J. E. Till

Doctor-patient communication: the Toronto consensus statement.

This report was compiled on behalf of the staff at the Northern General Hospital, Sheffield, the staff at the Royal Hallamshire Hospital, Sheffield, and the many people who helped at the scene. The efforts of hundreds of professionals and volunteers were vital and greatly appreciated. We thank Neil Appleyard, David Edbrooke, David Dawson, Stuart Yates, Ian Winston, John Duncan, G A Baker, Charlie Cooper, Kath Sherry, Tim Shaw, and A Moss for access to the neuropsychological reports on some of the survivors.

A rapid method for the isolation of L-cell surface membranes using an aqueous two-phase polymer system.

SummaryA dextran-polythylene glycol aqueous two-phase system has been used to separate cell surface membranes from other cellular organelles. The surface membranes have been identified on the basis of morphology, content of Na+, K+-ATPase, and presence of surface antigen as detected by a51Cr release method. Contamination of the surface membrane preparations by smooth endoplasmic reticulum, mitochondria, and nuclei has been found to be minimal. An average of 6.5% of the total protein was found in the membrane fraction. Less than two hours is required to isolate the membrane fraction after preparation of a Dounce homogenate. Fractionation by aqueous two-phase polymer systems appears to be a rapid and effective method for the isolation of surface membranes.

Ouabain-resistant mutants of mouse and hamster cells in culture

Abstract Somatic cell mutants resistant to ouabain, which inhibits the plasma membrane Na/K ATPase, have been isolated from mouse L and Chinese hamster ovary (CHO) cells. Ouabain at concentrations ≥ 1 mM with 5–6 mM K + , or ≥ 0.1 mM with 0.5 mM K + , inhibits the growth of the wild-type cells and is ultimately cytotoxic. Clones 2- to 100-fold more resistant than wild type in terms of dose can be obtained by single-step selection from a wild-type population in the presence of ouabain. The phenotypes of ouabain-resistant (OUA R ) clones are reproducible with high fidelity and stable over long intervals of growth in the absence of the selecting drug. Wild-type and OUA R L cell clones were compared with respect to their susceptibility to ouabain inhibition of 42 K uptake by whole cells and of Na/K ATPase activity in isolated plasma membranes. In both respects the OUA R cells are less sensitive to the drug than are wild-type cells. Conditions for optimal ATPase activity in the absence of ouabain were indistinguishable for the wild-type and one OUA R clone examined in detail and were comparable to requirements reported for ATPase preparations from other source materials. The frequency of OUA R cells in a wild-type population can be substantially increased, to approximately 10 −4 per viable cell, by exposure to the chemical mutagen EMS. The spontaneous mutation rate to 10-fold increase in ouabain-resistance is estimated by Luria-Delbruck fluctuation analyses to be 5–6 × 10 −8 per cell per generation for both L and CHO cells. Cell-cell hybridization experiments utilizing OUA R and wild-type CHO cells indicate that resistance to ouabain behaves as a codominant trait, and that this marker can be useful for selection of somatic cell hybrids.

Spleen-Colony Formation in Anemic Mice of Genotype WW

The hemopoietic cells from anemic mice of genotype WW are less able by 200-fold to take part in colony formationin the spleen than cells from the normal littermates of genotype ww. The genetic defect shows itself in the colony-forming cells, since cells from normal littermate mice formcolonies in the spleens of unirradiated mice of genotype WW. Use of animals of genotype WVVWT as recipients improves the spleen-colony method by removing bias resulting fromthe death of irradiated recipients.

The radiation sensitivity of normal mouse bone marrow cells, determined by quantitative marrow transplantation into irradiated mice.

Description: Quantitative bone marrow transplantation was used to obtain an estimate of the radiation sensitivity of normal mouse bone marrow progenitor cells. Reproduced from Radiation Research 1960(Jul); 13(1): 115-125 by copyright permission of the Radiation Research Society (www.radres.org).

Early repair processes in marrow cells irradiated and proliferating in vivo.

Early repair of sublethal radiation damage was demonstrated in surviving spleen-colonizing cells in vivo by means of dose-fractionation experiments. A study of the kinetics of the early repair process indicated that early repair reached an initial maximum at about 5 hours after the first dose fraction, followed by an intermediate minimum at about 11 hours. An assay procedure that may be used for the study of the behavior of spleen-colonizing cells in situ was developed. (auth)

DNA synthesis in individual L-strain mouse cells

The time relationship between DNA synthesis and mitosis has been determined for L-strain mouse cells cultivated in vitro. DNA synthesis was detected autoradiographically by following the uptake of [3H]thymidine into the cell nucleus. DNA synthesis in this cell system was found to take place in an approximately linear fashion over a single period of six to seven hours, ending three to four hours before mitosis, for a total generation time of twenty hours. A mathematical treatment for exponentially multiplying cultures is presented.

The Sensitivity of Cells from Normal Mouse Bone Marrow to Gamma Radiation in Vitro and in Vivo

1. A survival curve for the colony-forming ability of mouse bone marrow cells irradiated in vivo with Co60 gamma-rays has been obtained. The curve may be characterized by D0 of 95 rads and an extrapolation number of 1.5. 2. Comparison with the survival curve obtained for irradiated in vitro indicated a statistically significant difference in extrapolation number. Possible explanations for this finding are considered.

Describing Health States: Methodologic Issues in Obtaining Values for Health States

In health status index construction quantitative values for different states of health are frequently obtained by presenting written descriptions to raters whose values are elicited using one or more methods. In this study the authors examined the influence of several aspects of this measurement process upon the quantitative results obtained. They prepared a set of written descriptions of health states, each state being described in both a standard point-form and a narrative format. The narrative format was written in the first person singular, and listed all symptoms or problems associated with the state, whereas the point-form description included only the most severe symptom or problem. Values for these states were elicited from a group of 64 patients using two commonly employed methods, the standard gamble of Von Neumann and Morgenstern and category rating. The results indicate that the type of scenario presented to the rater and the sequence in which the methods of assessment were used had a major influence on the results. This work indicates that there is a need to examine systematically the process of obtaining quantitative values before reliance can be placed upon the results.

The proliferative states of mouse granulopoietic progenitor cells.

Summary Mouse granulopoietic progenitor cells can be detected by their capacity to form colonies in culture (CFU-C). The proliferative state of these cells was studied by determining the degree to which their colony-forming capacity was destroyed following exposure to a pulse of high specific-activity 3HTdR. When marrow was obtained from normal adult mice 35% of CFU-C were inactivated by this procedure. In contrast, 80% of CFU-C were inactivated when cell populations were obtained from regenerating bone marrow. These results are interpreted to mean that CFU-C in normal mice are partitioned into two populations, one proliferating rapidly and the other slowly or not at all. In regenerating marrow the partition is changed, with all or almost all of the cells proliferating rapidly.