A fluorescence polarization immunoassay (FPIA) based on a monoclonal antibody for the determination of ochratoxin A (OTA) was developed. Fluorescein-labelled OTA derivative (tracer) was synthesized and purified by thin-layer chromatography. The optimized OTA FPIA had a dynamic range from 5 to 200 ng mL )1 with IC 50 value of 30 ng mL )1 and a detection limit of 3 ng mL )1 . The method developed was characterized by high specificity and reproducibility. Cross-reactivity with other mycotoxins (zearalenone, aflatoxins, patulin and T-2 toxin) was negligible (<0.1%). Methanol extracts of barley samples were used for the analysis. The results of OTA determination in barley were compared with those determined by indirect competitive enzyme-linked immunosorbent assay (ELISA). Recoveries for the samples spiked at 50, 100 and 500 ng g )1 levels were 91, 90 and 97%, respectively, for FPIA, and 98, 98 and 102%, for ELISA. Naturally contaminated barley samples were analysed by these methods but some disagreement was observed between the results. The FPIA method can be applied for screening of food samples for OTA residues without a complicated clean-up.

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An assay based on multiplex PCR was applied for the detection of potential aflatoxin-producing molds in Korean fermented foods and grains. Three genes, avfA, omtA, and ver-1, coding for key enzymes in aflatoxin biosynthesis, were used as aflatoxin-detecting target genes in multiplex PCR. DNA extracted from Aspergillus flavus, Aspergillus parasiticus, Aspergillus oryzae, Aspergillus niger, Aspergillus terreus, Penicillium expansum, and Fusarium verticillioides was used as PCR template to test specificity of the multiplex PCR assay. Positive results were achieved only with DNA that was extracted from the aflatoxigenic molds A. flavus and A. parasiticus in all three primer pairs. This result was supported by aflatoxin detection with direct competitive enzyme-linked immunosorbent assay (DC-ELISA). The PCR assay required just a few hours, enabling rapid and simultaneous detection of many samples at a low cost. A total of 22 Meju samples, 24 Doenjang samples, and 10 barley samples commercially obtained in Korea were analyzed. The DC-ELISA assay for aflatoxin detection gave negative results for all samples, whereas the PCR-based method gave positive results for 1 of 22 Meju samples and 2 of 10 barley samples. After incubation of the positive samples with malt extract agar, DC-ELISA also gave positive results for aflatoxin detection. All Doenjang samples were negative by multiplex PCR and DC-ELISA assay, suggesting that aflatoxin contamination and the presence of aflatoxin-producing molds in Doenjang are probably low.

A total of 50 raw milk samples from Gyeongnam Province of Korea were examined for the incidence of Listeria monocytogenes between July 1998 and August 1998. L. monocytogenes isolated by biochemical test was confirmed by polymerase chain reaction (PCR) with two sets of primers designed from the invasion-associated protein (iap) gene. After standard PCR with external primers, the amplified DNA was confirmed by a second round of PCR with internal primers (nested PCR). Both the external and internal primers generated 468-bp and 287-bp products. respectively. Only one (G9 strain) of the three suspect samples that tested positive in biochemical tests for L. monocytogenes from 50 raw milk samples was also PCR positive. Following this procedure. PCR-positive G9 strain was confirmed by Southern blot using the 287-bp internal iap probe again. The detection limit of G9 strain by standard PCR assay was as few as 102 cells, equivalent to approximately I pg of L. monocytogenes DNA. These PCR assays may be useful for novel detection as well as rapid confirmation for L. monocytogenes from food samples and the field.

This study was done to identify the relationship between nurses' compliance with safety guidelines for the use of antineoplastic agents, observable symptoms, and stress from occupational exposure. Methods: The participants were 172 nurses from six general hospitals in a metropolitan area. They had administered antineoplastic agents at least three months prior to the study. Data were collected using self-report questionnaires, and then analyzed using SPSS/WIN 23.0 for descriptive statistics, t-test, one-way ANOVA, Scheffé method, and Pearson correlation coefficient. Results: The average score on the guideline for safety compliance was 87.75 points out of a total of 100. The average score for observable symptoms of exposure to antineoplastic agents was 30.12 (28~56) points, and that for mean stress was 33.52 (15~60) points. Observable symptoms and stress from occupational exposure showed a statistically significant positive correlation (r=0.34, p<.001). Conclusion: To increase the degree of compliance with safety guidelines for antineoplastic agents, hospitals should lower the chance of exposure to antineoplastic agents, as well as minimize the observable symptoms and stress from occupational exposure. Periodic education and policy support are needed to improve compliance with safety guidelines for antineoplastic agent use.