Comparison of participation in federal worksite and community health promotion programs.

The extent to which employees rely on the worksite exclusively for health promotion programs was examined in a cross-sectional study of 10 federal worksites. Responses were received from 3,403 of the 5,757 employees surveyed (59%). Fewer than 10% of employees exclusively used agency programs for physical fitness, nutrition, substance abuse, smoking cessation, and support group meetings. A higher percentage participated in health risk assessment (27%), health and disease risk education activities (17%), medical care services (23%), personal safety and first aid training 26%, and stress management programs (17%) only at the worksite. Men were more likely than women to participate exclusively in workplace programs.

In vitro activity of pleconaril and AG7088 against selected serotypes and clinical isolates of human rhinoviruses.

BACKGROUND: We tested the in vitro activity of pleconaril and AG7088 against five numbered human rhinovirus (HRV) serotypes and 46 clinical HRV isolates of undefined serotype recovered from patients with common colds. Antiviral effect of pleconaril and AG7088 were assessed by cytophathic effect (CPE) inhibition assays in Ohio HeLaI cells using microscopic and spectrophotometric methods. Both compounds were tested at concentrations of 1.0, 0.1 and 0.01 microg/ml. For the numbered HRV serotypes, the median EC(50) value determined by the microscopic CPE inhibition was slightly better for AG7088 compared to pleconaril (P=0.02) but was similar by spectrophotometric assay (P=0.15). For clinical HRV isolates the median EC(50) value determined microscopically was 0.01 microg/ml range, <0.01-0.04 microg/ml) for AG7088 compared to 0.07 microg/ml (range, <0.01->1 microg/ml) for pleconaril (P<0.001). The median EC(50) value determined by spectrophotometric assay was 0.01 microg/ml (range, <0.01-0.04 microg/ml) for AG7088 compared to 0.04 microg/ml (range, <0.01->1 microg/ml) for pleconaril (P<0.001). By either the microscopic or spectrophotometric methods the median EC(50) value of AG7088 was <1.0 microg/ml for all isolates and was >10.0 microg/ml of pleconaril for approximately 9% of isolates. In vitro AG7088 appeared to be more potent and to have a broader antirhinoviral spectrum than pleconaril among clinical HRV isolates. The clinical relevance of these in vitro results needs to be determined in controlled clinical trials.

Comparative susceptibilities of human embryonic fibroblasts and HeLa cells for isolation of human rhinoviruses.

The recovery of human rhinovirus (HRV) from nasal washings and nasal and pharyngeal swabs from volunteers with naturally acquired colds was compared in different cell types. Human embryonic lung fibroblast (HELF) strain WI-38 (sensitivity, 61 to 84%) and HeLa-I, an HRV-susceptible HeLa clone (sensitivity, 86 to 94%), were the most sensitive cell types used. HELF-WI-38 cells showed a cytopathic effect earlier than the other cells used, and the different strains of HRV-susceptible HeLa cells varied in their sensitivities for HRV isolation. HRV was detected in a single cell type in 20 to 35% of the positive samples, suggesting that use of a combination of different HRV-susceptible cell lines is the best approach for the recovery of HRV. Although nasal washings tended to yield more HRV isolates than nasal and pharyngeal swabs, the two sampling methods were not found to be significantly different.

Effect of organization-level variables on differential employee participation in 10 federal worksite health promotion programs.

Guided by a conceptual model, the authors used both qualitative data (e.g., individual interviews, focus groups) and quantitative data from an employee survey (N = 3,388) in 10 federal agencies to investigate whether organization context and implementation process affected participation in worksite health promotion and disease prevention (HPDP) activities among demographic subgroups. Overall, employees on average participated in fewer than two agency-supported health-related activities per year (17% in fitness, 40% in health risk assessment activities). Employees participated more where coworkers endorsed such programs. Minority employees and employees in lower level positions were more likely to participate in fitness activities when organizations had a more comprehensive program structure, engaged in more marketing strategies, gave time off to employees to participate, or had on-site facilities. Management support for the program was related to participation by employees who were male, white, and had upper level positions. The data supported the proposed model; also confirmed was two predicted relationships between model constructs, which provided a better understanding of differential participation by employee groups.

Comparative antirhinoviral activities of soluble intercellular adhesion molecule-1 (sICAM-1) and chimeric ICAM-1/immunoglobulin A molecule.

We conducted a comparative study of the antirhinovirus activities of soluble intercellular adhesion molecule-1 (sICAM-1) and a chimeric ICAM-1/immunoglobulin A (IgA) molecule (ICI-5D/IgA) for nine major receptor group human rhinovirus (HRV) serotypes and for a variant of HRV-39 relatively resistant to inhibition by sICAM-1. ICI-5D/IgA inhibited the infectivity of eight of the nine wild-type HRVs and the resistant HRV-39 variant and was 60 to 170 times more potent than sICAM-1 on a molar basis. In contrast to sICAM-1, ICI-5D/IgA directly neutralized the infectivity of the representative HRVs by approximately 1 log10. These results expand on the antirhinovirus spectrum of ICI-5D/IgA, confirm that dimeric forms of sICAM-1 have a higher antirhinoviral potency than monomeric sICAM-1, and indicate that cross-linking of two adjacent receptor binding sites on the virus capsid by a divalent receptor enhances the direct inactivation of viral infectivity.

In vitro selection of human rhinovirus relatively resistant to soluble intercellular adhesion molecule-1.

Variants of human rhinovirus serotype 39 (HRV-39) relatively resistant to inhibition by soluble intercellular adhesion molecule-1 (sICAM-1) were selected by serial passages in HeLa or WI-38 cells in the presence of sICAM-1. Moderate resistance (four- to fivefold increases in 50% effective inhibitory concentrations [EC50s]) was observed after the second passage in HeLa cells and remained constant during six further passages in the presence of 10 micrograms of sICAM-1 per ml. A 7- to 17-fold increase in EC50s was observed in WI-38 cells during passage with 10 micrograms/ml, and reversion to a nonresistant phenotype was not observed after four passages in the absence of sICAM-1. Resistance of a higher degree was obtained by passing HRV-39 in the presence of 100 micrograms of sICAM-1 per ml in HeLa cells (30-fold EC50 increase). The sICAM-1-resistant phenotype was estimated to constitute 1 in 10(4) to 1 in 10(5) PFU of a nonexposed HRV-39 population. Low to moderate levels of resistance to sICAM-1 inhibition emerge readily during in vitro passage in the presence of sICAM-1 and appear to be phenotypically stable.

In vitro studies of the antirhinovirus activity of soluble intercellular adhesion molecule-1.

We studied the in vitro antirhinovirus activity of a soluble form of intercellular adhesion molecule-1 (sICAM-1). sICAM-1 inhibited the cytopathic effect of 10 representative human rhinovirus (HRV) serotypes of the major receptor group with, 50% effective concentrations (EC50s) of 0.1 to 7.9 micrograms/ml. Cell type-dependent variation in the inhibitory activity of sICAM-1 was observed for two major receptor group serotypes in HeLa cells (EC50, greater than 32 micrograms/ml), and no inhibitory effect was observed for two serotypes which use different cell receptors. Yield reduction assays showed that sICAM-1 inhibited the replication of HRV serotype 39 (HRV-39) in human adenoid explants in a concentration-dependent manner. No direct inactivation of infectivity of HRV-39 (EC50, 0.5 microgram/ml) was observed after incubation with sICAM-1 (32 micrograms/ml) for up to 24 h. Single-cycle-of-replication experiments with the addition of sICAM-1 at 10 micrograms/ml at different times showed that the inhibitory effect occurs only when sICAM-1 is added within 30 min after infection. In experiments in which absorption was carried out at 4 degrees C and then a single cycle of replication incubation was carried out at 33 degrees C, it was found that sICAM-1 at 10 micrograms/ml was inhibitory only when it was present during the absorption period. Our data show that sICAM-1 is inhibitory for representative major receptor group serotypes of HRV in two cell lines and human respiratory epithelium, that the interaction of sICAM-1 with HRV is readily reversible by dilution, and that the inhibitory effect of sICAM-1 on virus replication is present early in the infection cycle.