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21.
Wanda Peczyńska-Czoch Jarosław Osiadacz Łukasz Kaczmarek Tomasz Żal 《Biotechnology letters》1996,18(2):123-128
Summary Microbial transformation of cytotoxic 5,11-dimethyl-5H-indolo[2,3-b]quinoline (a compound displaying antitumor activity and affecting the activity of calf thymus DNA topoisomerase II) was performed by the Rhizopus arrhizus strain and yielded a 9-hydroxy derivative. The metabolite obtained displayed a stronger cytotoxity against KB cells than the parent compound (ID50=0.001 mol/mL), and stimulated also the formation of calf thymus topoisomerase II mediated pSP65 DNA cleavage in vitro at the concentration of 3 M. Being analogous to 9-hydroxyellipticine (which is an antitumor alkaloid), this novel indolo[2,3-b] quinoline derivative can be regarded as a novel potential antitumor agent. 相似文献
22.
To clarify the way in which the light available for growth affectsrespiration in leaves of sun and shade plants, we examined therespiratory properties of mature leaves of Spinacia oleraceaL., a sun species, and of Alocasia macrorrhiza (L.) G. Don.,a shade species, that had been grown at various irradiances.In leaves of S. oleracea, the respiratory rates, on a dry massbasis, decreased with time during the night, and the higherwas the growth irradiance during the day, the higher was therespiratory rate. The marked decreases in the respiratory rateduring the night were accompanied by decreases in the concentrationof carbohydrates in the leaves. By contrast, the respiratoryrates of leaves of A. macrorrhiza were virtually constant throughoutthe night and the absolute rates were lower than those of S.oleracea even though the absolute value of the concentrationof carbohydrates and its decrease at night resembled to thosein S. oleracea. The maximum activities of respiratory enzymeswere also similar to those in S. oleracea. However, the leavesof A. macrorrhiza contained less soluble protein than thoseof S. oleracea. These results suggest that, in S. oleracea,the concentration of carbohydrates might determine the respiratoryrate while such is not the case in A. macrorrhiza. The lowerrespiratory rates in A. macrorrhiza might be due to a lowerdemand for ATP. (Received November 29, 1995; Accepted February 15, 1996) 相似文献
23.
Sewage sludge from the Upper Silesia Region of Poland were surveyed for keratinolytic fungi. Out of 100 Petri dishes examined, 89 were positive for these micro-organisms. Altogether, 185 fungal appearances belonging to 10 species were observed. Trichophyton terrestre with its teleomorph Arthroderma quadrifidum, T. ajelloi with A. uncinatum, Microsporum gypseum with Arthroderma sp., and Chrysosporium keratinophilum with Aphanoascus keratinophilus prevailed in the sludges. The sewage treatment technologies together with the sludge structure, humidity and pH were found to be critical factors determining the occurrence of keratinolytic fungi in the sludge environment. The qualitative and quantitative composition of keratinolytic fungi could be a useful tool in evaluation of sludge treatment processes. 相似文献
24.
Lidia Jabłońska Michał Walski Urszula Rafałowska 《Cellular and molecular neurobiology》1994,14(6):701-709
Summary 1. The effect of lead (in vivo) on the uptake of GABA, dopamine, and histidine as a precursor of histamine in synaptosomes obtained from chronically lead-treated rats was studied.2. Lead decreased the uptake of GABA, increased the uptake of dopamine, and did not change the uptake of histidine. These effects were independent of calcium concentration.3. Lead administration to the rat changed the morphology of the synaptosomes, as manifested in the decreased number of synaptic vesicles and disturbed mitochondrial structure.4. The results suggest the existence of several mechanisms of lead toxicity on uptake, related to individual neurotransmitters, which are not necessarily connected with a Pb2+/Ca2+ interaction. 相似文献
25.
J. Haplová V. Farkaš M. Hejtmánek R. Koďousek J. Malínský 《Archives of microbiology》1994,161(4):340-344
Rylux BSU, a new fluorescent brightener from the family of 4,4-diaminostilbene-2,2disulfonic acid derivatives, inhibited growth and cytokinesis of the yeast Saccharomyces cerevisiae. In the presence of 0.1–1 mg/ml Rylux BSU the cells grew in clumps, had irregular shape and were larger than controls. They formed apparently normal primary septa but their secondary septa and lateral cell walls, especially those in older cells, were abnormally thick with large deposits of amorphous wall material in the periplasmic spaces all over the cell surface. Chitin content in the cell walls of cells grown in the presence of Rylux BSU was increased 2 to 5 times in comparison to that of the controls and glucan content was reduced by up to 30%. In the in vitro assays with particulate membrane fractions, Rylux BSU acted as a non-competitive inhibitor of -1,3-glucan synthase with inhibitory constant K
i=1.75 mg/ml whereas the chitin synthase was inhibited to a much lesser extent. From the difference of the effects of Rylux BSU on the synthesis of chitin in vivo and in vitro it is concluded that the brightener interacts with chitin synthase only indirectly, possibly by influencing the properties of integral plasma membrane.Abbreviations RBSU
Rylux BSU, 1,4-benzenedisulfonic acid-2,2-[ethyleneidy]bis[(3-sulpho-4,1-phenylene)imino[6-bis(2-hydroxyethyl)amino]-1,3,5-triazine-4,2-diylamino]]bis-, hexasodium salt
- FB
fluorescent brightener 相似文献
26.
J. Błaszkowski 《Mycorrhiza》1994,5(1):71-88
In the years 1985–1989, the occurrence of arbuscular fungi and mycorrhizae on the Hel Peninsula (Poland) was investigated with the help of 45 soil and root samples collected under 20 plant species of eight families. Except for Zea mays, the other plant species were from uncultivated sites. All soil samples contained spores of arbuscular fungi, of which about 45% were of the genus Glomus. Acaulospora spp. preferred members of the Cupressaceae. Spores of Gigaspora occurred rarely and only in two plant families. Glomus spp. were most frequently associated with plants of the Rosaceae, and species of Scutellospora were found at markedly higher frequencies among roots of plants of the Gramineae and Cupressaceae. A total of 29 spore-forming species and Glomus tenue (a fungus recognizable by its distinctive infections) were found. The most frequently recovered fungus, Glomus tenue, was present in roots of 56.8% of examined plants. Of the spore-forming fungi, the most frequently isolated spores were those of Scutellospora dipurpurascens, then Glomus constrictum, Acaulospora 61, and Glomus microcarpum. The overall spore density in examined samples averaged 99.8 in 100 g dry soil in the range 1 to 547, and was highest in a sample taken from around roots of Festuca arundinacea. The dominant fungi forming spores in sampled soils were Glomus constrictum, Glomus microcarpum, and Scutellospora dipurpurascens. The average species density was 3.9 in 100 g dry soil in the range 1 to 10, and was highest in Corynephorus canescens, Rosa canina, and Thuja occidentalis. Levels of colonization by arbuscular fungi ranged from 0.0 to94.0% (mean 23.3%) of the root length and were highest in Festuca arundinaceae and Zea mays. 相似文献
27.
28.
Mateusz Okrutniak Irena M. Grześ Anna K. Kucharska Filip Turza Małgorzata Zimocha Sabrina Kerdiane Patryk Jabłoński 《Entomological Science》2023,26(3):e12549
In ants, workers of different sizes may perform various tasks, even in so-called monomorphic species with relatively low body size variation. However, it is unclear if the body size diversity of monomorphic workers correlates with task efficiency, especially in stressful contingencies. Here we tested if the body size variation of workers corresponds with its efficiency in transferring pupae. Transferring brood is a pre-set behavioral response to stress, e.g. suboptimal temperature. Here we applied a laboratory experiment simulating nest damage. The study was performed on the common garden ant (Lasius niger (Linnaeus, 1758)) – a species with no distinct worker subcastes. The efficiency of workers was measured as the latency of transferring pupae from a lit part of the experimental colony to a darkened part, while the body size diversity was expressed as the within-colony coefficient of variation in head width. We did not find any significant correlation between efficiency and body size variation. Summarizing the existing studies and the present results, we propose the hypothesis that the body size diversity of L. niger may have implications for workers’ division of labor but not for their task efficiency in a stressful contingency. 相似文献
29.
Erwin Stresemann und Eugeniusz Nowak 《Journal of Ornithology》1958,99(3):243-296
Zusammenfassung Die Türkentaube war ursprünglich auf semi-aride Gebiete Südasiens beschränkt. Dort lassen sich drei geographische Rassen unterscheiden. Eine davon,Streptopelia decaocto decaocto, bewohnte bis zum Beginn des historischen Zeitalters nur Indien, nordwärts bis zum Himalaya, ostwärts etwa bis zum Brahmaputra. Später ist sie, vermutlich auf dem Seewege, nach Nord-China eingeführt worden, wo sie sich stark ausgebreitet hat.Auch nach Vorder-Asien ist sie von Indien her erst in historischer Zeit gelangt. Es ist wahrscheinlich, aber nicht sicher, daß sie nach Mesopotamien durch den Menschen gebracht wurde. Von dort aus ist sie nach Syrien und (schwerlich vor der Mitte des 16. Jahrhunderts) nach Anatolien und weiter nach Südost-Europa vorgedrungen, wo die Türken ihr eine besondere Hege angedeihen ließen. In der europäischen Türkei entwickelten sich Populationen in sehr vielen Städten und Dörfern. Einige davon (z. B. in Mostar und Bessarabien) sind wahrscheinlich auf importierte Paare zurückzuführen.Nach dem Zusammenbruch der türkischen Herrschaft in Bessarabien (1812), Griechenland (1828), Rumelien, Bulgarien, Serbien, Albanien, Montenegro, Herzegowina (1878), verloren die Türkentauben dort ihre Beschützer. Ihr Bestand ging sehr stark zurück, in weiten Gebieten (Bessarabien, Griechenland), wurden sie gänzlich ausgerottet. Erst nach 1900 breiteten sie sich in Bulgarien und wohl auch in Serbien wieder aus. Das war nach Ansicht der Verff. die Folge oekologischer Umstellung vom Nisten an Häusern und unter Dächern zum Brüten auf Bäumen.Von vorgeschobenen, dicht besiedelten Kolonien (Mostar, Belgrad, Orten an der bulgarisch-rumänischen Grenze) aus drangen Türkentauben um 1930 über die Grenzen des einstigen osmanischen Reiches in drei Richtungen vor, und zwar nach der Küste Dalmatiens, nach Ungarn und nach der Walachei.Infolge der dort einsetzenden starken Vermehrung (wahrscheinlich ermöglicht durch verminderten Feinddruck) hat sich die Türkentaube schnell weiter verbreitet. In einem günstigen Jahr kann eine örtliche Population, wie nachgewiesen, um mehr als 250% zunehmen.Zur Zeit ist die Türkentaube in der Po-Ebene bis nach Turin, nördlich der Alpen bis an die Küste der Nordsee (Belgien, Holland, Cuxhaven), des Skagerrak (Skagen) und der Ostsee (Wismar, Rostock, Danzig, Reval), und über Rumänien bis zum Dnjestr und sogar bis Kiew vorgedrungen. Schon haben einzelne Paare in Ost-England, Schottland und Süd-Schweden mit Erfolg gebrütet.Bisher sind 15, meist am Geburtsort beringte Türkentauben in größerer Entfernung (bis 720 km) wiedergefunden worden. Sie beweisen, daß die von ihrer Stamm-Kolonie abwandernden (wohl meist noch nicht einjährigen) Individuen dies ohne Bevorzugung einer Himmelsrichtung tun, also wahllos streuen. Das kann zu jeder Jahreszeit geschehen. Der Ort der endgültigen Ansiedlung abgewanderter Individuen oder Paare ist mitunter über 700 km weit vom Geburtsort entfernt.Daß das Vordringen der Türkentaube infolge ihrer Eigenschaft, den Winter am Brutplatz oder in dessen Nähe zu verbringen, an einer klimatisch bedingten Ausbreitungsgrenze (Winter-Isotherme?) enden wird, ist wahrscheinlich. Diese Grenze scheint bisher noch nicht erreicht zu sein. Der nördlichste bisherige Brut- und zugleich Überwinterungsort liegt dicht bei Reval (= Tallinn), 59° 45 N (südlichstes Siedlungsgebiet ist Nord-Ceylon, 9° 45 N).Man kennt weder morphologische noch ethologische Unterschiede zwischen den nördlichsten und den südlichsten, durch 50 Breitengrade getrennten Populationen. Starker Frost kann bei den europäischen Türkentauben eine Schädigung der Zehen bewirken, die dem Vogel das Umfassen von Zweigen und das Laufen erschwert. Ob die indischen noch empfindlicher gegen Kälte sind, wurde bisher noch nicht untersucht. 相似文献
30.
Diuron treatment for weed control greatly increased anthurium root rot caused by Pythium splendens, P. spinosum, P. vexans and Calonectria crotalariac. Diuron in agar medium was inhibitory to the growth of mycelium, formation and germination of sporangia of P. splendens. Sporangia of P. splendens produced in diuron-amended medium did not differ in pathogenecity to anthurium roots from those produced in diuron-free medium. When diuron was applied to kill weeds in the planting medium, the population of P. splendens in it was not decreased during the test. Diuron was inhibitory to a number of micro-organisms in the platiting medium. Exudation of anthursum roots was not increased by diuron treatment. Increase in severity of anthurium root rot by diuron treatment was similar whether the experiments were performed in the presence or absence of planting medium, suggesting that the enhancing effect of diuron on root rot is mainly due to an increase in susceptibility of the host plants. 相似文献