| 1. |
- Yu, He, et al.
(författare)
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Palaeogenomic analysis of black rat (Rattus rattus) reveals multiple European introductions associated with human economic history
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- The distribution of the black rat (Rattus rattus) has been heavily influenced by its association with humans. The dispersal history of this non-native commensal rodent across Europe, however, remains poorly understood, and different introductions may have occurred during the Roman and medieval periods. Here, in order to reconstruct the population history of European black rats, we first generate a de novo genome assembly of the black rat. We then sequence 67 ancient and three modern black rat mitogenomes, and 36 ancient and three modern nuclear genomes from archaeological sites spanning the 1st-17th centuries CE in Europe and North Africa. Analyses of our newly reported sequences, together with published mitochondrial DNA sequences, confirm that black rats were introduced into the Mediterranean and Europe from Southwest Asia. Genomic analyses of the ancient rats reveal a population turnover in temperate Europe between the 6th and 10th centuries CE, coincident with an archaeologically attested decline in the black rat population. The near disappearance and re-emergence of black rats in Europe may have been the result of the breakdown of the Roman Empire, the First Plague Pandemic, and/or post-Roman climatic cooling. 'Archaeogenetic analysis of black rat remains reveals that this species was introduced into temperate Europe twice, in the Roman and medieval periods. This population turnover was likely associated with multiple historical and environmental factors.'
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| 2. |
- Hillman, Jan, 1952-, et al.
(författare)
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A microdialysis technique for routine measurement of macromolecules in the injured human brain
- 2005
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 56:6, s. 1264-1268
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate a new intracerebral microdialysis catheter with a high-cutoff membrane and its potential for the study of macromolecules in the human brain. METHODS: Paired intracerebral microdialysis catheters were inserted in 10 patients who became comatose after subarachnoid hemorrhage or traumatic brain injury and were then treated in our neurosurgical unit. The only differences from the routine use of microdialysis in our clinic were the length (20 mm) and cutoff properties of the catheter membranes (100 kD) and the perfusion fluids used (standard perfusion fluid, 3.5% albumin, or Ringer-dextran 60). Samples were weighed (for net fluid fluxes) and analyzed at bedside (for routine metabolites) and later in the laboratory (for total protein and interleukin-6). The in vitro recovery of glucose, glutamate, and glycerol were also investigated under different conditions. RESULTS: Even brief perfusion with standard perfusion fluid resulted in a significant loss of volume from the microdialysis system. For albumin and Ringer-dextran 60 fluid, recovery was comparable to standard settings. Interleukin-6 (highest value close to 25,000 pg/ml) was sampled from all catheters, and total protein was analyzed from catheters perfused with Ringer-dextran 60 (average concentration, 234 μg protein/ml). There were detectable patterns of variations in the concentration of interleukin-6, seemingly related to concomitant variations in intracerebral conditions. In the present study, no direct comparison was made with the standard CMA 70 catheter (CMA Microdialysis, Stockholm, Sweden), but in vivo, the measured mean concentrations of glucose, glycerol, lactate, and pyruvate were comparable to those previously reported from standard catheters. In vitro, the recovery of metabolites was better when using Ringer-dextran 60 compared with albumin. CONCLUSION: Microdialysis catheters with high-cutoff membranes can be used in routine clinical practice, allowing for sampling and analysis of cytokines and other macromolecules.
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| 3. |
- Hillman, Jan, 1952-, et al.
(författare)
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Intracerebral microdialysis in neurosurgical intensive care patients utilising catheters with different molecular cut-off (20 and 100 kD)
- 2006
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Ingår i: Acta Neurochirurgica. - : Springer Science and Business Media LLC. - 0001-6268 .- 0942-0940. ; 148:3, s. 319-324
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To compare the properties of a new intracerebral micro-dialysis catheter with a high cut-off membrane (molecular cut-off 100 kDalton) with a standard catheter (CMA70, molecular cut-off 20 kDalton).Methods. Paired intracerebral microdialysis catheters were inserted in fifteen comatose patients treated in a neurosurgical intensive care unit following subarachnoid haemorrhage or traumatic brain injury. The high-cut-off catheter (D100) differed from the CMA 70 catheter by the length (20 mm) and cut-off properties of the catheter membranes (100 kDalton) and the perfusion fluids used (Ringer-Dextran 60). Samples were collected every 4–6 hours, analyzed bedside (for glucose, glutamate, glycerol, lactate, pyruvate and urea) and later in the laboratory (for total protein).Results. Fluid recovery was similar for the two types of catheters, but significantly more protein was recovered by the D100 catheter. The recovery of glycerol and pyruvate did not differ, while minor differences in recovery of glutamate and glucose were observed. The recovery of lactate was considerably lower in the D100 catheter (p < 0.01), influencing the lactate/pyruvate-ratio. The patterns of concentration changes over time were consistent for all metabolites, and independent of type of catheter.Conclusion. Microdialysis catheters with high cut-off membranes can be used in routine clinical practice in the NSICU, adding the possibility of macro-molecule sampling from the extracellular space during monitoring.
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| 4. |
- Hillman, Jan, 1952-, et al.
(författare)
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Variations in the response of interleukins in neurosurgical intensive care patients monitored using intracerebral microdialysis
- 2007
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Ingår i: Journal of Neurosurgery. - : Journal of Neurosurgery Publishing Group (JNSPG). - 0022-3085 .- 1933-0693. ; 106:5, s. 820-825
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Tidskriftsartikel (refereegranskat)abstract
- Object. The aim of this study was to make a preliminary evaluation of whether microdialysis monitoring of cytokines and other proteins in severely diseased neurosurgical patients has the potential of adding significant information to optimize care, thus broadening the understanding of the function of these molecules in brain injury. Methods. Paired intracerebral microdialysis catheters with high-cutoff membranes were inserted in 14 comatose patients who had been treated in a neurosurgical intensive care unit following subarachnoidal hemorrhage or traumatic brain injury. Samples were collected every 6 hours (for up to 7 days) and were analyzed at bedside for routine metabolites and later in the laboratory for interleukin (IL)-1 and IL-6, in two patients, vascular endothelial growth factor and cathepsin-D were also checked. Aggregated microprobe data gave rough estimations of profound focal cytokine responses related to morphological tissue injury and to anaerobic metabolism that were not evident from the concomitantly collected cerebrospinal fluid data. Data regarding tissue with no macroscopic evidence of injury demonstrated that IL release not only is elicited in severely compromised tissue but also may be a general phenomenon in brains subjected to stress. Macroscopic tissue injury was strongly linked to IL-6 but not IL-1b activation. Furthermore, IL release seems to be stimulated by local ischemia. The basal tissue concentration level of IL-1b was estimated in the range of 10 to 150 pg/ml, for IL-6, the corresponding figure was 1000 to 20,000 pg/ml. Conclusions. Data in the present study indicate that catheters with high-cutoff membranes have the potential of expanding microdialysis to the study of protein chemistry as a routine bedside method in neurointensive care.
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