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Biomedical subjects

S Grove

Publications and source records attributed to S Grove.

8 recordsLinked to original sources

A sequential study of pathological findings in Atlantic halibut, Hippoglossus hippoglossus (L), throughout one year after an acute outbreak of viral encephalopathy and retinopathy.

Following a natural outbreak of viral encephalopathy and retinopathy (VER) at a commercial farm in Norway, surviving Atlantic halibut, Hippoglossus hippoglossus, were sequentially studied for distribution of nodavirus, immune response and histopathology over 1 year. Typical clinical signs and histopathology of VER were observed during the acute stage of the disease. Most of the surviving fish became subclinical carriers of nodavirus with clusters of nodavirus-containing cells in the central nervous system. Four random samplings of presumably healthy fish were performed from two fish groups, with low and high growth rates respectively, over a 7-month period. Immunohistochemical (IHC) examination revealed a higher number of nodavirus-positive cells in fish with a low growth rate than in fish with a high growth rate. All IHC positive fish were also reverse transcriptase polymerase chain reaction (RT-PCR) positive for nodavirus and for nodavirus antibodies detected by enzyme-linked immunosorbent assay (ELISA) at all sampling points. The percentage of PCR- and ELISA-positive fish remained high throughout the year, while the number of IHC-positive fish decreased, especially in the group with a high growth rate. Several other histopathological changes were observed, including pericarditis, steatitis, changes in liver and kidney, and necrosis of the intestinal wall. None of these findings seemed to be related to the nodavirus infection. Nodavirus was reisolated in cell culture from subclinically infected fish one year after the acute VER outbreak, which indicates that the virus was still infectious.

Animals↗

Experimental infection of Atlantic halibut Hippoglossus hippoglossus with nodavirus: tissue distribution and immune response.

Atlantic halibut Hippoglossus hippoglossus, age 8 mo and weighing 20 g, were challenged by either intraperitoneal injection (i.p.) or by bath exposure using nodavirus isolated from Atlantic halibut. Fish were sampled at intervals over a 41 d period, starting on Day 5 post-challenge. Although no clinical disease or mortality was recorded, the data show that nodavirus did successfully propagate in i.p.-challenged fish. Using conventional end-point reverse transcription (RT)-PCR, nodavirus was detected in the kidney of all examined i.p.-challenged fish, and further in the head, heart, liver and posterior intestine of most of these individuals. Quantitative real-time RT-PCR revealed that the amount of virus in head samples from the i.p.-challenged group increased during the experiment. The presence of nodavirus in nervous tissue of i.p.-challenged fish was detected by immunohistochemistry from Day 13 post-challenge. In the retina, virus positive cells were found adjacent to the circumferential germinal zone at the ciliary margin towards the iris. In the brain, a few positive cells were detected in the tectum opticum. An ELISA was developed to detect anti-nodavirus activity in plasma. The method included an optimized coating procedure, which allowed the use of non-purified nodavirus as the coating antigen in a simple indirect ELISA. An anti-nodavirus antibody response was detected from Day 19 post-challenge in i.p.-challenged fish, while a response was not detected in the bath-challenged or control fish. This experiment demonstrates a subclinical nodavirus infection in Atlantic halibut at a post-juvenile stage induced by i.p. injection of virus.

Animals↗

Distribution and retention of antigens of Aeromonas salmonicida in Atlantic salmon (Salmo salar L.) vaccinated with a DeltaaroA mutant or formalin-inactivated bacteria in oil-adjuvant.

In this study we report the differences in distribution and retention of Aeromonas salmonicida antigens after vaccination with two different vaccines. Parr of Atlantic salmon (Salmo salar) were given intraperitoneal injections of either a commercial, monovalent furunculosis vaccine (Apoject) or live, attenuated A. salmonicida (DeltaaroA). Fish were sampled at weeks 2, 4 and 12 post-vaccination and head kidney and spleen were collected. Presence of LPS and 16S rDNA in isolated leukocytes were investigated by immunocytochemistry and polymerase chain reaction (PCR).16S rDNA was detected in head kidney and spleen of all DeltaaroA vaccinated and most Apoject-vaccinated fish at weeks 2 and 4. At week 12, 16S rDNA was detected in none of the DeltaaroA vaccinated fish, but it was detected in head kidney of 75% of Apoject-vaccinated fish. LPS was detected in both vaccination groups at all sampling times, but most frequently in the DeltaaroA vaccinated fish (in head kidney 75-83% vs. 50%, in spleen 58-67% vs. 17-25%).

Adjuvants, Immunologic↗

Specific protein kinases modulated during T cell mitogenesis. Activity of a 55-kDa serine kinase is associated with growth arrest in human T cells.

The intracellular events which are involved in controlling the G1 to S phase transition during the eucaryotic cell cycle are important to define in order to understand the mechanisms by which mitogenic and growth arrest-inducing agents control cell growth. Because a change in protein kinase activity is associated with the initial response of cells to mitogenic stimulants and growth factors, we used a kinase renaturation assay to identify specific protein kinases which are modulated as human T cells make the G1 to S phase transition after mitogenic stimulation with lectin. We identified four protein serine/threonine kinases of 180, 97, 85, and 38 kilodaltons which are increased in activity as these cells enter S phase. A-55 kDa serine/threonine kinase (PK55) was shown to have maximal activity during G0 and its activity was reduced by 95% upon movement into S phase. PK55 is inducible in human T cells by removal of interleukin 2 and low serum incubation which arrests cells in G1 phase, indicating that it is closely associated with G1 phase growth arrest. Furthermore, a similar PK55 activity was induced upon growth arrest in HL-60 cells treated with dimethyl sulfoxide and in Daudi cells treated with interferon alpha. Because the cAMP-dependent protein kinase (PK-A) family has been shown to be antiproliferative to lectin stimulated T cells, we were interested in determining whether PK55 was in fact an isozyme of PK-A. Comparative analysis using a specific peptide inhibitor of PK-A activity revealed that PK55 is catalytically distinct from PK-A. This data suggest that increases in PK55 may be associated with the growth-arrested state and further that PK55 is distinct from PK-A.

Cell Line↗

Steroid hormones in ovarian vein and cyst fluid of a virilizing stromal tumor.

A 23-year-old female with clinical signs of excessive androgen and estrogen production was found to have a gonadal stromal tumor. The clinical symptoms correlated well with steroid hormone values in ovarian vein blood and ovarian cyst fluid of the ovarian tumor. Ovarian vein blood draining the ovarian tumor measured as follows: estrone, 162 pg/ml; estradiol, 1688 pg/ml; progesterone, 9.6 ng/ml; testosterone, 9775 ng/100 ml; and dihydrotestosterone, 2905 ng/100 ml. The ovarian cyst fluid produced higher estrogen and lower androgen values compared with ipsilateral ovarian vein blood. Peripheral levels of immunoreactive testosterone ranged from 210 to 244 ng/100 ml. It is concluded that excessive androgen and estrogen production may arise from a gonadal stromal tumor that has been previously classified as a purely virilizing ovarian tumor.

Adult↗