Visualization of gas flow and diffusion in porous media

The transport of gases in porous materials is a crucial component of many important processes in science and technology. In the present work, we demonstrate how magnetic resonance microscopy with continuous flow laser-polarized noble gases makes it possible to "light up" and thereby visualize, with unprecedented sensitivity and resolution, the dynamics of gases in samples of silica aerogels and zeolite molecular sieve particles. The "polarization-weighted" images of gas transport in aerogel fragments are correlated to the diffusion coefficient of xenon obtained from NMR pulsed-field gradient experiments. The technique provides a unique means of studying the combined effects of flow and diffusion in systems with macroscopic dimensions and microscopic internal pore structure.     

Cisapride treatment for gastro-oesophageal reflux in children: a systematic review of randomized controlled trials

The aim of the systematic review was to determine the effect of cisapride compared with placebo or other non-surgical therapies for the treatment of symptoms of gastro-oesophageal reflux in children. We searched MEDLINE, EMBASE, the Cochrane Controlled Trials Register, Science Citation Index and reference lists for randomized controlled trials which compared cisapride with placebo or other non-surgical therapy in children. We included only trials which reported reflux-related symptoms as an outcome, provided that cisapride was administered orally for at least I week. Seven trials (286 children in total) compared cisapride with placebo. Two trials reported good concealment of treatment allocation. The pooled odds ratio for the 'same or worse' symptoms was 0.34 (95% CI 0.10, 1.19). There was substantial heterogeneity between studies (P < 0.00001) and the funnel plot was asymmetrical. Adverse effects (mainly diarrhoea) were not significantly increased with cisapride (pooled odds ratio (OR) 1.80: 0.87, 3.70). The reflux index was significantly reduced in children treated with cisapride (weighted mean difference -6.49: -10.13, -2.85). One study (50 children) compared cisapride with gaviscon plus carobel: the OR for the 'same or worse' symptoms was 3.26 (0.93, 11.38). There was no clear evidence that cisapride reduced symptoms of gastro-oesophageal reflux. As smaller, poorer quality studies were biased in favour of a positive treatment effect, the pooled OR overestimated the potential benefits of cisapride. There was some evidence to suggest that gaviscon plus carobel may be a more effective option than cisapride.     

Helicobacter pylori "test and treat" or endoscopy for managing dyspepsia: an individual patient data meta-analysis

BACKGROUND & AIMS: Helicobacter pylori "test and treat" has been recommended for the management of young dyspeptic patients without alarm symptoms, and trials have suggested that it is as effective as endoscopy. However, none of these trials have had sufficient sample size to confirm that "test and treat" costs less or to detect small differences in effect. A collaborative group has prospectively registered trials comparing prompt endoscopy with a "test and treat" approach, with the aim of performing an individual patient data meta-analysis of both effect and resource utilization data. METHODS: Researchers provided data for meta-analysis, pooling effects of interventions on individual dyspepsia symptoms. Standardized unit costs were applied to resource utilization, and net benefit was calculated at patient level. Effects, costs, and net benefit were then pooled at study level. RESULTS: Five trials were identified, containing 1924 patients (946 endoscopy [mean age, 40 years], 978 "test and treat" [mean age, 41 years]). The relative risk (RR) of remaining symptomatic after 1 year was reduced with endoscopy compared with "test and treat" (RR = 0.95; 95% confidence interval [CI]: 0.92-0.99). "Test and treat" cost 389 dollars less per patient (95% CI: 275-502 dollars). Using the net benefit approach, at no realistic level of willingness to pay per patient symptom-free did prompt endoscopy become cost-effective. CONCLUSIONS: Prompt endoscopy confers a small benefit in terms of cure of dyspepsia but costs more than "test and treat" and is not a cost-effective strategy for the initial management of dyspepsia.     

Fertility and pregnancy-related events in women with celiac disease: a population-based cohort study

BACKGROUND & AIMS: Previous studies have raised concern about reduced fertility and increased adverse pregnancy-related events in women with celiac disease, but none has estimated overall fertility compared with the general female population. METHODS: We compared computerized primary care data for 1521 women with celiac disease with data for 7732 age- and practice-matched women without celiac disease. We estimated population-based rates of fertility and adverse pregnancy outcomes. RESULTS: Crude fertility rates were 48.2 and 47.7 live births per 1000 person-years for women with and without celiac disease, respectively (rate ratio, 1.01; 95% confidence interval, 0.90-1.14). Age-specific fertility rates showed that women with celiac disease had lower fertility when younger but higher fertility when older compared with women without celiac disease. This increase in relative fertility with increasing age held whether women had treated or untreated celiac disease. Risks of cesarean section (odds ratio, 1.33; 95% confidence interval, 1.03-1.70) and miscarriage (rate ratio, 1.31; 95% confidence interval, 1.06-1.61) were moderately higher in women with celiac disease, but risks of assisted birth, breech birth, preeclampsia, postpartum hemorrhage, ectopic pregnancy, stillbirth, and termination were similar. CONCLUSIONS: Overall, women with celiac disease have fertility similar to that of the general female population, but they have their babies at an older age. Although our findings may reflect a disease effect, the age shift in fertility rates and the increase in cesarean section risk is consistent with socioeconomic or educational advantages of women with celiac disease.     

Sun protection as a family health project in families with adolescents

This study examined sun protection in families with adolescents from an action-theoretical perspective. Interview data were collected from 20 families about their attitudes and behaviors around sunbathing and sun protection. The data support the understanding of project as joint goal-directed action over time as the basis on which these behaviors are organized in families. Families used the language of goal-directed action to discuss family sun protection. Differences between families with focused and diffuse sun-protection projects are identified. Sun protection in families as one part of an array of family goal-directed actions and projects has implications for health promotion.     

Primary nocturnal enuresis: omega-3 fatty acids may be of therapeutic value

Primary nocturnal enuresis (PNE), or bed-wetting, is a distressing urinary condition which can persist through childhood and beyond. Altered prostaglandin and nitric oxide production have been observed in children with PNE, and prostaglandin inhibitors are known to be of therapeutic value. Omega-3 fatty acids have the potential to influence the symptoms of PNE by inhibition of prostaglandin and renal nitric oxide production. In addition, children with PNE have an inappropriate startle response and an apparent maturational delay of the central nervous system. Research clearly shows that omega-3 fatty acids play a critical role in the development and function of the central nervous system. It is our contention that inadequate omega-3 intake may play a role in the lack of inhibitory input to the startle and micturition centers in PNE.