| 1. |
- Aare, Sudhakar, et al.
(author)
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Mechanisms underlying the sparing of masticatory versus limb muscle function in an experimental critical illness model
- 2011
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In: Physiological Genomics. - : American Physiological Society. - 1094-8341 .- 1531-2267. ; 43:24, s. 1334-1350
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Journal article (peer-reviewed)abstract
- Acute quadriplegic myopathy (AQM) is a common debilitating acquired disorder in critically ill intensive care unit (ICU) patients which is characterized by tetraplegia/generalized weakness of limb and trunk muscles. Masticatory muscles, on the other hand, are typically spared or less affected, yet the mechanisms underlying this striking muscle-specific difference remain unknown. This study aims to evaluate physiological parameters and the gene expression profiles of masticatory and limb muscles exposed to factors suggested to trigger AQM, such as mechanical ventilation, immobilization, neuromuscular blocking agents (NMBA), corticosteroids (CS) and sepsis for five days by using a unique porcine model mimicking the ICU conditions. Single muscle fiber cross-sectional area and force-generating capacity, i.e., maximum force normalized to fiber cross-sectional area (specific force), revealed maintained masseter single muscle fiber cross-sectional area and specific-force after five days exposure to all triggering factors. This is in sharp contrast to observations in limb and trunk muscles, showing a dramatic decline in specific force in response to five days exposure to the triggering factors. Significant differences in gene expression were observed between craniofacial and limb muscles, indicating a highly complex and muscle specific response involving transcription and growth factors, heat shock proteins, matrix metalloproteinase inhibitor, oxidative stress responsive elements and sarcomeric proteins underlying the relative sparing of cranial versus spinal nerve innervated muscles during exposure to the ICU intervention.
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| 2. |
- Banduseela, Varuna, et al.
(author)
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Impaired autophagy, chaperone expression, and protein synthesis in response to critical illness interventions in porcine skeletal muscle
- 2013
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In: Physiological Genomics. - : American Physiological Society. - 1094-8341 .- 1531-2267. ; 45:12, s. 477-486
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Journal article (peer-reviewed)abstract
- Critical illness myopathy (CIM) is characterized by a preferential loss of the motor protein myosin, muscle wasting, and impaired muscle function in critically ill intensive care unit (ICU) patients. CIM is associated with severe morbidity and mortality and has a significant negative socioeconomic effect. Neuromuscular blocking agents, corticosteroids, sepsis, mechanical ventilation, and immobilization have been implicated as important risk factors, but the causal relationship between CIM and the risk factors has not been established. A porcine ICU model has been used to determine the immediate molecular and cellular cascades that may contribute to the pathogenesis prior to myosin loss and extensive muscle wasting. Expression profiles have been compared between pigs exposed to the ICU interventions, i.e., mechanically ventilated, sedated, and immobilized for 5 days, with pigs exposed to critical illness interventions, i.e., neuromuscular blocking agents, corticosteroids, and induced sepsis in addition to the ICU interventions for 5 days. Impaired autophagy as well as impaired chaperone expression and protein synthesis were observed in the skeletal muscle in response to critical illness interventions. A novel finding in this study is impaired core autophagy machinery in response to critical illness interventions, which when in concert with downregulated chaperone expression and protein synthesis may collectively affect the proteostasis in skeletal muscle and may exacerbate the disease progression in CIM.
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| 3. |
- Eriksson, Anna, 1977-, et al.
(author)
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AKN-028 induces cell cycle arrest, downregulation of Myc associated genes and a dose dependent reduction of kinase activity in acute myeloid leukemia
- 2014
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In: Biochemical Pharmacology. - : Elsevier. - 0006-2952 .- 1356-1839. ; 87:2, s. 284-291
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Journal article (peer-reviewed)abstract
- AKN-028 is a novel tyrosine kinase inhibitor with preclinical activity in acute myeloid leukemia (AML), presently undergoing investigation in a phase I/II study. It is a potent inhibitor of the FMS-like kinase 3 (FLT3) but shows in vitro activity in a wide range of AML samples. In the present study, we have characterized the effects of AKN-028 on AML cells in more detail. AKN-028 induced a dose-dependent G(0)/arrest in AML cell line MV4-11. Treatment with AKN-028 caused significantly altered gene expression in all AML cell types tested (430 downregulated, 280 upregulated transcripts). Subsequent gene set enrichment analysis revealed enrichment of genes associated with the proto-oncogene and cell cycle regulator c-Myc among the downregulated genes in both AKN-028 and midostaurin treated cells. Kinase activity profiling in AML cell lines and primary AML samples showed that tyrosine kinase activity, but not serine/threonine kinase activity, was inhibited by AKN-028 in a dose dependent manner in all samples tested, reaching approximately the same level of kinase activity. Cells sensitive to AKN-028 showed a higher overall tyrosine kinase activity than more resistant ones, whereas serine/threonine kinase activity was similar for all primary AML samples. In summary, AKN-028 induces cell cycle arrest in AML cells, downregulates Myc-associated genes and affect several signaling pathways. AML cells with high global tyrosine kinase activity seem to be more sensitive to the cytotoxic effect of AKN-028 in vitro.
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| 4. |
- Gunnarsson, Rebeqa, et al.
(author)
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Array-based genomic screening at diagnosis and during follow-up in chronic lymphocytic leukemia
- 2011
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In: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 1592-8721 .- 0390-6078. ; 96:8, s. 1161-1169
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Journal article (peer-reviewed)abstract
- Background High-resolution genomic microarrays enable simultaneous detection of copy-number aberrations such as the known recurrent aberrations in chronic lymphocytic leukemia [del(11q), del(13q), del(17p) and trisomy 12], and copy-number neutral loss of heterozygosity. Moreover, comparison of genomic profiles from sequential patients' samples allows detection of clonal evolution. Design and Methods We screened samples from 369 patients with newly diagnosed chronic lymphocytic leukemia from a population-based cohort using 250K single nucleotide polymorphism-arrays. Clonal evolution was evaluated in 59 follow-up samples obtained after 5-9 years. Results At diagnosis, copy-number aberrations were identified in 90% of patients; 70% carried known recurrent alterations, including del(13q) (55%), trisomy 12 (10.5%), del(11q) (10%), and del(17p) (4%). Additional recurrent aberrations were detected on chromosomes 2 (1.9%), 4 (1.4%), 8 (1.6%) and 14 (1.6%). Thirteen patients (3.5%) displayed recurrent copy-number neutral loss of heterozygosity on 13q, of whom 11 had concurrent homozygous del(13q). Genomic complexity and large 13q deletions correlated with inferior outcome, while the former was linked to poor-prognostic aberrations. In the follow-up study, clonal evolution developed in 8/24 (33%) patients with unmutated IGHV, and in 4/25 (16%) IGHV-mutated and treated patients. In contrast, untreated patients with mutated IGHV (n=10) did not acquire additional aberrations. The most common secondary event, del(13q), was detected in 6/12 (50%) of all patients with acquired alterations. Interestingly, aberrations on, for example, chromosome 6q, 8p, 9p and 10q developed exclusively in patients with unmutated IGHV. Conclusions Whole-genome screening revealed a high frequency of genomic aberrations in newly diagnosed chronic lymphocytic leukemia. Clonal evolution was associated with other markers of aggressive disease and commonly included the known recurrent aberrations.
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| 5. |
- Gustafsson, Mats G., et al.
(author)
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Improving Bayesian credibility intervals for classifier error rates using maximum entropy empirical priors
- 2010
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In: Artificial Intelligence in Medicine. - : Elsevier BV. - 0933-3657 .- 1873-2860. ; 49:2, s. 93-104
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Journal article (peer-reviewed)abstract
- Objective:Successful use of classifiers that learn to make decisions from a set of patient examples require robust methods for performance estimation. Recently many promising approaches for determination of an upper bound for the error rate of a single classifier have been reported but the Bayesian credibility interval (Cl) obtained from a conventional holdout test still delivers one of the tightest bounds. The conventional Bayesian CI becomes unacceptably large in real world applications where the test set sizes are less than a few hundred. The source of this problem is that fact that the Cl is determined exclusively by the result on the test examples. In other words, there is no information at all provided by the uniform prior density distribution employed which reflects complete lack of prior knowledge about the unknown error rate. Therefore, the aim of the study reported here was to study a maximum entropy (ME) based approach to improved prior knowledge and Bayesian CIs, demonstrating its relevance for biomedical research and clinical practice.Method and material:It is demonstrated how a refined non-uniform prior density distribution can be obtained by means of the ME principle using empirical results from a few designs and tests using non-overlapping sets of examples.Results:Experimental results show that ME based priors improve the CIs when employed to four quite different simulated and two real world data sets.Conclusions:An empirically derived ME prior seems promising for improving the Bayesian Cl for the unknown error rate of a designed classifier.
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| 6. |
- Halldórsdóttir, Anna M., et al.
(author)
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High-resolution genomic screening in mantle cell lymphoma : specific changes correlate with genomic complexity, the proliferation signature and survival
- 2011
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In: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 50:2, s. 113-121
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Journal article (peer-reviewed)abstract
- Mantle cell lymphoma (MCL) is characterized by the t(11;14)(q13;q32) and numerous copy number aberrations (CNAs). Recently, gene expression profiling defined a proliferation gene expression signature in MCL where high scores predict shorter survival. We investigated 31 MCL cases using high-density single nucleotide polymorphism arrays and correlated CNA patterns with the proliferation signature and with clinical data. Many recurrent CNAs typical of MCL were detected, including losses at 1p (55%), 8p (29%), 9q (29%), 11q (55%), 13q (42%) and 17p (32%), and gains at 3q (39%), 8q (26%), 15q (23%) and 18q (23%). A novel deleted region at 20q (16%) contained only one candidate gene, ZFP64, a putative tumor suppressor. Unsupervised clustering identified subgroups with different patterns of CNAs, including a subset (19%) characterized by the presence of 11q loss in all cases and by the absence of 13q loss, and 3q and 7p gains. Losses at 1p, 8p, 13q and 17p were associated with increased genomic complexity. High proliferation signature scores correlated with increased number of large (>15 Mbp) CNAs (P = 0.03) as well as copy number gains at 7p (P = 0.02) and losses at 9q (P = 0.04). Furthermore, large/complex 13q losses were associated with improved survival (P < 0.05) as were losses/copy number neutral LOH at 19p13 (P = 0.01). In summary, this high-resolution genomic analysis identified novel aberrations and revealed that several CNAs correlated with genomic complexity, the proliferation status and survival.
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| 7. |
- Halldorsdottir, Anna Margret, et al.
(author)
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Mantle cell lymphoma displays a homogenous methylation profile : A comparative analysis with chronic lymphocytic leukemia
- 2012
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In: American Journal of Hematology. - : John Wiley & Sons. - 0361-8609 .- 1096-8652. ; 87:4, s. 361-367
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Journal article (peer-reviewed)abstract
- Mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL) are mature CD5(+) B-cell malignancies with different biological/clinical characteristics. We recently reported an association between different prognostic subgroups of CLL (i.e., IGHV mutated and unmutated) and genomic methylation pattern. However, the relationship between DNA methylation and prognostic markers, such as the proliferation gene expression signature, has not been investigated in MCL. We applied high-resolution methylation microarrays (27,578 CpG sites) to assess the global DNA methylation profiles in 20 MCL (10 each with high/low proliferation signature) and 30 CLL (15 poor-prognostic IGHV unmutated subset #1 and 15 good-prognostic IGHV mutated subset #4) samples. Notably, MCL and each CLL subset displayed distinct genomic methylation profiles. After unsupervised hierarchical clustering, 17/20 MCL cases formed a cluster separate from CLL, while CLL subsets #1 and #4 formed subclusters. Surprisingly, few differentially methylated genes (n = 6) were identified between high vs. low proliferation MCL. In contrast, distinct methylation profiles were demonstrated for MCL and CLL. Importantly, certain functional classes of genes were preferentially methylated in either disease. For instance, developmental genes, in particular homeobox transcription factor genes (e.g., HLXB9, HOXA13), were more highly methylated in MCL, whereas apoptosis-related genes were enriched among targets methylated in CLL (e.g., CYFIP2, NR4A1). Results were validated using pyrosequencing, RQ-PCR and reexpression of specific genes. In summary, the methylation profile of MCL was homogeneous and no correlation with the proliferation signature was observed. Compared to CLL, however, marked differences were discovered such as the preferential methylation of homeobox genes in MCL.
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| 8. |
- Halldorsdottir, Anna Margret, et al.
(author)
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Mantle cell lymphoma displays a homogenous methylation profile: A comparative analysis with chronic lymphocytic leukemia
- 2012
-
In: American Journal of Hematology. - : Wiley. - 0361-8609 .- 1096-8652. ; 87:4, s. 361-367
-
Journal article (peer-reviewed)abstract
- Mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL) are mature CD5(+) B-cell malignancies with different biological/clinical characteristics. We recently reported an association between different prognostic subgroups of CLL (i.e., IGHV mutated and unmutated) and genomic methylation pattern. However, the relationship between DNA methylation and prognostic markers, such as the proliferation gene expression signature, has not been investigated in MCL. We applied high-resolution methylation microarrays (27,578 CpG sites) to assess the global DNA methylation profiles in 20 MCL (10 each with high/low proliferation signature) and 30 CLL (15 poor-prognostic IGHV unmutated subset #1 and 15 good-prognostic IGHV mutated subset #4) samples. Notably, MCL and each CLL subset displayed distinct genomic methylation profiles. After unsupervised hierarchical clustering, 17/20 MCL cases formed a cluster separate from CLL, while CLL subsets #1 and #4 formed subclusters. Surprisingly, few differentially methylated genes (n = 6) were identified between high vs. low proliferation MCL. In contrast, distinct methylation profiles were demonstrated for MCL and CLL. Importantly, certain functional classes of genes were preferentially methylated in either disease. For instance, developmental genes, in particular homeobox transcription factor genes (e.g., HLXB9, HOXA13), were more highly methylated in MCL, whereas apoptosis-related genes were enriched among targets methylated in CLL (e.g., CYFIP2, NR4A1). Results were validated using pyrosequencing, RQ-PCR and reexpression of specific genes. In summary, the methylation profile of MCL was homogeneous and no correlation with the proliferation signature was observed. Compared to CLL, however, marked differences were discovered such as the preferential methylation of homeobox genes in MCL. Am. J. Hematol., 2012. (C) 2012 Wiley Periodicals, Inc.
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| 9. |
- Hassan, Saadia Bashir, et al.
(author)
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Alpha Terpineol : A Potential Anticancer Agent which Acts through Suppressing NF-kappa B Signalling
- 2010
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In: Anticancer Research. - 0250-7005 .- 1791-7530. ; 30:6, s. 1911-1919
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Journal article (peer-reviewed)abstract
- Background: Alpha terpineol is a bioactive component of Salvia libanotica essential oil extract and has shown antitumour activity. Materials and Methods: The cytotoxicity of alpha terpineol towards different tumour cell lines was evaluated in vitro. Mechanistic characterization was performed using analysis of drug activity in a cell line panel and drug-induced gene expression perturbation using the connectivity map approach. Results: The small cell lung carcinoma was the cell line most sensitive to alpha terpineol. The results proposed alpha terpineol as an NF-kappa B inhibitor, which was confirmed by the observed dose-dependent inhibition of NF-kappa B translocation and activity using two NF-kappa B assays, and by the down-regulation of the expression of several NE-kappa B-related genes such as IL-1 beta and IL1R1. Conclusion: The results suggest that alpha terpineol inhibits the growth of tumour cells through a mechanism that involves inhibition of the NF-kappa B pathway.
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| 10. |
- Johansson, Henrik, et al.
(author)
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Targeted resequencing of candidate genes using Selector Probes
- 2011
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In: Nucleic Acids Research. - : Oxford University Press (OUP). - 0305-1048 .- 1362-4962. ; 39:2, s. e8-
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Journal article (peer-reviewed)abstract
- Targeted genome enrichment is a powerful tool for making use of the massive throughput of novel DNA-sequencing instruments. We herein present a simple and scalable protocol for multiplex amplification of target regions based on the Selector technique. The updated version exhibits improved coverage and compatibility with next-generation-sequencing (NGS) library-construction procedures for shotgun sequencing with NGS platforms. To demonstrate the performance of the technique, all 501 exons from 28 genes frequently involved in cancer were enriched for and sequenced in specimens derived from cell lines and tumor biopsies. DNA from both fresh frozen and formalin-fixed paraffin-embedded biopsies were analyzed and 94 specificity and 98 coverage of the targeted region was achieved. Reproducibility between replicates was high (R 2=0, 98) and readily enabled detection of copy-number variations. The procedure can be carried out in <24 h and does not require any dedicated instrumentation.
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