A novel source for dioxins present in recycled fat from gelatin production.

Within a survey on dioxins in animal fat used as feed ingredient, a sample originating from pigs offal was shown to contain 50 ng Toxic Equivalents (TEQ) PCDD/PCDFs kg(-1) fat. Further investigation revealed fat samples with levels as high as 440 ng TEQ kg(-1) fat and contaminated feed with a highest level of 8.4 ng TEQ kg(-1) feed. The congener pattern was dominated by 1,2,3,7,8-PeCDD and 2,3,7,8-TCDD, and was not recognized from any previous incident or known dioxin source. Remarkably, 2,3,7,8-substituted congeners were much more abundant than their non-2,3,7,8-substituted counterparts. The sampled fat was derived from a gelatin production plant. Broken filters, used to clean the hydrochloric acid (HCl) used in the process, caused the dioxin contamination. The fat was primarily used for pig feed. A new physiologically-based pharmacokinetic (PBPK) model for lipophilic contaminants in growing slaughter pigs predicted levels at slaughter varying between 40 pg TEQ g(-1) fat (worst-case) and 2.5-7pgTEQ g(-1) fat under more realistic scenarios. Almost 300 farms were temporarily blocked. Many fat samples of pigs were analyzed using a combined approach of DR CALUX and GC/HRMS. Levels in contaminated pig fat were around the EU-limit of 1 pg TEQ g(-1) fat, with some samples up to 2-3 pg TEQ g(-1) fat. Of 80 negative samples analyzed by DR CALUX and GC/HRMS no false-negatives were obtained, whereas 36 and 62 of the 80 samples classified suspected with the bioassay had GC/HRMS levels above respectively the tolerance and action limits. It is concluded that novel and unexpected dioxin sources remain a threat to the food chain and require the proper evaluation and monitoring of production processes, including chemicals used therein.

Radiotherapy for oesophagus carcinoma: the impact of p53 on treatment outcome.

BACKGROUND AND PURPOSE: Wildtype p53 protein plays an important role in the cellular response to ionizing radiation and other DNA damaging agents and is mutated in many human tumours. We evaluated the relationship of the immunohistochemically determined p53 protein status and the disease control with radiotherapy alone for carcinoma of the oesophagus. MATERIALS AND METHODS: Immunostaining for p53 protein was performed on paraffin-embedded specimens from 69 patients with adeno- and squamous cell carcinoma of the oesophagus. All patients were treated by radiotherapy exclusively, consisting of a combination of external irradiation and intraluminal brachytherapy, using two different dose levels. RESULTS: Fifty-four percent (37/69) of the tumours showed overexpression of the p53 protein. No difference in pre-treatment parameters for p53-positive and p53-negative cases was detected. In multivariate analysis p53 was significantly associated with overall survival (OS) next to weight loss, tumour stage and N-stage. For metastatic-free survival (MFS) p53 status proved to be the sole independent prognostic factor. The influence of p53 on local recurrence-free survival (LRFS), however, was not as strong as on OS and MFS. CONCLUSIONS: Immunohistochemically detected overexpression of mutated p53 protein in oesophagus carcinoma was an independent prognostic factor in a group of patients treated with radiotherapy alone.

E-cadherin expression in oesophageal carcinoma treated with high-dose radiotherapy; correlation with pretreatment parameters and treatment outcome.

BACKGROUND AND PURPOSE: E-cadherin plays an important role in the cell-cell contact of normal epithelium. Loss of E-cadherin expression may be related to tumour invasiveness and metastatic potential. In a group of patients treated for oesophageal carcinoma by radiotherapy only, we found that immunohistochemically detected p53 expression correlated with reduced survival, mainly because of the occurrence of distant metastases. We questioned whether, in this group of patients, E-cadherin expression was concomitantly altered and served as a predictive factor for the development of distant metastases. MATERIALS AND METHODS: Immunostaining for E-cadherin was performed on paraffin- embedded biopsy specimens from patients with adenocarcinoma and squamous cell carcinoma of the oesophagus. E-cadherin status and its correlation with regard to pretreatment parameters and treatment outcome were determined. RESULTS: An aberrant staining pattern of E-cadherin did not correlate with any of the pretreatment parameters. In a univariate analysis, a significantly reduced metastatic potential was found for tumours that had an aberrant cellular staining pattern for E-cadherin, which was strongest for squamous cell carcinomas. However, in a multivariate analysis only p53 status correlated significantly with the occurrence of distant metastases. CONCLUSION: Although, in univariate analysis, aberrant E-cadherin expression served as a better, rather than a worse prognostic factor, p53 status remained the only significant parameter in multivariate analysis, in this group of patients with oesophageal carcinoma. No relationship between p53 status and E-cadherin expression was found.

Earthworm and food interactions on bioaccumulation and disappearance in soil of polycyclic aromatic hydrocarbons: studies on phenanthrene and fluoranthene.

The present study describes some novel phenomena with regard to the environmental fate of polycyclic aromatic hydrocarbons (PAHs) in the terrestrial soil environment. Laboratory experiments were conducted on: (1) the influence of earthworms on the disappearance rate of PAHs in soil, and (2) the bioaccumulation of these compounds in the earthworm body. It is demonstrated that the disappearance of phenanthrene and fluoranthene in soil is accelerated by the presence of the earthworm Lumbricus rubellus. Possible explanations and practical implications of this effect are discussed. In the bioaccumulation part of the study it is demonstrated that earthworms may take up and accumulate fluoranthene and, to a lesser extent, also phenanthrene in their body tissues. Bioaccumulation was found to be reduced by changes in bioavailability associated with aging of the PAH-amended soil. Finally, it was observed that earthworms indicate a strongly enhanced bioaccumulation of PAHs under conditions of food limitation.