Mycoplasma pneumoniae and Nocardia asteroides in lung biopsy tissue of an immunodeficient infant.

Mycoplasma pneumoniae and Nocardia asteroides were recovered from lung tissue of an infant with an immunologic deficit. The isolate suggests a possible role of M. pneumoniae as an opportunistic pathogen. This case underscores the importance of comprehensive evaluation of lung biopsy specimens and the usefulness of Mycoplasma cultures.

Receptor-specific mediation by immunoglobulin E of antigen-induced contraction of tracheal and lung parenchymal strips isolated from the guinea pig.

The guinea pig is much like humans in the cells and mediators involved in immediate hypersensitivity reactions. However, the major anaphylactic antibody in this species is IgG1, not IgE. Recently, we have been successful in producing IgE antibody in guinea pigs. The current study examined whether guinea pig IgE antibody could mediate pulmonary smooth muscle contraction. IgE antibody to picryl and oxazolone determinants was induced by immunizing Hartley strain guinea pigs pretreated with cyclophosphamide. Hyperimmune serum from these animals was passed through a heavy chain-specific anti-IgG1 affinity column. The presence of IgE anti-hapten antibody in the filtrate fraction was verified by passive cutaneous anaphylaxis (PCA) testing with a 7-d period of local passive sensitization and by heat lability (56 degrees C X 4 h) of PCA activity. This IgE-rich fraction, and purified IgG1 anti-hapten antibody were transferred to normal guinea pigs. Both fractions sensitized trachea and pulmonary parenchyma for antigen-induced smooth muscle contraction. The IgG1-mediated antigen-induced contractile response was not affected by heat (56 degrees C X 4 h) and was inhibited in a dose-dependent fashion by IgG1 blocking antibody (anti-OA). The IgE-mediated antigen-induced contractile response was significantly decreased by heat and was not affected by the anti-OA blocking antibody even at a concentration of 100 mg/kg. Thus, two antigen-specific factors in guinea pig serum can mediate antigen-induced pulmonary smooth muscle contraction: IgG1 and IgE antibodies. Our data also suggests that these antibodies mediate the contractile response through separate receptors. The finding that guinea pig IgE can mediate pulmonary smooth muscle contraction suggests this species can be a model for IgE-mediated events in the lung.

An immunological assessment of patients with anorexia nervosa.

Patients with most forms of protein-calorie malnutrition are typically more susceptible to infection. We studied the immunological consequences of a subgroup of malnourished subjects--nine patients with anorexia nervosa, who typically have a lower incidence of infection. The profiles of the patients with anorexia nervosa deviated from the reported typical profile of significantly depressed cell-mediated immunity in subjects with more common forms of protein-calorie malnutrition, demonstrating normal T-lymphocyte populations and unimpaired proliferative lymphocyte responsiveness to mitogenic stimulation with phytohemagglutinin and concanavalin A. In fact, mitogen responsiveness was significantly elevated above that of controls, and with nutritional repletion, this enhanced responsiveness regressed toward control values. Since impaired cell-mediated immunity has been consistently documented in other malnourished populations, and presumably contributes to their increased propensity toward infection, the maintenance of a relatively intact cell-mediated immune system may be an important factor separating the malnourished anorexia nervosa patient from other protein-calorie malnourished patients.

Respiratory syncytial virus infection: ten-year follow-up.

Studies within the last 20 years have shown that the incidence of asthma is increased in children who have been hospitalized with bronchiolitis due to respiratory syncytial virus. To evaluate such respiratory consequences in an ambulatory population, a follow-up study was done of 37 children who had respiratory syncytial virus infection documented at a community pediatric clinic in 1968 when they were younger than 4 years. This study, done ten years later by chart review and parental interview, showed that asthma had subsequently been diagnosed in three (8%). Thus, an increased risk for the development of asthma after respiratory syncytial virus infection was not found. Comparison of these data with those from previous reviews questions a causative role for respiratory syncytial virus in childhood asthma.

The effect soaking pea seeds with or without seedcoats has on seedling growth.

Pea seeds (Pisum sativum L. ;Alaska') with intact seedcoats (WC) and with seedcoats removed (WOC) were soaked in distilled water for 24 hours at 20 degrees . The water, containing the pea diffusate, was decanted after the second, fourth, sixth, eighth, twelfth, and twenty-fourth hour and analyzed for total nitrogen, alpha-amino nitrogen, carbohydrate, and total solute dry weight. The seeds were germinated at 20 degrees in a 16 hour photoperiod of 300 foot candles. Stem lengths and dry weights of roots, shoots and cotyledons were determined after 4, 11, and 18 days of growth. WOC seeds imbibed more water than WC seeds during the 24 hour imbibition period. Diffusates from WOC seeds always contained more solute than diffusates from WC seeds. Maltose, glucose, and fructose were not detected in the early diffusates from WOC seeds but were found in WC seed diffusates at all times. Seedlings from WC seeds had longer stems than those from WOC seeds. The dry weight of stems and roots of WC seedlings was greater than those from WOC seedlings. The dry weight of cotyledons from 18 day-old WC seedlings was less than from WOC seedlings. Water absorption by WC seeds was slower than by WOC seeds. Removal of the seedcoat allowed rapid imbibition resulting in seed injury presumably because of the loss of solutes which included monosaccharides, disaccharides, amino acids, and other nitrogen containing compounds. These results are consistent with the hypothesis that rapid imbibition disrupts membrane organization leading to reduction of seedling growth.