epithelial origin, the remainder being mesenchymal tumors (Table 21-2). Most epithelial tumors are composed of urothelial (transitional) type cells and are thus interchangeably called urothelial or transitional tumors, but squamous and glandular carcinomas also occur. Here, we discuss the urothelial cell tumors in some detail and only touch on the others.
1. Urothelial (Transitional Cell) Tumo
cell calluses may be made to differentiate into the specialized tissues of a whole plant, with the addition of a number of hormones or enzymes. This is an ability known as totipotency.
A callus is often the target of a gene gun for specific DNA insertion experiments.
Callus tissue is of particular use in micropropagation where it can be used to grow genetically identical copies of plants with d
Stem cell calssification
1. Based upon location
Embryonic stem cells
Somatic/ adult stem cells
2. Based upon function
Totipotent
Pluripotent
Multipotent
Unipotent
Reject Response
Traditional Immuno-repressents
Constant administration
Little engraftment after 3~4 weeks
Host immune system impaired
Vulnerable to Infection
↓Need brief immuno-re
1908 - The term "stem cell" was proposed for scientific use by the Russian histologist Alexander Maksimov (1874–1928) at congress of hematologic society in Berlin. It postulated existence of haematopoietic stem cells.
1998 - James Thomson and coworkers derive the first human embryonic stem cell line at the University of Wisconsin–Madison.
2004–2005 - Korean researcher Hwan
Discovery of the iPS cell
Expect to solve the problems of ES cells
How to think?
Active factor(protein) in ES cells skin cells
Aug, 2006, Pro. Yamanaka ’s laboratory in Kyoto produced ‘pluripotent cells’
Nov, 2007, the first Human iPS cells
iPS cells are a type of pluripotent stem cell
artificially derived from a differentiated cell,
by inducing a “forced”