Monday, August 26, 2013

The Epidemiology of Diabetes Melitus Ebook PDF

Diabetes mellitus is a disease that was recognized in antiquity. Polyuric states resembling diabetes mellitus were described as early as 1550 BC in the ancient Egyptian papyrus discovered by George
Ebers (1). The term ‘diabetes’, which is from the Ionian Greek meaning ‘to pass through‘, was first used by Aretaeus of Cappadocia in the second century AD as a generic description of conditions causing increased urine output (2). The association of polyuria with a sweet-tasting substance in the urine was noted in the fifth to sixth century AD by two Indian physicians, Susruta and Charuka (1,2). The urine of certain polyuric patients was described as tasting like honey, sticky to the touch and attracting ants. Two forms of diabetes could be distinguished in the Indians’ descriptions: one affected older, fatter people and the other thin people who did not survive long; this strongly reminds us the present clinical description of Type 2 and Type 1 diabetes.
The term diabetes mellitus, an allusion to the honeyed taste of the urine, was first used in the late
eighteenth century by John Rollo and others (3) to distinguish it from other polyuric states in which
the urine was tasteless. The concept that diabetes was a systemic disease arising in the blood was
elaborated a century before (in the seventeenth century) by Matthew Dobson, a physician in Liverpool (England) who published a series of experiments showing that the serum of a patient
with diabetes, as well as the urine, contained a sweet-tasty substance namely sugar (4). The nineteenth century is the key century that has greatly contributed to the understanding of diabetes. Claude Bernard made numerous discoveries in the field of metabolism and diabetes.
He described the storage of glucose in the liver as a glycogen and the acute hyperglycemia that
followed experimental damage of the medulla oblongata known as ‘piqiire’ diabetes (5). Oskar
Minkowski and Josef Von Mering noted that total pancreatectomy produced diabetes in dogs (6). The pancreatic islets were named after Paul Langerhans by Edouard Lafresse. Langerhans had suggested that pancreatic isfets produced a giucose-lowering substance. This substance was named insulin by Jean de Meyer in 1909, almost a decade before insulin was discovered (7). Although diabetes mellitus has been recognized for many centuries and major advances have been accomplished since the discovery of insulin in the understanding of diabetes and metabolism, there was no clear or widely accepted definition of the diabetic state until the early 80s.
In 1980, the World Health Organization (WHO) Expert Committee on diabetes mellitus (8) defined the diabetic state as a state of chronic hyperglycemia which may result from many environmental and genetic factors often acting jointly.
Hyperglycemia is due to defects in insulin secretion, insulin action or both. This imbalance leads
to disturbances of carbohydrate, fat and protein metabolism. The major effects of diabetes mellitus
include long-term damage, dysfunction and failure of various organs. Diabetes mellitus may present with characteristic symptoms: thirst, polyuria, polydypsia, blurring of vision, weight loss, and infections. In its most severe forms, ketoacidosis or a non-ketotic hyperosmolar state may develop and lead to stupor, coma and, in absence of effective treatment, death. Most of the time, symptoms are not severe, or may be absent, and consequently hyperglyceniia of sufficient degree to cause pathological and functional changes may be present for a long time before the diagnosis is made. The longterm complications of diabetes mellitus include progressive development of disease of the capillaries of the kidney and retina, damage to the peripheral nerves and excessive atherosclerosis.
The clinical manifestations of these complications therefore include nephropathy that may lead to
renal failure, retinopathy with potential blindness, neuropathy with risk of foot ulcers, amputation,
Charcot joints, and features of autonomic dysfunction, including sexual dysfunction.
People with diabetes are at increased risk of cardiovascular, peripheral vascular and cerebrovascular
disease. Diabetes mellitus is thus defined as a set of abnormalities characterized by a state of sustained hypgerglycemia. It is a clinical description with a clienucal definition. Pathogenic mechanisms and various explanations, to be found, lie behind the sustained hyperglycemia. Processes which destroy the beta-cells of the pancreas with consequent insulin deficiency, and others that result in resistance to insulin action are part of a possible group of to insulin action are part of a possible group of processes involved


Problem-Based Behavioral Science and Psychiatry PDF EBOOK

Welcome to Problem-Based Behavioral Science and Psychiatry. In this chapter, our aims are to illustrate how the problem-based learning process works so that you can apply it to the other cases in this textbook.
The goals of this chapter are:
1. To provide the reader with a guided experience on “how to use this textbook”
2. To review basic principles of problem-based learning and the rationale for why
this approach is used
3. To illustrate, with a sample case, the processes of
(a) “Progressive disclosure”
(b) Identifying facts/problems, hypotheses/differential diagnoses, additional
clinical information needed, and learning issues
(c) Thinking about underlying neurobiology and other physiological mechanisms
to understand the signs and symptoms of a case
4. To review the more generic process of bio-psycho-social-cultural-spiritual formulation,
in order to understand the various perspectives offered by patient cases

Because a textbook is not the same as a patient encounter or face-to-face smallgroup discussion, we are not claiming to represent problem-based learning (PBL) in a pure or “authentic” form (Barrows, 1986,2000). However, we hope to integrate many of the principles and potential benefits of PBL into this textbook.
PBL, as described by Norman and Schmidt (1992), aims to endow learners with the skills of clinical reasoning, cooperative learning, and patient-based integration of knowledge. In its ideal form, it begins with an initial free-inquiry process, in which learners explicitly discuss hypotheses and additional lines of investigation.

This is followed by a period of self-directed learning and a synthesis and application of information back to the case. The student then has an opportunity to critically evaluate the initial clinical reasoning process. Because PBL attempts to integrateinformation from multiple disciplines, all phases of the process emphasize attentionto the biological, behavioral, and populational aspects of the case. Certain articles (Guerrero, 2001; Guerrero et al., 2003) have discussed how certain learning tools can be used to ensure that beneficial PBL processes actually occur in the course of studying a case.We will illustrate these tools, including “mechanistic case diagramming,” as part of this sample case.

When compared to traditional learning methods, PBL may enhance the application of concepts to clinical situations, long-term retention of knowledge, and lifelong interest in learning (Norman and Schmidt, 1992). It has been shown to improve student and faculty satisfaction and educational outcomes in numerous
clinical disciplines, including family medicine, pediatrics, obstetrics, and psychiatry (Washington et al., 1999; McGrew et al., 1999; Kaufman and Mann, 1999; Curtis et al., 2001; Nalesnik et al., 2004; McParland et al., 2004). Furthermore, we believe that psychiatry and the behavioral sciences, because of the inherently integrative and holistic approaches of these subject areas, are particularly well suited for study in a PBL format (Frick, 2005; Zisook, 2005). Peters et al. (2000) reports on the longitudinal outcomes of a randomized controlled trial and concludes that the New Pathways Program at Harvard Medical School—of which PBL is one important component—improved students’ interpersonal skills and humanistic approach to
patient care, with no loss in medical knowledge.

We will illustrate the problem-based learning process as applied to cases in this textbook. Typically, each chapter will begin with an introductory paragraph for a case.

Tuesday, August 20, 2013


Dengue fever (DF) is an old disease; the fi rst record of a clinically compatible
disease being recorded in a Chinese medical encyclopaedia in 992. As the global ship-
ping industry expanded in the 18th and 19th centuries, port cities grew and became
more urbanized, creating ideal conditions for the principal mosquito vector, Aedes
aeg ypti. Both the mosquitoes and the viruses were thus spread to new geographic areas
causing major epidemics. Because dispersal was by sailing ship, however, there were
long intervals (10–40 years) between epidemics. In the aftermath of World War II,
rapid urbanization in Southeast Asia led to increased transmission and hyperendemicity.
The fi rst major epidemics of the severe and fatal form of disease, dengue haemorrhagic
fever (DHF), occurred in Southeast Asia as a direct result of this changing ecology. In
the last 25 years of the 20th century, a dramatic global geographic expansion of epidemic
DF/DHF occurred, facilitated by unplanned urbanization in tropical developing coun-
tries, modern transportation, lack of effective mosquito control and globalization. As
we go into the 21st century, epidemic DF/DHF is one of the most important infectious
diseases affecting tropical urban areas. Each year there are an estimated 50–100 million
dengue infections, 500 000 cases of DHF that must be hospitalized and 20 000–25 000
deaths, mainly in children. Epidemic DF/DHF has an economic impact on the com-
munity of the same order of magnitude as malaria and other important infectious dis-
eases. There are currently no vaccines nor antiviral drugs available for dengue viruses;
the only effective way to prevent epidemic DF/DHF is to control the mosquito vector,