QUESTION One of my patients had a computed tomography scan of her abdomen a week ago and has just found out she is 7 weeks pregnant. What should I tell her about the pregnancy and the risk to her fetus? ANSWER Your patient is not at increased risk of miscarriage or major congenital fetal malformations due to radiation exposure. Her risk is similar to that of the general population (ie, 1% to ...

1.1 Ionizing radiation Human exposure to ionizing radiation is a natural part of life on earth. These exposures occur every day from radiation associated with naturally occurring radionuclides in soil, air, and food, and also from cosmic rays. In addition, many people are exposed to dental and medical diagnostic procedures and therapy involving: x rays, gamma rays, charged particles, radionucli...

Recent preclinical studies have suggested that radiotherapy in combination with antiangiogenic/vasculature targeting agents enhances the therapeutic ratio of ionizing radiation alone. Because radiotherapy is one of the most widely used treatments for cancer, it is important to understand how best to use these two modalities to aid in the design of rational patient protocols. The mechanisms of i...

There is little known about the regulation of gene expression by ionizing radiation exposure. The present studies demonstrate transcriptional activation of a mammalian gene, the c-jun protooncogene, by x-rays. The c-jun gene encodes a component of the AP-1 protein complex and is important in early signaling events involved in various cellular functions. The increase in c-jun transcripts by ioni...

Both ionizing radiation and docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid (PUFA), have been shown to inhibit tumor cell growth at least in part by increasing oxidative stress. In this study, the effects of ionizing radiation, DHA, or a combination of the two on cell proliferation, anchorage-independent growth, apoptosis, and lipid peroxidation in A549 lung adenocarcinoma cells w...

When ionizing radiation passes through a material it imparts some of its energy to that material. The imparted energy may be high enough to cause a break in bonds inside the molecules or between molecules or both, in such cases, free radicals are created. The type, lifetime, extent, fate and origin of those free radicals may differ according to several factors; most of them are beyond the subje...

BACKGROUND Melanin pigments are ubiquitous in nature. Melanized microorganisms are often the dominating species in certain extreme environments, such as soils contaminated with radionuclides, suggesting that the presence of melanin is beneficial in their life cycle. We hypothesized that ionizing radiation could change the electronic properties of melanin and might enhance the growth of melanize...

The effect of ionizing radiation on neuronal membrane function was assessed by measurement of neurotoxin-stimulated 22Na+ uptake by rat brain synaptosomes. High-energy electrons and gamma photons were equally effective in reducing the maximal uptake of 22Na+ with no significant change in the affinity of veratridine for its binding site in the channel. Ionizing radiation reduced the veratridine-...

mobile phone use and wireless communication technology have grown explosively over the past decades. this rapid growth has caused widespread global concern about the potential detrimental effects of this technology on human health. stem cells generate specialized cell types of the tissue in which they reside through normal differentiation pathways. considering the undeniable importance of stem ...