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181.
Mats F. Nilsson Helen Ritchie William S. Webster 《Birth defects research. Part B, Developmental and reproductive toxicology》2013,98(5):416-427
In this study, we compared the effects of four ion channel blockers on rat embryonic heart function during the organogenic period from gestational day (GD) 10 to 15, to determine the changes in dependence on ion channels during rat cardiac development. Rat embryos in culture were exposed to either the human ether‐á‐go‐go‐related gene potassium channel blocker, dofetilide (400 nM); the sodium channel blocker, lidocaine (250 μM); the L‐type calcium channel blocker, nifedipine (1.8 μM); or the multichannel blocker, phenytoin (200 μM). Lidocaine slowed the heart rate (HR) with the effect becoming more severe with increasing GD. Dofetilide slowed the embryonic HR and caused arrhythmias with the most severe effect on GD 11 to 13. Nifedipine primarily caused a negative inotropic effect except on GD 10 when it stopped the heart in most embryos. Phenytoin stopped the heart of most GD 10 to 12 embryos while on GD 13 to 15 phenytoin slowed the heart. The results demonstrate that as the rat heart develops during the organogenic period its functional dependence on ion channels changes markedly. These changes are important for understanding drug effects on the embryo during pregnancy and the methodology used provides a simple procedure for assessing drug effects on the developing heart. 相似文献
182.
Eleanor Y. Chen Kimberly P. Dobrinski Kim H. Brown Ryan Clagg Elena Edelman Myron S. Ignatius Jin Yun Helen Chen Jillian Brockmann G. Petur Nielsen Sridhar Ramaswamy Charles Keller Charles Lee David M. Langenau 《PLoS genetics》2013,9(8)
Human cancer genomes are highly complex, making it challenging to identify specific drivers of cancer growth, progression, and tumor maintenance. To bypass this obstacle, we have applied array comparative genomic hybridization (array CGH) to zebrafish embryonal rhabdomyosaroma (ERMS) and utilized cross-species comparison to rapidly identify genomic copy number aberrations and novel candidate oncogenes in human disease. Zebrafish ERMS contain small, focal regions of low-copy amplification. These same regions were commonly amplified in human disease. For example, 16 of 19 chromosomal gains identified in zebrafish ERMS also exhibited focal, low-copy gains in human disease. Genes found in amplified genomic regions were assessed for functional roles in promoting continued tumor growth in human and zebrafish ERMS – identifying critical genes associated with tumor maintenance. Knockdown studies identified important roles for Cyclin D2 (CCND2), Homeobox Protein C6 (HOXC6) and PlexinA1 (PLXNA1) in human ERMS cell proliferation. PLXNA1 knockdown also enhanced differentiation, reduced migration, and altered anchorage-independent growth. By contrast, chemical inhibition of vascular endothelial growth factor (VEGF) signaling reduced angiogenesis and tumor size in ERMS-bearing zebrafish. Importantly, VEGFA expression correlated with poor clinical outcome in patients with ERMS, implicating inhibitors of the VEGF pathway as a promising therapy for improving patient survival. Our results demonstrate the utility of array CGH and cross-species comparisons to identify candidate oncogenes essential for the pathogenesis of human cancer. 相似文献
183.
Aditya Malkar Neil A. Devenport Helen J. Martin Pareen Patel Matthew A. Turner Phillip Watson Ronald J. Maughan Helen J. Reid Barry L. Sharp C. L. Paul Thomas James C. Reynolds Colin S. Creaser 《Metabolomics : Official journal of the Metabolomic Society》2013,9(6):1192-1201
A method has been developed for metabolite profiling of the salivary metabolome based on protein precipitation and ultra-high performance liquid chromatography coupled with ion mobility-mass spectrometry (UHPLC–IM–MS). The developed method requires 0.5 mL of human saliva, which is easily obtainable by passive drool. Standard protocols have been established for the collection, storage and pre-treatment of saliva. The use of UHPLC allows rapid global metabolic profiling for biomarker discovery with a cycle time of 15 min. Mass spectrometry imparts the ability to analyse a diverse number of species reproducibly over a wide dynamic range, which is essential for profiling of biofluids. The combination of UHPLC with IM–MS provides an added dimension enabling complex metabolic samples to be separated on the basis of retention time, ion mobility and mass-to-charge ratio in a single chromatographic run. The developed method has been applied to targeted metabolite identification and untargeted metabolite profiling of saliva samples collected before and after exercise-induced physiological stress. δ-Valerolactam has been identified as a potential biomarker on the basis of retention time, MS/MS spectrum and ion mobility drift time. 相似文献
184.
185.
Margaret C. Stanley Helen W. Nathan Lara K. Phillips Sarah J. Knight Josie A. Galbraith Chris J. Winks Darren F. Ward 《Arthropod-Plant Interactions》2013,7(1):59-67
The direct and indirect interactions of invasive ants with plants, insect herbivores, and Hemiptera are complex. While ant and Hemiptera interactions with native plants have been well studied, the effects of invasive ant–scale insect mutualisms on the reproductive output of invasive weeds have not. The study system consisted of Argentine ants (Linepithema humile), boneseed (Chrysanthemoides monilifera monilifera), and sap-sucking scale insects (Hemiptera: Saissetia oleae and Parasaissetia nigra), all of which are invasive in New Zealand. We examined the direct and indirect effects of Argentine ants on scale insects and other invertebrates (especially herbivores) and on plant reproductive output. Argentine ants spent one-third of their time specifically associated with scale insects in tending behaviours. The invertebrate community was significantly different between uninfested and infested plants, with fewer predators and herbivores on ant-infested plants. Herbivore damage was significantly reduced on plants with Argentine ants, but sooty mould colonisation was greater where ants were present. Herbivore damage increased when ants were excluded from plants. Boneseed plants infested with Argentine ants produced significantly more fruits than plants without ants. The increase in reproductive output in the presence of ants may be due to increased pollination as the result of pollinators being forced to relocate frequently to avoid attack by ants, resulting in an increase in pollen transfer and higher fruit/seed set. The consequences of Argentine ant invasion can be varied; not only does their invasion have consequences for maintaining biodiversity, ant invasion may also affect weed and pest management strategies. 相似文献
186.
Nicholas Glozier Helen Christensen Sharon Naismith Nicole Cockayne Liesje Donkin Bruce Neal Andrew Mackinnon Ian Hickie 《PloS one》2013,8(3)
Background and Aim
Mild to moderate depression is common in those with cardiovascular disease and undertreated. We aimed to evaluate the effectiveness of internet-delivered Cognitive Behaviour Therapy (iCBT) on depressive symptom severity and adherence to medical advice and lifestyle interventions in adults with mild to moderate depression and high cardiovascular disease (CVD) risks.Methods
Randomised double-blind, 12 week attention-controlled trial comparing an iCBT programme (E-couch) with an internet-delivered attention control health information package (HealthWatch, n = 282). The primary outcome was depression symptom level on the nine-item Patient Health Questionnaire (PHQ-9) (trial registration: ACTRN12610000085077).Results
487/562 (88%) participants completed the endpoint assessment. 383/562 (70%) were currently treated for cardiovascular disease and 314/562 (56%) had at least one other comorbid condition. In ITT analysis of 562 participants iCBT produced a greater decline in the mean PHQ-9 score compared to the attention control of 1.06 (95% CI: 0.23–1.89) points, with differences between the two arms increasing over the intervention period (time by treatment effect interaction p = .012). There were also larger improvements in adherence (2.16 points; 95% CI: 0.33–3.99), reductions in anxiety (0.96 points; 95% CI: 0.19–1.73), and a greater proportion engaging in beneficial physical activity (Odds Ratio 1.91, 95%CI: 1.01–3.61) in the iCBT participants but no effect upon disability, or walking time/day. There were no withdrawals due to study related adverse events.Conclusions
In people with mild to moderate depression and high levels of CVD risk factors, a freely accessible iCBT programme (http://www.ecouch.anu.edu.au) produced a small, but robust, improvement in depressive symptoms, adherence and some health behaviours.Trial Registration
Australian and New Zealand Clinical Trials Registry ACTRN12610000085077 相似文献187.
Cornelia Schuster Helen Brosi Katja Stifter Bernhard O. Boehm Reinhold Schirmbeck 《PloS one》2013,8(8)
Coinhibitory PD-1/PD-L1 (B7-H1) interactions provide critical signals for the regulation of autoreactive T-cell responses. We established mouse models, expressing the costimulator molecule B7.1 (CD80) on pancreatic beta cells (RIP-B7.1 tg mice) or are deficient in coinhibitory PD-L1 or PD-1 molecules (PD-L1−/− and PD-1−/− mice), to study induction of preproinsulin (ppins)-specific CD8 T-cell responses and experimental autoimmune diabetes (EAD) by DNA-based immunization. RIP-B7.1 tg mice allowed us to identify two CD8 T-cell specificities: pCI/ppins DNA exclusively induced Kb/A12–21-specific CD8 T-cells and EAD, whereas pCI/ppinsΔA12–21 DNA (encoding ppins without the COOH-terminal A12–21 epitope) elicited Kb/B22–29-specific CD8 T-cells and EAD. Specific expression/processing of mutant ppinsΔA12–21 (but not ppins) in non-beta cells, targeted by intramuscular DNA-injection, thus facilitated induction of Kb/B22–29-specific CD8 T-cells. The A12–21 epitope binds Kb molecules with a very low avidity as compared with B22–29. Interestingly, immunization of coinhibition-deficient PD-L1−/− or PD-1−/− mice with pCI/ppins induced Kb/A12–21-monospecific CD8 T-cells and EAD but injections with pCI/ppinsΔA12–21 did neither recruit Kb/B22–29-specific CD8 T-cells into the pancreatic target tissue nor induce EAD. PpinsΔA12–21/(Kb/B22–29)-mediated EAD was efficiently restored in RIP-B7.1+/PD-L1−/− mice, differing from PD-L1−/− mice only in the tg B7.1 expression in beta cells. Alternatively, an ongoing beta cell destruction and tissue inflammation, initiated by ppins/(Kb/A12–21)-specific CD8 T-cells in pCI/ppins+pCI/ppinsΔA12–21 co-immunized PD-L1−/− mice, facilitated the expansion of ppinsΔA12–21/(Kb/B22–29)-specific CD8 T-cells. CD8 T-cells specific for the high-affinity Kb/B22–29- (but not the low-affinity Kb/A12–21)-epitope thus require stimulatory ´help from beta cells or inflamed islets to expand in PD-L1-deficient mice. The new PD-1/PD-L1 diabetes models may be valuable tools to study under well controlled experimental conditions distinct hierarchies of autoreactive CD8 T-cell responses, which trigger the initial steps of beta cell destruction or emerge during the pathogenic progression of EAD. 相似文献
188.
Yu-Tao Xiang Robert W. Buchanan Gabor S. Ungvari Helen F. K. Chiu Kelly Y. C. Lai You-Hong Li Tian-Mei Si Chuan-Yue Wang Edwin H. M. Lee Yan-Ling He Shu-Yu Yang Mian-Yoon Chong Ee-Heok Kua Senta Fujii Kang Sim Michael K. H. Yong Jitendra K. Trivedi Eun-Kee Chung Pichet Udomratn Kok-Yoon Chee Norman Sartorius Chay-Hoon Tan Naotaka Shinfuku 《PloS one》2013,8(6)
189.
Doxorubicin is one of the most effective anti-cancer agents. However, its use is associated with adverse cardiac effects, including cardiomyopathy and progressive heart failure. Given the multiple beneficial effects of the mitochondrial division inhibitor (mdivi-1) in a variety of pathological conditions including heart failure and ischaemia and reperfusion injury, we investigated the effects of mdivi-1 on doxorubicin-induced cardiac dysfunction in naïve and stressed conditions using Langendorff perfused heart models and a model of oxidative stress was used to assess the effects of drug treatments on the mitochondrial depolarisation and hypercontracture of cardiac myocytes. Western blot analysis was used to measure the levels of p-Akt and p-Erk 1/2 and flow cytometry analysis was used to measure the levels p-Drp1 and p-p53 upon drug treatment. The HL60 leukaemia cell line was used to evaluate the effects of pharmacological inhibition of mitochondrial division on the cytotoxicity of doxorubicin in a cancer cell line. Doxorubicin caused a significant impairment of cardiac function and increased the infarct size to risk ratio in both naïve conditions and during ischaemia/reperfusion injury. Interestingly, co-treatment of doxorubicin with mdivi-1 attenuated these detrimental effects of doxorubicin. Doxorubicin also caused a reduction in the time taken to depolarisation and hypercontracture of cardiac myocytes, which were reversed with mdivi-1. Finally, doxorubicin caused a significant elevation in the levels of signalling proteins p-Akt, p-Erk 1/2, p-Drp1 and p-p53. Co-incubation of mdivi-1 with doxorubicin did not reduce the cytotoxicity of doxorubicin against HL-60 cells. These data suggest that the inhibition of mitochondrial fission protects the heart against doxorubicin-induced cardiac injury and identify mitochondrial fission as a new therapeutic target in ameliorating doxorubicin-induced cardiotoxicity without affecting its anti-cancer properties. 相似文献
190.