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E Mercer

Publications and source records attributed to E Mercer.

22 records · Page 2Linked to original sources

Purification of rabbit bone inhibitor of collagenase.

1. Rabbit bones in tissue culture synthesize an inhibitor of collagenase during the first 4 days of culture. 2. The inhibitor was purified by a combination of gel filtration, concanavalin A--Sepharose chromatography, ion-exchange chromatography and zinc-chelate affinity chromatography. 3. The purified inhibitor migrated as a single band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and had a mol.wt. of 28000. 4. The inhibitor blocked the activity of the metalloproteinases collagenase, gelatinase, neutral proteinase III (proteoglycanase), human leucocyte collagenase and gelatinase, but not thermolysin or bacterial collagenase. The serine proteinases plasmin and trypsin were not inhibited. 5. The inhibitor interacted with purified rabbit bone collagenase with 1:1 stoichiometry. 6. The inhibitory activity was lost after incubation for 1 h at 90 degrees C, after treatment with trypsin (250 micrograms/ml) at 37 degrees C for 30 min and after reduction and alkylation.

Animals↗

The activation of latent pig synovial collagenase.

Latent pig synovial collagenase (EC 3.4.24.7) can be activated by a variety of different treatments to give an active enzyme form of lower molecular weight which rapidly degrades collagen. Trypsin and plasmin effectively activated the latent collagenase whilst elastase and cathepsin G degraded most of the latent enzyme before it was activated. A number of mercurials were compared and maximum activation was achieved using 4-aminophenylmercuric acetate and phenylmercuric chloride. The latent collagenase bound to a mercurial-Sepharose column and was eluted in the active form with NaCl. The latent collagenase also activated spontaneously and the conditions which encouraged and prevented this activation were studied. High NaCl concentration, diisopropylphosphofluoridate, soybean trypsin inhibitor, low Zn2+ concentration and high and low pH all prevented the spontaneous activation of latent pig synovial collagenase.

Animals↗

Intracardiac rhabdomyosarcoma: transesophageal echocardiographic findings and diagnosis.

Transesophageal echocardiography (TEE) was performed on a 41-year-old woman who presented with a cerebrovascular accident. TEE confirmed the presence of a morphologically bizarre biatrial tumor with precarious, vigorous motion throughout the cardiac cycle. Surgical intervention was decided on, and the patient underwent cardiac surgery for tumor excision 16 hours after TEE. Intraoperative frozen section diagnosis was spindle cell sarcoma, and subsequent immunohistochemical analysis showed the tumor to be a rhabdomyosarcoma. The data are presented here, and the role of TEE to establish a preoperative diagnosis of intracardiac tumor is discussed.

Adult↗