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1.
Numerous investigations have been carried out on the spectral distribution of the light of different species of fireflies. Here we record the emission spectrum of the Indian species of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae) on a color film. Green and red color-sectors, with an intense yellow one in between, appear in this spectrum. Intensity profile of this spectrum reveals a hitherto undetected strong narrow yellow line, which lies within the full-width-at-half maximum (FWHM) of the intensity profile. The spectrum recorded in a high-resolution spectrometer confirms the presence of this sharp intense line. This finding lends support to an earlier drawn analogy between the in vivo emission of the firefly and laser light. 相似文献
2.
3.
Effects of retinoid beta-glucuronides and N-retinoyl amines on the differentiation of HL-60 cells in vitro 总被引:2,自引:0,他引:2
J M Gallup A B Barua H C Furr J A Olson 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1987,186(3):269-274
Retinoyl beta-glucuronide and retinyl beta-glucuronide, which are naturally occurring water-soluble metabolites of vitamin A, induce the granulocytic differentiation of HL-60 cells in vitro, as evidenced by an increased reduction of nitroblue tetrazolium. The relative effectiveness of various retinoids in differentiation is retinoic acid greater than retinoyl beta-glucuronide greater than retinyl beta-glucuronide. Under the selected assay conditions, retinol, hydroxyphenyl-retinamide, retinamide, and N-retinoyl-phenylalanine are essentially inactive in differentiation. At concentrations of retinoids from 10(-9) to 10(-5) M, cell viability was best with the retinoid beta-glucuronides and retinamide, less with retinoic acid and retinol, and poorest with the N-retinoyl aromatic amines. Cellular growth was depressed only slightly by retinyl beta-glucuronide and retinamide, but to a greater degree by the other derivatives. Retinoyl beta-glucuronide was hydrolyzed in part to retinoic acid, whereas retinyl beta-glucuronide was cleaved to retinol, if at all, at a very slow rate. Under the selected assay conditions, retinoic acid and the retinoid beta-glucuronides primarily induce the differentiation of HL-60 cells, whereas the N-retinoyl aromatic amines show cytotoxicity. 相似文献
4.
Dipak Kumar Banerjee 《Journal of biosciences》1987,11(1-4):311-319
Radio-labelled amphomycin (3H-amphomycin) forms a complex with dolichylmonophosphate in presence of Ca2+. Complex formation has also been documented with retinylmonophosphate and perhydromonoeneretinylmonophosphate. Analysis of
the space-filling model suggested both fatty acylated aspartic acid residue at the N-terminus of the lipopeptide and phosphate
head group of dolichylmonophosphate are necessary for the complex formation. The binding ability of amphomycin is then utilized
to localize dolichylmonophosphate in the microsomal membrane. Studies with microsomal membranes from hen oviduct suggested
that dolichylmonophosphate is located in the cytoplasmic side of the membrane. 相似文献
5.
Hajime Otani Hitomi Otan Masao Morita Dipak K. Das 《Molecular and cellular biochemistry》1989,90(2):111-120
We investigated the effect of Ca2+ overload on the phospholipase C-catalyzed hydrolysis of phosphoinositides in the rat left ventricular papillary muscle. Ca2+ overload on the papillary muscle was induced by treatment with 0.3 mM ouabain in Ca2+-containing medium following either Ca2+-containing or Ca2+-free superfusion. The phosphoinositide breakdown was evaluated by determining accumulations of [3H]inositol phosphates ([3H]IPs) in the tissues prelabeled with [3H]inositol. Ca2+ repletion following Ca2+-free superfusion resulted in a rapid but small increase in resting tension that was not followed by contracture, nor was it associated with a significant increase in [3H]IPs accumulations. Treatment with ouabain following Ca2+-containing superfusion increased resting tension after a lag period of several minutes and produced contracture associated with an increase in [3H]IPs accumulations. The ouabain induced increases in resting tension, and accumulations of [3H]IPs were significantly potentiated by prior Ca2+-free superfusion instead of Ca2+-containing superfusion. There was a significant positive correlation between increases in resting tension and the phosphoinositide breakdown. The increased resting tension and the accumulations of [3H]IPs were not antagonized by treatments with prazosin plus atropine or indomethacin, but were abolished by superfusion with Ca2+-free buffer solution. Although the enhanced phospholipase C-catalyzed hydrolysis of phosphoinositides appears to be a consequence rather than a cause of increased intracellular Ca2+, such a biochemical change may provoke a positive feedback mechanism to develop the muscle contracture through the putative intracellular messenger action of inositol triphosphate and diacylglycerol.Abbreviations [3H]IPs
[3H]Inositol Phosphates
- IP
Inositol Phosphate
- IP2
Inositol Bisphosphate
- IP3
Inositol Trisphosphate
- PI
Phosphatidylinositol
- PI-4-P
Phosphatidylinositol-4-phosphate
- PI-4,5-P2
Phosphatidylinositol 4,5-bisphosphate
- PRZ
Prazosin
- ATR
Atropine
- INDO
Indomethacin
- min
Minutes 相似文献
6.
Chemical synthesis of all-trans-[11-3H]retinoyl beta-glucuronide and its metabolism in rats in vivo. 下载免费PDF全文
All-trans-[11-3H]retinoyl beta-glucuronide (RAG) was synthesized in a single step from all-trans-[11-3H]retinoyl fluoride, with a 24% yield. After its intraperitoneal injection into rats, RAG was detected in the blood, liver, intestine and kidney during the following 24 h period. Although the concentration of radiolabelled metabolites decreased with time, RAG predominated at nearly all times in nearly all tissues. Small amounts of retinoic acid (RA) were also universally present, together with unidentified polar metabolites and small amounts of non-polar esters of RA. The major excretion products of RAG in faeces and urine were RA and polar metabolites. Thus RAG, although converted in part to RA in vivo, persists as a major component in blood and tissues for at least 24 h. These observations support the concept that the retinoid beta-glucuronides might serve a physiologically significant role in the function of vitamin A. 相似文献
7.
Dipak K. Das Richard M. Engelman Xuekun Liu Swapna Maity John A. Rousou Joseph Flack Jitendra Laksmipati Randall M. Jones M. Renuka Prasad David W. Deaton 《Molecular and cellular biochemistry》1992,111(1-2):77-86
Reperfusion injury occurs during open-heart surgery after prolonged cardioplegic arrest. Cardiopulmonary bypass also is known to cause hemolysis. Since reperfusion of ischemic myocardium is associated with the generation of oxygen free radicals, and since free radicals can attack a protein molecule, it seems reasonable to assume that hemolysis might be the consequence of free radical attack on hemoglobin protein. The results of this study demonstrated that reperfusion following ischemic arrest caused an increase in free hemoglobin and free heme concentrations, simultaneously releasing free iron and generating hydroxyl radicals. In vitro studies using pure hemoglobin indicated that superoxide anion generated by the action of xanthine oxidase on xanthine could release iron from the heme ring and cause deoxygenation of oxyhemoglobin into ferrihemoglobin. This study further demonstrated that before the release of iron from the heme nucleus, oxyhemoglobin underwent deoxygenation to ferrihemoglobin. The released iron can catalyze the Fenton reaction, leading to the formation of cytotoxic hydroxyl radical (OH·). In fact, the formation of OH. in conjunction with hemolysis occurs during cardiac surgery, and when viewed in the light of the in vitro results, it seems likely that oxygen-derived free radicals may cause hemolysis during cardiopulmonary bypass and simultaneously release iron from the heme ring, which can catalyze the formation of OH·. 相似文献
8.
Preparation of retinamides by use of retinoyl fluoride 总被引:1,自引:0,他引:1
Retinoyl fluoride (2) prepared from retinoic acid (1) by reaction with diethylaminosulfurtrifluoride is a stable crystalline compound not easily hydrolyzed by water. By reacting retinoyl fluoride with water-soluble amines in the presence of sodium bicarbonate, retinamide (4), N-retinoyl glycine (6), N-retinoyl DL-phenylalanine (7), alpha-N-retinoyl-L-lysine (11), N-retinoyl 4-aminophenol (4-hydroxyphenylretinamide) (8), and N-retinoyl-2-amino-2-deoxy-D-glucose (2-deoxy-D-glucose-2-retinamide) (9) have been prepared in good yields and characterized by UV absorption, 1H NMR, IR spectra, mass spectrometry, and elemental analysis. 相似文献
9.
Sunil Palchaudhuri Ranajit Kumar Dipak Sen Ruma Pal Sajal Ghosh Banwarilal Sarkar Sujit K. Bhattacharya Sudhir C. Pal 《FEMS microbiology letters》1985,30(1-2):187-191
Abstract Multiple antibiotic-resistant Shigella dysenteriae type 1 isolates from a recent epidemic in West Bengal (India) showed identical plasmid patterns. All isolates were resistant to ampicillin (Am), chloramphenicol (Cm), tetracycline (Tc), streptomycin (Sm) and trimethoprim (Tp) and contained 6 plasmids, ranging from 2.5–120 kb. The Am resistance determinant was located on the 120 kb plasmid. This plasmid was unstable when the S. dysenteriae strains were grown above 37°C. The Bangladesh strains of S. dysenteriae type 1 showed identical plasmid patterns, except that many isolates were Am-sensitive and lacked the 120 kb plasmid. In strains from both Bangladesh and West Bengal, predominantly group-B plasmids conferred resistance to Cm and Tc. Comparisons of Eco R1 fragments generated from the total plasmid DNA content of each strain support the view that the plasmids present in the S. dysenteriae type 1 strains isolated from all recent epidemics in India and Bangladesh were identical. 相似文献
10.
1. ;Naturally occurring anhydrovitamin A(2)' obtained from the liver oil of freshwater fish Bagarius bagarius yielded, after six-stage chromatography, a pure product showing characteristic bands at 350, 368 (E(1%) (1cm.) 1006) and 390mmu in ethanol, and producing a green colour with antimony trichloride (E(1%) (1cm.) 1884 at 693mmu). 2. On distribution of the material between light petroleum and 95% methanol, 70% of it is found in methanol, which points to its hydroxylic character. 3. It gives an acetyl derivative, from which the original hydroxy compound can be regenerated on hydrolysis. 4. The infrared spectrum shows, besides other bands, one at 3460cm.(-1) attributable to a hydroxy group. 5. On passing a light-petroleum solution of naturally occurring anhydrovitamin A(2) through manganese dioxide a 6% conversion into retinene(2) is observed. 6. A 3-hydroxyanhydroretinol structure is proposed for naturally occurring anhydrovitamin A(2) and a mechanism of its transformation into retinene(2) on this basis is suggested. 相似文献