A Simple Method to Replace Islet Equivalents for Volume Quantification of Human Islets

Cell Transplantation

Article

Lisa Stehno-Bittel¹  Karthik Ramachandran²  Han-Hung Huang³ 

[1] Department of Physical Therapy and Rehabilitation Science, University of Kansas Medical Center, Kansas City, KS, USA;Likarda, LLC, Kansas City, KS, USA;Physical Therapy Program, Angelo State University, Member, Texas Tech University System, San Angelo, TX, USA;

关键词: Islet;    Islet equivalent (IEQ);    Human;    Insulin;    ATP;    Viability;   

DOI  :  10.3727/096368914X681928

 received in 2014-01-04, accepted in 2014-05-13,  发布年份 2015

来源: Sage Journals

【 摘 要 】

Human islets come in a variety of sizes and shapes, and the total volume of islets used for research or clinical transplants must be estimated in a manner that is simple and valid. Islet equivalent (IEQ) measurements are the standard estimate of islet volume. We published a new method (the Kansas method) for estimating rat islet volume using cell numbers that was reliable and valid. Here we modified the method for human islets. We measured the dimensions of isolated human islets showing that they are not spherical and became less so in larger islets, with an average smallest/largest diameter ratio of 0.73 in large islets and 0.85 in small islets. Human islets were individually loaded into 96-well plates, dissociated into single cells, and the total cell number per islet determined with computer-assisted cytometry. Based on the counted cell number per islet, a regression model was created to convert islet diameter to cell number with a high R2 value (0.99). Separate regression equations for male and female donors or young and old donors were not significantly different than the pooled data and did not improve the regression values. There was an inverse correlation between the cell number per IEQ and islet size. The Kansas method was validated with ATP/cell and cell viability data. Compared to the actual cell count, conventional IEQ measurements overestimated tissue volume of large islets by nearly double. Examples of differences in results obtained from the same data sets normalized to IEQ or the Kansas method included viability and insulin secretion concentrations. The implications of the error associated with the current IEQ method of volume estimation are discussed.

【 授权许可】

Unknown   
© 2015 Cognizant Comm. Corp.

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