Quantitative Analysis of Endogenous Gibberellins in Normal and Dwarf Cultivars of Rice

Endogenous levels of gibberellins in shoots and ears of twodwarf rice (Oryza sativa L.) cultivars, Tan-ginbozu (dx mutant)and Waito-C (dy mutant), were analyzed and compared with thoseof normal rice cultivar, Nihonbare. The endogenous levels of13-hydroxylated gibberellins in Tan-ginbozu were much lowerthan those in Nihonbare. In Waito-C, the levels of GA₁₉ andGA₂₀ in the shoots were higher but that of GA₁ was lower thanthe levels of these gibberellins in Nihonbare. These resultssupport the hypothesis that the dy gene controls the 3ß-hydroxylationof GA₂₀ to GA₁ while the dx gene controls a much earlier stepin the gibberellin biosynthesis. Our results indicate that GA₁is the active gibberellin that regulates the vegetative growthof rice. The endogenous levels of GA₄ in the ears of the twodwarf cultivars of rice were higher than the level of GA₄ inthe ears of the normal cultivar, Nihonbare suggesting that thebiosynthesis of gibberellin is not blocked in the anthers ofthe dwarf rice. (Received April 27, 1989; Accepted July 12, 1989)     

Cardiovascular changes associated with decreased aerobic capacity and aging in long-distance runners

Fifty-five male runners aged between 30 to 80 years were examined to determine the relative roles of various cardiovascular parameters which may account for the decrease in maximal oxygen uptake (VO2max) with aging. All subjects had similar body fat composition and trained for a similar mileage each week. The parameters tested were VO2max, maximal heart rate (HRmax), cardiac output (Q), and arteriovenous difference in oxygen concentration (Ca-Cv)O2 during graded, maximal treadmill running. Average body fat and training mileage were roughly 12% and 50 km.week-1, respectively. The average 10-km run-time slowed significantly by 6.0%.decade-1 [( 10-km run-time (min) = 0.323 x age (years) + 24.4] (n = 49, r = 0.692, p less than 0.001]. A strong correlation was found between age and VO2max [( VO2max (ml.kg-1.min-1) = -0.439 x age + 76.5] (n = 55, r = -0.768, p less than 0.001]. Thus, VO2max decreased by 6.9%.decade-1 along with reductions of HRmax (3.2%.decade-1, p less than 0.001) and Q (5.8%.decade-1, p less than 0.001), while no significant change with age was observed in estimated (Ca-Cv)O2. It was concluded that the decline of VO2max with aging in runners was mainly explained by the central factors (represented by the decline of HR and Q in this study), rather than by the peripheral factor (represented by (Ca-Cv)O2).     

Comparison of growth properties of carrot hairy root in various bioreactors

Summary Growth properties of carrot hairy root cells in various bioreactors were investigated. A turbine-blade reactor and an immobilized rotating drum reactor were found to be advantageous for the hairy root culture because of a high oxygen transfer coefficient (k in L a). After 30 days of culture, 10 g/l of dry hairy root cells were obtained in both bioreactors and maximum growth rates (V _m ) were found to be 0.63 and 0.61 g/l per day for the turbine-blade reactor and immobilized rotating drum reactor, respectively. Specific growth rates () at various cultivation times were observed to be linearly proportional to X/k _l a for both bioreactor configurations where X is the cell concentration. The estimated specific oxygen uptake rate of 0.34 mmol O₂/g dry cells per hour compares fairly well with an experimental value of 0.3.     

Distribution of FMRFamide-like immunoreactivity in the brain and neurohypophysis of the lamprey,Lampetra japonica

Summary Distribution of molluscan cardio-excitatory tetrapeptide Phe—Met—Arg—Phe—NH₂ (FMRFamide) was determined by means of immunohistochemistry in the brain and neurohypophysis of the lamprey, Lampetra japonica. Many FMRFamide-like immunoreactive neurons were found in the periventricular nuclear region and in a region near the mammillary recess. Neurons situated in the former region were larger. The immunoreactive cell groups were shown to be located at sites differing from those of the AF-positive cell groups. The fibers of immunoreactive neurons extended in all directions within the brain and towards the spinal cord, some reaching the third ventricle and capillaries. Thus, FMRFamide-like immunoreactive peptides appear to function as neurotransmitters or neuromodulators and possibly also as neurohormones. FMRFamide-like immunoreactive material was rarely observed in the posterior neurohypophysis (neural lobe), but was noted to be present to a limited extent in the caudal part of the anterior neurohypophysis (median eminence). It would thus follow that FMRFamide-like immunoreactive neurons may not necessarily be related to the hypothalamo-neural lobe system, but may possibly be associated with the hypothalamoadenohypophysial system. The pineal body showed no FMRFamide-like immunoreactivity.     

Adaptive on-line optimizing control of bioreactor systems

Several on-line optimizing control strategies were proposed and tested by computer simulation for the efficient operation of bioreactors. The control task was divided into two, one of which was to search for the optimal operating point and passed the set point to the lower layer of which task was to make the process output follow the set point as soon as possible. It was shown to be effective for the upper layer to express the objective function as a polynomial with respect to the measurement variable and to make use of it for finding the optimum point. Noting that the major dynamic characteristics of bioreactor system is the time-varying and nonlinear nature, the adaptive type control system is in evitable. It was shown to be quite effective to use discrete type self-tuning PID controller and the optimal controller compensated for the interaction between the control loops.Application was made to the cell recycle system for the production of lactic acid and baker's yeast cultivation. I was found from the former application that the control quality can be significantly improved by incorporating the decoupling strategy into the lower layer closed-loop system. It was also found from the latter application that the initial startup period can be significantly reduced by making use of the rough mathematical model.     

Macrophage chemotactic factor (MCF) produced by a human T cell hybridoma clone

A human T cell hybridoma clone, D6-18, producing high levels of macrophage chemotactic factor (MCF) was established by the emetine-actinomycin D selection method. MCF was found to be present not only in the culture medium but also in the cell lysate of D6-18 cells. The secretion of the MCF from D6-18 cells was effectively inhibited by disodium cromoglycate, which is an inhibitor of the degranulation of mast cells, suggesting that MCF is stored in granules. The MCF of D6-18 cells was purified from the sonicated cell lysate by ion-exchange chromatographies and high-performance liquid chromatography. The amino acid sequence of the purified MCF was revealed to be WLGREDGSE or WLGRQDGSE. The synthetic peptide WLGREDGSE showed chemotactic activity against guinea pig macrophages and human monocytes at the concentration of about 10(-8) M.     

Nitrilase of Rhodococcus rhodochrous J1. Purification and characterization

Nitrilase was purified from an extract of isovaleronitrile-induced cells of Rhodococcus rhodochrous J1 in seven steps. In the last step, the enzyme was crystallized by adding ammonium sulfate. The crystallized enzyme appeared to be homogeneous by polyacrylamide electrophoresis, ampholyte electrofocusing and double immunodiffusion in agarose. The enzyme has a molecular mass of about 78 kDa and consists of two subunits identical in molecular mass. The purified enzyme exhibits a pH optimum of 7.6 and a temperature optimum of 45 degrees C. The enzyme catalyzed stoichiometrically the hydrolysis of benzonitrile to benzoic acid and ammonia, and no formation of amide was detected. The enzyme required thiol compounds such as dithiothreitol, L-cysteine or reduced glutathione to exhibit maximum activity. The enzyme was specific for nitrile groups attached to an aromatic or heteroaromatic ring, e.g. benzonitrile, 3-chlorobenzonitrile, 4-tolunitrile, 2-furonitrile and 2-thiophenecarbonitrile. The comparison of the properties of the enzyme with other nitrilases and nitrile hydratases has been also discussed.     

Purification of GTP-binding proteins from bovine brain membranes. Identification of heterogeneity of the alpha-subunit of Go proteins

Using high-resolution Mono Q column chromatography, we purified 6 distinct peaks of GTP-binding proteins from bovine brain membranes. Five of them consisted of 3 polypeptides with alpha beta gamma-subunits and served as the substrate of islet-activating protein (IAP), pertussis toxin. The other one was purified as alpha-subunit alone and was also ADP-ribosylated by IAP in the presence of beta gamma-subunits. When each alpha-subunit was characterized by immunoblot analysis using various antibodies with defined specificity, the two of them were identified as Gi-1 and Gi-2, and other 4 appeared to be Go or Go-like G proteins. The alpha-subunits of immunologically Go-like proteins were apparently distinguishable from one another on elution profiles from the Mono Q column. Thus, there was a heterogeneity of the alpha-subunit of Go in the brain membranes.     

Nippostrongylus brasiliensis: radioresistant IgE antibody-forming cells in infected rats

In Nippostrongylus brasiliensis-infected rats, anti-N. brasiliensis IgE antibody production was observed at 20 weeks postinfection, long after the worms, as a source of antigen, had been expelled. The persistent IgE production was not abrogated after whole body irradiation (800 R) administered at 12 or 20 weeks, suggesting the participation of radioresistant IgE-forming cells. Help of T cells and recruitment of B memory cells in the irradiated rats seems to be ruled out by the findings that the irradiation completely inhibited the initiation of anti-N. brasiliensis IgE production in rats shortly after the infection with N. brasiliensis or after primary and secondary immunization with N. brasiliensis-antigen. Moreover, clearance of anti-N. brasiliensis IgE antibody from circulation did not seem to be crucially affected by the irradiation. The radioresistant cells forming anti-N. brasiliensis IgE were most productive in mesenteric lymph nodes as compared to other lymph nodes. The recognition of antigens fractionated by chromatography on Sephadex G-200 was the same for IgE-forming cells from rats 12 weeks after infection as for those from 3 weeks after infection. Based on these results, one of the mechanisms of persistent elevation of IgE antibody in the host infected with helminth parasites might be explained by the participation of radioresistant IgE-forming cells.