Preventing overuse of laboratory diagnostics: a case study into diagnosing anaemia in Dutch general practice

BACKGROUND: More information is often thought to improve medical decision-making, which may lead to test overuse. This study assesses which out of 15 laboratory tests contribute to diagnosing the underlying cause of anaemia by general practitioners (GPs) and determines a potentially more efficient subset of tests for setting the correct diagnosis. METHODS: Logistic regression was performed to determine the impact of individual tests on the (correct) diagnosis. The statistically optimal test subset for diagnosing a (correct) underlying cause of anaemia by GPs was determined using data from a previous survey including cases of real-world anaemia patients. RESULTS: Only 9 (60%) of the laboratory tests, and patient age, contributed significantly to the GPs' ability to diagnose an underlying cause of anaemia (CRP, ESR, ferritin, folic acid, haemoglobin, leukocytes, eGFR/MDRD, reticulocytes and serum iron). Diagnosing the correct underlying cause may require just five (33%) tests (CRP, ferritin, folic acid, MCV and transferrin), and patient age. CONCLUSIONS: In diagnosing the underlying cause of anaemia a subset of five tests has most added value. The real-world impact of using only this subset should be further investigated. As illustrated in this case study, a statistical approach to assessing the added value of tests may reduce test overuse

Long-term outcomes in patients newly diagnosed with iron deficiency anaemia in general practice: A retrospective cohort study

Objectives To describe all iron deficiency anaemia (IDA)-related causes during follow-up of patients newly diagnosed with IDA and to assess whether a delayed colorectal cancer (CRC) diagnosis influences survival. Design and setting Retrospective cohort study of patients from general practices in the Dordrecht area, the Netherlands. Participants Men and women aged ≥50 years with a new diagnosis of IDA (ie, no anaemia 2 years previously). Method From February 2007 to February 2018, all relevant data were collected from the files of the referral hospital. Early IDA-related cause was defined as established within 18 weeks after IDA diagnosis. Cox proportional-hazards regression was u

Culture of human mesenchymal stem cells on microcarriers in a 5 l stirred-tank bioreactor

This article was published in the journal, Biotechnology Letters [© Springer Science+Business Media] and the definitive version is available at: http://dx.doi.org/10.1007/s10529-013-1211-9For the first time, fully functional human mesenchymal stem cells (hMSCs) have been cultured at the litre-scale on microcarriers in a stirred-tank 5 l bioreactor, (2.5 l working volume) and were harvested via a potentially scalable detachment protocol that allowed for the successful detachment of hMSCs from the cell-microcarrier suspension. Over 12 days, the dissolved O2 concentration was >45 % of saturation and the pH between 7.2 and 6.7 giving a maximum cell density in the 5 l bioreactor of 1.7 × 105 cells/ml; this represents >sixfold expansion of the hMSCs, equivalent to that achievable from 65 fully-confluent T-175 flasks. During this time, the average specific O2 uptake of the cells in the 5 l bioreactor was 8.1 fmol/cell h and, in all cases, the 5 l bioreactors outperformed the equivalent 100 ml spinner-flasks run in parallel with respect to cell yields and growth rates. In addition, yield coefficients, specific growth rates and doubling times were calculated for all systems. Neither the upstream nor downstream bioprocessing unit operations had a discernible effect on cell quality with the harvested cells retaining their immunophenotypic markers, key morphological features and differentiation capacity

MicroRNA expression in tumor cells from Waldenstrom's macroglobulinemia reflects both their normal and malignant cell counterparts

MicroRNAs (miRNAs) are involved in the regulation of many cellular processes including hematopoiesis, with the aberrant expression of differentiation-stage specific miRNA associated with lymphomagenesis. miRNA profiling has been essential for understanding the underlying biology of many hematological malignancies; however the miRNA signature of the diverse tumor clone associated with Waldenstrom's macroglobulinemia (WM), consisting of B lymphocytes, plasmacytes and lymphoplasmacytic cells, has not been characterized. We have investigated the expression of over 13 000 known and candidate miRNAs in both CD19+ and CD138+ WM tumor cells, as well as in their malignant and non-malignant counterparts. Although neither CD19+ nor CD138+ WM cells were defined by a distinct miRNA profile, the combination of all WM cells revealed a unique miRNA transcriptome characterized by the dysregulation of many miRNAs previously identified as crucial for normal B-cell lineage differentiation. Specifically, miRNA-9*/152/182 were underexpressed in WM, whereas the expression of miRNA-21/125b/181a/193b/223/363 were notably increased (analysis of variance; P<0.0001). Future studies focusing on the effects of these dysregulated miRNAs will provide further insight into the mechanisms responsible for the pathogenesis of WM

Scale-up of an intensified bioprocess for the expansion of bovine adipose-derived stem cells (bASCs) in stirred tank bioreactors

Cultivated meat is an emerging field, aiming to establish the production of animal tissue for human consumption in an in vitro environment, eliminating the need to raise and slaughter animals for their meat. To realise this, the expansion of primary cells in a bioreactor is needed to achieve the high cell numbers required. The aim of this study was to develop a scalable, microcarrier based, intensified bioprocess for the expansion of bovine adipose-derived stem cells as precursors of fat and muscle tissue. The intensified bioprocess development was carried out initially in spinner flasks of different sizes and then translated to fully controlled litre scale benchtop bioreactors. Bioprocess intensification was achieved by utilising the previously demonstrated bead-to-bead transfer phenomenon and through the combined addition of microcarrier and medium to double the existing surface area and working volume in the bioreactor. Choosing the optimal time point for the additions was critical in enhancing the cell expansion. A significant fold increase of 114.19 ± 1.07 was obtained at the litre scale in the intensified bioprocess compared to the baseline (**p < .005). The quality of the cells was evaluated pre- and post-expansion and the cells were found to maintain their phenotype and differentiation capacity

Production process for stem cell based therapeutic implants: expansion of the production cell line and cultivation of encapsulated cells

Cell based therapy promises the treatment of many diseases like diabetes mellitus, Parkinson disease or stroke. Microencapsulation of the cells protects them against host-vs-graft reactions and thus enables the usage of allogenic cell lines for the manufacturing of cell therapeutic implants. The production process of such implants consists mainly of the three steps expansion of the cells, encapsulation of the cells, and cultivation of the encapsulated cells in order to increase their vitality and thus quality. This chapter deals with the development of fixed-bed bioreactorbased cultivation procedures used in the first and third step of production. The bioreactor system for the expansion of the stem cell line (hMSC-TERT) is based on non-porous glass spheres, which support cell growth and harvesting with high yield and vitality. The cultivation process for the spherical cell based implants leads to an increase of vitality and additionally enables the application of a medium-based differentiation protocol

Expansion of human mesenchymal stem cells in a fixed-bed bioreactor system based on non-porous glass carrier – Part B: Modeling and scale-up of the system

Human mesenchymal stem cells (hMSC) are a promising cell source for the manufacturing of cell therapeutic or tissue engineered implants. In part A of this publication a fixed-bed bioreactor system based on non-porous borosilicate glass spheres and procedures for the automated expansion of hMSC with high yield and vitality has been introduced. Part B of this study deals with the modeling of the process in order to transfer the bioreactors system from the laboratory to the production scale. Relevant model parameters have been obtained by fitting them to the experimental data of hMSC-TERT cultivations in scales up to 300 cm3. Scale-up calculations were carried out exemplarily for a target cell number of twenty billion cells

Expansion of mesenchymal stem cells using a microcarrier-based cultivation system: growth and metabolism

For the continuous and fast expansion of mesenchymal stem cells (MSCs), microcarriers have gained increasing interest. The aim of this study was to evaluate the growth and metabolism profiles of MSCs, expanded in a microcarrier-based cultivation system. We investigated various cultivation conditions to expand goat mesenchymal stem cells on Cytodex 1 microcarriers. These conditions differed in feeding regime, i.e. the addition of fresh proliferation medium, with or without new microcarriers. For all conditions, cell attachment, cell proliferation, energy source consumption, metabolite production, and cell distribution on the microcarriers were studied. Attachment efficiencies of 40% were obtained followed by successful expansion up to 15 cultivation days. Depending on the feeding regime, an exponential growth, stationary growth, and decline growth phase could be distinguished. Addition of 30% fresh medium containing microcarriers every three days showed the longest continuous proliferation of goat MSCs on microcarriers. This feeding regime has the advantage that metabolites, such as ammonia, are diluted and that new energy sources, such as glucose and glutamine, and additional surface area are provided to the cells. In addition, by adding extra microcarriers a more homogenous cell distribution on the microcarriers is obtained as a result of bead-to-bead transfer. A correlation between nutrient consumption, metabolite production and cell growth was observed. The decreasing yield of lactate from glucose over time indicated a possible shift in cellular metabolism