Biosynthesis and excretion of hydrolases in germinating cereal seeds

The initial formation site of hydrolases in germinating cerealseeds and their subsequent release were examined using the substrate-filmtechnique. Early in the germination of cereal seeds, e.g., barley,wheat, rye, oat and maize, -amylase invariably appeared in theregion of the epithelial cells of the scutellum, whereas itlater gradually diffused into the entire region of the endospermtissues. The initial formation site of proteinase and RNA-asein germinating barley seeds was also confirmed to be in theepithelium. We conclude that the epithelium has a more importantrole in the enzymic breakdown of reserve substances stored inthe endosperm tissues than the aleurone layer. (Received October 19, 1979; )     

Streptococcal preparation OK-432 augments cytotoxic activity against an erythroleukemic cell line in humans

Summary The effects of OK-432, an inactivated and lyophilized preparation of a low-virulence strain of Streptococcus pyogenes, were evaluated on the cytotoxicity of lymphoid cells against a natural killer (NK)-sensitive erythroleukemic cell line K562 in patients with malignant diseases. When ten patients were treated postoperatively with daily injections of OK-432, a significant degree of augmentation in the cytotoxicity of peripheral blood lymphoid cells was evoked in all the patients, and the maximum level of cytotoxicity was on the third day after the beginning of the treatment. In spite of the successive daily administration, the level of cytotoxicity declined thereafter, but stayed higher than the pretreatment level. When OK-432 was injected IP in three patients with carcinomatous peritonitis, the cytotoxic activity of ascitic lymphoid cells was significantly enhanced. Cytotoxicity of in vitro-cultured lymphoid cells taken from peripheral blood of normal donors was also augmented by the addition of OK-432.     

Ecological and mathematical considerations on self-thinning in even-aged pure stands

It is emphasized in growth analysis of self-thinning populations that relative mortality rate pertains to the difference between relative growth rates and net assimilation rates, each of which are definable on a mean plant size basis or on a biomass basis. The time trends of the ratio of relative mortality rate to relative growth rates to be expected according to Tadaki's, Shinozaki's and Hozumi's models are compared with that of the eastern white pine population, and a good agreement is exhibited. As an alternative to Hozumi's model, a new model is constructed to unite the logistic theory of plant growth and the 3/2 power law concerning self-thinning, which so far have usually been applied independently to growth analysis. To construct the model the following assumptions are made: the fundamental equation to relate mean plant weight with density in self-thinning population proposed by Shinozaki, and a special population with a specific initial density which follows thew-p trajectory of the 3/2 power law type and has an exponential decrease in its density with biological time. Properties of the model are examined from ecological and mathematical viewpoints.     

Photoreaction of tyrosin-iodinated bacteriorhodopsin at low temperature

To elucidate the role of tyrosine residues in the shift of max and the light-driven proton pump of bacteriorhodopsin~ the photochemical reaction of tyrosine-iodinated bacteriorhodopsin (tyr-mod-bR) was investigated by low-temperature spectrophotometry. After 4–5 of 11 tyrosine residues of bacteriorhodopsin were iodinated, the meta-intermediate of tyr-mod-bR in 75% glycerol solution became so stable that its decay could be observed even at room temperature and i t was stable in the dark for several hours at –65°C.Four batho-intermediates were formed by irradiation with green light (500 nm) at –170°C. Like native bacteriorhodopsin, these batho-intermediates were photoreversible at –170°C. Four corresponding meta-intermediates were also formed by irradiation at –60°C. Using the difference spectra between meta-intermediates and tyr-mod-bR, the absorption spectra of four kinds of tyr-mod-bRs, batho-intermediates, and meta-intermediates were estimated. Each was at shorter wavelengths than that of its corresponding type in native bacteriorhodopsin. The results indicate that two or more tyrosine residues have some role in determining color in native bacteriorhodopsin.     

Regulatory mechanism of reagin production in mice at the T cell level. I. Suggestive evidence for the generation of class specific PPD-reactive helper T cell population in Mycobacterium-primed cells.

Helper T cell activities specific for purified protein derivative (PPD) generated by immunization with Mycobacterium tuberculosis (Tbc) or PPD were investigated concerning adoptive IgE and IgG antibody responses. It is interesting that preferential triggering activity of IgG antibody response was observed when PPD-reactive cells from mice immunized with Tbc were used as a helper cell source. The selective triggering of IgG B cells by Tbc-primed cells was consistently observed using DNP-primed B cell populations from mice immunized with DNP-carrier conjugate in either ICFA or alum. T cell dependency of helper activity was demonstrated by the fact that treatment of Tbc-primed cells with anti-Thy 1 antiserum plus complement abolished their helper activity. We also demonstrated that purified T cell populations selectively triggerred IgG B cells. Selective triggering of IgG B lymphocytes by Tbc-primed T cells may not be due to the influence of suppressor T cells supposedly present in Tbc-primed cells since this selectivity was not affected by X-irradiation of Tbc-primed T cell populations which may inactivate suppressor T cells. Furthermore, passive transfer of Tbc-primed cells into normal recipient mice, the condition which may detect the suppressor T cell effect much more sensitively in IgE production, or preimmunization with Tbc 2 weeks before, did not suppress primary anti-DNP IgE antibody response to DNP-PPD. Thus, the observations presented here are favorable to the concept of the presence of IgG class-specific helper T lymphocytes. Furthermore, PPD-reactive T cells from mice immunized with PPD itself exerted their helper function for triggering B cells of both IgE and IgG classes. This may also indicate that some of the components associated with Tbc other than PPD might negatively affect the development of PPD-reactive helper T cells specific to the IgE class. The generation of such IgG-specific T cell activity in the presence of Tbc will be discussed in the light of the T cell population involved in the regulation of antibody responses of different immunoglobulin classes.     

Inhibition of the synthesis of microbial cellulose by coumarin

Coumarin, a specific inhibitor of the biosynthesis of celluloseof higher plant cell walls, inhibited the cellulose formationof Acetobacter xylinum. The degree of inhibition reached 55%in the presence of 1 mM coumarin, which causes 70% inhibitionin the case of plant cellulose. (Received April 12, 1976; )     

Multiple-flash development of thermoluminescence bands in dark-grown spruce leaves

Spruce leaves greened in darkness were devoid of three of the five thermoluminescence bands found for mature leaves. These bands were developed rapidly by exposure of the dark-grown leaves to continuous light. The development of these bands was studied by illumination with repetitive flashes at varied intervals. Flashes at intervals of 1 s were the most effective in inducing these bands. Those at shorter or longer intervals were less effective. It was deduced from these data that the development of these bands is a multiquantum process which involves at least two photo-events with a dark reaction between them.     

Remarkable retardation of the senecence of tobacco leaf disks by cordycepin, an inhibitor of RNA polyadenylation

The antibiotic cordycepin (3'-deoxyadenosine), a known specificinhibitor of nucleic acid synthesis and polyadenylation of RNA,remarkably retarded decrease in the chlorophyll and proteincontents of senescing tobacco leaf disks. The effectivenessof cordycepin, at its optimum concentration (ca. 4 x 10^–5M), was 53% as effective as a cytokinin, benzyladenine at 10^–6M. Adenosine and 2'-deoxyadenosine had no anti-senescence action. (Received May 29, 1975; )