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941.
A technique is described for the rapid gas-liquid chromatographic analysis of mixtures of carbohydrate trimethylsilyl ethers prepared at mutarotation equilibrium. A mixture containing arabinose, ribose, xylose, fructose, glucose, galactose, mannose, sucrose, maltose, and cellobiose can be determined in less than 16 min using high-rate temperature programming. 相似文献
942.
L-GLUTAMIC ACID DECARBOXYLASE IN NON-NEURAL TISSUES OF THE MOUSE 总被引:7,自引:5,他引:2
Abstract— Low levels of γ-aminobutyric acid (GABA) and of glutamic acid decarboxylase (GAD) activity have been detected in mouse kidney, liver, spleen and pancreas. Quantitation of both 14 CO2 and [14 C]GABA produced in radiometric assays from [U-14 CJglutamic acid has shown that measurement of 14 CO2 evolution alone is not, in all cases, a valid estimate of true GAD activity. As evidenced by increased ,14 CO2 production upon addition of NAD and CoA to assay mixtures, radiometric assay of GAD activity in crude homogenates may yield 14 CO2 via the coupled reactions of glutamic acid dehydrogenase and a-ketoglutarate dehydrogenase. The addition of 1 mM aminooxyacetic acid (AOAA) to assays of kidney homogenates inhibited [,14 C]GABA production 92 per cent while 14 CO2 production was inhibited only 53 per cent. No evidence was found to confirm the reported existence of a second form of the enzyme, GAD II. previously described by Haber el al. (H aber B., K uriyama K. & R oberts E. (1970) Biochem. Pharmac. 19, 1119-1136). Based on sensitivity-to AOAA and chloride inhibition, the GAD activity in mouse kidney is. apparently, indistinguishable from that of neural origin. 相似文献
943.
The localization, isolation and partial characterization of a collagenolytic enzyme from the land planarian Bipalium kewense is described. This enzyme can be obtained by direct extraction of the organism, and can be separated from non-collagenous proteolytic activity by (NH(4))(2)SO(4) precipitation and Sephadex-gel chromatography. Its mode of attack on collagen and sensitivity to a variety of inhibitors indicate that this enzyme differs from vertebrate collagenases and a previously described invertebrate collagenase. 相似文献
944.
Dwight E. Phillips 《Cell and tissue research》1973,140(2):145-167
Summary An electron-microscopic study has been made of the glial cells in the developing lateral funiculus of the cervical spinal cord in fetal rhesus monkeys. The various macroglial cell types, their precursor cells, and microglia are discussed in detail. An astrocytic lineage is proposed in which glioblasts present in the lateral funiculus give rise to astroblasts that then develop into mature astrocytes. Oligoblasts apparently migrate into the lateral funiculus as such and develop into active oligocytes. The active oligocytes become most predominant during the initial stages of myelinogenesis and are in direct continuity with developing myelin. The active oligocytes develop into mature oligocytes after myelination is completed. Microglia cells are present throughout development as three forms; resting microglia, globose microglia, and active microglia. The globose and active microglia predominates at specific times early in development when degeneration of apparent neuronal processes is taking place. The microglia cells are characterized by dense nuclear chromatin clumps, lipid inclusion bodies, dense vesicles, and, often, intracellular debris.Supported in part by a Parson Trust Endowment Research Grant at the University of South Dakota School of Medicine. The author gratefully acknowledges the help of Dr. Ronald DiGiacomo who was responsible for the surgery involved in the fetal deliveries. 相似文献
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Miles H. Phillips 《BMJ (Clinical research ed.)》1933,1(3768):536-537
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