A study of the mechanism of air-ion-induced growth stimulation in HORDEUM VULGARIS

1963 ◽  
Vol 7 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Albert P. Krueger ◽  
Sadao Kotaka ◽  
Paul C. Andriese
Author(s):  
R. W. Tucker ◽  
N. S. More ◽  
S. Jayaraman

The mechanisms by which polypeptide growth factors Induce DNA synthesis in cultured cells is not understood, but morphological changes Induced by growth factors have been used as clues to Intracellular messengers responsible for growth stimulation. One such morphological change has been the transient disappearance of the primary cilium, a “9 + 0” cilium formed by the perinuclear centriole in interphase cells. Since calcium ionophore A23187 also produced both mitogenesis and ciliary changes, microtubule depolymerization might explain ciliary disappearance monitored by indirect immunofluorescence with anti-tubulin antibody. However, complete resorption and subsequent reformation of the primary cilium occurs at mitosis, and might also account for ciliary disappearance induced by growth factors. To settle this issue, we investigated the ultrastructure of the primary cilium using serial thin-section electron microscopy of quiescent BALB/c 3T3 cells before and after stimulation with serum.


2018 ◽  
pp. 5-29 ◽  
Author(s):  
V. A. Mau

The paper deals with the global and national trends of economic and social development at the final stage of the global structural crisis. Special attention is paid to intellectual challenges economists will face with in the post-crisis world: prospects of growth without inflation, new global currencies and the role of cryptocurrencies, central banks independence and their role in economic growth stimulation, new tasks and patterns of government regulation, inequality and growth. Special features of Russian post-crisis development are also under consideration. Among them: prospects of macroeconomic support of growth, inflation targeting, new fiscal rule, social dynamics and new challenges to welfare state. The paper concludes that the main obstacles for economic growth in Russia are concentrated in the non-economic area.


1974 ◽  
Vol 75 (4) ◽  
pp. 669-682 ◽  
Author(s):  
K.-G. Thorngren ◽  
L. I. Hansson

ABSTRACT The growth stimulating effect of growth hormone was determined with tetracycline as intravital marker of the longitudinal bone growth of proximal tibia in female Sprague-Dawley rats hypophysectomized at 60 days of age. After a post-operative control period of 15 days growth hormone (NIH-GH-B16) was given daily for 5 or 10 days followed by a 10 day period after its withdrawal. L-thyroxine was given in association with the growth hormone administration to potentiate the growth stimulation. A linear log dose-response relation was found for the two administration models with a high precision. The thyroxine-treatment increased the sensitivity of the bioassay. An administration period of 5 days was found sufficient for the bioassay of growth hormone in thyroxine-treated hypophysectomized rats. Compared with the earlier bioassay methods for growth hormone, the present bioassay is more favourable when all the factors, such as precision, sensitivity, specificity, and administration period are considered.


1975 ◽  
Vol 10 (1) ◽  
pp. 73-83
Author(s):  
J.E.S. Graham ◽  
T.C. Hutchinson

Abstract Crude oil spills are increasingly likely to occur from drilling, pumping and transportation activities as oil development proceeds at a rapid pace. These spills may occur over the wide range of climatic conditions which obtain in Canada. Little is known of oil toxicity at different temperatures; consequently, laboratory studies were made of the variability of the toxicity of aqueous extracts of a Norman Wells crude oil to freshwater algae over the temperature range 5°C to 35°C. Two unicellular green algae were studied: Chlamydomonas eugametos and Chlorella vulgaris. Their response (measured by cell numbers) varied with temperature and species. Whereas Chlamydomonas eugametos showed a general pattern of growth inhibition by oil at all temperatures with maximum inhibition at 25°C, Chlorella vulgaris showed general growth stimulation by oil with maximum stimulation at 25°C, this temperature was chosen for all further experimentation. All experiments were done using unialgal cultures and sterile technique. Cells were grown in 50 ml of nutrient medium (BBM) in 125 ml Erlenmeyer flasks. Such flasks allow gas exchange and permit loss of volatile hydrocarbons. Aqueous extracts were made by slowly stirring 5% crude oil with the nutrient medium for six hours using a magnetic mixer. The extract was then allowed to sit for two to four hours before the lower fraction was drawn off for use. Experiments were carried out in controlled environment chambers (±2°C) with a twelve hour light-dark cycle. All further experiments used a similar methodology. (Note: Chlamydomonas eugametos experiments were carried out on a rotary shaker at 125 rpm.) An attempt was made to determine the reason for the remarkable stimulation in growth of Chlorella vulgaris #29 at 25°C. This organism has been described in the literature as heterotrophic. Thus three reasons for stimulation seemed possible: 1. heterotrophic uptake of hydrocarbons directly from solution; 2. heterotrophic uptake of organic compounds formed or released by microbial breakdown of hydrocarbons (the aqueous extract of crude was not sterile); or 3. the use of CO2 released to solution by microbial respiration. The original experiment was repeated in the dark at 20°C to determine if stimulation still occurred. It did not, since cells exposed to the aqueous extract decreased in numbers. However, after two weeks the cells were illuminated and even though experimental flasks started off with depleted populations, they outgrew the control cells within two weeks. This suggested that if stimulation was related to heterotrophism, it must, at least in this case, have been the unusual case of photoheterotrophism. The reasons for this stimulation of growth are currently under investigation. Several methods are being employed to investigate the suspected heterotrophism. Experiments will be done to determine whether light energy is essential to the stimulation. Two varieties of Chlorella vulgaris, i.e. #29 and #260 are heterotrophic and autotrophic respectively, are to be used in experiments. Sterile aqueous extracts made by pressure ultrafiltration will be used. These experiments should determine whether algal growth stimulation is related to heterotrophism or whether microbial degradation of hydrocarbons is the real source of stimulation. Although the toxicity of crude oil may be rapidly ameliorated by physical and/or biological phenomena, one must still be aware of the possibility of a large input of organic carbon causing extensive eutrophication. Thus both toxicity and eutrophication will cause a selection, in terms of survival, in a natural environment. It is evident that although an oil spill may not totally destroy an ecosystem, it will certainly alter its natural composition considerably.


2021 ◽  
Vol 10 (10) ◽  
pp. 2100
Author(s):  
Hiroshi Sakagami ◽  
Sachie Nakatani ◽  
Ayame Enomoto ◽  
Sana Ota ◽  
Miku Kaneko ◽  
...  

Efficient utilization of alkaline extracts of several plants for the treatment of oral diseases has been reported. To investigate the mechanism of anti-inflammatory activity of alkaline extract of the leaves of Sasa sp. (SE), multi-omics analysis using metabolomics and DNA array was performed. Human gingival fibroblasts (HGFs) were treated for IL-1β to induce inflammation (detected by PGE2 production in culture medium) in the presence or absence of SE. Both IL-1β and SE showed slight hormetic growth stimulation against HGF. SE inhibited PGE2 production dose- and time-dependently. Its inhibitory action was more pronounced by first treating the cells with SE, rather than with IL-1β. At 3 h after IL-1β treatment, 18 amino acids (except cysteine and glutamic acid), total glutathione (GSH, GSSG, Cys-GSH disulfide), Met-sulfoxide, 5-oxoproline, and SAM declined, whereas DNA expressions of AKT, CASP3, and CXCL3 were elevated. These changes were reversed by simultaneous treatment with SE. The present study suggests that the anti-inflammatory action of SE is mediated via various metabolic pathways for cell survival, apoptosis, and leukocyte recruitment.


Author(s):  
Han‐Qing Liu ◽  
Xiang‐Bin Lu ◽  
Zi‐Han Li ◽  
Chang‐Yan Tian ◽  
Jie Song

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