Enhancement of murine IgE antibody detection by IgG removal

RATIONALE: Although animal models for the study of allergic reactions are desirable, the use of mice has been hindered by the lack of sufficiently sensitive in vitro immunoglobulin epsilon (IgE) antibody assays. The aim of this study was to enhance IgE antibody measurements by immunoglobulin gamma (IgG) depletion. METHODS: Seven- to eight-week-old female mice of four strains (C3H/HeJ, CBA/J, C57Bl/6J, and Balb/c) were immunized (20 mice/group) with shrimp or peanut extracts using Al(OH)(3) as adjuvant. Following immunization, animals were sacrificed by exsanguination and the sera of each group pooled. Initial measurements of IgE antibody levels by enzyme-linked immunosorbent assay (ELISA) were relatively low; IgG and IgE reactivity patterns by immunoblot were similar. Thus, sera from shrimp or peanut immunized mice were depleted of IgG (absorbed 3-6 times with immobilized protein G) and then tested for IgE antibody to shrimp or peanut allergen. RESULTS: A 3- to 5-fold increase in IgE antibody reactivity as measured by ELISA was demonstrated when >80-90% of the IgG was removed. This increase in detection of allergen-specific IgE occurred in sera from all mouse strains and to all allergens tested. In addition, reactivity of IgE antibodies to peanut or shrimp allergens by immunoblot increased visually approximately 4- to 10-fold. CONCLUSIONS: These studies indicate that allergen-specific IgG antibodies, which may be in more than 100-fold excess to IgE antibodies, interferes with detection of allergen-specific IgE, probably by competitive binding to allergenic epitopes. Substantial depletion of IgG antibodies (>80%) result in a significant increase in the sensitivity of the antibody measurements.     

Granulocyte precursors are the principal cells in bone marrow that stimulate allospecific cytolytic T-lymphocyte responses.

Mouse bone marrow cells were fractionated and enriched for functional activity as stimulators of allospecific cytolytic T-lymphocyte (CTL) responses in vitro. The relevant stimulator cells were enriched sequentially in the low-density fraction of bone marrow, its 2-hr adherent and 18-hr non-adherent fractions and in the FcR-negative fraction of 18-hr non-adherent cells. The functionally enriched cell population contained over 90% granulocyte precursors by ultrastructural analysis. The results indicate that granulocyte precursors are the principal cells in bone marrow that stimulate alloreactive T-cell responses.     

Distinct Leishmania braziliensis isolates induce different paces of chemokine expression patterns

Inflammatory events during Leishmania braziliensis infection in mice were investigated. Large lesions were directly correlated with the inflammatory reaction but not with parasite burden. Different L. braziliensis strains induce different paces of chemokine expression patterns, leading to diverse cell recruitment and differential inflammatory responses.     

The 4p- syndrome—An autopsy study

The autopsy of an infant with the 4p- or Wolf-Hirschhorn syndrome revealed visceral abnormalities not previously described, i.e., agenesis of the gallbladder and spleen. The parent's chromosomes were normal.     

Comparison of isolation of Haemophilus vaginalis (Corynebacterium vaginale) from peptone-starch-dextrose agar and Columbia colistin-nalidoxic acid agar.

A total of 447 cervical or vaginal specimens were inoculated in parallel onto peptone-starch-dextrose (PSD) and Columbia colistin (10 mg/ml)-nalidixic acid (15 mug/ml) (CNA) agar and were incubated for 48 h at 35 degrees C in an atmosphere with 2 to 10% CO2. One hundred (22.4%) of the cultures were positive for Haemophilus vaginalis. Forty-eight of the isolates were recovered from both PSD and Columbia CNA agar, five from PSD only, and 47 from Columbia CNA agar only (P less than 0.001). On Columbia CNA agar, 76 of the isolates were detected after 24 h of incubation, and the remainder were detected within 4 days of incubation.     

Education of medical technologists in North America

The increasing complexity of diseases and advancing medical technologies have recently raised the number of test items and their use. This has caused each department to ask for clinical support by medical technologists, including consultation services on clinical laboratory tests in Japan. Under these circumstances, we think it is necessary to consider a Japanese education system for medical technologists to foster people with advanced ability capable in providing adequate clinical support. It is important that we study medical technologist systems and education systems superior to than ours. Therefore, to investigate the state of the Japanese education system for medical technologists, we conducted a comparison between the medical technologist systems and education systems in foreign countries and those of Japan. The social background in which medical technologists are positioned, their scope of work, and the education systems overseas are different from Japan on many points and we were given many suggestions for what a system in Japan should be like.     

Antibodies to cell envelope proteins of Pseudomonas aeruginosa in cystic fibrosis patients.

Many vaccines containing somatic and secreted antigens of Pseudomonas aeruginosa have been reported. The vaccines containing lipopolysaccharide have been found to provide type-specific protection, but the endotoxin content of these vaccines does not make it feasible to use them in patients who are already debilitated. Outer membrane proteins could be effective as vaccines, as they can be purified free of lipopolysaccharide, and also because they are common to all serotypes of P. aeruginosa. To be effective as a vaccine, such proteins must be immunogenic and accessible from the outside of the intact bacterial cell. In this study, we showed that systemic antibodies were produced frequently to two cell envelope proteins with masses of 58,500 and 37,500 daltons and occasionally to 34,000-dalton protein of P. aeruginosa in cystic fibrosis patients with chronic lung infections. In rabbits immunized with whole, fixed cells of P. aeruginosa, antibodies were also produced against the 58,500-dalton proteins. Thus, the 58,500-dalton cell envelope protein of P. aeruginosa was the only immunogenic protein that was accessible to the immune system when whole, fixed cells were used for immunization. These serum antibodies did not protect the cystic fibrosis patients against further lung infection with P. aeruginosa.     

Deposition and passage of transthyretin through the blood-nerve barrier in recipients of familial amyloid polyneuropathy livers

Familial amyloid polyneuropathy (FAP) is characterized by deposition of mutated transthyretin (TTR) in the peripheral nervous system. Prior to amyloid fibrils, nonfibrillar TTR aggregates are deposited inducing oxidative stress with increased nitration (3-NT). As the major source of TTR is the liver, liver transplantation (LT) is used to halt FAP. Given the shortage of liver donors, domino LT (DLT) using FAP livers is performed. The correlation between TTR deposition in the skin and nerve was tested in biopsies from normal individuals, asymptomatic carriers (FAP 0) and FAP patients; in FAP 0, nonfibrillar TTR was observed both in the skin and nerve in the same individuals; in patients, amyloid was detected in both tissues. The occurrence of amyloidosis in recipients of FAP livers was evaluated 1-7 years after DLT: TTR deposition occurred in the skin 3 years after transplantation either as amyloid or aggregates; in one of the recipients, fibrillar TTR was present in the epineurium 6 years after DLT. Deposits were scarce and 3-NT immunostaining was irrelevant. Nerve biopsies from DLT recipients had no FAP-related neuropathy. Our findings suggest that TTR amyloid formation occurs faster than predicted and that TTR of liver origin can cross the blood-nerve barrier. Recipients of FAP livers should be under surveillance for TTR deposition and tissue damage.     

Variability of clarithromycin and erythromycin susceptibility tests with Haemophilus influenzae in four different broth media and correlation with the standard disk diffusion test.

Four separate laboratories performed antimicrobial susceptibility tests with 40 Haemophilus influenzae isolates, each tested in triplicate. Erythromycin and a new macrolide, clarithromycin (A-56268; TE-031), were tested by the disk diffusion method, by the agar dilution procedure in two different media, and by broth microdilution tests in four different media. Erythromycin MICs for 90% of the strains were 16 micrograms/ml in Mueller-Hinton broth with 3% lysed horse blood and NAD, 4.0 micrograms/ml in hemophilus test medium, and 2.0 micrograms/ml in supplemented Schaedler broth or in the fastidious broth medium from Beckman Instruments, Inc. Clarithromycin MICs were generally 1 doubling dilution greater than erythromycin MICs in each of the media. Erythromycin disk tests corresponded best with MICs determined in the fastidious broth medium. In that same medium, clarithromycin MICs were about 1 doubling dilution greater than what would be expected from the results of disk tests. Because there were fewer growth failures, hemophilus test medium is recommended for microdilution tests with H. influenzae. Incubation of all tests for a full 24 h without an increased CO2 atmosphere was needed to achieve maximal precision of the tests. Interlaboratory and intralaboratory reproducibility of all tests was satisfactory.