194 research outputs found

    Ternatin and improved synthetic variants kill cancer cells by targeting the elongation factor-1A ternary complex.

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    Cyclic peptide natural products have evolved to exploit diverse protein targets, many of which control essential cellular processes. Inspired by a series of cyclic peptides with partially elucidated structures, we designed synthetic variants of ternatin, a cytotoxic and anti-adipogenic natural product whose molecular mode of action was unknown. The new ternatin variants are cytotoxic toward cancer cells, with up to 500-fold greater potency than ternatin itself. Using a ternatin photo-affinity probe, we identify the translation elongation factor-1A ternary complex (eEF1AĀ·GTPĀ·aminoacyl-tRNA) as a specific target and demonstrate competitive binding by the unrelated natural products, didemnin and cytotrienin. Mutations in domain III of eEF1A prevent ternatin binding and confer resistance to its cytotoxic effects, implicating the adjacent hydrophobic surface as a functional hot spot for eEF1A modulation. We conclude that the eukaryotic elongation factor-1A and its ternary complex with GTP and aminoacyl-tRNA are common targets for the evolution of cytotoxic natural products

    Tales from the EMR: Does a 21st-Century Data Warehouse Facilitate Clinical Research for Pancreatic Cancer?

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    Background: The importance of an electronic medical record has been highlighted for both clinical care and research. In the current era, data warehouses and repositories have been established to serve the dual function of patient care and investigation. Purpose: The aim of this study was to compare a newly developed institutional clinical data warehouse, linked with the hospital information system (HIS), to a prospectively-maintained departmental database. Methods: A novel HIS-linked institutional clinical data warehouse was queried for 9 primary and secondary ICD-9-CM discharge diagnosis codes for pancreatic cancer. The database captured inpatient and outpatient clinical and billing information from a pool of over 2 million patients evaluated at an academic medical institution and its affiliates since 1995. A cohort was identified; following Institutional Review Board approval, demographic and clinical data was obtained. This data was compared to a manually-entered and prospectively-maintained surgical oncology database of the same institution, tracking 394 patients since 1999. Duplicated patients, and those unique to either dataset, were flagged. Patients with diagnosis dates prior to 1999 were excluded to allow comparison over the same time period. For validation purposes, a 10% random sample of remaining patients unique to each dataset underwent manual review of medical records including clinic notes, admission/discharge notes, diagnostic imaging, and pathology reports. Results: 1107 patients were identified from the HIS-linked dataset with pancreatic neoplasm-associated diagnosis codes dating from 1999 to 2009. Of these, 254 (22.9%) were captured in both datasets, while 853 (77.1%) were only in the HIS-linked dataset. Manual review of the 10% subset of the HIS-only group demonstrated that 55.6% of patients were without identifiable pancreatic pathology, suggesting miscoding, while 31.7% had diagnoses consistent with pancreatic neoplasm, and 12.7% had pseudocyst or pancreatitis. Of the 394 patients tracked by surgical oncology, 254 (64.5%) were captured in both datasets, while 140 (35.5%) had not been captured in the HIS-linked dataset. Manual review of the 10% subset of the non-captured patients demonstrated 93.3% with pancreatic neoplasm and 6.7% with pseudocyst or pancreatitis. Lastly, a review of the 10% subset of the 254 patient overlap demonstrated that 87.5% of patients were with pancreatic neoplasm, 8.3% with pseudocyst or pancreatitis, and 4.2% without pancreatic pathology. Conclusions: While technological advances provide a powerful means to automate institutional-level cohort identification and data collection, a high degree of misclassification may be present if queries are based solely on ICD-9-CM discharge codes. For that reason, careful validation and data cleaning are critical steps prior to research use. These results also suggest cautious interpretation of national-level administrative data utilizing ICD-9-CM diagnosis codes. Our findings suggest that the current state-of-the-art data warehouses continue to require clinical correlation and validation through traditional retrospective mechanisms

    Foregut Surgery in the Modern Era: A National Survey

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    Background: Foregut surgery is technically complex. In recent years, increasing attention has been paid to high-stakes surgery outcomes, including mortality and complications. In addition, the use of advanced technology including minimally invasive approaches has been introduced. The current study aims to determine national trends in utilization and outcomes of potentially curative cancer resections of the foregut, including esophagus, stomach, liver, and pancreas. Methods: The Nationwide Inpatient Sample was queried to identify all esophageal, gastric, liver and pancreas resections performed for cancer during 1998-2009. Annual incidence, major in-hospital postoperative complications, length of stay and in-hospital mortality were evaluated. Univariate and multivariate analysis performed by chi square and logistic regression. For all comparisons, p-values Results: 298,871 patients (nationally-weighted) underwent cancer directed foregut surgery 1998-2009. Of those 19,002 (6%) were esophagectomies, 123,198 (41%) were gastrectomies, 62,313 (21%) were hepatectomies and 94,358 (32%) were pancreatectomies. From early years (1998-2000) to late years (2007-2009) use of laparoscopy in foregut surgery increased from 3% to 5%. Laparoscopy in esophagectomy increased the most from 1% to 5%, while its use in hepatectomy remained unchanged at 4%. Gastrectomy and pancreatectomy involving minimally invasive techniques increased from 2% to 5% and 5% to 6%, respectively. For all four foregut surgery types, patient comorbidities increased over time; patients with ā‰„2 major comorbidities increased from 53% to 64%. Conversely, patient mortality and length of stay (LOS) decreased over time. However, we observed an increase in complications for all sites combined from 22.8% to 24.4%. Laparoscopy was not significantly associated with decreased complications, but was associated with lower mortality when compared to open resection alone 3.1% vs. 5%. Independent predictors of increased complications included older age, gender, higher comorbidity, hospital volume. Older age, male sex, higher comorbidity, low volume center and non-use of laparoscopy were independent predictors of in-hospital mortality. Conclusion: Foregut surgery in the modern era is being increasingly deployed on sicker patients. While decreased in-hospital mortality and LOS are commendable, complication rates remain substantial and nondecreasing. Minimally invasive techniques have minor but increasing penetrance in foregut surgery. Our results suggest comparable advances and potential pitfalls among major types of foregut surgery in the current era

    Kinetic intermediates in amyloid assembly

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    In contrast to an expected Ostwald-like ripening of amyloid assemblies, the nucleating core of the Dutch mutant of the AĪ² peptide of Alzheimerā€™s disease assembles through a series of conformational transitions. Structural characterization of the intermediate assemblies by isotope-edited IR and solid-state NMR reveals unexpected strand orientation intermediates and suggests new nucleation mechanisms in a progressive assembly pathway

    Is pancreatic cancer palliatable? A national study

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    Background: Pancreatic cancer is frequently diagnosed at advanced stages where potentially curative resection is no longer possible. Palliative procedures can be performed; however, results on a national level are unknown. This study examines pancreatic cancer patients who underwent potentially palliative procedures including gastric bypass, biliary bypass surgery, celiac block, biliary stent, gastrostomy or jejunostomy, and examines post-intervention complications and 30-day mortality. Methods: SEER-Medicare 1991-2005 was used to identify patients with Stage 3-4 pancreatic cancer. Complication rates were calculated including post-op infection, myocardial infarction, aspiration pneumonia, DVT/PE, pulmonary compromise, gastric bleed, acute renal failure, and reoperation. Kaplan-Meier survival analysis was performed. Finally, Cox proportional hazards modeling was used to control for the effects of age, sex, race, stage, and resection. Results: Of 22,314 pancreatic cancer patients, 858 (3.9%) patients were Stage 3, and 11,149 (50.0%) stage 4. Post-procedure median survival for all patients is approximately two months, with longest survival for biliary bypass patients (3.2mo, 95% CI(2.9-3.7), and lowest survival for jejunostomy 1.3 mo (1.2-1.5) and gastrostomy 1.5 mo (1.4-1.8). Post-procedure 30-day mortality was highest for gastrostomy patients at 41.5%; followed by jejunostomy (39.1%), celiac plexus block (30.0%), gastric bypass (23.8%), biliary bypass (17.8%), and biliary stent (21.2%). The rate of complications averaged 40%, with highest rate for gastrostomy (47.4%) and gastric bypass (45.3%) and lowest for celiac plexus block (29.3%). Stage 4 disease was an independent predictor of death for patients undergoing five out of six procedures. Conclusion: We found that morbidity and mortality of palliative procedures in unresectable pancreatic cancer is high, especially in stage 4 patients. Further studies need to be conducted to identify patients who will have sufficient expected post-procedure survival to benefit from these palliative interventions

    Itā€™s RAINing : Remotely Accessible Instruments in Nanotechnology to Promote Student Success

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    Remotely Accessible Instruments in Nanotechnology (RAIN) is a community of educators that aims to bring advanced technologies into K-12 and college classrooms via remote access. RAIN\u27s mission is to facilitate the study of nanoscale science by lowering barriers for instructors to deliver relevant educational activities for younger students interested in learning about nanotechnology across traditional STEM fields. Additionally, RAIN engages the next generation STEM workforce with a connection to experts, tools and institutions where cutting-edge research is being performed. This resource is particularly vital for underrepresented and minority students, especially those attending institutions that cannot provide on-site access to advanced technologies. Currently the RAIN network consists of ten sites across the United States and offers its services free of charge to make STEM education more accessible to the students that would otherwise not encounter these resources. Data shows that RAIN is effective at fostering a passion for the sciences when used in K-12 thru college curricula

    Outbreak of Neisseria meningitidis capsular group W among scouts returning from the World Scout Jamboree, Japan, 2015

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    The 23rd World Scout Jamboree was held in Japan from 28 July to 8 August 2015 and was attended by over 33,000 scouts from 162 countries. An outbreak of invasive meningococcal disease capsular group W was investigated among participants, with four confirmed cases identified in Scotland, who were all associated with one particular scout unit, and two confirmed cases in Sweden; molecular testing showed the same strain to be responsible for illness in both countries. The report describes the public health action taken to prevent further cases and the different decisions reached with respect to how wide to extend the offer of chemoprophylaxis in the two countries; in Scotland, chemoprophylaxis was offered to the unit of 40 participants to which the four cases belonged and to other close contacts of cases, while in Sweden chemoprophylaxis was offered to all those returning from the Jamboree. The report also describes the international collaboration and communication required to investigate and manage such multinational outbreaks in a timely manner

    Appropriate disclosure of a diagnosis of dementia : identifying the key behaviours of 'best practice'

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    Background: Despite growing evidence that many people with dementia want to know their diagnosis, there is wide variation in attitudes of professionals towards disclosure. The disclosure of the diagnosis of dementia is increasingly recognised as being a process rather than a one-off behaviour. However, the different behaviours that contribute to this process have not been comprehensively defined. No intervention studies to improve diagnostic disclosure in dementia have been reported to date. As part of a larger study to develop an intervention to promote appropriate disclosure, we sought to identify important disclosure behaviours and explore whether supplementing a literature review with other methods would result in the identification of new behaviours. Methods: To identify a comprehensive list of behaviours in disclosure we conducted a literature review, interviewed people with dementia and informal carers, and used a consensus process involving health and social care professionals. Content analysis of the full list of behaviours was carried out. Results: Interviews were conducted with four people with dementia and six informal carers. Eight health and social care professionals took part in the consensus panel. From the interviews, consensus panel and literature review 220 behaviours were elicited, with 109 behaviours over-lapping. The interviews and consensus panel elicited 27 behaviours supplementary to the review. Those from the interviews appeared to be self-evident but highlighted deficiencies in current practice and from the panel focused largely on balancing the needs of people with dementia and family members. Behaviours were grouped into eight categories: preparing for disclosure; integrating family members; exploring the patient's perspective; disclosing the diagnosis; responding to patient reactions; focusing on quality of life and well-being; planning for the future; and communicating effectively. Conclusion: This exercise has highlighted the complexity of the process of disclosing a diagnosis of dementia in an appropriate manner. It confirms that many of the behaviours identified in the literature (often based on professional opinion rather than empirical evidence) also resonate with people with dementia and informal carers. The presence of contradictory behaviours emphasises the need to tailor the process of disclosure to individual patients and carers. Our combined methods may be relevant to other efforts to identify and define complex clinical practices for further study.This project is funded by UK Medical Research Council, Grant reference number G0300999

    Ecological distribution and population physiology defined by proteomics in a natural microbial community

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    Community proteomics applied to natural microbial biofilms resolves how the physiology of different populations from a model ecosystem change with measured environmental factors in situ.The initial colonists, Leptospirillum Group II bacteria, persist throughout ecological succession and dominate all communities, a pattern that resembles community assembly patterns in some macroecological systems.Interspecies interactions, and not abiotic environmental factors, demonstrate the strongest correlation to physiological changes of Leptospirillum Group II.Environmental niches of subdominant populations seem to be determined by combinations of specific sets of abiotic environmental factors
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