Predicting severe pain after major surgery: a secondary analysis of the Peri-operative Quality Improvement Programme (PQIP) dataset.

Acute postoperative pain is common, distressing and associated with increased morbidity. Targeted interventions can prevent its development. We aimed to develop and internally validate a predictive tool to pre-emptively identify patients at risk of severe pain following major surgery. We analysed data from the UK Peri-operative Quality Improvement Programme to develop and validate a logistic regression model to predict severe pain on the first postoperative day using pre-operative variables. Secondary analyses included the use of peri-operative variables. Data from 17,079 patients undergoing major surgery were included. Severe pain was reported by 3140 (18.4%) patients; this was more prevalent in females, patients with cancer or insulin-dependent diabetes, current smokers and in those taking baseline opioids. Our final model included 25 pre-operative predictors with an optimism-corrected c-statistic of 0.66 and good calibration (mean absolute error 0.005, p = 0.35). Decision-curve analysis suggested an optimal cut-off value of 20-30% predicted risk to identify high-risk individuals. Potentially modifiable risk factors included smoking status and patient-reported measures of psychological well-being. Non-modifiable factors included demographic and surgical factors. Discrimination was improved by the addition of intra-operative variables (likelihood ratio χ2 496.5, p < 0.001) but not by the addition of baseline opioid data. On internal validation, our pre-operative prediction model was well calibrated but discrimination was moderate. Performance was improved with the inclusion of peri-operative covariates suggesting pre-operative variables alone are not sufficient to adequately predict postoperative pain.

Management of tracheostomy-related tracheomegaly in a patient with COVID-19 pneumonitis.

Acquired tracheomegaly is a rare condition associated with pulmonary fibrosis, connective tissue disease and the use of cuffed tracheal tubes. We describe the urgent tracheal re-intubation and subsequent tracheal repair of a previously well 58-year-old man who developed tracheostomy-related tracheomegaly during prolonged mechanical ventilation for coronavirus disease 2019 pneumonitis. Urgent tracheal re-intubation was required due to a persistent cuff leak, pneumomediastinum and malposition of the tracheostomy tube. We describe the additional challenges and risks associated with airway management in patients with tracheomegaly, and discuss how even in urgent cases these can be mitigated through planning and teamwork. We present a stepwise approach to tracheal re-intubation past a large tracheal dilatation, including the use of an Aintree catheter inserted via the existing tracheal stoma for oxygenation or tracheal re-intubation if required. Computed tomography imaging was valuable in characterising the defect and developing a safe airway management strategy before starting the procedure. This report emphasises the role of planning, teamwork and the development of an appropriate airway strategy in the safe management of complex cases.

Examining Radiation-Induced In Vivo and In Vitro Gene Expression Changes of the Peripheral Blood in Different Laboratories for Biodosimetry Purposes: First RENEB Gene Expression Study.

The risk of a large-scale event leading to acute radiation exposure necessitates the development of high-throughput methods for providing rapid individual dose estimates. Our work addresses three goals, which align with the directive of the European Union's Realizing the European Network of Biodosimetry project (EU-RENB): 1. To examine the suitability of different gene expression platforms for biodosimetry purposes; 2. To perform this examination using blood samples collected from prostate cancer patients (in vivo) and from healthy donors (in vitro); and 3. To compare radiation-induced gene expression changes of the in vivo with in vitro blood samples. For the in vitro part of this study, EDTA-treated whole blood was irradiated immediately after venipuncture using single X-ray doses (1 Gy/min(-1) dose rate, 100 keV). Blood samples used to generate calibration curves as well as 10 coded (blinded) samples (0-4 Gy dose range) were incubated for 24 h in vitro, lysed and shipped on wet ice. For the in vivo part of the study PAXgene tubes were used and peripheral blood (2.5 ml) was collected from prostate cancer patients before and 24 h after the first fractionated 2 Gy dose of localized radiotherapy to the pelvis [linear accelerator (LINAC), 580 MU/min, exposure 1-1.5 min]. Assays were run in each laboratory according to locally established protocols using either microarray platforms (2 laboratories) or qRT-PCR (2 laboratories). Report times on dose estimates were documented. The mean absolute difference of estimated doses relative to the true doses (Gy) were calculated. Doses were also merged into binary categories reflecting aspects of clinical/diagnostic relevance. For the in vitro part of the study, the earliest report time on dose estimates was 7 h for qRT-PCR and 35 h for microarrays. Methodological variance of gene expression measurements (CV ≤10% for technical replicates) and interindividual variance (≤twofold for all genes) were low. Dose estimates based on one gene, ferredoxin reductase (FDXR), using qRT-PCR were as precise as dose estimates based on multiple genes using microarrays, but the precision decreased at doses ≥2 Gy. Binary dose categories comprising, for example, unexposed compared with exposed samples, could be completely discriminated with most of our methods. Exposed prostate cancer blood samples (n = 4) could be completely discriminated from unexposed blood samples (n = 4, P < 0.03, two-sided Fisher's exact test) without individual controls. This could be performed by introducing an in vitro-to-in vivo correction factor of FDXR, which varied among the laboratories. After that the in vitro-constructed calibration curves could be used for dose estimation of the in vivo exposed prostate cancer blood samples within an accuracy window of ±0.5 Gy in both contributing qRT-PCR laboratories. In conclusion, early and precise dose estimates can be performed, in particular at doses ≤2 Gy in vitro. Blood samples of prostate cancer patients exposed to 0.09-0.017 Gy could be completely discriminated from pre-exposure blood samples with the doses successfully estimated using adjusted in vitro-constructed calibration curves.

Time, dose and ataxia telangiectasia mutated (ATM) status dependency of coding and noncoding RNA expression after ionizing radiation exposure.

Studies of gene expression have proved important in defining the molecular mechanisms of radiation action and identifying biomarkers of ionizing radiation exposure and susceptibility. The full transcriptional response to radiation is very complex since it also involves epigenetic mechanisms triggered by radiation exposure such as modifications of expression of noncoding RNA such as microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) that have not been fully characterized. To improve our understanding of the transcriptional response to radiation, we simultaneously monitored the expression of ten protein-coding genes, as well as 19 miRNAs and 3 lncRNAs in a time- and dose-dependent manner in stimulated human T lymphocytes obtained from two healthy donors (C1 and C2) and one patient with ataxia telangiectasia (AT), which is a well characterized radiosensitivity disorder. After 2 Gy X irradiation, expression levels were monitored at time points ranging from 15 min up to 24 h postirradiation. The majority of genes investigated responded rapidly to radiation exposure, with the peak up-regulation (CDKN1A, SESN1, ATF3, MDM2, PUMA and GADD45A) or down-regulation (CCNB1) occurring 2-3 h postirradiation, while DDB2, FDXR and CCNG1 responded with slower kinetics reaching a peak of expression between 5 and 24 h. A significant modification of expression after radiation exposure was observed for miR-34a-5p and miR-182-5p, with an up-regulation occurring at late time points reaching two to threefold at 24 h. Differences between two donors in miR-182-5p response to radiation were detected: for C2, up-regulation reached a plateau-phase around 5 Gy, while for C1, up-regulation was at its maximum around 3 Gy and then decreased at higher doses. Among the three lncRNAs studied, TP53TG1 demonstrated a weak up-regulation, reaching a maximum of 1.5-fold at 24 h after radiation exposure. Conversely, FAS-AS1 was up-regulated up to fivefold by 5 Gy irradiation. Our results indicate that expression of the majority of protein-coding genes allows discrimination of the AT from healthy donors when analyzed at 2 h. However, differences in expression between AT and healthy donors are no longer detectable 24 h postirradiation although, interestingly, linear dose responses for some of the genes studied are obtained at this time point. Furthermore, our study shows that miRNAs miR-34a-5p and miR-182-5p are responsive to radiation exposure in a dose- and time-dependent manner. Additionally, to the best of our knowledge, this is the first study to report that FAS-AS1 lncRNA is up-regulated by radiation exposure in an ATM-dependent fashion in human T lymphocytes.

Effect of diabetes on the cutaneous microcirculation of the feet in patients with intermittent claudication.

AIMS: To evaluate endothelial-dependent and - independent cutaneous vasodilator responses in the feet of patients with peripheral arterial disease (PAD) with or without Type 2 diabetes. METHODS: Cutaneous microvascular responses in the dorsum of both lower limbs were measured in the supine position using Laser Doppler Fluximetry combined with iontophoretic administration of endothelial-dependent (acetylcholine, Ach) and -independent (sodium nitroprusside, SNP) vasodilators in diabetic (n = 19) and non diabetic (n = 17) patients with PAD (presenting as unilateral calf intermittent claudication (IC). RESULTS: In patients with diabetes and IC, endothelial-dependent vasodilation was significantly impaired in the symptomatic limb [74 (57,105) vs 68 (24,81) PU, Z =-2.79, p = 0.005] compared to the asymptomatic limb. Patients without diabetes showed no impairment of vasodilation. Resting ankle-brachial pressure index did not identify the presence of abnormalities in microvascular function. CONCLUSIONS: The combination of diabetes and PAD is associated with a reduction in endothelial-dependent cutaneous vasodilation in the feet without an associated reduction in endothelial independent vasodilation.

Deoxyribonucleic acid damage-associated biomarkers of ionising radiation: current status and future relevance for radiology and radiotherapy.

Diagnostic and therapeutic radiation technology has developed dramatically in recent years, and its use has increased significantly, bringing clinical benefit. The use of diagnostic radiology has become widespread in modern society, particularly in paediatrics where the clinical benefit needs to be balanced with the risk of leukaemia and brain cancer increasing after exposure to low doses of radiation. With improving long-term survival rates of radiotherapy patients and the ever-increasing use of diagnostic and interventional radiology procedures, concern has risen over the long-term risks and side effects from such treatments. Biomarker development in radiology and radiotherapy has progressed significantly in recent years to investigate the effects of such use and optimise treatment. Recent biomarker development has focused on improving the limitations of established techniques by the use of automation, increasing sensitivity and developing novel biomarkers capable of quicker results. The effect of low-dose exposure (0-100 mGy) used in radiology, which is increasingly linked to cancer incidences, is being investigated, as some recent research challenges the linear-no-threshold model. Radiotherapy biomarkers are focused on identifying radiosensitive patients, determining the treatment-associated risk and allowing for a tailored and more successful treatment of cancer patients. For biomarkers in any of these areas to be successfully developed, stringent criteria must be applied in techniques and analysis of data to reduce variation among reports and allow data sets to be accurately compared. Newly developed biomarkers can then be used in combination with the established techniques to better understand and quantify the individual biological response to exposures associated with radiology tests and to personalise treatment plans for patients.

Counterion condensation theory of attraction between like charges in the absence of multivalent counterions.

There is abundant experimental evidence suggesting the existence of attractive interactions among identically charged polyelectrolytes in ordinary salt solutions. The presence of multivalent counterions is not required. We review the relevant literature in detail and conclude that it merits more attention than it has received. We discuss also some recent observations of a low ionic strength attraction of negatively charged DNA to the region of a negatively charged glass nanoslit where the floor of the nanoslit meets the walls, again in the absence of multivalent ions. On the theoretical side, it has become clear that purely electrostatic interactions require the presence of multivalent counterions if they are to generate like-charge attraction. Any theory of like-charge attraction in the absence of multivalent counterions must therefore contain a non-electrostatic component. We point out that counterion condensation theory, which has predicted like-charge polyelectrolyte attraction in an intermediate range of distances in ordinary 1:1 salt conditions, contains both electrostatic and non-electrostatic elements. The non-electrostatic component of the theory is the modeling constraint that the counterions fall into two explicit populations, condensed and uncondensed. As reviewed in the paper, this physically motivated constraint is supported by strong experimental evidence. We proceed to offer an explanation of the nanoslit observations by showing in an idealized model that the line of intersection of two intersecting planes is a virtual polyelectrolyte. Since we have previously developed a counterion condensation theory of attraction of two like-charged polyelectrolytes, our suggestion is that the DNA is attracted to the virtual polyelectrolytes that may be located in the nanoslit where floor meets walls. We present the detailed calculations needed to document this suggestion: an extension of previous theory to the case of polyelectrolytes with like but not identical charges; the demonstration of counterion condensation on a plane with bare charge density greater than an explicitly exhibited critical value; a calculation of the free energy of the plane; a calculation of the interaction of a line charge polyelectrolyte with a like-charged plane; and the detailed demonstration that the line of intersection of two planes is a virtual polyelectrolyte.

A counterion condensation theory for the relaxation, rise, and frequency dependence of the parallel polarization of rodlike polyelectrolytes.

We calculate the relaxation, rise, and frequency dependence of the parallel polarization of counterions condensed on rodlike polyelectrolytes and charged colloids. Emphasis is placed on an effective counterion mobility along the rod as strongly influenced by electrostatic interactions.

Assessment of lower limb microcirculation: exploring the reproducibility and clinical application of laser Doppler techniques.

PURPOSE OF STUDY: Non-invasive laser Doppler fluximetry (LDF) and laser Doppler imaging (LDI), combined with iontophoresis, have been used to study the microcirculation in a range of clinical conditions including lower limb venous disease. A prerequisite for an accurate measurement tool is that it is reproducible. However, there is currently no literature with respect to the reproducibility of LDF and LDI combined with iontophoresis in the lower limb (in general) and in the upright position (in specific). Furthermore, the two techniques have been used interchangeably by researchers and the association between these two different measurement methods has not been explored, nor have the factors that affect them been well described. Thus the aim of this study was to determine the reproducibility of LDF and LDI with iontophoresis in the lower limb and investigate factors that influence their clinical application. PROCEDURES: Cutaneous microvascular responses in the lower limb were measured in the supine and standing positions using LDF and LDI combined with iontophoretic administration of endothelial-dependent (acetylcholine, ACh) and -independent (sodium nitroprusside) vasodilators in 25 patients with uncomplicated isolated superficial venous incompetence (ISVI) and 26 healthy controls. RESULTS: Maximum perfusion had the best reproducibility assessed by LDF (CV 20.5-24.3%) and LDI (15.8-17.6%). Both techniques were positively influenced by iontophoretic dose (e.g. p = 0.0001 for LDF) and the use of vasodilator agents (e.g. p = 0.0001 for LDF), but negatively influenced in the standing position and/or in the presence of ISVI (p = 0.0016 and 0.045, respectively, for LDF). There was a statistically significant positive relationship between the two techniques, for example ACh maximum perfusion versus LDF ACh maximum perfusion (r = 0.404, p = 0.016). CONCLUSIONS: Both techniques are reproducible, in line with similar studies undertaken in other areas of the human body, and provide useful information for the study of the lower-limb microcirculation. Direct comparison between techniques based on absolute numbers should be avoided and the technique choice should be based on individual study needs.

Nitrosopumilus maritimus genome reveals unique mechanisms for nitrification and autotrophy in globally distributed marine crenarchaea.

Ammonia-oxidizing archaea are ubiquitous in marine and terrestrial environments and now thought to be significant contributors to carbon and nitrogen cycling. The isolation of Candidatus "Nitrosopumilus maritimus" strain SCM1 provided the opportunity for linking its chemolithotrophic physiology with a genomic inventory of the globally distributed archaea. Here we report the 1,645,259-bp closed genome of strain SCM1, revealing highly copper-dependent systems for ammonia oxidation and electron transport that are distinctly different from known ammonia-oxidizing bacteria. Consistent with in situ isotopic studies of marine archaea, the genome sequence indicates N. maritimus grows autotrophically using a variant of the 3-hydroxypropionate/4-hydroxybutryrate pathway for carbon assimilation, while maintaining limited capacity for assimilation of organic carbon. This unique instance of archaeal biosynthesis of the osmoprotectant ectoine and an unprecedented enrichment of multicopper oxidases, thioredoxin-like proteins, and transcriptional regulators points to an organism responsive to environmental cues and adapted to handling reactive copper and nitrogen species that likely derive from its distinctive biochemistry. The conservation of N. maritimus gene content and organization within marine metagenomes indicates that the unique physiology of these specialized oligophiles may play a significant role in the biogeochemical cycles of carbon and nitrogen.

Transverse polarizability of an aligned assembly of charged rods.

The low-field transverse polarizability of the counterions condensed on an isolated charged rod is small. We show that it can be much larger if the rod is a member of an assembly of aligned rods. The polarization free energy of the assembly of rods in a transverse field is then similar to its polarization free energy in a field parallel to the rods. The polarization free energy of the assembly in a transverse field becomes lower than in a parallel field if the extent of the assembly (as measured, for example, by the diameter of a cylindrical assembly) is larger than the length of the individual rods. We suggest that this model may provide a reasonable explanation for the occurrence of "anomalous" birefringence in systems of interacting charged rodlike particles.

Analysis of rewarming curves in Raynaud's phenomenon of various aetiologies.

This study investigated whether a modified Cold Provocation Test could distinguish between 86 normal subjects and 31 patients with Raynaud's phenomenon or 59 with hand arm vibration syndrome (HAVS). Of the HAVS subjects, 56 were seen for medical reports as they were involved in litigation. Their assessments were done in a different location but the same protocol was used. A standardised cold stress was used to reduce the finger temperature to 15 degrees C or less without inducing reflex hyperaemia. This test had acceptable repeatability for subjects without HAVS with an intra-class correlation of 0.7. Baseline temperature, temperature rise in the first 30 seconds and the time taken to rewarm by 5 degrees C were measured. Patients with Raynaud's phenomenon and HAVS had cooler hands than controls. HAVS patients rewarmed most in the first 30 seconds. Patients with Raynaud's phenomenon take longer to rewarm by 5 degrees C than controls or those with HAVS (P<0.001). A baseline difference of >7.5 degrees C between the temperature of the digit and that of the room is unlikely to occur in patients with Raynaud's phenomenon or HAVS. A temperature gain of > or =2.2 degrees C in the first 30 seconds on rewarming combined with a low baseline temperature strongly suggests HAVS. This modified cold provocation test may differentiate between patients with Raynaud's phenomenon, HAVS and controls but this observation requires independent verification in subjects not involved in litigation and tested in the same facility.

Contrasting effects of varicose vein surgery on endothelial-dependent and -independent cutaneous vasodilation in the perimalleolar region.

OBJECTIVES: To evaluate the effects of varicose vein surgery on cutaneous microvascular perfusion and vasodilator responses to acetylcholine (Ach) and sodium nitroprusside (SNP) in the gaiter area of patients with great saphenous vein insufficiency. METHODS: Twenty-nine patients with isolated great saphenous vein incompetence attended three study mornings (before surgery, and 6-8 weeks and 6 months after sapheno-femoral ligation+partial stripping) during which cutaneous microvascular responses were measured in the supine and standing positions using laser Doppler fluximetry (LDF) combined with incremental-dose iontophoretic administration of endothelial-dependent (Ach) and -independent (SNP) vasodilators. RESULTS: Varicose vein surgery had no significant effect on baseline cutaneous perfusion or the microvascular response to Ach: e.g. peak vasodilator responses to the 1000 microC stimulus were mean 58 SEM 7, 64 SEM 6 and 65 SEM 7PU on the pre-operative, 6-8 weeks and 6 months assessments. In contrast, the corresponding responses to SNP were significantly increased following surgery: e.g. at 2000 microC, mean 63 SEM 9, 142 SEM 4 and 157 SEM 9PU (p<0.0001) in the upright position. CONCLUSIONS: Sapheno-femoral ligation and partial stripping in patients with great saphenous vein insufficiency improves endothelial-independent cutaneous vasodilator function at the gaiter area, which may at least partly explain the benefits of surgery in reducing the risk of venous ulceration.

Comparison of the biotypes of Yersinia enterocolitica isolated from pigs, cattle and sheep at slaughter and from humans with yersiniosis in Great Britain during 1999-2000.

AIMS: To investigate the relationship between livestock carriage of Yersinia enterocolitica and human disease. The biotypes/serotypes of strains recovered from the faeces of pigs, cattle and sheep at slaughter during a national survey in Great Britain in 1999-2000, were compared with those of strains isolated from human cases of yersiniosis during the same period. METHODS AND RESULTS: The faecal carriage of Y. enterocolitica by cattle, sheep and pigs at slaughter was 6.3, 10.7 and 26.1%, respectively. Yersinia enterocolitica biotype (BT) 1a was the most frequently isolated biotype from livestock (58%) and was the predominant biotype (53%) isolated from human cases over the same period. The main recognized pathogenic Y. enterocolitica biotype isolated from livestock was BT3 (O:5,27) (35% of sheep, 22% of pigs and 4% of cattle) but this biotype was not detected in any of the human isolates investigated. The major pathogenic biotypes of strains isolated from humans were BT3 (O:9) (24%) and BT4 (O:3) (19%) whereas of the veterinary isolates investigated, only pigs (11%) carried BT3 (O:9) strains. CONCLUSIONS: Because of significant overlaps in phenotypes of the veterinary and human strains it is not possible to comment on the correlation between host and pathogenicity, especially of biotype 1a. SIGNIFICANCE AND IMPACT OF THE STUDY: The data suggest that further investigations using methods with greater discriminatory power are required. However the data also suggests that pigs may be the primary reservoir for human pathogenic Y. enterocolitica infection.

Effects of posture and venous insufficiency on endothelial-dependent and -independent cutaneous vasodilation in the perimalleolar region.

OBJECTIVES: To assess the effects of posture, endothelial function and venous insufficiency on cutaneous microvascular vasodilator function in the gaiter area, in particular defining factors which may affect microangiopathy and ulcer formation. METHODS: Endothelial-dependent and -independent vasodilator responses to incremental-doses of acetylcholine (Ach) and sodium nitroprusside (SNP) were evaluated in the perimalleolar region in the supine and standing positions in middle-aged patients with isolated superficial venous insufficiency (ISVI) (n = 25) and healthy controls (n = 28) using laser Doppler fluximetry (LDF) and iontophoresis of vasodilators. RESULTS: The venoarteriolar reflex (vasoconstriction on standing) was equally present in both groups, and reduced the vasodilator responses to SNP in the upright position (e.g., for patients with ISVI, peak SNP response was 82 +/- 11 PU [standing] vs 123 +/- 15 PU [supine]). The presence of ISVI had no effect on endothelial vasodilator function in the supine position, but on standing cutaneous reactivity to Ach was significantly reduced (e.g., peak Ach response 69 +/- 8 PU [ISVI] vs 109 +/- 11 PU [controls], p < 0.003). CONCLUSIONS: Upright posture impairs cutaneous endothelial-dependent vasodilation in the gaiter area of patients with ISVI. This may be of clinical and prognostic utility in identifying which patients with uncomplicated ISVI are at highest risk of tissue breakdown and ulcer formation in the gaiter area.

The protein kinase complement of the human genome.

We have catalogued the protein kinase complement of the human genome (the "kinome") using public and proprietary genomic, complementary DNA, and expressed sequence tag (EST) sequences. This provides a starting point for comprehensive analysis of protein phosphorylation in normal and disease states, as well as a detailed view of the current state of human genome analysis through a focus on one large gene family. We identify 518 putative protein kinase genes, of which 71 have not previously been reported or described as kinases, and we extend or correct the protein sequences of 56 more kinases. New genes include members of well-studied families as well as previously unidentified families, some of which are conserved in model organisms. Classification and comparison with model organism kinomes identified orthologous groups and highlighted expansions specific to human and other lineages. We also identified 106 protein kinase pseudogenes. Chromosomal mapping revealed several small clusters of kinase genes and revealed that 244 kinases map to disease loci or cancer amplicons.

Checkerboard DNA-DNA hybridisation technology focused on the analysis of Gram-positive cariogenic bacteria.

Checkerboard DNA-DNA hybridisation enabled the quantitative analysis of plaque samples against 40 microbial species simultaneously, using digoxygenin-labelled, whole-genome DNA probes. This technique was initially developed to study the predominantly Gram-negative sub-gingival plaque microbiota. The aim of this study was to apply it to a suite of predominantly Gram-positive microorganisms, such as those implicated in cariogenesis. To specifically target Gram-positive species (and Candida albicans) required optimisation and modification of DNA extraction, prehybridisation, hybridisation, and antibody detection conditions. The suitability of the revised technique for clinical and epidemiological studies was confirmed using interproximal plaque from small groups of 5- to 6-year-old children of high (decayed, missing, or filled teeth (dmft)> or =5, n=8) and zero (n=5) caries rates.