Validation of the MARS: a combined physiological and laboratory risk prediction tool for 5- to 7-day in-hospital mortality.

BACKGROUND: The Medical Admission Risk System (MARS) uses 11 physiological and laboratory data and had promising results in its derivation study for predicting 5- and 7- day mortality. AIM: To perform an external independent validation of the MARS score. DESIGN: An unplanned secondary cohort study. METHODS: Patients admitted to the medical admission unit at The Hospital of South West Jutland were included from 2 October 2008 until 19 February 2009 and 23 February 2010 until 26 May 2010 were analysed. Validation of the MARS scores using 5- and 7- day mortality was the primary endpoint. RESULTS: Patients of 5858 were included in the study. Patients of 2923 (49.9%) were women with a median age of 65 years (15-107). The MARS score had an area under the receiving operator characteristic curve of 0.858 (95% CI: 0.831-0.884) for 5-day mortality and 0.844 (0.818-0.870) for 7 day mortality with poor calibration for both outcomes. CONCLUSION: The MARS score had excellent discriminatory power but poor calibration in predicting both 5- and 7-day mortality. The development of accurate combination physiological/laboratory data risk scores has the potential to improve the recognition of at risk patients.

The apoB/apoA1 ratio predicts future cardiovascular events in patients with rheumatoid arthritis.

OBJECTIVES: Patients with rheumatoid arthritis (RA) have increased mortality and morbidity due to cardiovascular disease (CVD). A high apolipoprotein (apo)B/apoA1 ratio is known to predict cardiovascular events (CVEs) in the population. apoA1 has, besides anti-atherogenic effects, anti-inflammatory properties. The importance of apolipoproteins in the development of CVEs, in the context of lipids, haemostatic factors, and inflammation, was evaluated over 18 years in patients with RA. METHOD: Seventy-four patients with inflammatory active RA (61 females/13 males, mean age 63.6 years, disease duration 22.1 years) had been previously investigated in a study of haemostatic factors [tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI)-1, von Willebrand factor (vWF)], lipids (cholesterol and triglycerides), apolipoproteins (apoA1 and apoB), lipoprotein(a) [Lp(a)], and markers of inflammation [erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and haptoglobin]. After 18 years, the first CVE during follow-up and the presence of traditional CV risk factors, extra-articular disease, and pharmacological treatment were registered. Cox proportional hazards regression was used to identify predictors of a new CVE. RESULTS: A new CVE (n = 34) was predicted by the apoB/apoA1 ratio (p < 0.01), the triglyceride level (p < 0.01), PAI-1 (p < 0.01) and tPA (p < 0.01) activities, vWF (p < 0.001), ESR (< 0.001), CRP (< 0.05), and haptoglobin (p < 0.05). apoA1 (p = 0.056) and apoB (p < 0.05) correlated weakly and inversely with haptoglobin and CRP, respectively. In a multiple Cox regression model, adjusted for gender and previous CVD, the apoB/apoA1 ratio significantly predicted a new CVE, as did vWF, PAI-1, and ESR. CONCLUSIONS: The apoB/apoA1 ratio was a good predictor of CVE during 18 years of follow-up in patients with active RA. Apolipoproteins correlated negatively with inflammation.

Cardiovascular event in systemic lupus erythematosus in northern Sweden: incidence and predictors in a 7-year follow-up study.

INTRODUCTION: An increased rate of cardiovascular disease (CVD) has been suggested in patients with systemic lupus erythematosus (SLE). The risk for myocardial infarction (MI), coronary artery disease and stroke has been reported as particularly prevalent in younger females compared with the reference population. This study was performed to analyse the standard incidence ratio (SIR) of and predictors for cardiovascular events (CVEs) in patients with SLE from northern Sweden, with a fairly homogenous population. METHODS: In 2000 all prevalent patients with SLE (≥4 American College of Rheumatology [ACR] criteria; n = 277) from the four northern-most counties of Sweden were assessed with clinical and laboratory analyses. Seven years follow-up data concerning MI and stroke were extracted from the national registers of hospitalization and death in Sweden. The incidence ratio among the patients was compared with that for the general population from the same catchment area using data from the same register and Statistics Sweden. To identify time to event and CVE predictors, two matched controls for each patient were used and disease related variables as CVD predictors. RESULTS: The SIR for a CVE was 1.27 (95% CI 0.82-1.87) and for females separately aged 40-49 years was 8.00 (95% CI 1.65-23.38). The overall SIR for MI was 2.31 (95% CI 1.34-3.7), for females overall was 1.75 (95% CI 0.84-3.22) and for females aged between 40 and 49 years was 8.7 (95% CI 1.1-31.4). The time to an event was significantly shorter among SLE patients (p < 0.001) and was predicted by hypertension adjusted for smoking and disease. High SLEDAI and anti-cardiolipin IgG antibodies predicted an event in Cox proportional hazards regression models adjusted for age and previous MI. Diabetes, smoking ever and sex did not affect the prediction models. CONCLUSION: The risk of a CVE, or MI, was eight- or nine-fold greater among middle-aged female SLE patients. Time to event was significantly shorter and CVE was associated with SLE-related factors including hypertension and age.

Perivascular visceral adipose tissue induces atherosclerosis in apolipoprotein E deficient mice.

OBJECTIVE: Epicardial adipose tissue is associated with coronary artery disease, however the causal relationship between perivascular adipose tissue and local atherogenesis is unclear. METHODS AND RESULTS: Apolipoprotein E deficient (ApoE(-/-)) mice underwent transplantation of visceral or subcutaneous adipose tissue immediately adjacent to the right common carotid artery. Carotid arteries with fat transplants were analyzed for atherosclerosis by surface oil-red-O staining and cross-sectional analysis. Vascular function of the carotid arteries was assessed using pressure myography. Visceral fat transplants were also performed to ApoE(-/-) mice with neutralization of P-selectin glycoprotein ligand-1 (Psgl-1). Atherosclerosis surface area and lesion thickness were greater in mice receiving the perivascular visceral fat compared to the subcutaneous fat. Mice with visceral fat transplants also displayed more complicated atherosclerotic lesions with evidence of atherothrombosis. Serum Mcp-1 was higher in mice receiving visceral fat transplants compared to subcutaneous transplants. Visceral fat transplantation also caused impaired endothelial-dependent relaxation of the carotid artery. Psgl-1 deficiency or neutralization of Psgl-1 with an anti-Psgl-1 antibody was protective against perivascular visceral adipose tissue-induced atherosclerosis and was associated with reduced Mcp-1 levels. CONCLUSIONS: Perivascular visceral fat leads to endothelial dysfunction and accelerated atherosclerosis. This proatherogenic effect of perivascular adipose tissue is blocked by neutralization of Psgl-1.

Crucial knowledge gaps in current understanding of climate change impacts on coral reef fishes.

Expert opinion was canvassed to identify crucial knowledge gaps in current understanding of climate change impacts on coral reef fishes. Scientists that had published three or more papers on the effects of climate and environmental factors on reef fishes were invited to submit five questions that, if addressed, would improve our understanding of climate change effects on coral reef fishes. Thirty-three scientists provided 155 questions, and 32 scientists scored these questions in terms of: (i) identifying a knowledge gap, (ii) achievability, (iii) applicability to a broad spectrum of species and reef habitats, and (iv) priority. Forty-two per cent of the questions related to habitat associations and community dynamics of fish, reflecting the established effects and immediate concern relating to climate-induced coral loss and habitat degradation. However, there were also questions on fish demographics, physiology, behaviour and management, all of which could be potentially affected by climate change. Irrespective of their individual expertise and background, scientists scored questions from different topics similarly, suggesting limited bias and recognition of a need for greater interdisciplinary and collaborative research. Presented here are the 53 highest-scoring unique questions. These questions should act as a guide for future research, providing a basis for better assessment and management of climate change impacts on coral reefs and associated fish communities.

Increased incidence of stroke and impaired prognosis after stroke among patients with seropositive rheumatoid arthritis.

OBJECTIVE: To examine the incidence of, and outcome after, a stroke in patients with rheumatoid arthritis (RA) compared with the general population. METHODS: The northern Sweden MONICA register was used to compare the incidence of stroke in a cohort of RA patients with the general population. Forty RA patients who had also suffered a stroke were identified. For each patient with RA, three controls with a history of stroke but without RA were randomly collected from the same register, and matched for age and sex. RESULTS: The standardised incidence ratio (SIR) for stroke was 2.7 in RA patients compared with the general population (p<0.05). During the follow-up, RA patients had a higher overall case fatality (CF) following stroke compared with controls (hazard ratio (HR) =1.70, p<0.05). CONCLUSIONS: Both the incidence of a stroke, and the subsequent CF, were higher among RA patients compared with the general population. The results emphasize the necessity of optimising the prevention of stroke and follow-up care after a stroke in RA.

A-to-I editing challenger or ally to the microRNA process.

Adenosine to inosine (A-to-I) modification by the ADAR (adenosine deaminase that acts on RNA) enzymes perform the most common type of RNA editing in metazoans. ADARs use double stranded RNA as substrates but allow interruptions of bulges and loops in the structure. It is well known that these enzymes can use messenger RNA as targets for A-to-I editing and thereby recode the transcript. Both ADAR1 and ADAR2 have been proven to be able to also target short double stranded RNA molecules of the same size as a microRNA. However, it is not until recently shown that A-to-I editing occurs in microRNAs and its precursors. Since the editing activity is found both in the nucleus and the cytoplasm there are several steps during the microRNA maturation pathway that can be targeted for modification. This review will give an overview of what is known today about the interactions between the endogenous RNA interference process and RNA editing. It will also give some insight into the power of A-to-I modification in its ability to increase the variety of microRNA gene silencing.

Deletion of a major neutralizing epitope of human papillomavirus type 16 virus-like particles.

Human papillomavirus type 16 (HPV-16) is a major cause of human cancer. Effective prophylactic vaccines are based on type-specific neutralizing antibodies. A major neutralizing epitope has been defined by the monoclonal antibody H16.V5. To investigate the importance of this epitope for overall immunogenicity of HPV-16, HPV-16 virus-like particles devoid of the H16.V5 epitope were engineered by site-directed mutagenesis of ten non-conserved, surface-exposed residues. Removal of the H16.V5-defined epitope had only a marginal effect on antigenic reactivity with antibodies in sera from infected subjects, but affected immunogenicity in experimental immunization of mice, with reduced induction of both antibody responses and CTL responses.

Generation of soluble P- and E-selectins in vivo is dependent on expression of P-selectin glycoprotein ligand-1.

BACKGROUND: Factors contributing to the generation of soluble P- and E-selectins remain unclear. RESULTS: This work demonstrates that mice lacking P-selectin glycoprotein ligand-1 (Psgl-1(-/-)) are deficient in soluble P-selectin (sP-sel), which is due to a defective binding interaction between PSGL-1 and P-sel, because mice lacking alpha(1,3)-fucosyltransferase-VII are also deficient in sP-sel. Psgl-1(-/-) mice are also deficient in soluble E-selectin (sE-sel) indicating that leukocyte interactions with endothelial cells lead to the generation of sE-sel. The generation of sE-sel requires an interaction between PSGL-1 and P-sel, as deficiency of sE-sel is observed in both Psgl-1(-/-) and P-sel(-/-) mice. Bone marrow transplantation from Psgl-1(-/-) to Psgl-1(+/+) mice leads to deficiency of sP-sel and sE-sel in recipient mice, establishing the importance of bone marrow-derived PSGL-1 toward the generation of sP-sel and sE-sel. Bone marrow transplantation from P-sel(-/-) to P-sel1(+/+) mice does not lead to a significant reduction in sP-sel, confirming the importance of the endothelium toward the liberation of sP-sel. CONCLUSION: sP-sel and sE-sel reflect an interaction between leukocyte PSGL-1 and endothelial P-sel.

MicroRNA sequence motifs reveal asymmetry between the stem arms.

The processing of micro RNAs (miRNAs) from their stemloop precursor have revealed asymmetry in the processing of the mature and its star sequence. Furthermore, the miRNA processing system between organism differ. To assess this at the sequence level we have investigated mature miRNAs in their genomic contexts. We have compared profiles of mature miRNAs within their genomic context of the 5' and 3' stemloop precursor arms and we find asymmetry between mature sequences of the 5' and 3' stemloop precursor arms. The main observation is that vertebrate organisms have a characteristic motif on the 5' arm which is in contrast to the 3' arm motif which mainly show the conserved U at the position of the mature start. Also the vertebrate 5' arm motif show a semi-conserved G 13 nucleotides upstream from the first position. We compared the 5' and 3' arm profiles using the average log likelihood ratio (ALLR) score, as defined by Wang and Stormo (2003) [Wang T., Stormo, G.D., 2003. Combining phylogenetic data with co-regulated genes to identify regulatory motifs. Bioinformatics 2369-2380.] and computing a p-value we find that the two profiles differs significantly in their 3' end where the 5' arm motif (in contrast to the 3' arm motif) has a semi-conserved GU rich region. Similar findings are also obtained for other organisms, such as fly, worm and plants. The observed similarities and differences between closely and distantly related organisms are discussed and related to current knowledge of miRNA processing.

Which factors are related to the presence of atherosclerosis in rheumatoid arthritis?

OBJECTIVE: An accelerated progression of atherosclerosis may contribute to the increased mortality due to cardiovascular disease reported in rheumatoid arthritis (RA). The aim of this study was to identify variables, related to disease onset as well as to disease progression, of importance for the presence of atherosclerosis, as diagnosed by B-mode ultrasonography, in patients with medium-term RA. The results are based on the co-analysis of retrospective data as well as cross-sectional data. The impact of RA per se on atherosclerosis was evaluated relative to age- and sex-matched controls. METHODS: Thirty-nine RA patients, with a maximum age of 65 years, who had previously been included in a large retrospective cohort study, were assessed by duplex scanning after a disease duration of 19-23 years. In the present study, factors identified in the two earlier studies were assessed for their potential relationship with intima-media wall thickness (IMT) of the common carotid artery (CCA), and the presence and grade of atherosclerotic plaques of the CCA and the common femoral artery, in regression models. The candidate co-variates were: variables reflecting inflammatory activity at disease onset and at the time of ultrasound assessment, established cardiovascular risk factors, pharmacological treatment [corticosteroids, disease-modifying anti-rheumatic drugs (DMARDs)], and the presence of complications and co-morbidity identified during disease progression, as well as lipid levels, anti-lipid antibodies, haemostatic factors, and markers of immune activation measured at ultrasound assessment. RESULTS: In patients with RA, analysis of simple linear regression models revealed those variables significantly associated with IMT-CCA to be age, tissue plasminogen activator (tPA) antigen, cholesterol, low density lipoprotein (LDL)-cholesterol, triglycerides, and atherosclerotic plaques while neither inflammatory status at disease onset, traditional cardiovascular risk factors, or pharmacological treatment during disease had any significant impact on IMT. In an estimated multiple linear regression model, variables associated with increasing log of IMT-CCA were the log of cholesterol and of soluble intracellular adhesion molecule 1 (sICAM-1), while methotrexate treatment tended to have a decreasing effect. In simple binary logistic regression, atherosclerotic plaques were associated with age, IMT-CCA, smoking, and the levels of sICAM-1, sE-selectin, interleukin-2 soluble receptor alpha (IL-2sRalpha), plasminogen activator inhibitor-1 (PAI-1) mass, cholesterol, LDL-cholesterol, and the LDL/high density lipoprotein (HDL) ratio. A multiple approach indicated that plaques were associated with age, cholesterol, and sE-selectin. Severe plaques were associated with LDL-cholesterol and disease duration. Logistic regression in the age- and sex-matched case-control study revealed that IMT-CCA was, together with the D-dimer, associated with RA per se. CONCLUSION: Levels of lipids and adhesion molecules were associated with the presence of atherosclerosis in RA. IMT-CCA was associated with RA per se. Disease duration could predict severe atherosclerotic plaques. Treatment with methotrexate seemed to decrease the IMT-CCA.

Density-dependent mortality in an oceanic copepod population.

Planktonic copepods are primary consumers in the ocean and are perhaps the most numerous metazoans on earth. Secondary production by these zooplankton supports most food webs of the open sea, directly affecting pelagic fish populations and the biological pump of carbon into the deep ocean. Models of marine ecosystems are quite sensitive to the formulation of the term for zooplankton mortality, although there are few data available to constrain mortality rates in such models. Here we present the first evidence for nonlinear, density-dependent mortality rates of open-ocean zooplankton. A high-frequency time series reveals that per capita mortality rates of eggs of Calanus finmarchicus Gunnerus are a function of the abundance of adult females and juveniles. The temporal dynamics of zooplankton populations can be influenced as much by time-dependent mortality rates as by variations in 'bottom up' forcing. The functional form and rates chosen for zooplankton mortality in ecosystem models can alter the balance of pelagic ecosystems, modify elemental fluxes into the ocean's interior, and modulate interannual variability in pelagic ecosystems.

Bonded dimethylacrylamide as a permanent coating for capillary electrophoresis.

A method for coating capillaries for capillary electrophoresis with chemically bonded polydimethylacrylamide has been developed, and the properties of the capillaries have been evaluated. The coated capillaries provided high separation efficiency, 12 x 10(5) theoretical plates/m was obtained for cytochrome c. The electroosmotic flow at pH 8.0 was 10 x 10(-10) to 6 x 10(-10) m2 V(-1) s(-1). The coated capillaries were quite stable at high pH. At least 150 runs could be done at pH 10 without appreciable performance deterioration. The excellent performance of the coated capillaries was illustrated by separation of basic proteins, acidic proteins, 9-fluorenylmethyl chloroformate-derivatized neurotransmitter amino acids, peptide reference mixtures and peptides digested from a bacteria protein.

Quantitative-trait-locus analysis of body-mass index and of stature, by combined analysis of genome scans of five Finnish study groups.

In recent years, many genomewide screens have been performed, to identify novel loci predisposing to various complex diseases. Often, only a portion of the collected clinical data from the study subjects is used in the actual analysis of the trait, and much of the phenotypic data is ignored. With proper consent, these data could subsequently be used in studies of common quantitative traits influencing human biology, and such a reanalysis method would be further justified by the nonbiased ascertainment of study individuals. To make our point, we report here a quantitative-trait-locus (QTL) analysis of body-mass index (BMI) and stature (i.e., height), with genotypic data from genome scans of five Finnish study groups. The combined study group was composed of 614 individuals from 247 families. Five study groups were originally ascertained in genetic studies on hypertension, obesity, osteoarthritis, migraine, and familial combined hyperlipidemia. Most of the families are from the Finnish Twin Cohort, which represents a population-wide sample. In each of the five genome scans, approximately 350 evenly spaced markers were genotyped on 22 autosomes. In analyzing the genotype data by a variance-component method, we found, on chromosome 7pter (maximum multipoint LOD score of 2.91), evidence for QTLs affecting stature, and a second locus, with suggestive evidence for linkage to stature, was detected on chromosome 9q (maximum multipoint LOD score of 2.61). Encouragingly, the locus on chromosome 7 is supported by the data reported by Hirschhorn et al. (in this issue), who used a similar method. We found no evidence for QTLs affecting BMI.

Separation of divinyl ether fatty acid isomers by micellar electrokinetic chromatography.

A micellar electrokinetic chromatography (MEKC) method has been developed for the direct resolution of divinyl ether type of hydrophobic fatty acid isomers. The fatty acid isomers resolved include colneleic acid (CL), colnelenic acid (CLn), 14(Z)-etheroleic acid (14(Z)-EL), 14(Z)-etherolenic acid (14(Z)-Eln), 11(Z)-etheroleic acid (11(Z)-EL), 11(Z)-etherolenic acid (11(Z)-Eln), etheroleic acid (EL) and etherolenic acid (Eln). These fatty acid isomers differ in number, position and spatial arrangement of the double bonds and the position of the ether oxygen. A central composite design was employed for the optimization of the key variables of the separation, namely the concentrations of sodium dodecyl sulfate (SDS) and organic modifiers. The use of micelles combined with an organic modifier in the background electrolyte made it possible to dissolve and separate relatively hydrophobic fatty acid isomers, and to achieve high separation efficiency. Using heptakis-(2,3-dimethyl-6-sulfato)-beta-cyclodextrin (HDMS-beta-CD) as a buffer additive, complete separation of the examined eight divinyl ethers was achieved. Separation efficiencies up to 5 x 10(5) theoretical plates/m were achieved under optimized conditions. Direct UV was applied for detection of the fatty acids. The results were compared with those obtained from high-performance liquid chromatography (HPLC) separation.

The 1997/1998 mass mortality of corals: effects on fish communities on a Tanzanian coral reef.

The abnormally high surface temperatures in the world's oceans during 1997/1998 resulted in widespread coral bleaching and subsequent coral mortality. An experiment was performed to study the effects of this coral mortality as well as the influence of the structural complexity on fish communities on a Tanzanian coral reef. Changes in fish communities were investigated on plots of transplanted corals after 88% of these corals had died. A distinct shift in fish community composition was found, although diversity was not affected. Fish abundance rose by 39% mostly due to an increase in herbivores, which seemed to benefit from enhanced algal growth on the dead corals. Fish abundance, species diversity and community composition were also strongly influenced by the structural complexity provided by the live and dead corals. This suggests that a coral reef can support abundant and diverse fish populations also after the corals have died as long as the reef structure is sustained.

Chemometric modeling of neurotransmitter amino acid separation in normal and reversed migration micellar electrokinetic chromatography.

A chemometric experimental design has been applied for the optimization of neurotransmitter amino acid separation in capillary electrophoresis. The optimizations were carried out for normal micellar electrokinetic chromatography (N-MEKC) and reversed migration micellar electrokinetic chromatography (RM-MEKC). In order to optimize three separation factors and study the interaction between factors, a response function was optimized via searching its optimum (minimum/maximum). For this purpose a central composite design with multivariate linear regression (MLR) analysis was utilized. Modeling with good regression coefficients from the MLR adequately described the interaction of factors such as background electrolyte and sodium dodecylsulfate concentrations which had a large impact on selectivity and migration behaviors. Similar optimal conditions regarding resolution and number of theoretical plates but different retention behaviors as a function of background electrolyte and micellar concentrations were observed for N-MEKC and RM-MEKC. Improved overall performance from the RM-MEKC separation of five neurotransmitter acids, superior to N-MEKC, is demonstrated in terms of repeatability, peak symmetry, sensitivity, and in particular, impurity determination in an overloaded separation system.

Influence of algal farming on fish assemblages.

We examined the influence of algal farming on fish assemblages in two shallow coastal lagoons in Zanzibar, Tanzania. Fish assemblages were visually investigated using a belt transect method and the line-intercept technique was used to examine the substrate composition. 101 species of fish belonging to 31 families were recorded. Algal farming affected the associated fish fauna in terms of abundance, species richness, trophic identity and fish community composition. However, the impact differed between the lagoons. Algal farms in one lagoon hosted a more abundant and diversified fish fauna than controls, whereas farms in the other lagoon exhibited lower fish densities and similar species diversity compared to controls. The discrepancies between lagoons may be an effect of differences in farming intensity and character of the substratum.