Isolation and characterization of acetylated LM-pectins extracted from okra pods

Pectin was isolated by aqueous extraction at pH 6.0 or 2.0 from okra (Abelmoschus esculentus L.) pods. An isolation protocol was designed to extract pectin and to study the influence of the extraction pH on their composition and physicochemical properties. The extracted pectin was assessed using sugar compositional analysis (neutral sugars, galacturonic acid, acetyl and methyl contents). FT-IR and NMR spectroscopy, size exclusion chromatography (SEC) and dilute solution viscometry were also used to determine the macromolecular characteristics of isolated pectin. The extraction protocols resulted in the isolation of pectin of high purity as evidenced by their high total carbohydrate (70.0–81.8%) and low protein (4.3–6.3%) contents. Samples contained between 46 and 56% galacturonic acid, had broad molecular weight distributions, a low degree of methylation (40.0 and 24.6%) and high degree of acetylation (52.2 and 37.6%). Neutral sugar analysis showed that the pectin extracted at pH 6.0 contained more neutral sugars, particularly, galactose (21.7–25.7 mol%), rhamnose (10.1–13.2 mol%) and arabinose (7.1–7.3 mol%) than that extracted at pH 2.0 indicating variations in fine structure. In addition, molecular parameters of the isolated pectins, such as intrinsic viscosity (2.8–4.4 dL g−1), critical concentration (0.15–0.45 dL g−1) and coil overlap parameter (0.66–1.51), showed that extraction conditions resulted in pectin with different chain morphology. The yield and physico-chemical characteristics of the extracted pectin from okra pods were influenced by the extraction conditions

The consequences of minimum wage laws Some theoretical ideas revisited

SIGLEAvailable from British Library Document Supply Centre-DSC:3597.760(no 02/530) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Cognitive dysfunction in congestive heart failure: transcranial Doppler evidence of microembolic etiology Disfunção cognitiva na insuficiência cardíaca congestiva: evidência de etiologia microembólica ao Doppler transcraniano

Cognitive symptoms are common in patients with congestive heart failure (CHF) and are usually attributed to low cerebral blood flow. In the present study, we aimed to evaluate global cognitive function (Mini Mental State Exam MMSE) in relation to both cardiac function (evaluated by echocardiogram) and cerebrovascular hemodynamics (evaluated by transcranial Doppler TCD) in CHF patients. In 83 patients studied, no correlation was found between echocardiographic parameters and MMSE scores. In contrast, a significant correlation was found between right middle cerebral artery (RMCA) mean flow velocity and MMSE score (r=0.231 p=0.039), as well as between RMCA pulsatility index and MMSE score (r s= -0.292 p=0.015). After excluding patients with a previous history of stroke, only RMCA pulsatility index correlated with MMSE score (r s=-0,314 p=0,007). The relationship between high cerebrovascular resistance and worse cognitive scores suggest that microembolism may be responsible for a significant proportion of cognitive symptoms in CHF patients.<br>Sintomas cognitivos são comuns em pacientes com insuficiência cardíaca congestiva (ICC) e são geralmente atribuídos a um regime de baixo fluxo sanguíneo cerebral. Neste estudo, objetivamos avaliar a função cognitiva global (Mini Exame do Estado Mental MEEM) em pacientes com ICC e sua relação com o grau de disfunção cardíaca (avaliada pelo ecocardiograma) e a hemodinâmica cerebral (avaliada pelo Doppler transcraniano DTC). Em 83 pacientes estudados, nenhuma correlação foi encontrada entre a pontuação no MEEM e parâmetros ecocardiográficos. Em contraste, uma correlação significativa foi encontrada entre a velocidade média na artéria cerebral média direita (ACMD) e a pontuação no MEEM (r=0,231 p=0,039), assim como entre o índice de pulsatilidade na ACMD e a pontuação no MEEM (r s=-0,292 p=0,015). Após excluir pacientes com histórico prévio de acidente vascular encefálico, somente o índice de pulsatilidade na ACMD manteve uma correlação com a pontuação no MEEM (r s=-0,314 p=0,007). A relação entre maior resistência vascular cerebral e pior desempenho cognitivo sugere que microembolia pode ser responsável por uma proporção significativa de sintomas cognitivos em pacientes com ICC