Comparing cooling systems for the COBE 2991 cell separator used in the purification of human pancreatic islets of Langerhans.

Two different approaches of controlled cooling of the COBE 2991 cell-separator for islet purification were evaluated. The first method is the new Geneva COBE cooling system (GCCS), which consists of an electronically controlled liquid nitrogen injection system. The second is the University of Illinois at Chicago cooling system (UICCS), which consists of a specially designed "Cold Room" maintained at 1-8 C. For the GCCS, the mean temperatures of the gradient solutions were measured at the beginning and end of centrifugation were found to be 7 +/-0.7 C and 6.8 +/-0.6 C respectively. For the UICCS, the mean temperature of the gradients at the beginning and end of centrifugation were 4.7 +/-0.53 C and 7.03 C+/-0.91 C respectively. The presented COBE cooling systems can easily be adapted to a COBE 2991 cell-separator and are efficient in maintaining gradient solutions at a defined low temperature during centrifugation.

[Efficacy of organ exchange rules in a 7 million population nation]. / Effizienz der Organaustauschregeln in einer 7 Mio Nation.

The suitability of organ exchange rules were analysed retrospectively in a country with a population of 7 million not connected to international organ sharing organisations following the opening of a national coordination centre 2 years previously. The results demonstrate that the sharing rules work frictionless and efficiently, and that compulsory registration of every organ donor (cadaveric and living) guarantees entire transparency of organ source and exchange, therefore preventing any illegal activity. An unacceptably high mortality rate for patients awaiting a highly urgent organ (specifically heart or liver) shows that connection to an international organ exchange organisation is desirable in this respect.

[Transplantation of islets of Langerhans in man]. / Transplantation d'îlots de Langerhans chez l'humain.

Islet of Langerhans transplantation is an alternative to whole pancreas transplantation for type I diabetic patients, in whom exogenous insulin therapy has not prevented the occurrence of systemic complications. Thanks to a new isolation technique of human islets, 45 patients have been transplanted worldwide since 1988, of whom only 7 have become totally insulin-independent. Rejection and quality of the islet preparations are problems which remain to be solved. Autotransplantation of islets has been proposed in patients undergoing a pancreatectomy for benign disease. The present report concerns two of our patients who had a pancreatectomy with islet autotransplantation. Both patients are insulin-independent 3 and 11 months postoperatively, with satisfactory metabolic tests. Islet autotransplantation can be proposed when pancreatectomy for non-malignant disease is performed. This method may prevent the development of insulin-dependent diabetes, known to be particularly labile. Because of the sophisticated technical procedures required, human islet isolation is at present only performed in a small number of medical centers and still is in the field of medical experimentation.