The modulated, 160‐MeV proton beam produced by the Harvard Cyclotron has been examined in detail for its ability to kill mammalian cells as assayed by colony forming ability. Using two different cell ...exposure techniques, the characteristics of position and total dose in producing cell death in two aneuploid cell lines selected for their radiobiological relevance have been determined. The parameters which describe the survival curves after proton or 60Co irradiation show no statistical differences, except on the distal portion of the final Bragg peak of the proton beam, where RBE increases to approximately 1.4. This increase in RBE results in extending the cell killing effect of the beam by approximately 2 mm. This effect may be of practical significance in the irradiation of tissue such as the pituitary where the position of the Bragg peak is of great importance. The overall killing efficiency ratio between the modulated high‐energy proton beam and 60Co γ rays was 1.00 ± .01 (standard error).
Survival of an X-ray-resistant hybrid cell line$({\rm HD}_{1})$and a normally responsive cell line$({\rm H}_{4})$have been compared when irradiated under induced hypoxia by both protons and X rays. ...The two cell lines are similarly protected when irradiated under hypoxic conditions with oxygen enhancement ratios of 2.8 and 2.7, respectively. The protection is consistent with a dose-modifying factor. No statistically significant difference is observed between cell inactivation by X rays and protons in either cell line, whether irradiated under aerobic or hypoxic conditions.
An interstitial deletion of chromosome 13 with breakpoints at 13q22 and 13q32 is presented. The clinical findings associated with this deletion are discussed in relation to the correlations of ...specific chromosomal bands with constellations of congenital defects as described by Niebuhr and Ottosen (1973), Niebuhr (1977). Lewandowski and Yunis (1975), and Noel et al. (1976).
Genetic vaccination has tremendous potential for the treatment and prevention of cancer. This chapter briefly discusses the advances in research aimed at increasing the effectiveness of genetic ...vaccine formulations. Particular emphasis is placed on in vivo nonviral delivery technologies and modifications to safely achieve optimal antigen expression. We will also discuss implications for the future of genetic vaccines.
Reviews of Books Mitchell, Richard E.; Whittaker, C. R.; Thrower, Norman J. W. ...
International history review,
06/1997, Letnik:
19, Številka:
2
Journal Article
PDF
