Representative Of Tmas

An important concern connected to the TMA technology is the question whether or not ''tiny'' tissue cores measuring less than 0.6 mm in diameter are representative of an entire tumor.[2-6] To date, at least 20 studies have addressed this question, comparing immunohistochemistry (IHC) findings on TMAs with the corresponding traditional ''large'' sections (e.g., Refs. [2-5,7]). Most of these studies reported a high level of concordance of results, and concluded that the inclusion of more than one tissue core per donor block further increases the concordance. For example, Camp et al. studied the expression of ER, PR, and Her2 in 2-10 tissue cores obtained from the same donor blocks in a set of 38 invasive breast carcinomas. They found that analysis of two cores was sufficient to obtain identical results, compared to the corresponding whole tissue sections in 95% of cases. A concordance of 99% is reached if four cores were analyzed, and analysis of additional cores did not result in a significant further increase of concordance.1-2-1

However, it is important to note that both large sections and TMA tissue cores represent only a very small fraction of the tumor bulk from which they derive. Perhaps, even more important than comparing individual results obtained on large sections and on TMA sections, is the question of whether or not the whole tumor can be represented by any type of size-limited histological samples such as TMAs or large sections.

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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