Radioiodinated cryptococcal polysaccharide was used to study binding of the soluble polysaccharide to encapsulated and non-encapsulated cryptoccoci. Binding of polysaccharide to non-encapsulated cryptococci occurred rapidly over a 30-min period and was largely complete after 2 h. Bound, labeled polysaccharide was slowly eluted from Cryptococcus neoformans after the addition of unlabeled polysaccharide, indicating reversibility of binding. Non-encapsulated cryptococci bound polysaccharide in two ways. Specific binding to the yeast was saturable by ca. 82 ng of polysaccharide per 106 yeast cells. Nonspecific binding also occurred which was not saturable under the conditions used in our experiments. Phagocytosis of the nonencapsulated yeast strain was inhibited when the specific binding was ca. 50% saturated. Binding of polysaccharide to an encapsulated strain showed nonspecific, nonsaturable binding, but little specific binding occurred. Presumably the specific binding sites were saturated in the encapsulated strain. Polysaccharides obtained from a hypocapsular mutant (A61) and a normally encapsulated strain competed effectively with labeled serotype D polysaccharide for binding sites on non-encapsulated cryptococci and had identical phagocytosis-inhibiting properties. Similarly, polysaccharides from all four cryptococcal serotypes competed effectively with labeled serotype D polysaccharide for binding sites on the nonencapsulated strain, and all four polysaccharides inhibited phagocytosis of non-encapsulated Cryptococcus neoformans. Unmodified, de-O-acetylated, carboxyl-reduced, periodate-oxidized and reduced (polyalcohol), and Smith-degraded polysaccharides competed with labeled polysaccharide for binding sites on the cell. The unmodified, de-O-acetylated and carboxyl-reduced polysaccharides inhibited phagocytosis of nonencapsulated cells, but the polyalcohol and Smith product were unable to inhibit phagocytosis. Cryptococcus neoformans is surrounded by a capsular polysaccharide that inhibits phagocytosis of the yeast by macrophages (21). Non-encapsulated cryptococci are en
A hybridoma produced by the polyethylene glycol fusion of the NS-1 variant of the P3x63Ag8 BALB/c plasmacytoma to splenocytes harvested from a BALB/ c mouse immunized with whole gonococci was found to be producing antibody to a common region on gonococcal lipopolysaccharide (LPS). Enzyme-linked immunosorbent assay inhibition systems were established by utilizing this antibody, designated 3F11, and 100% inhibition occurred with both LPS and the LPSderived polysaccharides from each of the six prototype strains. Meningococcal LPS and LPS-derived polysaccharides partially inhibited the enzyme-linked immunosorbent assay, whereas similar preparations isolated from Escherichia coli 0:111, the J-5 mutant of this strain, and Salmonella minnesota Re595 failed MATERIALS AND METHODS Strains. Prototype strains representative of the six gonococcal LPS serotypes were obtained from our own collection. These were strain 1342 (serotype Gc,), strain 1291 (serotype GC2), strain 4505 (serotype GC3), strain 8551 (serotype Gc4), strain PID2 (serotype Gcs), and strain 3893 (serotype Gc6). Strain 4505r was also 751 on August 1, 2020 by guest http://iai.asm.org/ Downloaded from
Newborn screening (NBS), a comprehensive system that includes testing, diagnosis, follow-up, treatment, education, and evaluation, was recently named one of the Top 10 Great Public Health Achievements by the Centers for Disease Control and Prevention (CDC). 1 Each year, approximately 10,000 infants are identified with NBS conditions, which frequently go unnoticed at birth. 2 NBS is administered by state public health programs across the country and provides for early identification of newborns with certain congenital, metabolic, endocrine, hematologic, and other genetic conditions. Early identification of these conditions in newborns facilitates timely interventions that result in significant decreases in morbidity, mortality, and disability. 1 Screening begins by pricking a newborn's heel to get enough blood to fill a few circles on a filter paper card. The specimen, referred to as a dried blood spot, is collected by a health-care provider-typically at the birthing facilityduring the first 24-48 hours of life. Some states are required to collect two specimens, in which case the second specimen is collected between seven and 15 days of life. The specimens are then sent to a state-designated NBS laboratory for analysis. When a test result is out of normal range, laboratory or follow-up personnel contact the birthing facility and the newborn's physician to ensure the child receives the appropriate diagnostic work-up and treatment. NBS goes beyond blood-spot screening to include point-of-care testing for hearing and, in some states, critical congenital heart disease. These tests are performed at the hospital shortly after birth, and the state NBS program performs follow-up testing. Although there is some variability in protocols among states, most NBS programs have similar components, including specimen collection, laboratory testing, follow-up, education of providers and the public, verification of a diagnosis, treatment, and ongoing program evaluation. 3 Newborn Screening 15Public Health Reports / 2013 Supplement 2 / Volume 128
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