Cadmium-binding protein in a cadmium-resistant strain of Saccharomyces cerevisiae.

A Cd-binding protein in the Cd2+-resistant strain 301N of Saccharomyces cerevisiae was induced by administration to 0.5 mM CdSO4. The protein was purified by a gel-permeation and subsequent ion-exchange column chromatographies. The purified Cd-binding protein had the characteristics of metallothioneins: (1) low molecular weight (9.0 kDa), (2) high Cd content (63 micrograms/mg protein), (3) amino-acid composition rich in cysteine (18%), basic and acidic amino acids and free from aromatic amino acids, and (4) an absorption shoulder at near 250 nm. Acid pH or EDTA treatments abolished 250 nm absorption of the Cd-binding protein, and the formed apoprotein was capable of binding Cd2+, Cu2+ and Zn2+, respectively. Heat treatment (75 degrees C) little affected the ultraviolet absorption or sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles of Cd-binding protein. These results suggest that metallothionein generally found in animals also occurs in Cd-adapted yeast cells and thus has a role in its Cd-resistance.

Resection and reconstruction for carcinoma of the thoracic oesophagus.

The technique and results of oesophageal resection through a right thoracotomy and laparotomy with reconstruction utilizing the stomach via a retrosternal route are reported. Forty patients underwent this procedure, with no mortality. The average blood loss during operation was 424 ml, and 72% of this series underwent the operation without blood transfusion. It is believed that this type of one-stage operation for carcinoma of the oesophagus is reasonable from the viewpoint of adequate resection of malignancies, and it can be performed with minimal surgical risk. With experience, perhaps it will become a standard method such as the Billroth I method in gastric surgery.

Total esophageal reconstruction after extraction of the esophagus.

During the period between 1971 and 1974, 25 cases of carcinoma of the hypopharynx and cervical esophagus underwent esophageal extraction and total esophageal reconstruction without operative mortality. The operative methods used for this series were blunt dissection, or everting stripping of the thoracic esophagus without thoractomy followed by pharyngogastro or -colostomy as a one stage procedure via a posterior mediastinal route created by esophageal extraction. The operative technique of esophageal extraction without thoracotomy is described. It is obvious that mediastinal tunnel is the shortest route through which to put the chosen organ for esophageal substitution. This operation is to be recommended for lesion of the hypopharynx and cervical esophagus as well as some esophageal stricture because of its operative simplicity, ease, safety and rare postoperative complications.