Construction of the knowledge file for an image understanding system.

To enable an image understanding system to provide an automated interpretation of diagnostic imagery it must have access to all of the concepts, procedures and methods used by human experts. The paper describes information elicitation from experts of different domains and the construction of a knowledge file. Uncertainty management is based on Bayesian belief network methods.     

Circulatory and extracirculatory effects of angiotensin-converting enzyme inhibition.

The antihypertensive effects of angiotensin-converting enzyme (ACE) inhibitors cannot be fully explained by their actions on the circulating renin-angiotensin system (RAS). Agents such as captopril or enalapril maintain efficacy during long-term therapy even when plasma concentrations of converting enzyme or angiotensin II are not fully suppressed. Components of the entire RAS exist at several sites, thereby making it possible for drugs to produce effects at extracirculatory locations. An ACE inhibitor such as quinapril that has a comparatively short plasma concentration half-life binds strongly to plasma ACE as well as to ACE in key tissues including artery wall, heart, and kidney. The effects of ACE inhibition on the tissue RAS are of potential importance in fully explaining the blood pressure-lowering effects of these drugs. ACE inhibitors might also reduce blood pressure by blocking nonhemodynamic actions of angiotensin II. They affect vascular properties by increasing compliance of arteries and they act on baroreceptors and central regulatory mechanisms. Furthermore, ACE inhibitors affect other neuroendocrine systems, including aldosterone, kinins, and prostaglandins; attenuation of sympathetic activity can contribute further to their antihypertensive properties. Actions independent of circulating renin effects do not necessarily require plasma ACE inhibition throughout a 24-hour period. Sustained antihypertensive effects by drugs with short durations of plasma ACE inhibition give credibility to therapeutic targets beyond the circulating RAS.     

Diffuse peripheral odontogenic fibroma: report of 3 cases

Since peripheral odontogenic fibroma (POF) is characteristically described as a solitary lesion and no diffuse POF had been reported in the literature, our cases should be considered as extremely unusual. Three diffuse cases of POF are described of which one case was seen in association with ocular and skin lesions. The question arises whether POF should be considered as a true odontogenic tumor rather than a diffuse hamartomatous lesion caused by uncontrolled induction of the gingiva. It is also possible that such lesions could be part of a yet undescribed syndrome.     

2-Aminofluorene-DNA adducts in mouse urinary bladder: effect of age, sex and acetylator phenotype.

Formation of urinary bladder DNA-2-aminofluorene adducts in inbred and acetylator congenic mice was measured 3 h after a 60 mg/kg dose of the arylamine carcinogen. The sensitivity of 32P-postlabeling with HPLC analysis permitted quantitation of adducts in individual mouse bladders. Acetylator phenotype was a significant determinant of DNA damage in female mice as slow acetylators had higher levels of bladder DNA adducts than rapids. This correlation is the reverse of that seen with hepatic DNA. Age was also a significant determinant of DNA damage as older mice (20-23 weeks) formed more bladder DNA adducts than young (7 week) mice. The age-related increase in bladder adduct formation was seen in both sexes of all mouse lines. Male B6 mice exposed to 2-aminofluorene at 20-23 weeks of age showed a 26-fold higher level of bladder DNA adducts than males exposed at 7 weeks. In addition to the large increase in total adduct level, the older male B6 mice produced significant amounts of an unidentified, early-eluting adduct peak that had chromatographic properties similar to an aminofluorene-DNA adduct produced through peroxidative activation. These results indicate that age, sex and acetylator phenotype are all important determinants of aromatic amine-bladder DNA adduct formation in mice.     

Die obere Halswirbelsäule — eine besondere Herausforderung

Ohne Zusammenfassung     

Disseminated microsporidiosis (Encephalitozoon hellem) and acquired immunodeficiency syndrome. Autopsy evidence for respiratory acquisition.

Microsporidia are obligate intracellular protozoal parasites that infect a variety of cell types in a broad range of invertebrates and vertebrates. They have recently come to medical attention due to the increased frequency with which members of two microsporidian genera, Enterocytozoon and Encephalitozoon, are being diagnosed in patients with the acquired immunodeficiency syndrome (AIDS). The majority of published reports of human microsporidiosis describe Enterocytozoon infection of small intestinal enterocytes. In addition, a growing number of AIDS patients have been identified with infection due to the two species of Encephalitozoon-Encephalitozoon cuniculi and Encephalitozoon hellem, observed in conjunctival, corneal, and, recently, sinonasal tissues. However, there are scant data regarding the systemic pathology and epidemiology of these infections. This article describes a patient with AIDS who died with systemic Encephalitozoon infection. The etiologic microsporidian was found to be E hellem by using antemortem biochemical and antigenic analyses. A complete autopsy, the first to be reported in a patient with this infection, revealed organisms in the eyes, urinary tract, and respiratory tract. A surprising observation was the occurrence of numerous organisms within the lining epithelium of almost the entire length of the tracheobronchial tree, suggestive of respiratory acquisition. Detailed light and electron microscopic findings and the biological and diagnostic features of microsporidiosis are discussed.