| 1. |
- Vukusic, Kristina, 1979, et al.
(author)
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The Atrioventricular Junction: A Potential Niche Region for Progenitor Cells in the Adult Human Heart
- 2019
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In: Stem Cells and Development. - : Mary Ann Liebert Inc. - 1547-3287 .- 1557-8534. ; 28:16, s. 1078-1088
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Journal article (peer-reviewed)abstract
- A stem cell niche is a microenvironment where stem cells reside in a quiescent state, until activated. In a previous rat model, we combined 5-bromo-2-deoxy-uridine labeling with activation of endogenous stem cells by physical exercise and revealed a distinct region, in the atrioventricular junction (AVj), with features of a stem cell niche. In this study, we aim to investigate whether a similar niche exists in the human heart. Paired biopsies from AVj and left ventricle (LV) were collected both from explanted hearts of organ donors, not used for transplantation (N = 7) and from severely failing hearts from patients undergoing heart transplantation (N = 7). Using antibodies, we investigated the expression of stem cell, hypoxia, proliferation and migration biomarkers. In the collagen-dense region of the AVj in donor hearts, progenitor markers, MDR1, SSEA4, ISL1, WT1, and hypoxia marker, HIF1-alpha, were clearly detected. The expression gradually decreased with distance from the valve. At the myocardium border in the AVj costaining of the proliferation marker Ki67 with cardiomyocyte nuclei marker PCM1 and cardiac Troponin-T (cTnT) indicated proliferation of small cardiomyocytes. In the same site we also detected ISL1(+)/WT1(+)/cTnT cells. In addition, heterogeneity in cardiomyocyte sizes was noted. Altogether, these findings indicate different developmental stages of cardiomyocytes below the region dense in stem cell marker expression. In patients suffering from heart failure the AVj region showed signs of impairment generally displaying much weaker or no expression of progenitor markers. We describe an anatomic structure in the human hearts, with features of a progenitor niche that coincided with the same region previously identified in rats with densely packed cells expressing progenitor and hypoxia markers. The data provided in this study indicate that the adult heart contains progenitor cells and that AVj might be a specific niche region from which the progenitors migrate at the time of regeneration.
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| 2. |
- Andersson, Henrik, et al.
(author)
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Assaying cardiac biomarkers for toxicity testing using biosensing and cardiomyocytes derived from human embryonic stem cells
- 2010
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In: JOURNAL OF BIOTECHNOLOGY. - : Elsevier Science B.V., Amsterdam.. - 0168-1656 .- 1873-4863. ; 150:1, s. 175-181
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Journal article (peer-reviewed)abstract
- Human embryonic stem cell (hESC) derived cardiomyocytes are in the present study being used for testing drug-induced cardiotoxicity in a biosensor set-up. The design of an in vitro testing alternative provides a novel opportunity to surpass previous methods based on rodent cells or cell lines due to its significantly higher toxicological relevance. In this report we demonstrate how hESC-derived cardiomyocytes release detectable levels of two clinically decisive cardiac biomarkers, cardiac troponin T and fatty acid binding protein 3, when the cardiac cells are exposed to the well-known cardioactive drug compound. doxorubicin. The release is monitored by the immuno-biosensor technique surface plasmon resonance, particularly appropriate due to its capacity for parallel and high-throughput analysis in complex media.
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| 3. |
- Asp, Julia, 1973, et al.
(author)
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Cardiomyocyte clusters derived from human embryonic stem cells share similarities with human heart tissue.
- 2010
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In: Journal of molecular cell biology. - : Oxford University Press (OUP). - 1759-4685 .- 1674-2788. ; 2:5, s. 276-83
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Journal article (peer-reviewed)abstract
- Cardiotoxicity testing is a key activity in the pharmaceutical industry in order to detect detrimental effects of new drugs. A reliable human in vitro model would both be beneficial in selection of lead compounds and be important for reducing animal experimentation. However, the human heart is a complex organ composed of many distinct types of cardiomyocytes, but cardiomyocyte clusters (CMCs) derived from human embryonic stem cells could be an option for a cellular model. Data on functional properties of CMCs demonstrate similarities to their in vivo analogues in human. However, development of an in vitro model requires a more thorough comparison of CMCs to human heart tissue. Therefore, we directly compared individually isolated CMCs to human fetal, neonatal, adult atrial and ventricular heart tissues. Real-time qPCR analysis of mRNA levels and protein staining of ion channels and cardiac markers showed in general a similar expression pattern in CMCs and human heart. Moreover, a significant decrease in beat frequency was noted after addition of Zatebradine, a blocker to I(f) involved in regulation of spontaneous contraction in CMCs. The results underscore the similarities of CMCs to human cardiac tissue, and further support establishment of novel cardiotoxicity assays based on the CMCs in drug discovery.
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| 4. |
- Bridel, Claire, et al.
(author)
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Diagnostic Value of Cerebrospinal Fluid Neurofilament Light Protein in Neurology : A Systematic Review and Meta-analysis
- 2019
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In: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149 .- 2168-6157. ; 76:9, s. 1035-1048
-
Research review (peer-reviewed)abstract
- Importance Neurofilament light protein (NfL) is elevated in cerebrospinal fluid (CSF) of a number of neurological conditions compared with healthy controls (HC) and is a candidate biomarker for neuroaxonal damage. The influence of age and sex is largely unknown, and levels across neurological disorders have not been compared systematically to date.Objectives To assess the associations of age, sex, and diagnosis with NfL in CSF (cNfL) and to evaluate its potential in discriminating clinically similar conditions.Data Sources PubMed was searched for studies published between January 1, 2006, and January 1, 2016, reporting cNfL levels (using the search terms neurofilament light and cerebrospinal fluid) in neurological or psychiatric conditions and/or in HC.Study Selection Studies reporting NfL levels measured in lumbar CSF using a commercially available immunoassay, as well as age and sex.Data Extraction and Synthesis Individual-level data were requested from study authors. Generalized linear mixed-effects models were used to estimate the fixed effects of age, sex, and diagnosis on log-transformed NfL levels, with cohort of origin modeled as a random intercept.Main Outcome and Measure The cNfL levels adjusted for age and sex across diagnoses.Results Data were collected for 10 059 individuals (mean [SD] age, 59.7 [18.8] years; 54.1% female). Thirty-five diagnoses were identified, including inflammatory diseases of the central nervous system (n = 2795), dementias and predementia stages (n = 4284), parkinsonian disorders (n = 984), and HC (n = 1332). The cNfL was elevated compared with HC in a majority of neurological conditions studied. Highest levels were observed in cognitively impaired HIV-positive individuals (iHIV), amyotrophic lateral sclerosis, frontotemporal dementia (FTD), and Huntington disease. In 33.3% of diagnoses, including HC, multiple sclerosis, Alzheimer disease (AD), and Parkinson disease (PD), cNfL was higher in men than women. The cNfL increased with age in HC and a majority of neurological conditions, although the association was strongest in HC. The cNfL overlapped in most clinically similar diagnoses except for FTD and iHIV, which segregated from other dementias, and PD, which segregated from atypical parkinsonian syndromes.Conclusions and Relevance These data support the use of cNfL as a biomarker of neuroaxonal damage and indicate that age-specific and sex-specific (and in some cases disease-specific) reference values may be needed. The cNfL has potential to assist the differentiation of FTD from AD and PD from atypical parkinsonian syndromes.
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| 5. |
- Bräutigam, Marcus, 1968, et al.
(author)
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Development of Swedish winter oat with gene technology and molecular breeding
- 2006
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In: J. Seed Science. - 0039-6990. ; 116:1-2, s. 12-35
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Journal article (peer-reviewed)abstract
- In Sweden, oat (Avena sativa) is only grown as a spring crop. A Swedish winter oat, on the other hand, would give increased yields and would secure oat in Swedish agriculture. During three consecutive winters we performed field trials with oat aiming at identifying potential winter material. More than 300 varieties, originating from breeding programs all over the world, were tested. Plants were rated according to winter survival, vigour and general performance during the following growth season and more than 20 lines were identified that were cold hardier than present commercial oat varieties. In parallel experiments a cDNA library was constructed from cold induced English winter oat (Gerald) and ca 10000 EST sequences were generated. After data mining a UniGene set of 2800 oat genes was obtained. By detailed analysis of microarray data from cold stressed Arabidopsis and by advanced bioinformatics, gene interactions in the complex cold induced signal transduction pathway were deduced. By comparison to the oat UniGene set, several genes potentially involved in the regulation of cold hardiness in oat were identified. An Agrobacterium mediated transformation protocol was developed for one oat genotype. Key regulatory genes in cold acclimation will be introduced to oat by genetic transformation or modified by TILLING. Such genes will be used as molecular markers in intogression of winter hardiness to commercial oat.
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| 6. |
- Chawade, Aakash, 1980, et al.
(author)
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Development of a model system to identify differences in spring and winter oat
- 2012
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7
-
Journal article (peer-reviewed)abstract
- Our long-term goal is to develop a Swedish winter oat (Avena sativa). To identify molecular differences that correlate with winter hardiness, a winter oat model comprising of both non-hardy spring lines and winter hardy lines is needed. To achieve this, we selected 294 oat breeding lines, originating from various Russian, German, and American winter oat breeding programs and tested them in the field in south- and western Sweden. By assaying for winter survival and agricultural properties during four consecutive seasons, we identified 14 breeding lines of different origins that not only survived the winter but also were agronomically better than the rest. Laboratory tests including electrolytic leakage, controlled crown freezing assay, expression analysis of the AsVrn1 gene and monitoring of flowering time suggested that the American lines had the highest freezing tolerance, although the German lines performed better in the field. Finally, six lines constituting the two most freezing tolerant lines, two intermediate lines and two spring cultivars were chosen to build a winter oat model system. Metabolic profiling of non-acclimated and cold acclimated leaf tissue samples isolated from the six selected lines revealed differential expression patterns of 245 metabolites including several sugars, amino acids, organic acids and 181 hitherto unknown metabolites. The expression patterns of 107 metabolites showed significant interactions with either a cultivar or a time-point. Further identification, characterisation and validation of these metabolites will lead to an increased understanding of the cold acclimation process in oats. Furthermore, by using the winter oat model system, differential sequencing of crown mRNA populations would lead to identification of various biomarkers to facilitate winter oat breeding. © 2012 Chawade et al.
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| 7. |
- Jonsson, Marianne, 1962, et al.
(author)
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Novel 3D culture system with similarities to the human heart for studies of the cardiac stem cell niche.
- 2010
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In: Regenerative medicine. - : Future Medicine Ltd. - 1746-076X .- 1746-0751. ; 5:5, s. 725-36
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Journal article (peer-reviewed)abstract
- AIMS: The aim of this study was to develop a 3D culture system with similarities to the human heart, which was suitable for studies of adult cardiac stem or progenitor cells. MATERIALS & METHODS: Dissociated cells from human cardiac biopsies were placed in high-density pellet cultures and cultured for up to 6 weeks. Gene and protein expressions, analyzed by quantitative real-time PCR and immunohistochemistry, and morphology were studied in early and late pellets. RESULTS: Cells cultured in the 3D model showed similarities to human cardiac tissue. Moreover, markers for cardiac stem and progenitor cells were also detected after 6 weeks of culture, in addition to markers for signaling pathways active in stem cell niche regulation. CONCLUSIONS: The described 3D culture model could be a valuable tool when studying the influence of different compounds on proliferation and differentiation processes in cardiac stem or progenitor cells in cardiac regenerative research.
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| 8. |
- Sandstedt, Joakim, et al.
(author)
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C-kit+ CD45- cells found in the adult human heart represent a population of endothelial progenitor cells.
- 2010
-
In: Basic research in cardiology. - : Springer Science and Business Media LLC. - 1435-1803 .- 0300-8428. ; 105:4, s. 545-56
-
Journal article (peer-reviewed)abstract
- Although numerous reports support the existence of stem cells in the adult heart, few studies have been conducted using human cardiac tissue. Therefore, cells from human cardiac atrial biopsies were analyzed regarding progenitor properties. Expression of stem cell markers was analyzed using fluorescence-activated cell sorting. This identified a small population of C-kit+ cells, which could be further subdivided based on expression of CD45. The C-kit+ CD45+ population was determined to be of mast cell identity, while the C-kit+ CD45- population expressed mRNA of the endothelial lineage. Since the number of cells obtainable from biopsies was limited, a comparison between directly isolated and monolayer and explant cultured cells, respectively, was carried out. While both cultures retained a small population of mast cells, only monolayer culture produced a stable and relatively high percentage of C-kit+ CD45- cells. This population was found to co-express endothelial progenitor cell markers such as CD31, CD34, CXCR4, and FLK-1. The mRNA expression profile was similar to the one from directly isolated cells. When sorted cells were cultured in endothelial differentiation medium, the C-kit+ CD45- population retained its expression of endothelial markers to a large extent, but downregulated progenitor markers, indicating further differentiation into endothelial cells. We have confirmed that the human cardiac atrium contains a small C-kit+ CD45- population expressing markers commonly found on endothelial progenitor cells. The existence of an endothelial progenitor population within the heart might have future implications for developing methods of inducing neovascularization after myocardial infarction.
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| 9. |
- Sandstedt, Joakim, et al.
(author)
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Human C-kit+CD45- cardiac stem cells are heterogeneous and display both cardiac and endothelial commitment by single-cell qPCR analysis.
- 2014
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In: Biochemical and biophysical research communications. - : Elsevier BV. - 1090-2104 .- 0006-291X. ; 443:1, s. 234-238
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Journal article (peer-reviewed)abstract
- C-kit expressing cardiac stem cells have been described as multipotent. We have previously identified human cardiac C-kit+CD45- cells, but only found evidence of endothelial commitment. A small cardiac committed subpopulation within the C-kit+CD45- population might however be present. To investigate this at single-cell level, right and left atrial biopsies were dissociated and analyzed by FACS. Only right atrial biopsies contained a clearly distinguishable C-kit+CD45- population, which was single-cell sorted for qPCR. A minor portion of the sorted cells (1.1%) expressed early cardiac gene NKX2.5 while most of the cells (81%) expressed late endothelial gene VWF. VWF- cells were analyzed for a wider panel of genes. One group of these cells expressed endothelial genes (FLK-1, CD31) while another group expressed late cardiac genes (TNNT2, ACTC1). In conclusion, human C-kit+CD45- cells were predominantly localized to the right atrium. While most of these cells expressed endothelial genes, a minor portion expressed cardiac genes.
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| 10. |
- Sandstedt, Joakim, et al.
(author)
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Left atrium of the human adult heart contains a population of side population cells.
- 2012
-
In: Basic research in cardiology. - : Springer Science and Business Media LLC. - 1435-1803 .- 0300-8428. ; 107:2
-
Journal article (peer-reviewed)abstract
- Cardiac "side population" (SP) cells have previously been found to differentiate into both endothelial cells and cardiomyocytes in mice and rats, but there are no data on SP cells in the human adult heart. Therefore, human cardiac atrial biopsies were dissociated, stained for SP cells and analyzed with FACS. Identified cell populations were analyzed for gene expression by quantitative real-time PCR and subjected to in vitro differentiation. Only biopsies from the left atrium contained a clearly distinguishable population of SP cells (0.22±0.08%). The SP population was reduced by co-incubation with MDR1 inhibitor Verapamil, while the ABCG2 inhibitor FTC failed to decrease the number of SP cells. When the gene expression was analyzed, SP cells were found to express significantly more MDR1 than non-SP cells. For ABCG2, there was no detectable difference. SP cells also expressed more of the stem cell-associated markers C-KIT and OCT-4 than non-SP cells. On the other hand, no significant difference in the expression of endothelial and cardiac genes could be detected. SP cells were further subdivided based on CD45 expression. The CD45-SP population showed evidence of endothelial commitment at gene expression level. In conclusion, the results show that a SP population of cells is present also in the human adult heart.
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| 11. |
- Sandstedt, Joakim, et al.
(author)
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SSEA-4+ CD34- Cells in the Adult Human Heart Show the Molecular Characteristics of a Novel Cardiomyocyte Progenitor Population.
- 2014
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In: Cells, tissues, organs. - : S. Karger AG. - 1422-6421 .- 1422-6405. ; 199:2-3, s. 103-116
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Journal article (peer-reviewed)abstract
- Stage-specific embryonic antigen (SSEA) expression is used to describe the differentiation state of an embryonic stem cell (ESC). In human ESCs, SSEA-3 and SSEA-4 are highly expressed in undifferentiated cells and downregulated upon differentiation. SSEA-4 has also been described as a marker for adult stem cells in various tissues, including human neonatal cardiac tissue. However, there is currently little data on the expression of SSEAs in human adult cardiac tissue. We obtained right and left atrial biopsies from patients undergoing cardiac surgery. These were dissociated, stained for SSEAs and other cardiac stem cell markers and analyzed by flow cytometry. Directly isolated cells expressed variable levels of SSEA-1, SSEA-3 and SSEA-4. The SSEA-1+ population was established as contaminating hematopoietic cells. The SSEA-4+ population, on the other hand, could be subdivided based on the endothelial progenitor marker CD34. The SSEA-4+ CD34- population in the right atrium had a high gene expression of both early (TBX5, NKX2.5) and late (TNNT2) cardiomyocyte markers. The SSEA-4+ CD34+ population, on the other hand, overlapped with previously described C-kit+ CD45- cardiac stem cells. Primary monolayer-cultured cells retained expression of SSEAs while the cardiomyogenic specification in the SSEA-4+ CD34- population was lost. In tissue sections, SSEA-4+ cells could be identified both within and outside the myocardium. Within the myocardium, some SSEA-4+ cells coexpressed cardiomyogenic markers. In conclusion, the results show that the adult human heart expresses SSEAs and that there is a subpopulation of SSEA-4+ CD34- cells that show features of a cardiomyocyte progenitor population. © 2014 S. Karger AG, Basel.
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| 12. |
- Sandstedt, Mikael, 1990, et al.
(author)
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Intracellular flow cytometry may be combined with good quality and high sensitivity RT-qPCR analysis.
- 2015
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In: Cytometry. Part A : the journal of the International Society for Analytical Cytology. - : Wiley. - 1552-4930. ; 87:12, s. 1079-1089
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Journal article (peer-reviewed)abstract
- Flow cytometry (FCM) has become a well-established method for analysis of both intracellular and cell-surface proteins, while quantitative RT-PCR (RT-qPCR) is used to determine gene expression with high sensitivity and specificity. Combining these two methods would be of great value. The effects of intracellular staining on RNA integrity and RT-qPCR sensitivity and quality have not, however, been fully examined. We, therefore, intended to assess these effects further. Cells from the human lung cancer cell line A549 were fixed, permeabilized and sorted by FCM. Sorted cells were analyzed using RT-qPCR. RNA integrity was determined by RNA quality indicator analysis. A549 cells were then mixed with cells of the mouse cardiomyocyte cell line HL-1. A549 cells were identified by the cell surface marker ABCG2, while HL-1 cells were identified by intracellular cTnT. Cells were sorted and analyzed by RT-qPCR. Finally, cell cultures from human atrial biopsies were used to evaluate the effects of fixation and permeabilization on RT-qPCR analysis of nonimmortalized cells stored prior to analysis by FCM. A large amount of RNA could be extracted even when cells had been fixed and permeabilized. Permeabilization resulted in increased RNA degradation and a moderate decrease in RT-qPCR sensitivity. Gene expression levels were also affected to a moderate extent. Sorted populations from the mixed A549 and HL-1 cell samples showed gene expression patterns that corresponded to FCM data. When samples were stored before FCM sorting, the RT-qPCR analysis could still be performed with high sensitivity and quality. In summary, our results show that intracellular FCM may be performed with only minor impairment of the RT-qPCR sensitivity and quality when analyzing sorted cells; however, these effects should be considered when comparing RT-qPCR data of not fixed samples with those of fixed and permeabilized samples. © 2015 International Society for Advancement of Cytometry.
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| 13. |
- Sandstedt, Mikael, 1990, et al.
(author)
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Regional transcriptomic profiling reveals immune system enrichment in nonfailing atria as well as all chambers of the failing human heart
- 2023
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In: American Journal of Physiology. Heart and Circulatory Physiology. - : American Physiological Society. - 0363-6135 .- 1522-1539. ; 325:6, s. H1430-H1445
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Journal article (peer-reviewed)abstract
- The different chambers of the human heart demonstrate regional physiological traits and may be differentially affected during pathologic remodeling, resulting in heart failure. Few previous studies have, however, characterized the different chambers at a transcriptomic level. We therefore conducted whole-tissue RNA sequencing and gene set enrichment analysis of biopsies collected from the four chambers of adult failing (n = 8) and nonfailing (n = 11) human hearts. Atria and ventricles demonstrated distinct transcriptional patterns. Compared to nonfailing ventricles, the transcriptional pattern of nonfailing atria was enriched for a large number of gene sets associated with cardiogenesis, the immune system and bone morphogenetic protein (BMP), transforming growth factor beta (TGF beta), MAPK/JNK and Wnt signaling. Differences between failing and nonfailing hearts were also determined. The transcriptional pattern of failing atria was distinct compared to that of nonfailing atria and enriched for gene sets associated with the innate and adaptive immune system, TGF beta/SMAD signaling, and changes in endothelial, smooth muscle cell and cardiomyocyte physiology. Failing ventricles were also enriched for gene sets associated with the immune system. Based on the transcriptomic patterns, upstream regulators associated with heart failure were identified. These included many immune response factors predicted to be similarly activated for all chambers of failing hearts. In summary, the heart chambers demonstrate distinct transcriptional patterns that differ between failing and nonfailing hearts. Immune system signaling may be a hallmark of all four heart chambers in failing hearts, and could constitute a novel therapeutic target.
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| 14. |
- Sjölin, Jacob, et al.
(author)
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Expression of Stem Cell Niche-Related Biomarkers at the Base of the Human Tricuspid Valve
- 2023
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In: Stem Cells and Development. - : Mary Ann Liebert Inc. - 1547-3287 .- 1557-8534. ; 32:5-6, s. 140-151
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Journal article (peer-reviewed)abstract
- Stem cell niches have been thoroughly investigated in tissue with high regenerative capacity but not in tissues where cell turnover is slow, such as the human heart. The left AtrioVentricular junction (AVj), the base of the mitral valve, has previously been proposed as a niche region for cardiac progenitors in the adult human heart. In the present study, we explore the right side of the human heart, the base of the tricuspid valve, to investigate the potential of this region as a progenitor niche. Paired biopsies from explanted human hearts were collected from multi-organ donors (N = 12). The lateral side of the AVj, right atria (RA), and right ventricle (RV) were compared for the expression of stem cell niche-related biomarkers using RNA sequencing. Gene expression data indicated upregulation of genes related to embryonic development and extracellular matrix (ECM) composition in the proposed niche region, that is, the AVj. In addition, immunohistochemistry showed high expression of the fetal cardiac markers MDR1, SSEA4, and WT1 within the same region. Nuclear expression of HIF1 alpha was detected suggesting hypoxia. Rare cells were found with the co-staining of the proliferation marker PCNA and Ki67 with cardiomyocyte nuclei marker PCM1 and cardiac Troponin T (cTnT), indicating proliferation of small cardiomyocytes. WT1+/cTnT+ and SSEA4+/cTnT+ cells were also found, suggesting cardiomyocyte-specific progenitors. The expression of the stem cell markers gradually decreased with distance from the tricuspid valve. No expression of these markers was observed in the RV tissue. In summary, the base of the tricuspid valve is an ECM-rich region containing cells with expression of several stem cell niche-associated markers. Co-expression of stem cell markers with cTnT indicates cardiomyocyte-specific progenitors. We previously reported similar data from the base of the mitral valve and thus propose that human adult cardiomyocyte progenitors reside around both atrioventricular valves.
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| 15. |
- Synnergren, Jane, et al.
(author)
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Transcriptional sex and regional differences in paired human atrial and ventricular cardiac biopsies collected in vivo
- 2020
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In: Physiological Genomics. - : American Physiological Society. - 1094-8341 .- 1531-2267. ; 52:2, s. 110-120
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Journal article (peer-reviewed)abstract
- Transcriptional studies of the human heart provide insight into physiological and pathophysiological mechanisms, essential for understanding the fundamental mechanisms of normal cardiac function and how they are altered by disease. To improve the understanding of why men and women may respond differently to the same therapeutic treatment it is crucial to learn more about sex-specific transcriptional differences. In this study the transcriptome of right atrium and left ventricle was compared across sex and regional location. Paired biopsies from five male and five female patients undergoing aortic valve replacement or coronary artery bypass grafting were included. Gene expression analysis identified 620 differentially expressed transcripts in atrial and ventricular tissue in men and 471 differentially expressed transcripts in women. In total 339 of these transcripts overlapped across sex but notably, 281 were unique in the male tissue and 162 in the female tissue, displaying marked sex differences in the transcriptional machinery. The transcriptional activity was significantly higher in atrias than in ventricles as 70% of the differentially expressed genes were upregulated in the atrial tissue. Furthermore, pathway- and functional annotation analyses performed on the differentially expressed genes showed enrichment for a more heterogeneous composition of biological processes in atrial compared with the ventricular tissue, and a dominance of differentially expressed genes associated with infection disease was observed. The results reported here provide increased insights about transcriptional differences between the cardiac atrium and ventricle but also reveal transcriptional differences in the human heart that can be attributed to sex.
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| 16. |
- Vukusic, Kristina, 1979, et al.
(author)
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High Density Sphere Culture of Adult Cardiac Cells Increases the Levels of Cardiac and Progenitor Markers and Shows Signs of Vasculogenesis
- 2013
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In: Biomed Research International. - : Hindawi Limited. - 2314-6133 .- 2314-6141.
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Journal article (peer-reviewed)abstract
- 3D environment and high cell density play an important role in restoring and supporting the phenotypes of cells represented in cardiac tissues.. e aim of this study was therefore to investigate the suitability of high density sphere (HDS) cultures for studies of cardiomyocyte-, endothelial-, and stem-cell biology. Primary adult cardiac cells from nine human biopsies were cultured using different media for up to 9 weeks.. e possibilities to favor a certain cell phenotype and induce production of extra cellular matrix (ECM) were studied by histology, immunohistochemistry, and uantitative real-time PCR. Defined media gave significant increase in both cardiac-and progenitor-specific markers and also an intraluminal position of endothelial cells over time. Cardiac media showed indication of differentiation and maturity of HDS considering the ECM production and activities within NOTCH regulation but no additional cardiac differentiation. Endothelial media gave no positive effects on endothelial phenotype but increased proliferation without fibroblast overgrowth. In addition, indications for early vasculogenesis were found. It was also possible to affect the Wnt signaling in HDS by addition of a glycogen synthase kinase 3 (GSK3) inhibitor. In conclusion, these findings show the suitability of HDS as in vitro model for studies of cardiomyocyte-, endothelial-, and stem-cell biology.
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| 17. |
- Allwood, Carl Martin, 1952, et al.
(author)
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Child witnesses meta-memory realism
- 2006
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In: Scandinavian Journal of Psychology. - 0036-5564 .- 1467-9450. ; 47, s. 461-470
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Journal article (peer-reviewed)
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| 18. |
- Allwood, Carl Martin, 1952, et al.
(author)
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Child witnesses’ metamemory realism
- 2006
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In: Scandinavian Journal of Psychology. - : Wiley. - 0036-5564 .- 1467-9450. ; 47, s. 461-470
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Journal article (peer-reviewed)abstract
- This study investigated the degree of realism in the confidence judgments of 11-12 year old children (N=81) of their answers to questions relating to a short film clip showing a kidnapping event. Four different confidence scales were used: a numeric scale, a picture scale, a line scale, and a written scale. The results demonstrated that the children showed a high level of overconfidence in their memories. However, no significant differences between the four confidence scales were found. The results indicate that, at least in the context investigated, 11-12 year-old children’s confidence in their event memory show poor realism. A comparison with previous research on adults indicates that children show noticeably poorer realism.
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| 19. |
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| 20. |
- Allwood, Carl Martin, 1952, et al.
(author)
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The effects of source and type of feedback on child witnesses' metamemory accuracy
- 2005
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In: Applied Cognitive Psychology. - : Wiley. - 0888-4080 .- 1099-0720. ; 19:3, s. 331-344
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Journal article (peer-reviewed)abstract
- This study investigated the effect of feedback on the accuracy (realism) of 12-year-old children's metacognitive judgments of their answers to questions about a film clip. Two types of judgments were investigated: confidence judgments (on each question) and frequency judgments (i.e. estimates of overall accuracy). The source of feedback, whether it was presented as provided by a teacher or a peer child, did not influence metacognitive accuracy. Four types of feedback were given depending on whether the participant's answer was correct and depending on whether the feedback confirmed or disconfirmed the child's answer. The children showed large overconfidence when they received confirmatory feedback but much less so when they received disconfirmatory feedback. The children gave frequency judgments implying that they had more correct answers than they actually had. No main gender differences were found for any of the measures. The results indicate a high degree of malleability in children's metacognitive judgments.
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| 21. |
- Asp, Julia, 1973, et al.
(author)
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Comparison of human cardiac gene expression profiles in paired samples of right atrium and left ventricle collected in vivo
- 2012
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In: Physiological Genomics. - : American Physiological Society. - 1094-8341 .- 1531-2267. ; 44:1, s. 89-98
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Journal article (peer-reviewed)abstract
- Studies of expressed genes in human heart provide insight into both physiological and pathophysiological mechanisms. This is of importance for extended understanding of cardiac function as well as development of new therapeutic drugs. Heart tissue for gene expression studies is generally hard to obtain, particularly from the ventricles. Since different parts of the heart have different functions, expression profiles should likely differ between these parts. The aim of the study was therefore to compare the global gene expression in cardiac tissue from the more accessible auricula of the right atrium to expression in tissue from the left ventricle. Tissue samples were collected from five men undergoing aortic valve replacement or coronary artery bypass grafting. Global gene expression analysis identified 542 genes as differentially expressed between the samples extracted from these two locations, corresponding to similar to 2% of the genes covered by the microarray; 416 genes were identified as abundantly expressed in right atrium, and 126 genes were abundantly expressed in left ventricle. Further analysis of the differentially expressed genes according to available annotations, information from curated pathways and known protein interactions, showed that genes with higher expression in the ventricle were mainly associated with contractile work of the heart. Transcription in biopsies from the auricula of the right atrium on the other hand indicated a wider area of functions, including immunity and defense. In conclusion, our results suggest that biopsies from the auricula of the right atrium may be suitable for various genetic studies, but not studies directly related to muscle work.
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| 22. |
- Bajor, Antal, 1962, et al.
(author)
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Normal or increased bile acid uptake in isolated mucosa from patients with bile acid malabsorption.
- 2006
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In: Eur J Gastroenterol Hepatol. - 0954-691X. ; 18:4, s. 397-403
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Journal article (peer-reviewed)abstract
- Introduction: Bile acid malabsorption as reflected by an abnormal 75Se-labelled homocholic acid-taurine (75SeHCAT) test is associated with diarrhoea, but the mechanisms and cause-and-effect relations are unclear. Objectives: Primarily, to determine whether there is a reduced active bile acid uptake in the terminal ileum in patients with bile acid malabsorption. Secondarily, to study the linkage between bile acid malabsorption and hepatic bile acid synthesis. Methods: Ileal biopsies were taken from patients with diarrhoea and from controls with normal bowel habits. Maximal active bile acid uptake was assessed in ileal biopsies using a previously validated technique based on uptake of 14C-labelled taurocholate. To monitor the hepatic synthesis, 7[alpha]-hydroxy-4-cholesten-3-one, a bile acid precursor, was assayed in blood. The 75SeHCAT-retention test was used to diagnose bile acid malabsorption. Results: The taurocholate uptake in specimens from diarrhoea patients was higher compared with the controls [median, 7.7 (n=53) vs 6.1 [mu]mol/g per min (n=17)] (P<0.01) but no difference was seen between those with bile acid malabsorption (n=18) versus diarrhoea with a normal 75SeHCAT test (n=23). The 75SeHCAT values and 7[alpha]-hydroxy-4-cholesten-3-one were inversely correlated. Conclusions: The data do not support bile acid malabsorption being due to a reduced active bile acid uptake capacity in the terminal ileum. (C) 2006 Lippincott Williams & Wilkins, Inc.
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| 23. |
- Bakidou, Anna, 1996, et al.
(author)
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On Scene Injury Severity Prediction (OSISP) model for trauma developed using the Swedish Trauma Registry
- 2023
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In: BMC Medical Informatics and Decision Making. - 1472-6947. ; 23:1
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Journal article (peer-reviewed)abstract
- Background: Providing optimal care for trauma, the leading cause of death for young adults, remains a challenge e.g., due to field triage limitations in assessing a patient’s condition and deciding on transport destination. Data-driven On Scene Injury Severity Prediction (OSISP) models for motor vehicle crashes have shown potential for providing real-time decision support. The objective of this study is therefore to evaluate if an Artificial Intelligence (AI) based clinical decision support system can identify severely injured trauma patients in the prehospital setting. Methods: The Swedish Trauma Registry was used to train and validate five models – Logistic Regression, Random Forest, XGBoost, Support Vector Machine and Artificial Neural Network – in a stratified 10-fold cross validation setting and hold-out analysis. The models performed binary classification of the New Injury Severity Score and were evaluated using accuracy metrics, area under the receiver operating characteristic curve (AUC) and Precision-Recall curve (AUCPR), and under- and overtriage rates. Results: There were 75,602 registrations between 2013–2020 and 47,357 (62.6%) remained after eligibility criteria were applied. Models were based on 21 predictors, including injury location. From the clinical outcome, about 40% of patientswere undertriaged and 46% were overtriaged. Models demonstrated potential for improved triaging and yielded AUC between 0.80–0.89 and AUCPR between 0.43–0.62. Conclusions: AI based OSISP models have potential to provide support during assessment of injury severity. The findings may be used for developing tools to complement field triage protocols, with potential to improve prehospital trauma care and thereby reduce morbidity and mortality for a large patient population.
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| 24. |
- Barbu, Mikael, et al.
(author)
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Serum biomarkers of brain injury after uncomplicated cardiac surgery: Secondary analysis from a randomized trial
- 2022
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In: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 66:4, s. 447-453
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Journal article (peer-reviewed)abstract
- Background: Postoperative cognitive dysfunction is common after cardiac surgery. Postoperative measurements of brain injury biomarkers may identify brain damage and predict cognitive dysfunction. We describe the release patterns of five brain injury markers in serum and plasma after uncomplicated cardiac surgery. Methods: Sixty-one elective cardiac surgery patients were randomized to undergo surgery with either a dextran-based prime or a crystalloid prime. Blood samples were taken immediately before surgery, and 2 and 24h after surgery. Concentrations of the brain injury biomarkers S100B, glial fibrillary acidic protein (GFAP), tau, neurofilament light (NfL) and neuron-specific enolase (NSE)) and the blood–brain barrier injury marker β-trace protein were analyzed. Concentrations of brain injury biomarkers were correlated to patients’ age, operation time, and degree of hemolysis. Results: No significant difference in brain injury biomarkers was observed between the prime groups. All brain injury biomarkers increased significantly after surgery (tau +456% (25th–75th percentile 327%−702%), NfL +57% (28%−87%), S100B +1145% (783%−2158%), GFAP +17% (−3%−43%), NSE +168% (106%−228%), while β-trace protein was reduced (−11% (−17−3%). Tau, S100B, and NSE peaked at 2h, NfL and GFAP at 24h. Postoperative concentrations of brain injury markers correlated to age, operation time, and/or hemolysis. Conclusion: Uncomplicated cardiac surgery with cardiopulmonary bypass is associated with an increase in serum/plasma levels of all the studied injury markers, without signs of blood–brain barrier injury. The biomarkers differ markedly in their levels of release and time course. Further investigations are required to study associations between perioperative release of biomarkers, postoperative cognitive function and clinical outcome. © 2022 The Authors. Acta Anaesthesiologica Scandinavica published by John Wiley & Sons Ltd on behalf of Acta Anaesthesiologica Scandinavica Foundation.
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| 25. |
- Barreto Henriksson, Helena, et al.
(author)
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Transplantation of human mesenchymal stems cells into intervertebral discs in a xenogeneic porcine model.
- 2009
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In: Spine. - 1528-1159. ; 34:2, s. 141-8
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Journal article (peer-reviewed)abstract
- STUDY DESIGN: Experimental and descriptive study of a xenotransplantation model in minipigs. OBJECTIVE: To study survival and function of human mesenchymal stem cells (hMSCs) after transplantation into injured porcine spinal discs, as a model for cell therapy. SUMMARY OF BACKGROUND DATA: Biologic treatment options of the intervertebral disc are suggested for patients with chronic low back pain caused by disc degeneration. METHODS: Three lumbar discs in each of 9 minipigs were injured by aspiration of the nucleus pulposus (NP), 2 weeks later hMSCs were injected in F12 media suspension (cell/med) or with a hydrogel carrier (Puramatrix) (cell/gel). The animals were sacrificed after 1, 3, or 6 months. Disc appearance was visualized by magnetic resonance imaging. Immunohistochemistry methods were used to detect hMSCs by antihuman nuclear antibody staining, and further performed for Collagen II, Aggrecan, and Collagen I. SOX 9, Aggrecan, Versican, Collagen IA, and Collagen IIA and Collagen IIB human mRNA expression was analyzed by real-time PCR. RESULTS: At magnetic resonance imaging all injured discs demonstrated degenerative signs. Cell/gel discs showed fewer changes compared with cell/med discs and only injured discs at later time points. hMSCs were detected in 9 of 10 of the cell/gel discs and in 8 of 9 of the cell/med discs. Immunostaining for Aggrecan and Collagen type II expression were observed in NP after 3 and 6 months in gel/cell discs and colocalized with the antihuman nuclear antibody. mRNA expression of Collagen IIA, Collagen IIB, Versican, Collagen 1A, Aggrecan, and SOX9 were detected in both cell/med and cell/gel discs at the time points 3 and 6 months by real-time PCR. CONCLUSION: hMSCs survive in the porcine disc for at least 6 months and express typical chondrocyte markers suggesting differentiation toward disc-like cells. As in autologous animal models the combination with a three-dimensional-hydrogel carrier seems to facilitate differentiation and survival of MSCs in the disc. Xenotransplantation seems to be valuable in evaluating the possibility for human cell therapy treatment for intervertebral discs.
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