Distensibility of the esophagogastric junction assessed with the functional lumen imaging probe (FLIP™) in achalasia patients

BACKGROUND

The functional lumen imaging probe (FLIP), measures esophagogastric junction (EGJ) distensibility (cross-sectional area/luminal pressure) during volume-controlled distension. The aim of this study is to apply this tool to the assessment of the EGJ in untreated and treated achalasia patients and to compare EGJ distensibility with other diagnostic tools utilized in managing achalasia.

METHODS

Findings from FLIP, high-resolution manometry (HRM), timed barium esophagram, and symptom assessment by Eckardt Score (ES) were compared in 54 achalasia patients (23 untreated, 31 treated). Twenty healthy volunteers underwent FLIP as a comparator group. The EGJ distensibility index (EGJ-DI) was defined at the 'waist' of the FLIP bag during volumetric distension, expressed in mm(2)  mmHg(-1) . The ES was used to gauge treatment outcome: good response < 3 or poor response ≥ 3.

KEY RESULTS

Of the 31 treated patients, 17 had good and 14 poor treatment response. The EGJ-DI was significantly different among groups, greatest in the control subjects and least in the untreated patients; patients with good treatment response had significantly greater EGJ-DI than untreated or patients with poor response. The correlations between EGJ-DI and ES and integrated relaxation pressure on HRM were significant.

CONCLUSIONS & INFERENCES

The FLIP provided a useful measure of EGJ distensibility in achalasia patients that correlated with symptom severity. The measurement of EGJ distensibility was complementary to existing tests suggesting a potentially important role in the clinical management of achalasia.

Debunking health IT usability myths

Poor usability is a threat to patient safety and linked to productivity loss, workflow disruption, user frustration, sub-optimal product use and system de-installations. Although usability is receiving more attention nationally and internationally, myths about usability persist. This editorial debunks five common myths about usability (1) usability only concerns the look and feel of a product and is, therefore, only a minor concern, (2) usability is not measurable, (3) usability stifles innovation, (4) vendors are solely responsible for product usability, and (5) usability methods are not practical for use in healthcare.

Abstract 84: Thirty-day Mortality of Patients with ST-Elevation Myocardial Infarction (STEMI) According to Hospital Reperfusion Strategy: The Importance of Examining Outcomes of Both Treated and Not Treated Patients

BACKGROUND: In Quebec (Canada), patients with STEMI present to 1 of 4 types of hospitals: 1) primary percutaneous coronary intervention (PPCI) centers; 2) non-PPCI centers that systematically transfer patients for PPCI; 3) ‘mixed centers’ that transfer some patients for PPCI and treat others with fibrinolysis; and 4) centers that exclusively treat with fibrinolysis. In all centers, substantial proportions of STEMI patients do not receive any reperfusion therapy for a variety of reasons. Overall STEMI outcomes may vary by type of reperfusion strategy and who is selected to receive it.

METHODS: All acute care centers that annually treated ≥ 30 acute myocardial infarctions participated in 2 field evaluations (n=80 in 2006-7; n=81 in 2008-9). All patients had a final diagnosis of myocardial infarction, characteristic symptoms and STEMI confirmed by centralized ECG interpretation. Clinical factors and comorbidities were compared across type of center for all patients, and by reperfusion therapy status. Odds ratios (OR) of 30-day mortality were estimated separately for treated, untreated and all STEMI patients.

RESULTS: Of the 3731 STEMI patients, 29.7% presented to PPCI-capable centers, 33.0% to exclusive PPCI transfer centers, 26.7% to mixed centers (66% transferred for PPCI, 34% received fibrinolysis) and 10.6% to exclusive fibrinolysis centers. The proportion of untreated patients increased with decreasing PPCI access: 16.7% in PPCI centers, 21.4% in transfer PPCI centers, 24.9% in mixed centers and 29.8 % in fibrinolysis centers. Mixed center patients transferred for PPCI had the longest treatment delays (only 17% within guidelines). For treated patients, there were no significant differences in adjusted OR across type of center (see Table). However, for untreated patients, risk of death was significantly higher in transfer PPCI and mixed centers compared to PPCI centers. Risk was significantly higher in mixed centers for all STEMI patients combined.

CONCLUSION: These findings suggest that in centers that transfer for PPCI, treatment selection bias may mask important disparities in STEMI outcomes, especially in centers with long transfer delays. When evaluating hospital outcomes for STEMI, it is important to examine not only those who are treated but also patients who do not receive reperfusion therapy.

Abstract 175: Evaluation of 30-day Mortality in Patients With ST-Elevation Myocardial Infarction (STEMI) Across All Hospital Centers Performing Primary Percutaneous Coronary Intervention (PPCI) in Quebec, Canada

BACKGROUND: PPCI is the predominant reperfusion treatment for STEMI in Quebec, Canada. Our systematic field evaluation, during a 6-month period in 2008-9, provided the opportunity to compare patient characteristics, processes of care and 30-day mortality across Quebec’s 13 PPCI centers.

METHODS: All STEMI patients, who either presented directly or were transferred to one of these 13 PPCI centers, were included in the analyses. Patients transferred after fibrinolytic treatment were excluded. Since patient outcomes within the same hospital may be correlated, generalized estimating equation (GEE) models were used to compare 30-day mortality across centers, adjusting for patient-level risk factors (sex, TIMI index, anterior myocardial infarction, history of heart failure/shock) and for hospital-level characteristics.

RESULTS: The majority of patients treated in the 13 PPCI centers were transferred for PPCI from non-tertiary centers (n=785, 62%), and these patients were unlikely to receive timely treatment (i.e., only 26% with first door-to-device time ≤90 min). Of the remaining 490 (38%) patients who presented directly to a PPCI center, 70% had timely treatment. Across the 13 PPCI centers, crude 30-day mortality varied widely (1.5% - 16.3%) and variation persisted after adjustment for patient risk factors (2.1% - 11.2%). STEMI volume per PPCI center and the presence of cardiac surgery on-site were not associated with 30-day mortality. In the final GEE model containing all patient factors considered and 3 hospital-level factors (proportion of patients treated with a radial approach, proportion of patients transferred for PPCI, proportion of patients with timely PPCI), the odds ratio for death decreased by 18% for every 20% increase in the proportion of patients treated with a radial approach, and decreased by 25% for every 20% increase in the proportion of patients with timely PPCI. Conversely, the odds ratio increased by 28% for every 20% increase in the proportion of transferred patients.

CONCLUSION: Thirty-day STEMI mortality can vary substantially across PPCI centers within a complete system of care. Our findings suggest that 30-day STEMI mortality could be reduced if PPCI centers discouraged transfers with expected untimely delays.

Abstract 82: Comparison of Outcomes by Type of Treatment for Patients with ST-Elevation Myocardial Infarction (STEMI) who presented to Hospitals without Percutaneous Coronary Intervention (PCI) Facilities in Quebec, Canada

BACKGROUND: Guidelines recommend that STEMI patients who present to non-PCI centers generally be treated with fibrinolysis instead of untimely transfer for primary PCI (i.e., first medical contact [FMC] to device ≥120 min). Little real-world evidence exists for this recommendation since transfer patients are often excluded from clinical registries. A provincial field evaluation of the whole system of STEMI care in Quebec (Canada) provided the opportunity to compare the effectiveness of different treatment modalities, including, importantly, inter-hospital transfer for primary PCI.

METHODS: All STEMI patients who presented to non-PCI hospitals during two 6-month periods in 2006-7 and 2008-9 were identified (N=2623) and followed up to one year. Detailed information on patient risk factors and treatment delays was extracted from medical charts. We used a multivariate Cox proportional hazards model with time-dependent treatment modelling to assess the hazard ratio of death for 5 treatment modalities: on-site fibrinolysis without later transfer to a PCI center; on-site fibrinolysis with subsequent transfer; timely transfer for primary PCI; untimely transfer for primary PCI; no reperfusion therapy.

RESULTS: Median FMC-to-device delay for transfer primary PCI patients was 131 min (interquartile range, IQR: 107-166) and only 29% had timely treatment. Median door-to-needle delay was 30 min (IQR: 20-48) with 70% being transferred, after fibrinolysis, to a PCI center (81% subsequently received PCI). Median time to transfer after fibrinolysis was 17.8 hours (IQR: 3.3-77.3). Compared with untimely transfer for primary PCI, the adjusted hazard ratio was 0.29 (95% CI: 0.15-0.56) for timely primary PCI transfer, 0.52 (95% CI: 0.29-0.95) for fibrinolysis with subsequent transfer, 1.18 (95% CI: 0.75-1.84) for fibrinolysis alone and 1.74 (95% CI: 1.31-2.31) for no reperfusion therapy.

CONCLUSION: Timely treatment delay is associated with improved STEMI survival. These results also provide real-world evidence to support the guideline recommendation to prioritize on-site treatment with fibrinolysis (with consideration of subsequent transfer to a PCI center) over untimely transfer for primary PCI. Transfer to a PCI center after fibrinolysis mostly occurred the following day, suggesting that transfer need not necessarily be immediate.

Inhibition of 12/15-lipoxygenase by baicalein induces microglia PPARβ/δ: a potential therapeutic role for CNS autoimmune disease

12/15-Lipoxygenase (12/15-LO) is an enzyme that converts polyunsaturated fatty acids into bioactive lipid derivatives. In this study, we showed that inhibition of 12/15-LO by baicalein (BA) significantly attenuated clinical severity of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Inhibited migration of autoimmune T cells into the central nervous system (CNS) by BA treatment could be attributed to reduced activation of microglia, which was indicated by suppressed phagocytosis, and decreased production of proinflammatory cytokines and chemokines in the CNS. We further observed that inhibition of 12/15-LO with BA led to increased expression of peroxisome proliferator-activated receptor (PPAR)β/δ in microglia of EAE mice. This was confirmed in vitro in primary microglia and a microglia cell line, BV2. In addition, we demonstrated that BA did not affect 12/15-LO or 5-lipoxygenase (5-LO) expression in microglia, but significantly decreased 12/15-LO products without influencing the levels of 5-LO metabolites. Moreover, among these compounds only 12/15-LO metabolite 12-hydroxyeicosatetraenoic acid was able to reverse BA-mediated upregulation of PPARβ/δ in BV2 cells. We also showed that inhibition of microglia activation by PPARβ/δ was associated with repressed NF-κB and MAPK activities. Our findings indicate that inhibition of 12/15-LO induces PPARβ/δ, demonstrating important regulatory properties of 12/15-LO in CNS inflammation. This reveals potential therapeutic applications for MS.

miR-200b inhibits TGF-β1-induced epithelial-mesenchymal transition and promotes growth of intestinal epithelial cells

Inflammatory bowel disease (IBD), which consists of Crohn's disease (CD) and ulcerative colitis (UC), is a chronic, inflammatory disorder of the gastro-intestinal tract with unknown etiology. Current evidence suggests that intestinal epithelial cells (IECs) is prominently linked to the pathogenesis of IBD. Therefore, maintaining the intact of epithelium has potential roles in improving pathophysiology and clinical outcomes of IBD. MicroRNAs (miRNAs) act as post-transcriptional gene regulators and regulate many biological processes, including embryonal development, cell differentiation, apoptosis and proliferation. In this study, we found that miR-200b decreased significantly in inflamed mucosa of IBD, especially for UC, when compared with their adjacent normal tissue. Simultaneously, we also found that the genes of E-cadherin and cyclin D1 were reduced significantly and correlated positively to the miR-200b. In addition, the upregulation of transforming growth factor-beta 1 (TGF-β1) was inversely correlated to the miR-200b in IBD. To investigate the possible roles of miR-200b in IECs maintaining, we used TGF-β1 to induce epithelial-mesenchymal transition (EMT) in IEC-6 initially. After sustained over-expressing miR-200b in IEC-6, the EMT was inhibited significantly that was characterized by downregulation of vimentin and upregulation of E-cadherin. Furthermore, we found that miR-200b enhanced E-cadherin expression through targeting of ZEB1, which encode transcriptional repressors of E-cadherin. SMAD2 was found to act as a target of miR-200b with direct evidence that miR-200b binding to the 3′ UTR of SAMD2 and the ability of miR-200b to repress SMAD2 protein expression. With SMAD2 depletion, the expression of vimentin decreased correspondingly, which suggested miR-200b might reduce vimentin through regulating the SMAD2. With endogenous over-expression of miR-200b, the proliferation of IEC-6 cells increased significantly by increasing S-phase entry and promoting expression of the protein cyclin D1. Summarily, our study suggested a potential role for mir-200b in maintaining intact of intestinal epithelium through inhibiting EMT and promoting proliferation of IECs.

Characterization of the major histocompatibility complex class I A alleles in cynomolgus macaques of Vietnamese origin

Cynomolgus macaques (Macaca fascicularis, Mafa) have emerged as an important animal model for infectious disease and transplantation research. Extensive characterization of their major histocompatibility complex (MHC) polymorphism regions therefore becomes urgently required. In this study, we identified 41 MHC class I A nucleotide sequences in 34 unrelated cynomolgus macaques of Vietnamese origin farmed in Southern China, including eight novel Mafa-A sequences. We found two sequences with perfect identity and six sequences with close similarity to previously defined MHC class I alleles from other populations, especially from Indonesian-origin macaques. We also found three Vietnamese-origin cynomolgus macaque MHC class I sequences for which the predicted protein sequences identical throughout their B and F binding pockets to Mamu-A1*001:01 and Mamu-A3*13:03, respectively. This is important because Mamu-A1*001:01 and Mamu-A3*13:03 are associated with longer survival and lower set-point viral load in simian immunodeficiency virus (SIV)-infected rhesus monkeys. These findings have implications for the evolutionary history of Vietnamese-origin cynomolgus macaque as well as for the use of this model in SIV/SHIV (a virus combining parts of the HIV and SIV genomes) research.

Delayed administration of a PTEN inhibitor BPV improves functional recovery after experimental stroke

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) inhibitors administered prior to or immediately after experimental stroke confer acute neuroprotection. However, it remains unclear if delayed treatment with a PTEN inhibitor improves long-term functional recovery after stroke. We addressed the issue in this study. Adult male mice were subjected to 1h of middle cerebral artery occlusion (MCAO) followed by treatment with a well-established PTEN inhibitor BPV or saline daily for 14 days, starting at 24h after MCAO. Functional recovery was assessed with behavioral tests and acute infarct volumes were analyzed histologically. Delayed BPV treatment did not reduce infarction during the acute phase, but significantly improved long-term functional recovery after MCAO. Since PTEN is a critical intrinsic inhibitory factor in axonal regeneration, we further examined BPV effects on axonal densities following MCAO using bielschowsky silver staining and immunohistochemistry with antibodies against myelin basic protein. Delayed BPV treatment significantly increased axon densities in the ischemic brain at 14 days after MCAO. Moreover, PTEN expression persistently remained high in the ischemic brain over 14 days after MCAO, and BPV treatment increased post-ischemic activation of Akt and mTOR in the ischemic brain. Akt and mTOR activation are the well-established cascades downstream to PTEN inhibition and have been shown to contribute to post-injury axonal regrowth in response to PTEN inhibition. Consistently, in an in vitro neuronal ischemia model, BPV enhanced axonal outgrowth of primary cortical neurons after oxygen-glucose deprivation and the enhancing effects were abolished by Akt/mTOR inhibition. In conclusion, delayed BPV treatment improved functional recovery from experimental stroke possibly via enhancing axonal growth and Akt/mTOR activation contributed to BPV-enhanced post-stroke axon growth.

Transcatheter aortic valve implantation: recommendations for practice based on a multidisciplinary review including cost-effectiveness and ethical and organizational issues

Transcatheter aortic valve implantation (TAVI) is a relatively new technology for the treatment of severe and symptomatic aortic valve stenosis. TAVI offers an alternative therapy for patients unable to be treated surgically because of contraindications or severe comorbidities. It is being rapidly dispersed in Canada, as it is worldwide. The objective of this article is to present our recommendations for the use of TAVI, based on a multidisciplinary evaluation of recently published evidence. We systematically searched and summarized published data (2008-2011) on benefits, risks, and cost-effectiveness of TAVI. We also examined ethical issues and organizational aspects of delivering the intervention. We discussed the soundness and applicability of our recommendations with clinical experts active in the field. The published TAVI results for high-risk and/or inoperable patients are promising in terms of survival, function, quality of life, and cost-effectiveness, although we noted large variability in the survival rates at 1 year and in the frequency of important adverse outcomes such as stroke. Until more data from randomized controlled trials and registries become available, prudence and discernment are necessary in the choice of patients most likely to benefit. Patients need to be well-informed about gaps in the evidence base. Our recommendations support the use of TAVI in the context of strict conditions with respect to patient eligibility, the patient selection process, organizational requirements, and the tracking of patient outcomes with a mandatory registry.

Icariin: a potential promoting compound for cartilage tissue engineering

OBJECTIVE

To investigate whether icariin, which is a widely used pharmacological constituent in traditional Chinese herbal medicine, can be a potential promoting compound for cartilage tissue engineering.

DESIGN

Icariin was added into cell-hydrogel constructs derived from neonatal rabbit chondrocytes and collagen type I. The chondrogenic gene expressions and the synthesis of cartilage matrix of the seeded cells were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Biochemical assay. The effects of icariin-added cell-hydrogel constructs on the restoration of supercritical-sized osteochondral defects of adult rabbit were investigated by histological observation. The cell-hydrogel constructs without Icariin were set for controls.

RESULTS

Icariin obviously up-regulate the expressions included aggrecan, sox9, and collagen type II of seeded chondrocytes from 99.7% to 248%. It increases the synthesis of glycosaminoglycan and collagen type II about fourfold to fivefolds from week 1 to week 4, and accelerates the formation of chondroid tissue in the cell-hydrogel constructs. Even, it improves the restoration efficiency of supercritical-sized osteochondral defects in adult rabbit model, and enhances the integration of new-formed cartilage with subchondral bone.

CONCLUSIONS

Icariin can be a potential promoting compound for cartilage tissue engineering, and it can be a substitute for the use of some growth factors. The long history and extensive cases of safe use in China, Japan and Korea make it more attractive.