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Summary Cellular fatty acids inLactobacillus büchneri were transmethylated with H2SO4 catalyst in methanol at elevated temperature. By optimising the reaction time and the amounts of catalyst and methanol used at a fixed temperature it was possible to maximise the lactobacillic acid yield. The yield of lactobacillic acid with this method was better than with the traditional method using base-catalysed saponification followed by HCL-catalysed methylation. 相似文献
3.
Decreased muscarinic receptor binding in cerebral cortex and hippocampus in Alzheimer's disease 总被引:3,自引:0,他引:3
Muscarinic (cholinergic) receptor binding sites (MRB) were studied by determining the 3H-QNB binding in four cortical areas and hippocampus of 20 histologically confirmed Alzheimer patients and comparing these with corresponding controls. Alzheimer patients dying at younger age (less than or equal to 80) with profound decrease in choline-acetyltransferase activity (by 61-85%) and without any, possibly MRB modifying, drug treatment showed 30% decrease in MRB in the frontal cortex (p less than 0.05), 28% in the temporal cortex (p less than 0.05) and 37% in the hippocampus (p less than 0.01). These findings further suggest that muscarinic receptors are affected in Alzheimer's disease, at least in advanced state of the disease. 相似文献
4.
Tapani Tuomi Jouni Ilvesoksa Simo Laakso Heikki Rosenqvist 《Journal of Plant Growth Regulation》1993,12(3):149-156
The molds Botrytis cinerea, Cladosporium cladosporioides, and the yeast Aureobasidium pullulans, isolated from the leaves of three short-rotation Salix clones, were found to produce indole-3-acetic acid (IAA). Abscisic acid (ABA) production was detected in B. cinerea. The contents of IAA and ABA in the leaves of the Salix clones and the amounts of fungal propagules in these leaves were also measured, in order to evaluate whether the amounts of plant growth regulators produced by the fungi would make a significant contribution to the hormonal quantities of the leaves. The content of ABA, and to a lesser degree that of IAA, showed a positive correlation with the frequency of infection by the hormone-producing organisms. The amounts of hormone-producing fungi on leaves that bore visible colonies were, however, not sufficiently high to support the claim that either the fungal production of ABA or IAA would significantly contribute to the hormonal contents of the leaves of the Salix clones. It is therefore suggested that the effect of fungal IAA production on plants is limited to the rhizosphere and that B. cinerea, which is a known pathogen, induces ABA production by the mother plant as a response to physiological stress.Abbreviations ABA
abscisic acid
- ABA-Me
abscisic acid methyl ester
- GC-MS-SIM
gas chromatography-selected ion monitoring-mass spectrometry
- IAA
indole-3-acetic acid
- IAA-Me
indole-3-acetic acid methyl ester
Author for correspondence. 相似文献
5.
The chemiluminescent reaction of luminol during lipoxygenase-catalyzed oxygenations was studied with the purpose of developing a specific luminometric assay for cis,cis-1,4-pentadiene fatty acids directly in aqueous solutions. The addition of picomole levels of either linoleic or arachidonic acids to reaction systems containing 0.04 mM luminol and 40 micrograms/ml of purified soybean lipoxygenase-1 gave light emission curves with a single sharp maximum. Under these conditions the peak heights were linearly dependent on the fatty acid concentration and the detection limit for both of the fatty acids was 2 pmol with a signal to noise ratio of 2. For maximum reproducibility of the assays a procedure for the proper quantitation of the enzyme was developed. The fact that the assay proved to be relatively interference-free was ascribed to the high molar enzyme/substrate ratio (above 1). 相似文献
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Streptomyces griseus showed three different modes of changing fatty acids in response to temperature change. In Brevibacterium fermentans, two such responses were found. The responses involved changes in fatty acid branching, unsaturation, or chain length, depending on growth temperature range. Changes in unsaturation of branched-chain acids were characteristic at low growth temperatures. 相似文献
8.
Differential response of cycling and noncycling cells to inducers of DNA synthesis and mitosis 总被引:1,自引:0,他引:1 下载免费PDF全文
The objective of this study was to determine whether cells in G(0) phase are functionally distinct from those in G(1) with regard to their ability to respond to the inducers of DNA synthesis and to retard the cell cycle traverse of the G(2) component after fusion. Synchronized populations of HeLa cells in G(1) and human diploid fibroblasts in G(1) and G(0) phases were separately fused using UV-inactivated Sendai virus with HeLa cells prelabeled with [(3)H]ThdR and synchronized in S or G(2) phases. The kinetics of initiation of DNA synthesis in the nuclei of G(0) and G(1) cells residing in G(0)/S and G(1)/S dikaryons, respectively, were studied as a function of time after fusion. In the G(0)/G(2) and G(1)/G(2) fusions, the rate of entry into mitosis of the heterophasic binucleate cells was monitored in the presence of Colcemid. The effects of protein synthesis inhibition in the G(1) cells, and the UV irradiation of G(0) cells before fusion, on the rate of entry of the G(2) component into mitosis were also studied. The results of this study indicate that DNA synthesis can be induced in G(0)nuclei after fusion between G(0)- and S-phase cells, but G(0) nuclei are much slower than G(1) nuclei in responding to the inducers of DNA synthesis because the chromatin of G(0) cells is more condensed than it is in G(1) cells. A more interesting observation resulting from this study is that G(0) cells is more condensed than it is in G(1) cells. A more interesting observation resulting from this study is that G(0) cells differ from G(1) cells with regard to their effects on the cell cycle progression of the G(2) nucleus into mitosis. This difference between G(0) and G(1) cells appears to depend on certain factors, probably nonhistone proteins, present in G(1) cells but absent in G(0) cells. These factors can be induced in G(0) cells by UV irradiation and inhibited in G(1) cells by cycloheximide treatment. 相似文献
9.
Metabolic epidemiology of large bowel cancer. Fecal mutagens in high- and low-risk population for colon cancer. A preliminary report 总被引:2,自引:0,他引:2
Because of potential significance of fecal mutagens in the pathogenesis of colon cancer, the dietary pattern and fecal mutagens of 3 populations with distinct risk for the development of colon cancer, a high-risk population in New York Metropolitan area (non-Seventh-Day Adventists), a low-risk population of vegetarian Seventh-Day Adventists in New York Metropolitan area and a low-risk population in rural Kuopio, Finland were studied. The average daily intake of protein was the same in the 3 groups, but the sources were different, a greater portion coming from meat in the New York non-Seventh-Day Adventists and from vegetables in Seventh-Day Adventists. The intake of fat was lower in Seventh-Day Adventists and higher in Kuopio and in New York non-Seventh-Day Adventists. The intake of dietary fiber was high in Kuopio compared to other groups. Fecal samples collected for 2 days were freeze-dried extracted with peroxide-free diethyl ether, partially purified on a silica-gel column and assayed for mutagenicity using the Salmonella/mammalian microsome mutagenicity test. The mutagenic activity was observed with Salmonella typhimurium tester strain TA98 without microsomal activation and with TA100 with and without microsomal activation in high-risk subjects from New York consuming a high-fat, high-meat diet. The incidence of fecal mutagen activity was higher in volunteers from New York consuming a high-fat, high-meat diet compared to low-risk rural Kuopio population. None of the vegetarian Seventh-Day Adventists showed any mutagenic activity. 相似文献
10.
Danilo ML Prado Fabiana B Benatti Ana L de Sá-Pinto Ana P Hayashi Bruno Gualano Rosa MR Pereira Adriana ME Sallum Eloisa Bonfá Clovis A Silva Hamilton Roschel 《Arthritis research & therapy》2013,15(2):R46