Chlamydia DNA extraction for use in PCR: stability and sensitivity in detection.

We evaluated multiple procedures for extracting chlamydial DNA from specimens for detection in PCR tests. Commercial kits and an in-house method were tested for their sensitivity and utility. Quantifiable chlamydial elementary bodies (EB) were used for spiking buffy coats from EDTA-collected blood.

Application of a nested, multiplex PCR to psittacosis outbreaks.

We developed a nested, multiplex PCR for simultaneous detection of three species of chlamydiae in human and avian specimens. The PCR was designed to increase sensitivity and to circumvent inhibitors of PCR present in clinical specimens. The target sequence was the 16S rRNA gene.

ELISPOT assay for Chlamydia-specific, antibody-producing cells correlated with conventional complement fixation and microimmunofluorescence.

Chlamydia antigens cross-reactive with pneumoniae (TWAR), psittaci, and trachomatis strains were used to evaluate the ELISPOT assay for detecting antigen-specific, antibody-secreting cells (ASC). Human blood specimens from healthy and hospitalized persons were randomly collected and tested by coating the nitrocellulose membrane at the base of microtiter wells. Ficoll-separated mononuclear cells from blood specimens collected in EDTA were incubated in the wells with Iscove's growth medium in CO2 atmosphere at 37 degrees C.

Utility of complement fixation and microimmunofluorescence assays for detecting serologic responses in patients with clinically diagnosed psittacosis.

The serodiagnosis of human psittacosis was considerably improved by a microimmunofluorescence (MIF) assay that uses selected strains of Chlamydia psittaci, C. pneumoniae, and C. trachomatis as antigens.

Morphologic and staining characteristics of a cyanobacterium-like organism associated with diarrhea.

A spherical organism 9-10 microns in diameter, seen in three outbreaks of diarrhea in Southeast Asia and the United States during the past 2 years, bore characteristics of a cyanobacterium when observed in formalin-preserved stool specimens and by electron microscopy. Organisms in freshly passed stool specimens showed an internal morula of lipid-containing globules. In fresh water, the morula divided into two sausage-shaped structures resembling the sporocysts of an isosporid coccidian.

Comparative study with in situ hybridization and immunocytochemistry in detection of HIV-1 in formalin-fixed paraffin-embedded cell cultures.

The sensitivities of three immunohistological techniques were compared in this study for detecting human immunodeficiency virus (HIV-1) in infected cultured human lymphocytes that had been formalin-fixed and paraffin-embedded. The techniques included in situ hybridization (ISH) with HIV-1 cDNA; immunocytochemistry with HIV-1 p24 monoclonal antibody (ICC-m); and immunocytochemistry with HIV-1 polyclonal antibody from a patient with acquired immunodeficiency syndrome (AIDS) (ICC-p). Procedures were optimized for enzyme digestion and for antibody reaction conditions.

Immunoglobulin bound to platelets as immune complexes or specific antibody in specimens from acquired immunodeficiency syndrome and immune thrombocytopenic purpura.

Acquired immunodeficiency syndrome (AIDS), lymphadenopathy syndrome (LAS), and immune thrombocytopenic purpura (ITP) specimens were tested by an enzyme-linked immunosorbent assay (ELISA) for immunoglobulin (Ig) bound to platelets. All specimen evaluations were performed with General Diagnostic's newly developed kit procedure. The test measured but did not distinguish immune complex (IC) binding with platelet Fc receptor sites from platelet-specific antibody (PAb) binding with platelet antigen Fab-binding sites.

Autoimmune implications of immune complexes in clinical variants of hepatitis B.

Immune complexes (IC) were investigated in sera from 208 individuals with various clinical types of viral hepatitis diagnosed by clinical and laboratory criteria, including liver biopsy. Immune complexes were assessed by platelet aggregation (PI A) and by radioimmunoassay (RIA). The data were related to autoimmune phenomena (especially rheumatoid factors) and to the role that the IgM class of hepatitis B (HB) antibody might have in IC formation.

Circulating immune complexes in ulcerative colitis. I. Correlation to disease activity.

Twenty-two patients with ulcerative colitis were studied for occurrence of circulating immune complexes (IC) by three independent methods, a complement consumption assay, a Clq-binding assay and a RF-binding assay. All patients had the disease in an active stage when the study was initiated. Positiveness in two or more test systems was considered to indicate the presence of IC in the serum sample examined.

A survey for circulating immune complexes in patients with acute myocardial infarction. Use of a C1q-binding assay with soluble protein A as indicator.

A new assay for the detection of circulating C1q-binding immune complexes (IC) is described. The assay makes use of solid-phase C1q and iodinated soluble protein A, extracted from the cell wall of Staphylococcus aureus. In a model system the assay could detect heat-aggregated IgG down to a concentration of about 50 ng/ml.

Platelet aggregation by hepatitis B surface antigen-antibody complexes.

Platelet aggregation indicating antigen-antibody complex formation was observed when hepatitis B surface (HBs) antigen and antibody were mixed. Platelet aggregation titers were determined for serum specimens found positive by radioimmunoassay for either HBs antigen or HBs antibody. From these determinations, incidence of HBs antigen-antibody complexes was found to be higher in HBs antigen seraas than in HBs antibody sera.

Interactions of standard antibody with Australia antigens in Au Ag-Ab radioimmunoassay.

Human antisera against Australia (Au) antigen have been characterized by liquid-phase radioimmunoassay (RIA) for their precipitation of (125)I-labeled Au antigen. The end-point dilutions of sera (anti-Au) which precipitated 50% of (125)I-Au antigen by RIA correlated well with complement fixation titers but had a much wider range, indicating a greater precision and perhaps a better sensitivity of assay. Anti-Au serum diluted to precipitate 50% of (125)I-labeled Au antigen was used as standard antibody in RIA tests to detect either inhibition or enhancement of the reaction by preincubated mixtures of Au antigen and antibody specimens.

Mumps class-specific immunoglobulins in radioimmunoassay and conventional serology.

Antibodies against mumps virus have been studied by using immunoglobulin class-specific indicators labeled with (125)I in the radioimmunoassay (RIA) procedure. The immunoglobulins in paired acute and convalescent sera were allowed to react with mumps virus in a solid-phase RIA system. Class-specific immunoglobulin indicators (anti-immunoglobulin M [IgM] and anti-immunoglobulin G [IgG]) labeled with (125)I revealed that immunoglobulins of early antisera were preponderantly IgM, whereas immunoglobulins of late antisera were predominantly IgG.

Mumps class-specific immunoglobulins in radioimmunoassay and conventional serology.

In assessing the host cell range of bovine parvoviruses, these viruses were found to replicate optimally in actively dividing bovine fetal lung and spleen cells. Other primary bovine fetal cells supported growth to a lesser extent, but bovine line cells and line cells of other animal species tested did not. Minimal infectivity remained after passage of bovine parvovirus in cells from chicken embryos and guinea pig fetuses.

Solid-phase radioimmunoassay of total and influenza-specific immunoglobulin G.

An antigen-antibody system of polystyrene tubes coated with immunoglobulin antibody was used for quantitating immunoglobulins. A similar radioimmunoassay method was adapted for a viral antigen-antibody system. The viral system can be used for quantitating viruses and for measuring virus-specific antibodies by reacting with (125)iodine-labeled anti-immunoglobulin G (IgG).

Quantitative investigations of idiotypic antibodies. I. Analysis of precipitating antibody populations.

Specifically purified anti-p-azobenzoate antibodies of the IgG class from individual rabbits were used to elicit anti-idiotypic antibodies in recipient rabbits. Allotypes of each donor and recipient were matched. When polymerized antibodies were used for immunization, more than 80% of the recipients responded with the formation of antibodies that precipitated the monomeric donor antibody.