Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Operative blood loss adversely affects short and long-term outcomes after colorectal cancer surgery: results of a systematic review and meta-analysis

BACKGROUND

The aim of this meta-analysis was to assess the impact of operative blood loss on short and long-term outcomes following colorectal cancer surgery.

METHODS

A systematic literature review and meta-analysis were performed, from inception to the 10th of August 2020. A comprehensive literature search was performed on the 10th of August 2020 of PubMed MEDLINE, Embase, Science Citation Index Expanded, and Cochrane Central Register of Controlled Trials. Only studies reporting on operative blood loss and postoperative short term or long-term outcomes in colorectal cancer surgery were considered for inclusion.

RESULTS

Forty-three studies were included, reporting on 59,813 patients. Increased operative blood loss was associated with higher morbidity, for blood loss greater than 150-350 ml (odds ratio [OR] 2.09, p < 0.001) and > 500 ml (OR 2.29, p = 0.007). Anastomotic leak occurred more frequently for blood loss above a range of 50-100 ml (OR 1.14, p = 0.007), 250-300 ml (OR 2.06, p < 0.001), and 400-500 ml (OR 3.15, p < 0.001). Postoperative ileus rate was higher for blood loss > 100-200 ml (OR 1.90, p = 0.02). Surgical site infections were more frequent above 200-500 ml (OR 1.96, p = 0.04). Hospital stay was increased for blood loss > 150-200 ml (OR 1.63, p = 0.04). Operative blood loss was significantly higher in patients that suffered morbidity (mean difference [MD] 133.16 ml, p < 0.001) or anastomotic leak (MD 69.56 ml, p = 0.02). In the long term, increased operative blood loss was associated with worse overall survival above a range of 200-500 ml (hazard ratio [HR] 1.15, p < 0.001), and worse recurrence-free survival above 200-400 ml (HR 1.33, p = 0.01). Increased blood loss was associated with small bowel obstruction caused by colorectal cancer recurrence for blood loss higher than 400 ml (HR 1.97, p = 0.03) and 800 ml (HR 3.78, p = 0.02).

CONCLUSIONS

Increased operative blood loss may adversely impact short term and long-term postoperative outcomes. Measures should be taken to minimize operative blood loss during colorectal cancer surgery. Due to the uncertainty of evidence identified, further research, with standardised methodology, is required on this important subject.

Multiscale study of high energy attosecond pulse interaction with matter and application to proton-Boron fusion

For several decades, the interest of the scientific community in aneutronic fusion reactions such as proton-Boron fusion has grown because of potential applications in different fields. Recently, many scientific teams in the world have worked experimentally on the possibility to trigger proton-Boron fusion using intense lasers demonstrating an important renewal of interest of this field. It is now possible to generate ultra-short high intensity laser pulses at high repetition rate. These pulses also have unique properties that can be leveraged to produce proton-Boron fusion reactions. In this article, we investigate the interaction of a high energy attosecond pulse with a solid proton-Boron target and the associated ion acceleration supported by numerical simulations. We demonstrate the efficiency of single-cycle attosecond pulses in comparison to multi-cycle attosecond pulses in ion acceleration and magnetic field generation. Using these results we also propose a path to proton-Boron fusion using high energy attosecond pulses.

Quantification of FAM20A in human milk and identification of calcium metabolism proteins

BACKGROUND

FAM20A, a recently discovered protein, is thought to have a fundamental role in inhibiting ectopic calcification. Several studies have demonstrated that variants of FAM20A are causative for the rare autosomal recessive disorder, enamel-renal syndrome (ERS). ERS is characterized by defective mineralization of dental enamel and nephrocalcinosis suggesting that FAM20A is an extracellular matrix protein, dysfunction of which causes calcification of the secretory epithelial tissues. FAM20A is a low-abundant protein that is difficult to detect in biofluids such as blood, saliva, and urine. Thus, we speculated the abundance of FAM20A to be high in human milk, since the secretory epithelium of lactating mammary tissue is involved in the secretion of highly concentrated calcium. Therefore, the primary aim of this research is to describe the processes/methodology taken to quantify FAM20A in human milk and identify other proteins involved in calcium metabolism.

METHOD

This study used mass spectrometry-driven quantitative proteomics: (1) to quantify FAM20A in human milk of three women and (2) to identify proteins associated with calcium regulation by bioinformatic analyses on whole and milk fat globule membrane fractions.

RESULTS

Shotgun MS/MS driven proteomics identified FAM20A in whole milk, and subsequent analysis using targeted proteomics also successfully quantified FAM20A in all samples. Combination of sample preparation, fractionation, and LC-MS/MS proteomics analysis generated 136 proteins previously undiscovered in human milk; 21 of these appear to be associated with calcium metabolism.

CONCLUSION

Using mass spectrometry-driven proteomics, we successfully quantified FAM20A from transitional to mature milk and obtained a list of proteins involved in calcium metabolism. Furthermore, we show the value of using a combination of both shotgun and targeted driven proteomics for the identification of this low abundant protein in human milk.

Appraisal of the current guidelines for the management of diverticular disease using the Appraisal of Guidelines Research and Evaluation II (AGREE II) instrument

INTRODUCTION

Diverticular disease is one of the most frequent reasons for attending emergency departments and surgical causes of hospital admission. In the past decade, many surgical and gastroenterological societies have published guidelines for the management of diverticular disease. The aim of the present study was to appraise the methodological quality of these guidelines using the Appraisal of Guidelines Research and Evaluation II (AGREE II) tool.

METHODS

PubMed, Embase, Cochrane Library and Google Scholar databases were searched systematically. The methodological quality of the guidelines was appraised independently by five appraisers using the AGREE II instrument.

FINDINGS

A systematic search of the literature identified 12 guidelines. The median overall score of all guidelines was 68%. Across all guidelines, the highest score of 85% was demonstrated in the domain 'Scope and purpose'. The domains 'Clarity and presentation' and 'Editorial independence' both scored a median of 72%. The lowest scores were demonstrated in the domains 'Stakeholder involvement' and 'Applicability' at 46% and 40%, respectively. Overall, the National Institute for Health and Care Excellence (NICE) guidelines performed consistently well, scoring 100% in five of six domains; NICE was one of the few guidelines that specifically reported stakeholder involvement, scoring 97%. Generally, the domain of 'Stakeholder involvement' ranked poorly with seven of twelve guidelines scoring below 50%, with the worst score in this domain demonstrated by Danish guidelines at 25%.

CONCLUSION

Six of twelve guidelines (NICE, American Society of Colon & Rectal Surgeons (ASCRS), European Society of Coloproctology (ESCP), American Gastroenterological Association, German Society of Gastroenterology/German Society for General and Visceral Surgery (German), Netherlands Society of Surgery) scored above 70%. Only three, NICE, ASCRS and ESCP, scored above 75% and were voted unanimously by the appraisers for use as they are. Therefore, use of AGREE II may help improve the methodological quality of guidelines and their future updates.

Pre-operative iron allows correction of anaemia before abdominal surgery: A systematic review and meta-analysis of randomized controlled trials

Objective

Professional surgical societies recommend the identification and treatment of pre-operative anaemia in patients scheduled for abdominal surgery. However, the evidence supporting this recommendation has been of poor quality until the recent release of several randomized controlled trials (RCT) addressing the question. Our aim was to determine if pre-operative iron allows correction of haemoglobin concentration and decreased incidence of peri-operative blood transfusion in patients undergoing major abdominal surgery.

Methods

MEDLINE, Embase and CENTRAL were searched for RCTs written in English and assessing the effect of pre-operative iron on the incidence of peri-operative allogeneic blood transfusion in patients undergoing major abdominal surgery. Pooled relative risk (RR), risk difference (RD) and mean difference (MD) were obtained using models with random effects. Heterogeneity was assessed using the Q-test and quantified using the I2 value.

Results

Four RCTs were retained for analysis out of 285 eligible articles. MD in haemoglobin concentration between patients with pre-operative iron and patients without pre-operative iron was of 0.81 g/dl (3 RCTs, 95% CI: 0.30 to 1.33, I2: 60%, p = 0.002). Pre-operative iron did not lead to reduction in the incidence of peri-operative blood transfusion in terms of RD (4 RCTs, RD: -0.13, 95% CI: -0.27 to 0.01, I2: 65%, p = 0.07) or RR (4 RCTs, RR: 0.57, 95% CI: 0.30 to 1.09, I2: 64%, p = 0.09).

Conclusion

Pre-operative iron significantly increases haemoglobin concentration by 0.81 g/dl before abdominal surgery but does not reduce the need for peri-operative blood transfusion. Important heterogeneity exists between existing RCTs in terms of populations and interventions. Future trials should target patients suffering from iron-deficiency anaemia and assess the effect of intervention on anaemia-related complications.

Diversion, resection, or stenting as a bridge to surgery for acute neoplastic left-sided colonic obstruction: a systematic review and network meta-analysis of studies with curative intent

INTRODUCTION

The debate on the best surgical management strategy for acute malignant left-sided colonic obstruction is ongoing. Decompressing colostomy (DC) and stenting as a bridge to surgery (SBTS) are the currently proposed alternative approaches to emergency colectomy (EC). However, the results of a traditional meta-analysis were inconclusive. Therefore, a network meta-analysis (NMA) was conducted to compare the three approaches for acute left-sided colonic obstruction.

METHODS

A systematic literature search of Embase, PubMed, Google Scholar and the Cochrane library was performed. A traditional meta-analysis and subsequent NMA were conducted.

FINDINGS

A significantly greater number of primary anastomoses were performed in the DC cohort than in the EC and SBTS cohorts. The 90-day mortality rate was significantly lower in the DC cohort than in the EC and SBTS cohorts. Higher costs were associated with the SBTS cohort (by US$2,000) than with the EC cohort. The locoregional recurrence rate was higher for the SBTS cohort than for the EC cohort.

CONCLUSIONS

Evidence from the first NMA suggests there may be some clinical advantages associated with DC as an alternative approach to the EC and SBTS approaches for adequately selected patients with malignant large bowel obstruction.

Dysphagia presentation and management following COVID-19: an acute care tertiary centre experience

OBJECTIVES

As the pathophysiology of COVID-19 emerges, this paper describes dysphagia as a sequela of the disease, including its diagnosis and management, hypothesised causes, symptomatology in relation to viral progression, and concurrent variables such as intubation, tracheostomy and delirium, at a tertiary UK hospital.

RESULTS

During the first wave of the COVID-19 pandemic, 208 out of 736 patients (28.9 per cent) admitted to our institution with SARS-CoV-2 were referred for swallow assessment. Of the 208 patients, 102 were admitted to the intensive treatment unit for mechanical ventilation support, of which 82 were tracheostomised. The majority of patients regained near normal swallow function prior to discharge, regardless of intubation duration or tracheostomy status.

CONCLUSION

Dysphagia is prevalent in patients admitted either to the intensive treatment unit or the ward with COVID-19 related respiratory issues. This paper describes the crucial role of intensive swallow rehabilitation to manage dysphagia associated with this disease, including therapeutic respiratory weaning for those with a tracheostomy.

Robotic vs laparoscopic total mesorectal excision for rectal cancers: has a paradigm change occurred? A systematic review by updated meta-analysis

AIM

The debate about the oncological adequacy, safety and efficiency of robotic vs laparoscopic total mesorectal excision for rectal cancers continues. Therefore, an updated, traditional and cumulative meta-analysis was performed with the aim of assessing the new evidence on this topic.

METHOD

A systematic search of the literature for data pertaining to the last 25 years was performed. Fixed- and random-effects models were used to cumulatively assess the accumulation of evidence over time.

RESULTS

Patients with a significantly higher body mass index (BMI), tumours located approximately 1 cm further distally and more patients undergoing neoadjuvant therapy were included in the robotic total mesorectal excision (RTME) cohort compared with those in the laparoscopic total mesorectal excision (LTME) cohort [RTME, mean difference (MD) = 0.22 (0.07, 0.36), P = 0.005; LTME, MD = -0.97 (-1.57, 0.36), P < 0.002; OR = 1.47 (1.11, 1.93), P = 0.006]. Significantly lower conversion rates to open surgery were observed in the RTME cohort than in the LTME cohort [OR = 0.33 (0.24, 0.46), P < 0.001]. Operative time in the LTME cohort was significantly reduced (by 50 min) compared with the RTME cohort. Subgroup analysis of the three randomized controlled trials (RCTs) challenged all the significant results of the main analysis and demonstrated nonsignificant differences between the RTME cohort and LTME cohort.

CONCLUSION

Although the RTME cohort included patients with a significantly higher BMI, more distal tumours and more patients undergoing neoadjuvant therapy, this cohort demonstrated lower conversion rates to open surgery when compared with the LTME cohort. However, subgroup analysis of the RCTs demonstrated nonsignificant differences between the two procedures.

Systematic review and meta-analysis of the anatomical variants of the left colic artery

AIM

To provide a comprehensive evidence-based assessment of the anatomical variations of the left colic artery (LCA).

METHOD

A thorough systematic search of the literature up until 1 April 2019 was conducted on the electronic databases PubMed, SCOPUS and Web of Science (WOS) to identify studies eligible for inclusion. Data were extracted and pooled into a meta-analysis using the Metafor package in R. The primary outcomes of interest were the absence of the LCA and the anatomical variants of its origin. The secondary outcomes were the distance (mean ± SD) between the origin of the inferior mesenteric artery (OIMA) and the origin of the left colic artery (OLCA).

RESULTS

A total of 19 studies (n = 2040 patients) were included. The pooled prevalence estimate (PPE) of LCA absence was 1.2% (95% CI 0.0-3.6%). Across participants with either a Type I or Type II LCA, the PPE of a Type I LCA was 49.0% (95% CI 40.2-57.8%). The PPE of a Type II LCA was therefore 51.0%. The pooled mean distance from the OIMA to the OLCA was 40.41 mm (95 CI% 38.69-42.12 mm). The pooled mean length of a Type I LCA was 39.12 mm (95% CI 36.70-41.53 mm) while the pooled mean length of a Type IIa and Type IIb LCA was 41.43 mm (95% CI 36.90-43.27 mm) and 39.64 mm (95% CI 37.68-41.59 mm), respectively.

CONCLUSION

Although the absence of the LCA is a rare occurrence (PPE 1.2%), it may be associated with an important risk of anastomotic leakage as a result of insufficient vascularization of the proximal colonic conduit. It is also necessary to distinguish variants I and II of Latarjet, the frequency of which is identical, with division of the LCA being technically more straightforward in variant I of Latarjet. Surgeons should be aware that technical difficulties are likely to be more common with variant II of Latarjet, as LCA ligation may be more difficult due to its close proximity to the inferior mesenteric vein (IMV).

Total extraperitoneal endoscopic hernioplasty (TEP) versus Lichtenstein hernioplasty: a systematic review by updated traditional and cumulative meta-analysis of randomised-controlled trials

Background–purpose

Totally extraperitoneal (TEP) endoscopic hernioplasty and Lichtenstein hernioplasty are the most commonly used approaches for inguinal hernia repair. However, current evidence on which is the preferred approach is inconclusive. This updated meta-analysis was conducted to track the accumulation of evidence over time.

Methods

Studies were identified by a systematic literature search of the EMBASE, PubMed, Cochrane Library, and Google Scholar databases. Fixed- and random-effects models were used to cumulatively assess the accumulation of evidence over time.

Results

The TEP cohort showed significantly higher rates of recurrences and vascular injuries compared to the Lichtenstein cohort; [Peto Odds ratio (OR) = 1.58 (1.22, 2.04), p = 0.005], [Peto OR = 2.49 (1.05, 5.88), p = 0.04], respectively. In contrast, haematoma formation rate, time to return to usual activities, and local paraesthesia were significantly lower in the TEP cohort compared to the Lichtenstein cohort; [Peto OR = 0.26 (0.16, 0.41), p ≤ 0.001], [mean difference = − 6.32 (− 8.17, − 4.48), p ≤ 0.001], [Peto OR = 0.26 (0.17, 0.40), p ≤ 0.001], respectively.

Conclusions

This study, which is based on randomised-controlled trials (RCTs) of high quality, showed significantly higher rates of recurrences and vascular injuries in the TEP cohort than in the Lichtenstein cohort. In contrast, rate of postoperative haematoma formation, local paraesthesia, and time to return to usual activities were significantly lower in the TEP cohort than in the Lichtenstein cohort. Future multicentre RCTs with strict adherence to the standards recommended in the Consolidated Standards of Reporting Trials guidelines will shed further light on the topic.

Electronic supplementary material

The online version of this article (10.1007/s10029-019-02049-w) contains supplementary material, which is available to authorized users.

Typing complex meningococcal vaccines to understand diversity and population structure of key vaccine antigens

Background: Protein-conjugate capsular polysaccharide vaccines can potentially control invasive meningococcal disease (IMD) caused by five (A, C, W, X, Y) of the six IMD-associated serogroups.  Concerns raised by immunological similarity of the serogroup B capsule to human neural cell carbohydrates, meant that 'serogroup B substitute' vaccines target more variable subcapsular protein antigens.  A successful approach using outer membrane vesicles (OMVs) as major vaccine components had limited strain coverage. In 4CMenB (Bexsero ^®), recombinant proteins have been added to ameliorate this problem.  Methods: Scalable, portable, genomic techniques were used to investigate the Bexsero ^® OMV protein diversity in meningococcal populations. Shotgun proteomics identified 461 proteins in the OMV, defining a complex proteome. Amino acid sequences for the 24 proteins most likely to be involved in cross-protective immune responses were catalogued within the PubMLST.org/neisseria database using a novel OMV peptide Typing (OMVT) scheme. Results: Among these proteins there was variation in the extent of diversity and association with meningococcal lineages, identified as clonal complexes (ccs), ranging from the most conserved peptides (FbpA, NEISp0578, and putative periplasmic protein, NEISp1063) to the most diverse (TbpA, NEISp1690).  There were 1752 unique OMVTs identified amongst 2492/3506 isolates examined by whole-genome sequencing (WGS). These OMVTs were grouped into clusters (sharing ≥18 identical OMVT peptides), with 45.3% of isolates assigned to one of 27 OMVT clusters. OMVTs and OMVT clusters were strongly associated with cc, genogroup, and Bexsero ^® antigen variants, demonstrating that combinations of OMV proteins exist in discrete, non-overlapping combinations associated with genogroup and Bexsero ^® Antigen Sequence Type. This highly structured population of IMD-associated meningococci is consistent with strain structure models invoking host immune and/or metabolic selection. Conclusions: The OMVT scheme facilitates region-specific WGS investigation of meningococcal diversity and is an open-access, portable tool with applications for vaccine development, especially in the choice of antigen combinations, assessment and implementation.

Typing complex meningococcal vaccines to understand diversity and population structure of key vaccine antigens

Background: Protein-conjugate capsular polysaccharide vaccines can potentially control invasive meningococcal disease (IMD) caused by five (A, C, W, X, Y) of the six IMD-associated serogroups.  Concerns raised by immunological similarity of the serogroup B capsule to human neural cell carbohydrates, meant that ‘serogroup B substitute’ vaccines target more variable subcapsular protein antigens.  A successful approach using outer membrane vesicles (OMVs) as major vaccine components had limited strain coverage. In 4CMenB (Bexsero ^®), recombinant proteins have been added to ameliorate this problem. 

Methods: Scalable, portable, genomic techniques were used to investigate the Bexsero ^® OMV protein diversity in meningococcal populations. Shotgun proteomics identified 461 proteins in the OMV, defining a complex proteome. Amino acid sequences for the 24 proteins most likely to be involved in cross-protective immune responses were catalogued within the PubMLST.org/neisseria database using a novel OMV peptide Typing (OMVT) scheme.

Results: Among these proteins there was variation in the extent of diversity and association with meningococcal lineages, identified as clonal complexes (ccs), ranging from the most conserved peptides (FbpA, NEISp0578, and putative periplasmic protein, NEISp1063) to the most diverse (TbpA, NEISp1690).  There were 1752 unique OMVTs identified amongst 2492/3506 isolates examined by whole-genome sequencing (WGS). These OMVTs were grouped into clusters (sharing ≥18 identical OMVT peptides), with 45.3% of isolates assigned to one of 27 OMVT clusters. OMVTs and OMVT clusters were strongly associated with cc, genogroup, and Bexsero ^® antigen variants, demonstrating that combinations of OMV proteins exist in discrete, non-overlapping combinations associated with genogroup and Bexsero ^® Antigen Sequence Type. This highly structured population of IMD-associated meningococci is consistent with strain structure models invoking host immune and/or metabolic selection.

Conclusions:The OMVT scheme facilitates region-specific WGS investigation of meningococcal diversity and is an open-access, portable tool with applications for vaccine development, especially in the choice of antigen combinations, assessment and implementation.

Comparison of single radial immunodiffusion, SDS-PAGE and HPLC potency assays for inactivated influenza vaccines shows differences in ability to predict immunogenicity of haemagglutinin antigen

The current gold-standard potency test for inactivated influenza vaccines is the single radial immunodiffusion (SRD) assay. A number of alternative potency tests for inactivated influenza vaccines have been proposed in recent years. Evaluation of these new potency tests commonly involves comparison with SRD, in order to ascertain that the new method obtains values that correlate with those measured by the standard potency test. Here, we extended comparison of two methods, reverse-phase HPLC and SDS-PAGE, with SRD by assessing the methods' capacity to detect loss of potency induced by various deliberate treatments of vaccine samples. We demonstrate that neither of these methods detected the loss of potency observed by SRD; importantly, neither SDS-PAGE nor reverse-phase HPLC reflected results from mouse experiments that showed decreased immunogenicity and protection in vivo. These results emphasise the importance of assessing the stability-indicating nature, ie the ability to measure loss of vaccine potency, of any potential new potency assay.

Developing a national colorectal educational agenda: a survey of the Association of Coloproctology of Great Britain and Ireland

AIM

In order to develop its education agenda, the Association of Coloproctology of Great Britain and Ireland (ACPGBI) sought the opinion of its members on current coloproctology training needs. The aims of this study were to canvass multidisciplinary needs and explore the perceived gaps and barriers to meeting them.

METHOD

A learner-needs analysis was performed between July 2015 and October 2016. A bespoke electronic survey was sent to 1453 colorectal healthcare professionals [ACPGBI membership (1173), colorectal nurse specialists and allied health professionals (NAHPs) (261) and regional chapter-leads (19)] seeking their needs, experiences and barriers to training across the coloproctology disciplines.

RESULTS

In all, 390 responses were received [26.8% overall; 180 consultants/trainees (15%); 196 NAHPs (75%); 14 (74%) chapter-leads]. Lack of funding and difficulties in obtaining study leave were the most frequently reported barriers to course and conference attendance. Transanal total mesorectal excision and laparoscopic training were the top educational needs for consultants and trainees respectively. 79% of NAHP respondents reported education gaps on a broad range of clinical and non-clinical topics. NAHPs lacked information on relevant training opportunities and 27% felt available courses were insufficient to meet their educational needs. Wide heterogeneity in ACPGBI chapter composition and activity was reported. All groups felt the ACPGBI should increase the number of courses offered with coloproctology knowledge updates commonly requested.

CONCLUSION

A series of training needs across the coloproctology disciplines have been identified. These will underpin the development of the educational agenda for the ACPGBI.

Environmental Toxins Found Historically in the Polycythemia Vera Cluster Area and their Potential for Inducing DNA Damage

In 2006, the Agency for Toxic Substances and Disease Registry received a request to determine whether a cluster of polycythemia vera patients existed in a northeast Pennsylvania community. A significant cluster of PV cases was identified at the nexus of three counties near several hazardous waste sites. The current study evaluated the potential for a select number of environmental contaminants previously detected in the cluster area to induce DNA damage using in vitro assays with hematopoietic stem-cell derived progenitor cells.

CD34+ cells were isolated from normal cord blood samples and were cultured for 48–72 hours to generate erythroid progenitor cells. Eighteen compounds were chosen for the assay; arsenic trioxide, benzo(a)pyrene, benzene, methylene chloride, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), trichloroethylene, potassium chloride, ethylbenzene, benzo[k]fluoranthene, styrene, cadmium chloride, hydroquinone, 1,1,1-trichloroethane, sodium cyanide, manganese chloride, chromium oxide, lead oxide, and sodium arsenite. Genotoxicity of the compounds was determined using the comet assay, and toxicity determined via the cell viability assay.

Using the comet assay, 16 compounds at 10 nM concentration, induced a significant amount of DNA damage compared to the control. When evaluating whether a dose-dependent relationship was present, seventeen of the eighteen compounds led to greater DNA damage with increasing exposure concentrations. 2,3,7,8-TCDD was particularly potent, inducing DNA damage in virtually all cells at 1 μM. In conclusion, most of the toxins evaluated using the comet assay showed potential to induce DNA damage in hematopoietic cells, and the genotoxic effects were dose-dependent.

Crystal plasticity as an indicator of the viscous-brittle transition in magmas

Understanding the flow of multi-phase (melt, crystals and bubbles) magmas is of great importance for interpreting eruption dynamics. Here we report the first observation of crystal plasticity, identified using electron backscatter diffraction, in plagioclase in andesite dome lavas from Volcán de Colima, Mexico. The same lavas, deformed experimentally at volcanic conduit temperature and load conditions, exhibit a further, systematic plastic response in the crystalline fraction, observable as a lattice misorientation. At higher stress, and higher crystal fraction, the amount of strain accommodated by crystal plasticity is larger. Crystal plastic distortion is highest in the intact segments of broken crystals, which have exceeded their plastic limit. We infer that crystal plasticity precludes failure and can punctuate the viscous-brittle transition in crystal-bearing magmas at certain shallow magmatic conditions. Since crystal plasticity varies systematically with imposed conditions, this raises the possibility that it may be used as a strain marker in well-constrained systems.

Thermal control of virulence factors in bacteria: a hot topic

Pathogenic bacteria sense environmental cues, including the local temperature, to control the production of key virulence factors. Thermal regulation can be achieved at the level of DNA, RNA or protein and although many virulence factors are subject to thermal regulation, the exact mechanisms of control are yet to be elucidated in many instances. Understanding how virulence factors are regulated by temperature presents a significant challenge, as gene expression and protein production are often influenced by complex regulatory networks involving multiple transcription factors in bacteria. Here we highlight some recent insights into thermal regulation of virulence in pathogenic bacteria. We focus on bacteria which cause disease in mammalian hosts, which are at a significantly higher temperature than the outside environment. We outline the mechanisms of thermal regulation and how understanding this fundamental aspect of the biology of bacteria has implications for pathogenesis and human health.

Use of a modified Delphi approach to develop research priorities for the association of coloproctology of Great Britain and Ireland

AIM

The modified Delphi approach is an established method for reaching a consensus opinion among a group of experts in a particular field. We have used this technique to survey the entire membership of the Association of Coloproctology of Great Britain and Ireland (ACPGBI) to reach a consensus on prioritizing clinical research questions in colorectal disease.

METHOD

Three rounds of surveys were conducted using a web-based tool. In the first, the ACPGBI membership was invited to submit research questions. In Rounds 2 and 3 they were asked to score questions on priority. A steering group analysed the results of each round to identify those questions ranked as being of highest priority.

RESULTS

Five hundred and two questions were submitted in Round 1. Following two rounds of voting and analysis, a list of 25 priority questions was produced, including 15 cancer-related and 10 noncancer-related questions.

CONCLUSION

It is anticipated that these results will: (i) set the research agenda over the next few years for the study of colorectal disease in the United Kingdom, (ii) promote development and (iii) define funding of new research and prioritize areas of unmet clinical need where the potential clinical impact is greatest.

Establishment of a novel cell line for the enhanced production of recombinant adeno-associated virus vectors for gene therapy

Adeno-associated viral (AAV) vectors show great promise because of their excellent safety profile; however, pre-existing immune responses have necessitated the administration of high titer AAV, posing a significant challenge to the advancement of gene therapy involving AAV vectors. Recombinant AAV vectors contain minimum viral proteins necessary for their assembly and gene delivery functions. During the process of AAV assembly and production, AAV vectors acquire, inherently and submissively, various cellular proteins, but the identity of these proteins is poorly characterized. We reason that by identifying host cell proteins inherently associated with AAV vectors we may better understand the contribution of cellular components to AAV vector assembly and, ultimately, may improve the production of AAV vectors for gene therapy. In this study, three serotypes of recombinant AAV, namely AAV2, AAV5, and AAV8, were investigated. We used liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) methods to identify protein composition in purified AAV vectors, confirmed protein identities using western blotting, and explored the potential function of selected proteins in AAV vector production using small hairpin (shRNA) methods. Using LC-MS/MS, we identified 44 AAV-associated cellular proteins including Y-box binding protein (YB1). We showed for the first time that the establishment of a novel producer cell line by introducing an shRNA sequence down-regulating YB1 resulted in up to 45- and 9-fold increase in physical vector genome titers of AAV2 and AAV8, respectively, and up to 7-fold increase in AAV2 transduction vector genome titers. Our results revealed that YB1 gene knockdown promoted AAV2 rep expression and vector DNA production and reduced the number of empty particles in AAV2 products, suggesting that YB1 plays an important role in AAV vector assembly by competition with adenovirus E2A and AAV capsid proteins for binding to the inverted terminal repeat (ITR) sequence. The significance and implications of our findings in future improvement of AAV production are discussed.

Determining the rp-process flow through 56Ni: resonances in 57Cu(p,γ)58Zn identified with GRETINA

An approach is presented to experimentally constrain previously unreachable (p, γ) reaction rates on nuclei far from stability in the astrophysical rp process. Energies of all critical resonances in the (57)Cu(p,γ)(58)Zn reaction are deduced by populating states in (58)Zn with a (d, n) reaction in inverse kinematics at 75 MeV/u, and detecting γ-ray-recoil coincidences with the state-of-the-art γ-ray tracking array GRETINA and the S800 spectrograph at the National Superconducting Cyclotron Laboratory. The results reduce the uncertainty in the (57)Cu(p,γ) reaction rate by several orders of magnitude. The effective lifetime of (56)Ni, an important waiting point in the rp process in x-ray bursts, can now be determined entirely from experimentally constrained reaction rates.

Attosecond pulse shaping around a Cooper minimum

High harmonic generation (HHG) is used to measure the spectral phase of the recombination dipole matrix element (RDM) in argon over a broad frequency range that includes the 3p Cooper minimum (CM). The measured RDM phase agrees well with predictions based on the scattering phases and amplitudes of the interfering s- and d-channel contributions to the complementary photoionization process. The reconstructed attosecond bursts that underlie the HHG process show that the derivative of the RDM spectral phase, the group delay, does not have a straightforward interpretation as an emission time, in contrast to the usual attochirp group delay. Instead, the rapid RDM phase variation caused by the CM reshapes the attosecond bursts.

Responsivity to criminogenic need in forensic intellectual disability services

BACKGROUND

Research has shown for some time that addressing criminogenic need is one of the crucial aspects of reducing reoffending in all types of offenders. Criminogenic need such as anger or inappropriate sexual interest is considered to be crucial in the commission of the offence. The aim of the present study is to investigate the extent to which forensic services address the needs of those accepted into services.

METHOD

This study reviews the treatment for 197 offenders with intellectual disability accepted into a range of services. Participants' case files were examined to ascertain the extent to which need was addressed through recognised therapies. A standard pro forma was used on which we had established good reliability across four research assistants.

RESULTS

The most frequently referred problems were violence and sexual offending. Specialist forensic intellectual disability community services were significantly more likely to provide treatment specifically designed to address index behaviours when compared to generic community services and secure services.

CONCLUSIONS

Various possible explanations of these findings are explored including staffing levels, diagnosed mental illness, expertise of staff and clarity of purpose in services.

Spontaneous reversal of the developmental aging of normal human cells following transcriptional reprogramming

AIM

To determine whether transcriptional reprogramming is capable of reversing the developmental aging of normal human somatic cells to an embryonic state.

MATERIALS & METHODS

An isogenic system was utilized to facilitate an accurate assessment of the reprogramming of telomere restriction fragment (TRF) length of aged differentiated cells to that of the human embryonic stem (hES) cell line from which they were originally derived. An hES-derived mortal clonal cell strain EN13 was reprogrammed by SOX2, OCT4 and KLF4. The six resulting induced pluripotent stem (iPS) cell lines were surveyed for telomere length, telomerase activity and telomere-related gene expression. In addition, we measured all these parameters in widely-used hES and iPS cell lines and compared the results to those obtained in the six new isogenic iPS cell lines.

RESULTS

We observed variable but relatively long TRF lengths in three widely studied hES cell lines (16.09-21.1 kb) but markedly shorter TRF lengths (6.4-12.6 kb) in five similarly widely studied iPS cell lines. Transcriptome analysis comparing these hES and iPS cell lines showed modest variation in a small subset of genes implicated in telomere length regulation. However, iPS cell lines consistently showed reduced levels of telomerase activity compared with hES cell lines. In order to verify these results in an isogenic background, we generated six iPS cell clones from the hES-derived cell line EN13. These iPS cell clones showed initial telomere lengths comparable to the parental EN13 cells, had telomerase activity, expressed embryonic stem cell markers and had a telomere-related transcriptome similar to hES cells. Subsequent culture of five out of six lines generally showed telomere shortening to lengths similar to that observed in the widely distributed iPS lines. However, the clone EH3, with relatively high levels of telomerase activity, progressively increased TRF length over 60 days of serial culture back to that of the parental hES cell line.

CONCLUSION

Prematurely aged (shortened) telomeres appears to be a common feature of iPS cells created by current pluripotency protocols. However, the spontaneous appearance of lines that express sufficient telomerase activity to extend telomere length may allow the reversal of developmental aging in human cells for use in regenerative medicine.

Rotational Skin Stretch Feedback: A Wearable Haptic Display for Motion

We present a wearable haptic feedback device that imparts rotational skin stretch to the hairy skin, along with the results of psychophysical tests to determine its resolution and accuracy for motion display. Tracking experiments with visual markers reveal the pattern of skin motion and strain imparted by the device, confirming subjective impressions that the design represents a trade-off between perception at low stimulus levels and comfort at maximum stimulus levels. In an isolated environment, users were able to discriminate between different rotational displacements of stretch within two to five degrees, depending on the reference stimulus. In a more realistic setting, subjects were able to use feedback from the device to control the positioning of a virtual object within six degrees or ±6.5 degrees of the total range of motion. When subjects were passive and exposed to arbitrary rotations of the device, the accuracy was poorer, although it improved with training. The results suggest that wearable skin stretch devices can be an effective means of providing feedback about a user's controlled joint or limb motions for motion training and similar applications.

The Lewisian Complex: insights into deep crustal evolution

The Lewisian Complex is an Archaean/Proterozoic craton fragment found in NW Scotland and throughout the Outer Hebrides. The 1907 memoir recognized, simply from field relationships and petrographic observation, key features of Lewisian evolution. The bulk of the Lewisian is an old, deformed complex consisting mainly of acid igneous rocks, with some basics, ultrabasics and metasediments. In the Central District of the mainland these are pyroxene bearing (now recognized as granulite facies). The Lewisian Complex was intruded by a suite of basic and ultrabasic dykes which show variable states of later deformation, the intensity of strain being correlated with the development of hornblende schist in the dykes and amphibolite facies assemblages in the country rocks. In the Northern and Southern Districts, this deformation is pervasive and the dykes become concordant hornblende schist sheets. The new foliation with transposed dykes and metasediment sheets is then folded around NW–SE axes. Today there is no single agreed model for the evolution of the complex but an outline is as follows. In the pre-dyke (Scourian) history, subduction led to melting of oceanic crust which provided vast volumes of tonalite-trondhjemite-granodiorite in the period 3100–2700 Ma. Ages show geographic variations but it is not proven whether that implies large displacements between pieces of crust or whether it represents intrusions into other intrusions. The subcontinental lithospheric mantle dates from c. 3000 Ma. K, U and other large ion lithophile elements are depleted in the Central District of the mainland; this is due to depletion in the downgoing oceanic slab which in turn is a result of dehydration prior to melting. Other areas are not depleted in such elements, so various tectonic settings were involved. Remnants of metabasic material in the Lewisian may be relics of oceanic crust. Granulite facies metamorphism with, in places, P>10 kb and T>1000 °C occurred a considerable time after intrusion so is not necessarily linked to igneous events. This ‘Badcallian’ episode affected mainly the Central District and a part of the southern Outer Hebrides; other areas show only amphibolite facies. Zircon dating indicates two high-grade events at 2500 and 2700 Ma. During the ‘Inverian’ episode a series of wide amphibolite-facies shear zones affected the granulite-facies Scourian gneiss prior to the intrusion of the Scourie dykes. The Scourie dykes were intruded from 2400–2000 Ma and are largely quartz tholeiites derived from enriched subcontinental lithospheric mantle; there are some picrites which yield the oldest ages but are also seen to crosscut basic dykes. The dykes trend NW–SE and are steep where not affected by later deformation except where they intrude along, and are controlled by, Inverian fabrics. Post-dyke (Laxfordian) history involves the development of calc-alkaline igneous rocks in the Outer Hebrides and mainland (c. 1900 Ma). Volcanics associated with sediments younger than 2000 Ma comprise an accretionary complex formed in a subduction setting; they are now intercalated between slabs of Archaean basement indicating that the complex was involved in collision with continental crust. Huge strains transposing dykes and country rocks affected almost all of the Outer Hebrides and the mainland except for the Central District. The NW–SE trending lineation indicates the collision direction; the metasediments on the mainland and the South Harris Igneous Complex may mark a folded suture between two continents. Metamorphism was amphibolite facies almost everywhere; in South Harris it was granulite facies at c. 1880 Ma. At 1750–1675 Ma, a distinct event, called late Laxfordian but much younger than earlier Laxfordian metamorphism and with a distinct tectonic setting, caused folding of the previous structures along NW–SE axes, migmatization and renewed amphibolite facies metamorphism.

Attosecond synchronization of high-order harmonics from midinfrared drivers

The group delay dispersion, also known as the attochirp, of high-order harmonics generated in gases has been identified as the main intrinsic limitation to the duration of Fourier-synthesized attosecond pulses. Theory implies that the attochirp, which is inversely proportional to the laser wavelength, can be decreased at longer wavelength. Here we report the first measurement of the wavelength dependence of the attochirp using an all-optical, in situ method [N. Dudovich, Nature Phys. 2, 781 (2006)10.1038/nphys434]. We show that a 2 microm driving wavelength reduces the attochirp with respect to 0.8 microm at comparable intensities.

Defining distinct caregiver subpopulations by intensity of end-of-life care provided

Interventions designed to assist informal caregivers who serve individuals at or near the end of life have predominantly focused on caregiving spouses. Can we define other caregiver subpopulations--by intensity of care provided--so as to enable better a) identification of caregiver needs and b) targeting of support to caregivers? The Health Omnibus Survey, an annual face-to-face survey in South Australia, collects health-related data from a representative sample of 4400 households. Piloted questions included in the 2001-2005 Health Omnibus surveys addressed death of a loved one, caregiving provided, impact of caregiving and caregiver characteristics. Of 18,224 respondents, 5302 reported a loved one's death due to terminal illness in the previous 5 years. In all, 502 (10%) provided daily care [5-7 days/week], 619 (12%) provided intermittent care [2-4 days/week] and 425 (8%) provided rare care. Active (daily plus intermittent) caregivers, compared with non-active (rare) caregivers, were more often women (63% vs 50%; P < 0.0001). Daily caregivers were distinguishable from intermittent; daily caregivers were more often widowed (95% vs 7%; P < 0.0001) and >or=60 years (80% vs 64%; P < 0.0001); intermittent caregivers were more commonly children/parents (35%), other relatives (33%), or friends (26%; P < 0.0001) and were better educated, more active in paid work and wealthier. Financial burden, experience at time of death, ability to move on after the death and need for grief support also differed by intensity of caregiving. Caregiver subpopulations can be defined according to intensity of caregiving with distinct demographic features helping to distinguish them.