CO2 hydrogenation to higher hydrocarbons on K/Fe–Al–O spinel catalysts promoted with Si, Ti, Zr, Hf, Mn and Ce

Si and Zr species grafted on Fe–Al–O catalysts act as an inhibitor and promoter, respectively, in CO₂ hydrogenation.

Continuous renal replacement therapy for haemodynamic collapse and rhabdomyolysis induced by pheochromocytoma crisis

Pheochromocytoma associated with pregnancy is not common. Caesarean section may induce pheochromocytoma crisis, resulting in a lethal condition. The clinical picture of pheochromocytoma crisis is extremely variable. In this report, we describe a case of severe pheochromocytoma crisis induced by caesarean section presenting with hyperpyrexia, haemodynamic collapse, muscle weakness, heart failure, and acute kidney injury. Furthermore, we report that the muscle weakness was a manifestation of rhabdomyolysis, resulting from the pheochromocytoma crisis. Standard medical therapy failed to halt the patient's rapidly deteriorating condition. Continuous renal replacement therapy removed catecholamines from the circulation, resulting in improvement of haemodynamics and abrogation of rhabdomyolysis.

Bone marrow cells for heart repair: clinical evidence and perspectives

More than 15 years ago, bone marrow cell (BMC) therapy for cardiac repair was hailed as a highly promising and revolutionary treatment approach that was poised to benefit countless patients with ischemic heart disease (IHD) and heart failure. The ensuing years have unfortunately witnessed endless controversy not only about the mechanisms of action of cardiac repair with cell therapy, but also regarding the efficacy of such approach. Somewhat discordant results from smaller clinical trials with diverse study designs, BMC types, routes of injection, timing after myocardial infarction (MI), and other key study variables have been less than conclusive. Because of this uncertainty regarding outcomes of BMC therapy, a large number of meta-analyses have been performed, also with dissimilar findings. Although the field continues to evolve with emergence of data from newer and larger clinical trials with more stringent design, the overall evidence does support efficacy of BMC injection in patients with IHD with regard to improvement in cardiac parameters as well as patient outcomes. Given the limitless potential of adult stem cell therapy in general, at this juncture, a careful appraisal of the cumulative evidence is critically necessary to appreciate the true impact of BMC therapy on injured heart. This review will discuss the clinical evidence and perspectives from trials and meta-analyses of BMC therapy in patients with IHD that have accumulated in published literature.

A feasibility study of educational tools for osteomalacia

Many people in the UK, particularly people of South Asian origin, are advised to supplement their vitamin D intake, yet most do not. This suggests an unmet educational need. The osteomalacia mind map was developed to meet this need. The mind map contains culturally sensitive images, translated into Urdu and made interactive on a DVD. This study explores the feasibility of a randomised controlled study to measure the effect of education on improving vitamin D knowledge and adherence. This was a pilot and feasibility study. Cluster randomisation was used to avoid inter person contamination. Two South Asian women's groups were recruited to receive information about osteomalacia either by interactive DVD or an Arthritis Research UK leaflet. Knowledge and compliance were tested before and after the educational interventions via a knowledge questionnaire and the measurement of vitamin D and parathormone levels. The groups were found to be mismatched for knowledge, educational attainment and language at baseline. There were also organisational difficulties and possible confounding due to different tutors and translators. The DVD group had high knowledge at baseline which did not improve. The leaflet group had low knowledge at baseline that did improve. The DVD group had lower parathormone which did not change. The leaflet group had an increase in vitamin D but parathormone remained high. Performing a randomised study with this population utilising an educational intervention was difficult to execute. If cluster randomisation is used, extreme care must be taken to match the groups at baseline.

Deletion of Interleukin-6 Attenuates Pressure Overload-Induced Left Ventricular Hypertrophy and Dysfunction

RATIONALE

The role of interleukin (IL)-6 in the pathogenesis of cardiac myocyte hypertrophy remains controversial.

OBJECTIVE

To conclusively determine whether IL-6 signaling is essential for the development of pressure overload-induced left ventricular (LV) hypertrophy and to elucidate the underlying molecular pathways.

METHODS AND RESULTS

Wild-type and IL-6 knockout (IL-6(-/-)) mice underwent sham surgery or transverse aortic constriction (TAC) to induce pressure overload. Serial echocardiograms and terminal hemodynamic studies revealed attenuated LV hypertrophy and superior preservation of LV function in IL-6(-/-) mice after TAC. The extents of LV remodeling, fibrosis, and apoptosis were reduced in IL-6(-/-) hearts after TAC. Transcriptional and protein assays of myocardial tissue identified Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and signal transducer and activator of transcription 3 (STAT3) activation as important underlying mechanisms during cardiac hypertrophy induced by TAC. The involvement of these pathways in myocyte hypertrophy was verified in isolated cardiac myocytes from wild-type and IL-6(-/-) mice exposed to prohypertrophy agents. Furthermore, overexpression of CaMKII in H9c2 cells increased STAT3 phosphorylation, and exposure of H9c2 cells to IL-6 resulted in STAT3 activation that was attenuated by CaMKII inhibition. Together, these results identify the importance of CaMKII-dependent activation of STAT3 during cardiac myocyte hypertrophy via IL-6 signaling.

CONCLUSIONS

Genetic deletion of IL-6 attenuates TAC-induced LV hypertrophy and dysfunction, indicating a critical role played by IL-6 in the pathogenesis of LV hypertrophy in response to pressure overload. CaMKII plays an important role in IL-6-induced STAT3 activation and consequent cardiac myocyte hypertrophy. These findings may have significant therapeutic implications for LV hypertrophy and failure in patients with hypertension.

Functionalised type-I collagen as a hydrogel building block for bio-orthogonal tissue engineering applications

Modulating the hydrogel properties from injectable to implantable scaffolds using the bio-orthogonal thiol-Michael addition click reaction.

Adult Bone Marrow Cell Therapy for Ischemic Heart Disease: Evidence and Insights From Randomized Controlled Trials

RATIONALE

Notwithstanding the uncertainties about the outcomes of bone marrow cell (BMC) therapy for heart repair, further insights are critically needed to improve this promising approach.

OBJECTIVE

To delineate the true effect of BMC therapy for cardiac repair and gain insights for future trials through systematic review and meta-analysis of data from eligible randomized controlled trials.

METHODS AND RESULTS

Database searches through August 2014 identified 48 eligible randomized controlled trials (enrolling 2602 patients). Weighted mean differences for changes in left ventricular (LV) ejection fraction, infarct size, LV end-systolic volume, and LV end-diastolic volume were analyzed with random-effects meta-analysis. Compared with standard therapy, BMC transplantation improved LV ejection fraction (2.92%; 95% confidence interval, 1.91-3.92; P<0.00001), reduced infarct size (-2.25%; 95% confidence interval, -3.55 to -0.95; P=0.0007) and LV end-systolic volume (-6.37 mL; 95% confidence interval, -8.95 to -3.80; P<0.00001), and tended to reduce LV end-diastolic volume (-2.26 mL; 95% confidence interval, -4.59 to 0.07; P=0.06). Similar effects were noted when data were analyzed after excluding studies with discrepancies in reporting of outcomes. The benefits also persisted when cardiac catheterization was performed in control patients as well. Although imaging modalities partly influenced the outcomes, LV ejection fraction improved in BMC-treated patients when assessed by magnetic resonance imaging. Early (<48 hours) BMC injection after myocardial Infarction was more effective in reducing infarct size, whereas BMC injection between 3 and 10 days proved superior toward improving systolic function. A minimum of 50 million BMCs seemed to be necessary, with limited additional benefits seen with increasing cell numbers. BMC therapy was safe and improved clinical outcomes, including all-cause mortality, recurrent myocardial Infarction, ventricular arrhythmia, and cerebrovascular accident during follow-up, albeit with differences between acute myocardial Infarction and chronic ischemic heart disease subgroups.

CONCLUSIONS

Transplantation of adult BMCs improves LV ejection fraction, reduces infarct size, and ameliorates remodeling in patients with ischemic heart disease. These effects are upheld in the analyses of studies using magnetic resonance imaging and also after excluding studies with discrepant reporting of outcomes. BMC transplantation may also reduce the incidence of death, recurrent myocardial Infarction, ventricular arrhythmia, and cerebrovascular accident during follow-up.

Use of contact force sensing technology during radiofrequency ablation reduces recurrence of atrial fibrillation: A systematic review and meta-analysis

The suboptimal outcomes of atrial fibrillation (AF) ablation have been attributed to lack of transmural lesions during pulmonary vein isolation. The advent of contact force (CF) sensing technology enables real-time assessment of the applied force at the catheter-tissue interface and increases the chances of transmural lesions. We sought to perform a meta-analysis of data from eligible studies to delineate the true impact of CF technology. Database searches through April 2015 identified 9 eligible studies (enrolling 1148 patients). The relative risk of AF recurrence at follow-up was used as the primary end point and assessed with random-effects meta-analysis. Radiofrequency (RF) duration, total procedure length, and fluoroscopy exposure were assessed as secondary outcomes using weighted mean difference with the random-effects model. Compared with standard technology, the use of CF technology showed a 37% reduction (relative risk 0.63; 95% confidence interval 0.44-0.91; P = .01) in AF recurrence at a median follow-up of 12 months and a 7.3-minute reduction (95% confidence interval -14.05 to -0.55; P = .03) in RF use during ablation. There was no significant difference in total procedure length and fluoroscopy exposure between the 2 groups. In conclusion, this meta-analysis shows that the use of CF technology decreases AF recurrence at a median follow-up of 12 months and also led to decreased use of RF during ablation. There was no difference in total procedure length and fluoroscopy exposure.