Infection of mice with respiratory syncytial virus during neonatal life primes for enhanced antibody and T cell responses on secondary challenge.

Primary neonatal immune responses to infection or vaccines are weak when compared with those of adults. In addition, memory responses of neonatally primed animals may be absent, weak or T helper type 2 (Th2)-biased. Respiratory syncytial virus (RSV) is an important pathogen of human infants and infection during the neonatal period has been linked to the development of asthma in later life. Here we report that acute intranasal infection of neonatal mice with RSV induces significant RSV-specific antibody and CD8 T cell responses. These responses were boosted after RSV rechallenge during adulthood, demonstrating the establishment of memory after neonatal priming. Primary infection during neonatal life was associated, following rechallenge, with limited viral replication in the lung. Recall responses of both spleen and lymph node cells from neonatally primed and adult-primed mice were associated with interferon-gamma secretion, indicative of a Th1-type response. However, interleukin (IL)-4 and IL-5 secretion were enhanced only in spleen and lymph node cells from neonatally primed mice. Rechallenge of neonatally primed mice was also associated with increased concentrations of chemokines monocyte chemoattractant protein-1, macrophage inflammatory protein-1alpha and regulated upon activation normal T cell expressed and secreted in the lung. These may play a role in the enhanced inflammatory cell recruitment and immunopathology induced following RSV reinfection. Our results demonstrate therefore that immunity to RSV can be established during neonatal life and, importantly, that the quality of the subsequent response is dependent upon the age of first infection.

Ozone trends in Atlanta, Georgia: have emission controls been effective?

Nine years of summertime ozone data from the Atlanta metropolitan area are analyzed and compared to local emissions of volatile organic carbon and nitrogen oxides. Trends from 1979 to 1987 were studied for the number of days per year ozone exceeded the NAAQS standard, the second-highest ozone level observed per year, and the first quartile summertime average ozone observed, as well as the mean difference between the ozone level observed downwind and upwind of the city. Because this last parameter is sensitive to chemical factors but relatively insensitive to the number of days each year with meteorological conditions conducive to ozone formation, its trend may be best suited for determining how effective emission controls have been in reducing O3 in the Atlanta area. In spite of the fact that sizeable reductions have been claimed for volatile organic carbon emissions over the past several years, the data give no indication that ozone levels have decreased and in fact imply that summertime ozone production may have increased. The results imply that either emissions have not decreased as much as has been claimed or that ozone is not sensitive to anthropogenic volatile organic carbon emissions. In either event, a reevaluation of our nation's strategy for O3 abatement in Atlanta and comparable cities is needed.

The role of biogenic hydrocarbons in urban photochemical smog: Atlanta as a case study.

The effects of natural hydrocarbons must be considered in order to develop a reliable plan for reducing ozone in the urban atmosphere. Trees can emit significant quantities of hydrocarbons to metropolitan areas such as Atlanta, and model calculations indicate that these natural emissions can significantly affect urban ozone levels. By neglecting these compounds, previous investigators may have overestimated the effectiveness of an ozone abatement strategy based on reducing anthropogenic hydrocarbons.

Urinary incontinence in the geriatric population of an acute care hospital.

To determine the incidence, prevalence, and duration of urinary incontinence, a survey was undertaken of all patients aged 65 and over admitted to a university hospital during a six-week period. The daily prevalence of incontinence, which was 19 per cent for the entire study population, was highly variable from one nursing unit to another. Twenty-five per cent of those on the acute care general medical units and 17 per cent of those on the general surgical units were incontinent on any given day. The burn unit had the highest daily prevalence of incontinence (75 per cent). The incidence of incontinence per hospital stay, which was determined for the 315 patients who were followed from admission to discharge, was 19 per cent. Of the 348 patients discharged to home during the survey period, 10.9 per cent were incontinent within the 24 hours prior to leaving the hospital, and, of the 27 referred to another institution, 48 per cent had been incontinent during that interval. The authors conclude that a substantial proportion of geriatric patients are incontinent at some stage during their hospital stays.