Serial phenotypic analysis of mouse peripheral blood leukocytes.

Repeated phenotypic analysis of mouse peripheral blood leukocytes over short periods of time (2 weeks) has been difficult because of the very limited volumes of blood available under guidelines of the Institutional Animal Care and Use Committee. The loss of leukocytes and variations among laboratories during conventional flow cytometry sample preparation based on lysing and repeated washing have been limiting factors when measuring multiple parameters in small samples. We describe a method of phenotypic analysis using a no-lyse, no-wash staining technique combined with fluorescent triggering for data collection that can be performed on volumes of 20 muL or less of whole blood per set of markers in one tube.

Flow cytometric enumeration of micronucleated reticulocytes: high transferability among 14 laboratories.

This laboratory previously described a single-laser flow cytometric method, which effectively resolves micronucleated erythrocyte populations in rodent peripheral blood samples. Even so, the rarity and variable size of micronuclei make it difficult to configure instrument settings consistently and define analysis regions rationally to enumerate the cell populations of interest. Murine erythrocytes from animals infected with the malaria parasite Plasmodium berghei contain a high prevalence of erythrocytes with a uniform DNA content.

Immune response of infants and children to disseminated infections with Neisseria meningitidis.

Acute- and convalescent-phase sera from 34 children and 10 young adults were studied to determine if, at what age, and to which antigens of Neisseria meningitidis they respond during disseminated disease. Seven children older than two years of age who were infected with group C or Y strains developed significant increases in both binding and bactericidal antibody. Children infected with group B strains infrequently (eight [31%] of 26) had measurable increases in serum antibody to this capsular polysaccharide; response was meager when it did occur, was unrelated to age, and was considerably poorer than that of young adults, of whom 80% responded.

Human immune response to various doses of group Y and W135 meningococcal polysaccharide vaccines.

A divalent vaccine containing equal weights of Neisseria meningitidis group Y and group W135 capsular polysaccharides was inoculated subcutaneously into groups of 32 military recruit volunteers at doses of 10, 25, 50, and 100 micrograms in 10-microliter/microgram volumes. At 4 weeks, the two higher doses induced significantly greater binding antibody responses than did the two lower doses. Differences in response were not found between the two higher doses or between the two lower doses.

Heterogenity of serotypes of Neisseria meningitidis that cause endemic disease.

Three collections of strains of Neisseria meningitidis that caused meningococcal disease during nonepidemic periods were serotyped to determine whether serotypes that cause endemic disease are more heterogeneous than those responsible for epidemic disease. Thirty-four strains isolated from pediatric patients in Houston, Texas, from February 1977 to March 1978 were of three separate serogroups and 11 serotypes; 27 contemporary (1977-1978) strains from predominantly military populations, obtained nationwide, were of six serogroups and six serotypes, while 11 strains isolated at military posts in the southwest United States from 1970 through 1976 were of four serogroups and five serotypes. Between 9% and 20% of the strains were nontypable, while type II strains which were responsible for the epidemics in the Northern and Western Hemispheres earlier in the 1970's, accounted for only 20%-44% of the strains.

Separation and purification of immunoglobulins M,A and G from small volumes of human sera by a continuous, inline chromatographic process.

A continuous, in-line chromatographic process for the separation of immunoglobulins M, A and G from small volumes of human sera is described. The process involves the sequential and uninterrupted application of molecular sieve, ion-exchange, immunoadsorbent-affinity and de-saltin-concentrating chromatographic methodologies. From 1-3 ml of starting serum it yields 45-55%, by weight, of the three classes of immunoglobulins in 36 h.

Immunoepidemiology of meningococcal disease in military recruits. I. A model for serogroup independency of epidemic potential as determined by serotyping.

One hundred twenty strains of Neisseria meningitidis were serotyped with use of cross-absorbed rabbit antisera in a bactericidal test. Fifty-eight epidemic strains of serogroup B, C, and Y that occurred simultaneously among military recruits at two basic training centers during a period of epidemic meningococcal disease were compared with 62 strains of serogroups A, B, C, and Y isolated worldwide. Antisera to the six original antigenic factors of the Gold serotyping schema were adequate for typing 94% of strains, including all of the epidemic strains.

Response to antigenic determinants of Neisseria meningitidis lipopolysaccharide investigated with a new radioactive antigen-binding assay.

Adaptations of the Farr technique have resulted in a specific and reproducible radioactive antigen-binding assay for antibodies directed against the lipopolysaccharide (LPS) of Neisseria meningitidis. LPS was intrinsically labeled with 14C acetate during 16-hr growth in a modified Frantz media, extracted by hot phenol-H2O, and purified by dialysis, ultracentrifugation, and ethanol precipitation. LPS, which aggregates in aqueous solutions, was maintained in a monomeric form in 3% sodium deoxycholate (NaD) as determined by gel filtration on Sephadex G-75.