1,052 research outputs found
Retargeting the \u3ci\u3eClostridium botulinum\u3c/i\u3e C2 toxin to the neuronal cytosol
Many biological toxins are known to attack specific cell types, delivering their enzymatic payloads to the cytosol. This process can be manipulated by molecular engineering of chimeric toxins. Using toxins with naturally unlinked components as a starting point is advantageous because it allows for the development of payloads separately from the binding/translocation components. Here the Clostridium botulinum C2 binding/translocation domain was retargeted to neural cell populations by deleting its non-specific binding domain and replacing it with a C. botulinum neurotoxin binding domain. This fusion protein was used to deliver fluorescently labeled payloads to Neuro-2a cells. Intracellular delivery was quantified by flow cytometry and found to be dependent on artificial enrichment of cells with the polysialoganglioside receptor GT1b. Visualization by confocal microscopy showed a dissociation of payloads from the early endosome indicating translocation of the chimeric toxin. The natural Clostridium botulinum C2 toxin was then delivered to human glioblastoma A172 and synchronized HeLa cells. In the presence of the fusion protein, native cytosolic enzymatic activity of the enzyme was observed and found to be GT1b-dependent. This retargeted toxin may enable delivery of therapeutics to peripheral neurons and be of use in addressing experimental questions about neural physiology
An evaluation of the relative efficacy of an open airway, an oxygen reservoir and continuous positive airway pressure 5 cmH2O on the non-ventilated lung
Publisher's copy made available with the permission of the publisher © Australian Society of AnaesthetistsThe aim of this study, during one-lung ventilation, was to evaluate if oxygenation could be improved by use of a simple oxygen reservoir or application of 5 cmH2O continuous positive airway pressure (CPAP) to the non-ventilated lung compared with an open airway. Twenty-three patients with lung malignancy, undergoing thoracotomy requiring at least 60 minutes of one-lung ventilation before lung lobe excision, were studied. After routine induction and establishment of one-lung ventilation, the three treatments were applied in turn to the same patient in a sequence selected randomly. The first treatment was repeated as a fourth treatment and these results of the repeated treatment averaged to minimize the effect of slow changes. Arterial oxygenation was measured by an arterial blood gas 15 minutes after the application of each treatment. Twenty patients completed the study. Mean PaO2 (in mmHg) was 210.3 (SD 105.5) in the 'OPEN' treatment, 186.0 (SD 109.2) in the 'RESERVOIR' treatment, and 240.5 (SD 116.0) in the 'CPAP' treatment. This overall difference was not quite significant (P=0.058, paired ANOVA), but comparison of the pairs showed that there was a significant better oxygenation only with the CPAP compared to the reservoir treatments (t=2.52, P=0.021). While the effect on the surgical field was not apparent in most patients, in one patient surgery was impeded during CPAP. Our results show that the use of a reservoir does not give oxygenation better than an open tube, and is less effective than the use of CPAP 5 cmH2O on the non-ventilated lung during one-lung ventilation.J. Slimani, W. J. Russell, C. Jurisevichttp://www.aaic.net.au/Article.asp?D=200404
Halothane potentiates the alcohol-adduct induced TNF-alpha release in heart endothelial cells
BACKGROUND: The possibility exists for major complications to occur when individuals are intoxicated with alcohol prior to anesthetization. Halothane is an anesthetic that can be metabolized by the liver into a highly reactive product, trifluoroacetyl chloride, which reacts with endogenous proteins to form a trifluoroacetyl-adduct (TFA-adduct). The MAA-adduct which is formed by acetaldehyde (AA) and malondialdehyde reacting with endogenous proteins, has been found in both patients and animals chronically consuming alcohol. These TFA and MAA-adducts have been shown to cause the release of inflammatory products by various cell types. If both adducts share a similar mechanism of cell activation, receiving halothane anesthesia while intoxicated with alcohol could exacerbate the inflammatory response and lead to cardiovascular injury. METHODS: We have recently demonstrated that the MAA-adduct induces tumor necrosis factor-α (TNF-α) release by heart endothelial cells (HECs). In this study, pair and alcohol-fed rats were randomized to receive halothane pretreatments intra peritoneal. Following the pretreatments, the intact heart was removed, HECs were isolated and stimulated with unmodified bovine serum albumin (Alb), MAA-modified Alb (MAA-Alb), Hexyl-MAA, or lipopolysaccharide (LPS), and supernatant concentrations of TNF-α were measured by ELISA. RESULTS: Halothane pre-treated rat HECs released significantly greater TNF-α concentration following MAA-adduct and LPS stimulation than the non-halothane pre-treated in both pair and alcohol-fed rats, but was significantly greater in the alcohol-fed rats. CONCLUSION: These results demonstrate that halothane and MAA-adduct pre-treatment increases the inflammatory response (TNF-α release). Also, these results suggest that halothane exposure may increase the risk of alcohol-induced heart injury, since halothane pre-treatment potentiates the HEC TNF-α release measured following both MAA-Alb and LPS stimulation
Conducting Research on the Worldâs Changing Mediascape: Principles and Practices
As digital technology sweeps across the globe, bringing far-reaching changes to the media environment and beyond, international research on the nature and impact of these changes is essential. This commentary situates media research within the broader flow of knowledge and offers a critical perspective on the principles and practices that should guide that research to maximize its potential contribution to both knowledge and to the public
Defining the gap between research and practice in public relations programme evaluation - towards a new research agenda
The current situation in public relations programme evaluation is neatly summarized by McCoy who commented that 'probably the most common buzzwords in public relations in the last ten years have been evaluation and accountability' (McCoy 2005, 3). This paper examines the academic and practitioner-based literature and research on programme evaluation and it detects different priorities and approaches that may partly explain why the debate on acceptable and agreed evaluation methods continues. It analyses those differences and proposes a research agenda to bridge the gap and move the debate forward
Media justice: Madeleine McCann, intermediatization and "trial by media" in the British press
Three-year-old Madeleine McCann disappeared on 3 May 2007 from a holiday apartment in Portugal. Over five years and multiple investigations that failed to solve this abducted child case, Madeleine and her parents were subject to a process of relentless âintermediatizationâ. Across 24â7 news coverage, websites, documentaries, films, YouTube videos, books, magazines, music and artworks, Madeleine was a mediagenic image of innocence and a lucrative story. In contrast to Madeleineâs media sacralization, the representation of her parents, Kate and Gerry McCann, fluctuated between periods of vociferous support and prolonged and libellous âtrial by mediaâ. This article analyses how the global intermediatization of the âMaddie Mysteryâ fed into and fuelled the âtrial by mediaâ of Kate and Gerry McCann in the UK press. Our theorization of âtrial by mediaâ is developed and refined through considering its legal limitations in an era of âattack journalismâ and unprecedented official UK inquiries into press misconduct and criminality
Complications from Surgeries Related to Ovarian Cancer Screening
The aim of this study was to evaluate complications of surgical intervention for participants in the Kentucky Ovarian Cancer Screening Program and compare results to those of the Prostate, Lung, Colorectal and Ovarian Cancer Screening trial. A retrospective database review included 657 patients who underwent surgery for a positive screen in the Kentucky Ovarian Cancer Screening Program from 1988â2014. Data were abstracted from operative reports, discharge summaries, and office notes for 406 patients. Another 142 patients with incomplete records were interviewed by phone. Complete information was available for 548 patients. Complications were graded using the ClavienâDindo (CâD) Classification of Surgical Complications and considered minor if assigned Grade I (any deviation from normal course, minor medications) or Grade II (other pharmacological treatment, blood transfusion). CâD Grade III complications (those requiring surgical, endoscopic, or radiologic intervention) and CâD Grade IV complications (those which are life threatening) were considered âmajorâ. Statistical analysis was performed using SAS 9.4 software. Complications were documented in 54/548 (10%) subjects. For women with malignancy, 17/90 (19%) had complications compared to 37/458 (8%) with benign pathology (p \u3c 0.003). For non-cancer surgery, obesity was associated with increased complications (p = 0.0028). Fifty patients had minor complications classified as CâD Grade II or less. Three of 4 patients with Grade IV complications had malignancy (p \u3c 0.0004). In the Prostate, Lung, Colorectal and Ovarian Cancer Screening trial, 212 women had surgery for ovarian malignancy, and 95 had at least one complication (45%). Of the 1080 women with non-cancer surgery, 163 had at least one complication (15%). Compared to the Prostate, Lung, Colorectal and Ovarian Cancer Screening trial, the Kentucky Ovarian Cancer Screening Program had significantly fewer complications from both cancer and non-cancer surgery (p \u3c 0.0001 and p = 0.002, respectively). Complications resulting from surgery performed as a result of the Kentucky Ovarian Cancer Screening Program were infrequent and significantly fewer than reported in the Prostate, Lung, Colorectal and Ovarian Cancer Screening trial. Complications were mostly minor (93%) and were more common in cancer versus non-cancer surgery
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