What is qualitative research? |

Introduction

Qualitative methodology is a type of scientific inquiry that emphasizes the qualities or essences of the phenomenon under study. This type of research relies on nonnumerical data, such as words and images. For example, Rosemarie Rizzo Parse in Qualitative Inquiry: The Path of Sciencing (2001) defined qualitative research as “the systematic study of phenomena with rigorous adherence to a design, the data of which comprises oral, written, or artistic descriptions of human experiences, and for which there are no digital findings.”

Historical Foundations

Qualitative research grew out of naturalistic inquiries conducted in the disciplines of sociology, anthropology, and linguistics, but is now readily applied across the social sciences. This methodological approach has been used to investigate research questions in psychology and has been widely used in the fields of anthropology, sociology, nursing, social work, administration, community services, management, education, and medicine.

Qualitative methods have been used to investigate research questions ill-suited to quantitative methods, provide rich descriptions of particularly complex or multidimensional phenomena, give voice to traditionally marginalized groups, serve as an initial exploration toward the development of theories or quantitative measures, illuminate the diverse perspectives and experiences of several people experiencing a similar event, and connect research to applied practice.

Features of Qualitative Research

Qualitative investigations contain several common features that distinguish them from other types of scientific inquiry. For example, in Qualitative Research and Evaluation Methods(3d ed., 2002), Michael Quinn Patton has outlined ten primary characteristics of qualitative research: naturalistic inquiry, inductive analysis, holistic perspective, qualitative data, personal contact and insight, dynamic systems, unique case orientation, context sensitivity, empathic neutrality, and design flexibility. Psychology’s interest in qualitative approaches has grown in the twenty-first century. Several events have occurred that are examples of the emergence of qualitative methods in psychology. Psychology journals (such as the Journal of Counseling Psychology) have published special issues devoted to qualitative methods. There has also been an increased appreciation for how qualitative methods can be used to bridge the science-practice gap within the field of psychology. Researchers have also expressed a growing understanding of how such methods are congruent with the paradigms that characterize the helping professions. Psychological researchers have also increasingly begun using mixed models. Common qualitative approaches include phenomenology, case study, and grounded theory.

Phenomenology

Phenomenology seeks to describe the meaning individuals give their life experiences and is based on the philosophy that observable, measurable, duplicable (that is, quantitative) approaches to psychological inquiry are prone to missing, or even altogether eliminating, the most important phenomenon under study, human experience. It concerns itself not with explanation and control but rather with understanding and description. According to Paul F. Colaizzi in his essay “Psychological Research as the Phenomenologist Views It,” in Existential-Phenomenological Alternatives for Psychology (1978), it is “a refusal to tell the phenomenon what it is, but a respectful listening to what the phenomenon speaks of itself.”

There is no single phenomenological method, but most approaches fall under one of two major methodological umbrellas: hermeneutic or empirical. Hermeneutic phenomenological approaches are concerned with analyzing and understanding written narratives to understand and describe human experience. The goal is to produce a rich, deep description of a phenomenon as it emerges within a text, which can be done by analyzing the life texts, or written experience, of participants, or by studying previously written historical or literary narratives. The researcher works to overcome personal assumptions to understand and describe the phenomenon itself, as viewed in context from the text’s perspective. Phenomenology seeks to explore and describe the unique meaning assigned to experience by persons who have lived through a common phenomenon. Phenomenology also provides a flexible step-by-step process for data analysis, the result of which is a description of the essence of participants’ experience in terms of both their common and unique experiences.

Case Study

Case study research has a long and rich history, especially within the disciplines of medicine, law, business, and the social sciences. Yet, this form of qualitative research was not conceptualized as a specific approach until the late 1970s and 1980s. The emphasis of case study research is on understanding phenomena from a specific case or cases within a bounded system. According to Patton, the primary function of case study research is “to gather comprehensive, systematic, and in-depth information about each case of interest.” Robert E. Stake suggests that there are three different types of case studies. The primary investigation into one specific case is known as an intrinsic case study. In an instrumental case study, researchers study a particular case as a means to better understanding a specific issue. A collective case study involves the use of numerous cases to understand a particular phenomenon.

Case study research differs from other qualitative methods in several ways. It seeks to determine and describe the prevailing processes of the phenomena under investigation. Another key characteristic of case study research is that it makes a comparison of all the data sources, such as interviews, documents, and observations, within a contextual and historical framework. Case study research also attempts to integrate empirical data with theory. According to Sharan B. Merriam in Case Study Research in Education: A Qualitative Approach (1988), this approach to research also focuses on “thick” descriptions of the phenomena being studied; case study research uses “complete, literal description of the incident or entity being investigated.” In addition, case study procedures engage the researcher in examining the data from the onset of the investigation.

Several basic assumptions are innate to case study research. First, a case may be chosen because it is unique and therefore is of interest. Second, the phenomenon under study is bound to a specific system, consisting of complex and interrelated elements. Third, an emphasis should be placed on understanding the intrinsic particulars of a phenomenon. Fourth, the research process is influenced by the perceptions of the researcher. Moreover, through careful comparative analysis of the data, and theory, a greater understanding of the phenomenon can be obtained.

Grounded Theory

Grounded theory is a major qualitative tradition. Sociologists Barney G. Glasser and Anselm L. Strauss introduced this qualitative tradition in Discovery of Grounded Theory: Strategies for Qualitative Research (1967). The goal of grounded theory is to discover and develop comprehensive theories. It is a general methodology for theory development that comes from systematically gathered and analyzed data. The emphasis of grounded theory is on theory generation (developing theory from data) rather than on theory confirmation, or hypothesis testing. As a result, researchers have the freedom to modify procedures (for example, sampling changes) and methods (for example, reworking interview protocols) in accordance with the data.

Several basic assumptions are unique to grounded theory. The social phenomenon under study is seen as both complex and repeatedly adapting to the environment. Through a systematic approach, researchers can understand, predict, and control human behavior. Grounded theory also recognizes that the research process is subjective in nature and views the researcher as an active participant. Theory emerges through careful comparative analysis of the data.

Evaluative Criteria

The criteria that should be used to evaluate qualitative research have been the cause of great debate among many qualitative researchers. Several researchers have attempted to evaluate qualitative research in terms of internal validity, external validity, reliability, and objectivity, which have traditionally been used in quantitative approaches. Kelly J. Devers states, in his 1999 article on qualitative research, that these criteria largely evolved out of the positivistic paradigm, which judged the scientific method suitable for researching all forms of knowledge (natural and social) and defined what that method should entail. Yet, qualitative research is based in postpositivistic philosophy, which proposes “reality is dynamic, contextual, and socially constructed.” The differences in philosophical perspectives lead to a split between many quantitative and qualitative researchers.

During the late 1970s and mid-1980s, several qualitative researchers started challenging the positivistic criteria that had been used to evaluate qualitative research and began calling for a new set of criteria. Out of this dialogue came several diverse sets of evaluative criteria. Among these new advances were the criteria set forth by Norman Lincoln and Yvonna Guba: credibility, transferability, dependability, and confirmability. Credibility refers to the degree to which the results of a study have merit and accurately represent the experienced reality of its participants. Transferability is the qualitative counterpart of the quantitative concept of external validity or generalizability. It refers to the degree to which findings can be generalized or transferred to people, settings, and times similar to those found in the original study. Dependability is the qualitative counterpart to quantitative reliability. Dependable investigations can be relied on to accurately and impartially report the findings that emerged. Confirmability refers to the degree to which the results of the investigation can be objectively corroborated by the obtained data.

Bibliography

Bamberg, Paul M., Jean E. Rhodes, and Lucy Yardley, eds. Qualitative Research in Psychology: Expanding Perspectives in Methodology and Design. Washington, DC: Amer. Psychological Assn., 2003. Print.

Creswell, John W. Qualitative Inquiry and Research Design: Choosing Among the Five Traditions. Thousand Oaks: Sage, 1998. Print.

Creswell, John W. Research Design: Qualitative, Quantitative, and Mixed Methods Approaches. Thousand Oaks: Sage, 2002. Print.

Denzin, Norman K., and Lincoln Yvonna, eds. Handbook of Qualitative Research. Thousand Oaks: Sage, 2000. Print.

Devers, Kelly J. “How Will We Know ’Good’ Qualitative Research When We See It? Beginning the Dialogue in Health Services Research.” Health Services Research 34 (1999): 1153–88. Print.

Forrester, Michael A., ed. Doing Qualitative Research in Psychology. Thousand Oaks: Sage, 2010. Print.

Frost, Nollaig. Qualitative Research Methods in Psychology: Combining Core Approaches. Maidenhead: Open UP, 2011. Print.

Glasser, Barney G., and Anselm L. Strauss. The Discovery of Grounded Theory: Strategies for Qualitative Research. New York: Aldine de Gruyter, 1967. Print.

Patton, Michael Quinn. Qualitative Research and Evaluation Methods. 3rd ed. Thousand Oaks: Sage, 2002. Print.

Willig, Carla. Introducing Qualitative Research in Psychology. 3rd ed. New York: McGraw, 2013. Print.

What is tattoo removal? |

Indications and Procedures

Application of a tattoo is relatively easy, although the process is painful. A design is drawn on the skin. Needles are used to push the ink down into the skin. When the skin heals from the multiple punctures, the design remains permanently in place. Attempts have been made to remove tattoos since the first one was applied. Scrubbing with sandpaper or table salt has been tried to scour the surface of the skin and remove the tattoo. The results have usually been disfigurement or scarring.

Currently, laser therapy is the most effective way of removing unwanted tattoos. The Food and Drug Administration (FDA) has approved several types of lasers for tattoo removal. The standard device now used is some form of Q-switched laser, which produces a pulsed beam with much higher power at the peak of the pulse than a continuous wave laser. When applied to a tattoo, the ink embedded in the skin absorbs the pulse of energy. The laser energy causes the tattoo ink to break up into fragments that can be removed by cells of the body’s immune system. The treatment feels like a rubber band snapping against the skin, and local anesthetics may be necessary when attempting to remove large tattoos. Immediately after the laser treatment, the treated area turns white and might swell slightly; over the next few days, blisters and scabs may form. Within seven to ten days, the skin will look normal. Several such treatments are required, spaced a number of weeks apart.

Other, significantly less popular methods of tattoo removal include dermabrasion, where the outer layers of skin that hold the ink are abraded (scraped or rubbed away) with a spinning abrasive pad, and surgical excision, in which small tattoos can be removed by cutting them out and closing the skin with stitches

Uses and Complications

The number of treatments required to remove a tattoo depends on several factors: the color of ink, the amount of ink, the depth of the tattoo, and the location of the tattoo. Professional tattoos may require more treatments to remove than those applied by amateurs, because professionals tend to use more ink and to apply the ink deeper into the skin. Ideally, treatments are spaced several weeks apart to allow the body’s immune system to remove the maximum amount of ink between sessions; this time is also necessary to allow the skin to recover fully before the next treatment.

It is more problematic to remove tattoos from areas of the body with thin skin, such as the face, genitals, and ankles. In the case of tattoo removal, laser treatments are designed to remove the unwanted buildup of abnormal pigment (ink) in the skin; however, people with dark skin have high amounts of natural pigment (melanin) in their skin. Sometimes, lasers cannot distinguish between tattoo ink pigment and normal skin pigment. As a result, both types of pigment are destroyed, leaving pale patches on the skin; these patches can fade with time. Conversely, an increase in pigmentation can be seen after treatment, causing dark patches on the skin; these patches can also fade with time. It is recommended that patients stay out of the sun before and after treatment for tattoo removal. Tattoo removal can lead to scarring, but with the modern laser methods, this is becoming rarer. The most striking side effect of laser tattoo removal is the cost, typically much higher than the cost of the original tattoo. Nonetheless, according to the American Society for Dermatologic Surgery, its members performed some 100,000 tattoo removals in 2011, up from 86,000 in 2010.

Bibliography

Ahluwalia, Gurpreet S., ed. Cosmetic Applications of Laser and Light-Based Systems. Norwich, N.Y.: William Andrew, 2009.

Camphausen, Rufus C. Return of the Tribal: A Celebration of Body Adornment: Piercing, Tattooing, Scarification, Body Painting. Rochester, Vt.: Park Street Press, 1997.

Graves, Bonnie B. Tattooing and Body Piercing. Mankato, Minn.: LifeMatters, 2000.

Hewitt, Kim. Mutilating the Body: Identity in Blood and Ink. Bowling Green, Ohio: Bowling Green State University Popular Press, 1997.

"Inked and Regretful: Removing Tattoos." U.S. Food and Drug Administration, January 30, 2013.

Kirby, William, Emily Holmes, Alpesh Desai, and Tejas Desai. "Best Clinical Practices in Laser Tattoo Removal." Dermatologist (June 2012): 23–28.

Miller, Jean-Chris. The Body Art Book: A Complete, Illustrated Guide to Tattoos, Piercings, and Other Body Modifications. Rev. ed. New York: Berkley, 2004.

Wilkinson, Beth. Coping with the Dangers of Tattooing, Body Piercing, and Branding. New York: Rosen, 1998.

"Unwanted Tattoos." American Society for Dermatologic Surgery, 2013.

Did Hamlet love Ophelia before and then fall out of it due to his mad desire for revenge in Hamlet?

Hamlet loved Ophelia before he feigned madness, and he continues to love her without ceasing, actually.  He only pretends to stop loving her for one of two reasons (both are plausible): either because he feels betrayed by her and her obedience to her father, who Hamlet believes to be corrupt as a result of his close association with Claudius, or because he wants to protect her from any potential fall-out with Claudius that might occur...

Hamlet loved Ophelia before he feigned madness, and he continues to love her without ceasing, actually.  He only pretends to stop loving her for one of two reasons (both are plausible): either because he feels betrayed by her and her obedience to her father, who Hamlet believes to be corrupt as a result of his close association with Claudius, or because he wants to protect her from any potential fall-out with Claudius that might occur as a result of his vow to exact revenge on the king for killing Hamlet's father.  When Hamlet learns that the grave being prepared in Act 5, Scene 1, is actually for Ophelia, he fights with Laertes, her brother, about who loved her more.  Hamlet says, "I loved Ophelia.  Forty thousand brothers / Could not with all their quantity of love / Make up my sum" (5.1.285-287).  He swears that he is willing to be buried with her in order to prove his loving devotion.  Thus, Hamlet never stopped loving Ophelia.

What are artificial sweeteners? Do they cause cancer?

Government-approved artificial sweeteners: Artificial sweeteners are nonnutritive in nature since they provide no calories or energy to the body. There are five artificial sweeteners aspartame (NutraSweet, Equal), saccharin (Sweet’N Low, Sweet Twin, Necta Sweet), acesulfame K (Sunnet, Sweet One), neotame, and sucralose (Splenda) approved for use in the United States by the US Food and Drug Administration (FDA). Two artificial sweeteners that the FDA has not approved are alitame and cyclamate.

Aspartame is two hundred times sweeter than sugar and was approved for use as a general-purpose sweetener in all foods and drinks in 1996. Saccharin is two hundred to seven hundred times sweeter than sugar. It is used as a tabletop sweetener and in soft drinks and chewing gum. Acesulfame K was first approved by the FDA as a tabletop sweetener and is about two hundred times sweeter than sugar. Neotame, which is about seven thousand to fourteen thousand times sweeter than sugar, was approved in 2002 as a general-purpose sweetener in a wide variety of food products. Sucralose is the only artificial sweetener that has three chlorine atoms in its chemical structure and is six hundred times sweeter than sugar. It was approved in 1998 for use in food products, such as beverages, chewing gum, and frozen desserts. Sucralose was approved by the FDA as a general-purpose sweetener in all foods in 1999.

Metabolism: Sucrose, the chemical entity in natural table sugar, binds to special receptor proteins in the taste buds. This binding initiates a cascade of events that finally results in a signal sent to the brain that causes the sensation of sweet taste. Additionally, sugar is a carbohydrate that is metabolized by the body to provide calories. Artificial sweeteners have a greater affinity for the receptor proteins and work by binding two hundred to fourteen hundred times more strongly to the receptor proteins than sucrose. As a result of their stronger binding capacity, the artificial sweeteners are needed in much lower quantities than sugar to produce the same degree of sweetness.

The artificial sweeteners are either excreted by the body or converted to by-products with little or no caloric output. Saccharin, sucralose, and acesulfame K are excreted unchanged by the body and do not provide any calories. The enzymes in the body hydrolyze neotame and produce methanol as a by-product. Aspartame is broken down in the body to produce methanol and the amino acids aspartic acid and phenylalanine and very few calories compared with sugar. Methanol is further degraded to formaldehyde in the body. Both methanol and formaldehyde are toxic to human beings at high doses. People with the genetic disease phenylketonuria (PKU) lack the enzyme that breaks down phenylalanine. Because phenylalanine is produced as a by-product of aspartame digestion, people with PKU should not ingest aspartame. Foods containing aspartame must carry a label warning consumers with PKU that the product is a source of phenylalanine.

Cancer risk: Questions regarding the risk of cancer associated with the consumption of artificial sweeteners arose when early studies indicated that saccharin caused bladder cancer in test animals. Subsequent epidemiological studies of groups of people did not find a definitive correlation between saccharin use and bladder cancer. There are two more controversial reports on the correlation between aspartame use and cancer. One study found more lymphomas and leukemias in rats fed very high doses of aspartame while the other study did not find a link between aspartame use and cancer.

Artificial sweeteners are regulated by the Food and Drug Administration. Before artificial sweeteners can be launched in the US market, the FDA reviews numerous safety studies conducted with them, including the studies that assess their potential cancer risk. The reviews have not conclusively demonstrated any strong positive correlation between various cancers and artificial sweetener use. Studies continue to be conducted, and the FDA will continue to review and evaluate the results.

Artificial sweeteners are beneficial for people with diabetes and for people on weight-loss plans. The effects of their long-term use on weight-maintenance and cancer risk are controversial because they are not clearly understood. In the light of insufficient experimental data and all the controversy swirling around the use of artificial sweeteners, moderation should be the watchword for everyone using them.

Bibliography

Abegaz, E. M. “Aspartame Not Linked to Cancer.” Environmental Health Perspectives 115.1 (2007): A16–17. Print.

Cantley, Lewis C. “Cancer, Metabolism, Fructose, Artificial Sweeteners, and Going Cold Turkey on Sugar.” BMC Biology 12.8 (2014): n. pag. BioMed Central. BioMed Central, 31 Jan. 2014. Web. 27 Aug. 2014.

Gallus, S., et al. “Artificial Sweeteners and Cancer Risk in a Network of Case-Control Studies.” Annals of Oncology 18.1 (2007): 40–44.

Lim, U., et al. “Consumption of Aspartame-Containing Beverages and Incidence of Hematopoietic and Brain Malignancies.” Cancer Epidemiology Biomarkers and Prevention 15 (2006): 1654–659. Print.

Schernhammer, Eva S., et al. “Consumption of Artifical Sweetener- and Sugar-Containing Soda and Risk of Lymphoma and Leukemia in Men and Women. American Journal of Clinical Nutrition 96.6 (2012): 1419–428. Print.

Soffritti, Morando, et al. “First Experimental Demonstration of the Multi-potential Carcinogenic Effects of Aspartame Administered in the Feed to Sprague-Dawley Rats.” Environmental Health Perspectives 114.3 (2006): 379–85.

United States. Dept. of Health and Human Services. Natl. Toxicology Program. Report on Carcinogens. 12th ed. Research Triangle Park: Dept. of Health and Human Services, 2011. Print.

What are human genetics? |

Human Genome Project

Human genetics is the discipline concerned with identifying and studying the genes carried by humans, the control and expression of traits caused by these genes, their transmission from generation to generation, and their expression in offspring. Modern human genetics properly begins with the elucidation of the structure of DNA in 1953 by James D. Watson and Francis H. Crick. This discovery led to very rapid advances in acquisition of genetic information and ultimately spawned the Human Genome Project (HGP), which was initiated in 1986 by the DOE (Department of Energy). In 1990 the DOE combined efforts with the National Institutes of Health (NIH) and private collaborators, including the Wellcome Trust of the United Kingdom, along with private companies based in Japan, France, Germany, and China. The ultimate goal of HGP was to determine the precise genetic makeup of humans as well as explore human genetic variation and human gene function. The first high-quality draft of the human genetic sequence was completed in April of 2003, thereby providing a suitable salute to the fiftieth anniversary of the discovery of DNA, which opened the modern era of human genetics.

Almost all current human genetics is directly related to the enormous mass of genetic data obtained and made available by the HGP. Some of the many themes now being explored include medical genetics, genetic bioinformatics, proteomics, toxicogenomics, the inheritance and prevention of gene-related cancers and other diseases, and policy and ethical issues related to genetic concerns of humans.

The human genome consists of genes located in chromosomes, along with a much smaller gene content, found in mitochondria, that is called mitochondrial DNA or mtDNA. About 99.7 percent of the human genome is located in the chromosomes, and another 0.3 percent consists of the mtDNA genome, which encodes for a number of enzymes involved in cellular respiration. The mtDNA is inherited almost entirely through the female line, so its genetic transmission and expression differ from that of classical Mendelian genetics. Studies of human mtDNA have revealed a number of medical pathologies associated with this unique mode of inheritance transmission. Studies have also proven useful in determining significant trends in the evolutionary development of Homo sapiens and elucidating relationships with the near-species Homo neanderthalensis (the now extinct Neanderthals).

The HGP effort decoded the genetic arrangement—the gene sequence of roughly 3 billion nucleotide base pairs of between 25,000 and 45,000 genes that collectively form the human genome. Many, but not all, of these have been sequenced and their locations on chromosomes mapped. Structurally, base-sequencing studies reveal that human genes showed great variations in size, ranging from several thousand base pairs to some genes comprising nearly half a million base pairs. The genetic functions have been determined for about half of the human genes that have been identified and sequenced. HGP provided so much information that a new field called bioinformatics was developed to handle the enormous amounts of genetic sequencing data for the human genome.

Bioinformatics

The purpose of bioinformatics is to help organize, store, and analyze genetic biological information in a rapid and precise manner, dictated by the need to be able to access genetic information quickly. In the United States the online database that provides access to these gene sequences is called GenBank, which is under the purview of the National Center for Biotechnology Information (NCBI) and has been made available on the Internet. In addition to human genome sequence records, GenBank provides genome information about plants, bacteria, and other animals.

Proteomics

Bioinformatics provides the basis for all modern studies of human genetics, including analysis of genes and gene sequences, determining gene functions, and detecting faulty genes. The study of genes and their functions is called proteomics, which involves the comparative study of protein expression. That is, exactly what is the metabolic and morphological relationship between the protein encoded within the genome and how that protein works. Geneticists are now classifying proteins into families, superfamilies, and folds according to their configuration, enzymatic activity, and sequence. Ultimately proteomics will complete the picture of the genetic structure and functioning of all human genes.

Toxicogenomics

Another newly developing field that relies on bioinformatics is the study of toxicogenomics, which is concerned with how human genes respond to toxins. Currently, this field is specifically concerned with evaluating how environmental factors negatively interact with messenger RNA (mRNA) translation, resulting in disease or dysfunction.

Medical Genetics

Almost all of current human medical genetics rests on the identification of human gene sequences that were provided by the HGP and made accessible through bioinformatics. Human medical genetics begins with recognition of defective genes that are either nonfunctioning or malfunctioning and that cause diseases or tissue malformation. Once defective genes have been identified and cataloged, patients can be screened with gene testing procedures to determine if they carry such genes. Following detection of a defective gene, several options may be explored and implemented, including genetic counseling, gene therapy, and pharmacogenetics.

At least four thousand diseases of humans are known to have a genetic basis and can be passed from generation to generation. In addition to many kinds of human cancers, all of which have a genetic basis, human genetic disorders include diabetes, heart disease, and cystic fibrosis. Other diseases and disorders that have been directly linked to human genetic anomalies include predispositions for colon cancer, Alzheimer’s disease, and breast cancer.

Gene Testing

In a gene-testing protocol, a sample of blood or body fluids is examined to detect a genetic anomaly such as the transposition of part of a chromosome or an altered sequence of the bases that comprise a specific gene, either of which can lead to a genetically based disorder or disease. Currently more than six hundred tests are available to detect malfunctioning or nonfunctioning genes. Most gene tests have focused on various types of human cancers, but other tests are being developed to detect genetic deficiencies that cause or exacerbate infectious and vascular diseases.

The emphasis on the relationship between genetics and cancer lies in the fact that all human cancers are genetically triggered by genes or have a genetic basis. Some cancers are inherited as mutations, but most result from random genetic mutations that occur in specific cells, often precipitated by viral infections or environmental factors not yet well understood.

At least four types of genetic problems have been identified in human cancers. The normal function of oncogenes, for example, is to signal the start of cell division. However, when mutations occur or oncogenes are overexpressed, the cells keep on dividing, leading to rapid growth of cell masses. The genetic inheritance of certain kinds of breast cancers and ovarian cancers results from the nonfunctioning tumor-suppressor genes
that normally stop cell division. When genetically altered tumor-suppressor genes are unable to stop cell division, cancer results. Conversely, the genes that cause inheritance of colon cancer result from the failure of DNA repair genes to correct mutations properly. The accumulation of mutations in these “proofreading” genes makes them inefficient or less efficient, and cells continue to replicate, producing a tumor mass.

If a gene screening reveals a genetic problem several options may be available, including gene therapy and genetic counseling. If the detected genetic anomaly results in disease, then pharmacogenomics holds promise of patient-specific drug treatment.

Gene Therapy

The science of gene therapy uses recombinant DNA technology to cure diseases or disorders that have a genetic basis. Still in its experimental stages, gene therapy may include procedures to replace a defective gene, repair a defective gene, or introduce healthy genes to supplement, complement, or augment the function of nonfunctional or malfunctioning genes. Several hundred protocols are being used in gene therapy trials, and many more are under development. Current trials focus on two major types of gene therapy, somatic gene therapy and germ-line gene therapy.

Somatic gene therapy focuses on altering a defective gene or genes in human body cells in an attempt to prevent or lessen the debilitating impact of a disease or other genetic disorder. Some examples of somatic cell gene therapy protocols now being tested include ones for adenosine deaminase (ADA) deficiency, cystic fibrosis, lung cancer, brain tumors, ovarian cancer, and AIDS.

In somatic gene therapy a sample of the patient’s cells may be removed and treated, and then reintegrated into body tissue carrying the corrected gene. An alternative somatic cell therapy is called gene replacement, which typically involves insertion of a normally functioning gene. Some experimental delivery methods for gene insertion include use of retroviral vectors and adenovirus vectors. These viral vectors are used because they are readily able to insert their genomes into host cells. Hence, adding the needed (or corrective) gene segment to the viral genome guarantees delivery into the cell’s nuclear interior. Nonviral delivery vectors that are being investigated for gene replacement include liposome fat bodies, human artificial chromosomes, and naked DNA (free DNA, or DNA that is not enclosed in a viral particle or any other “package”).

Another type of somatic gene therapy involves blocking gene activity, whereby potentially harmful genes such as those that cause Marfan syndrome and Huntington’s disease are disabled or destroyed. Two types of gene-blocking therapies now being investigated include the use of antisense molecules that target and bind to the messenger RNA (mRNA) produced by the gene, thereby preventing its translation, and the use of specially developed ribozymes that can target and cleave gene sequences that contain the unwanted mutation.

Germ-line therapy is concerned with altering the genetics of male and female reproductive cells, the gametes, as well as other body cells. Because germ-line therapy will alter the individual’s genes as well as those of his or her offspring, both concepts and protocols are still very controversial. Some aspects of germ-line therapy now being explored include human cloning and genetic enhancement.

The next steps in human genetic therapy involve determining the underlying mechanisms by which genes are transcribed, translated, and expressed, which is called proteomics.

Clinical Genetics

Clinical genetics is that branch of medical genetics involved in the direct clinical care of people afflicted with diseases caused by genetic disorders. Clinical genetics involves diagnosis, counseling, management, and support. Genetic counseling is a part of clinical genetics directly concerned with medical management, risk determination and options, and decisions regarding reproduction of afflicted individuals. Support services are an integral feature of all genetic counseling themes.

Clinical genetics begins with an accurate diagnosis that recognizes a specific, underlying genetic cause of a physical or biochemical defect following guidelines outlined by the NIH Counseling Development Conference. Clinical practice includes several hundred genetic tests that are able to detect mutations such as those associated with breast and colon cancers, muscular dystrophies, cystic fibrosis, sickle-cell disease, and Huntington’s disease.

Genetic counseling follows clinical diagnosis and focuses initially on explaining the risk factors and human problems associated with the genetic disorder. Both the afflicted individual and family members are involved in all counseling procedures. Important components include a frank discussion of risks, of options such as preventive operations, and of options involved in reproduction. All reproductive options are described along with their potential consequences, but genetic counseling is a support service rather than a directive mode. That is, it does not include recommendations. Instead, its ultimate mission is to help both the afflicted individuals and their families recognize and cope with the immediate and future implications of the genetic disorder.

Pharmacogenomics

That branch of human medical genetics dealing with the correlation of specific drugs to fit specific diseases in individuals is called pharmacogenomics. This field recognizes that different individuals may metabolically respond differentially to therapeutic medicines based on their genetic makeup. It is anticipated that testing human genome data will greatly speed the development of new drugs that not only target specific diseases but also will be tailored to the specific genetics of patients.

Policy and Ethical Concerns and Issues in Human Genetics

The “new genetics” of humans has raised a number of critical concerns that are currently being addressed on a number of levels. Some of these concerns are related to the ownership of genetic information obtained by the Human Genome Project, privacy issues, and use of genetic information in risk assessment and decision making.

Privacy issues have focused on psychological impact, possible discrimination, and stigmatization associated with identifying personal genetic disorders. For example, policy guarantees must be established to protect the privacy of persons with genetic disorders to prevent overt or covert societal discrimination against the affected individual. Another question arising from this is exactly who has the right to the genetic information of persons.

Use of information obtained by the Human Genome Project has provided entrepreneurial opportunities that will undoubtedly prove economically profitable. That is, the limits of commercialization of products, patents, copyrights, trade secrets, and trade agreements have to be determined. If patents of DNA sequences are permitted, will they limit accessibility and free scientific interchange among and between peoples of the world? This question becomes critical when it is recognized that the human genome is properly the property of all humans.

Noncoding “Junk” DNA

Like that of other organisms, the human genome consists of long segments of DNA that contain noncoding sequences called introns (intervening sequences). These vary from a few hundred to several thousand base pairs in length and often consist of repetitive DNA elements with no known function; that is, they do not code for proteins. Because they appear functionless but take up valuable chromosomal space, these noncoding sequences have been considered useless and have been termed junk DNA or selfish DNA.
Some studies, however, lend strong support to the possibility that the seemingly useless repetitive DNA may actually play a number of important genetic roles, from providing a substrate on which new genes can evolve to maintaining chromosome structure and participating in some sort of genetic control. Consequently, it is now out of fashion among geneticists to refer to these parts of the genome as junk DNA, but rather as DNA of unknown function.

Forensic Genetics

Law enforcement agencies are increasingly relying on a branch of human genetics called forensic genetics. The aims of forensic genetics typically are to determine the identity or nonidentity of suspects in crimes, based on an analysis of DNA found in hair, blood, and other body substances retrieved from the scene of the crime in comparison with that of suspects. Popularly called DNA fingerprinting,
forensic genetics relies on the fact that the DNA of every human carries unique tandem repeats of 20 or more kilobase pairs that can be compared and identified using radioactive probes. Thus, comparisons can establish identity or nonidentity to a very high level of probability. DNA fingerprinting is also used in recognizing genetic parentage of children, identifying victims—sometimes from fragments of bodies—and identifying relationships of missing children.

Phylogeny and Evolution

Another rapidly developing field in human genetics is the use of human gene sequences in both nuclear and mitochondrial DNA (mtDNA) to explore questions of human origins, evolution, phylogeny, bioarchaeology, and past human migration patterns.

Much of the analytical work has involved mtDNA to study relationships. Because it is inherited strictly through the egg line or female component, mtDNA is somewhat more useful, but comparisons of DNA sequences along the Y chromosome of human populations have also yielded valuable information regarding human origins and evolution.

One of the more interesting of these studies involves comparing mtDNA over a broad spectrum of global human populations. Comparisons of DNA sequencing of these populations has revealed differences in DNA sequences of about 0.33 percent, which is considerably less than seen in other primate species. These minor differences strongly suggest that all members of the human species, Homo sapiens, are far more closely related to one another than are members of many other vertebrate species.

A separate study compared human gene sequences among different human populations across the globe. This study revealed that the highest variations in DNA sequences are found among the human populations of Africa. Since populations that exhibit the highest genome variations are thought to be the oldest populations (because chance mutations have a longer time to accumulate in older populations as opposed to younger populations), these results strongly suggest that humans originated in Africa and subsequently dispersed into other regions of the world. This “out of Africa” theory has received compelling support from the DNA evidence, and the theory also explains why all other human populations are so remarkably similar. Since all other global human populations show minimal DNA sequence differences, it is hypothesized that a small group of humans emigrated from Africa to spread across and eventually colonize the other continents. Tests of gene sequences along Y chromosomes show similar patterns, leading to the proposal that all humans came from a
mitochondrial Eve and a Y chromosome Adam who lived between 160,000 and 200,000 years ago.

DNA-based phylogeny studies are also shedding light on the relationship between the Neanderthals (Homo neanderthalensis), a species that disappeared between 30,000 and 60,000 years ago, and the more modern Cro-Magnon humans (Homo sapiens) that replaced them. Comparisons of mtDNA between the two Homo species indicate that Neanderthals began diverging from modern humans half a million years ago and were significantly different in genomic content to be placed in a separate species. These findings also support the suggestion that Neanderthals were ecologically replaced by modern humans rather than genetically amalgamated into present human populations, as was once proposed. Although such arguments are not universally accepted, many more geneticists, paleoanthropologists, and forensic scientists are now using comparative analysis of DNA sequences among and between human populations to study questions of human evolutionary history.

Key terms



bioinformatics

:

The science of compiling and managing genetic and other biology data using computers, requisite in human genome research




dysmorphology

:

Abnormal physical development resulting from genetic disorder




forensic genetics

:

the application of genetics, particularly DNA technology, to the analysis of evidence used in civil cases, criminal cases, and paternity testing




gene therapy

:

the use of a viral or other vector to incorporate new DNA into a person’s cells with the objective of alleviating or treating the symptoms of a disease or condition




gene transfer

:

Using a viral or other vector to incorporate new DNA into a person’s cells. Gene transfer is used in gene therapy




genetic screening

:

the use of the techniques of genetics research to determine a person’s risk of developing, or his or her status as a carrier of, a disease or other disorder




genetic testing

:

the process of investigating a specific individual or population of people to detect the presence of genetic defects




genomics

:

the branch of genetics dealing with the study of the genetic sequences of organisms, including the human being




pharmacogenomics

:

The branch of human medical genetics that evaluates how an individual’s genetic makeup influences his or her response to drugs




proteomics

:

the study of how proteins are expressed in different types of cells, tissues, and organs




toxicogenomics

:

evaluating ways in which genomes respond to chemical and other pollutants in the environment





Bibliography

Andrews, Lori B. The Clone Age: Adventures in the New World of Reproductive Technology. New York: Holt, 1999. Print.

Baudrillard, Jean. The Vital Illusion. Ed. Julia Witwer. New York: Columbia UP, 2000. Print.

Hartwell, Leland, et al. Genetics: From Genes to Genomes. 4th ed. Boston: McGraw, 2010. Print.

Hekimi, Siegfried, ed. The Molecular Genetics of Aging. New York: Springer, 2000. Print.

Jorde, Lynn B., et al. Medical Genetics. 4th ed. St. Louis: Mosby, 2009. Print.

Lewis, Ricki. Human Genetics: Concepts and Applications. 10th ed. Dubuque: McGraw, 2011. Print.

Pasternak, Jack J. An Introduction to Human Molecular Genetics: Mechanisms of Inherited Diseases. 2nd ed. Hoboken: Wiley, 2005. Print.

Rudin, Norah, and Keith Inman. An Introduction to Forensic DNA Analysis. Boca Raton: CRC, 2002. Print.

Shostak, Stanley. Becoming Immortal: Combining Cloning and Stem-Cell Therapy. Albany: State U of New York P, 2002. Print.

Wilson, Edward O. On Human Nature. Cambridge: Harvard UP, 1978. Print.

Is Omelas a true utopia in "The Ones Who Walk Away from Omelas" by Ursula Le Guin?

Omelas is not a true utopia because suffering exists within its community.

Omelas is described as an idyllic community, but the conditions for this happiness are "strict and absolute"; therefore, there are flaws in its perfection. For one thing, the structure of happiness is fashioned by man, who is himself imperfect. Yet, the evil is walled in, so some feel that they are safe in Omelas. Or, they feel that the child who is confined...

Omelas is not a true utopia because suffering exists within its community.

Omelas is described as an idyllic community, but the conditions for this happiness are "strict and absolute"; therefore, there are flaws in its perfection. For one thing, the structure of happiness is fashioned by man, who is himself imperfect. Yet, the evil is walled in, so some feel that they are safe in Omelas. Or, they feel that the child who is confined so that they can be happy is "too degraded and imbecile to know any real joy," and he/she cannot be freed, anyway.

Omelas is a town that holds that the greater good is served by having the one miserable being confined.

If the child were brought up into the sunlight out of that vile place, if it were cleaned and fed and comforted, that would be a good thing, indeed; but if it were done, in that day and hour all the prosperity and beauty and delight of Omelas would wither and be destroyed.

Some stay because they accept the concept of the "greater good" on which Omelas is based. Those who cannot accept this miserable being's existence as the condition for the happiness of others must walk away from Omelas. They feel that Omelas is no utopia because there is suffering, and it is selfishness to continue to allow the single person to suffer.  

How does law enforcement regulate drugs?

History of Drug Laws

With the passage of the landmark Harrison Narcotics Tax
Act in 1914, introduced by US Representative Francis Burton Harrison of New York, the US federal government began its continuous oversight of psychoactive substances. The new law made illegal and began regulating such drugs as narcotics, cocaine, and marijuana and numerous prescription and nonprescription drugs, including amphetamines.

The act taxed physicians only $1.00 annually for the right to legally prescribe opium, morphine, and coca leaves and their various derivatives, mislabeling the latter as a narcotic instead of a stimulant. However, nonphysicians were charged $1,000 for each exchange of any of these drugs, essentially prohibiting exchange under the strict penalty of law for tax evasion. Also, physicians were prohibited from prescribing opiates to treat addicts for maintenance purposes because addiction was not considered a disease, and physicians had to register with the federal government each prescription written and the name of each user.

From its enactment until 1970, the act was the prototypic antidrug law, spawning a succession of legislation drafted to limit the production, distribution, sale, and possession of unlawful substances. Following the legislative model of the 1914 act, the 1937 Marijuana Tax Act
was introduced by Robert Doughton of North Carolina and passed over the objections of the American Medical Association. The law prohibited the sale of hemp, cannabis, or marijuana by anyone other than registered and licensed commercial establishments. Each transaction of these products required a transfer tax. The Marijuana Tax Act was repealed by the Comprehensive Drug Prevention and Control Act of 1970, known as the Controlled Substances Act
(CSA), which incorporated under one statute many of the extant federal drug laws (for example, the Opium Poppy Control Act of 1942, the Boggs Act of 1951, and the Narcotic Control Act of 1956).

The CSA created a schedule of drugs (I–V) that classified substances, in a hierarchy, according to their widely accepted medical use (ascending order) and potential for abuse and dependence (descending order). According to this hierarchy, drugs in schedule I have no accepted medical use and the highest potential for abuse and dependence, whereas drugs in schedule V have an accepted medical use and the lowest potential for abuse and dependence. Many schedule V drugs (such as codeine) were available as over-the-counter medications (in small amounts in cough syrup). The CSA also transferred the authority for drug regulation from the US Department of Commerce to the Department of Justice, thereby criminalizing all aspects of the drug trade—from production to trafficking, sales, and possession.

Federal Anti-drug Agencies

The US Drug Enforcement Administration (DEA) was established in 1973 as the federal government’s lead agency for ensuring that domestic drug laws are obeyed and that drug offenders are arrested and punished. With an annual budget of more than $2 billion as of 2014, the DEA also directs many drug investigations abroad. The forerunner to the DEA was the Federal Bureau of Narcotics (FBN), housed under the Department of Treasury and led by Harry Anslinger. The FBN undertook numerous domestic and international operations in an effort to halt narcotics smuggling.

Reflecting the federal government’s abiding and serious interest in eradicating illegal drugs, it created, through the passage of the Anti-Drug Abuse Act of 1986, the White House Office of National Drug Control Policy (ONDCP), which remains under the auspices of the executive branch of the federal government. The ONDCP sets policy, allocates resources, and engages in public information campaigns to prevent and control drug sales and use throughout the country and to prohibit illegal drugs from entering the United States. The director of the ONDCP, the so-called drug czar, is appointed by the US president to serve as the leading authority on drug enforcement initiatives. The directorship, once a cabinet-level post, has been held by William Bennett (former secretary of education), Barry McCaffrey (a retired US Army general), and John Walters (former assistant to the secretary of education). Michael Botticelli, a longtime recovering alcoholic and former deputy director, was sworn into the position in February 2015.

Enforcement Activities

The enforcement of drug laws in general occurs at four levels: international, national, state, and local. The international and national levels are under the aegis of the federal government. State and local police departments have specialized units for drug enforcement activities.

In certain instances, resources at each level are combined and coordinated through special task forces that concentrate on a particular drug (such as methamphetamine) or on a particular drug-trafficking enterprise (for example, outlaw motorcycle gangs). To prevent drugs from being smuggled across country or state borders in conveyances (for example, airplanes, boats, cars, trucks, and trains), the government employs agents from the FBI, DEA, Department of Homeland Security (US Customs and Border Patrol), and Transportation Security Administration to perform searches for illegal substances in a multistage interdiction process that involves intelligence gathering, surveillance, pursuit, and capture of smugglers.

To identify smugglers, trained officers implement drug-courier profiling techniques, watching vehicles and persons for telltale signs of drug trafficking. Drugs can be hidden in legitimate cargo or in false compartments in suitcases and in vehicle trunks and door panels. To uncover illegal substances, agents use advanced imaging technologies, trained dogs, pat-downs, body scans, and searches of persons. Drug smugglers have attempted to thwart officials by swallowing drug-filled balloons or by hiding drugs in bodily orifices—a dangerous practice that can result in death if the balloons burst and their contents are absorbed through the stomach or mucosa.

In cooperation with foreign governments, the DEA has engaged in crop eradication efforts that destroy the plants that are later processed into drugs for street sales. Such efforts to destroy crops involve the use of deracination (uprooting) techniques and chemical (for example, paraquat) and incendiary agents. US and foreign governments have subsidized the growers of illegal crops (for example, poppies for opium) to encourage them to cultivate legal crops and to discourage them from participating in the drug trade.

Drug enforcement efforts also focus on interrupting the processing of crops into saleable substances. For example, the milky juice from poppies, which is turned into a brownish gummy matter and then to a powder, becomes heroin for sale and consumption. Other drug factories produce cocaine from coca leaves. More sophisticated factories produce the main ingredient for methamphetamine (pseudoephedrine). The makeshift drug laboratories that produce methamphetamine are usually located in rural areas to hide the noxious odors and toxic, environmentally hazardous chemicals that are by-products of the production process. Drug enforcement agents seize, close, and destroy drug-producing factories of every type.

At the street level, police officers in specialized drug enforcement units gather intelligence from hotlines, local residents, and low-level criminals and informants to uncover drug-selling entities, such as street gangs in urban areas or freelance drug sellers. Officers disrupt operations by raiding houses in which drugs are packaged and stored for sale. Large amounts of drugs and money are seized from these premises as evidence.

In poor communities, drugs are often sold on the street. The public nature of these transactions makes it easier for police to engage in undercover enforcement activities known as buy-and-bust operations. In sting operations, officers pose as drug customers. In reverse-sting operations, officers pose as drug sellers. In both types of activities, an arrest is made after money and drugs are exchanged.

Closed markets are more difficult to police because drug sellers engage in transactions only with known drug customers or those vouched for by trusted friends or criminal associates. Local police can enforce drug laws by implementing other strategies as well, including the use of visible area patrols, crackdowns or sweeps in drug-infested neighborhoods, and partnerships with community-based antidrug programs. Police also can enforce nuisance abatement laws, which close down or seize properties where drugs are stashed or sold, and ordinances that allow them to seal vacant buildings, which are havens for drug sellers and users.

Bibliography

Levinthal, Charles F. Drugs, Society, and Criminal Justice. Boston: Prentice Hall, 2012. Print.

Rowe, Thomas C. Federal Narcotics Laws and the War on Drugs. New York: Haworth, 2006. Print.

Zilney, Lisa Anne. Drugs: Policy, Social Costs, and Justice. Boston: Prentice Hall, 2011. Print.

What are angiotensin-converting enzyme inhibitors? How do they interact with other drugs?

Arginine

Effect: Possible Harmful Interaction

Arginine is an amino acid that has been used to improve immunity in
hospitalized persons and used for many other conditions. Based on experience with
intravenous arginine, it is possible that the use of high-dose oral arginine might
alter potassium levels in the body, especially in people with severe liver
disease. This is a potential concern for persons who take ACE inhibitors.

Licorice

Effect: Possible Harmful Interaction

Licorice root, a member of the pea family, has been used since ancient times as both food and medicine. Whole licorice (Glycyrrhiza glabra or G. uralensis) can cause sodium retention and increase blood pressure, thus counteracting the intended effects of ACE inhibitors. An often unrecognized source of licorice is chewing tobacco. A special form of licorice known as DGL (deglycyrrhizinated licorice) is a deliberately altered form of the herb that should not cause these problems.

Potassium

Effect: Possible Harmful Interaction

ACE inhibitors cause the body to retain more potassium than usual. This could raise blood levels of potassium too high, a condition called hyperkalemia, which can be dangerous. Depending on how high a person’s potassium levels, the symptoms could include irregular heart rhythm, muscle weakness, nausea, vomiting, irritability, and diarrhea. Persons taking any ACE inhibitors should not take potassium supplements except on medical advice.

Because ingesting more potassium makes the problem worse, it is important to be aware of the various sources of extra potassium. Besides potassium supplements, sources include high-potassium diets, salt substitutes containing potassium, and potassium-sparing diuretics (diuretics that cause the body to retain potassium).

Dong Quai, St. John’s wort

Effect: Possible Harmful Interaction

St. John’s wort (Hypericum perforatum) is primarily used to
treat mild to moderate depression. The herb dong quai
(Angelica sinensis) is often recommended for menstrual
disorders such as dysmenorrhea, PMS, and irregular menstruation.

ACE inhibitors have been reported to cause increased sensitivity to the sun, amplifying the risk of sunburn or skin rash. Because St. John’s wort and dong quai may also cause this problem, taking these herbal supplements during treatment with ACE inhibitors might add to this risk. It may be a good idea to wear sunscreen or protective clothing during sun exposure if also taking one of these herbs while using an ACE inhibitor.

Iron

Effect: Possible Benefits and Risks

Persons taking ACE inhibitors frequently develop a dry cough as a side effect. One study suggests that iron supplementation can alleviate this symptom. In this four-week, double-blind, placebo-controlled trial of nineteen persons, use of iron as ferrous sulfate significantly reduced cough symptoms compared with placebo.

One should keep in mind that it is not healthy to get too much iron. For this reason, it is recommended that one seek medical advice before starting iron supplements. However, iron supplements can interfere with the absorption of captopril and perhaps other ACE inhibitors. Iron appears to bind with captopril, resulting in a compound that the body cannot absorb. This also impairs iron absorption. To minimize any potential problems, one should take iron supplements and ACE inhibitors two to three hours apart.

Zinc

Effect: Supplementation Possibly Helpful

ACE inhibitors may cause zinc depletion. The ACE inhibitors captopril and enalapril attach to the trace mineral zinc. Because zinc in this bound form cannot replace the zinc that the body uses to meet its normal needs, a gradual loss of zinc from body tissues may result. Continued drug therapy could lead to zinc deficiency.

It has been suggested, though not proven, that zinc deficiency might account for some of the side effects seen with ACE inhibitors. These side effects include taste disturbances, poor appetite, and skin numbness or tingling.

Whether zinc supplementation will prevent ACE inhibitor-induced zinc deficiency has not been examined, so it seems that taking extra zinc could help. Generally, zinc supplements should also contain copper to prevent zinc-induced copper deficiency.

Bibliography

AHFS Drug Information. Bethesda, Md.: American Society of Health-System Pharmacists, 2000.

Golik, A., et al. “Effects of Captopril and Enalapril on Zinc Metabolism in Hypertensive Patients.” Journal of the American College of Nutrition 17 (1998): 75-80.

Good, C. B., L. McDermott, and B. McCloskey. “Diet and Serum Potassium in Patients on ACE Inhibitors.” Journal of the American Medical Association 274 (1995): 538.

Lee, S. C., et al. “Iron Supplementation Inhibits Cough Associated with ACE Inhibitors.” Hypertension 38 (2001): 166-170.

In Harper Lee's To Kill a Mockingbird, what does the phrase "immune to imaginative literature" mean and how does it relate to the students?

The children in Miss Caroline’s class are not used to fictional stories with talking cats and are not entertained by them.

Miss Caroline is a new teacher, and she is also new to Maycomb.  She has been trained in the newest teaching methods, but they are a little too new for Maycomb.  The children in Maycomb apparently do not get many stories told to them or books read to them, or at least not of...

The children in Miss Caroline’s class are not used to fictional stories with talking cats and are not entertained by them.

Miss Caroline is a new teacher, and she is also new to Maycomb.  She has been trained in the newest teaching methods, but they are a little too new for Maycomb.  The children in Maycomb apparently do not get many stories told to them or books read to them, or at least not of the imaginative fictional variety.  Scout says the first grade class is immune to imaginative literature because they do not seem at all interested in her story about talking cats.

Miss Caroline began the day by reading us a story about cats. The cats had long conversations with one another, they wore cunning little clothes and lived in a warm house beneath a kitchen stove. By the time Mrs. Cat called the drugstore for an order of chocolate malted mice the class was wriggling like a bucketful of catawba worms. (Ch. 2)

Miss Caroline doesn’t seem to notice the class's reaction to the book.  Everything about Maycomb is new to her, and she seems to make mistakes with everything she does. She tells Burris Ewell to take a bath (and asks him how to spell his name, which is probably not a good thing to ask any first grader on the first day of school).  She tries to lend Walter Cunningham a quarter.

It’s an uphill battle for Miss Caroline from the beginning.  From the minute the children find out she is from Winston County, they are suspicious.  Heritage means everything in Maycomb.  It is something children are taught very young.

(When Alabama seceded from the Union on January 11, 1861, Winston County seceded from Alabama, and every child in Maycomb County knew it.) North Alabama was full of Liquor Interests, Big Mules, steel companies, Republicans, professors, and other persons of no background.  (Ch. 2)

Scout and some of the other children try to help Miss Caroline out and explain how things work in Maycomb.  She can't be expected to get it all in one day, but she certainly got off to a bad start.  Stories about anthropomorphized cats are not going to mean much to a group of small town kids and farm kids in the Depression-era South.

What are worm infections? |

Definition

Parasitic worms are pathogenic organisms that attach to the internal structures of their
hosts, including humans. Worm infections can range from mild
discomfort to severe illness and death. Worms usually enter the body in the form
of eggs or cysts; they then mature within the tissues they infect, including the intestines, liver, muscles, lungs, and brain, and in the bloodstream.

Worm infections are rare in the United States and Europe but are common in
developing nations in Asia, Africa, Central America, and South America. Parasitic
worms are classified by their shape as either roundworms
(nematodes and nemathelminths) or flatworms (flukes and platyhelminths).

Causes

A worm has three life stages: egg, larva, and adult. Some worms form cysts within a host’s body that can develop into larvae when circumstances are favorable. Eggs or larvae of parasitic worms can enter the body (or host) through the mouth or through skin surfaces. Some are transmitted through an insect bite. This intermediate insect host is known as a vector. Examples of worm infections include tapeworm, hookworm, liver fluke, trichinosis, filariasis, and pinworm.

Tapeworm. Tapeworm infections occur from eating
the raw or undercooked meat of animals infected with the larvae of these
flatworms. Tapeworm infections mainly occur in Southeast Asia, Africa, the Middle
East, Mexico, South America, Russia, and areas of the former Yugoslavia. In the
United States, some forms may be acquired by swallowing the infected fleas of
infected dogs or cats.

Taenia

saginata infects beef and T. solium infects pigs. The larvae attach to the intestinal wall and mature into adult tapeworms, which can grow to be more than twelve feet long and live many years. Segments of the worm, which contain eggs, are released and then pass from the body in feces. Animals eat the feces, the grass, or other contaminated foods, thus perpetuating the cycle.

Hookworm. Hookworms are roundworms existing as
two types: Ancylostoma duodenale
and Necator americanus
. A. duodenale is found in North Africa, the Middle
East, and India; in the past, the worm was present in southern Europe. N.
americanus is present in the Americas, Southeast Asia, China,
Indonesia, and sub-Saharan Africa.

Hookworm larvae live in moist soil. The larvae are able to penetrate the soles of the feet or other skin areas that contact soil. The larvae then enter small veins and the lymphatic system, work their way to the lungs, and enter the alveoli (sacs) in the lung. They are then coughed up into the infected person’s mouth and passed down into the intestines, where they mature into adults. The adult worms release eggs, which pass out of the person’s body in the feces. If the feces are deposited in the soil, the cycle repeats.

Liver fluke. Liver flukes (Fasciola hepatica
) are flatworms that infect the liver of humans and other mammals. They are present in temperate areas where sheep are raised because these flukes use sheep and humans as a host. Most human infections occur in Southeast Asia, northern Africa, South America, and Cuba. Occasional infections occur in the United Kingdom, southern Europe, and Australia. The flukes require an intermediate host such as Galba truncatula
, an aquatic snail, to complete its life cycle. Larvae enter the snail and develop into what is known as metacercariae; these organisms leave the snail and attach to plants such as water chestnuts and watercress. When eaten, further development of the parasite occurs; these organisms then burrow through the intestinal wall and into the liver; they then enter the bile ducts and mature into the adult form. The adults lay eggs, which pass through the bile duct into the intestines; they are then excreted, completing the life cycle.

Trichinosis. Trichinosis is caused by the roundworm Trichinella spiralis
. Infections were once common in the United States; however, they are
now quite rare. Infections are more common in developing nations and in eastern
Europe. Pigs become infected with trichinosis when they eat infected rodents or
meat from other pigs. Humans become infected when they eat infected pork. The
infection is passed in the form of cysts within skeletal muscles. When infected
muscle is eaten, the cysts develop into adults and mate in the small intestine.
Their eggs develop into larvae, which pierce the small intestine and enter the
bloodstream and migrate to other structures such as the heart or eye, or to the
lymphatic system. The skeletal musculature is the only place where they can
survive and form cysts.

Filariasis. Lymphatic filariasis, also known as
elephantiasis, is caused by the roundworms Brugia malayi
, B. timori, and Wuchereria
bancrofti
. About one-third of infected persons live in Africa, about one-third
in India, and the rest in other parts of Asia, the Americas,and the Pacific
Islands. The disease is transmitted from human to human by some species of mosquitoes. Mosquito species that can transmit the disease are Culex
quinquefasciatus and some Anopheles species;
Brugia roundworms are primarily transmitted by
Mansonia mosquitoes. Another type of filariasis is a tropical
skin and eye disease, Loa loa filariasis, which is also known as African eye worm. It is contracted through the bite of a deer fly or mango fly.

In filarial infections, the parasites enter the bloodstream as microfilariae and develop into adults. The adults mate and
produce more microfilariae. If a person is bitten by a host insect, the
microfilariae infect that insect and, thus, complete the life cycle. The
microfilariae travel from the bloodstream into the lymphatic
system, which is a network of vessels that maintain a delicate fluid
balance between body tissue and the bloodstream. They lodge in the lymphatic
system, where they mature into adult worms. These worms live for four to six years
and produce millions of immature microfilariae that circulate in the blood. The
adult worms block the normal flow of lymphatic fluid, damaging the lymphatic
system. Adult Loa loa worms often travel to the conjunctiva (just
below the surface of the eyeball); the worms transit the eyeball in about fifteen
minutes, causing much pain; however, the transit does not usually affect
vision.

Pinworm. The pinworm (Enterobius
species) is a roundworm that is a common intestinal parasite
worldwide. It is most common in children. Persons are infected by eating food
contaminated with the eggs. The eggs hatch in the duodenum (the first portion of
the small intestine). The eggs develop into larvae and migrate toward the colon
(the large intestine). The larvae become adults in the ileum (the lower part of
the small intestine) and mate. After mating, the males die and pass from the body
in the stool. The pregnant females attach themselves to the ileum and the first
portion of the large intestine, where they feed on the intestinal contents. The
female body becomes filled with eleven thousand to sixteen thousand eggs. The
females then migrate to the infected person’s anus, where they release the eggs
and die.

Risk Factors

The major risk factor for many parasitic worm infections is living in an area where the worms are endemic (always present). Infections are more common in slums and poor communities. Poor personal hygiene and poor sanitation increase the risk of infection. Contact with fecal material increases the risk of infection with intestinal worms. In developing nations, humans defecate on the soil or use fecal material (night soil) as fertilizer. Going barefoot in contaminated areas can result in a hookworm infection. Eating raw or incompletely cooked pork increases the risk of trichinosis. Pinworms are more common among people in close contact (such as in a classroom or in crowded living conditions). Immigrants from areas where parasitic infections are endemic can expose the persons of the new country or region to these infections.

Symptoms

The symptoms of worm infection vary, depending on the type of worm involved.

Tapeworms. Often, tapeworm infections do not have any specific
symptoms. Weight loss and anemia can occur. Sometimes, a person will notice
tapeworm segments in the stool. Rarely, tapeworms can cause intestinal
obstruction, which produces nausea, vomiting, and severe abdominal pain. On
occasion, cysts can form in the brain and the meninges (the
tissues surrounding the brain). If this occurs, the patient may experience
neurologic symptoms such as headaches, seizures, and confusion. On rare occasions,
cysts can form in the eyes, which can cause blindness, or in the spinal cord,
which can result in muscle weakness or paralysis.

Hookworms. General symptoms, such as itching on the soles of the feet, can occur soon after infection. Cough and pneumonitis (lung inflammation) can occur when the worms break into the alveolae in the lungs. When the larvae enter the small intestine, diarrhea and gastrointestinal discomfort can occur. Heavy infestations result in iron deficiency anemia from intestinal blood loss and malnutrition. Long-term blood loss can result in facial edema (swelling). Children with chronic hookworm infections can suffer from growth retardation and intellectual impairment.

Liver flukes. Infected persons suffer from abdominal pain, nausea, vomiting headaches, and anemia. Some develop jaundice (yellowing of the skin), hives, and muscle pains. Over time, blockage of the bile ducts can occur.

Trichinosis. Within a week after becoming infected, persons
experience gastrointestinal symptoms such as nausea, heartburn, and diarrhea.
After the larvae migrate from the intestines to the muscles, symptoms include
fatigue, muscle pain, fever, and edema (swelling). A characteristic sign of a
trichinosis infection is periorbital edema (swelling around the eyes). Splinter
hemorrhages in the nails may occur. These appear as narrow, red to reddish-brown
lines of blood beneath the nails. Occasionally, the worms invade the central
nervous system (the brain and the spinal cord), where they can produce serious
neurological conditions such as ataxia (a lack of muscle coordination),
respiratory paralysis, and death.

Filariasis. In lymphatic filariasis, the adult worms block the
normal flow of lymphatic fluid, damaging the lymphatic system. This blockage
produces tremendous enlargement of the arms, legs, or genitals, which may swell up
to several times the normal size. The worms also lodge in the kidneys, causing
damage. Loa loa filariasis can also produce swelling of the
extremities. Transit of the worm across the eyeball is a unique sign of this
disease. Lymphedema (swelling of the limbs) can occur if the worms
block lymphatic channels in the arms and legs. Intermittent swelling, known as
Calabar swellings, of the arms can occur because of an allergic reaction. Calabar
swellings may be accompanied by urticaria (rash) and pruritus (itching).

Pinworms. Itching around the anus is a common symptom. The skin around the anus may also be inflamed. Vaginal itching can occur in young girls if the worms enter the vagina rather than the anus.

Screening and Diagnosis

Many worm infections produce an allergic response. Often, these infections will
cause an increase in the eosinophils in the bloodstream, causing a condition known
as eosinophilia. A complete blood count (CBC), including a
differential count, reveals the number of eosinophils present in the bloodstream.
Eosinophils are a type of white blood cell, which increases with an allergic
response. A blood test, which can be done in most medical laboratories, may reveal
specific antibodies to the type of worm present. A more complex but
highly accurate test can be done in a genetics laboratory that can conduct
deoxyribonucleic acid (DNA) sequencing for parasite-specific DNA in a blood
sample.

In cases of suspected tapeworm infection, a stool sample will reveal tapeworm eggs or body segments containing eggs. For hookworms, except for early infections, a stool sample will contain hookworm eggs. For liver flukes, a stool sample is often positive for eggs. Adult worms can sometimes be present in a sputum sample or in vomit.

Trichinosis can be diagnosed after learning the infected person has eaten contaminated meat. If a sample of the meat is available, microscopic examination will reveal cysts. The characteristic signs of periorbital edema and splinter hemorrhages in the nails aid the diagnosis. As in many other worm infections, eosinophilia is present.

For cases of filariasis, examination of a blood sample may reveal the presence of microfilariae. Their presence in the bloodstream is periodic; thus, the sample must be drawn when the microfilaria are likely to be present. Visualization of a worm transiting the eyeball is diagnostic for Loa loa filariasis. A simple card test detects antigens to lymphatic filariasis; however, antibody tests are not particularly helpful with Loa loa filariasis because cross-reactivity between Loa loa and other worm infections often occurs.

For pinworm infections, the worms are seen in the anus, particularly at night when they lay their eggs. Placing a piece of tape against the anus will collect eggs for microscopic examination.

Treatment and Therapy

A number of anthelminthic (antiworm) medications are available to treat worm infestations. Inasmuch as many worm infections can produce anemia, iron supplements are helpful.

Tapeworms can be treated with a single-dose oral medication. Niclosamide is the drug of choice; however, praziquantel and albendazole are also effective.

While still in the skin, hookworm infections can be treated by cryotherapy
(localized freezing). During migration to the intestines and while in the
intestines, albendazole (Albenza) or mebendazole are effective. Triclabendazole is
the drug of choice to treat liver flukes. Resistant strains, however, have been
reported in Ireland and Australia.

If given early, albendazole or mebendazole can eradicate the intestinal worms
and larvae in trichinosis. These medications are less effective after cysts form;
however, they are beneficial if the larvae enter the central nervous system,
heart, or lungs. Analgesics (pain relievers) are given for muscular pain. Over
time, the cysts often calcify; this destroys the larvae, and the muscle pain and
fatigue resolve. Corticosteroids are given to reduce allergic reactions and
inflammation when dead or dying larvae release chemicals within the muscles.

The drug of choice for filariasis (both lymphatic and Loa loa) is diethylcarbamazine (DEC); ivermectin is also effective. Doxycycline is under investigation as a supplementary agent to use with DEC. DEC is most effective against the microfilariae; it is less effective against the adult worms. Sometimes, after receiving a course of medication, the surviving worms are surgically excised. For pinworms, a single dose of either albendazole or mebendazole is effective. These medications are available by prescription and over the counter.

Prevention and Outcomes

Tapeworm infections can be prevented by avoiding raw meat and by cooking meat to a core temperature greater than 140° Fahrenheit for five minutes. Freezing meat to −4° F for twenty-four hours will also kill the eggs. Self-reinfection can be prevented by good hygiene and thorough handwashing after using the toilet.

Hookworm infections can be avoided by not walking barefoot in any area suspected of having infected soil, by defecating only into a toilet connected to a sewage system, and by avoiding the use of human feces for fertilization.

Liver fluke infections can be prevented by the avoidance of eating raw vegetables from any region inhabited by aquatic snails, such as G. truncatula. Filariasis infections can be prevented by avoiding the fly bites that spread Loa loa. Spraying homes with the pesticide dieldrin is an effective method of destroying the insect vectors.

Pinworm infections can be prevented by thorough handwashing before meals and after using the toilet, cleaning toilet seats daily, washing bed linens twice a week, keeping fingernails short and clean, and by not scratching infected areas around the anus.

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