Describe the application of hyperfractionation OR accelerated fractionation in the clinical setting and discuss the rationale behind the fractionation schedule you have selected - Use a case scenario to illustrate your answer.
Chapter VI - Radiobiology . 800 words (+-10%), in essay format, double-spaced, typed with a 1 1/2" margin. Quote references if applicable. Describe the application of hyperfractionation OR accelerated fractionation in the clinical setting and discuss the rationale behind the fractionation schedule you have selected. Use a case scenario to illustrate your answer. The case scenario can be that of breast cancer or other cancer sites. I have had little exposure to hyperfractionation in the clinical setting at the NWORCC during my 18 years practicing as a Radiation Therapist. Experience with this unconventional fractionation scheme is through a limited number of patients in the clinical trial setting with advanced unresectable disease of head and neck, non-small cell lung or brain cancers. Through my research, hyperfractionation studies have been preformed all over the world on the following disease sites: cervix, head and neck, lung, esophagus, paranasal sinus & nasopharynx, ovarian, bladder, pancreas, thyroid and breast. One conclusion that can be drawn from my literature review is that many trials feature more than one strategy in fractionation schemes ?1,3,6,7,8?. Another word that has been used to describe hyperfractionation is superfractionation1. For the purposes of this essay, hyperfractionated radiation therapy is defined as radiation therapy given in a
This essay sets out to discuss the physiological consequences of chronic stress on the body, with particular attention to the impact that it has on the Nervous, Endocrine, Cardiovascular and Immune systems.
With the prevalence of chronic stress affecting individuals worldwide, the subject of stress and its relation to illness has fuelled an abundance of research. The main essence of chronic stress is the body’s psychological and physiological response to coping with and adjusting to real or perceived threats which are excessive or unrelenting. Such stressors can be defined as emotional, physical, social and environmental demands brought on by fear, intensive exercise, illness, negative relationships or poor living conditions (UMMC, 2011). This essay sets out to discuss the physiological consequences of chronic stress on the body, with particular attention to the impact that it has on the Nervous, Endocrine, Cardiovascular and Immune systems. The human body is naturally equipped with a built in mechanism which provides a biochemical reaction that adapts and responds to stress, and this is referred to as the ‘Fight or Flight Response’ (Harari & Legge, 2001: 75). The two main controllers of the stress response are the Sympathetic Nervous System (SNS) and the Hypothalamic-Pituitary-Adrenal (HPA) Axis. In responding to biochemical and environmental demands, both these systems work together in tandem via a feedback loop and are responsible for ensuring timely control and activation of physiological responses and maintenance of homeostasis throughout the body (Tortora &
The Relationship Between Protein Misfolding and Human Diseases
THE RELATIONSHIP BETWEEN PROTEIN MISFOLDING AND HUMAN DISEASES DEFINITION AND SCOPE OF PROTEIN MISFOLDING: Folding and unfolding of proteins are crucial factors which determine the biological activity and targeting to various cellular locations (Vendruscolo et al., 2003). Synthesis of various proteins is initiated by ribosomes through the cellular information contained in the DNA. Formation of proteins begins by synthesis of amino acids and the process in which the amino acids transform is described as protein folding (Hardesty and Kramer, 2001). Protein folding depends upon multiple contributing and intrinsic properties of amino acids and forms the basis of many cellular functions. One of the most common mechanisms which are prevalent in many diseases is the aggregation of misfolded proteins escaping the quality control measures of the cell (Vendruscolo et al., 2003). The relative thermodynamic and kinetic properties are responsible for the interconversion of folding and misfolding states. These conversions are highly regulated by proteolytic enzymes, molecular chaperones and environment and the failure of the regulation is main cause for protein misfolding and diseases associated with it (Dobson, 2004). Figure 1: Depiction of Amyloid fibril with a representation of its highly misfolded structure (Adapted from Dobson, 2004) In relation to protein misfolding and the
'Diseases are cultural constructs.' Discuss with reference to Mesopotamia.
'Diseases are cultural constructs.' Discuss with reference to Mesopotamia. A discussion about disease invariably turns into discourse about health, which is generally defined in terms of the 'scientific' theories of contemporary cultures. Hence, notions about 'health' and 'disease' tend to be cultural constructs, dependent on the collective attitudes of a certain society within a certain period of history. As cultures evolve over time, influenced by political, economic and social factors, ideas about 'health' and 'disease' also change. The existing ideas themselves influence ideas about 'the body', and vice versa; both of which have an influence on the way disease is treated. Galenic notions of disease, for example, regard an imbalance of bodily 'humours' as the origin of illness. Treatment of such illness requires a restoration of the balance. In contrast, Mesopotamians attributed illness (or any misfortune, in fact) to the wrath of a god; in this case, rituals would be performed to appease the said god, or solicit the assistance of a personal god. In this essay, I intend to explore the Mesopotamian notions of 'disease', how they changed, and their influences with respect to social and cultural factors. It is a common notion that 'disease' is a condition that is deviant from the social and cultural norm of 'health'; in effect, health and illness are seen as mutually
CD4+ Cell Development, Function & Dysregulation in Allergy and Autoimmune Diseases
CD4+ Cell Development, Function & Dysregulation in Allergy and Autoimmune Diseases The helper T (TH) cells in the body are central to all branches of the immune system. They are very aggressive cells, due to their role as 'molecular guardians of the body' and so they must be regulated and controlled. If this regulation or self-tolerance breaks down, then this provides a window for the development of allergy, being a "disease following a response by the immune system to an otherwise innocuous antigen" [12], or autoimmunity, where the body's immune system targets self antigens. Before an understanding of the role of different CD4+ cells in immunopathology can be achieved, an appreciation of the different characteristics and interactions of these cells must first be considered. After preparation of antigen onto a major histocompatibility complex-II (MHC-II), an antigen presenting cell (APC), typically a dendritic cell (DC) or macrophage, will present this to a naive TH cell. Depending on what type of pathogen has been encountered, the APC will stimulate the polarisation of the naive cell to one subset of TH cells. This is achieved by the release of specific cytokines from the APC to the TH cell, and the subsets of CD4+ cells are each defined by their unique surface receptors, the cytokines they release and by the types of invaders they target. The first subset to be
Pushing Your Body Too Hard.
Pushing Your Body Too Hard A major source of stress is overdriving. If you are working 16 hours a day, you will have reduced your available time for rest. Sooner or later, the energy drain on your system will cause the body to fall behind in its repair work. There will not be enough time or energy for the body to fix broken cells, or replace used up brain neurotransmitters. Changes will occur in your body's internal environment. You will "hit the wall" or "run out of gas". If you continue, permanent damage may be done. The body's fight to stay healthy in the face of the increased energy that you are expending is major stress. Environment Very hot or very cold climates can be stressful. Very high altitude may be a stress. Toxins or poisons are a stress. Each of these factors threatens to cause changes in your body's internal environment. The Special Case of Tobacco Use * Tobacco is a powerful toxin!! Smoking destroys cells that clean your trachea, bronchi, and lungs. Smoking causes emphysema and chronic bronchitis, which progress to slow suffocation. The carbon monoxide from cigarette smoking causes chronic carbon monoxide poisoning. Tobacco use damages the arteries in your body, causing insufficient blood supply to the brain, heart, and vital organs. Cigarette smoking increases the risk of cancer 50 fold. * Chewing tobacco or snuff is no safe haven. It also damages your
Gas Phase Atmospheric Chemistry.
Assessed Exercise, Gas Phase Atmospheric Chemistry. Vicky Thornber. Unlike stratospheric ozone, which is necessary for life on earth, tropospheric ozone has been found to have many negative consequences. It has detrimental effects on both human health (causes respiratory problems) and on the growth of crops and vegetation. Tropospheric ozone is often called "bad" ozone because it can damage living tissue and break down certain materials. Ozone affects plants in several ways. High concentrations of ozone cause plants to close their stomata, which slows down photosynthesis and plant growth. Ozone may also enter the plants through the stomata and directly damage internal cells. Rubber, textile dyes, fibres, and certain paints may be weakened or damaged by exposure to ozone. Some elastic materials can become brittle and crack, while paints and fabric dyes may fade more quickly. When ozone pollution reaches high levels, pollution alerts are issued urging people with respiratory problems to take extra precautions or to remain indoors. Smog can damage respiratory tissues through inhalation. Ozone has been linked to tissue decay, the promotion of scar tissue formation, and cell damage by oxidation. It can impair an athlete's performance, create more frequent attacks for individuals with asthma, cause eye irritation, chest pain, coughing, nausea, headaches and chest congestion and
Stress and Bodily response
Psychology Individual tasks Stress and Bodily response . Outline the different ways of defining stress Stress - Stress can be defined in three ways ) A response or a reaction to something 2) A stimulus or stressor 3) A lack of fit between demands of the environment and the ability to cope with those demands. Response There are two main ways in which our body responds to stress. This happens in the adrenal glands near our kidneys. The glands send different sets of hormones into the bloodstream. Hans Selye identified these hormones affecting stress and he wondered why they should be activated under these conditions. Stimulus/Stressor A stimulus is something that has stimulated the brain to react to anything in the environment that produces the stress-response, or anything involved with working conditions. 2. Describe how Hans Selye discovered General Adaptation Syndrome General Adaptation Syndrome is a model about how the body reacts during stressful situations. Selye did a lot of experimental studies on stress and response. He said that 'any physical or psychological stressor activated the two pathways'. (The two pathways being those of the two adrenal glands - hypothalamic-pituitary-adrenal cortex pathway and the hypothalamic-autonomic nervous system-adrenal medulla pathway). He made a model to show this, which explained the short-term effects of exposure to
Thermal Regulation and acclimatization.
THERMOREGULATION AND ACCLIMATIZATION Adapted from: Haymes EM, Wells CL. Environment and Human Performance. Champaign, IL: Human Kinetics; 1986. Reference List available upon request. Thermal Regulation in the Human Organism Ecology is the branch of biology that deals with the relations between living organisms and their environments. Today, it is widely recognized that an organism is at the center of an ecosystem. As such, it is influenced by a multitude of physical and biological environmental factors. It is the essence of living things to be part of an ecosystem and yet to be capable of resisting, to some extent, the impact of the environment (Prosser, 1964). Organisms progress in complexity from a clump of cells that must closely conform to the conditions of their environment to more highly organized accumulations of soft tissues and organs that are capable of independent action. No organism's internal composition is exactly similar to its environment. Regulating organisms are capable of maintaining a relatively constant internal condition (homeostasis) despite widely fluctuating environmental conditions. The internal conditions of conforming organisms, on the other hand, are more closely restricted to the conditions of the surrounding environment. The human is an excellent example of a regulating organism that is able to maintain a relatively constant internal
Case Study A: The Case Of The Worried Tax Inspector.
Case Study A: The Case Of The Worried Tax Inspector ) From the primary diagnosis Albert was diagnosed with pulmonary embolism. A pulmonary embolism is a sudden blockage in a lung artery, usually due to a blood clot that travelled to the lung from the leg. A clot that forms in one part of the body and travels to another part of the body is called an embolus. Our diagnosis of Albert is deep vein thrombosis (DVT). A more complicated condition of deep vein thrombosis is pulmonary embolism. In DVT blood clots form in the deep veins of the body, most often in the legs. These clots can break free and travel to the lung and block an artery. 2) Prolonged bed rest isn't a good idea after surgery, as skeletal muscle contraction is needed for venous return of blood to the heart. Slowing or stopping of blood flow in a vessel is associated with an increased risk of thrombosis. Roddie and Wallis, 1975 stated that there is an 'increased chance of the accumulation of a large thrombus when there is no swift blood flow to sweep away the beginnings of such thrombus'. ( pg.386) 3) In order to prevent thromboemboli in a person undergoing extensive bed rest they must do gentle exercise as soon as they feel able. The sooner they move around the less chance there is of the blood flow slowing down and an accumulation of a thrombus. Albert must reduce or even stop smoking, reduce his alcohol