47 research outputs found

    Separating Lentiviral Vector Injection and Induction of Gene Expression in Time, Does Not Prevent an Immune Response to rtTA in Rats

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    BACKGROUND: Lentiviral gene transfer can provide long-term expression of therapeutic genes such as erythropoietin. Because overexpression of erythropoietin can be toxic, regulated expression is needed. Doxycycline inducible vectors can regulate expression of therapeutic transgenes efficiently. However, because they express an immunogenic transactivator (rtTA), their utility for gene therapy is limited. In addition to immunogenic proteins that are expressed from inducible vectors, injection of the vector itself is likely to elicit an immune response because viral capsid proteins will induce "danger signals" that trigger an innate response and recruit inflammatory cells. METHODOLOGY AND PRINCIPAL FINDINGS: We have developed an autoregulatory lentiviral vector in which basal expression of rtTA is very low. This enabled us to temporally separate the injection of virus and the expression of the therapeutic gene and rtTA. Wistar rats were injected with an autoregulatory rat erythropoietin expression vector. Two or six weeks after injection, erythropoietin expression was induced by doxycycline. This resulted in an increase of the hematocrit, irrespective of the timing of the induction. However, most rats only responded once to doxycycline administration. Antibodies against rtTA were detected in the early and late induction groups. CONCLUSIONS: Our results suggest that, even when viral vector capsid proteins have disappeared, expression of foreign proteins in muscle will lead to an immune respons

    Associations Between Eight Earth Observation-Derived Climate Variables and Enteropathogen Infection : An Independent Participant Data Meta-Analysis of Surveillance Studies With Broad Spectrum Nucleic Acid Diagnostics

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    Diarrheal disease, still a major cause of childhood illness, is caused by numerous, diverse infectious microorganisms, which are differentially sensitive to environmental conditions. Enteropathogen-specific impacts of climate remain underexplored. Results from 15 studies that diagnosed enteropathogens in 64,788 stool samples from 20,760 children in 19 countries were combined. Infection status for 10 common enteropathogens-adenovirus, astrovirus, norovirus, rotavirus, sapovirus, Campylobacter, ETEC, Shigella, Cryptosporidium and Giardia-was matched by date with hydrometeorological variables from a global Earth observation dataset-precipitation and runoff volume, humidity, soil moisture, solar radiation, air pressure, temperature, and wind speed. Models were fitted for each pathogen, accounting for lags, nonlinearity, confounders, and threshold effects. Different variables showed complex, non-linear associations with infection risk varying in magnitude and direction depending on pathogen species. Rotavirus infection decreased markedly following increasing 7-day average temperatures-a relative risk of 0.76 (95% confidence interval: 0.69-0.85) above 28 degrees C-while ETEC risk increased by almost half, 1.43 (1.36-1.50), in the 20-35 degrees C range. Risk for all pathogens was highest following soil moistures in the upper range. Humidity was associated with increases in bacterial infections and decreases in most viral infections. Several virus species' risk increased following lower-than-average rainfall, while rotavirus and ETEC increased with heavier runoff. Temperature, soil moisture, and humidity are particularly influential parameters across all enteropathogens, likely impacting pathogen survival outside the host. Precipitation and runoff have divergent associations with different enteric viruses. These effects may engender shifts in the relative burden of diarrhea-causing agents as the global climate changes. Plain Language Summary Diarrheal disease is a big health problem for children. It can be caused by different bugs, which can be caught more easily in certain weather conditions, though not much is understood about this because the climate varies so much from one place to the next. This study combined data from many different countries where diarrhea-causing bugs were diagnosed in children's stool. Satellites recorded what the weather was like on the day each sample was collected. Rotavirus is easiest to catch in cold weather and when water washes over the ground after rain. Dry weather also makes it and other viruses easy to catch. Bacteria spread best when the air is warm and humid, and the soil moist, though one type of E. coli can also be spread in rainwater. Climate change will make dry places drier, wet places wetter and everywhere warmer. This might lead to more diarrhea caused by bacteria and less by viruses in some places, though places with moist soil might see more of every kind of bug.Peer reviewe

    Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

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    Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

    Rising rural body-mass index is the main driver of the global obesity epidemic in adults

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    Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe

    Self-Service Data Preprocessing and Cohort Analysis for Medical Researchers

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    Medical researchers are increasingly interested in data-driven approaches to support informed decisions in many medical areas. They collect data about the patients they treat, often creating their own specialized data tables with more characteristics than what is defined in their clinical information system (CIS). Usually, these data tables or sEHR (small electronical health records) are rather small, maybe containing the data of only hundreds of patients. Medical researchers are struggling to find an easy way to first clean and transform these sEHR, and then create cohorts and perform confirmative or exploratory analysis. This paper introduces a methodology and identifies requirements for building systems for self-service data preprocessing and cohort analysis for medical researchers. We also describe a system based on this methodology and the requirements that shows the benefits of our approach. We further highlight these benefits with an example scenario from our projects with clinicians specialized on head&neck cancer treatment

    Reform of Prescription Drug Reimbursement and Pricing in the German Social Health Insurance Market: A Comparison of Three Scenarios

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    We review regulation of two important parameters for third-party payers and manufacturers of prescription drugs: regulation of reimbursement and pricing. We find that centralised regulation of reimbursement and pricing prevails in the 15 original EU member countries (EU-15) and in European Free Trade Association (EFTA) countries. Compared with countries such as Switzerland, The Netherlands, France and England, regulation in the German social health insurance system is rather unique. First, market approval is nearly always equivalent to reimbursement. Second, manufacturers are free to determine prices but internal reference prices restrict them from actually doing so for generics and therapeutic substitutes. In order to contain rising expenditures for prescription drugs in Germany, and to set incentives for physicians to consider the costs as well as the benefits of prescriptions, three reform scenarios are feasible. The first scenario maintains centralised reimbursement and centralised pricing; the second maintains centralised reimbursement but switches to decentralised pricing (similar to social health insurance in Israel and Medicare in the US). Third-party payers would be able to negotiate with manufacturers about discounts and market shares for genetic and therapeutic substitutes. In the third scenario, pricing and reimbursement would be decentralised (similar to private health insurance in the US). We suggest that the second scenario is a viable compromise between consumer protection and a more competitive and cost-effective market for prescription drugs in German social health insurance and other similar markets for prescription drugs.Health-insurance, Pricing, Regulatory-process, Reimbursement

    Synthetic gene regulation circuits for control of cell expansion

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    A major drawback in the analysis of primary cells and in regenerative sciences concerns the limited number and homogeneity of cells. This limitation could be overcome by in vitro cell expansion that retains the properties of the cell types of interest. However, for most primary differentiated cells the proliferation capacity is finite and/or proliferation is associated with dedifferentiation of cells. We have developed a flexible cell expansion strategy that allows strict and reliable control of cell proliferation. This system relies on synthetic gene modules that employ positive feedback loops based on Tetracycline control. These gene modules were constructed and transduced by lentiviral vectors. We succeeded in the generation of murine and importantly also of human endothelial cell lines. The key feature of the established cell lines is that their proliferation status can be strictly controlled while the expression of relevant markers is maintained. This strict control of proliferation was observed in cell clones and in cell pools and was even maintained when two independent immortalizing genes were simultaneously employed. Thus, this strategy is flexible, easy to handle, and reliable. Most importantly, it allows expansion of human cells with a primary-like phenotyp

    Transgenic blockade of interleukin 6 transsignaling abrogates inflammation

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    The immunoregulatory cytokine Interleukin-6 (IL6) acts in a pro- and anti-inflammatory fashion. Synthesized by myeloid cells, fibroblasts and endothelial cells, IL6 on target cells, binds to the IL6 receptor (IL6R) and signals via complex formation with the ubiquitously expressed gp130 receptor. Paradoxically, most cells, which respond to IL6 during inflammatory states do not express the IL6R and are themselves not directly responsive to the cytokine. A naturally occurring soluble form of the IL6R renders all cells responsive to IL6. This alternative signaling process is called IL6-trans-signaling. Here we developed a transgenic strategy based on the overexpression of the soluble form of gp130, which specifically blocks all IL6 responses mediated by the soluble IL6R but does not affect IL6 responses via the membrane bound IL6R. In these mice, inflammatory processes are blocked as in IL6-/- mice strongly arguing for a major role of the soluble IL6R during inflammation in vivo
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