The problem of peptic ulcer

Rethinking the history of peptic ulcer disease and its relevance for network epistemology

The history of the research on peptic ulcer disease (PUD) is characterized by a premature abandonment of the bacterial hypothesis, which subsequently had its comeback, leading to the discovery of Helicobacter pylori-the major cause of the disease. In this paper we examine the received view on this case, according to which the primary reason for the abandonment of the bacterial hypothesis in the mid-twentieth century was a large-scale study by a prominent gastroenterologist Palmer, which suggested no bacteria could be found in the human stomach. To this end, we employ the method of digital textual analysis and study the literature on the etiology of PUD published in the decade prior to Palmer's article. Our findings suggest that the bacterial hypothesis had already been abandoned before the publication of Palmer's paper, which challenges the widely held view that his study played a crucial role in the development of this episode. In view of this result, we argue that the PUD case does not illustrate harmful effects of a high degree of information flow, as it has frequently been claimed in the literature on network epistemology. Moreover, we argue that alternative examples of harmful effects of a high degree of information flow may be hard to find in the history of science.

A collection of the etiological theories, characteristics, and observations/phenomena of peptic ulcers in existing data

In this article, we compiled 13 etiological theories, 15 characteristics, and 81 observations/phenomena of peptic ulcers, reported in reproducible, peer-reviewed studies from the literature, to reflect the historical evolution of studies on peptic ulcers and to provide a multidisciplinary view of this disease. This data was collected during the systematic review of topics on peptic ulcers including genetics, etiology, epidemiology, psychology, anatomy, neurology, bacteriology, pathology, and clinical statistics. The data curated herein was extracted via application of recently published basic theories and methodologies.

Plasma prednisolone levels in man following administration in plain and enteric-coated forms

1 Prednisolone plasma levels were measured in seven patients by a competitive protein binding method after administration of prednisolone (20 mg) by mouth as plain or enteric-coated tablets. 2 The mean peak plasma prednisolone concentration after the enteric-coated preparation, 199 ng ml-1, was significantly lower than after the plain tablet, 268 ng ml-1, and occurred later, at 4.69 h compared with 1.72 h. The bioavailability of the two preparations was similar. 3 It is concluded that, although the plasma concentration versus time profiles are different, the absorption of prednisolone from plain and enteric-coated preparations is equal.