The geometry of triple-balloon dilation

Triple-balloon dilation (TBD) of a variety of luminal structures has been successfully, though infrequently, used. A mathematical model is presented for the selection of balloon sizes, and equations and tables are derived that allow the user to estimate more accurately the size of balloons needed for TBD of structures with large lumina. With TBD, an approximately circular lumen can be formed. Also, TBD allows smaller, higher-pressure balloons to be used instead of single, low-pressure, large balloons. However, multiple puncture sites may be required for TBD.     

Insulin-forming activity of monolayer cultures of bovine fetal pancreatic islet cells

The insulin concentration in the growth medium of primary monolayer cultures of bovine fetal pancreatic islet cells grown in the presence of a normal and increased (300 mg%) glucose content, was determined by a radioimmunologic method. A high glucose concentration led to increased secretion of insulin. The results of the cytological study showed definite correlation between mitotic activity of the cells of the culture and the intensity of insulin secretion into the medium.Laboratory of Biological Standardization of Hormones, Institute of Experimental Endocrinology and Hormone Chemistry, Academy of Medical Sciences of the USSR, Moscow. Laboratory of Pathomorphology, Institute of Transplantation of Organs and Tissues, Ministry of Health of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Yudaev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 8, pp. 235–238, August, 1978.