Population-based analysis of POT1 variants in a cutaneous melanoma case-control cohort.

Pathogenic germline variants in the protection of telomeres 1 gene (POT1) have been associated with predisposition to a range of tumour types, including melanoma, glioma, leukaemia and cardiac angiosarcoma. We sequenced all coding exons of the POT1 gene in 2928 European-descent melanoma cases and 3298 controls, identifying 43 protein-changing genetic variants. We performed POT1-telomere binding assays for all missense and stop-gained variants, finding nine variants that impair or disrupt protein-telomere complex formation, and we further define the role of variants in the regulation of telomere length and complex formation through molecular dynamics simulations. We determine that POT1 coding variants are a minor contributor to melanoma burden in the general population, with only about 0.5% of melanoma cases carrying germline pathogenic variants in this gene, but should be screened in individuals with a strong family history of melanoma and/or multiple malignancies.

Addressing the variation in adjuvant chemotherapy treatment for colorectal cancer: Can a regional intervention promote national change?

Analysis of routine population-based data has previously shown that patterns of surgical treatment for colorectal cancer can vary widely, but there is limited evidence available to determine if such variation is also seen in the use of chemotherapy. This study quantified variation in adjuvant chemotherapy across both England using cancer registry data and in more detail across the representative Yorkshire and Humber regions. Individuals with Stages II and III colorectal cancer who underwent major resection from 2014 to 2015 were identified. Rates of chemotherapy were calculated from the Systemic Anticancer Treatment database using multilevel logistic regression. Additionally, questionnaires addressing different clinical scenarios were sent to regional oncologists to investigate the treatment preferences of clinicians. The national adjusted chemotherapy treatment rate ranged from 2% to 46% (Stage II cancers), 19% to 81% (Stage III cancers), 24% to 75% (patients aged <70 years) and 5% to 46% (patients aged ≥70 years). Regionally, the rates of treatment and the proportions of treated patients receiving combination chemotherapy varied by stage (Stage II 4%-26% and 0%-55%, Stage III 48%-71% and 40%-84%) and by age (<70 years 35%-68% and 49%-91%; ≥70 years 15%-39% and 6%-75%). Questionnaire responses showed significant variations in opinions for high-risk Stage II patients with both deficient and proficient mismatch repair tumours and Stage IIIB patients aged ≥70 years. Following a review of the evidence, open discussion in our region has enabled a consensus agreement on an algorithm for colorectal cancer that is intended to reduce variation in practice.

National variation in pulmonary metastasectomy for colorectal cancer.

AIM: Evidence on patterns of use of pulmonary metastasectomy in colorectal cancer patients is limited. This population-based study aims to investigate the use of pulmonary metastasectomy in the colorectal cancer population across the English National Health Service (NHS) and quantify the extent of any variations in practice and outcome. METHODS: All adults who underwent a major resection for colorectal cancer in an NHS hospital between 2005 and 2013 were identified in the COloRECTal cancer data Repository (CORECT-R). All inpatient episodes corresponding to pulmonary metastasectomy, occurring within 3 years of the initial colorectal resection, were identified. Multi-level logistic regression was used to determine patient and organizational factors associated with the use of pulmonary metastasectomy for colorectal cancer, and Kaplan-Meier and Cox models were used to assess survival following pulmonary metastasectomy. RESULTS: In all, 173 354 individuals had a major colorectal resection over the study period, with 3434 (2.0%) undergoing pulmonary resection within 3 years. The frequency of pulmonary metastasectomy increased from 1.2% of patients undergoing major colorectal resection in 2005 to 2.3% in 2013. Significant variation was observed across hospital providers in the risk-adjusted rates of pulmonary metastasectomy (0.0%-6.8% of patients). Overall 5-year survival following pulmonary resection was 50.8%, with 30-day and 90-day mortality of 0.6% and 1.2% respectively. CONCLUSIONS: This study shows significant variation in the rates of pulmonary metastasectomy for colorectal cancer across the English NHS.

Influence of age on surgical treatment and postoperative outcomes of patients with colorectal cancer in Denmark and Yorkshire, England.

AIM: Denmark and Yorkshire are demographically similar and both have undergone changes in their management of colorectal cancer to improve outcomes. The differential provision of surgical treatment, especially in the older age groups, may contribute to the magnitude of improved survival rates. This study aimed to identify differences in the management of colorectal cancer surgery and postoperative outcomes according to patient age between Denmark and Yorkshire. METHOD: This was a retrospective population-based study of colorectal cancer patients diagnosed in Denmark and Yorkshire between 2005 and 2016. Proportions of patients undergoing major surgical resection, postoperative mortality and relative survival were compared between Denmark and Yorkshire across several age groups (18-59, 60-69, 70-79 and ≥80 years) and over time. RESULTS: The use of major surgical resection was higher in Denmark than in Yorkshire, especially for patients aged ≥80 years (70.5% versus 50.5% for colon cancer, 49.3% versus 38.1% for rectal cancer). Thirty-day postoperative mortality for Danish patients aged ≥80 years was significantly higher than that for Yorkshire patients with colonic cancer [OR (95% CI) = 1.22 (1.07, 1.38)] but not for rectal cancer or for 1-year postoperative mortality. Relative survival significantly increased in all patients aged ≥80 years except for Yorkshire patients with colonic cancer. CONCLUSION: This study suggests that there are major differences between the management of elderly patients with colorectal cancer between the two populations. Improved selection for surgery and better peri- and postoperative care in these patients appears to improve long-term outcomes, but may come at the cost of a higher 30-day mortality.

Prediction of treatment response in rheumatoid arthritis patients using genome-wide SNP data.

Although a number of treatments are available for rheumatoid arthritis (RA), each of them shows a significant nonresponse rate in patients. Therefore, predicting a priori the likelihood of treatment response would be of great patient benefit. Here, we conducted a comparison of a variety of statistical methods for predicting three measures of treatment response, between baseline and 3 or 6 months, using genome-wide SNP data from RA patients available from the MAximising Therapeutic Utility in Rheumatoid Arthritis (MATURA) consortium. Two different treatments and 11 different statistical methods were evaluated. We used 10-fold cross validation to assess predictive performance, with nested 10-fold cross validation used to tune the model hyperparameters when required. Overall, we found that SNPs added very little prediction information to that obtained using clinical characteristics only, such as baseline trait value. This observation can be explained by the lack of strong genetic effects and the relatively small sample sizes available; in analysis of simulated and real data, with larger effects and/or larger sample sizes, prediction performance was much improved. Overall, methods that were consistent with the genetic architecture of the trait were able to achieve better predictive ability than methods that were not. For treatment response in RA, methods that assumed a complex underlying genetic architecture achieved slightly better prediction performance than methods that assumed a simplified genetic architecture.

Variation in the Use of Resection for Colorectal Cancer Liver Metastases.

OBJECTIVE: The aim of this study was to investigate variation in the frequency of resections for colorectal cancer liver metastases across the English NHS. BACKGROUND: Previous research has shown significant variation in access to liver resection surgery across the English NHS. This study uses more recent data to identify whether inequalities in access to liver resection still persist. METHODS: All adults who underwent a major resection for colorectal cancer in an NHS hospital between 2005 and 2012 were identified in the COloRECTal cancer data Repository (CORECT-R). All episodes of care, occurring within 3 years of the initial bowel operation, corresponding to liver resection were identified. RESULT: During the study period 157,383 patients were identified as undergoing major resection for a colorectal tumor, of whom 7423 (4.7%) underwent ≥1 liver resections. The resection rate increased from 4.1% in 2005, reaching a plateau around 5% by 2012. There was significant variation in the rate of liver resection across hospitals (2.1%-12.2%). Patients with synchronous metastases who have their primary colorectal resection in a hospital with an onsite specialist hepatobiliary team were more likely to receive a liver resection (odds ratio 1.22; 95% confidence interval, 1.10-1.35) than those treated in one without. This effect was absent in resection for metachronous metastases. CONCLUSIONS: This study presents the largest reported population-based analysis of liver resection rates in colorectal cancer patients. Significant variation has been observed in patient and hospital characteristics and the likelihood of patients receiving a liver resection, with the data showing that proximity to a liver resection service is as important a factor as deprivation.

A large-scale genetic analysis reveals a strong contribution of the HLA class II region to giant cell arteritis susceptibility.

We conducted a large-scale genetic analysis on giant cell arteritis (GCA), a polygenic immune-mediated vasculitis. A case-control cohort, comprising 1,651 case subjects with GCA and 15,306 unrelated control subjects from six different countries of European ancestry, was genotyped by the Immunochip array. We also imputed HLA data with a previously validated imputation method to perform a more comprehensive analysis of this genomic region. The strongest association signals were observed in the HLA region, with rs477515 representing the highest peak (p = 4.05 × 10(-40), OR = 1.73). A multivariate model including class II amino acids of HLA-DRß1 and HLA-DQα1 and one class I amino acid of HLA-B explained most of the HLA association with GCA, consistent with previously reported associations of classical HLA alleles like HLA-DRB1(∗)04. An omnibus test on polymorphic amino acid positions highlighted DRß1 13 (p = 4.08 × 10(-43)) and HLA-DQα1 47 (p = 4.02 × 10(-46)), 56, and 76 (both p = 1.84 × 10(-45)) as relevant positions for disease susceptibility. Outside the HLA region, the most significant loci included PTPN22 (rs2476601, p = 1.73 × 10(-6), OR = 1.38), LRRC32 (rs10160518, p = 4.39 × 10(-6), OR = 1.20), and REL (rs115674477, p = 1.10 × 10(-5), OR = 1.63). Our study provides evidence of a strong contribution of HLA class I and II molecules to susceptibility to GCA. In the non-HLA region, we confirmed a key role for the functional PTPN22 rs2476601 variant and proposed other putative risk loci for GCA involved in Th1, Th17, and Treg cell function.

Genome-wide association study of response to methotrexate in early rheumatoid arthritis patients.

Methotrexate (MTX) monotherapy is a common first treatment for rheumatoid arthritis (RA), but many patients do not respond adequately. In order to identify genetic predictors of response, we have combined data from two consortia to carry out a genome-wide study of response to MTX in 1424 early RA patients of European ancestry. Clinical endpoints were change from baseline to 6 months after starting treatment in swollen 28-joint count, tender 28-joint count, C-reactive protein and the overall 3-component disease activity score (DAS28). No single nucleotide polymorphism (SNP) reached genome-wide statistical significance for any outcome measure. The strongest evidence for association was with rs168201 in NRG3 (p = 10-7 for change in DAS28). Some support was also seen for association with ZMIZ1, previously highlighted in a study of response to MTX in juvenile idiopathic arthritis. Follow-up in two smaller cohorts of 429 and 177 RA patients did not support these findings, although these cohorts were more heterogeneous.

A novel recurrent mutation in MITF predisposes to familial and sporadic melanoma.

So far, two genes associated with familial melanoma have been identified, accounting for a minority of genetic risk in families. Mutations in CDKN2A account for approximately 40% of familial cases, and predisposing mutations in CDK4 have been reported in a very small number of melanoma kindreds. Here we report the whole-genome sequencing of probands from several melanoma families, which we performed in order to identify other genes associated with familial melanoma. We identify one individual carrying a novel germline variant (coding DNA sequence c.G1075A; protein sequence p.E318K; rs149617956) in the melanoma-lineage-specific oncogene microphthalmia-associated transcription factor (MITF). Although the variant co-segregated with melanoma in some but not all cases in the family, linkage analysis of 31 families subsequently identified to carry the variant generated a log of odds (lod) score of 2.7 under a dominant model, indicating E318K as a possible intermediate risk variant. Consistent with this, the E318K variant was significantly associated with melanoma in a large Australian case-control sample. Likewise, it was similarly associated in an independent case-control sample from the United Kingdom. In the Australian sample, the variant allele was significantly over-represented in cases with a family history of melanoma, multiple primary melanomas, or both. The variant allele was also associated with increased naevus count and non-blue eye colour. Functional analysis of E318K showed that MITF encoded by the variant allele had impaired sumoylation and differentially regulated several MITF targets. These data indicate that MITF is a melanoma-predisposition gene and highlight the utility of whole-genome sequencing to identify novel rare variants associated with disease susceptibility.

Fine mapping of genetic susceptibility loci for melanoma reveals a mixture of single variant and multiple variant regions.

At least 17 genomic regions are established as harboring melanoma susceptibility variants, in most instances with genome-wide levels of significance and replication in independent samples. Based on genome-wide single nucleotide polymorphism (SNP) data augmented by imputation to the 1,000 Genomes reference panel, we have fine mapped these regions in over 5,000 individuals with melanoma (mainly from the GenoMEL consortium) and over 7,000 ethnically matched controls. A penalized regression approach was used to discover those SNP markers that most parsimoniously explain the observed association in each genomic region. For the majority of the regions, the signal is best explained by a single SNP, which sometimes, as in the tyrosinase region, is a known functional variant. However in five regions the explanation is more complex. At the CDKN2A locus, for example, there is strong evidence that not only multiple SNPs but also multiple genes are involved. Our results illustrate the variability in the biology underlying genome-wide susceptibility loci and make steps toward accounting for some of the "missing heritability."

A matter of emphasis: Linguistic stress habits modulate serial recall.

Models of short-term memory for sequential information rely on item-level, feature-based descriptions to account for errors in serial recall. Transposition errors within alternating similar/dissimilar letter sequences derive from interactions between overlapping features. However, in two experiments, we demonstrated that the characteristics of the sequence are what determine the fates of items, rather than the properties ascribed to the items themselves. Performance in alternating sequences is determined by the way that the sequences themselves induce particular prosodic rehearsal patterns, and not by the nature of the items per se. In a serial recall task, the shapes of the canonical "saw-tooth" serial position curves and transposition error probabilities at successive input-output distances were modulated by subvocal rehearsal strategies, despite all item-based parameters being held constant. We replicated this finding using nonalternating lists, thus demonstrating that transpositions are substantially influenced by prosodic features-such as stress-that emerge during subvocal rehearsal.

Evidence of NLRP3-inflammasome activation in rheumatoid arthritis (RA); genetic variants within the NLRP3-inflammasome complex in relation to susceptibility to RA and response to anti-TNF treatment.

BACKGROUND: The NLRP3-inflammasome, implicated in the pathogenesis of several inflammatory disorders, has been analysed in rheumatoid arthritis (RA). METHODS: Relative gene expression of NLRP3-inflammasome components was characterised in PBMCs of 29 patients receiving infliximab. A total of 1278 Caucasian patients with RA from the Biologics in Rheumatoid Arthritis Genetics and Genomics Study Syndicate (BRAGGSS) cohort receiving tumour necrosis factor (TNF) antagonists (infliximab, adalimumab and etanercept) were genotyped for 34 single nucleotide polymorphisms (SNPs), spanning the genes NLRP3, MEFV and CARD8. Regression analyses were performed to test for association between genotype and susceptibility and treatment response (disease activity score across 28 joints (DAS28) and EULAR improvement criteria) at 6 months, with secondary expression quantitative trait loci (eQTL) analyses. RESULTS: At baseline, gene expression of ASC, MEFV, NLRP3-FL, NLRP3-SL and CASP1 were significantly higher compared with controls whereas CARD8 was lower in the patients. Caspase-1 and interleukin-18 levels were significantly raised in patients with RA. SNPs in NLRP3 showed association with RA susceptibility and EULAR response to anti-TNF in the BRAGGSS cohort, and in monocytes but not B cells, in eQTL analysis of 283 healthy controls. CARD8 SNPs were associated with RA susceptibility and DAS28 improvement in response to anti-TNF and eQTL effects in monocytes and B cells. CONCLUSIONS: This study found evidence of modulation of the NLRP3-inflammasome in patients with RA prior to receiving infliximab and some evidence of association for SNPs at NLRP3 and CARD8 loci with RA susceptibility and response to anti-TNF. The SNPs associated with susceptibility/response are not the main eQTL variants for either locus, and the associations with treatment response require replication in an independent cohort.

Minimally Invasive Surgery for Colorectal Cancer: Benchmarking Uptake for a Regional Improvement Programme.

BACKGROUND: The uptake of minimally invasive surgery (MIS) for patients with colorectal cancer has progressed at differing rates, both across countries, and within countries. This study aimed to investigate uptake for a regional colorectal cancer improvement programme in England. METHOD: We calculated the proportion of patients receiving elective laparoscopic and robot-assisted surgery amongst those diagnosed with colorectal cancer over 3 time periods (2007-2011, 2012-2016 and 2017-2021) in hospitals participating in the Yorkshire Cancer Research Bowel Cancer Improvement Programme (YCR BCIP). These were benchmarked against national rates. Regression analysis and funnel plots were used to develop a data driven approach for analysing trends in the use of MIS at hospitals in the programme. RESULTS: In England, resections performed by MIS increased from 34.9% to 72.9% for colon cancer and from 28.8% to 72.5% for rectal cancer. Robot-assisted surgery increased from 0.1% to 2.7% for colon cancer and from 0.2% to 7.9% for rectal cancer. Wide variation in the uptake of MIS was observed at a hospital level. Detailed analysis of the YCR BCIP region identified a decreasing number of surgical departments, since the start of the programme, as potential outliers for MIS when compared to the English national average. CONCLUSION: Wide variation in use of MIS for colorectal cancer exists within the English National Health Service and a data-driven approach can help identify outlying hospitals. Addressing some of the challenges behind the uptake of MIS, such as ensuring adequate provision of surgical training and equipment, could help increase its use.

Reduced type II interleukin-4 receptor signalling drives initiation, but not progression, of colorectal carcinogenesis: evidence from transgenic mouse models and human case-control epidemiological observations.

We investigated the role of interleukin (IL)-4 receptor (IL-4R) signalling during mouse carcinogen-induced colorectal carcinogenesis and in a case-control genetic epidemiological study of IL-4Rα single nucleotide polymorphisms (SNPs). Azoxymethane-induced aberrant crypt focus (ACF; 6 weeks) and tumours (32 weeks) were analysed in wild-type (WT) BALB/c mice, as well as in IL-4Rα (-) (/-) , IL-13 (-/-) and 'double-knockout' (DKO) animals. Colorectal cancer (CRC) cases (1502) and controls (584) were genotyped for six coding IL-4Rα SNPs. The association with CRC risk and CRC-specific mortality was analysed by logistic regression. Lack of IL-4Rα expression was associated with increased ACFs [median 8.5 ACFs per mouse (IL-4Rα (-/-) ) versus 3 (WT); P = 0.007], but no difference in the number of colorectal tumours [mean 1.4 per mouse (IL-4Rα (-/-) ) versus 2 (WT)], which were smaller and demonstrated reduced nuclear/cytoplasmic ß-catenin translocation compared with WT tumours. Tumour-bearing IL-4Rα (-/-) mice had fewer CD11b(+)/Gr1(+) myeloid-derived suppressor splenocytes than WT animals. IL-13 (-/-) mice developed a similar number of ACFs to IL-4Rα (-/-) and DKO mice. There was a significant increase in CRC risk associated with the functional SNP Q576R [odds ratio 1.54 (95% confidence interval 0.94-2.54), P trend 0.03 for the minor G allele]. There was no effect of IL-4Rα genotype on either CRC-specific or all-cause mortality. These combined pre-clinical and human data together demonstrate that reduced IL-4R signalling has stage-specific effects on colorectal carcinogenesis (increased CRC initiation and risk but reduced tumour progression and no effect on CRC mortality). These results should prompt evaluation of the effect of pharmacological manipulation of IL-4R signalling on future CRC risk and for CRC treatment.

Association between functional polymorphisms in genes involved in the MAPK signaling pathways and cutaneous melanoma risk.

Genome-wide association studies (GWASs) have mainly focused on top significant single nucleotide polymorphisms (SNPs), most of which did not have clear biological functions but were just surrogates for unknown causal variants. Studying SNPs with modest association and putative functions in biologically plausible pathways has become one complementary approach to GWASs. To unravel the key roles of mitogen-activated protein kinase (MAPK) pathways in cutaneous melanoma (CM) risk, we re-evaluated the associations between 47 818 SNPs in 280 MAPK genes and CM risk using our published GWAS dataset with 1804 CM cases and 1026 controls. We initially found 105 SNPs with P ≤ 0.001, more than expected by chance, 26 of which were predicted to be putatively functional SNPs. The risk associations with 16 SNPs around DUSP14 (rs1051849) and a previous reported melanoma locus MAFF/PLA2G6 (proxy SNP rs4608623) were replicated in the GenoMEL dataset (P < 0.01) but failed in the Australian dataset. Meta-analysis showed that rs1051849 in the 3' untranslated regions of DUSP14 was associated with a reduced risk of melanoma (odds ratio = 0.89, 95% confidence interval: 0.82-0.96, P = 0.003, false discovery rate = 0.056). Further genotype-phenotype correlation analysis using the 90 HapMap lymphoblastoid cell lines from Caucasians showed significant correlations between two SNPs (rs1051849 and rs4608623) and messenger RNA expression levels of DUSP14 and MAFF (P = 0.025 and P = 0.010, respectively). Gene-based tests also revealed significant SNPs were over-represented in MAFF, PLA2G6, DUSP14 and other 16 genes. Our results suggest that functional SNPs in MAPK pathways may contribute to CM risk. Further studies are warranted to validate our findings.

Common co-morbidities in polymyalgia rheumatica and giant cell arteritis: cross-sectional study in UK Biobank.

Objective: The aim was to determine prevalent co-morbidities in cases with PMR or GCA compared with matched controls. Methods: This was a nested, cross-sectional case-control study within the UK Biobank, which recruited participants aged 40-69 years. Case status was defined as self-reported prior diagnosis of PMR or GCA. Ten controls per case were matched for age, sex, ethnicity and assessment centre. Associations with selected self-reported co-morbidities were studied using conditional logistic regression. Results: Of PMR (n = 1036) or GCA (n = 102) cases, 72% were female, 98% White, and 58% reported current use of glucocorticoids. Mean age was 63 years. At the time of the assessment visit, compared with controls, PMR/GCA cases were more likely to report poor general health and at least several days of low mood in the past 2 weeks. PMR was associated with hypothyroidism [odds ratio (OR) = 1.34; 95% CI = 1.07, 1.67] and ever-use of HRT (OR = 1.26; 95% CI = 1.07, 1.47). Regarding common co-morbidities, PMR and GCA were both associated with hypertension (PMR: OR = 1.21; 95% CI = 1.06, 1.39; GCA: OR = 1.86; 95% CI = 1.23, 2.81) and cataract (PMR: OR = 1.51; 95% CI = 1.19, 1.93; GCA: OR = 3.84; 95% CI = 2.23, 6.60). Additionally, GCA was associated with depression (OR = 3.05; 95% CI = 1.59, 5.85). Neither condition was associated with diabetes. Conclusion: Participants with a history of PMR/GCA, including those not currently taking glucocorticoids, rated their health as poorer than matched controls. Some previously described disease associations (hypothyroidism and early menopause) were replicated. Hypertension and cataract, both of which can be exacerbated by long-term glucocorticoid therapy, were over-represented in both diseases, particularly GCA.

Relationship between area-level socio-economic deprivation and autoantibody status in patients with rheumatoid arthritis: multicentre cross-sectional study.

OBJECTIVES: The aims of this study were to assess the association between area-level socio-economic deprivation and the phenotype of rheumatoid arthritis (RA), defined by rheumatoid factor (RF) and anticitrullinated peptide antibody (AC PA) status, and to determine whether any observed association can be explained by smoking. METHODS: The authors performed logistic regression analysis of 6298 patients with RA, defined by American College of Rheumatology classification criteria modified for genetic studies. Analysis was stratified by cohort/recruitment centre. Socio-economic deprivation was measured using the Townsend Index. RESULTS: Deprivation predicted RF but not ACPA positivity, independent of smoking. The ORs for trend across tertiles, adjusted for smoking, gender, period of birth and cohort/recruitment centre, were 1.14 (95% CI 1.01 to 1.29) for RF and 1.01 (95% CI 0.87 to 1.16) for ACPA. Even after adjusting for deprivation, smoking was strongly associated with ACPA positivity (OR 1.38, 95% CI 1.22 to 1.55). There was no evidence of any effect modification by the RA risk alleles (HLA-DRB1 shared epitope and PTPN22 rs2476601) that have previously been shown to modify the effect of smoking on ACPA and RF positivity. CONCLUSIONS: Among patients with RA, deprivation predicted RF positivity but not ACPA positivity. The effect of deprivation did not appear to be explained by smoking. Deprivation may be a marker for previously unrecognised, potentially modifiable environmental influences on the immunological phenotype of RA. Furthermore, given the known associations of RF positivity with prognosis and response to treatment in RA, these findings have potential implications for resource allocation and healthcare delivery.

Structural basis for the stability of a thermophilic methionine adenosyltransferase against guanidinium chloride.

The methionine adenosyltransferase from the thermophile Methanococcus jannaschii is fully and irreversibly unfolded in the presence of guanidinium chloride. Unfolding of this dimeric protein is a three-state process in which a dimeric intermediate could be identified. The less stable secondary structural elements of the protein are the C-terminal ends of ß-strands E2 and E6, as deduced from the behavior of tyrosine to tryptophan mutants at residues 72 and 170, which are located in the subunit interface. Unraveling of these elements at the monomer interface may soften intersubunit interactions, leading to the observed 85% activity loss. Accumulation of the intermediate was associated with maintenance of residual activity, an increase in the elution volume of the protein upon gel filtration and a decrease in the sedimentation coefficient. Elimination of the remaining enzymatic activity occurred in conjunction with a 50% reduction in helicity and fluorescence alterations illustrating a transient burial of tryptophans at ß-strands E2, E3 and E9. The available 3D-model predicted that these ß-strands are involved in the central and N-terminal domains of the monomer structure. Severe perturbation of this area of the monomer-monomer interface may destroy the remaining intermolecular interactions, thus leading to dissociation and aggregation. Finally, transition to the denatured state includes completion of the changes detected in the microenvironments around tryptophans included at α-helixes H5 and H6, the loops connecting H5-E8 and E9, ß-strands E3 and E12.

Recovery of consciousness following acute symptomatic seizures due to central nervous system infections in children.

AIM: The aim of this study was to assess whether acute symptomatic epileptic seizures associated with central nervous system infections (AS(inf) ) have a different ictal and postictal course to seizures of other aetiologies. METHOD: A case note analysis of 81 children (47 males; 34 females; age range 1mo-15y 6mo; median age 12mo) with central nervous system infections was undertaken. Seizure type, duration, aetiology, and timing were recorded. Recovery time to full consciousness in those not intubated was determined. Intubation rates and recovery times were compared with those from previous studies. RESULTS: Of the 81 children, 40 (49.4%) had one or more AS(inf) . The different aetiologies were bacterial meningitis, aseptic meningitis, abscess/empyema, encephalitis, and postoperative infection. Twenty-two had status epilepticus. The intubation rate in children with AS(inf) was higher than that in children with seizures of other aetiologies (21/40 [52.5%] vs 4/124 [3.23%]; p < 0.0001). Median postictal recovery time was 4.33 hours (0-207h). Children with AS(inf) took 4.3 (p<0.01), 3.0 (p=0.004), and 8.8 (p<0.001) times longer to recover than children who had seizures from all causes, remote symptomatic seizures, and febrile seizures respectively. INTERPRETATION: AS(inf) in children are often longer, more likely to be associated with status epilepticus, more likely to necessitate intubation, and take longer to recover from than seizures of other aetiologies. This may help in the early diagnosis of central nervous system infection in children presenting with seizures.

Differences in the management of patients requiring an emergency resection for colonic cancer in two European populations.

BACKGROUND: Patients with colonic cancer who require emergency colonic cancer surgery often experience poorer outcomes compared with their elective counterparts. In this setting, several treatments approaches are available. In 2009, Danish guidelines recommended treatment with stent for obstruction in left-sided tumours as a bridge to surgery, if expertise is accessible. The aim of this study was to compare the use of elective and emergency resections for colonic cancer and postoperative mortality in two similar demographic populations. METHODS: All patients who underwent a major resection for colonic cancer, between 2005 and 2016 in Denmark and Yorkshire (UK) were identified. The proportion undergoing emergency surgery, the proportion receiving a stent procedure before their resection, and 30-day postoperative mortality were compared between the populations. Logistic regression was used to determine changes in the proportion of those undergoing emergency surgery and 30-day postoperative mortality. RESULTS: Out of 45 397 patients treated during the study interval, 41 880 were selected. Emergency surgery decreased in Denmark from 16.6 per cent in 2005-07 to 12.9 per cent in 2014-16, but increased in Yorkshire (13.5 per cent to 16.8 per cent). Danish patients with left-sided tumours were less likely to undergo emergency surgery (risk ratio 0.90, 95 per cent c.i. 0.82 to 0.99) and an increase in stent use coincided with a statistically significant decrease in emergency surgery in these patients. Thirty-day postoperative mortality in all resections (elective and emergency) decreased in both populations, but a larger decrease was observed in Denmark (7.7 per cent to 3.0 per cent in Denmark and 7.1 per cent to 3.3 per cent in Yorkshire). CONCLUSION: Patients in Denmark experienced a reduction in the use of emergency resection and increase in stenting procedures, following the policy implemented in some departments of converting potential emergency resections into elective resections.