摘要:

There is no need for me to say how great an honour it is to be invited to give the Silvanus Thompson Memorial Lecture of the British Institute of Radiology and how inadequate I feel when I recall the names of the previous Memorial lecturers. It is also a very great pleasure to be asked to give this lecture in Southampton, the city of my birth, and in the University where I studied, though now very different in appearance from the University College I knew.Silvanus Thompson and my student days here are connected because, like so many others, it was his book that introduced me to the Calculus and also like many others I was greatly comforted by what appeared on the first page …“What one fool can do, another can”(Ancient Simian Proverb)though it was false comfort, since Silvanus Thompson was indeed no fool, but a man who illuminated any subject to which he turned his attention, be it science, biography or art.However, this philosophy has perhaps had more influence on me than I suspect, and without the conceit it inspired I could not possibly have taken as my topic the subject of the comparative cell population kinetics of normal and malignant tissues and its application to cancer therapy. I am also grateful for one other circumstance, that Professor Tubiana should have taken for the subject of last year's Mackenzie Davidson Lecture “The kinetics of tumour cell proliferation and radiotherapy” (Tubiana, 1971).

DOI:10.1259/0007-1285-45-531-161

出版商:The British Institute of Radiology    

年代:1972

数据来源: WILEY

摘要:

AbstractSomewhat conflicting data from earlier experiments by ourselves and others suggested that under certain conditions, survival curves for the reproductive capacity of mammalian cells irradiated at ultra-high dose-rates (nanosecond-to-microsecond pulses) with X rays or high-energy electrons exhibited an inflected “hockey-stick” shape. Other workers failed to observe such “hockey-stick” survival curves when using apparently similar radiation conditions.Using a 400 keV electron beam with a pulse duration of about 3 ns, dense monolayers of HeLa cells were irradiated attached to plastic Petri dishes, or dense monolayers of P.388 murine ascites leukaemia cells were irradiated suspended on membrane filters. The cells were either aerobic, hypoxic, or in a 0·35 per cent oxygen/nitrogen atmosphere at the time of irradiation. Survival of HeLa cells was assessed by the ability to form macroscopic clonesin vitro; survival of P.388 leukaemia cells was assessedin vivoby tumour “takes” from serial dilutions of the tumour cells in isologous mice.Up to doses of about 1,500 rads (surviving fraction ∼10−3for HeLa, ∼10−6for P.388) the survival curves were uninflected, as were the curves for irradiation in nitrogen up to doses of about 3,500 rads. OER values were>2·5 for both HeLa cells and the P.388 leukaemia. However, irradiation in 0·35 per cent oxygen/nitrogen produced an inflected “hockey-stick” survival curve which, above doses of a few hundred rads, was effectively parallel to the curve for cells irradiated in nitrogen.The present results clearly indicate that “radiobiological hypoxia” can be produced in mammalian cells by irradiation with nanosecond pulsesonlyin cells already at a reduced level of oxygen. This makes the prospect for the use of these short radiation pulses for radiotherapy considerably less attractive than had been suggested by our earlier studies.

DOI:10.1259/0007-1285-45-531-171

出版商:The British Institute of Radiology    

年代:1972

数据来源: WILEY

摘要:

This attractive and handy book is intended as a practical guide to those whose work involves tracer techniques but whose time for a deep study of nucleonics and radiation measurement has been denied them. Although not specifically planned for the medical isotope technician, the subject matter and scheme of study is well adapted to the needs of many a new recruit to this field of work, such as a schoolleaver with O-level standards in physics (or general science) and mathematics. Not only would he be enabled to partake earlier and more meaningfully in the routine work, but his training by the senior staff would be facilitated, if backed by the study of this book.

DOI:10.1259/0007-1285-45-531-177

出版商:The British Institute of Radiology    

年代:1972

数据来源: WILEY

摘要:

AbstractCultured cells of human kidney origin (T−1 cells) have been used to measure the oxygen-enhancement ratio of π−mesons at the peak of the depth-dose distribution and the biological effectiveness of π−mesons was compared with that of60Co γ rays. The OER appears to be dose dependent, and has values of 1·9 and 1·5 at survival levels of 50 and 10 per cent respectively. The relative biological effectiveness of π−mesons was found to be between 2·2 and 2·4 for oxygenated cells. The OER of60Co γ rays (240 R/hour) was 2·6 and 2·3 measured at 50 and 10 per cent survival, respectively. Similar measurements with Chang liver cells yielded identical values for the OER of π−mesons.

DOI:10.1259/0007-1285-45-531-178

出版商:The British Institute of Radiology    

年代:1972

数据来源: WILEY

摘要:

This is the first book to be devoted to the relatively new field of angiography of the spinal cord. It comes from a team which pioneered the method of selective spinal angiography and which has gained extensive experience in its application. The thoroughness with which the potential uses of spinal angiography have explored is remarkable and the results of this valuable experience are clearly presented in the profusely illustrated monography.

DOI:10.1259/0007-1285-45-531-181

出版商:The British Institute of Radiology    

年代:1972

数据来源: WILEY

摘要:

AbstractThe cellular incorporation of67Ga was investigated in a murine ascites tumour and in normal bone marrow cells from mice. In both tissues a high proliferation rate corresponded to a high incorporation of67Ga, and it is suggested that the concentration of67Ga in the cells, malignant or nonmalignant, is related to, or possibly dependent on, the rate of cellular proliferation in the tissue.

DOI:10.1259/0007-1285-45-531-182

出版商:The British Institute of Radiology    

年代:1972

数据来源: WILEY

摘要:

AbstractTotal body opacification is the radiological phenomenon in which, after intravenous injection, contrast agent opacifies the structures of the body in proportion to their blood supply. Avascular lesions can thus be rendered radiologically visible as lucencies newly contrasting with surrounding opacified structures. Appreciation of the total body opacification effect is widely useful in diagnostic radiology, especially in the delineation and characterization of neonatal abdominal masses.

DOI:10.1259/0007-1285-45-531-185

出版商:The British Institute of Radiology    

年代:1972

数据来源: WILEY

摘要:

This excellent book, written in French, is part of the 20−volume text-bookTraité de Radiodiagnostic. It deals with the neuroradiology of the spinal canal and its contents as this is practised on the Continent. Although there is a large number of contributors, there is minimal repetition and the text is maintained at a high standard throughout, being up to date and without dead wood.

DOI:10.1259/0007-1285-45-531-192

出版商:The British Institute of Radiology    

年代:1972

数据来源: WILEY

摘要:

AbstractThe radiation doses given to 20 mothers and foetuses during intra-uterine transfusions for Rh-iso-immunization are assessed. Details are given of the method used for these calculations together with the technique of the procedure, as used in this hospital.It is calculated that the average mother received a skin exposure of 3,312 mR during amniography and 3,310 mR during fluoroscopy. For radiography the range was 1,450 mR (Case 8) to 5,230 (Case 14) and for fluoroscopy from 942 mR (Case 5) to 7,795 mR (Case 3). The average foetal dose was assessed at 617 mrads—varying from 247 mrads in Case 5 to 1,117 mrads in Case 3.The sources of error inherent in these calculations are given.It is concluded that the foetal radiation dose in this series is acceptable, although it is probably above 1 rad in several cases.

DOI:10.1259/0007-1285-45-531-193

出版商:The British Institute of Radiology    

年代:1972

数据来源: WILEY

摘要:

AbstractA method of pelvimetry is presented in which the use of 100 cm focal–film distance is utilized to simplify determination of correction factors. A slide rule is helpful but not essential. The procedure is easily learned and applied in the departments of radiology and obstetrics.

DOI:10.1259/0007-1285-45-531-197

出版商:The British Institute of Radiology    

年代:1972

数据来源: WILEY