Physicochemical properties of pseudorabies virus hemagglutinin.

Pseudorabies virus hemagglutinin was readily adsorbed on mouse erythrocytes at 4, 22, or 37 degrees C, but not on cattle erythrocytes. The adsorbed hemagglutinin could not be eluted from the cells by resuspending in phosphate-buffered saline (PBS), by incubating at 37 or 50 degrees C, or by incubating in the presence of neuraminidase. The receptor on mouse erythrocytes for the hemagglutinin was inactivated by trypsin, but not by neuraminidase, sodium deoxycholate (DOC), potassium periodate (KIO4), dithiothreitol (DTT), 2-mercaptoethanol (2-ME) and formalin. The hemagglutinin was inactivated by trypsin, alpha-amylase, pepsin, DOC, KIO4, and ethylendiamine-tetraacetic acid (EDTA), but not by papain, beta-glucosidase, phospholipase C, neuraminidase, DTT, 2-ME, Tween-80, ethylether, chloroform, trichloro-trifluoroethane, beta-propiolactone and formalin, suggesting that the hemagglutinin active component involved glycoproteins. The hemagglutinin was stable at 37 degrees C for lower temperatures but not at 60 degrees C or higher. The hemagglutinin activity was resistant to ultraviolet irradiation, while the infectivity was very susceptible. The hemagglutinin and the infectivity were readily sedimented by ultracentrifugation at 48,000 x g for 3 hr. In rate zonal centrifugation of the preparation on a sucrose density gradient, the hemagglutination (HA) activity showed a sharp peak at 1.22 g/ml coinciding with the peak of infectivity. The HA activity in the peak fraction seemed to be structually associated with virus particles. After fractionation of the virus by Nonidet P-40, the HA activity was found only in the fraction of the envelope material, indicating that the hemagglutinin is situated in the viral envelop.     

Improved hemagglutination of simbu group arboviruses with higher sodium chloride molarity diluent

Hemagglutination (HA) with the Simbu group arboviruses is found to be dependent on pH as well as NaCl molarity of the diluent. The current method of arbovirus HA by Clarke and Casals (1958) was modified by using a diluent with 0.4 M NaCl, 0.2 M phosphate at pH 6.0–6.2 for HA and HA inhibition with these viruses.     

Antibodies to Akabane virus in horses,sheep and goats in Japan

High prevalences of neutralizing (NT) antibody to Akabane virus were obtained with horse (72%), sheep (38%) and goat (67%) serum samples collected in Chiba Prefecture, where outbreaks of abortion and congenital deformities caused by Akabane virus occurred among cattle. In these animal sera, titers of hemagglutination-inhibiting (HI) antibody to Akabane virus and of NT antibody were closely correlated.     

IBARAKI DISEASE AND ITS RELATIONSHIP TO BLUETONGUE

Ibaraki disease, an epizootic disease of cattle in Japan resembling bluetongue, is characterized by fever and lesions affecting the mucous membranes, the skin, the musculature and vascular system. Degeneration of striated muscular tissue is observed in the oesophagus, larynx, pharynx, tongue and the skeletal muscles. Oedema and haemorrhage are marked in the mouth, lips, abomasum, around the coronets, etc., and are occasionally followed by degeneration of the epithelium leading to erosions or ulcerations. Severe lesions affecting the oesophageal and laryngopharyngeal musculature cause difficulty in swallowing which in turn produces dehydration and emaciation, and occasionally the aspiration pneumonia, which constitute the major causes of death of affected animals. These clinical and pathological findings indicate the similarity of the disease to bluetongue in sheep and cattle. Ibaraki disease was first recognised in Japan in 1959 and 1960. Seasonally its occurrence is limited to late summer and autumn, and geographically to the central and western parts of Japan, roughly south of 37 degrees north latitude. It is absent from the higher altitudes. The seasonal and geographical incidence suggests the possibility of an arthropod vector; but direct evidence for such a vector is still lacking. Serological data suggest the presence of Ibaraki virus on Bali Island in Indonesia and in Taiwan. The disease can be transmitted serially in calves by the intravenous inoculation of blood obtained at the height of a febrile reaction. Ibaraki virus can be isolated in bovine cell cultures from both natural and experimentally produced cases of the disease. The virus multiplies and induces cytopathic effects in primary cultures of bovine, sheep and hamster lung origin, and L cells; but it does not grow in primary cultures of horse and swine kidney nor in HeLa cell cultures. The virus is readily passaged serially in 4 to 5-day-old eggs by yolk-sac inoculation and incubation at 33.5 degrees C. It multiplies in the brains of mice of any age after incracerebral inoculation but younger mice give a better viral growth and develop encephalitis. No evidence has been obtained that rabbits and guinea pigs are susceptible to Ibaraki virus...     

Comparison of plasma concentrations of estradiol-17β and progesterone, and conception in dairy cows with cystic ovarian diseases between Ovsynch and Ovsynch plus CIDR timed AI protocols

The objectives of this study were 1) to determine the effects of adding a CIDR to the Ovsynch protocol on plasma concentrations of estradiol-17β and progesterone and conception in dairy cows with cystic ovarian diseases and 2) to examine associations among the estradiol-17β and progesterone concentrations and conception. Cows were diagnosed as having cystic ovarian diseases if they were found to have a cystic follicle (diameter ≥25 mm) without a corpus luteum by two palpations per rectum with an interval for 7 to 14 days. They were treated with either the Ovsynch (GnRH on Day 0, PGF(2α) on Day 7 and GnRH on Day 9, with AI on Day 10; n=15) or Ovsynch+CIDR protocol (Ovsynch protocol plus a CIDR from Day 0 to Day 7; n=23). Plasma estradiol-17β concentrations were determined on Days 0, 7 and 9, and plasma progesterone concentrations were determined on Days 0, 7, 9 and 17. The plasma estradiol-17β and progesterone concentrations at all of the days examined and conception rates did not differ significantly between the two timed AI protocols. The progesterone concentrations on Day 17 and conception rates were lower (P<0.05) for cows with low concentrations of estradiol-17β (<2 pg/ml) on Day 9 than for cows with high concentrations of estradiol-17β (≥2 pg/ml). The present study suggests that, in dairy cows with cystic ovarian diseases, addition of a CIDR to the Ovsynch protocol had no remarkable effects on plasma estradiol-17β and progesterone concentrations during and after the treatments or on conception after timed AI. This study indicates that the low plasma estradiol-17β concentration at the second administration of GnRH in the protocols can be a predictor for impaired luteal formation and lower likelihood of pregnancy in dairy cows with cystic ovarian diseases.     

Preferential translocation of boron to young leaves in Arabidopsis thaliana Regulated by the BOR1 Gene

A mutant of Arabidopsis thaliana, bor1-1 (Noguchi et al. 1997: Plant Physiol., 115, 901–916) requires high levels of boron (B) for normal growth. We analyzed the B-deficiency symptoms of bor1-1 mutant plants in detail. A low B supply retarded the growth of the mutant plants more evidently in leaves than in roots. In particular, cell expansion and formation of air spaces were severely impaired by B deficiency in young rosette leaves. Such defects in growth were correlated with the reduced contents of B in leaves. These defects were not observed when a sufficient amount of B was supplied. Uptake experiments with ¹⁰B-enriched tracer B demonstrated that B taken up through roots was preferentially transported to young leaves compared to old leaves in the wild-type plants under a low B supply. Such a preferential transport to young leaves was not evident in the mutant plants. In conclusion, our data demonstrated that in A. thaliana plants B is preferentially transported to young organs under a low B supply and that this transport process is controlled at least in part by the BOR1 gene.     

Isolation and preliminary characterization of an orbivirus of the Palyam serogroup from biting midge Culicoides oxystoma in Japan

An orbivirus of the Palyam serogroup was isolated from Culicoides oxystoma collected in a cowshed in Kagoshima, Southern Kyushu Island, Japan. This is the first isolation of an orbivirus of the Palyam serogroup in Japan. The virus was a spherical non-enveloped RNA virus, approximately 60 nm in diameter. The virus was resistant to ethyl ether, sodium deoxycholate and freezing-thawing, but readily inactivated by trypsin. The virus was not stabilized by 1 M MgCl2, was labile at pH 3.0 and was not precipitated by protamine sulfate. Indirect immunofluorescent staining of infected Vero cells indicated the virus to be antigenically related to D'Aguilar and Bunyip Creek viruses of the Palyam serogroup. Neutralization tests showed the virus to have no relationship with D'Aguilar virus, but to have a one-way cross-reaction with Bunyip Creek virus. The virus was tentatively designated as Kagoshima virus. A serological survey indicated dissemination of the virus in cattle populations in Kagoshima Prefecture.     

Hemagglutination-inhibition test applied to the study of akabane virus infection in domestic animals

Some factors affecting the hemagglutination-inhibition (HI) reaction with Akabane virus were investigated and an HI test developed. The test was proven to be useful in studies of antibody responses in cattle and other domestic animals infected with Akabane virus. HI antibody titers of individual animals were shown to be closely correlated with their neutralizing antibody titers and to remain undiminished for a relatively long time. In some early sera from domestic animals infected with Akabane virus, HI antibody sensitive to 2-mercaptoethanol was demonstrated.