A systematic review of high-fibre dietary therapy in diverticular disease

The exact pathogenesis of diverticular disease of the sigmoid colon is not well established. However, the hypothesis that a low-fibre diet may result in diverticulosis and a high-fibre diet will prevent symptoms or complications of diverticular disease is widely accepted. The aim of this review is to assess whether a high-fibre diet can improve symptoms and/or prevent complications of diverticular disease of the sigmoid colon and/or prevent recurrent diverticulitis after a primary episode. Clinical studies were eligible for inclusion if they assessed the treatment of diverticular disease or the prevention of recurrent diverticulitis with a high-fibre diet. The following exclusion criteria were used for study selection: studies without comparison of the patient group with a control group. No studies concerning prevention of recurrent diverticulitis with a high-fibre diet met our inclusion criteria. Three randomised controlled trials (RCT) and one case-control study were included in this systematic review. One RCT of moderate quality showed no difference in the primary endpoints. A second RCT of moderate quality and the case-control study found a significant difference in favour of a high-fibre diet in the treatment of symptomatic diverticular disease. The third RCT of moderate quality found a significant difference in favour of methylcellulose (fibre supplement). This study also showed a placebo effect. High-quality evidence for a high-fibre diet in the treatment of diverticular disease is lacking, and most recommendations are based on inconsistent level 2 and mostly level 3 evidence. Nevertheless, high-fibre diet is still recommended in several guideline

Transcriptomic response of the red tide dinoflagellate, Karenia brevis, to nitrogen and phosphorus depletion and addition

<p>Abstract</p> <p>Background</p> <p>The role of coastal nutrient sources in the persistence of <it>Karenia brevis </it>red tides in coastal waters of Florida is a contentious issue that warrants investigation into the regulation of nutrient responses in this dinoflagellate. In other phytoplankton studied, nutrient status is reflected by the expression levels of N- and P-responsive gene transcripts. In dinoflagellates, however, many processes are regulated post-transcriptionally. All nuclear encoded gene transcripts studied to date possess a 5' <it>trans</it>-spliced leader (SL) sequence suggestive, based on the trypanosome model, of post-transcriptional regulation. The current study therefore sought to determine if the transcriptome of <it>K. brevis </it>is responsive to nitrogen and phosphorus and is informative of nutrient status.</p> <p>Results</p> <p>Microarray analysis of N-depleted <it>K. brevis </it>cultures revealed an increase in the expression of transcripts involved in N-assimilation (nitrate and ammonium transporters, glutamine synthetases) relative to nutrient replete cells. In contrast, a transcriptional signal of P-starvation was not apparent despite evidence of P-starvation based on their rapid growth response to P-addition. To study transcriptome responses to nutrient addition, the limiting nutrient was added to depleted cells and changes in global gene expression were assessed over the first 48 hours following nutrient addition. Both N- and P-addition resulted in significant changes in approximately 4% of genes on the microarray, using a significance cutoff of 1.7-fold and p ≤ 10^-4. By far, the earliest responding genes were dominated in both nutrient treatments by pentatricopeptide repeat (PPR) proteins, which increased in expression up to 3-fold by 1 h following nutrient addition. PPR proteins are nuclear encoded proteins involved in chloroplast and mitochondria RNA processing. Correspondingly, other functions enriched in response to both nutrients were photosystem and ribosomal genes.</p> <p>Conclusions</p> <p>Microarray analysis provided transcriptomic evidence for N- but not P-limitation in <it>K. brevis</it>. Transcriptomic responses to the addition of either N or P suggest a concerted program leading to the reactivation of chloroplast functions. Even the earliest responding PPR protein transcripts possess a 5' SL sequence that suggests post-transcriptional control. Given the current state of knowledge of dinoflagellate gene regulation, it is currently unclear how these rapid changes in such transcript levels are achieved.</p

CE IGCC repowering project: Materials for coal gasification environment. Topical report, June 1993

A task to develop material requirements and a materials testing strategy was established with the Materials and Water Chemistry Department of the ABB Power plant Laboratories. This involved examining the requirements for each system under ABB CE scope. The basis for the material recommendations was largely based on in-house test programs under DOE contract and ABB CE experience. Consultants were utilized in a parallel task to assist in the design and material specification for the solids handling systems. ABB CE experience includes operating data from a former process development unit (PDU) located in Windsor, Connecticut. The unit gasified Pittsburgh seam coal at a nominal firing rate of 120 tons per day. The objectives of the program were to produce clean, low-Btu gas from coal, and to provide the design information for scale-up to commercial-size plants. The results of the task were used to specify and, depending on scope, design the equipment used in the plant. A detailed document was developed and used to generate a Metallurgical Flow Diagram. Specifications were developed from this diagram. For the equipment designed, these selections were provided to representatives of cognizant design and manufacturing departments. In addition, where appropriate, recommendations were made for operating procedures and for design changes. Specified materials will be again evaluated during detailed engineering. In some areas the results of the task were not conclusive. Additional investigation will be required. These areas are the types of approaches which can be taken to accommodate product gas sulfidation resistance and solids transport erosion