Genetic and pathogenic characterization of Akabane viruses isolated from cattle with encephalomyelitis in Korea

A large-scale outbreak of Akabane viral encephalomyelitis in cattle was reported in the southern part of Korea in 2010. Fifteen Akabane virus (AKAV) strains were isolated from the brain and spinal cord samples by using BHK-21 and/or HmLu-1 cells. To examine the genetic relationships and characteristics of the isolates, nucleotide sequences of the S, M, and L segments of the 15 isolates were determined and analyzed. Complete sequence analysis of the 15 AKAV isolates showed 99.9-100% amino acid identities, indicating that the 15 isolates originated from a single strain. The S and M RNA segments of a representative isolate (AKAV-7/SKR/2010) were also compared with the segments of representative reference sequences. This AKAV-7/SKR/2010 strain showed the highest identity with the Iriki and KM-1/Br/06 strains. Neighbor-joining phylogenetic trees of S and M RNA segments were constructed. Four representative AKAV isolates were classified into subgroup Ia, which contains the Iriki and KM-1/Br/06 strains recognized to cause encephalomyelitis in calves and adult cattle in Japan. Moreover, experimental intraperitoneal infection was performed using the AKAV-7/SKR/2010 and AKAV-17/SKR/2010 strains to assess pathogenesis in suckling mice. The 2 isolates, genetically related to the Iriki strain, were neurovirulent and caused neurological signs in suckling mice. In contrast, the 93FMX strain and the K0505 strain, related to the OBE-1 strain, were avirulent in mice. The present results indicate that these isolates most likely had originated from the Iriki strain and are closely related to the Iriki strain both genetically and pathogenically.     

Modification of ascorbic acid using transglycosylation activity of Bacillus stearothermophilus maltogenic amylase to enhance its oxidative stability

Ascorbic acid (1), a natural antioxidant, was modified by employing transglycosylation activity of Bacillus stearothermophilus maltogenic amylase with maltotriose and acarbose as donor molecules to enhance its oxidative stability. The transglycosylation reaction with maltotriose as donor created mono- and di-glycosyl transfer products with an alpha-(1,6)-glycosidic linkage. In addition, two acarviosine-glucosyl transfer products were generated when transglycosylation was performed with acarbose as a donor. All transfer products were observed by TLC and HPLC, and purified by Q-sepharose anion exchange and Biogel P-2 gel permeation chromatographies. LC/MS and (13)C NMR analyses revealed that the structures of the transfer products were 6-O-alpha-D-glucosyl- (2) and 6-O-alpha-D-maltosyl-ascorbic acids (3) in the reaction of maltotriose, and 6-O-alpha-acarviosine-D-glucosyl- (4) and 2-O-alpha-acarviosine-D-glucosyl ascorbic acids (5) in the reaction of acarbose. The stability of the transglycosylated ascorbic acid derivatives was greatly enhanced against oxidation by Cu(2+) ion and ascorbate oxidase. Among them, compound 3 proved to be the most stable against in vitro oxidation. The antioxidant effects of glycosyl-derivatives of ascorbic acid on the lipid oxidation in cooked chicken breast meat patties indicated that they had antioxidant activities similar to that of ascorbic acid. It is suggested that the transglycosylated ascorbic acids can possibly be applied as effective antioxidants with improved stability in food, cosmetic, and other applications.     

Acaricidal and oviposition deterring effects of santalol identified in sandalwood oil against two-spotted spider mite, <Emphasis Type="Italic">Tetranychus urticae</Emphasis> Koch (Acari: Tetranychidae)

Thirty-four plant essential oils were screened for their acaricidal and oviposition deterrent activities against two-spotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae), in the laboratory using a leaf-dip bioassay. From initial trials, sandalwood and common thyme oils were observed to be the most effective against TSSM adult females. Subsequent trials confirmed that only sandalwood oil was significantly active (87.2 ± 2.9% mortality) against TSSM adult females. Sandalwood oil also demonstrated oviposition deterring effects based on a 89.3% reduction of the total number of eggs on leaf disks treated with the oil. GC–MS analysis revealed that the main components of the sandalwood oil were α-santalol (45.8%), β-santalol (20.6%), β-sinensal (9.4%), and epi-β-santalol (3.3%). A mixture of α- and β-santalol (51.0:22.9, respectively) produced significantly higher mortality (85.5 ± 2.9%) and oviposition deterrent effects (94.7% reduction in the number of eggs) than the control. Phytotoxicity was not shown on rose shoots to which a 0.1% solution of sandalwood oil was applied.     

Individual difference in serum oxytocin concentrations of calves and the correlation with those in dams

We examined individual differences in serum oxytocin concentrations (OT) of calves, and assessed whether these differences were correlated with their dams’ milk and serum OT. Eight Holstein (H), nine Japanese Shorthorn (JS), and six Japanese Black (JB) calves were examined. Blood was collected three times during the first month in H calves, while their dams’ blood was collected three times prior to parturition. Milk was collected twice after parturition from H cows. Blood from JS and JB calves were collected at 1 and 4 months old, while of their dams only once before parturition. Serum OT in H calves at 7 days old was significantly correlated with that at 30 days. Serum OT of JS calves at 1 month old was significantly correlated to that at 4 months, while of JB calves was also positively correlated (r = 0.70). Serum OT of calves showed significant individual differences in each breed. Serum OT of calves was not correlated with the milk OT of dams, except for 3‐day‐old calves that fed on their dams’ milk. We concluded that although serum OT differed among individuals, this difference was stable within each individual and not affected by the serum OT of the dams.     

Actions of intravenous injections of AVP and oxytocin on plasma ACTH,GH, insulin and glucagon concentrations in goats

This study was conducted to investigate the arginine‐vasopressin (AVP)‐ and oxytocin‐induced changes in plasma adrenocorticotropic hormone (ACTH), growth hormone (GH), insulin and glucagon levels and their metabolite concentrations in goats. In this study, five goats were intravenously injected with either AVP (0.3 nmol/kg body weight (BW)) or oxytocin (0.7 IU/kg BW). AVP injection significantly increased ACTH and GH secretions compared to controls, although insulin and glucagon concentrations were not altered. The incremental areas (ICAs) of the ACTH and GH concentrations were higher in the AVP group than in the saline group. Oxytocin injections increased insulin and glucagon secretions, while ACTH level was not altered. GH levels became elevated 30 min after the oxytocin injection. The ICAs of insulin and glucagon after oxytocin was injected were higher than those of the control. Results indicate that AVP is a potent stimulant of ACTH and GH secretions, while oxytocin uses different pathways to regulate insulin and glucagon secretions in goats.     

Isolation and characterization of a low pathogenic duck hepatitis A virus 3 from South Korea

The D11-JW-018 strain of duck hepatitis A virus (DHAV) was isolated from 7-day-old ducklings in Kyeonggi province, South Korea with no clinical signs of typical hepatitis.