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Biomedical subjects

J A Abel

Publications and source records attributed to J A Abel.

6 recordsLinked to original sources

Ultra-conservative skin-sparing 'keyhole' mastectomy and immediate breast and areola reconstruction.

The popularity of skin-sparing mastectomy (SSM) which preserves the breast skin envelope is increasing, but the risks and benefits of this approach are only beginning to emerge. A technique involving ultra-conservative SSM and immediate breast reconstruction (IBR) has been evaluated to establish the surgical and oncological sequelae of skin conservation. Between 1994-1998, 67 consecutive patients underwent 71 SSM and expander-assisted immediate latissimus dorsi (LD) breast reconstructions (follow up, 24.1 months; range, 2-52 months). Breast resection, axillary dissection and reconstruction were performed through a 5-6 cm circular peri-areolar 'keyhole' incision. Patients were discharged 6.5 days (range, 5-15 days) after the 3.9 h (range, 3.0-5.5 h) procedure, and expansion was completed by 4.0 months (range, 0-10 months). Local recurrence occurred in 3% of breasts at risk, skin envelope necrosis occurred in 10%, and contralateral surgery was required to achieve symmetry in 14%. SSM and IBR is an oncologically safe, minimal-scar procedure which can be performed by surgeons trained in 'oncoplastic' techniques. It results in low rates of local recurrence and complication, and reduces the need for contralateral surgery.

Adult↗

Purification and characterization of the human ovarian LH/hCG receptor and comparison of the properties of mammalian LH/hCG receptors.

Methods previously published by us [Wimalasena et al., J Biol Chem 260: 10689-10697, 1985; Wimalasena et al., J Biol Chem 261: 9416-9420, 1986] were utilized to solubilize the human corpus luteal leuteinizing hormone/human chorionic gonadotropin (LH/hCG) receptor with 3-[(3-cholamide-propyl)dimethylammonio]-1-propanesulfonate (CHAPS) and to purify the receptor by two steps of hCG-Sepharose affinity chromatography. The specific binding capacity (SBC) of the purified human receptor was 7510 pmol/mg protein, and KA = 2.2 x 10(9) M-1 when iodo hCG was competed by hCG; the yield was 4-7% of starting activity. When hLH was used in competition with hCG, specific binding capacity was 7900 pmol/mg protein and KA 1.0 x 10(9) M-1. Silver staining and autoradiography demonstrated a single protein of Mr 78,000 under reducing and Mr 58-62 x 10(3) under nonreducing conditions. Rat ovarian LH/hCG receptor was purified by similar methods and the KA of 3.5 x 10(10) M-1 for hCG was substantially different from the KA for hLH which was 2.1 x 10(9) M-1. Mr of the rat protein was 78-82 x 10(3) (reduced) and 58-62 x 10(3) (nonreduced) when analyzed by silver staining and autoradiography. For the first time, human LH/hCG receptor has been purified to apparent homogeneity, and its Mr of 78,000 was essentially identical to the Mr values of purified rat and porcine receptors.

Animals↗

The porcine ovarian luteinizing hormone/human chorionic gonadotropin receptor II. Is the purified receptor an oligomer of identical subunits?

Purified porcine luteinizing hormone/human chorionic gonadotropin receptors were analyzed by sodium dodecyl sulfate/polyacrylamide gel electrophoresis following reduction and thermal denaturation and stained with Coomassie Brilliant Blue. A major protein of Mr = 77 +/- 4 X 10(3) and a minor protein of Mr = 66 +/- 4 X 10(3) were observed. Iodoreceptor proteins were resolved into a major component of Mr = 77 +/- 3 X 10(3) and a minor component of Mr = 62 +/- 5 X 10(3) after reduction and thermal denaturation. In the absence of reduction, the iodoreceptor had a major component of Mr 63 +/- 3 X 10(3). Purified human chorionic gonadotropin specifically transferred part of the iodoreceptor from the Mr = 63 X 10(3) species to an Mr = 110-120 X 10(3) species. Purified receptors were analyzed by nondenaturing polyacrylamide gel electrophoresis and identified by specific binding of iodo-human chorionic gonadotropin. Three binding species with approximate Mr = 60 X 10(3), 130 X 10(3), and 260 X 10(3) were identified. Iodoreceptors co-migrated with the Mr = 60 X 10(3) species under the same conditions. Similar results were obtained following renaturation of receptors separated by sodium dodecyl sulfate/polyacrylamide gel electrophoresis without reduction and thermal denaturation. These results suggest for the first time that the porcine corpus luteum luteinizing hormone/human chorionic gonadotropin receptor may be a hormone binding monomer of Mr = 60-65 X 10(3), and that the monomer may associate to form hormone binding polymeric receptor complexes.

Animals↗