Mechanized blood grouping: a hospital trial using an 8-channel grouping machine.

ABO and Rh (D) groups of 6403 blood samples were assessed on an 8/9-channel autoanalyser in the Serology Department of the London Hospital; the results were independently checked at the Regional Blood Transfusion Centre, Brentwood, using the routine methods for grouping donor blood. Results of this comparative study are given and instances are described in which anomalous results or incorrect groupings occurred; the possible causes are discussed. The 8/9-channel automated blood group analyser is evaluated in terms of routine hospital laboratory practice.

A method for the in vitro study of drug transfer across ruminal epithelium.

A simple method for the in vitro study of drug diffusion across ruminal epithelium is described. The characteristics of the isolated membrane were defined by studies of ketone production from butyrate, histological studies, phenolsulphonthalein penetration and permeability to pentobarbital, antipyrine and tetraethylammonium. The preparation was found to be suitable for studies of less than 12 hours duration; after that time the integrity of the membrane as a barrier was lost due to degenerative changes.

D-alanine oxidase from Escherichia coli: participation in the oxidation of L-alanine.

Cell wall-membrane preparations of Escherichia coli, prepared by the ethylenediaminetetraacetic acid-lysozyme method, contain enzymes which catalyze the oxidation of d-alanine and, to a lesser extent, l-alanine into pyruvate and ammonia without the formation of hydrogen peroxide. The kinetic parameters were (i) pH optima of 8.3 to 8.

D-alanine oxidase form Escherichia coli: localization and induction by L-alanine.

Dialyzed membranes of Escherichia coli prepared by an ethylenediaminetetraacetic acid-lysozyme method catalyze the oxidation of both l-alanine and d-alanine. The specific activities for the oxidations of both d-alanine and l-alanine are increased fivefold when the cells are grown in the presence of either l-alanine or dl-alanine, but are increased only slightly when grown in the presence of d-alanine. In the dl-alanine-induced system, the specific activities for the oxidations of some other d-amino acids are also raised.

The long-term storage of blood for transfusion using an improved container for freezing the red cells in liquid nitrogen.

Considerable experience has been gained in the operation of a bank of blood frozen in liquid nitrogen. The procedure for freezing and recovering the red cells is, in principle, that described by Krijnen, Kuivenhoven, and de Wit (1970). An improved metal freezing container offers greater freedom from liquid nitrogen leaks and hence, bacterial contamination.