987 research outputs found

    Activation of endogenous p53 by combined p19Arf gene transfer and nutlin-3 drug treatment modalities in the murine cell lines B16 and C6

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    <p>Abstract</p> <p>Background</p> <p>Reactivation of p53 by either gene transfer or pharmacologic approaches may compensate for loss of p19Arf or excess mdm2 expression, common events in melanoma and glioma. In our previous work, we constructed the pCLPG retroviral vector where transgene expression is controlled by p53 through a p53-responsive promoter. The use of this vector to introduce p19Arf into tumor cells that harbor p53wt should yield viral expression of p19Arf which, in turn, would activate the endogenous p53 and result in enhanced vector expression and tumor suppression. Since nutlin-3 can activate p53 by blocking its interaction with mdm2, we explored the possibility that the combination of p19Arf gene transfer and nutlin-3 drug treatment may provide an additive benefit in stimulating p53 function.</p> <p>Methods</p> <p>B16 (mouse melanoma) and C6 (rat glioma) cell lines, which harbor p53wt, were transduced with pCLPGp19 and these were additionally treated with nutlin-3 or the DNA damaging agent, doxorubicin. Viral expression was confirmed by Western, Northern and immunofluorescence assays. p53 function was assessed by reporter gene activity provided by a p53-responsive construct. Alterations in proliferation and viability were measured by colony formation, growth curve, cell cycle and MTT assays. In an animal model, B16 cells were treated with the pCLPGp19 virus and/or drugs before subcutaneous injection in C57BL/6 mice, observation of tumor progression and histopathologic analyses.</p> <p>Results</p> <p>Here we show that the functional activation of endogenous p53wt in B16 was particularly challenging, but accomplished when combined gene transfer and drug treatments were applied, resulting in increased transactivation by p53, marked cell cycle alteration and reduced viability in culture. In an animal model, B16 cells treated with both p19Arf and nutlin-3 yielded increased necrosis and decreased BrdU marking. In comparison, C6 cells were quite susceptible to either treatment, yet p53 was further activated by the combination of p19Arf and nutlin-3.</p> <p>Conclusions</p> <p>To the best of our knowledge, this is the first study to apply both p19Arf and nutlin-3 for the stimulation of p53 activity. These results support the notion that a p53 responsive vector may prove to be an interesting gene transfer tool, especially when combined with p53-activating agents, for the treatment of tumors that retain wild-type p53.</p

    Serial bone marrow transplantation reveals in vivo expression of the pCLPG retroviral vector

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    <p>Abstract</p> <p>Background</p> <p>Gene therapy in the hematopoietic system remains promising, though certain aspects of vector design, such as transcriptional control elements, continue to be studied. Our group has developed a retroviral vector where transgene expression is controlled by p53 with the intention of harnessing the dynamic and inducible nature of this tumor suppressor and transcription factor. We present here a test of <it>in vivo </it>expression provided by the p53-responsive vector, pCLPG. For this, we used a model of serial transplantation of transduced bone marrow cells.</p> <p>Results</p> <p>We observed, by flow cytometry, that the eGFP transgene was expressed at higher levels when the pCLPG vector was used as compared to the parental pCL retrovirus, where expression is directed by the native MoMLV LTR. Expression from the pCLPG vector was longer lasting, but did decay along with each sequential transplant. The detection of eGFP-positive cells containing either vector was successful only in the bone marrow compartment and was not observed in peripheral blood, spleen or thymus.</p> <p>Conclusions</p> <p>These findings indicate that the p53-responsive pCLPG retrovirus did offer expression <it>in vivo </it>and at a level that surpassed the non-modified, parental pCL vector. Our results indicate that the pCLPG platform may provide some advantages when applied in the hematopoietic system.</p

    Prevalence and Determinants of Obesity among Primary School Children in Dar es Salaam, Tanzania.

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    Childhood obesity has increased dramatically and has become a public health concern worldwide. Childhood obesity is likely to persist through adulthood and may lead to early onset of NCDs. However, there is paucity of data on obesity among primary school children in Tanzania. This study assessed the prevalence and determinants of obesity among primary school children in Dar es Salaam. A cross sectional study was conducted among school age children in randomly selected schools in Dar es Salaam. Anthropometric and blood pressure measurements were taken using standard procedures. Body Mass Index (BMI) was calculated as weight in kilograms divided by the square of height in meters (kg/m2). Child obesity was defined as BMI at or above 95th percentile for age and sex. Socio-demographic characteristics of children were determined using a structured questionnaire. Logistic regression was used to determine association between independent variables with obesity among primary school children in Dar es Salaam. A total of 446 children were included in the analysis. The mean age of the participants was 11.1±2.0 years and 53.1% were girls. The mean BMI, SBP and DBP were 16.6±4.0 kg/m2, 103.9±10.3mmHg and 65.6±8.2mmHg respectively. The overall prevalence of child obesity was 5.2% and was higher among girls (6.3%) compared to boys (3.8%). Obese children had significantly higher mean values for age (p=0.042), systolic and diastolic blood pressures (all p<0.001). Most obese children were from households with fewer children (p=0.019) and residing in urban areas (p=0.002). Controlling for other variables, age above 10 years (AOR=3.3, 95% CI=1.5-7.2), female sex (AOR=2.6, 95% CI=1.4-4.9), urban residence (AOR=2.5, 95% CI=1.2-5.3) and having money to spend at school (AOR=2.6, 95% CI=1.4-4.8) were significantly associated with child obesity. The prevalence of childhood obesity in this population was found to be low. However, children from urban schools and girls were proportionately more obese compared to their counterparts. Primary preventive measures for childhood obesity should start early in childhood and address socioeconomic factors of parents contributing to childhood obesity

    Emotions in business-to-business service relationships

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    Emotion in business-to-business service relationships regarding cargo services is explored. The service relationship is characterised by mutual trust and cooperation. Contact is mainly via telephone or e-mail with some face-to-face interactions and participants providing a complex, multi-skilled seamless service. Experience rather than training plays a vital role with long-term service relationships built up and maintained. Emotional sensitivity is acquired partly by experience and a repeat customer base but mainly through a genuine desire to help and get to know others. In contrast to the view of emotional labour bringing managerial control or adverse affects to service staff, the emotion engendered by this work is authentic expression bringing personal satisfaction

    Prophylactic cranial irradiation in locally advanced non-small cell lung cancer: outcome of recursive partitioning analysis group 1 patients

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    <p>Abstract</p> <p>Background</p> <p>Prophylactic cranial irradiation (PCI) has been demonstrated to reduce or delay the incidence of brain metastases (BM) in locally advanced non-small cell lung carcinoma (LA-NSCLC) patients with various prognostic groups. With this current cohort we planned to evaluate the potential usefulness of prophylactic cranial irradiation (PCI) specifically in recursive partitioning analysis (RPA) Group 1, which is the most favorable group of LA-NSCLC patients.</p> <p>Methods</p> <p>Between March 2007 and February 2008, 62 patients in RPA group 1 were treated with sequential chemoradiotherapy and PCI for stage IIIB NSCLC. The induction chemotherapy consisted of 3 courses of cisplatin (80 mg/m<sup>2</sup>) and docetaxel (80 mg/m<sup>2</sup>); each course was given every 21 days. Thoracic radiotherapy (TRT) was given at a dose of 60 Gy using 3-D conformal planning. All patients received a total dose of 30 Gy PCI (2 Gy/fr, 5 days a week), beginning on the first day of the TRT. Then, all patients received 3 further courses of the same chemotherapy protocol.</p> <p>Results</p> <p>Six (9.7%) patients developed brain metastases during their clinical course. Only one (2%) patient developed brain metastasis as the site of first treatment failure. Median brain metastasis-free survival, overall survival, and progression free survival were 16.6, 16.7, and 13.0 months, respectively. By univariate analysis, rates of BM were significantly higher in patients younger than 60 years of age (p = 0.03). Multivariate analysis showed no significant difference in BM-free survival according to gender, age, histology, and initial T- and N-stage.</p> <p>Conclusion</p> <p>The current finding of almost equal bone metastasis free survival and overall survival in patients with LA-NSCLC in RPA group 1 suggests a longer survival for patients who receive PCI, and thereby have a reduced risk of BM.</p

    Nowhere to go: How stigma limits the options of female drug users after release from jail

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    <p>Abstract</p> <p>Background</p> <p>Drug and alcohol using women leaving prison or jail face many challenges to successful re-integration in the community and are severely hampered in their efforts by the stigma of drug or alcohol use compounded by the stigma of incarceration.</p> <p>Methods</p> <p>This qualitative study is based on individual semi-structured interviews and focus groups with 17 women who had recently left jail about the challenges they faced on reentry.</p> <p>Results</p> <p>Our analysis identified three major themes, which are related by the overarching influence of stigma: survival (jobs and housing), access to treatment services, and family and community reintegration.</p> <p>Conclusion</p> <p>Stigma based on drug use and incarceration works to increase the needs of women for health and social services and at the same time, restricts their access to these services. These specific forms of stigma may amplify gender and race-based stigma. Punitive drug and social policies related to employment, housing, education, welfare, and mental health and substance abuse treatment make it extremely difficult for women to succeed.</p

    Seeking legitimacy through CSR: Institutional Pressures and Corporate Responses of Multinationals in Sri Lanka

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    Arguably, the corporate social responsibility (CSR) practices of multinational enterprises (MNEs) are influenced by a wide range of both internal and external factors. Perhaps most critical among the exogenous forces operating on MNEs are those exerted by state and other key institutional actors in host countries. Crucially, academic research conducted to date offers little data about how MNEs use their CSR activities to strategically manage their relationship with those actors in order to gain legitimisation advantages in host countries. This paper addresses that gap by exploring interactions between external institutional pressures and firm-level CSR activities, which take the form of community initiatives, to examine how MNEs develop their legitimacy-seeking policies and practices. In focusing on a developing country, Sri Lanka, this paper provides valuable insights into how MNEs instrumentally utilise community initiatives in a country where relationship-building with governmental and other powerful non-governmental actors can be vitally important for the long-term viability of the business. Drawing on neo-institutional theory and CSR literature, this paper examines and contributes to the embryonic but emerging debate about the instrumental and political implications of CSR. The evidence presented and discussed here reveals the extent to which, and the reasons why, MNEs engage in complex legitimacy-seeking relationships with Sri Lankan institutions

    Patient preferences for the allocation of deceased donor kidneys for transplantation: a mixed methods study

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    <p>Abstract</p> <p>Background</p> <p>Deceased donor kidneys are a scarce health resource, yet patient preferences for organ allocation are largely unknown. The aim of this study was to determine patient preferences for how kidneys should be allocated for transplantation.</p> <p>Methods</p> <p>Patients on dialysis and kidney transplant recipients were purposively selected from two centres in Australia to participate in nominal/focus groups in March 2011. Participants identified and ranked criteria they considered important for deceased donor kidney allocation. Transcripts were thematically analysed to identify reasons for their rankings.</p> <p>Results</p> <p>From six groups involving 37 participants, 23 criteria emerged. Most agreed that matching, wait-list time, medical urgency, likelihood of surviving surgery, age, comorbidities, duration of illness, quality of life, number of organs needed and impact on the recipient's life circumstances were important considerations. Underpinning their rankings were four main themes: enhancing life, medical priority, recipient valuation, and deservingness. These were predominantly expressed as achieving equity for all patients, or priority for specific sub-groups of potential recipients regarded as more "deserving".</p> <p>Conclusions</p> <p>Patients believed any wait-listed individual who would gain life expectancy and quality of life compared with dialysis should have access to transplantation. Equity of access to transplantation for all patients and justice for those who would look after their transplant were considered important. A utilitarian rationale based on maximizing health gains from the allocation of a scarce resource to avoid "wastage," were rarely expressed. Organ allocation organisations need to seek input from patients who can articulate preferences for allocation and advocate for equity and justice in organ allocation.</p

    Serratia marcescens internalization and replication in human bladder epithelial cells

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    BACKGROUND: Serratia marcescens, a frequent agent of catheterization-associated bacteriuria, strongly adheres to human bladder epithelial cells in culture. The epithelium normally provides a barrier between lumal organisms and the interstitium; the tight adhesion of bacteria to the epithelial cells can lead to internalization and subsequent lysis. However, internalisation was not shown yet for S. marcescens strains. METHODS: Elektronmicroscopy and the common gentamycin protection assay was used to assess intracellular bacteria. Via site directed mutagenesis, an hemolytic negative isogenic Serratia strain was generated to point out the importance of hemolysin production. RESULTS: We identified an important bacterial factor mediating the internalization of S. marcescens, and lysis of epithelial cells, as the secreted cytolysin ShlA. Microtubule filaments and actin filaments were shown to be involved in internalization. However, cytolysis of eukaryotic cells by ShlA was an interfering factor, and therefore hemolytic-negative mutants were used in subsequent experiments. Isogenic hemolysin-negative mutant strains were still adhesive, but were no longer cytotoxic, did not disrupt the cell culture monolayer, and were no longer internalized by HEp-2 and RT112 bladder epithelial cells under the conditions used for the wild-type strain. After wild-type S. marcescens became intracellular, the infected epithelial cells were lysed by extended vacuolation induced by ShlA. In late stages of vacuolation, highly motile S. marcescens cells were observed in the vacuoles. S. marcescens was also able to replicate in cultured HEp-2 cells, and replication was not dependent on hemolysin production. CONCLUSION: The results reported here showed that the pore-forming toxin ShlA triggers microtubule-dependent invasion and is the main factor inducing lysis of the epithelial cells to release the bacteria, and therefore plays a major role in the development of S. marcescens infections
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