30-Day postoperative COVID-19 outcomes in 398 patients from regional hospitals utilising a designated COVID-19 minimal surgical site pathway.

INTRODUCTION: Postoperative pulmonary complications and mortality rates during the COVID-19 pandemic have been higher than expected, leading to mass cancellation of elective operating in the UK. To minimise this, the Guy's and St Thomas' Hospital NHS Foundation Trust elective surgery hub and the executive team at London Bridge Hospital (LBH) created an elective operating framework at LBH, a COVID-19 minimal site, in which patients self-isolated for two weeks and proceeded with surgery only following a negative preoperative SARS-CoV-2 polymerase chain reaction swab. The aim was to determine the rates of rates of postoperative COVID-19 infection. METHODS: The collaboration involved three large hospital trusts, covering the geographic area of south-east London. All patients were referred to LBH for elective surgery. Patients were followed up by telephone interview at four weeks postoperatively. RESULTS: Three hundred and ninety-eight patients from 13 surgical specialties were included in the analysis. The median age was 60 (IQR 29-71) years. Sixty-three per cent (252/398) were female. In total, 78.4% of patients had an American Society of Anesthesiologists grade of 1-2 and the average BMI was 27.2 (IQR 23.7-31.8) kg/m2. Some 83.6% (336/402) were 'major' operations. The rate of COVID-19-related death in our cohort was 0.25% (1/398). Overall, there was a 1.26% (5/398) 30-day postoperative all-cause mortality rate. Seven patients (1.76%) reported COVID-19 symptoms, but none attended the emergency department or were readmitted to hospital as a result. CONCLUSION: The risk of contracting COVID-19 in our elective operating framework was very low. We demonstrate that high-volume major surgery is safe, even at the peak of the pandemic, if patients are screened appropriately preoperatively.

External validation of the Surgical Outcome Risk Tool (SORT) in 3305 abdominal surgery patients in the independent sector in the UK.

BACKGROUND: Assessing the risk of post-surgical mortality is a key component of pre-surgical planning. The Surgical Outcome Risk Tool (SORT) uses pre-operative variables to predict 30-day mortality. The aim of this study was to externally validate SORT in patients undergoing major abdominal surgery. METHODS: Data were collected from patients treated in five independent hospitals in the UK. Individualised SORT scores were calculated, and area under the receiver operating characteristic (AUROC) and precision-recall curves (PRC) plus 95% confidence intervals (CI) were drawn to test the ability of SORT to identify in-hospital death. Outcomes of patients with a SORT predicted risk of mortality of ≥ 5% (high risk) were compared to those with a predicted risk of < 5% (standard risk). RESULTS: The study population comprised 3305 patients, mean age 51 years, 2783 (84.2%) underwent elective surgery most frequently involving the colon (24.6%), or liver, pancreas or gallbladder (18.2%). Overall, 1551 (46.9%) patients were admitted to ICU and 29 (0.88%) died. The AUROC of SORT for discriminating patients at risk of death in hospital was 0.899 (95% CI 0.849 to 0.949) and the PRC 0.247. In total, 72 (2.18%) patients were stratified as high risk. There were more unplanned ICU admissions and deaths in this group compared to the standard risk group (25.0% and 3.3%, versus 3.1% and 0.5%, respectively). CONCLUSION: We externally validated SORT in a large population of abdominal surgery patients. SORT performed well in patients with lower risk profiles, but underpredicted adverse outcomes in the higher risk group.

Analytical evaluation and critical appraisal of early commercial SARS-CoV-2 immunoassays for routine use in a diagnostic laboratory.

Background: The objective of this study was to evaluate the performance characteristics of early commercial SARS-CoV-2 antibody assays in mild and asymptomatic subjects to enable the selection of suitable immunoassays for routine diagnostic use.Methods: We used serum samples from a pre-COVID era patient cohort (n = 50, pre-December 2019), designated SARS-CoV-2 negative, and serum samples from a SARS-CoV-2 RT-PCR-positive cohort (n = 90) taken > 14 days post-symptom onset (April-May 2020). Six ELISA assays were evaluated, including one confirmation assay to investigate antibody specificity. We also evaluated one point-of-care lateral flow device (LFIA) and one high throughput electrochemiluminescence immunoassay (CLIA).Results: The ELISA specificities ranged from 84% to 100%, with sensitivities ranging from 75.3% to 90.0%. The LFIA showed 100% specificity and 80% sensitivity using smaller sample numbers. The Roche CLIA immunoassay showed 100% specificity and 90.7% sensitivity. When used in conjunction, the Euroimmun nucleocapsid (NC) and spike-1 (S1) IgG ELISA assays had a sensitivity of 95.6%. The confirmation Dia.Pro IgG assay showed 92.6% of samples tested contained both NC and S1 antibodies, 32.7% had NC, S1 and S2 and 0% had either S1 or S2 only.Conclusions: The Roche assay and the Euroimmun NC and S1 assays had the best sensitivity overall. Combining the assays detecting NC and S1/S2 antibody increased diagnostic yield. These first-generation assays were not calibrated against reference material and the results were reported qualitatively. A portfolio of next-generation SARS-CoV-2 immunoassays will be necessary to investigate herd and vaccine-induced immunity.

Increased multimodality treatment options has improved survival for Hepatocellular carcinoma but poor survival for biliary tract cancers remains unchanged.

BACKGROUND: Primary hepatobiliary cancer incidence in the UK is rising and survival rates are low. Surgery is the main curative option for these cancers, but multimodality therapies are expanding. The aim of our original study was to determine trends in survival, over an 8-year period, of patients treated for primary hepatobiliary cancers at our tertiary referral Centre. METHOD: Patients treated for the most common types of primary hepatobiliary cancers, namely Hepatocellular carcinoma (HCC), Cholangiocarcinoma and Gallbladder cancer between January 2009 and December 2016 were retrospectively analysed from a prospective database linked to UK Hospital Episode Statistics data. RESULTS: A total of 1536 patients with primary hepatobiliary cancers were assessed and treatment plans formulated at our supra-regional specialist Hepatobiliary MDT. The primary hepatobiliary cancers treated were HCC (n = 836), Cholangiocarcinoma (n = 516), and Gallbladder cancer (n = 184). Survival for all the 3 cancers was significantly better with curative treatment. Overall median survival times were 350, 180, and 150 days respectively for HCC, Cholangiocarcinoma and Gallbladder cancer. Excluding best supportive care patients, the respective survival figures were 900, 600, and 400 days. Survival for HCC patients improved over time and was significantly increased in the final 3 years of the study (p ≤ 0.011 for all). Cholangiocarcinoma and Gallbladder cancer survivals were poor and did not change significantly over time. CONCLUSION: HCC outcome has improved in association with expanded multimodal therapies. Survivals for cholangiocarcinoma and gallbladder cancer remain poor in parallel with limited expansion of multimodal therapies highlighting an unmet therapeutic need for biliary tract cancers.

Physiological effects of stress related to helicopter travel in Federal Emergency Management Agency search-and-rescue canines.

Working canines are deployed by the Federal Emergency Management Agency (FEMA), as part of a National Disaster Response Plan. Stress associated with helicopter flight and the resulting physical effects on the dog are unknown. Our objective was to test the hypotheses that (1) helicopter travel affects the physiology and faecal microbiota of working canines, but that (2) physiological consequences of helicopter travel will not negatively affect their work performance. A total of nine FEMA canines were loaded onto helicopters and flown for 30 min in July 2015. Rectal temperature, behavioural stress indicators and saliva swabs (for cortisol) were collected at baseline, loading, mid-flight and post-flight. After flight, canines completed a standardised search exercise to monitor work performance. Faecal samples were collected for microbial DNA extraction and Illumina sequencing. All canines were on a standardised diet (CANIDAE® Grain Free PURE Land®) for 3 weeks prior to the study. Visible indicators of stress were observed at loading and at mid-flight and corresponded with an increase (P < 0·05) in salivary cortisol from 5·4 µg/l (baseline) to 6·4 µg/l (loading). Additionally, rectal temperature increased (P < 0·05) from 38·61°C (baseline) to 39·33°C (mid-flight) and 39·72°C (post-flight). Helicopter travel did not affect search performance (P > 0·05). We found that α- and ß-diversity measures of faecal microbiota were not affected (P > 0·05). Our data suggest that although helicopter travel may cause physiological changes that have been associated with stress in working dogs, it does not make an impact on their search performance or the stability of faecal microbiota.

Ultrasound surveillance for hepatocellular carcinoma: service evaluation of a radiology-led recall system in a tertiary-referral centre for liver diseases in the UK.

AIM: To review the radiology-led ultrasound (US) surveillance programme for the detection of hepatocellular carcinoma (HCC) in cirrhotic patients in a UK tertiary-referral centre. MATERIALS AND METHODS: The radiology information system was searched for patients who had undergone US for surveillance of cirrhosis from September 2009 to May 2013. Patient demographics and cirrhosis aetiology were documented. Data including numbers of surveillance scans, abnormal findings suspicious for HCC, subsequent radiological investigations, numbers of HCC and survival for HCC patients were recorded. Service performance data, such as rates of attendance and rebooking, were also recorded. RESULTS: Eight hundred and four patients entered surveillance and 2,366 surveillance US examinations were performed; 368 (46%) underwent follow-up (6-monthly US). Abnormalities leading to further radiological investigations were found in 81 patients. Reasons for incomplete surveillance included non-attendance and radiology failure to re-book appointments. HCC was diagnosed in 22 patients. Fourteen had HCC diagnosed on a surveillance scan, eight had HCC diagnosed on a scan performed for other reasons. Patients diagnosed with HCC on a surveillance scan were more likely to be treated with curative intent and had longer survival. CONCLUSION: Even with a radiology-led recall service for HCC surveillance, the proportion of patients receiving scans 6-monthly was low, due in part to the lack of organisational support that is available for other screening programmes. This study gives a realistic representation of the implementation of surveillance in a UK hospital at the current time and of the rates of HCC proceeding to treatment.

A national survey of the provision of ultrasound surveillance for the detection of hepatocellular carcinoma.

OBJECTIVE: Hepatocellular carcinoma (HCC), the sixth most common cancer worldwide and third most common cause of cancer related death, is closely associated with the presence of cirrhosis. Survival is determined by the stage of the cancer, with asymptomatic small tumours being more amenable to treatment. Early diagnosis is dependent on regular surveillance and the primary objective of this survey was to gain a better understanding of the baseline attitudes towards and provision of ultrasound surveillance (USS) HCC surveillance in the UK. In addition, information was obtained on the stages of cancer of the patients being referred to and discussed at regional multidisciplinary team meetings. DESIGN: UK hepatologists, gastroenterologists and nurse specialists were sent a questionnaire survey regarding the provision of USS for detection of HCC in their respective hospitals. RESULTS: Provision of surveillance was poor overall, with many hospitals lacking the necessary mechanisms to make abnormal results, if detected, known to referring clinicians. There was also a lack of standard data collection and in many hospitals basic information on the number of patients with cirrhosis and how many were developing HCC was not known. For the majority of new HCC cases was currently being made only at an incurable late stage (60%). CONCLUSIONS: In the UK, the current provision of USS based HCC surveillance is poor and needs to be upgraded urgently.

Quantifying heritable variation in fitness-related traits of wild, farmed and hybrid Atlantic salmon families in a wild river environment.

Farmed fish are typically genetically different from wild conspecifics. Escapees from fish farms may contribute one-way gene flow from farm to wild gene pools, which can depress population productivity, dilute local adaptations and disrupt coadapted gene complexes. Here, we reanalyse data from two experiments (McGinnity et al., 1997, 2003) where performance of Atlantic salmon (Salmo salar) progeny originating from experimental crosses between farm and wild parents (in three different cohorts) were measured in a natural stream under common garden conditions. Previous published analyses focussed on group-level differences but did not account for pedigree structure, as we do here using modern mixed-effect models. Offspring with one or two farm parents exhibited poorer survival in their first and second year of life compared with those with two wild parents and these group-level inferences were robust to excluding outlier families. Variation in performance among farm, hybrid and wild families was generally similar in magnitude. Farm offspring were generally larger at all life stages examined than wild offspring, but the differences were moderate (5-20%) and similar in magnitude in the wild versus hatchery environments. Quantitative genetic analyses conducted using a Bayesian framework revealed moderate heritability in juvenile fork length and mass and positive genetic correlations (>0.85) between these morphological traits. Our study confirms (using more rigorous statistical techniques) previous studies showing that offspring of wild fish invariably have higher fitness and contributes fresh insights into family-level variation in performance of farm, wild and hybrid Atlantic salmon families in the wild. It also adds to a small, but growing, number of studies that estimate key evolutionary parameters in wild salmonid populations. Such information is vital in modelling the impacts of introgression by escaped farm salmon.

Measurement of regional forearm muscle haemodynamics via the near-infrared spectroscopy venous occlusion technique: the impact of hand circulatory occlusion.

The purpose of this study was to examine whether circulatory occlusion of the hand impacts on regional forearm muscle haemodynamics as determined by the near-infrared spectroscopy (NIRS) venous occlusion technique (NIRSVOT). Twenty-five young, healthy participants (18 males and 7 females; 28 ± 4 years; 71 ± 7 kg) completed two experimental protocols that were performed on the dominant arm: (1) a series of five venous occlusion trials with a suprasystolic cuff (>260 mmHg) applied to the wrist and (2) five venous occlusion trials without hand-occlusion. Both protocols were performed twice in a counterbalanced manner. NIRS data were obtained from the flexor digitorum superficialis (FDS) muscle using a dual wavelength, continuous-wave spectrophotometer. FDS muscle blood flow (Q(FDS)), vascular conductance (C(FDS)), O2 consumption (Vo(2FDS)), and venous O2 saturation (SvO2) were calculated from NIRS data during the initial 5 s of venous occlusion. Circulatory occlusion of the hand via wrist cuffing significantly (P < 0.05) reduced Q(FDS) (-36 ± 23%), CFDS (-37 ± 23%), Vo2(FDS) (-14 ± 31%) and SvO2 (-14 ± 12%). These findings indicate that hand-occlusion, via wrist cuffing, adversely impacts on regional forearm haemodynamics as determined by the NIRS-VOT. Consequently, it is recommended that future investigators avoid hand-occlusion when using the NIRS-VOT to quantify spontaneous haemodynamics of regional forearm muscle.

Assignment of oriented sample NMR resonances from a three transmembrane helix protein.

Oriented sample solid state NMR techniques have been routinely employed to determine the structures of membrane proteins with one or two transmembrane helices. For larger proteins the technique has been limited by spectral resolution and lack of assignment strategies. Here, a strategy for resonance assignment is devised and applied to a three transmembrane helix protein. Sequence specific assignments for all labeled transmembrane amino acid sites are obtained, which provide a set of orientational restraints and helix orientations in the bilayer. Our experiments expand the utility of solid state NMR in membrane protein structure characterization to three transmembrane helix proteins and represent a straightforward strategy for routinely characterizing multiple transmembrane helix protein structures.

The liver to abdominal area ratio (LAAR): a novel imaging score for prognostication in cirrhosis.

BACKGROUND: Anecdotally, liver size is important in determining prognosis in patients with end-stage liver disease (ESLD). AIMS: To assess if a ratio of liver area and abdominal area on cross-sectional imaging could accurately predict mortality in ESLD. METHODS: A retrospective-prospective cohort study was performed on patients with ESLD in a training set. The censor point used was date of patient death or liver transplant (LT). The liver to abdominal area ratio (LAAR) was calculated using the formula {LAAR = [liver area (cm(2))/abdominal area (cm(2))] × 100}. A validation set was collected from a different institution. RESULTS: Three hundred and sixteen patients were identified. Complete imaging and survival data were available in 158 subjects, 100 male (63%). The LAAR score detected progression to death/LT in our cohort (P < 0.003). Its prognostic accuracy at 90, 360 and 720 days, using the optimal cut-off (32.1), from baseline CT date to death/LT using the log-rank test was P = 0.28, P = 0.06 (OR 1.347, 95% CI 0.94-1.94) and P < 0.0001 (OR 1.89, 95% CI 1.25-2.85) respectively. On multivariate analysis, LAAR (P = 0.008), MELD (P = 0.004) and MELD-Na (P = 0.03) were independently associated with the primary study outcome measurement at 720 days. The validation set of 52 patients confirmed the utility of the LAAR to determine risk of death or need for LT, AUROC 0.89 (0.78-0.97), and P < 0.0001. CONCLUSIONS: The liver to abdominal area ratio (LAAR) score offers a new paradigm in disease modelling in end-stage liver disease (ESLD) and offers prognostic accuracy at 2 years from computer tomography (CT) imaging.

Beaufort trout MicroPlex: a high-throughput multiplex platform comprising 38 informative microsatellite loci for use in resident and anadromous (sea trout) brown trout Salmo trutta genetic studies.

A flexible panel consisting of 38 informative microsatellite markers for Salmo trutta is described. These markers were selected from a pool of over 150 candidate loci that can be readily amplified in four multiplex PCR groups but other permutations are also possible. The basic properties of each markers were assessed in six population samples from both the Burrishoole catchment, in the west of Ireland, and Lough Neagh, in Northern Ireland. A method to assess the relative utility of individual markers for the detection of population genetic structuring is also described. Given its flexibility, technical reliability and high degree of informativeness, the use of this panel of markers is advocated as a standard for S. trutta genetic studies.

Rapid, economical single-nucleotide polymorphism and microsatellite discovery based on de novo assembly of a reduced representation genome in a non-model organism: a case study of Atlantic cod Gadus morhua.

By combining next-generation sequencing technology (454) and reduced representation library (RRL) construction, the rapid and economical isolation of over 25 000 potential single-nucleotide polymorphisms (SNP) and >6000 putative microsatellite loci from c. 2% of the genome of the non-model teleost, Atlantic cod Gadus morhua from the Celtic Sea, south of Ireland, was demonstrated. A small-scale validation of markers indicated that 80% (11 of 14) of SNP loci and 40% (6 of 15) of the microsatellite loci could be amplified and showed variability. The results clearly show that small-scale next-generation sequencing of RRL genomes is an economical and rapid approach for simultaneous SNP and microsatellite discovery that is applicable to any species. The low cost and relatively small investment in time allows for positive exploitation of ascertainment bias to design markers applicable to specific populations and study questions.

Balancing selection on MHC class I in wild brown trout Salmo trutta.

Evidence is reported for balancing selection acting on variation at major histocompatibility complex (MHC) in wild populations of brown trout Salmo trutta. First, variation at an MHC class I (satr-uba)-linked microsatellite locus (mhc1) is retained in small S. trutta populations isolated above waterfalls although variation is lost at neutral microsatellite markers. Second, populations across several catchments are less differentiated at mhc1 than at neutral markers, as predicted by theory. The population structure of these fish was also elucidated.

Mycobacterium tuberculosis CwsA interacts with CrgA and Wag31, and the CrgA-CwsA complex is involved in peptidoglycan synthesis and cell shape determination.

Bacterial cell division and cell wall synthesis are highly coordinated processes involving multiple proteins. Here, we show that Rv0008c, a novel small membrane protein from Mycobacterium tuberculosis, localizes to the poles and on membranes and shows an overall punctate localization throughout the cell. Furthermore, Rv0008c interacts with two proteins, CrgA and Wag31, implicated in peptidoglycan (PG) synthesis in mycobacteria. Deletion of the Rv0008c homolog in M. smegmatis, MSMEG_0023, caused bulged cell poles, formation of rounded cells, and defects in polar localization of Wag31 and cell wall synthesis, with cell wall synthesis measured by the incorporation of the [(14)C]N-acetylglucosamine cell wall precursor. The M. smegmatis MSMEG_0023 crgA double mutant strain showed severe defects in growth, viability, cell wall synthesis, cell shape, and the localization of the FtsZ, FtsI, and Wag31 proteins. The double mutant strain also exhibited increased autolytic activity in the presence of detergents. Because CrgA and Wag31 proteins interact with FtsI individually, we believe that regulated cell wall synthesis and cell shape maintenance require the concerted actions of the CrgA, Rv0008c, FtsI, and Wag31 proteins. We propose that, together, CrgA and Rv0008c, renamed CwsA for cell wall synthesis and cell shape protein A, play crucial roles in septal and polar PG synthesis and help coordinate these processes with the FtsZ-ring assembly in mycobacteria.

MHC-mediated spatial distribution in brown trout (Salmo trutta) fry.

Major histocompatibility complex (MHC) class I-linked microsatellite data and parental assignment data for a group of wild brown trout (Salmo trutta L.) provide evidence of closer spatial aggregation among fry sharing greater numbers of MHC class I alleles under natural conditions. This result confirms predictions from laboratory experiments demonstrating a hierarchical preference for association of fry sharing MHC alleles. Full-siblings emerge from the same nest (redd), and a passive kin association pattern arising from limited dispersal from the nest (redd effect) would predict that all such pairs would have a similar distribution. However, this study demonstrates a strong, significant trend for reduced distance between pairs of full-sibling fry sharing more MHC class I alleles reflecting their closer aggregation (no alleles shared, 311.5 ± (s.e.)21.03 m; one allele shared, 222.2 ± 14.49 m; two alleles shared, 124.9 ± 23.88 m; P<0.0001). A significant trend for closer aggregation among fry sharing more MHC class I alleles was also observed in fry pairs, which were known to have different mothers and were otherwise unrelated (ML-r = 0) (no alleles: 457.6 ± 3.58 m; one allele (422.4 ± 3.86 m); two alleles (381.7 ± 10.72 m); P<0.0001). These pairs are expected to have emerged from different redds and a passive association would then be unlikely. These data suggest that sharing MHC class I alleles has a role in maintaining kin association among full-siblings after emergence. This study demonstrates a pattern consistent with MHC-mediated kin association in the wild for the first time.

Characterization of CrgA, a new partner of the Mycobacterium tuberculosis peptidoglycan polymerization complexes.

The role(s) in cell division of the Mycobacterium tuberculosis Rv0011c gene product, a homolog of the Streptomyces CrgA protein that is responsible for coordinating growth and cytokinesis in sporogenic aerial hyphae, is largely unknown. We show that an enhanced cyan fluorescent protein-M. tuberculosis CrgA (ECFP-CrgA(MT)) fusion protein is localized to the cell membrane, midcell, and cell pole regions in Mycobacterium smegmatis. Furthermore, the ECFP-CrgA(MT) fusion protein colocalized with FtsZ-enhanced yellow fluorescent protein (EYFP) in M. smegmatis. Bacterial two-hybrid assays indicated strong interactions of M. tuberculosis CrgA with FtsZ, FtsQ, and the class B penicillin-binding proteins, FtsI (PBPB) and PBPA. The midcell localization of CrgA(MT) was severely compromised under conditions of FtsZ depletion, which indicated that CrgA localizes to the midcell region after assembly of the FtsZ ring. M. tuberculosis cells with reduced CrgA levels were elongated and grew more slowly than wild-type cells, which indicated defects in cell division, whereas CrgA overproduction did not show growth defects. A M. smegmatis ΔcrgA strain exhibited a bulged cell morphology, elongated cells with a chain-like phenotype, cells with polar bulbous structures, and a modest growth defect. FtsZ and FtsI levels were not affected in cells producing altered levels of CrgA. Septal and membrane localization of GFP-FtsI was enhanced by CrgA overproduction and was diminished in a ΔcrgA strain, which indicates that one role of CrgA is to promote and/or stabilize FtsI localization. Overall, these data indicate that CrgA is a novel member of the cell division complex in mycobacteria and possibly facilitates septum formation.