158 research outputs found

    Prevention of wound complications following salvage laryngectomy using free vascularized tissue

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    Background. Total laryngectomy following radiation therapy or concurrent chemoradiation therapy is associated with unacceptably high complication rates because of wound healing difficulties. With an ever increasing reliance on organ preservation protocols as primary treatment for advanced laryngeal cancer, the surgeon must develop techniques to minimize postoperative complications in salvage laryngectomy surgery. We have developed an approach using free tissue transfer in an effort to improve tissue vascularity, reinforce the pharyngeal suture line, and minimize complications in this difficult patient population. The purpose of this study was to outline our technique and determine the effectiveness of this new approach. Methods. We conducted a retrospective review of a prospective cohort and compared it with a historical group (surgical patients of Radiation Therapy Oncology Group (RTOG)-91-11 trial). Eligibility criteria for this study included patients undergoing salvage total laryngectomy following failed attempts at organ preservation with either high-dose radiotherapy or concurrent chemo/radiation therapy regimen. Patients were excluded if the surgical defect required a skin paddle for pharyngeal closure. The prospective cohort consisted of 14 consecutive patients (10 males, 4 females; mean age, 58 years) who underwent free tissue reinforcement of the pharyngeal suture line following total laryngectomy. The historical comparison group consisted of 27 patients in the concomitant chemoradiotherapy arm of the RTOG-91-11 trial who met the same eligibility criteria (26 males, 1 female; mean age, 57 years) but did not undergo free tissue transfer or other form of suture line reinforcement. Minimum follow-up in both groups was 12 months. Results. The overall pharyngocutaneous fistula rate was similar between groups—4/14 (29%) in the flap group, compared with 8/27 (30%) in the RTOG-91-11 group. There were no major wound complications in the flap group, compared with 4 (4/27, 14.8%) in the RTOG-91-11 group. There were no major fistulas in the flap group, compared with 3/27 (11.1%) in the RTOG-91-11 group. The rate of pharyngeal stricture requiring dilation was 6/14 (42%) in the flap group, compared with 7/27 (25.9%) in the RTOG-91-11 group. In our patients, the rate of tracheoesophageal speech was 14/14 (100%), and complete oral intake was achieved in 13/14 (93%) patients. Voice-Related Quality of Life Measure (V-RQOL) and Performance Status Scale for Head and Neck Cancer Patients (PSS-HN) scores suggest that speech and swallowing functions are reasonable following free flap reinforcement. Conclusions. Free vascularized tissue reinforcement of primary pharyngeal closure in salvage laryngectomy following failed organ preservation is effective in preventing major wound complications but did not reduce the overall fistula rate. Fistulas that developed following this technique were relatively small, did not result in exposed major vessels, and were effectively treated with outpatient wound care rather than readmission to the hospital or return to operating room. Speech and swallowing results following this technique were comparable to those following total laryngectomy alone. © 2007 Wiley Periodicals, Inc. Head Neck 2007Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56020/1/20492_ftp.pd

    Immunohistochemical analysis of oxidative stress and DNA repair proteins in normal mammary and breast cancer tissues

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    <p>Abstract</p> <p>Background</p> <p>During the course of normal cellular metabolism, oxygen is consumed and reactive oxygen species (ROS) are produced. If not effectively dissipated, ROS can accumulate and damage resident proteins, lipids, and DNA. Enzymes involved in redox regulation and DNA repair dissipate ROS and repair the resulting damage in order to preserve a functional cellular environment. Because increased ROS accumulation and/or unrepaired DNA damage can lead to initiation and progression of cancer and we had identified a number of oxidative stress and DNA repair proteins that influence estrogen responsiveness of MCF-7 breast cancer cells, it seemed possible that these proteins might be differentially expressed in normal mammary tissue, benign hyperplasia (BH), ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC).</p> <p>Methods</p> <p>Immunohistochemistry was used to examine the expression of a number of oxidative stress proteins, DNA repair proteins, and damage markers in 60 human mammary tissues which were classified as BH, DCIS or IBC. The relative mean intensity was determined for each tissue section and ANOVA was used to detect statistical differences in the relative expression of BH, DCIS and IBC compared to normal mammary tissue.</p> <p>Results</p> <p>We found that a number of these proteins were overexpressed and that the cellular localization was altered in human breast cancer tissue.</p> <p>Conclusions</p> <p>Our studies suggest that oxidative stress and DNA repair proteins not only protect normal cells from the damaging effects of ROS, but may also promote survival of mammary tumor cells.</p

    Knowledge based identification of essential signaling from genome-scale siRNA experiments

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    <p>Abstract</p> <p>Background</p> <p>A systems biology interpretation of genome-scale RNA interference (RNAi) experiments is complicated by scope, experimental variability and network signaling robustness. Over representation approaches (ORA), such as the Hypergeometric or z-score, are an established statistical framework used to associate RNA interference effectors to biologically annotated gene sets or pathways. These methods, however, do not directly take advantage of our growing understanding of the interactome. Furthermore, these methods can miss partial pathway activation and may be biased by protein complexes. Here we present a novel ORA, protein interaction permutation analysis (PIPA), that takes advantage of canonical pathways and established protein interactions to identify pathways enriched for protein interactions connecting RNAi hits.</p> <p>Results</p> <p>We use PIPA to analyze genome-scale siRNA cell growth screens performed in HeLa and TOV cell lines. First we show that interacting gene pair siRNA hits are more reproducible than single gene hits. Using protein interactions, PIPA identifies enriched pathways not found using the standard Hypergeometric analysis including the FAK <it>cytoskeletal remodeling pathway</it>. Different branches of the <it>FAK </it>pathway are distinctly essential in HeLa versus TOV cell lines while other portions are uneffected by siRNA perturbations. Enriched hits belong to protein interactions associated with cell cycle regulation, anti-apoptosis, and signal transduction.</p> <p>Conclusion</p> <p>PIPA provides an analytical framework to interpret siRNA screen data by merging biologically annotated gene sets with the human interactome. As a result we identify pathways and signaling hypotheses that are statistically enriched to effect cell growth in human cell lines. This method provides a complementary approach to standard gene set enrichment that utilizes the additional knowledge of specific interactions within biological gene sets. </p

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

    Interactive Effects of Time, CO\u3csub\u3e2\u3c/sub\u3e, N, and Diversity on Total Belowground Carbon Allocation and Ecosystem Carbon Storage in a Grassland Community

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    Predicting if ecosystems will mitigate or exacerbate rising CO2 requires understanding how elevated CO2 will interact with coincident changes in diversity and nitrogen (N) availability to affect ecosystem carbon (C) storage. Yet achieving such understanding has been hampered by the difficulty of quantifying belowground C pools and fluxes. Thus, we used mass balance calculations to quantify the effects of diversity, CO2, and N on both the total amount of C allocated belowground by plants (total belowground C allocation, TBCA) and ecosystem C storage in a periodically burned, 8-year Minnesota grassland biodiversity, CO2, and N experiment (BioCON). Annual TBCA increased in response to elevated CO2, enriched N, and increasing diversity. TBCA was positively related to standing root biomass. After removing the influence of root biomass, the effect of elevated CO2 remained positive, suggesting additional drivers of TBCA apart from those that maintain high root biomass. Removing root biomass effects resulted in the effects of N and diversity becoming neutral or negative (depending on year), suggesting that the positive effects of diversity and N on TBCA were related to treatmentdriven differences in root biomass. Greater litter production in high diversity, elevated CO2, and enhanced N treatments increased annual ecosystem C loss in fire years and C gain in non-fire years, resulting in overall neutral C storage rates. Our results suggest that frequently burned grasslands are unlikely to exhibit enhanced C sequestration with increasing atmospheric CO2 levels or N deposition

    Comorbidity and dementia: a scoping review of the literature.

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    BACKGROUND: Evidence suggests that amongst people with dementia there is a high prevalence of comorbid medical conditions and related complaints. The presence of dementia may complicate clinical care for other conditions and undermine a patient's ability to manage a chronic condition. The aim of this study was to scope the extent, range and nature of research activity around dementia and comorbidity. METHODS: We undertook a scoping review including all types of research relating to the prevalence of comorbidities in people with dementia; current systems, structures and other issues relating to service organisation and delivery; patient and carer experiences; and the experiences and attitudes of service providers. We searched AMED, Cochrane Library, CINAHL, PubMed, NHS Evidence, Scopus, Google Scholar (searched 2012, Pubmed updated 2013), checked reference lists and performed citation searches on PubMed and Google Scholar (ongoing to February 2014). RESULTS: We included 54 primary studies, eight reviews and three guidelines. Much of the available literature relates to the prevalence of comorbidities in people with dementia or issues around quality of care. Less is known about service organisation and delivery or the views and experiences of people with dementia and their family carers. There is some evidence that people with dementia did not have the same access to treatment and monitoring for conditions such as visual impairment and diabetes as those with similar comorbidities but without dementia. CONCLUSIONS: The prevalence of comorbid conditions in people with dementia is high. Whilst current evidence suggests that people with dementia may have poorer access to services the reasons for this are not clear. There is a need for more research looking at the ways in which having dementia impacts on clinical care for other conditions and how the process of care and different services are adapting to the needs of people with dementia and comorbidity. People with dementia should be included in the debate about the management of comorbidities in older populations and there needs to be greater consideration given to including them in studies that focus on age-related healthcare issues
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