Multi-endpoint biological monitoring in combined, carcinogenic occupational exposures.

We aimed to develop a relevant multi-endpoint biomonitoring system by studying different genotoxicity biomarkers in complex carcinogenic exposures under occupational situations. Altogether 109 workers were followed in five different workplaces. The combined carcinogenic exposures were monitored in the urine and peripheral blood samples using Ames mutagenicity test and cytogenetic analyzes. The different genotoxicity endpoints studied showed different results in the same carcinogenic exposure situations. The urinary mutagenicity tests provided more information and proved to be more sensitive compared to the cytogenetic tests in the majority of cases. In complex exposures multistep biomonitoring panel should be applied, because the exact mechanisms of the combination of single exposing agents are not known. Such a panel should involve monitoring different endpoints, e.g. point mutations, chromosomal mutations. A relatively affordable and rapid testing panel was developed using validated tests as Ames and cytogenetic assays, but its practical use should be confirmed by further investigations.

Renal capsule-parathymic lymph node complex: a new in vivo metastatic model in rats.

BACKGROUND: The ultimate cause of cancer death is, in most cases, the appearance of metastases. The aim of the present study was to contribute to animal experimental investigations of metastatic tumor development. MATERIALS AND METHODS: Rat hepatocarcinoma (He/De), mesoblastic nephroma (Ne/De) cells, and in other cases tumor-bearing lymph nodes were transplanted under the renal capsule of F344 rats. Metastatic potential of tumor cells was examined by whole body autoradiography and phosphor image analysis. The organ distribution of cells was also investigated. RESULTS: Transplanted tumor cells resulted in metastases in the parathymic lymph nodes. Implanted India ink also demonstrated connection between the lymphatic vessels of the renal capsule and the parathymic lymph nodes. The metastatic potential was independent of the primary tumor growth rate. CONCLUSION: The renal capsule-parathymic lymph node complex seems to be suitable for the isolated in vivo examination of metastatic development and for the detailed analysis of secondary tumors.