Ethics and biobanks HANSSON, M. G
British journal of cancer,
01/2009, Letnik:
100, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Biobank research has been the focus of great interest of scholars and regulatory bodies who have addressed different ethical issues. On the basis of a review of the literature it may be concluded ...that, regarding some major themes in this discussion, a consensus seems to emerge on the international scene after the regular exchange of arguments in scientific journals. Broad or general consent is emerging as the generally preferred solution for biobank studies and straightforward instructions for coding will optimise privacy while facilitating research that may result in new methods for the prevention of disease and for medical treatment. The difficult question regarding the return of information to research subjects is the focus of the current research, but a helpful analysis of some of the issues at stake and concrete recommendations have recently been suggested.
Many important cell types in adult vertebrates have a mesenchymal origin, including fibroblasts and vascular mural cells. Although their biological importance is undisputed, the level of mesenchymal ...cell heterogeneity within and between organs, while appreciated, has not been analyzed in detail. Here, we compare single-cell transcriptional profiles of fibroblasts and vascular mural cells across four murine muscular organs: heart, skeletal muscle, intestine and bladder. We reveal gene expression signatures that demarcate fibroblasts from mural cells and provide molecular signatures for cell subtype identification. We observe striking inter- and intra-organ heterogeneity amongst the fibroblasts, primarily reflecting differences in the expression of extracellular matrix components. Fibroblast subtypes localize to discrete anatomical positions offering novel predictions about physiological function(s) and regulatory signaling circuits. Our data shed new light on the diversity of poorly defined classes of cells and provide a foundation for improved understanding of their roles in physiological and pathological processes.
We describe a system for culturing human embryonic stem (hES) cells and induced pluripotent stem (iPS) cells on a recombinant form of human laminin-511, a component of the natural hES cell niche. The ...system is devoid of animal products and feeder cells and contains only one undefined component, human albumin. The hES cells self-renewed with normal karyotype for at least 4 months (20 passages), after which the cells could produce teratomas containing cell lineages of all three germ layers. When plated on laminin-511 in small clumps, hES cells spread out in a monolayer, maintaining cellular homogeneity with approximately 97% OCT4-positive cells. Adhesion of hES cells was dependent on alpha6beta1 integrin. The use of homogeneous monolayer hES or iPS cell cultures provides more controllable conditions for the design of differentiation methods. This xeno-free and feeder-free system may be useful for the development of cell lineages for therapeutic purposes.
How to make a cardiomyocyte Später, Daniela; Hansson, Emil M; Zangi, Lior ...
Development (Cambridge),
12/2014, Letnik:
141, Številka:
23
Journal Article
Recenzirano
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During development, cardiogenesis is orchestrated by a family of heart progenitors that build distinct regions of the heart. Each region contains diverse cell types that assemble to form the complex ...structures of the individual cardiac compartments. Cardiomyocytes are the main cell type found in the heart and ensure contraction of the chambers and efficient blood flow throughout the body. Injury to the cardiac muscle often leads to heart failure due to the loss of a large number of cardiomyocytes and its limited intrinsic capacity to regenerate the damaged tissue, making it one of the leading causes of morbidity and mortality worldwide. In this Primer we discuss how insights into the molecular and cellular framework underlying cardiac development can be used to guide the in vitro specification of cardiomyocytes, whether by directed differentiation of pluripotent stem cells or via direct lineage conversion. Additional strategies to generate cardiomyocytes in situ, such as reactivation of endogenous cardiac progenitors and induction of cardiomyocyte proliferation, will also be discussed.
We present a new common stratigraphic timescale for the North Greenland Ice Core Project (NGRIP) and GRIP ice cores. The timescale covers the period 7.9–14.8 kyr before present and includes the ...Bølling, Allerød, Younger Dryas, and early Holocene periods. We use a combination of new and previously published data, the most prominent being new high‐resolution Continuous Flow Analysis (CFA) impurity records from the NGRIP ice core. Several investigators have identified and counted annual layers using a multiparameter approach, and the maximum counting error is estimated to be up to 2% in the Holocene part and about 3% for the older parts. These counting error estimates reflect the number of annual layers that were hard to interpret, but not a possible bias in the set of rules used for annual layer identification. As the GRIP and NGRIP ice cores are not optimal for annual layer counting in the middle and late Holocene, the timescale is tied to a prominent volcanic event inside the 8.2 kyr cold event, recently dated in the DYE‐3 ice core to 8236 years before A. D. 2000 (b2k) with a maximum counting error of 47 years. The new timescale dates the Younger Dryas‐Preboreal transition to 11,703 b2k, which is 100–150 years older than according to the present GRIP and NGRIP timescales. The age of the transition matches the GISP2 timescale within a few years, but viewed over the entire 7.9–14.8 kyr section, there are significant differences between the new timescale and the GISP2 timescale. The transition from the glacial into the Bølling interstadial is dated to 14,692 b2k. The presented timescale is a part of a new Greenland ice core chronology common to the DYE‐3, GRIP, and NGRIP ice cores, named the Greenland Ice Core Chronology 2005 (GICC05). The annual layer thicknesses are observed to be log‐normally distributed with good approximation, and compared to the early Holocene, the mean accumulation rates in the Younger Dryas and Bølling periods are found to be 47 ± 2% and 88 ± 2%, respectively.
Under field conditions, steel is embedded in concrete for a long period of time before chlorides penetrate. In studying the corrosion behaviour of steel in concrete, mortar or in simulated pore ...solution, it is essential to allow enough time for the steel to create a passive layer which is the subject of this study. This time is given to steel in chloride free concrete, naturally; while it should be provided to steel in synthetic pore solution, before adding chloride to the solution. For determining this time, samples were made with steel with different surface conditions: as-received with mill scales and sand-blasted. One set of steel bars (as-received and sand-blasted) were embedded in mortar and one set were immersed in synthetic pore solution. Corrosion of each steel bar was monitored every hour by LPR technique for total time of 300 h. Also, half-cell potential of steel bars was measured during that time. Results show that steel needs to be kept at least three days in synthetic pore solution and seven days in mortar to be passivated.
Human pluripotent stem cell （hPSC）-derived endothelial lineage cells constitutes a promising source for therapeutic revascularization, but progress in this arena has been hampered by a lack of ...clinically-scalable differentiation protocols and inefficient formation of a functional vessel network integrating with the host circulation upon transplantation. Using a human embryonic stem cell reporter cell line, where green fluorescent protein expression is driven by an endothelial cell-specific VE-cadherin （VEC） promoter, we screened for 〉 60 bioactive small molecules that would promote endothelial differentiation, and found that administration of BMP4 and a GSK-3β inhibitor in an early phase and treatment with VEGF-A and inhibition of the Notch signaling pathway in a later phase led to efficient differentiation of hPSCs to the endothelial lineage within six days. This sequential approach generated 〉 50% conversion of hPSCs to endothelial cells （ECs）, specifically VEC^＋CD31^＋CD34^＋CD14^-KDR^high endothelial progenitors （EPs） that exhibited higher angiogenic and clonogenic proliferation potential among endothelial lineage cells. Pharmaceutical inhibition or genetical knockdown of Notch signaling, in combination with VEGF-A treatment, resulted in efficient formation of EPs via KDR^＋ mesodermal precursors and blockade of the conversion of EPs to mature ECs. The generated EPs successfully formed functional capillary vessels in vivo with anastomosis to the host vessels when transplanted into immunocompromised mice. Manipulation of this VEGF-A-Notch signaling circuit in our protocol leads to rapid large-scale production of the hPSC-derived EPs by 12- to 20-fold vs current methods, which may serve as an attractive cell population for regenerative vascularization with superior vessel forming capability compared to mature ECs.
Cells typically respond to chemical or physical perturbations via complex signaling cascades which can simultaneously affect multiple physiological parameters, such as membrane voltage, calcium, pH, ...and redox potential. Protein-based fluorescent sensors can report many of these parameters, but spectral overlap prevents more than ~4 modalities from being recorded in parallel. Here we introduce the technique, MOSAIC, Multiplexed Optical Sensors in Arrayed Islands of Cells, where patterning of fluorescent sensor-encoding lentiviral vectors with a microarray printer enables parallel recording of multiple modalities. We demonstrate simultaneous recordings from 20 sensors in parallel in human embryonic kidney (HEK293) cells and in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), and we describe responses to metabolic and pharmacological perturbations. Together, these results show that MOSAIC can provide rich multi-modal data on complex physiological responses in multiple cell types.
The Impact of Corrosion on Society Hansson, C. M.
Metallurgical and materials transactions. A, Physical metallurgy and materials science,
10/2011, Letnik:
42, Številka:
10
Journal Article
Recenzirano
Almost all metals and alloys are unstable in the Earth’s atmosphere and will always be susceptible to corrosion. The basic principles of corrosion are briefly described in order to explain the ...observations of corrosion, which render our personal items as well as industrial machinery and public property dysfunctional, aesthetically displeasing, and potentially dangerous. This is followed by a discussion, with case study examples, of three aspects of the impact of corrosion on society: (1) direct effects resulting in injury or death, (2) contamination of the environment, and (3) the financial costs.
Parastomal hernias are a frequent complication of enterostomies that require surgical treatment in approximately half of patients. This systematic review aimed to evaluate and compare the safety and ...effectiveness of the surgical techniques available for parastomal hernia repair.
Systematic review was performed in accordance with PRISMA. Assessment of methodological quality and selection of studies of parastomal hernia repair was done with a modified MINORS. Subgroups were formed for each surgical technique. Primary outcome was recurrence after at least 1-year follow-up. Secondary outcomes were mortality and postoperative morbidity. Outcomes were analyzed using weighted pooled proportions and logistic regression.
Thirty studies were included with the majority retrospective. Suture repair resulted in a significantly increased recurrence rate when compared with mesh repair (odds ratio OR 8.9, 95% confidence interval CI 5.2-15.1; P < 0.0001). Recurrence rates for mesh repair ranged from 6.9% to 17% and did not differ significantly. In the laparoscopic repair group, the Sugarbaker technique had less recurrences than the keyhole technique (OR 2.3, 95% CI 1.2-4.6; P = 0.016). Morbidity did not differ between techniques. The overall rate of mesh infections was low (3%, 95% CI 2) and comparable for each type of mesh repair.
Suture repair of parastomal hernia should be abandoned because of increased recurrence rates. The use of mesh in parastomal hernia repair significantly reduces recurrence rates and is safe with a low overall rate of mesh infection. In laparoscopic repair, the Sugarbaker technique is superior over the keyhole technique showing fewer recurrences.
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