Fermentable carbohydrate restriction reduces luminal bifidobacteria and gastrointestinal symptoms in patients with irritable bowel syndrome

Preliminary studies indicate that dietary restriction of fermentable short-chain carbohydrates improves symptoms in irritable bowel syndrome (IBS). Prebiotic fructo-oligosaccharides and galacto-oligosaccharides stimulate colonic bifidobacteria. However, the effect of restricting fermentable short-chain carbohydrates on the gastrointestinal (GI) microbiota has never been examined. This randomized controlled trial aimed to investigate the effects of fermentable carbohydrate restriction on luminal microbiota, SCFA, and GI symptoms in patients with IBS. Patients with IBS were randomized to the intervention diet or habitual diet for 4 wk. The incidence and severity of symptoms and stool output were recorded for 7 d at baseline and follow-up. A stool sample was collected and analyzed for bacterial groups using fluorescent in situ hybridization. Of 41 patients randomized, 6 were withdrawn. At follow-up, there was lower intake of total short-chain fermentable carbohydrates in the intervention group compared with controls (P = 0.001). The total luminal bacteria at follow-up did not differ between groups; however, there were lower concentrations (P < 0.001) and proportions (P < 0.001) of bifidobacteria in the intervention group compared with controls when adjusted for baseline. In the intention-to-treat analysis, more patients in the intervention group reported adequate control of symptoms (13/19, 68%) compared with controls (5/22, 23%; P = 0.005). This randomized controlled trial demonstrated a reduction in concentration and proportion of luminal bifidobacteria after 4 wk of fermentable carbohydrate restriction. Although the intervention was effective in managing IBS symptoms, the implications of its effect on the GI microbiota are still to be determined.     

Evaluation of scattered radiation in a calibration range using exposure rate energy spectra

ISO standard 4037 specifies that for calibrating protection level dosimeters, scattered radiation should contribute less than 5% of the exposure. In previous work, the authors reported the results of an MCNP analysis of the shadow shield technique that was performed for a calibration range with a Cs irradiator. This paper examines the energy distribution of the photons contributing to the exposure percent scatter (S%) and the detailed origin of the scatter that originates in the irradiator. In summary, it reports that: 1) the majority of S% is due to photons with energies that are significantly below the source energy, 2) a significant percentage of S% is due to photons that scatter within the source and source capsule walls, and 3) S% due to scatter within the irradiator is even more significant than previously reported.     

New Zealand green-lipped mussels (Perna canaliculus) enhance non-haem iron absorption in vitro

Fe bioavailability can be manipulated by the nutritional composition of a meal. Ascorbic acid and unidentified components of meat, fish and poultry, but particularly beef, all appear to enhance the absorption of non-haem Fe. The aim of the present study is to identify whether extracts of green-lipped mussels (GLM; Perna canaliculus) enhance non-haem Fe absorption in Caco-2 cells and to compare the effect with that of beef. Raw GLM and raw beef homogenates were digested in vitro with pepsin at pH 2, and pancreatin and bile salts at pH 7. Tracer 55Fe was used to measure cellular Fe uptake. Ascorbic acid was used as a positive control and egg albumin, exposed to the same in vitro digestion process, was used as a negative control. Caco-2 cell monolayers were incubated with treatments for 60?min. All values were standardised per μg of GLM, egg albumin, beef or ascorbic acid. The results showed that ascorbic acid enhanced non-haem Fe absorption to the highest degree. Beef and GLM digestates both significantly enhanced Fe absorption compared with egg albumin. In conclusion, GLM digestate significantly enhances non-haem Fe uptake in Caco-2 cells with a similar magnitude to that of beef.     

Linear dimensions and volumes of human lungs obtained from CT images

This work provides the results of a collaboration between the Human Monitoring Laboratory (HML) and the Centre Hospitalier de l'Université de Montréal (CHUM) in which CHUM provided CT lung image sets from 166 patients for the analysis of linear dimensions and lung volume. This work has shown that a large amount of data exists in the medical community that can be of value to the health physics community. The intent of this study was to determine the range of linear dimensional parameters that could be used for torso phantom development for males and females; understand and characterize the variability of linear lung dimensions for males and females; replace the brief table in ICRP 23 with more modern data for males and females; identify an empirical formula that would predict linear dimensions of human lungs from age, height and/or weight for males and females; characterize the left, right, and total lung volumes of males and females in this data set; and compare the lung volumes of males and females to published equations for determining lung volumes. It was found that linear dimensions of lungs are essentially independent of age, height, and weight, so predictive equations cannot be formulated; however, the ranges of those parameters have now been established for the population studied herein. The data presented here are more modern than the brief table that appeared in ICRP 23, and the average values could be used as future guidelines. Whole lung volumes have been determined from the voxel lung phantoms, and empirical formulae have been developed for males and females in this data set; these compare favorably with the published values in ICRP 66.     

One Community’s Effort to Control Genetic Disease

In 1989, we established a small community health clinic to provide care for uninsured Amish and Mennonite children with genetic disorders. Over 20 years, we have used publicly available molecular data and sophisticated technologies to improve diagnostic efficiency, control laboratory costs, reduce hospitalizations, and prevent major neurological impairments within a rural underserved community. These actions allowed the clinic’s 2010 operating budget of $1.5 million to save local communities an estimated $20 to $25 million in aggregate medical costs. This exposes an unsettling fact: our failure to improve the lot of most people stricken with genetic disease is no longer a matter of scientific ignorance or prohibitive costs but of choices we make about how to implement existing knowledge and resources.KEY FINDINGS

• ▪ Successful integration of molecular technologies into primary care can improve diagnostic efficiency, control laboratory costs, reduce hospitalizations, and prevent catastrophic clinical outcomes.
• ▪ Population-specific genetic information is a strong foundation for regional preventative health services. New high-density, low-cost genotyping methods afford the opportunity to actuate this model of care in small underserved communities throughout the world.
• ▪Scaling molecular studies to small populations and even individual families is a reasonable scientific alternative to large scale genome wide association studies, and may help solve some intractable problems in human disease research and public health.

“I have no doubt that it is possible to give a new direction to technological development, a direction that shall lead it back to the real needs of man.”E. F. Schumacher, 19741“Stunning scientific and technological advances in genetics will mean little if they do not benefit people.”A. Guttmacher et al., 20012

     

Global air quality and health co-benefits of mitigating near-term climate change through methane and black carbon emission controls

Background: Tropospheric ozone and black carbon (BC), a component of fine particulate matter (PM ≤ 2.5 µm in aerodynamic diameter; PM_2.5), are associated with premature mortality and they disrupt global and regional climate.Objectives: We examined the air quality and health benefits of 14 specific emission control measures targeting BC and methane, an ozone precursor, that were selected because of their potential to reduce the rate of climate change over the next 20–40 years.Methods: We simulated the impacts of mitigation measures on outdoor concentrations of PM_2.5 and ozone using two composition-climate models, and calculated associated changes in premature PM_2.5- and ozone-related deaths using epidemiologically derived concentration–response functions.Results: We estimated that, for PM_2.5 and ozone, respectively, fully implementing these measures could reduce global population-weighted average surface concentrations by 23–34% and 7–17% and avoid 0.6–4.4 and 0.04–0.52 million annual premature deaths globally in 2030. More than 80% of the health benefits are estimated to occur in Asia. We estimated that BC mitigation measures would achieve approximately 98% of the deaths that would be avoided if all BC and methane mitigation measures were implemented, due to reduced BC and associated reductions of nonmethane ozone precursor and organic carbon emissions as well as stronger mortality relationships for PM_2.5 relative to ozone. Although subject to large uncertainty, these estimates and conclusions are not strongly dependent on assumptions for the concentration–response function.Conclusions: In addition to climate benefits, our findings indicate that the methane and BC emission control measures would have substantial co-benefits for air quality and public health worldwide, potentially reversing trends of increasing air pollution concentrations and mortality in Africa and South, West, and Central Asia. These projected benefits are independent of carbon dioxide mitigation measures. Benefits of BC measures are underestimated because we did not account for benefits from reduced indoor exposures and because outdoor exposure estimates were limited by model spatial resolution.     

Designing and implementing a COPD discharge care bundle

National surveys have revealed significant differences in patient outcomes following admission to hospital with acute exacerbation of COPD which are likely to be due to variations in care. We developed a care bundle, comprising a short list of evidence-based practices to be implemented prior to discharge for all patients admitted with this condition, based on a review of national guidelines and other relevant literature, expert opinion and patient consultation. Implementation was then piloted using action research methodologies with patient input. Actively involving staff was vital to ensure that the changes introduced were understood and the process followed. Implementation of a care bundle has the potential to produce a dramatic improvement in compliance with optimum health care practice.     

Preoperative anemia predicts thrombosis and free flap failure in microvascular reconstruction

ABSTRACT: Patients undergoing microvascular reconstruction are often anemic from a combination of iatrogenic hemodilution and acute blood losses. No major clinical study describes the impact of preoperative anemia on free flap morbidity. The plastic surgery service at a high-volume academic center performed 156 free flaps among 147 patients from December 2005 to December 2010. One hundred thirty-two had a preoperative hemoglobin (Hb) or hematocrit (Hct), with mean values of 11.8 ± 2.4 g/dL and 35.2% ± 7.0%, respectively. The overall failure rate was 9% (12/132), primarily from vascular thrombosis (6/12). Through logistic regression analysis, Hb and Hct were significant predictors of flap failure (P < 0.005) and vascular thrombosis (P < 0.05). Fisher exact test revealed a significant increase in failure risk at Hct level less than 30% (Hb < 10 g/dL) (relative risk, 4.76, P = 0.006), and probit analysis demonstrated an exposure-response relationship to decreased Hct level (P < 0.005). These findings support that preoperative anemia could significantly impact free flap morbidity.