Radiation Exposure Ebooks Catalog

EMF Health Summit

The EMF health summit 2018 event is a pure representative of a rare, unique opportunity which uses fully proven strategies to help everyone learn how to protect themselves from the EMF products and live a healthy lifestyle. This program has seen a lot of creativity in its design as a team a health expert have come together to share all that they have discovered throughout their experience about the EMF. These experts will also educate you on the health hazards associated with the EMF as well as -give you lessons on how you can protect yourself from the EMF and live a healthy lifestyle. It is factual that we experience the magnified radiations from different appliances that we use as well as through the use of cell phones, WIFI, and Bluetooth. By registering for the EMF health summit program, you will instantly get access to free bonuses given by these health experts to help you live a healthy lifestyle. Based on the many benefits associated with the EMF health summit 2018 program, I highly recommend everyone who has not yet joined the program to do so and mark the beginning of a healthy lifestyle.

EMF Health Summit Summary

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How To Beat Electrical Sensitivity

This ebook is the complete guide to learning about electrical sensitivity and how to prevent getting it in your life. You will learn what electrical sensitivity is, and what causes it. Once you have started learning about it you will learn how to get rid of it and protect yourself from the dangers of electrical sensitivity. You will also learn how to heal yourself. This book is the product of careful research by the scientific and medical communities into the dangers and preventative measures of electrical sensitivity. ES is one of the most under-diagnosed conditions in the world right now, and this ebook is designed to education people as to how it works and how to prevent it. Do not let it take hold of your family; take control and prevent it now! Do not let yourself get any more hurt; learn about this condition and fight it!

How To Beat Electrical Sensitivity Summary

Contents: Ebook
Author: Lloyd Burrell
Official Website: electricsenseinterviews101.com
Price: $67.00

Electromagnetic Energy

In general, all imaging technologies require the use of electromagnetic energy. Each imaging modality exploits a different part of the electromagnetic energy spectrum. The spectrum includes gamma rays, X-rays, visible light, ultrasonic waves, and radiowaves. All of these waves are photons of energy, but they differ in their wavelength and, therefore, energy. Each imaging instrument is designed to detect a particular range of electromagnetic energy. Most often, the instrument also generates the requisite energy for the imaging application, and the detection occurs after interaction with the imaging subject. The exception is with gamma-ray imaging, where the requisite energy is provided by decay of an administered radioactive probe that is not part of the instrument.

How can anesthesiologists protect themselves from radiation exposure

Most institutions abide by the ALARA philosophy when it comes to protecting their workers radiation exposure should be kept As Low As Reasonably Achievable. There are three basic strategies to the ALARA philosophy Thus increasing the distance from an x-ray machine or a fluoroscope when in use can profoundly affect the intensity of radiation exposure. Six feet of air provides the equivalent protection of 9 inches of concrete or 2.5 mm of lead. Minimize the time of exposure Most medical occupational radiation exposure comes from x-rays scattered by both the patient and surrounding equipment. Obviously this scatter occurs only when the machine is on. A person's radiation exposure is directly proportional to the length of exposure thus every reasonable effort to limit the time of exposure is beneficial. Use shields Most aprons contain the equivalent of 0.25 to 0.5 mm of lead, which is effective at blocking most scattered radiation in medical settings. Uncovered areas such as the lens of...

Identifying The Vascular Lesion

There are two widely used noncontrast-based MRA techniques time-of-flight (TOF) MRA and phase contrast (PC) MRA. The physical principles underlying both techniques are far more complicated than those underlying catheter angiogra-phy and CTA and are beyond the scope of this chapter. Both are unlike other vascular imaging techniques used in acute stroke, in that they are completely noninvasive, requiring no exogenous contrast material whatsoever, thereby obviating concerns regarding contrast allergies and contrast-induced nephropathy (Fig. 2.4). Unlike catheter angiography and CTA, MRI uses no ionizing radiation. Like catheter angiography (but not CTA), both TOF and PC MRA can be used to demonstrate the direction of blood flow, which can be helpful in assessing the direction of flow in a vessel providing collateral perfusion or in situations such as suspected subclavian steal. Additionally, PC MRA can quantitatively measure the velocity of flow, an ability shared only by ultrasound, a...

Focal Adhesion Kinase FAK

Integrins and adhesion of cells to extracellular membranes confer higher resistance to ionizing radiation and cytotoxic drugs.28 The survival-promoting effects of integrins has been identified in tumor response to conventional chemothera-peutic agents such as paclitaxel.28,51,52 Integrins, as well as integrin-associated proteins, modulate the radiation response of cells. ILK has been found in high levels in radiosensitive tumor cells.28,53 Because integrin-associated proteins are involved in all major signal transduction pathways regarding cell proliferation and survival, they are strong potential candidates for targeted therapy.28

At the Chromosomal Level

Defects in DNA replication and repair often manifest themselves at the time of cell division when sister chromatids separate and cells undergo cytokinesis. Reverse genetic approaches using model organisms have thus provided the primary, phenomenological evidence that sumoylation is intimately involved in chromosome structure and function. Mitotic defects, such as anaphase bridges and cohesion defects that lead to chromosome loss or fragmentation, have been associated with mutations in essentially all genes that encode SUMO pathway components (see Table 1 and below). Moreover, cells hypomorphic for, or lacking SUMO, E1, E2 or E3, or Ulp functions, display hypersensitivities to DNA-damaging agents (ionizing radiation, UV or genotoxic chemicals) that either activate cell cycle checkpoints or are the cause of aberrant mitosis (or both). There has been significant progress in our understanding of the underlying molecular mechanisms, and we will first discuss some key findings that link...

Intrinsic Death Pathway

Cells can respond to various stressful stimuli and metabolic disturbances by triggering apoptosis. Drugs, toxins, heat, radiation, hypoxia, and viral infections are some of the stimuli known to activate death pathways. Cell death, however, is not necessarily inevitable after exposure to these agents, and the mechanisms determining the outcome of the injury are a topic of active interest. The current consensus appears to be that it is the intensity and the duration of the stimulus that determine the outcome. The stimulus must go beyond a threshold to commit cells to apoptosis. Although the exact mechanism used by each stimulus may be unique and different, a few broad patterns can be identified. For example, agents that damage DNA, such as ionizing radiation and certain xenobiotics, lead to activation of p53-mediated mechanisms that commit cells to apoptosis, at least in part through transcriptional upregula-tion of proapoptotic proteins.64 Other stresses induce increased activity of...

Screens Films and Film Processing Systems

The goal in screen-film mammography for mass screening and diagnosis is to produce consistently high-contrast, high-resolution, low-noise images at the lowest radiation dose consistent with these image-quality requirements. In recent years, there have been many significant technologic improvements in mammographic screen-film combinations (AAPM, 1990 Haus, 1991 1999b KimmeSmith, 1991 Rothenberg and Haus, 1995 Yaffe, 1990). Until the early 1970s, direct-exposure (industrial type) x-ray films were used which often required long exposure times (causing blur due to motion) and resulted in high radiation exposure (Bassett et al., 1992 Egan, 1976 Gold et al., 1990 Haus and Cullinan, 1989). Films were processed manually in tanks or in film processors with long processing times. In the early 1970s, screen-film combinations for mammography became commercially available (Bassett et al., 1992 Haus and Cullinan, 1989 Ostrum et al., 1973 Wayrynen, 1979).

Small Bowel XRay Series and Enteroclysis

Barium studies are often used for further workup of the small bowel in obscure bleeding, either before enteroscopy or when push enteroscopy has failed to reveal a source. Per oral ingestion of a barium suspension is used for the small bowel follow-through (SBFT) X-ray series, whereas enteroclysis involves instillation of contrast material through a small tube placed in the proximal intestine either directly or facilitated by endoscopy. Diluted methylcellulose solution enhances the double contrast effect, thereby improving the quality of the study. Although radiation exposure and patient discomfort are higher with enteroclysis, studies have documented significantly higher overall diagnostic yield, higher sensitivity, and shorter procedure times than with SBFT. When enteroclysis is used for the diagnosis of obscure bleeding, its yield can range from 10 to 21 , which is higher than the yield of SBFT (0-5.6 ). The sensitivity of enteroclysis in the diagnosis of small bowel neoplasia is...

Molecules Are Involved in the Control of the Cell Mitogenic and Survival Signals and of Genomic Stability

Analysis of X- - mice and cells has, in the last few years, corroborated the notion that the blockade or the interference with pathways normally regulated by these molecules can indeed play a critical role in APL pathogenesis. While the main outcome resulting from X gene heterozygosity and the interference of the fusion protein with the function of the remaining normal X allele product was originally proposed to lend a proliferative and survival advantage to the leukemic cells, more recent data indicate that these events may also cause an underlying genomic instability that could greatly contribute to APL multistep leukemogenesis. Analysis of PML, PLZF, and NPM KO mice is currently ongoing and has been instrumental in reaching these conclusions. Primary PML KO cells such as mouse embryonic fibroblasts (MEFs) or primary thymocytes display a marked proliferative advantage (Wang et al. 1998a). Furthermore, PML- - cells of various histological origins including hematopoietic cells and...

Imaging Methods The Case for MRI

The success of MRI in characterizing plaque composition derives from its excellent contrast between soft tissues, which provides excellent anatomical and compositional detail. Contrast can also be changed by adjusting any of several imaging parameters. Multiple images with different contrast weightings can thus be combined for increased sensitivity to tissue differences. Additionally, MRI is noninvasive and does not use ionizing radiation, making it ideal for serial studies.

Radiation Proctopathy

The rectum, because of its fixed position in the pelvis and proximity to the prostate and uterus, is the most common GI site of radiation injury (50,51). In a series of 738 patients with prostate cancer treated with radiation, proctitis of at least moderate severity was seen in 5 and anorectal stricture or fibrosis in 1 (52). The incidence of severe proctitis was less than 1 , and most presented within 2-5 years after radiation exposure. Other studies have noted rates of proctitis of up to 20 . Acute radiation injury may develop during or shortly after radiation

Animal Models of Lung Cancer

Conventional multimodality therapy for lung cancer incorporates surgery, radiation, and chemotherapy using a variety of clinical protocols dictated by the subtype and extent of disease. Theoretically, gene therapies may play important synergistic roles in augmenting the effectiveness of conventional approaches. For many such strategies, there already exists a scientific rationale to test them in combination with conventional multimodality therapy. For example, one may enhance the radiation-sensitivity or chemosensitivity of tumor cells (e.g., p53 or kBa gene therapy) 127, 128 or modify normal tissue susceptibility to cytoablative therapy (e.g., mucosal tissue protection by virtue of MDR-1 or bFGF gene transfer). Examples of synergism with the suicide gene therapy approaches have also been studied. The HSV thymidine kinase gene ganciclovir system induces radiation sensitivity into transduced tumor cells 129 , suggesting that these two forms of therapy can be combined to potentiate...

Tumor Suppressor p53 A Major Regulator of Cell Growth and Death

It is well-established that p53 functions primarily as a transcription factor that is induced as part of the cellular response to DNA damage (Vousden 2002). The p53 DNA damage response to ionizing radiation and other genotoxic agents occurs in proliferating cells. Following activation, p53 translocates to the nucleus where it either promotes or suppresses the expression of a diverse group of genes, many of which are involved in cell growth control and apoptosis (Morrison et al. 2003 Hughes et al. 1997). Accordingly, p53 activation has been shown to block cell cycle progression at two major cell cycle checkpoints, the G1-S interphase or in G2

Radiation Risks of Mammography

A number of epidemiologic studies of adult women have contributed knowledge of the long-term risks of ionizing radiation to the female breast (Boice, 2001 Preston et al., 2002a UNSCEAR, 2000). Among these studies are those of Japanese atomic-bomb survivors (Shimizu et al., 1990 Thompson et al., 1994) female tuberculosis patients in Massachusetts who received multiple chest fluoroscopies in conjunction with artificial pneumothorax (Boice et al., 1991) a similar series of female tuberculosis patients in Canada (Howe and McLaughlin, 1996) women in New York State receiving radiotherapy for postpartum mastitis (Shore et al., 1986) and Swedish women receiving x-ray treatment for fibroadenomatosis and other benign breast conditions (Baral et al., 1977 Mattsson et al., 1993).

Do patients with devices need to avoid microwave ovens or other hospital electronics

In general modern devices are shielded against routine electromagnetic interference. This shielding is inadequate for radiofrequency (intraoperative electrocautery) or transcutaneous electrical nerve stimulation units. This may lead to false detection of extracardiac noise, leading to inappropriate inhibition of pacing, or to defibrillation caused by inappropriate arrhythmia detection with ICDs. Other forms of strong magnetic fields such as arc welding and some short-wave radios may lead to device reprogramming or other malfunction. Cellular phones generally are not problematic unless in a pocket overlying the device they should be used in the contralateral hand.

Radiation Risk Versus Benefit of Mammographic Screening

In this Section, a comparison is presented between the risks of breast cancer induced by radiation exposure of the breast during mammography and the possible reduction in breast cancer mortality arising from mammographic screening. Risks are estimated in terms of the BEIR V models (NAS NRC, 1990), presented above, and benefits are considered in terms of various assumed reductions in breast cancer mortality rates as a consequence of mammo-graphic screening. The benefit risk model uses standard life table

Cell Proliferation and Cancer

The genetic basis of cancer is confounding, because different combinations of different mutant genes can give rise to the same type of cancer. Some gene mutations are common among different cancers, whereas others are confined to a specific cell type. Many of the mutations that lead to cancer occur spontaneously. Others are caused by chemical agents (carcinogens) in tobacco smoke, foods, and the workplace by ultraviolet light and ionizing radiation and by viruses that either commandeer the cell division process of a tissue or insert a viral genome into a locus responsible for cell proliferation.

Activation Of The Apoptotic Machinery By Chemotherapeutic Agents

For the majority of anticancer drugs, previous studies not only ruled out an essential role for the Fas FasL pathway in drug-induced apoptosis (see first paragraph of this Section) but also directly implicated the mitochondrial pathway in this process. Observations that are important in this regard include the demonstration that cytochrome c release accompanies induction of apoptosis by a variety of agents (113,120,223,224), the determination that Bax translocates to mitochondria in response to various drugs independent of (i.e., upstream of) caspase activity (83,225), and the demonstration that combined deletion of BAX and BAK inhibits drug-induced apoptosis (87,226). As might be expected, if the mitochondrial pathway plays a predominant role, dominant-negative caspase-9 constructs (227,228) and antiapoptotic Bcl-2 family members (210,229) inhibit drug-induced apoptosis. The demonstration that Caspase9 or Apaf-1 gene deletion delays the induction of apoptosis by staurosporine,...

Magnetic Resonance Imaging

Ultimately, the major promise of MRI in the diagnosis of breast disease is its potential to image the radiographically dense breast with uniquely high contrast, perhaps also permitting the differentiation of benign from malignant tissue on the basis of the physiological information transmitted via contrast enhancement techniques combined with new pulse sequences. Another advantage of MRI is that it does not involve ionizing radiation. Indeed, in its current clinical form, it causes no known genetic damage (Wolff et al., 1980) and there is no indication of other

Are Alterations In The Apoptotic Machinery Determinants Of Drug Sensitivity

P53 alterations appear to affect sensitivity to both ionizing radiation and drugs. Studies in tissue culture have led to the conclusion that p53 deficiency can render both ElA ras-transformed fibroblasts (265) and HCT116 colon cancer cells (266) resistant to the induction of apoptosis by various anticancer drugs in vitro. When the same cell lines are grown as xenografts, responses are diminished in the absence of p53. Consistent with these results, studies have also established that ionizing radiation or high-dose 5-fluorouracil induces less apoptosis in epithelial cells of the small and large intestines of p53+ + mice compared with that of p53+ + littermates (267,268). Collectively, these results suggest that changes in p53 status can affect drug sensitivity in at least some cell types. Information regarding the role of BH3-only protein alterations in drug resistance is likewise incomplete. In perhaps the best-studied example, Bim gene deletion not only renders murine thymocytes...

Gamma Rays and Detection

In the electromagnetic energy spectrum, the highest energy photons (shortest wavelength, highest frequency) are gamma rays. Gamma rays arise out of nuclear events during radioactive decay. For in vivo imaging purposes, the best gamma rays are of low energy, in the range of 100-511 keV. Gamma rays in this energy range can be efficiently stopped and therefore measured

Magnetic Resonance Imaging and Spectroscopy

The proton is the element responsible for the signal generation in proton MRI, and can be viewed as a minimagnet due to the spinning single electron. MRI utilizes two energies, a strong magnetic field and pulses of radio frequency (RF) electromagnetic energy. RF energy is not ionizing, and a trillion times less in magnitude than X-rays. The sensitivity of the technology is related to the large number of protons that are present in water and fat, the primary constituents of a human or animal. When protons are placed in a magnetic field, they become aligned with, or opposed to, the external field. Excitation with a precise resonance frequency (MHz) results in excited-state protons, all of which are in phase, but tilted away from the direction of the external magnetic field. The in-phase aspect is unique to the excited state, since ground-state protons are not in phase. Therefore, to summarize, absorption of a resonance RF energy by the proton results in an excited state, where all the...

Microbial Proteomics in Pathogen Detection

Though in its infancy, proteomic technology has the potential to play a key role in the future of clinical microbiology diagnostics as techniques become more rapid, affordable, and the list of applicable biomarkers expands. Mass spectroscopy (MS) and 2-D gel electrophoresis are the 2 common techniques in microbial proteomics (Douglas, 2004). In 2-D gel electrophoresis, proteins are first separated by their isoelectric point (pI) in glass tubes (Bjellqvist et al., 1982). Gels are then removed from glass and placed horizontally on top of polyacrylamide slab gels, and polyacrylamide gel electrophoresis (PAGE) further separates proteins with similar charges by their size (molecular weight). Gel electrophoresis is a simple method to catalogue microbial proteins grown under different conditions and disease states. A mass spectrometer can take proteins from PAGE and further separate them by producing charged particles (ions) (Shevchenko et al., 1996). The mass spectrometer differentially...

Imaging Biomarkers for Vulnerable Plaques

Radiation exposure electron bean CT for the detection of calcified coronary artery plaques. The disadvantages of CT include radiation exposure and its inability to differentiate the compositional changes in the noncalcified plaque areas. One study performed by multislice detector CT showed that statin therapy led to a significant reduction of noncalcified plaque burden that was not reflected in calcium scoring or total plaque burden 47 , suggesting the potential to monitor medical treatment in patients with coronary atherosclerosis. Recent advances in CT are aided by contrast enhancement (CT angi-ography or CTA) and the use of multidetector row CT (MDCT) with submillimeter collimation and retrospective ECG gating, that permit high-resolution imaging of coronary artery stenosis and atherosclerotic plaques. However, the recent study of CTA using MDCT failed to reliably identify the functional significance of coronary lesions in patients with stable angina and atypical chest pain,...

Unconventional Theories Of Allergy

Environmental illness and multiple chemical sensitivities are names applied to a condition described as allergic toxemia, but in this case the cause is attributed to numerous common everyday environmental chemicals. In most cases these chemicals include pesticides, solvents, perfumes, new carpets, plastic materials, new clothing, and virtually any synthetic chemical or commercial product with an odor. Occasionally, electromagnetic fields generated by nearby electric power lines or even household appliances are

Radiation Hybrid Mapping

A monochromosomal hybrid or whole human genome cell line can be used for building radiation hybrid maps. The cells of the cell line (donor cells) are treated with a dose of ionizing radiation from X or gamma (g) rays that will kill the cells. Both X and g rays bombard living matter with particles that induce ion formation. The ions have damaging effects, such as disrupting membranes, inactivating enzymes, and fragmenting chromosomes. The standard unit of biologically absorbed energy from ionizing radiation is called a rad (radiation absorbed dose), which is equivalent to 0.01 joule of energy per kilogram of tissue (100 ergs per gram of tissue). Generally, a dose of 3000rads is lethal to cells growing in culture. The larger the dose in rads, the greater the damage and the smaller the DNA fragments produced.

DNA Repair Counters DNA Damage

DSBs are considered to be the most lethal of all DNA lesions, and, thus, DSB repair may be particularly important to neuronal vulnerability following neurological insults. Surprisingly, while being potentially a very important contributor to vulnerability to neuronal injury, our knowledge of DSB formation, detection, and repair comes almost exclusively from nonneural cells. DSBs are repaired by several pathways, including homologous recombination, single-strand annealing, and nonhomologous-end-joining (NHEJ) (Singleton and Jeggo 1999). There is tremendous overlap in the initial detection and signaling events occurring before each of these repair pathways. One of the earliest events to happen after a DSB is the phosphorylation of histone H2A.X (termed g-H2AX) over megabase domains near the lesion site (Fig. 16.2a). Thousands of H2A.X molecules are phosphory-lated near each DSB, occurring within minutes of ionizing radiation. It has been suggested that ATM is primarily responsible for...

Other Breast Imaging Modalities

Other breast imaging methods currently have less widespread application these include ultrasonography, magnetic resonance imaging (MRI), thermography, transillumination, CT, and nuclear imaging. Except for ultrasonography, all involve electromagnetic wave radiation. CT exposes breast tissue to higher levels of ionizing radiation than screen-film or digital mammography, making it unsuitable for annual screening and it does not have the spatial resolution of conventional mammography. Thermography, and nuclear imaging have not been shown to contribute significantly to either lesion detection or characterization. Ultrasound has specific applications for evaluating breast masses and guiding interven-tional procedures. MRI is currently being studied for its potential roles in screening for and staging breast cancer, as well as other indications.

Intracellular Signaling Targets for Cancer Chemosensitization

Introduction - Chemotherapy and radiation exposure are the major options for the treatment of cancer. The application of both of these therapies is limited by severe adverse effects on normal tissues and the frequent development of tumor cell resistance. It is therefore highly desirable to improve the efficacy of these treatments without increasing the toxic side effects and to counteract the resistance mechanisms that can render tumors insensitive to therapy.

Usefulness of Mammography for Breast Cancer Screening

There is little, if any, opposition to the practice of diagnostic mammography, probably because of the compelling clinical need for the information obtained. Many mammography examinations are performed for diagnostic purposes, and mammographic screening programs have also been widely implemented. There has been some opposition to screening in the past for a variety of reasons (1) concern over a few published indications of a relatively unfavorable benefit risk ratio, (2) concern about exposure to ionizing radiation, (3) concern about benefit in comparison to the number of false-positive mammograms, (4) the relatively high cost of mammography examinations and the cost of the biopsy procedures

Azacitidine Anticancer [913

Azacitidine is an antineoplastic agent launched last year for the treatment of myelodysplastic syndrome (MDS). MDS is a group of closely related diseases caused by abnormal blood-forming stem cells of the bone marrow. They are characterized by a hyperproliferative bone marrow, the presence of clonal blood cells with impaired morphology and maturation, and peripheral blood cytopenias resulting from ineffective blood cell production. The initial stem cell injury can be from cytotoxic chemotherapy, radiation exposure, chemical exposure, or genetic predisposition. Subsequently a clonal mutation predominates over bone marrow thereby suppressing healthy stem cells. Azacitidine is indicated for the treatment of all five subtypes of MDS, which consist of refractory anemia, refractory anemia with ringed sideroblasts, refractory anemia with excess blasts, refractory anemia with excess blasts in transformation, and chronic myelomonocytic leukemia. Azacitidine is an analog of cytidine in which...

Primer on Medical Imaging

Cone-beam CT (CBCT) is a technique for 3D X-ray imaging whereby a large X-ray field, emitted in a cone shape, rotates about a subject in conjunction with an opposed 2D detector, such as an image intensifier (II) or amorphous silicon detector. CBCT enables acquisition of a full 3D volume of data in a single rotation of the X-ray source and detector, compared with the slice-by-slice acquisitions in traditional CT (or the slab-by-slab acquisitions of multislice CT). CBCT requires significant computing power to process large volumes of data but has the potential to acquire significant amounts of that data rapidly while exposing subjects to a smaller dose of ionizing radiation than traditional CT (Danforth, Dus and Mah, 2003). Currently, CBCT devices are commercially available for head and neck and intraoperative imaging at very high spatial resolution, but with lower contrast resolution than traditional CT. This can be expected to improve with refinements in detector technology....

Series Introduction

Normal metabolism is dependent upon oxgyen, a free radical. Through evolution, oxygen was chosen as the terminal electron acceptor for respiration. The two unpaired electrons of oxygen spin in the same direction thus, oxygen is a biradical, but is not a very dangerous free radical. Other oxygen-derived free radical species, such as superoxide or hydroxyl radicals, formed during metabolism or by ionizing radiation are stronger oxidants and are therefore more dangerous.

Autophagy

Cells produce energy-generating basic molecules from complex polymers such as proteins, lipids, polysaccharides, and nucleic acids through sequestration and degradation of some of the cytoplasm and organelles. In this regard, it is argued that autophagy may help cancer cells to survive under nutrient-limiting and low-oxygen conditions and against ionizing radiation.1011 However, recent observations that there is decreased autophagy during experimental carcinogenesis and heterologous disruption of Beclin 1 (Atg6),1214 an autophagy gene, in breast and ovarian cancers suggest that breakdown of autophagic machinery may contribute to development of cancer. 1 5 In addition, Atg6 heterozygous mice develop tumors spontaneously, suggesting tumor suppressor activity of Atg6.12 Similarly, mice deficient in another autophagy gene, Atg4C, a cysteine protease, are susceptible to chemical carcinogenesis.16 However, the mechanism of how autophagy suppresses tumorigenesis is still unclear. Other...

Cell Death Pathways

It has been well established for many years that at least one other mode of cell death, that of mitotic catastrophe, is quite common, particularly in tumors that have been exposed to ionizing radiation. However, the basis for the cell choosing or preferring a particular mode of cell death is not understood, even at the most fundamental level. Relatively recently, at least one additional mode of cell death has been recognized, known as autophagy. Autophagy is a complex response because, unlike apoptosis or mitotic catastrophe, autophagy can function as a cytoprotective mechanism when initiated under certain modes of cell stress, such as nutrient deprivation. Finally, an area that is appropriately receiving renewed attention is a subspecies of apoptosis that is termed anoikis, or cell death subsequent to loss of adhesion to substratum. The ability of tumor cells to resist anoikis may provide the necessary survival advantage that permits a tumor cell to metastasize.

Apoptotic Signatures

There is significant evidence to suggest that specific toxic exposures will produce discernable expression signatures. Studies in yeast and mammalian cells have demonstrated that a reproducible subset of genes will show altered expression in response to specific conditions such as anoxia, nutrient deprivation, exposure to alkylating agents, chemotherapeutic agents, and so on (41-43). It is therefore reasonable to hypothesize that toxicant signatures will exist for individual classes of toxins such as polycyclic aromatic hydrocarbons (PAH), alkylating agents, ionizing radiation, neurotoxins, and so forth. Moreover, the individual signatures will almost certainly reflect underlying mechanisms of toxicity such as oxidative stress, DNA damage, inhibition of oxidative phosphorylation, disruption of cell membrane potentials, and so on (44,45). Since many toxicants will have multiple mechanisms of action, a gene-expression signature will also reflect this complexity of mechanisms. As an...

The Drake equation

N R* x fp x ne x fl x fi x fc x L where N the number of civilisations in the galaxy from which electromagnetic emissions are detectable R* the rate of formation of stars that are compatible with the development of life fp the fraction of those stars that have planetary systems ne the number of planets with life-supporting environments orbiting each of these stars fl the fraction of these planets on which life appears fi the fraction of life-bearing planets on which intelligent life evolves fc the fraction of civilisations that develop an advanced technology, emitting detectable radio signals and L the length of time during which these civilisations release detectable signals.

Instrumentation

The molecular dipoles of the individual molecules with the applied oscillating electromagnetic radiation (microwaves). Early claims of non-thermal heating effects using microwave irradiation have been reinterpreted as the effects of superheating (5). Several technological advances in microwave instrumentation from the traditional multi-mode domestic microwave have enabled their expanded use and safety. Several new multi-mode and single-mode microwave instruments are commercially available today. These instruments allow for safe and reliable temperature and pressure control of samples during the microwave heating process. Systems are available which allow the chemist to perform up to 50 reactions in parallel in one microwave source to speed up the optimization and production processes. Alternatively, single vessel instruments integrated with a liquid handling robot are available. These instruments allows for unattended sequential microwave experiments. Optimization of reaction...

Summary

Its ability to detect a cancer before the tumor mass becomes large enough to be palpable, thereby permitting early diagnosis. It has also been proven an invaluable tool to distinguish benign from malignant lesions and can facilitate prompt biopsy of cancers, while encouraging clinical observation (rather than biopsy) of many benign masses. Other breast imaging methods have, thus far, been considered less successful these include thermography, transillumination, ultrasonography, and MRI and MRS all of which do not utilize ionizing radiation. Computed tomography (Section 8.4) and digital mammography (Section 3.3) which use x rays, and therefore involve the potential risk of mammary carcinogenesis are being subjected to clinical investigation to determine their role in breast cancer diagnosis. Explanations of the principles of operation, a chronology of developments, and an extensive discussion of the limitations of each of these methods is contained in Sections 3.3 and 8.4.

Burns Physiology

Burns are the leading cause of accidental death. They are usually caused by fires, kitchen spills, or excessively hot bath water, but they also can be caused by sunlight, ionizing radiation, strong acids and bases, or electrical shock. Burn deaths result primarily from fluid loss, infection, and the toxic effects of eschar (ESS-car) the burned, dead tissue.

Ultrasound

Ultrasonography employs mechanical energy (sound) rather than electromagnetic radiation to produce a pictorial representation of the internal structure of the breast. The image is produced by transmission of sound pulses into the breast and measurement of the returning echoes at later times, depending upon the depth of interfaces between different tissue types. The transducer functions as both transmitter and receiver. An attractive feature of sono-graphic imaging is that there are no known carcinogenic effects of ultrasound at the power levels employed for diagnostic purposes.

Operating Room

Medical professionals keep their radiation exposure as low as reasonably achievable (ALARA),and below the CDC's recommendation of less than 5000 mrem year, by maximizing their distance to x-ray and fluoroscopes when in use, minimizing their time of exposure, and using shields.

Absorbed Dose

Gamma Rays Attenuation Vacuum

The characteristic of a radiation beam that is typically measured is called the Radiation Exposure. This quantity expresses how much ionisation the beam causes in the air through which it travels. We will see in the following chapter that one of the major things that happens when radiation encounters matter is that ions are formed - air being the form of matter it encounters in this case. So the radiation exposure produced by a radiation beam is expressed in terms of the amount of ionisation which occurs in air. The SI unit of radiation exposure is the coulomb per kilogram - and is given the symbol C kg-1. It is defined as the quantity of X- or gamma-rays such that the associated electrons emitted per kilogram of air at standard temperature and pressure (STP) produce ions carrying 1 coulomb of electric charge. The traditional unit of radiation exposure is the roentgen, named in honour of Wilhelm Roentgen (who discovered X-rays) and is given the symbol R. The roentgen is defined as the...