274   The Bradyarrhythmias: Disorders of the Sinoatrial Node David D. Spragg, Gordon F. Tomaselli Electrical activation of the heart normally originates in the sinoatrial (SA) node, the predominant pacemaker. Other…

236   Histoplasmosis Chadi A. Hage, L. Joseph Wheat ETIOLOGY Histoplasma capsulatum, a thermal dimorphic fungus, is the etiologic agent of histoplasmosis. In most endemic areas, H. capsulatum var. capsulatum is…

PYROGENS The term pyrogen (Greek pyro, “fire”) is used to describe any substance that causes fever. Exogenous pyrogens are derived from outside the patient; most are microbial products, microbial toxins,…

It is now appreciated that genotypes of T. gondii prevalent in South America may be more virulent than those typically seen in North America or Europe. These genotypes may be…

PART 14: Disorders of the Gastrointestinal System SECTION 1 DISORDERS OF THE ALIMENTARY TRACT   344   Approach to the Patient with Gastrointestinal Disease William L. Hasler, Chung Owyang ANATOMIC CONSIDERATIONS…

236   Histoplasmosis Chadi A. Hage, L. Joseph Wheat ETIOLOGY Histoplasma capsulatum, a thermal dimorphic fungus, is the etiologic agent of histoplasmosis. In most endemic areas, H. capsulatum var. capsulatum is…

PYROGENS The term pyrogen (Greek pyro, “fire”) is used to describe any substance that causes fever. Exogenous pyrogens are derived from outside the patient; most are microbial products, microbial toxins,…

It is now appreciated that genotypes of T. gondii prevalent in South America may be more virulent than those typically seen in North America or Europe. These genotypes may be…

Molecular Defects     More than 90% of patients clinically classified as having MFS by the “Ghent criteria” have a mutation in the gene for fibrillin-1 (FBN1). Mutations in the same gene are…

POLYURIA By history, it is often difficult for patients to distinguish urinary frequency (often of small volumes) from true polyuria (>3 L/d), and a quantification of volume by 24-h urine…