A systematic review of the studies testing the integrated motivational-volitional model of suicidal behaviour

Despite the influence of the integrated motivational-volitional (IMV)1 model on research and practice, the supporting literature has not been systematically synthesised. This systematic review aims to synthesise the literature testing the IMV model of suicidal behaviour. Using citation and database searching, PsycINFO, EMBASE, PubMed, Web of Science, and Google Scholar were searched for studies referencing the IMV model (last searched on 28th March 2023). Included studies empirically tested the hypotheses of the model. Quality assessment was conducted using the National Institute of Health tool. Findings from 98 records (100 studies, 138,365 participants) were narratively synthesised. Results from studies directly testing the hypothesised pathways of the model supported the defeat-entrapment-suicidal ideation pathway of the IMV model. Case-control studies comparing differences between control, ideation, and enactment groups were consistent with hypotheses in univariate and cross-sectional analyses. However, support for the model was mixed for case-control multivariate and prospective studies. Due to low overlap in variables studied, the role of specific pre-motivational phase variables and stage-specific moderators was inconclusive. The studies received overall good quality ratings. The IMV model presents a promising framework for understanding and preventing suicide. Defeat, entrapment, and key variables may be useful in informing suicide prevention measures.

Ultra-rapid real-time microfluidic RT-PCR instrument for nucleic acid analysis

The polymerase chain reaction (PCR) is paramount in nucleic acid amplification testing, and for many assays, the use of PCR or qPCR is considered the 'gold standard'. While instrumentation for executing PCR has advanced over the last two decades, a growing interest in point-of-need testing has highlighted the deficit that exists for 'rapid PCR' systems. Here, we describe a field-forward prototype instrument capable of ultra-fast thermal cycling for real-time PCR amplification of DNA and RNA. The custom-designed, injection-molded microfluidic chips interface with a novel mechatronic system to complete 40 cycles of real-time PCR in under 10 minutes, an 84% reduction in time compared to a standard 50 minute assay. Such rapid amplification is enabled by two thermoelectric Peltiers capable of efficiently heating and cooling the sample at 12 and 10 °C s-1, respectively. Judicious selection and strategic placement of the thermal cyclers and fluorescence detector relative to the microchip enable synchronized thermal cycling and fluorescence monitoring, further reducing time-to-result. Robust amplification and detection of DNA and RNA targets empowers laboratories to achieve rapid, actionable information in endless applications.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Renal Clearance of Fibroblast Growth Factor-23 (FGF23) and its Fragments in Humans

Relative abundance of fibroblast growth factor-23 (FGF23) measured by the C-terminal (cFGF23, which measures both intact FGF23 and C-terminal fragments) versus intact (iFGF23, measures only intact hormone) assays varies by kidney function in humans. Differential kidney clearance may explain this finding. We measured cFGF23 and iFGF23 in the aorta and bilateral renal veins of 162 patients with essential hypertension undergoing renal angiography. Using multivariable linear regression, we examined factors associated with aorta to renal vein reduction of FGF23 using both assays. Similar parameters and with addition of urine concentrations of cFGF23 and iFGF23 were measured in six Wistar rats. Mean ± standard deviation (SD) age was 54 ± 12 years, 54% were women, and mean creatinine clearance was 72 ± 48 mL/min/100 g. The human kidney reduced the concentrations of both cFGF23 (16% ± 12%) and iFGF23 (21% ± 16%), but reduction was higher for iFGF23. Greater kidney creatinine and PTH reductions were each independently associated with greater reductions of both cFGF23 and iFGF23. The greater kidney reduction of iFGF23 compared to cFGF23 appeared stable and consistent across the range of creatinine clearance evaluated. Kidney clearance was similar, and urine concentrations of both assays were low in the rat models, suggesting kidney metabolism of both cFGF23 and iFGF23. Renal reduction of iFGF23 is higher than that of creatinine and cFGF23. Our data suggest that FGF23 is metabolized by the kidney. However, the major cell types involved in metabolization of FGF23 requires future study. Kidney clearance of FGF23 does not explain differences in C-terminal and intact moieties across the range of kidney function. © 2022 American Society for Bone and Mineral Research (ASBMR).

The unfolded protein response and apoptotic regulation in the human placenta due to maternal cigarette smoking and pre-eclampsia

Maternal cigarette smoking (CS) and pre-eclampsia (PE) alter placental function and expression of important proteins which maintain homeostasis. Two interlinked pathways of interest are the unfolded protein response (UPR) and apoptosis. The UPR is upregulated in the PE placenta, but no data is available on the effects of CS and how it correlates with apoptotic expression. Samples of human placental tissue from normotensive non-smokers (n = 8), women with PE (n = 8), and CS (n = 8) were analysed using immunohistochemistry for 3 UPR markers (phosphorylated PKR-like endoplasmic reticulum (ER) kinase (pPERK), inositol-requiring enzyme 1 (IRE1), activating transcription factor 6 (ATF6)), and an antibody microarray for 19 apoptotic and stress regulating markers. For the PE group compared to the normotensive group, staining for pPERK was increased in decidual tissue and villi, and for IRE1, the overall percentage of stained villi per field of view was increased. There were no differences in UPR expression comparing CS to controls. Of the apoptotic markers, only IκBα (Ser32/36), which is part of an inhibitory pathway, showed a significant decrease in the PE and CS groups compared to controls. These findings suggest UPR regulation is more evident in PE with a general increase in ER stress due to decreased inhibition of apoptosis as compared to CS for which UPR was not altered.

Effect of phenylephrine on cerebral oxygen saturation and cardiac output in adults when used to treat intraoperative hypotension: a systematic review

OBJECTIVE

The objective of this review was to examine the effect of phenylephrine on cerebral oxygen saturation, cardiac output, and middle cerebral artery blood flow velocity when used to treat intraoperative hypotension.

INTRODUCTION

While the etiology of postoperative cognitive dysfunction in adults following surgery is likely multifactorial, intraoperative cerebral hypoperfusion is a commonly proposed mechanism. Research evidence and expert opinion are emerging that suggest phenylephrine adversely affects cerebral oxygen saturation and may also adversely affect cerebral perfusion via a reduction in cardiac output or cerebral vascular vasoconstriction. The administration of phenylephrine to treat intraoperative hypotension is common anesthesia practice, despite a lack of evidence to show it improves cerebral perfusion. Therefore, a systematic review of the effect of phenylephrine on cerebral hemodynamics has significant implications for anesthesia practice and future research.

INCLUSION CRITERIA

Studies of adults 18 years and over undergoing elective, non-neurosurgical procedures involving anesthesia were included. In these studies, participants received phenylephrine to treat intraoperative hypotension. The effect of phenylephrine on cerebral oxygen saturation, cardiac output, or middle cerebral artery blood flow velocity was measured.

METHODS

Key information sources searched included MEDLINE (Ovid), Embase, CINAHL (EBSCO), and Google Scholar. The scope of the search was limited to English-language studies published from 1999 through 2017. The recommended JBI approach to critical appraisal, study selection, data extraction, and data synthesis were used.

RESULTS

This systematic review found that phenylephrine consistently decreased cerebral oxygen saturation values despite simultaneously increasing mean arterial pressure to normal range. Results also found that ephedrine and dopamine were superior to phenylephrine in maintaining or increasing values. Phenylephrine was found to be similar to vasopressin in the extent to which both decreased cerebral oxygen saturation values. Results also showed that phenylephrine resulted in statistically significant declines in cardiac output, or failed to improve abnormally low preintervention values. The effect of phenylephrine on middle cerebral artery blood flow velocity was only measured in one study and showed that phenylephrine increased flow velocity by about 20%. Statistical pooling of the study results was not possible due to the gross variation in how the intervention was administered and how effect was measured.

CONCLUSIONS

This review found that phenylephrine administration resulted in declines in cerebral oxygen saturation and cardiac output. However, the research studies were ineffective in informing phenylephrine's mechanism of action or its impact on postoperative cognitive function.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO (CRD42018100740).

Second surgery for progressive glioblastoma: a multi-centre questionnaire and cohort-based review of clinical decision-making and patient outcomes in current practice

PURPOSE

Glioblastoma prognosis is poor. Treatment options are limited at progression. Surgery may benefit, but no quality guidelines exist to inform patient selection. We sought to describe variations in surgical management at progression, highlight where further evidence is needed, and build towards a consensus strategy.

METHODS

Current practice in selection of patients with progressive GBM for second surgery was surveyed online amongst specialists in the UK and Europe. We complemented this with an assessment of practice in a retrospective cohort study from six United Kingdom neurosurgical units. We used descriptive statistics to analyse the data.

RESULTS

234 questionnaire responses were received. Maintaining or improving patient quality of life was key to decision making, with variation as to whether patient age, performance status or intended extent of resection was relevant. MGMT methylation status was not important. Half considered no minimum time after first surgery. 288 patients were reported in the cohort analysis. Median time to second surgery from first surgery 390 days. Median overall survival 815 days, with no association between time to second surgery and time to death (p = 0.874).

CONCLUSIONS

This is the most wide-ranging examination of contemporaneous practice in management of GBM progression. Without evidence-based guidelines, the variation is unsurprising. We propose consensus guidelines for consideration, to reduce heterogeneity in decision making, support data collection and analysis of factors influencing outcomes, and to inform clinical trials to establish whether second surgery improves patient outcomes, or simply selects to patients already performing well.

The Hudson Brace technique for emergency burr holes, an aide-memoire for the front-line military surgeon

Traumatic brain injury is the leading cause of death in conflict and early surgical intervention achieves better outcomes. The British Army surgical kit includes a Hudson Brace and bit and Gigli saw for decompression of the cranial cavity. Here we demonstrate the Hudson Brace technique for non-neurosurgeons.

The identity of Chelodina oblonga Gray 1841 (Testudines: Chelidae) reassessed

The identity of Chelodina oblonga has been unclear because it has been variously defined to include populations of snake-necked chelid turtle from the southwest of Western Australia, across northern Australia, Cape York and southern New Guinea in its broadest conception, from just the northern part of this range (northern Australia and New Guinea), or restricted to the southwest corner of Western Australia in its narrowest conception. Uncertainty over the identity of the type specimens has added to the confusion. In this paper, we review the historical data on the extent of the type series of Chelodina oblonga, and its potential provenance, and find evidence that resolves some of the inconsistencies in previous literature on the identification of the type. Our analysis casts doubt on the northern Australian provenance of the type material. Hence, we return the name C. oblonga to the south-western species, in accordance with the genetic evidence for the provenance of the type in the Natural History Museum, London, and the external morphology of the type series. We designate a lectotype for the species, and redefine the subgeneric names that apply to the Australasian genus Chelodina, providing a new subgeneric name for one lineage.

Aryl Hydrocarbon Receptor Contributes to the Transcriptional Program of IL-10-Producing Regulatory B Cells

Regulatory B cells (Bregs) play a critical role in the control of autoimmunity and inflammation. IL-10 production is the hallmark for the identification of Bregs. However, the molecular determinants that regulate the transcription of IL-10 and control the Breg developmental program remain unknown. Here, we demonstrate that aryl hydrocarbon receptor (AhR) regulates the differentiation and function of IL-10-producing CD19+CD21hiCD24hiBregs and limits their differentiation into B cells that contribute to inflammation. Chromatin profiling and transcriptome analyses show that loss of AhR in B cells reduces expression of IL-10 by skewing the differentiation of CD19+CD21hiCD24hiB cells into a pro-inflammatory program, under Breg-inducing conditions. B cell AhR-deficient mice develop exacerbated arthritis, show significant reductions in IL-10-producing Bregs and regulatory T cells, and show an increase in T helper (Th) 1 and Th17 cells compared with B cell AhR-sufficient mice. Thus, we identify AhR as a relevant contributor to the transcriptional regulation of Breg differentiation.

Effect of renal tubule-specific knockdown of the Na+/H+ exchanger NHE3 in Akita diabetic mice

Na+/H+ exchanger isoform 3 (NHE3) contributes to Na+/bicarbonate reabsorption and ammonium secretion in early proximal tubules. To determine its role in the diabetic kidney, type 1 diabetic Akita mice with tubular NHE3 knockdown [Pax8-Cre; NHE3-knockout (KO) mice] were generated. NHE3-KO mice had higher urine pH, more bicarbonaturia, and compensating increases in renal mRNA expression for genes associated with generation of ammonium, bicarbonate, and glucose (phosphoenolpyruvate carboxykinase) in proximal tubules and H+ and ammonia secretion and glycolysis in distal tubules. This left blood pH and bicarbonate unaffected in nondiabetic and diabetic NHE3-KO versus wild-type mice but was associated with renal upregulation of proinflammatory markers. Higher renal phosphoenolpyruvate carboxykinase expression in NHE3-KO mice was associated with lower Na+-glucose cotransporter (SGLT)2 and higher SGLT1 expression, indicating a downward tubular shift in Na+ and glucose reabsorption. NHE3-KO was associated with lesser kidney weight and glomerular filtration rate (GFR) independent of diabetes and prevented diabetes-associated albuminuria. NHE3-KO, however, did not attenuate hyperglycemia or prevent diabetes from increasing kidney weight and GFR. Higher renal gluconeogenesis may explain similar hyperglycemia despite lower SGLT2 expression and higher glucosuria in diabetic NHE3-KO versus wild-type mice; stronger SGLT1 engagement could have affected kidney weight and GFR responses. Chronic kidney disease in humans is associated with reduced urinary excretion of metabolites of branched-chain amino acids and the tricarboxylic acid cycle, a pattern mimicked in diabetic wild-type mice. This pattern was reversed in nondiabetic NHE3-KO mice, possibly reflecting branched-chain amino acids use for ammoniagenesis and tricarboxylic acid cycle upregulation to support formation of ammonia, bicarbonate, and glucose in proximal tubule. NHE3-KO, however, did not prevent the diabetes-induced urinary downregulation in these metabolites.

Knockout of Na+-glucose cotransporter SGLT1 mitigates diabetes-induced upregulation of nitric oxide synthase NOS1 in the macula densa and glomerular hyperfiltration

Na⁺-glucose cotransporter (SGLT)1 mediates glucose reabsorption in late proximal tubules. SGLT1 also mediates macula densa (MD) sensing of an increase in luminal glucose, which increases nitric oxide (NO) synthase 1 (MD-NOS1)-mediated NO formation and potentially glomerular filtratrion rate (GFR). Here, the contribution of SGLT1 was tested by gene knockout (-/-) in type 1 diabetic Akita mice. A low-glucose diet was used to prevent intestinal malabsorption in Sglt1^-/- mice and minimize the contribution of intestinal SGLT1. Hyperglycemia was modestly reduced in Sglt1^-/- versus littermate wild-type Akita mice (480 vs. 550 mg/dl), associated with reduced diabetes-induced increases in GFR, kidney weight, glomerular size, and albuminuria. Blunted hyperfiltration was confirmed in streptozotocin-induced diabetic Sglt1^-/- mice, associated with similar hyperglycemia versus wild-type mice (350 vs. 385 mg/dl). Absence of SGLT1 attenuated upregulation of MD-NOS1 protein expression in diabetic Akita mice and in response to SGLT2 inhibition in nondiabetic mice. During SGLT2 inhibition in Akita mice, Sglt1^-/- mice had likewise reduced blood glucose (200 vs. 300 mg/dl), associated with lesser MD-NOS1 expression, GFR, kidney weight, glomerular size, and albuminuria. Absence of Sglt1 in Akita mice increased systolic blood pressure, associated with suppressed renal renin mRNA expression. This may reflect fluid retention due to blunted hyperfiltration. SGLT2 inhibition prevented the blood pressure increase in Sglt1^-/- Akita mice, possibly due to additive glucosuric/diuretic effects. The data indicate that SGLT1 contributes to diabetic hyperfiltration and limits diabetic hypertension. Potential mechanisms include its role in glucose-driven upregulation of MD-NOS1 expression. This pathway may increase GFR to maintain volume balance when enhanced MD glucose delivery indicates upstream saturation of SGLTs and thus hyperreabsorption.

Mitogenomics of historical type specimens of Australasian turtles: clarification of taxonomic confusion and old mitochondrial introgression

Diagnosability is central to taxonomy as are type specimens which define taxa. New advances in technologies and the discovery of new informative traits must be matched with previous taxonomic decisions based on name-bearing type specimens. Consequently, the challenge of sequencing highly degraded DNA from historical types becomes an inevitability to resolve the very many taxonomic issues arising from, by modern standards, poor historical species descriptions leading to difficulties to assign names to genetic clusters identified from fresh material. Here we apply high-throughput parallel sequencing and sequence baiting to reconstruct the mitogenomes from 18 type specimens of Australasian side-necked turtles (Chelidae). We resolve a number of important issues that have confused the taxonomy of this family, and analyse the mitogenomes of the types and those of fresh material to improve our understanding of the phylogenetic relationships of this morphologically conservative group. Together with previously published nuclear genomic data, our study provides evidence for multiple old mitochondrial introgressions.

P79 Is length of stay (LOS) equivalent for elective anterior cervical discectomy (ACD) patients in an NHS hospital and as waiting list initiative cases in a private hospital?

Objectives

To investigate if there is a significant difference between the LOS for patients admitted as waiting list initiative patients to a private hospital versus standard care in an NHS hospital.

Design

Retrospective analysis between 2015 and 2017 of all ACD procedures at the two hospitals.

Subjects

674 elective NHS patients were included, 340 were admitted to the NHS hospital and 334 as waiting list initiative patients to the private hospital. Acute patients were excluded.

Methods

Retrospective database search of electronic hospital records for all ACD procedures carried out between 2015 and 2017. The student standard t test analysis was used to compare the difference in LOS.

Results

In both groups 100% were admitted on the day of surgery. The mean NHS LOS was 3.3 (SD=6.34) days and the private hospital was 1.1 (SD=0.97) days. (p<0.001) For the patients admitted to the private hospital 96% of the patients went home with 1 night stay, only 61% of the patients went home in the same period in the NHS hospital.

Conclusions

We found that length of stay is significantly shorter in the private hospital than in the NHS hospital. This could be due to patient selection, a swifter patient pathway or a combination of the two and these factors will be explored.

P54 Formative test questions in neurology and neurosurgery

Objectives

To provide a formative educational test of knowledge that allows clinicians to measure themselves against their peers.

Design

Annual Neurosurgery and Neurology knowledge tests, supported by the ABN & SBNS, have been available since 2014 (NSurg) and 2017 (Neurol). The NSurg test requires all candidates to participate over 3 days, answers are available after the test whereas the Neurol formative questions are available over 6 weeks, answers are available immediately.

Subjects

There have been 821 first attempts at the formative questions; NSurg; 44, 63,187,143,164 and Neurol; 74, 146. Candidates are mostly from UK (NSurg 92%, Neurol 69%) and mostly specialty trainees (NSurg 98%, Neurol 63%).

Methods

The formative questions are delivered through the ebrain virtual learning platform, statistics are generated automatically. Proposed questions are written by candidates as ‘payment’ for doing the formative test.

Results

Mean Cronbach’s alpha was 87.3%. The mean score for the tests was 60.4% (Range 55.9%–77.9%). Feedback is voluntary: In 2018 17 feedback comments were received, 10 were unambiguously positive, 5 were mixed including criticism of one or more questions, 2 were judged to be neutral. Examples of feedback comments received this year included ‘Comprehensive exam that covers a wide range of topics’ and ‘This is of great value’.

Conclusions

This formative educational initiative has high internal consistency and solid feedback. Although set up differently, it is proving both valuable and popular in both specialties.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Anaemia as a risk stratification tool for symptomatic patients referred via the two-week wait pathway for colorectal cancer

Introduction Anaemia is associated with cancer. In 2014 a new form was introduced in our department requesting a haemoglobin (Hb) result on every two-week wait referral for suspected colorectal cancer (CRC). The aim of this study was to review the impact of this intervention. In particular, the significance of any evidence of anaemia (without additional indices) was investigated. Methods A review was conducted of 1,500 consecutive suspected CRC referrals recorded prospectively over a 10-month period. Data on demographics, referral Hb, referral criteria and outcomes were analysed. Anaemia was defined according to World Health Organization criteria (Hb <120g/l for women, Hb <130g/l for men). Results Overall, 1,015 patients were eligible for inclusion in the study. Over a third (38.2%) were documented as anaemic on referral. These patients were three times more likely to be diagnosed with CRC than non-anaemic patients (odds ratio [OR]: 3.22, 95% confidence interval [CI]: 1.87-5.57). Using a more stringent threshold (Hb <100g/l for women and <110g/l for men), they were four times more likely to have CRC (OR: 4.27, 95% CI: 2.35-7.75). Almost a quarter (23.7%) were actually anaemic at the time of referral but not referred with anaemia. In this subgroup, there was a 2.8-fold increase in risk of CRC diagnosis compared with non-anaemic patients (adjusted OR: 2.77, 95% CI: 1.55-4.95). Conclusions Nearly a quarter of patients not referred with iron deficiency anaemia had evidence of anaemia and this was still associated with a higher rate of CRC detection. A full blood count alone might help to risk stratify symptoms such as change in bowel habit in patients on urgent pathways and identify those cases most likely to benefit from invasive investigation.

A standardised pathway for the surveillance of stable vestibular schwannoma

Introduction Conservative management of patients with a stable vestibular schwannoma (VS) places a significant burden on National Health Service (NHS) resources and yet patients' surveillance management is often inconsistent. Our unit has developed a standardised pathway to guide surveillance imaging of patients with stable VS. In this article, we provide the basis for our imaging protocol by reviewing the measurement, natural history and growth patterns of VS, and we present a cost analysis of implementing the pathway both regionally and nationally. Methods Patients with an extrameatal VS measuring ≤20mm in maximal diameter receive magnetic resonance imaging (MRI) six months after their index imaging, followed by three annual MRI scans, two two-year interval MRI scans, a single three-year interval MRI scan and then five-yearly MRI scans to be continued lifelong. Patients with purely intrameatal tumours follow the same protocol but the initial six-month imaging is omitted. A cost analysis of the new pathway was modelled on our unit's retrospective data for 2015 and extrapolated to reflect the cost of VS surveillance nationally. Results Based on an estimation that imaging surveillance would last approximately 25 years (+/- 10 years), the cost of implementing our regional surveillance programme would be £151,011 per year (for 99 new referrals per year) and it would cost the NHS £1,982,968 per year if implemented nationally. Conclusions A standardised surveillance pathway promotes safe practice in the conservative management of VS. The estimated cost of a national surveillance programme compares favourably with other tumour surveillance initiatives, and would enable the NHS to provide a safe and economical service to patients with VS.

Straight-to-test colonoscopy for 2-week-wait referrals improves time to diagnosis of colorectal cancer and is feasible in a high-volume unit

AIM

We have introduced 'straight-to-test' (STT) colonoscopy as part of our 2-week-wait (2WW) pathway to address increasing numbers of urgent referrals for colorectal cancer (CRC) within the National Health Service. In this study we evaluated the ability of this initiative to shorten the time to diagnosis of CRC.

METHOD

We amended our 2WW referral form to include performance status and comorbidities. General practitioners were asked to provide data on estimated glomerular filtration rate and full blood count/ferritin. Our 2WW referrals were screened by a colorectal consultant and a nurse specialist. Those deemed unsuitable for STT were offered outpatient assessment (OPA).

RESULTS

Of 553 2WW referrals screened, 352 were considered suitable, 65 of whom failed a telephone assessment or were uncontactable, and accordingly 287 were offered the STT pathway. The STT group was significantly younger than the OPA group (median 65.9 years vs 78.7 years; P < 0.0001). STT colonoscopy significantly reduced the time to first test (13 days vs 22 days; P < 0.0001) and tissue diagnosis from the referral date (17 days vs 24.5 days; P < 0.0001). Thirty-seven (6.8%) CRCs were detected. Proportionately fewer patients in the STT pathway were managed with 'best supportive care only' compared with patients attending OPA (one of 15 vs six of 22, respectively). STT colonoscopy obviated the need for clinic attendance before testing in 287 patients, representing a potential net cost benefit of at least £48 500 in 4 months.

CONCLUSION

STT colonoscopy was safe and effective for selecting out a group of symptomatic patients who could proceed straight to endoscopic examination and receive a diagnosis more rapidly.

Fatigue and cognitive function in systemic lupus erythematosus: associations with white matter microstructural damage. A diffusion tensor MRI study and meta-analysis

Objective The objective of this study was to investigate fatigue and cognitive impairments in systemic lupus erythematous (SLE) in relation to diffuse white matter microstructural brain damage. Methods Diffusion tensor MRI, used to generate biomarkers of brain white matter microstructural integrity, was obtained in patients with SLE and age-matched controls. Fatigue and cognitive function were assessed and related to SLE activity, clinical data and plasma biomarkers of inflammation and endothelial dysfunction. Results Fifty-one patients with SLE (mean age 48.8 ± 14.3 years) were included. Mean diffusivity (MD) was significantly higher in all white matter fibre tracts in SLE patients versus age-matched healthy controls ( p < 0.0001). Fatigue in SLE was higher than a normal reference range ( p < 0.0001) and associated with lower MD ( ß = -0.61, p = 0.02), depression ( ß = 0.17, p = 0.001), anxiety ( ß = 0.13, p = 0.006) and higher body mass index ( ß = 0.10, p = 0.004) in adjusted analyses. Poorer cognitive function was associated with longer SLE disease duration ( p = 0.003) and higher MD ( p = 0.03) and, in adjusted analysis, higher levels of IL-6 ( ß = -0.15, p = 0.02) but not with MD. Meta-analysis (10 studies, n = 261, including the present study) confirmed that patients with SLE have higher MD than controls. Conclusion Patients with SLE have more microstructural brain white matter damage for age than the general population, but this does not explain increased fatigue or lower cognition in SLE. The association between raised IL-6 and worse current cognitive function in SLE should be explored in larger datasets.

Gene expression profiles predictive of cold-induced sweetening in potato

Cold storage (2-4 °C) used in potato production to suppress diseases and sprouting during storage can result in cold-induced sweetening (CIS), where reducing sugars accumulate in tuber tissue leading to undesirable browning, production of bitter flavors, and increased levels of acrylamide with frying. Potato exhibits genetic and environmental variation in resistance to CIS. The current study profiles gene expression in post-harvest tubers before cold storage using transcriptome sequencing and identifies genes whose expression is predictive for CIS. A distance matrix for potato clones based on glucose levels after cold storage was constructed and compared to distance matrices constructed using RNA-seq gene expression data. Congruence between glucose and gene expression distance matrices was tested for each gene. Correlation between glucose and gene expression was also tested. Seventy-three genes were found that had significant p values in the congruence and correlation tests. Twelve genes from the list of 73 genes also had a high correlation between glucose and gene expression as measured by Nanostring nCounter. The gene annotations indicated functions in protein degradation, nematode resistance, auxin transport, and gibberellin response. These 12 genes were used to build models for prediction of CIS using multiple linear regression. Nine linear models were constructed that used different combinations of the 12 genes. An F-box protein, cellulose synthase, and a putative Lax auxin transporter gene were most frequently used. The findings of this study demonstrate the utility of gene expression profiles in predictive diagnostics for severity of CIS.

Error Propagation Dynamics of PIV-based Pressure Field Calculations: How well does the pressure Poisson solver perform inherently?

Obtaining pressure field data from particle image velocimetry (PIV) is an attractive technique in fluid dynamics due to its noninvasive nature. The application of this technique generally involves integrating the pressure gradient or solving the pressure Poisson equation using a velocity field measured with PIV. However, very little research has been done to investigate the dynamics of error propagation from PIV-based velocity measurements to the pressure field calculation. Rather than measure the error through experiment, we investigate the dynamics of the error propagation by examining the Poisson equation directly. We analytically quantify the error bound in the pressure field, and are able to illustrate the mathematical roots of why and how the Poisson equation based pressure calculation propagates error from the PIV data. The results show that the error depends on the shape and type of boundary conditions, the dimensions of the flow domain, and the flow type.

A new species of freshwater turtle of the genus Elseya (Testudinata: Pleurodira: Chelidae) from the Northern Territory of Australia

The genus Elseya has had a checkered taxonomic history, but is now restricted to species characterized by an alveolar ridge on the triturating surfaces of the jaw. The Australian forms were once regarded as a single widespread species extending from the Mary River of south-eastern Queensland to the Fitzroy River of north Western Australia, but a number of Australian species have now been identified based on a combination of molecular and morphological data-Elseya dentata, E. irwini, E. lavarackorum and E. albagula. The genus is represented in New Guinea by E. branderhorsti, E. novaeguineae, E. schultzii, and E. rhodini. One additional Australian taxon first identified in 1981 and subsequently established as a distinct taxon by molecular studies, is described here. It is a large chelid turtle that can be distinguished from all other Australian members of the genus Elseya by the distinctive cream or yellow plastron, free of the dark streaking, blotches or suffusing present in other species; an extensive bridge with little or no abrupt angle between the bridge and the ventral surface of the plastron; a head shield broken into a series of small plates rather than a single unit; flat uncornified temporal scales; and a narrower, less robust skull. Osteologically, it can be distinguished from Elseya dentata by the contact of the vomer and the pterygoids. The carapace is typically a light to medium brown in color whereas the carapace of Elseya dentata is typically dark brown to almost black in color. Distribution is the Mary, South Alligator, East Alligator, Goyder and Mann River drainages of the north east of the Northern Territory, Australia. It does not appear to be in sympatry with any other member of Elseya. It is, however, in sympatry with three species of Chelodina, at least two species of Emydura, Myuchelys latisternum and Carettochelys insculpta.

Intimal smooth muscle cells are a source but not a sensor of anti-inflammatory CYP450 derived oxylipins

Vascular pathologies are associated with changes in the presence and expression of morphologically distinct vascular smooth muscle cells. In particular, in complex human vascular lesions and models of disease in pigs and rodents, an intimal smooth muscle cell (iSMC) which exhibits a stable epithelioid or rhomboid phenotype in culture is often found to be present in high numbers, and may represent the reemergence of a distinct developmental vascular smooth muscle cell phenotype. The CYP450-oxylipin - soluble epoxide hydrolase (sEH) pathway is currently of great interest in targeting for cardiovascular disease. sEH inhibitors limit the development of hypertension, diabetes, atherosclerosis and aneurysm formation in animal models. We have investigated the expression of CYP450-oxylipin-sEH pathway enzymes and their metabolites in paired intimal (iSMC) and medial (mSMC) cells isolated from rat aorta. iSMC basally released significantly larger amounts of epoxy-oxylipin CYP450 products from eicosapentaenoic acid > docosahexaenoic acid > arachidonic acid > linoleic acid, and expressed higher levels of CYP2C12, CYP2B1, but not CYP2J mRNA compared to mSMC. When stimulated with the pro-inflammatory TLR4 ligand LPS, epoxy-oxylipin production did not change greatly in iSMC. In contrast, LPS induced epoxy-oxylipin products in mSMC and induced CYP2J4. iSMC and mSMC express sEH which metabolizes primary epoxy-oxylipins to their dihydroxy-counterparts. The sEH inhibitors TPPU or AUDA inhibited LPS-induced NFκB activation and iNOS induction in mSMC, but had no effect on NFκB nuclear localization or inducible nitric oxide synthase in iSMC; effects which were recapitulated in part by addition of authentic epoxy-oxylipins. iSMCs are a rich source but not a sensor of anti-inflammatory epoxy-oxylipins. Complex lesions that contain high levels of iSMCs may be more resistant to the protective effects of sEH inhibitors.

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We examined oxylipin production in different SMC phenotypes.

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Intimal SMC produced more oxylipins than medial SMC.

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CYPs were differentially expressed and regulated by LPS in intimal and medial SMC.

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sEH inhibitors reduce inflammation in medial but not intimal SMC.

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Intimal SMC are a source but not sensor of epoxy-oxylipins.

Polar vortices on Earth and Mars: A comparative study of the climatology and variability from reanalyses

Polar vortices on Mars provide case-studies to aid understanding of geophysical vortex dynamics and may help to resolve long-standing issues regarding polar vortices on Earth. Due to the recent development of the first publicly available Martian reanalysis dataset (MACDA), for the first time we are able to characterise thoroughly the structure and evolution of the Martian polar vortices, and hence perform a systematic comparison with the polar vortices on Earth. The winter atmospheric circulations of the two planets are compared, with a specific focus on the structure and evolution of the polar vortices. The Martian residual meridional overturning circulation is found to be very similar to the stratospheric residual circulation on Earth during winter. While on Earth this residual circulation is very different from the Eulerian circulation, on Mars it is found to be very similar. Unlike on Earth, it is found that the Martian polar vortices are annular, and that the Northern Hemisphere vortex is far stronger than its southern counterpart. While winter hemisphere differences in vortex strength are also reported on Earth, the contrast is not as large. Distinctions between the two planets are also apparent in terms of the climatological vertical structure of the vortices, in that the Martian polar vortices are observed to decrease in size at higher altitudes, whereas on Earth the opposite is observed. Finally, it is found that the Martian vortices are less variable through the winter than on Earth, especially in terms of the vortex geometry. During one particular major regional dust storm on Mars (Martian year 26), an equatorward displacement of the vortex is observed, sharing some qualitative characteristics of sudden stratospheric warmings on Earth.

From parent to 'peer facilitator': a qualitative study of a peer-led parenting programme

BACKGROUND

Peer-led interventions are increasingly common in community health settings. Although peer-led approaches have proven benefits for service users, relatively little is known about the process and outcomes of participation for peer leaders. This study investigated experiences of parents who had participated as 'peer facilitators' in Empowering Parents, Empowering Communities (EPEC), a peer-led programme designed to improve access to evidence-based parenting support in socially disadvantaged communities.

METHOD

A qualitative cross-sectional design was used. Semi-structured interviews were conducted with 14 peer facilitators and scrutinized using thematic analysis.

RESULTS

Peer facilitators developed their knowledge and skills through personal experience of receiving parenting support, participation in formal training and supervised practice, access to an intervention manual, and peer modelling. Peer facilitators described positive changes in their own families, confidence and social status. Transformative personal gains reinforced peer facilitators' role commitment and contributed to a cohesive 'family' identity among EPEC staff and service users. Peer facilitators' enthusiasm, openness and mutual identification with families were seen as critical to EPEC's effectiveness and sustainability. Peer facilitators also found the training emotionally and intellectually demanding. There were particular difficulties around logistical issues (e.g. finding convenient supervision times), managing psychosocial complexity and child safeguarding.

CONCLUSIONS

The successful delivery and sustained implementation of peer-led interventions requires careful attention to the personal qualities and support of peer leaders. Based on the findings of this study, support should include training, access to intervention manuals, regular and responsive supervision, and logistical/administrative assistance. Further research is required to elaborate and extend these findings to other peer-led programmes.

A thin layer angiogenesis assay: a modified basement matrix assay for assessment of endothelial cell differentiation

Background

Basement matrices such as Matrigel™ and Geltrex™ are used in a variety of cell culture assays of anchorage-dependent differentiation including endothelial cell tube formation assays. The volumes of matrix recommended for these assays (approximately 150 μl/cm²) are costly, limit working distances for microscopy, and require cell detachment for subsequent molecular analysis. Here we describe the development and validation of a thin-layer angiogenesis (TLA) assay for assessing the angiogenic potential of endothelial cells that overcomes these limitations.

Results

Geltrex™ basement matrix at 5 μl/cm² in 24-well (10 μl) or 96-well (2 μl) plates supports endothelial cell differentiation into tube-like structures in a comparable manner to the standard larger volumes of matrix. Since working distances are reduced, high-resolution single cell microscopy, including DIC and confocal imaging, can be used readily. Using MitoTracker dye we now demonstrate, for the first time, live mitochondrial dynamics and visualise the 3-dimensional network of mitochondria present in differentiated endothelial cells. Using a standard commercial total RNA extraction kit (Qiagen) we also show direct RNA extraction and RT-qPCR from differentiated endothelial cells without the need to initially detach cells from their supporting matrix.

Conclusions

We present here a new thin-layer assay (TLA) for measuring the anchorage-dependent differentiation of endothelial cells into tube-like structures which retains all the characteristics of the traditional approach but with the added benefit of a greatly lowered cost and better compatibility with other techniques, including RT-qPCR and high-resolution microscopy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12860-014-0041-5) contains supplementary material, which is available to authorized users.

Lipid-metabolizing CYPs in the regulation and dysregulation of metabolism

The cytochrome P450s (CYPs) represent a highly divergent class of enzymes involved in the oxidation of organic compounds. A subgroup of CYPs metabolize ω3-arachidonic and linoleic acids and ω6-docosahexaenoic and eicosapentaenoic polyunsaturated fatty acids (PUFAs) into a series of related biologically active mediators. Over the past 20 years, increasing evidence has emerged for a role of these PUFA-derived mediators in physiological and pathophysiological processes in the vasculature, during inflammation, and in the regulation of metabolism. With recent technological advances and increased availability of lipid mass spectroscopy, we are now starting to discern the patterns of these CYP-PUFA products in health and disease. These analyses not only are revealing the diverse spectrum of lipid nutrients regulated by CYPs, but also clearly indicate that the balance of these mediators changes with dietary intake of different PUFA classes. These findings suggest that we are only just beginning to understand all of the relevant lipid species produced by CYP pathways. Moreover, we are still a long way from understanding the nature and presence of their receptors, their tissue expression, and the pathophysiological processes they regulate. This review highlights these future issues in the context of lipid-metabolizing CYP enzymes, focusing particularly on the CYP450 family of epoxygenases and the lipid mediators they produce.