Impact of adrenomedullin levels on clinical risk stratification and outcome in subarachnoid haemorrhage.

PURPOSE: To use classification tree analysis to identify risk factors for nonsurvival in a neurological patients with subarachnoid haemorrhage (SAH) and to propose a clinical model for predicting of mortality. METHODS: Prospective study of SAH admitted to a Critical Care Department and Stroke Unit over a 2-year period. Middle region of pro-ADM plasma levels (MR-proADM) was measured in EDTA plasma within the first 24 hours of hospital admission using the automatic immunofluorescence test. A regression tree was made to identify prognostic models for the development of mortality at 90 days. RESULTS: Ninety patients were included. The mean MR-proADM plasma value in the samples analysed was 0.78 ± 0.41 nmol/L. MR-proADM plasma levels were significantly associated with mortality at 90 days (1.05 ± 0.51 nmol/L vs 0.64 ± 0.25 nmol/L; P < .001). Regression tree analysis provided an algorithm based on the combined use of clinical variables and one biomarker allowing accurate mortality discrimination of three distinct subgroups with high risk of 90-day mortality ranged from 75% to 100% (AUC 0.9; 95% CI 0.83-0.98). CONCLUSIONS: The study established a model (APACHE II, MR-proADM and Hunt&Hess) to predict fatal outcomes in patients with SAH. The proposed decision-making algorithm may help identify patients with a high risk of mortality.

17p12 Influences Hematoma Volume and Outcome in Spontaneous Intracerebral Hemorrhage.

BACKGROUND AND PURPOSE: Hematoma volume is an important determinant of clinical outcome in spontaneous intracerebral hemorrhage (ICH). We performed a genome-wide association study (GWAS) of hematoma volume with the aim of identifying novel biological pathways involved in the pathophysiology of primary brain injury in ICH. METHODS: We conducted a 2-stage (discovery and replication) case-only genome-wide association study in patients with ICH of European ancestry. We utilized the admission head computed tomography to calculate hematoma volume via semiautomated computer-assisted technique. After quality control and imputation, 7 million genetic variants were available for association testing with ICH volume, which was performed separately in lobar and nonlobar ICH cases using linear regression. Signals with P<5×10-8 were pursued in replication and tested for association with admission Glasgow coma scale and 3-month post-ICH dichotomized (0-2 versus 3-6) modified Rankin Scale using ordinal and logistic regression, respectively. RESULTS: The discovery phase included 394 ICH cases (228 lobar and 166 nonlobar) and identified 2 susceptibility loci: a genomic region on 22q13 encompassing PARVB (top single-nucleotide polymorphism rs9614326: ß, 1.84; SE, 0.32; P=4.4×10-8) for lobar ICH volume and an intergenic region overlying numerous copy number variants on 17p12 (top single-nucleotide polymorphism rs11655160: ß, 0.95; SE, 0.17; P=4.3×10-8) for nonlobar ICH volume. The replication included 240 ICH cases (71 lobar and 169 nonlobar) and corroborated the association for 17p12 (P=0.04; meta-analysis P=2.5×10-9; heterogeneity, P=0.16) but not for 22q13 (P=0.49). In multivariable analysis, rs11655160 was also associated with lower admission Glasgow coma scale (odds ratio, 0.17; P=0.004) and increased risk of poor 3-month modified Rankin Scale (odds ratio, 1.94; P=0.045). CONCLUSIONS: We identified 17p12 as a novel susceptibility risk locus for hematoma volume, clinical severity, and functional outcome in nonlobar ICH. Replication in other ethnicities and follow-up translational studies are needed to elucidate the mechanism mediating the observed association.

Meta-analysis of genome-wide association studies identifies 1q22 as a susceptibility locus for intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) is the stroke subtype with the worst prognosis and has no established acute treatment. ICH is classified as lobar or nonlobar based on the location of ruptured blood vessels within the brain. These different locations also signal different underlying vascular pathologies. Heritability estimates indicate a substantial genetic contribution to risk of ICH in both locations. We report a genome-wide association study of this condition that meta-analyzed data from six studies that enrolled individuals of European ancestry. Case subjects were ascertained by neurologists blinded to genotype data and classified as lobar or nonlobar based on brain computed tomography. ICH-free control subjects were sampled from ambulatory clinics or random digit dialing. Replication of signals identified in the discovery cohort with p < 1 × 10(-6) was pursued in an independent multiethnic sample utilizing both direct and genome-wide genotyping. The discovery phase included a case cohort of 1,545 individuals (664 lobar and 881 nonlobar cases) and a control cohort of 1,481 individuals and identified two susceptibility loci: for lobar ICH, chromosomal region 12q21.1 (rs11179580, odds ratio [OR] = 1.56, p = 7.0 × 10(-8)); and for nonlobar ICH, chromosomal region 1q22 (rs2984613, OR = 1.44, p = 1.6 × 10(-8)). The replication included a case cohort of 1,681 individuals (484 lobar and 1,194 nonlobar cases) and a control cohort of 2,261 individuals and corroborated the association for 1q22 (p = 6.5 × 10(-4); meta-analysis p = 2.2 × 10(-10)) but not for 12q21.1 (p = 0.55; meta-analysis p = 2.6 × 10(-5)). These results demonstrate biological heterogeneity across ICH subtypes and highlight the importance of ascertaining ICH cases accordingly.

Genetic variants in CETP increase risk of intracerebral hemorrhage.

OBJECTIVE: In observational epidemiologic studies, higher plasma high-density lipoprotein cholesterol (HDL-C) has been associated with increased risk of intracerebral hemorrhage (ICH). DNA sequence variants that decrease cholesteryl ester transfer protein (CETP) gene activity increase plasma HDL-C; as such, medicines that inhibit CETP and raise HDL-C are in clinical development. Here, we test the hypothesis that CETP DNA sequence variants associated with higher HDL-C also increase risk for ICH. METHODS: We performed 2 candidate-gene analyses of CETP. First, we tested individual CETP variants in a discovery cohort of 1,149 ICH cases and 1,238 controls from 3 studies, followed by replication in 1,625 cases and 1,845 controls from 5 studies. Second, we constructed a genetic risk score comprised of 7 independent variants at the CETP locus and tested this score for association with HDL-C as well as ICH risk. RESULTS: Twelve variants within CETP demonstrated nominal association with ICH, with the strongest association at the rs173539 locus (odds ratio [OR] = 1.25, standard error [SE] = 0.06, p = 6.0 × 10-4 ) with no heterogeneity across studies (I2 = 0%). This association was replicated in patients of European ancestry (p = 0.03). A genetic score of CETP variants found to increase HDL-C by ∼2.85mg/dl in the Global Lipids Genetics Consortium was strongly associated with ICH risk (OR = 1.86, SE = 0.13, p = 1.39 × 10-6 ). INTERPRETATION: Genetic variants in CETP associated with increased HDL-C raise the risk of ICH. Given ongoing therapeutic development in CETP inhibition and other HDL-raising strategies, further exploration of potential adverse cerebrovascular outcomes may be warranted. Ann Neurol 2016;80:730-740.

Heritability estimates identify a substantial genetic contribution to risk and outcome of intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Previous studies suggest that genetic variation plays a substantial role in occurrence and evolution of intracerebral hemorrhage (ICH). Genetic contribution to disease can be determined by calculating heritability using family-based data, but such an approach is impractical for ICH because of lack of large pedigree-based studies. However, a novel analytic tool based on genome-wide data allows heritability estimation from unrelated subjects. We sought to apply this method to provide heritability estimates for ICH risk, severity, and outcome. METHODS: We analyzed genome-wide genotype data for 791 ICH cases and 876 controls, and determined heritability as the proportion of variation in phenotype attributable to captured genetic variants. Contribution to heritability was separately estimated for the APOE (encoding apolipoprotein E) gene, an established genetic risk factor, and for the rest of the genome. Analyzed phenotypes included ICH risk, admission hematoma volume, and 90-day mortality. RESULTS: ICH risk heritability was estimated at 29% (SE, 11%) for non-APOE loci and at 15% (SE, 10%) for APOE. Heritability for 90-day ICH mortality was 41% for non-APOE loci and 10% (SE, 9%) for APOE. Genetic influence on hematoma volume was also substantial: admission volume heritability was estimated at 60% (SE, 70%) for non-APOEloci and at 12% (SE, 4%) for APOE. CONCLUSIONS: Genetic variation plays a substantial role in ICH risk, outcome, and hematoma volume. Previously reported risk variants account for only a portion of inherited genetic influence on ICH pathophysiology, pointing to additional loci yet to be identified.

Burden of risk alleles for hypertension increases risk of intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Genetic variation influences risk of intracerebral hemorrhage (ICH). Hypertension (HTN) is a potent risk factor for ICH and several common genetic variants (single nucleotide polymorphisms [SNPs]) associated with blood pressure levels have been identified. We sought to determine whether the cumulative burden of blood pressure-related SNPs is associated with risk of ICH and pre-ICH diagnosis of HTN. METHODS: We conducted a prospective multicenter case-control study in 2272 subjects of European ancestry (1025 cases and 1247 control subjects). Thirty-nine SNPs reported to be associated with blood pressure levels were identified from the National Human Genome Research Institute genomewide association study catalog. Single-SNP association analyses were performed for the outcomes ICH and pre-ICH HTN. Subsequently, weighted and unweighted genetic risk scores were constructed using these SNPs and entered as the independent variable in logistic regression models with ICH and pre-ICH HTN as the dependent variables. RESULTS: No single SNP was associated with either ICH or pre-ICH HTN. The blood pressure-based unweighted genetic risk score was associated with risk of ICH (OR, 1.11; 95% CI, 1.02-1.21; P=0.01) and the subset of ICH in deep regions (OR, 1.18; 95% CI, 1.07-1.30; P=0.001), but not with the subset of lobar ICH. The score was associated with a history of HTN among control subjects (OR, 1.17; 95% CI, 1.04-1.31; P=0.009) and ICH cases (OR, 1.15; 95% CI, 1.01-1.31; P=0.04). Similar results were obtained when using a weighted score. CONCLUSIONS: Increasing numbers of high blood pressure-related alleles are associated with increased risk of deep ICH as well as with clinically identified HTN.

Genotoxic analysis of four lipid-peroxidation products in the mouse lymphoma assay.

Lipid-peroxidation products are formed by the thermal treatment of foodstuffs, as well as by endogenous processes. In addition, they are also common environmental pollutants originating from many different sources. Since conflicting data exist on their possible risk for humans, we have selected four lipid-peroxidation products namely acrolein, crotonaldehyde, 4-hydroxy-hexenal (4-HHE) and 4-oxo-2-nonenal (4-ONE) to determine their ability to induce mutagenicity in mammalian cells. There is an important lack of mutagenicity data on mammalian cells for such products, which presents an important gap for any risk-assessment estimation. We have used the mouse lymphoma assay (MLA) to determine the mutagenic potential of these four compounds. This assay detects a broad spectrum of mutational events, from point mutations to chromosome alterations. The results obtained indicate that the four selected compounds are mutagenic in the MLA assay, showing a direct dose-effect relationship. The relative mutagenic potencies according to the induced mutant frequency (IMF) are as follows: crotonaldehyde (IMF=758.5×10(-6)), 4-ONE (IMF=700.5×10(-6)), acrolein (IMF=660.5×10(-6)) and 4-HHE (IMF=572×10(-6)). Although the differences between the induced mutant frequencies for these compounds are not very large, the α,ß-unsaturated aldehyde 4-oxo-2-nonenal turned out to be the agent most mutagenic. This is because its induced mutant frequency was reached after treatment with 10µM, while 50µM of the other compounds was needed to reach the reported frequencies.

Arsenic trioxide mutational spectrum analysis in the mouse lymphoma assay.

It has been well documented that long-term exposure to inorganic arsenic induces cancers and vascular diseases in a dose-response relationship. Nevertheless, arsenic has also demonstrated to have anticancer activity; thus, arsenic trioxide (ATO, As2O3) is an inorganic trivalent arsenic form, currently used in the treatment against acute promyelocytic leukaemia (APL). The open discussion about how arsenic compounds induce genotoxic damage has moved us to evaluate the mutational spectrum induced by ATO in mouse lymphoma cells. Thus, 49 Tk-/- mutant colonies obtained in the mouse lymphoma assay (MLA), after treatments lasting for 4h with 10microM ATO, and 49 spontaneous mutant colonies from independent untreated cultures, were used to analyse and to characterise the mutational spectrum induced by this arsenic compound, to understand its mechanism of action. RT-PCR analysis of Tk cDNA and PCR amplifications of eight selected microsatellite sequences, located on chromosome 11, were used to carry out this screening. Our results show that, in mouse lymphoma cells, ATO is a strong clastogenic compound inducing large deletions, at chromosomal level, covering the Tk gene, as well as other regions of chromosome 11.

Gene-mutation induction by arsenic compounds in the mouse lymphoma assay.

Arsenic compounds are generally considered as poor inducers of gene mutations. To investigate the mutagenicity of several arsenic compounds at the thymidine kinase (Tk) gene, a reporter gene for mutation induction, we used the mouse lymphoma assay (MLA). This test is widely applied and detects a broad spectrum of mutational events, from point mutations to chromosome alterations. The selected arsenic compounds were two inorganic (sodium arsenite and arsenic trioxide) and four organic compounds (monomethylarsonic acid, dimethylarsinic acid, tetraphenylarsenium and arsenobetaine). The results show that sodium arsenite, arsenic trioxide, monomethylarsonic acid and dimethylarsinic acid are mutagenic, showing a clear dose-response pattern. On the other hand, tetraphenylarsenium and arsenobetaine are not mutagenic. Inorganic arsenic compounds are the more potent agents producing significant effects in the micromolar range, while the mutagenic organic arsenic compounds induce similar effects but in the millimolar range.

Beyond qualitative and subjective techniques to assess usability of banking interfaces for senior citizens.

Senior citizens can benefit from banking services but the lack of usability hampers this possibility. New approaches based on physiological response, eye tracking and user movement analysis can provide more information during interface interaction. This research shows the differences depending on user knowledge and use of technology, gender and type of interface.