What is chelation therapy? |

Overview

When medical researchers first investigated the phenomenon known as hardening
of the arteries (closely related to atherosclerosis), they discovered that
the damaged, brittle vessels found in people with heart disease
were lined with calcium deposits. This finding inspired the notion that calcium
deposits were the cause of the problem.

Some early researchers investigated the possible therapeutic effect of removing such deposits. However, subsequent research indicated that the calcium deposits of atherosclerosis were a symptom rather than a cause, and mainstream interest turned elsewhere. Certain physicians nonetheless maintained an interest in removing calcium; thus, chelation therapy was born.

Chelation therapy for heart disease consists of intravenous infusions of a chemical called ethylenediaminetetraacetic acid (EDTA). This synthetic substance is used in conventional medicine to remove heavy metals, such as lead, from the body, but it also has an effect on calcium, which is why it came into use in chelation therapy.

Proponents claim that EDTA chelation is an effective alternative to heart
surgery and that it also offers many other health benefits. To support these
claims, proponents cite numerous anecdotes of cures apparently brought about by
its use. However, anecdotes cannot possibly prove a treatment effective. Only
double-blind,
placebo-controlled trials can do so, and such studies have
failed to find chelation therapy effective.

In 2000, a highly respected researcher reviewed the literature on chelation therapy and concluded that
The most striking finding is the almost total lack of convincing evidence for efficacy. . . . Only 2 controlled clinical trials were located. They provide no evidence that chelation therapy is efficacious beyond a powerful placebo effect. . . . Given the potential of chelation therapy to cause severe adverse effects, this treatment should now be considered obsolete.

Subsequent to this review, a well-designed study compared chelation therapy to placebo in eighty-four people with coronary artery disease. People receiving EDTA chelation showed improvement; however, those receiving placebo also improved, and did so to the same extent. This finding is a reminder of why double-blind, placebo-controlled studies are necessary to establish the effectiveness of a treatment. If researchers had performed this study without a placebo group, they might have concluded that EDTA chelation really works. Instead, the fact that the same level of benefits was seen in the fake-treatment group indicates that chelation therapy does not work.

Another double-blind study evaluated the potential benefits of chelation therapy when added to conventional therapy in the treatment of people with coronary artery disease. Researchers were looking for improvements in the ability of a blood vessel in the arm (the brachial artery) to dilate, but they did not find any. However, this study had several limitations in its design, making its results less meaningful than they might have been.

Safety Issues

EDTA chelation not only appears to be ineffective; it also may present some safety risks. This treatment is generally given in a series of ten to thirty sessions. If the practitioner fails to take proper precautions, severe adverse consequences, such as kidney damage, may result. While it appears to be the case that properly performed chelation therapy is unlikely to cause harm, there is no justification for using such an invasive method in the absence of evidence that it will help.

Anderson, T. J., et al. “Effect of Chelation Therapy on Endothelial Function in Patients with Coronary Artery Disease.” Journal of the American College of Cardiology 41 (2003): 420-425.

Ernst, E. “Chelation Therapy for Coronary Heart Disease: An Overview of All Clinical Investigations.” American Heart Journal 140 (2000): 4-5.

Knudtson, M. L., et al. “Chelation Therapy for Ischemic Heart Disease.” Journal of the American Medical Association 287 (2002): 481-486.

What is the relationship between HIV/AIDS and substance abuse?

Causes

HIV causes AIDS. The virus enters immune cells, especially CD4 T-helper cells. Dormancy in those cells is possible, and activation of the virus to the replicative stage leads to the destruction of those immune cells. AIDS results when the infected person’s T-helper cell count is reduced to the extent that frequent opportunistic infections occur.

Risk Factors

Drug abuse makes addicts vulnerable to infection. The sharing of needles and cocaine straws, for example, exposes users to each other’s body fluids. Also, intravenous drug abusers inject substances with immunosuppressive effects.

Immunologic defenses also are compromised by the simultaneous abuse of alcohol and tobacco and by personal neglect. The addict also may have impaired functioning of phagocytosis, reduced superoxide production, and reduced T-cell function, making the immune system ineffective at neutralizing the virus.

Also a risk factor for HIV infection is engaging in unprotected sex. Anal and vaginal penetration that causes injury can make a person vulnerable to HIV infection.

Symptoms

The symptoms of HIV infection can be limited to the presence of anti-HIV antibodies. After the reduction of T-helper cell count, otherwise rare cancers, such as Kaposi’s sarcoma, may result. Numerous bacteria, viruses, and fungi cause infection when the immune system is compromised by a reduced count of T-helper cells.

Screening and Diagnosis

Four rapid HIV tests are available. Each has received marketing approval by the US Food and Drug Administration. These tests are OraQuick Advance Rapid HIV-1/2 Antibody Test, manufactured by OraSure Technologies; Reveal G2 Rapid HIV-1 Antibody Test by MedMira; Uni-Gold Recombigen HIV Test, made by Trinity BioTech; and Multispot HIV-1/HIV-2 Rapid Test by Bio-Rad Laboratories. Each of these tests is an HIV enzyme immunoassay (EIA), and each is considered a screening test. Also, each test mandates additional confirmatory tests if the results are positive.

The basis of these tests is the ability to detect anti-HIV antibodies in body fluids. Antibodies are products of the immune system that are produced in response to exposure to a virus and its component proteins. Antigens, or proteins, from the virus are embedded in or affixed to a filter. Because antibodies generated after exposure to HIV bind specifically to the viral proteins, antibodies in a person’s body fluids will bind to the filter exactly where the protein in the test kit was placed. To determine if antibodies from the sample are present on the filter, a second antibody from the test kit is added.

The secondary antibody specifically binds to the person’s antibodies. When an exposed person takes the test, the secondary antibody binds and creates a complex. The complex is created only when the person has anti-HIV antibodies in his or her fluids.

Detection of the complex on the filter paper is possible because the secondary antibodies in the test kit come with an enzyme linked to them. This enzyme catalyzes a reaction that results in a color change. The color is detected by visual inspection of the filter paper. Because these kits detect the presence of antibody in the person’s fluids and not the virus, a positive result requires additional testing.

The polymerase chain reaction works by detecting the genetic material unique to the HIV virus. This assay works by adding the necessary components for the replication of genetic material to the sample. If HIV genetic material is present, it will be multiplied to generate quantities that can be detected by a color-forming reaction not unlike the EIA tests.

Treatment and Therapy

Highly active antiretroviral therapy (HAART) is the recommended treatment for HIV. HAART is administered as a combination of three or more anti-HIV medications from a minimum of two different classes. Nucleoside reverse transcriptase inhibitors comprise one class of anti-HIV drug. These drugs inhibit the HIV enzyme reverse transcriptase by means of blockage with a nucleoside. Non-nucleoside reverse transcriptase inhibitors inhibit the same viral enzyme through means other than the addition of nucleosides. Protease inhibitors block another key enzyme from the virus.

Three additional classes of anti-HIV drugs block functions critical to the infection process. They are entry inhibitors, fusion inhibitors, and integrase inhibitors. Because each class of medications blocks the virus in a different way, the combination of several medications increases the chances of preventing viral replication and decreases the chance that the virus will survive long enough to mutate into a resistant form. Some of the drugs are available as a combination pill of two or more different anti-HIV medications from one or more classes.

Prevention

Prevention of HIV infection and the development of AIDS in the drug abuser centers on behavior modification. Because HIV is a blood-borne pathogen, one should not share needles. The virus also can be transmitted through sharing cocaine straws among users with damaged nasal mucosa.

Sexual activity also can expose participants to body fluids and, thus, the virus. The use of condoms is recommended. The close association of drug abuse and prostitution makes prevention difficult. Despite numerous vaccination strategies tested for the prevention of AIDS or reduction of replication of the HIV virus, no effective vaccine has been found as of 2015.

Bibliography

Levine, Donald P., and Jack D. Sobel, eds. Infections in Intravenous Drug Abusers. New York: Oxford UP, 1999. Print.

Ruiz, Pedro, Eric C. Strain, and John G. Langrod. “HIV Infections and AIDS.” The Substance Abuse Handbook. Philadelphia: Wolters, 2007. Print.

Tortora, Gerard J., Berdell R. Funke, and Christine L. Case. Microbiology: An Introduction. 11th ed. New York: Pearson, 2012. Print.

What are support groups for cancer?

The need for support: At critical points in the course of cancer, such as designation of high-risk status, diagnosis, initiation or cessation of treatment, and recurrence, patients face challenges that can be overwhelming. They may find that their usual ways of coping are ineffective and find it difficult to talk to family and friends. Commonly, patients want to protect their family and friends from their pain or are reluctant to admit how scared they feel.

Support groups can help patients feel less isolated, improve their coping skills, and afford the opportunity to express concerns to others who share similar problems. The group format provides multiple perspectives on many issues; thus, participants can acquire new information, learn new skills, and observe, firsthand, better ways to manage problems that they would not have thought of on their own.

Cancer support groups can also assist with managing practical aspects of cancer, such as providing patients with knowledge of innovative ways to manage treatment effects or tips about returning to work after treatment. In the United States, the National Cancer Institute lists over one hundred cancer-related patient support and advocacy groups, and many have been instrumental in providing assistance to people affected by cancer.

Goals of groups: General goals of cancer support groups include the following:

• Provision of support among homogeneous groups affected by cancer





• Improvement of morale and self-esteem





• Enhancement of coping skills, personal control, and problem-solving abilities





• Reduction of emotional distress





• Provision of education regarding cancer and treatment-specific issues





• Clarification of medical information that may be missed in other settings because of anxiety





• Clarification of misconceptions and misinformation regarding cancer and its treatment





• Normalizing emotional reactions that occur throughout the course of the patient’s cancer

Attainment of group goals is often enhanced by the disease-specific or role-specific membership of cancer support groups and the nonmedical environment in which they meet.

Types of groups and therapeutic approaches: Cancer support groups employ a variety of psychotherapeutic approaches. They vary widely in structure, focus, and activities. Some are time limited with specific content and goals, or teach a specific skill targeted to improving quality of life. In general the these types are called psycho-educational groups.

Other cancer groups may be ongoing, patient-centered, and focused on general expression of fears and concerns that may be too painful for patients to reveal to family and friends. These groups are called psychotherapy groups. Psychotherapy groups should be run by a professional with special training in both mental health and group intervention modalities relevant to patients with cancer.

Some cancer support groups include a combination of education, group interaction, support, and behavioral training. Behavioral training teaches new skills such as progressive muscle relaxation, meditation, or biofeedback, which can be effective in reducing stress and minimizing treatment side effects. The fact that behavioral skills are learned and self-administered is of benefit in improving symptom management, self-efficacy, and quality of life.

Cancer-specific versus general support groups: General psychotherapy groups tend to explore a range of life experiences, often promote confrontation among members in an effort to identify and eradicate maladaptive communication styles and relationship patterns, and may focus on past rather that current experiences to examine the origin of destructive relationship patterns. However, groups specifically for people with cancer typically maintain a focus on the cancer diagnosis, including its meaning and implications, and offer education and support specific to cancer-related topics. They are usually time limited and use a brief therapy, supportive, or crisis-intervention model. Normalizing emotional distress, providing realistic reassurance, bolstering strengths and positive coping skills, and gently suggesting behavioral alternatives to replace destructive methods of coping are essential components of the cancer support group’s process and goals. Cancer support groups offer participants a range of perspectives about cancer-specific topics within the context of guidance, protection, and boundaries provided by a knowledgeable leader. Confrontational communication, exploration of past trauma, and problems not directly relevant to current issues are usually not addressed. Obviously, the rationale for this approach is based on the goal of enhancing coping skills and keeping stress within manageable limits.

Group composition: Cancer support groups exist for a range of individuals affected by cancer. Usually membership is limited to individuals with similar characteristics and problems. For example, new genetic technologies have given rise to groups for those at risk but not yet diagnosed with cancer. These groups offer multiple perspectives and education about issues such as genetic testing, risks and benefits of testing, and various prevention and screening practices. Membership may be centered on characteristics including cancer site, point in the course of cancer, and relationship to patient (for example, parents with an affected child, children with an affected parent). The benefit of a homogeneous group is the focus on similar content and themes that are relevant to all participants; thus members are protected from painful experiences that do not pertain to them and could overwhelm and undermine rather that enhance their coping skills.

Groups for cancer caregivers: Family and friends may benefit from participating in a cancer support group, especially if they love, depend on, or take care of the affected person. Family members may need help in dealing with stresses such as family disruptions, financial worries, and changing roles.

To help meet these needs, some support groups are designed just for family members of cancer patients. There has been an increase in the number of groups designed for family cancer caregivers that combine education, support, and links to community services, although far more caregiver resources are needed. This rapidly growing need is based on changes in health care financing and delivery and resultant trends that have displaced a large burden of cancer care onto family members. Patients are discharged from hospitals while still needing some care; they often require highly technical, complex care that at one time was performed by professionals in a clinical setting.

For example, it has become common practice for a breast cancer patient to be discharged from the hospital on the day of a mastectomy. Drains are still in place, pain management and risk for infection are primary concerns, and the need for monitoring, direct care, functional assistance, and support is constant. Coupled with dramatic reductions in third-party reimbursement for home health services, the burden of this complex care falls to family and friends who typically are not equipped, from an educational or emotional standpoint, to manage it. Stress may be compounded among caregivers who work and depend on maintenance of their income, have others who depend on them such as children or other ill or elderly family members, have limited finances or people available to provide assistance and respite, are ill themselves, or are experiencing countless other issues.

Caregiver burden and the need for additional services promise to be critical well into the future. The practical and emotional needs of family caregivers and the far-reaching impact of these issues on the social and economic welfare of the United States and its citizens are immense. There are support groups specific to the needs of professional caregivers, although more resources are needed in this area. Professional caregiver support groups are valuable for countless reasons, not the least of which are validation of the stressful nature of the work and stress management in the service of maintaining professional morale and promoting and maintaining high-quality oncology care.

Research regarding efficacy: One of the most important predictors regarding the efficacy of any behavioral or group technique is whether the person receiving the treatment believes it will be helpful. That is a major limitation to studies examining efficacy of cancer support group treatments. Although several studies have demonstrated positive outcomes, from increased survival time to improved quality of life among support group members, subjects are largely self-selected, meaning that they participate in the support group because they start out with the belief that it will benefit them. The consensus among researchers is that cancer support groups enhance quality of life by providing information, reducing isolation and helplessness, and normalizing emotions. Studies have shown that participation in cancer support groups promotes positive coping; reduces symptoms such as tension, anxiety, fatigue, and confusion; and improves compliance with cancer treatment.

One of the most widely publicized studies regarding efficacy of cancer support group treatment was a 1989 clinical trial of women with metastatic breast cancer conducted by physician David Spiegel. Study findings suggested that women who participated in a cancer support group lived eighteen months longer than a control group of women who did not participate. The study was later criticized because average rather than median survival was the statistic used to compare group survival differences. Averages can be dramatically skewed in one direction or another by just one early death or long-term survivor in a particular group; therefore it was concluded that study findings were misleading. A subsequent clinical trial that followed a sample of women with breast cancer found no survival differences between support group participants and nonparticipants, and yet another study reported that patients with malignant
melanoma who had taken part in a psycho-educational cancer group lived longer than those who did not take part.

A 2005 review of four studies of women with breast cancer found no relationship between support group participation and survival other than that reported in Spiegel’s study. Limitations of studies that have examined the link between support group participation and survival include the self-selective nature of research samples and the group’s impact on treatment compliance, which directly impacted survival. One study at the Ontario Cancer Institute found that women with breast cancer who lacked support from their families and friends were helped the most by support groups; therefore there may be factors that predispose some patients to benefit from participation in support groups. Finally some data link cancer support group participation with negative consequences.

At this point, there is insufficient evidence to support the efficacy of cancer support group interventions. Nonetheless there is abundant anecdotal evidence to support the benefits of attending if participants believe the experience will help and are not unduly stressed by exposure to the feelings and problems of others, and their needs are met by the group’s content, goals, and activities.

Internet-based groups: Recent years have seen an explosion of Internet sites designed to provide information, support, and education for individuals affected by cancer. They usually involve interaction in real time among individuals who communicate via computer in chat rooms. Other sites are informational in nature. Questions can be posed and answers received at a future time, or individuals may be directed to a number of question-specific predetermined resources.

Internet-based groups vary widely in content, process, and quality. Some are led by moderators; others are not moderated or monitored at all. At present, there is scant empirical evidence supporting the efficacy of Internet-based cancer support. Even more problematic is that there are no quality control measures to ensure accuracy of information, nor are there procedures to screen or assist those who may be upset or otherwise harmed by content.

Tension between patient advocacy groups, clinicians, and groups devoted to freedom of information has prevented the limitation of the content of Internet sites or access to sites by specific vulnerable populations. Although many cancer-related sites provided by respected institutions and organizations such as the American Cancer Society and the National Cancer Institute are of excellent quality and aim to assist patients in every way, the Internet has provided a breeding ground for unscrupulous practices. Vulnerable patients especially those with progressive illness or those not faring well with conventional treatment can fall prey to false hope and financial as well as psychological exploitation, whether visiting an unmonitored support group or other website. The virtual explosion of technology, websites, unclear laws, and the ability of Internet sites to disappear and emerge overnight under new names makes their regulation difficult. Further, the technological expertise of unscrupulous website administrators often surpasses that of law enforcement, although that gap is closing. Therefore, the safety, accuracy, and ethics of Internet support groups and the validity of their informational content will remain a formidable challenge.

Amer. Cancer Soc. Cancer Support Groups: A Guide for Facilitators. Atlanta: ACS, 2013. Digital file.

Amer. Soc. of Clinical Oncology. "Support Groups." Cancer.net. ASCO, July 2014. Web. 13 Jan. 2015.

Breitbart, W. “Spirituality and Meaning in Supportive Care: Spirituality- and Meaning-Centered Group Psychotherapy Interventions in Advanced Cancer.” Journal of Supportive Care in Cancer 10.4 (2002): 272–280. Print.

Cunningham, A. J., et al. “A Randomized Controlled Trial of the Effects of Group Psychological Therapy on Survival in Women with Metastatic Breast Cancer.” Psycho-Oncology 7 (1998): 508–517. Print.

Edmonds, C. V., G. A. Lockwood, and A. J. Cunningham. “Psychological Response to Long-Term Group Therapy: A Randomized Trial with Metastatic Breast Cancer Patients.” Psycho-Oncology 8 (1999): 74–91. Print.

Fawzy, F. I., N. W. Fawzy, L. A. Arndt, and R. O. Pasnau. “Critical Review of Psychosocial Interventions in Cancer Care.” Archives of General Psychiatry 52 (1995): 100–113. Print.

Goodwin, Pamela J. “Support Groups in Advanced Breast Cancer.” Cancer 104.suppl. 11 (2005): 2596–2601. Print.

Goodwin, Pamela J. “Support Groups in Breast Cancer: When a Negative Result Is Positive.” Jour. of Clinical Oncology 22.21 (2004): 4244–4246. Print.

Natl. Cancer Inst. "Organizations That Offer Support Services." Supportorgs.cancer.gov. NCI/NIH, n.d. Web. 13 Jan. 2015.

Zabalegui, A., S. Sanchez, P. D. Sanchez, and C. Juando. “Nursing and Cancer Support Groups.” Jour. of Advanced Nursing 51.4 (2005): 369–381. Print.

Define industrial psychology and explain its nature, scope, development over time, and overall importance.

Industrial psychology (often expanded to "industrial and organizational psychology") is the application of psychological science to the behavior of human beings in workplaces and other complex institutions. Like most psychology, it overlaps with cognitive science and neuroscience; because it involves the behavior of institutions it also overlaps with sociology, economics, and political science.Industrial psychology emerged in the 20th century as a response to the Industrial Revolution; initially its goals were primarily focused on improving...

Industrial psychology (often expanded to "industrial and organizational psychology") is the application of psychological science to the behavior of human beings in workplaces and other complex institutions. Like most psychology, it overlaps with cognitive science and neuroscience; because it involves the behavior of institutions it also overlaps with sociology, economics, and political science.

Industrial psychology emerged in the 20th century as a response to the Industrial Revolution; initially its goals were primarily focused on improving worker efficiency and reducing turnover.

Over time, industrial psychology expanded to encompass a wider range of questions involved in work and organization, and found applications outside private sector business in government agencies, the military, and nonprofit organizations.

It is because of industrial psychology that we have concepts like "ergonomics", "human factors", "human capital", and "human resources". Industrial psychology has been used to promote both more efficient production and safer, more pleasant work environments. It has taught us that happier workers are usually more efficient workers, which makes improvements in workplace safety and comfort a win-win for both workers and employers.

What is the Minnesota model?

Background and Treatment Philosophy

The Minnesota model (MM) was established in 1948 as a new form of drug treatment. The first MM residential program, known as Pioneer House, was established in an old warehouse in Minnesota and was modeled after the principles of Alcoholics Anonymous (AA). The treatment centers Hazelden and Willmar State Hospital, both in Minnesota, adopted a similar model in 1949 and 1950, respectively. Collectively, these three programs constitute the origins of MM. Pioneer House is now the Hazelden Center for Youth and Families. MM was initially designed as a residential treatment program, although outpatient variants of the model exist today and the model itself is amenable to a variety of delivery settings.

The principles and philosophy of AA and the disease concept of addiction, a central element of AA, are essential parts of the MM treatment philosophy. The disease concept of addiction views addicts as having an incurable or chronic disease. Addicts are believed to be biologically different from nonaddicts. They are not blamed for their addiction, but they are considered responsible for facing their disease. The program emphasizes that addicts can change their beliefs, behaviors, and lifestyles and can become well, but only through complete abstinence from all chemical substances.

The typical residential stay ranges from three to six weeks, with a common twenty-eight-day program of inpatient treatment and lifelong aftercare, primarily through AA, to manage the disease. Aftercare may also include family counseling and extended care. The residential treatment program comprises many dimensions of care, including individual counseling, group therapy, family counseling, working the AA twelve-step program, attendance at AA or Narcotics Anonymous meetings, daily reflection and readings (usually of AA’s “big book”), and lectures.

MM-based programs are staffed by different professionals, a central feature of the model’s multiprofessional and comprehensive approach to treatment, and include nurses, clergy, professional social workers, psychologists, and counselors. Counselors are recovering addicts themselves and have trained through the residential program.

The client is treated as a whole person with professional attention devoted to the mind, body, and spirit, a focus sometimes referred to as the physical-psychological-spiritual model of treatment. Clients are treated with dignity by staff and other residents. Although there are no standard guidelines as to what a treatment center must do to officially claim the MM concept, the common elements discussed here make up a typical program of treatment. The Betty Ford Center and Hazelden are among the larger and more recognizable residential treatment programs based on MM today.

MM is similar to concept houses and therapeutic communities in their emphasis on mutual aid, the peer community, and treating the whole person. The heavy emphasis on AA philosophy—the belief in the disease model of addiction instead of the moral shortcomings of addicts—and shorter durations of residency are two of the primary differences between MM and other therapeutic communities. Some clients of MM may participate in a therapeutic community, or extended care, after completing a program of inpatient care.

Criticisms and Successes

Criticisms of MM often focus on aspects of the treatment philosophy instead of on the whole model itself. A common basis for criticism is found in the tenets of AA, such as the insistence on complete abstinence over controlled drinking; the emphasis on spirituality and a higher power, which may not resonate with all addicts; and the rigidness of the AA philosophy, resulting in an inflexible program. Addicts who do not wish to seek help from AA have few helpful exit strategies because of the intolerance of AA members to treatment alternatives.

Other criticisms are directed toward the disease concept of addiction, which some argue relieves the addict of too much responsibility for his or her addiction and which can reinforce self-indulgent behavior and undermine treatment. Despite criticisms, research suggests that the multiprofessional approach to treatment grounded in the principles of AA is a successful form of treatment for many addicts.

Although there are challenges in studying the success of treatment programs, and although many studies have methodological flaws, evidence shows that MM graduates do as well as, and possibly better than, graduates of other treatment programs. Completion of the program results in long-term abstinence for many addicts and shortens periods of repeated drug use for persons who may fail to maintain abstinence. There are documented improvements in the psychosocial well-being of graduates, improvements involving self-esteem, family relationships, and employment, and in overall physical health.

At the same time, Hazelden began incorporating the use of anti-addiction drugs, such as Suboxone, into its program in 2013. Professionals at the facility hoped that this move—which mainly targeted those suffering from opioid addictions—away from the program's foundation in abstinence would help patients having difficulty adhering to the MM.

Bibliography

Cook, Christopher. “The Minnesota Model in the Management of Drug and Alcohol Dependency: Miracle, Method, or Myth? Part I. The Philosophy and the Programme.” British Journal of Addiction 83 (1988): 625–34. Print.

Cook, Christopher. “The Minnesota Model in the Management of Drug and Alcohol Dependency: Miracle, Method, or Myth? Part II. Evidence and Conclusions.” British Journal of Addiction 83 (1988): 735–48. Print.

Spicer, Jerry. The Minnesota Model: The Evolution of the Multidisciplinary Approach to Addiction Recovery. Center City: Hazelden, 1993. Print.

Szalavitz, Maia. "Hazelden Introduces Antiaddiction Medications into Recovery for First Time." Time. Time, 5 Nov. 2012. Web. 29 Oct. 2015.

What is marshmallow as a dietary supplement?

Overview

The similarity in name between the herb marshmallow and the sweet treat is more
than a coincidence, although the modern sugar-puff ball no longer bears much
relationship to the old-fashioned candy flavored with marshmallow herb.

Besides inspiring makers of campfire food, the marshmallow has also been used
medicinally since the time of ancient Greece. Hippocrates
spoke of it as a treatment for bruises and blood loss, and subsequent Roman
physicians recommended marshmallow for toothaches, insect bites, chilblains, and
irritated skin. In medieval Europe, herbalists used marshmallow to soothe
toothaches, coughs, sore throats, chapped skin, indigestion, and diarrhea.

Therapeutic Dosages

Marshmallow can be made into a soothing tea by steeping roots overnight in water and diluting to taste. This tea can be drunk as desired for symptomatic relief. Alternatively, one can take marshmallow in capsules (5 to 6 grams daily) or in tincture according to label directions. Marshmallow ointments can be applied directly to soothe inflamed or irritated skin.

Therapeutic Uses

Marshmallow contains large sugar molecules called mucilage, which are thought to
exert a soothing effect on mucous membranes; this is the basis of most proposed
uses of the herb. However, only double-blind, placebo-controlled
studies can prove a treatment effective, and no such studies
of marshmallow have been reported.

On the basis of its supposed soothing properties, tea or lozenges containing
marshmallow tea are often recommended for asthma, cough, colds, and sore throat.
Marshmallow taken as tea or in capsules is sometimes recommended for
Crohn’s
disease or ulcers, on the theory that mucilage
might sooth the lining of the digestive tract. Finally, marshmallow ointment is
sometimes recommended for irritated skin.

Safety Issues

Marshmallow is believed to be entirely safe. It is approved for use in foods, and its chemical makeup does not suggest any but benign effects. However, detailed safety studies have not been performed. One study suggests that marshmallow can slightly lower blood sugar levels. For this reason, people with diabetes should use caution when taking marshmallow. Safety in young children, pregnant or nursing women, and those with severe liver or kidney disease has not been established.

Bibliography

“Althaea officinalis, Marshmallow.” In The Western Herbal Tradition, by Graeme Tobyn, Alison Denham, and Margaret Whitelegg. New York: Churchill Livingstone/Elsevier, 2011.

Tomoda, M., et al. “Hypoglycemic Activity of Twenty Plant Mucilages and Three Modified Products.” Planta Medica 53 (1987): 8-12.

What precautions are taken during blood transfusion?

Blood transfusions are an important part of emergency medical services and operative procedures, but it's not as simple as taking blood from one person and putting it into another. There are several different types of blood with certain antibodies which aren't always compatible with one another. What's more, many illnesses may be passed on through blood. To make sure that someone receiving a blood transfusion doesn't become sick from or have an allergic reaction to the blood, several things happen prior to the actual transfusion.

First, when a person donates blood, he or she must be clear of any blood-borne illnesses like Human Immunodeficiency Virus or Hepatitis. It's also helpful if someone can state their blood type when making a donation, although blood can be tested afterwards. Blood is packaged in sterile plastic bags and then clearly labeled. There are eight different types of blood based on antibody compositions — A, B, AB, and O, each of which may be either RhD positive or negative. Blood may go through additional screening for potential illness-causing agents or be separated for special-purpose transfusions of white or red blood cells, platelets, or plasma.

After any additional screening or separation, blood is sent to a hospital or doctor's office, where it remains in a refrigerated storage space to prevent cell degradation. When a patient needs a transfusion, medical staff always double check a person's blood type before administering an intravenous transfusion. Giving a patient the wrong type of blood can make them break out in a serious reaction as their body's immune system tries to fight off foreign antibodies. Some people can receive or donate any type of blood regardless of antibody composition. Type O+ blood is considered the "universal recipient" of blood products, while type O- is the "universal donor."

When it's time to give the transfusion, an intravenous catheter is inserted. The area is cleaned with an alcohol swab and a fresh, sterile needle is used to create the puncture. The catheter is then flushed with saline solution to make sure there is no tissue or blood cells blocking the portion inside of the patient's vein. Blood transfusions are typically co-administered with saline solution in a slow fashion to prevent any shock to the body. In emergency situations where someone has lost quite a lot of blood or has inadequate platelets, a transfusion might be done more quickly.

Perhaps the most important part of precautions for blood transfusions is the routine testing of blood for pathogens. This screening, performed by organizations like the Center for Disease Control, ensures a healthy and safe supply of blood is available for people who need it. 

What are natural treatments for hypertension?

Introduction

Most people cannot tell when their blood pressure is high, which is why
hypertension is called the “silent killer.” Elevated blood
pressure can lead to a greatly increased risk of heart attack, stroke, and many
other serious illnesses. Along with high cholesterol and smoking, hypertension is
a major cause of atherosclerosis. In turn, atherosclerosis causes heart
attacks, strokes, and other diseases of impaired circulation.

The mechanism by which high blood pressure produces atherosclerosis is somewhat similar to what happens in a hose fitted with a high-pressure nozzle. All such nozzles come with a warning label that states that pressure in the hose should be discharged after use. Many people, however, leave the hose with full pressure after using it. This rather common practice does not produce any immediate consequences. The hose does not develop leaks at the seams or burst outright on the first occasion it is left untended. However, a garden hose that is frequently left under pressure will begin to age more rapidly than it would otherwise. Its lining will begin to crack, its flexibility will diminish, and within a season or two the hose will develop and show leaks.

When human blood vessels are exposed to constant high pressure, a similar process is set in motion. Blood pressure that elevates to, for example, a reading of 220/170 (systolic pressure/diastolic pressure), which is quite common during certain physical activities such as weight lifting, do no harm. Only when excessive pressure is sustained do blood vessel linings begin to be injured and undergo the unhealthy changes known as atherosclerosis.

Although it is important to lower blood pressure, only rarely does it need to be lowered instantly. In most situations, a person has plenty of time to work on bringing down blood pressure. However, this does not mean that one should ignore it. Over time, high blood pressure can damage nearly every organ in the body.

The best way to determine one’s blood pressure is to take several readings at different times during the day and on different days of the week. Blood pressure readings will vary from moment to moment; what matters most is the average blood pressure. Thus, if many low readings balance out a few high readings, the net result may be satisfactory. However, it is essential not to ignore a high value that may have been caused by stress, for example. To record an accurate number, all measurements must be included in the calculations.

In most cases, the cause of hypertension is unknown. The kidneys play an important role in controlling blood pressure, and the level of squeezing tension in the blood vessels also makes a large contribution.

Lifestyle changes, such as quitting cigarettes, losing weight, and increasing exercise, can dramatically reduce blood pressure. One study found that engaging in aerobic exercise sixty to ninety minutes weekly may be sufficient for producing maximum benefits. Another study found that taking ten-minute brisk walks four times per day significantly improves blood pressure.

For many years doctors advised persons with hypertension to cut down on salt in the diet. Today, however, the value of this dietary change has undergone significant questioning. Considering how rapidly knowledge is evolving, it is suggested that one consult a physician to learn the latest recommendations.

If lifestyle changes fail to reduce blood pressure, or if one cannot make these alterations, many effective drugs are available. Sometimes experimentation with a few drugs helps in finding the most effective one.

Principal Proposed Natural Treatments

There are no herbs or supplements for hypertension with solid scientific support. However, the supplement coenzyme Q10 and extracts from the herb Stevia rebaudiana have shown some promise in preliminary trials.

Coenzyme Q
10. The supplement coenzyme Q10

(CoQ10) has shown promise as a treatment for high blood pressure,
but the evidence that it works is not strong. An eight-week, double-blind,
placebo-controlled study of fifty-nine men already taking medication for high
blood pressure found that 120 milligrams (mg) daily of CoQ10 reduced
blood pressure by about 9 percent compared with placebo. In addition, a
twelve-week, double-blind, placebo-controlled study of eighty-three people with
isolated systolic hypertension (a type of high blood pressure in which only the
“top” number is high) found that the use of CoQ10 at a dose of 60 mg
daily improved blood pressure measurements to a similar extent.

Also, in a twelve-week, double-blind, placebo-controlled trial of seventy-four people with diabetes, the use of CoQ10 at a dose of 100 mg twice daily significantly reduced blood pressure compared with placebo. Antihypertensive effects were also seen in earlier smaller trials, but most of them were not double-blind, so they mean little.

Stevia rebaudiana. The herb Stevia rebaudiana is best known as a sweetener. Its active ingredients are known as steviosides. In a one-year, double-blind, placebo-controlled study of 106 people in China with moderate hypertension (approximate blood pressure of 165/103), steviosides at a dose of 250 mg three times daily reduced blood pressure by approximately 10 percent. Full benefits took months to develop. However, this study is notable for finding no benefits in the placebo group. This is unusual and tends to cast doubt on the results.

Benefits also were reported in a two-year, double-blind, placebo-controlled study, also in China, of 174 people with milder hypertension (average initial blood pressure of approximately 150/95). This study used twice the dose of the previous study: 500 mg three times daily. A reduction in blood pressure of approximately 6 to 7 percent was seen in the treatment group compared with the placebo group, beginning within one week and enduring throughout the two years of the study. At the end of the study, 34 percent of those in the placebo group showed heart damage from high blood pressure (left ventricular hypertrophy), while only 11.5 percent of the stevioside group did, a difference that was statistically significant. No significant adverse effects were seen. However, once again, no benefits were seen in the placebo group. This is a red flag for problems in study design. Furthermore, a study by an independent set of researchers failed to replicate these findings.

Another study involving people with diabetes and healthy persons found that
stevia, at a dose of 250 mg three times daily, had no
significant effect on blood pressure after three months of treatment. A study by
an independent set of researchers failed to replicate these findings.

Relaxation therapies. Although it seems intuitive that relaxation
should lower blood pressure, the evidence for the benefits of relaxation
therapies for treating hypertension is far from convincing.
In a review of twenty-five studies investigating various relaxation therapies
(totaling 1,198 participants), researchers found that those studies employing a
control group reported no significant effect on lowering blood pressure compared
to sham (placebo) therapies.

More specifically, biofeedback is widely advocated for
treating hypertension. However, in an analysis of twenty-two studies, real
biofeedback when used alone was found to be no more effective than sham (fake)
biofeedback. A subsequent review of thirty-six trials with 1,660 participants
found inconsistent evidence for the effectiveness of biofeedback for treatment of
hypertension in comparison to drug therapy, sham biofeedback, no intervention, or
other relaxation techniques.

However, some studies have been supportive. A review of nine randomized trials
concluded that the regular use of Transcendental Meditation significantly
reduced both systolic and diastolic blood pressure compared to a control.
Similarly, an analysis of seventeen randomized controlled trials of various
relaxation therapies found that only Transcendental Meditation resulted in
significant reductions in blood pressure. Biofeedback, progressive muscle
relaxation, and stress management training produced no
such benefit. In addition, a trial of eighty-six persons with hypertension
suggested that daily, music-guided, slow breathing reduced systolic blood pressure
measured in a twenty-four-hour period.

Other Proposed Natural Treatments

The Iranian herb Achillea wilhelmsii was tested in a
double-blind trial of sixty men and women with mild hypertension. The results
showed that treatment with an A. wilhelmsii extract significantly
reduced blood pressure readings. Also, in a double-blind study of forty-three men
and women with hypertension, the use of a proprietary Ayurvedic herbal combination
containing Terminali arjuna and about forty other herbs proved
almost as effective for controlling blood pressure as the drug methyldopa.

Although the research record is mixed, it appears that fish oil may
reduce blood pressure, at least slightly. Fish oil contains two major active
ingredients, DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). Some
evidence suggests that it is the DHA in fish oil, not the EPA, that is responsible
for this benefit.

Several studies have found that glucomannan, a dietary fiber derived
from the tubers of Amorphophallus konjac, may improve high blood
pressure. Other forms of fiber also may be helpful.

Milk fermented by certain probiotics (friendly bacteria) may provide a small blood-pressure-lowering effect. Also, growing evidence supports the use of a green coffee bean extract for high blood pressure. Three preliminary double-blind studies found that chocolate (high in polyphenols) might help mild hypertension. A review including several additional studies drew a similar conclusion.

Numerous studies have found weak evidence that garlic lowers blood pressure slightly, perhaps 5 to 10 percent more than placebo. It remains unclear whether garlic supplements can help persons with high blood pressure safely eliminate or avoid antihypertensive medications.

People who are deficient in calcium may be at great risk of developing high blood pressure. Among people who already have hypertension, increased intake of calcium might slightly decrease blood pressure, according to some studies. In an extremely large, randomized, placebo-controlled trial involving 36,282 postmenopausal women, 1,000 mg of calcium plus 400 international units of vitamin D given daily did not significantly reduce blood pressure in seven years in women with or without hypertension. Weak evidence hints that the use of calcium by pregnant women might reduce the risk of hypertension in their children. Also, study results are mixed on whether magnesium or potassium supplements can improve blood pressure. At most, the benefit is likely quite small.

In a thirty-day, double-blind, placebo-controlled study of thirty-nine people
taking medications for hypertension, treatment with 500 mg of vitamin C
daily reduced blood pressure by about 10 percent. Smaller benefits were seen in
studies of people with normal blood pressure or borderline hypertension. One
double-blind study compared 500, 1,000, and 2,000 mg of vitamin C and found an
equivalent level of benefit in all three groups. (Because of the lack of a placebo
group, this study cannot be used as proof of effectiveness, only as a
demonstration of the equivalence of the doses.) However, other studies have failed
to find evidence of benefit with vitamin C. This mixed evidence suggests, on
balance, that if vitamin C does have any blood-pressure-lowering effect, it is at
most quite modest.

Unexpectedly, one study found that a combination of vitamin C (500 mg daily)
and grape seed oligomeric proanthocyanidins (1,000 mg daily) slightly increased
blood pressure. Whether this was a fluke of statistics or a real combined effect
remains unclear.

Other studies suggest possible benefit with the Ayurvedic herb Eclipta alba (also known as Bhringraja or Keshraja), beta-hydroxy-beta-methylbutyrate, theanine from black tea, blue-green algae products, chitosan, concord grape juice, garlic, gamma-aminobutyric acid, various forms of the herb hawthorn, kelp, lipoic acid combined with carnitine, quercetin, Salvia hispanica (a grain), and sweetie fruit (a hybrid between grapefruit and pummelo, high in citrus bioflavonoids). However, the supporting evidence cannot be considered reliable for any of these treatments.

There is mixed evidence on whether soy protein and its associated isoflavones are helpful for blood pressure. A comprehensive review of studies investigating the influence of phytoestrogens (including soy) on blood pressure found no meaningful effect. However, another review found that soy protein alone could significantly reduce blood pressure.

Three small, double-blind, placebo-controlled studies found evidence that melatonin may slightly reduce nighttime blood pressure. Getting adequate vitamin D may help prevent the development of hypertension. The vitamin folate may help decrease blood pressure (and might provide other heart-healthy effects) in smokers.

The herbs astragalus, barberry, Coleus forskohliibacailin, hibiscus, maitake, maca, and olive leaf, and the supplements beta-carotene, Cordyceps, flaxseed oil, royal jelly, and taurine, are sometimes recommended for high blood pressure, but there is no meaningful evidence that they work. Also, reducing homocysteine with B vitamins does not appear to reduce blood pressure in healthy people with high homocysteine.

One study was quoted as having showed that a traditional Chinese herbal formula
can reduce blood pressure, but the study actually failed to find any effect on
blood pressure. In a review of twenty-six published studies examining the
effectiveness of Tai Chi for high blood pressure, 85 percent demonstrated a
reduction in blood pressure. However, only five of these twenty-six studies were
of acceptable quality.

A substantial study (192 participants) failed to find acupuncture helpful for high blood pressure. However, another study, this one enrolling 160 people, did report benefit, but the study was small and had problems in its use of statistics. In a review of eleven randomized-controlled trials on the subject, researchers determined that acupuncture’s ability to lower blood pressure remains inconclusive.

The alternative therapies hatha yoga, qigong, and
Tai Chi have shown some potential benefit for high blood pressure, the mechanism
of action probably being similar for each. A later review of multiple studies
investigating the effectiveness of self-practiced qigong, for example, concluded
that this therapy was more effective at lowering blood pressure than no- treatment
controls. However, it was no more effective than standard treatments for
hypertension: antihypertensive medications or conventional exercise.

In a twelve-week study of 140 men and women with stage I hypertension, chiropractic spinal manipulation plus dietary change did not produce any greater benefit than dietary change alone. For many years, the American Heart Association and other major foundations have recommended reducing saturated fat and increasing carbohydrates in one’s diet. However, growing evidence suggests that it is preferable to keep carbohydrate levels relatively low while replacing saturated fat with monounsaturated fats such as olive oil.

Herbs and Supplements to Use Only with Caution

There is one highly credible case report of severe, dangerous hypertension caused by consumption of isoflavones made from soy during the course of a clinical trial on this supplement. This is most likely a rare, highly individual response, but if it could occur with one person, it also could occur with another.

As noted, in one study, a combination of vitamin C and grape seed oligomeric proanthocyanidins mildly increased blood pressure. In another study, the use of vitamin E raised blood pressure in people with type 2 diabetes.

The herb
Citrus aurantium
(bitter orange) may increase blood pressure. In addition, various herbs and supplements may interact adversely with drugs used to treat hypertension.

Bibliography

Anderson, J. W., C. Liu, and R. J. Kryscio. “Blood Pressure Response to Transcendental Meditation.” American Journal of Hypertension 21 (2008): 310–16. Print.

Erkkila, A. T., et al. “Effects of Fatty and Lean Fish Intake on Blood Pressure in Subjects with Coronary Heart Disease Using Multiple Medications.” European Journal of Nutrition 47 (2008): 319–28. Print.

Greenhalgh, J., R. Dickson, and Y. Dundar. “Biofeedback for Hypertension.” Journal of Hypertension 28 (2010): 644–52. Print.

Heather, O. D., et al. “Relaxation Therapies for the Management of Primary Hypertension in Adults.” Cochrane Database of Systematic Reviews (2008): CD004935. EBSCO DynaMed Systematic Literature Surveillance. Web. 27 Jan. 2016.

“High Blood Pressure.” MedlinePlus. US Natl. Lib. of Medicine, 6 Oct. 2015. Web. 27 Jan. 2016.

Hooper, L., et al. “Flavonoids, Flavonoid-Rich Foods, and Cardiovascular Risk.” American Journal of Clinical Nutrition 88 (2008): 38–50. Print.

Lee, H., et al. “Acupuncture for Lowering Blood Pressure.” American Journal of Hypertension 22 (2009): 122–28. Print.

Margolis, K. L., et al. “Effect of Calcium and Vitamin D Supplementation on Blood Pressure.” Hypertension 52 (2008): 847–55. Print.

Modesti, P. A., et al. “Psychological Predictors of the Antihypertensive Effects of Music-Guided Slow Breathing.” Journal of Hypertension 28 (2010): 1097-1103.

Ried, K., et al. “Effect of Garlic on Blood Pressure.” BMC Cardiovascular Disorders 9 (2008): 13. Print.

Rogers, P. J., et al. “Time for Tea: Mood, Blood Pressure, and Cognitive Performance Effects of Caffeine and Theanine Administered Alone and Together.” Psychopharmacology 195 (2008): 569–77. Print.

Wahabi, H. A., et al. “The Effectiveness of Hibiscus sabdariffa in the Treatment of Hypertension.” Phytomedicine 17 (2010): 83–86. Print.

In "The Frog And The Nightingale," what offer did the frog make and what was his real motive?

The frog presented himself as an expert in music and offered to coach the nightingale. The nightingale was too naïve to recognize the frog’s evil scheme. Before the nightingale arrived, the frog was the sole singer in Bingle Bog. However, his singing was horrible, and it only served to torment the rest of the animals. The nightingale’s first performance attracted and entertained all the animals in Bingle Bog. The animals showered her with praises after...

The frog presented himself as an expert in music and offered to coach the nightingale. The nightingale was too naïve to recognize the frog’s evil scheme. Before the nightingale arrived, the frog was the sole singer in Bingle Bog. However, his singing was horrible, and it only served to torment the rest of the animals. The nightingale’s first performance attracted and entertained all the animals in Bingle Bog. The animals showered her with praises after her performance. The spectacle infuriated the frog, making him jealous of the nightingale.

The frog offered to train the nightingale, but in reality, he just wanted to do away with the competition by wrecking the nightingale’s singing ability. The nightingale accepted the offer, and the frog maliciously carried out his plan. The frog made the nightingale sing every single night and day. He also made her train in spite of poor weather. The frog was relentless, and this took a toll on the nightingale. The situation led to the nightingale’s death from a ruptured vein after the frog forced her to sing in spite of her tired condition.

"Without Proper training such as I
- And few others can supply.
You'll remain a mere beginner.
But with me you'll be a winner"

How are Atticus and Scout presented in To Kill a Mockingbird?

Each of these characters is complex, just like individuals are in real life. As a result, the way they are represented is multi-faceted.

Scout is presented as innocent, rowdy, intelligent, insensitive to some things and overly sensitive to others, ignorant (meaning she literally does not know certain things due to her age), moral, precocious, and genuine. Because she is only six when the book begins, she has a lot of room for growth as the...

Each of these characters is complex, just like individuals are in real life. As a result, the way they are represented is multi-faceted.

Scout is presented as innocent, rowdy, intelligent, insensitive to some things and overly sensitive to others, ignorant (meaning she literally does not know certain things due to her age), moral, precocious, and genuine. Because she is only six when the book begins, she has a lot of room for growth as the story progresses. Her interactions with some people are different than others, so she is presented in different ways according to those interactions and circumstances. For example, she is a tomboy and her "rowdy" side is often seen in the chapters of the book where she is playing with Jem and Dill, or when she is getting into scraps with children at school or with her cousin Frances. 

Atticus is presented in an overwhelmingly positive light in the novel. He is literally considered one of best fictional characters in literature in terms of how "good" he is in nature. He is presented as being moral, fair, respectful, intelligent, thoughtful, wise (different than intelligent), careful, honest, genuine, caring, tolerant, and loving. Atticus plays a smaller role in the beginning of the novel because so much of it focuses on Scout, Jem, and Dill. However, once the Tom Robinson case comes into full play, we learn a lot more about Atticus. For example, each of the traits listed above can be seen as he defends Tom in front of a town eager to convict him. 

What are radiopharmaceuticals? |

The Fundamentals of Radioactivity

All matter consists of atoms, which contain a central nucleus and tiny particles called electrons that revolve around the nucleus. Electrons carry a small negative charge, while the nucleus is made up of particles called neutrons, which have no charge, and protons, which carry a positive charge. Atoms are generally neutral, with the number of protons in the nucleus equaling the number of electrons. Most objects are made up of atoms in which the neutron and proton numbers in their nuclei are arranged in such a way that they are stable. If the proton number or the neutron number in the nucleus is altered, the atom may become unstable. Such unstable atoms are termed radioactive and tend to reach a stable state by emitting radiation. This process is referred to as radioactive decay, and the elemental atoms that emit radiation are called radioisotopes or radionuclides. All stable elements can be made into radioactive elements by either adding or removing neutrons or protons, a process known as the artificial production of radioactivity. The few naturally occurring radioisotopes, such as radon 222 and uranium 235, are not used in nuclear medicine.

Radioactivity was first discovered by the French scientist Antoine-Henri Becquerel in 1896, when he observed that a photographic plate sitting next to a uranium sample had darkened. Appropriately, the international unit of radioactivity was chosen to be the becquerel. Radioactivity is a property of unstable atomic nuclei, and the rate of decay cannot be affected by normal physical and chemical processes such as heat, pressure, or the presence of magnetic or electric fields. The nuclei in a radioactive sample do not decay spontaneously or all at once. Rather, they decay randomly at a rate that is characteristic of the given radioisotope. While it is impossible to tell when a particular nucleus will decay or disintegrate, the fraction of nuclei in a sample that will decay in a given time can be determined. The decay rate of a radioactive sample is usually expressed in terms of its half-life, the time required for one-half of the original sample nuclei to decay. Half-life is a characteristic property of a particular radionuclide. The half-lives of radioactive isotopes vary from a small fraction of a second to millions of years. For example, carbon 14 has a half-life of 5,730 years, while the half-life of iodine 123 is thirteen hours. Naturally occurring uranium 238 decays with a half-life of 4.5 billion years, which is the approximate age of Earth itself. Hence, at present there remains only half of the original uranium 238 that was formed when the earth was born.

Radionuclides emit three types of radiation: alpha particles, beta particles, and gamma rays. Alpha particles are positively charged ions containing two protons and two neutrons. Beta particles are either positively (positron) or negatively (electron) charged and have the same mass as an electron. In contrast, gamma rays are electromagnetic waves that have no mass or charge and are sometimes called photons. Because alpha particles are relatively massive, they can be totally absorbed by a sheet of paper. Beta particles can penetrate up to about a centimeter or so into an object, depending on their energy. On the other hand, gamma rays of moderate energy can easily penetrate through the body, as with x-rays. When radionuclides that emit gamma rays are administered to patients, the gamma rays exit the body and are captured by a scintillation camera, which produces an image. The desirable energy of the gamma rays for external detection and imaging with gamma cameras is generally in the range of 100 kilo-electron volts to 300 kilo-electron volts. The half-life of the radionuclide emitting the gamma rays should be long enough to allow its uptake by the organ of interest, then subsequent imaging with a gamma camera, and short enough so as not to irradiate the patient long after the image is obtained. Half-lives between three hours and three days are considered optimal for diagnostic purposes. When radionuclides are used for therapy, the half-life is generally required to be in the range of several days, and the preferred form of radiation consists of beta particles because they tend to deposit their energy near the disintegration site.

Uses and Complications

If the physician is interested in imaging a particular organ, drugs that take the radionuclide preferentially to that organ are necessary. This is achieved by chemically attaching the radionuclide to a pharmaceutical carrier. Once the radiopharmaceutical is localized in the organ, the gamma rays that it emits are detected by a gamma camera, which electronically displays an image that is representative of the radionuclide distribution. Such images are of substantial diagnostic value. Similarly, radionuclides attached to drugs that selectively target cancer
cells can potentially deliver lethal doses of radiation to the cancer cells, a process called radioimmunotherapy. Hence, radiopharmaceuticals play an important role in medicine, providing new and promising avenues for diagnosis and therapy.

Radiopharmaceuticals are generally administered intravenously to patients. Blood flow to the organ of interest determines the fraction of the administered radioactivity that will be delivered. The ability of the organ to accumulate the circulating radiopharmaceutical is also an important determinant of the pathological condition of the organ. Such considerations are usually taken into account in developing appropriate pharmaceuticals.

Although many radionuclides are available, the most preferred one is called technetium 99m, an excited (metastable) state of technetium 99. This radionuclide is readily available, has a convenient half-life of six hours, and has very desirable radiation properties. Accordingly, many pharmaceuticals are labeled with this radionuclide for diagnostic nuclear medicine purposes. A few other radionuclides, such as thallium 201, iodine 123, gallium 67, and indium 111, can be used when technetium 99m compounds are not available.

The most widely used radiopharmaceutical for brain
imaging is technetium 99m pertechnetate. The primary advantage of this chemical is that it is inexpensive and can be easily prepared. Other radiopharmaceuticals used for
brain studies are technetium 99m diethylenetriamine-pentacetic acid (DTPA) and technetium 99m glucoheptonate. Brain imaging usually consists of a dynamic study immediately after bolus intravenous injection of the compound in which rapid sequential images are obtained as the radiopharmaceutical enters the brain. This is followed by a static image one hour later. When a brain lesion is suspected, a delayed static image is sometimes necessary three to four hours after an injection. These imaging techniques are valuable in detecting neoplastic tissue, inflammatory processes, infarction, Alzheimer’s disease, and stroke. Another class of radiopharmaceuticals has also been developed to study brain function. These compounds, such
as carbon 11 N-methylpiperone, use very short-lived radionuclides that need on-site radionuclide production facilities and require a sophisticated imaging system called a
positron emission tomography (PET) scanning unit. Imaging of cerebrospinal fluid is performed using DTPA labeled with indium 111 after an intrathecal administration. Radiopharmaceuticals for such administrations are tested carefully for their safety.

Lung imaging using radiopharmaceuticals is usually performed to study either pulmonary
perfusion or ventilation. For perfusion studies, the radiopharmaceutical of choice is microaggregated albumin (MAA) labeled with technetium 99m. Ventilation studies are performed using the radioactive inert gas xenon 133. The patient breathes while the images are obtained with a gamma camera. These lung studies are used extensively to detect several conditions, including pulmonary embolism, asthma, bronchitis, tumors, inflammatory disease, congestive heart failure, and deep-vein thrombus.

Bone imaging with radiopharmaceuticals often provides earlier diagnosis and better detection of lesions than other radiographic procedures. Furthermore, the extent of metastatic disease may be determined using radionuclide imaging techniques. Other applications of bone imaging include determination of the viability of bone; detection of infections in prosthetic joints, necrosis, and infarction; and evaluation of fractures and bone pain. Bone-seeking compounds are usually similar to calcium or phosphates in their chemical behavior. Hence, diphosphonate labeled with technetium 99m and its analogs are the compounds of choice for this purpose.

Radionuclide imaging techniques play an important role in evaluating the function of the heart. Coronary artery perfusion is studied using thallium 201 chloride. The patient is asked to exercise on a treadmill, and the radionuclide is injected at peak stress. The patient continues to exercise for an additional minute, and redistribution of the thallium 201 within the myocardium occurs immediately after cessation of the exercise. Gamma camera images are obtained soon thereafter. Abnormal thallium distribution is the basis for the detection and diagnosis of stress-induced ischemia and permanent myocardial damage. Acute myocardial infarction can be detected using pyrophosphate labeled with technetium 99m within twenty-four to seventy-two hours after the onset of symptoms. Other radiopharmaceuticals using technetium 99m as a label are also under development. To evaluate ventricular function, the radiochemical is administered intravenously and images are obtained during the first pass of the radionuclide through the heart, lungs, and great vessels. An alternate technique for this
purpose is to obtain images of the cardiac blood pool after the radiopharmaceutical has achieved equilibrium in the intravascular space. Such noninvasive studies are invaluable in the diagnosis of heart problems and in the management of patients with heart disease.

Evaluation of thyroid function using radioisotope techniques marked the beginning of the field of nuclear medicine. The element iodine is actively transported into the thyroid gland, where it is retained. Therefore, the readily available radioiodines iodine 131 and iodine 123 have been used for this purpose. Technetium 99m pertechnetate is sometimes used because of its low cost and favorable radiation characteristics. Thyroid uptake tests usually involve administration of a small dose of sodium iodide 131 in either liquid or capsule form and measurement of the radioiodine in the thyroid eighteen to twenty-four hours later. Significantly higher uptake compared to the normal value is a reflection of an overactive gland (hyperthyroidism). Conversely, a lower uptake indicates an underactive gland (hypothyroidism). Thyroid imaging is performed using either sodium iodide 123 or technetium 99m pertechnetate to detect cancer. Effective treatment of benign and malignant cancers, as well as hyperthyroidism, is accomplished by administering larger doses of iodine 131. Although the strong uptake of radioactive iodine by the thyroid gland is useful in nuclear medicine, uptake of iodine 131 in the thyroids of people living in nuclear-fallout zones, such as the one around the Chernobyl nuclear reactor, is a major concern. The risk from such exposure can be reduced by saturating the thyroid with nonradioactive iodine using orally administered doses of Lugol’s iodine solution.

Radiopharmaceutical studies of
kidneys are sometimes necessary to evaluate structural and functional abnormalities. Renal imaging is indicated to assess renal blood flow and the differential and quantitative functioning of natural or transplanted kidneys. Among the radiopharmaceuticals used for these studies are technetium-labeled glucoheptonate, 2,3-dimercaptosuccinic acid (DMSA), and DTPA. Iodine 123 hippurate is also employed for glomerular filtration studies.

Nuclear medicine techniques to image the
liver and
spleen are also available. Alcohol-related liver diseases can be readily diagnosed using liver images obtained after injection of technetium-labeled sulfur colloid. Primary liver cancers and metastases can also be detected, and the physiological functioning of transplanted livers can be assessed. Spleen imaging with technetium 99m sulfur colloid has been useful in detecting hepatomas, cysts, infarctions, and neoplasms. Gastrointestinal hemorrhaging and associated bleeding are identified by removing a small portion of the patient’s red blood cells, labeling them with technetium 99m, and injecting the labeled cells back into the patient. Similarly, white blood cells labeled with indium 111 are used to image abscesses and inflammation. Radionuclide procedures also provide a method to assess digestive disorders and esophageal transit noninvasively. A variety of tumors can be diagnosed when gallium 67 citrate is used for imaging. This radionuclide is also used in studying
patients with Acquired immunodeficiency syndrome (AIDS).

Radiopharmaceuticals are also playing an important role in treating many functional disorders and cancers. As pointed out earlier, hyperthyroidism and thyroid carcinoma are best treated with iodine 131. Malignant pheochromocytomas and other neuroendocrine lesions can be treated with metaiodine 131 benzylguanidine. Gold 198 colloid has been used to assist in the therapy of peritoneal metastases and recurrent malignant ascites. Phosphorus 32 colloids are employed in treating malignant pericardial effusion associated with breast and lung carcinomas. Intra-arterial injection of phosphorus 32 colloid to treat inflammatory arthritis of bone joints is also common. The uncontrolled proliferation of bone marrow cells is checked by administering phosphorus 32 orthophosphate. Patients with advanced bone metastases and intractable bone pain are also often treated with single or multiple doses of phosphorus 32 orthophosphate. Other radionuclides that are useful for this purpose are strontium 89, rhenium 186, and yttrium 90.

The implementation of
monoclonal antibodies labeled with suitable radionuclides to treat cancer has received considerable attention. This approach involves selecting an antibody that is directed against a tumor-specific antigen and labeling the antibody with an energetic beta particle-emitting radionuclide. If the tumor selectively concentrates these labeled antibodies, then it can be lethally irradiated without seriously affecting the normal tissues and organs. Thus far, however, clinical trials using this approach have met with limited success because of insufficient tumor uptake and bone marrow toxicity. Nevertheless, labeled antibodies are becoming useful in diagnosing a variety of primary and metastatic tumors.

Perspective and Prospects

Although radioactivity was discovered in the late nineteenth century, application of radionuclides as biological tracers did not begin until 1924, when Georg von Hevesy used a bismuth radionuclide to study circulation in rabbits. In that same year, bismuth 214 was used in humans to measure the blood circulation time after injecting the radionuclide in one arm and then following the arrival of radioactivity in the other arm. The researchers found that it takes eighteen seconds in normal patients, and longer in patients with heart disease. The discovery of artificial radioactivity by Frédéric Joliot and Irène Joliot-Curie in 1934 led to the wider use of radionuclides as tracers. When Enrico Fermi artificially produced several radionuclides, Hevesy used phosphorus 32 to study phosphorus metabolism in rats. Such artificial production of radionuclides became possible after the pioneering work of Ernest Lawrence, who invented the cyclotron in 1929. Cyclotrons are still widely employed to produce a variety of radionuclides for medical use. The most commonly used one in nuclear medicine imaging is technetium 99m; this radionuclide is generated in the decay of another radionuclide called molybdenum 99, which was first produced by a cyclotron in 1938.

Radiopharmaceuticals and nuclear medicine took a major leap forward when technetium 99m, the radionuclide of choice for imaging, became readily available. Concurrent development of the scintillation camera by Hal Anger in 1958 advanced the field of nuclear medicine imaging. Radiolabeled compounds are also used extensively in biomedical research to trace biologically important molecules. The
radioimmunoassay is another area in which labeled compounds are used to diagnose diseases; here, an antigen-antibody interaction is utilized. These procedures require only a trace amount of radioactivity, along with a blood sample of the patient.

Radiopharmaceutical imaging techniques have become important for the diagnosis and treatment of many diseases, and they will continue to play a major role in improving the quality of health care. Improvements in imaging instrumentation technology and the availability of computer technology to process the images are likely to further the accuracy of nuclear medicine images. Future developments in biotechnology should also assist in designing new pharmaceuticals that are more target-specific, thus further reducing the risks and enhancing both the diagnostic quality of the images and the therapeutic efficacy of radiolabeled compounds.

Another challenge for future research may include searching for new ways to create and manufacture radiopharmaceuticals. In the early part of the twenty-first century, planned and unplanned closures of nuclear reactors created shortages of radiopharmaceutical materials in Europe; given this, one area of future research may be to find the means to develop these materials in other ways. In December, 2009, the Food and Drug Administration issued a ruling (effective December, 2011) on regulations about the manufacturing process of radiopharmaceuticals for PET scanning, designed to accommodate producers in commercial and nonprofit, academically oriented institutions.

Bibliography

Cherry, Simon R., James A. Sorenson, and Michael E. Phelps. Physics in Nuclear Medicine. 4th ed. Philadelphia: Elsevier/Saunders, 2012.

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