In vitro ectomycorrhization of Tricholoma matsutake strains is differentially affected by soil type

The Japanese delicacy Tricholoma matsutake has been conducted in vitro ectomycorrhizal syntheses for more than 20 y. The development of its ectomycorrhizal structures varies among experimental systems. Here, we examined the effects of soil-fungus interactions on the early stage of in vitro T. matsutake ectomycorrhization. Axenic Pinus densiflora seedlings were transplanted into autoclaved natural inorganic soil, inoculated with the cultured mycelium of T. matsutake, and incubated for 90 d in vitro. Both soil type and fungal strain significantly affected host plant growth; host plant growth and mycorrhization levels significantly differed among soil type/fungal strain combinations. Therefore, the selection of T. matsutake strains for optimal mycorrhization must take into account such fungal and soil properties.     

Protection against metastasis by immunization with an allogeneic lymphocyte antigen

Q5 antigens are expressed on the surface of various experimental murine tumor cells. They share partially common antigenicity with Qa-2 alloantigens expressed on normal lymphocytes. For that reason we tested the immunoprotection by anti-Qa-2 immunization of mice against a Q5+ tumor. Nerve fibrosarcoma (NSFA) tumor, which specifically develops metastasis in the lung, has been reported to be poorly immunogenic. However, expression of the Q5 antigen was evident on the surface of NFSA cells. After immunizing (C3H/He x B6.K1)F1 (Qa-2-) mice with B6 (Qa-2+) lymphocytes, the protection against the proliferation of the semi-syngeneic NFSA tumor was examined First, immunization of normal mice induced resistance to NFSA cell transplants. Second, when the tumor cells were transplanted to the hind foot of a mouse and the resulting tumor was removed by amputating the leg, the mice were protected against the development of lung metastasis after immunization by intraperitoneal inoculation of B6 cells 3 days after tumor removal. Immunization with attenuated NFSA cells in this system failed to protect the mice from lung metastasis. On the other hand, inoculation of the mice with B6 cells without removal of the original tumor on the foot showed little effect on the progression of the tumor. Thus, cytotoxic T lymphocytes (CTL), which seemed to be present in an inactive form in the mice from which the tumor had not been removed, were induced in the mice after the removal of the major tumor followed by immunization with B6 lymphocytes. The induction of CTL by the immunization was suppressed in mice bearing large tumors. Cells stimulated by the tumor antigen seemed to be involved in the suppression. It was also shown that the Q5 antigen is the direct recognition target of the CTL since the activity of Q5-specific CTL clones in lysing tumor cells was inhibited by a monoclonal antibody specific for the Q5 antigen. In contrast to immunization with attenuated tumor cells, our novel allogeneic lymphocyte immunization procedure offers high CTL activation, by-passing the induction of T cell unresponsiveness.     

Revised sequence of the nusA gene of Escherichia coli and identification of nusA11 (ts) and nusA1 mutations which cause changes in a hydrophobic amino acid cluster

Summary The mutant nusA DNAs (nusA11 and nusA1) were sequenced. Single base substitutions caused by these mutations were found in the coding region of nusA. The nusA11 mutation, which is conditionally lethal, substituted Thr for the 181st Ala. Also, nusA1, which restricts growth, substituted Ala for the 183rd Ser. These two positions were located in the same hydrophobic amino acid cluster. This cluster seemed to be an essential region in the functional domain of NusA. In the course of these experiments, several mistakes in the published nusA nucleotide sequence were found. These errors are revised in this article. The molecular weight of NusA is accordingly revised to 54,430.     

Freeze-fracture images of exocytosis and endocytosis in anterior pituitary cells of rabbits and mice

Summary Freeze-fracture images of exocytosis and endocytosis were studied in various kinds of secretory cells of the anterior pituitary of mice and rabbits. Exocytotic figures are frequently observed in thin section of the anterior pituitary cells. In freeze-fracture images, small elevated membrane areas without membrane particles are often seen on the PF of the plasma membrane of the secretory cells. There is a secretory granule in the cytoplasm just beneath the particle-free membrane area, and limiting membrane of the granule is also devoid of the membrane particles at the part facing the plasma membrane. The fusion of membranes for exocytosis may occur at this particle-free area.The limiting membrane of the granule which is continuous with the plasma membrane is almost always coated after release of the granule core. This invagination of coated membrane may be an initiation site for the membrane retrieval after exocytosis. In freeze-fracture images, this depressed region with an accumulation of the membrane particles is observed on the PF of the plasma membrane. This particle-rich depressed region is thought to correspond to the coated area of the plasma membrane observed in thin section. It is thought that the membrane retrieval by pinocytosis initiates at the particle-rich depressed region of the plasma membrane.This study was supported by a grant from the Japan Ministry of Education     

Interaction of vitamin D-binding protein with immobilized cibacron blue F3-GA.

An interaction of vitamin D-binding protein to immobilized Cibacron Blue F3-GA was studied under urea containing buffers. In these buffers, this protein was adsorbed to the immobilized dye and was eluted with salt gradients as in the same buffer without urea. The protein was also adsorbed to immobilized diethylaminoethyl but not to immobilized carboxymethyl. It is implicated that a combination of pseudo-ligand affinity and/or hydrogen bonding interaction plays a large role whereas ionic, hydrophobic and lipophilic interactions act little between the protein and the immobilized blue dye.     

Affinity separation of human plasma gelsolin on Affi-Gel Blue

Human plasma gelsolin was specifically eluted with 1 mM adenosine 5'-triphosphate from an Affi-Gel Blue column. Since the ionic strength of sodium chloride required to elute the protein from the dye column was much higher than that of 1 mM adenosine 5'-triphosphate, the binding of plasma gelsolin with the dye-ligand appeared to be biospecific. Taking advantage of this affinity interaction, we have developed a revised purification method of human plasma gelsolin. The purification included ammonium sulfate precipitation, diethylaminoethyl-Sepharose chromatography, Affi-Gel Blue chromatography, and Phenyl-Sepharose chromatography. The method allowed a reproducible purification of the protein to apparent homogeneity, producing a 331-fold purification with a yield of 6%.     

An Antifungal Constituent in Enkianthus perulatus

A new cinnamate was isolated as an antifungal constituent from young leaves and shoots of Enkianthus perulatus. The structure was shown to be 1 on the basis of the chemical and spectroscopic studies.