Tumor Growth Induces Oxidative Clustered DNA Lesions Damage in Distant Mouse Tissue in vivo

Our goal was to ascertain if DNA damage induced by oxidative stress is capable of being exploited as a precancerous or cancer biomarker. The specific DNA damage that we assessed was oxidatively induced non-DSB clustered DNA lesions (OCDLs). We further wanted to investigate if OCDL formation could be decreased by reducing reactive oxygen species (ROS) and oxidative stress. To accomplish this, we utilized the superoxide dismutase antioxidant, Tempol. Finally, we wanted to assess the role of specific cytokines and their part of inducing OCDLs in tissues both proximal and distal to a tumor mass.  For our first experiment, lung carcinoma cells were injected into nude mice in collaboration with the National Cancer Institute. We evaluated the DNA damage in various tissue samples, distal and proximal to the tumor, and compared the level the damage to control B6 mice with normal immune system. To conclude if reducing ROS effects OCDL accumulation, a cohort of NUDE mice were fed the antioxidant Tempol. To establish the effects of a fully functioning immune system on OCDL formation, tumor cells were also injected into a cohort of normal B6 mice.  The second experiment was performed to evaluate the specific roles that cytokines and inflammation play in inducing OCDL damage in tissues from tumor bearing mice. A cytokine analysis was previously performed by Redon et al. which indicated in the presence of Sarcoma, monocyte chemoattractant protein-1 (MCP-1) was up regulated. To implement the specific role of MCP-1 in mediating the "bystander effect", our experiment entailed MCP-1 being knocked out for a group of mice and assessing the amount of OCDL damage in various tissues.   We utilized repair enzymes as probes to measure the level of OCDLs. These repair enzymes, human APE1, human OGG1, and E. coli Endo III, have functional activity in vivo. Once detection of a lesion in a cluster occurs, excision of the damaged base and of the DNA strand will transpire. Each DNA strand will now display a single stranded break which, if within 1-10 base pairs, results into a double stranded break. These additional breaks are measured as clustered lesions and assessed via neutral agarose gel electrophoresis and calculated with number average length analysis (NALA).  Earlier prognosis and detection of a growing tumor is a significant aspect of successful treatment. From these experiments, we hope to establish OCDLs as precancerous or cancer biomarkers in the case of high oxidative stress. It is hopeful one day clinical biopsies can be performed to screen for this specific damage and indicate early complications and tumor growth.   Future experiments can be projected based on our study. Different tumors can be utilized to assess OCDL damage. An inclusion of wider variety of tissues will further establish the complex DNA damage induced by the bystander/distal effect with ROS and inflammation as mediators of this damage.  M.S

Inspired to Adopt: The Role of Social Norms in Media Inspiration

We consider the potential for inspirational media content (inspiring videos about dogs) and injunctive norms (social media comments on the videos) to motivate dog adoption behaviors and intentions. In an online experiment, participants were exposed to pretested inspiring (or non-inspiring) videos and social norms cues and were given an opportunity to browse among a series of dogs on a mock adoption website. Participants also indicated their intention to adopt a dog and completed a series of socio-demographic measures. Results indicated that, although both the inspiring videos and the norm cues successfully induced inspiration and perceived injunctive norms, only injunctive norms significantly affected intention to adopt. The effect of norms remained significant when controlling for barriers to adoption such as financial, time, and space considerations. Discussion focuses on implications for inspiring entertainment and social norms theories, and implications for adoptions and other prosocial behaviors

Incorporating Virtual Reality Training in an Introductory Public Speaking Course

This study presents the results of two studies using a virtual reality (VR) public-speaking training simulation as an instructional aid in a basic communication course. Results from the first study suggest that VR practice was associated with higher subsequent speech delivery grades in the course compared to no practice. However, VR practice did not reduce public speaking anxiety (PSA). In a follow-up study, VR practice was compared with other forms of lab-based practice including in front of a mirror and a recorded video session. All forms of lab practice (VR, mirror, or video) were associated with higher speech grades than no practice, but there were no differences between lab-practice conditions in terms of outcomes. Results are discussed in terms of adopting and using virtual public-speaking simulations in large undergraduate public-speaking courses

Connecting

Laura Milner—Steve\u27s Story. Candace Walworth—War & Peace in a Two-Car Garage. Dave Waddell—Caring. Vic Kryston—Ralph and the Unexpected Fix. Richard L. Graves—The Abraham Dream

Elevated expression of artemis in human fibroblast cells is associated with cellular radiosensitivity and increased apoptosis

Copyright @ 2012 Nature Publishing GroupThis article has been made available through the Brunel Open Access Publishing Fund.Background: The objective of this study was to determine the molecular mechanism(s) responsible for cellular radiosensitivity in two human fibroblast cell lines 84BR and 175BR derived from two cancer patients. Methods: Clonogenic assays were performed following exposure to increasing doses of gamma radiation to confirm radiosensitivity. γ-H2AX foci assays were used to determine the efficiency of DNA double strand break (DSB) repair in cells. Quantitative-PCR (Q-PCR) established the expression levels of key DNA DSB repair proteins. Imaging flow cytometry using Annexin V-FITC was used to compare artemis expression and apoptosis in cells. Results: Clonogenic cellular hypersensitivity in the 84BR and 175BR cell lines was associated with a defect in DNA DSB repair measured by the γ-H2AX foci assay. Q-PCR analysis and imaging flow cytometry revealed a two-fold overexpression of the artemis DNA repair gene which was associated with an increased level of apoptosis in the cells before and after radiation exposure. Over-expression of normal artemis protein in a normal immortalised fibroblast cell line NB1-Tert resulted in increased radiosensitivity and apoptosis. Conclusion: We conclude elevated expression of artemis is associated with higher levels of DNA DSB, radiosensitivity and elevated apoptosis in two radio-hypersensitive cell lines. These data reveal a potentially novel mechanism responsible for radiosensitivity and show that increased artemis expression in cells can result in either radiation resistance or enhanced sensitivity.This work was supported in part by The Vidal Sassoon Foundation USA. This article is made available through the Brunel Open Access Publishing Fund

Peak flow rate and death due to coronary heart disease: 30-year results from the Northwick Park Heart cohort study.

OBJECTIVE: Numerous studies have reported that chronic obstructive pulmonary disease or impaired lung function are associated with later coronary heart disease (CHD). However, it is unclear if lung function is an independent risk factor, as many of these studies have included only limited measures of other factors associated with CHD. METHODS: In total 2167 men of all ages in the first Northwick Park Heart Study were followed for a median of 30 years. Cox regression models were used to assess the relationship between peak flow rate (PFR) and CHD mortality adjusted for potential confounders measured at baseline. Analyses allowed for missing data, and secondary analyses for repeat measures on some men and competing risks of CHD death. RESULTS: There were 254 CHD deaths with some evidence of an association between PFR and CHD mortality. The adjusted HRs (95% CIs) from the lowest to the highest of four PFR quartiles were 1.53 (1.04 to 2.25), <430 L/min; 1.43 (0.99 to 2.08), 430 - <490 L/min; and 1.31 (0.93 to 1.86), 490 - <550 L/min; compared with the reference group of ≥550 L/min (trend test p=0.025). Other associations with CHD mortality were observed for systolic blood pressure (p<0.0001), body mass index (p=0.0002), smoking status (p=0.015), blood cholesterol (p=0.005), plasma fibrinogen (p=0.001) and high-risk ECG (p=0.021). There were no strong associations for factors V and VIII or platelet count. CONCLUSIONS: After allowing for a range of other risk factors associated with CHD, there was only limited evidence of a relation between PFR and CHD mortality

Rescue of DNA damage after constricted migration reveals a mechano-regulated threshold for cell cycle.

Migration through 3D constrictions can cause nuclear rupture and mislocalization of nuclear proteins, but damage to DNA remains uncertain, as does any effect on cell cycle. Here, myosin II inhibition rescues rupture and partially rescues the DNA damage marker γH2AX, but an apparent block in cell cycle appears unaffected. Co-overexpression of multiple DNA repair factors or antioxidant inhibition of break formation also exert partial effects, independently of rupture. Combined treatments completely rescue cell cycle suppression by DNA damage, revealing a sigmoidal dependence of cell cycle on excess DNA damage. Migration through custom-etched pores yields the same damage threshold, with ∼4-µm pores causing intermediate levels of both damage and cell cycle suppression. High curvature imposed rapidly by pores or probes or else by small micronuclei consistently associates nuclear rupture with dilution of stiff lamin-B filaments, loss of repair factors, and entry from cytoplasm of chromatin-binding cGAS (cyclic GMP-AMP synthase). The cell cycle block caused by constricted migration is nonetheless reversible, with a potential for DNA misrepair and genome variation

Metabolic syndrome and carotid intima-media thickness in chronic obstructive pulmonary disease

BACKGROUND: The aim of this study is to investigate the prevalence of metabolic syndrome (MetS), carotid intima media thickness (IMT), and serum C-reactive protein (CRP) levels in patients with chronic obstructive pulmonary disease (COPD), and the possible relationships among them. METHODS: Fifty stable COPD patients and 40 healthy controls were included in the study. The participants were further divided into four groups according to their smoking status. Pulmonary function tests were performed in COPD patients. Anthropometric measurements and blood chemistry analysis, serum CRP levels and carotid intima-media thickness (IMT) measurements were performed in all the study population. RESULTS: Prevalence of metabolic syndrome was 43% in COPD patients and 30% in the control group (p = 0.173). FEV(1)% and FEV(1)/FVC were higher in COPD patients with MetS (p = 0.001 and p = 0.014, respectively) compared to those without MetS. Prevalence of MetS was significantly different among the COPD patients with different stages (p = 0.017) with the highest value in stage 2 (59%). Carotid IMT was significantly higher in COPD patients than in control group (1.07 ± 0.25 mm and 0.86 ± 0.18 mm, respectively; p < 0.001). Serum CRP levels were not different in COPD patients and controls, however they were higher in individuals with MetS compared to those without MetS regardless of COPD presence (p = 0.02). CONCLUSIONS: Early markers of atherogenesis, in terms of carotid IMT, were found to be higher in COPD patients than in healthy controls. MetS prevalence was observed to decrease as the severity of airflow obstruction increased. Therefore, screening COPD patients for these cardiovascular risk factors would be a novel approach even in absence of symptoms