Self reporting RNA probes as an alternative to cleavable small molecule mass tags

The large size of biological molecules such as proteins and oligonucleotides makes them inherently problematic to analyse and quantify directly by mass spectrometry. For these molecules, electrospray ionisation produces multiply charged species and associated alkali metal adducts which can reduce sensitivity and complicate quantification. Whereas time-of-flight mass analysers, often coupled to matrix-assisted laser desorption/ionisation, can have insufficient mass resolution to resolve these large molecules in the higher m/z range. This has led to the development of cleavable small molecule mass tag approaches for the indirect analysis of biomolecules such as proteins and oligonucleotides. Existing methodologies require the design and synthesis of a cleavable linker to join the biomolecule and the mass tag. Here, an alternative approach to small molecule mass tags is presented, which exploits the properties of the RNA molecule to afford self-reporting probes which can be easily synthesised using automated phosphoramidite chemistry. The sugar-phosphate backbone of RNA was used as a built-in enzyme cleavable linker and through the use of RNase digestion of bromine labelled oligonucleotides the observation of a range of small molecule mass tags by mass spectrometry is demonstrated. This study provides a proof-of-concept that RNase digestion can be used to produce labelled small molecule mass tags from oligonucleotide probes, thus eliminating the need for custom design and synthesis of a cleavable linker

Interobserver Agreement in the Diagnosis of Stroke Type

Interobserver Agreement is Essential to the Reliability of Clinical Data from Cooperative Studies and Provides the Foundation for Applying Research Results to Clinical Practice. in the Stroke Data Bank, a Large Cooperative Study of Stroke, We Sought to Establish the Reliability of a Key Aspect of Stroke Diagnosis: The Mechanism of Stroke. Seventeen Patients Were Evaluated by Six Neurologists. Interobserver Agreement Was Measured When Diagnosis Was based on Patient History and Neurologic Examination Only, as Well as When It Was based on Results of a Completed Workup, Including a Computed Tomographic Scan. Initial Clinical Impressions, based Solely on History and One Neurologic Examination, Were Fairly Reliable in Establishing the Mechanism of Stroke (Ie, Distinguishing among Infarcts, Subarachnoid Hemorrhages, and Parenchymatous Hemorrhages). Classification into One of Nine Stroke Subtypes Was Substantially Reliable When Diagnoses Were based on a Completed Workup. Compared with Previous Findings for the Same Physicians and Patients, the Diagnosis of Stroke Type Was Generally More Reliable Than Individual Signs and Symptoms. These Results Suggest that Multicentered Studies Can Rely on the Independent Diagnostic Choices of Several Physicians When Common Definitions Are Employed and Data from a Completed Workup Are Available. Furthermore, Reliability May Be Less for Individual Measurements Such as Signs or Symptoms Than for More-Complex Judgments Such as Diagnoses. © 1986, American Medical Association. All Rights Reserved

Interobserver Reliability in the Interpretation of Computed Tomographic Scans of Stroke Patients

Interobserver Reliability in Interpretation of Computed Tomographic Images Was Studied by Six Senior Neurologists Who Independently Evaluated on a Standardized Stroke Data Bank Form the Brain Lesions of 17 Patients. the Results Analyzed with K Statistics Yielded Moderate to Substantial Agreement on Most Items of Interest Including the Stroke Pathology and Anatomy. in General, the Levels of Agreement Were as High as Previously Reported for the Diagnosis of the Mechanism of the Stroke, and Much Higher Than on Many Stroke History Items and Items of Neurologic Examination. Excellent Agreement Was Obtained for the Detection of Infarcts and Intracerebral Hemorrhage, and Substantial Agreement Was Obtained on Whether the Computed Tomographic Images Were Normal or Indicative of Small Deep Infarcts, Superficial and Deep Infarcts, and Aneurysms. the Level of Agreement on Anatomy of the Lesions Was Best for the Frontal, Parietal, and Temporal Lobes, Putamen, Cerebellum, and Subarachnoid Space. Implications for Clinical Research and Diagnosis Are Discussed. © 1987 American Medical Association All Rights Reserved

Interobserver Variability in the Assessment of Neurologic History and Examination in the Stroke Data Bank

Interobserver Reliability in Obtaining Neurologic Histories and Examinations Was Investigated among Neurologists Collaborating in the Stroke Data Bank (SDB). Seventeen In-Hospital Stroke Patients Were Examined by Six Neurologists Experienced in Stroke over the Course of Three Days. Patients Were Examined Twice a Day for Two Successive Days, with Each Patient Seen by Four Different Neurologists. Data Were Recorded on SDB Forms, According to Definitions and Procedures Established for the SDB. Percent Agreement and Κ Coefficients Were Calculated to Assess the Levels of Agreement for Each Item. Important Differences in Levels of Agreement Were Found among Items on Both Neurologic History and Examination. Agreement among Neurologists Was Higher for Neurologic Examination Than for History. Patterns of Agreement for Items with Low Prevalence or with Numerous Unknown Ratings Are Discussed. Improvement in Interobserver Agreement Due to Data Editing for Intra-Observer Consistency Was Shown. © 1985, American Medical Association. All Rights Reserved

Lipid-Based Passivation in Nanofluidics

Stretching DNA in nanochannels is a useful tool for direct, visual studies of genomic DNA at the single molecule level. To facilitate the study of the interaction of linear DNA with proteins in nanochannels, we have implemented a highly effective passivation scheme based on lipid bilayers. We demonstrate virtually complete long-term passivation of nanochannel surfaces to a range of relevant reagents, including streptavidin-coated quantum dots, RecA proteins, and RecA-DNA complexes. We show that the performance of the lipid bilayer is significantly better than that of standard bovine serum albumin-based passivation. Finally, we show how the passivated devices allow us to monitor single DNA cleavage events during enzymatic degradation by DNase I. We expect that our approach will open up for detailed, systematic studies of a wide range of protein-DNA interactions with high spatial and temporal resolution

The State Socialist Mortality Syndrome

Death rates for working-age men in European state socialist countries deviated from general improvements in survival observed in the rest of Europe during the 20th century. The magnitude of structural labor force changes across countries correlates with lagged increases in death rates for men in the working ages. This pattern is consistent with a hypothesis that hyper-development of heavy industry and stagnation (even contraction) of the service sector created anomic conditions leading to unhealthy lifestyles and self-destructive behavior among men moving from primary-sector to secondary-sector occupations. Occupational contrasts within countries similarly show concentration of rising male death rates among blue collar workers. Collapse of state socialist systems produced rapid corrections in labor force structure after 1990, again correlated with a fading of the state socialist mortality syndrome in following decades

Comparing population health in the United States and Canada

<p>Abstract</p> <p>Background</p> <p>The objective of the paper is to compare population health in the United States (US) and Canada. Although the two countries are very similar in many ways, there are potentially important differences in the levels of social and economic inequality and the organization and financing of and access to health care in the two countries.</p> <p>Methods</p> <p>Data are from the Joint Canada/United States Survey of Health 2002/03. The Health Utilities Index Mark 3 (HUI3) was used to measure overall health-related quality of life (HRQL). Mean HUI3 scores were compared, adjusting for major determinants of health, including body mass index, smoking, education, gender, race, and income. In addition, estimates of life expectancy were compared. Finally, mean HUI3 scores by age and gender and Canadian and US life tables were used to estimate health-adjusted life expectancy (HALE).</p> <p>Results</p> <p>Life expectancy in Canada is higher than in the US. For those < 40 years, there were no differences in HRQL between the US and Canada. For the 40+ group, HRQL appears to be higher in Canada. The results comparing the white-only population in both countries were very similar. For a 19-year-old, HALE was 52.0 years in Canada and 49.3 in the US.</p> <p>Conclusions</p> <p>The population of Canada appears to be substantially healthier than the US population with respect to life expectancy, HRQL, and HALE. Factors that account for the difference may include access to health care over the full life span (universal health insurance) and lower levels of social and economic inequality, especially among the elderly.</p

Are hygiene and public health interventions likely to improve outcomes for Australian Aboriginal children living in remote communities? A systematic review of the literature

Background Australian Aboriginal children living in remote communities still experience a high burden of common infectious diseases which are generally attributed to poor hygiene and unsanitary living conditions. The objective of this systematic literature review was to examine the epidemiological evidence for a relationship between various hygiene and public health intervention strategies, separately or in combination, and the occurrence of common preventable childhood infectious diseases. The purpose was to determine what intervention/s might most effectively reduce the incidence of skin, diarrhoeal and infectious diseases experienced by children living in remote Indigenous communities. Methods Studies were identified through systematically searching electronic databases and hand searching. Study types were restricted to those included in Cochrane Collaboration Effective Practice and Organisation of Care Review Group (EPOC) guidelines and reviewers assessed the quality of studies and extracted data using the same guidelines. The types of participants eligible were Indigenous populations and populations of developing countries. The types of intervention eligible for inclusion were restricted to those likely to prevent conditions caused by poor personal hygiene and poor living environments. Results The evidence showed that there is clear and strong evidence of effect of education and handwashing with soap in preventing diarrhoeal disease among children (consistent effect in four studies). In the largest well-designed study, children living in households that received plain soap and encouragement to wash their hands had a 53% lower incidence of diarrhoea (95% CI, 0.35, 0.59). There is some evidence of an effect of education and other hygiene behaviour change interventions (six studies), as well as the provision of water supply, sanitation and hygiene education (two studies) on reducing rates of diarrhoeal disease. The size of these effects is small and the quality of the studies generally poor. Conclusion Research which measures the effectiveness of hygiene interventions is complex and difficult to implement. Multifaceted interventions (which target handwashing with soap and include water, sanitation and hygiene promotion) are likely to provide the greatest opportunity to improve child health outcomes in remote Indigenous communities