Pathogens in FRI - Do bugs matter? - An analysis of FRI studies to assess your enemy

Fracture-related infection (FRI) is a devasting complication for both patients and their treating Orthopaedic surgeon that can lead to loss of limb function or even amputation. The unique and unpredictable features of FRI make its diagnosis and treatment a significant challenge. It has substantial morbidity and financial implications for patients, their families and healthcare providers. In this article, we perform an in-depth and comprehensive review of FRI through recent and seminal literature to highlight evolving definitions, diagnostic and treatment approaches, focusing on common pathogens such as Staphylococcus aureus, polymicrobial infections and multi-drug-resistant organisms (MDRO). Furthermore, multiple resistance mechanisms and adaptations for microbial survival are discussed, as well as modern evidence-based medical and surgical advancements in treatment strategies in combating FRI.

Prevalence and temporal trends of anemia in patients with heart failure

BACKGROUND

Anemia is an important comorbidity in heart failure (HF), and it is associated with increased adverse disease experience and mortality. Previous reports have focused mainly on HF presenting in healthcare settings. We, therefore, set out to establish the nationwide prevalence and temporal trends of anemia in community-based patients with HF in the US.

AIM

To establish the nationwide prevalence and temporal trends of anemia in community-based patients with HF in the US.

DESIGN

The NHANES dataset, conducted by the CDC National Center for Health Statistics was used to collect nationally representative data on the health and nutritional status of the non-institutionalized US population.

METHODS

We utilized the National Health and Nutrition Examination data collected over five survey cycles (2007-16). Included were participants aged 20-80 years with self-reported diagnosis of HF. Anemia was defined using 2 sex specific cut offs of 13 and 12 g/dl (cutoff 1), and 12 and 11 g/dl (cutoff 2), for men and women, respectively. The Chi square test was used to compare prevalence across different categories and survey cycles. Data analysis was done using STATA 16 with P-values < 0.05 considered statistically significant.

RESULTS

The median hemoglobin in all HF patients was 13.5 g/dl (IQR 12.4-14.5). The prevalence of anemia among community-based patients with HF in the US was 21.34% (cutoff 1) and 9.03% (cutoff 2) and has been stable from 2007 to 2016. The burden of anemia was disproportionately higher in NH Blacks (34.48%, 95% CI 27.12-42.67) and those with BMI < 25 Kg/m2 (17.4%, 95% CI 10.9-26.64).

CONCLUSION

The prevalence of anemia in patients with HF in the US is at least 9% and has remained stable over the past decade. This high persistent burden with limited proven interventions should spur further efforts aimed at identifying impactful ways of addressing anemia in patients with HF.

Clinical features and natural history of RASopathy-associated hypertrophic cardiomyopathy in children

Background

The RASopathies are a group of genetic disorders caused by germline mutations in genes encoding components of the RAS/MAPK signalling pathway and frequently associated with hypertrophic cardiomyopathy (HCM). The clinical features and outcomes of RASopathy-related HCM are incompletely understood and most published studies are limited by relatively small numbers and incomplete clinical characterisation.

Purpose

To describe the clinical features outcomes in a large, single-centre cohort of patients with RASopathy-associated HCM diagnosed &lt;18 years.

Methods

Data from 105 patients [68 (64.8%) males] diagnosed in childhood with RASopathy-associated HCM at a single specialist centre between 1985 and 2020 were retrospectively analysed.

Results

The RASopathy diagnosis was Noonan syndrome in 69 patients (65.7%); NSML in 10 (9.5%); CFC in 6 (5.7%); Costello in 5 (4.8%) and 15 patients (14.2%) had another Noonan-like variant. 72 patients (68.6%) had a pathogenic/likely pathogenic variant in a RAS-MAPK gene, most commonly PTPN11 [n=25 (34.7%)], followed by RAF 1 [n=13 (18.1%)]. 100 patients (95.2%) were probands, 9 (8.6%) had family history of cardiomyopathy and 2 (1.9%) family history of sudden cardiac death (SCD). 52 (49.5%) had concomitant congenital heart defects (CHD) [ASD 13 (25%), VSD 6 (11.5%), PDA 1 (1.9%), &gt;1 CHD 32 (61.5%)]. 29 (27.6%) had symptoms at baseline assessment and 56 (53.3%) were on cardiac medication. The distribution of left ventricular hypertrophy (LVH) was concentric in 47 (44.7%); 32 (30.5%) had asymmetric septal hypertrophy (ASH), and undocumented in 25 patients (23.8%). 45 patients (42.9%) had biventricular hypertrophy (BVH). Resting left ventricular outflow tract obstruction (LVOTO) was present in 39 (37.1%) with haemodynamically significant LVOTO (≥50mmHg) in 23 (21.9%). Resting right ventricular outflow tract obstruction (RVOTO) was present in 21 (20%). Over a median follow up time of 6 years, 19 patients (18.1%) died [1 (5.3%) SCD; 2 (10.5%) due to Heart Failure-related death; 1 (5.3%) due to another CVS cause; 5 (26.3%) due to a non-CVS cause and for 10 (52.6%) cause of death was unknown]. Incidence rate of death was calculated at 2.7 deaths per 100 person-years. Surgical septal myectomy was performed in 9 patients (8.6%) and 3 (2.9%) underwent cardiac transplantation. 14 patients (13.3%) suffered arrhythmic events [atrial tachycardia 6 (42.9%), Non-Sustained Ventricular Tachycardia 4 (3.8%), and Ventricular Tachycardia/Ventricular Fibrillation 4 (3.8%)].

Conclusion

To our knowledge, this is the largest cohort of RASopathy-associated HCM. The findings show a heterogeneous clinical presentation with a high prevalence of morbidity and mortality. Further work is needed to determine predictors of outcome in this population.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Onassis Foundation

330 Comparing Outcomes in Right Versus Left Kidney Transplantation; A Systematic Review and Meta-Analysis

Introduction

Transplantation of right kidneys can pose technical challenges due to the short right renal vein. Whether this results in inferior outcomes remains controversial.

Method

We used Healthcare Database Advanced Search (HDAS) to identify relevant studies. Two authors independently reviewed each study. Statistical analyses were performed using random effects models and results expressed as HR or relative risk (RR) with 95% confidence intervals. Subgroup analyses were performed in kidneys from deceased donors (DD) and living donors (LD).

Results

35 studies (257,429 participants) were identified. Both deceased and living donor right kidneys were at increased risk of delayed graft function (DGF; RR = 1.10[1.07-1.12] p &lt; 0.00001). In absolute terms, for each 100 kidney pairs of DD kidneys transplanted there are 2.72 (1.67-3.78, p &lt; 0.00001) excess episodes of DGF in right kidneys. Graft thrombosis rate was also significantly higher in right kidneys, in both DD and LD settings (RR = 1.55[1.41-1.69] p &lt; 0.00001). Compared to DD left kidneys, DD right kidneys were at significantly higher risk of graft failure due to technical causes (RR = 1.54[1.25-1.90], P &lt; 0.0001). The two largest DD studies (179,124 participants) found right kidneys to have significantly poorer graft survival; time-varying analyses demonstrated this was caused by early graft losses within the first year. There was no evidence that laterality alters long term graft survival in LD or DD.

Conclusions

Right kidneys are at increased risk of early complications in both DD and LD settings, although the absolute effects are small. Improved vascular reconstruction techniques for the right renal vein, which avoid detrimental impacts on ischaemia times, are essential.

How do you develop systems leadership in public health? Insights from a scoping study

OBJECTIVES

Systems leadership is widely acknowledged to be needed to address the many 'wicked issues' challenging public health systems. However, there is a lack of evidence on how to develop public health professionals into effective systems leaders. This study scoped the possibilities for developing the systems leadership capacity of public health specialists in England.

STUDY DESIGN

This was a mixed-methods qualitative scoping study design.

METHODS

The study involved three stages. In the first, a rapid literature review mapped key documents in three relevant areas: systems leadership theory and practice, the changing context of public health in the UK, and training and development for UK public health professionals. In the second, 29 stakeholders were consulted to understand the context and needs for systems leadership development in public health. A third phase involved stakeholders codesigning a potential development framework for the project commissioners.

RESULTS

Four main themes were identified: the nature and purpose of systems leadership; development needs and opportunities for public health specialists; the enabling environment; and wider contextual factors impacting public health.

CONCLUSIONS

Key principles of, and a framework for, a systems leadership development approach are identified, which could be applied to any public health system.

O59: USE OF DEXTRAN 40 FOLLOWING PANCREAS TRANSPLANT MAY REDUCE EARLY INFLAMMATION AND SIGNIFICANT BLEEDING COMPARED TO A HEPARIN-BASED PROTOCOL

Introduction

Dextran 40 (D40) is a synthetic colloid with anticoagulant properties, which is commonly used instead of heparin following pancreas transplantation, however there is a lack of evidence over which is more effective. Graft thrombosis and pancreatitis, which may be mediated through micro or macrothrombosis within the graft, remain significant complications following pancreas transplantation. We hypothesised that D40 reduces inflammation through its antithrombotic pro-microcirculatory effects. We aimed to evaluate D40 compared to a heparin-based protocol by comparing post-operative complications and post-transplant levels of inflammation.

Method

Data were collected retrospectively for pancreas transplant patients between December 2009 and August 2018 – 26 patients had been treated with the pre-Dextran protocol and 37 had received D40. Post-operative complications and inflammatory markers (WCC, CRP and amylase) on post-operative days 1, 2, 3 and 7 were compared between the two groups. Potential confounders were also recorded.

Result

Patients in the D40 group had similar thrombosis rates but were less likely to have had substantial post-operative bleeding compared to the heparin-based protocol. The group who received D40 had significantly lower CRP and WCC on days 2, 3 and 7. The differences on days 3 and 7 remained when the results were adjusted for the significant confounders - cold ischaemic time and donor age.

Conclusion

D40 appears to be as effective as IV heparin at preventing graft thrombosis following pancreas transplant, and to confer a reduced risk of bleeding. It may also reduce post-operative inflammatory processes, leading to reduced graft pancreatitis.

Take-home message

Using Dextran 40 as an anticoagulant after pancreas transplantation is as effective as IV heparin at preventing graft thromboses and has a reduced risk of bleeding.

O67: PERFUSATE GLUCOSE REFLECTS TISSUE GLYCOGENATION DURING LIVER PERFUSION

Introduction

Normothermic machine perfusion (NMP) is a method of organ preservation that aims to replicate the physiological environment, achieved by perfusing the livers with a blood-based perfusate at physiological inflow pressures and temperature. NMP also permits viability assessment through evaluation of the perfusate flow rates through the portal vein and hepatic artery. In addition to this, biochemical assessment and perfusate gas analysis can be performed to provide insights into the metabolic activity of the liver.

Method

Discarded human liver grafts (n=6), were perfused for 24 hours. Core biopsies and perfusate samples were taken from each liver at 5 distinct time intervals over 24 hours. Core biopsies were fixed and stained with periodic acid-Schiff and analysed with Leica software to provide a quantitative estimate of the hepatocellular glycogen content.

Result

Hepatic glycogen concentration rose during the first hour, followed by a steady decline thereafter until the end of perfusion. Contrary to our initial hypothesis that glucose concentration within the circuit would show an inverse relationship to glycogen stores in the liver cells, we found that glucose concentration closely followed the same trend.

Conclusion

Change in hepatocyte glycogen content provides an important insight into the synthetic function of a liver destined for transplant. Our research suggests that glucose concentration can be used as a surrogate marker for the synthetic function of a liver on NMP and provides valuable information on the glycogen-synthesising capability of the hepatocytes. In future, this could potentially aid the decision-making process with regards to liver graft transplant viability.

Take-home message

Perfusate glucose concentration could provide an insight into the viability of liver transplants

O25: TARGETING THE RENAL TUBULAR EPITHELIUM WITH ANTI-MIRNA THERAPY: A POTENTIAL MECHANISM FOR MINIMISING ISCHAEMIA REPERFUSION INJURY

Introduction

Ischaemia reperfusion injury (IRI) is an unavoidable, significant consequence of renal transplantation. MicroRNAs are small, non-coding RNA molecules that regulate multiple downstream mRNA targets. MiRNA-21-5p and miRNA-24-3p have been previously implicated in IRI. Antisense oligonucleotides (ASOs) block specific microRNAs, with previous work by our group demonstrating their delivery to kidneys using normothermic machine perfusion. Imaging these kidneys revealed ASO localisation around proximal tubule epithelial cells (PTECs). This project aimed to characterise ASO blockade against miRNA-21-5p and miRNA-24-3p in PTECs.

Method

HKC8 cells, a human PTEC cell line, were used throughout these experiments. Cells were placed in a hypoxic incubator for 24hrs, followed by 6hrs of reoxygenation to mimic IRI. HKC8s were transfected with ASOs using lipofectamine. RT-qPCR and Western Blots were used to evaluate expression of antioxidant targets, SOD2 and HMOX1.

Result

MiRNA-21-5p and miRNA-24-3p levels were high throughout hypoxia and reoxygenation. Single blockade with anti-miRNA-21-5p resulted in a significant increase in its downstream target SOD2 (P&lt;0.05). Anti-miRNA-24-3p treatment resulted in no change in either of its downstream targets, HMOX1 or SOD2. This was reflected in the failure of dual blockade to produce a synergistic effect on the shared target, SOD2.

Conclusion

Anti-miRNA-21-5p results in a significant increase of SOD2, which is well characterised as protective during IRI. Anti-miRNA-24-3p appears to have no effect on PTECs, contrary to previous work in endothelial cells, perhaps suggesting a cell specific response of microRNAs. Normothermic machine perfusion could be used to deliver dual ASOs; allowing simultaneous targeting of different kidney cell types.

Take-home message

The delivery of anti-miRNA-21-5p therapy pre-transplant, using normothermic machine perfusion, has the potential to reduce ischaemia reperfusion injury and improve kidney transplant outcomes.

Partial Articular Resurfacing Secondary to Pediatric Hip Chondroblastoma Curettage with a 5-YearFollow-Up: A Case Report

CASE

This report describes a case of pediatric femoral head chondroblastoma, which was initially treated by minimally invasive curettage. At the 18-month follow-up, a subsequent osteochondral defect occurred, which was treated with a partial articular resurfacing system. At 5.5 years follow-up, he was symptom-free with minor degenerative x-ray changes.

CONCLUSION

We describe a technique of focal anatomic hip resurfacing using the HemiCAP system in a pediatric chondroblastoma patient who presented with an osteochondral defect after primary curettage. This approach yielded good short-term to midterm results and is a potential alternative to total hip arthroplasty in young patients.

Imaging-based characterization of convective tissue properties

Convective transport is an important phenomenon for nanomedicine delivery. We present an imaging-based approach to recover tissue properties that are significant in the accumulation of nanoparticles delivered via systemic methods. The classical pharmacokinetic analysis develops governing equations for the particle transport from a first principle mass balance. Fundamentally, the governing equations for compartmental mass balance represent a spatially invariant mass transport between compartments and do not capture spatially variant convection phenomena. Further, the parameters recovered from this approach do not necessarily have direct meaning with respect to the governing equations for convective transport. In our approach, a framework is presented for directly measuring permeability in the sense of Darcy flow through porous tissue. Measurements from our approach are compared to an extended Tofts model as a control. We demonstrate that a pixel-wise iterative clustering algorithm may be applied to reduce the parameter space of the measurements. We show that measurements obtained from our approach are correlated with measurements obtained from the extended Tofts model control. These correlations demonstrate that the proposed approach contains similar information to an established compartmental model and may be useful in providing an alternative theoretical framework for parameterizing mathematical models for treatment planning and diagnostic studies involving nanomedicine where convection dominated effects are important.

Gene Mutations in 21 Unrelated Cases of Phenotypic Heterozygous Protein C Deficiency and Thrombosis

Mutations have been identified in the protein C gene in 21 patients with venous thromboembolism and phenotypic heterozygous protein C deficiency. In 20 probands, single mutations were the only abnormalities identified by sequencing all coding regions, intron exon boundaries and the promoter region back to -1540. In one proband 2 mutations were identified and in another family 2 mutations were identified (but not both in the proband). Of the 23 mutations, 18 resulted in predicted amino acid substitutions, 3 were mutations resulting in stop codons, one was a mutation within a consensus splice sequence and another a 9 base pair insertion within exon 5 (this region within exon 5 is proposed as a deletion/insertion hot spot). A novel polymorphism was also, uniquely, identified in the propeptide region of the molecule (Pro-21 Pro; CCT to CCC) in a kindred from Hong Kong. Cosegregation of the protein C gene mutation with protein C deficiency could be determined in 13 families. In a further family, phenotypic protein C deficiency and the genetic mutation cosegregated in only 4/5 members.

The first thrombotic incident occurred in the probands between the ages of 11 and 59 years and 12 individuals suffered recurrent thrombosis. Thrombosis occurred in at least one other family member in 9/21 families, but in 2 of these it was inconsistently associated with protein C deficiency. An independent genetic risk factor, factor V Arg506Gln (FV Leiden) was identified in 2 probands (and 3 family members) and in 4 protein C deficient members of a third family but not in the proband. The results suggest that in the majority of probands with thrombosis and phenotypic protein C deficiency, a single protein C gene mutation is associated with thrombosis. However, it is also possible that additional unknown genetic risk factors contribute to the thrombotic risk. An added, acquired, risk factor leads to thrombosis at an early age (< 25 years).

Educating Psychiatric Patients about their Treatment: Do Fact Sheets Work?

Psychiatric patients are sometimes given fact sheets about their treatment but the benefits of these are uncertain. We tested three strategies in three cohorts of psychiatric inpatients—fact sheets alone, fact sheets and subsequent discussion, and control. Knowledge of medication was assessed by questionnaire.

For various reasons, only 33 of the 77 patients were included in the study or analysis. Of the patients who had been given fact sheets, 87% independently read them and reported finding them helpful whilst all asked for more information. Receiving a fact sheet alone had no significant effect, whereas having discussed it with a health care professional was associated with a significant increase in knowledge about medication. Patients receiving fact sheets selectively learned more about side-effects than about drug action or precautions.

This strategy for patient education could be used by ward nurses and deserves further evaluation.

Normothermic machine perfusion for the assessment and transplantation of declined human kidneys from donation after circulatory death donors

BACKGROUND

A significant proportion of donation after circulatory death (DCD) kidneys are declined for transplantation because of concerns over their quality. Ex vivo normothermic machine perfusion (NMP) provides a unique opportunity to assess the quality of a kidney and determine its suitability for transplantation.

METHODS

In phase 1 of this study, declined human DCD kidneys underwent NMP assessment for 60 min. Kidneys were graded 1-5 using a quality assessment score (QAS) based on macroscopic perfusion, renal blood flow and urine output during NMP. In phase 2 of the study, declined DCD kidneys were assessed by NMP with an intention to transplant them.

RESULTS

In phase 1, 18 of 42 DCD kidneys were declined owing to poor in situ perfusion. After NMP, 28 kidneys had a QAS of 1-3, and were considered suitable for transplantation. In phase 2, ten of 55 declined DCD kidneys underwent assessment by NMP. Eight kidneys had been declined because of poor in situ flushing in the donor and five of these were transplanted successfully. Four of the five kidneys had initial graft function.

CONCLUSION

NMP technology can be used to increase the number of DCD kidney transplants by assessing their quality before transplantation.

A prospective study of pre-trauma risk factors for post-traumatic stress disorder and depression

BACKGROUND

It is unclear which potentially modifiable risk factors best predict post-trauma psychiatric disorders. We aimed to identify pre-trauma risk factors for post-traumatic stress disorder (PTSD) or major depression (MD) that could be targeted with resilience interventions.

METHOD

Newly recruited paramedics (n = 453) were assessed for history of mental disorders with structured clinical interviews within the first week of their paramedic training and completed self-report measures to assess hypothesized predictors. Participants were assessed every 4 months for 2 years to identify any episodes of PTSD and MD; 386 paramedics (85.2%) participated in the follow-up interviews.

RESULTS

In all, 32 participants (8.3%) developed an episode of PTSD and 41 (10.6%) an episode of MD during follow-up. In all but nine cases (2.3%), episodes had remitted by the next assessment 4 months later. At 2 years, those with episodes of PTSD or MD during follow-up reported more days off work, poorer sleep, poorer quality of life, greater burn-out; and greater weight-gain for those with PTSD. In line with theories of PTSD and depression, analyses controlling for psychiatric and trauma history identified several pre-trauma predictors (cognitive styles, coping styles and psychological traits). Logistic regressions showed that rumination about memories of stressful events at the start of training uniquely predicted an episode of PTSD. Perceived resilience uniquely predicted an episode of MD.

CONCLUSIONS

Participants at risk of developing episodes of PTSD or depression could be identified within the first week of paramedic training. Cognitive predictors of episodes of PTSD and MD are promising targets for resilience interventions.

Commissioning for COPD care: a new, recordable metric that supports the patient interest

BACKGROUND

Healthcare metrics have been used to drive improvement in outcome and delivery in UK hospital stroke and cardiac care. This model is attractive for chronic obstructive pulmonary disease (COPD) care because of disease frequency and the burden it places on primary, secondary and integrated care services.

METHODS

Using 'hospital episode statistics' (UK 'coding'), we examined hospital 'bed days/1000 population' in 150 UK Primary Care Trusts (PCTs) during 2006-07 and 2007-08. Data were adjusted for COPD prevalence. We looked at year-on-year consistency and factors which influenced variation.

RESULTS

There were 248 996 COPD admissions during 2006-08. 'Bed days/1000 PCT population' was consistent between years (r = 0.87; P < 0.001). There was a >2-fold difference in bed days between the best and worst performing PCTs which was primarily a consequence of variation in emergency admission rate (P < 0.001) and proportion of emergency admissions due to COPD (P < 0.001) and to only a lesser extent length of hospital stay (P < 0.001).

CONCLUSIONS

Bed days/1000 population appears a useful annual metric of COPD care quality. Good COPD care keeps patients active and out of hospital and requires co-ordinated action from both hospital and community services, with an important role for integrated care. This metric demonstrates that current care is highly variable and offers a measurable target to commission against.

High IP-10 levels decrease T cell function in HIV-1-infected individuals on ART

HIV-1-infected subjects, despite control of viral replication with ART, have an altered immune cytokine/chemokine milieu. Changes in systemic cytokines and chemokines can alter immune responses. IP-10, in particular, has been associated with pathogenesis in a number of conditions, and we found that IP-10 is increased in serum in subjects who are HIV-1 infected and on stable ART compared with HIV-1-uninfected individuals. In a series of in vitro studies, we found that PBMCs exposed to IP-10 showed a significant decrease in the number of cells capable of secreting IFN-γ, as well as other cytokines, when stimulated with recall antigens. Furthermore, treatment with IP-10 led to decreased antigen-specific calcium signaling and MAPK38 phosphorylation. Importantly, the cytokines, as well as proliferative responses, could be enhanced with an IP-10 Nab. Our findings suggest that IP-10-modulating drugs may potentially enhance T cell responses to vaccination and HIV-1 in HIV+ subjects on ART.

Cerebrospinal fluid and urinary biomarkers in multiple sclerosis

OBJECTIVES

Biomarkers with the potential for longitudinal measurements are needed in multiple sclerosis (MS). Urine is easy to collect, and repeated sampling is possible.

METHODS

39 paired CSF and urine samples were taken. Oligoclonal bands (OCBs) were measured in CSF. Kappa and lambda free light chain (FLC), neopterin and ubiquitin C-terminal hydrolase-L1 (UCHL1) were measured in CSF and urine.

RESULTS

16/39 samples had OCBs unique to the CSF. CSF FLC levels (P < 0.0001) were higher in OCB-positive subjects, with no difference in urinary FLC. CSF and urinary FLC did not correlate. There were a significant correlation between total CSF FLC and CSF neopterin in MS samples (correlation coefficient = 0.588, P = 0.016) and a strong correlation between CSF lambda FLC and CSF neopterin in MS samples (correlation coefficient = 0.875, P < 0.001). There was a strong correlation between urinary neopterin/creatinine levels and urinary total FLC/protein levels (correlation coefficient = 0.452, P = 0.004). Only three CSF samples (8%) had detectable levels of UCHL1. 18/38 (48%) (8/15 MS and 10/23 control) urine samples had detectable levels of UCLH1.

CONCLUSIONS

This study confirms the relationship between CSF OCBs and CSF FLCs, highlighting the importance of intrathecal B- and plasma-cell activation in MS. There is a relationship between CSF FLC and CSF neopterin in MS, highlighting the multifaceted immune activation seen in MS. Correlations in the OCB-positive group highlight the multifaceted immune activation seen in MS. Further studies are required to evaluate CSF and urinary biomarkers.

Genotype and clinical care correlations in craniosynostosis: findings from a cohort of 630 Australian and New Zealand patients

Craniosynostosis is one of the most common craniofacial disorders encountered in clinical genetics practice, with an overall incidence of 1 in 2,500. Between 30% and 70% of syndromic craniosynostoses are caused by mutations in hotspots in the fibroblast growth factor receptor (FGFR) genes or in the TWIST1 gene with the difference in detection rates likely to be related to different study populations within craniofacial centers. Here we present results from molecular testing of an Australia and New Zealand cohort of 630 individuals with a diagnosis of craniosynostosis. Data were obtained by Sanger sequencing of FGFR1, FGFR2, and FGFR3 hotspot exons and the TWIST1 gene, as well as copy number detection of TWIST1. Of the 630 probands, there were 231 who had one of 80 distinct mutations (36%). Among the 80 mutations, 17 novel sequence variants were detected in three of the four genes screened. In addition to the proband cohort there were 96 individuals who underwent predictive or prenatal testing as part of family studies. Dysmorphic features consistent with the known FGFR1-3/TWIST1-associated syndromes were predictive for mutation detection. We also show a statistically significant association between splice site mutations in FGFR2 and a clinical diagnosis of Pfeiffer syndrome, more severe clinical phenotypes associated with FGFR2 exon 10 versus exon 8 mutations, and more frequent surgical procedures in the presence of a pathogenic mutation. Targeting gene hot spot areas for mutation analysis is a useful strategy to maximize the success of molecular diagnosis for individuals with craniosynostosis.

Pharmacologic reversion of epigenetic silencing of the PRKD1 promoter blocks breast tumor cell invasion and metastasis

INTRODUCTION

DNA methylation-induced silencing of genes encoding tumor suppressors is common in many types of cancer, but little is known about how such epigenetic silencing can contribute to tumor metastasis. The PRKD1 gene encodes protein kinase D1 (PKD1), a serine/threonine kinase that is expressed in cells of the normal mammary gland, where it maintains the epithelial phenotype by preventing epithelial-to-mesenchymal transition.

METHODS

The status of PRKD1 promoter methylation was analyzed by reduced representation bisulfite deep sequencing, methylation-specific PCR (MSP-PCR) and in situ MSP-PCR in invasive and noninvasive breast cancer lines, as well as in humans in 34 cases of "normal" tissue, 22 cases of ductal carcinoma in situ, 22 cases of estrogen receptor positive, HER2-negative (ER+/HER2-) invasive lobular carcinoma, 43 cases of ER+/HER2- invasive ductal carcinoma (IDC), 93 cases of HER2+ IDC and 96 cases of triple-negative IDC. A reexpression strategy using the DNA methyltransferase inhibitor decitabine was used in vitro in MDA-MB-231 cells as well as in vivo in a tumor xenograft model and measured by RT-PCR, immunoblotting and immunohistochemistry. The effect of PKD1 reexpression on cell invasion was analyzed in vitro by transwell invasion assay. Tumor growth and metastasis were monitored in vivo using the IVIS Spectrum Pre-clinical In Vivo Imaging System.

RESULTS

Herein we show that the gene promoter of PRKD1 is aberrantly methylated and silenced in its expression in invasive breast cancer cells and during breast tumor progression, increasing with the aggressiveness of tumors. Using an animal model, we show that reversion of PRKD1 promoter methylation with the DNA methyltransferase inhibitor decitabine restores PKD1 expression and blocks tumor spread and metastasis to the lung in a PKD1-dependent fashion.

CONCLUSIONS

Our data suggest that the status of epigenetic regulation of the PRKD1 promoter can provide valid information on the invasiveness of breast tumors and therefore could serve as an early diagnostic marker. Moreover, targeted upregulation of PKD1 expression may be used as a therapeutic approach to reverse the invasive phenotype of breast cancer cells.

Biliary epithelial senescence and plasticity in acute cellular rejection

Biliary epithelial cells (BEC) are important targets in some liver diseases, including acute allograft rejection. Although some injured BEC die, many can survive in function compromised states of senescence or phenotypic de-differentiation. This study was performed to examine changes in the phenotype of BEC during acute liver allograft rejection and the mechanism driving these changes. Liver allograft sections showed a positive correlation (p < 0.0013) between increasing T cell mediated acute rejection and the number of BEC expressing the senescence marker p21(WAF1/Cip) or the mesenchymal marker S100A4. This was modeled in vitro by examination of primary or immortalized BEC after acute oxidative stress. During the first 48 h, the expression of p21(WAF1/Cip) was increased transiently before returning to baseline. After this time BEC showed increased expression of mesenchymal proteins with a decrease in epithelial markers. Analysis of TGF-β expression at mRNA and protein levels also showed a rapid increase in TGF-β2 (p < 0.006) following oxidative stress. The epithelial de-differentiation observed in vitro was abrogated by pharmacological blockade of the ALK-5 component of the TGF-β receptor. These data suggest that stress induced production of TGF-β2 by BEC can modify liver allograft function by enhancing the de-differentiation of local epithelial cells.