Health laboratory science最新文献

An antigen extracted and purified from Neisseria gonorrhoeae B370, type 4, was employed to sensitize charcoal particles for use in an agglutination assay of human sera for antibodies that indicate active gonorrheal infection. The screening card test is more sensitive than the fluorescent gonorrheal test-heated (FGT-H), especially in men. A simple one-step absorption improved the specificity without reducing the sensitivity of the test.

While studying variations amony immunizing potentials of rabies vaccines, we were led to consider the possibility that the antigen in the vaccine derived from duck embryos may have been degraded by enzymes arising from host tissues. Such an enzyme, a neuraminidase, was found in duck embryo rabies vaccine through the application of a periodate-linked thiobarbituric acid assay. This acitvity could not be found in two other rabies vaccines derived from tissue cultures. We have thus concluded that there is a strong possibility that a modified antigen is present in duck embryo vaccine. In addition, the injection of this vaccine will introduce a neuraminidase which may produce localized effects in the tissues of the recipient.

A simple (2% oxgall) agar medium is described for the production of both germ tubes and chlamydospores by over 500 clinical isolates of Candida albicans. In comparison studies between the 2% oxgall agar and the more complex "cream of rice" infusion-oxgall-Tween 80 agar (RIOT), germ tubes were formed by 478 isolates in both media, by 9 isolates in only the oxgall medium and by 11 isolates in only the RIOT medium. Chlamydospores were formed by 481 isolates in both media, by 2 isolates in only the oxgall medium and by 9 isolates in only the RIOT medium. The data also show that both the germ tubes and chlamydospores were needed for the presumptive clinical identification of C. albicans.

Since 1928, 22 professional agencies have established certification procedures for 52 categories or levels of health laboratory personnel. Surveys indicate that 55% of technical personnel are certified by at least one registry or board. After reviewing some of the pros and cons of certification and its expanding role, the author concludes that certification has become a positive factor in calling attention to the need for quality personnel in health laboratories and has helped meet the needs of individuals and the public. Current movements to work together in a National Commission for Health Certifying Agencies and toward national certification standards are encouraging.

Sulfamethoxazole-trimethoprim blood agar (SXT-BA), neomycin blood agar (NEO-BA) and plain sheep blood agar plates (SBA) were compared for isolating group A streptococci in 1,954 throat cultures. SBA and SXT-BA had similar isolation rates (approximately 75% of all positive isolates). NEO-BA was significantly better (87% recovery). A combination of any two media gave 92-95% recovery of group A streptococci from throat specimens.

From a survey of 22 U.S. veterinary schools and the university campuses where they are located, it was found that none of the schools had a full- or part-time health and safety officer whereas 16 campuses did. On 18 campuses some form of safety committee existed whereas such committees had been formed in only 12 schools. There was no relationship between the level of school or campus safety organization and presence (10 schools) or absence (12 schools) of an OSHA approved state occupational safety and health plan. An occupational health "bookshelf" reference list is appended.

In a proficiency testing program, slides bearing acid-fast bacilli were sent to laboratories in New York State. The most reliable results were obtained in laboratories using the Ziehl-Neelsen method. Cold staining procedures were less reliable. The auramine-rhodamine fluorescent stain, which produced many false positives, should be confirmed by the Ziehl-Neelsen procedure. The testing program described can be used to determine whether laboratories perform the acid-fast stain effectively.