Does timely reporting of preoperative CT scans influence outcomes for patients following emergency laparotomy?

INTRODUCTION: Timely preoperative computed tomography (CT) scans are important for patients requiring emergency laparotomy. United Kingdom guidelines state that a CT scan should be reported within 1h for 'critical' patients (will alter management at the time) and within 12h for 'urgent' patients (will alter management but not necessarily that day). METHODS: An observational study included patients who were added to the National Emergency Laparotomy Audit (NELA) at a National Health Service trust from 2014 to 2021. The association of compliance with timings guidance and mortality was investigated. Multivariable logistic regression was used to determine the odds ratio of adherence to guidelines according to age, gender, night time admission, American Society of Anesthesiology (ASA) score, NELA mortality risk and category of scan. Further models determined the influence of adherence to guidelines on mortality, also adjusted for these variables. RESULTS: There were 1,299 patients (48% 'critical' and 52% 'urgent' CT scans). Only 360/1,299 (28%) of scans were undertaken with adherence to the timing guidelines. Critical scans were less likely to adhere to guidelines. Although univariable analysis suggested that adherence to guidelines was associated with reduced mortality, this was not the case in the multivariable model: only age, ASA and NELA mortality risk remained significantly associated with mortality. CONCLUSIONS: A minority of patients met the recommended preoperative CT report timings, and this was less likely for scans designated 'critical'. This did not appear to affect mortality when adjusted for key variables of risk. This illustrates the phenomenon of guideline adherence appearing to affect patient outcomes as a product of selection bias rather than causality.

Surgical training during the COVID-19 pandemic at a designated 'cold' site: are we meeting the challenge?

INTRODUCTION: There has been a marked reduction in surgical operative training opportunities during the COVID-19 pandemic. This may be improved by the establishment of 'cold' sites for NHS elective surgery. We investigated the training opportunities at a newly designated elective surgery cold site in the West Midlands, UK. METHODS: An observational retrospective study was undertaken to include all gastrointestinal and urological elective surgery at a single 'cold' site during the first peak of the COVID-19 pandemic. Patient demographics, details of surgery and data relating to surgical training such as primary surgeon and portfolio index procedure were collected. Factors affecting the likelihood of trainees being the primary surgeon were analysed using logistic regression models. RESULTS: There were 880 patients, with a median (interquartile range) age of 62 (48-74). Some 658 (74.8%) procedures were defined as 'index procedures' for specialty training year 4 (ST4) level: 409/509 (80.4%) for urology, 155/235 (66%) for colorectal and 94/136 (69.1%) for upper gastrointestinal (GI). Only 253/880 (28.8%) procedures were performed by a trainee as the primary surgeon: 201/509 (39.4%) for urology, 21/235 (8.9%) for colorectal and 31/136 (22.8%) for upper GI. The likelihood of a trainee being the primary surgeon was reduced for major surgery (p<0.001) and for GI surgery when compared with urology (p<0.001). CONCLUSIONS: Surgical training was facilitated at an elective surgery 'cold' site during the COVID-19 pandemic, but at lower levels than anticipated. Type of surgery influenced trainee participation. Surgical training should be incorporated into 'cold' site elective surgical services if trainees are to be prepared for the future.

Comparing the surgical management of acute paediatric scrotal pain between adult urologists and general surgeons in the UK: an observational study.

INTRODUCTION: Acute scrotal pain is a common paediatric surgical emergency. Assessment and timely exploration are required to rule out testicular torsion (TT) and prevent unnecessary morbidity. METHODS: A retrospective observational cohort study was carried out at two district general hospitals in the UK for boys aged ≤16 years presenting with acute scrotal pain between January 2014 and October 2017 managed by adult general surgery (AGS) at one hospital and adult urology (AU) at the other. RESULTS: Some 565 patients were eligible for inclusion (n=364 AGS, n=201 AU). A higher proportion of patients underwent surgical exploration at AGS compared with AU (277/346 (80.1%) vs 96/201 (47.8%); p<0.001). Of those who underwent exploration, 101/373 (27.1%) had TT, of whom 25/101 (24.8%) underwent orchidectomy and 125/373 (33.5%) had torted testicular appendage. There was no statistically significant difference in rates of orchidectomy between AGS (19/68, 27.9%) and AU (6/33, 18.2%) with testicular salvage rates of 72.1% and 81.8%, respectively (p=0.334). Patients were twice as likely to be readmitted at AGS as at AU (28/346 (8.1%) vs 8/201 (4.0%); p=0.073). CONCLUSION: Although intraoperative findings were similar between adult general surgeons and urologists, there were significant differences in surgical management, with a higher rate of surgical exploration by general surgeons. Testicular salvage and 30-day postoperative morbidity rates at both institutions were acceptable but the readmission rate was high at 6.6%. It is not known why there is a heterogeneity in management of acute scrotal pain between specialist centres, and further prospective investigations are warranted.

Does declared surgeon specialist interest influence the outcome of emergency laparotomy?

INTRODUCTION: In the UK, general surgeons must demonstrate competency in emergency general surgery before obtaining a certificate of completion of training. Subsequently, many consultants develop focused elective specialist interests which may not mirror the breadth of procedures encountered during emergency practice. Recent National Emergency Laparotomy Audit analysis found that declared surgeon special interest impacted emergency laparotomy outcomes, which has implications for emergency general surgery service configuration. We sought to establish whether local declared surgeon special interest impacts emergency laparotomy outcomes. METHODS: Adult patients having emergency laparotomy were identified from our prospective National Emergency Laparotomy Audit database from May 2016 to May 2019 and categorised as colorectal or oesophagogastric according to operative procedure. Outcomes included 30-day mortality, return to theatre and length of stay. Binomial logistic regression was used to identify any association between declared consultant specialist interest and outcomes. RESULTS: Of 600 laparotomies, 358 (58.6%) were classifiable as specialist procedures: 287 (80%) colorectal and 71 (20%) oesophagogastric. Discordance between declared specialty and operation undertaken occurred in 25% of procedures. For colorectal emergency laparotomy, there was an increased risk of 30-day mortality when performed by a non-colorectal consultant (unadjusted odds ratio 2.34; 95% confidence interval 1.10-5.00; p = 0.003); however, when adjusted for confounders within multivariate analysis declared surgeon specialty had no impact on mortality, return to theatre or length of stay. CONCLUSION: Surgeon-declared specialty does not impact emergency laparotomy outcomes in this cohort of undifferentiated emergency laparotomies. This may reflect the on-call structure at Birmingham Heartlands Hospital, where a colorectal and oesophagogastric consultant are paired on call and provide cross-cover when needed.

Antenatal sildenafil citrate treatment increases offspring blood pressure in the placental-specific Igf2 knockout mouse model of FGR.

Fetal growth restriction (FGR), where a fetus fails to reach its genetic growth potential, affects up to 8% of pregnancies and is a major risk factor for stillbirth and adulthood morbidity. There are currently no treatments for FGR, but candidate therapies include the phosphodiesterase-5 inhibitor sildenafil citrate (SC). Randomized clinical trials in women demonstrated no effect of SC on fetal growth in cases of severe early onset FGR; however, long-term health outcomes on the offspring are unknown. This study aimed to assess the effect of antenatal SC treatment on metabolic and cardiovascular health in offspring by assessing postnatal weight gain, glucose tolerance, systolic blood pressure, and resistance artery function in a mouse model of FGR, the placental-specific insulin-like growth factor 2 (PO) knockout mouse. SC was administered subcutaneously (10 mg/kg) daily from embryonic day (E)12.5. Antenatal SC treatment did not alter fetal weight or viability but increased postnatal weight gain in wild-type (WT) female offspring (P < 0.05) and reduced glucose sensitivity in both WT (P < 0.01) and P0 (P < 0.05) female offspring compared with controls. Antenatal SC treatment increased systolic blood pressure in both male (WT vs. WT-SC: 117 ± 2 vs. 140 ± 3 mmHg, P < 0.0001; P0 vs. P0-SC: 113 ± 3 vs. 140 ± 4 mmHg, P < 0.0001; means ± SE) and female (WT vs. WT-SC: 121 ± 2 vs. 140 ± 2 mmHg, P < 0.0001; P0 vs. P0-SC: 117 ± 2 vs. 144 ± 4 mmHg, P < 0.0001) offspring at 8 and 13 wk of age. Increased systolic blood pressure was not attributed to altered mesenteric artery function. In utero exposure to SC may result in metabolic dysfunction and elevated blood pressure in later life.NEW & NOTEWORTHY Sildenafil citrate (SC) is currently used to treat fetal growth restriction (FGR). We demonstrate that SC is ineffective at treating FGR, and leads to a substantial increase systolic blood pressure and alterations in glucose homeostasis in offspring. We therefore urge caution and suggest that further studies are required to assess the safety and efficacy of SC in utero, in addition to the implications on long-term health.

Epigenetic biomarkers in progression from non-dysplastic Barrett's oesophagus to oesophageal adenocarcinoma: a systematic review protocol.

INTRODUCTION: Barrett's oesophagus (BO), a metaplastic condition affecting the lower oesophagus due to long-standing gastro-oesophageal reflux and chronic inflammation, is a precursor lesion for oesophageal adenocarcinoma (OADC). There is no clinical test to predict which patients with BO will progress to OADC. The British Society of Gastroenterology recommends endoscopic surveillance of patients with BO. Epigenetic changes have been well characterised in the neoplastic progression of ulcerative colitis to colonic carcinoma, another gastrointestinal cancer associated with chronic inflammation. This systematic review protocol aims to identify and evaluate studies which examine epigenetic biomarkers in BO and their association with progression to OADC. METHODS AND ANALYSIS: All prospective and retrospective primary studies, and existing systematic reviews investigating epigenetic markers including DNA methylation, histone modification, chromatin remodelling, micro and non-coding RNAs of all types will be eligible for inclusion. Eligible patients are those over the age of 18 with BO, BO with dysplasia, OADC or unspecified oesophageal cancer. A comprehensive search of bibliographic databases using combinations of text and index words relating to the population, prognostic markers and outcome will be undertaken with no language restrictions. Results will be screened by 2 independent reviewers and data extracted using a standardised proforma. The quality and risk of bias of individual studies will be assessed using the Quality in Prognostic Studies (QUIPS) tool. A narrative synthesis of all evidence will be performed with key findings tabulated. Meta-analysis will be considered where studies and reported outcomes are considered sufficiently homogeneous, both clinically and methodologically. Findings will be interpreted in the context of the quality of included studies. The systematic review will be reported according to PRISMA guidelines. ETHICS AND DISSEMINATION: This is a systematic review of completed studies and no ethical approval is required. Findings from the full systematic review will be submitted for publication and presentation at national and international conferences which will inform future research on risk stratification in patients with BO. REVIEW REGISTRATION NUMBER: CRD42016038654.

Surgery in the era of the 'omics revolution.

BACKGROUND: Surgery is entering a new phase with the revolution in genomic technology. Cheap, mass access to next-generation sequencing is now allowing the analysis of entire human genomes at the DNA and RNA level. These data sets are being used increasingly to identify the molecular differences that underlie common surgical diseases, and enable them to be stratified for patient benefit. METHODS: This article reviews the recent developments in the molecular biology of colorectal, oesophagogastric and breast cancer. RESULTS: The review specifically covers developments in genetic predisposition, next-generation sequencing studies, biomarkers for stratification, prognosis and treatment, and other 'omics technologies such as metabolomics and proteomics. CONCLUSION: There are unique opportunities over the next decade to change the management of surgical disease radically, using these technologies. The directions that this may take are highlighted, including future advances such as the 100,000 Genomes Project.

Sex differences in regional specialisation across the placental surface.

There may be regional specialisation in structure and function across the placental surface. In Riyadh, Saudi Arabia, the length and the breadth of the placental surface at birth were highly correlated, but the breadth was more closely associated with the size of the baby. To replicate this we studied 321 pregnant Saudi women in the town of Baish. We measured the size of the newborn babies and their placentas. The association of the length and breadth of the placental surface on the baby's body size differed in boys and girls. Among boys the breadth had a stronger association with all birth measurements except crown-heel length. This was similar to the findings in Riyadh. Placental surface length was related to crown-heel length. For each centimetre in surface length, crown-heel length increased by 0.27 cm (95% CI 0.09-0.44, p = 0.004). Among girls placental surface breadth was related to crown-heel length, whereas surface length was related to birth weight, head and thigh circumferences. For each centimetre in surface breadth, crown-heel length increased by 0.33 cm (0.13-0.53, p = 0.001). We conclude that, within Saudi Arabia, there are both geographical and sex differences in regional specialisation across the placental surface. In the adverse circumstances of Baish, linked to the mothers' short stature, boys were smaller at birth than girls. Boys may have compensated for under-nutrition by increasing the depth of spiral artery invasion rather than by recruiting additional spiral arteries. Girls may have had more effective regional specialisation across the placental surface.

Review: Transport across the placenta of mice and women.

Since the advent of technologies to produce genetic knockout and transgenic mice, the number of mouse strains suggested to be useful as models for pregnancy-related complications in the human has risen substantially. Some of these share features in common with fetal growth restriction (FGR) and preeclampsia (PE) and could be useful for investigating aetiologies and for testing potential therapeutics to improve outcome in these diseases. However, since placental pathology is a major underlying factor in both FGR and PE, it is important to understand the similarities and differences in structure and function of the placenta between mice and women. The main aim of this review is to directly compare placental exchange physiology between human and mouse. The review will compare human and mouse in both normal and pathological circumstances, to attempt to answer the question of whether placental studies in the mouse can be translated to the human. The review includes descriptions of placental structure between the species, comparisons of nutrient transport, including amino acids, glucose and calcium, and evidence of how these transport systems are altered in both human FGR and mouse models of this disease. Finally, our review will conclude by examining studies in which mouse models of FGR/PE have been treated with drugs of potential therapeutic value in women and consider whether data obtained in mice can be a prelude for clinical trials in human.

Crossing mice deficient in eNOS with placental-specific Igf2 knockout mice: a new model of fetal growth restriction.

We tested the hypothesis that crossing two mouse models of fetal growth restriction (FGR) of differing phenotype would induce more severe FGR than either model alone. Female endothelial nitric oxide synthase knockout mice (eNOS(-/-)) were mated with placental-specific Igf2 knockout males (P0). Resultant fetuses were no more growth restricted than those with P0 deletion alone. However, P0 deletion attenuated the reduced placental system A amino acid transporter activity previously observed in eNOS(-/-) mice. Manipulating maternal and fetal genotypes provides a means to compare maternal and fetal regulation of fetal growth.

IFPA Meeting 2011 workshop report I: Placenta: Predicting future health; roles of lipids in the growth and development of feto-placental unit; placental nutrient sensing; placental research to solve clinical problems--a translational approach.

Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2011 there were twelve themed workshops, four of which are summarized in this report. These workshops related to both basic science and clinical research into placental growth and nutrient sensing and were divided into 1) placenta: predicting future health; 2) roles of lipids in the growth and development of feto-placental unit; 3) placental nutrient sensing; 4) placental research to solve clinical problems: a translational approach.

Defining fetal growth restriction in mice: A standardized and clinically relevant approach.

The increasing number of mouse models of fetal growth restriction (FGR) make it crucial to standardize the way FGR is defined. By constructing growth curves in the placental-specific Igf2 knockout mouse (P0) it was demonstrated that 93% of P0 fetuses fell below the 5th centile of wild-type weights at E18.5, up from 44% at E16.5. This analysis, coupled with anthropomorphic measurements showing evidence of head sparing in P0 fetuses, allows clinical comparisons of FGR in mice through the use of clinically relevant growth curves. We suggest this as a standardized approach to defining FGR in mouse, and other animal models.

System A activity and vascular function in the placental-specific Igf2 knockout mouse.

OBJECTIVES: Deletion of the placental-specific P0 transcript of the insulin-like growth factor gene (Igf2) reduces placental growth from early pregnancy onwards. In Igf2 P0 knockout fetuses (P0), maternofetal flux of (14)C-methylaminoisobutyric acid ((14)C-MeAIB) mediated by system A amino acid transporter activity is increased at embryonic day 16 (E16), but this stimulation is not sustained, and by E19, fetal growth restriction (FGR) ensues. Here, we investigated whether upregulated (14)C-MeAIB transfer does occur concomitantly with a change in System A amino acid transporter activity and whether altered uteroplacental vascular function contributes to the FGR. We tested the hypothesis that FGR in P0 mice is attributable to altered nutrient transport rather than aberrant uteroplacental vascular function. METHODS: Plasma membrane vesicles were isolated from placentas of P0 and wild-type (WT) fetuses at E16 and E19. System A amino acid transporter activity was measured as sodium-dependent (14)C-MeAIB uptake over 60s. Wire myography was performed on uterine artery branches supplying P0 or WT implantation sites and agonist-induced constriction and dilation measured. RESULTS: Sodium-dependent uptake of (14)C-MeAIB (at 60s) was significantly (P < 0.05) higher in P0 compared to WT vesicles at E16; at E19 (14)C-MeAIB uptake was similar between P0 and WT. Uterine artery branch vascular reactivity was comparable between groups. CONCLUSIONS: System A activity in the maternal-facing plasma membrane of syncytiotrophoblast layer II underpins the adaptations observed in the transplacental MeAIB flux of P0 mice. Unaltered uterine artery vascular function suggests that the FGR phenotype of P0 fetuses is primarily due to deficient placental nutrient exchange capacity.

Placental-specific Igf2 knockout mice exhibit hypocalcemia and adaptive changes in placental calcium transport.

Evidence is emerging that the ability of the placenta to supply nutrients to the developing fetus adapts according to fetal demand. To examine this adaptation further, we tested the hypothesis that placental maternofetal transport of calcium adapts according to fetal calcium requirements. We used a mouse model of fetal growth restriction, the placental-specific Igf2 knockout (P0) mouse, shown previously to transiently adapt placental System-A amino acid transporter activity relative to fetal growth. Fetal and placental weights in P0 mice were reduced when compared with WT at both embryonic day 17 (E17) and E19. Ionized calcium concentration [Ca(2+)] was significantly lower in P0 fetal blood compared with both WT and maternal blood at E17 and E19, reflecting a reversal of the fetomaternal [Ca(2+)] gradient. Fetal calcium content was reduced in P0 mice at E17 but not at E19. Unidirectional maternofetal calcium clearance ((Ca) K (mf)) was not different between WT and P0 at E17 but increased in P0 at E19. Expression of the intracellular calcium-binding protein calbindin-D(9K), previously shown to be rate-limiting for calcium transport, was increased in P0 relative to WT placentas between E17 and E19. These data show an increased placental transport of calcium from E17 to E19 in P0 compared to WT. We suggest that this is an adaptation in response to the reduced fetal calcium accumulation earlier in gestation and speculate that the ability of the placenta to adapt its supply capacity according to fetal demand may stretch across other essential nutrients.

Increased maternofetal calcium flux in parathyroid hormone-related protein-null mice.

The role of parathyroid hormone-related protein (PTHrP) in fetal calcium homeostasis and placental calcium transport was examined in mice homozygous for the deletion of the PTHrP gene (PTHrP-/- null; NL) compared to PTHrP+/+ (wild-type; WT) and PTHrP+/- (heterozygous; HZ) littermates. Fetal blood ionized calcium was significantly reduced in NL fetuses compared to WT and HZ groups at 18 days of pregnancy (dp) with abolition of the fetomaternal calcium gradient. In situ placental perfusion of the umbilical circulation at 18 dp was used to measure unidirectional clearance of (45)Ca across the placenta in maternofetal ((Ca)K(mf)) and fetoplacental ((Ca)K(fp)) directions; (Ca)K(fp) was < 5% of (Ca)K(mf) for all genotypes. At 18 dp, (Ca)K(mf) across perfused placenta and intact placenta ((Ca)K(mf(intact))) were similar and concordant with net calcium accretion rates in vivo. (Ca)K(mf) was significantly raised in NL fetuses compared to WT and HZ littermates. Calcium accretion was significantly elevated in NL fetuses by 19 dp. Placental calbindin-D(9K) expression in NL fetuses was marginally enhanced (P < 0.07) but expression of TRPV6/ECaC2 and plasma membrane Ca2+-ATPase (PMCA) isoforms 1 and 4 were unaltered. We conclude that PTHrP is an important regulator of fetal calcium homeostasis with its predominant effect being on unidirectional maternofetal transfer, probably mediated by modifying placental calbindin-D(9K) expression. In situ perfusion of mouse placenta is a robust methodology for allowing detailed dissection of placental transfer mechanisms in genetically modified mice.

The vbs genes that direct synthesis of the siderophore vicibactin in Rhizobium leguminosarum: their expression in other genera requires ECF sigma factor RpoI.

A cluster of eight genes, vbsGSO, vbsADL, vbsC and vbsP, are involved in the synthesis of vicibactin, a cyclic, trihydroxamate siderophore made by the symbiotic bacterium Rhizobium leguminosarum. None of these vbs genes was required for symbiotic N2 fixation on peas or Vicia. Transcription of vbsC, vbsGSO and vbsADL (but not vbsP) was enhanced by growth in low levels of Fe. Transcription of vbsGSO and vbsADL, but not vbsP or vbsC, required the closely linked gene rpoI, which encodes an ECF sigma factor of RNA polymerase. Transfer of the cloned vbs genes, plus rpoI, to Rhodobacter, Paracoccus and Sinorhizobium conferred the ability to make vicibactin on these other genera. We present a biochemical genetic model of vicibactin synthesis, which accommodates the phenotypes of different vbs mutants and the homologies of the vbs gene products. In this model, VbsS, which is similar to many non-ribosomal peptide synthetase multienzymes, has a central role. It is proposed that VbsS activates L-N5-hydroxyornithine via covalent attachment as an acyl thioester to a peptidyl carrier protein domain. Subsequent VbsA-catalysed acylation of the hydroxyornithine, followed by VbsL-mediated epimerization and acetylation catalysed by VbsC, yields the vicibactin subunit, which is then trimerized and cyclized by the thioesterase domain of VbsS to give the completed siderophore.

Lead exposure in scaffolders during refurbishment construction activity--an observational study.

The toxic effects of lead have been known for centuries. Occupational exposure to this chemical hazard has also been well documented in relation to various industry groups, including construction, where workers are recognized as being significantly exposed during refurbishment work, in particular through inhalation and ingestion of lead fumes and dust. It is easy to see how so-called 'burners', 'cutters' and 'blasters'--workers directly involved in removing old lead paint--may become exposed; the influence of personal hygiene, smoking, eating/drinking and nail biting has also been documented in the literature. We now report on one group, the scaffolders, not previously considered to be at risk. Although not directly involved in the paint removal, anecdotal and personal experience of the authors indicate that these workers, who erect and later dismantle access structures during the renovation of previously lead-painted surfaces, may take up significant amounts of lead, mainly by ingestion, to raise their personal blood lead levels (and body burden) in line with recognized 'lead workers'. Exposures of this magnitude would also bring the scaffolders involved in such refurbishment work under the Control of Lead at Work Regulations 1998. The authors make various recommendations on measures to minimize and control exposure of scaffolders to lead.

Application of a very high-throughput digital imaging screen to evolve the enzyme galactose oxidase.

Directed evolution has become an important enabling technology for the development of new enzymes in the chemical and pharmaceutical industries. Some of the most interesting substrates for these enzymes, such as polymers, have poor solubility or form highly viscous solutions and are therefore refractory to traditional high-throughput screens used in directed evolution. We combined digital imaging spectroscopy and a new solid-phase screening method to screen enzyme variants on problematic substrates highly efficiently and show here that the specific activity of the enzyme galactose oxidase can be improved using this technology. One of the variants we isolated, containing the mutation C383S, showed a 16-fold increase in activity, due in part to a 3-fold improvement in K(m). The present methodology should be applicable to the evolution of numerous other enzymes, including polysaccharide-modifying enzymes that could be used for the large-scale synthesis of modified polymers with novel chemical properties.