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Biomedical subjects

W B Cherry

Publications and source records attributed to W B Cherry.

At least 37 records · Page 2Linked to original sources
PubMed1977

Isolation of Francisella tularensis from infected frozen human blood.

Francisella tularensis was isolated from human blood that was frozen for 3 months before it was examined. Before he became ill, the patient operated a "bush-hog" in an area thickly populated with rabbits. His illness was undiagnosed and untreated before his death. Portions of blood and tissue homogenates from necropsy were injected intraperitoneally into mice and inoculated onto glucose-cysteine-blood agar plates. F. tularensis did not grow from the culture plates, but mice inoculated with the blood died in 48 to 72 h. Fluorescent-antibody stains of mouse liver and spleen impression smears showed clumps of cells or amorphous masses of brightly staining envelope material around the cells. Tissue impressions of liver, spleen, and heart blood inoculated onto glucose-cysteine-blood agar yielded pure cultures of F. tularensis.

Agglutination Tests↗
PubMed1977

Cellular fatty acid composition of isolates from Legionnaires disease.

The cellular fatty acids of four isolates from Legionnaires disease and two antigenically related isolates were identified by gas chromatography, mass spectrometry, and associated techniques. The six isolates had essentially the same fatty acid composition, which was characterized by large amounts (greater than 80%) of branched-chain acids.

Bacteria↗
PubMed1976

Physicochemical characterization of direct fluorescent antibody reagents.

When the data from performance and physicochemical studies of conjugates are combined for analysis, the performance data and specific titers show a direct relationship to the physicochemical data (Table 2). These reagents were prepared from the same lot of antiserum. The specific titers are very misleading without the accompanying data (Table 2). The protein concentrations range from 4 to 10 mg/ml, the F/P ratios from 10 to 30, and CASE shows gamma-globulin to constitute 30 to 100% of the protein. CASE also shows the gamma-globulin F/P ratio to be only 10 to 20. Using these data, we calculated the concentrations of the gamma-globulins and normalized their titers to 10 mg/ml. The value of good fractionation procedures for recovering gamma-globulin and the desirability of obtaining optimal F/P ratios are reflected in the adjusted titers. Physicochemical characterization of conjugates identifies superior and deficient reagents and frequently reveals the cause of inadequate performance. In this way it serves as a quide for improving reagent quality.

Blood Proteins↗
PubMed1976

Optimum immunization of rabbits for Streptococcus mutans antiserum and conjugate production and studies of batch immunoabsorption methods.

By far, the most significant rises in titers were seen with the immunization protocol used in series 6. Conjugates prepared from bleedings on the 33rd day produced exceptionally high titers for type b S mutans, and reasonably high titers for type a were obtained in a short time. A concentrated antigen with Formalin (13.4 ml) was given during a ten-day period followed by a two-week rest period, after which booster doses of either antigen with Formalin or live antigen were given (Fig 1). Based on evaluation of the immunization protocol just described, series 6 resulted in the highest titered reagents, but the data are insufficient to permit recommending that particular schedule without limitations. Our experience in the use of live antigens of S mutans for immunization is limited in that only types b, c, and e have been used in this way. The rabbits survived these injections, but the pathogenicity of other strains and other serotypes has not been determined. In addition, protocols including combined injections of killed and living organisms should be tested further for possible improvement in antibody production. In view of these considerations, our recommendations for production of high titered antiserums for S mutans in rabbits are as follows: -Take a preimmunization bleeding from each rabbit and screen by indirect FA tests with the antigens to be used. -Inject heavy concentrations (40 IU/ml) of Formalin-killed cells, intravenously. -Inject for eight to ten consecutive days, giving increasing doses of antigen ranging from 0.2 to 5.0 ml for a total of 12 to 15 ml. -Rest the rabbits for one week. If you are monitoring the progress of immunization, bleed the rabbits before giving booster injections. -Give booster injections on four consecutive days, giving 0.25, 0.5, 1.0, and 1.5 ml of live antigen that has been washed one time to remove traces of media and adjusted to a concentration of 40 IU/ml. If live antigen is not used, continue to give booster injections with killed antigen, injecting 2.0 ml on each of three consecutive days. -Rest the rabbits for one week and take sufficient blood to produce the trial reagents needed, or exsaguinate the rabbits. Absorption of type a conjugates resulted in the total loss of titer for type a cells. The cross-reactions with type b conjugate were easily eliminated by dilution, with the exception of the cross-reaction with S sanguis JC-43. Bratthall's absorption method eliminated all cross-reactions of the type b conjugate. Absorption of type c conjugate successfully removed the cross-reaction with type e cells; however, the loss of homologous type c titer was so great that this absorption is of limited value. High-titered conjugates for types d and e have been obtained by using batch absorption procedures.

Absorption↗
PubMed1975

Evaluation of a semiautomated system for direct fluorescent antibody detection of salmonellae.

A semi-automatic system under development by Aerojet Medical and Biological Systems for the direct fluorescent antibody detection of salmonellae was evaluated with various food, feed, and environmental samples. All samples were simultaneously examined by Automated Bioassay System (ABS), manual direct fluorescent antibody procedures and cultural procedures. The ABS gave satisfactory results with the processed samples. It detected all of the culturally positive powdered egg and candy samples with no false-negative results and gave only 6.6 and 5.3% false-positive rates, respectively. With meatmeal samples the ABS failed to detect one culturally positive specimen that was also positive by manual fluorescent antibody and gave one (1.1%) false-positive result. A high rate of false-negative results was obtained by ABS on unprocessed samples of creek water, poultry, and sausage. Adding another enrichment step to the protocol reduced the false-negative rate considerably but severely increased the false-positive rate. The instruments worked reasonably well, but research is needed to improve enrichment procedures for samples to be processed by the system.

Evaluation Studies as Topic↗
PubMed1975

Dection of salmonellae in the environment.

The incidence of salmonellae in contrasting environments was compared in this study. Samples collected from or near surface waters in a lush hardwood forest yielded four salmonellae serotypes from six culturally positive samples. A total of 76 samples collected from the top of a granite outcropping over a 3-month period yielded 10 positive samples. Only two salmonellae serotypes were isolated, and one of these was isolated only once. The nature of the sample material had no significant effect on the detection of salmonellae from the two sampling sites. However, the presence or absence of visible moisture in the sample significantly affected the recovery of salmonellae. The results showed that even a harsh environment such as that found on top of Stone Moutain may serve as an ecological niche for the survival and transmission of salmonellae.

Ecology↗
PubMed1973

Standardization of diagnostic materials. 4. Diagnostic immunofluorescence.

The standardization of diagnostic immunofluorescence is a complex problem because diagnostic results are greatly influenced by interacting factors, such as the equipment, materials, and techniques for expressing and recording fluorescence. Furthermore, the characteristics of immunofluorescence reagents depend on how they are manufactured and used. The adoption of stable reference preparations of such reagents appears to be the only practicable way of standardizing laboratory test results. Several professional and regulatory organizations are actively promoting this objective. Consensus evaluation may be the best method of introducing proposed standards. Basic and applied research must provide the information needed to improve reagents and tests.Material fluorescent standards are proving helpful in standardizing fluorescence emission, but the most promising development is the use of insolubilized antigens to provide standards for more relevant immunological-fluorescence comparisons.Several important direct and indirect diagnostic immunofluorescence tests and reagents currently used in microbiological, histological, and pathological examinations require standardization. The medical profession should insist that commercial reagents be adequately characterized and that manufacturers supply the data necessary for their safe and informed use.

Biological Products↗
PubMed1972

Use of gas chromatography for determining catabolic products of arginine by bacteria.

A rapid and sensitive procedure for determining catabolic products of arginine metabolism by bacteria was developed. The method consists of inoculating a solution of L-arginine with a heavy cell suspension of the test organism. After a 2-hr incubation period, dissimilation products (citrulline, ornithine, agmatine, putrescine) are converted to volatile derivatives and analyzed by gas-liquid chromatography. Compared with conventional microbiological tests, the new procedure is rapid and can be used for sensitive quantitative measurements of specific metabolites from arginine.

Arginase↗
PubMed1972

Salmonellae as an index of pollution of surface waters.

Screening enrichments of surface water specimens by means of a polyvalent fluorescent antibody reagent for the salmonellae yielded approximately 60% more positive specimens than was obtained by cultural procedures. It is not known what fraction of the excess of fluorescent antibody-positive over culturally positive specimens represents staining of non-salmonellae or non-arizonae as opposed to the staining of non-cultivatable organisms of these two genera. Cotton gauze and rayon-polypropylene fiber swabs were equally sensitive for collecting salmonellae from the streams examined. Tetrathionate enrichment incubated at 41.5 C appeared to be superior to selenite-cystine for isolation of salmonellae from surface waters. Twenty-eight serotypes of Salmonella and two serotypes of Arizona were identified in the 121 positive specimens. In water rated moderately polluted, 65% of all specimens tested were positive; in minimally polluted waters, 38% were positive; and in unpolluted streams, 44% were positive.

Bacteriological Techniques↗
PubMed1969

Practical physiological schema for the identification of Herellea vaginicola and its differentiation from similar organisms.

A seven-test schema is presented that will identify Herellea vaginicola and differentiate it from Mima, Moraxella, and other gram-negative organisms whose biochemical reactions are similar to those of Herellea. Of 133 cultures examined, 49 were Herellea strains accurately identified by this schema: 34 of the 49 cultures were the capsular type strains of Herellea and 15 strains were from a group of 53 ATCC cultures listed under several different taxons. The remaining 84 non-Herellea cultures yielded 4 (4.7%) false positive identifications for Herellea; two were from a selected group of organisms (EO-1) whose taxonomic position is undetermined and two were Klebsiella ozaenae. Since neither of these groups is frequently encountered in clinical specimens, from a practical viewpoint they present no particular problem in the identification of Herellea. We recommend the use of the seven tests as described in this paper as a routine procedure for the identification of H. vaginicola.

Acinetobacter↗
PubMed1969

Cultural characteristics and fatty acid composition of propionibacteria.

The cultural characteristics and cellular fatty acid composition of 40 strains representing 7 species of Propionibacterium and of 9 cultures of anaerobic corynebacteria were studied. The cultures were characterized by means of 23 separate cultural and biochemical tests. Cultures of the two genera differed consistently in only two reactions; the propionibacteria did not produce indole or liquefy gelatin, whereas the anaerobic corynebacteria were consistently positive with these tests. The fatty acids were extracted from whole cells and examined as methyl esters by gas-liquid chromatography. The most abundant acid in the seven Propionibacterium species was a C(15)-saturated branched-chain acid which was present in both the iso-and anteiso-form. Based on a comparison of the relative abundance of these isomers (i-C(15) and a-C(15)), the species were separated into two groups. P. freudenreichii and P. shermanii (group one) were similar and contained the a-C(15) isomer as the predominant acid. The i-C(15) isomer was the most abundant acid in the second group (P. arabinosum, P. jensenii, P. pentosaceum, P. thoenii, and P. zeae). The fatty acid profiles of the anaerobic corynebacteria were somewhat similar to those of the second group of propionibacteria, but were distinct from the profiles of P. freudenreichii and P. shermanii. The addition of branched-chain amino acids (l-leucine and l-isoleucine) to the growth medium increased the synthesis of the specific fatty acid(s) structurally related to the added amino acid.

Bacteriological Techniques↗