Ibaraki Virus,an Agent of Epizootic Disease of Cattle Resembling Bluetongue

Replication of Ibaraki virus was not inhibited by 5-iodo-2′-deoxyuridine, indicating that the virus is an RNA virus. The virus was resistant to ether, chloroform and deoxycholate, sensitive to trypsin, very labile at acidic pH but stable at pH 6.4 or higher, and was resistant to repeated freezing and thawing. The virus was readily inactivated at 56 C or higher, was fairly stable at 37 C, and very stable at 4 C, while it rapidly lost infectivity when stored frozen at —20 C. The virus was readily sedimented by centrifugation at 40 000Xg for 60 min. It readily passed through membrane filters of 200 mμ pore size, passed through 100 μfilters but only with some titer loss and did not through 50 mμ filters. In these tests, the bluetongue virus used as a control behaved in the same manner as Ibaraki virus. These findings provide additional evidence for the similarity of Ibaraki virus to bluetongue virus which had been previously demonstrated on the basis of seasonal incidence, symptomatology and pathology of the diseases caused by these viruses and the behavior of the viruses in cell cultures, embryonated eggs and laboratory animals. The present study, however, provided no evidence for any serological relation between these two viruses. More Information is needed to reach a final decision on the classification of Ibaraki virus, particularly regarding the morphology of the virion, the doublestrandedness of the viral RNA and other basic features.     

Solid-state modifications of poly(γ-ethyl-L-glutamate)

Several modification of the arrangements of α-helical molecules were found in the solid films of poly (γ-ethyl-L -glutamate), depending on the casting solvent and the temperature. The helical conformation is somewhat looser than the normal 18-residue, 5-turn α-helix. Using x-ray diffraction, the types of molecular arrangements were classified into tetragonal, pseudohexagonal, and hexagonal ones. Tetragonal packing was observed in the filmm (form T) prepared by casting the solution in trifluorethanol or dichlorethane. The sample obtained from chloroform solution is a well-ordered, pseudohexagonal modification (form I). Forms I and T change into a poorly crystalline form III by annealing at temperatures above 130° C. It is particularly noteworthy that the less-ordered form III exhibits a thermoreversible transition around 110°C into a well-ordered form H with the hexagonal molecular packing.     

Bovine Diarrhea Virus

Five strains of bovine diarrhea virus were isolated from Japanese cattle using bovine tissue cultures. These are the first isolations of this virus from Japanese cattle to be reported. Of importance is the finding that the new isolates, which are non-cytopathogenic, induce an exaltation of Newcastle disease virus in bovine testicular cell culture. This finding has provided a laboratory tool whereby the assay of the virus and its neutralizing antibody can readily be performed.     

Bacterial cometabolic degradation of chlorinated paraffins

Summary Cometabolic dechlorination of chlorinated paraffins was demonstrated in the presence of n-hexadecane by bacterial strains (HK-3, HK-6, HK-8, and HK-10) isolated from soil samples.Eleven per cent of chlorine of chlorinated paraffin-150 (CP-150) was released by strain HK-3. The mixed culture of strain HK-3, catalyzing the dechlorination of terminal chlorine of chloroalkane, and strain H15-4, capable of releasing the chlorine from 2-chlorinated fatty acids, dechlorinated CP-150 up to 13%. The mixed culture of the four strains (HK-3, HK-6, HK-8, and HK-10) performed the dechlorination of CP-150 by cometabolism in a jar fermentor pH at 7.0. The amount of chloride released from the chlorinated paraffins tested was in the range of 15–57%.The activated sludge acclimatized to n-hexadecane for 60 days showed a little dechlorination activity to CP-150.     

Purification and properties of haloalkane dehalogenase from Corynebacterium sp. strain m15-3

A haloalkane dehalogenase was purified to electrophoretic homogeneity from cell extracts of a 1-chlorobutane-utilizing strain, m15-3, which was identified as a Corynebacterium sp. The enzyme hydrolyzed C2 to C12 mono- and dihalogenated alkanes, some haloalcohols, and haloacids. The Km value of the enzyme for 1-chlorobutane was 0.18 mM. Its molecular weight was estimated to be 36,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 33,000 by gel filtration. The isoelectric point was pH 4.5. The optimum pH for enzyme activity was found to be 9.4, and the optimum temperature was 30 to 35 degrees C. The enzyme was stable for 1 h at temperatures ranging from 4 to 30 degrees C but was progressively less stable at 40 and 50 degrees C.     

Quantitative immunogold localization of Na, K-ATPase along rat nephron.

Ultrastructural localization of Na, K-ATPase alpha-subunit along rat nephron segments was investigated quantitatively by immunogold electron microscopy on LR-White ultrathin sections using affinity-purified antibody against alpha-subunit of the enzyme. Ultrathin sections were incubated with the antibody at a saturation level and the number of gold particles bound per micron of the plasma membrane (particle density) of the tubular epithelial cells from the proximal tubule to the collecting duct was determined. In all the tubular epithelial cells, gold particles were located exclusively on the basolateral surface, and no significant binding of gold particles to the apical surface was observed. Distribution of gold particles on the basolateral membranes was quite heterogeneous; lateral membranes and infolded basal membranes were highly labeled, whereas the basal membranes which are in direct contact with the basal lamina were scarcely labeled. The average particle density on the basal surface was highest in the distal straight tubule cells (11.4 units), very high in the distal convoluted tubule cells (9.8 units), intermediate in the proximal tubule cells (3.3 units), in the connecting tubule cells (4.3 units), and in the principal cells of the collecting duct (5.6-3.8 units), low in the thin limb of Henle's loop (1.0 unit), and at the control level in the intercalated cells in the connecting and collecting duct. The relative number of gold particles/mm nephron segment and the relative number of gold particles in the various nephron segments were calculated using quantitative morphological data. The estimated distribution profile of the former was in good agreement with the Na, K-ATPase activity profile in rat nephron, which was determined biochemically with a microenzymatic method.     

The combined effect of lymphokine activated killer cell and radiation therapy on rat brain tumorin vitro

Thein vitro effect of a combined treatment with lymphokine activated killer (LAK) cell and radiation therapy on rat brain tumor was examined using⁵¹Cr release assay. The tumor cell-line used in this experiment was 9L rat brain tumor derived from a Fischer 344 rat. LAK cells were obtained by culturing rat lymphocytes with recombinant human interleukin 2 for at least 3 days. The cytotoxic activity of the LAK cells was examined by⁵¹Cr release assay. Irradiation was done by exposing the microtiter plate in which the¹⁵Cr labeled 9L cells and LAK cells were cultured to a¹³⁷Cs gamma cell unit. Without irradiation, there was 18% cytotoxicity in the 1:100 tumor-to-LAK cell ratio specimen after 24 hrs cocultivation. However, if 5 Gy of irradiation was given, followed by 12 hrs incubation, the cytotoxicity was enhanced significantly at the same cell ratio (30%). This enhancement effect was the most prominent when the cell ratio was 1:100 and the irradiation dose was 5 Gy. To generate the enhancement effect, an incubation time of over 8 hrs both before and after irradiation was required. The supernatant of the LAK cells showed 19.8% and 11.4% cytotoxicity with and without irradiation, respectively. This result indicates the participation of a cytotoxic factor released from LAK cells.This work is supported in part by grant from Univeristy of Tsukuba Project Research.     

In vitro growth of adult amphibian (Xenopus laevis) hepatocytes and characterization of hepatocyte-proliferating activity in homologous serum

Adult frog (Xenopus laevis) hepatocytes were found to proliferate in a culture medium containing adult homologous serum. Insulin and dexamethasone were required for a net proliferation of hepatocytes. Dose-response analysis showed that a low concentration of serum (greater than or equal to 0.5%) was enough to induce DNA synthesis and mitosis, but a higher concentration (5%) caused certain necrotic changes. Under optimal conditions, there was a two- to threefold increase in nuclei per culture 10 days after serum treatment. Heterologous sera (fetal bovine, calf and chick) showed less proliferative activity. Based on our results, hepatocyte-proliferating activity in adult frog serum is considered to be heat-unstable and acidic protein(s). Thus, adult frog serum may contain hepatopoietin possibly different from well-known growth factors.     

Iodine distribution in the thyroid follicles of the hagfish,Eptatretus burgeri and lamprey,Lampetra japonica: Electron-probe X-ray microanalysis

Summary In the thyroid follicles of species of cyclostomes, a hagfish and a lamprey, the distribution of stable iodine was examined by electron-probe X-ray microanalysis. A high concentration of stable iodine, heterogeneously distributed, was observed in the follicular cells of hagfish thyroid follicles. In the lamprey a low concentration of iodine was seen in the follicular lumina. The relative values for stable iodine determined in this way corresponded to values obtained by a chemical analytical method.