Hydrophobicity of Fusobacterium necrophorum biovars A and B

Abstract Biovar A strains of Fusobacterium necrophorum exhibited high hydrophobicity when examined by the method of Rosenberg et al. Biovar B strains showed a lower cell surface hydrophobicity than biovar A strains. Biovar B strains were divided into 2 groups according to their hydrophobic activity. The strains of biovar A and the first group of biovar B were increasingly removed from aqueous phase to octane phase by increasing the volume of octane, but the turbidity of the second group of biovar B was not significantly affected. The hydrophobicity of biovar A strains decreased on heating at 60 and 100°C for 30 min.     

A case of sporotrichosis caused by two genetically differentSporothrix schenckii strains

A survey for the natural occurrence of Fusarium mycotoxins, deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN), in Dutch cereals (totaling 29 samples) harvested in 1984/1985, showed that 90%, 79% and 62% of samples were contaminated with DON, NIV and ZEN, respectively. Average contents (ng/g) in the total of positive samples were 221 (DON), 123 (NIV) and 61 (ZEN). Among the cereals examined, the highest concentrations (ng/g) was 3198 (DON), 1875 (NIV) and 677 (ZEN) in a yellow corn sample for animal feed. The results of this survey show that Dutch cereals were relatively significantly contaminated with Fusarium mycotoxins.     

The augmentation of tumor-specific immunity using haptenic muramyl dipeptide (MDP) derivatives

Summary A previous paper has demonstrated that enhanced tumor-specific immunity could be induced by priming mice with Bacillus Calmette Guerin (BCG) and subsequently immunizing them with syngeneic tumor cells modified with BCG-cross-reactive muramyl dipeptide (MDP) hapten [15]. The present study establishes a tumorspecific immunotherapy protocol for a murine chronic leukemia based on the above T-T cell collaboration between antitumor effector T cells and anti-MDP hapten helper T cells induced by BCG priming. BALB/c mice which had been primed to BCG were injected intravenously (i.v.) with viable, syngeneic BCL1 leukemia cells. One week later, these mice were immunized intraperitoneally (i.p.) with unmodified or MDP hapten-modified, 10,000 R X-irradiated BCL1 cells, followed by 4 booster immunizations at 5-day intervals. The administration of unmodified BCL1 tumor cells into BCG-primed mice failed to prevent them from tumor death due to the persistent growth of preinjected BCL1 cells. In contrast, the immunization of BCG-primed, BCL1 leukemia-cell-bearing mice with MDP-modified BCL1 cells resulted in a high growth inhibition of leukemia cells and protection of these mice from death by leukemia. It was also revealed that potent tumorspecific, T-cell-mediated immunity was generated in mice which survived in this immunotherapy model. Thus, these results indicate that administration of MDP hapten-modified, syngeneic leukemia cells into leukemia-bearing mice which have been primed with BCG results in potent tumor-specific, T-cell-mediated immunity attributable to preventing the growth of disseminated leukemic cells.This work was supported by a Grant-in-Aid for the Special Project Cancer-Bioscience from the Ministry of Education, Science, and Culture, Japan Abbreviations used: TATA, tumor-associated transplantation antigens; MDP, muramyl dipeptide; MTP, muramyl tripeptide; BCG, Bacillus Calmette Guerin     

Alpha-interferon treatment for adult T cell leukemia: low levels of circulating alpha-interferon and it's clinical effectiveness

We describe a patient with adult T cell Leukemia to whom alpha-interferon therapy was highly effective. Although a combination chemotherapy (ACVP) first introduced was effective in reducing total leukocyte counts, the percentage of leukemic cells relative to total leukocyte counts was decreased first after the institution of alpha-interferon therapy. The patient is now under complete remission for four years. It was noted in this patient that circulating alpha-interferon, measured by a sensitive radioimmunoassay, was consistently low as compared with the value found in the age-, sex-matched healthy control (p less than 0.001). Since adult T cell leukemia is pathogenetically related to the retrovirus infection, low levels of circulating alpha-interferon of the patient may be important from both pathogenetic and therapeutic standpoints. Alpha-interferon therapy may be an useful additive for the chemotherapy of adult T cell leukemia.     

Polymorphism and stability of histone gene clusters in Drosophila melanogaster cultured cells

In a previous communication (Saigo, K., Millstein, L. and Thomas, C.A., Jr. (1981) Cold Spring Harbor Symp. Quant. Biol. 45, 815–827), the overall structure of histone genes of Schneider line 2 cells was shown to extensively differ from that of Oregon-R embryo from which the cell line was established, and it was speculated that the histone genes might be reshuffled extensively during either the periods of the establishment, or maintenance of cell lines, or both. To establish the validity of this notion the structure of histone genes was examined in Drosophila melanogaster cultured cells. The overall organization of histone gene clusters was found to be stably maintained in both the periods for the establishment and maintenance of cultured cells, indicating that the previous assumption is inadequate. Instead of an extensive rearrangement, minor structural changes were found to occasionally occur probably by simple base substitutions and/or, deletion or insertion of very short DNA pieces. It was also shown that the extensive variation in structures of histone genes in cultured cells such as Schneider line 2 are attributable to polymorphism on the level of individual flies.     

Inactivation of T Antigen-Forming Capacities of Simian Virus 40 and Adenovirus 12 by Ultraviolet Irradiation

Methods to measure T antigen-forming capacities of simian virus 40 (SV40) and adenovirus 12 (Ad12) were investigated, and a method to measure the capacity in terms of T antigen-forming units was employed by the use of cytosine arabinoside. Plaque-forming units and T antigen-forming units of SV40, SV40 deoxyribonucleic acid, or Ad12 were inactivated by ultraviolet (UV) irradiation at the same rate, roughly following a single-hit curve. T-antigen formation by UV-irradiated SV40 and Ad12 was enhanced in cells multiply infected and in cells in a growing state. These observations showed that it was difficult or impossible to estimate the size of the gene for T antigen by UV inactivation.     

A Drosophila receptor-type tyrosine kinase (DFR1) acts as a fibroblast growth factor receptor in Xenopus embryos

Members of the fibroblast growth factor (FGF) family play important roles in various developmental processes in vertebrates. Since two genes closely related to the vertebrate FGF receptor (FGFR) genes DFR1 and DFR2/breathless have already been reported in Drosophila , the existence of a Drosophila FGF has been predicted. In the present study, we examined whether DFR1 is functionally interchangeable with a vertebrate FGFR in the Xenopus system. First, we found that the expression of DFR1 promoted Ca²⁺ efflux in response to human basic (b)FGF in Xenopus oocytes, whereas the coexpression of a dominant negative form of DFR1 (ΔDFR1) with a chick FGFR1/cek1 inhibited promotion of Ca²⁺ efflux induced by the expression of cek1 in the oocyte. Second, the expression of ΔDFR1 was observed to induce a defect in the posterior structure of the Xenopus embryo at stage 30, as observed with a dominant negative form of cek1 (Δcek1). Third, we found that the expression of ΔDFR1 inhibited the expression of FGF-regulated genes such as Xbra, Xnot , and Xshh in Xenopus embryos at stage 11, while the coexpression of DFR1 with ΔDFR1 could rescue the inhibited expression of FGF-regulated genes. These results indicate that DFR1 acts as an FGFR in Xenopus embryos and that an FGF is likely to exist in Drosophila .     

Conversion of NfsB, a minor Escherichia coli nitroreductase, to a flavin reductase similar in biochemical properties to FRase I, the major flavin reductase in Vibrio fischeri, by a single amino acid substitution.

NfsB is an oxygen-insensitive nitroreductase of Escherichia coli with significant amino acid sequence homology to the major flavin reductase (FRase I) of Vibrio fischeri. Here, we show that NfsB is convertible to an FRase I-like flavin reductase three times as active as the authentic FRase I by a single amino acid substitution in the least-conserved region.