Following on from the Annual Fish Veterinary Society Conference, this symposium was organised wit... more Following on from the Annual Fish Veterinary Society Conference, this symposium was organised with the Laboratory Animal Science Association and brought together experts from ornamental (pond and aquarium) fish practice, aquaculture and aquatic-research facilities to discuss good practice of anaesthesia. This proceedings paper gives an overview of relevant experiences involving a range of immersion drugs including tricaine, benzocaine and isoeugenol, as well as a summary of the main topics of discussion. While fish anaesthesia is commonplace, administration methods, drugs and monitoring procedures may often be regarded as antiquated when compared with mammalian practice. These limitations notwithstanding, individual fish will benefit from good anaesthetic monitoring. Although the most common anaesthetic drugs may be perceived as equally efficacious and therefore interchangeable for different settings, challenges are different for the anaesthesia of grouped fish, when determining spe...
This report provides a detailed description of sinusoidal and perisinusoidal structures in the no... more This report provides a detailed description of sinusoidal and perisinusoidal structures in the normal liver of the juvenile Atlantic salmon (Salmo salar L.), a teleost species. The liver was studied by light, transmission, and scanning electron microscopy, and organ specimens were sampled after retrograde, whole-body perfusion through the dorsal aorta using 3% glutaraldehyde. Detailed characterization of perisinusoidal stellate cells also included immunohistochemical staining for desmin and evaluation of autofluorescence of the same cells upon excitation in ultraviolet (UV) light. The sinusoid is lined by one cell type only: the endothelial cell. No intraluminal pit cells or Kupffer cells are present. The space of Disse contains reticulin fibres, visualized by Gomori's silver stain, and perisinusoidal stellate cells (PSC). PSC exhibited autofluorescence in UV light, indicating that these cells store vitamin A in cytoplasmic lipid droplets. Immunohistochemically, PSC were found negative for desmin. The space of Disse, extending deep down between adjacent hepatocytes, receives long, slender microvilli from parenchymal cells. In addition to scattered macrophages, interhepatocytic cells (IHC) are found perisinusoidally. Hepatocytes of Atlantic salmon form branching and anastomosing tubules. The sinusoids of Atlantic salmon liver are lined by a fenestrated endothelium, with PSC located in the space of Disse, with macrophages and IHC as inhabitants of the interhepatocytic space. IHC show ultrastructural similarities to mammalian pit cells and teleostean large granular lymphocytes, as well as to piscine monocytes. PSC might be storage cells for vitamin A in Atlantic salmon as shown by autofluorescence in these cells, while immunohistochemical studies indicate that desmin does not seem to be an adequate immunohistochemical marker for PSC in the juvenile Atlantic salmon. Methodologically, fixation for electron microscopy was performed by a new and convenient perfusion method: arterial retrograde whole body perfusion. Liver specimens intended for scanning electron microscopy were fractured at room temperature after prolonged osmium postfixation, leaving hepatocytes intact and producing images well suited to document the three-dimensional structure of cells and tissue.
The present study describes light and electron microscopic changes in the liver of Atlantic salmo... more The present study describes light and electron microscopic changes in the liver of Atlantic salmon during the development of infectious salmon anemia (ISA). Atlantic salmon postsmolts weighing 80-100 g were infected by intraperitoneal injections, and liver samples were collected sequentially between day 0 and day 25 post infection (p.i.), with time intervals of 3-4 days. At each collection time, livers from five infected fish and two control fish were examined. Changes involving the perisinusoidal macrophages were observed by transmission electron microscopy, from day 4 p.i. Large vacuoles, containing a fine-granular material with low electron density, accumulated in the cytoplasm. These changes persisted and became more severe throughout the investigation, leading to a considerable increase in the size of the cells. At day 14 p.i., degenerative features of the sinusoidal endothelium were observed. By day 18 p.i., areas of the liver were devoid of a sinusoidal endothelial lining, br...
ABSTRACT The present authors report the first description of a bacterial disease, Varracalbmi, re... more ABSTRACT The present authors report the first description of a bacterial disease, Varracalbmi, recorded sporadically among seawater-reared Atlantic salmon in northern Norway between 1989 and early 1992. The causative organism, a Gram-negative, non-motile, capsule-forming, oxidase-positive and facultatively anaerobic rod, has not previously been described. The mean water temperatures during the outbreaks varied from 2.5 to 8 °C. The disease was characterized by haemorrhagic and necrotizing pyogranulomatous inflammation which targeted the eye and resulted in panophthalmitis. Accompanying lesions included deep dermal ulcerations, necrotizing and haemorrhagic pyogranulomatous lesions in the visceral organs, and necrosis of the pseudobranch. The proposed name of the disease, Varracalbmi, is the Lappish name for ‘bloody eye’.
Efficacy and side-effects of anti-furunculosis vaccination were studied in an experimental trial.... more Efficacy and side-effects of anti-furunculosis vaccination were studied in an experimental trial. One unadjuvanted and eight adjuvanted bacterins were administered by intraperitoneal injection to Atlantic salmon (Salmo salarL.) presmolts held in fresh water. Adjuvant systems represented were mineral oil, aluminium salts, glucan and levamisole. Protection, plasma antibodies, and side-effects were determined six weeks, three months, and six months after vaccination.
Following on from the Annual Fish Veterinary Society Conference, this symposium was organised wit... more Following on from the Annual Fish Veterinary Society Conference, this symposium was organised with the Laboratory Animal Science Association and brought together experts from ornamental (pond and aquarium) fish practice, aquaculture and aquatic-research facilities to discuss good practice of anaesthesia. This proceedings paper gives an overview of relevant experiences involving a range of immersion drugs including tricaine, benzocaine and isoeugenol, as well as a summary of the main topics of discussion. While fish anaesthesia is commonplace, administration methods, drugs and monitoring procedures may often be regarded as antiquated when compared with mammalian practice. These limitations notwithstanding, individual fish will benefit from good anaesthetic monitoring. Although the most common anaesthetic drugs may be perceived as equally efficacious and therefore interchangeable for different settings, challenges are different for the anaesthesia of grouped fish, when determining spe...
This report provides a detailed description of sinusoidal and perisinusoidal structures in the no... more This report provides a detailed description of sinusoidal and perisinusoidal structures in the normal liver of the juvenile Atlantic salmon (Salmo salar L.), a teleost species. The liver was studied by light, transmission, and scanning electron microscopy, and organ specimens were sampled after retrograde, whole-body perfusion through the dorsal aorta using 3% glutaraldehyde. Detailed characterization of perisinusoidal stellate cells also included immunohistochemical staining for desmin and evaluation of autofluorescence of the same cells upon excitation in ultraviolet (UV) light. The sinusoid is lined by one cell type only: the endothelial cell. No intraluminal pit cells or Kupffer cells are present. The space of Disse contains reticulin fibres, visualized by Gomori's silver stain, and perisinusoidal stellate cells (PSC). PSC exhibited autofluorescence in UV light, indicating that these cells store vitamin A in cytoplasmic lipid droplets. Immunohistochemically, PSC were found negative for desmin. The space of Disse, extending deep down between adjacent hepatocytes, receives long, slender microvilli from parenchymal cells. In addition to scattered macrophages, interhepatocytic cells (IHC) are found perisinusoidally. Hepatocytes of Atlantic salmon form branching and anastomosing tubules. The sinusoids of Atlantic salmon liver are lined by a fenestrated endothelium, with PSC located in the space of Disse, with macrophages and IHC as inhabitants of the interhepatocytic space. IHC show ultrastructural similarities to mammalian pit cells and teleostean large granular lymphocytes, as well as to piscine monocytes. PSC might be storage cells for vitamin A in Atlantic salmon as shown by autofluorescence in these cells, while immunohistochemical studies indicate that desmin does not seem to be an adequate immunohistochemical marker for PSC in the juvenile Atlantic salmon. Methodologically, fixation for electron microscopy was performed by a new and convenient perfusion method: arterial retrograde whole body perfusion. Liver specimens intended for scanning electron microscopy were fractured at room temperature after prolonged osmium postfixation, leaving hepatocytes intact and producing images well suited to document the three-dimensional structure of cells and tissue.
The present study describes light and electron microscopic changes in the liver of Atlantic salmo... more The present study describes light and electron microscopic changes in the liver of Atlantic salmon during the development of infectious salmon anemia (ISA). Atlantic salmon postsmolts weighing 80-100 g were infected by intraperitoneal injections, and liver samples were collected sequentially between day 0 and day 25 post infection (p.i.), with time intervals of 3-4 days. At each collection time, livers from five infected fish and two control fish were examined. Changes involving the perisinusoidal macrophages were observed by transmission electron microscopy, from day 4 p.i. Large vacuoles, containing a fine-granular material with low electron density, accumulated in the cytoplasm. These changes persisted and became more severe throughout the investigation, leading to a considerable increase in the size of the cells. At day 14 p.i., degenerative features of the sinusoidal endothelium were observed. By day 18 p.i., areas of the liver were devoid of a sinusoidal endothelial lining, br...
ABSTRACT The present authors report the first description of a bacterial disease, Varracalbmi, re... more ABSTRACT The present authors report the first description of a bacterial disease, Varracalbmi, recorded sporadically among seawater-reared Atlantic salmon in northern Norway between 1989 and early 1992. The causative organism, a Gram-negative, non-motile, capsule-forming, oxidase-positive and facultatively anaerobic rod, has not previously been described. The mean water temperatures during the outbreaks varied from 2.5 to 8 °C. The disease was characterized by haemorrhagic and necrotizing pyogranulomatous inflammation which targeted the eye and resulted in panophthalmitis. Accompanying lesions included deep dermal ulcerations, necrotizing and haemorrhagic pyogranulomatous lesions in the visceral organs, and necrosis of the pseudobranch. The proposed name of the disease, Varracalbmi, is the Lappish name for ‘bloody eye’.
Efficacy and side-effects of anti-furunculosis vaccination were studied in an experimental trial.... more Efficacy and side-effects of anti-furunculosis vaccination were studied in an experimental trial. One unadjuvanted and eight adjuvanted bacterins were administered by intraperitoneal injection to Atlantic salmon (Salmo salarL.) presmolts held in fresh water. Adjuvant systems represented were mineral oil, aluminium salts, glucan and levamisole. Protection, plasma antibodies, and side-effects were determined six weeks, three months, and six months after vaccination.
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Papers by Lars Speilberg