MISCELLANEA

'Copies of the video [£50.00/ $100.00 + $25 (p+p)] can be obtained from Dr Terry Allen,

Paterson Institute for Cancer

Research, Christie Hospital NHS

Trust, Wilmslow Road,

Manchester, UK M20 9BX.

M y r t l e Gordon

Leukaemia Research Fund at

the Institute of Cancer Research,

Chester Beatty Laboratories,

Fulham Road, London,

UK SW3 6JB.

Haemopoiesis cinematography

The Living Haemopoietic Microenvironment

by T. D. Allen and T. M. Dexter, Paterson Institute for Cancer

Research°/Vector Television, 1991. £50.00/$100.00 (30 min)

Many studies of interactions be- tween haemopoietic progenitor cells and stromal cells of the bone marrow microenvironment have used the long-term bone marrow culture sys- tem originally developed by Mike Dexter. These cultures consist of an adherent heterogeneous stromal cell layer together with haemopoietic cells that depend on the stroma for survival and proliferation and are, indeed, found in intimate contact with the stromal cells as well as in the culture supernatant. The associ- ations between the haemopoietic cells and stromal cells involve inter- cellular contact and adhesion, stimu- lation of proliferation, and migration of haemopoietic cells among the stromal cells and from the stromal layer to the liquid phase of the cul- ture. This dynamic aspect of the cellular relationships can be effect- ively captured only by time.lapse cinematography, as demonstrated by Terry Allen.

The video production of The Living Haemopoietic Microenvironment by Terry Allen and Mike Dexter is a re- markable demonstration of the in- formation that can be gained simply by observing haemopoietic cells as they grow and interact with stroma in the long-term culture system. The time-lapse video sequences are ac- companied by scanning electron micrographs in which cells are use- fully tinted (in the most unlikely shades) for emphasis. The informa- tion is further explained in diagrams showing events in haemopoietic cell development and the interactions between haemopoietic and stromal cells in vitro.

I was asked to review this video as a potentially valuable teaching aid. However, an appropriate audience is neither obvious nor effectively tar- geted. The presentation is too com- plex for students with only a basic

understanding of haemopoiesis, and several specialized terms are intro- duced without sufficient definition. Also, it would be useful if it was ex- plained that real cells are not blue, orange or green, as portrayed in the scanning electron microscopy views. The description of erythroid cell development and formation of eryth- roblast islands is confused and, at the stage of red cell enucleation, is

Scanning electron micrograph of a granulocyte island showing seven

mature granulocytes on the surface of a macrophage in a long-term bone marrow culture. Micrograph kindly

provided by Terry Allen.

very misleading. Finally, for a teach- ing aid, the diagrams are too com- plex and attempt to concentrate too much information. However, the video would also not satisfy a more expert audience. While the time- lapse video sequences are com- pelling viewing for those of us who are fascinated by haemopoieUc- stromal cell interactions, the rest of the information is too basic.

On a production level, the voice- over is ineffective. It is clear that a professional narrator is speaking and, not unreasonably, that he is unfamiliar with and has no enthus- iasm for the subject. The lack of emphasis throughout verges on the soporific. It would have been much better if, for example, Mike Dexter had brought his exuberant enthus- iasm to the production.

Having said all that, this video rep- resents a first in a new generation of visual teaching aids for experimental haematology and it can be hoped that more productions will follow. It has made a significant contribution in terms of revealing some of the pitfalls and the lessons that can be learned from them.

Focusing on EM Electron Microscopy in

Biology: A Practical Approach

edited by I. R. Harris, IRL Press, 1991. £22.50 (xix + 308 pages)

ISBN 0 19 963215 4

This book is intended as a sup- plement to an earlier volume in the 'A Practical Approach' series entitled Electron Microscopy in Molecular Biology, which covered methods for preparing nucleic acids and ribo- nucleoproteins for electron micros- copy. Many common electron mi- croscopy methods that were not directly relevant to the subject of the earlier book are included in the new volume, with little overlap between the two. Neither of the volumes is intended as a primer on basic elec- tron microscopy theory and oper- ation. The emphasis is on methods for preparing specimens for electron

microscopy, mainly transmission electron microscopy.

Most of the chapters follow the now familiar format of this series, in which detailed step-by-step exper- imental protocols are interspersed among concise background infor- mation. When successful, these chapters are helpful in overcoming the inertia that often exists between understanding a technique and actually attempting it in the labora- tory. Unfortunately, some techniques in electron microscopy do not lend themselves well to this approach. Specifically, procedures requiring specialized and complex auxiliary equipment or extensive theoretical exposition cannot reasonably be described in a 'how to do it' fashion in the 30-40 pages allotted. The chapters on freeze-fracture tech- niques (by S. Fujikawa), quantitative X-ray microanalysis (by A. Warley and B. L. Gupta), and three-dimen- sional electron microscopy (by N. lames) fall into these categories; the topic of the latter chapter, in par- ticular, was too broad to be reason- ably treated as 'a practical ap- proach'. Understandably, most of the authors who tackled these topics

21 4 TRENDS IN CELL BIOLOGY VOL. 2 JULY 1992