ELN and FBN2 gene variants as risk factors for two sports-related musculoskeletal injuries

The proteins ELN and FBN2 are important in extracellular matrix function. The ELN rs2071307 and FBN2 rs331079 gene variants have been associated with soft tissue pathologies. We aimed to determine whether these variants were predisposing factors for both Achilles tendinopathy (AT) and anterior cruciate ligament (ACL) ruptures. For the AT study, 135 cases (TEN group) and 239 asymptomatic controls were recruited. For the ACL rupture study our cohort consisted of 141 cases (ACL group) and 219 controls. Samples were genotyped for both the ELN rs2071307 and FBN2 rs331079 variants using TaqMan assays. Analysis of variance and chi-squared tests were used to determine whether either variant was associated with AT or ACL rupture with significance set at p<0.05. The GG genotype of the FBN2 variant was significantly over-represented within the TEN group (p=0.035; OR=1.83; 95% CI 1.04-3.25) compared to the CON group. We also found that the frequency of the G allele was significantly different between the TEN (p=0.017; OR=1.90; 95% CI 1.11-3.27) and ACL groups (p=0.047; OR=1.76; 95% CI 1.00-3.10) compared to controls. The ELN rs207137 variant was not associated with either AT or ACL rupture. In conclusion, DNA sequence variation within the FBN2 gene is associated with both AT and ACL rupture.

Endothelial progenitor cell mobilization by preoperative exercise: a bone marrow response associated with postoperative outcome

BACKGROUND

Preoperative anaemia is associated with increased morbidity in patients undergoing major surgery. Whether erythrocytes are the only bone-marrow-derived cell lineage that associates with increased surgical complications is unknown. This prospective observational trial studied the mobilization of endothelial progenitor cells (EPCs) in response to exercise in association with postoperative complications.

METHODS

After IRB approval, 60 subjects undergoing major thoracic surgery were exercised to exhaustion (peak V̇(O₂)). Peripheral blood collected before and after peak exercise was quantified for EPC lineages by fluorescence-activated cell sorter analysis. Complication analysis was based on the Clavien-Dindo classification.

RESULTS

Exhaustive exercise increased EPC [CD45-133+34+ cells=150 (0.00-5230) to 220 (0.00-1270) cells μl(-1); median change (range)=20 (-4,180-860) cells μl(-1); P=0.03] but not mature endothelial cell (EC) subpopulations. Pre-exercise levels [odds ratio (OR)=0.86, 95% confidence interval (CI): 0.37-2.00, P=0.72), change after exercise as a continuous variable (OR=0.95, 95% CI: 0.41-2.22, P=0.91) and a positive response after exercise (change >0 cells μl(-1); OR=0.41, 95% CI: 0.13-1.28, P=0.12) were not statistically significantly associated with the incidence of postoperative complications. Post-hoc receiver operating characteristic curve analyses revealed that subjects with a CD45-133+34+ increase ≥60 cells μl(-1) in response to exercise suffered fewer postoperative complications [86% sensitivity, 48% specificity and AUC=0.67 (95% CI: 0.52-0.81)].

CONCLUSIONS

Preoperative exercise induces EPC into the peripheral circulation. Subjects with a poor EPC response had a pre-existing propensity for postoperative complications. This warrants further research into the role of bone marrow function as a critical component to endothelial repair mechanisms.

CLINICAL TRIAL REGISTRATION

IRB 2003-0434 (University of Texas M.D. Anderson Cancer Center, Houston, TX, USA).

Assessment of predictors of response and long-term survival of patients with neuroendocrine tumour treated with peptide receptor chemoradionuclide therapy (PRCRT)

PURPOSE

To review the response and outcomes of (177)Lu-DOTA-octreotate chemoradionuclide therapy (LuTate PRCRT) in patients with neuroendocrine tumour (NET) expressing high levels of somatostatin receptors with uncontrolled symptoms or disease progression.

METHODS

A total of 68 patients (39 men; 17 - 76 years of age) who had completed an induction course of at least three cycles of LuTate PRCRT between January 2006 and June 2010 were reviewed. Ten patients were treated for uncontrolled symptoms and 58 had disease progression despite conventional treatment. The majority had four induction LuTate cycles (median treatment duration 5 months and cumulative activity 31 GBq), and 63 patients had concomitant 5-FU radiosensitizing infusional chemotherapy. Factors predicting overall survival were assessed using the log-rank test and Cox proportional hazards regression.

RESULTS

Of those treated for uncontrolled symptoms, 70 % received benefit maintained for at least 6 months after treatment. Among patients with progressive disease 68 % showed stabilization or regression on CT, 67 % on molecular imaging and 56 % biochemically up to 12 months after treatment; 32 patients died. Overall survival rates at 2 and 5 year were 72.1 % and 52.1 %, respectively. Median overall survival was not estimable at a median follow-up of 60 months (range 5 - 86 months). Nonpancreatic primary sites, dominant liver metastases, lesion size <5 cm and the use of 5-FU chemotherapy were statistically significantly associated with objective response. A disseminated pattern and a high disease burden (whole-body retention index) were associated with an increased risk of death. Objective biochemical, molecular imaging and CT responses were all associated with longer overall survival.

CONCLUSION

A high proportion of patients with progressive NET or uncontrolled symptoms received therapeutic benefit from LuTate with concomitant 5-FU chemotherapy. The achievement of objective biochemical, molecular or CT responses within 12 months was associated with improved overall survival. Patients with a primary pancreatic site and larger lesions (>5 cm) appeared to have lower objective response rates and may need a more aggressive treatment approach.

The role of tissue plasminogen activator use and systemic hypercoagulability in central line-associated bloodstream infections

BACKGROUND

Central line-associated bloodstream infections (CLABSIs) impact patient outcomes and increase cost of hospitalization. In situ thrombus is known to promote microbial adhesion and colonization and potentially lead to CLABSI. Clinical validation of this theory, adjusting for presence of systemic hypercoagulability, is needed.

METHODS

This study is a retrospective review of all adult and pediatric patients with peripherally inserted central catheter placement over a 4-year period at our tertiary care center. Tissue plasminogen activator (TPA) use was utilized as indicator for line site thrombus. CLABSIs rates were compared in patients with or without TPA use, adjusting for the presence of hypercoagulable conditions, age, and severity of illness.

RESULTS

A total of 3,723 patients with peripherally inserted central catheter lines was evaluated, 40% of whom received TPA. The adjusted odds of developing a CLABSI was 3.59 times greater in those patients who received TPA compared with those who did not (95% confidence interval [CI]: 1.86-6.94). Neither severity of illness (odds ratio [OR], 1.00; 95% CI: 0.51-1.96) nor primary (OR, 3.41; 95% CI: 0.43-26.7) or secondary hypercoagulability (OR, 0.91; 95% CI: 0.44-1.88) were statistically associated with a higher risk of infection.

CONCLUSION

The use of TPA, as a possible indicator in situ thrombus, was associated with a higher risk of developing CLABSI. Neither primary nor secondary hypercoagulability was correlated with risk of developing CLABSI.

Attitudinal barriers to participation in oncology clinical trials: factor analysis and correlates of barriers

Patient participation in cancer clinical trials is low. Little is known about attitudinal barriers to participation, particularly among patients who may be offered a trial during an imminent initial oncology consult. The aims of the present study were to confirm the presence of proposed subscales of a recently developed cancer clinical trial attitudinal barriers measure, describe the most common cancer clinical trials attitudinal barriers, and evaluate socio-demographic, medical and financial factors associated with attitudinal barriers. A total of 1256 patients completed a survey assessing demographic factors, perceived financial burden, prior trial participation and attitudinal barriers to clinical trials participation. Results of a factor analysis did not confirm the presence of the proposed four attitudinal barriers subscale/factors. Rather, a single factor represented the best fit to the data. The most highly-rated barriers were fear of side-effects, worry about health insurance and efficacy concerns. Results suggested that less educated patients, patients with non-metastatic disease, patients with no previous oncology clinical trial participation, and patients reporting greater perceived financial burden from cancer care were associated with higher barriers. These patients may need extra attention in terms of decisional support. Overall, patients with fewer personal resources (education, financial issues) report more attitudinal barriers and should be targeted for additional decisional support.

Exploring areas of consensus and conflict around values underpinning public involvement in health and social care research: a modified Delphi study

OBJECTIVE

There is growing interest in the potential benefits of public involvement (PI) in health and social care research. However, there has been little examination of values underpinning PI or how these values might differ for different groups with an interest in PI in the research process. We aimed to explore areas of consensus and conflict around normative, substantive and process-related values underpinning PI.

DESIGN

Mixed method, three-phase, modified Delphi study, conducted as part of a larger multiphase project.

SETTING

The UK health and social care research community.

PARTICIPANTS

Stakeholders in PI in research, defined as: clinical and non-clinical academics, members of the public, research managers, commissioners and funders; identified via research networks, online searches and a literature review.

RESULTS

We identified high levels of consensus for many normative, substantive and process-related issues. However, there were also areas of conflict in relation to issues of bias and representativeness, and around whether the purpose of PI in health and social care research is to bring about service change or generate new knowledge. There were large differences by group in the percentages endorsing the ethical justification for PI and the argument that PI equalises power imbalances. With regard to practical implementation of PI, research support infrastructures were reported as lacking. Participants reported shortcomings in the uptake and practice of PI. Embedding PI practice and evaluation in research study designs was seen as fundamental to strengthening the evidence base.

CONCLUSIONS

Our findings highlight the extent to which PI is already embedded in research. However, they also highlight a need for 'best practice' standards to assist research teams to understand, implement and evaluate PI. These findings have been used in developing a Public Involvement Impact Assessment Framework (PiiAF), which offers guidance to researchers and members of the public involved in the PI process.

Interleukin 13 and serotonin: linking the immune and endocrine systems in murine models of intestinal inflammation

Objective

Infiltration of activated immune cells and increased cytokine production define the immunophenotype of gastrointestinal (GI) inflammation. In addition, intestinal inflammation is accompanied by alteration in the numbers of serotonin (5-hydroxytryptamine; 5-HT) synthesizing enterochromaffin (EC) cells and in 5-HT amount. It has been established that EC cells express interleukin (IL)-13 receptor, additionally IL-13 has been implicated in the pathogenesis of ulcerative colitis. In this study, we investigated the role of IL-13 mediated 5-HT signaling in pathogenesis of colitis.

Methodology

Colitis was induced in IL-13 deficient (IL-13−/−) and wild-type (WT) mice with dextran sulfate sodium (DSS) and dinitrobenzene sulfonic acid (DNBS), as well as in IL-13−/− mice given recombinant mouse IL-13 (rmIL-13) and 5-hydroxytryptamine (5-HTP), the direct precursor of 5-HT.

Principal Findings and Conclusion

Elevated colonic IL-13 levels were observed in WT mice receiving DSS in comparison to control. IL-13−/− mice administered DSS exhibited significantly reduced severity of colitis compared to WT mice as reflected by macroscopic and histological damage assessments. Following DSS administration, significantly lower pro-inflammatory cytokine production and fewer infiltrating macrophages were observed in IL-13−/− mice compared to WT. The reduced severity of colitis observed in IL-13−/− mice was also accompanied by down-regulation of EC cell numbers and colonic 5-HT content. In addition, increasing colonic 5-HT content by administration of rmIL-13 or 5-HTP exacerbated severity of DSS colitis in IL-13−/− mice. IL-13−/− mice also exhibited reduced severity of DNBS-induced colitis. These results demonstrate that IL-13 plays a critical role in the pathogenesis of experimental colitis and 5-HT is an important mediator of IL-13 driven intestinal inflammation. This study revealed important information on immune-endocrine axis in gut in relation to inflammation which may ultimately lead to better strategy in managing various intestinal inflammatory conditions including inflammatory bowel disease.

New experimental evidence for in-chain amino acid racemization of serine in a model peptide

The facile racemization of protein-bound amino acids plays an important role in the aging and pathologies of living tissues, and it can be exploited for protein geochronological studies in subfossil biominerals. However, the in-chain degradation pathways of amino acids are complex and difficult to elucidate. Serine has proven to be particularly elusive, and its ability to racemize as a peptide-bound residue (like asparagine and aspartic acid) has not been demonstrated. This study investigates the patterns of degradation of a model peptide (WNSVWAW) at elevated temperatures, quantifying the extent of racemization and peptide bond hydrolysis using reverse-phase high-performance liquid chromatography (RP-HPLC) and tracking the presence of degradation products by MALDI-MS. We provide direct evidence that, under these experimental conditions, both serine and asparagine are able to undergo racemization as internally bound residues, which shows their potential for initiating protein breakdown and provides an explanation for the presence of d-enantiomers in living mammalian tissues.

Pathology of the tendo Achillis: do our genes contribute?

The incidence of acute and chronic conditions of the tendo Achillis appear to be increasing. Causation is multifactorial but the role of inherited genetic elements and the influence of environmental factors altering gene expression are increasingly being recognised. Certain individuals' tendons carry specific variations of genetic sequence that may make them more susceptible to injury. Alterations in the structure or relative amounts of the components of tendon and fine control of activity within the extracellular matrix affect the response of the tendon to loading with failure in certain cases. This review summarises present knowledge of the influence of genetic patterns on the pathology of the tendo Achillis, with a focus on the possible biological mechanisms by which genetic factors are involved in the aetiology of tendon pathology. Finally, we assess potential future developments with both the opportunities and risks that they may carry.

Genomic analysis of extra-intestinal pathogenic Escherichia coli urosepsis

Urosepsis is a bacteraemia infection caused by an organism previously causing an infection in the urinary tract of a patient, a diagnosis which has been classically confirmed by culture of the same species of bacteria from both blood and urine samples. Given the new insights afforded by sequencing technologies into the complicated population structures of infectious agents affecting humans, we sought to investigate urosepsis by comparing the genome sequences of blood and urine isolates of Escherichia coli from five patients with urosepsis. The results confirm the classical urosepsis hypothesis in four of the five cases, but also show the complex nature of extra-intestinal E. coli infection in the fifth case, where three distinct strains caused two distinct infections. Additionally, we show there is little to no variation in the bacterial genome as it progressed from urine to blood, and also present a minimal set of virulence genes required for bacteraemia in E. coli based on gene association. These suggest that most E. coli have the genetic propensity to cause bacteraemia.