Long-term (35 years) cryopreservation of Echinococcus multilocularis metacestodes.

The metacestode of Echinococcus multilocularis is the etiological agent of alveolar echinococcosis. The metacestode stage used for research is maintained in rodents by serial passages. In order to determine whether cryopreservation of E. multilocularis metacestodes would be suitable for long-term maintenance and replace serial passages, isolates of different geographic origin were cryopreserved in 1984-1986. The aim of the current study was to test the viability of cryopreserved isolates following long-term cryopreservation (up to 35 years) and to determine the phylogenetic clades these isolates belonged to. Cryopreserved isolates were tested for viability in vitro and in vivo in gerbils. In vitro results of 5 isolates indicated protoscolex survival in 13 of 17 experiments (76%) and metacestode survival in 5 of 12 (42%) in vivo experiments. In vivo results showed 'abortive lesions' in 13 of the 36 animals, 15 were negative and 8 harboured proliferating metacestode tissue containing protoscoleces. Genetic analysis confirmed the isolates belonged to European, Asian and North-American clades. In conclusion, the results of the current study indicate that metacestodes of E. multilocularis are able to survive long-term cryopreservation. Therefore, cryopreservation is a suitable method for long-term storage of E. multilocularis metacestode isolates and reduces the number of experimental animals.

Mediastinal pheochromocytoma with single coronary blood supply: a case report.

Primary pheochromocytomas located outside the adrenal glands account for only 10% of all pheochromocytomas. Mediastinal pheochromocytomas are even rarer and usually represent a therapeutic challenge as they often infiltrate adjacent structures. We report the case of a large primary mediastinal pheochromocytoma in a 65-year-old patient presenting with a sudden angina-like chest pain and dyspnea. Thoracic multislice computed tomography showed an 8 x 5 x 6-cm retrocardiac mass causing compression of both atria and infiltrating the left superior pulmonary vein. The tumor was highly vascularized and presented a blood supply derived from the circumflex artery. The mass was successfully removed by open heart surgery, and the patient was discharged 10 days postoperatively.