Assessing goodness-of-fit for evaluation of dose-proportionality.

For the clinical development of a new drug, the determination of dose-proportionality is an essential part of the pharmacokinetic evaluations, which may provide early indications of non-linear pharmacokinetics and may help to identify sub-populations with divergent clearances. Prior to making any conclusions regarding dose-proportionality, the goodness-of-fit of the model must be assessed to evaluate the model performance. We propose the use of simulation-based visual predictive checks to improve the validity of dose-proportionality conclusions for complex designs. We provide an illustrative example and include a table to facilitate review by regulatory authorities.

Wnt/ß-catenin signalling induces MLL to create epigenetic changes in salivary gland tumours.

We show that activation of Wnt/ß-catenin and attenuation of Bmp signals, by combined gain- and loss-of-function mutations of ß-catenin and Bmpr1a, respectively, results in rapidly growing, aggressive squamous cell carcinomas (SCC) in the salivary glands of mice. Tumours contain transplantable and hyperproliferative tumour propagating cells, which can be enriched by fluorescence activated cell sorting (FACS). Single mutations stimulate stem cells, but tumours are not formed. We show that ß-catenin, CBP and Mll promote self-renewal and H3K4 tri-methylation in tumour propagating cells. Blocking ß-catenin-CBP interaction with the small molecule ICG-001 and small-interfering RNAs against ß-catenin, CBP or Mll abrogate hyperproliferation and H3K4 tri-methylation, and induce differentiation of cultured tumour propagating cells into acini-like structures. ICG-001 decreases H3K4me3 at promoters of stem cell-associated genes in vitro and reduces tumour growth in vivo. Remarkably, high Wnt/ß-catenin and low Bmp signalling also characterize human salivary gland SCC and head and neck SCC in general. Our work defines mechanisms by which ß-catenin signals remodel chromatin and control induction and maintenance of tumour propagating cells. Further, it supports new strategies for the therapy of solid tumours.

Variability in detection and quantification of interferon ß-1b-induced neutralizing antibodies.

BACKGROUND: Interferon-beta (IFNB) therapy for multiple sclerosis can lead to the induction of neutralizing antibodies (NAbs) against IFNB. Various methods are used for detection and quantification of NAbs. METHODS: Blood samples from 125 IFNB-1b-treated patients, which were tested NAb negative or NAb positive after conclusion of a clinical study, were retested three years after first being assessed in four different laboratories that offer routine NAb testing to practicing neurologists. The myxovirus protein A (MxA) induction assay, the cytopathic effect (CPE) assay (two laboratories), or the luciferase assay were used. Intra- and inter-laboratory agreement between assays with respect to NAb detection and NAb titer quantification were evaluated. RESULTS: High agreement for NAb detection (kappa coefficient, 0.86) and for titer levels was observed for the intra-laboratory comparison in the laboratory using the MxA induction assay performed three years ago and now. A similarly high agreement for NAb detection (kappa coefficient, 0.87) and for titer quantification was noted for the MxA assay of this laboratory with one of two laboratories using the CPE assay. All other inter-laboratory comparisons showed kappa values between 0.57 and 0.68 and remarkable differences in individual titer levels. CONCLUSIONS: There are considerable differences in the detection and quantification of IFNB-induced NAbs among laboratories offering NAb testing for clinical practice using different assay methods. It is important that these differences are considered when interpreting NAb results for clinical decision-making and when developing general recommendations for potentially clinically meaningful NAb titer levels.

Genome-wide meta-analysis identifies novel multiple sclerosis susceptibility loci.

OBJECTIVE: To perform a 1-stage meta-analysis of genome-wide association studies (GWAS) of multiple sclerosis (MS) susceptibility and to explore functional consequences of new susceptibility loci. METHODS: We synthesized 7 MS GWAS. Each data set was imputed using HapMap phase II, and a per single nucleotide polymorphism (SNP) meta-analysis was performed across the 7 data sets. We explored RNA expression data using a quantitative trait analysis in peripheral blood mononuclear cells (PBMCs) of 228 subjects with demyelinating disease. RESULTS: We meta-analyzed 2,529,394 unique SNPs in 5,545 cases and 12,153 controls. We identified 3 novel susceptibility alleles: rs170934(T) at 3p24.1 (odds ratio [OR], 1.17; p = 1.6 × 10(-8)) near EOMES, rs2150702(G) in the second intron of MLANA on chromosome 9p24.1 (OR, 1.16; p = 3.3 × 10(-8)), and rs6718520(A) in an intergenic region on chromosome 2p21, with THADA as the nearest flanking gene (OR, 1.17; p = 3.4 × 10(-8)). The 3 new loci do not have a strong cis effect on RNA expression in PBMCs. Ten other susceptibility loci had a suggestive p < 1 × 10(-6) , some of these loci have evidence of association in other inflammatory diseases (ie, IL12B, TAGAP, PLEK, and ZMIZ1). INTERPRETATION: We have performed a meta-analysis of GWAS in MS that more than doubles the size of previous gene discovery efforts and highlights 3 novel MS susceptibility loci. These and additional loci with suggestive evidence of association are excellent candidates for further investigations to refine and validate their role in the genetic architecture of MS.

The WNT10B Network Is Associated with Survival and Metastases in Chemoresistant Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) commonly develops resistance to chemotherapy, yet markers predictive of chemoresistance in this disease are lacking. Here, we define WNT10B-dependent biomarkers for ß-CATENIN/HMGA2/EZH2 signaling predictive of reduced relapse-free survival. Concordant expression of HMGA2 and EZH2 proteins is observed in MMTV-Wnt10bLacZ transgenic mice during metastasis, and Hmga2 haploinsufficiency decreased EZH2 protein expression, repressing lung metastasis. A novel autoregulatory loop interdependent on HMGA2 and EZH2 expression is essential for ß-CATENIN/TCF-4/LEF-1 transcription. Mechanistically, both HMGA2 and EZH2 displaced Groucho/TLE1 from TCF-4 and served as gatekeepers for K49 acetylation on ß-CATENIN, which is essential for transcription. In addition, we discovered that HMGA2-EZH2 interacts with the PRC2 complex. Absence of HMGA2 or EZH2 expression or chemical inhibition of Wnt signaling in a chemoresistant patient-derived xenograft (PDX) model of TNBC abolished visceral metastasis, repressing AXIN2, MYC, EZH2, and HMGA2 expression in vivo. Combinatorial therapy of a WNT inhibitor with doxorubicin synergistically activated apoptosis in vitro, resensitized PDX-derived cells to doxorubicin, and repressed lung metastasis in vivo. We propose that targeting the WNT10B biomarker network will provide improved outcomes for TNBC. SIGNIFICANCE: These findings reveal targeting the WNT signaling pathway as a potential therapeutic strategy in triple-negative breast cancer.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/5/982/F1.large.jpg.

Lipoprotein (a) in patients with spontaneous venous thromboembolism.

INTRODUCTION: Elevated lipoprotein (a) (Lp (a)) has been established as a risk factor of coronary heart disease and stroke. Findings concerning the risk of venous thromboembolism (VTE) in adults are contradictory. The aim of our study was to investigate, whether elevated Lp (a) levels are an independent risk factor of spontaneous symptomatic venous thromboembolism (VTE). Our study was further designed to detect differences in risk profiles between thrombosis patients with and without symptomatic PE. MATERIALS AND METHODS: We investigated Lp (a) in 128 patients with spontaneous symptomatic deep vein thrombosis (DVT, group 1), 105 with spontaneous symptomatic pulmonary embolism with or without DVT (PE, group 2) and 122 healthy controls. Lp (a) was measured with an immunoturbidimetric assay (Tina-quant(R), Roche, Grenzach-Wyhlen, Germany) on a Hitachi-Modular system. RESULTS: Lp (a) levels (mg/L) were not significantly different among groups, median levels (25th-75th percentiles) were 170 (51-386) in group 1, 140 (<20-427) in group 2 and 126 (54-331) in controls, respectively. As continuous variable, odds ratios for VTE for a 100 mg/L increase of Lp (a) were 1.1 [95% confidence interval 0.98-1.2] for group 1 versus controls and 1.1 [0.95-1.2] for group 2 versus controls. The prevalence of Lp (a) above 300 mg/L was not significantly different among patients and controls (group 1: 30%, group 2: 32% and controls: 25%, p=0.4, p=0.2, respectively). CONCLUSIONS: In conclusion we found no association between Lp (a) and VTE regardless whether DVT occurred together with PE or not.

A lack of antinociceptive or antiinflammatory effect of botulinum toxin A in an inflammatory human pain model.

Several in vitro and in vivo investigations have shown that botulinum toxin A (BoNT/A) can inhibit the release of substance P and excitatory amino acids. Recently, a marked antinociceptive effect of BoNT/A and inhibition of glutamate release was observed in an animal pain model with inflammatory sensitization. In the present study, we tested the antiinflammatory and antihyperalgetic effect of BoNT/A in a well-characterized human inflammatory pain model. Using a randomized, double-blind, paired study design, we compared the effects of 100 mouse units of BoNT/A versus pure saline. Thermal and mechanical pain testings and superficial skin blood flow measurements were performed at baseline, at 48 h (in normal skin), and at 72 h (in inflamed skin) thereafter. Ultraviolet B irradiation resulted in a local inflammation with significant primary and secondary hyperalgesia. However, despite the evidence of efficacy on sudomotor function, BoNT/A had no effect on pain measures in either normal or inflamed skin. Signs of inflammation and primary and secondary hyperalgesia were found to be unaffected by BoNT. We have confirmed that BoNT/A has no direct effect on acute, noninflammatory pain. Furthermore, despite highly promising data from animal research, we have not observed antiinflammatory or antinociceptive effects of BoNT/A in human inflammatory pain.

Native DIGE proteomic analysis of mitochondria from substantia nigra and striatum during neuronal degeneration and its compensation in an animal model of early Parkinson's disease.

Cause of Parkinson's disease (PD) is still not understood. Motor symptoms are not observed at early stages of disease due to compensatory processes. Dysfunction of mitochondria was indicated already at preclinical PD. Selective toxin 6-OHDA was applied to kill dopaminergic neurons in substantia nigra and disturb neuronal transmission in striatum. Early phase of active degeneration and later stage, when surviving cells adapted to function normally, were analysed. 2D BN/SDS difference gel electrophoresis (DIGE) of mitochondrial proteome enabled to point out crucial processes involved at both time-points in dopaminergic structures. Marker proteins such as DPYSL2, HSP60, ATP1A3, EAAT2 indicated structural remodelling, cytoskeleton rearrangement, organelle trafficking, axon outgrowth and regeneration. Adaptations in dopaminergic and glutamatergic neurotransmission, recycling of synaptic vesicles, along with enlargement of mitochondria mass were proposed as causative for compensation. Changed expression of carbohydrates metabolism and oxidative phosphorylation proteins were described, including their protein-protein interactions and supercomplex assembly.

Contribution of nicotine to acute endothelial dysfunction in long-term smokers.

OBJECTIVES: The aim of this study was to determine whether nicotine, a constituent of cigarette smoke, contributes to acute endothelial dysfunction after smoking one cigarette. BACKGROUND: Animal studies suggest that nicotine might cause an impairment of endothelium-dependent vasodilation via an increase in oxidative stress. METHODS: Sixteen healthy smokers were entered into a randomized, observer-blinded crossover study comparing the effects of nicotine nasal spray (1-mg nicotine) and cigarette smoke (1-mg nicotine, 12 mg tar) on vascular reactivity in the brachial artery. Using high-resolution ultrasound, flow-mediated dilation (FMD) and endothelium-independent, nitroglycerin-induced dilation were assessed at baseline and 20 min after the administration of nicotine (spray or cigarette). RESULTS: In response to similar increases in nicotine serum levels, FMD values declined from 10.2 +/- 4.4% to 6.7 +/- 4.0% after the spray (mean difference: -3.6 +/- 2.0%, 95% confidence interval: -4.6; -2.5, p < 0.0001) and from 9.4 +/- 3.8% to 4.3 +/- 2.8% after the cigarette (-5.1 +/- 2.6%, -6.5; -3.7, p < 0.0001). Nitroglycerin-induced dilation remained similar within both periods. Performing a period effect analysis of variance, a significant influence on FMD was found for the mode of administration (p = 0.017) and the baseline value (p = 0.021). The effect on FMD was more pronounced after the cigarette than after the spray (estimated average effect difference: 1.9% FMD). Oxidation parameters did not increase significantly after nicotine spray or tobacco exposure. CONCLUSIONS: These results demonstrate that nicotine alone causes acute endothelial dysfunction, although to a lesser extent than smoking a cigarette of the same nicotine yield. However, the precise mechanisms by which nicotine leads to this altered vascular reactivity remain unclear.

Rofecoxib attenuates both primary and secondary inflammatory hyperalgesia: a randomized, double blinded, placebo controlled crossover trial in the UV-B pain model.

The analysis of drug's influence on peripheral and central sensitisation can give useful information about its mode of action and can lead to more efficacy in the treatment of pain. Peripheral inflammation is associated with peripheral expression and up-regulation of cyclooxygenase 2 (COX-2) in the CNS. The relative contribution of COX-2 mediated central sensitisation may be prominent under inflammatory conditions. In this randomized, double blinded, placebo controlled cross-over trial the effects of multidoses of the COX-2 selective inhibitor rofecoxib on primary and secondary hyperalgesia were evaluated in the UVB pain model. Twenty-four hours after local UVB irradiation at the upper leg of 42 healthy volunteers heat pain perception (HPPT) and heat pain tolerance thresholds (HPTT) were assessed within the inflammation. The area of secondary hyperalgesia was determined by pin prick test. Subjects received oral rofecoxib 50, 250, 500 mg or placebo. Pain testing was repeated after 3 and 6 h. Compared to placebo, rofecoxib significantly increased HPPT (1.55 and 1.08 degrees C, P<0.0001 and P=0.0333), HPTT (1.74 and 1.58 degrees C, P<0.0001 and P<0.0001), and reduced the mean area of secondary hyperalgesia by 15.6% (P=0.007) and 16.8% (P<0.001) after 3 and 6 h. No significant difference between the three dosage groups was observed. These data confirm peripheral effects of rofecoxib in a human inflammatory UV-B pain model and provide circumstantial evidence that even a standard clinical dose of rofecoxib reduces central hyperalgesia in inflammatory pain. We confirm that the effect of single oral dose of rofecoxib plateaus at 50 mg.

The adaptive immune system and long-term outcome in patients with stable coronary disease. Predictive value of routine laboratory measurements.

Components of the adaptive immune system, in particular lymphocytes and immunoglobulin, play a major role in advanced atherosclerotic lesions. We sought to determine whether routine, measurements of the relative number of circulating lymphocytes (%L) and gamma-globulin (%G) reflecting immunoglobulin are related to event-free survival in patients with stable coronary artery disease (CAD). We prospectively studied the combined endpoint all-cause mortality, myocardial infarction and coronary revascularization procedures in 141 patients after successful percutaneous coronary intervention during a median follow-up time of 13.2 years. Using Cox regression, we found a significant influence of %L on event-free survival (P=0.007) with a relative risk of 2.21 comparing third to first tertile. Subjects with higher %G values likewise had a shorter event-free survival (P=0.008) with a relative risk of 1.67 comparing third to first tertile. The predictive value of %L and %G remained significant after adjustment for demographic data, cardiovascular risk factors, extent of CAD and other inflammatory markers. We conclude that the fraction of gamma-globulin and in particular the relative lymphocyte cell count may serve as readily available and reliable prognostic tools for the long-term outcome in patients with stable CAD.

Basal high-sensitivity-C-reactive protein levels in patients with spontaneous venous thromboembolism.

The role of C-reactive protein (CRP) in venous thromboembolism (VTE) is still under discussion because of controversial results in the literature. Conflicting data may have partly been due to bias by exogenous factors altering CRP levels. We investigated CRP concentrations in patients with spontaneous VTE applying a study design that allowed the measurement of basal high sensitivity (hs)-CRP levels. Patients with a history of deep vein thrombosis (DVT, n=117) and pulmonary embolism (PE, n=97) were compared to healthy individuals (n=104). Hs-CRP levels (mg/dl) were significantly higher in patients (n=214, median/interquartile range: 0.171/0.082-0.366) than in controls (0.099/0.053-0.245, p=0.001). The unadjusted odds ratio (OR) for VTE per 1 mg/dl increase of CRP was 2.8 [95% confidence interval (CI): 1.1-6.8, p=0.03]. This association remained significant after adjustment for factor V Leiden, prothrombin G20210A and factor VIII activity above 230% (OR = 2.9, 95% CI [1.1-7.5]), but became remarkably attenuated and lost its statistical significance after adjustment for BMI alone (OR = 1.7 [0.7-4.0]). CRP was also not independently associated with VTE in subgroups of patients (those with DVT without symptomatic PE, those with PE and patients without established risk factor) in multiple regression analysis. In summary, we observed significantly higher basal hs-CRP levels in patients with spontaneous VTE compared to healthy controls. This association was independent of hereditary and laboratory risk factors for VTE, but lost its significance after adjustment for BMI. Increased basal CRP levels do not appear to represent an independent risk factor for VTE.

The Fc gammaRIIa polymorphism R/H131, autoantibodies against the platelet receptors GPIb alpha and Fc gammaRIIa and a risk for thromboembolism in lupus anticoagulant patients.

There is a clear propensity of individuals with lupus anticoagulant (LA) for thromboembolic disease (TE). Yet, it is not clear how individuals at risk for TE can be differentiated from those who are not. The Fc gammaRIIa receptor is the only Fc receptor expressed by platelets. As platelets can be activated via this receptor, we have compared gene frequencies of the Fc gammaRIIa polymorphism R/H131 in 46 and 27 patients with (LA/TE+) and without TE (LA/TE-), respectively, in an exploratory study. Furthermore, we investigated the presence of autoantibodies against Fc gammaRIIa and/or GPIb alpha, which is in close proximity to the Fc gammaRIIa and interacts with it functionally, and a possible linkage of antibody formation to HLA class II alleles. The Fc gammaRIIa-R/R131 genotype was significantly less frequent in patients with LA compared to controls (p<0.025). These findings were due to an increased frequency of heterozygous patients in the LA/TE+ cohort (odds ratio 6.76, 95% confidence interval 1.55-62.03, p<0.008). For the first time, heterozygosity, rather than homozygosity, can be linked to disease, which may be explained by the dual function of the Fc gammaRIIa, namely binding of antibodies to platelets and thereby their activation, and, on the other hand, clearance of antibody coated platelets by the phagocyte system. There was no correlation between the presence of anti-Fc gammaRIIa or anti-GPIb alpha autoantibodies and the Fc gammaRIIa-R/H131 polymorphism, nor the incidence of TE, nor HLA class II alleles.

Symptomatic venous thromboembolism in acute leukemia. Incidence, risk factors, and impact on prognosis.

The association between malignant disorders and occurrence of venous thromboembolism is well established. Patients with cancer and venous thromboembolism have adverse prognosis. No systematic study on the incidence and prognostic impact of venous thromboembolism in acute leukemia has been performed as yet. We retrospectively evaluated the incidence of symptomatic venous thromboembolism before chemotherapy in 719 patients (371 males and 348 females, median age of 57.4 years), diagnosed with acute leukemia [534 with acute myelogenous leukemia, 185 with acute lymphoblastic leukemia]. Furthermore, the relationship of venous thromboembolism to clinical and laboratory parameters and its impact on prognosis was assessed. Fifteen patients (2.09%) had venous thromboembolism (objectively confirmed in 13 patients) in close temporal relationship to the onset of acute leukemia. The incidence of venous thromboembolism was the same in acute myelogenous and lymphoblastic leukemia. In five patients, pulmonary embolism was documented. Venous thromboembolism occurred in all subtypes of acute leukemia, but was most common in promyelocytic leukemia. All but one patient were treated with anticoagulants. No patient died from treatment-related bleedings or venous thromboembolism. Overall, survival, disease-free survival, and remission duration did not differ between the patient groups with and without venous thromboembolism. In contrast to solid tumors, venous thromboembolism before or at diagnosis of acute leukemia is not associated with poor prognosis.

Long-term results (10 years) of intensive breast conserving therapy including a high-dose and large-volume interstitial brachytherapy boost (LDR/HDR) for T1/T2 breast cancer.

BACKGROUND AND PURPOSE: During the past 15 years many retrospective studies and prospective randomized trials have been published supporting the use of breast conserving treatment (BCT) including surgery and radiotherapy. However, there are still many controversies on the necessary amount of resection, the width of the resection margins and the optimal radiation technique, dose and volume, in particular of the boost. In this retrospective study a large cohort of 410 women with early breast cancer treated with BCT including an interstitial brachytherapy (BT) boost is evaluated after a long follow-up period. MATERIAL AND METHODS: In order to clarify the impact of the different treatment-related factors on local control, these were carefully discriminated, based on widely accepted classification and reporting systems for surgery as well as for radiotherapy. The surgical approach was classified according to EORTC criteria and a high rate of quadrantectomies (60%) was found. Dose and volume of interstitial BT is reported according to recommendations of ICRU 58, and reveals a significant radiation dose and volume: minimum target dose, mean central dose (MCD) and '85% of MCD' for low-dose rate (LDR) BT was mean 20, 28 and 24 Gy, for high-dose rate (HDR) BT it was mean '10, 15 and 13 Gy, respectively; the treated volume was 104 cc for LDR BT and 83 cc for HDR BT. RESULTS: The actuarial rates for overall survival, disease-free survival and disease-specific survival were 97, 90 and 98% at 5 years and 85, 79 and 92% at 10 years. There have been only 16 breast recurrences in 410 treated patients resulting in a 5- and 10-year actuarial local recurrence rate of 2 and 3.9%, respectively; six recurrences (1.5%) were in the original quadrant. Except age and menopausal status, all tumour- and patient-related risk factors had no significant impact on local control. CONCLUSIONS: Our data confirm that intensive BCT leads to excellent long-term results in terms of local control, masking classical risk factors. This high-dose and large-volume interstitial BT seems to be superior to classical BCT without BT.

Individual variations in the sulcal anatomy of the basal temporal lobe and its relevance for epilepsy surgery: an anatomical study performed using magnetic resonance imaging.

OBJECT: The concept of selective amygdalohippocampectomy is based on pathophysiological insights into the epileptogenicity of the hippocampal region and the definition of the clinical syndrome of mesial temporal lobe epilepsy (TLE). High-resolution magnetic resonance (MR) imaging allows correlation of the site of histologically conspicuous tissue with anatomical structure. The highly variable sulcal pattern of the basal temporal lobe, however, definitely complicates the morphometric analysis of histomorphologically defined subdivisions of the hippocampal region. The goal of this study was to define individual variations in the sulcal anatomy on the basis of preoperative MR images obtained in patients suffering from TLE. METHODS: The authors analyzed coronal MR images obtained in 50 patients for the presence of and intrinsic relationships among the rhinal, collateral, and occipitotemporal sulci. The surface relief of consecutive sections of 100 temporal lobes was graphically outlined and the resulting maps were used for visual analysis. The sulci were characterized by measurement of their depth, distance to the temporal horn, and laterality. The anatomical measurements and frequencies of sulcal patterns were assessed for statistical correlation with patients' histories and the lateralization of the seizure focus. CONCLUSIONS: Statistical assessment shows that patient sex is a significant factor in sulcal patterns. Anatomical measurements are significantly decreased on the side of the seizure origin, which relates to loss of white matter, a known morphological abnormality associated with TLE. Magnetic resonance imaging allows for accurate preoperative knowledge of individual sulcal patterns and facilitates intraoperative orientation to anatomical landmarks.

Do monthly or seasonal variations exist in suicides in a high-risk setting?

An unequal distribution of suicides over months and seasons has been a consistent finding in epidemiological surveys on suicide. Jails and prisons are a high-risk setting for suicide all over the world. The high prevalence of both outward and self-directed violence in prison populations indicates dysfunctional central serotonin (5-HT) neurotransmission and, therefore, could account for an unequal distribution of suicides over months and seasons due to underlying bioclimatic factors. Within a total survey of suicides in the Austrian penitentiary system, the weekly, monthly and seasonal distribution of custodial suicides between 1947 and 1999 was studied. After an explorative comparison of suicide distribution over weekdays, months and seasons of the year by chi2-tests, a harmonic Poisson regression model was performed to detect seasonality of suicides. No unequal distribution of suicides was evident over the 53-year period. A limitation of this study was its sample size of 412, a low number compared with population-based samples, where a spring suicide peak was consistently found. An explanation for lacking seasonality could be that bioclimatic factors are less relevant in urban, industrialized areas, where jails and prisons usually are located. One of the core characteristics of penal institutions is the limited possibility for communication and social interaction. This social isolation is independent of seasonal changes. If the individual's possibilities for social interactions are limited, the influence of seasonal changes in social activities may be less relevant. This could explain the absence of seasonal changes in custodial suicide incidence.

Is hypertension a major risk factor in aneurysmal subarachnoid hemorrhage?

OBJECTIVE: The role of hypertension as a major risk factor for the development and rupture of cerebral aneurysms is a subject of considerable debate. METHODS: In order to substantiate or weaken the hypothesis of the atherogenic, degenerative origin of this disease, in addition to hypertension the influence of smoking and the covariates body weight, hematocrit, fibrinogen and leukocrit were examined in a hospital-based case-control and cohort study. 141 consecutive patients with subarachnoid hemorrhage (SAH) and verified cerebral aneurysms, admitted between September 1994 and August 1998, were investigated. RESULTS: An association was found between hypertension and SAH of cerebral aneurysm in the entire patient group (P < 0.0001). In the stepwise logistic regression, the exposure odds ratio (OR) for hypertension was 6.8 (CI (95%): 3.53-13.14). Smokers have a twofold higher risk, with an OR of 2.2 (CI (95%): 1.19-4.06). Age was found to have a prognostic impact on the disease (P = 0.0089). Age obviously was a confounding factor for hypertension, which was associated with the outcome (P = 0.048). CONCLUSION: Patients with hypertension had a nearly seven-fold higher risk of aneurysmal subarchnoid hemorrhage. This seems to substantiate the hypothesis that aneurysm is an acquired and hemodynamically induced chronic disease.

WNT10B/ß-catenin signalling induces HMGA2 and proliferation in metastatic triple-negative breast cancer.

Wnt/ß-catenin signalling has been suggested to be active in basal-like breast cancer. However, in highly aggressive metastatic triple-negative breast cancers (TNBC) the role of ß-catenin and the underlying mechanism(s) for the aggressiveness of TNBC remain unknown. We illustrate that WNT10B induces transcriptionally active ß-catenin in human TNBC and predicts survival-outcome of patients with both TNBC and basal-like tumours. We provide evidence that transgenic murine Wnt10b-driven tumours are devoid of ERα, PR and HER2 expression and can model human TNBC. Importantly, HMGA2 is specifically expressed during early stages of embryonic mammogenesis and absent when WNT10B expression is lost, suggesting a developmentally conserved mode of action. Mechanistically, ChIP analysis uncovered that WNT10B activates canonical ß-catenin signalling leading to up-regulation of HMGA2. Treatment of mouse and human triple-negative tumour cells with two Wnt/ß-catenin pathway modulators or siRNA to HMGA2 decreases HMGA2 levels and proliferation. We demonstrate that WNT10B has epistatic activity on HMGA2, which is necessary and sufficient for proliferation of TNBC cells. Furthermore, HMGA2 expression predicts relapse-free-survival and metastasis in TNBC patients.

Retention of iodine and expression of biomarkers for renal damage in the kidney after application of iodinated contrast media in rats.

OBJECTIVE: Commercially available iodinated contrast media (CM) show significantly different physico-chemical properties. The relevance of the viscosity of CM may be underestimated as a contributing factor for clinically relevant renal failure as suggested by a large registry data analysis (Swedish registry study). The objective of this preclinical study is to assess differences of a low and high-viscous CM regarding their retention time in the kidney. Furthermore, we investigated the expression of marker genes for renal damage and hypoxia to evaluate a potential renal damage and hypoxia after application of iodinated CM. MATERIAL AND METHODS: After application of Iopromide 300 and Iodixanol 320 CM, the iodine concentration over time was determined using computed tomography and x-ray fluorescence analysis in healthy Han Wistar and renally impaired ZSF1 rats. The latter served as a model for age and diabetes-related renal impairment. X-ray attenuation (Hounsfield units) in the renal cortex was analyzed by 2 independent blinded readers. Furthermore, the expression of kidney injury molecule 1 (Kim-1/Havcr1) and heme oxygenase I (HO-1/HMOX1) was measured by quantitative reverse transcription-polymerase chain-reaction. RESULTS: Computed tomography and x-ray fluorescence analysis in the kidneys of animals treated with Iodixanol revealed significantly prolonged retention of iodine in the kidney as compared with animals treated with Iopromide. This difference was even more pronounced in renally impaired rats. Twenty-four hours after Iodixanol treatment, significantly increased levels of Kim-1/Havcr1 and HO-1/HMOX1 transcript levels were observed compared with the saline and Iopromide treatment. CONCLUSIONS: A prolonged retention of contrast media in the kidney was observed after administration of dimeric CM (Iodixanol 320). One possible explanation for this effect could be the high viscosity of the dimeric CM (Iodixanol 320) and the lack of dilution by osmotic diuresis. This prolonged exposure is possibly associated with higher renal toxicity as indicated by the elevated expression of biomarkers for hypoxia and renal injury.