Acute MI. Age-related presentations and treatment options.

At least 60% of all acute myocardial infarctions (AMIs) occur in patients age 65 and older and about one-third in patients older than age 75. The presentation of AMI is modified by age-related changes in endothelial function, smooth muscle cell activity, diastolic function, and responses to circulating catecholamines. Atypical presentations are common in the older patient and require the physician to maintain a high index of suspicion for AMI. ECG findings of ST-segment depression make many older patients ineligible for reperfusion by thrombolytic therapy. Acute and post-MI medical therapies are underused in the older population and should be individualized, based on the presence of comorbid conditions.

Rubella immunity in a cohort of pregnant women.

To assess the rubella immune status of a cohort of high-risk pregnant women visiting a Midwestern clinic, we retrospectively studied 50 random pregnancies per year from 1990 through 1996. Of 350 patients analyzed, 53 (15.1%) were not immune to rubella, and vaccination opportunities were missed.

Binding and germination of Aspergillus fumigatus conidia on cultured A549 pneumocytes.

Invasive pulmonary aspergillosis is acquired through inhalation of conidia. Little is known about early interactions between Aspergillus fumigatus conidia and alveolar epithelial cells, so an in vitro model was developed to study binding between conidia and A549 cells, a line of type II pneumocytes. Conidia rapidly became attached to confluent monolayers of A549 cells in serum-free medium, reaching a plateau within 40 min. Scanning electron microscopy (EM) showed a random pattern of early adherence; viable conidia subsequently became clustered on pneumocyte surfaces. Following germination of pneumocyte-adherent conidia for 12 h, direct penetration of epithelial cells by hyphae could be demonstrated by scanning and transmission EM. These data suggest that an early event following inhalation of A. fumigatus conidia may be binding of conidia to pneumocytes, followed by hyphal penetration of the epithelial cell layer.

Aspergillus fumigatus complement inhibitor: production, characterization, and purification by hydrophobic interaction and thin-layer chromatography.

Aspergillus fumigatus has previously been shown to produce a soluble extracellular inhibitor of the alternative complement pathway, called Aspergillus complement inhibitor, or CI. We now report an efficient method for production of CI which relies on the fact that poorly conidiating cultures yielded CI activity with approximately sevenfold-higher potency than CI produced by conidiating cultures. CI from poorly conidiating cultures provided 50% inhibition of alternative pathway-mediated binding of 125I-labeled complement component C3 to cryptococcal blastoconidia at a mean concentration of 60 micrograms/ml. The ability of crude CI to inhibit the alternative complement pathway seemed to be independent of intact protein or polysaccharide structure, as evidenced by resistance of inhibitory activity to digestion by proteases, including subtilisin, alpha-chymotrypsin, papain, and pepsin as well as endoglycosidases F and H. Separation of the active inhibitory component of CI from contaminating materials contained in crude CI preparations was achieved by using Phenylsuperose hydrophobic interaction chromatography in a fast protein liquid chromatography system. The active material proved to be extremely hydrophobic, desorbing from the column only during elution with ethanol; it contained only 15% protein and 5% polysaccharide. Furthermore, results from preparative thin-layer chromatography indicated that lipids which comigrated with phosphatidylserine/phosphatidylinositol and phosphatidylethanolamine possessed significant complement-inhibitory activity. Taken together, these data suggested that phospholipids from A. fumigatus contributed to the functional activity of CI.