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Biomedical subjects

Q L Li

Publications and source records attributed to Q L Li.

52 records · Page 3Linked to original sources
PubMed1990

[Effect of combined treatment of diltiazem and digoxin on serum digoxin concentration].

Diltiazem is one of the effective calcium channel blocking agents. Up to now it has not been reported in our country that whether the combined use of digoxin and diltiazem can increase the serum concentration of digoxin The results of a study of ten cases with chronic congestive heart failure showed that diltiazem can increase the serum concentration of digoxin from 38.7% to 49.6%. Four of the ten cases appeared to have signs of digitalis poisoning in the electrocardiogram.

Adult↗
PubMed1988

Application of partial restriction procedure in both shotgun and non-random strategies for nucleotide sequencing.

Partial digestion of a target DNA fragment with 4-bp-recognition restriction enzymes followed by a forced ligation to an M13 vector was employed for the construction of a subfragment library. The library can be used for either shotgun or non-random nucleotide sequencing. Application of the partial digests generated with the 4-bp recognition restriction enzymes instead of DNase I in the improved non-random strategy for nucleotide sequencing (Li and Wu, 1987) made the procedure as easy as that of the random strategy. The library can also be used in shotgun nucleotide sequencing directly, and few self-ligated subfragments were found. The usefulness of this procedure was demonstrated by the sequencing of a goat 6.5-kb EcoRI fragment, which is located 5' to the epsilon globin gene.

Animals↗
PubMed1988

An analysis of postsynaptic potentials of tectal neurons of the frog: correlation with impulses recorded from the terminals of retinotectal afferents.

The purpose of this study is to examine the synaptic action between terminals of retinal ganglion cell axons and tectal neurons. To accomplish this, an extracellular single unit identified as retinotectal fiber was first isolated from the superficial layer of the optic tectum and intracellular responses were recorded from a tectal neuron in the vicinity of the extracellular recording electrode. "On-off" retinal fibers and both E-E (EPSP at "on" and "off" of diffuse light) and EI-EI type (EPSP-IPSP combination at "on" and "off" of diffuse light) tectal neurons were selected for the pre- and postsynaptic pair. Postsynaptic responses to a small moving square were averaged by triggering with the isolated presynaptic impulses. The latency of the resultant EPSPs indicated that most of the E-E and EI-EI type tectal neurons were monosynaptically activated by "on-off" retinal fibers. One of the E-E type tectal neurons was identified as a large ganglionic neuron in layer 8.

Action Potentials↗
PubMed1987

A versatile and simplified non-random strategy for nucleotide sequencing.

We describe a versatile and simplified non-random strategy for nucleotide sequencing. This procedure avoids exposure of the vector DNA to endo- or exonucleases during construction of the subfragment library. The advantages resulting from this strategy are: (1) minimal manipulation in construction of the subfragment library, (2) no need for compatible restriction sites, (3) no insert size limitation, (4) can be used with both chemical and enzymatic sequencing methods. Hence, the procedure provides simplicity, universality and versatility for non-random nucleotide sequencing. We demonstrate the usefulness of this procedure by obtaining the nucleotide sequence of a goat 3.7-kb EcoRI fragment, which is 5' of the epsilon globin gene.

Animals↗
PubMed1980

Restriction endonucleases from three strains of Haemophilus influenzae.

The restriction endonucleases, Hin P1 I1), Hin S1 I and Hin S2 I are isolated from three strains of Haemophilus influenzae respectively. By polymin P treatment, ammonium sulphate, precipitation and column chromatography on phosphocellulose and on heparin-Sepharose Hin P1 I is partially purified. No contaminating deoxyribonuclease activities have been detected in this purified enzyme preparation. The fact that the digestion patterns of Hin P2 I and Hha I on phage lambda, plasmids ColE1 an pBR 322 DNAs are identical that they are isoschizomers but theri splitting sites are different. The banding patterns of Hin S1 I and Hin S2 I are also the same as that of Hha I.

DNA Restriction Enzymes↗