The lysosomal hexosaminidase isozymes.

In the 15 years since the demonstration that HEX A is the defective enzyme in patients with TSD, intensive efforts in many laboratories have revealed much about the HEX group of enzymes. In contradistinction to the two isozymes described by Robinson and Stirling [1968], we now know that there are several different species. They include the products of at least three genes which code for the alpha and beta polypeptides as well as for an enzyme that we have called HEX D.

[Parenteral antibiotic prophylaxis or oral antimicrobial bowel preparation for colorectal surgery (author's transl)].

A prospective randomized trial was designed to establish whether parenteral antibiotic prophylaxis was as effective as oral antimicrobial bowel preparation in preventing sepsis after colorectal surgery. Patients scheduled for elective resection of colorectal cancer received metronidazole and kanamycin either orally in the preoperative phase or parenterally as a short-term perioperative prophylaxis. The former regimen resulted in reduction of the microbial concentrations in the bowel contents in the absence of therapeutic serum concentrations at the time of operation, whereas the latter achieved therapeutic intraoperative serum levels without altering the colonic microflora.

Case report of actinomycosis caused by Arachnia propionica.

Arachnia propionica was isolated from a cervicofacial lesion. During the antibiotic therapy the swelling was measured. A response to ampicillin was observed.

Kinetics of rat liver GM2 ganglioside-beta-D-N-acetylhexosaminidase.

The kinetics of beta-D-N-acetylhexosaminidase against GM2 ganglioside were examined. We used a crude preparation of rat liver as the enzyme source because purification of beta-D-N-acetylhexosaminidase results in a decrease in specific activity against GM2 ganglioside. Kinetic plots were not linear but showed a break.

Preparation of radiolabeled GM2 and GA2 gangliosides.

GM2 and GA2 gangliosides from the brain of a patient who died of Sandhoff's disease were purified by solvent partition, silicic acid and silica gel column chromatography, and silica gel preparative thin-layer chromatography. They were tritiated in the terminal N-acetylgalactosamine residue using galactose oxidase and sodium [3H]borohydride with the inclusion of catalase and peroxidase into the oxidation reaction. The specific activities were 4.