A clinically applicable technique to study cytoskeletal dynamics in normal and abnormal polymorphonuclear leukocytes isolated from small volume blood samples.

Shape change and motility of polymorphonuclear leukocytes (PMNs) are essential for host defense and require dynamic reorganizations of microfilamentous cytoskeleton by reversible polymerization of G-actin into filaments (F-actin). Although clinical disorders of actin polymerization are rare, recently described simple methodologies for assaying actin dynamics in PMNs make the technique readily applicable to clinical studies. To develop a clinically useful F-actin assay, the authors investigated the optimal preparation conditions for PMN isolation that resulted in the least in vitro cytoskeletal activation and evaluated the variability in actin dynamics in acutely and chronically infected patients. Basal and chemotactic factor-activated PMN F-actin content was measured by a previously described flow cytometric technique in fixed, permeabilized, NBDphallacidin-stained PMNs isolated by centrifugation in Percoll or Ficoll-Hypaque density gradients or by countercurrent elutriation. F-actin content is expressed as mean fluorescent channel or relative fluorescence intensity. Basal F-actin in PMNs prepared from countercurrent elutriation (mean fluorescent channel = 79.0 +/- 4.5, n = 6) or by Ficoll Hypaque (82.0 +/- 3.5, n = 4) was significantly higher than endotoxin free, Percoll purified PMNs, whether purified in bulk (56.1 +/- 7.9, n = 8) or by the small volume modification applicable to clinical studies (53.3 +/- 8.7, n = 15). Basal Ficoll Hypaque purified PMNs have evidence of shape change, whereas endotoxin free, Percoll purified PMNs are smooth and round and represent the most basal cell equivalent in F-actin content to a circulating PMN.(ABSTRACT TRUNCATED AT 250 WORDS)

Foot blister risk factors in an ROTC summer camp population.

Data that establish risk factors for foot blister morbidity among ROTC cadets at summer camp are presented. The subjective blister attack rate was 42.1 per 100 cadets. Women had a relative risk of 1.6 that of men (p < 0.001). Cadets with a history of blisters in the 2 years before camp had an increased relative risk of blister formation. Cadets who reported wearing their boots less than 20 hours per week during the 2 weeks immediately before camp had elevated risk. Other factors are examined. These data suggest that the foot must become conditioned to its footwear to prevent blister formation.

Hemothorax in a patient with asthma.

Treatment of chronic illnesses such as asthma can often become routine. This is a case report that emphasizes the importance of a thorough history and physical examination for each exacerbation of asthma. An 11-year-old girl with a history of asthma presented to the emergency room with wheezing and dyspnea that was assumed to be an exacerbation of her chronic illness. After careful history taking and physical examination, a chest radiograph was recommended. The x-ray revealed a hemothorax and a new diagnosis was made, thoracic Ewing's sarcoma.