bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcomes are Worse in US Patients Undergoing Surgery on Weekends Compared With Weekdays
Authors: Glance Laurent G. , Osler Turner , Li Yue , Lustik Stewart J. , Eaton Michael P. , Dutton Richard P. , Dick Andrew W.
Published: April 2016

Background:

Increasing surgical access to previously underserved populations in the United States may require a major expansion of the use of operating rooms on weekends to take advantage of unused capacity. Although the so-called weekend effect for surgery has been described in other countries, it is unknown whether US patients undergoing moderate-to-high risk surgery on weekends are more likely to experience worse outcomes than patients undergoing surgery on weekdays.

Objective:

The aim of this study was to determine whether patients undergoing surgery on weekends are more likely to die or experience a major complication compared with patients undergoing surgery on a weekday.

Research Design:

Using all-payer data, we conducted a retrospective cohort study of 305,853 patients undergoing isolated coronary artery bypass graft surgery, colorectal surgery, open repair of abdominal aortic aneurysm, endovascular repair of abdominal aortic aneurysm, and lower extremity revascularization. We compared in-hospital mortality and major complications for weekday versus weekend surgery using multivariable logistic regression analysis.

Results:

After controlling for patient risk and surgery type, weekend elective surgery [adjusted odds ratio (AOR)=3.18; 95% confidence interval (CI), 2.26–4.49; P<0.001] and weekend urgent surgery (AOR=2.11; 95% CI, 1.68–2.66; P<0.001) were associated with a higher risk of death compared with weekday surgery. Weekend elective (AOR=1.58; 95% CI, 1.29–1.93; P<0.001) and weekend urgent surgery (AOR=1.61; 95% CI, 1.42–1.82; P<0.001) were also associated with a higher risk of major complications compared with weekday surgery.

Conclusions:

Patients undergoing nonemergent major cardiac and noncardiac surgery on the weekends have a clinically significantly increased risk of death and major complications compared with patients undergoing surgery on weekdays. These findings should prompt decision makers to seek to better understand factors, such physician and nurse staffing, which may contribute to the weekend effect.
Accuracy of Medicare Claim–based Algorithm to Detect Breast, Prostate, or Lung Cancer Bone Metastases
Authors: Sathiakumar Nalini , Delzell Elizabeth , Yun Huifeng , Jooste Rene , Godby Kelly , Falkson Carla , Yong Mellissa , Kilgore Meredith L.
Published: April 2016

Background:

We had previously developed an algorithm for Medicare claims data to detect bone metastases associated with breast, prostate, or lung cancer. This study was conducted to examine whether this algorithm accurately documents bone metastases on the basis of diagnosis codes in Medicare claims data.

Methods:

We obtained data from Medicare claims and electronic medical records of patients 65 years or older with a breast, prostate, or lung cancer diagnosis at a teaching hospital and/or affiliated clinics during 2005 or 2006. We calculated the sensitivity and positive predictive value (PPV) of our algorithm using medical records as the “gold standard.” The κ statistic was used to measure agreement between claims and medical record data.

Results:

The agreement between claims and medical record data for bone metastases among breast, prostate, and lung cancer patients was 0.93, 0.90, and 0.69, respectively. The sensitivities of our algorithm for bone metastasis in patients with breast, prostate, and lung were 96.8% [95% confidence interval (CI)=83.8% to 99.4%], 91.7% (95% CI=78.2% to 97.1%), and 74.1% (95% CI=55.3% to 86.8%), respectively; and the PPVs were 90.9% (95% CI=76.4% to 96.9%), 91.7% (95% CI=78.2% to 97.1%), and 71.4% (95% CI=52.9% to 84.8%), respectively.

Conclusions:

The algorithm for detecting bone metastases in claims data had high sensitivity and PPV for breast and prostate cancer patients. Sensitivity and PPV were lower but still moderate for lung cancer patients.
When the Appendix Is Not Seen on Ultrasound for Right Lower Quadrant Pain
Authors: Ly Donald Le , Khalili Korosh , Gray Sara , Atri Mostafa , Hanbidge Anthony , Thipphavong Seng
Published: April 2016

A survey was administered to 166 academic emergency department (ED) physicians to determine their interpretation and practice after receiving an ultrasound (US) report with nonvisualization of the appendix (NVA). Annual incidence of reported NVA from 2 academic hospitals was calculated for 2002–2013. A retrospective review of the same hospitals revealed that 291 (17.4%) of 1672 USs performed for appendicitis in 2012 indicated NVA. These cases underwent a chart review to determine the negative predictive value of reported NVA and utility of secondary findings. Univariate analysis was performed to determine significant predictors of secondary signs of appendicitis on computed tomography. Ninety eight (59%) of 166 ED physicians completed the survey. Forty nine (52%) of 94 respondents agreed that in the setting of reported NVA with no other acute findings, appendicitis has not been excluded and requires further imaging. There was a significant rise in the incidence rate of reported NVA for appendicitis, 22.5% (2002) up to 41.2% (2013, P < 0.0001). Negative predictive value for reported NVA was 216 (94.3%) of 229; in 9 (69%) of 13 patients, secondary signs of appendicitis were noted. Inflammatory changes in right lower quadrant (P = 0.01) and focal tenderness (P = 0.02) noted on US were significant predictors of a positive computed tomography scan. Current perceptions and practice of some ED physicians equate NVA on US as an inadequate study to exclude appendicitis. However, reported NVA is itself a highly predictive sign (94.3%) of absence of appendicitis even when an alternate cause of pain is not seen.
Papillary Thyroid Carcinoma Arising Within a Follicular Adenoma
Authors: Kim Yeun Jeong , Hong Hyun Sook , Jeong Sun Hye , Lee Eun Hye , Kwak Jeong Ja
Published: April 2016

Papillary thyroid carcinoma (PTC) arising within a follicular adenoma is an exceptionally rare histopathological subtype that shows the nuclear features of PTC within a benign-appearing, circumscribed follicular adenoma. Although it is clinically significant because of its malignant nature, its ultrasonographic features have not been described previously. A 26-year-old man presented with a heterogeneous isoechoic solid nodule with a marked hypoechoic solid focus and a low echoic peripheral rim in the right thyroid gland on ultrasonography. On color Doppler images, markedly increased vascularity was seen in the hypoechoic solid component. An ultrasound-guided gun biopsy suggested a follicular neoplasm. In the evaluation of a hemithyroidectomy specimen, thyroid follicles and a thin fibrous capsule were seen, which favored a follicular adenoma with tumor cells in a focal area indicating papillary carcinoma. Here, we report a case of PTC arising within a follicular adenoma and discuss possible considerations in thyroid ultrasonographic examinations.
Epigenetic control of phenotypic plasticity in a filamentous fungusNeurospora crassa
Authors: Kronholm Ilkka , Johannesson Hanna , Ketola Tarmo
Published: April 2016

Phenotypic plasticity is the ability of a genotype to produce different phenotypes under different environmental or developmental conditions. Phenotypic plasticity is an ubiquitous feature of living organisms, and is typically based on variable patterns of gene expression. However, the mechanisms by which gene expression is influenced and regulated during plastic responses are poorly understood in most organisms. While modifications to DNA and histone proteins have been implicated as likely candidates for generating and regulating phenotypic plasticity, specific details of each modification and its mode of operation have remained largely unknown. In this study, we investigated how epigenetic mechanisms affect phenotypic plasticity in the filamentous fungusNeurospora crassa. By measuring reaction norms of strains that are deficient in one of several key physiological processes we show that epigenetic mechanisms play a role in homeostasis and phenotypic plasticity of the fungus across a range of controlled environments. Effects on plasticity are specific to an environment and mechanism, indicating that epigenetic regulation is context dependent and is not governed by general plasticity genes. In our experiments withNeurospora, histone methylation and the RNA interference pathway had the greatest influence on phenotypic plasticity, while lack of DNA methylation had the least.
Fast, scalable and accurate differential expression analysis for single cells
Authors: Sengupta Debarka , Rayan Nirmala Arul , Lim Michelle , Lim Bing , Prabhakar Shyam
Published: April 2016

Analysis of single-cell RNA-seq data is challenging due to technical variability, high noise levels and massive sample sizes. Here, we describe a normalization technique that substantially reduces technical variability and improves the quality of downstream analyses. We also introduce a nonparametric method for detecting differentially expressed genes that scales to > 1,000 cells and is both more accurate and ~10 times faster than existing parametric approaches.
The Higher Plant Plastid Complex I (NDH) is a Reversible Proton Pump that increases ATP production by Cyclic Electron Flow Around Photosystem I
Authors: Strand Deserah D. , Fisher Nicholas , Kramer David M.
Published: April 2016

Cyclic electron flow around photosystem I (CEF) is critical for balancing the photosynthetic energy budget of the chloroplast, by generating ATP without net production of NADPH. We demonstrate that the chloroplast NADPH dehydrogenase complex (NDH), a homolog to respiratory Complex I, pumps approximately two protons from the chloroplast stroma to the lumen per electron transferred from ferredoxin to plastoquinone, effectively increasing the efficiency of ATP production via CEF by two-fold compared to CEF pathways involving non-proton-pumping plastoquinone reductases. Under certain physiological conditions, the coupling of proton and electron transfer reactions within NDH should enable a non-canonical mode of photosynthetic electron transfer, allowing electron transfer from plastoquinol to NADPH to be driven by the thylakoid proton motive force possibly helping to sense or remediate mismatches in the photosynthetic budget.
Different Evolutionary Paths to Complexity for Small and Large Populations of Digital Organisms
Authors: LaBar Thomas , Adami Christoph
Published: April 2016

A major aim of evolutionary biology is to explain the respective roles of adaptive versus non-adaptive changes in the evolution of complexity. While selection is certainly responsible for the spread and maintenance of complex phenotypes, this does not automatically imply that strong selection enhances the chance for the emergence of novel traits, that is, the origination of complexity. Population size is one parameter that alters the relative importance of adaptive and non-adaptive processes: as population size decreases, selection weakens and genetic drift grows in importance. Because of this relationship, many theories invoke a role for population size in the evolution of complexity. Such theories are difficult to test empirically because of the time required for the evolution of complexity in biological populations. Here, we used digital experimental evolution to test whether large or small asexual populations tend to evolve greater complexity. We find that both small and large—but not intermediate-sized—populations are favored to evolve larger genomes, which provides the opportunity for subsequent increases in phenotypic complexity. However, small and large populations followed different evolutionary paths towards these novel traits. Small populations evolved larger genomes by fixing slightly deleterious insertions, while large populations fixed rare beneficial insertions that increased genome size. These results demonstrate that genetic drift can lead to the evolution of complexity in small populations and that purifying selection is not powerful enough to prevent the evolution of complexity in large populations.

Author Summary

Since the early days of theoretical population genetics. scientists have debated the role of population size in shaping evolutionary dynamics. Do large populations possess an evolutionary advantage towards complexity due to the strength of natural selection in these populations? Or do small populations have the advantage, as genetic drift allows for the exploration of fitness landscapes inaccessible to large populations? There are many theories that predict whether large or small populations–those with strong selection or those with strong drift–should evolve the greatest complexity. Here, we use digital experimental evolution to examine the interplay between population size and the evolution of complexity. We found that genetic drift could lead to increased genome size and phenotypic complexity in very small populations. However, large populations also evolved similar large genomes and complexity. Small populations evolved larger genomes through the fixation of slightly deleterious insertions, while large populations utilized rare beneficial insertions. Our results suggest that both strong drift and strong selection can allow populations to evolve similar complexity, but through different evolutionary trajectories.
Fused regression for multi-source gene regulatory network inference
Authors: Lam Kari Y. , Westrick Zachary M. , Müller Christian L. , Christiaen Lionel , Bonneau Richard
Published: April 2016

Understanding gene regulatory networks is critical to understanding cellular differentiation and response to external stimuli. Methods for global network inference have been developed and applied to a variety of species. Most approaches consider the problem of network inference independently in each species, despite evidence that gene regulation can be conserved even in distantly related species. Further, network inference is often confined to single data-types (single platforms) and single cell types. We introduce a method for multi-source network inference that allows simultaneous estimation of gene regulatory networks in multiple species or biological processes through the introduction of priors based on known gene relationships such as orthology incorporated using fused regression. This approach improves network inference performance even when orthology mapping and conservation are incomplete. We refine this method by presenting an algorithm that extracts the true conserved subnetwork from a larger set of potentially conserved interactions and demonstrate the utility of our method in cross species network inference. Last, we demonstrate our method’s utility in learning from data collected on different experimental platforms.
Htm1p-Pdi1p is a folding sensitive mannosidase that marks N-glycoproteins for ER-associated protein degradation
Authors: Liu Yi-Chang , Fujimori Danica Galonić , Weissman Jonathan S.
Published: April 2016

Our understanding of how the endoplasmic reticulum-associated protein degradation (ERAD) machinery efficiently targets terminally misfolded proteins while avoiding the misidentification of nascent polypeptides and correctly folded proteins is limited. For luminal N-glycoproteins, demannosylation of their N-glycan to expose a terminal α1,6-linked mannose is necessary for their degradation via ERAD, but whether this modification is specific to misfolded proteins is unknown. Here we report that the Htm1p-Pdi1p complex acts as a folding-sensitive mannosidase for catalyzing this first committed step. We reconstitute this stepin vitrowith Htm1p-Pdi1p and model glycoprotein substrates whose structural states we can manipulate. We find that Htm1p-Pdi1p is a glycoprotein-specific mannosidase, which preferentially targets nonnative glycoproteins trapped in partially structured states. As such, Htm1p-Pdi1p is suited to act as a licensing factor that monitors folding in the ER lumen and preferentially commits glycoproteins trapped in partially structured states for degradation.
Solvency stress testing of Islamic commercial banks
Authors: Chattha Jamshaid Anwar , Archer Simon
Published: April 2016

Purpose

This paper aims to provide a methodology for designing and conducting solvency stress tests, under the standardised approach as per IFSB-15, including the establishment of macro-financial links, running scenarios with variation of assumptions and stress scenario parameters; apply and illustrate this methodology by providing a stylised numerical example through a tractable Excel-based framework, through which Islamic Commercial Banks (ICBs) can introduce additional regulatory requirements and show that they would remain in compliance with all capital requirements after a moderate to severe shock; and identify the potential remedial actions that can be envisaged by an ICB.

Design/methodology/approach

The paper uses the data of the one of the groups to which certain amendments and related assumptions are applied to develop a stylised numerical example for solvency stress-testing purposes. The example uses a Stress Testing Matrix (STeM; a step-by-step approach) to illustrate the stress-testing process. The methodology of the paper uses a two-stage process. The first stage consists of calculating the capital adequacy ratio (CAR) of the ICB using the IFSB formulae, depending on how the profit sharing investment account (PSIA) are treated in the respective jurisdiction. The second stage is the application of the stress scenarios and shocks.

Findings

Taking into account the specificities of ICBs such as their use of PSIA, the results highlighted the sensitivity of the CAR of an ICB with respect to the changes in the values of alpha and the proportion of unrestricted PSIA on the funding side. The simulation also indicated that an ICB operating above the minimum CAR could be vulnerable to shocks of various degrees of gravity, thus bringing the CAR below the minimum regulatory requirement and necessitating appropriate remedial actions.

Practical implications

The paper highlights various implications and relationships arising out of stress testing for ICBs, including the vulnerability of an ICB under defined scenarios, demanding appropriate immediate remedial actions on future capital resources and capital needs. The findings of the paper provide a preliminary discussion on developing a comprehensive toolkit for the ICBs similar to what is developed by the International Monetary Fund Financial Sector Assessment Programme.

Originality/value

This paper focuses on the gap with respect to the stress testing of capital adequacy. The main contribution of the paper is twofold. The first is the development of an STeM – a step-by-step approach, which provides a method for simulating solvency (i.e. capital adequacy) stress tests for ICBs; the second is the demonstration of the potentially crucial impact of profit-sharing investment accounts and the way they are managed by ICBs (notably the smoothing of profit payouts) in assessing the capital adequacy of the ICBs.
Moving employee talent key to competitive edge
Authors: Herbert Brynne
Published: April 2016

Purpose

The purpose of this paper is to focus on the current transformation occurring in the global workforce due to changing demands from employees and how they stay engaged in the workplace. Companies realize that appealing to talent with benefits and good pay is no longer enough, and it is time to embrace new tactics to attract and retain personnel.

Design/methodology/approach

CEO Brynne Herbert of MOVE Guides, a leading company in relocation management, looks at how companies have leveraged talent mobility to engage employees and the fragmented, manual processes they use that are no longer suitable for global organizations looking to streamline relocation and offer employees a simpler, more powerful approach.

Findings

The author explores how companies can use technology, like Software as a Service (SaaS), to take aim at optimizing their talent mobility programs and eradicate their inefficient and time-consuming manual operations. Using survey data, a case study from international bank Société Générale and other findings, Brynne discusses how the financial juggernaut was able to implement a cloud-based SaaS platform that updated their HR, finance and payroll and management.

Originality/value

Leveraging technology to attract and engage talent will be ever important in today and tomorrow’s global landscape. Therefore, the companies that move the fastest – and the most strategically – to get the right talent to the right place at the right time will have the competitive edge.
Changes in obestatin gene and GPR39 receptor expression in peripheral tissues of rat models of obesity, type 1 and type 2 diabetes
Authors: Kolodziejski Pawel Antoni , Pruszynska‐Oszmalek Ewa , Sassek Maciej , Kaczmarek Przemyslaw , Szczepankiewicz Dawid , Billert Maria , Mackowiak Paweł , Strowski Mathias Z. , Nowak Krzysztof W.
Published: April 2016

Background

Obestatin has a role in regulating food intake and energy expenditure, but the roles of obestatin and the GPR39 receptor in obesity and type 1 and type 2 diabetes mellitus (T1DM and T2DM, respectively) are not well understood. The aim of the present study was to investigate changes in obestatin and GPR39 in pathophysiological conditions like obesity, T1DM, and T2DM.

Methods

Using rat models of diet‐induced obesity (DIO), T1DM and T2DM (n = 14 per group), obestatin, its precursor protein preproghrelin, and GPR39 expression was investigated in tissues involved in glucose and lipid homeostasis regulation. Furthermore, serum obestatin and ghrelin concentrations were determined.

Results

Serum obestatin concentrations were positively correlated with glucagon (r = 0.6456; P < 0.001) and visfatin (r = 0.5560; P < 0.001), and negatively correlated with insulin (r = –0.4362; P < 0.05), adiponectin (r = –0.3998; P < 0.05), and leptin (r = –0.4180; P < 0.05). There were differences in GPR39 and preproghrelin expression in the three animal models. Hepatic GPR39 and preproghrelin mRNA expression was greater in T1DM, T2DM, and obese rats than in lean controls, whereas pancreatic GPR39 mRNA and protein and preproghrelin mRNA expression was decreased in T1DM, T2DM, and DIO rats. Higher GPR39 and preproghrelin protein and mRNA levels were found in adipose tissues of T1DM compared with control. In adipose tissues of T2DM and DIO rats, GPR39 protein levels were lower than in lean or T1DM rats. Preproghrelin mRNA was higher in adipose tissues of T1DM, T2DM, and DIO than lean rats.

Conclusion

We hypothesize that changes in obestatin, GPR39, and ghrelin may contribute to metabolic abnormalities in T1DM, T2DM, and obesity.
Allogenic Lymphocyte Immunotherapy for Unexplained Recurrent Spontaneous Abortion: A Meta‐Analysis
Authors: Liu Zhilan , Xu Haijing , Kang Xiaomin , Wang Tongfei , He Liying , Zhao Aimin
Published: April 2016

Allogenic lymphocyte immunotherapy (LIT) as a treatment for unexplained recurrent spontaneous abortion (URSA) is still controversial due to the lack of enough controls to evaluate its effectiveness. Eighteen randomized, placebo‐controlled trials with LIT for URSA were included in the meta‐analysis. Live birth rates for each group were extracted, and the overall odds ratio (OR) for LIT was calculated. The success rate of treatment group was significantly higher (OR 3.74, 95% CI 3.07 ~ 4.57). LIT performed before and during pregnancy had dramatically improved the live birth rate in women with URSA (OR 4.67, 95% CI 3.70 ~ 5.90). The overall OR was 5.25 (95% CI 4.16 ~ 6.64), which supports a low dose of lymphocytes for treating URSA. Our results indicate that LIT provides a significantly beneficial effect over placebo for URSA. LIT given before and during pregnancy is superior to LIT given only before pregnancy, and the lower doses per treatment (less than 100 × 106 lymphocytes or 100 mL peripheral blood) achieved a better outcome.
Evidence of seasonality and effects of psychrometry in dry eye disease
Authors: van Setten Gysbert , Labetoulle Marc , Baudouin Christophe , Rolando Maurizio
Published: April 2016

Purpose

Current models consider the development of dry eye disease (DED) as a more or less continuous process with only minor daily variations. Clinical evidence, however, does suggest the existence of phase‐like recurring dry eye complaints that may be linked to seasonal environmental conditions. In this survey‐based study, we examined the influence of seasonality in dry eye pathophysiology.

Methods

A specific protocol for a telephone interview was created. Then, 738 patients suffering from dry eye and/or Sjögren's syndrome were interviewed and asked about the impact of the four seasons and other weather conditions on their ocular symptoms. Data were statistically analysed. All data were compared in respect to the relation between season, gender, country of origin and the presence of comorbidities.

Results

Overall, 47% of respondents stated that seasonal conditions had a high impact on their DED symptoms, with only 15% reporting that there was no seasonal impact on their symptoms. Wind was the most commonly reported weather condition to impact dry eye symptoms (for 71% of patients), followed by sunshine (60%) and heat (42%). Cold weather was also reported to aggravate dry eye sensation by 34% of patients. The two seasons most commonly associated with dry eye complaints were summer and winter (for 51% and 43% of patients, respectively). Only 8% stated that no weather conditions affected their symptoms.

Discussion

This study confirms the seasonal enhancement of dry eye sensations and symptoms. Environmental characteristics such as cold and heat as well as wind were the most commonly cited triggering factors. Geographical differences do exist between the countries surveyed and the seasonal peak of complaints appears related to temperature and humidity. The main seasons of dry eye complaints in Europe were winter and summer. Such seasonal characteristics in ocular surface disease should be kept in mind when considering diagnosis and treatment as well when investigating the ocular surface.

Conclusion

Our study confirmed high prevalence of both seasonal and weather‐related enhancement of dry eye sensations and symptoms.
Visual working memory and number sense: Testing the double deficit hypothesis in mathematics
Authors: Toll Sylke W. M. , Kroesbergen Evelyn H. , Van Luit Johannes E. H.
Published: April 2016

Background

Evidence exists that there are two main underlying cognitive factors in mathematical difficulties: working memory and number sense. It is suggested that real math difficulties appear when both working memory and number sense are weak, here referred to as the double deficit (DD) hypothesis.

Aims

The aim of this study was to test the DD hypothesis within a longitudinal time span of 2 years.

Sample

A total of 670 children participated. The mean age was 4.96 years at the start of the study and 7.02 years at the end of the study.

Methods

At the end of the first year of kindergarten, both visual–spatial working memory and number sense were measured by two different tasks. At the end of first grade, mathematical performance was measured with two tasks, one for math facts and one for math problems.

Results

Multiple regressions revealed that both visual working memory and symbolic number sense are predictors of mathematical performance in first grade. Symbolic number sense appears to be the strongest predictor for both math areas (math facts and math problems). Non‐symbolic number sense only predicts performance in math problems. Multivariate analyses of variance showed that a combination of visual working memory and number sense deficits (NSDs) leads to the lowest performance on mathematics.

Conclusions

Our DD hypothesis was confirmed. Both visual working memory and symbolic number sense in kindergarten are related to mathematical performance 2 years later, and a combination of visual working memory and NSDs leads to low performance in mathematical performance.
Predictive factors for extrahepatic recurrence of hepatocellular carcinoma following liver transplantation
Authors: Andreou Andreas , Bahra Marcus , Schmelzle Moritz , Öllinger Robert , Sucher Robert , Sauer Igor M. , Guel‐Klein Safak , Struecker Benjamin , Eurich Dennis , Klein Fritz , Pascher Andreas , Pratschke Johann , Seehofer Daniel
Published: April 2016

Background

Recurrence of hepatocellular carcinoma (HCC) in patients treated with liver transplantation (LT) is associated with diminished survival. Particularly, extrahepatic localization of HCC recurrence contributes to poor prognosis.

Patients and methods

Clinicopathological data of patients who underwent LT for HCC between 1989 and 2010 in a high‐volume transplant center were retrospectively evaluated, and predictors of extrahepatic recurrence were identified.

Results

Three hundred and sixty‐four patients underwent LT for HCC. After a median follow‐up time of 78 months, 93 patients (25%) were diagnosed with a recurrence. Median time to recurrence was 19 months. Recurrence was located exclusively in the liver in 19 cases (20%), and 74 patients (80%) had extrahepatic recurrence. Factors associated with extrahepatic recurrence in multivariate analysis included HCC beyond the Milan criteria (p < 0.0001) and the presence of macrovascular tumor invasion (p = 0.035). In patients with HCC beyond the Milan criteria who developed a recurrence (N = 73), macrovascular invasion was the only positive predictor of extrahepatic recurrence in multivariate analysis (p < 0.0001). In patients with HCC within the Milan criteria who recurred after LT (N = 20), DNA‐index >1.5 (p = 0.013) was the only predictive factor for extrahepatic recurrence in multivariate analysis.

Conclusions

Advanced HCC beyond the Milan criteria and the presence of macrovascular invasion are associated with an increased risk for extrahepatic recurrence and are currently considered as relative contraindications to LT. In patients with HCC within the Milan criteria, the DNA‐index represents a valuable prognostic marker for the development of extrahepatic recurrence and may support the selection of patients for intensified postoperative tumor surveillance.
Exenatide decreases liver fat content and epicardial adipose tissue in patients with obesity and type 2 diabetes: a prospective randomized clinical trial using magnetic resonance imaging and spectroscopy
Authors: Dutour A. , Abdesselam I. , Ancel P. , Kober F. , Mrad G. , Darmon P. , Ronsin O. , Pradel V. , Lesavre N. , Martin J. C. , Jacquier A. , Lefur Y. , Bernard M. , Gaborit B.
Published: April 2016

Aim

To conduct a prospective randomized trial to investigate the effect of glucagon‐like peptide‐1 (GLP‐1) analogues on ectopic fat stores.

Methods

A total of 44 obese subjects with type 2 diabetes uncontrolled on oral antidiabetic drugs were randomly assigned to receive exenatide or reference treatment according to French guidelines. Epicardial adipose tissue (EAT), myocardial triglyceride content (MTGC), hepatic triglyceride content (HTGC) and pancreatic triglyceride content (PTGC) were assessed 45 min after a standardized meal with 3T magnetic resonance imaging and proton magnetic resonance spectroscopy before and after 26 weeks of treatment.

Results

The study population had a mean glycated haemoglobin (HbA1c) level of 7.5 ± 0.2% and a mean body mass index of 36.1 ± 1.1 kg/m2. Ninety five percent had hepatic steatosis at baseline (HTGC ≥ 5.6%). Exenatide and reference treatment led to a similar improvement in HbA1c (−0.7 ± 0.3% vs. −0.7 ± 0.4%; p = 0.29), whereas significant weight loss was observed only in the exenatide group (−5.5 ± 1.2 kg vs. −0.2 ± 0.8 kg; p = 0.001 for the difference between groups). Exenatide induced a significant reduction in EAT (−8.8 ± 2.1%) and HTGC (−23.8 ± 9.5%), compared with the reference treatment (EAT: −1.2 ± 1.6%, p = 0.003; HTGC: +12.5 ± 9.6%, p = 0.007). No significant difference was observed in other ectopic fat stores, PTGC or MTGC. In the group treated with exenatide, reductions in liver fat and EAT were not associated with homeostatic model assessment of insulin resistance index, adiponectin, HbA1c or fructosamin change, but were significantly related to weight loss (r = 0.47, p = 0.03, and r = 0.50, p = 0.018, respectively).

Conclusion

Our data indicate that exenatide is an effective treatment to reduce liver fat content and epicardial fat in obese patients with type 2 diabetes, and these effects are mainly weight loss dependent.
An integrative framework of coexistence mechanisms in competitive metacommunities
Authors: Fournier Bertrand , Mouquet Nicolas , Leibold Mathew A. , Gravel Dominique
Published: April 2016

Species distribution in a metacommunity varies according to their traits, the distribution of environmental conditions and connectivity among localities. These ingredients contribute to coexistence across spatial scales via species sorting, patch dynamics, mass effects and neutral dynamics. These mechanisms however seldom act in isolation and the impact of landscape configuration on their relative importance remains poorly understood. We present a new model of metacommunity dynamics that simultaneously considers these four possible mechanisms over spatially explicit landscapes and propose a statistical approach to partition their contribution to species distribution. We find that landscape configuration can induce dispersal limitations that have negative consequences for local species richness. This result was more pronounced with neutral dynamics and mass effect than with species sorting or patch dynamics. We also find that the relative importance of the four mechanisms varies not only among landscape configurations, but also among species, with some species being mostly constrained by dispersal and/or drift and others by sorting. Changes in landscape properties might lead to a shift in coexistence mechanisms and, by extension, to a change in community composition. This confirms the importance of considering landscape properties for conservation and management. Our results illustrate the idea that ecological communities are the results of multiple mechanisms acting at the same time and complete our understanding of spatial processes in competitive metacommunities.
How do different aspects of biodiversity change through time? A case study on an Australian bird community
Authors: Yen Jian D. L. , Thomson James R. , Keith Jonathan M. , Paganin David M. , Nally Ralph Mac
Published: April 2016

The study of ecological communities through time can reveal fundamental ecological processes and is key to understanding how natural and human pressures will affect biodiversity. Most studies of ecological communities through time consider only one or a few summary measures (e.g. species richness, total abundance), which might neglect important aspects of community structure or function. We studied temporal variation in several measures of species diversity, size diversity, and species composition in an intensively sampled bird community to determine whether different biodiversity measures change synchronously. We used a novel function regression model, which supports the study of diversity measures that are distributions (e.g. species abundance distributions) alongside measures that are scalar values (e.g. species richness). Most diversity measures changed predictably within years, but inter‐annual changes in size diversity and species composition were not reflected in species diversity. Within and among years, there was considerable variation in distributional measures that was not captured in scalar measures. Predictable variation within years probably was related to seasonal variation in weather patterns or food availability, but variation in size diversity among years probably resulted from stochastic changes in species composition. These results suggest that species and size diversity may be decoupled, and that inferences on scalar diversity measures might not reflect fundamental changes to community structure or function. Our method supports the inclusion of size‐based measures and distributional measures in ecological analyses, and broader uptake of our approach is likely to provide new insight into the processes structuring ecological communities, and inform the links between structure and function in ecological communities.
Does surprise enhancement or repetition suppression explain visual mismatch negativity?
Authors: Amado Catarina , Kovács Gyula
Published: April 2016

A long tradition of electrophysiological studies, using oddball sequences, showed that the neural responses to a given stimulus differ when their presentation occurs frequently (standards) as compared to rare, infrequent presentations (deviants). This difference, originally described in acoustic perception, can also be detected in the visual modality and is termed as visual mismatch negativity (vMMN). Also, a large number of studies detected the reduction of the neuronal response after the repetition of a given stimulus (repetition suppression – RS) and it was suggested that RS is the major mechanism of MMN, an explanation currently also supported by animal studies. However, human studies have proposed that a surprise‐related response enhancement for the deviant stimuli might also underlie vMMN. Therefore, the aim of the current study was to disentangle which neural mechanism explains vMMN better: the surprise related response enhancement for the presentation of rare deviants or the RS related to the frequent presentation of the standards. Since the MMN depends strongly on the applied categories, we tested the neural mechanisms of vMMN for different stimulus categories (faces, chairs, real and false characters) using a visual oddball paradigm. We found significant vMMN for every stimulus category. Interestingly, the neural mechanisms behind vMMN were found to be category dependent (assuming no cross‐adaptation effects): for faces and chairs it was largely driven by RS, whereas for real and false characters it was mainly due to surprise‐related changes.
Relationship between anxiety and cognitive performance in an elderly population with a cognitive complaint
Authors: Delphin‐Combe F. , Bathsavanis A. , Rouch I. , Liles T. , Vannier‐Nitenberg C. , Fantino B. , Dauphinot V. , Krolak‐Salmon P.
Published: April 2016

Background and purpose

Almost half of elderly patients being consulted in memory clinics present anxiety disorders, either with or without an associated depressive syndrome. This study investigates the relationship between the level of anxiety and cognitive performance in a population complaining of memory difficulties.

Methods

The study population (n = 149) was selected from the EVATEM cohort, which included subjects aged 65 years or older. All subjects presented memory complaints and patients with depression were excluded. Anxiety level was assessed with the Hamilton Anxiety Rating Scale. A standard neuropsychological battery, including a free and cued episodic memory test, was administered to examine the different processes of verbal episodic memory, visual memory, executive, visuoconstructive and instrumental functions.

Results

Subjects with moderate to severe anxiety had worse performance than subjects with no anxiety in retrieval and storage processes of verbal episodic memory (respectively P = 0.004 and P = 0.02) and in visual recognition memory (P = 0.01). No relationship was found between anxiety and executive, visual‐constructive or instrumental functions.

Conclusion

Anxiety impacts several stages of verbal memory, notably the processes of storage and retrieval, and visual recognition memory within a population having cognitive complaints. This study suggests that anxiety should be considered as a factor of memory vulnerability for patients being treated in memory clinics.
Frequency and predictors of acute ischaemic lesions on brain magnetic resonance imaging in young patients with a clinical diagnosis of transient ischaemic attack
Authors: Tanislav C. , Grittner U. , Fazekas F. , Thijs V. , Tatlisumak T. , Huber R. , von Sarnowski B. , Putaala J. , Schmidt R. , Kropp P. , Norrving B. , Martus P. , Gramsch C. , Giese A. K. , Rolfs A. , Enzinger C.
Published: April 2016

Background and purpose

Acute lesions in patients with transient ischaemic attack (TIA) are important as they are associated with increased risk for recurrence. Characteristics associated with acute lesions in young TIA patients were therefore investigated.

Methods

The sifap1 study prospectively recruited a multinational European cohort (n = 5023) of patients aged 18–55 years with acute cerebrovascular event. The detection of acute ischaemic lesions was based on diffusion‐weighted imaging (DWI). The frequency of DWI lesions was assessed in 829 TIA patients who met the criteria of symptom duration <24 h and their association with demographic, clinical and imaging variables was analysed.

Results

The median age was 46 years (interquartile range 40–51 years); 45% of the patients were female. In 121 patients (15%) ≥1 acute DWI lesion was detected. In 92 patients, DWI lesions were found in the anterior circulation, mostly located in cortical‐subcortical areas (n = 63). Factors associated with DWI lesions in multiple regression analysis were left hemispheric presenting symptoms [odds ratio (OR) 1.92, 95% confidence interval (CI) 1.27−2.91], dysarthria (OR 2.17, 95% CI 1.38−3.43) and old brain infarctions on MRI (territories of the middle and posterior cerebral artery: OR 2.43, 95% CI 1.42−4.15; OR 2.41, 95% CI 1.02−5.69, respectively).

Conclusions

In young patients with a clinical TIA 15% demonstrated acute DWI lesions on brain MRI, with an event pattern highly suggestive of an embolic origin. Except for the association with previous infarctions there was no clear clinical predictor for acute ischaemic lesions, which indicates the need to obtain MRI in young individuals with TIA.
Carotid plaque echogenicity predicts cerebrovascular symptoms: a systematic review and meta‐analysis
Authors: Jashari F. , Ibrahimi P. , Bajraktari G. , Grönlund C. , Wester P. , Henein M. Y.
Published: April 2016

Background and purpose

Many reports have shown an association between hypoechoic (echolucent) carotid atherosclerotic plaques and unstable features. In this meta‐analysis our aim was to determine the role of carotid plaque echogenicity in predicting future cerebrovascular (CV) symptoms.

Methods

Electronic databases (PubMed, MEDLINE, EMBASE and Cochrane Center Register) up to September 2015 were systematically searched. Studies with ultrasound‐based characterization of carotid artery plaque echogenicity and its association with focal neurological symptoms of vascular origin were eligible for analysis. In the meta‐analysis, heterogeneity was measured using I2 statistics and publication bias was evaluated using the Begg–Mazumdar test. In addition several comparisons between subgroups were performed.

Results

Of 1387 identified reports, eight studies with asymptomatic patients and three studies with symptomatic patients were meta‐analyzed. Pooled analysis showed an association between echolucent carotid plaques and future CV events in asymptomatic patients [relative risk 2.72 (95% confidence interval 1.86–3.96)] and recurrent symptoms in symptomatic patients [relative risk 2.97 (95% confidence interval 1.85–4.78)]. The association was preserved for all stenosis degrees in asymptomatic patients, whilst patients with echolucent plaques and severe stenosis were at higher risk of future events. Also, computer‐assisted methods for assessment of carotid plaque echogenicity and studies analyzing ultrasound data collected after the year 2000 showed better prediction.

Conclusions

In asymptomatic and symptomatic patients, analysis of carotid plaque echogenicity could identify those at high risk of CV events.
Stem‐galling moths provide cetoniine beetles with feeding sites via sap exudation of invasive alien plants
Authors: Yamazaki Kazuo , Sugiura Shinji
Published: April 2016

The alien moth Epiblema sugii (Lepidoptera: Tortricidae) induces stem galls on an invasive alien weed, Ambrosia trifida. During summer, along riverbanks in central Japan, the native insects Protaetia brevitarsis, P. orientalis submarumorea (Coleoptera: Scarabaeidae: Cetoniinae), and Camponotus vitiosus (Hymenoptera: Formicidae) feed on the sap exuded from the galls. The cetoniine beetles are highly aggregated among the galls and make wounds on the galls to facilitate sap exudation. Feeding on gall sap may be beneficial to the beetles due to the efficient intake of water and sugar, and the beetles’ inflicting wounds and feeding on the sap seem to have little effect on the gallers. This is a unique finding, where alien plant–galler interaction provides a feeding site for native insects.
Analysis of the genetic ancestry of patients with oral clefts from South American admixed populations
Authors: Vieira‐Machado Camilla D. , de Carvalho Flavia M. , Santana da Silva Luiz C. , dos Santos Sidney E. , Martins Claudia , Poletta Fernando A. , Mereb Juan C. , Vieira Alexandre R. , Castilla Eduardo E. , Orioli Iêda M.
Published: April 2016

Increased susceptibility to cleft lip, with or without cleft palate (CL±P) has been observed in South America, as related to Amerindian ancestry, using epidemiological data, uniparental markers, and blood groups. In this study, it was evaluated whether this increased risk remains when Amerindian ancestry is estimated using autosomal markers and considered in the predictive model. Ancestry was estimated through genotyping 62 insertion and deletion (INDEL) markers in sample sets of patients with CL±P, patients with cleft palate (CP), and controls, from Patagonia in southern Argentina and Belém in northern Brazil. The Amerindian ancestry in patients from Patagonia with CL±P was greater than in controls although it did not reach statistical significance. The European ancestry in patients with CL±P from Belém and in patients with CP from Belém and Patagonia was higher than in controls and statistically significant for patients with CP who were from Belém. This high contribution of European genetic ancestry among patients with CP who were from Belém has not been previously observed in American populations. Our results do not corroborate the currently accepted risks for CL±P and CP estimated by epidemiological studies in the North American populations and probably reflect the higher admixture found in South American ethnic groups when compared with the same ethnic groups from the North American populations.
The diversity and composition of moth assemblages of protected and degraded raised bogs in Ireland
Authors: Flynn Ciara , Griffin Christine T. , Coll John , Williams Christopher D.
Published: April 2016

Peatlands are globally important habitats, which act as net carbon stores. As a result of drainage, peat extraction and agricultural intensification, raised bogs in the midlands of Ireland are a diminishing and increasingly fragmented peatland habitat. A network of protected sites has been established, which is intended to represent the best abiotic and plant community systems.

Lepidoteran communities are an important component of raised bog biodiversity and may be useful as biodiversity indicators, yet they are a neglected area of research.

We address this by surveying night‐flying macro‐moths on six protected and six degraded raised bogs to establish whether there is a distinct moth fauna associated with the wettest areas of protected sites by comparing them to assemblages found on degraded sites where this wet habitat has been lost.

In general, differences between moth assemblages on protected and degraded raised bogs are rather subtle, with assemblages on both site types generally similar. But, a number of species were found to be associated with protected sites, three of which are bog‐associated species of conservation concern and may be particularly vulnerable due to the continuing loss of the wettest areas of raised bogs.

Degraded sites were found to harbour a significant number of bog‐associated species of conservation concern and may have a role to play in peatland invertebrate conservation, hitherto undervalued. To determine this, further research is required to describe the invertebrate fauna of these sites and of marginal areas of protected sites.