Irritable bowel syndrome with constipation: a European-focused systematic literature review of disease burden

OBJECTIVE

To conduct a systematic literature review to assess burden of disease and unmet medical needs in patients with irritable bowel syndrome (IBS) with constipation (IBS-C), with a focus on five European countries (France, Germany, Italy, Spain, UK).

METHODS

MEDLINE, EMBASE, and grey literature searches were carried out using terms for IBS and constipation, to identify studies reporting epidemiological, clinical, humanistic, or economic outcomes for IBS-C, published between 2000 and 2010.

RESULTS

Searches identified 885 unique abstracts and 33 supplementary articles, of which 100 publications and six grey literature sources met the inclusion criteria. Among patients with IBS, the prevalence estimates of IBS-C ranged from 1 to 44%. Co-morbid conditions, such as personality traits, psychological distress, and stress, were common. Patients with IBS-C had lower health-related quality-of-life (HRQoL) compared with the general population, and clinical trials suggested that effectively treating IBS-C improves HRQoL. The European societal cost of IBS-C is largely unknown, as no IBS-C-specific European cost-of-illness studies were identified. Two cost analyses demonstrated the substantial societal impact of IBS-C, including reduced productivity at work and work absenteeism. Guidelines offered similar recommendations for the diagnosis and management of IBS; however, recommendations specifically for IBS-C varied by country. Current IBS-C treatment options have limited efficacy and the risk:benefit profile of early 5-HT(4) agonists restricts clinical use.

CONCLUSIONS

This systematic review indicates a clear need for European-focused IBS-C burden-of-disease and cost-of-illness studies to address identified evidence gaps. There is a need for new therapies for IBS-C that are effective, well tolerated, and have a positive impact on HRQoL.

Reverse genetics in Chlamydomonas: a platform for isolating insertional mutants

A method was developed to identify insertional mutants of Chlamydomonas reinhardtii disrupted for selected target genes. The approach relies on the generation of thousands of transformants followed by PCR-based screenings that allow for identification of strains harboring the introduced marker gene within specific genes of interest. Our results highlight the strengths and limitations of two independent screens that differed in the nature of the marker DNA used (PCR-amplified fragment containing the plasmid-free marker versus entire linearized plasmid with the marker) and in the strategies used to maintain and store transformants.

Anxiety is more common in children with asthma

OBJECTIVE

There are a variety of reasons why there may be an association between asthma and anxiety in children. Research into the relation between asthma and anxiety has been limited by the sole use of parent-reported or self-reported asthma symptoms to define asthma status. The objective of this study was to determine if children with physician-defined asthma are more likely to suffer anxiety than children without asthma.

DESIGN

A population-based, cross-sectional assessment, of self-reported anxiety symptoms.

SETTING AND PARTICIPANTS

Children aged 5-13 years from Barwon region of Victoria, Australia. Asthma status was determined by review with a paediatrician. Controls were a sample of children without asthma symptoms (matched for age, gender and school).

OUTCOME MEASURE

The Spence Children's Anxiety Scale (SCAS) written questionnaire. The authors compared the mean SCAS score, and the proportion of children with an SCAS score in the clinical range, between the groups.

RESULTS

Questionnaires were issued to 205 children with asthma (158 returned, response rate 77%), and 410 controls (319 returned, response rate 78%). The SCAS scores were higher in asthmatics than controls (p<0.001); and were more likely to be in the clinical range (OR=2.5, 95% CI 1.1 to 5.8, p=0.036). There was no evidence that these associations could be explained by known confounding factors.

CONCLUSIONS

Children with asthma are substantially more likely to suffer anxiety than children without asthma. Future studies are required to determine the sequence of events that leads to this comorbidity, and to test strategies to prevent and treat anxiety among children with asthma.

More than health: the added value of health services in remote Scotland and Australia

Health services are suggested to contribute to remote communities in the ways that extend beyond healthcare delivery. This international multiple case-study research provides qualitative evidence of the social, economic and human contributions (the 'added-value') that may be lost should remote communities lose in-situ health provision. We present a typology of added-value contributions that differentiates institutional aspects (residing in buildings, or embodied in the specific status, capabilities and skills of health professionals) and individual aspects (attributable to health professionals' unique personalities and choices). This typology has relevance for communities, policymakers and managers when considering the impacts of potential service changes.

How to run an effective journal club: a systematic review

BACKGROUND

Health-based journal clubs have been in place for over 100 years. Participants meet regularly to critique research articles, to improve their understanding of research design, statistics and critical appraisal. However, there is no standard process of conducting an effective journal club. We conducted a systematic literature review to identify core processes of a successful health journal club.

METHOD

We searched a range of library databases using established keywords. All research designs were initially considered to establish the body of evidence. Experimental or comparative papers were then critically appraised for methodological quality and information was extracted on effective journal club processes.

RESULTS

We identified 101 articles, of which 21 comprised the body of evidence. Of these, 12 described journal club effectiveness. Methodological quality was moderate. The papers described many processes of effective journal clubs. Over 80% papers reported that journal club intervention was effective in improving knowledge and critical appraisal skills. Few papers reported on the psychometric properties of their outcome instruments. No paper reported on the translation of evidence from journal club into clinical practice.

CONCLUSION

Characteristics of successful journal clubs included regular and anticipated meetings, mandatory attendance, clear long- and short-term purpose, appropriate meeting timing and incentives, a trained journal club leader to choose papers and lead discussion, circulating papers prior to the meeting, using the internet for wider dissemination and data storage, using established critical appraisal processes and summarizing journal club findings.

The Early Language in Victoria Study: predicting vocabulary at age one and two years from gesture and object use

The Macarthur-Bates Communicative Development Inventories (CDI) have been used widely to document early communicative development. The paper reports on a large community sample of 1,447 children recruited from low, middle and high socioeconomic (SES) areas across metropolitan Melbourne, Australia. Regression analyses were conducted to determine the extent to which communicative behaviours reported at 0 ; 8 and 1 ; 0 predicted vocabulary development at 1 ; 0 and 2 ; 0. In support of previous findings with smaller, often less representative samples, gesture and object use at 1 ; 0 were better predictors of 2 ; 0 vocabulary than were gesture and object use at 0 ; 8. At 1 ; 0, children from the lower SES groups were reported to understand more words than children from the higher SES groups, but there were no SES differences for words produced at 1 ; 0 or 2 ; 0. The findings add to our understanding of the variability in the development of early communicative behaviours.

No interaction between the serotonin transporter polymorphism (5-HTTLPR) and childhood adversity or recent stressful life events on symptoms of depression: results from two community surveys

In this study we investigated interactions between the 5-HTTLPR genotype and environmental risk factors (G x E) on symptoms of depression in two large Australian community samples of adolescents and young adults. We postulated that a significant interaction between the 5-HTTLPR genotype and environmental risk factors of childhood adversity or stressful life events on symptoms of depression would be observed in subjects with at least one short allele (s/l or s/s) compared with subjects with no short alleles (l/l). We did not find significant G x E interactions between the 5-HTTLPR genotype and recent stressful life events or childhood adversity on symptoms of depression in our sample populations. However, we did find adolescents aged 17-18 years homozygous for the long allele (l/l) and exposed to persistently high levels of family adversity over a 6-year period were at a greater risk of depression than subjects with the same genotype exposed to no or persistently low levels of family adversity. This interaction should be interpreted cautiously due to the small number of depressed subjects in the sample with persistently high levels of family adversity.

Effects of smoking on cardiopulmonary baroreceptor activation and peripheral vascular resistance

PATIENTS AND METHODS

We studied 16 healthy smokers and 16 nonsmokers acting as controls. We subjected smokers and nonsmokers to cardiopulmonary baroreceptor stimulation by studying forearm and common carotid haemodynamic and sympathovagal balance. Smokers repeated the tests after smoking one cigarette. Smokers and controls were subjected to passive elevation of the legs and the trunk in a horizontal position with pressure monitoring and measurement of the calibre and flow in the brachial and common carotid arteries using a colourDoppler ultrasound. We calculated forearm resistance and carotid wall tension. We also studied R-R variability, calculating the ratio between low frequency (LF) and high frequency (HF) R-R interval variability.

RESULTS

During stimulation diastolic blood pressure values decreased in controls and in smokers at rest. After smoking one cigarette, smokers showed an increase in systolic and diastolic blood pressure as well as in the heart rate during stimulation. Humeral artery increased the calibre during stimulation in both groups; after cigarette smoking the calibre declined throughout the study phases. Forearm resistance decreased in both groups during stimulation at rest, but increased after cigarette smoking. The LF/HF ratio decreased during stimulation in both groups, and it increased at rest after smoking. Carotid diameter did not change in either group, and wall tension increased in smokers after smoking one cigarette.

CONCLUSIONS

Smoking one cigarette increases resistance, impairs baroreflex and increases carotid wall tension in mild smokers. These findings may explain the higher rate of a cardiovascular event in smokers.

Haemodynamic effects of AT1 inhibition and Ca2+-channel blockade in hypertensive patients during isometric stress

To assess the effects of valsartan and amlodipine on the haemodynamics of forearm circulation in hypertensive patients undergoing isometric stress. A total of 24 patients with essential hypertension were subjected to a double blind-cross-over study. The artery left arm flow (strain gauge plethysmography), distensibility of digital arteries (piezoelectric plethysmography) and blood pressure were measured. District resistance was calculated as the ratio between mean arterial pressure and blood flow. The tests were performed at basal conditions (T0) and after 8 days (T8) of therapy with valsartan (160 mg) or amlodipine (10 mg), at rest and during handgrip (HG); treatments were inverted after 15 days of washout. Valsartan and amlodipine reduced blood pressure after 8 days (P<0.05), handgrip increased systolic and diastolic values and heart rate at T0 and only a slight raising in diastolic values at T8. The recovery time of pressure values was longer in hypertensives treated with amlodipine (P<0.05). The forearm flow increased after HG (at T0 an T8) and increased even further after valsartan (P<0.005). Valsartan increased arteriolar distensibility, expressed by the ratio between time to peak and total time (PT/TT) calculated on the sphygmic wave. Amlodipine did not affect PT/TT ratio, whereas it reduced local resistance (T8 vs T0, P<0.05). The reduction effect of valsartan on resistance was detectable also during handgrip, on the contrary amlodipine did not control the increase. Inhibition of AT1 is able to reduce haemodynamic modifications elicited by isometric stress in hypertensive patients.

Src homology 3-domain growth factor receptor-bound 2-like (endophilin) interacting protein 1, a novel neuronal protein that regulates energy balance

To identify genes involved in the central regulation of energy balance, we compared hypothalamic mRNA from lean and obese Psammomys obesus, a polygenic model of obesity, using differential display PCR. One mRNA transcript was observed to be elevated in obese, and obese diabetic, P. obesus compared with lean animals and was subsequently found to be increased 4-fold in the hypothalamus of lethal yellow agouti (A(y)/a) mice, a murine model of obesity and diabetes. Intracerebroventricular infusion of antisense oligonucleotide targeted to this transcript selectively suppressed its hypothalamic mRNA levels and resulted in loss of body weight in both P. obesus and Sprague Dawley rats. Reductions in body weight were mediated by profoundly reduced food intake without a concomitant reduction in metabolic rate. Yeast two-hybrid screening, and confirmation in mammalian cells by bioluminescence resonance energy transfer analysis, demonstrated that the protein it encodes interacts with endophilins, mediators of synaptic vesicle recycling and receptor endocytosis in the brain. We therefore named this transcript Src homology 3-domain growth factor receptor-bound 2-like (endophilin) interacting protein 1 (SGIP1). SGIP1 encodes a large proline-rich protein that is expressed predominantly in the brain and is highly conserved between species. Together these data suggest that SGIP1 is an important and novel member of the group of neuronal molecules required for the regulation of energy homeostasis.

Dopamine antagonist modulation of amphetamine response as detected using pharmacological MRI

Functional magnetic resonance imaging (fMRI), employing BOLD-contrast, was used to measure changes in regional brain activation following amphetamine administration, either alone or after pre-treatment with the dopamine D1 receptor antagonist SCH23390, or the dopamine D2 receptor antagonist, sulpiride, in anaesthetised rat. After obtaining baseline data, rats (n=8) were given amphetamine (3 g/kg i.v) and volume data sets collected for 90 mins. Acute amphetamine challenge caused widespread increases in BOLD signal intensity in many subcortical structures with rich dopaminergic innervation, with decreases in BOLD contrast observed in the superficial layers of the cortex. Pretreatment with SCH23390 (n=8, 0.5 mg/kg, i.v) substantially attenuated the increases in BOLD activity in response to amphetamine, with lesser effects on the amphetamine-evoked decreases in BOLD signal. In contrast, sulpiride (n=8, 50 mg/kg, i.v) predominantly blocked the decrease in BOLD signal, having a smaller effect on the increases in BOLD signal. In summary, these data are supportive of the notion that different dopamine receptor types are responsible for separate components of the full amphetamine response. Furthermore the utility of BOLD contrast fMRI as a means of characterising the mechanisms of drug action in the whole brain has been demonstrated. Such studies may be of particular use for investigation of localised action and interaction of different dopaminergic agents.

What kind of visual spatial attention is impaired in neglect?

The distribution of spatial attention across the horizontal meridian of the visual field, as assessed by a simple reaction time (RT) paradigm, is dramatically abnormal in neglect patients. In the contralesional hemifield, RT increases sharply from centre to periphery, while in the ipsilesional hemifield, it decreases paradoxically from centre to mid-periphery. In the present study, we firstly asked whether this abnormal distribution of spatial attention is still present when patients know in advance the location of the impending stimulus, and second whether and to which extent it may be influenced by the concomitant presence of hemianopia. In Experiment 1, the stimuli were presented either predictably (blocks of same-point presentations) or unpredictably (blocks of randomised presentations) to one of several contralesional and ipsilesional field locations. As was the case for control subjects, neglect patients showed an overall RT decrease with same-point presentations. However, their abnormal contralesional RT lengthening and ipsilesional speeding were still present. In Experiment 2, the trials were blocked to same-hemifield presentations. In the ipsilesional field condition, neglect patients with and without hemianopia showed the same distorted distribution of attention favouring mid-periphery over central field locations. Two conclusions can be drawn from these experiments: first, the bulk of the abnormal deployment of spatial attention in neglect patients is related to an impairment of exogenous attention which cannot be compensated for by a spared endogenous control. Second, hemianopia does not affect the paradoxical speeding up of RT typically found in the mid-periphery of the ipsilesional field of neglect patients.