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psyc 314 - ch 14.docx

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Department
Psychology
Course Code
PSYC 314
Professor
Frances Chen

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Chapter 14 What is Cancer? • Extremely rapid cell growth & proliferation • Dysfunction in part of DNA that controls cell Growth and reproduction • Heterogeneous: more than 100 different types of Cancer Psychoneuroimmunology: - The interactions among behavioural, neuroendocrine, and immunological processes of adaptation. The Immune System: Surveillance system of the body Primary function of the immune system is to distinguish between what it “self” and what is foreign and then to attack and rid the body of foreign invaders Profile of the immune system: Natural immunity: involved in defense against a variety of pathogens. - Largest group of cells involved in natural immunity is granulocytes, include neutrophils and macrophages (both are phagocytic cells that engulf target pathogens) - Neutrophils and macrophages congregate at the site of an injury or infection and release toxic substances. - Macrophages release cytokines that lead to information and fever, among other side effects and promote wound healing. - Natural killer cells are also in natural immunity; they recognize non-self material (such as viral infections or cancer cells) and lyse (break up disintegrate) those cells by releasing toxic substances. - Natural killer cells are believed to be important in signaling potential malignancies and in limiting early phases of viral infections. Specific immunity: slower, more specific than natural immunity. - The lymphocytes involved in specific immunity have receptor sites on their cell surfaces that fit with one of antigen. - When they are activated, these antigen-specific cells divide and create a population of cells called the proliferative response. Natural and specific immunity work together, such that natural immunity contains an infection or wood rapidly and early on following invasion of a pathogen, whereas specific immunity involved a delay of up to several days before a full defense can be mounted Humoral and Cell-mediated immunity: - Specific immunity is of two types: - Humoral immunity is mediated by B-lymphocytes, which provide protection against bacteria, neutralize toxins produced by bacteria and prevent viral reinfection. - Cell mediated immunity, involving T lymphocytes from the thymus gland, operates at the cellular level. Cytotoxic (Tc) cells respond to specific antigens and kill by producing toxic substances that destroy virally infected cells. Helper T (Th) cells enhances the function of Tc cells, B cells and macrophages by producing lymphokines. Lymphokines also appear to service a counter regulatory immune function that suppresses immune Activity. Assessing Immunocompetence: General approaches of indicating immune functioning: - Measuring the numbers of different kids of cells in the immune system by looking at blood samples. - Assessing the functioning of immune cells. When indicators such as these suggest the immune system is working effectively, a state of immunocompetence is said to exist. When these indicators suggest that immune functioning may have been disrupted or reduced below a normal level, a state of immunocompromise is said to exist. Stress and Immune Functioning: Many commonplace stressors can adversely affect the immune system. Over 300 studies examine the relation of stress to immune functioning in humans. Different kids of stressor create different demands on the body therefore show different effects on the I.S. Human beings likely evolved so that in response to sudden stress changes in the immune system could take place quickly. Leading to wound repair and infection prevention. Different types of stressful events make different demands on the body that are reflected in different patterns of immune activity - Intense short term stressors recruit cells that may help defend against wounds and infection Sympathetic activation in response to stress has immediate effects of increasing immune activity, especially natural killer cell activity. Stress-related changes in hypothalamic adrenocortical functioning have immunosuppressive effects. Examples of Stress studies: Study that relates to immunological changes is an investigation of the impact of space flight on astronauts’ immune functioning: 11 astronauts flew 5 different space shuttle flights ranging from 4-16 days. Were studied before and after launching/landing. Space flight was associated with a significant increase in number of circulating white blood cells and natural killer cells decreased. At landing EPI and NOREPI increased substantially as did white blood cells. Effects were stronger for astronauts who had been in space approximately a week but in those who had experience long-term flight (~2 weeks) the effects were attenuated. Evidence: stress of space flight and landing produces a sympathetic nervous system response that mediates redistribution of circulating leukocytes but this response may be attenuated after longer missions. (Stress of landing = muted by relief of being home) Health Risks: Research suggests that children and adults under stress show increased vulnerability to infectious disease, including colds, flus, and herpes virus infections, (cold sores, genital lesions, chicken pox, mononucleosis) Among people who are already ill such as people with respiratory infection, stress predicts more sever illness and higher production of cytokinesis Disease that are influenced by proinflammatory cytokines are also potential health risks associated with stress related immune changes (CVD, arthritis, other major chronic illness) Autoimmune Disorders: Immune system attacks the body’s own tissues, falsely identifying them as invaders A.I. Diseases include more than 80 conditions and virtually every organ is potentially vulnerable. Examples. - Graves’ disease, (involving excessive production of thyroid hormone) - Chronic active hepatitis (involving the chronic inflammation of the liver) - Lupus *chronic inflammation of the connective tissue which can affect multiple organ systems) - Multiple sclerosis (destruction of the myelin sheath that surrounds nerves and which produces a range of neurological symptoms - Rheumatoid arthritis (immune system attacks and inflames the tissue lining the joints - Inflammatory bowel disease (IBD, Crohn’s disease or ulcerative colitis) – causes inflammation of the intestines; type 1 diabetes. Nearly 80% of people who have these and other autoimmune disorders are women Reason why women are so vulnerable might be hormonal changes relating to estrogen modulate the occurrence and severity of symptoms. Many women first develop symptoms in their 20s when estrogen levels are high Another theory: testosterone may help protect against A.I., disorders and women have a short supply of it. Theory: during pregnancy, mother and fetus exchange bodily cells, which can remain in the mother’s body for years. Although these cells are very similar to the others own, they’re not identical and the immune system may get confused and attack both the leftover fetal cells and the maternal cells that look similar Since A.I. disorders are related group of conditions, it’s likely that one can be suffering form one and then contracts another. Genetic factors are implicated in autoimmunity Negative Affect and Immune Functioning Stress increases negative emotions such as depression or anxiety Clinic review relating depression to immunity found depression to be associated with several alterations in cellular immunity – lowered proliferative response of lymphocytes to mitogens, lowered NK cell activity, and alterations in numbers of white blood cells. (Stronger among older people and sick) The more depressed a person is the more compromise of cellular immunity is like to occur Depressive symptoms can be associated with amplified and prolonged inflammatory responses Stress, Immune Functioning and Interpersonal Relationships Human and animal research suggests the importance of personal relationships to health Lonely people have poorer health and show more immunocompromse on certain indicators People with insecure attachments to others show lower NK cell cytotoxicity, which may pose potential health risks Marital Disruption and Conflict Study results: women who had been separated one year or less had poorer functioning on some immune parameters than did their matched married counterparts Women separated or divorced that still continue attachments to their ex-husbands show poorer immune functioning, depression and loneliness (results for men were similar) Partner violence tied to adverse changes in immune functioning Short term marital conflict can have a neg. effect on the immune system Even in long term marriages people are not protected against adverse immunological effects of marital conflict Adverse effects of marital problems and conflict appear to fall more heavily on women than men Positive behaviour during marital conflicts lead to steeper declines in stress hormones with associated beneficial effects on immunity Caregiver Studies have found the stress of caregiving has adverse effects on wound repair, defects in NK cell function and reactions to flu vaccine Experience emotional distress (i.e. Anger or depression) is at a risk for adverse effects on the I.S. One can cope with effects and mitigate the distress Severe and long-term stressors, such as those that result from caregiving (especially in the elderly) may leave caregivers vulnerable to a range of health-related problems. Effects can continue even after caregiving activity has ceased Protective Effects of Social Support Perceived social support predicted greater NK cell activity Individuals with higher levels of social support had greater NK cell activity in tumor- infiltrating lymphocytes Individuals with small social networks and who experience loneliness show poor antibody response to influenza vaccination Coping and coping resources as moderators of the stress-immune functioning relationship These resources may moderate the relation between stress and immune functioning: Optimism: many studies show links between optimism and enhanced immune functioning Self-Efficacy/Personal Control: less immunocompromise under stress. Changes can come about in 3 ways: - Perceived self-efficacy may reduce the experience of stress itself - May reduce the tendency to develop depression in response to stressful events - It may create some expectancy-based central nervous system modulation of immunological reactivity. When people are exposed to controllable or uncontrollable stressors (noise) those who perceive that they can control it show little change in immune parameters. Those exposed to uncontrollable stressors are more likely to show adverse effects. Interventions to Enhance Immunocompetence - Emotional disclosure appears to enhance health and mood in individuals who have suffered a traumatic event - Written emotional disclosure on wound healing as stress is known to impair the progress of wound healing Relaxation: may mute the effects of stress on the I.S. - Shows consistent benefits - Massages decrease cortisol levels, increase leukocyte circulation What is AIDS? History of AIDS: We don’t know when acquired immune deficiency syndrome (AIDS) first appeared Began in Central Africa (maybe early 1970s) Spread rapidly throughout Zaire, Uganda, central African nations, mainly because origins were not understood High rate of extramarital sex, little condom use, high rate of gonorrhea also facilitated the spread of the AIDS virus in the heterosexual population. Diseases made its way from Africa to Europe then Haiti and into the US Estimated 33 million people are living with HIV/AIDS worldwide (most are women, children and youth) 41% of new infections are among young adults and 60% of these are young women ~2/3 of these people live in sub-Saharan Africa; another 22% live in Asia and the pacific. 11 of every 1,000 adults ages 15-49 are infected with HIV. Over 60,000 Canadian residents have been diagnosed as HIV-positive since first care in 1982. 13,000 Canadians have died of AIDS 15,000 may be unaware of their infection Researchers predict 120 million deaths from AIDS by 2030. Unless major investigation to treatment takes place Epidemic is still in early stages and spreading to every part of the world AIDS is the 6 leading cause of death worldwide AIDS in Canada First reported case of IADS in Canada was in 1982. In 2000, over 16,000 people in Canada had AIDS and over 45,000 people were HIV positive By 2006, 20,000 people had AIDS and 60,000 were HIV positive The viral agent is a retrovirus, the human immunodeficiency virus (HIV), and it attacks the helper T cells and macrophages of the immune system The virus appears to be transmitted exclusively by the exchange of cell containing bodily fluids, especially semen and blood Period between contracting virus and developing symptoms is highly variable. From a few months to a few years. Therefore person may test HIV-seropositive but be free of AIDS and during the asymptomatic period, pass on the virus to others How is HIV transmitted? Among drug users, needle sharing leads to the exchange of bodily fluids thereby spreading the virus Homosexual men, exchange of virus is tied to sexual practices (especially anal- receptive sex, involving the exchange of semen without a condom) Heterosexual population, vaginal intercourse is associated with transmission (women more at risk than men) How HIV infection progresses Following transmission, the virus grows rapidly within first few weeks of infection and spreads throughout the body Early symptoms: swollen glands, fluid-like symptoms predominating After three to 6 weeks: infection may abate, leading to a long asymptomatic period, during which viral growth is slow and controlled Amount of virus typically rises gradually, eventually severely compromising the immune system by killing the helper T cells and producing a vulnerability to opportunistic infections that leads to the diagnosis of AIDS Early disease process: being to show abnormalities in their neuroendocrine and cardiovascular responses to stress Antiretroviral Therapy - Highly active antiretroviral therapy (HAART) is a combo of antiretroviral medications that has dramatically improved the health of HIV individuals - So successful that in some cases HIV can’t be seen in the bloodstream - Must take drugs faithfully, often several times a day or else they don’t work - In addiction, depression, a common condition among people with HIV is well known to predict non-adherence and further threaten adherence with HAART regimen Researcher in Ottawa made intervention program to increase psychological readiness for taking HAART: - Readiness for change and coping strategies for dealing with barriers to adherence were explored to maximize adherence success - Socioeconomic factors, such as housing status Who gets AIDS? Two major at –risk groups for early Canadian epidemics = homosexual men and intravenous drug users. These groups still have largest numbers but other aboriginal people and other minorities are increasingly at risk In all populations adolescents and young adults are the most at risk because they’re the most sexually active group, having more sex with different partners than any other age group ~Half of all new infections reported worldwide occur within that age group Evidence that individuals who have multiple risk factors are at increase risk for IDS Canadian aboriginal women, a history of physical abuse or childhood sexual abuse, and having one or both partners who went to residential schools was associated with having AIDS Women working in the sex trade now represent a common source of the spread of infection Surveys show that the availability of antiretroviral therapeutic agents have relived psychological distress I the gay community Optimism regarding IDADS may have indirectly fuelled an increase in risk-related behaviour because of the new treatments relieve worries about unsafe sex Psychosocial impact of HIV infection Depression is common with diagnosis of HIV most likely to occur among those who have little social support who engage in avoidant coping and have more sever symptoms Over longer term people cope with AIDS fairly well Majority of people diagnosed with AIDS appear to make positive changes in their health behaviors immediately after diagnosis: Diet, More exercise, Quitting or reducing smoking, Reducing or eliminating drug use Interventions that reduce depression are potentially valuable in the fight against IADS because depression exacerbates many immune-related disorders Disclosure: - Not disclosing HIV status or lying about risk factors (egg. Number of partners one has had) is a major barrier to controlling spread of HIV - Less likely to disclose HIV serosatus to sex partners also more likely to use cocain
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