Development and characterisation of a non-thermal plasma source suitable for biological application, and its effects on mammalian cells, with a particular focus on fibroblasts and macrophage-like cells

Plasma medicine is the research field investigating the use of non-thermal plasmas (NTP) for medical treatment. NTP is already used clinically in areas such as the enhancement of wound healing. The motivation behind this work performed on this project was to further develop understanding of the biomedical effects of NTP, particularly those relating cells of the immune system. In this project, a dielectric barrier discharge (DBD) NTP source, with a pin-plate style electrode arrangement, was designed to apply NTP to aqueous liquid which either contained in vitro mammalian cell samples(direct treatment), or which was later added to such samples (plasma-activated medium (PAM) treatment). During liquid exposure to NTP for 30 minutes in the designed device, concentrations of hydrogen peroxide (H2O2) and nitrite (NO2-), two key substances in plasma medicine, rose linearly to 5.2 mM and 13.0 mM respectively. These are within the range used for similar work in the literature. Testing on cells also showed that the designed device was capable of reducing viability with both directly and via PAM. Together, this chemical and biological data showed the suitability of the designed NTP source for use in plasma medicine research. The precision of the pin-plate DBD design style was also demonstrated. A range of dilutions of PAM from the device were applied to a pro-inflammatory macrophage-like cell line, differentiated U937, and resulting in several novel findings. Sublethal PAM treatments did not influence phagocytic ability, nor the expression of two genes related to antioxidants superoxide dismutase 1 and 2 (SOD1 and SOD2). The release of pro-inflammatory chemokines and other cytokines was altered however, and notably the overall cytokine profile was dependent upon the PAM dilution used. This raises the possibility of fine-tuning the inflammatory environment through NTP.Plasma medicine is the research field investigating the use of non-thermal plasmas (NTP) for medical treatment. NTP is already used clinically in areas such as the enhancement of wound healing. The motivation behind this work performed on this project was to further develop understanding of the biomedical effects of NTP, particularly those relating cells of the immune system. In this project, a dielectric barrier discharge (DBD) NTP source, with a pin-plate style electrode arrangement, was designed to apply NTP to aqueous liquid which either contained in vitro mammalian cell samples(direct treatment), or which was later added to such samples (plasma-activated medium (PAM) treatment). During liquid exposure to NTP for 30 minutes in the designed device, concentrations of hydrogen peroxide (H2O2) and nitrite (NO2-), two key substances in plasma medicine, rose linearly to 5.2 mM and 13.0 mM respectively. These are within the range used for similar work in the literature. Testing on cells also showed that the designed device was capable of reducing viability with both directly and via PAM. Together, this chemical and biological data showed the suitability of the designed NTP source for use in plasma medicine research. The precision of the pin-plate DBD design style was also demonstrated. A range of dilutions of PAM from the device were applied to a pro-inflammatory macrophage-like cell line, differentiated U937, and resulting in several novel findings. Sublethal PAM treatments did not influence phagocytic ability, nor the expression of two genes related to antioxidants superoxide dismutase 1 and 2 (SOD1 and SOD2). The release of pro-inflammatory chemokines and other cytokines was altered however, and notably the overall cytokine profile was dependent upon the PAM dilution used. This raises the possibility of fine-tuning the inflammatory environment through NTP

Study profile: the Durban Diabetes Study (DDS): a platform for chronic disease research.

The Durban Diabetes Study (DDS) is a population-based cross-sectional survey of an urban black population in the eThekwini Municipality (city of Durban) in South Africa. The survey combines health, lifestyle and socioeconomic questionnaire data with standardised biophysical measurements, biomarkers for non-communicable and infectious diseases, and genetic data. Data collection for the study is currently underway and the target sample size is 10 000 participants. The DDS has an established infrastructure for survey fieldwork, data collection and management, sample processing and storage, managed data sharing and consent for re-approaching participants, which can be utilised for further research studies. As such, the DDS represents a rich platform for investigating the distribution, interrelation and aetiology of chronic diseases and their risk factors, which is critical for developing health care policies for disease management and prevention. For data access enquiries please contact the African Partnership for Chronic Disease Research (APCDR) at [email protected] or the corresponding author.The study was supported by the Wellcome Trust (grant number 098051), the African Partnership for Chronic Disease Research (Medical Research Council UK partnership grant number MR/K013491/1), the National Institute for Health Research Cambridge Biomedical Research Centre (UK), the Gates Cambridge Scholarship programme (UK), Novo-Nordisk (South Africa), Sanofi-Aventis (South Africa), and MSD Pharmaceuticals (Pty) Ltd (Southern Africa).This is the final version of the article. It first appeared from Cambridge University Press via http://dx.doi.org/10.1017/gheg.2015.

Chlamydia Pneumoniae CdsL Regulates CdsN ATPase Activity, and Disruption with a Peptide Mimetic Prevents Bacterial Invasion

Chlamydiae are obligate intracellular pathogens that likely require type III secretion (T3S) to invade cells and replicate intracellularly within a cytoplasmic vacuole called an inclusion body. Chlamydia pneumoniae possess a YscL ortholog, CdsL, that has been shown to interact with the T3S ATPase (CdsN). In this report we demonstrate that CdsL down-regulates CdsN enzymatic activity in a dose-dependent manner. Using Pepscan epitope mapping we identified two separate binding domains to which CdsL binds viz. CdsN221–229 and CdsN265–270. We confirmed the binding domains using a pull-down assay and showed that GST–CdsN221–270, which encompasses these peptides, co-purified with His–CdsL. Next, we used orthology modeling based on the crystal structure of a T3S ATPase ortholog from Escherichia coli, EscN, to map the binding domains on the predicted 3D structure of CdsN. The CdsL binding domains mapped to the catalytic domain of the ATPase, one in the central channel of the ATPase hexamer and one on the outer face. Since peptide mimetics have been used to disrupt essential protein interactions of the chlamydial T3S system and inhibit T3S-mediated invasion of HeLa cells, we hypothesized that if CdsL–CdsN binding is essential for regulating T3S then a CdsN peptide mimetic could be used to potentially block T3S and chlamydial invasion. Treatment of elementary body with a CdsN peptide mimetic inhibited C. pneumoniae invasion into HeLa cells in a dose-dependent fashion. This report represents the first use of Pepscan technology to identify binding domains for specific T3S proteins viz. CdsL on the ATPase, CdsN, and demonstrates that peptide mimetics can be used as anti-virulence factors to block bacterial invasion

Access to recreational physical activities by car and bus : an assessment of socio-spatial inequalities in mainland Scotland

Obesity and other chronic conditions linked with low levels of physical activity (PA) are associated with deprivation. One reason for this could be that it is more difficult for low-income groups to access recreational PA facilities such as swimming pools and sports centres than high-income groups. In this paper, we explore the distribution of access to PA facilities by car and bus across mainland Scotland by income deprivation at datazone level. GIS car and bus networks were created to determine the number of PA facilities accessible within travel times of 10, 20 and 30 minutes. Multilevel negative binomial regression models were then used to investigate the distribution of the number of accessible facilities, adjusting for datazone population size and local authority. Access to PA facilities by car was significantly (p<0.01) higher for the most affluent quintile of area-based income deprivation than for most other quintiles in small towns and all other quintiles in rural areas. Accessibility by bus was significantly lower for the most affluent quintile than for other quintiles in urban areas and small towns, but not in rural areas. Overall, we found that the most disadvantaged groups were those without access to a car and living in the most affluent areas or in rural areas

Failing boys and moral panics: perspectives on the underachievement debate

The paper re-examines the underachievement debate from the perspective of the ‘discourse of derision’ that surrounds much writing in this area. It considers the contradictions and inconsistencies which underpin much of the discourse – from a reinterpretation of examination scores, to the conflation of the concepts of ‘under’ and ‘low’ achievement and finally to the lack of consensus on a means of defining and measuring the term underachievement. In doing so, this paper suggests a more innovative approach for understanding, re-evaluating and perhaps rejecting the notion of underachievement

Light smoking at base-line predicts a higher mortality risk to women than to men; evidence from a cohort with long follow-up

BACKGROUND: There is conflicting evidence as to whether smoking is more harmful to women than to men. The UK Cotton Workers’ Cohort was recruited in the 1960s and contained a high proportion of men and women smokers who were well matched in terms of age, job and length of time in job. The cohort has been followed up for 42 years. METHODS: Mortality in the cohort was analysed using an individual relative survival method and Cox regression. Whether smoking, ascertained at baseline in the 1960s, was more hazardous to women than to men was examined by estimating the relative risk ratio women to men, smokers to never smoked, for light (1–14), medium (15–24), heavy (25+ cigarettes per day) and former smoking. RESULTS: For all-cause mortality relative risk ratios were 1.35 for light smoking at baseline (95% CI 1.07-1.70), 1.15 for medium smoking (95% CI 0.89-1.49) and 1.00 for heavy smoking (95% CI 0.63-1.61). Relative risk ratios for light smoking at baseline for circulatory system disease was 1.42 (95% CI 1.01 to 1.98) and for respiratory disease was 1.89 (95% CI 0.99 to 3.63). Heights of participants provided no explanation for the gender difference. CONCLUSIONS: Light smoking at baseline was shown to be significantly more hazardous to women than to men but the effect decreased as consumption increased indicating a dose response relationship. Heavy smoking was equally hazardous to both genders. This result may help explain the conflicting evidence seen elsewhere. However gender differences in smoking cessation may provide an alternative explanation