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Biomedical subjects

P A Jordan

Publications and source records attributed to P A Jordan.

5 recordsLinked to original sources

p53 overexpression in formalin-fixed, paraffin-embedded tissue detected by immunohistochemistry.

Mutation and overexpression of the p53 gene have been noted in a wide range of human cancers and are thought to play a role in malignant transformation. Previously, immunohistochemical detection of p53 has been possible only in fresh-frozen tissues. We examined p53 expression in paraffin-embedded tissues from 50 epithelial ovarian cancers and 25 primary breast cancers with a modified immunohistochemical (IHC) technique developed in this laboratory, using monoclonal antibody (MAb) PAb1801. The 75 cases were selected from a group of patients in whom the expression levels had already been assessed in a fresh-tissue IHC assay. An identical staining reactivity was observed in both formalin-fixed, paraffin-embedded tissue and fresh-frozen tissue in 48 of 50 (96%) epithelial ovarian cancers and in 23 of 25 (92%) primary breast cancers. Immunodetection of p53 in paraffin-embedded tissue blocks will be a useful alternative to the standard fresh-tissue assay and can accurately reflect the level of p53 expression in human tumors.

Antibodies, Monoclonal

Pragmatic factors influencing the detection of Neisseria gonorrhoeae.

The effects of the suboptimal temperature caused by delayed incubation or prolonged transport on the recovery of Neisseria gonorrhoeae were studied in 2 separate patient populations. The individual components of the John E. Martin Biological Environmental Chamber were used to define more precisely other variables that might influence the incidence of recovery. In a study of 1500 urethral and endocervical specimens processed in parallel for N gonorrhoeae, results quantitatively and qualitatively superior were achieved when an immediate source of CO2 and a zip-lock bag were used. The zip-lock bag appears to be a significant factor in the enhanced demonstration of N gonorrhoeae. Failure to incubate specimens before transportation decreased the numeric representation of N gonorrhoeae in 50 sets of triple cultures studied in parallel. Most low-inoculum cultures subjected to prolonged transportation without prior incubation will not demonstrate the presence of N gonorrhoeae. Even if preincubated before transportation, the cultures demonstrate a significant reduction in the number of colony-forming units per plate when subjected to normal room temperature during the course of transportation.

Bacteriological Techniques

Urinary tract infection caused by Staphylococcus saprophyticus.

This study was designed to determine whether Staphylococcus saprophyticus was an important cause of urinary tract infection (UTI), as has been reported by European, but not by American, investigators, S. saprophyticus was the second most common cause of UTI in young (mean age, 20 years), sexually active female outpatients without known preexisting kidney disease or preceding manipulation of the urinary tract. Most cases presented as acute cystitis, but frank pyelonephritis and UTI in pregnant females were observed. The organism was rarely found as a contaminant in urine cultures. When present in the mucocutaneous flora of the anal-urogenital area, the organism was significantly associated with UTI by the same organism. These results show that S. saprophyticus should be accepted as an important urinary tract pathogen of young female patients in the United States. A simple adequate laboratory identification may be based on resistance to novobiocin (disk diffusion test), absence of hemolysis and coagulase, and intense pigment production (65% of strains yellow, 35% white).

Adolescent