17 research outputs found

    Counter-current chromatography for the separation of terpenoids: A comprehensive review with respect to the solvent systems employed

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    Copyright @ 2014 The Authors.This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.Natural products extracts are commonly highly complex mixtures of active compounds and consequently their purification becomes a particularly challenging task. The development of a purification protocol to extract a single active component from the many hundreds that are often present in the mixture is something that can take months or even years to achieve, thus it is important for the natural product chemist to have, at their disposal, a broad range of diverse purification techniques. Counter-current chromatography (CCC) is one such separation technique utilising two immiscible phases, one as the stationary phase (retained in a spinning coil by centrifugal forces) and the second as the mobile phase. The method benefits from a number of advantages when compared with the more traditional liquid-solid separation methods, such as no irreversible adsorption, total recovery of the injected sample, minimal tailing of peaks, low risk of sample denaturation, the ability to accept particulates, and a low solvent consumption. The selection of an appropriate two-phase solvent system is critical to the running of CCC since this is both the mobile and the stationary phase of the system. However, this is also by far the most time consuming aspect of the technique and the one that most inhibits its general take-up. In recent years, numerous natural product purifications have been published using CCC from almost every country across the globe. Many of these papers are devoted to terpenoids-one of the most diverse groups. Naturally occurring terpenoids provide opportunities to discover new drugs but many of them are available at very low levels in nature and a huge number of them still remain unexplored. The collective knowledge on performing successful CCC separations of terpenoids has been gathered and reviewed by the authors, in order to create a comprehensive document that will be of great assistance in performing future purifications. © 2014 The Author(s)

    Impact of age and comorbidities on health-related quality of life for patients with prostate cancer: evaluation before a curative treatment

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    <p>Abstract</p> <p>Background</p> <p>Interpretation of comparative health-related quality of life (HRQOL) studies following different prostate cancer treatments is often difficult due to differing patient ages. Furthermore, age-related changes can hardly be discriminated from therapy-related changes. The evaluation of age-and comorbidity-related changes was in focus of this study.</p> <p>Methods</p> <p>HRQOL of 528 prostate cancer patients was analysed using a validated questionnaire (Expanded Prostate Cancer Index Composite) before a curative treatment. Patients were divided into age groups ≤65, 6670, 7175 and >75 years. The impact of specific comorbidities and the Charlson Comorbidity Index (CCI) were evaluated. The questionnaire comprises 50 items concerning the urinary, bowel, sexual and hormonal domains for function and bother. For assessment of sexual and hormonal domains, only patients without prior hormonal treatment were included (n = 336).</p> <p>Results</p> <p>Urinary incontinence was observed increasingly with higher age (mean function scores of 92/88/85/87 for patients ≤65, 6670, 7175 and >75 years) complete urinary control in 78%/72%/64%/58% (p < 0.01). Sexual function scores decreased particularly (48/43/35/30), with erections sufficient for intercourse in 68%/50%/36%/32% (p < 0.01) a decrease of more than a third comparing patients ≤65 vs. 6670 (36%) and 6670 vs. 7175 years (39%). The percentage of patients with comorbidities was lowest in the youngest group (48% vs. 66%/68%/63% for ages 6670/7175/>75 years; p < 0.05). A multivariate analysis revealed an independent influence of both age and comorbidities on urinary incontinence, specifically diabetes on urinary bother, and both age and diabetes on sexual function/bother. Rectal domain scores were not significantly influenced by age or comorbidities. A CCI>5 particularly predisposed for lower urinary and sexual HRQOL scores.</p> <p>Conclusion</p> <p>Urinary continence and sexual function are the crucial HRQOL domains with age-related and independently comorbidity-related decreasing scores. The results need to be considered for the interpretation of comparative studies or longitudinal changes after a curative treatment.</p
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