Susceptibility of isogeneic ginbuna Carassius auratus langsdorfii Temminck et Schlegel to cyprinid herpesvirus-2 (CyHV-2) as a model species.

Herpesviral haematopoietic necrosis (HVHN), caused by cyprinid herpesvirus-2 (CyHV-2), has affected the commercial production of the goldfish Carassius auratus and gibelio carp Carassius auratus gibelio. High water temperature treatments are reported to reduce the mortality rate of infected goldfish and elicit immunity in the survivors. To define the mechanism by which this intervention induces resistance, clonal ginbuna Carassius auratus langsdorfii, which is closely related to both species and has been used in fish immunology, may represent a promising model species. In this study, we investigated the susceptibility of clonal ginbuna strains to CyHV-2 and the effect of high water temperature treatment on infected ginbuna and goldfish. Experimental intraperitoneal infection with CyHV-2 at 25 °C caused 100% mortality in ginbuna strains, which was accompanied by histopathological changes typical of HVHN. Both infected ginbuna S3n strain and goldfish, exposed to high temperature for 6 days [shifting from 25 °C (permissive) to 34 °C (non-permissive)], showed reduced mortalities after the 1st inoculation, and subsequent 2nd virus challenge to 0%, indicating induction of immunity. It was concluded that ginbuna showed a similar susceptibility and disease development in CyHV-2 infection compared to goldfish, suggesting that ginbuna can be a useful fish model for the study of CyHV-2 infection and immunity.

A cloning of cytidine monophospho-N-acetylneuraminic acid hydroxylase from porcine endothelial cells.

INTRODUCTION: The Hanganutziu-Deicher (H-D) antigen with terminal N-glycolyl neuraminic acid-(NeuGc) is widely distributed in mammalian species including monkeys and apes, but is not found in humans and birds. After the knock out of α1, 3galactosyltransfease, the H-D antigen became a major antigen of the "non-Gal antigen." The expression of NeuGc is controlled by the activity of cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH). In this study, molecular cloning of pig CMAH was performed, as the first step in producing H-D knockout pigs. METHODS: A pig endothelial cell line, MYP30, was used. The DNA sequence of pig CMAH was queried in dbEST (NCBI) using the BLAST program to search for cDNA fragments of pig CMAH, based on an alignment analysis of the mouse CMAH sequence. A polymerase chain reaction experiment was performed and candidate cDNA clones were isolated. To obtain the 5'-end and 3'-end of the open reading frame sequence, a 5'-full RACE Core Set and 3'-full RACE Core Set were used. RESULTS: We cloned and characterized the pig CMAH gene. The ATG is located in exon 4, which corresponds to the mouse gene, and the stop codon is in exon 17. In the case of the 5' site of the gene, exon 3 was identified but exons 1 and 2 are still being investigated. On the other hand, exon 18 was newly identified in the 3' site of the gene. CONCLUSION: The results represent useful information for future clinical xenotransplantation studies.

Depletion of dietary n-3 fatty acid affects the level of cyclic AMP in rat hippocampus.

Prolonged depletion of dietary n-3 fatty acid induces a neurological disturbance. To ascertain the deficit of neurotransmission at the time of n-3 deficiency, the concentrations of cAMP and inositol triphosphate, and the activities of protein kinases A and C were examined in vitro in rat hippocampus. Furthermore, the saturation binding study of [3H]quinuclidinyl benzilate, a specific antagonist to muscarinic cholinergic receptor, was performed. Rats were fed a safflower oil diet as the deficient group and a soybean oil diet as the control group. Hippocampi were obtained from rats in the 3rd generation in the deficient group and in the 2nd generation in the control group. Dietary effect was not observed in the parameters except for the concentration of cAMP, which was significantly higher in the deficient group than in the control group.

Three mutant insulins in man.

We have previously identified a structurally abnormal insulin in the serum and pancreas of a middle-aged man with diabetes mellitus which arose from a leucine for phenylalanine substitution at position 24 or 25 of the insulin B chain; further analysis of the patient's leukocyte DNA showed that one of the patient's insulin alleles had undergone mutation resulting in loss of an MboII restriction site normally present in the human insulin gene. Two additional and unrelated patients with the same clinical syndrome have now been identified (ref. 4 and unpublished results). All of these patients showed hyperglycaemia typical of diabetes and with marked hyperinsulinaemia typical of insulin resistance, but all three show normal tolerance to exogenously administered insulin. As the opportunity of examining pancreatic tissue from patients suspected of secreting insulin variants is rare, we have developed a method combining HPLC and radioimmunoassay to identify insulin variants isolated from human sera. By this method we have shown that all three patients noted above secrete structurally variant and chemically distinct insulins. In correction of our original assignment, one is identified as [LeuB25]insulin.