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Biomedical subjects

G Wang

Publications and source records attributed to G Wang.

At least 865 records · Page 48Linked to original sources
PubMed1987

Involvement of a nucleolar component, perichromonucleolin, in the condensation and decondensation of chromosomes.

A component of the nucleolar material, perichromonucleolin (PCN), was identified by a specific antiserum against nucleoli obtained from a scleroderma patient. The distribution and changes of PCN during the mitotic cycle were followed using this antiserum and indirect immunofluorescence microscopy. Based upon the behavior of PCN during mitosis, it could be differentiated into chromosomal and nonchromosomal portions. During prophase the former gradually associates with the surface of the condensing chromosomes and forms the coat or pellicle around the metaphase and anaphase chromosomes. This pellicle PCN is carried by the anaphase chromosomes to the daughter nuclei. During the time from telophase to interphase, the pellicle PCN dissociates from the decondensing chromosomes and is incorporated into the new nucleoli. The nonchromosomal PCN, after the breakdown of the nuclear membrane, distributes in the cytoplasmic region around the condensed chromosomes and diffuses into the cytoplasm during anaphase. Preliminary biochemical analysis by immunoblotting showed that the PCN consists of two main proteins with molecular masses of 36 kDa and 30 kDa.

Animals↗
PubMed1987

Beta decay of 20O.

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Journal Article↗
PubMed1986

The use of immunoblotting and immunoprecipitation of (U) small nuclear ribonucleoproteins in the analysis of sera of patients with mixed connective tissue disease and systemic lupus erythematosus. A cross-sectional, longitudinal study.

Antibodies to ribonucleoproteins (RNP) and to the Sm antigen in sera from patients with mixed connective tissue disease (MCTD) and systemic lupus erythematosus were studied using the techniques of immunoblotting and immunoprecipitation of U small nuclear RNPs. A cross-sectional study indicated that antibodies reacting with a 68K protein were associated with anti-RNP specificity in MCTD, but rarely occurred in systemic lupus erythematosus patients' sera. A longitudinal study demonstrated the persistence of MCTD blotting patterns over many years, and the subsequent disappearance of those specificities in sera from patients who were in prolonged remission.

Antibodies↗
PubMed1986

Stage-specific expression of a homeo box-containing gene in the non-segmented sea urchin embryo.

Hybridization of Drosophila homeo box DNA probes to Southern transfers of genomic DNA from the Hawaiian sea urchin Tripneustes gratilla has revealed that the sea urchin genome contains at least five homeo boxes. Examination of the DNA from several individuals shows that the sequences flanking these homeo boxes exhibit little restriction fragment length polymorphism, indicating they are more highly conserved than the majority of sea urchin DNA. Several clones in a T. gratilla genomic DNA library which hybridized with Drosophila homeo box probes were identified, and one found to be transcribed during embryogenesis was selected for further study. Southern transfer hybridizations showed the cloned gene to be single-copy. DNA sequencing of the sea urchin gene defined a homeo box 70-73% homologous to the Drosophila homeo box probes and an encoded homeo domain 78-88% homologous to those encoded by the probes. Hybridization of DNA probes from the sea urchin homeo box-containing gene to Northern transfers of embryonic RNA demonstrated that the gene produces two transcripts of 6.9 kb and 7.7 kb. Transcripts first accumulate at blastula stage and increase to a maximum level at gastrula stage before decreasing considerably in abundance by pluteus stage.

Amino Acid Sequence↗
PubMed1986

Plasma levels of antiprogestin RU 486 following oral administration to non-pregnant and early pregnant women.

RU 486 is a synthetic steroid which acts as an antiprogestin at the receptor level. The clinical usefulness of the compound for menstrual regulation and termination of early pregnancy is currently being evaluated. The aim of the present study was to determine the plasma levels of RU 486 following the oral administration of the compound to 42 pregnant and 10 non-pregnant women. The levels of RU 486 were measured by a radioimmunoassay method which uses chromatography on Sephadex LH 20 columns. The identity of the compound assayed as RU 486 was confirmed, but the presence of small amounts of two highly cross-reacting metabolites (monodemethyl and didemethyl RU 486) in the analyzed fractions could not be excluded. Following the ingestion of a single tablet containing 25 and 50 mg of the compound, a peak plasma value of approximately 3.5 to 4.0 mumol/l in both the pregnant and non-pregnant subjects was reached one to two hours later. The half-lives of elimination were about 20 hours in both the pregnant and the non-pregnant women. Following the repeated oral administration of 50, 100 or 200 mg of RU 486 daily for four days, maximum plasma levels of 2.9, 4.5 and 5.4 mumol/l, respectively, were found. Thus, the increase in plasma levels was not directly proportional to the increase in the dose. No accumulation of RU 486 in the plasma was found, even when the duration of treatment was prolonged to six days. The data partly explain the reported lack of relation between ingested dose and frequency of induced abortion and they may be useful for designing future studies on the use of compound to prevent implantation, induce menstruation or terminate an early pregnancy.

Abortifacient Agents↗
PubMed1986

Pharmacokinetics of the progesterone antagonist 17 beta-hydroxy-11 beta-(4-dimethylaminophenyl)-17 alpha-(1-propynyl) estra-4,9-dien-3-one in the rabbit.

Pharmacokinetic characteristics of compound RU 486 (17 beta-hydroxy-11 beta-(4-dimethylaminophenyl)-17 alpha-(1-propynyl)estra-4,9-dien-3-one) were investigated in 6 immature estrogenized female rabbits. A dose of 3.4 mg/kg was administered either intravenously or orally, in both cases together with 3H-RU 486 (13.4 muCi/kg). The concentration of RU 486 was measured in blood plasma following isolation by thin-layer chromatography. The concentration of ether-extractable metabolites was obtained from the difference between the total ether-extractable radioactivity and the radioactivity of the isolated RU 486. Following the i.v. administration it was found that the disposition of RU 486 could be described by a biexponential curve. The half-life of the slow disposition phase of RU 486 was significantly lower (t1/2 = 52 min: P greater than 0.05) than those of RU 486 metabolites (t1/2 = 99 min). High apparent volumes of distribution of RU 486 and RU 486 metabolites (5.8 and 6.0 l/kg, respectively) indicated a high extravascular binding. Following the oral administration in oil solution, RU 486 could not be found in plasma in reliably detectable amounts due to a poor absorption and a probable first-pass effect. In the measurements of the "total RU 486" (sum of RU 486 and ether-extractable metabolites), a similar rate of terminal disposition was found for both routes of administration.

Animals↗