The Tentative Nature of Scientific Knowledge Why Should We Teach More about Diabetes Mellitus?

Abstract

HE of an can be used to illustrate the tentative nature of scientific knowledge. Students very often have the mistaken idea that whatever they read in their textbooks is fact engraved in stone. Learning about the disease mellitus gives students an indication as to the complexity of scientific puzzles. Clinical applications often arise out of painstaking research into difficult problems. Scientists may have to delve into many intricate avenues of research before valuable clinical applications emerge. Standard college human anatomy and physiology textbooks discuss the disease diabetes mellitus in a somewhat superficial manner. Granted, these textbooks stress normal, rather than abnormal, physiology, yet they rarely share with readers the difficulties encountered in understanding abnormal conditions. Diabetes mellitus, as a disease, illustrates the heterogenous nature of an illness. In addition, it also demonstrates how the etiology of an illness is elucidated by modern science. It is necessary for college teachers training health professionals to be well versed in the mechanics of science in order for them to convey to their students an appreciation of the problems involved in understanding, alleviating, arresting or curing any pathological condition as intricate as this disease. What do we know about diabetes mellitus? It is a term referring to an increased output of urine (diabetes, means shunt) and a high sugar content (mellitus, meaning sugar). In other words, diabetes mellitus refers to a metabolic shunt away from the use of sugar (glucose). The osmotic pressure of the urine is raised by excessive sugar, since it is not used, causing abnormally large quantities of water and electrolytes to be excreted. In the textbook, Principles of Anatomy and Physiology by Tortora and Anagnostakos, the authors indicate the heterogeneity of the disease. Research has led many to conclude that diabetes is not a single hereditary disease, but rather a heterogeneous group of hereditary diseases, all of which ultimately lead to an elevation of glucose in the blood (hyperglycemia) and excretion of glucose in the urine as hyperglycemia increases (p. 421). A brief discussion follows concerning the difference between maturity-onset diabetes (most common type) and juvenile-onset diabetes. Though this textbook's discussion of diabetes mellitus is sufficient to explain the pathological outcomes of the disease, it does not encompass the intricate nature of the defects leading to the disorder. Diabetes mellitus is a relatively common disease. Table 1 illustrates the prevalence of the disease in the United States by race and sex. Since the first extraction of the water-soluble protein hormone insulin from the pancreatic tissue of dogs by Banting and Best in 1921 (Duncan 1982), the elucidation of its action has been a prime concern of investigators. Its effect upon carbohydrate, fat and protein metabolism has been ascertained. In addition, the synthesis and processing of insulin by the beta cells of the islets of Langerhans of the pancreas has been defined. Further, the insulin cell surface receptor has been characterized. Early contributions to the comprehension of diabetes mellitus as a disease are illustrated in Table 2. Following Banting and Best's isolation of insulin, Table 1. Sex and race of diabetics-Rate per 1000 population over age 18.