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A H Chan

Publications and source records attributed to A H Chan.

26 records · Page 2Linked to original sources
PubMed1977

Radioactive conversion products of intramuscularly injected [4-14C]formononetin including sulfates in the urine of hens.

The phytoestrogen formononetin was injected intramuscularly as [4-14C]formononetin into two adult hens. Radioactive materials in the urine for the succeeding 14 days (hen 1) or 16 days (hen 2) were fractionated on DEAE-Sephadex-25 columns by elution with a gradient of NaCl; the four major fractions thus separated were examined by solvent partition, thin-layer chromatography, and enzymic cleavage. The following seven radioactive components were identified in the urine, the average proportions of each being given in terms of percentage of total 14C recovered from the urine: [14C]formononetin (4.3%); [14C]diaidzein (11.4%); [14C]equol (6.8%); [14C]daidzein monosulfate (30.4%); [14C]equol monosulfate (5.8%); [14C]diadzein disulfate (19.8%); and [14C]equol disulfate (6.5%). Small proportions of sulfates of unidentified radioactive phenols were present. Tests for presence of glucosiduronates of 14C-labelled material gave negative results. Radioactive formononetin sulfate was not detected in the urine of either hen.

Animals↗
PubMed1976

A note on amounts of [14C] in laying hens' blood after intramuscular administration of [4-14C]-estrone.

[4-14C]-Estrone in 2 ml. ethylene glycol was injected into the breast muscles of S.C. White Leghorn laying hens and the amounts of plasma [14C] per ml. whole blood were measured at various times thereafter. Maximal values were observed at 30 to 50 minutes after injection. The values then declined logarithmically with time and with a half-life of about 80 minutes between 40 and 270 minutes after injection.

Animals↗
PubMed1975

Identifications of radioactive steroid estrogen conjugates in blood plasma of laying hens after intramuscular injection of (4--14C)-estrone.

[4--14C] Estrone was injected intramuscularly into six laying hens. Fifty minutes later the hens were exsanguinated. The plasmas were examined for conjugates of radioactive phenolic steroids by recovery on columns of Amberlite XAD-2 or by extraction with tetrahydrofuran followed by chromatography on a column of DEAE-Sephadex A-25 in a gradient of NaCl. The biggest Sephadex chromatographic fraction (50,4% of total) contained about 42% of its radioactivity as estradiol-17alpha-3-sulfate and 18% as estradiol-17beta-3-sulfate and the remaining 40% was identified tentatively as estradiol-17alpha-17-sulfate plus a small proportion of estradiol-17beta-17-sulfate. The second biggest Sephadex chromatographic fraction (12.7% of total) was a mixture of conjugates not further identified. Minor fractions identified comprised estrone-beta-glucuronide (2.8%), estradiol-17alpha-3-beta-glucuronide (2.8%), estradiol-17beta-3-beta-glucuronide (2.3%) and estrone sulfate (6.0%). Evidence was obtained for the presence of small proportions of estradiol-17alpha disulfate and estradiol-17beta disulfate.

Animals↗
PubMedDate not supplied

Molecular cloning and characterization of a RING-H2 finger protein, ANAPC11, the human homolog of yeast Apc11p.

Yeast Apc11p together with Rbx1 and Roc2/SAG define a new class of RING-H2 fingers in a superfamily of E3 ubiquitin ligases. The human homolog of Apc11p, ANAPC11 was identified during a large-scale partial sequencing of a human liver cancer cDNA library and partial characterization was performed. This 514 bp full-length cDNA has a predicted open reading frame (ORF) encoding 84 amino acids. The ORF codes for ANAPC11, the human anaphase promoting complex subunit 11 (yeast APC11 homolog), which possesses a RING-H2 finger motif and exhibits sequence similarity to subunits of E3 ubiquitin ligase complexes. In Northern blot hybridization with poly(A) RNA of various human tissues using radio-labelled ANAPC11 cDNA probe, we found strong signals detected in skeletal muscle and heart; moderate signals detected in brain, kidney, and liver; and detectable but low signals in colon, thymus, spleen, small intestine, placenta, lung, and peripheral blood leukocyte. The ANAPC11 gene is located at the human chromosome 17q25. ANAPC11 is distributed diffusely in the cytoplasm and nucleus with discrete accumulation in granular structures in all the cell lines (AML 12, HepG2, and C2C12) transfected. Expression level of ANAPC11 is found higher in certain types of cancer determined in the RNA dot blot experiment.

Anaphase-Promoting Complex-Cyclosome↗