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- Olsson, Sara K., et al.
(författare)
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Elevated levels of kynurenic acid in the cerebrospinal fluid of patients with bipolar disorder
- 2010
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Ingår i: Journal of Psychiatry & Neuroscience. - : CMA Joule Inc.. - 1180-4882 .- 1488-2434. ; 35:3, s. 195-199
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Tidskriftsartikel (refereegranskat)abstract
- Background: Patients with schizophrenia show elevated brain levels of the neuroactive tryptophan metabolite kynurenic acid (KYNA) This astrocyte] derived mediator acts as a neuroprotectant and modulates sensory gating and cognitive functiona We measured the levels of KYNA in the cerebrospinal fluid T vSyU of patients with bipolar disorder and healthy volunteers to investigate the putative involvement of KYNA in bipolar disorder. Methods: We obtained CSF by lumbar puncture from 23 healthy men and 31 euthymic men with bipolar disorder. We analyzed the samples using high] performance liquid chromatography. Results: Patients with bipolar disorder had increased levels of KYNA in their CSF compared with healthy volunteers (1.71 nM, standard error of the mean [SEM] cad, va dad, nM, SEM cacln p = 0.002. The levels of KYNA were positively correlated with age among bipolar patients but not healthy volunteersa Limitations: The influence of ongoing drug treatment among patients cannot be ruled outa We conducted our study during the euthymic phase of the diseasea Conclusion: Brain KYNA levels are increased in euthymic men with bipolar disorder. In addition, KYNA levels increased with age in these patientsa These findings indicate shared mechanisms between bipolar disorder and schizophrenia. Elevated levels of brain KYNA may provide further insight to the pathophysiology and progression of bipolar disorder.
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| 2. |
- Peter, Hannes, et al.
(författare)
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Function-specific response to depletion of microbial diversity
- 2011
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Ingår i: The ISME Journal. - : Springer Science and Business Media LLC. - 1751-7362 .- 1751-7370. ; 5:2, s. 351-361
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Tidskriftsartikel (refereegranskat)abstract
- Recent meta-analyses suggest that ecosystem functioning increases with biodiversity, but contradictory results have been presented for some microbial functions. Moreover, observations of only one function underestimate the functional role of diversity because of species-specific trade-offs in the ability to carry out different functions. We examined multiple functions in batch cultures of natural freshwater bacterial communities with different richness, achieved by a dilution-to-extinction approach. Community composition was assessed by molecular fingerprinting of 16S rRNA and chitinase genes, representing the total community and a trait characteristic for a functional group, respectively. Richness was positively related to abundance and biomass, negatively correlated to cell volumes and unrelated to maximum intrinsic growth rate. The response of chitin and cellulose degradation rates depended on the presence of a single phylotype. We suggest that species identity and community composition rather than richness matters for specific microbial processes.
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