A surrogate method for assessment of beta(2)-integrin-dependent adhesion of human eosinophils to ICAM-1.

We have developed and validated an inexpensive and equivalent method for measuring eosinophil adhesion by beta(2)-integrin to endothelial ICAM-1 using bovine serum albumin (BSA) as a surrogate for the immunoglobulin supergene. The number of adherent eosinophils on BSA or ICAM-1 coated microplates was quantified by residual eosinophil peroxidase activity. Non-stimulated eosinophils did not adhere to either BSA or ICAM-1. However, after IL-5 stimulation, either BSA or ICAM-1 caused comparable and concentration-dependent adhesion of eosinophils. Eosinophil adhesion was rapid and occurred within 15 to 30 min of incubation for either BSA or ICAM-1. Preincubation of cells with CD11b or CD18 antibody specifically decreased adhesion to either BSA or ICAM-1. IL-5, PAF and fMLP all induced adhesion of eosinophils to either BSA or ICAM-1 in a concentration-dependent manner, and the optimal IL-5, fMLP and PAF concentrations for adhesion to BSA were the same as for adhesion to ICAM-1. BSA-binding was specific for beta(2)-integrin; neither alpha-CD49d mAb directed against the alpha(4)-chain or alpha-CD29 directed against the common beta(1)-chain of VLA-4 blocked adhesion to BSA or ICAM-1 controls. The protein tyrosine kinase inhibitor, genistein, the phosphatidylinositol 3-kinase (PI-3 kinase) inhibitor, wortmanin, and mitogen-activated protein kinase kinase (MEK) inhibitor, U0126, all inhibited IL-5-induced eosinophil adhesion to either BSA or ICAM-1 comparably. These results indicate that BSA is a reliable and economical surrogate ligand for ICAM-1 adhesion to beta(2)-integrin-dependent adhesion to ICAM-1. Ligation characteristics of BSA are identical to those for soluble ICAM-1, and the assay is suitable for assessment of signal transduction pathways mediating adhesion.

Tuberculosis control policies in major metropolitan health departments in the United States. VI. Standard of practice in 1996.

Since 1980, we have surveyed at 4-yr intervals the metropolitan health departments initially reporting > 250 cases of tuberculosis to determine the perceived standard of practice for tuberculosis control and the factors affecting formulation of treatment policies. Between 1992 and 1996, use of supervised short-course (6 to 9 mo) intermittent therapy with multiple drugs including isoniazid, ethambutol, pyrazinamide, and rifampin increased from 4.3% to 46% of all new patients. Pyrazinamide use for initial treatment for children has increased substantially and now predominates (74.2% of patients in 1996 versus 48.1% of patients in 1992). Duration of treatment, which was 20 +/- 2.1 mo in 1980, is now 8.00 +/- 2.29 mo in 1996. The incidence of human immunodeficiency virus-associated tuberculosis, which was virtually unrecognized in 1984, has remained the same between 1992 and 1996 (18.0%). As in previous years, there was a wide variance among health departments in the incidence (< 5% to > 40%) of HIV-associated tuberculosis. After years of funding decreases, there has been an impressive increase in resources in the past 4 yr. In 1988, mean budget allocation for health departments decreased by 7.9% versus the prior 4 yr and, in 1992, there was no overall change in budget allocation after inflation versus 1988. In 1996, however, funds for treatment increased by 84 +/- 33%. This increase in funding has been translated into the greatly expanded use of supervised intermittent therapy and aggressive screening programs, which likely have resulted in the decreased incidence of tuberculosis since the prior survey.

Assessment of agonist- and cell-mediated responses in airway microsections by computerized videomicrometry.

The objective of this investigation was to develop a method for real-time measurement of changes in luminal area in microexplants of airways during pharmacological and physiological interventions. After guinea pigs were killed, tracheal rings (1- to 2-mm thick) were excised and placed in 300-microliters chambers. The area of the airway lumen was calculated as pixel number with the use of computerized videomicrometry. In 29 epithelium-intact airways, 10(-3) M acetylcholine (ACh) caused decrease in luminal area of 38.1 +/- 2.80% (P < 0.001 vs. 10(-9) M). Spontaneous tone also was demonstrated in 34 preparations from 4 guinea pigs; decrease in area of 17.0 +/- 1.45% after 60-min incubation in buffer alone was blocked completely by 10(-5) M indomethacin (P = 0.01). Luminal narrowing caused by < or = 10(-6) M ACh was reversed completely by 10(-6) M albuterol (P = 0.002). Addition of 100,000 activated human eosinophils caused 24.7 +/- 4.41% decrease in luminal area vs. 7.24 +/- 5.51% for nonactivated cells (P = 0.048). We demonstrate a real-time method for the assessment of auxotonic changes in airway caliber that utilizes microsections of explanted airways and permits the use of extremely small numbers of isolated cells to achieve physiological activation. Concentration-response characteristics and spontaneous tone are similar to those of large chamber preparations, and narrowing is reversed by beta 2-adrenoceptor activation.

Tuberculosis control policies in major metropolitan health departments in the United States. IV. Standards in 1988.

Twenty-eight metropolitan health departments reporting greater than 250 cases annually in 1978 were surveyed to determine the standard of practice in the control of pulmonary tuberculosis and the factors affecting treatment policy. The results were compared to previous surveys in 1978, 1980, and 1984 to determine the impact of policies recommended by the Centers for Disease Control, state health departments, and other agencies. A high degree of uniformity again was demonstrated in chemoprophylaxis and hospitalization policies. However, screening, drug toxicity monitoring, and post-treatment follow-up varied widely among programs. A major trend toward short-course chemotherapy (mean duration of treatment, 20.8 +/- 2.34 months in 1980 versus 7.59 +/- 1.02 months in 1988) accompanied inclusion of pyrazinamide in first-line treatment of 59.4% of all patients in 1988 versus none in 1980. The prevalence of acquired immune deficiency syndrome (AIDS) in association with tuberculosis was estimated to be 7.72% in 1988 versus 2.52% in 1984; nine programs identified AIDS + tuberculosis in greater than 5% of all new cases in 1988 versus only two programs in 1984. Health departments identified the recommendations of the Centers for Disease Control and their respective state health departments as the major source of treatment policy; recommendations of the World Health Organization, American Academy of Pediatrics, and peer-reviewed literature had little effect upon treatment policies. This survey identifies substantial departures from prior treatment policies, some of which are attributed to reduction in available funding, development of shorter-course technology, and recognition of new groups of patients at risk to develop tuberculosis in the major cities in the major cities in the United States.(ABSTRACT TRUNCATED AT 250 WORDS)