2,4-Disubstituted pyridine derivatives are effective against intracellular and biofilm-forming tubercle bacilli

It was recently reported that 4-substituted picolinohydrazonamides carrying hydrophilic cyclic amines, such as morpholine and pyrrolidine, at the end of their thiosemicarbazide chain have potent antimycobacterial activity in vitro at concentrations below 1 μg/ml. Here, two selected compounds, 2,4-disubstituted pyridine derivatives 11 and 15, revealed significant bactericidal activity against Mycobacterium tuberculosis localized intracellularly within human macrophages, as well as against biofilm-forming tubercle bacilli. Mutants were selected that were resistant to the investigated compounds at an efficiency similar to that identified in the presence of the first line antituberculosis drug rifampicin. The resistant mutants were viable in the presence of the tested compounds exclusively on solid media. Genome-wide sequencing of the mutants selected in the presence of compound 11 revealed the accumulation of nonsynonymous mutations in the mmpR5 gene encoding a transcriptional repressor of the MmpS5-MmpL5 efflux pump, whose upregulation has been associated with bedaquiline resistance. The depletion of MmpR5 in wild-type M. tuberculosis using CRISPR–Cas9 technology increased the resistance of this strain to compound 11. Mass spectrometry-based proteomics (LC–MS/MS) of wild-type tubercle bacilli growing in subinhibitory concentrations of compounds 11 or 15 revealed 15 overproduced proteins not detectable in the control cells, including virulence-related proteins.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

British Journal of Surgery Society.

31 Quality or Quantity? An Analysis of the Colorectal Cancer Resection Volume-Outcome Relationship From the 2019 National Bowel Cancer Audit Data

Aim

Despite increasing evidence supporting cancer services centralisation, no consensus exists in the association between high-hospital or high-surgeon volume and mortality following colorectal cancer surgery. This study aimed to identify and characterise a volume-outcome relationship in colorectal cancer.

Method

National Bowel Cancer Audit (NBOCA) dataset was combined with the Association of Coloproctology of Great Britain and Ireland (ACPGBI) Clinical Outcomes Publication (COP) 2019 report. Adjusted 90-day and 2-year mortality were derived from patients included in the 2018 and 2016 datasets, respectively. The impact of centre volume, surgeon volume and ACPGBI membership rates on outcomes was assessed. Cumulative sum (CUSUM) analysis was performed to identify the centre and surgeon volume threshold.

Results

144 hospitals were included, with 17,235 and 17,703 patients from the 2018 and 2016 datasets, respectively. 781 surgeons were identified, with 478 holding ACPGBI memberships. No significant difference was found between centre or surgeon volumes for adjusted 90-day and 2-year mortality. High ACPGBI membership rates were significantly associated with a reduced 90-day (p=0.006), but not 2-year mortality (p=0.198). CUSUM analysis found 36 per year as threshold centre volume (p=0.003) and 15 surgeries per year as the threshold surgeon volume (p=0.241).

Conclusions

The high degree of existing centralisation for cancer services in the UK limits the number of true low-volume centres compared to other countries. Surgeon volume may be a better predictor of colorectal cancer surgery outcomes than centre volume. More granular data is needed to improve the current understanding of the association between surgeon volume, ACPGBI membership and outcomes in colorectal surgery.

245 An Introduction to Surgery: Effectiveness of An Online, Lecture-Based Programme in Providing Surgical Career Guidance for Pre-Clinical Students

Aim

Early exposure to surgery has been found to impact medical students’ decisions to pursue a career in surgery. Despite this, students are often not exposed to surgical specialties until senior years of medical school. The aim of this study was to determine if a student-led, three-month online lecture series can facilitate early exposure to surgical careers.

Method

Participants volunteered to complete pre- and post-lecture questionnaires. The four domains discussed across the lecture series included: what a surgical career entails, the day-to-day life of a surgeon, advances in surgery and surgical portfolio. Participants self-rated confidence in the knowledge of each of the four domains was measured on a five-step Likert scale. Changes in perceived confidence were measured using a paired Student’s t-test. Data were analysed using R 4.03 (Vienna, Austria). The threshold of significance was <0.05.

Results

A total of 45 respondents completed both pre- and post-lecture questionnaires. Most respondents (57.8%) were first- or second-year students. Following the course, there was a significant increase in confidence across all four domains investigated (mean rating 2.64 vs 4.07, p < 0.001). More than 9 out of 10 respondents (99.3%) gained new knowledge and (95.2%) agreed that an online event format did not hinder their learning.

Conclusions

Student-led online lecture series can increase knowledge of core concepts pertaining to a career in surgery for pre-clinical students. The findings provide a basis for further large-scale investigation of surgical education during early years of medical school and for the potential value of extracurricular, student- or trainee-led courses.

244 Traumatic Brain Injury Related Paediatric Mortality and Morbidity in Low- And Middle-Income Countries: A Systematic Review and Meta-Analysis

Aim

Three million cases of paediatric traumatic brain injury (pTBI) occur annually, the majority of which occur in low-and-middle-income countries (LMICs). However, there is a paucity of data on the outcomes of pTBI available. We aimed to systematically review and synthesise the reported morbidity and mortality from pTBI in the published literature about LMICs.

Method

A systematic review and meta-analysis were conducted. MEDLINE, EMBASE, Global Health, and Global Index Medicus were searched for relevant articles from January 2000 to May 2020. Observational or experimental studies on pTBI (individuals between the ages of 0 to 16 years) in LMICs were included. Morbidity data were descriptively analysed, and a random-effects model was used to pool mortality rates. PROSPERO ID: CRD42020171276.

Results

We included 145 studies from 38 countries representing 174073 patients with pTBI. Males were twice (95% CI: 1.6 – 2.4) as likely to have a pTBI than females. Where available, mild TBI represented ≥ 60% of all pTBI cases in most reports (n = 24/43, 56%). The commonest cited cause of pTBI was road traffic accidents (n = 16643/43083, 39%), followed by falls (n = 10927/43083, 25%). 4385 patients (n = 4385/18092, 24%) had a reduction from normal function on discharge. On average, there were 6.7 deaths per 100 cases of pTBI.

Conclusions

Only 38 LMICs have published data on the volume and burden of pTBI in their country. Limited data available suggests that young male children are at a high-risk of pTBIs in LMICs, particularly from road traffic accidents.

430 A Review of Artificial Intelligence Solutions for Hepatocellular Carcinoma

Introduction

Hepatocellular carcinoma (HCC) is a significant cause of morbidity and mortality worldwide. Despite significant advancements, the diagnosis and management of HCC remain a challenge. This review aims at exploring artificial intelligence (AI) solutions applied to HCC.

Method

A review of the literature from Embase, MEDLINE and Cochrane Library was conducted to determine the role of AI in HCC, across three domains: detection, characterisation, and prediction. 56 relevant original research studies were identified and included in a qualitative synthesis.

Results

AI models can be implemented into detection of HCC, as they excel at analysis and integration of large datasets. Moreover, AI outclasses traditional statistical models at tumour characterisation based on radiological and pathological images. Predicting treatment outcomes and survival using AI can shape future HCC guidelines and support clinical decision making, especially treatment choice. AI in HCC has limitations, hindering its clinical adoption. Small sample size, single-centre data, non-transparent reporting, lack of external validation, and overfitting all results in low generalisability of findings.

Conclusions

AI has immense potential; however, interdisciplinary collaboration is needed to improve, validate, and implement it across all aspects of HCC. AI has a multifaceted role in HCC and its importance can increase in the future, as more sophisticated technologies emerge.

428 Hepatic Epithelioid Hemangioendothelioma: A Rare Vascular Malignancy Mimicking as Intrahepatic Cholangiocarcinoma

Hepatic epithelioid hemangio-endothelioma (EHE) is a rare, often misdiagnosed malignancy of vascular origin. We describe a case of a 36-year-old, who presented with a burning sensation in his chest on exercise and was believed to have bilobar intrahepatic cholangiocarcinoma. After receiving chemotherapy with partial response, the patient underwent staged resection modified ALPPS (associating liver partition with portal vein ligation for staged hepatectomy) procedure – laparoscopic radiofrequency assisted ALPPS (RALPPS). Histological examination of the stage 1 specimen revealed EHE deposits in the left lobe of the liver. The patient proceeded to have stage 2 open right hepatectomy with concurring histology. 90-days follow-up CT scan showed almost complete resolution of EHE lesions.

Low incidence, non-specific clinical and radiological characteristics all contribute to high EHE misdiagnosis rate. Histological analysis can be used for confirmation of the diagnosis; however, specialist staining is required, which is not routinely performed. Multiple treatments are available against EHE, but only liver resection and liver transplantation are potentially curative. ALPPS and its modifications (such as RALPPS) offer an alternative for conventional two-stage hepatectomy for patients with extensive bilobar EHE, who are at risk of developing post-hepatectomy liver failure or patients with anomalous hepatic vasculature anatomy, which makes PVE challenging.

A search for genetic markers associated with egg production in the ostrich (Struthio camelus)

The aim of the current study was to search for genetic markers, microsatellite loci associated with laying performance in ostriches. The material consisted of two groups of ostrich hens characterized by high or low laying performance (over 75 and less than 25 eggs per season, respectively). The investigation covered 30 microsatellite loci characteristic for the ostrich (the CAU group) and led to identification of significant differences in allele and genotype frequencies between the two groups of hens considered. Out of a total of 30 microsatellite loci examined, 28 showed different alleles in relation to analyzed performance groups. In hens of high laying performance (HP group, n = 12), specific alleles occurred in 23 microsatellite loci (40 alleles of 243 identified), while in those of low egg production (LP group, n = 12), they occurred in 22 (51 alleles of 243 identified). The results indicate the usefulness of the microsatellite loci as the potential genetic markers associated with laying performance that can be applied for genetic improvement of ostrich flocks.

The use of microsatellite polymorphism in genetic mapping of the ostrich (Struthio camelus)

The aim of this study was to determine microsatellite polymorphism in ostriches and using it in creation the genetic map of the ostrich. The polymorphism analysis covered 30 microsatellite markers characteristic of ostrich, for the CAU (China Agricultural University) group. The material consisted of 150 ostriches (Struthio camelus). The 30 microsatellite loci was examined and a total of 343 alleles was identified. The number of alleles at a single locus ranged from 5 at locus CAU78 to 34 at locus CAU85. The values for the observed heterozygosity H_o ranged from 0.467 (locus CAU78) to 0.993 (locus CAU16), whereas for the expected heterozygosity H_e - from 0.510 (locus CAU78) to 0.953 (locus CAU85). Analyzing the individual loci, the highest PIC value, more than 0.7 was observed for: loci CAU85 (0.932), CAU64 (0.861) and CAU32, 75 (0.852), respectively. It should be noted, that the microsatellite markers used in our study were very polymorphic as evidenced by the large number of detected alleles and high rates of heterozygosity, PIC and PE as well. The analysed microsatellite markers may be used in genetic linkage mapping of ostrich, the construction of a comparative genetic map with other ratites, such as emu and rhea, and population genetics studies or phylogenetic studies of these birds.

Genetic characteristics of the ostrich population using molecular methods

A genetic analysis was performed on Polish ostriches from the 3 principal ostrich breeds: red-, blue-, and black-necks. The analysis was based on 2 molecular methods: DNA fingerprinting and microsatellites. The DNA fingerprinting patterns were obtained using the restriction enzyme HinfI and Jeffrey's 33.15 probe. The second method consisted of a PCR procedure, for which 5 VIAS-OS primers specific to the ostrich were used. The PCR products were separated on polyacrylamide gel using ALFexpress (Authomated Laser Fluorescent DNA Sequencer). The study aimed at assessing the genetic variability within and among the 3 ostrich breeds as well as evaluating the genetic distance between them, and represents the first report on the genetic characteristics of the ostrich breeds. The results obtained by both methods showed considerable compatibility, especially with regard to the relationship among the breeds analyzed. The diversity within breeds, obtained on the basis of the DNA fingerprinting analysis, proved to be low. Among the ostrich populations analyzed, the highest variability potential was observed for black-necked ostriches (the mean diversity of patterns amounted to 29.04%, whereas the mean heterozygosity was 0.30) and the lowest was observed for the red-necks. The largest genetic similarity was recorded between red- and blue-necked ostriches, but the greatest genetic distance was between the red- and black-necks. This means that the use of birds of those breeds in crosses should result in the highest heterotic effect. Both of these methods measured the genetic distance between the analyzed ostrich breeds that was expected from the geographic origin of these birds. The results obtained in the present study showed that both analytic methods used can be successfully applied when elaborating on the genetic characteristics of the ostrich.