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R C Warren

Publications and source records attributed to R C Warren.

At least 55 records · Page 3Linked to original sources

Comparison of the growth of virulent and attenuated strains of Candida albicans in the kidneys of normal and cortison-treated mice by chitin assay.

Candida albicans strain 22114 was avirulent for mice compared with strain 19321 in that, administered intravenously, 10(6) blastospores of 22114 failed to kill whereas 10(6) blastospores of 19321 produced 100% mortality. Cortisone treatment rendered mice susceptible to killing by 22114. Chitin assay showed that cortisone stimulated the growth of both strains in the mouse kidney. Growth of 19321 was increased up to five-fold and 22114 up to forty-fold. The strains may have differential susceptibility to cortisone-sensitive host defences which control fungal growth in vivo.

Animals↗

Detection of circulating antigen of Aspergillus fumigatus in sera of mice and rabbits by enzyme-linked immunosorbent assay.

Circulating antigen of Aspergillus fumigatus was demonstrated in the sera of experimentally infected, cortisone-treated mice and rabbits by enzyme-linked immunosorbent assay (micro-ELISA), confirming earlier results where fungal antigen had been detected by counter-immunoelectrophoresis (CIE). Peaks of detection of circulating antigen by CIE and micro-ELISA in mice were not simultaneous suggesting that the nature of the predominant antigens may have altered during the course of infection. CIE failed to detect fungal antigen in infected rabbits whereas micro-ELISA monitored antigenemia until death. Both CIE and micro-ELISA demonstrated the rapid clearance of intravenously inoculated Aspergillus-antigen from the rabbit circulation.

Animals↗

Enzyme-linked immunosorbent assay of antigens from Candida albicans circulating in infected mice and rabbits: the role of mannan.

Various antisera raised either to antigens of Candida albicans or to sub-lethal infections of blastospores (convalescent sera) were tested for their efficacy in diagnosing systemic disease in artifically infected animals. Globulin from convalescent serum, when conjugated with alkaline phosphatase and used in enzyme-linked immunosorbent assays (ELISA), was the only antiserum type which detected circulating Candida-related antigen in the serum of infected animals. Conjugates made from anti-mannan, anti-blastospore or antimycelial globulin did not detect antigen. Mannan did not appear to be related to an antigen produced in sera of experimentally infected mice. The significance of these results in the diagnosis of systemic candidosis is discussed.

Animals↗

The occurrence and treatment of false positive reactions in enzyme-linked immunosorbent assays (ELISA) for the presence of fungal antigens in clinical samples.

Non-specific positive reactions have been revealed in enzyme-linked immunosorbent assays (ELISA) of sera for the presence of fungal antigen. These false positives were recognized by their occurrence in tests for both Candida albicans and Aspergillus fumigatus antigens and by their response to dithiothreitol, combined with their reaction with non-immune rabbit globulin. A scheme is proposed which differentiates between true and false positive reactions. Use of fractionated anti-fungal globulin in conjugates reduced the incidence of false positive results in sera from hospitalized patients and eliminated them from sera of healthy subjects. The test scheme was applied to two panels of sera containing samples from patients with (a) invasive candidosis and (b) invasive aspergillosis. The relevance of ELISA tests for the detection of fungal antigen in human serum is discussed.

Animals↗

Diagnosis of invasive candidosis by enzyme immunoassay of serum antigen.

Enzyme immunoassay was used to measure Candida albicans-related antigen in sera of rabbits and mice infected with C albicans. A range of heterologous antigens tested gave no cross reactions. Of the three patients who were investigated and gave positive reactions, two were confirmed as having deep candida infections. Enzyme immunoassay is efficient, simple, and sensitive, and may prove valuable in the early diagnosis of invasive candida infections.

Adult↗

Survey of graduates of the Epidemic Intelligence Service as an approach to enhancing ethnic diversity among the nation's epidemiologists.

A survey was conducted to improve the recruitment, training, and retention of epidemiologists in the Epidemic Intelligence Service (EIS) Program of the Centers for Disease Control. The authors compared minority graduates of the program and nonminority graduates in several areas: reasons for application, degree of satisfaction, appropriateness of preparation for epidemiologic practice, and current professional activities. A closed-ended questionnaire was mailed to all 87 minority graduates from the program during the period 1970-88, and to 172 randomly selected nonminority graduates. Of 259 graduates surveyed, 234 or 90.3 percent returned the questionnaire--89.6 percent of minority graduates and 90.7 percent of nonminority graduates. Virtually all graduates were satisfied with their EIS experience (95.2 percent), have encouraged others to apply (96.1 percent), and are the most frequent sources of initial contact of prospective officers (38.2 percent). Most EIS graduates (71.2 percent) were still working in epidemiology. Compared with the nonminority graduates, the minority graduates were more likely to be women and to be single. Minority graduates were less likely than non minorities to hold academic appointments (44.2 percent versus 60.0 percent) and less likely to work in academic settings as their primary job (11.5 percent versus 18.7 percent). At the same time, minority graduates were more likely to have learned of the EIS Program from academic advisors (32.1 percent versus 19.4 percent). Graduates express high levels of satisfaction with the EIS Program and continue to practice epidemiology following graduation. Few differences between the minority and nonminority graduates were found. Because fewer minority graduates are in academic settings to serve as mentors or role models, alternative recruitment methods must be developed to sustain a high level of interest among minority groups in the EIS Program.

Career Choice↗