The association between iron deficiency and outcomes: a secondary analysis of the intravenous iron therapy to treat iron deficiency anaemia in patients undergoing major abdominal surgery (PREVENTT) trial

In the intravenous iron therapy to treat iron deficiency anaemia in patients undergoing major abdominal surgery (PREVENTT) trial, the use of intravenous iron did not reduce the need for blood transfusion or reduce patient complications or length of hospital stay. As part of the trial protocol, serum was collected at randomisation and on the day of surgery. These samples were analysed in a central laboratory for markers of iron deficiency. We performed a secondary analysis to explore the potential interactions between pre-operative markers of iron deficiency and intervention status on the trial outcome measures. Absolute iron deficiency was defined as ferritin <30 μg.l^-1 ; functional iron deficiency as ferritin 30-100 μg.l^-1 or transferrin saturation < 20%; and the remainder as non-iron deficient. Interactions were estimated using generalised linear models that included different subgroup indicators of baseline iron status. Co-primary endpoints were blood transfusion or death and number of blood transfusions, from randomisation to 30 days postoperatively. Secondary endpoints included peri-operative change in haemoglobin, postoperative complications and length of hospital stay. Most patients had iron deficiency (369/452 [82%]) at randomisation; one-third had absolute iron deficiency (144/452 [32%]) and half had functional iron deficiency (225/452 [50%]). The change in pre-operative haemoglobin with intravenous iron compared with placebo was greatest in patients with absolute iron deficiency, mean difference 8.9 g.l^-1 , 95%CI 5.3-12.5; moderate in functional iron deficiency, mean difference 2.8 g.l^-1 , 95%CI -0.1 to 5.7; and with little change seen in those patients who were non-iron deficient. Subgroup analyses did not suggest that intravenous iron compared with placebo reduced the likelihood of death or blood transfusion at 30 days differentially across subgroups according to baseline ferritin (p = 0.33 for interaction), transferrin saturation (p = 0.13) or in combination (p = 0.45), or for the number of blood transfusions (p = 0.06, 0.29, and 0.39, respectively). There was no beneficial effect of the use of intravenous iron compared with placebo, regardless of the metrics to diagnose iron deficiency, on postoperative complications or length of hospital stay.

Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).

Patterns and mechanisms of major trauma injuries during and after the UK Covid-19 Nationwide lockdown: analysis from a UK Major Trauma Centre

PURPOSE

To compare patterns and mechanisms of injuries during and after the UK Nationwide lockdown during the COVID-19 pandemic.

METHODS

This prospective cohort study included all major trauma admissions during the 10-week period of the nationwide lockdown (09/03/2020-18/05/2020), compared with admissions in the 10-weeks following the full lifting of lockdown restrictions (04/07/20-12/09/2020). Differences in the volume, spectrum and mechanism of injuries presenting during and post-lockdown were compared using Fisher's exact and Chi-squared tests as appropriate. The associated risk of 30-day mortality was examined using univariable and multivariable logistic regression.

RESULTS

A total of 692 major trauma admissions were included in this analysis. Of these, 237 patients were admitted during the lockdown and 455 patients were admitted post-lockdown. This represented a twofold increase in trauma admission between the two periods. Characteristically, both cohorts had a higher proportion of male patients (73.84% male during lockdown and 72.5% male post-lockdown). There was a noted shift in age groups between both cohorts with an overall more elderly population during lockdown (p = 0.0292), There was a significant difference in mechanisms of injury between the two cohorts. The 3-commonest mechanisms during the lockdown period were: Road traffic accidents (RTA)-31.22%, Falls of less than 2 m-26.58%, and falls greater than 2 m causing 22.78% of major trauma admissions. However, in the post-lockdown period RTAs represented 46.15% of all trauma admissions with falls greater than 2 m causing 17.80% and falls less than 2 m causing 15.16% of major trauma injuries. With falls in the elderly associated with an increased risk of mortality. In terms of absolute numbers, there was a twofold increase in major trauma injuries due to stabbings and shootings, rising from 25 admitted patients during the lockdown to 53 admitted patients post-lockdown.

CONCLUSIONS

The lifting of lockdown restrictions resulted in a twofold increase in major trauma admissions that was also associated with significant changes in both the demographic and patterns of injuries with RTA's contributing almost half of all injury presentations.

TRIAL REGISTRATION

This study was classed as a service evaluation and registered with the local audit department, registration number: 20-177C.

National population prevalence of antibodies to SARS-CoV-2 among pregnant women in Scotland during the second wave of the COVID-19 pandemic: a prospective national serosurvey

OBJECTIVES

This study aimed to determine SARS-CoV-2 seroprevalence among pregnant women in the Scottish population during the second wave of the COVID-19 pandemic.

STUDY DESIGN

Prospective national serosurvey.

METHODS

We tested 13,428 residual samples retrieved from pregnant women participating in the first trimester combined ultrasound and biochemical screening for fetal trisomy across Scotland for SARS-CoV-2 antibodies over a 6-month period from November 2020 to April 2021. Seroprevalence estimates were adjusted for the sensitivity and specificity of the assays and weighted to reference populations.

RESULTS

Seroprevalence rates in the antenatal samples significantly increased from 5.5% (95% confidence interval [CI] 4.7%-6.5%) in the 5-week period up to and including International Organization for Standardization (ISO) Week 51 (w/b Monday 14 December 2020) to 11.3% (95% CI 10.1%-12.6%) in the 5-week period up to and including ISO Week 14 (w/b Monday 5 April 2021). Increasing seroprevalence trends across the second wave were observed among all age groups.

CONCLUSIONS

By the end of the second wave of the COVID-19 pandemic, approximately one in 10 women tested around the end of the first trimester of pregnancy had antibodies to SARS-CoV-2, suggesting that the vast majority were still susceptible to COVID-19 as they progressed to the later stages of pregnancy, when risks from infection are elevated for both mother and baby.

664 The ICON Trauma Study: The Impact of the COVID-19 Lockdown on Major Trauma Workload in the UK

Introduction

Anecdotal evidence suggest a direct impact of the SARS-COV-2-pandemic on presentation and severity of major trauma.

Method

This observational study from a UK Major Trauma Centre matched a cohort of patients admitted during a 10-week period of the SARS-CoV-2-pandemic (09/03/2020 to 18/05/2020) to a historical cohort admitted during a similar time period in 2019 (11/03/2019 to 20/05/2019). Demographic differences, injury method and severity were compared using Fisher’s and Chi-squared tests. Multivariable logistic regression examined the associated factors predicting 30-day mortality.

Results

Of 642 patients, 405 and 237 were in the 2019 and 2020 cohorts respectively. 1.69%(4/237) of the 2020 cohort tested SARS-CoV-2 positive. There was a 41.5% decrease in trauma admissions in 2020. The 2020 cohort was older (median 46 vs.40 years), more comorbid and frailer (p < 0.0015). There was a significant difference in injury method with a decrease in vehicle related trauma, but an increase in falls. There was a 2-fold increased risk of mortality in the 2020 cohort that in adjusted models, was explained by higher injury severity and frailty. Positive SARS-CoV-2 status was not associated with increased mortality on multivariable analysis.

Conclusions

Patients admitted during the SARS-CoV-2-pandemic were older, frailer, more co-morbid and had an increased risk of mortality.

Enhanced surveillance of COVID-19 in Scotland: population-based seroprevalence surveillance for SARS-CoV-2 during the first wave of the epidemic

Objectives

The impact of the COVID-19 pandemic in Scotland has been amongst the most severe in Europe. Serological surveillance is critical to determine the overall extent of infection across populations and to inform the public health response. This study aimed to estimate the proportion of people who have antibodies to SARS-CoV-2 (‘seroprevalence’) in the general population of Scotland and to see if this changes over time.

Study design/Methods

Between International Organization for Standardization (ISO) week 17 (i.e. week commencing 20th April) and ISO week 25 (week commencing 15 June), 4751 residual blood samples were obtained from regional biochemistry laboratories in six participating regional health authority areas covering approximately 75% of the Scottish population. Samples were tested for the presence of anti-SARS-CoV-2 IgG antibodies using the LIAISON®SARS-CoV-2 S1/S2 IgG assay (DiaSorin, Italy). Seroprevalence rates were adjusted for the sensitivity and specificity of the assay using Bayesian methods.

Results

The combined adjusted seroprevalence across the study period was 4.3% (95% confidence interval: 4.2%–4.5%). The proportion varied each week between 1.9% and 6.8% with no difference in antibody positivity by age, sex or geographical area.

Conclusions

At the end of the first wave of the COVID-19 pandemic, only a small fraction of the Scottish population had antibodies to SARS-CoV-2. Control of COVID-19 requires the ability to detect asymptomatic and mild infections that would otherwise remain undetected through existing surveillance systems. This is important to determine the true number of infections within the general population which, in turn, can help to understand transmission, inform control measures and provide a denominator for the estimation of severity measures such as the proportion of infected people who have been hospitalised and/or have died.

Temporal validation of metabolic nodal response of esophageal cancer to neoadjuvant chemotherapy as an independent predictor of unresectable disease, survival, and recurrence

Objectives

We recently described metabolic nodal stage (mN) and response (mNR) of cancer of the esophagus and gastro-esophageal junction (GEJ) to neoadjuvant chemotherapy (NAC) using ¹⁸F-FDG PET-CT as new markers of disease progression, recurrence, and death. We aimed to validate our findings.

Methods

Our validation cohort comprised all patients consecutive to our discovery cohort, staged before and after NAC using PET-CT from 2014 to 2017. Multivariate binary logistic and Cox regression were performed.

Results

Fifty-one of the 200 patients had FDG-avid nodes after NAC (25.5%; i.e., lack of complete mNR), and were more likely to progress during NAC to incurable disease on PET-CT or at surgery: odds ratio 3.84 (1.46–10.1; p = 0.006). In 176 patients undergoing successful resection, patients without complete mNR had a worse prognosis: disease-free survival hazard ratio 2.46 (1.34–4.50); p = 0.004. These associations were independent of primary tumor metabolic, pathological response, and stage. In a hybrid pathological/metabolic nodal stage, avid nodal metastases conferred a worse prognosis than non-avid metastases. Lack of complete mNR predicted recurrence or death at 1 and 2 years: positive predictive values 44.4% (31.7–57.8) and 74.1% (56.6–86.3) respectively.

Conclusions

This study provides temporal validation for mNR as a new and independent predictive and prognostic marker of esophageal and GEJ cancer treated with NAC and surgery, although external validation is required to assess generalizability. mNR may provide surrogate information regarding the phenotype of metastatic cancer clones beyond the mere presence of nodal metastases, and might be used to better inform patients, risk stratify, and personalize management, including adjuvant therapy.

Key Points

• We previously described metabolic nodal response (mNR) of esophageal cancer to neoadjuvant chemotherapy using¹⁸F-FDG PET-CT as a predictor of unresectable disease, early recurrence, and death.

• We report the first validation of these findings. In an immediately consecutive cohort, we found consistent proportions of patients with and without mNR, and associations with abandoned resection, early recurrence, and death.

• This supports mNR as a new and actionable biomarker in esophageal cancer. Although external validation is required, mNR may provide surrogate information about the chemosensitivity of metastatic subclones, and the means to predict treatment success, guide personalized therapy, and follow-up.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06310-9) contains supplementary material, which is available to authorized users.

Risk of infection associated with intravenous iron preparations: protocol for updating a systematic review

INTRODUCTION

The benefits and risk of intravenous iron have been documented in previous systematic reviews and continue to be the subject of randomised controlled trials (RCTs). An ongoing issue that continues to be raised is the relationship between administering iron and developing infection. This is supported by biological plausibility from animal models. We propose an update of a previously published systematic review and meta-analysis with the primary focus being infection.

METHODS AND ANALYSIS

We will include RCTs and non-randomised studies (NRS) in this review update. We will search the relevant electronic databases. Two reviewers will independently extract data. Risk of bias for RCTs and NRS will be assessed using the relevant tools recommended by The Cochrane Collaboration. Data extracted from RCTs and NRS will be analysed and reported separately. Pooled data from RCTs will be analysed using a random effects model. We will also conduct subgroup analyses to identify any patient populations that may be at increased risk of developing infection. We will provide a narrative synthesis on the definitions, sources and responsible pathogens for infection in the included studies. Overall quality of evidence on the safety outcomes of mortality and infection will be assessed using the Grading of Recommendations, Assessment, Development and Evaluation approach.

ETHICS AND DISSEMINATION

This systematic review will only investigate published studies and therefore ethical approval is not required. The results will be broadly distributed through conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

PROSPERO (CRD42018096023).

Longer-than-unit-length viroid minus strands are present in RNA from infected plants

Nucleic acids isolated from uninfected and potato spindle tuber viroid-infected Rutgers tomato plants were fractionated on agarose gels under two different sets of denaturing conditions and hybridized to (125)I-labeled viroid in a series of blot hybridization experiments. Complementary strand nucleic acids detected in extracts of infected plants were heterogeneous in size, with four discrete bands containing molecules approximately 700, 1050, 1500, and 1800 nucleotides long. Enzymatic studies indicated that these viroid minus strands are composed exclusively of RNA and, as extracted, are present in complexes containing extensive double-stranded regions. After treatment with several RNases under conditions favoring digestion of single-stranded regions, the high molecular weight minus strands can no longer be detected and roughly unit-length minus strands appear. A model for the structure of the viroid replication intermediate is proposed.

Potato spindle tuber and citrus exocortis viroids undergo no major sequence changes during replication in two different hosts

Potato spindle tuber viroid and citrus exocortis viroid, each purified from tomato (Lycopersicon esculentum) and from Gynura aurantiaca, were iodinated in vitro with (125)I, digested with ribonuclease T1, and subjected to two-dimensional RNA fingerprinting analysis. With the exception of minor variations, each viroid retained its distinctive fingerprint pattern irrespective of the host species from which it was isolated. We conclude that the nucleotide sequences of these viroids are principally determined by the infecting viroid and not by the host.

A phylogeny of the chloroplast gene rbcL in the Leguminosae: taxonomic correlations and insights into the evolution of nodulation

Phylogenetic analysis of the chloroplast-encoded rbcL gene in Leguminosae are consistent with previous hypotheses in suggesting that the family as a whole is monophyletic, but that only two of its three subfamilies are natural. The earliest dichotomies in the family appear to have involved tribes Cercideae or Cassieae (subtribe Dialiinae), followed by Detarieae/ Macrolobieae, all of which are members of subfamily Caesalpinioideae. The remainder of the family is divided into two clades: (1) Mimosoideae and the caesalpinioid tribes Caeasalpinieae and Cassieae (subtribes Ceratoniinae and Cassiinae); (2) Papilionoideae. Basal groups within Papilionoideae are, as expected, elements of the grade tribes Sophoreae and Swartzieae. Major clades within Papilionoideae include: (1) a Genistoid Alliance comprising Genisteae, Crotalarieae, Podalyrieae, Thermopsideae, Euchresteae, and also some Sophoreae; (2) a clade marked by the absence of one copy of the chloroplast inverted repeat, with which are associated Robinieae. Loteae, and some Sophoreae; (3) Phaseoleae, Desmodieae. Psoraleeae, and most Millettieae, a group also marked by presence of pseudoracemose inflorescences; and (4) a well-supported clade comprising Aeschynomeneae, Adesmieae, and some Dalbergieae. Nodulation is most parsimoniously optimized on the rbcL strict consensus tree as three parallel gains, occurring in Papilionoideae, the caesalpioioid ancestors of Mimosoideae, and in the genus Chamaecrista (Caesalpinieae: Cassieae).

Formation of water-soluble porphyrins and protoporphyrin IX in 5-aminolevulinic-acid-incubated carcinoma cells

The bioconversion of 5-aminolevulinic acid (ALA) into hydrophobic protoporphyrin IX and other water-soluble porphyrins was investigated in Ehrlich ascite carcinoma (EAC) cells and in a myeloma cell line. The effects of irradiation (514 nm), temperature, incubation time and added glucose on the relative porphyrin concentrations (protoporphyrin vs. water-soluble porphyrins) were examined. Variations in these parameters induced a change in the amount of water-soluble porphyrins relative to protoporphyrin IX. The main component of the hydrophilic porphyrins was found to be uroporphyrin (Up), with minor components of coproporphyrin (Cp) and other carboxyporphyrins. The enhanced production of water-soluble porphyrins appears to be associated with alterations in the activities of the various enzymes in the heme biosynthetic pathway, resulting, for example, in the reduction in the activity of mitochondrial enzymes.

Structure and distribution of Alu family sequences or their analogs within heterogeneous nuclear RNA of HeLa, KB, and L cells

We studied the distribution of repetitive sequence elements capable of forming double-stranded regions in nuclear RNA of HeLa, KB, and L cells. In human RNA populations, we called these regions duplex Alu family RNA (dAfRNA) because they represent transcripts of the highly reiterated family of DNA regions known as "Alu family DNA" (Rubin et al., Nature (London) 284:372-374, 1980). Although the dAfRNA populations of both human cell lines (HeLa and KB) have low sequence complexity, they represent 5% of the total heterogeneous nuclear RNA and have identical fingerprints; mouse L-cell dAf-like RNA (which has a similar complexity) represents only 2% of the total heterogeneous nuclear RNA and has an entirely different fingerprint. We utilized Escherichia coli RNase III as a highly specific reagent for the recognition of RNA:RNA duplex structure. This enzyme cleaves within the six characteristic RNase T1-resistant oligonucleotides of HeLa- and KB-cell dAfRNA (Robertson et al., J. Mol. Biol. 115:571-589, 1977). In addition, the size of heterogeneous nuclear RNA from all three cell types is reduced from greater than 32S to about 15S after RNase III treatment. We conclude that this size shift is a result of cleavage within dAfRNA regions and that such regions are present in most or all of the large RNA transcripts of these cells.

Specific RNA-cleaving activities from HeLa cells

Subcellular fractionation of HeLa cells was carried out under gentle conditions to isolate enzymes that cleave RNA precursors in a specific manner. Four separate activities--cleavage of HeLa cell heterogeneous nuclear RNA, the HeLa cell 45S rRNA precursor, RNA . DNA hybrids (RNase H), and the Escherichia coli tRNATyr precursor (RNase P)--were revealed by these studies. The specificity and limited nature of these cleavages suggest that they are due to eukaryotic RNA-processing enzymes. The virtual absence of random nucleases from these enzymes was demonstrated by their inability to cleave the 8000-base early mRNA precursor of bacteriophage T7, E. coli 30S rRNA precursor, or HeLa cytoplasmic poly(A)-containing RNA.

Identification of the RNA region transferred from a representative primer, beta-globin mRNA, to influenza mRNA during in vitro transcription

Capped eukaryotic mRNAs strongly stimulate influenza viral RNA transcription in vitro and donate their cap and also additional nucleotides to the viral transcripts (1). To identify which bases of a given primer mRNA are transferred, we synthesized influenza viral mRNA using a primer rabbit globin mRNA (enriched in beta-globin mRNA) which had been labeled in vitro to high specific activity with 125I. We show that during transcription the same 125I-labeled oligonucleotides were transferred to the 5' termini of each of the eight viral mRNA segments. The predominant sequence, representing 75 percent of the transferred oligonucleotides, was identical to the first 13 nucleotides at the 5' end of beta-globin mRNA (m7G5'ppp5'm6AmC(m)ACUUGCUUUUG). Because only the C-residues are labeled with 125I, these results indicate that either the first 12, 13 or 14 5' terminal bases of beta-globin mRNA were transferred to the viral mRNAs. 125I-labeled oligonucleotides recovered from the viral mRNA in minor yields indicated that shorter 5' terminal pieces of beta-globin mRNA were sometimes transferred and that G was probably the first base inserted by transcription.

Approaches to sequence analysis of 125I-labeled RNA

A method is described for the initial steps of sequence analysis of RNase T1-and pancreatic RN-ase-resistant oligonucleotides of RNA containing cytidylate residues labeled in vitro with 125I. In many cases an oligonucleotide sequence can be deduced from a consideration of (i) its relative position in the two-dimensional fingerprint (with DEAE thin layer homochromatographic second dimension), (ii) its electrophoretic mobility on DEAE paper at pH 1.9, and (iii) identification of its products of further enzymatic digestion by comparison with a set of marker oligonucleotides. Additional methods including analysis of oligonucleotides following chemical blocking of uridylate residues with CMCT and analysis of products of incomplete enzymatic digestion are also discussed.

A nucleotide sequence from a ribonuclease III processing site in bacteriophage T7 RNA

Transcription of that portion of the bacteriophage T7 genome encoding early functions yields RNA molecules about 7500 nucleotides long representing this entire early region. These long transcripts can be cleaved in vitro by highly purified Escherichia coli ribonuclease III (endoribonuclease III; EC 3.1.4.24), yielding five messenger RNAs identical to those produced in vivo. During this reaction, a small RNA fragment called F5 RNA is released, which is specified by the region of the T7 genome between genes 1.1 and 1.3. The following sequence of 32P-labeled F5 RNA has been determined using standard RNA sequencing techniques: pU-A-A-G-G-U-C-G-C-U-C-U-C-U-A-G-G-A-G-U-G-G-C-C-U-U-A-G-Uoh. The relative contributions of sequence and structure to ribonuclease III processing signals are considered in light of these findings.

Potential regulatory roles for RNA in cellular development

In addition to its widely accepted messenger and structural roles, RNA has been implicated in several other biological events: transfer of specificity of the immune response, interferon induction, and infection of plants by viroids. In none of these cases is the mechanism of RNA action understood. As a result of recent advances in the understanding of RNA metabolism in eukaryotic nuclei and potential specificity of nucleases that cleave such RNA, we have suggested specific ways in which "extra" RNA could be involved in regulation of the development of cells. A survey of literature concerning mammalian cell differentiation both in embryos and in the immune system leads to the observation that there appears to be a line of communication between macromolecules on cell surfaces and the genome. Making the conservative assumption that the DNA retains its integrity throughout development, it seems likely that highly specific signals are sometimes required to transfer information from outside the cell to the DNA,resulting in a change in state of differentiation. We propose a way in which RNA could be utilized in this process.