Land use response to agricultural policy and market movements on Finnish dairy-farms

Selostus: Tuki- ja hintamuutosten vaikutus maitotilojen pellon käyttöön

KRAS mutation testing for predicting response to anti-EGFR therapy for colorectal carcinoma: proposal for an European quality assurance program.

Novel therapeutic agents targeting the epidermal growth factor receptor (EGFR) have improved outcomes for patients with colorectal carcinoma. However, these therapies are effective only in a subset of patients. Activating mutations in the KRAS gene are found in 30-40% of colorectal tumors and are associated with poor response to anti-EGFR therapies. Thus, KRAS mutation status can predict which patient may or may not benefit from anti-EGFR therapy. Although many diagnostic tools have been developed for KRAS mutation analysis, validated methods and standardized testing procedures are lacking. This poses a challenge for the optimal use of anti-EGFR therapies in the management of colorectal carcinoma. Here we review the molecular basis of EGFR-targeted therapies and the resistance to treatment conferred by KRAS mutations. We also present guideline recommendations and a proposal for a European quality assurance program to help ensure accuracy and proficiency in KRAS mutation testing across the European Union.

S100A1 deficiency results in prolonged ventricular repolarization in response to sympathetic activation.

S100A1 is a Ca(2+)-binding protein and predominantly expressed in the heart. We have generated a mouse line of S100A1 deficiency by gene trap mutagenesis to investigate the impact of S100A1 ablation on heart function. Electrocardiogram recordings revealed that after beta-adrenergic stimulation S100A1-deficient mice had prolonged QT, QTc and ST intervals and intraventricular conduction disturbances reminiscent of 2 : 1 bundle branch block. In order to identify genes affected by the loss of S100A1, we profiled the mutant and wild type cardiac transcriptomes by gene array analysis. The expression of several genes functioning to the electrical activity of the heart were found to be significantly altered. Although the default prediction would be that mRNA and protein levels are highly correlated, comprehensive immunoblot analyses of salient up- or down-regulated candidate genes of any cellular network revealed no significant changes on protein level. Taken together, we found that S100A1 deficiency results in cardiac repolarization delay and alternating ventricular conduction defects in response to sympathetic activation accompanied by a significantly different transcriptional regulation.

The vitamin D receptor gene bAt (CCA) haplotype impairs the response to pegylated-interferon/ribavirin-based therapy in chronic hepatitis C patients.

BACKGROUND: Chronic hepatitis C infection is a major cause of end-stage liver disease. Therapy outcome is influenced by 25-OH vitamin D deficiency. To further address this observation, our study investigates the impact of the vitamin D receptor (NR1I1) haplotype and combined effects of plasma vitamin D levels in a well-described cohort of hepatitis C patients. METHODS: A total of 155 chronic hepatitis C patients were recruited from the Swiss Hepatitis C Cohort Study for NR1I1 genotyping and plasma 25-OH vitamin D level measurement. NR1I1 genotype data and combined effects of plasma 25-OH vitamin D level were analysed regarding therapy response (sustained virological response). RESULTS: A strong association was observed between therapy non-response and the NR1I1 CCA (bAt) haplotype consisting of rs1544410 (BsmI) C, rs7975232 (ApaI) C and rs731236 (TaqI) A alleles. Of the HCV patients carrying the CCA haplotype, 50.3% were non-responders (odds ratio [OR] 1.69, 95% CI 1.07, 2.67; P=0.028). A similar association was observed for the combinational CCCCAA genotype (OR 2.94, 95% CI 1.36, 6.37; P=0.007). The combinational CCCCAA genotype was confirmed as an independent risk factor for non-response in multivariate analysis (OR 2.50, 95% CI 1.07, 5.87; P=0.034). Analysing combined effects, a significant impact of low 25-OH vitamin D levels on sustained virological response were only seen in patients with the unfavourable NR1I1 CCA (bAt) haplotype (OR for non-SVR 3.55; 95% CI 1.005, 12.57; P=0.049). CONCLUSIONS: NR1I1 vitamin D receptor polymorphisms influence response to pegylated-interferon/ribavirin-based therapy in chronic hepatitis C and exert an additive genetic predisposition to previously described low 25-OH vitamin D serum levels.

Fish Glucose Transporter (GLUT)-4 Differs from Rat GLUT4 in Its Traffic Characteristics but Can Translocate to the Cell Surface in Response to Insulin in Skeletal Muscle Cells

In mammals, glucose transporter (GLUT)-4 plays an important role in glucose homeostasis mediating insulin action to increase glucose uptake in insulin-responsive tissues. In the basal state, GLUT4 is located in intracellular compartments and upon insulin stimulation is recruited to the plasma membrane, allowing glucose entry into the cell. Compared with mammals, fish are less efficient restoring plasma glucose after dietary or exogenous glucose administration. Recently our group cloned a GLUT4-homolog in skeletal muscle from brown trout (btGLUT4) that differs in protein motifs believed to be important for endocytosis and sorting of mammalian GLUT4. To study the traffic of btGLUT4, we generated a stable L6 muscle cell line overexpressing myc-tagged btGLUT4 (btGLUT4myc). Insulin stimulated btGLUT4myc recruitment to the cell surface, although to a lesser extent than rat-GLUT4myc, and enhanced glucose uptake. Interestingly, btGLUT4myc showed a higher steady-state level at the cell surface under basal conditions than rat-GLUT4myc due to a higher rate of recycling of btGLUT4myc and not to a slower endocytic rate, compared with rat-GLUT4myc. Furthermore, unlike rat-GLUT4myc, btGLUT4myc had a diffuse distribution throughout the cytoplasm of L6 myoblasts. In primary brown trout skeletal muscle cells, insulin also promoted the translocation of endogenous btGLUT4 to the plasma membrane and enhanced glucose transport. Moreover, btGLUT4 exhibited a diffuse intracellular localization in unstimulated trout myocytes. Our data suggest that btGLUT4 is subjected to a different intracellular traffic from rat-GLUT4 and may explain the relative glucose intolerance observed in fish.

Cultivar response to fungicide application in relation to rice blast control, productivity and sustainability

Four field trials were conducted, from 1995 to 1997, with the objective of studying the response of four upland cultivars to foliar fungicide application in relation to panicle blast control, grain yield and sustainability. Differential disease control and yield response of cultivars to fungicide treatment were obtained. Losses in grain yield of cultivars IAC 202, Caiapó, Rio Paranaíba and Araguaia due to panicle blast were 44.8%, 27.4%, 24.4% and 18.2%, respectively. Two applications of tricyclazole or benomyl controlled panicle blast, as indicated by lower values of disease progress curve and relative panicle blast severity, and increased grain yield of the cultivar IAC 202. The losses in 100 panicle grain weight and grain yield were significantly reduced by 22.3% and 25.1% in IAC 202 and 23.6% and 20.5% in Caiapó, respectively, with two sprays of tricyclazole. Sustainable value index for yield was maximum with two applications of tricyclazole (0.59), followed by one application at booting (0.46) and at heading (0.40) in cultivar IAC 202. Results showed no yield response of the cultivars Rio Paranaíba and Araguaia to fungicide applications for panicle blast control.

Coping with continuous human disturbance in the wild: insights from penguin heart rate response to various stressors.

ABSTRACT: BACKGROUND: A central question for ecologists is the extent to which anthropogenic disturbances (e.g. tourism) might impact wildlife and affect the systems under study. From a research perspective, identifying the effects of human disturbance caused by research-related activities is crucial in order to understand and account for potential biases and derive appropriate conclusions from the data. RESULTS: Here, we document a case of biological adjustment to chronic human disturbance in a colonial seabird, the king penguin (Aptenodytes patagonicus), breeding on remote and protected islands of the Southern ocean. Using heart rate (HR) as a measure of the stress response, we show that, in a colony with areas exposed to the continuous presence of humans (including scientists) for over 50 years, penguins have adjusted to human disturbance and habituated to certain, but not all, types of stressors. When compared to birds breeding in relatively undisturbed areas, birds in areas of high chronic human disturbance were found to exhibit attenuated HR responses to acute anthropogenic stressors of low-intensity (i.e. sounds or human approaches) to which they had been subjected intensely over the years. However, such attenuation was not apparent for high-intensity stressors (i.e. captures for scientific research) which only a few individuals experience each year. CONCLUSIONS: Habituation to anthropogenic sounds/approaches could be an adaptation to deal with chronic innocuous stressors, and beneficial from a research perspective. Alternately, whether penguins have actually habituated to anthropogenic disturbances over time or whether human presence has driven the directional selection of human-tolerant phenotypes, remains an open question with profound ecological and conservation implications, and emphasizes the need for more knowledge on the effects of human disturbance on long-term studied populations.

Contribution of S6K1/MAPK signaling pathways in the response to oxidative stress: activation of RSK and MSK by hydrogen peroxide

Cells respond to different kind of stress through the coordinated activation of signaling pathways such as MAPK or p53. To find which molecular mechanisms are involved, we need to understand their cell adaptation. The ribosomal protein, S6 kinase 1 (S6K1), is a common downstream target of signaling by hormonal or nutritional stress. Here, we investigated the initial contribution of S6K1/MAPK signaling pathways in the cell response to oxidative stress produced by hydrogen peroxide (H2O2). To analyze S6K1 activation, we used the commercial anti-phospho-Thr389-S6K1 antibody most frequently mentioned in the bibliography. We found that this antibody detected an 80-90 kDa protein that was rapidly phosphorylated in response to H2O2 in several human cells. Unexpectedly, this phosphorylation was insensitive to both mTOR and PI3K inhibitors, and knock-down experiments showed that this protein was not S6K1. RSK and MSK proteins were candidate targets of this phosphorylation. We demonstrated that H2O2 stimulated phosphorylation of RSK and MSK kinases at residues that are homologous to Thr389 in S6K1. This phosphorylation required the activity of either p38 or ERK MAP kinases. Kinase assays showed activation of RSK and MSK by H2O2. Experiments with mouse embryonic fibroblasts from p38 animals" knockout confirmed these observations. Altogether, these findings show that the S6K1 signaling pathway is not activated under these conditions, clarify previous observations probably misinterpreted by non-specific detection of proteins RSK and MSK by the anti-phospho-Thr389-S6K1 antibody, and demonstrate the specific activation of MAPK signaling pathways through ERK/p38/RSK/MSK by H2O2.

Vitamin D deficiency and a CYP27B1-1260 promoter polymorphism are associated with chronic hepatitis C and poor response to interferon-alfa based therapy.

BACKGROUND & AIMS: Vitamin D is an important immune modulator and preliminary data indicated an association between vitamin D deficiency and sustained virologic response (SVR) rates in hepatitis C virus (HCV) genotype 1 patients. We, therefore, performed a comprehensive analysis on the impact of vitamin D serum levels and of genetic polymorphisms with functional relevance within the vitamin D cascade on chronic hepatitis C and its treatment. METHODS: Vitamin D serum levels, genetic polymorphisms within the vitamin D receptor and 1α-hydroxylase were determined in a cohort of 468 HCV genotype 1, 2, and 3 infected patients who were treated with interferon-alfa based regimens. RESULTS: Chronic hepatitis C was associated with a high incidence of severe vitamin D deficiency compared to controls (25(OH)D(3)<10 ng/ml in 25% versus 12%, p<0.00001). 25(OH)D(3) deficiency correlated with SVR in HCV genotype 2 and 3 patients (50% and 81% SVR for patients with and without severe vitamin D deficiency, respectively, p<0.0001). In addition, the CYP27B1-1260 promoter polymorphism rs10877012 had substantial impact on 1,25-dihydroxyvitamin D serum levels (72, 61, and 60 pmol/ml for rs10877012 AA, AC, and CC, respectively, p=0.04) and on SVR rates in HCV genotype 1, 2, and 3 infected patients (77% and 65% versus 42% for rs10877012 AA, AC, and CC, respectively, p=0.02). CONCLUSIONS: Chronic hepatitis C virus infection is associated with vitamin D deficiency. Reduced 25-hydroxyvitamin D levels and CYP27B1-1260 promoter polymorphism leading to reduced 1,25-dihydroxyvitamin D levels are associated with failure to achieve SVR in HCV genotype 1, 2, and 3 infected patients.

Intravenous fish oil blunts the physiological response to endotoxin in healthy subjects

Résumé L'administration par voie orale d'acides gras polyinsaturés de type ω-3 contenus dans l'huile de poisson exerce des effets bénéfiques sur la réponse métabolique et inflammatoire chez des sujets sains soumis à une injection d'endotoxine. Ce modèle expérimental a été validé pour l'investigation clinique. Il simule un sepsis et induit une réponse comparable à un état grippal, accompagné de modifications métaboliques et inflammatoires. L'objectif de cette étude est de déterminer les effets de l'huile de poisson administré par voie intraveineuse sur la réponse à l'endotoxine chez le sujet sain. L'hypothèse est qu'il sera possible de réduire le temps de latence en comparaison avec la voie orale. Pour ce faire, nous avons inclut dans une étude prospective randomisée 16 volontaires sains âgés de 16 à 35 ans et les avons répartis en 2 groupes : l'un recevant une émulsion lipidique contenant les acides gras polyinsaturés EPA et DHA et l'autre, sans traitement, constituant le groupe contrôle. Huit sujets reçoivent une perfusion continue de 0.5g/kg d'huile de poisson durant 6h, 48h et 24h avant la journée test. Lors de cette journée test, tous les volontaires ont reçu une dose d'endotoxine (2mg/kg) au temps t0. Les paramètres vitaux sont monitorés et enregistrés : fréquence cardiaque, respiratoire, pression artérielle, saturation artérielle en oxygène, ainsi que température. Des prises de sang sont effectuées à intervalles réguliers pour déterminer 1) l'incorporation membranaire des thrombocytes en EPA et DHA ; 2) le taux plasmatique d'hormones (insulin, glucagon, cortisol, ACTH et catécholamines), de marqueurs inflammatoires (TNF-α, IL-6, hsCRP), ainsi que de substrats énergétiques (glucose, lactate, acides gras libres et triglycérides). La dépense énergétique est déterminée par calorimétrie indirecte. L'analyse statistique est effectuée par analyse de variance (ANOVA). Les résultats montrent une incorporation significative de EPA et DHA au niveau membranaire des thrombocytes. L'huile de poisson induit une atténuation significative de la réponse neuro-endocrinienne et inflammatoire en réponse à l'injection d'endotoxine avec diminution de la fièvre (-0.7°C), ainsi que du taux plasmatique ,d'ACTH (-68%), TNF-α (-63%) et de noradrénaline (-%) dans le groupe huile de poisson. En conclusion, cette étude montre que la supplémentation de 2 doses d'huile de poisson par voie intraveineuse modifie la composition phospholipidique des membranes des thrombocytes et diminue la réaction inflammatoire et neuroendocrinienne en réponse à l'endotoxine. Ces résultats positifs ouvrent la perspective d'une supplémentation parentérale préopératoire en acides gras polyinsaturés ω-3 pour diminuer le stress lié à la chirurgie majeure.

IL28B polymorphisms predict response to therapy among chronic hepatitis C patients with HCV genotype 4.

Summary.  Genetic polymorphisms near IL28B are associated with spontaneous and treatment-induced clearance of hepatitis C virus (HCV). Our objective was to assess the predictive value of IL28B polymorphisms in the treatment of chronic hepatitis C of patients with HCV genotypes 4, for which data are currently limited. We analysed the association of IL28B polymorphisms with the virological response to treatment among 182 naïve chronic hepatitis C patients with HCV genotype 4, all from Syria. Associations of alleles with the response patterns were evaluated by univariate analysis and multivariate logistic regression, accounting for all relevant covariates. Sustained virological response (SVR) was achieved in 26% of rs8099917 TG/GG carriers compared with 60% of TT carriers (P < 0.0001) and 35% of rs12979860 CT/TT carriers compared with 62% of CC carriers (P = 0.0011). By multivariate analysis, the association between rs8099917 and SVR remained significant (OR = 0.19, 95% CI 0.07-0.50, for TG/GG vs TT, P = 0.0007), with the only significant covariate being advanced fibrosis (OR = 0.13, 95% CI 0.04-0.37, P = 0.0002). In conclusion, IL28B polymorphisms are the strongest predictors of response to therapy among chronic hepatitis C patients with HCV genotype 4.

ABCB1 and cytochrome P450 genotypes and phenotypes: influence on methadone plasma levels and response to treatment.

BACKGROUND AND OBJECTIVE: The in vivo implication of various cytochrome P450 (CYP) isoforms and of P-glycoprotein on methadone kinetics is unclear. We aimed to thoroughly examine the genetic factors influencing methadone kinetics and response to treatment. METHODS: Genotyping for CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP3A4, CYP3A5, ABCB1, and UGT2B7 polymorphisms was performed in 245 patients undergoing methadone maintenance treatment. To assess CYP3A activity, the patients were phenotyped with midazolam. RESULTS: The patients with lower CYP3A activity presented higher steady-state trough (R,S)-methadone plasma levels (4.3, 3.0, and 2.3 ng/mL x mg for low, medium, and high activity, respectively; P = .0002). As previously reported, CYP2B6*6/*6 carriers had significantly higher trough (S)-methadone plasma levels (P = .0001) and a trend toward higher (R)-methadone plasma levels (P = .07). CYP2D6 ultrarapid metabolizers presented lower trough (R,S)-methadone plasma levels compared with the extensive or intermediate metabolizers (2.4 and 3.3 ng/mL x mg, respectively; P = .04), whereas CYP2D6 poor metabolizer status showed no influence. ABCB1 3435TT carriers presented lower trough (R,S)-methadone plasma levels (2.7 and 3.4 ng/mL . mg for 3435TT and 3435CC carriers, respectively; P = .01). The CYP1A2, CYP2C9, CYP2C19, CYP3A5, and UGT2B7 genotypes did not influence methadone plasma levels. Only CYP2B6 displayed a stereoselectivity in its activity. CONCLUSION: In vivo, CYP3A4 and CYP2B6 are the major CYP isoforms involved in methadone metabolism, with CYP2D6 contributing to a minor extent. ABCB1 genetic polymorphisms also contribute slightly to the interindividual variability of methadone kinetics. The genetic polymorphisms of these 4 proteins had no influence on the response to treatment and only a small influence on the dose requirement of methadone.

The EuroSIDA study: Regional differences in the HIV-1 epidemic and treatment response to antiretroviral therapy among HIV-infected patients across Europe--a review of published results.

EuroSIDA is a pan-European observational study that follows 14,265 HIV-infected patients from 31 European countries, Israel and Argentina, of which 2,560 are patients from eastern Europe (EE). The study group has performed several analyses addressing regional differences in the HIV-epidemic across Europe, where all countries were divided into five regions: south, west central, north, east central Europe and EE. Significant regional differences in patients' characteristics and pattern of AIDS diagnoses were documented. More patients from EE were diagnosed with tuberculosis compared to other regions. Significantly fewer HIV-infected patients in EE, who fulfilled the criteria for starting combination antiretroviral therapy (cART), actually received cART as compared with other regions of Europe. Those, receiving cART in EE had a lower initial virologic response rate irrespectively of the regimen used, although it has improved within years. Besides, treatment failure was more common in this region. Thus, improvements in the clinical management of HIV patients in EE are urgently needed. Strategies include creating scientific collaborations for HIV clinicians as well as teaching clinicians about the most advanced HIV management at clinically oriented courses held in eastern Europe.