| 41. |
- Kugelberg, Fredrik, 1974-, et al.
(författare)
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Postmortem redistribution of the enantiomers of citalopram and its metabolites : an experimental study in rats
- 2004
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Ingår i: Journal of Analytical Toxicology. - : Oxford University Press (OUP). - 0146-4760 .- 1945-2403. ; 28:8, s. 631-637
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Tidskriftsartikel (refereegranskat)abstract
- A rat model was used to study if postmortem redistribution of the S- and R-enantiomers of citalopram (CIT) and its metabolites demethylcitalopram (DCIT) and didemethylcitalopram (DDCIT) occurs after three different subcutaneous dosing procedures with racemic CIT. Two groups underwent chronic administration (20 mg/kg daily) using osmotic pumps. After 10 days, 1 of these groups received an acute-on-chronic drug challenge with a single injection of 100 mg/kg. The third group received the single 100 mg/kg dose only. Heart blood and brain samples were collected antemortem and 1, 3, or 24 h postmortem for enantioselective HPLC analysis. Increased postmortem blood drug and metabolite concentrations compared with corresponding antemortem concentrations were observed in all groups (p < 0.05 to p < 0.001). At 24 h after death, the ratios between postmortem and antemortem blood concentrations were around 3–4 for CIT as well as for the metabolites. In the brain, no major differences between antemortem and postmortem drug and metabolite concentrations were observed. The enantiomeric (S/R) concentrations ratios of CIT and metabolites in blood and brain were of similar magnitude before and after death. No differences between antemortem and postmortem parent drug-to-metabolite (P/M) ratios for CIT/DCIT in blood were observed. Finally, this animal model demonstrates that the S- and R-enantiomers of CIT and its metabolites were redistributed to the same extent postmortem.
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| 42. |
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| 43. |
- Nordigården, Amanda, et al.
(författare)
-
Irreversible pan-ERBB inhibitor canertinib elicits anti-leukaemic effects and induces the regression of FLT3-ITD transformed cells in mice
- 2011
-
Ingår i: British Journal of Haematology. - : Blackwell Publishing. - 0007-1048 .- 1365-2141. ; 155:2, s. 198-208
-
Tidskriftsartikel (refereegranskat)abstract
- Recent findings have indicated that tyrosine kinase inhibitors (TKIs) targeting the ERBB receptor family display anti-leukaemic effects, despite the lack of receptor expression on human leukaemic cells. The occurrence of activating mutations in the gene encoding FMS-like tyrosine kinase 3 (FLT3) in patients with acute myeloid leukaemia (AML) has rendered inhibition of this receptor a promising therapeutic target. Due to possibility of cross-reactivity, we investigated the effect of the irreversible pan-ERBB inhibitor canertinib (CI-1033) on leukaemic cells expressing FLT3. The drug had anti-proliferative and apoptotic effects on primary AML cells and human leukaemic cell lines expressing mutated FLT3. In several AML patient samples, a blast cell population expressing FLT3-internal tandem duplication (ITD) was eradicated by canertinib. Canertinib inhibited receptor autophosphorylation and kinase activity of both mutated and FLT3 ligand stimulated wildtype FLT3, leading to inhibition of the PI3-kinase and MAP kinase pathways. Apoptotic induction was dependent on pro-apoptotic BH3-only protein BCL2L11/BIM because siRNA silencing attenuated apoptosis. Moreover, the drug induced regression of cells expressing FLT3-ITD in a murine in vivo-transplantation model at previously described tolerated doses. These results indicate that canertinib, as an irreversible TKI, could constitute a novel treatment regimen in patients with mutated or overexpressed FLT3.
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| 44. |
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| 45. |
- Radoi, Vlad, et al.
(författare)
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Non-Peptide Opioids Differ in Effects on Mu-Opioid (MOP) and Serotonin 1A (5-HT1A) Receptors Heterodimerization and Cellular Effectors (Ca2+, ERK 1/2 and p38) Activation
- 2022
-
Ingår i: Molecules. - : MDPI AG. - 1431-5157 .- 1420-3049. ; 27:7
-
Tidskriftsartikel (refereegranskat)abstract
- The importance of the dynamic interplay between the opioid and the serotonin neuromodulatory systems in chronic pain is well recognized. In this study, we investigated whether these two signalling pathways can be integrated at the single-cell level via direct interactions between the mu-opioid (MOP) and the serotonin 1A (5-HT1A) receptors. Using fluorescence cross-correlation spectroscopy (FCCS), a quantitative method with single-molecule sensitivity, we characterized in live cells MOP and 5-HT1A interactions and the effects of prolonged (18 h) exposure to selected non-peptide opioids: morphine, codeine, oxycodone and fentanyl, on the extent of these interactions. The results indicate that in the plasma membrane, MOP and 5-HT1A receptors form heterodimers that are characterized with an apparent dissociation constant K-d(app) = (440 +/- 70) nM). Prolonged exposure to all non-peptide opioids tested facilitated MOP and 5-HT1A heterodimerization and stabilized the heterodimer complexes, albeit to a different extent: K-d,Fentanyl(app) = (80 +/- 70) nM), K-d,FMorphine(app) = (200 +/- 70) nM, K-d,Codeine(app) = (100 +/- 70) nM and K-d,(app)(Oxycodone) = (200 +/- 70) nM. The non-peptide opioids differed also in the extent to which they affected the mitogen-activated protein kinases (MAPKs) p38 and the extracellular signal-regulated kinase (Erk1/2), with morphine, codeine and fentanyl activating both pathways, whereas oxycodone activated p38 but not ERK1/2. Acute stimulation with different non-peptide opioids differently affected the intracellular Ca2+ levels and signalling dynamics. Hypothetically, targeting MOP-5-HT1A heterodimer formation could become a new strategy to counteract opioid induced hyperalgesia and help to preserve the analgesic effects of opioids in chronic pain.
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| 46. |
- Reu, Pedro, et al.
(författare)
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The Lifespan and Turnover of Microglia in the Human Brain
- 2017
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Ingår i: Cell Reports. - Cambridge, MA 02139, USA : Elsevier BV. - 2211-1247. ; 20:4, s. 779-784
-
Tidskriftsartikel (refereegranskat)abstract
- The hematopoietic system seeds the CNS with microglial progenitor cells during the fetal period, but the subsequent cell generation dynamics and maintenance of this population have been poorly understood. We report that microglia, unlike most other hematopoietic lineages, renew slowly at a median rate of 28% per year, and some microglia last for more than two decades. Furthermore, we find no evidence for the existence of a substantial population of quiescent long-lived cells, meaning that the microglia population in the human brain is sustained by continuous slow turnover throughout adult life.
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| 47. |
- Seldén, Tor, et al.
(författare)
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LC-MS-MS analysis of buprenorphine and norbuprenorphine in whole blood from suspected drug users
- 2011
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Ingår i: Forensic Science International. - : Elsevier. - 0379-0738 .- 1872-6283. ; 209:1-3, s. 113-119
-
Tidskriftsartikel (refereegranskat)abstract
- A liquid chromatography tandem mass spectrometry method is described for the analysis of buprenorphine and norbuprenorphine in whole blood. Linearity was achieved between 0.2-5 ng/g for buprenorphine and 0.5-5 ng/g for norbuprenorphine. Stability studies on spiked whole blood and an authentic sample showed no degradation of buprenorphine- and norbuprenorphine-glucuronide to their respective aglycones. Buprenorphine and norbuprenorphine showed some degradation when stored at 4 degrees C for three weeks, but was stable when stored at -20 degrees C for 4 weeks. The method was applied to forensic cases of driving under the influence of drugs (DUID) and petty drug offences (PDO) during 2007-2009. Out of 2459 cases analyzed, 322 were positive for both buprenorphine and norbuprenorphine (13%), 219 for buprenorphine only (9%), and 12 for norbuprenorphine only (0.5%). The mean and median concentrations (N = 322) were 1.7 and 1.0 ng/g, respectively, for buprenorphine and norbuprenorphine. The mean and median norbuprenorphine/buprenorphine ratios were 1.5 and 1.1, respectively. There was no significant difference in concentration ratios for DUID and PDO cases (p andgt; 0.05). We conclude that the described method for analysis of buprenorphine and norbuprenorphine in whole blood could be used to investigate use or misuse of buprenorphine but that many of the cases presented with very low concentrations of buprenorphine. We also conclude that analysis should be performed within two weeks unless samples are stored frozen prior to analysis.
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| 48. |
- Seldén, Tor, et al.
(författare)
-
Toxicological and pathological findings in a series of buprenorphine related deaths. Possible risk factors for fatal outcome
- 2012
-
Ingår i: Forensic Science International. - : Elsevier. - 0379-0738 .- 1872-6283. ; 220:1-3, s. 284-290
-
Tidskriftsartikel (refereegranskat)abstract
- Buprenorphine is considered to have little respiratory side effects at therapeutic doses and the partial agonistic properties should produce a "ceiling effect for respiratory depression at higher doses. Still, there are several reports on buprenorphine related deaths. Most deaths involve drug users and the co-administration of other CNS depressant drugs as well as reduced tolerance have been suggested to be risk factors. The primary aims were to investigate if lack of tolerance and/or co-ingestion of other psychotropic drugs are significant risk factors in buprenorphine fatalities. From July 2005 to September 2009, all autopsy cases where buprenorphine or norbuprenorphine had been detected in femoral blood and where analysis of buprenorphine had been performed in urine were selected. Results from the postmortem examination and toxicology were compiled. Postmortem toxicology was performed using the routine methodology at the laboratory. In total, 97 subjects were included in the study. These were divided into four groups; Intoxication with buprenorphine (N = 41), Possible intoxication with buprenorphine (N = 24), Control cases where buprenorphine was not the cause of death (N = 14), and Unclear (N = 18). The metabolite to parent compound ratios in both blood and urine in the Intoxication group were significantly different from those in the Control and Unclear groups. An extensive poly-drug use was seen in all groups with several additional opioids in the Possible group (54%) and in the Unclear group (78%) and hypnotics or sedatives in more than 75% of the Intoxication, Possible, and Unclear cases. Illicit drugs were present in all groups but not to a great extent with amphetamine and tetrahydrocannabinol as the main findings. Interestingly, 4 cases in the Intoxication group presented with no other significant drugs in blood other than buprenorphine. We conclude that a lethal concentration of buprenorphine in blood cannot be defined. Instead the analysis of blood as well as urine can be an important tool to show that the drug was taken shortly before death and to rule out a continuous use of buprenorphine supporting the notion that abstinence is an important risk factor. The presence of alprazolam in more than 40% of the Intoxications and the presence of hypnotics and sedatives in 75% of the Intoxications suggests that these drugs interact with buprenorphine producing toxic effects that buprenorphine alone would not have produced. Still, in 10% of the Intoxications no other drugs were found indicating that under certain circumstances buprenorphine alone may produce respiratory depression resulting in death.
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| 49. |
- Sounart, Hailey, et al.
(författare)
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Dual spatially resolved transcriptomics for human host–pathogen colocalization studies in FFPE tissue sections
- 2023
-
Ingår i: Genome Biology. - : Springer Nature. - 1465-6906 .- 1474-760X. ; 24:1
-
Tidskriftsartikel (refereegranskat)abstract
- Technologies to study localized host–pathogen interactions are urgently needed. Here, we present a spatial transcriptomics approach to simultaneously capture host and pathogen transcriptome-wide spatial gene expression information from human formalin-fixed paraffin-embedded (FFPE) tissue sections at a near single-cell resolution. We demonstrate this methodology in lung samples from COVID-19 patients and validate our spatial detection of SARS-CoV-2 against RNAScope and in situ sequencing. Host–pathogen colocalization analysis identified putative modulators of SARS-CoV-2 infection in human lung cells. Our approach provides new insights into host response to pathogen infection through the simultaneous, unbiased detection of two transcriptomes in FFPE samples.
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| 50. |
- Spaulding, Kirsty, et al.
(författare)
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Dynamics of Hippocampal Neurogenesis in Adult Humans
- 2013
-
Ingår i: Cell. - Maryland Heights, MO, USA : Elsevier. - 0092-8674 .- 1097-4172. ; 153:6, s. 1219-1227
-
Tidskriftsartikel (refereegranskat)abstract
- Adult-born hippocampal neurons are important for cognitive plasticity in rodents. There is evidence for hippocampal neurogenesis in adult humans, although whether its extent is sufficient to have func- tional significance has been questioned. We have assessed the generation of hippocampal cells in humans by measuring the concentration of nuclear- bomb-test-derived 14C in genomic DNA, and we present an integrated model of the cell turnover dy- namics. We found that a large subpopulation of hip- pocampal neurons constituting one-third of the neu- rons is subject to exchange. In adult humans, 700 new neurons are added in each hippocampus per day, corresponding to an annual turnover of 1.75% of the neurons within the renewing fraction, with a modest decline during aging. We conclude that neu- rons are generated throughout adulthood and that the rates are comparable in middle-aged humans and mice, suggesting that adult hippocampal neuro- genesis may contribute to human brain function.
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