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Biomedical subjects

A Lu

Publications and source records attributed to A Lu.

At least 91 records · Page 5Linked to original sources
PubMed1992

Partial inhibition of skeletal muscle contraction by dantrolene sodium and its modification with perchlorate and Bay K 8644.

The effects of dantrolene sodium (DAN) on the dihydropyridine receptor (DHPR) of the transverse (T) tubule voltage sensor (Ca2+ channel) was studied with single fibers from bullfrog toe muscle. Perchlorate (ClO4-), which acts selectively on the DHPR, overcame DAN-induced inhibition of twitch tension. Bay K 8644, a DHPR agonist, slowed the rate of twitch inhibition by DAN. DAN inhibited twitch tension to a greater extent in Ca(2+)-free solution than in Ringer solution or solution containing Zn2+, whereas twitch inhibition by DAN was less in caffeine-containing solution than in the control. The effects of DAN on Zn(2+)- and caffeine-treated fibers and on fibers in Ca(2+)-free solution suggest that DAN must act near the voltage sensor of the T tubule. However, differences in net twitch inhibition by DAN between control fibers and fibers potentiated by ClO4- or Bay K 8644 suggest that DAN does not bind to the same site as these potentiating agents do. The role of myoplasmic Ca2+ in DAN-induced inhibition of twitch and the effects of DAN on the mechanical threshold and membrane potential in skeletal muscle are discussed.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1992

[Chemical constituents of Actinidia kolomikta (Rupr. et Maxim.) Planch].

Two crystalline components I and II were isolated from the roots of Actinidia kolomikta. I was identified as delta 7-stigmasterol and II was named alpha-kolomiktriose and elucidated as 2, 3-di-0-beta-D-galactopyranosyl-alpha-D-galactopyranose on the basis of spectral data (13C NMR, 1H NMR, IR and EI-MS).

Drugs, Chinese Herbal↗
PubMed1991

Nucleotide sequence of a gene essential for viral DNA replication in the baculovirus Autographa californica nuclear polyhedrosis virus.

The nucleotide sequence of the 60.1- to 65.5-m.u. region of Autographa californica nuclear polyhedrosis virus (AcMNPV) was determined. Seven large open reading frames were identified. Two open reading frames potentially encoding gene products of 143 and 38 kDa were found in the counterclockwise direction upstream of the p6.9 gene. Four additional open reading frames were found in the opposite direction. Analysis of the predicted amino acid sequence of the 143-kDa gene revealed a potential leucine zipper motif, a putative nuclear localization signal, and seven amino acid motifs previously identified in a number of proteins involved in NTP binding and DNA/RNA unwinding. The mutation in a DNA replication defective temperature-sensitive mutant was fine mapped to the carboxy terminus of the ORF1(p143) gene. Sequence analysis of the mutation site identified a single base change of a guanine to an adenine, resulting in the substitution of a methionine for valine. This mutation resides seven amino acids downstream of the putative NTP-binding motif of the ORF1(p143) gene product and results in a DNA negative mutant. Together these data strongly suggest that the ORF1(p143) gene product is a baculovirus helicase.

Amino Acid Sequence↗
PubMed1991

P450/losec.

Explore the source record for details and available documents.

Acetaminophen↗
PubMed1990

Isolation of temperature sensitive mutants of Autographa californica nuclear polyhedrosis virus: phenotype characterization of baculovirus mutants defective in very late gene expression.

Temperature sensitive mutants of Autographa californica nuclear polyhedrosis virus were isolated following exposure of parental replicating virus to 5-bromo-2'-deoxyuridine. Two mutants designated ts317 and ts538 were characterized in detail. Both mutants synthesized viral DNA but were defective in infectious extracellular virus production at the nonpermissive temperature suggesting defects in late gene regulation. Pulse-labeling experiments indicated that a switch to late protein synthesis occurred but this synthesis was not maintained with either mutant since all protein synthesis was gradually inhibited by 20 hr postinfection at 33 degrees. Western blots probed with antisera directed against either extracellular virus proteins or very late proteins showed a reduction in late structural proteins, a 10-fold reduction in polyhedrin, and an absence of p10 at the nonpermissive temperature. Northern blots of total intracellular RNA showed that specific late and very late transcripts were synthesized in greatly reduced amounts at the nonpermissive temperature suggesting the absence of very late proteins was a result of inhibition of virus-specific transcription. The genetic analyses indicate that the mutations lie in two closely linked genes, both important in regulating the induction of very late transcription and translation.

Animals↗
PubMed1990

Nucleotide sequence and transcriptional analysis of the HindIII P region of a temperature-sensitive mutant of Autographa californica nuclear polyhedrosis virus.

DNA sequence analysis of the HindIII P region of a temperature-sensitive mutant of Autographa californica nuclear polyhedrosis virus confirmed the specific amplification of 1.4 kb of viral DNA from this region of the genome. The sequenced region included an open reading frame, translated in a counterclockwise direction, which would potentially encode a 74K protein. The amplified DNA was contained within this open reading frame, resulting in in-frame amplifications of a domain within the protein. Transcription studies revealed the presence of a ladder of viral RNA species corresponding to a 2.5 kb transcript carrying tandem repeats of about 1.4 kb. This indicated that the duplicated DNA was transcribed in the same orientation as the p10 gene. We predict that transcripts synthesized from the opposite DNA strand also consist of a ladder of related mRNAs which would be translated to produce a family of p74 proteins with multiple internal domains.

Amino Acid Sequence↗
PubMed1988

Maternal corneal thickness during pregnancy.

We measured central corneal thickness in 89 pregnant women. It was increased 16 micron (P = .01) compared to the control eyes of 18 nongravid and 17 postpartum women. There was no significant difference (P = .79) in corneal thickness between the nongravid and postpartum groups. When comparing subjects by week of gestation, there was no trend over time in corneal thickness (analysis by linear regression). Intraocular pressure was lowered during pregnancy, but it did not correlate with corneal thickness for either the pregnant or nonpregnant group.

Adult↗
PubMed1988

Time-resolved pulsed fluorescence immunometric assays of carcinoembryonic antigen.

A time-resolved pulsed fluorescence immunometric assay (TR-PFIA) for carcinoembryonic antigen is described in which either Eu(III) or Tb(III) chelate is used as label. Described in detail is the assay involving the well-documented format of microtiter matrix and Eu(III) fluorescence enhanced with a beta-diketone and quantified in a commercial time-resolving fluorometer. We have also used the same basic assay, but one with a Tb(III) chelate as label, and we read the fluorescence signal directly off a surface without the application of enhancement solution. The Tb(III) fluorescence is then brought into solution by using an analog of dipicolinic acid in an enhancement solution. The latter approach demonstrates the scope of the methodology, which invokes the extra complexity of enhancement only when increased sensitivity might be required. The power and versatility of the enhancement methodology are demonstrated.

Carcinoembryonic Antigen↗