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Biomedical subjects

E Lee

Publications and source records attributed to E Lee.

At least 433 records · Page 24Linked to original sources
PubMed1983

A simple, rapid, high-resolution chromosome technic for lymphocytes.

Phytohemagglutinin (PHA) stimulated lymphocytes were exposed to a hypotonic solution consisting of equal parts of 0.075 M 2-Mercaptoethanol and 0.075 M KCl, followed by addition of colcemid. The cells were fixed and washed in the usual manner. The slides then were subjected to trypsin-Giemsa banding. This method yields a high percentage of mitotic figures in prophase and prometaphase, ideal for high-resolution chromosome analysis.

Humans↗
PubMed1982

Unicalyceal single kidney.

A rare congenital malformation of the kidneys, consisting of renal agenesis on the left and a small kidney on the right with only a single calyx, abnormal renal vasculature and impaired medullary function, is described. This was associated with long phocomelia of the right arm. The coexistence of these rare malformations has not been reported before.

Abnormalities, Multiple↗
PubMed1982

Solubilization of adenylate cyclase of brain membranes by lipid peroxidation.

Adenylate cyclase in the membrane fractions of bovine and rat brains, but not in rat liver plasma membranes, was solubilized by treatment with Fe2+ (10 microM) plus dithiothreitol (5 mM). Solubilization of the enzyme by these agents was completely prevented by simultaneous addition of N,N'-diphenyl-p-phenylenediamine (DPPD), an inhibitor of lipid peroxidation. Ascorbic acid also solubilized the enzyme from the brain membranes. Lipid peroxidation of the brain membranes was characterized by a selective loss of phosphatidylethanolamine. Solubilization of membrane-bound enzymes by Fe2+ plus dithiothreitol was not specific for adenylate cyclase, because phosphodiesterase, thiaminediphosphatase and many other proteins were also solubilized. Solubilized adenylate cyclase had a high specific activity and was not activated by either NaF, 5'-guanylyl imidodiphosphate (Gpp[NH]p) or calmodulin. These results suggested that lipid peroxidation of the brain membranes significantly solubilized adenylate cyclase of high specific activity.

Adenylyl Cyclases↗
PubMed1982

Cysteine sulfinic acid in the central nervous system: antagonistic effect of taurine on cysteine sulfinic acid-stimulated formation of cyclic AMP in guinea pig hippocampal slices.

The stimulatory effect of cysteine sulfinic acid on cyclic AMP formation was examined in slices from three different regions of guinea pig brain. The inhibitory effect of taurine on the stimulated formation of cyclic AMP was also studied. Cysteine sulfinic acid (1--10 mM) greatly increased the cyclic AMP level in striatal, cortical, and especially hippocampal slices. In hippocampal slices, taurine (0.1--30 mM) markedly lowered the increase of cyclic AMP induced by cysteine sulfinic acid, but not that induced by glutamate or aspartate. In this region, taurine also reduced the stimulatory effects on cyclic AMP formation of adenosine, norepinephrine, and histamine, but not of depolarizing agents. It did not, however, inhibit the effects of any of these stimulants in cortical slices. These results suggest that sulfur-containing amino acids, such as cysteine sulfinic acid and taurine, regulate the cyclic AMP level in the hippocampus.

Animals↗
PubMed1982

A search for an enriched source of polymeric IgA in human thoracic duct lymph, portal vein blood and aortic blood.

Because human bile contains a lot of secretory IgA, it has been suspected that the human liver, like rat liver, transfers polymeric IgA from plasma to bile. Hence, a rich source of polymeric IgA might enter the general circulation of man. We examined human thoracic duct lymph, portal vein blood and aortic blood for content and molecular size of IgA. None of the fluids was found to have either a higher total concentration of IgA or a higher proportion of polymeric IgA than that found in peripheral venous blood. It is possible that hepatic clearance of plasma IgA does not occur in man to the extent that it does in the rat, and a relatively larger proportion of human biliary IgA might originate from synthesis in hepatobiliary tissues.

Aged↗
PubMed1981

Activation of adenylate cyclase of rat brain by lipid peroxidation.

The relationship between adenylate cyclase activity in the synaptic membrane fraction (M1) of rat brain and lipid peroxidation of these membranes was examined. In the presence of 5 mM dithiothreitol (DTT), 1 to 10 microM Fe/+ activated adenylate cyclase 2- to 4-fold. Of several metal ions, Fe2+ was the most effective. Other enzymes in M1, such as Mg2+-ATPase, (Na+-K+)-ATPase, 5'-nucleotidase, acetylcholinesterase, and phosphodiesterase, were not activated by Fe2+ plus DTT. Activation of adenylate cyclase by Fe2+ plus DTT was accompanied by production of malondialdehyde, a product of lipid peroxidation. Formation of malondialdehyde was completely parallel with enzyme activation. Ascorbic acid or a NADPH system also stimulated enzyme activity and caused lipid peroxidation. Activation of the enzyme and lipid peroxidation induced by Fe2+ plus DTT, ascorbic acid, or NADPH was completely prevented by simultaneous addition of N,N'-diphenyl-p-phenylenediamine, an inhibitor of lipid peroxidation. This inhibitor also prevented the decrease in turbidity of the enzyme preparation induced by Fe2+ plus DTT. The stimulatory effects of NaF, guanylyl-5'-imidodiphosphate and calmodulin, respectively, and that of Fe2+ plus DTT on the enzyme activity were additive. Activation of adenylate cyclase by Fe2+ plus DTT was only observed in brain synaptic membranes, not in erythrocyte ghosts, liver plasma membranes, or cardiac sarcolemma. These results indicate that lipid peroxidation of synaptic membranes was accompanied by specific stimulation of adenylate cyclase activity.

Adenosine Triphosphate↗