Nanoparticle-Assisted Immunoassays for Point-of-Care Testing - With Specific Interest in Minimally Interference-Prone Assays for Cardiac Troponin I

Cardiac troponins (cTn) I and T are the current golden standard biochemical markers in the diagnosis and risk stratification of patients with suspected acute coronary syndrome. During the past few years, novel assays capable of detecting cTn‐concentrations in >50% of apparently healthy individuals have become readily available. With the emerging of these high sensitivity cTn assays, reductions in the assay specificity have caused elevations in the measured cTn levels that do not correlate with the clinical picture of the patient. The increased assay sensitivity may reveal that various analytical interference mechanisms exist. This doctoral thesis focused on developing nanoparticle‐assisted immunometric assays that could possibly be applied to an automated point‐of‐care system. The main objective was to develop minimally interference‐prone assays for cTnI by employing recombinant antibody fragments. Fast 5‐ and 15‐minute assays for cTnI and D‐dimer, a degradation product of fibrin, based on intrinsically fluorescent nanoparticles were introduced, thus highlighting the versatility of nanoparticles as universally applicable labels. The utilization of antibody fragments in different versions of the developed cTnI‐assay enabled decreases in the used antibody amounts without sacrificing assay sensitivity. In addition, the utilization of recombinant antibody fragments was shown to significantly decrease the measured cTnI concentrations in an apparently healthy population, as well as in samples containing known amounts of potentially interfering factors: triglycerides, bilirubin, rheumatoid factors, or human anti‐mouse antibodies. When determining the specificity of four commercially available antibodies for cTnI, two out of the four cross‐reacted with skeletal troponin I, but caused crossreactivity issues in patient samples only when paired together. In conclusion, the results of this thesis emphasize the importance of careful antibody selection when developing cTnI assays. The results with different recombinant antibody fragments suggest that the utilization of antibody fragments should strongly be encouraged in the immunoassay field, especially with analytes such as cTnI that require highly sensitive assay approaches.

How Were Conflicts of Interest Handled?

Conflicts of interest were potentially great but they were minimized by the great conviction from both Doctors and Health Ministry that something had to be done to improve data on perinatal health. To decrease the number of hospitals where deliveries took place, to concentrate doctors, nurses and equipment, to define staff and to acquire equipment and to train nurses and paediatricians was the way. One the point of view of cost-effectiveness, centralization of expensive technologies, and development of expertise concentrating cases in a same centre - Surgery, VLBW, etc- and lowering mortality rates and get better outcomes were clear health gains. In 1989 after the political decision of closing small maternities the committee return to villages and cities to explain to political local power and people, the decision, which kind of care they will have in the future, why and expected gains. Level I hospitals and Health Centers stop to have deliveries; Health Centers were given a great responsibility: the follow up of the most part of the normal pregnancies by GP. There was no economic pressure because the National Health Service is free, there are no economic incentives for obstetrical or neonatal care, hospitals are financed through ICD, hospital level is defined according to both delivery and newborn care. In 1989 the rule was “No results can be obtained without the interested and responsible participation of all – institutions and people”. At that time the emphasis was on training. There are geographic influences on regionalization for example for islands and inner and far geographic areas. Also we would like to emphasize the influence of demographics on regionalization. As birth rate continues to decrease the hospitals left open 20 years ago with more than 1500 deliveries have to be closed now because the number of deliveries decreased. It was much more difficult and unacceptable to close some few maternities now than 20 years ago. All the difference was that at that time reasons were explained and now it was a Minister order. Other fearful events are the opening of private hospitals, the lowering gross national income, the economic difficulties and financial problems.

Conflict of Interest Policies at Canadian Universities and Medical Schools: Some Lessons from the AMSA PharmFree Scorecard

Article

Tobit estiamtion with unknown point of censoring with an application to milk market participation in the Ethiopian highlands

Data augmentation is a powerful technique for estimating models with latent or missing data, but applications in agricultural economics have thus far been few. This paper showcases the technique in an application to data on milk market participation in the Ethiopian highlands. There, a key impediment to economic development is an apparently low rate of market participation. Consequently, economic interest centers on the “locations” of nonparticipants in relation to the market and their “reservation values” across covariates. These quantities are of policy interest because they provide measures of the additional inputs necessary in order for nonparticipants to enter the market. One quantity of primary interest is the minimum amount of surplus milk (the “minimum efficient scale of operations”) that the household must acquire before market participation becomes feasible. We estimate this quantity through routine application of data augmentation and Gibbs sampling applied to a random-censored Tobit regression. Incorporating random censoring affects markedly the marketable-surplus requirements of the household, but only slightly the covariates requirements estimates and, generally, leads to more plausible policy estimates than the estimates obtained from the zero-censored formulation

INFERENCES FOR THE CHANGE-POINT OF THE EXPONENTIATED WEIBULL HAZARD FUNCTION

In many applications of lifetime data analysis, it is important to perform inferences about the change-point of the hazard function. The change-point could be a maximum for unimodal hazard functions or a minimum for bathtub forms of hazard functions and is usually of great interest in medical or industrial applications. For lifetime distributions where this change-point of the hazard function can be analytically calculated, its maximum likelihood estimator is easily obtained from the invariance properties of the maximum likelihood estimators. From the asymptotical normality of the maximum likelihood estimators, confidence intervals can also be obtained. Considering the exponentiated Weibull distribution for the lifetime data, we have different forms for the hazard function: constant, increasing, unimodal, decreasing or bathtub forms. This model gives great flexibility of fit, but we do not have analytic expressions for the change-point of the hazard function. In this way, we consider the use of Markov Chain Monte Carlo methods to get posterior summaries for the change-point of the hazard function considering the exponentiated Weibull distribution.

Optimisation of chemical lysis protocol for point-of-care leukocyte differentiation

The full blood cell (FBC) count is the most common indicator of diseases. At present hematology analyzers are used for the blood cell characterization, but, recently, there has been interest in using techniques that take advantage of microscale devices and intrinsic properties of cells for increased automation and decreased cost. Microfluidic technologies offer solutions to handling and processing small volumes of blood (2-50 uL taken by finger prick) for point-of-care(PoC) applications. Several PoC blood analyzers are in use and may have applications in the fields of telemedicine, out patient monitoring and medical care in resource limited settings. They have the advantage to be easy to move and much cheaper than traditional analyzers, which require bulky instruments and consume large amount of reagents. The development of miniaturized point-of-care diagnostic tests may be enabled by chip-based technologies for cell separation and sorting. Many current diagnostic tests depend on fractionated blood components: plasma, red blood cells (RBCs), white blood cells (WBCs), and platelets. Specifically, white blood cell differentiation and counting provide valuable information for diagnostic purposes. For example, a low number of WBCs, called leukopenia, may be an indicator of bone marrow deficiency or failure, collagen- vascular diseases, disease of the liver or spleen. The leukocytosis, a high number of WBCs, may be due to anemia, infectious diseases, leukemia or tissue damage. In the laboratory of hybrid biodevices, at the University of Southampton,it was developed a functioning micro impedance cytometer technology for WBC differentiation and counting. It is capable to classify cells and particles on the base of their dielectric properties, in addition to their size, without the need of labeling, in a flow format similar to that of a traditional flow cytometer. It was demonstrated that the micro impedance cytometer system can detect and differentiate monocytes, neutrophils and lymphocytes, which are the three major human leukocyte populations. The simplicity and portability of the microfluidic impedance chip offer a range of potential applications in cell analysis including point-of-care diagnostic systems. The microfluidic device has been integrated into a sample preparation cartridge that semi-automatically performs erythrocyte lysis before leukocyte analysis. Generally erythrocytes are manually lysed according to a specific chemical lysis protocol, but this process has been automated in the cartridge. In this research work the chemical lysis protocol, defined in the patent US 5155044 A, was optimized in order to improve white blood cell differentiation and count performed by the integrated cartridge.

Partnership in times of crisis: challenges for the Eastern European countries' integration with Europe. OSW Point of View Number 36, July 2013

Over the four years since its launch, the Eastern Partnership initiative has created frameworks and mechanisms for the integration of Eastern Partnership countries with the European Union. Despite this, the partner countries have so far made little meaningful progress in modernisation, implementation of reforms or integration with the EU.Since the European Neighbourhood Policy was launched in 2004, the situation in areas of key importance for the EU, such as democratisation, free-market transformations, European integration, political stability and regional security, has not improved significantly. In this context, it is legitimate to ask questions about the extent to which the European Neighbourhood Policy and the Eastern Partnership have brought the Union closer to achieving its declared objectives in the relations with eastern neighbours. What is the underlying cause of the dwindling involvement and declining interest in achieving real progress in integration? How may the events that have been dominating the political agenda – i.e. the EU’s financial crisis, the debate on the future of the Union, but also the political processes taking place within the partner countries – affect the future of mutual relations?

The Pro-Western Turn in Russia's Foreign Policy: Causes, Consequences and Prospects. OSW Point of View, September 2002

From Europe and Poland's point of view, one of the most important recent developments in international politics was the re-orientation of Russia's foreign policy. This paper aims to answer three important questions relating to this issue: 4. When and why did the "pro-Western turn" in the Russian Federation's policy take place? 5. Has it been profitable for Russia? 6. What goals will the Russian policy pursue in the future? An analysis of the last two years in Russia's foreign policy leads to the several conclusions, including those: 5. Clearly, the Russian leaders realise that in the longer term, Russia - in its desire for more influence in the world - will not be able to survive as an independent pole of power in international politics and it will have to join forces with the West (most likely, the European Union). 6. September 11 was not the cause of Russia's pro-Western turn, but rather a catalyst that put the process which started when Vladimir Putin took his office in sharp focus. 7. In the nearest future, this new direction of Russia's foreign policy seems not be challenged by internal opposition in Russia. 8. The "pro-Western turn" proved to be beneficial for Russia, although: d. Russia has not become a strategic ally of the US e. There has been no breakthrough in the relations between Russia and the European Union, and Moscow has not gained any real influence on NATO's important decisions. f. Russia has not become a major decision-maker of international politics. 5. Russia's closing to the West is in Poland's and Europe's interest.

Belarus-Russia: Whither Integration? OSW Point of View (unspecified), May 2003

Of the re-integration processes currently taking place in the former Soviet Union, the formation of a Russian-Belarusian so-called 'Union State' is one of the most advanced. A customs union was formally announced between the two countries as early as 1995 and the process of constructing the Union State itself was launched in December 1999. However, both events were largely driven by the perceived need to match societal demands, without much concrete action and the Union State remained largely 'virtual'. Only in the last few years has the Russian initiative allowed for moving from symbolic gestures to political action and since late 2002 debate and policy have intensified on specific issues of economic and political co-operation. However, despite such advances in the integration process, its objectives remain vague and there is little or no agreement on the principles that should govern the process. Furthermore, current bilateral relations questions still dominate the dialogue. The project seems at present to be driven mainly by the political interests of both countries' presidents and also, to a lesser extent, by the interests of business, political, military and security elites, each apparently motivated by self- and group-interest in the emerging dialogue of integration. In contrast to EU integration, the societies of the two countries involved appear to have had little or no say in the process. Thus, several questions naturally arise. What is the real nature of such integration? What motivates the parties involved? What stage has the process reached? What likely future course will it take? What might be the consequences of it for Belarusian independence? Answers to these questions should ultimately determine the stance and policies of the enlarged EU in this area.

The "Pro-Western Turn" in Russia's Foreign Policy: Causes, Consequences and Prospects. OSW Point of View (unspecified), September 2002

From Europe and Poland's point of view, one of the most important recent developments in international politics was the re-orientation of Russia's foreign policy. This paper aims to answer three important questions relating to this issue: 1. When and why did the "pro-Western turn" in the Russian Federation's policy take place? 2. Has it been profitable for Russia? 3. What goals will the Russian policy pursue in the future? An analysis of the last two years in Russia's foreign policy leads to the several conclusions, including those: a. Clearly, the Russian leaders realise that in the longer term, Russia - in its desire for more influence in the world - will not be able to survive as an independent pole of power in international politics and it will have to join forces with the West (most likely, the European Union). b. September 11 was not the cause of Russia's pro-Western turn, but rather a catalyst that put the process which started when Vladimir Putin took his office in sharp focus. 7. In the nearest future, this new direction of Russia's foreign policy seems not be challenged by internal opposition in Russia. c. The "pro-Western turn" proved to be beneficial for Russia, although: d. Russia has not become a strategic ally of the US e. There has been no breakthrough in the relations between Russia and the European Union, and Moscow has not gained any real influence on NATO's important decisions. f. Russia has not become a major decision-maker of international politics. g. Russia's closing to the West is in Poland's and Europe's interest.

Point of view filming and the elicitation interview

Face-to-face interviews are a fundamental research tool in qualitative research. Whilst this form of data collection can provide many valuable insights, it can often fall short of providing a complete picture of a research subject's experiences. Point of view (PoV) interviewing is an elicitation technique used in the social sciences as a means of enriching data obtained from research interviews. Recording research subjects' first person perspectives, for example by wearing digital video glasses, can afford deeper insights into their experiences. PoV interviewing can promote making visible the unverbalizable and does not rely as much on memory as the traditional interview. The use of such relatively inexpensive technology is gaining interest in health profession educational research and pedagogy, such as dynamic simulation-based learning and research activities. In this interview, Dr Gerry Gormley (a medical education researcher) talks to Dr Jonathan Skinner (an anthropologist with an interest in PoV interviewing), exploring some of the many crossover implications with PoV interviewing for medical education research and practice.

On Seliger and Whitham`s variational principle for hydrodynamic systems from the point of view of `fictitious particles`

FAPESP, the Sao Paulo State Research Foundation[04/04611-5]

The economic determinants of the Brazilian nominal term structure of interest rates

The purpose of this study is to identify the effects of monetary policy and macroeconomic shocks on the dynamics of the Brazilian term structure of interest rates. We estimate a near-VAR model under the identification scheme proposed by Christiano et al. (1996, 1999). The results resemble those of the US economy: monetary policy shocks that flatten the term structure of interest rates. We find that monetary policy shocks in Brazil explain a significantly larger share of the dynamics of the term structure than in the USA. Finally, we analyse the importance of standard macroeconomic variables (e. g. GDP, inflation and measure of country risk) to the dynamics of the term structure in Brazil.

Analyzing the connectivity between regions of interest: An approach based on cluster Granger causality for NRI data analysis

The identification, modeling, and analysis of interactions between nodes of neural systems in the human brain have become the aim of interest of many studies in neuroscience. The complex neural network structure and its correlations with brain functions have played a role in all areas of neuroscience, including the comprehension of cognitive and emotional processing. Indeed, understanding how information is stored, retrieved, processed, and transmitted is one of the ultimate challenges in brain research. In this context, in functional neuroimaging, connectivity analysis is a major tool for the exploration and characterization of the information flow between specialized brain regions. In most functional magnetic resonance imaging (fMRI) studies, connectivity analysis is carried out by first selecting regions of interest (ROI) and then calculating an average BOLD time series (across the voxels in each cluster). Some studies have shown that the average may not be a good choice and have suggested, as an alternative, the use of principal component analysis (PCA) to extract the principal eigen-time series from the ROI(s). In this paper, we introduce a novel approach called cluster Granger analysis (CGA) to study connectivity between ROIs. The main aim of this method was to employ multiple eigen-time series in each ROI to avoid temporal information loss during identification of Granger causality. Such information loss is inherent in averaging (e.g., to yield a single ""representative"" time series per ROI). This, in turn, may lead to a lack of power in detecting connections. The proposed approach is based on multivariate statistical analysis and integrates PCA and partial canonical correlation in a framework of Granger causality for clusters (sets) of time series. We also describe an algorithm for statistical significance testing based on bootstrapping. By using Monte Carlo simulations, we show that the proposed approach outperforms conventional Granger causality analysis (i.e., using representative time series extracted by signal averaging or first principal components estimation from ROIs). The usefulness of the CGA approach in real fMRI data is illustrated in an experiment using human faces expressing emotions. With this data set, the proposed approach suggested the presence of significantly more connections between the ROIs than were detected using a single representative time series in each ROI. (c) 2010 Elsevier Inc. All rights reserved.

Orbitofrontal cortex gray matter volumes in bipolar disorder patients: a region-of-interest MRI study

Objectives: Functional and postmortem studies suggest that the orbitofrontal cortex (OFC) is involved in the pathophysiology of bipolar disorder (BD). This anatomical magnetic resonance imaging (MRI) study examined whether BD patients have smaller OFC gray matter volumes compared to healthy comparison subjects (HC). Methods: Twenty-eight BD patients were compared to 28 age- and gender-matched HC. Subjects underwent a 1.5T MRI with 3D spoiled gradient recalled acquisition. Total OFC and medial and lateral subdivisions were manually traced by a blinded examiner. Images were segmented and gray matter volumes were calculated using an automated method. Results: Analysis of covariance, with intracranial volume as covariate, showed that BD patients and HC did not differ in gray matter volumes of total OFC or its subdivisions. However, total OFC gray matter volume was significantly smaller in depressed patients (n = 10) compared to euthymic patients (n = 18). Moreover, total OFC gray matter volumes were inversely correlated with depressive symptom intensity, as assessed by the Hamilton Depression Rating Scale. OFC gray matter volumes were not related to lithium treatment, age at disease onset, number of episodes, or family history of mood disorders. Conclusions: Our results suggest that abnormal OFC gray matter volumes are not a pervasive characteristic of BD, but may be associated with specific clinical features of the disorder.