TINNiK: Inference of the Tree of Blobs of a Species Network Under the Coalescent

The tree of blobs of a species network shows only the tree-like aspects of relationships of taxa on a network, omitting information on network substructures where hybridization or other types of lateral transfer of genetic information occur. By isolating such regions of a network, inference of the tree of blobs can serve as a starting point for a more detailed investigation, or indicate the limit of what may be inferrable without additional assumptions. Building on our theoretical work on the identifiability of the tree of blobs from gene quartet distributions under the Network Multispecies Coalescent model, we develop an algorithm, TINNiK, for statistically consistent tree of blobs inference. We provide examples of its application to both simulated and empirical datasets, utilizing an implementation in the MSCquartets 2.0 R package.

MSC Classification

92D15, 92D20.

From little things big things grow: enhancement of an acoustic telemetry network to monitor broad-scale movements of marine species along Australia's east coast

BACKGROUND

Acoustic telemetry has become a fundamental tool to monitor the movement of aquatic species. Advances in technology, in particular the development of batteries with lives of > 10 years, have increased our ability to track the long-term movement patterns of many species. However, logistics and financial constraints often dictate the locations and deployment duration of acoustic receivers. Consequently, there is often a compromise between optimal array design and affordability. Such constraints can hinder the ability to track marine animals over large spatial and temporal scales. Continental-scale receiver networks have increased the ability to study large-scale movements, but significant gaps in coverage often remain.

METHODS

Since 2007, the Integrated Marine Observing System's Animal Tracking Facility (IMOS ATF) has maintained permanent receiver installations on the eastern Australian seaboard. In this study, we present the recent enhancement of the IMOS ATF acoustic tracking infrastructure in Queensland to collect data on large-scale movements of marine species in the northeast extent of the national array. Securing a relatively small initial investment for expanding receiver deployment and tagging activities in Queensland served as a catalyst, bringing together a diverse group of stakeholders (research institutes, universities, government departments, port corporations, industries, Indigenous ranger groups and tourism operators) to create an extensive collaborative network that could sustain the extended receiver coverage into the future. To fill gaps between existing installations and maximise the monitoring footprint, the new initiative has an atypical design, deploying many single receivers spread across 2,100 km of Queensland waters.

RESULTS

The approach revealed previously unknown broad-scale movements for some species and highlights that clusters of receivers are not always required to enhance data collection. However, array designs using predominantly single receiver deployments are more vulnerable to data gaps when receivers are lost or fail, and therefore "redundancy" is a critical consideration when designing this type of array.

CONCLUSION

Initial results suggest that our array enhancement, if sustained over many years, will uncover a range of previously unknown movements that will assist in addressing ecological, fisheries, and conservation questions for multiple species.

Risk profiles and incidence of cardiovascular events across different cancer types

BACKGROUND

Cancer survivors are at increased risk for cardiovascular (CV) disease, although additional data are needed to better understand the incidence of CV events across different malignancies. This study sought to characterize the incidence of major adverse CV events [myocardial infarction, stroke, unstable angina (MACE), or heart failure (HF)] across multiple cancer types after cancer diagnosis.

PATIENTS AND METHODS

Patients were identified from a USA-based administrative claims database who had index cancer diagnoses of breast, lung, prostate, melanoma, myeloma, kidney, colorectal, leukemia, or lymphoma between 2011 and 2019, with continuous enrollment for ≥12 months before diagnosis. Baseline CV risk factors and incidence rates of CV events post-index were identified for each cancer. Multivariable Cox hazards models assessed the cumulative incidence of MACE, accounting for baseline risk factors.

RESULTS

Among 839 934 patients across nine cancer types, CV risk factors were prevalent. The cumulative incidence of MACE was highest in lung cancer and myeloma, and lowest in breast cancer, prostate cancer, and melanoma. MACE cumulative incidence for lung cancer was 26% by 4 years (2.7-fold higher relative to breast cancer). The incidence of stroke was especially pronounced in lung cancer, while HF was highest in myeloma and lung cancer.

CONCLUSIONS

CV events were especially increased following certain cancer diagnoses, even after accounting for baseline risk factors. Understanding the variable patient characteristics and associated CV events across different cancers can help target appropriate CV risk factor modification and develop strategies to minimize adverse CV events and improve patient outcomes.

Diet high in linoleic acid dysregulates the intestinal endocannabinoid system and increases susceptibility to colitis in Mice

Inflammatory bowel disease (IBD) is a multifactorial disease with increasing incidence in the U.S. suggesting that environmental factors, including diet, are involved. It has been suggested that excessive consumption of linoleic acid (LA, C18:2 omega-6), which must be obtained from the diet, may promote the development of IBD in humans. To demonstrate a causal link between LA and IBD, we show that a high fat diet (HFD) based on soybean oil (SO), which is comprised of ~55% LA, increases susceptibility to colitis in several models, including IBD-susceptible IL10 knockout mice. This effect was not observed with low-LA HFDs derived from genetically modified soybean oil or olive oil. The conventional SO HFD causes classical IBD symptoms including immune dysfunction, increased intestinal epithelial barrier permeability, and disruption of the balance of isoforms from the IBD susceptibility gene Hepatocyte Nuclear Factor 4α (HNF4α). The SO HFD causes gut dysbiosis, including increased abundance of an endogenous adherent invasive Escherichia coli (AIEC), which can use LA as a carbon source. Metabolomic analysis shows that in the mouse gut, even in the absence of bacteria, the presence of soybean oil increases levels of LA, oxylipins and prostaglandins. Many compounds in the endocannabinoid system, which are protective against IBD, are decreased by SO both in vivo and in vitro. These results indicate that a high LA diet increases susceptibility to colitis via microbial and host-initiated pathways involving alterations in the balance of bioactive metabolites of omega-6 and omega-3 polyunsaturated fatty acids, as well as HNF4α isoforms.

The tree of blobs of a species network: identifiability under the coalescent

Inference of species networks from genomic data under the Network Multispecies Coalescent Model is currently severely limited by heavy computational demands. It also remains unclear how complicated networks can be for consistent inference to be possible. As a step toward inferring a general species network, this work considers its tree of blobs, in which non-cut edges are contracted to nodes, so only tree-like relationships between the taxa are shown. An identifiability theorem, that most features of the unrooted tree of blobs can be determined from the distribution of gene quartet topologies, is established. This depends upon an analysis of gene quartet concordance factors under the model, together with a new combinatorial inference rule. The arguments for this theoretical result suggest a practical algorithm for tree of blobs inference, to be fully developed in a subsequent work.

Textbook outcome following oesophagectomy for cancer: international cohort study

Background

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

Methods

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

Results

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter ‘no major postoperative complication’ had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P < 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P < 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

Conclusion

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Textbook outcome following oesophagectomy for cancer: international cohort study

BACKGROUND

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

METHODS

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

RESULTS

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter 'no major postoperative complication' had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P < 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P < 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

CONCLUSION

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND

The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting.

METHODS

Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups.

RESULTS

Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005).

CONCLUSION

Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery.

MSCquartets 1.0: quartet methods for species trees and networks under the multispecies coalescent model in R

SUMMARY

MSCquartets is an R package for species tree hypothesis testing, inference of species trees and inference of species networks under the Multispecies Coalescent model of incomplete lineage sorting and its network analog. Input for these analyses are collections of metric or topological locus trees which are then summarized by the quartets displayed on them. Results of hypothesis tests at user-supplied levels are displayed in a simplex plot by color-coded points. The package implements the QDC and WQDC algorithms for topological and metric species tree inference, and the NANUQ algorithm for level-1 topological species network inference, all of which give statistically consistent estimators under the model.

AVAILABILITY AND IMPLEMENTATION

MSCquartets is available through the Comprehensive R Archive Network: https://CRAN.R-project.org/package=MSCquartets.

MSCquartets 1.0: quartet methods for species trees and networks under the multispecies coalescent model in R

SUMMARY

MSCquartets is an R package for species tree hypothesis testing, inference of species trees and inference of species networks under the Multispecies Coalescent model of incomplete lineage sorting and its network analog. Input for these analyses are collections of metric or topological locus trees which are then summarized by the quartets displayed on them. Results of hypothesis tests at user-supplied levels are displayed in a simplex plot by color-coded points. The package implements the QDC and WQDC algorithms for topological and metric species tree inference, and the NANUQ algorithm for level-1 topological species network inference, all of which give statistically consistent estimators under the model.

AVAILABILITY AND IMPLEMENTATION

MSCquartets is available through the Comprehensive R Archive Network: https://CRAN.R-project.org/package=MSCquartets.

Comparison of short-term outcomes from the International Oesophago-Gastric Anastomosis Audit (OGAA), the Esophagectomy Complications Consensus Group (ECCG), and the Dutch Upper Gastrointestinal Cancer Audit (DUCA)

BACKGROUND

The Esophagectomy Complications Consensus Group (ECCG) and the Dutch Upper Gastrointestinal Cancer Audit (DUCA) have set standards in reporting outcomes after oesophagectomy. Reporting outcomes from selected high-volume centres or centralized national cancer programmes may not, however, be reflective of the true global prevalence of complications. This study aimed to compare complication rates after oesophagectomy from these existing sources with those of an unselected international cohort from the Oesophago-Gastric Anastomosis Audit (OGAA).

METHODS

The OGAA was a prospective multicentre cohort study coordinated by the West Midlands Research Collaborative, and included patients undergoing oesophagectomy for oesophageal cancer between April and December 2018, with 90 days of follow-up.

RESULTS

The OGAA study included 2247 oesophagectomies across 137 hospitals in 41 countries. Comparisons with the ECCG and DUCA found differences in baseline demographics between the three cohorts, including age, ASA grade, and rates of chronic pulmonary disease. The OGAA had the lowest rates of neoadjuvant treatment (OGAA 75.1 per cent, ECCG 78.9 per cent, DUCA 93.5 per cent; P < 0.001). DUCA exhibited the highest rates of minimally invasive surgery (OGAA 57.2 per cent, ECCG 47.9 per cent, DUCA 85.8 per cent; P < 0.001). Overall complication rates were similar in the three cohorts (OGAA 63.6 per cent, ECCG 59.0 per cent, DUCA 62.2 per cent), with no statistically significant difference in Clavien-Dindo grades (P = 0.752). However, a significant difference in 30-day mortality was observed, with DUCA reporting the lowest rate (OGAA 3.2 per cent, ECCG 2.4 per cent, DUCA 1.7 per cent; P = 0.013).

CONCLUSION

Despite differences in rates of co-morbidities, oncological treatment strategies, and access to minimal-access surgery, overall complication rates were similar in the three cohorts.

Gene tree discord, simplex plots, and statistical tests under the coalescent

A simple graphical device, the simplex plot of quartet concordance factors, is introduced to aid in the exploration of a collection of gene trees on a common set of taxa. A single plot summarizes all gene tree discord, and allows for visual comparison to the expected discord from the multispecies coalescent model (MSC) of incomplete lineage sorting on a species tree. A formal statistical procedure is described that can quantify the deviation from expectation for each subset of four taxa, suggesting when the data is not in accord with the MSC, and thus that either gene tree inference error is substantial or a more complex model such as that on a network may be required. If the collection of gene trees is in accord with the MSC, the plots reveal when substantial incomplete lineage sorting is present. Applications to both simulated and empirical multilocus data sets illustrate the insights provided.

Convergence of Olfactory Inputs within the Central Nervous System of a Cartilaginous and a Bony Fish: An Anatomical Indicator of Olfactory Sensitivity

The volume of the olfactory bulbs (OBs) relative to the brain has been used previously as a proxy for olfactory capabilities in many vertebrate taxa, including fishes. Although this gross approach has predictive power, a more accurate assessment of the number of afferent olfactory inputs and the convergence of this information at the level of the telencephalon is critical to our understanding of the role of olfaction in the behaviour of fishes. In this study, we used transmission electron microscopy to assess the number of first-order axons within the olfactory nerve (ON) and the number of second-order axons in the olfactory peduncle (OP) in established model species within cartilaginous (brownbanded bamboo shark, Chiloscyllium punctatum [CP]) and bony (common goldfish, Carassius auratus [CA]) fishes. The total number of axons varied from a mean of 18.12 ± 7.50 million in the ON to a mean of 0.38 ± 0.21 million in the OP of CP, versus 0.48 ± 0.16 million in the ON and 0.09 ± 0.02 million in the OP of CA. This resulted in a convergence ratio of approximately 50:1 and 5:1, respectively, for these two species. Based on astroglial ensheathing, axon type (unmyelinated [UM] and myelinated [M]) and axon size, we found no differentiated tracts in the OP of CP, whereas a lateral and a medial tract (both of which could be subdivided into two bundles or areas) were identified for CA, as previously described. Linear regression analyses revealed significant differences not only in axon density between species and locations (nerves and peduncles), but also in axon type and axon diameter (p < 0.05). However, UM axon diameter was larger in the OPs than in the nerve in both species (p = 0.005), with no significant differences in UM axon diameter in the ON (p = 0.06) between species. This study provides an in-depth analysis of the neuroanatomical organisation of the ascending olfactory pathway in two fish taxa and a quantitative anatomical comparison of the summation of olfactory information. Our results support the assertion that relative OB volume is a good indicator of the level of olfactory input and thereby a proxy for olfactory capabilities.

The autoimmune susceptibility gene, PTPN2, restricts expansion of a novel mouse adherent-invasive E. coli

Inflammatory bowel disease (IBD) pathogenesis involves significant contributions from genetic and environmental factors. Loss-of-function single-nucleotide polymorphisms (SNPs) in the protein tyrosine phosphatase non-receptor type 2 (PTPN2) gene increase IBD risk and are associated with altered microbiome population dynamics in IBD. Expansion of intestinal pathobionts, such as adherent-invasive E. coli (AIEC), is strongly implicated in IBD pathogenesis as AIEC increases pro-inflammatory cytokine production and alters tight junction protein regulation - suggesting a potential mechanism of pathogen-induced barrier dysfunction and inflammation. We aimed to determine if PTPN2 deficiency alters intestinal microbiome composition to promote expansion of specific bacteria with pathogenic properties. In mice constitutively lacking Ptpn2, we identified increased abundance of a novel mouse AIEC (mAIEC) that showed similar adherence and invasion of intestinal epithelial cells, but greater survival in macrophages, to the IBD-associated AIEC, LF82. Furthermore, mAIEC caused disease when administered to mice lacking segmented-filamentous bacteria (SFB), and in germ-free mice but only when reconstituted with a microbiome, thus supporting its classification as a pathobiont, not a pathogen. Moreover, mAIEC infection increased the severity of, and prevented recovery from, induced colitis. Although mAIEC genome sequence analysis showed >90% similarity to LF82, mAIEC contained putative virulence genes with >50% difference in gene/protein identities from LF82 indicating potentially distinct genetic features of mAIEC. We show for the first time that an IBD susceptibility gene, PTPN2, modulates the gut microbiome to protect against a novel pathobiont. This study generates new insights into gene-environment-microbiome interactions in IBD and identifies a new model to study AIEC-host interactions.

Interpersonal Gut Microbiome Variation Drives Susceptibility and Resistance to Cholera Infection

The gut microbiome is the resident microbial community of the gastrointestinal tract. This community is highly diverse, but how microbial diversity confers resistance or susceptibility to intestinal pathogens is poorly understood. Using transplantation of human microbiomes into several animal models of infection, we show that key microbiome species shape the chemical environment of the gut through the activity of the enzyme bile salt hydrolase. The activity of this enzyme reduced colonization by the major human diarrheal pathogen Vibrio cholerae by degrading the bile salt taurocholate that activates the expression of virulence genes. The absence of these functions and species permits increased infection loads on a personal microbiome-specific basis. These findings suggest new targets for individualized preventative strategies of V. cholerae infection through modulating the structure and function of the gut microbiome.

P3584Optimal medical therapy improves survival in patients with ischaemic cardiomyopathy: an analysis of the STICH trial

Background

Prior studies have demonstrated underuse of optimal medical therapy (OMT) in patients with coronary artery disease (CAD) after revascularization. However, there are limited studies assessing compliance with OMT on long-term survival in patients with CAD and no studies evaluating the impact of OMT in patients with severe CAD and reduced left ventricular (LV) function. The Surgical Treatment for Ischaemic Heart Failure (STICH) Trial was a randomized clinical trial that compared coronary-artery bypass grafting (CABG) with medical therapy versus medical therapy alone in the treatment of ischemic cardiomyopathy.

Purpose

This study sought to determine compliance with OMT over time and the impact of OMT compliance on survival in patients with or without revascularization.

Methods

STICH was a multicenter, randomized clinical trial of patients with an LV ejection fraction of 35% or less and CAD amenable to CABG who were randomized to CABG plus medical therapy (N=610) or medical therapy alone (N=602). A medication history was obtained at hospital discharge or 30 days after enrollment, 1 year, 5 years, and 10 years. OMT was defined as the combination of at least 1 antiplatelet drug, a statin, a beta-blocker, and an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker. The primary outcome was all-cause mortality. Comparison of mortality between the OMT and non-OMT groups was performed using multivariate Cox regression modeling with OMT as a time-dependent covariate.

Results

Of the 1212 patients randomized, at a median follow-up of 9.8 years, all-cause mortality was 58.9% in the CABG group and 66.1% in the medical therapy group. In the CABG arm, 63.6% of patients were on OMT throughout the study period compared to 66.5% of patients in the medical therapy arm (p=0.3). Those on OMT were younger (59.6 vs. 61.4 years, p<0.001); were more often in NYHA class I-II (67.4% vs. 56%, p<0.001); and lower rates of atrial fibrillation (9.4% vs. 18.1%, p<0.001), current smoking (18.6% vs. 24.5%, p=0.015), and depression (4.8% vs. 8.8%, p=0.005). Those on OMT had higher rates of hyperlipidemia (63.8% vs. 54.4%, p=0.001) and prior myocardial infarction (79.4% vs. 73.1%, p=0.01). There was no difference in sex, diabetes, and hypertension between those on OMT and non-OMT. In multivariate survival analysis, OMT was associated with a significant reduction in mortality (adjusted hazard ratio, 0.69; 95% confidence interval, 0.58–0.81; p<0.001). The treatment effect with OMT (31% relative reduction in mortality over 10 years) was numerically greater than the treatment effect of CABG (24% relative reduction in mortality with CABG versus medical therapy alone).

Conclusions

OMT improves long-term survival in patients with ischaemic cardiomyopathy regardless of revascularization status. Strategies to improve OMT use and adherence in this population is needed to maximize survival.

Hypothesis testing near singularities and boundaries

The likelihood ratio statistic, with its asymptotic χ ² distribution at regular model points, is often used for hypothesis testing. However, the asymptotic distribution can differ at model singularities and boundaries, suggesting the use of a χ ² might be problematic nearby. Indeed, its poor behavior for testing near singularities and boundaries is apparent in simulations, and can lead to conservative or anti-conservative tests. Here we develop a new distribution designed for use in hypothesis testing near singularities and boundaries, which asymptotically agrees with that of the likelihood ratio statistic. For two example trinomial models, arising in the context of inference of evolutionary trees, we show the new distributions outperform a χ ².

Distinguishing Between Convergent Evolution and Violation of the Molecular Clock for Three Taxa

We give a non-technical introduction to convergence-divergence models, a new modeling approach for phylogenetic data that allows for the usual divergence of lineages after lineage-splitting but also allows for taxa to converge, i.e. become more similar over time. By examining the $3$-taxon case in some detail, we illustrate that phylogeneticists have been "spoiled" in the sense of not having to think about the structural parameters in their models by virtue of the strong assumption that evolution is tree-like. We show that there are not always good statistical reasons to prefer the usual class of tree-like models over more general convergence-divergence models. Specifically, we show many $3$-taxon data sets can be equally well explained by supposing violation of the molecular clock due to change in the rate of evolution along different edges, or by keeping the assumption of a constant rate of evolution but instead assuming that evolution is not a purely divergent process. Given the abundance of evidence that evolution is not strictly tree-like, our discussion is an illustration that as phylogeneticists we need to think clearly about the structural form of the models we use. For cases with four taxa, we show that there will be far greater ability to distinguish models with convergence from non-clock-like tree models. [Akaike information criterion; convergence-divergence models; distinguishability; identifiability; likelihood; molecular clock; phylogeny.].

Quantifying the impact of environmental variables upon catch per unit effort of the blue shark Prionace glauca in the western English Channel

The effect of environmental variables on blue shark Prionace glauca catch per unit effort (CPUE) in a recreational fishery in the western English Channel, between June and September 1998-2011, was quantified using generalized additive models (GAMs). Sea surface temperature (SST) explained 1·4% of GAM deviance, and highest CPUE occurred at 16·7° C, reflecting the optimal thermal preferences of this species. Surface chlorophyll a concentration (CHL) significantly affected CPUE and caused 27·5% of GAM deviance. Additionally, increasing CHL led to rising CPUE, probably due to higher productivity supporting greater prey biomass. The density of shelf-sea tidal mixing fronts explained 5% of GAM deviance, but was non-significant, with increasing front density negatively affecting CPUE. Time-lagged frontal density significantly affected CPUE, however, causing 12·6% of the deviance in a second GAM and displayed a positive correlation. This outcome suggested a delay between the evolution of frontal features and the subsequent accumulation of productivity and attraction of higher trophic level predators, such as P. glauca.

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

BACKGROUND

Anecdotally, liver size is important in determining prognosis in patients with end-stage liver disease (ESLD).

AIMS

To assess if a ratio of liver area and abdominal area on cross-sectional imaging could accurately predict mortality in ESLD.

METHODS

A retrospective-prospective cohort study was performed on patients with ESLD in a training set. The censor point used was date of patient death or liver transplant (LT). The liver to abdominal area ratio (LAAR) was calculated using the formula {LAAR = [liver area (cm(2))/abdominal area (cm(2))] × 100}. A validation set was collected from a different institution.

RESULTS

Three hundred and sixteen patients were identified. Complete imaging and survival data were available in 158 subjects, 100 male (63%). The LAAR score detected progression to death/LT in our cohort (P < 0.003). Its prognostic accuracy at 90, 360 and 720 days, using the optimal cut-off (32.1), from baseline CT date to death/LT using the log-rank test was P = 0.28, P = 0.06 (OR 1.347, 95% CI 0.94-1.94) and P < 0.0001 (OR 1.89, 95% CI 1.25-2.85) respectively. On multivariate analysis, LAAR (P = 0.008), MELD (P = 0.004) and MELD-Na (P = 0.03) were independently associated with the primary study outcome measurement at 720 days. The validation set of 52 patients confirmed the utility of the LAAR to determine risk of death or need for LT, AUROC 0.89 (0.78-0.97), and P < 0.0001.

CONCLUSIONS

The liver to abdominal area ratio (LAAR) score offers a new paradigm in disease modelling in end-stage liver disease (ESLD) and offers prognostic accuracy at 2 years from computer tomography (CT) imaging.

Recombinant human insulin-like growth factor I (rhIGF-I) for the treatment of amyotrophic lateral sclerosis/motor neuron disease

BACKGROUND

Recombinant human insulin-like growth factor I (rhIGF-I) is a possible disease modifying therapy for amyotrophic lateral sclerosis (ALS, which is also known as motor neuron disease (MND)).

OBJECTIVES

To examine the efficacy of rhIGF-I in affecting disease progression, impact on measures of functional health status, prolonging survival and delaying the use of surrogates (tracheostomy and mechanical ventilation) to sustain survival in ALS. Occurrence of adverse events was also reviewed.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register (21 November 2011), CENTRAL (2011, Issue 4), MEDLINE (January 1966 to November 2011) and EMBASE (January 1980 to November 2011) and sought information from the authors of randomised clinical trials and manufacturers of rhIGF-I.

SELECTION CRITERIA

We considered all randomised controlled clinical trials involving rhIGF-I treatment of adults with definite or probable ALS according to the El Escorial Criteria. The primary outcome measure was change in Appel Amyotrophic Lateral Sclerosis Rating Scale (AALSRS) total score after nine months of treatment and secondary outcome measures were change in AALSRS at 1, 2, 3, 4, 5, 6, 7, 8, 9 months, change in quality of life (Sickness Impact Profile scale), survival and adverse events.

DATA COLLECTION AND ANALYSIS

Each author independently graded the risk of bias in the included studies. The lead author extracted data and the other authors checked them. We generated some missing data by making ruler measurements of data in published graphs. We collected data about adverse events from the included trials.

MAIN RESULTS

We identified three randomised controlled trials (RCTs) of rhIGF-I, involving 779 participants, for inclusion in the analysis. In a European trial (183 participants) the mean difference (MD) in change in AALSRS total score after nine months was -3.30 (95% confidence interval (CI) -8.68 to 2.08). In a North American trial (266 participants), the MD after nine months was -6.00 (95% CI -10.99 to -1.01). The combined analysis from both RCTs showed a MD after nine months of -4.75 (95% CI -8.41 to -1.09), a significant difference in favour of the treated group. The secondary outcome measures showed non-significant trends favouring rhIGF-I. There was an increased risk of injection site reactions with rhIGF-I (risk ratio 1.26, 95% CI 1.04 to 1.54). . A second North American trial (330 participants) used a novel primary end point involving manual muscle strength testing. No differences were demonstrated between the treated and placebo groups in this study. All three trials were at high risk of bias.

AUTHORS' CONCLUSIONS

Meta-analysis revealed a significant difference in favour of rhIGF-I treatment; however, the quality of the evidence from the two included trials was low. A third study showed no difference between treatment and placebo. There is no evidence for increase in survival with IGF1. All three included trials were at high risk of bias.

Riluzole for amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND)

BACKGROUND

Riluzole is approved for the treatment of amyotrophic lateral sclerosis in most countries. Questions persist about its clinical utility because of high cost and modest efficacy.

OBJECTIVES

To examine the efficacy of riluzole in prolonging survival and in delaying the use of surrogates (tracheostomy and mechanical ventilation) to sustain survival, and to assess the effect of riluzole upon functional health.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register (20 April 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (2011, Issue 2), MEDLINE (1966 to April 2011), EMBASE (1980 to May 2011) and made enquiries of authors of trials, Aventis (manufacturer of riluzole) and other experts in the field.

SELECTION CRITERIA

Types of studies: randomized controlled trials

TYPES OF PARTICIPANTS

adults with a diagnosis of amyotrophic lateral sclerosis Types of interventions: treatment with riluzole or placebo Types of outcome measures: Primary: pooled hazard ratio of tracheostomy-free survival over all time points with riluzole 100 mg. Secondary: per cent mortality with riluzole 50 mg, 100 mg and 200 mg; neurologic function, muscle strength and adverse events.

DATA COLLECTION AND ANALYSIS

One author performed data extraction and two other authors checked them. One author checked the data and entered them into the computer. The other authors verified the data entry. We obtained missing data from the trial authors whenever possible.

MAIN RESULTS

The four trials examining tracheostomy-free survival included a total of 974 riluzole-treated patients and 503 placebo-treated patients. No new randomized controlled trials were found when we updated the searches for this update in 2011. The methodological quality was acceptable and three trials were easily comparable, although one trial (169 participants) included older patients in more advanced stages of amyotrophic lateral sclerosis and one (195 participants) had multiple primary endpoints. Riluzole 100 mg per day provided a benefit for the homogeneous group of patients in the first two trials (hazard ratio (HR) 0.80, 95% confidence internal (CI) 0.64 to 0.99, P= 0.042) and there was no evidence of heterogeneity (P = 0.33). When the third trial (which included older and more seriously affected patients) was added, there was evidence of heterogeneity (P < 0.0001) and the overall treatment effect was reduced but still significant (HR 0.84, 95% CI 0.698 to 0.997, P= 0.046). This represented a 9% gain in the probability of surviving one year (49% in the placebo and 58% in the riluzole group), and increased median survival from 11.8 to 14.8 months. There was a small beneficial effect on both bulbar and limb function, but not on muscle strength. A three-fold increase in serum alanine transferase was more frequent in riluzole-treated patients than controls (mean difference 2.62, 95% CI 1.59 to 4.31).

AUTHORS' CONCLUSIONS

Riluzole 100 mg daily is reasonably safe and probably prolongs median survival by about two to three months in patients with amyotrophic lateral sclerosis.

A simple reminder system improves venous thromboembolism prophylaxis rates and reduces thrombotic events for hospitalized patients1

BACKGROUND

Compliance with venous thromboembolism (VTE) prophylaxis is poor.

OBJECTIVES

We sought to determine whether a simple electronic reminder applicable to all hospitalized patients would increase prophylaxis rates and reduce VTE rates.

METHODS

An electronic reminder was added to the electronic medical record admission note used by all services in our hospital. Prophylaxis, VTE and bleeding rates before and after implementation were compared. Data were analyzed with sas version 9.1.

RESULTS

Among all adult medical and surgical patients admitted to our hospital during the time periods studied, 42.8% (1236/2888) before and 60.0% (1410/2350) after the reminder was added received appropriate prophylaxis as per American College of Chest Physicians (ACCP) guidelines (P < 0.001). The difference reached significance for both medical (51.0% vs. 68.9%; P < 0.001) and surgical (48.0% vs. 61.0%; P < 0.001) services. Fewer patients were diagnosed with VTE after our reminder was added (1.1% vs. 0.3%; P = 0.001), and there was a trend towards fewer bleeds (1.1% vs. 0.6%; P = 0.09). The presence of the reminder was an independent predictor for prophylaxis being given (odds ratio [OR] 1.92, 95% confidence interval [CI] 1.70-2.18; P < 0.001), and was independently associated with a decreased risk for VTE (OR 0.30, 95% CI 0.14-0.64; P = 0.003) after adjustment for other VTE risk factors.

CONCLUSION

Adding an electronic reminder to the admission note improved prophylaxis rates and reduced VTE rates across services. The system is easily reproducible and applicable to other facilities. The improvement obtained was modest, so additional measures will probably be needed to optimize prophylaxis rates.

Emerging pharmacology and physiology of neuromedin U and the structurally related peptide neuromedin S

Neuromedin U (NMU) has been paired with the G-protein-coupled receptors (GPRs) NMU(1) (formerly designated as the orphan GPR66 or FM-3) and NMU(2) (FM-4 or hTGR-1). Recently, a structurally related peptide, neuromedin S (NMS), which shares an amidated C-terminal heptapeptide motif, has been identified in both rat and human, and has been proposed as a second ligand for these receptors. Messenger RNA encoding NMU receptor subtypes shows differential expression: NMU(1) is predominantly expressed in peripheral tissues, particularly the gastrointestinal tract, whereas NMU(2) is abundant within the brain and spinal cord. NMU peptide parallels receptor distribution with highest expression in the gastrointestinal tract and specific structures within the brain, reflecting its major role in the regulation of energy balance. The NMU knockout mouse has an obese phenotype and, in agreement, the Arg165Trp amino acid variant of NMU-25 in humans, which is functionally inactive, co-segregated with childhood-onset obesity. Emerging physiological roles for NMU include vasoconstriction mediated predominantly via NMU(1) with nociception and bone remodelling via NMU(2). The NMU system has also been implicated in the pathogenesis of septic shock and cancers including bladder carcinoma and acute myeloid leukaemia. Intriguingly, NMS is more potent at NMU(2) receptors in vivo where it has similar central actions in suppression of feeding and regulation of circadian rhythms to NMU. Taken together with its vascular actions, NMU may be a functional link between energy balance and the cardiovascular system and may provide a future target for therapies directed against the disorders that comprise metabolic syndrome.

Leber's hereditary optic neuropathy associated with multiple sclerosis: Harding's syndrome

We describe a 32-year-old woman with sequential, severe, painless visual loss in one eye and then the other, and three temporally distinct episodes of neurological disturbance suggestive of demyelination in the spinal cord. She was positive for the T14484C mutation in the mitochondrial genome, one of three common mutations causing Leber's hereditary optic neuropathy. In addition, MRI identified areas of demyelination within the periventricular white matter of the brain and within the spinal cord. The coexistence of multiple sclerosis and Leber's hereditary optic neuropathy (Harding's syndrome) is known to occur more often than would be expected by chance; therefore, screening for the Leber's mutations in multiple sclerosis patients with severe visual loss should be considered because this has important prognostic and genetic implications.

Descriptive epidemiology of amyotrophic lateral sclerosis: new evidence and unsolved issues

Amyotrophic lateral sclerosis (ALS) is a relatively rare disease with a reported population incidence of between 1.5 and 2.5 per 100,000 per year. Over the past 10 years, the design of ALS epidemiological studies has evolved to focus on a prospective, population based methodology, employing the El Escorial criteria and multiple sources of data to ensure complete case ascertainment. Five such studies, based in Europe and North America, have been published and show remarkably consistent incidence figures among their respective Caucasian populations. Population based studies have been useful in defining clinical characteristics and prognostic indicators in ALS. However, many epidemiological questions remain that cannot be resolved by any of the existing population based datasets. The working hypotheses is that ALS, like other chronic diseases, is a complex genetic condition, and the relative contributions of individual environmental and genetic factors are likely to be relatively small. Larger studies are required to characterise risks and identify subpopulations that might be suitable for further study. This current paper outlines the contribution of the various population based registers, identifies the limitations of the existing datasets and proposes a mechanism to improve the future design and output of descriptive epidemiological studies.

Recombinant human insulin-like growth factor I (rhIGF-I) for amyotrophic lateral sclerosis/motor neuron disease

BACKGROUND

Trophic factors, including recombinant human insulin-like growth factor I (rhIGF-I) are possible disease modifying therapies for amyotrophic lateral sclerosis.

OBJECTIVES

To examine the efficacy of recombinant human insulin-like growth factor I in amyotrophic lateral sclerosis.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Trials Register (March 2006), MEDLINE (January 1966 to March 2006) and EMBASE (January 1980 to March 2006) and asked the authors of randomised clinical trials and manufacturers of recombinant human insulin-like growth factor I.

SELECTION CRITERIA

We considered all randomised controlled clinical trials involving rhIGF-I treatment of amyotrophic lateral sclerosis in adults with a clinical diagnosis of definite or probable amyotrophic lateral sclerosis according to the El Escorial Criteria. The primary outcome measure was change in Appel Amyotrophic Lateral Sclerosis Rating Scale (AALSRS) total score after nine months treatment and secondary outcome measures were change in AALSRS at 1, 2, 3, 4, 5, 6, 7, 8, 9 months, change in quality of life (Sickness Impact Profile scale), survival and adverse events.

DATA COLLECTION AND ANALYSIS

We identified three randomised clinical trials. Only two were included in the analysis. Each author graded the studies for methodological quality. Data were extracted and entered by the lead author and checked by the other two. Some missing data had to be regenerated by calculations based on ruler measurements of data presented in published graphs.

MAIN RESULTS

In a European trial with 59 participants on placebo and 124 on rhIGF-I, 0.1 mg/kg/day the mean difference (MD) in change in AALSRS total score after nine months was -3.30 (95% confidence interval (CI) -8.68 to 2.08), non-significantly less in the treated than the placebo group. In a North American trial, in which 90 participants on placebo were compared with 89 on recombinant human insulin-like growth factor I 0.05 mg/kg/day, and 87 participants on 0.1 mg/kg/day, the MD after nine months was -6.00 (95%CI -10.99 to -1.01), significantly less on treatment. The combined analysis from both randomised clinical trials showed a weighted mean difference after nine months of -4.75 (95% CI -8.41 to -1.09), a significant difference in favour of the treated group. The secondary outcome measures showed non-significant trends favouring rhIGF-I. Similarly the data with the 0.05 mg/kg/day dose showed trends favouring rhIGF-I at all time points but did not reach significance at the five per cent level at any point. There was an increased risk of injection site reactions with rhIGF-I (relative risk 2.53, 95% CI 1.40 to 4.59).

AUTHORS' CONCLUSIONS

The available randomised placebo controlled trials do not permit a definitive assessment of the clinical efficacy of rhIGF-I on ALS. More research is needed and one trial is in progress. Future trials should include survival as an outcome measure.

Amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (known in the UK as motor neuron disease) is a devastating illness with uncertain pathogenesis. In this Seminar, we review its natural history, clinical features, diagnostic criteria, variant and mimic syndromes, genetic forms, and epidemiology. Several hypotheses about causes of the disorder are discussed, such as excitotoxicity and oxidant stress, and we review past and present putative disease-modifying treatments. Disease-management strategies, from telling the patient about their illness to end-of-life decisions and palliative care, are presented. We review options for control of the main symptoms of amyotrophic lateral sclerosis--including dysphagia, dysarthria, respiratory distress, pain, and psychological disorders--and care in the terminal phase. The need for good psychosocial and spiritual care of patients and families is emphasised. We conclude with an overview of some current major issues and future prospects, ranging from the search for disease markers to challenging developments such as stem-cell and gene therapy.

Riluzole for amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND)

BACKGROUND

Riluzole has been approved for treatment of patients with amyotrophic lateral sclerosis in most countries. Questions persist about its clinical utility because of high cost and modest efficacy.

OBJECTIVES

To examine the efficacy of riluzole in prolonging survival, and in delaying the use of surrogates (tracheostomy and mechanical ventilation) to sustain survival.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Register for randomized trials in December 2004 and made enquiries of authors of trials, Aventis (manufacturer of riluzole) and other experts in the field. We searched MEDLINE (January 1966 to August 25 2006) and EMBASE (January 1980 to September 30th 2006).

SELECTION CRITERIA

Types of studies: randomized trials.

TYPES OF PARTICIPANTS

adults with a diagnosis of amyotrophic lateral sclerosis. Types of interventions: treatment with riluzole or placebo. Types of outcome measures: Primary: pooled hazard ratio of tracheostomy-free survival over all time points with riluzole 100 mg. Secondary: per cent mortality with riluzole 50, 100 and 200 mg; neurologic function, muscle strength and adverse events.

DATA COLLECTION AND ANALYSIS

We identified four eligible randomized trials.

MAIN RESULTS

The four trials examining tracheostomy-free survival included a total of 974 riluzole treated patients and 503 placebo treated patients. The methodological quality was acceptable and three trials were easily comparable, although one trial included older patients in more advanced stages of amyotrophic lateral sclerosis and one had multiple primary endpoints. Riluzole 100 mg per day provided a benefit for the homogeneous group of patients in the first two trials (P value = 0.042, hazard ratio 0.80, 95% confidence interval 0.64 to 0.99) and there was no evidence of heterogeneity (P value = 0.33). When the third trial (which included older and more seriously affected patients) was added, there was evidence of heterogeneity (P value < 0.0001) and the random effects model, which takes this into account, resulted in the overall treatment effect estimate falling just short of significance (P value = 0.056, hazard ratio 0.84, 95% confidence interval 0.70 to 1.01). This represented a 9% gain in the probability of surviving one year (57% in the placebo and 66% in the riluzole group). There was a small beneficial effect on both bulbar and limb function, but not on muscle strength. A threefold increase in serum alanine transferase was more frequent in riluzole treated patients than controls (weighted mean difference 2.62, 95% confidence interval 1.59 to 4.31).

AUTHORS' CONCLUSIONS

Riluzole 100 mg daily is reasonably safe and probably prolongs median survival by about two to three months in patients with amyotrophic lateral sclerosis.

Patients' health-related quality-of-life and health state values for motor neurone disease/amyotrophic lateral sclerosis

Motor neurone disease (MND) has a severe impact on patient quality of life, especially in later stages of the disease. This study assesses the health-related quality of life (HRQL) of MND patients, and for the first time elicits health state values from patients for their present health state. A structured interview was conducted with 77 patients. Patients completed a disease specific health status measure (ALSAQ-40), a generic health status measure (EuroQol EQ-5D), a visual analogue scale (VAS) and a standard gamble (SG) exercise. The ALSAQ-40 was sensitive to disease severity. Patients' mean VAS rating of their own health ranged from 0.74 for stage 1 (early) disease severity (n = 15), to 0.37 for stage 4 (late stage) disease severity (n = 19). Utilities elicited via SG varied from a mean of 0.79 for stage 1 disease severity to a mean of 0.45 for stage 4 disease severity. The EQ-5D derived single index ranged from a mean of 0.63 for stage 1 disease severity to a mean of -0.01 for stage 4 disease severity. This study demonstrates that it is feasible and practical to obtain health state values from MND patients and it provides evidence that patients place a high value on their HRQL, even in cases where health status is very poor.

Riluzole for amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND)

BACKGROUND

Riluzole 100 mg probably prolongs survival in patients with amyotrophic lateral sclerosis by about two months and the safety of the drug is not a major concern. The evidence from randomized controlled trials indicates that patients taking riluzole probably survive longer than patients taking placebo. The beneficial effects are very modest and the drug is expensive. Adverse effects from riluzole are relatively minor and for the most part reversible after stopping the drug. Riluzole has been approved for treatment of patients with amyotrophic lateral sclerosis in many countries but not all. Questions persist about its clinical utility because of high cost, modest efficacy and concern over adverse effects.

OBJECTIVES

To examine the efficacy of riluzole in prolonging survival, and in delaying the use of surrogates (tracheostomy and mechanical ventilation) to sustain survival.

SEARCH STRATEGY

Search of the Cochrane Neuromuscular Disease Group Register for randomized trials and enquiry from authors of trials, Aventis (manufacturer of riluzole) and other experts in the field. The most recent search was November 2002.

SELECTION CRITERIA

Randomized trials of adults with diagnosis of amyotrophic lateral sclerosis (ALS), treated with riluzole or placebo. Types of outcome measures: Primary: pooled hazard ratio of tracheostomy-free survival over all time points with riluzole 100 mg. Secondary: per cent mortality as a function of time with riluzole 100 mg and other doses of riluzole; neurologic function, quality of life, muscle strength and adverse events.

DATA COLLECTION & ANALYSIS

We identified four eligible randomized trials. Each reviewer graded them for methodological quality. Data extraction was performed by a single reviewer and checked by two others. We obtained some missing data from investigators and regulatory agencies. We performed meta-analyses with Review Manager 4.1 software using a fixed effects model. A test of drug efficacy was based on the Parmar pooled hazard ratio.

RESULTS

The three trials examining tracheostomy-free survival included a total of 876 riluzole treated patients and 406 placebo treated patients. The data for tracheostomy-free survival was not available from the fourth trial. The methodological quality was acceptable and the three trials were easily comparable, although one trial included older patients in more advanced stages of amyotrophic lateral sclerosis. Riluzole 100 mg per day provided a benefit for the homogeneous group of patients in the first two trials (p=0.039, hazard ratio 0.80, 95% confidence interval 0.64 to 0.99) and there was no evidence of heterogeneity (p=0.33). When the third trial (which included older and more seriously affected patients) is added, there is evidence of heterogeneity (p<0.0001) and the random effects model, which takes this into account results in the overall treatment effect estimate falling just short of significance (p=0.056, hazard ratio 0.84, 95% confidence interval 0.70 to 1.01). This represents a 9% gain in the probability of surviving one year (57% in the placebo and 66% in the riluzole group). In secondary analyses of survival at separate time points, there was a significant survival advantage with riluzole 100 mg at six, nine, 12 and 15 months, but not at three or 18 months. There was a small beneficial effect on both bulbar and limb function, but not on muscle strength. There were no data on quality of life, but patients treated with riluzole remained in a more moderately affected health state significantly longer than placebo-treated patients (weighted mean difference 35.5 days, 95% confidence interval 5.9 to 65.0). A threefold increase in serum alanine transferase was more frequent in riluzole treated patients than controls (weighted mean difference 2.69, 95% confidence interval 1.65 to 4.38).

CONCLUSIONS

Riluzole 100 mg daily is reasonably safe and probably prolongs survival by about two months in patients with ALS. More studies are needed, especially to clarify its effect in older patients (over 75 years), and those with more advanced disease.

Dissection of the intracranial internal carotid artery producing isolated oculomotor nerve palsy with sparing of pupil

Dissection of the internal carotid artery usually occurs in the cervical segment, but rarely may involve the artery in the intracranial course (1). The clinical course of intracranial dissection is often catastrophic, with rapid onset of profound neurological deficit, as a result of middle and/or anterior cerebral artery involvement. When this occurs the mortality rate is generally considered high. We describe a case of intracranial internal carotid artery dissection following trivial trauma presented with an isolated painful pupillary sparing oculomotor nerve palsy.

Riluzole for amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND)

BACKGROUND

Riluzole has been approved for treatment of patients with amyotrophic lateral sclerosis in many countries but not all. Questions persist about its clinical utility because of high cost, modest efficacy and concern over adverse effects.

OBJECTIVES

To examine the efficacy of riluzole in prolonging survival, and in delaying the use of surrogates (tracheostomy and mechanical ventilation) to sustain survival.

SEARCH STRATEGY

Search of the Cochrane Neuromuscular Disease Group Register for randomized trials and enquiry from authors of trials, Aventis (manufacturer of riluzole) and other experts in the field. The most recent search was May, 2001 SELECTION CRITERIA: Types of studies: randomized trials

TYPES OF PARTICIPANTS

adults with a diagnosis of amyotrophic lateral sclerosis Types of interventions: treatment with riluzole or placebo Types of outcome measures: Primary: pooled hazard ratio of tracheostomy-free survival over all time points with riluzole 100 mg. Secondary: per cent mortality as a function of time with riluzole 100 mg and other doses of riluzole; neurologic function, quality of life, muscle strength and adverse events.

DATA COLLECTION AND ANALYSIS

We identified four eligible randomized trials. Each reviewer graded them for methodological quality. Data extraction was performed by a single reviewer and checked by two others. We obtained some missing data from investigators and regulatory agencies. We performed meta-analyses with Review Manager 4.1 software using a fixed effects model. A test of drug efficacy was based on the Parmar pooled hazard ratio.

MAIN RESULTS

The three trials examining tracheostomy-free survival included a total of 876 riluzole treated patients and 406 placebo treated patients. The data for tracheostomy-free survival was not available from the fourth trial. The methodological quality was acceptable and the three trials were easily comparable, although one trial included older patients in more advanced stages of amyotrophic lateral sclerosis. Riluzole 100 mg per day provided a benefit for the homogeneous group of patients in the first two trials (p=0.039, hazard ratio 0.80, 95% confidence interval 0.64 to 0.99) and there was no evidence of heterogeneity (p=0.33). When the third trial (which included older and more seriously affected patients) is added, there is evidence of heterogeneity (p<0.0001) and the random effects model, which takes this into account results in the overall treatment effect estimate falling just short of significance (p=0.056, hazard ratio 0.84, 95% confidence interval 0.70 to 1.01). This represents a 9% gain in the probability of surviving one year (57% in the placebo and 66% in the riluzole group). In secondary analyses of survival at separate time points, there was a significant survival advantage with riluzole 100 mg at six, nine, 12 and 15 months, but not at three or 18 months. There was a small beneficial effect on both bulbar and limb function, but not on muscle strength. There were no data on quality of life, but patients treated with riluzole remained in a more moderately affected health state significantly longer than placebo-treated patients (weighted mean difference 35.5 days, 95% confidence interval 5.9 to 65.0). A threefold increase in serum alanine transferase was more frequent in riluzole treated patients than controls (weighted mean difference 2.69, 95% confidence interval 1.65 to 4.38).

REVIEWER'S CONCLUSIONS

Riluzole 100 mg daily is reasonably safe and probably prolongs survival by about two months in patients with amyotrophic lateral sclerosis. More studies are needed, especially to clarify its effect in older patients (over 75 years), and those with more advanced disease.

Recombinant human insulin-like growth factor I (rhIGF-I) for amyotrophic lateral sclerosis/motor neuron disease

BACKGROUND

Trophic factors, including recombinant human insulin-like growth factor I have been postulated as possible disease modifying therapies for amyotrophic lateral sclerosis. Randomised clinical trials of recombinant human insulin-like growth factor I in amyotrophic lateral sclerosis to date have yielded conflicting results.

OBJECTIVES

The main objective of this review was to examine the efficacy of recombinant human insulin-like growth factor I in amyotrophic lateral sclerosis. Occurrence of adverse events has also been reviewed.

SEARCH STRATEGY

A search was carried out using the Cochrane Neuromuscular Disease Group register for randomised clinical trials of recombinant human insulin-like growth factor I in amyotrophic lateral sclerosis. Enquiries were also made of authors of randomised clinical trials as well as the manufacturers of recombinant human insulin-like growth factor I regarding any other randomised clinical trials which had not yet been published.

SELECTION CRITERIA

Types of studies: all randomised controlled clinical trials involving recombinant human insulin-like growth factor I treatment of amyotrophic lateral sclerosis.

TYPES OF PARTICIPANTS

Adults with a clinical diagnosis of definite or probable amyotrophic lateral sclerosis according to the El Escorial Criteria. Types of interventions: Treatment with recombinant human insulin-like growth factor I or placebo. Types of outcome measures: Primary: Change in Appel Amyotrophic Lateral Sclerosis Rating Scale (AALSRS) total score with 0.1mg/kg/day of recombinant human insulin-like growth factor I after nine months treatment. Secondary: Change in AALSRS with recombinant human insulin like growth factor I 0.1mg/kg/day and 0.05mg/kg/day at 1, 2, 3, 4, 5, 6, 7, 8, 9 months, change in quality of life (Sickness Impact Profile scale), survival and adverse events.

DATA COLLECTION AND ANALYSIS

We identified two randomised clinical trials. Each reviewer graded them for methodological quality. Data were extracted and entered by the lead reviewer and checked by the other two. Some missing data had to be regenerated by calculations based on ruler measurements of data presented in published graphs.

MAIN RESULTS

The primary outcome measure was change in disease progression as determined by the Appel ALS Rating Scale total score with 0.1 mg/kg/day of recombinant human insulin-like growth factor I subcutaneously after nine months treatment. The level of significance was lower in the European trial which compared 59 patients on placebo with 124 on insulin-like growth factor I 0.1 mg/kg/day (weighted mean difference -3.30, 95%CI -8.68 to 2.08) than in the North American trial which compared 90 patients on placebo with 89 on recombinant human insulin-like growth factor I 0.05 mg/kg/day 89 patients and 87 patients on 0.1mg/kg/day (weighted mean difference -6.00, 95%CI -10.99 to -1.01). The combined analysis from both randomised clinical trials showed a weighted mean difference of -4.75 (95% CI -8.41 to -1.09) favouring the treated group. The secondary outcome measures showed similar trends favouring recombinant human insulin-like growth factor I but these did not reach significance at the five per cent level. Similarly the data with the 0.05mg/kg/day dose showed trends favouring recombinant human insulin-like growth factor I at all time points but did not reach significance at the five per cent level at any point. Evaluation of adverse events showed an increased risk of injection site reactions/inflammation with recombinant human insulin-like growth factor I (relative risk 2.53, 95% CI 1.40 to 4.59). The drug was otherwise safe and well tolerated.

REVIEWER'S CONCLUSIONS

Recombinant human insulin-like growth factor I may be modestly effective but the evidence currently available is insufficient for a definitive assessment. Further randomised clinical trials need to be done.

Patients' health-related quality of life and utilities associated with different stages of amyotrophic lateral sclerosis

OBJECTIVES

Amyotrophic lateral sclerosis (ALS) is a devastating disease that has serious consequences in terms of impairments and disabilities, which are expected to impact on health-related quality of life (HRQL). The aim of the present study was to assess self-reported health status and HRQL, as well as patients' own valuation of their present health state in a sample of patients with different levels of severity of ALS.

METHODS

Structured interviews were conducted with 77 patients with different levels of disease severity. Patients completed a disease-specific health status measure (ALSAQ-40), a generic health status measure (EuroQol EQ-5D), visual analogue scale (VAS) rating of current health and a standard gamble (SG) exercise to provide health state utilities for their own health state.

RESULTS

The results from the ALSAQ-40 and EQ-5D descriptive system indicate that patients' HRQL decreases systematically with increasing severity of disease. Patients' mean VAS rating of their own health ranged from 0.74 for stage 1 (early) disease severity, to 0.37 for stage 4 (late stage) disease severity. Utilities elicited via SG were systematically higher than VAS scores and ranged from a mean of 0.79 for stage 1 disease severity to a mean of 0.45 for stage 4 disease severity.

Resection for bronchogenic carcinoma involving the carina: long-term results and effect of nodal status on outcome

OBJECTIVE

Bronchogenic carcinoma in close proximity to or involving the carina remains a challenging problem for thoracic surgeons. The operative procedures to allow complete resection are technically demanding and can be associated with significant morbidity and mortality. Little is known about long-term survival data to guide therapy in these patients.

METHODS

We conducted a single-institution retrospective review.

RESULTS

We have performed 60 carinal resections for bronchogenic carcinoma: 18 isolated carinal resections for tumor confined to the carinal or proximal main stem bronchus; 35 carinal pneumonectomies; 5 carinal plus lobar resections, and 2 carinal resections for stump recurrence after prior pneumonectomy. Thirteen patients (22%) had a history of lung or airway surgery. The overall operative mortality was 15%, improved from the first half of the series (20%) to the second half (10%), and varied according to the type of resection performed. Adult respiratory distress syndrome was responsible for 5 early deaths, and all late deaths were related to anastomotic complications. In 34 patients, all lymph nodes were negative for metastatic disease; 15 patients had positive N1 nodes, and 11 patients had positive N2/N3 nodes. Complete follow-up was accomplished in 90%, with a mean follow-up of 59 months. The overall 5-year survival including operative mortality was 42%, with 19 absolute 5-year survivors. Survival was highest after isolated carinal resection (51%). Lymph node involvement had a strong influence on survival: patients without nodal involvement had a 5-year survival of 51%, compared with 32% for patients with N1 disease and 12% for those with N2/N3 disease.

CONCLUSIONS

This constitutes one of the largest single-institution reports on carinal resection for bronchogenic carcinoma involving the carina. Morbidity and mortality rates are acceptable. The overall survival including operative mortality is 42%. Positive N2/N3 lymph nodes may be a contraindication to surgery because of poor prognosis.

Guidelines in motor neurone disease (MND)/amyotrophic lateral sclerosis (ALS)--from diagnosis to patient care

This paper reviews the scope of current guidelines in motor neurone disease (MND)/amyotrophic lateral sclerosis (ALS) and examines issues which have arisen in the preparation of these documents. The review concludes with an evaluation of the impact of the guidelines which have been produced to date and looks towards potential future developments in this area.

Amyotrophic lateral sclerosis: toxins and environment

The role of environmental influences in the aetiopathogenesis of amyotrophic lateral sclerosis (ALS) has exercised minds since the 19th century. Despite strong hunches that environmental agents might be implicated in the causation of ALS, research seeking more objective evidence has generally yielded results which have been confusing and difficult to understand in terms of a unitary aetiological hypothesis. This review attempts to draw this evidence together in the context of a semi-systematic review of the literature. Potential physical influences are described as well as the better known chemical factors. The interface with recent advances in molecular genetics is reviewed as well as foci of ALS variants as they occur in localized areas in various parts of the world. There is a discussion of large and small area geographical clustering and the review concludes by presenting a general view of the possible significance of these--at times--confusing pointers in the context of other current theories of the aetiology of ALS.

Clinical experience with carinal resection

OBJECTIVE

Pathologic processes that involve the carina pose a tremendous challenge to thoracic surgeons. Although techniques have been developed to allow primary resection and reconstruction, few institutions have accumulated sufficient experience to allow meaningful conclusions about the indications and the morbidity and mortality rates for this type of surgery.

METHODS

Since 1962, 135 patients have undergone 143 carinal resections (134 primary resection, 9 re-resection) at our institution. Indications for carinal resection included bronchogenic cancer (58 patients), other airway neoplasms (60 patients), and benign or inflammatory strictures (16 patients). Thirty-seven patients (28%) had a history of prior lung or airway surgery not involving the carina. Carinal resection without pulmonary resection was accomplished in 52 patients; 57 patients had carinal pneumonectomy (44 right, 13 left); 14 patients had carinal plus lobar resection, and 11 patients had carinal resection after pneumonectomy (9 left, 2 right). There were 15 different modes of reconstruction, based on the type and extent of resection. Techniques were used to reduce anastomotic tension.

RESULTS

The operative mortality rate in the 134 patients after primary carinal resection was 12.7%. Adult respiratory distress syndrome was responsible for 9 early deaths. Predominant predictors of operative death included postoperative mechanical ventilation (P =.001), length of resected airway (P =.03), and development of anastomotic complications (P =.04). Mortality rates varied by the type of procedure and the indication for resection. Left carinal pneumonectomy was associated with a high operative mortality rate (31%). Complications were noted in 52 patients (39%), including atrial arrhythmias (20 patients) and pneumonia (11 patients). Anastomotic complications, both early and late, were seen in a total of 23 patients (17%) and resulted in death or surgical reintervention in 21 patients (91%). The operative mortality rate for carinal re-resection was 11.1%.

CONCLUSIONS

Carinal resection with primary reconstruction may be accomplished with acceptable mortality rates, but the underlying pathologic process and chance for long-term survival must be carefully considered before the operation is recommended, especially in the case of left carinal pneumonectomy. Anastomotic complications exact a heavy toll on involved patients. Careful patient selection and meticulous anesthetic and surgical technique remain the key to minimizing morbidity and mortality rates.

Geographical epidemiology of residence of patients with motor neuron disease in Lancashire and south Cumbria

OBJECTIVES

To seek objective evidence for geographical clustering of places of residence of patients with motor neuron disease (MND).

METHODS

A complete residential history from birth to onset of disease was obtained from a cohort of 130 patients with MND from Lancashire and south Cumbria presenting to the Department of Neurology in Preston between 1 January 1989 and 31 December 1993. These data were compared with population based reference data from the 1991 UK Census.

RESULTS

Some areal units showed a greater, others a lesser, number of MND patient residences than expected. The results suggest that the background population incidence of MND is relatively low and that the overall incidence figures previously quoted have been skewed upwards by areas in which the incidence of MND is relatively increased. These findings were further tested by Poisson modelling. The Poisson model provided a poor fit for the data at postcode district and sector levels confirming that patients with MND were significantly more likely to have lived in some areas than others after allowing for variation in population of the different areal units and for variation in duration of residence.

CONCLUSIONS

These findings reinforce the results of previous work, much of which has been qualitative rather than quantitative. The results presented here suggest a low background incidence of MND in the context of generally quoted overall incidence figures. This low background incidence is, however, skewed upwards by some areal units with a relatively high incidence, thus achieving overall incidence rates comparable with generally quoted figures. We conclude that there is prima facie evidence of spatial patterns in the distribution of places of residence of patients with MND. Further examination of occupational and environmental factors in the lives of the patients with MND is required to obtain a better understanding of the importance of these findings.