Electromagnetic Radiation and Human Health

EMF Protection

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!

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Biological Effect of Ionizing Radiation

The biological effect of ionizing radiation occurs at the cellular level. DNA and other macromolecules of the cell may be directly ionized by radiation or indirectly damaged by highly reactive free radicals created by ionization of cellular water. High levels of radiation exposure may cause direct cell death. More commonly, lower levels of radiation interrupt the cell's reproductive process by damaging the cell's mitotic capability, making it unable to divide. Injury occurs at the time of exposure but

TABLE 2461 Fetal Radiation Exposure from Common Radiologic Studies

Some variation due to equipment quality, techniques used, and duration of study. Radiation exposure in CT may be reduced by performing modified studies and the use of dose-reducing techniques, such as reducing the number of slices obtained.13 Diagnostic evaluations with magnetic resonance imaging and ventilation-perfusion scanning have not been reported to cause adverse pregnancy outcomes. Potential effects of contrast agents have not been definitively studied, and their use requires individualization.

Ionizing Radiation Gamma Radiation

Several studies have been reported in which ionizing radiation with 60Co was utilized to reduce the toxicity of bacterial endotoxin. Bertok and Szeberenyi (47) describe the use of a 60Co-irradiated endotoxin preparation, TOLERIN that significantly decreased the endotoxin's lethal and hypotensive effects in a dose-related manner. Endotoxin's ability to activate the complement system was also affected, and immunoadjuvant properties and ability to stimulate nonspecific resistance were retained. Csako et al. (48) investigated the physical and biological properties of 60Co ionizing radiation. Physical and biological changes were reported to be dose dependent. A gradual loss of the polysaccharide components (O side chain and R core) was observed, and activity tests suggested that destruction of lipid A was dose related. Both pyrogenicity and LAL reactivity of the endotoxin were destroyed by increasing the doses of radiation. However, because it increases the possibility of unknown chemical...

Effects of Radiation Exposure on Humans

The quality factor has originally been developed for radiation protection purposes. Therefore it is mainly based on radiation risks for cancer induction in mammals. The effects of radiation exposure on humans can be grouped into two basic categories acute effects or delayed effects. Acute effects usually appear quite soon after exposure when people receive high The Acute Radiation Syndrome (ARS) is a sequence of phased symptoms which vary with individual radiation sensitivity, type of radiation, and the radiation dose absorbed. After radiation exposure with doses well above 1 Sv, the ARS is characterized by the rapid onset of nausea, vomiting, and malaise, which is followed by a nearly symptom free phase of weeks to days, depending on dose. Humans who have received doses of radiation between 0.7 and 4 Sv will have depression of bone-marrow function, known as the hematopoietic syndrome. This syndrome leads to decreased resistance to infections from lymphocyte deprivation and anemia...

Nonionizing and Ionizing Radiation

The electromagnetic radiation spectrum includes long wavelength, low frequency, low-energy forms of nonionizing radiation and progresses to short wavelength, high frequency, high-energy forms of ionizing radiation. Ionizing refers to the ability of high-energy radiation to displace electrons from atoms and cause matter through which it passes to become electrically charged. Nonionizing forms include ultraviolet rays, visible rays, infrared rays, microwaves, and radio waves. Lasers, ultrasound, and nuclear magnetic resonance systems are other examples of nonionizing radiation used in the medical field. X-rays and gamma waves are ionizing forms of electromagnetic radiation. Ionizing radiation is emitted from unstable forms of elements called radioisotopes. An isotope is a variation of an element with a different number of neutrons in the nucleus. Because its number of protons identifies an element, all isotopes of an element have the same number of protons and thus the same atomic...

Radiation Exposure

Teratogenic potential depends on the total radiation dose as well as the gestational age at exposure. The absorbed dose of radiation is measured in grays (Gy), the SI unit, or rads (1 Gy is equivalent to 100 rad). A dose of more than 50 to 100 mGy (5 to 10 rad) and or exposure at a gestational age of 8 to 15 weeks is of the most concern. Cumulative doses may also be hazardous to the developing embryo or fetus. TabJe 99. 3 lists the radiation doses of some common emergency department radiographic tests.14 For procedures in which radioactive material is administered, the dose absorbed by the fetus is variable. Fetal exposure may be minimized by adequate hydration to minimize bladder concentrations, maintain brisk urine output, and enhance clearance of the material. Exposure from a lung ventilation-perfusion scan using xenon 133 and technetium 99m is typically less than 5 mGy. Ultrasound and magnetic resonance are the only radiation-free imaging techniques. The short-term electromagnetic...

Ionizing Radiation

An important physical cause of toxic effects is a variety of forms of radiation. Ionizing radiation possesses enough energy to strip an electron from an atom. This can result in the formation of damaging free radicals or directly damage bonds in biochemical substances. The most sensitive system in living things is the DNA, since damage to a single molecule can transform a cell to malignancy. It is not necessary for a radioactive emission to damage a DNA molecule directly. The most abundant molecule in living things is water. Water can form free radicals when irradiated, and these in turn can produce toxic effects, including genotoxicity. Ionizing radiation may be electromagnetic (g-rays, x-rays, ultraviolet rays) or particulate. The major particulate forms of radiation are a and p, but they may include neutrons, other subatomic particles, or larger particles such as various atomic nuclei found in cosmic rays. Of primary interest here the a, p, and g emissions from the decay of...

Function of BRCA1 and BRCA2 proteins

Studies of the normal function of BRCA1 suggest that it encodes a protein involved in the cellular response to DNA damage, a role in transcription and cell cycle control. BRCA1 has been found to be part of a subnuclear focus known to contain RAD51, a human homologue of the yeast DNA damage checkpoint gene, thought to be involved in homologous recombination and double-strand break repair. It is also thought to have a role in regulating apoptotic cell death. From studies on human cell lines containing only mutant BRCA1 there is a suggestion that they have increased sensitivity to ionizing radiation, and are defective for transcription-coupled repair but not for double-strand repair. Evidence indicates a link between BRCA1 phosphorylation by Chk2 and ATM. This suggests that BRCA1 may link DNA repair functions of BRCA2 to pathways that signal DNA damage or incomplete DNA replication (Oddoux et al., 1996 Bertwistle et al., 1997 Hsu and White, 1998 Abbott et al., 1999 Chen et al., 1999).

Dna Repair And Carcinogenesis

The persistence of DNA adducts is the result, for the most part, of the failure of DNA repair, so that its structure returns to normal without evidence of alteration. The structural alterations that may occur in the DNA molecule as a result of interaction with reactive chemical species or directly with ultraviolet or ionizing radiation are considerable. A number of the more frequently seen structural changes in DNA are schematically represented in Figure 3.15. The reaction with chemical species produces adducts on bases, sugars, and the phosphate backbone. Bifunctional reactive chemicals may also cause the crosslinking of DNA strands through reaction with two opposing bases. Other structural changes, such as the pyrimidine dimer formation, are specific for ultraviolet radiation (see below), whereas double-strand DNA breaks are most commonly seen with ionizing radiation (see below). On the other hand, most of the remaining lesions demonstrated in Figure 3.15 may occur as a result of...

Pacemaker Malfunction

Oversensing is used to describe the situation where the pacemaker senses electrical activity not associated with atrial or ventricular depolarizations it is thus inhibited and generation of the pacemaker impulse is suppressed. Causes of oversensing include physiologic electrical activity (T waves, muscle potentials), external electromagnetic interference, and signals generated by the interaction of different portions of the pacing system. Unipolar electrodes are more sensitive to physiologic electrical activity and electromagnetic interference than bipolar electrodes.

Physical Carcinogenesis Radiation Carcinogenesis

Perhaps the first documented example of the induction of neoplasia by ionizing radiation was that of atypical epithelial hyperplasias and malignant epitheliomas observed on the hands of radiologists and scientists using x-ray devices and radium within a few years after their discovery near the turn of this century. In these cases, the human being was the experimental victim of radiation carcinogenesis. Fortunately, scientists rapidly became aware of the dangers of ionizing radiation and took precautions to prevent its effects in humans. Radiant energy in our universe comes in a variety of general types, all related to the wavelength and frequency of the waves. A diagram of the electromagnetic spectrum is seen in Figure 3.26. With our present-day knowledge, there is no solid evidence that radiant energy of wavelengths greater than 5 x 10-5 cm is carcinogenic. However, ultraviolet, Roentgen or x-rays, and gamma rays have carcinogenic effects. In addition, high-energy particles such as...

Dual Energy XRay Absorptiometry DXA

The DXA method evolved from earlier single and dual photon absorptiometry methods for evaluating bone mineral. DXA systems share in common an x-ray source that, after appropriate filtration, emits two photon energy peaks. The attenuation of the two energy peaks relative to each other depends on the elemental content of tissues through which the photons pass. Bone, fat, and lean soft tissues are relatively rich in calcium phosphorus, carbon, and oxygen, respectively. DXA systems are designed to separate pixels, based on appropriate models and relative attenuation, into these three components. There are no known factors, including hydration effects that significantly influence the validity of DXA fat and bone mineral estimates. Excessive or reduced fluid volume would be interpreted as changes in lean soft tissue. The radiation exposure is minimal and can be used in children and adults of all ages. DXA measures in persons who fit within the DXA field-of-view have good reproducibility for...

Magnetic Resonance Imaging Computed Tomography

The use of computed tomography (CT) has had limited application in body composition research due primarily to radiation exposure. Its use has primarily been limited to single slice acquisitions in the abdomen and mid-thigh whereby information on adipose tissue distribution and muscle cross-sectional area have been derived. The use of magnetic resonance imaging (MRI) has resulted in important advances in body composition phenotyping. MRI studies are safe and instruments are available in most hospital or related facilities. Expense is a limiting factor. The importance of both CT and MRI is that both methods acquire cross-sectional images of the body at pre-defined anatomic locations. Image analysis software then allows estimation of the adipose tissue, skeletal muscle, and organs based on pixel intensity. Acquiring images at predefined intervals and integrating the area between slices allows reconstruction of an entire organ of interest such as skeletal muscle mass. A significant...

Electron Beam Computed Tomography

Radiation exposure is a consideration with all CT scanning methods. With conventional or helical CT, radiation levels are 2 to 4 cGy (2 to 4 rad) per CT slice. If multiple slices are taken at the same level of the heart, then the radiation increases directly in proportion to the number of slices. Electron-beam CT has less exposure to radiation for the patient each slice has an exposure of 0.54 cGy (540 mrad). However, more imaging slices are acquired with electron-beam CT in obtaining a cine sequence of the heart, so that 10 cine frames would result in an exposure of 5.4 rad. For comparison purposes, a single x-ray of the lumbar spine is approximately equivalent to 1 cGy (1 rad), whereas radiation exposure from a chest x-ray is 0.06 cGy (60 mrad).

Radiopharmaceuticals and Imaging Techniques

GATED RADIoNUCLIDE ANGIoGRAPHY Gated radionuclide angiography (RNA) has remained a clinical gold standard for overall assessment of left ventricular function. This test has the advantage of being applicable to nearly all patients, regardless of body habitus or underlying illness. In addition, unlike echocardiography, RNA is relatively operator independent. Radiation exposure is present but insufficient to prevent serial examination of cardiac function in the same patient.

Principles of Magnetic Resonance Imaging

The basic process of MRI involves excitation of hydrogen nuclei (i.e., protons) with radio frequency energy. After sending electromagnetic energy into the patient, protons are excited to a higher-energy state. The radio frequency wave is then turned off, and protons relax to their baseline state. As the protons relax, they emit a radio frequency signal that can be picked up by an antenna, amplified, and used to form an image.

TABLE 572 Emergency Department Patients in the Magnetic Resonance MR Environment

ED personnel as well as their patients must be cleared for MR compatibility prior to entering the MR suite. A number of implanted medical devices are not MR compatible. The most common of these are certain brain aneurysm clips, cardiac pacemakers, cochlear implants, and internally placed pumps or electrical stimulators. Regarding brain aneurysm clips, the specific manufacturer of the clip and the model number should be provided to MR department personnel, who can advise on MR compatibility. Patients are also questioned to determine whether they have had injuries or a typical work history that would place them at risk for having metal fragments in or near the orbit or brain. Because of space limitations, all such devices cannot be reviewed in this chapter, and readers are advised to consult with MR personnel for any implanted device or device transported with the patient. Finally, although there is no known biohazard to humans or fetuses at approved energy levels specified by the Food...

TABLE 721 Presentations of Esophageal Foreign Bodies Warranting Endoscopy Consultation and Possible Hospital Admission

Progress of the object through the gastrointestinal tract must be monitored with repeat abdominal x-ray films, usually 2 to 4 h apart. The use of metal detectors, if available, has been advocated as a means of localizing and tracking the progression of metal objects, thereby avoiding repeated radiation exposure. Abdominal examinations should be done frequently to detect early signs of developing peritonitis should perforation occur. Virtually all symptomatic patients will require observation and esophagoscopy. If a nonfood object becomes lodged in the esophagus or is unable to pass through the pylorus, it must be removed as soon as possible, using esophagogastroscopy. Fatal lead encephalopathy has been reported in a child who ingested a lead curtain weight, which supposedly had been in the stomach for an extended time.8

Types Of Online Sensors

Sensor selection will also be based on consideration of the location in the process a measurement is needed. On-line measurements can be made at varying points during a process as shown in Figure 1. To select the ideal sensor for a given use, therefore, one must consider the selectivity for the property to be measured, the process operating conditions including the potential for electromagnetic interference caused by the process, the temperature, and potential interfering chemical species. For example, specificity of optical sensing has been expanded using the electromagnetic spectrum from the visible light range, to near infrared, to far infrared. Also, new optical materials have been developed that reduce signal loss and extend the useful signal transmission range making on-line use very attractive. For example, the Fiber Optic Materials Research Program at Rutgers University has developed porous fiber optic materials which can be used in conjunction with specific chemically...

Intravenous Urography

While intravenous urography (IVU) was considered the gold standard of radiological workup for urinary li-thiasis, its utility has greatly diminished since the advent of unenhanced helical CT. It is superior to ultrasound in diagnosis but IVU requires an injection of contrast solution and leads to a low but not inconsiderable dose of radiation, especially during the first trimester. Different examination protocols have been proposed aiming to limit the radiation exposure as much as possible to three or four radiographs plain abdomen, 30 s, 20 min (McAleer and Loughlin 2004 Sto-thers and Lee 1992) plus or minus one late x-ray (Dore 2004) plain abdomen, 20 min, late x-ray (Klein 1984). It is important to use high-sensitivity films, reduce the aperture as much as possible, have large radiology rooms available, choose digital radiology, and use a lead apron for the side of the healthy kidney (Biyani and Joyce 2002a McAleer and Loughlin 2004). Given bony superposition and the voluminous...

Principles of measurement 521 Theory behind NIR measurement

Infra-red light is part of the broad spectrum of energy known as electromagnetic radiation. Figure 5.1 shows the relative wavelengths and energies in the electromagnetic spectrum that are used in spectroscopy. While X-rays are of extremely high energy, capable of promoting inner electron transitions in high atomic number elements, the infra-red region is of relatively low energy and upon interaction with molecules, causes inter-atomic vibrations. Near infra-red 1013 1014 Hz, which is of the same order as the natural mechanical vibrational frequencies of many chemical groups. (The wavelength A (m) of electromagnetic radiation is related to the frequency v (Hz) by c vA, where c 3 x 10s m s 1 is the velocity of light.) The water molecule is one of the best known examples of an NIR absorber and exhibits several distinct vibrational modes which relate to infrared absorption at well-defined wavelengths or frequencies. The frequency of oscillation of any mode is dependent upon the atomic...

TABLE 971 Imaging Modalities in Renal Colic

Selecting IVP or ultrasound for an individual patient requires some clinical judgment. Certainly patients with contraindications to radiation and the administration of contrast should have an ultrasound. The clinician will have to further weigh the importance of ascertaining functional information about the kidney as well as the increased likelihood of identifying the location of the stone versus the added time and radiation exposure necessary to complete an IVP. One approach would be to obtain ultrasound in all patients presenting with signs and symptoms of renal colic and only proceed to IVP if the patient is deemed to require surgical intervention or if the diagnosis remains unclear.

Sebaceous Gland Differentiaton

Sebaceous carcinoma arises from meibomian (51 ) and Zeis glands (10 ) of the eyelid. The tumor is not caused by ultraviolet (UV) radiation but certain HPVs and ionizing radiation are contributing factors. Chronic chalazion is also a predisposing factor due to inflammation and production of oleic acid. Sebaceous carcinoma may occur singly or in association with keratoacanthomas and internal (GI tract) malignancies as part of the Muir-Torre syndrome (199). Sebaceous carcinoma affects women more than men, usually in the sixth or seventh decade of life. It predominates in Asians. Approximately 25 of cases are extraocular, mostly from the parotid gland (20 ). A multicentric origin is reported in 12 of cases. Clinically, the lesions present as yellowish nodules of variable size. Histopathological examination shows lobules and cords of neoplastic cells with sebaceous differentiation. Cells have a foamy cytoplasm, nuclear pleomorphism, and mitotic figures. A pagetoid pattern is observed in...

Sarcomas of Vascular Tissue

Angiosarcoma (AS) is a malignant tumor that originates from vascular endothelium and accounts for 1-4 of soft tissue sarcomas. The only known predisposing factors are ionizing radiation and chronic lymphedema. It is classified into cutaneous (60 ) and deep angiosarcoma (40 ) but we will review the former only (216).

Nonthermal Processes Yielding Microbial Inactivation

Food irradiation has gained prominence worldwide as a nonthermal method. Irradiation refers to ionizing electromagnetic radiation that inactivates microorganisms by producing high-energy electrons within the food product. Irradiation has been approved for use in the United States on a number of food products (Table 6). Specifically, the

Steven A De Jong Introduction

Differentiated thyroid carcinoma (DTC) refers to both papillary and follicular carcinomas which arise from the thyroid follicular cell. Thyroid cancers associated with low-dose external radiation exposure to the head or neck are also included, as most of these malignancies are papillary carcinoma. DTC is uncommon but highly curable when compared to other epithelial carcinomas and is usually discovered during the evaluation of a thyroid nodule, cervical mass, and or cervical lymphad-enopathy. Controversy surrounds the extent of surgical treatment required, the indication for use of radioactive iodine and the use of thyroxine for TSH suppression. Important advances have recently been made in understanding the potential causes and tumor biology of DTC, improving methods for diagnosis, staging and management and predicting the clinical behavior and prognosis of individual tumors. Cost effective strategies for early diagnosis have been developed, and treatment and follow up are often...

Epidemiology and Classification

Thyroid carcinoma is classified by many subtypes (Table 6.1) and accounts for 1.5 of all cancers in the United States. The age-adjusted annual incidence for thyroid carcinoma in the U.S. is less than 40 cases per one million people and 12,000-15,000 new cases are diagnosed each year.1,2 While 4-5 of the population have thyroid nodules, only four of these nodules actually contain differentiated thyroid carcinoma. Several factors however, can increase this incidence. Patients, for example, who are exposed to low dose irradiation to the head or neck, commonly develop nodular thyroid disease and harbor thyroid carcinoma in 30-40 of these thyroid nodules. Ten percent of all differentiated thyroid carcinomas occur in children and adolescents as they are uniquely sensitive to radiation exposure as a major risk factor for thyroid carcinogenesis. These young patients generally have more aggressive tumors, higher rates of recurrence and are more likely to develop cervical lymph node metastasis...

Combining traditional and new preservation techniques to control pathogens the case of E coli

Recent research has focused on combining traditional inactivation, survival and growth-limiting factors at subinhibitory levels with emerging novel non-thermal intervention food preservation techniques using bacteriolytic enzymes (lysozyme), lactic cultures and culture products (e.g., bacteriocins), ionizing radiation, high hydrostatic pressure, or pulsed electric field (PEF). For example, the efficacy of high pressure is considerably enhanced when combined with heat, antimicrobials, or ionizing radiation. The effect of the combined intervention strategies is either additive, or synergistic in which the interaction leads to a combined effect of greater magnitude than the sum of the constraints applied individually.

Spectral or Fourier Analysis

The modern methods of time series analysis are often used to simplify complicated waveforms such as EEG. Many industrial applications involve such methods as electric circuits, signal processing (television, radar, astronomy, etc.), and voice recognition. Most time series analyses are based on spectral (or Fourier) methods. Computers extract the amplitudes Anm and phases fnm associated with each data channel (m) and frequency (n) from the often complicated EEG, represented by Eq. (1). The computer unwraps the waveform Vm(t) to reveal its individual components. Such spectral analysis is analogous to the physical process performed naturally by atmospheric water vapor to separate light into its component colors. Each color is composed of electromagnetic waves within a narrow frequency band, forming rainbows.

Environmental Factors in the Etiology of Human Cancer Physical and Biological Agents

At our present state of knowledge, evidence argues that the majority of human neoplasms result from the chemical induction of neoplasia however, it is clear that radiation, both ionizing and ultraviolet, as well as infectious agents also contribute as primary factors in the development of a significant proportion of human neoplasia. Just as with chemical carcinogenesis, in the human the basis of our knowledge of the physical and infectious causation of human cancer derives from both epidemiological and experimental findings. However, unlike many chemical carcinogens whose carcinogenic activity in the human is based either entirely on experimental findings e.g., 2-acetylaminofluorene, dimethylnitrosamine, and ethyleneimine (Chapter 13) or solely on epidemiological findings e.g., organic arsenicals and ethanol (Chapter 11) , evidence for the ultraviolet and ionizing radiation-induced human neoplasia as well as a number of viruses as causative of human neoplasia is based solidly on both...

Physical Carcinogenesis In Humans

It is likely that radiogenic neoplasms have occurred in humans sporadically since the dawn of civilization but only in the 20th century, with the advent of our greater knowledge of the components of the electromagnetic spectrum and the existence of ionizing and ultraviolet radiation, have the cancer-inducing properties of these latter two agents been recognized. Although experiments in animals have shown us a great deal about the basic aspects of radiogenic neoplasia, epidemiological studies in humans have advanced our knowledge of radiogenic neoplasms to an almost equal or greater extent. The most unfortunate and at the same time the greatest single incidence of radiation-induced cancers in humans resulted from the atomic bomb explosions at Hiroshima and Nagasaki. Ionizing Radiation Exposure

Highpressure Processing

Consumers are shifting their food purchases from heat-processed to fresh-tasting, minimally processed foods since excessive heat treatment can reduce the perceived freshness of foods. Salads, fruits, vegetables, nuts, spices, oysters, and selected cheeses are traditionally consumed without heat treatment. However, the incidence of pathogenic microbes is increasing in minimally processed and in raw foods previously considered safe. Escherichia coli 0157 H7 has been found in fresh apple and orange juice. This has caused the U.S. Food and Drug Administration (FDA) to recommend pasteurization. High-pressure processing (HPP) is one alternative to heat to achieve the pasteurization or commercial sterility of many fresh and freshlike processed foods. An advantage of HPP is that the treatment does not break covalent bonds. As a result, HPP does not change the flavor, color, or nutrient content of the food. Heat and ionizing radiation break covalent bonds as a function of dose and thus have...

Practicalities Psychophysiological Laboratory in the Magnet Safety and Costs

In addition to the main, static magnetic field, there are strong varying electromagnetic fields from the gradient magnets (for generating images) and from the RF oscillator (for flipping the protons to obtain the NMR signal). Each of these fields has associated safety considerations. For the most part, this is a minor issue at 1.5 T. It can be more of an issue for some pulse sequences at higher fields. The manufacturers of MRI scanners are required to build in various safety measures to protect subjects (such as calculating the heating effects of the RF pulses for a person of a given

Strategies for treatment

In practical terms, this can be applied to breast conservation surgery versus mastectomy. The former is usually accompanied by ionizing radiation to the remaining breast tissue to avoid recurrence, as an alternative to removal of all breast tissue on the affected side. Because of the risk of contralateral breast cancer, bilateral mastectomies are performed in a number of cases. To the authors it is a logical mystery why ionizing radiation is considered to be an acceptable alternative to mastectomy for the remaining tissue in the diseased breast, while only surgical removal (and not ionizing radiation) is considered to minimize risk of tumour growth in the contralateral breast. We do need a debate on this subject. The balance between maximizing the prospects of cure, versus doing least possible harm, may be an individual question to be resolved by the patient. It is the common experience of counsellors, however, that patients do seek and actually follow advice. This is substantiated by...

Effectiveness of microbial inactivation

When exposed to intense electromagnetic energy in the form of high-intensity light, the viable microbial population on the surface of food products or food packaging materials is rapidly decreased. Inactivation of microorganisms may occur with as few as one pulse of 0.01 to 50 J cm2 with exposure times from 1 s to 0.1 s at the food. Dunn et al (1995) found that the lethality of high-intensity light increases with increasing light intensity and frequency of pulses.

Growing Interest In Food Irradiation

Ionizing energy is any form of energy whose individual quanta (discrete packets of energy) are energetic enough to create ions by ejecting electrons from the atoms within a material absorbing that energy. Such energy can be photonic (pure electromagnetic energy, with no physical particles involved) or particulate (real particles involved). Examples of the former type include y-rays, spontaneously given offby certain radioactive elements (like cobalt-60 or cesium-137) and X rays (produced by X-ray generating machines). Beams of high-energy electrons, generated by special machines called electron accelerators, constitute the most common form of particulate radiation. Any of these types of ionizing energy can be used for processing materials. However, to avoid potential induction of radioactivity in the treated material, electron energies must be kept below 10 MeV, while photons must not exceed 5 MeV.

Decreased Radiation Survival of Ras Transformed Cells After FTI277 Treatment

We have previously shown that H-Ras-transformed REF are significantly more radio-resistantthan REF and that REF immortalized by myc are not altered in radiation survival compared to the parental REF. Therefore, inhibition of H-Ras activity using a farne-sylation inhibitor might be expected to reduce radiation resistance in cells with onco-genic H-Ras. Cells were irradiated with the indicated doses of ionizing radiation and treated with FTI-277 for 24 h after irradiation (Fig. 9). The survival curves for 3.7 and 5R showed them to be more resistant to radiation than MR4 or REF, with MR4 being slightly more resistant than REF. After treatment with FTI-277, the radioresistance of3.7 and 5R were reduced to a level of survival similar to that seen in MR4, the myc immortalized REF or ofREF themselves. The shoulders ofthe survival curves were reduced as were the overall slopes. Exposure of the cell line MR4 or REF to FTI-277 had no effect on radiation survival. These results indicate that...

Sweat Gland Differentiation

Microcystic adnexal carcinoma (MAC) shows dual differentiation into sebaceous gland and sweat gland structures. There are no known causative factors, although in some cases there is history of ionizing radiation exposure. The incidence in men and women is approximately equal and the median age at presentation is 65 years (range, 11-82). MAC presents clinically as a nodule, plaque, or cyst that grows slowly over years (173). The lesion is markedly indurated and has surface telangiec-tasias. It rarely undergoes ulceration. The main clinical differential diagnosis is mor-pheaform BCC, SCC, dermatofibrosarcoma protuberans (DFSP), and other adnexal tumors. MAC metastasizes to lymph nodes only occasionally but may directly invade bone in advanced cases. On histological examination there is a desmoplastic stroma, nests and cords of basaloid cells with ductal structures, and keratin-filled cysts. MAC is a dermal tumor, the epidermis is rarely involved, and there is peri-neural involvement in...

The Sectional and Isotopic Imaging Modalities

Phrenicocolic Ligament

Ultrasonography has a sensitivity of almost 95 and a specificity approaching 100 if the study is not limited by bowel gas, obesity, and surgical wounds and band-ages.80-82 The absence of ionizing radiation makes it particularly safe in evaluating children and young women.

Colloidal Interactions

Intermolecular van der Waals interactions arise because of the attraction between molecules that have been electronically or orientationally polarized (Section 2.5). In addition to acting between individual molecules, van der Waals interactions also act between macroscopic bodies that contain large numbers of molecules, such as emulsion droplets (Hiemenz 1986). The van der Waals interactions between macroscopic bodies can be calculated using two different mathematical approaches (Hunter 1986, Derjaguin et al. 1987, Israelachvili 1992). In the microscopic approach, the van der Waals interaction between a pair of droplets is calculated by carrying out a pairwise summation of the interaction energies of all the molecules in one of the droplets with all of the molecules in the other droplet. Calculations made using this approach rely on a knowledge of the properties of the individual molecules, such as polarizabilities, dipole moments, and electronic energy levels. In the macroscopic...

Cell Transformation And The Natural History Of Neoplastic Development In Vitro

The definition of neoplasia noted in Chapter 2 was developed from observations of neoplastic disease in vivo. The criteria of transformation in cell culture listed in Table 14.1 did not define neoplastic disease in vitro but rather described a number of its characteristics. While neoplasia in vivo and cell transformation in vitro exhibit many apparent dissimilarities, considerable effort has been expended in trying to identify analogies in the natural history of the development of the neoplastic process in vivo and in vitro. We have already noted the changes spontaneously occurring in SHE cells transformed with chemical carcinogens or ionizing radiation (Table 14.2). However, a number of studies have been directed toward more controlled investigations of potential stages occurring during the development of cell transformation in vitro.

Phenolic Phytochemical Ingredients And Benefits

Phenolic phytochemicals are secondary metabolites synthesized by plants to protect themselves against biological and environmental stresses such as pathogen attack or high energy radiation exposure (1,2). These compounds involved in the plant defense response are one of the most abundant classes of phytochemicals and are also invariably important components of our diets (3,4,5). Commonly consumed fruits such as apples, bananas, grapes, and several types of berries and their beverages are examples of plant foods as sufficiently rich sources of phenolic phytochemicals. Similar phytochemicals in our diet are also obtained from diverse commonly consumed vegetables such as tomato, cabbage, and onions to grains such as cereals and millets as well as legumes such as soybean, common beans, mung beans, fava beans, and peas, depending on the specific regions of the world (4,5,6). In addition many different types of herbs and spices containing phenolic

Radiosensitization of 24kDa bFGF Expressing Cells by FTI277

We next determined the effect of FTase inhibition on radiation survival of HeLa 3A and HeLa PINA cell lines in clonogenic assays (Fig. 20). FTI-277 did not affect the sensitivity of HeLa PINA to radiation treatment. In contrast, the radioresistance of HeLa 3A was dramatically reduced in the presence of 20 pM FTI-277 prior to irradiation. Thus, FTI-277 increases the sensitivity of HeLa 3A but not HeLa PINA cells to ionizing radiation.

Internally Contaminated Patients

Internal contamination is medically significant because internally deposited radioactive material will continue to irradiate tissues until it decays to a stable isotope or is biologically eliminated. As with other types of radiation exposure, the dose received depends on the amount and energy of the radioactive material and the time exposed. Additionally, the route of intake into the body, the biochemical form, and the physical and biological half-life of the particular radionuclide affect the dose received from internal contamination. The biochemical nature of the radionuclide determines if it is disseminated throughout the body or concentrated in a specific

TABLE 1998 Commonly Treated Forms of Internal Contamination

The success of decorporation techniques depends on early administration. The risks associated with therapy must be weighed against the risk of untreated internal radiation exposure. Assistance from expert consultants should be requested prior to beginning decorporation therapy.

Chapter References

American Medical Association A Guide to the Hospital Management of Injuries Arising from Exposure to or Involving Ionizing Radiation, Chicago, IL, AMA, 1984. 15. Mettler FA Jr, Upton AC (eds) Radiation exposure in utero, in Mettler FA Jr, Upton AC (eds) Medical Effects of Ionizing Radiation, 2d ed. Philadelphia, PA, WB Saunders, 1995, pp 322-325. 16. US Nuclear Regulatory Commission Instructions Concerning Prenatal Radiation Exposure, Washington, DC, US Nuclear Regulatory Commission, 1987. US Nuclear Regulatory Guide 8.13, Rev. 2. 17. Brent RL Protocols Ionizing radiation. Contemp Obstet Gynecol 8 25, 1987.

Role of Nucleotide Analogs as Cytotoxic and Antiviral Drugs

Chemical and physical agents, including ionizing radiation and ultraviolet light. Proofreading activities guard against the incorporation of mismatched nucleotides during DNA replication or transcription. In contrast, the use of certain nucleotide analogs as drugs depends on their incorporation into DNA the chemical must be recognized and used by the replication enzymes but must prohibit further elongation of the nucleic acid chain. Analogs used in HIV therapy are incorporated by the reverse tran-scriptase of the virus and bring the reaction to a halt. Toxicity associated with several analogs is known to arise from erroneous incorporation into the patient's mitochondrial DNA because of less stringent proofreading by the mitochondrial DNA polymerase enzyme. Azidothymidine remains one of the most effective and least toxic drugs for AIDS, albeit it is now usually taken in triple therapy.

Solitary Thyroid Nodule

History and physical examination are invaluable in the management of the thyroid nodule. Nodules in the very young and very old (especially men) are more likely to be malignant. Exposure to ionizing radiation increases the incidence of both benign and malignant thyroid nodules and is a well-recognized risk factor for the development of thyroid carcinoma. A family history of thyroid malignancy, familial polyposis, or other endocrine disease also increases risk of cancer. Rapid nodule growth, pain, compressive symptoms, or hoarseness

Environmental Health in the United States

Third, in epidemiological studies a substance is tested by comparing the rate of disease in one population with that in another in an attempt to correlate differences between the two populations' rates of disease with differences in their rates of exposure. However, it is difficult to establish in that way a connection between a specific suspected toxin and illness or death because under normal conditions people are exposed constantly to many suspected toxins of various strengths for varying periods. It therefore is difficult to isolate the effect of any single substance. Also, the effect of exposure, if there is one, is often weak. In a small population, for example, few additional cancers can be expected to result from exposure to low-level radiation. In addition, the cancer effect is long delayed and spread out in the population over a forty-year period, making it difficult to detect at any specific time (Stewart). Finally, radiation exposure and cancer exist in the human...

Characteristics Of The Surface Membrane Of Normal And Transformed Cells In Vitro

In contrast, the parent cells from which the transformed cells were derived did not agglutinate when specific plant materials were added to the medium. The purified material responsible for the agglutination was found to be a glycoprotein with a molecular weight of approximately 18,000. This material reacted in a similar manner with a number of neoplastic cell types obtained from neoplasms growing in vivo as well as cells transformed in culture by chemicals, ionizing radiation, viruses, or spontaneously. In many instances, cells that had reverted

Safety And Exposure

MRI is widely regarded as a safe, innocuous imaging procedure that can be repeated at virtually any desirable interval. It is generally deemed as being safe for use with normal subjects within the context of research studies. MRI is accomplished without the use of ionizing radiation (X-rays). In addition to exposing the subject to a static magnetic field of considerable strength, the imaging process also requires that the subject be exposed to magnetic fields that oscillate at a frequency used in radio and television broadcasting and also to switched magnetic field gradients. No studies have demonstrated that MRI exposure has any adverse affects on health in the short or long term. Of course, failure to detect an effect does not necessarily

Computed tomography scan

The scan is usually performed without contrast and will detect a greater proportion of calculi than plain X-rays. It involves a similar radiation exposure as a standard IVU series and is considered to be the best investigation for detecting renal and ureteric stones.

Magnetic resonance scan

By employing a strong electromagnetic field, small magnetic changes can be stimulated in body tissues and the signal generated when the dipole is lost can be detected and measured. This non-invasive method of imaging is excellent at staging certain urological tumours, including prostate cancer. Lymph nodes can also be well demonstrated.

Mental Work and Brain Work

This was the first demonstration of a link between mental work and brain work in humans. However, the Xe-133 technique was too invasive to be used routinely in normal human subjects. The development of positron emission tomography (PET) paved the way for less invasive measurement of regional cerebral metabolism and blood flow. PET is an adaptation of autoradiographic techniques originally developed for measuring blood flow in animals. Regional cerebral glucose metabolism can be determined noninvasively using PET and radioactively labeled glucose (18-fluorodeoxyglucose), whereas regional cerebral blood flow may be assessed with PET and radioactively labeled oxygen (O-15) in water. PET was also more accurate than the older methods in localizing the specific cortical regions activated by cognitive task demands. Nevertheless, the spatial resolution of PET, particularly in individual subjects, had room for improvement. Furthermore, the need for ionizing radiation, although safe when used...

Introduction 11 Radiation on Earth

The surface of the Earth is largely spared from this cosmic radiation due to the deflecting effect of the Earth's magnetic field and the huge shield of 1000 g m2 provided by the atmosphere. The terrestrial average annual effective dose equivalent from cosmic rays amounts to 0.30 mSv (for definition of units, see Section 3.3 in this Chapter), which is about 100 times lower than that experienced in interplanetary space. Natural radiations from terrestrial radioactive elements and diagnostic medical exposures to radiation increase the total annual effective dose equivalent to about 2.4 mSv. In areas of high concentrations of natural radionuclides, such as Kerala in India, annual dose values up to 13 mSv are reached. The maximum allowed annual dose for radiation workers amounts to 20 mSv. Ordinarily, aggregate background and diagnostic medical levels of radiation as well as the limits for occupational radiation exposure pose little risk to human health. Under this clement level of...

Radiation in Low Earth Orbit

2 Bremsstrahlung (breaking radiation in German) is the electromagnetic radiation produced by the acceleration of a charged particle, such as an electron, when deflected by another charged particle, such as an atomic nucleus. The term is also used to refer to the process of producing the radiation.

Scope For Future Research

The past 20 years have seen a significant increase in our understanding of the chemical, physical and biological effects of ionizing radiation on food and methodology of irradiation detection, as well as remarkable advances in industrial irradation technology, design of food irradiation plants, dosimetry, and commercial applications. Today the use ionizing energy in the processing of various food items is approved. That the irradiation treatment is a major food preservation method of great potential is quite clear. However, major research efforts are needed to find the combinations of parameters required to maximize achievement of the desired objectives while minimizing unwanted side effects, e.g., softening of certain fresh fruits and vegetables, discoloration, off-flavors. Combinations of irradiation with heat treatment or with the addition of certain additives, e.g antioxidants, should be explored further.

The Science Of Poisons

Furthermore, we are mainly concerned here with environmental pollutants. The field of toxicology also deals with other toxins, such as pharmaceuticals, food additives, and those that occur naturally. Of particular interest are xenobiotics. Various forms of radiation, if capable of depositing enough energy to break chemical bonds, can also produce toxic effects. Radiation with sufficient energy is called ionizing radiation or just high-energy radiation. Examples include ultraviolet, x-ray, and gamma radiation from the electromagnetic spectrum, and high-energy particles such as alpha or beta radiation (helium nuclei and electrons, respectively) from radioactive decay.

Susceptibility to infection

Whole-body exposure to doses of radiation that are injurious to the hematopoietic system results in greatly increased susceptibility to infections, often leading to death. Susceptibility is increased not only to pathogenic microorganisms, but also to nonpathogenic normal flora of the gut and mucous membranes. Leukopenia, due to the stem cell killing, and the loss of physical integrity of mucous membranes, are the primary reasons for such opportunistic infections. Susceptibility to acute infections is most pronounced 3-4 days after radiation exposure, which correlates with the nadir in numbers of bone marrow and lymphoid cells. Increased permeability of biological barriers, such as skin, gastrointestinal tract and blood-tissue barrier, contribute greatly to disseminated infection. Radiation, however, may also alleviate symptoms of some viral infections (encephalitis in humans or choriomeningitis in mice) by destroying lymphocytes that contribute to the pathogenesis of the disease.

Radiologic Evaluation

The use of diagnostic radiologic imaging in the emergency treatment of pregnant trauma patients adheres to the fundamental principles of trauma management. While the judicious acquisition of studies is indicated to minimize fetal exposure to the potential effects of ionizing radiation ( IabJe 246-1), no tests should be withheld if necessary for appropriate maternal evaluation and treatment. The principal concerns regarding radiation exposure in utero are the possibilities of childhood neoplasia, fetal loss, congenital malformations, and microcephaly.13 Thus, studies should be limited to those needed, as radiation exposure sequelae are cumulative. The greatest risk to fetal viability is within the first 2 weeks following conception, and the highest potential for malformation is during embryonic organogenesis from 2 to 8 weeks after conception.13 Adverse fetal effects due to radiation exposure are negligible from doses of less than 10 rad. The standard trauma plain radiographs, such as...

Commercial inline instrumentation

The most widely used in-line techniques are based on spectroscopy. These use the absorbency, emission reflectance and fluorescent characteristics of the components being examined to defined parts of the electromagnetic spectrum, including UV, visible and infra-red and microwave. These systems are largely used for the identification and quantification of groups of chemical species (e.g., proteins, fats and ions) and measurement of particle size and molecular interaction of components.

Biological Radiation Monitoring

Complementary to physical dosimetry, biological dosimetry systems, i.e., which weight the different components of environmental radiation according to their biological efficacy, have been developed. Biological dosimetry systems are especially important when interactions of radiation with other parameters of spaceflight, especially microgravity, may occur. Basically two types of biological detecting or monitoring systems are available (a) the intrinsic biological dosimeters that record the individual radiation exposure (humans, plants, animals) in measurable units and (b) the extrinsic biological dosimeters indicators that record the accumulated dose in biological model system (summarized by Horneck 1998). b. Ability to give a record of the accumulated radiation exposure of individuals As described above, exposure of G0 lymphocytes to ionizing radiation leads to chromosome type aberrations such as polycentric and ring chromosomes. The frequencies of these aberrations are correlated...

Radiation Protection Considerations

On Earth, the radiation exposure limits are defined by the International Committee on Radiation Protection (ICRP). These limits prevent detrimental non-stochastic (acute) effects and reduce the probability of stochastic (late) effects to levels deemed to be acceptable. The annual terrestrial exposure limit for the public, in excess to the natural radiation exposure, lies at 1 mSv. The annual occupational limit is 20 mSv with a lifetime limit of 400 mSv. It is important to note that this level is an upper limit, according to a principle known as the ALARA (for As Low As Reasonably Achievable) Principle. The same guidelines are also used to set the limits of allowable radiation exposure during space missions.

Ipsi and contralateral breast cancer recurrences

Lumpectomy followed by radiation therapy, i.e. the conservative management of breast cancer, has been accepted as a standard of care for the majority of women with early breast cancer. Long-term follow-up data have consistently shown a risk of ipsilateral breast tumour recurrence (IBTR) of 0.5-2 per year (Recht et al., 1988 Fourquet et al., 1989 Kurtz et al., 1989 Fisher et al., 1991 Veronesi et al., 1995), but breast cancer survival was not significantly affected by IBTR when compared with patients undergoing a radical mastectomy (Haffty et al., 1991a Fisher et al., 1995 Jacobson et al., 1995 Veronesi et al., 1995 Winchester et al., 1997). Early age of onset is associated with an increased risk of IBTR (Schnitt et al., 1984 Haffty et al., 1991b de la Rochefordiere et al., 1993), but an association was not consistently found when the patient reported a positive family history of breast cancer (Chabner et al., 1998 Harrold et al., 1998). Young age at primary breast cancer diagnosis, a...

Negative consequences of not using a technology

One technology that is only 'emerging' because of its limited application in the market is that of irradiation. Treatment of foods with ionizing radiation has been researched for decades. A report by the World Health Organization concluded that food irradiated to any dose to achieve the intended technological objective is safe to consume and nutritionally adequate (WHO, 1999). However, consumers associate the process with the negative effects of radiation on humans resulting from atomic bombs and the fear of nuclear war and accidents at nuclear power facilities such as those at Chernobyl and Three Mile Island. Activists have viewed the process as a way to mask contamination, and they claim it destroys nutrients and creates harmful chemicals. Consumer misconceptions about the

Doseresponse Relationships

Toxicity is a relative measure of the ability of an agent to cause a harmful effect on a living organism. All substances have toxic properties. Even water is an irritant to the skin, and oxygen is toxic to humans at a high enough partial pressure and duration of exposure. On the other hand, some substances that are common industrial toxins are beneficial or even necessary to life at lower doses. This is particularly true with some of the metals, such as chromium or nickel. Even ionizing radiation can fit this category. Ultraviolet radiation from the sun converts 7-dehydrocholesterol in the skin into a form of vitamin D, a necessary nutrient. Figure 19.1 compares the type of response of necessary compounds with those that are not. Curve (a) represents the case in which the substance is a required nutrient curve (b) is the case for a substance that is not required. For case (a) there is a deficiency of the compound below the concentration C1, whereas it is toxic above C2. Concentration...

Pure Meaning Concept Of

In the early 1800s, the Czech-born German physiologist Jan Evangelista Purkinje (1787-1869) (also spelled Purkyne) described the change in color sensitivity as a visual stimulus moves from the center of the visual field to the periphery - where colors become gray at the periphery of the field and different colors change at different visual field locations. In 1825, Purkinje also reported that visual accommodation is caused by changes in the shape of the eye's lens. The Purkinje effect phenomenon shift refers to the manner in which colors emerge from darkness at dawn initially there is only black and gray (with red as the darkest), next the blues appear, and finally the reds appear. The Purkinje effect occurs when the illumination of objects is reduced, and the red and orange hues (at the long wavelength end of the electromagnetic spectrum) lose their perceived brightness faster than the green and blue hues (at the short wavelength end of the...

Calibration And Standardization

Calibration of the comet assay is based on the fact that ionizing radiation produces strand breaks in DNA with known efficiency. 16 By using the comet assay to measure the breaks introduced into cells irradiated with different doses of X-rays, a standard curve can be obtained (Fig. 2), allowing conversion of the comet assay parameters (percent DNA in tail or tail moment) in break frequency. With this approach, the sensitivity of the method has been evaluated as less than 0.5 breaks 109 Da of DNA, 17 similar to other established methods for DNA damage measurement.1-16-1 However, the comet assay saturates at lower levels of damage. A comparison between different methods for oxidative DNA damage detection was recently conducted by a European group to validate current protocols for the measurement of DNA oxida-tion. 18 This concerted effort showed that the values of

Regulation Of Pglycoprotein Expression

Most MDR1 transcripts arise from downstream promoter sequences located in the middle of exon 1,205 which lacks a TATA box. An inverted CCAAT box interacts with the trimeric transcription factor NF-Y and the Sp family transcription factors Sp1 and Sp3. In general, MDR1 transcription is up-regulated as part of a general cellular stress response to stimuli such as heat shock, exposure to anticancer drugs and carcinogens, serum deprivation, inflammation, hypoxia, and ionizing radiation. The activation of several signaling pathways, including the protein kinase C and mitogen-activated protein kinase cascades, an increase in intracellular Ca2+, and induction of NFkB, can up-regulate MDR1 expression.204 Chemical modification of chromatin may affect gene expression, and the MDR1 promoter is regulated negatively by methylation. Posttranscriptional mechanisms also appear to play a role in regulating MDR1 expression, and the stability of MDR1 mRNA is increased in cells subjected to various...

Susceptibility and chemoprevention Molecular Pathways

P53 is a tumor suppressor protein that when activated acts as a transcription factor to induce expression of a host of genes involved in responses to DNA damage (triggered by ultraviolet light, ionizing radiation, or carcinogenic chemicals) (6,10). The central function of p53 is to induce cell cycle arrest and decide if DNA damage can be fixed (arrest followed by resumption of the cell cycle), or is irreparable (activation of the apoptotic pathway). p53 thus plays a critical role in preventing genotoxic initiation of precancerous lesions. Mutation of the p53 gene or loss of p53 responsivity is one of the most common events identified in human breast cancer (detected in 50 of cases), and loss of the p53 allele in mouse models predisposes them to cancer. In fact, transformation of normal ductal epithelium to DCIS typically progresses to the formation of a malignant, invasive cancer of the breast, and is frequently linked to mutation of p53 (2). p53 can be sensitized, i.e., made more...

Iatrogenic Vascular Injuries

Patients with iatrogenic operative injuries are strikingly different from those with penetrating, blunt, or catheter-related vascular trauma. Renal vessels are vulnerable during oncologic procedures. Factors that increase technical difficulty are previous operation, tumor recurrence, radiation exposure, and chronic inflammatory changes. Renal vein injuries during elective abdominal operations are a serious complication with significant morbidity. Most patients with operative venous injuries have partial lacerations that can be managed with relatively simple techniques, such as ve-norraphy and patch angioplasty with autologous vein of ePTFE graft if venorraphy is not possible because of significant vessel narrowing (Oderich et al. 2004).

Historical Perspective

Although transplantation experiments conducted in the 1950s established the ability of cells derived from bone marrow and spleen to reverse hematopoietic failure after radiation exposure, HSCs were studied mainly on a morphologic basis before the 1960s. A major breakthrough came in 1961, when Till and McCulloch published an article describing the spleen colony-forming assay. This marked the first attempt to describe and quantitate stem cell activity in vivo. Shortly after this, tissue culture systems were developed that allowed the assay of hematopoietic progenitor cells in vitro. These assays provided quantitative results because of their clonal nature, whereby single cells proliferate to form a colony of differentiating progeny. The mouse became the animal of choice for the early studies of HSCs, because of the ability to obtain bone marrow easily and inexpensively and to perform transplant

Imaging Criteria for Radiographic Assessment in Adults

Decisions about radiographic imaging in cases of suspected renal trauma are based on the clinical findings and the mechanism of injury. Since the majority of renal injuries are not significant and resolve without any intervention, many attempts have been made to identify patients who could be spared the discomfort, radiation exposure, possible allergic reaction, and expense of a radiographic evaluation (Miller and McAninch 1995).

General Uses And Limitations

As CT technology has advanced, the role of CT in the emergency department (ED) has also increased enormously. A CT scanner is in, or adjacent to, many EDs today in the United States, in recognition of its fundamental utility and to minimize necessity for patient transport. The only real disadvantages of CT are its relatively high cost and the use of ionizing radiation. Standard charges for conventional and spiral CT are the same. Head CT continues to be the primary imaging study for screening ED patients acutely, particularly for detection of acute hemorrhage, trauma, and cerebrovascular accident. Magnetic resonance imaging (MRI), however, may have an additional role when posterior fossa pathology or subtle parenchymal abnormalities are suspected. In general, CT is the imaging study of choice for the examination of the retroperitoneum and for many disorders of the abdomen and pelvis. At many institutions, spiral CT has become the primary imaging modality for detection of acute...

Testing Emulsifier Efficiency

Fluorescent materials adsorb electromagnetic radiation at one wavelength and emit it at a higher wavelength (Skoog et al. 1994). A conventional bright-field optical microscope can be modified to act as a fluorescence microscope by adding two filters (or other suitable wavelength selectors). One filter is placed before the light enters the sample and produces a monochromatic excitation beam. The other filter is placed after the light beam has passed through the sample and produces a monochromatic emission beam. A variety of fluorescent dyes (fluorophores) are available which bind to specific components within a food (e.g., proteins, fats, or carbohydrates) (Larison 1992). Fluorescence microscopes usually use an ultraviolet light source to illuminate the specimen (which is therefore invisible to the human eye), whereas the light emitted by the fluorescent components within a specimen is in the visible part of the electromagnetic spectrum, and so they appear as bright objects against a...

Visionsight Theories Of One of

Nomenon - named after the French astronomer and physicist Francois Arago (1786-1853), is the relative insensitivity to light of the very center of the visual field at very low levels of illumination . According to modern vision theory, the stimulus for the sensory modality of vision sight is electromagnetic radiation (light) between approximately 380 and 740 nanometers (nm, where 1 nm 1 billionth of a meter), and where the initial processing of visual information is the receptor system consisting of photosensitive cells (rods and cones) in the retina of the eye. Vision is the process of transforming (transducing) physical light energy into biological neural impulses that can then be interpreted by the brain. The electromagnetic radiation can vary in intensity (perceived as a difference in brightness level) and wavelength (perceived as a difference in hue or color). The quantum theory of vision maintains that light energy travels to the eye in the form of discrete or discontinuous...

Color Vision Theorieslaws

The concept of color is a psychological (subjective) experience or sensation that is associated with the presence of a physical light source and depends on three aspects of the actual physical energy intensity (brightness), wavelength (hue), and purity (saturation). Most humans see the shorter visible wavelengths of the electromagnetic radiation spectrum as bluish (about 480 nanometers, or nm) the medium wavelengths as greenish (about 510 nm)

Urinary Tract Infection UTI

The voiding cystogram is used to demonstrate vesicoureteral reflux, the most common abnormality found in the urinary tract of children, which is seen in approximately 35 percent of children with UTI. Children at risk for vesicoureteral reflux include those with a family history of reflux and Caucasians. Voiding cystography can be done by radiographic or radionuclide technique. The radionuclide voiding cystogram utilizing technetium pertechnetate has the advantage of less radiation exposure but the disadvantage of poor visualization of urethral and bladder abnormalities, which are more commonly seen in boys. The radionuclide voiding cystogram is the imaging modality of choice in girls and is useful for the follow-up of patients and for screening siblings. Boys should undergo radiographic cystography. However, the relationship between vesicoureteral reflux and pyelonephritis remains controversial, with as many as 50 percent of children estimated to have another route of infection....

Evidence of a Role for Growth Factors in Radiation Resistance

BFGF expression has been associated with advanced stage or poor prognosis in a number of solid tumors, including pancreatic and renal malignancies (54-56), and is frequently expressed by glioblastoma cells (57-60). bFGF has been shown in several studies to be a radioprotector agent both for hematopoietic tissues and endothelial cells. In vitro, exogenous bFGF has been implicated in protection of bovine endothelial cells (BAEC) from the lethal effects of ionizing radiation via an autocrine loop (61). This radioprotective effect is not owing to preferential repair of DNA breaks but rather to an inhibition ofinterphase apoptosis (16) involving protein kinase C (62). Langley et al. (63) reported that bFGF has a radioprotective effect in microvessels cells, and that either bFGF withdrawal or ionizing radiation induce apoptosis in confluent monolayers of capillary endothelial cells, and that radiation apoptosis was decreased but not abolished in the presence of bFGF. Studies in vivo have...

History of food irradiation

As noted in Table 18.1, the benefits of ionizing radiation have been known since 1905. In addition to its potential to irradiation can be used to eliminate pests such as the screw worm fly, which preys on cattle, the Mediterranean fruit fly, and the tsetse fly, by the release of sterile insects. Worries about nuclear weapons, combinedwithanantiprogressideology, began to hinder food irradiation research afterthe war. Althoughthere wasatthat time an adequate supply of gamma rays, the high-energy, short-wavelength rays given off by radionuclides, the antitechnology factionconvincedtheCongressto control the development of nuclear technology for treating foods. Successful lobbying by well-known public figures in the movie and entertainment circles convinced the Congress to keep food irradiation under tight control, i.e., treating ionizing radiation as a food additive. This part of the 1958 law, known as the Delaney Clause, assured that no irradiated food could be approved for consumption...

Induction of Radiation Resistance by the 24kDa Form of bFGF

Clonogenic Survival Curves

Radiation survival curves of HeLa, HeLa PINA, HeLa 3A, HeLa5A. Cells were exposed to various ionizing radiation doses and the radiosensitivity ofthe different cell lines calculated using the clonogenic survival assay. A semi-logarithmic plot of data from the different cell lines is shown. Radiation survival curves were obtained using the quadratic linear model. (A) ( ), HeLa and (O), HeLa PINA cells (B) (O), HeLa PINA and ( ), HeLa 3A (C) (O), HeLa PINA and ( ), HeLa 5A. Each bar represents the mean SDofthree different experiments for one selected clone of each transfected cell line. (SD representing less than 1 of variation do not appear on the graph). Fig. 18. Radiation survival curves of HeLa, HeLa PINA, HeLa 3A, HeLa5A. Cells were exposed to various ionizing radiation doses and the radiosensitivity ofthe different cell lines calculated using the clonogenic survival assay. A semi-logarithmic plot of data from the different cell lines is shown. Radiation survival curves...

Electrical Aversion in the Treatment of Alcoholism

Limited in number and methodological adequacy. A probable contributing factor was the report by Garcia and Koelling in 1966 that in animals aversions to tastes were much more easily established to malaise produced by ionizing radiation than to electrical shock, whereas the reverse was true for aversions to visual and auditory stimuli. In his 1977 review pointing out the lack of randomized controlled studies evaluating electrical aversion in treatment of alcoholism, Lovibond recommended that to develop aversive control of excessive drinking, illness and malaise may be a more appropriate stimulus than electric shock. However, Smith, Frawley, and Polissar in 1997 reported a slightly superior abstinence at 6 and 12 months in patients treated for alcoholism with electrical as compared to chemical aversion.

TABLE 2446 Criteria for a Positive DPL

Abdominal CT scanning has been recommended for management of hemodynamically stable children with potential intraabdominal injury. Advantages of CT scanning include its noninvasiveness and the ability to visualize the retroperitoneum. Disadvantages of CT scanning include time spent in radiology away from the trauma room, lower accuracy for hollow organ and pancreatic injury, and radiation exposure. Indications for obtaining a CT scan in children include abdominal tenderness,

Interactions Between Light and Matter

Light can be regarded as a form of electromagnetic radiation that travels in waves and that can be defined by electric and magnetic vectors that are at right angles both to each other and to the direction of propagation. The relationship between the frequency and wavelength (the distance between wave crests) of the radiation is then expressed by a simple equation However, only light that has a frequency between approx 0.4 X 1015 Hz and 0.75 X 1015 Hz (a Hz, or hertz, is one cycle per second) or, alternatively, that has a wavelength between approx 400 nm (near UV) and 700 nm (red) is visible to the human eye. Although for many purposes it is convenient to consider light as a continuous long wave, it really comprises discrete short wave trains, called photons, that can also be considered as particles that have electromagnetic energy, but no mass. The electric and magnetic vectors of the wave arise from the force field that surrounds a pair of charges, the oscillating electric dipole,...

Functional Phytochemicals from Cranberries Their Mechanism of Action and Strategies to Improve Functionality

Phenolic compounds or phenolic phytochemicals are secondary metabolites of plant origin which constitute one of the most abundant groups of natural compounds and form an important component of both human and animal diets (1,2,3). These phenolic metabolites function to protect the plant against biological and environmental stresses and are therefore synthesized in response to pathogenic attack, such as fungal or bacterial infection, or high energy radiation exposure, such as prolonged UV exposure (4,5). Because of their important biological functions, phenolic phytochemicals are ubiquitous in plants and therefore find their place in almost all food groups. Common fruits such as apples, cranberries, grapes, raspberries, and strawberries, and fruit beverages like red wine and apple and orange juices, are rich sources of phenolic phytochemicals. In addition to fruits, vegetables such as cabbage and onion, and food grains such as sorghum, millet, barley, peas, and other legumes (6) are...

Methods of food preservation

(2000) have presented critical process parameters and data on microbial inactivation. Microwave and radio frequency heating uses electromagnetic waves of given frequencies to generate heat. Due to difficulties in achieving uniformity of heating, industrial preservation processes have not yet been consistently successful. Datta and Davidson (2000) have summarised microbial aspects of these rapid heating processes.

TABLE 1072 Chemotherapeutic Agents and Their Toxicities

Lastly, secondary malignancies may arise from radiation therapy. This results from the local nonmalignant tissue being exposed to ionizing radiation. The resulting damage to genetic material leads to mutation that is the presumed mechanism for carcinogenesis. The secondary malignancy is often observed years after the initial radiation therapy, and accuracy in predicting its occurrence is difficult at best.

Combining traditional and new preservation techniques

Termed 'thermosonication' (Hurst et al., 1995). An interesting combination of low pressure (0.3 MPa), mild heat treatment, and ultrasonic wave treatment is effective for destruction of microorganisms (Knorr, 1995). Also, irradiation can sensitize cells to subsequent heating. Since the principal target of ionizing radiation is DNA, vegetative cells treated first by ionizing radiation experience DNA damage, and then subsequent heat treatment damages enzymes necessary for DNA repair. Finally, the efficacy of the lethal effect of heat on microorganisms is increased if the bacteria are subsequently exposed to organic acids. This is a consequence of prior heating causing damage to the cell membrane, making it easier for weak acids to penetrate into the cytoplasm.

Technology And Science Preservation Processes

The basic strategy in eliminating microbial growth is to destroy the microbes outright or to render them incapable of replication. When thermal energy or ionizing radiation energy is absorbed, cell rupture occurs, cellular processes are disrupted, or the DNA is irreversibly damaged. Ther-moprocessing is very generally applied in stabilizing moist products for storage at ambient temperatures.

Pathology Pathogenesis and Carcinogenesis

The major risk factor for developing differentiated thyroid carcinoma is exposure to low-level external radiation. Enlargement of the thymus, scalp ringworm, recurrent tonsillitis, cervical adenopathy, facial acne and other head and neck disorders were commonly treated with 100-1500 cGy of external radiation from 1940 until the late 1960s. A dramatic increase in the diagnosis of differentiated thyroid carcinoma, predominately papillary carcinoma, resulted from these treatments and displayed an average latency period of 5 years from exposure to diagnosis. Young patients exposed between the ages of 5 and 15 seem to be at highest risk for developing radiation-associated thyroid carcinoma.6 This risk, which is increased after radiation exposure of as little as 10 cGy, is highest at 20 years after exposure and declines gradually thereafter. These same observations have been seen in Hiroshima and Nagasaki after the atomic bomb, in Nevada and in the Marshall Islands after atomic bomb testing...

Growth Factor Signaling

Numerous chemopreventative agents regulate TGF-b expression. Natural and synthetic retinoids will induce TGF-b 1 or 2 in a number of cell types (107-109). Retinoic acid and tamoxifen will increase the expression of latent TGF binding proteins (LTBPs) (110). Tamoxifen upregulates the expression of TGF-b 2 (111,112) and activates TGF-b 1 in MCF-7 cells (113-115). The upregulation of TGF-b family members may be responsible for controlling the proliferation in response to growth factors and hormones, and may play a role in regulating cell death in response to ionizing radiation. Death by ionizing radiation requires TGF-b in concert with p53. It is also known that TGF-b inhibits telom-erase activity (116).

Molecular Mechanisms In The Generation And Propagation Of Aberrant Dna Methylation Patterns In Prostate Cancer

One possibility is that targeting these genes for CGI hypermethylation provides a growth advantage for these cells early in prostate carcinogenesis. This hypothesis is indirectly supported by studies with GSTP1 overexpression in the LNCaP prostate cancer cell line. This cell line contains hypermethylated CGIs at all copies of GSTP1, and does not express this gene (55, 59, 93). When exposed to oxidizing stress from low dose ionizing radiation, LNCaP cells genetically modified to constitutively express GSTP1 exhibited significantly decreased amounts of oxidized DNA bases compared to unmodified LNCaPs and control transfectants (94). Presumably, GSTP1 scavenges the oxidant and electrophilic species before they can damage DNA. This would lead to an increase in glutathione-

Laboratory Evaluation

If the clinical examination and initial laboratory findings suggest intrahepatic cholestasis or extrahepatic biliary obstruction, ultrasound studies should be performed to look for gallstones, dilated extrahepatic biliary ducts, or masses in the liver, pancreas, or portal area. Computed tomography can also be used but is usually more costly, involves radiation exposure, and is less sensitive than is ultrasound at detecting stones in the gallbladder.

Effects on Particular Organs or Organ Systems

Ultraviolet light from the sun is a form of ionizing radiation that can cause skin cancer, or melanoma. The basal cells and melanocytes are vulnerable to UV. It is feared that the destruction of stratospheric ozone by substances such as chlorofluorocarbons will result in increased UV radiation at the ground level, leading to increased melanoma. Such an increase has already been observed in Australia, which has also experienced declines in stratospheric ozone. Physical agents Microwaves Ionizing radiation High temperatures

Sarcomas of Fibrous Tissue

Fibrosarcoma is a rare malignant tumor from deep tissues such as fascia or tendons. Well-established causative factors include ionizing radiation (204), chronic scars, and certain chromosomal aberrations. Fibrosarcoma affects all ages but is more common during the fourth to sixth decade of life. Tumors present clinically as subcutaneous masses with intact overlying skin. Ulceration indicates aggressive growth. Pain is present in 50 of cases. Approximately 50 of lesions occur on the lower extremity with marked predominance of the thigh (205). On histopathological examination, there are masses of spindle cells with variable differentiation, storiform pattern, and myxoid changes. IHC stains are positive for CD34 and vimentin, but not for epithelial, muscular, neural, melanocytic, or vascular markers (see below). Treatment is similar for all soft tissue sarcomas. Wide local excision with or without amputation is the usual approach. Adjuvant radiation therapy is indicated for aggressive or...

Water And Wastewater Disinfection Treatment

Wastewater Disinfection

Ionizing radiation using x-ray and gamma-ray beams with even higher energy levels than that of UV irradiation, can also be used in water, wastewater, and sludge disinfection. These ionizing mechanisms displace electrons during beam bombardment (i.e., at which point they are said to ionize), and in the presence of oxygen these displaced electrons elec-trochemically form a type of free radical (called hydroxyl radicals) that is highly toxic to microbial cells. Free radicals are highly reactive, having essentially no activation energy for their reaction. Given the acutely reactive nature of these radicals, they readily attack and destroy hydrogen bonds, double bonds, and ring structures essential to the metabolic utility of various cellular molecules. Yet another operative mechanism, and perhaps the key factor behind disinfection with ionizing irradiation, is that of a polymerizing impact (e.g., DNA thymine dimerization) whereby the biochemical effectiveness of complex molecules is...

Diagnostic Methods A Individual Processes 1 Structural Anatomy

Brain Bleed Scan

Arranged that it is coincident with the delivery of a bolus of iodinated contrast material into the cranial and cervical vessels from a peripheral vein. The resultant images are high-resolution depictions of the intracranial anatomy that can be reconstructed in three dimensions (Fig. 3A). Currently, limited information is available about the technique in terms of its clinical applications, but it is likely that there are circumstances in which it may be superior to conventional angiography. One of those is in the assessment of the local vascular anatomy of patients with aneurysms and arteriovenous malformations. In this case, conventional angiography, while high in spatial resolution, collapses the three-dimensional structure of such lesions into a two-dimensional projection. As such, the important relationship between aneurysm neck and a parent or daughter vessel may be difficult to ascertain or may require multiple intraarterial contrast injections and radiation exposure for the...

Summary And Conclusions

Since the first supposition of the existence of ionizing radiation originating from outer space at the beginning of the last century, a lot of work has been done in order to characterize the radiation field surrounding the Earth. A series of experiments has been initiated on the various components of cosmic radiation, their radiobiological importance, and the role of the other spaceflight factors in radiobiological processes. Using higher organisms including mammals, a few attempts were made to identify tissue damage along the passage of single HZE particles, such as microscopically visible injury in brain or eyes, or the light flash sensation. The latter one, correlated with orbital parameters, showed highest frequency during the passage of the South Atlantic Anomaly. To study potential interactions of ionizing radiation with microgravity, either additional irradiation was applied, pre-, in-, or postflight, or an onboard 1-g centrifuge is utilized in combination with methods of...

Development of a Telesurgical Robotic System

The Hopkins URobotics group has developed a system for image-guided percutaneous access 11 .This system was developed on the basis that a robot should be able to reduce tremor and position the needle exactly at the required location, thus increasing safety, speed, and accuracy, while reducing radiation exposure 12 . This new system was designed to mimic the standard percutaneous renal access technique, thus providing an easy-to-use, surgeon-friendly device. The system is based on an active and radiolucent needle driver, PAKY (percutaneous access to the kidney) 13 . PAKY utilizes an axial-loaded rotational-to-translational friction transmission principle to grasp, stabilize, and advance an 18-gauge access needle into the kidney percutaneously (Fig. 1).The trocar needle used for percutaneous procedures is secured by the needle driver along its barrel near the tip in order to minimize deflection or bowing of the unsupported length RCM-PAKY allows the needle tip to pivot about a fixed...

Teratogens and human malformations

Lists of human teratogens are dangerous, and have undoubtedly resulted in the deaths of many normal fetuses through needless therapeutic abortion. They are also notoriously contentious, and for good reasons. Should a list give what we know has happened, or what might happen Many chemicals probably would cause human malformation, given sufficient exposure. Should a list include only agents that cause structural defects What about miscarriage, functional effects, and so on Should a list include pharmacological effects, like the congenitally heroin-addicted baby, or neonatal meconium ileus after anticholinergics What evidence is required to place chemicals on the list Most importantly, what about dose Ionizing radiation and ethanol are undoubtedly human teratogens but all embryos are exposed to both from natural sources. Lest there be any doubt just because a pregnant woman has been exposed to a chemical listed as a human teratogen does not necessarily justify a termination of pregnancy,...