosis

The aim of this study was to compare the measurement of total body water (TBW) by deuterium ((H2O)-H-2) dilution and bioelectrical impedance analysis (BIA) in patients with cystic fibrosis (CF) and healthy controls. Thirty-six clinically stable patients with CF (age 25.4 +/- 5.6 yrs) and 42 healthy controls (age 25.4 +/- 4.8) were recruited into this study. TBW was measured by (H2O)-H-2 dilution and predicted by BIA in patients and controls. The TBW predicted from BIA was significantly different from TBW as measured using (H2O)-H-2 in patients (P

Measured and predicted total body water in children with myelomeningocele

Objective: Children with myelomeningocele (MMC) have an altered body composition and an atypical distribution of total body water (TBW). The aim of the present study was to determine the accuracy of current predictive equations, based on bioelectrical impedance analysis (BIA), in determining TBW when compared with measured TBW using deuterium dilution. Methods: Fourteen children with MMC were measured for whole body BIA and TBW (using deuterium dilution and the Plateau method). Total body water was predicted using equations based on the resistance and characteristic frequency from BIA measurements and heights of subjects. Results: The mean measured TBW was 15.46 +/- 8.28 L and the mean predictions for TBW using equations based on the resistance and characteristic frequency from BIA measurements and heights of subjects were 18.29 +/- 8.41 L, 17.72 +/- 11.42 L and 12.51 +/- 7.59 L, respectively. The best correlation was found using characteristic frequency. The limits of agreement between measured and predicted TBW values using Bland-Altman analysis were large. Conclusions: The present study suggests that the prediction of TBW in children with MMC can be made accurately using the equation of Cornish et al . based on BIA measurements of characteristic frequency.

A comparison of the whole-body and segmental methodologies of bioimpedance analysis

Theory supports the use of a segmental methodology (SM) for bioimpedance analysis (BIA) of body water (BW). However, previous studies have generally failed to show a significant improvement when the SM is used in place of a whole-body methodology. A pilot study was conducted to compare the two methodologies in control and overweight subjects. BW of each subject was measured by D2O dilution and also estimated from BIA measurements. Bland and Altman analysis was used to compare the two values of BW. The SM resulted in a small but not significantly improved limits of agreement of measured and BIA estimated BW (psimilar to0.3). This and the results of previous studies suggest that improvements in prediction of BW obtained from application of the SM may be intrinsically small and may not justify the additional effort in application.

Educa????o a dist??ncia em organiza????es p??blicas: mesa-redonda de pesquisa-a????o

O livro materializa a quintess??ncia dos debates travados pelo seleto grupo de representantes educadores ??? de diversas institui????es brasileiras ??? no ciclo de reuni??es promovidas sob a coordena????o da ENAP e que foram realizadas em Bras??lia, em 2006. ?? uma obra que busca ampliar as discuss??es sobre conceitos de educa????o que se desenrolam ao longo da vida, especialmente na contemporaneidade, no contexto da sociedade global que tem exigido compet??ncias e capacidades cada vez mais complexas para a forma????o profissional, notadamente para o setor de servi??os p??blicos

Ci??ncias e arte de educar

Agrade??o ao amigo ??? e mestre ??? Professor Fernando de Azevedo, o privil??gio de vos falar, ao encerrar-se ??ste semin??rio de educa????o, com o qual se inauguraram, em 1957, as atividades do Centro Regional de Pesquisas Educacionais, confiado, afortunadamente, ?? sua alta e s??bia dire????o. Este centro, como os seus cong??neres, o brasileiro e os demais centros regionais, representam elos no esf??r??o continuado com que o Brasil tem procurado acompanhar o desenvolvimento da arte de educar ??? a educa????o ??? nos ??ltimos cinq??enta anos, desenvolvimento que se caracteriza por uma revis??o de conceitos e de t??cnicas de estudo, ?? maneira, dir-se-ia, da transforma????o operada na arte de curar ??? a medicina quando se emancipou da tradi????o, do acidente, da simples ???intui????o??? e do empirismo e se f??z, como ainda se vem fazendo, cada vez mais cient??fica.

Electrospun silk-elastin-like fiber mats for tissue engineering applications

Protein-based polymers are present in a wide variety of organisms fulfilling structural and mechanical roles. Advances in protein engineering and recombinant DNA technology allow the design and production of recombinant protein-based polymers (rPBPs) with an absolute control of its composition. Although the application of recombinant proteins as biomaterials is still an emerging technology, the possibilities are limitless and far superior to natural or synthetic materials, as the complexity of the structural design can be fully customized. In this work, we report the electrospinning of two new genetically engineered silk-elastin-like proteins (SELPs) consisting of alternate silk- and elastin-like blocks. Electrospinning was performed with formic acid and aqueous solutions at different concentrations without addition of further agents. The size and morphology of the electrospun structures was characterized by scanning electron microscopy showing to be dependent of concentration and solvent used. Treatment with air saturated with methanol was employed to stabilize the structure and promote water insolubility through a time-dependent conversion of random coils into ��-sheets (FTIR). The resultant methanol-treated electrospun mats were characterized for swelling degree (570-720%), water vapour transmission rate (1083 g/m2/day) and mechanical properties (modulus of elasticity of ~126 MPa). Furthermore, the methanol-treated SELP fiber mats showed no cytotoxicity and were able to support adhesion and proliferation of normal human skin fibroblasts. Adhesion was characterized by a filopodia-mediated mechanism. These results demonstrate that SELP fiber mats can provide promising solutions for the development of novel biomaterials suitable for tissue engineering applications.

"Caindo na cana" com Marilyn Monroe: tempo, espa��o e "b��ias-frias"

Neste artigo pretendo discutir um drama social ("cair na cana") que marca a passagem para uma condi����o amb��gua, liminar. Se uma das experi��ncias associadas ao "modernismo" �� a de vivermos simultaneamente em tempos e espa��os diferentes, certamente os "b��ias-frias" s��o nossos contempor��neos modernistas. Paradoxalmente, em se tratando de uma imagem que certamente seduziu alguns campos intelectuais durante os anos 70 e 80, teriam as tentativas de definir o "b��ia-fria", transformando imagem em categoria, contribuindo para a sua constitui����o em uma esp��cie de f��ssil recente da produ����o academica?

Interven����o coron��ria percut��nea no enfarte agudo do mioc��rdio: influ��ncia no progn��stico dos doentes

Mestrado em Tecnologia de Diagn��stico e Interven����o Cardiovascular. ��rea de especializa����o: Interven����o Cardiovascular.

Estudo das propriedades dos adjuvantes na compatibilidade/robustez cimento/adjuvante

A qualidade do bet��o pode ser controlada pelo comportamento da fluidez da pasta de cimento, o qual est�� relacionado com a dispers��o das part��culas de cimento. Um dos maiores avan��os na tecnologia do bet��o tem sido o desenvolvimento de aditivos. Um destes tipos de aditivos, os Superplastificantes (SP), fornecem a possibilidade de se obter uma melhor dispers��o das part��culas de cimento, produzindo pastas com elevada fluidez. Com o desenvolvimento de bet��es de alta resist��ncia e elevado desempenho, os superplastificantes tornaram-se indispens��veis. Os superplastificantes s��o adsorvidos nas part��culas de cimento e esta adsor����o depende da composi����o do cl��nquer do cimento e do tipo de SP utilizado. Com a difus��o do emprego dos aditivos redutores de ��gua, t��m surgido v��rios problemas de compatibilidade cimento/adjuvante. Esta investiga����o dedicada aos superplastificantes, fortes redutores de ��gua, visou estudar quais as propriedades que poderiam influenciar a sua compatibilidade/robustez com o cimento. Tamb��m se procurou ganhar experi��ncia com as t��cnicas anal��ticas de caracteriza����o de adjuvantes. Assim, utilizou-se um tipo de cimento e dois tipos de superplastificantes (poli(��tercarboxilatos) e poli(naftalenossulfonatos)) dispon��veis no mercado portugu��s. Mantendo a mesma raz��o ��gua/cimento (A/C), pretendeu-se determinar a natureza qu��mica, grau de funcionaliza����o, teor e tipo de contra-i��o, teor de sulfatos/sulfonatos do adjuvante e o comportamento dos superplastificantes nas pastas ciment��cias, de forma a poder determinar indicadores de compatibilidade entre cimentos e superplastificantes. Constatou-se que a natureza qu��mica, o grau de funcionaliza����o e a quantidade consumida dos superplastificantes t��m influ��ncia nas pastas. Os indicadores de compatibilidade por parte dos superplastificantes parecem estar relacionados com o comprimento da cadeia lateral de ��ter e com o r��cio CO2R/CO2 -. A altera����o do momento da adi����o do adjuvante tem influ��ncia na compatibilidade cimento/adjuvante, sendo ben��fico para os poli(��tercarboxilatos) e prejudicial para o poli(naftalenossulfonato).

Conectividade em popula����es de lapas nas ilhas da Macaron��sia (Atl��ntico-NE): uma abordagem multidisciplinar

Jornadas "Ci��ncia nos A��ores ��� que futuro? Tema Ci��ncias Naturais e Ambiente", Ponta Delgada, 7-8 de Junho de 2013.

Cellular polarity in aging: role of redox regulation and nutrition

Cellular polarity concerns the spatial asymmetric organization of cellular components and structures. Such organization is important not only for biological behavior at the individual cell level, but also for the 3D organization of tissues and organs in living organisms. Processes like cell migration and motility, asymmetric inheritance, and spatial organization of daughter cells in tissues are all dependent of cell polarity. Many of these processes are compromised during aging and cellular senescence. For example, permeability epithelium barriers are leakier during aging; elderly people have impaired vascular function and increased frequency of cancer, and asymmetrical inheritance is compromised in senescent cells, including stem cells. Here, we review the cellular regulation of polarity, as well as the signaling mechanisms and respective redox regulation of the pathways involved in defining cellular polarity. Emphasis will be put on the role of cytoskeleton and the AMP-activated protein kinase pathway. We also discuss how nutrients can affect polarity-dependent processes, both by direct exposure of the gastrointestinal epithelium to nutrients and by indirect effects elicited by the metabolism of nutrients, such as activation of antioxidant response and phase-II detoxification enzymes through the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2). In summary, cellular polarity emerges as a key process whose redox deregulation is hypothesized to have a central role in aging and cellular senescence.