| 1. |
- Fridell, F, et al.
(författare)
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Effect of hyperoxygenation on the susceptibility of Atlantic salmon (Salmo salar L.) to experimental challenge of IPN virus
- 2007
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486. ; 270:1-4, s. 23-35
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Tidskriftsartikel (refereegranskat)abstract
- Intensive salmon smolt production normally includes reduced water flow and hyperoxygenation (added oxygen) of remaining water. There is little information on how different water quality parameters influence the fish health and the susceptibility to infectious diseases. The current experiment was carried out to evaluate if the combination of hyperoxygenation and reduced water flow (hyperoxic) can act as a chronic stressor to salmon in freshwater (FW) in such a way that it increases the susceptibility to IPN virus (IPNV) following seawater transfer. In FW, after 22 days of hyperoxic exposure plasma ion, TBARS and cortisol were measured. The cortisol levels were significantly (p = 0.011) higher in the hyperoxic group compared to controls maintained under normal oxygen saturation and water flow (normoxic), indicating chronic stress. Hyperoxygenation in FW caused decreased plasma [Cl−] compared to the normoxic group (p = 0.037), while [K+] tended to be higher in the hyperoxic group (p = 0.088). No significant differences were observed in plasma [Na+], total osmolality, TBARS or hematocrit, but there was a tendency towards a lower hct in the hyperoxic compared to the normoxic group. In SW the mortality was higher in the hyperoxic group challenged with IPNV (34%) compared to the normoxic group challenged with IPNV (20%) (p = 0.02), and no mortality was observed in the PBS injected fish. The challenged fish showed an overall increase in plasma cortisol day 8, 10, 12 and 14 post-challenge (p = 0.015, p = 0.000, p = 0.046 and p = 0.022 respectively). After SW transfer and challenge, plasma [K+] was elevated in both challenged groups, but no consistent trends were found for plasma [Cl−], [Na+] or total osmolality during the SW phase. There were no significant differences in the gene expression level of IFN 1α, Mx and IL 1β prior to challenge, suggesting that the basic expression level of these genes were not affected by hyperoxygenation. IPNV was detected in kidney and pylorus, by immunohistochemistry, cell culture, and RT-PCR in head kidney. This experiment indicates that chronic stress induced by a combination of low water flow and hyperoxygenation increases the susceptibility to IPNV challenge.
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| 2. |
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| 3. |
- Gadan, K, et al.
(författare)
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Slow release cortisol implants result in impaired innate immune responses and higher infection prevalence following experimental challenge with infectious pancreatic necrosis virus in Atlantic salmon (Salmo salar) parr.
- 2012
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Ingår i: Fish & shellfish immunology. - : Elsevier BV. - 1095-9947 .- 1050-4648. ; 32:5, s. 637-44
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Tidskriftsartikel (refereegranskat)abstract
- Stress can affect the immune system and increase susceptibility to various diseases but knowledge of the underlying mechanisms is scarce. There is a complex interaction between the immune system and the endocrine system of vertebrates. In fish, cortisol is a key hormone regulating stress response and recent studies have also suggested that this hormone can affect the immune system, where cortisol is mainly regarded as an immunosuppressive factor. The aim of the present study was to examine the impact of chronically elevated levels of cortisol on the immune response and susceptibility to experimental infection with infectious pancreatic necrosis virus (IPNV). Further, the effect of IPNV challenge on circulating levels of cortisol was investigated. Atlantic salmon parr were implanted intraperitoneally with sustained-release implants of bovine of cortisol (50 μg cortisol g(-1) body weight in an implant based on vegetable lipids). Vehicle implants were used as control (sham-injected). At 45 days after implantation (DAI), fish were challenged with a low virulent isolate of IPNV (by immersion). Samples of plasma, liver and head kidney was taken from fish before and 24 h, 48 h, 7 days week and 21 days post infection (DPI). Cortisol level in plasma was measured using radioimmunoassay and gene expression in liver and head kidney was analyzed with real-time PCR (RT-PCR). Infection prevalence in infected fish was assessed by virus culture and RT-PCR of head kidney samples. Cortisol implantation compared with sham-implanted fish had increased levels of plasma cortisol at 45 DAI. The relative expression of Interferon alpha-1 (IFNα-1), Myxo virus-1 Mx, Heat-shock protein 70 (HSP70), Serum amyloid A (SAA), Glucocorticoid receptor (GR) and Heat-shock protein 90 (HSP90) tends to be down-regulated by cortisol implantation. There was a higher prevalence of fish with detectable levels of IPNV, as measured by cell culture and RT-PCR, in the cortisol-implanted group challenged with IPNV (0 = 0.0305) relative to the group that received a sham implantation. Further, cortisol seems to delay the induction of the antiviral IFNα-1 pathway and Mx mRNA expression. This study shows that elevated plasma cortisol level leads to an impaired innate immune response, and higher virus (IPNV) prevalence in Atlantic salmon parr.
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| 4. |
- Popiolek, M., et al.
(författare)
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Total Mesorectal Excision for Mid-Rectal Cancer Without Anastomosis : Low Hartmann's Operation or Intersphincteric Abdomino-Perineal Excision?
- 2019
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Ingår i: Scandinavian Journal of Surgery. - : Sage Publications. - 1457-4969 .- 1799-7267. ; 108:3, s. 233-240
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: In mid-rectal cancer, the low colorectal anastomosis is, although feasible, sometimes avoided. The aim was to compare low Hartmann's procedure with intersphincteric abdomino-perineal excision of the rectum, in patients operated with total mesorectal excision for mid-rectal cancer in whom the low anastomosis was technically feasible but for patient-related reasons undesired.MATERIAL AND METHODS: A total of 64 consecutive patients with mid-rectal cancer who underwent low Hartmann's procedure (n = 34) or intersphincteric abdomino-perineal excision (n = 30) at one colorectal unit were compared regarding patient demography, short-term oncology, surgical outcome at 3 and 24 months, and long-term overall survival.RESULTS: There were no significant differences between intersphincteric abdomino-perineal excision and Hartmann's procedure regarding age, gender distribution, body mass index, preoperative radiotherapy, tumor level, or cancer stages. Operation time was shorter in Hartmann's procedure as compared with intersphincteric abdomino-perineal excision, median 174 and 256 min, (P < 0.001), and intraoperative blood loss was increased, 600 and 500 mL, respectively (P = 0.045). Number of lymph nodes and circumferential resection margin were comparable. In Hartmann's procedure compared with intersphincteric abdomino-perineal excision, the need for reoperation was 24% and 3%, (P = 0.020), complications classified as Clavien-Dindo 3-4 occurred in 32% and 10%, (P = 0.031), pelvic abscess in 21% and 10%, (P = 0.313), and mortality within 90 days was 3% and 0%, respectively, (P = 0.938). In intersphincteric abdomino-perineal excision, the perineal wound was not healed at 3 months in 13%, and in Hartmann's procedure 15% had chronic secretion from the anorectal remnant at 2 years postoperatively.CONCLUSION: The results from this study suggest that intersphincteric abdomino-perineal excision might be an alternative to Hartmann's procedure in patients with mid-rectal cancer, in whom a low colorectal anastomosis is undesired.
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| 6. |
- Sundh, Henrik, 1976, et al.
(författare)
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The effect of hyperoxygenation and reduced flow in fresh water and subsequent infectious pancreatic necrosis virus challenge in sea water, on the intestinal barrier integrity in Atlantic salmon, Salmo salar L
- 2009
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Ingår i: Journal of Fish Diseases. - 1365-2761. ; 32:8, s. 687-98
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Tidskriftsartikel (refereegranskat)abstract
- In high intensive fish production systems, hyperoxygenation and reduced flow are often used to save water and increase the holding capacity. This commonly used husbandry practice has been shown to be stressful to fish and increase mortality after infectious pancreatic necrosis virus (IPNV) challenge, but the cause and effect relationship is not known. Salmonids are particularly sensitive to stress during smoltification and the first weeks after seawater (SW) transfer. This work aimed at investigating the impact of hyperoxygenation combined with reduced flow in fresh water (FW), on the intestinal barrier in FW as well as during later life stages in SW. It further aims at investigating the role of the intestinal barrier during IPNV challenge and possible secondary infections. Hyperoxygenation in FW acted as a stressor as shown by significantly elevated plasma cortisol levels. This stressful husbandry condition tended to increase paracellular permeability (P(app)) as well as translocation of Aeromonas salmonicida in the posterior intestine of Atlantic salmon. After transfer to SW and subsequent IPNV challenge, intestinal permeability, as shown by P(app), and translocation rate of A. salmonicida increased in the anterior intestine, concomitant with further elevation in plasma cortisol levels. In the anterior intestine, four of five fish displayed alterations in intestinal appearance. In two of five fish, IPNV caused massive necrosis with significant loss of cell material and in a further two fish, IPNV caused increased infiltration of lymphocytes into the epithelium and granulocytes in the lamina propria. Hyperoxygenation and reduced flow in the FW stage may serve as stressors with impact mainly during later stages of development. Fish with an early history of hyperoxygenation showed a higher stress response concomitant with a disturbed intestinal barrier function, which may be a cause for the increased susceptibility to IPNV infection and increased susceptibility to secondary infections.
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