| 1. |
- Ekström, Peter, et al.
(författare)
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A morphometric study of age-related changes in serotonin-immunoreactive cell groups in the brain of the coho salmon, Oncorhynchus kisutch walbaum
- 1992
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Ingår i: Experimental Neurology. - 0014-4886. ; 116:2, s. 204-209
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Tidskriftsartikel (refereegranskat)abstract
- In the coho salmon there is a transient increase in total brain concentrations of serotonin during smolt transformation which occurs midlife, just before down-stream migration to the ocean. There is also a gradual age-related increase in total brain serotonin concentrations. These increases may be due to reorganization of the central serotonergic system, changes in serotonin turnover, or both. They may be related to the specific physiological conditions during different life stages of salmon, or to ongoing growth and plastic changes of the brain. In the present study we have compared serotonin-immunoreactive (5-HTir) cell groups in 1-year-old freshwater presmolt and 2-year-old seawater postsmolt salmon. Our data indicate a continuous growth of the 5-HTir cell groups in terms of an increase in numbers of 5-HTir neurons in the cell groups of the pretectum and the brain stem, and an increase in the volumes of such neurons and cell groups. However, when related to the increase in total brain volume, i.e., the volume that may be innervated by the 5-HTir neurons, the ratio of 5-HTir neurons per mm3 decreased. The largest decreases were observed in the median raphe nucleus (P < 0.005) and the B9 group (P < 0.05). The ratio of volumes of the brain nuclei containing 5-HTir neurons relative to total brain volume was remarkably constant when comparing pre- and postsmolt brains: only the pretectal nucleus showed a significant decrease (P < 0.01) in relative volume. The total volume of 5-HTir neurons increased in postsmolts (P < 0.005). Since there was no increase in size of 5-HTir somata in any nucleus, changes in total volume reflect the changes in numbers of 5-HTir neurons. Thus, to account for the observed age-related increase in total brain concentrations of serotonin, an increase in the net production of serotonin, possibly accompanied by an increase in the density of serotonergic innervation in certain brain areas, may be postulated. The transient surge of whole brain content of serotonin observed at smolt transformation probably reflects a transient change in serotonin metabolism rather than an increase in the number of neurons.
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| 2. |
- Holmqvist, Bo I., et al.
(författare)
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Nitric oxide synthase in the brain of a teleost
- 1994
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Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940. ; 171:1-2, s. 205-208
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Tidskriftsartikel (refereegranskat)abstract
- The presence and distribution of the nitric oxide (NO) converting enzyme, NO synthase (NOS), was investigated in the brain of a teleost, the Atlantic salmon. Both NOS immunoreactive and NADPH diaphorase positive, non-neuronal and neuronal cell bodies, fibers and putative nerve terminals were identified throughout the brain. Even so, the staining was not identical in all regions. NO, synthesized by NOS-like enzymes, may play an important role in a diversity of cellular mechanisms in the brain of the salmon, including in neural systems related to olfactory, visual, hypophysiotrophic, viscero-sensoric and motor functions.
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| 3. |
- Montelin, Hanna, 1984-, et al.
(författare)
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Treatment, outcomes and characterization of pathogens in urinary tract infections caused by ESBL-producing Enterobacterales : a prospective multicentre study
- 2024
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Ingår i: Journal of Antimicrobial Chemotherapy. - : OXFORD UNIV PRESS. - 0305-7453 .- 1460-2091.
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Treatment options for urinary tract infections (UTIs) caused by ESBL-producing Enterobacterales are limited. Moreover, evidence to support therapeutic decisions is lacking. This study assessed current treatment strategies and patient and pathogen characteristics in relation to clinical and microbiological outcomes.Methods: Patients with UTI caused by ESBL-producing Enterobacterales were prospectively recruited by investigators at 15 infectious disease hospital departments. Data were collected on patient characteristics, treatments, clinical and microbiological cure 10–14 days after the end of treatment, and relapse within 3 months. Bacterial isolates were subjected to MIC determination and WGS.Results: In total, 235 patients (107 febrile UTI, 128 lower UTI) caused by Escherichia coli (n = 223) and Klebsiella spp. (n = 12) were included. Clinical and microbiological cure rates were 83% and 64% in febrile UTI, and 79% and 65% in lower UTI. Great variability in treatments was observed, especially in oral therapy for febrile UTI. No difference was seen in clinical outcomes with piperacillin/tazobactam (n = 28) compared with carbapenems (n = 41). Pivmecillinam was frequently used in lower UTI (n = 62), and was also associated with high clinical cure rates when used as initial therapy (10/10) or follow-up (7/8) for febrile UTI. Recurrent infection, diabetes mellitus and urogenital disease were associated (P < 0.05) with clinical failure and relapse. In E. coli, ST131 was significantly associated with relapse, and haemolysin with microbiological failure or relapse.Conclusions: Antibiotic treatments were highly variable. Patient and pathogen factors were identified as potential determinants of disease presentation and outcomes and may prove useful to guide individualized treatment and follow-up.
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| 4. |
- Östholm, Thomas, et al.
(författare)
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Postsmolt change in numbers of acetylcholinesterase-positive cells in the pineal organ of the Pacific coho salmon
- 1992
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Ingår i: Cell & Tissue Research. - 0302-766X. ; 270:2, s. 281-286
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Tidskriftsartikel (refereegranskat)abstract
- We have examined the occurrence of acetylcholinesterase (AChE)-positive cells in the pineal organ of different developmental stages of the Pacific coho salmon. Large numbers of AChE cells were present in fresh-water living alevins, in all stages of presmolts (n=307-544), and in adult spawners (n=696-1774) whereas seawater-living postmolts displayed a total lack of labeled cells. The AChE-reactive cells were evently distributed within the pineal end-vesicle and stalk of the presmolts and adults. However, the AChE-positive cells that occurred in the pineal stalk were of a smaller type and more uniform in shape than the cells of the pineal endvesicle. The dense populations of AChE-stained cells in the alevins, were all situated in the caudal part of the pineal end-vesicle. We conclude that changes in pineal metabolism occur in postsmolt salmon that liver in saltwater. It is not clear whether the observed change in pineal AChE expression is an "unspecific" change caused by life in the sea, reflecting alterations that are related to aspects of osmoregulation, and/or is involved in the visual function of the pineal organ resulting from changes in the environmental lighting conditions, e.g., photoperiod, light-intensity, or spectral composition. This study adds to our previous findings of changes that occur in the central nervous system of the salmon during the time of the parr-smolt transformation and migration between limnic and marine environments and indicates a possible central role of the pineal organ in the control of these events.
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