NFκB1 is a suppressor of neutrophil-driven hepatocellular carcinoma

Hepatocellular carcinoma (HCC) develops on the background of chronic hepatitis. Leukocytes found within the HCC microenvironment are implicated as regulators of tumour growth. We show that diethylnitrosamine (DEN)-induced murine HCC is attenuated by antibody-mediated depletion of hepatic neutrophils, the latter stimulating hepatocellular ROS and telomere DNA damage. We additionally report a previously unappreciated tumour suppressor function for hepatocellular nfkb1 operating via p50:p50 dimers and the co-repressor HDAC1. These anti-inflammatory proteins combine to transcriptionally repress hepatic expression of a S100A8/9, CXCL1 and CXCL2 neutrophil chemokine network. Loss of nfkb1 promotes ageing-associated chronic liver disease (CLD), characterized by steatosis, neutrophillia, fibrosis, hepatocyte telomere damage and HCC. Nfkb1^S340A/S340Amice carrying a mutation designed to selectively disrupt p50:p50:HDAC1 complexes are more susceptible to HCC; by contrast, mice lacking S100A9 express reduced neutrophil chemokines and are protected from HCC. Inhibiting neutrophil accumulation in CLD or targeting their tumour-promoting activities may offer therapeutic opportunities in HCC.

The role of neutrophils in cancer development is not widely appreciated. Here, the authors show that NF-κB-deficient hepatocytes overproduce chemokines, leading to hepatocellular carcinoma due to excessive neutrophil recruitment, and that neutrophil depletion prevents liver cancer in these mice.

Coronary ostial compromise in aortic valve replacement: An avoidable complication

Background

We sought to determine the incidence of hospital death due to surgical compromise of the coronary ostia in aortic valve replacement. The mechanism of coronary ostium blockage was also investigated.

Methods

A retrospective review was conducted of prospectively collected clinical data and autopsy findings in 322 patients who died in hospital after aortic valve replacement with or without concomitant procedures in a single institution from January 1998 to March 2013.

Results

Over the 15-year period, more than 17 surgeons performed 7507 aortic valve replacements with or without other procedures. The mean age of the patients was 70.8 ± 11.78 years and 63% were male. Bioprosthetic valves were used in 75%, mechanical valves in 24.7%, and homografts in only 0.3%. Early mortality for all patients (combined, emergency, and redo procedures) was 4.29% (mean logistic EuroSCORE 10.7). There were 322 deaths after procedures involving the aortic valve. Autopsy examinations were carried out in all patients and showed that 3.4% ( n = 11) of deaths were at least partly attributed to encroachment on one or both coronary ostia. Causes of ostial compromise included the valve sutures, the valve sewing ring, and the aortotomy suture line.

Conclusions

Coronary ostial compromise in aortic valve replacement is a very rare but real problem occurring in at least 0.15% of aortic valve replacements and contributing to or directly causing one in every 29 aortic valve replacement deaths. Surgeons should have a high level of awareness of the risk of this rare but fatal and avoidable complication.

Validation and evaluation of VapA-specific IgG and IgG subclass enzyme-linked immunosorbent assays (ELISAs) to identify foals with Rhodococcus equi pneumonia

REASONS FOR PERFORMING STUDY

Rhodococcus equi (Rhodococcus hoagii/Prescottella equi) is a common cause of foal pneumonia, but its diagnosis remains a challenge for equine veterinarians. While the VapA-specific (virulence-associated protein A) immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) has low sensitivity and specificity for detecting pneumonic foals, little is known about VapA-specific IgG subclasses.

OBJECTIVES

To evaluate the performance of VapA-specific ELISA for IgG and its subclasses IgGa, IgGb and IgG(T) in the early diagnosis of pneumonia caused by R. equi.

STUDY DESIGN

Assay validation followed by assessment of diagnostic performance using archived samples from animals of known status.

METHODS

Serum samples from exposed (n = 125) and nonexposed adult horses (n = 10) and from experimentally challenged and naturally infected foals were used for ELISA validation. Post mortem and tissue culture records of the last 24 years from the Institute for Experimental Pathology at the University of Iceland in Keldur, Iceland laboratory were evaluated to confirm the absence of R. equi cases in Iceland. The diagnostic performance of VapA-specific IgG and its subclasses was evaluated using banked serum samples from pneumonic (n = 21) and healthy foals (n = 80). To evaluate each IgG assay, a cut-off value was selected based on receiver operating characteristic curve analysis and used to calculate sensitivity and specificity. The intra- and interassay coefficients of variation were calculated for each ELISA.

RESULTS

Using sera from Iceland, where R. equi infection has not been reported, the VapA-specific IgG ELISA differentiated exposed from nonexposed horses. When used to identify infected foals, VapA-specific IgG, IgGa and IgGb had no diagnostic value. In contrast, IgG(T) had high sensitivity and specificity.

CONCLUSIONS

Horses from Iceland are not exposed to VapA(+) R. equi and can serve as negative controls. VapA-specific IgG subclasses, with the exception of IgG(T), are poor predictors of disease. Further investigation on the use of IgG(T) as a diagnostic tool in field conditions is needed.

Excess NF-κB induces ectopic odontogenesis in embryonic incisor epithelium

Nuclear factor kappa B (NF-κB) signaling plays critical roles in many physiological and pathological processes, including regulating organogenesis. Down-regulation of NF-κB signaling during development results in hypohidrotic ectodermal dysplasia. The roles of NF-κB signaling in tooth development, however, are not fully understood. We examined mice overexpressing IKKβ, an essential component of the NF-κB pathway, under keratin 5 promoter (K5-Ikkβ). K5-Ikkβ mice showed supernumerary incisors whose formation was accompanied by up-regulation of canonical Wnt signaling. Apoptosis that is normally observed in wild-type incisor epithelium was reduced in K5-Ikkβ mice. The supernumerary incisors in K5-Ikkβ mice were found to phenocopy extra incisors in mice with mutations of Wnt inhibitor, Wise. Excess NF-κB activity thus induces an ectopic odontogenesis program that is usually suppressed under physiological conditions.

Administration of commercial Rhodococcus equi specific hyperimmune plasma results in variable amounts of IgG against pathogenic bacteria in foals

Rhodococcus equi is the most common cause of pneumonia in young foals. A vaccine is not available and the use of R equi-specific hyperimmune plasma (HIP) is common. Despite its widespread use, the efficacy of HIP in preventing disease remains controversial. The objectives of this study were (1) to evaluate the virulence associate protein A (VapA)-specific IgG and IgG subclasses in commercially available R equi HIP and (2) to evaluate serum VapA-specific IgG and IgG subclasses in foals following administration of commercial R equi HIP. Three different lots from four commercial R equi HIP were sampled. VapA-specific IgG and IgG subclasses were evaluated in all samples using an ELISA. Serum was collected from newborn foals either after commercial R equi HIP was administered (n=97) or not (n=70). Serum was also collected from each mare. Administration of HIP significantly (P<0.001) increased VapA-specific IgGs in recipient foals, however, there was a marked variation in VapA-specific IgGs in foals receiving the same product. VapA-specific IgGs were significantly different (P<0.001) between products and varied between lots, with coefficients of variation ranging from 17 to 123 per cent. These results may explain previously reported disparities in HIP efficacy.

Mesenteric ischaemia following cardiac surgery: the influence of intraoperative perfusion parameters

OBJECTIVES

Mesenteric ischaemia (MesI) remains a rare but lethal complication following cardiac surgery. Previously identified risk factors for MesI mortality (age, poor left ventricular (LV) function, cardiopulmonary bypass time and blood loss) are non-specific and cannot necessarily be modified. This study aims to identify potentially modifiable risk factors for MesI mortality through analysis of peri- and intraoperative perfusion data.

METHODS

Patients who underwent cardiac surgery between 2006 and 2011 at Papworth Hospital were retrospectively divided into 3 outcome categories: death caused by MesI; death due to other causes and survival to discharge. A published MesI risk calculator was used to estimate risk of MesI for each patient and then to create 3 cohorts of matched patients from each outcome group. Pre-, intra- and postoperative variables were collected and conditional logistic regression methods were used to identify parameters associated specifically with MesI deaths after cardiac surgery.

RESULTS

A total of 10 409 patients underwent cardiac surgery between 2006 and 2011. The incidence of MesI was 0.3% (30 patients). Two hundred and sixty-one patients died of non-MesI causes and 10 118 survived. It was possible to identify 25 patients in each group at equivalent risk of MesI. The following parameters were found to be associated with MesI mortality: recent myocardial infarction [odds ratio (OR) 4.98, 95% confidence interval (CI) 1.58-15.71, P = 0.01], standard EuroSCORE (OR 1.12, 95% CI 1.03-1.21, P = 0.01), vasopressor dose on bypass (OR 1.28, 95% CI 1.04-1.57, P = 0.02), metaraminol dose on bypass (OR 1.52, 95% CI 1.12-2.06, P = 0.01) and lowest documented mean arterial pressure (OR 0.90, 95% CI 0.83-0.97, P = 0.01). No other intraoperative perfusion-related parameters (e.g. flow, average activated clotting time or pressure) were associated with MesI mortality.

CONCLUSIONS

Our study not only confirms previously known predictive factors, but also demonstrates a new association between intraoperative vasopressor use and MesI mortality.

Cause and effect in studies on unemployment, mental health and suicide: a meta-analytic and conceptual review

BACKGROUND

There are ongoing questions about whether unemployment has causal effects on suicide as this relationship may be confounded by past experiences of mental illness. The present review quantified the effects of adjustment for mental health on the relationship between unemployment and suicide. Findings were used to develop and interpret likely causal models of unemployment, mental health and suicide.

METHOD

A random-effects meta-analysis was conducted on five population-based cohort studies where temporal relationships could be clearly ascertained.

RESULTS

Results of the meta-analysis showed that unemployment was associated with a significantly higher relative risk (RR) of suicide before adjustment for prior mental health [RR 1.58, 95% confidence interval (CI) 1.33-1.83]. After controlling for mental health, the RR of suicide following unemployment was reduced by approximately 37% (RR 1.15, 95% CI 1.00-1.30). Greater exposure to unemployment was associated with higher RR of suicide, and the pooled RR was higher for males than for females.

CONCLUSIONS

Plausible interpretations of likely pathways between unemployment and suicide are complex and difficult to validate given the poor delineation of associations over time and analytic rationale for confounder adjustment evident in the revised literature. Future research would be strengthened by explicit articulation of temporal relationships and causal assumptions. This would be complemented by longitudinal study designs suitable to assess potential confounders, mediators and effect modifiers influencing the relationship between unemployment and suicide.

Children with nephrotic syndrome have greater bone area but similar volumetric bone mineral density to healthy controls

BACKGROUND

Glucocorticoid use has been associated with an increased fracture risk and reduced bone mineral density (BMD), particularly in the trabecular compartment. However the contribution of the underlying inflammatory disease process to these outcomes is poorly understood. Childhood nephrotic syndrome (NS) typically follows a relapsing-remitting course often requiring recurrent courses of glucocorticoids, but with low systemic inflammation during remission. NS therefore represents a useful clinical model to investigate the effects of glucocorticoids on BMD and bone geometry in childhood.

METHODS

Children with NS were compared to age and sex matched healthy controls. Body composition and areal BMD (whole body, lumbar spine and hip) were assessed by DXA. Peripheral quantitative computed tomography (pQCT) scans were obtained at metaphyseal (4%) and diaphyseal (66%) sites of the tibia to determine volumetric BMD and bone cross-sectional geometry. Lifetime cumulative glucocorticoid exposure was calculated from medical records.

RESULTS

29 children with NS (55% male, age 10.7±3.1years) were compared to 29 healthy controls (55% male, age 11.0±3.0years). The children with NS were of similar height SDS to controls (p=0.28), but were heavier (0.65±1.28SDS vs -0.04±0.89SDS, p=0.022) and had greater body fat percentage SDS (0.31±1.01 vs -0.52±1.10, p=0.008). Tibial trabecular and cortical vBMD were similar between the two groups but bone cross-sectional area (CSA) was significantly greater in children with NS at both the metaphysis (954±234mm(2) vs 817±197mm(2), p=0.002) and diaphysis (534.9±162.7mm(2) vs 463.2±155.5mm(2), p=0.014). Endosteal and periosteal circumferences were greater in children with NS than controls (both p<0.01), resulting in reduced cortical thickness (2.4±0.7mm vs 2.8±0.7mm, p=0.018), but similar cortical CSA (p=0.22). The differences in cortical geometry were not statistically significant when weight was included as a confounding factor. There were no associations between cumulative steroid exposure, duration of NS or number of relapses and any bone parameter.

CONCLUSIONS

Tibial bone CSA is increased in children with NS. We speculate that this is a compensatory response to increased body weight. Defects in trabecular BMD were not identified in this cohort of children with NS.

The effect of leaving employment on mental health: testing 'adaptation' versus 'sensitisation' in a cohort of working-age Australians

OBJECTIVES

To investigate the 'adaptation' versus 'sensitisation' hypotheses in relation to mental health and labour market transitions out of employment to determine whether mental health stabilised (adaptation) or worsened (sensitisation) as people experienced one or more periods without work.

METHODS

The Household Income and Labour Dynamics of Australia (HILDA) longitudinal survey was used to investigate the relationship between the number of times a person had been unemployed or had periods out of the labour force (ie, spells without work) and the Mental Component Summary (MCS) of the Short Form 36 (SF-36). Demographic, health and employment related confounders were included in a series of multilevel regression models.

RESULTS

During 2001-2010, 3362 people shifted into unemployment and 1105 shifted from employment to not in the labour force. Compared with participants who did not shift, there was a 1.64-point decline (95% CI -2.05 to -1.23, p<0.001) in scores of the MCS SF-36 among those who had one spell of unemployment (excluding not in the labour force), and a 2.56-point decline (95% CI -3.93 to -1.19, p<0.001) among those who had two or more spells of unemployment after adjusting for other variables. Findings for shifts from employment to 'not in the labour force' were in the same direction; however, effect sizes were smaller.

CONCLUSIONS

These results indicate that multiple spells of unemployment are associated with continued, though small, declines in mental health. Those who leave employment for reasons other than unemployment experience a smaller reduction in mental health.

FIASCO II failure to achieve a satisfactory cardiac outcome study: the elimination of system errors

OBJECTIVES

Death in low-risk cardiac surgical patients provides a simple and accessible method by which modifiable causes of death can be identified. In the first FIASCO study published in 2009, local potentially modifiable causes of preventable death in low-risk patients with a logistic EuroSCORE of 0-2 undergoing cardiac surgery were inadequate myocardial protection and lack of clarity in the chain of responsibility. As a result, myocardial protection was improved, and a formalized system introduced to ensure clarity of the chain of responsibility in the care of all cardiac surgical patients. The purpose of the current study was to re-audit outcomes in low-risk patients to see if improvements have been achieved.

METHODS

Patients with a logistic EuroSCORE of 0-2 who had cardiac surgery from January 2006 to August 2012 were included. Data were prospectively collected and retrospectively analysed. The case notes of patients who died in hospital were subject to internal and external review and classified according to preventability.

RESULTS

Two thousand five hundred and forty-nine patients with a logistic EuroSCORE of 0-2 underwent cardiac surgery during the study period. Seven deaths occurred in truly low-risk patients, giving a mortality of 0.27%. Of the seven, three were considered preventable and four non-preventable. Mortality was marginally lower than in our previous study (0.37%), and no death occurred as a result of inadequate myocardial protection or communication failures.

CONCLUSION

We postulate that the regular study of such events in all institutions may unmask systemic errors that can be remedied to prevent or reduce future occurrences. We encourage all units to use this methodology to detect any similarly modifiable factors in their practice.

Chest X-ray and electrocardiogram in post-cardiac surgery follow-up clinics: should this be offered routinely or when clinically indicated?

OBJECTIVES

Many centres in the UK carry out routine chest X-ray (CXR) and/or electrocardiogram (ECG) when patients attend follow-up clinic after cardiac surgery. Current evidence to support this practice is weak. This study investigated the appropriateness of carrying out these investigations in the absence of clinical indication.

METHODS

All patients attending routine 6- to 8-week follow-up clinic after cardiac surgery in this hospital were prospectively reviewed over a 6-month period (October 2011-April 2012). Two groups were identified for comparison. Group A comprised patients who had CXR and/or ECG requested routinely, and those in Group B had the investigations only when clinically indicated. A proforma was designed to screen each patient for cardiac and respiratory symptoms, predischarge CXR abnormalities and the presence of atrial fibrillation/flutter postoperatively. Management alterations based on the findings from the investigations were noted. Patients who had thoracic, major aortic, or heart transplant surgery were excluded from the audit.

RESULTS

Three hundred and fifty patients were reviewed: 250 were in Group A and 100 in Group B. No patient had a significant management alteration in the absence of an indication for the tests. There were no differences in outcome between the two groups. In Group A, 111 (45%) patients had CXR and ECG done without indication and no abnormality was detected. In Group B, 52 patients had no indication for either tests and were thus not tested. None of these patients required readmission/intervention following discharge from clinic. Overall, 271 patients had CXR carried out, with only 83 being indicated. This led to a management alteration in 33 patients (12% overall, 40% if indicated). Two hundred and eighty-six patients had ECG carried out with 140 indicated. Management was altered in 122 patients (43% overall, 87% if indicated). The correlation between the clinical indication-based investigation and the resulting change in patient management was found to be significant (Goodman-Kruskal Gamma: 0.99, P = 0.000 for both investigations).

CONCLUSIONS

There is a strong correlation between clinical indication for CXR and/or ECG and management alterations. These investigations should be performed during the routine follow-up of adult cardiac surgical patients using a patient-centred approach based on signs and symptoms.

Chronic thromboembolic pulmonary hypertension: an underdiagnosed entity?

Chronic thromboembolic pulmonary hypertension (CTEPH) is the only cause of pulmonary hypertension for which there is a potential cure, which is in the form of pulmonary endarterectomy. There is a strong link between pulmonary embolism (PE) and the development of CTEPH. Although CTEPH was initially believed to be a rare complication, this belief has been reconsidered following several studies suggesting that up to 8.8% of patients develop CTEPH within the 2 years after PE. However, considering the incidence of PE, there is a significant discrepancy in the number of patients who are diagnosed, referred, and treated for CTEPH. Potential reasons for this include its often vague clinical presentation, the variable association of CTEPH with PE, and discrepancies when interpreting imaging studies. Underdiagnosis of CTEPH is preventing patients from accessing potentially curative therapy. Increased awareness about this condition is an important initial step to improving diagnostic rates and treatment.