Cities are rapidly increasing in importance as a major factor shaping the Earth system, and therefore, must take corresponding responsibility. With currently over half the world’s population, cities are supported by resources originating from primarily rural regions often located around the world far distant from the urban loci of use. The sustainability of a city can no longer be considered in isolation from the sustainability of human and natural resources it uses from proximal or distant regions, or the combined resource use and impacts of cities globally. The world’s multiple and complex environmental and social challenges require interconnected solutions and coordinated governance approaches to planetary stewardship. We suggest that a key component of planetary stewardship is a global system of cities that develop sustainable processes and policies in concert with its non-urban areas. The potential for cities to cooperate as a system and with rural connectivity could increase their capacity to effect change and foster stewardship at the planetary scale and also increase their resource security.

How chromatin folds into mitotic and interphase chromosomes has remained a difficult question for many years. We have used three generations of engineered chromosome regions as a means of visualizing specific chromosome regions in live cells and cells fixed under conditions which preserve large-scale chromatin structure. Our results confirm the existence of large-scale chromatin domains and fibers formed by the folding of 10 and 30 nm chromatin fibers into larger, spatially distinct domains. Transcription at levels within several fold of the levels measured for endogenous loci occur within these large-scale chromatin structures on a condensed template linearly compacted several hundred fold to one thousand fold relative to B-form DNA. However, transcriptional induction is accompanied by a several fold decondensation of this large-scale chromatin structure that propagates hundreds of kb beyond the induced gene. Examination of engineered chromosome regions in mouse ES and differentiated cells suggests a surprising degree of plasticity in this large-scale chromatin structure, allowing long-range DNA interactions within the context of large-scale chromatin fibers. Recapitulation of gene specific differences in large-scale chromatin conformation and nuclear positioning using these engineered chromosome regions will facilitate identification of cis and trans determinants of interphase chromosome architecture.

BACKGROUND

Point-of-care practice audits allow documentation of procedural outcomes to support quality improvement in endoscopic practice.

OBJECTIVE

To evaluate a colonoscopists’ practice audit tool that provides point-of-care data collection and peer-comparator feedback.

METHODS

A prospective, observational colonoscopy practice audit was conducted in academic and community endoscopy units for unselected patients undergoing colonoscopy. Anonymized colonoscopist, patient and practice data were collected using touchscreen smart-phones with automated data upload for data analysis and review by participants. The main outcome measures were the following colonoscopy quality indicators: colonoscope insertion and withdrawal times, bowel preparation quality, sedation, immediate complications and polypectomy, and biopsy rates.

RESULTS

Over a span of 16 months, 62 endoscopists reported on 1279 colonoscopy procedures. The mean cecal intubation rate was 94.9% (10th centile 84.2%). The mean withdrawal time was 8.8 min and, for nonpolypectomy colonoscopies, 41.9% of colonoscopists reported a mean withdrawal time of less than 6 min. Polypectomy was performed in 37% of colonoscopies. Independent predictors of polypectomy included the following: endoscopy unit type, patient age, interval since previous colonoscopy, bowel preparation quality, stable inflammatory bowel disease, previous colon polyps and withdrawal time. Withdrawal times of less than 6 min were associated with lower polyp removal rates (mean difference −11.3% [95% CI −2.8% to −19.9%]; P=0.01).

DISCUSSION

Cecal intubation rates exceeded 90% and polypectomy rates exceeded 30%, but withdrawal times were frequently shorter than recommended. There are marked practice variations consistent with previous observations.

CONCLUSION

Real-time, point-of-care practice audits with prompt, confidential access to outcome data provide a basis for targeted educational programs to improve quality in colonoscopy practice.

BACKGROUND:

The cost-effectiveness of initial strategies in managing Canadian patients with uninvestigated upper gastrointestinal symptoms remains controversial.

OBJECTIVE:

To assess the cost-effectiveness of six management approaches to uninvestigated upper gastrointestinal symptoms in the Canadian setting.

METHODS:

The present study analyzed data from four randomized trials assessing homogeneous and complementary populations of Canadian patients with uninvestigated upper gastrointestinal symptoms with comparable outcomes. Symptom-free months, quality-adjusted life-years (QALYs) and direct costs in Canadian dollars of two management approaches based on the Canadian Dyspepsia Working Group (CanDys) Clinical Management Tool, and four additional strategies (two empirical antisecretory agents, and two prompt endoscopy) were examined and compared. Prevalence data, probabilities, utilities and costs were included in a Markov model, while sensitivity analysis used Monte Carlo simulations. Incremental cost-effectiveness ratios and cost-effectiveness acceptability curves were determined.

RESULTS:

Empirical omeprazole cost $226 per QALY ($49 per symptom-free month) per patient. CanDys omeprazole and endoscopy approaches were more effective than empirical omeprazole, but more costly. Alternatives using H2-receptor antagonists were less effective than those using a proton pump inhibitor. No significant differences were found for most incremental cost-effectiveness ratios. As willingness to pay (WTP) thresholds rose from $226 to $24,000 per QALY, empirical antisecretory approaches were less likely to be the most cost-effective choice, with CanDys omeprazole progressively becoming a more likely option. For WTP values ranging from $24,000 to $70,000 per QALY, the most clinically relevant range, CanDys omeprazole was the most cost-effective strategy (32% to 46% of the time), with prompt endoscopy-proton pump inhibitor favoured at higher WTP values.

CONCLUSIONS:

Although no strategy was the indisputable cost-effective option, CanDys omeprazole may be the strategy of choice over a clinically relevant range of WTP assumptions in the initial management of Canadian patients with uninvestigated dyspepsia.

Folding of gene loci organized in tandem arrays reveals variation of chromatin structure as a function of cell differentiation.

Interphase chromatin compaction well above the 30-nm fiber is well documented, but the structural motifs underlying this level of chromatin folding remain unknown. Taking a reductionist approach, we analyzed in mouse embryonic stem (ES) cells and ES-derived fibroblasts and erythroblasts the folding of 10–160-megabase pair engineered chromosome regions consisting of tandem repeats of bacterial artificial chromosomes (BACs) containing ∼200 kilobases of mammalian genomic DNA tagged with lac operator (LacO) arrays. Unexpectedly, linear mitotic and interphase chromatid regions formed from noncontiguously folded DNA topologies. Particularly, in ES cells, these model chromosome regions self-organized with distant sequences segregating into functionally distinct, compact domains. Transcriptionally active and histone H3K27me3-modified regions positioned toward the engineered chromosome subterritory exterior, with LacO repeats and the BAC vector backbone localizing within an H3K9me3, HP1-enriched core. Differential compaction of Dhfr and α- and β-globin transgenes was superimposed on dramatic, lineage-specific reorganization of large-scale chromatin folding, demonstrating a surprising plasticity of large-scale chromatin organization.

BACKGROUND:

Assessment of current wait times for specialist health services in Canada is a key method that can assist government and health care providers to plan wisely for future health needs. These data are not readily available. A method to capture wait time data at the time of consultation or procedure has been developed, which should be applicable to other specialist groups and also allows for assessment of wait time trends over intervals of years.

METHODS:

In November 2008, gastroenterologists across Canada were asked to complete a questionnaire (online or by fax) that included personal demographics and data from one week on at least five consecutive new consultations and five consecutive procedure patients who had not previously undergone a procedure for the same indication. Wait times were collected for 18 primary indications and results were then compared with similar survey data collected in 2005.

RESULTS:

The longest wait times observed were for screening colonoscopy (201 days) and surveillance of previous colon cancer or polyps (272 days). The shortest wait times were for cancer-likely based on imaging or physical examination (82 days), severe or rapidly progressing dysphagia or odynophagia (83 days), documented iron-deficiency anemia (90 days) and dyspepsia with alarm symptoms (99 days). Compared with 2005 data, total wait times in 2008 were lengthened overall (127 days versus 155 days; P<0.05) and for most of the seven individual indications that permitted data comparison.

CONCLUSION:

Median wait times for gastroenterology services continue to exceed consensus conference recommended targets and have significantly worsened since 2005.

Objective

To determine whether a “test for Helicobacter pylori and treat” strategy improves symptoms in patients with uninvestigated dyspepsia in primary care.

Design

Randomised placebo controlled trial.

Setting

36 family practices in Canada.

Participants

294 patients positive for H pylori (13C- urea breath test) with symptoms of dyspepsia of at least moderate severity in the preceding month.

Intervention

Participants were randomised to twice daily treatment for 7 days with omeprazole 20 mg, metronidazole 500 mg, and clarithromycin 250 mg or omeprazole 20 mg, placebo metronidazole, and placebo clarithromycin. Patients were then managed by their family physicians according to their usual care.

Main outcome measures

Treatment success defined as no symptoms or minimal symptoms of dyspepsia at the end of one year. Societal healthcare costs collected prospectively for a secondary evaluation of actual mean costs.

Results

In the intention to treat population (n=294), eradication treatment was significantly more effective than placebo in achieving treatment success (50% v 36%; P=0.02; absolute risk reduction=14%; number needed to treat=7, 95% confidence interval 4 to 63). Eradication treatment cured H pylori infection in 80% of evaluable patients. Treatment success at one year was greater in patients negative for H pylori than in those positive for H pylori (54% v 39%; P=0.02). Eradication treatment reduced mean annual cost by $C53 (−86 to 180) per patient.

Conclusions

A “test for H pylori with 13C-urea breath test and eradicate” strategy shows significant symptomatic benefit at 12 months in the management of primary care patients with uninvestigated dyspepsia.

What is already known on this topicDyspepsia is a common problem in primary health care, although controversy exists about its definitionStudies of H pylori eradication in patients with uninvestigated dyspepsia have shown reduced need for endoscopy and thus significant cost savings compared with a strategy of prompt endoscopyThe “test for H pylori and treat” strategy has been recommended for uninvestigated dyspepsia, but there have been no randomised controlled trials showing improvement in symptomsWhat this study addsWhen given eradication treatment in primary care, H pylori positive patients with uninvestigated dyspepsia show improvement in overall dyspepsia symptoms at 12 monthsThis supports the “test for H pylori and treat” strategy