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J M Al-Hassan M Afzal M Ali M Thomson T Fatima S Fayad R S Criddle 《Comparative biochemistry and physiology. B, Comparative biochemistry》1986,85(1):41-47
Lipids associated with a threat induced epidermal gel secretion from the catfish, Arius thalassinus, have been analyzed. Phospholipids, neutral lipids and glycolipids are all present and each of these subclasses has been analyzed by thin layer and gas chromatography with a general similarity with membrane lipids being noted. The epidermal gel lipids differed from total liver lipids of the catfish. Fatty acid analysis showed the gel lipid to be rich in the unsaturated fatty acids: oleate (omega 7, C18:1), arachidonate (omega 6, C20:4), and docosahexaenoate (omega 3, C22:6). Some prostaglandins were quantitated in lipid extracts from the epidermal gel. 相似文献
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Mohanty Madhumita Jena; Ye Maian; Li Xingli; Rossi Noreen F. 《American journal of physiology. Cell physiology》2001,281(2):C555
Hypotonicswelling increases the intracellular Ca2+ concentration([Ca2+]i) in vascular smooth muscle cells(VSMC). The source of this Ca2+ is not clear. To study thesource of increase in [Ca2+]i in response tohypotonic swelling, we measured [Ca2+]i infura 2-loaded cultured VSMC (A7r5 cells). Hypotonic swelling produced a40.7-nM increase in [Ca2+]i that was notinhibited by EGTA but was inhibited by 1 µM thapsigargin. Priordepletion of inositol 1,4,5-trisphosphate (IP3)-sensitive Ca2+ stores with vasopressin did not inhibit the increasein [Ca2+]i in response to hypotonic swelling.Exposure of 45Ca2+-loaded intracellular storesto hypotonic swelling in permeabilized VSMC produced an increase in45Ca2+ efflux, which was inhibited by 1 µMthapsigargin but not by 50 µg/ml heparin, 50 µM ruthenium red, or25 µM thio-NADP. Thus hypotonic swelling of VSMC causes a release ofCa2+ from the intracellular stores from a novel sitedistinct from the IP3-, ryanodine-, and nicotinic acidadenine dinucleotide phosphate-sensitive stores. 相似文献
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Helen L. Henry Chhanda Dutta Noreen Cunningham Raymond Blanchard Robert Penny Chilung Tang Gail Marchetto Shu-Yin Chou 《The Journal of steroid biochemistry and molecular biology》1992,41(3-8)
The synthesis of 1,25(OH)2D3 is a critical control point in the regulation of calcium metabolism, and possibly in the growth and differentiation of a number of cell types. This paper reviews our current understanding of the regulation of this process at the cellular and molecular levels, with the emphasis on the mechanisms of feedback control 1,25(OH)2D3 itself, control of parathyroid hormone, the roles of cyclic AMP dependent protein kinase and protein kinase C, and the interaction between the various intracellular regulators of 1,25(OH)2D3 production. 相似文献
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Production and composition of phenylpyrrole metabolites prodcued by Pseudomonas cepacia 总被引:1,自引:0,他引:1
James N. Roitman Noreen E. Mahoney Wojciech J. Janisiewicz 《Applied microbiology and biotechnology》1990,34(3):381-386
Summary In shaken cultures, a strain of Pseudomonas cepacia isolated from apple leaves produced pyrrolnitrin and four other phenylpyrrole antibiotics. The concentrations of these metabolites were determined at intervals for 7 days in three different media at two initial pH levels. Optical density measurements revealed maximum cell concentrations after 24 h in nutrient broth, after 48 h in King's B medium, and after 96 h in minimum salts solution. The effects caused by initiating fermentations at pH 5.8 rather than 7.0 were in most cases not dramatic, although in some instances, especially in minimum salts broth, higher concentrations of metabolites were produced with the lower initial pH. Concentrations of the phenylpyrrole antibiotics were greatly affected by choice of culture medium and incubation time. Concentrations of the two nitrophenyl metabolites, pyrrolnitrin and 2-chloropyrrolnitrin, rose throughout the 7-day incubation and were more than 20 times greater in minimum salts medium than in either King's B medium or nutrient broth. The maximum concentrations of each of the three aminophenyl metabolites (dichloroamino, trichloroamino and monochloroamino) occurred in different media, the monochloro compound in nutrient broth, the dichloro compound in Kings B medium and the trichloro compound in minimum salts medium. The time dependence of the concentrations of the five metabolites supports the proposed biosynthesis of these pyrroles from tryptophan by successive chlorinations followed by oxidation of the amino group at the end of the pathway. 相似文献
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The effect of 12 surfactants on aflatoxin production, growth, and conidial germination by the fungus Aspergillus flavus is reported. Five nonionic surfactants, Triton X-100, Tergitol NP-7, Tergitol NP-10, polyoxyethylene (POE) 10 lauryl ether, and Latron AG-98, reduced aflatoxin production by 96 to 99% at 1% (wt/vol). Colony growth was restricted by the five nonionic surfactants at this concentration. Aflatoxin production was inhibited 31 to 53% by lower concentrations of Triton X-100 (0.001 to 0.0001%) at which colony growth was not affected. Triton X-301, a POE-derived anionic surfactant, had an effect on colony growth and aflatoxin production similar to that of the five POE-derived nonionic surfactants. Sodium dodecyl sulfate (SDS), an anionic surfactant, and dodecyltrimethylammonium bromide, a cationic surfactant, suppressed conidial germination at 1% (wt/vol). SDS had no effect on aflatoxin production or colony growth at 0.001%. The degree of aflatoxin inhibition by a surfactant appears to be a function of the length of the hydrophobic and hydrophilic chains of POE-derived surfactants. 相似文献
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Restriction enzymes are essential reagents to molecular biologists, but their relevance to bacterial populations is less obvious. Most bacteria encode restriction and modification systems and these are commonly considered to be a barrier to phage infection. Current evidence also supports a more general role for them in genetic recombination. 相似文献
10.
Mohd Imran Shahzad Ahmed Ahmad Zuhairi Abdullah Jabir Hakami Anis Ahmad Chaudhary Hassan Ahmad Rudayni Salah-Ud-Din Khan Afzal Khan Nosiba Suliman Basher 《Luminescence》2023,38(7):1064-1086
The penicillin derivative amoxicillin (AMX) plays an important role in treating various types of infections caused by bacteria. However, excessive use of AMX may have negative health effects. Therefore, it is of utmost importance to detect and quantify the AMX in pharmaceutical drugs, biological fluids, and environmental samples with high sensitivity. Therefore, this review article provides valuable and up-to-date information on nanostructured material-based optical and electrochemical sensors to detect AMX in various biological and chemical samples. The role of using different nanostructured materials on the performance of important optical sensors such as colorimetric sensors, fluorescence sensors, surface-enhanced Raman scattering sensors, chemiluminescence/electroluminescence sensors, optical immunosensors, optical fibre-based sensors, and several important electrochemical sensors based on different electrode types have been discussed. Moreover, nanocomposites, polymer, and MXenes-based electrochemical sensors have also been discussed, in which such materials are being used to further enhance the sensitivity of these sensors. Furthermore, nanocomposite-based photo-electrochemical sensors and the market availability of biosensors including AMX have also been discussed briefly. Finally, the conclusion, challenges, and future perspectives of the above-mentioned sensing techniques for AMX detection are presented. 相似文献