We have examined receptors mediating phagocytosis of the intracellular bacterial pathogen, Legionella pneumophila. Three mAbs against the type 3 complement receptor (CR3), which recognizes C3bi, inhibit adherence of L. pneumophila to monocytes by 64 +/- 8% to 74 +/- 11%. An mAb against the type 1 complement receptor (CR1), which recognizes C3b, inhibits adherence by 68 +/- 1%. mAbs against other monocyte surface antigens do not significantly influence adherence. Monocytes plated on substrates of L. pneumophila membranes modulate their CR1 and CR3 receptors but not Fc receptors; such monocytes bind 70% fewer C3b-coated erythrocytes and 53% fewer C3bi-coated erythrocytes than control monocytes. Adherence of L. pneumophila to monocytes in nonimmune sera is dependent on heat-labile serum opsonins; adherence is markedly reduced in heat-inactivated serum (84% reduction) or buffer alone (97% reduction) compared with fresh serum. mAbs against CR1 and CR3 receptors also inhibit L. pneumophila intracellular multiplication and protect monocyte monolayers from destruction by this bacterium. This study demonstrates that human monocyte complement receptors, CR1 and CR3, mediate phagocytosis of L. pneumophila. These receptors may play a general role in mediating phagocytosis of intracellular pathogens.
ABSTRACT. Objective. Long-term outcome, including school-age function, has been infrequently reported in infants born at ages as young as 23-26 weeks' gestation. The objective of this study is to report outcome on a large cohort of these infants to understand better the risks and factors that affect survival and long-term prognosis.Methods. Records from 1036 infants who were born between January 1, 1986, and December 31, 2000, were analyzed retrospectively by logistic regression to correlate multiple factors with both survival and long-term outcome. A total of 675 surviving infants were analyzed at a mean age of 47.5 months for developmental outcome. A subset of 147 surviving infants who were born before 1991 were followed through school-age years using the University of Vermont Achenbach Child Behavioral Checklist and Teachers Report Form. Longitudinal follow-up was performed comparing 1-year outcome with school-age performance.Results. Gestational age and recent year of birth correlated highly with survival. Maternal nonwhite race, female sex, inborn status, surfactant therapy, single gestation, and secondary sepsis also correlated positively with survival. Normal cranial ultrasound results, absence of chronic lung disease, female sex, cesarean delivery, and increased birth weight correlated favorably with long-term outcome. Infants who were born at 23 weeks were more likely to have severe impairments compared with those who were born at 24 -26 weeks. Early follow-up identified most subsequent physical impairments but correlated poorly with school-age function.Conclusions. Survival continues to improve for infants who are born at extremely early gestational ages, but long-term developmental concerns continue to be prevalent. Early outcomes do not reliably predict schoolage performance. Strategies that reduce severe intraventricular hemorrhage and chronic lung disease will likely yield the best chances to improve long-term outlook. Pediatrics 2004;113:e1-e6. URL: http://www.pediatrics. org/cgi/content/full/113/1/e1; prematurity, outcome, neurodevelopment, survival, follow-up.
NBIs are associated with increased hospital treatment costs and LOS but by varying amounts depending on the BW. Preventing a single NBI could reduce the treatment costs of a VLBW infant by at least several thousand dollars. These savings are a greater percentage of the total treatment costs in VLBW infants with BW 1001 to 1500 g than in smaller infants.
An appreciable number of these marginally viable fetal infants survive. They experienced a high rate of serious morbidities while in the NICU. There is very little information about long-term outcomes, as the medical and developmental status of few of these infants has been followed carefully. Parents should be made aware of the high incidence of serious problems, and concerted efforts should be made to follow the status of these infants.
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