A minor catalase/peroxidase from Burkholderia cenocepacia is required for normal aconitase activity

The opportunistic bacterium Burkholderia cenocepacia C5424 contains two catalase/peroxidase genes, katA and katB. To investigate the functions of these genes, katA and katB mutants were generated by targeted integration of suicide plasmids into the katA and katB genes. The catalase/peroxidase activity of the katA mutant was not affected as compared with that of the parental strain, while no catalase/peroxidase activity was detected in the katB mutant. However, the katA mutant displayed reduced resistance to hydrogen peroxide under iron limitation, while the katB mutant showed hypersensitivity to hydrogen peroxide, and reduced growth under all conditions tested. The katA mutant displayed reduced growth only in the presence of carbon sources that are metabolized through the tricarboxylic acid (TCA) cycle, as the growth defect was abrogated in cultures supplemented with glucose or glycerol. This phenotype was also correlated with a marked reduction in aconitase activity. In contrast, aconitase activity was not reduced in the katB mutant and parental strains. The authors conclude that the KatA protein is a specialized catalase/peroxidase that has a novel function by contributing to maintain the normal activity of the TCA cycle, while KatB is a classical catalase/peroxidase that plays a global role in cellular protection against oxidative stress.

Relatedness of O-specific lipopolysaccharide side chain genes from strains of Shigella boydii type 12 belonging to two clonal groups and from Escherichia coli O7:K1

The O-specific lipopolysaccharide side chains of Escherichia coli O7 and Shigella boydii type 12 possess similar but not identical chemical structures. We investigated the genetic relatedness between the O-specific side chain genes in members of these two species. Examination of outer membrane protein and lipopolysaccharide (LPS) banding patterns demonstrated that five strains which had been identified as S. boydii type 12 fell into two clonal groups, SB1 and SB2. Hybridizations with O7-specific radiolabeled probes derived from the chromosomal DNA of an E. coli O7 strain detected identical fragments among the three SB1 strains of S. boydii type 12 and the two E. coli O7 reference isolates. The two other S. boydii type 12 strains, which belonged to the SB2 clone, did not show homologies with the O7 probe under high-stringency conditions of hybridization. The homology between the O7 and type 12 LPS gene regions from the SB1 strains was further confirmed by the construction of O-specific side chain-deficient mutations in these strains by homologous recombination of a suicide plasmid containing O7-specific DNA sequences. Immunoblot experiments with O7 antiserum gave a weak cross-reaction with LPS purified from the SB2 strains but a very strong cross-reaction with the LPS from SB1 isolates. Antiserum raised to one of the SB2 strains cross-reacted only with S. boydii type 12 LPS from the SB1 clone but failed to react with O7 LPS.

Genetic analysis of the O7-polysaccharide biosynthesis region from the Escherichia coli O7:K1 strain VW187

We recently cloned biosynthesis genes for the O7-lipopolysaccharide (O7-LPS) side chain from the Escherichia coli K-1 strain VW187 (M. A. Valvano, and J. H. Crosa, Infect. Immun. 57:937-943, 1989). To characterize the O7-LPS region, the recombinant cosmids pJHCV31 and pJHCV32 were mutagenized by transposon mutagenesis with Tn3HoHo1, which carries a promoterless lac operon and can therefore generate lacZ transcriptional fusions with target DNA sequences. Cells containing mutated plasmids were examined for their ability to react by coagglutination with O7 antiserum. The LPS pattern profiles of the insertion mutants were also investigated by electrophoresis of cell envelope fractions, followed by silver staining and immunoblotting analysis. These experiments identified three phenotypic classes of mutants and defined a region in the cloned DNA of about 14 kilobase pairs that is essential for O7-LPS expression. Analysis of beta-galactosidase production by cells carrying plasmids with transposon insertions indicated that transcription occurs in only one direction along the O7-LPS region. In vitro transcription-translation experiments revealed that the O7-LPS region encodes at least 16 polypeptides with molecular masses ranging from 20 to 48 kilodaltons. Also, the O7-LPS region in VW187 was mutagenized by homologous recombination with subsets of the cloned O7-LPS genes subcloned into a suicide plasmid vector. O7-LPS-deficient mutants of VW187 were complemented with pJHCV31 and pJHCV32, confirming that these cosmids contain genetic information that is essential for the expression of the O7 polysaccharide.

Unheard Voices: Stories from the Troubles

Produced in association with WAVE Trauma Centre, this short film records the experiences of six victims and survivors of the Northern Irish Troubles. Filmed and edited collaboratively, UV addresses issues of trauma, loss, justice and recovery. The story-tellers range from a police widow, to the brother of a sectarian victim, to a youth worker who lost is legs in an explosion. This film has been screened, with public discussions, between 2010 and 2012 by the Good Relations Departments of the following Borough and City Councils - Belfast, Derry/Londonderry, Lisburn, Ballymena, Coleraine, Moyle and Newtownabbey. It has also been screened at the Hallwells Contemporary Arts Centre, Buffalo, and at St Bonaventure University, NY (2012)

http://www.wavetraumacentre.org.uk/about-us/wave-projects/unheard-voices

Further Information:

This 30 minute documentary film was produced in collaboration with WAVE Trauma Centre, Belfast. Working closely with six survivors of the Troubles violence in Northern Ireland through all stages of production and exhibition, the film contributes to on-going discussions about dealing with the conflicted past in a contested present. The role of storytelling, identified by two government reports – the Bloomfield Report and the Eames-Bradley Report - as an important method of addressing the violent past, is one of the key research questions involved in the research. Public screenings and discussions have been organised by the Good Relations Departments of seven borough councils (Belfast, Lisburn, Derry, Ballymena, Newtownabbey, Coleraine and Moyle). The film has also been screened in New York State and London. One of the recurring themes brought up in these public discussions in the role and limits of storytelling alongside the legal issues of justice, prosecutions and reparations. An accompanying co-written article with PhD student, Jolene Mairs, 'Unheard Voices' in Mc Keogh, C. and O'Connel, D. (eds) (2012) Documentary in a Changing State,Cork University Press, is part of the portfolio presented for REF.

Responding to desire to die statements from patients with advanced disease:recommendations for health professionals

It is not uncommon for patients with advanced incurable disease to express a desire to hasten their death. Health professionals often have difficulty responding to such statements, and find it challenging to ascertain why these statements are made. Health professionals may struggle to determine whether a 'desire to die' statement (DTDS) is about a request for hastened death, a sign of psychosocial distress, or merely a passing comment that is not intended to be heard literally as a death wish. Given the lack of guidelines to assist health professionals with this issue, we have prepared multidisciplinary recommendations for responding to a DTDS, underpinned by key principles of therapeutic communication and a systematic review of empirical literature. Where the relevant literature was lacking, the recommendations were drafted by the authors (clinicians and/ or academics from the following disciplines: nursing, medicine, psychiatry, psychology, sociology, aged care and theology), based on their expert opinion. Multiple drafts of the recommendations were circulated to the authors for refinement until consensus was reached. Strategies for advancing the evidence base for the maturation of guidelines in this area are offered.

Desire for hastened death in patients with advanced disease and the evidence base of clinical guidelines:a systematic review

Patients' desire for hastened death within the context of advanced disease and palliative care is a controversial topic, frequently discussed in the international literature. Much of the discussion has focused on opinion and debate about ethical matters related to hastened death. Not many research studies seem to have specifically targeted why palliative care patients may desire hastened death, and few have focused on clinical guidelines for responding to such requests.

Substance misuse in life and death in a 2-year cohort of suicides

Background: Although substance misuse is a key risk factor in suicide, relatively little is known about the relationship between lifetime misuse and misuse at the time of suicide.

Aims: To examine the relationship between substance misuse and subsequent suicide.

Method: Linkage of coroners' reports to primary care records for 403 suicides occurring over 2 years.

Results: With alcohol misuse, 67% of the cohort had previously sought help for alcohol problems and 39% were intoxicated at the time of suicide. Regarding misuse of other substances, 54% of the cohort was tested. Almost one in four (38%) tested positive, defined as an excess of drugs over the prescribed therapeutic dosage and/or detection of illicit substances. Those tested were more likely to be young and have a history of drug misuse.

Conclusions: A deeper understanding of the relationship between substance misuse and suicide could contribute to prevention initiatives. Furthermore, standardised toxicology screening processes would avoid diminishing the importance of psychosocial factors involved in suicide as a 'cause of death'.

Meeting the Needs of Vulnerable Young Men: A Study of Service Provider Views

This article uses a qualitative approach to elicit the views of 31 professionals who provide services to vulnerable young men. The findings reveal six key themes following focus group interviews: (i) the importance of masculinity in explaining problematic behaviour; (ii) the misuse of alcohol and drugs; (iii) alienation and social isolation; (iv) concerns about suicide and self-harm; (v) the quality of existing services; and (vi) recommendations for changes to services. Service providers generally acknowledged the social context in explaining these behaviours and argued for enhanced services and a more developed skills base in working with vulnerable young men. 

Concussion and Brain Injury in Contact Sport: Legal Implications

A concussed participant leaving the field of play is one of the most worrying sights in sport. It is also one that might have serious legal implications for sports governing bodies. Over the past number of years, a major class action suit has rumbled through the US courts as taken against that country's biggest professional sport, the National Football League. The NFL is at present attempting to settle the lawsuit from more than 4,500 retired players who claim that the NFL knew for decades about the chronic health risks associated with cumulative concussions in American football but failed to warn players or take preventative steps. Testimony from retired NFL players has revealed stories of chronic headaches, Alzheimer-like forgetfulness, altered personalities and sometimes a downward spiral into depression, violence and suicide. Medical research is suggesting that professional American football players are three times more likely to die as a result of certain neurodegenerative diseases than the general population. This paper notes that the concerns about concussion are not confined to the NFL and extend to contact sport more widely and notably rugby union. This paper also assesses the reaction of leading sports governing bodies globally to the recorded medical risks and accompanying legal vulnerabilities.

Hypoxia response element-driven cytosine deaminase/5-fluorocytosine gene therapy system:a highly effective approach to overcome the dynamics of tumour hypoxia and enhance the radiosensitivity of prostate cancer cells in vitro

BACKGROUND: We proposed to exploit hypoxia-inducible factor (HIF)-1alpha overexpression in prostate tumours and use this transcriptional machinery to control the expression of the suicide gene cytosine deaminase (CD) through binding of HIF-1alpha to arrangements of hypoxia response elements. CD is a prodrug activation enzyme, which converts inactive 5-fluorocytosine to active 5-fluorouracil (5-FU), allowing selective killing of vector containing cells.

METHODS: We developed a pair of vectors, containing either five or eight copies of the hypoxia response element (HRE) isolated from the vascular endothelial growth factor (pH5VCD) or glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (pH8GCD) gene, respectively. The kinetics of the hypoxic induction of the vectors and sensitization effects were evaluated in 22Rv1 and DU145 cells in vitro.

RESULTS: The CD protein as selectively detected in lysates of transiently transfected 22Rv1 and DU145 cells following hypoxic exposure. This is the first evidence of GAPDH HREs being used to control a suicide gene therapy strategy. Detectable CD levels were sustained upon reoxygenation and prolonged hypoxic exposures. Hypoxia-induced chemoresistance to 5-FU was overcome in both cell lines treated with this suicide gene therapy approach. Hypoxic transfectants were sensitized to prodrug concentrations that were ten-fold lower than those that are clinically relevant. Moreover, the surviving fraction of reoxygenated transfectants could be further reduced with the concomitant delivery of clinically relevant single radiation doses.

CONCLUSIONS: This strategy thus has the potential to sensitize the hypoxic compartment of prostate tumours and improve the outcome of current therapies.

Radiation to control transgene expression in tumors

Significant evidence has accumulated indicating that certain genes are induced by ionising radiation. An implication of this observation is that their promoter regions include radiation-responsive sequences. These sequences have been isolated in the promoter of several genes including Erg-1, p21/WAF-1, GADD45alpha and t-PA. The mechanism by which radiation induces gene expression remains unclear but involves putative binding sites for selected transcription factors and/or p53. Consensus CC(A/T)6GG sequences have been localized in the Erg-1 promoter and are referred to as serum response elements or CArG elements. The tandem combination of CArG elements has been shown to improve gene expression levels, with a 9-copy motif conferring maximum inducibility. The response of these genes to ionising radiation appears to follow a sigmoid relationship with time and dose. Therapeutic induction of suicide genes and significant cytotoxicity can be achieved at clinically relevant x-rays doses both in vitro and in vivo but was found to be cell-type dependent. Radiation-inducible gene therapy can be potentially enhanced by exploiting hypoxia through the inclusion of hypoxia-response element motifs in the expression cassette, the use of the anaerobic bacteria or the use of neutron irradiation. These results are encouraging and provide significant evidence that gene therapy targeted to the radiation field is a reasonably attractive therapeutic option and could help overcome hypoxic radioresistant tumors.

The impact of parental migration on health status and health behaviours among left behind adolescent school children in China.

BACKGROUND:

One out of ten of China's population are migrants, moving from rural to urban areas. Many leave their families behind resulting in millions of school children living in their rural home towns without one or both their parents. Little is known about the health status of these left behind children (LBC). This study compares the health status and health-related behaviours of left behind adolescent school children and their counterparts in a rural area in Southern China.

METHODS:

A cross-sectional study was conducted among middle school students in Fuyang Township, Guangdong, China (2007-2008). Information about health behaviours, parental migration and demographic characteristics was collected using a self-administered questionnaire. Overweight/obesity and stunting were defined based on measurements of height and weight. Univariate and multivariate analyses were used to estimate the differences in health outcomes between LBC and non-LBC.

RESULTS:

18.1% of the schoolchildren had one or both parents working away from home. Multivariate analysis showed that male LBC were at higher risk of skipping breakfast, higher levels of physical inactivity, internet addiction, having ever smoked tobacco, suicide ideation, and being overweight. LBC girls were more likely to drink excessive amounts of sweetened beverage, to watch more TV, to have ever smoked or currently smoke tobacco, to have ever drunk alcohol and to binge drinking. They were also more likely to be unhappy, to think of planning suicide and consider leaving home.

CONCLUSIONS:

Our findings suggest that parental migration is a risk factor for unhealthy behaviours amongst adolescent school children in rural China. Further research is required in addition to the consideration of the implications for policies and programmes to protect LBC.

Philosophy and Political Engagement: Reflection in the Public Sphere

Do philosophers have a responsibility to their society that is distinct from their responsibility to it as citizens? This edited volume explores both what type of contribution philosophy can make and what type of reasoning is appropriate when addressing public matters now. These questions are posed by leading international scholars working in the fields of moral and political philosophy. Each contribution also investigates the central issue of how to combine critical, rational analysis with a commitment to politically relevant public engagement. The contributions to this volume analyse issues raised in practical ethics, including abortion, embryology, and assisted suicide. They consider the role of ethical commitment in the philosophical analysis of contemporary political issues, and engage with matters of public policy such as poverty, the arts, meaningful work, as well as the evidence base for policy. They also examine the normative legitimacy of power, including the use of violence.