Possible causes of diabetes mellitus in cattle infected with bovine viral diarrhoea virus.

In cattle, we encountered insulin-dependent diabetes mellitus (IDDM) associated with bovine viral diarrhoea virus (BVDV) infection. To estimate the correlation between IDDM and BVDV infection, the distribution of BVDV in the pancreas and islet-cell antibody (ICA) were investigated. The distribution of BVDV in the pancreas was examined by in situ hybridization using two oligonucleotide probes that recognized the gp25- and p14-coding regions of the BVDV gene. ICA was examined by indirect fluorescence antibody assay using the sera from affected cattle and pancreata from normal cattle. In the pancreata of all BVDV-infected cattle, including IDDM-complicated cattle, oligonucleotide probe hybridized portions were recognized. In short, BVDV genes were detected not only in IDDM-complicated cattle but also in uncomplicated cattle. Moreover, there was no hybridized portion in the islet cells. In BVDV-infected and IDDM-complicated cattle, ICA was frequently detected. On the other hand, ICA was not detected in BVDV-infected and IDDM uncomplicated cattle. These results suggest that IDDM associated with BVDV infection is not a direct effect of BVDV on islet cells. Therefore, as BVDV did not induce IDDM in any cases, it appears that BVDV does not induce IDDM directly, but rather may be an autoimmune disease induced by autoantibodies against islet cells.     

Gene Defect of Dermatan Sulfate Proteoglycan of Cattle Affected With a Variant Form of Ehlers-Danlos Syndrome

A defect of the core protein of dermatan sulfate proteoglycan was suspected in a Holstein calf affected with a variant form of Ehlers-Danlos syndrome. The mutation was a guanine-to-adenine transition at nucleotide position 254, which resulted in a serine-to-asparagine substitution of the bovine proteoglycan core protein. This substitution occurred in the serine-glycine dipeptide repeat that was suspected to be the binding portion of dermatan sulfate. This point mutation in the genome was also detected by the use of restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) methods. The results of the RFLP and PCR indicated that the calf was a heterozygote of an abnormal gene and a normal gene of the core protein. The interpretation of these data revealed that the functional abnormality in cutaneous tissues of the calf was caused by an abnormal gene of the proteoglycan core protein, which induced a substitution of amino acid.     

Rumen bacteria are involved in the onset of onion-induced hemolytic anemia in sheep.

The mechanism of onion-induced hemolytic anemia in ruminants was investigated. The ether-extract obtained from the mixture of rumen fluid and onion juice incubated at 38.5 degrees C for 9 hr induced oxidative damage in sheep erythrocytes in vitro, indicating the production of certain oxidants in the mixture. The increase of the oxidative effect in the mixture was inhibited completely by the removal of rumen microorganisms and partly by treatment with antibiotics and by oxygen gas. The sheep fed onions (50 g/kg body weight/day) for 15 days developed more severe Heinz body hemolytic anemia than did the sheep fed the equivalent amount of onions with 5 g/day ampicillin sodium salt. The results indicated that certain rumen bacteria appear to be involved in the onset of onion-induced hemolytic anemia in sheep.     

Possible Causes of Diabetes Mellitus in Cattle Infected with Bovine Viral Diarrhoea Virus

In cattle, we encountered insulin-dependent diabetes mellitus (IDDM) associated with bovine viral diarrhoea virus (BVDV) infection. To estimate the correlation between IDDM and BVDV infection, the distribution of BVDV in the pancreas and islet-cell antibody (ICA) were investigated. The distribution of BVDV in the pancreas was examined by in situ hybridization using two oligonucleotide probes that recognized the gp25- and p14-coding regions of the BVDV gene. ICA was examined by indirect fluorescence antibody assay using the sera from affected cattle and pancreata from normal cattle. In the pancreata of all BVDV-infected cattle, including IDDM-complicated cattle, oligonucleotide probe hybridized portions were recognized. In short, BVDV genes were detected not only in IDDM-complicated cattle but also in uncomplicated cattle. Moreover, there was no hybridized portion in the islet cells. In BVDV-infected and IDDM-complicated cattle, ICA was frequently detected. On the other hand, ICA was not detected in BVDV-infected and IDDM uncomplicated cattle. These results suggest that IDDM associated with BVDV infection is not a direct effect of BVDV on islet cells. Therefore, as BVDV did not induce IDDM in any cases, it appears that BVDV does not induce IDDM directly, but rather may be an autoimmune disease induced by autoantibodies against islet cells.     

Nonsense mutation of feline beta-hexosaminidase beta-subunit (HEXB) gene causing Sandhoff disease in a family of Japanese domestic cats

G(M2) gangliosidoses are inherited metabolic disorders and are caused by severely reduced enzymatic activity of lysosomal beta-hexosaminidase. In the present study, the open reading frame (ORF) of the HEXB gene in a family of Japanese domestic cats with G(M2) gangliosidosis variant 0 (Sandhoff disease) was determined. Two types of abnormal cDNA clones were obtained from the liver of an affected cat tissue. One showed a single nucleotide substitution from C to T at nucleotide position 667 of the HEXB ORF. In the deduced amino acid sequence, the codon of arginine was altered to a stop codon. The genotyping, using PCR-primer introduced restriction analysis confirmed that Sandhoff disease in this family is associated with this nonsense mutation. Discovery of the nonsense mutation will permit the confirmation of the clinical diagnosis of Sandhoff disease in conjugation with the already established enzyme-based test.     

Endogenous gibberellins and their effects on flowering and stem elongation in cabbage (Brassica oleracea var. capitata)

Summary

Endogenous gibberellins were extracted from cabbage shoots and were analysed using gas chromatography and mass spectrometry. Nine gibberellins (GA₁, GA₁₉, GA₂₀, GA₄₄, GA₁₂, GA₄, GA_15, GA₂₄ and GA₂₅) were identified. Two gibberellin biosynthesis pathways were suggested, an early-13-hydroxlyated pathway and a non-13-hydroxylated pathway, to operate in cabbage shoots. GA₁, GA₄ and prohexadione calcium, a gibberellin biosynthesis inhibitor, were applied to the shoot tip of cabbage ‘Sousyu’ and ‘Kinkei No.201’ with or without cold treatment. Without cold treatment, stem elongation was increased by gibberellins and was suppressed by prohexadione calcium in both cultivars. But prohexadione calcium treatment, followed by gibberellin, promoted stem elongation more than gibberellin alone. Flowering was not induced by gibberellin or prohexadione calcium without cold treatment. When gibberellin and prohexadione calcium were applied during a cold treatment, stem elongation after the cold treatment was increased by gibberellins and was suppressed by prohexadione calcium in both cultivars. Flower bud appearance was promoted by GA₁ and GA₄ in ‘Sousyu’, but in ‘Kinkei No. 201’ only GA₄ was markedly effective. Inhibition of stem elongation and delay of flower bud appearance by prohexadione calcium were overcome by applying GA₁ or GA₄. Neither gibberellin nor prohexadione calcium treatment changed the number of leaf nodes at anthesis. These results indicated that stem elongation and flower bud development are regulated by gibberellins, but gibberellins might have little effect on flower induction.     

Collie eye anomaly in Hokkaido dogs: case study

Objective To describe a Hokkaido dog, one of the traditional Japanese breeds that was affected by Collie eye anomaly (CEA), and to report the genotype of this dog and the Hokkaido dog allelic frequency of the CEA‐associated mutation. Case A nine‐month‐old intact female Hokkaido dog without any obvious visual disturbance was diagnosed ophthalmoscopically with CEA. Severe choroidal hypoplasia was observed in the bilateral temporal area adjacent to the optic nerve head, appearing as whitish areas. Therefore, the dog was suspected of possessing the CEA‐associated mutation that was previously reported as an intronic 7.8‐kilo base deletion in the canine NHEJ1 gene. Procedures SYBR Green‐based real‐time PCR with a melting curve analysis, conventional PCR with agarose gel electrophoresis, and direct DNA sequencing were carried out to determine the genotype of the dog. Furthermore, a preliminary genotyping survey was carried out in 17 Hokkaido dogs from three kennels using the real‐time PCR method, and the pedigree relationships were analyzed using their pedigree papers. Results The Hokkaido dog affected by CEA was proven to possess the CEA‐associated mutation. Of these 17 Hokkaido dogs, 12 dogs were heterozygous carriers and five dogs were affected by this mutation. The preliminary genotyping survey and pedigree analysis demonstrated that the allelic frequency of the CEA‐associated mutation is very high in Hokkaido dogs. Conclusion These data suggest that the Hokkaido breed is highly susceptible to CEA because of the known CEA‐associated mutation much like the Collie‐related breeds.     

A case of suspected lysosomal storage disease in a neonatal Japanese black calf

A 5-day-old Japanese black calf was necropsied and intracytoplasmic vacuolations were histologically observed in many tissues. In the central nervous system, intracytoplasmic inclusions and vacuoles were found in neuronal cells. Intracytoplasmic inclusions were more conspicuous in the nuclei containing large nerve cells, especially in the brain stem and spinal cord. These inclusions were stained weak positive to positive with alcian blue, Giemsa, Luxol fast blue and periodic acid-Schiff stains but not with oil red O. Ultrastructurally, neuronal inclusions were observed in lysosomes and consisted of an amorphous electron-dense substance and occasional membranous structures. These findings seem to differ from the cases of bovine lysosomal diseases that have been reported, and this case may be another type of lysosomal storage disease.     

Suppressive effect of culture supernatant of erythrocytes and serum from dogs infected with Babesia gibsoni on the morphological maturation of canine reticulocytes in vitro

The present study evaluated the effects of infected culture supernatant of erythrocytes, fractionation of culture supernatant and serum from dogs infected with Babesia gibsoni (B. gibsoni) on the maturation of canine reticulocytes in vitro. The SDS-PAGE demonstrated that significantly broader bands were generated by both the infected culture supernatant of erythrocytes and the serum from dogs chronically infected with B. gibsoni. The culture supernatant of erythrocytes infected with B. gibsoni strongly suppressed the maturation of reticulocytes. Prior studies showed that chronically infected serum had inhibitory effects on both the maturation of reticulocytes and the canine pyrimidine 5''-nucleotidase subclass I and purine-specific 5''-nucleotidase activity. In addition, serum free infected culture supernatant of erythrocytes had an inhibitory effect on the morphological maturation of reticulocytes. These results suggest that infected serum and culture supernatant of erythrocytes might accumulate excess proteins and/or metabolites as a result of the inhibited maturation of reticulocytes and decreased activity of erythrocyte 5''-nucleotidase. Furthermore, the fractions observed at >150 kDa- and 150-70 kDa- in the infected culture supernatant and serum retarded the maturation of canine reticulocytes in vitro. The results obtained from the in vitro examinations, in the present study, suggested that B. gibsoni itself and/or its metabolites might release certain proteins in the infected culture supernatant and serum from infected dogs and as a result delay morphological maturation of canine reticulocytes.