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Biomedical subjects

W Johnson

Publications and source records attributed to W Johnson.

At least 199 records · Page 11Linked to original sources
PubMed1980

Immunogenicity of ribosomes from enzymatically lysed Streptococcus pyogenes.

Ribosomal fractions isolated from Streptococcus pyogenes by physical and enzymatic disruption of the cell wall were found to provide protection in mice against challenge with the homologous M type. Although ribosomal fractions isolated by physical disruption of the cells also provided protection against challenge with several heterologous M types, ribosomal fractions from enzymatically lysed cells did not provide protection against any of the heterologous M types. Ribosomes isolated by either method were found to be contaminated with cell surface proteins. Chemical analysis of the ribosomes showed a greater protein:ribonucleic acid ratio in ribosomes from physically disrupted cells than in ribosomes from enzymatically disrupted cells (2:1 versus 1:1). Antisera to ribosomes isolated from physically disrupted cells detected many more antigenic determinants on ribosomes isolated from enzymatically disrupted cells than did the corresponding homologous antisera. Immunodiffusion analysis suggested that ribosomes isolated from physically disrupted cells may contain cell wall antigenic determinants which are present on ribosomes isolated from enzymatically disrupted cells in a partially degraded form. Washing of ribosomes in high-molarity salt solutions suggested that some of the contaminating cell wall proteins are tightly bound to the ribosomes.

Animals↗
PubMed1980

Background prevalence of microagglutination antibodies to Legionella pneumophila serogroups 1, 2, 3, and 4.

The background prevalence of microagglutination antibodies to Legionella pneumophila was determined by testing the sera of 517 individuals who lived or worked in a small Iowa town. In this population, the upper limit of normal microagglutination titer for serogroups 1, 3, and 4 was 1:16, and that for serogroup 2 was 1:8. The prevalence of microagglutination titers of greater than or equal to 1:32 against any serogroup of L. pneumophila was only 7.4% and did not vary significantly with age or sex.

Antibodies, Bacterial↗
PubMed1980

Indirect immunofluorescence antibodies to Legionella pneumophila: frequency in a rural community.

The background prevalence of indirect immunofluorescence antibody to Legionella pneumophila in a rural community was determined by testing sera from 517 volunteers. The upper limit of normal antibody titer was found to be 1:64 with L. pneumophila serogroup 1 (Philadelphia 1) used as antigen. High titers (greater than or equal to 1:128) were found in 13.2% of the sera and occurred with similar frequencies in males and females. In individuals 40 years of age and older, however, high titers were 2.7 times as prevalent in males as females.

Adolescent↗
PubMed1979

A technique for quantitating enzyme histochemistry in adjuvant arthritic joints. II. Acid phosphatase.

This paper reports on the incorporation of acid phosphatase histochemistry with a quantitative technique designed to measure the percentage of histochemically-localized enzyme-reactive cells found in adjuvant arthritic articular cartilage, synovial membrane and bone marrow. With the data presented and the comparisons made, this incorporation is validated and adjuvant arthritic acid phosphatase "lesions" established. In addition to discussing the importance of the histochemical data and its relationship with intra-articular lysosomes, the applicability of the reactive cell values to drug inhibition studies is discussed.

Acid Phosphatase↗
PubMed1979

Mutagenic activity of gastric juice.

Gastric juice samples from patients of a rural area of the Colombian Andes at high risk to gastric cancer were tested for mutagenesis with Salmonella typhimurium strains TA100 and TA1538. Direct mutagenic effect was found in samples with detectable amounts of nitrite. This effect was not accountable by nitrite alone. Nitrite-negative samples from the same area and samples from the low-risk area of Cali were negative using the same mutagenesis assay.

Adult↗
PubMed1979

Identification of protective cell surface proteins in ribosomal fractions from Salmonella typhimurium.

Cell surface antigen preparations from Salmonella typhimurium SR-11 prepared by either trichloroacetic acid extraction or boiling in sodium dodecyl sulfate were able to protect C3H/HeJ, C3H/HeDub, and A/J mice. Some of the proteins found in these preparations were shown to exist in the protective ribosomal fraction isolated from S. typhimurium SR-11. Passage of ribosomes isolated from S. typhimurium SR-11 and 6707 through a Sepharose 2B column removed the protective immunogen from 6707 ribosomes but did not completely remove it from SR-11 ribosomes. Immunity to salmonella infection in C3H/HeJ mice induced by ribosomal vaccines may be dependent on the presence of cell surface proteins in the ribosomal fraction.

Animals↗
PubMed1979

Serospecificity and opsonic activity of antisera to Legionella pneumophila.

A high-molecular-weight surface component (F-1 fraction) has been isolated from the four serogroups of Legionella pneumophila. Antibody raised against live organisms was found by microagglutination assay to be specific for the homologous serogroup. Agglutinating activity of antiserum was markedly diminished after absorption with the homologous, but not heterologous, F-1 fraction. In addition, it was found that L. pneumophila organisms were not interiorized by rat alveolar macrophages or mouse peritoneal macrophages in the absence of antiserum, whereas homologous antiserum effectively opsonized the organisms. The opsonizing activity of serogroup-specific antisera was eliminated by absorption of the antisera with the homologous, but not heterologous, F-1 fraction. These data indicate that the serogroup-specific antigen of L. pneumophila resides in the F-1 fraction and that antibody to the F-1 fraction is required for phagocytosis of L. pneumophila by mammalian phagocytes.

Agglutination Tests↗
PubMed1979

Comparative features of pneumococcal, mycoplasmal, and Legionnaires' disease pneumonias.

Retrospectively, we clinically compared community-acquired cases of Legionnaires' disease, pneumococcal, and mycoplasmal pneumonias. Relative to pneumococcal and mycoplasmal pneumonias, patients with Legionnaires' disease were significantly more likely to present with unexplained encephalopathy, hematuria, and elevation of serum glutamic-oxalacetic transaminase than were those with pneumococcal and mycoplasmal pneumonias. We found upper respiratory symptoms infrequently in patients with Legionnaires' disease, and progression of pulmonary infiltrates occurred commonly. Differentiation of Legionnaires' disease pneumonia without encephalopathy from pneumococcal and mycoplasmal pneumonias may be difficult because of demographic, clinical, laboratory, and radiographic similarities.

Adult↗
PubMed1979

Legionnaires' disease in pneumonia patients in Iowa. A retrospective seroepidemiologic study, 1972-1977.

The frequency of Legionnaires' disease among 586 cases of pneumonia that occurred in Iowa between fiscal years 1972 and 1977 was studied retrospectively on the basis of paired sera. The frequency of confirmed Legionnaires' disease was 4.1% and of presumptive Legionnaires' disease was 11.4%. Infections with the Legionnaires' disease (LD) bacterium were most frequent in the summer. Of the 22% of pneumonias for which a cause could be defined, Legionnaires' disease was third in frequency behind Mycoplasma pneumoniae and influenza A virus infections. Infections with the LD bacterium occurred in association with pneumonias in most age groups. The youngest patient with LD infection was a 5-year-old boy with pneumonia. The disease occurred 3.2 times more often in males than in females. In males, the frequency of confirmed and presumptive Legionnaires' disease increased steadily to plateau after the fourth decade at about 12% and 28%, respectively. In females the frequency of presumptive Legionnaires' disease was 7% to 16%, relatively evenly distributed over all age groups. Pneumonias associated with LD bacterium infection should be considered in the differential diagnosis of community-acquired pneumonias in most age groups.

Adolescent↗
PubMed1979

A high molecular weight antigen in Legionnaires' disease bacterium: isolation and partial characterization.

We isolated a high molecular weight antigen of the Legionnaires' disease (LD) bacterium by column chromatography. The antigen was composed of 35% carbohydrate, 2.6% protein, 1.8% phospholipid, and 1% 2-keto-3-deoxyoctonate and was important in the host's antibody response because it inhibited the indirect immunofluorescent and microagglutination titers of convalescent sera from patients with Legionnaires' disease. The antigen also formed precipitin bands with seven of 10 convalescent sera from patients with Legionnaires' disease. We found chemical and biological evidence of endotoxinlike activity associated with the antigen. Cell sonicates and acid extracts of the LD bacterium gave multiple bands in immunodiffusion with human convalescent serum and rabbit antisera prepared against heat-killed LD bacteria. The antigenic structure of the LD bacterium therefore appears complex.

Animals↗
PubMed1979

Hypertrophy and hyperplasia of islets of Langerhans associated with androgen therapy.

Hypertrophy and hyperplasia of the islets of Langerhans were observed in three patients treated with androgen-anabolic steroids for aplastic anemia. These patients formed a unique subset of patients with aplastic anemia in that they all had Fanconi's anemia, all demonstrated glucose intolerance following institution of androgen therapy, all had received androgen for at least 42 months prior to death, and all had coexistent benign liver cell tumors. Androgen-induced glucose intolerance may play a major role in the pathogenesis of both the pancreatic and hepatic abnormalities.

Androgens↗
PubMed1978

Protective ability of Salmonella ribosomal protein and RNA in inbred mice.

Ribosomal vaccines prepared from Salmonella typhimurium were effective immunogens in A/J, C3H/HeDub, and C3H/HeJ mice. Purified ribosomal components were also tested as immunogens in the inbred mice. Protein isolated from a Salmonella ribosomal fraction could protect all three mouse strains. Although purified RNA was shown to be protective for A/J and C3H/HeDub mice, it was not protective for C3H/HeJ mice. Protective immunity could be induced in A/J and C3H/HeDub mice by various immunostimulants. Immunity in C3H/HeJ mice, however, could only be induced by Salmonella ribosomes or protein isolated from the Salmonella ribosomal fraction.

Animals↗
PubMed1978

A stable blood product for pH-blood-gas quality control.

We describe how to prepare, store, and use a hemolyzed blood product for simultaneous pH, pCO2, and pO2 quality control. Tonometry of the blood product with two oxygen and two carbon dioxide concentrations resulted in consistent and reproducible values during 38 weeks. The resulting pH values were consistent and reproducible, demonstrating the metabolic acid-base stability of the blood product. We conclude that the proper preparation, storage, and use of the product results in consistent, reproducible, and economical quality control for pH, pCO2 and pO2 blood measurements.

Blood Chemical Analysis↗
PubMed1977

An improved technique for the rapid continuous measurement of whole blood glucose, suitable for clinical application in an artificial endocrine pancreas.

An improved bedside technique for the continuous monitoring of glycemia is described. A linear relationship results between whole blood glucose concentration and plasma glucose levels, and allows the calibration of the system in terms of plasma glucose levels. In operation venous blood is withdrawn at a steady rate using a double-lumen catheter and directed to a continuous-flow laboratory analyzer, where glucose analysis is carried out using a modified glucose oxidase-peroxidase methodology. The improvements in this technique include: i) a reduction in the delay of the analyzer to 90 s, making it suitable for application in a system for blood glucose regulation, ii) a minimal blood requirement of 3 ml/h, permitting long-term monitoring, iii) elimination of the need for systemic anticoagulation, iv) an excellent correlation (r = 0.993) between the measured whole blood glucose and the actual plasma glucose concentration, v) an average baseline drift of +0.5 mg%/h, vi) a sensitivity loss of less than 0.1%/h, and vii) a reasonable operating cost. This technique was implemented as part of a clinical apparatus known as an artificial endocrine pancreas which has been reliably applied in clinical and animal studies.

Adult↗