SUMMARY:The recent development of tissue microarray technology has potentiated large-scale retrospective cohort studies using archival formalin-fixed, paraffin-embedded tissues. A major obstacle to broad acceptance of microarrays is that they reduce the amount of tissue analyzed from a whole tissue section to a disk, 0.6 mm in diameter, that may not be representative of the protein expression patterns of the entire tumor. In this study, we examine the number to disks required to adequately represent the expression of three common antigens in invasive breast carcinoma-estrogen receptor, progesterone receptor, and the Her2/neu oncogene-in 38 cases of invasive breast carcinoma. We compared the staining of 2 to 10 microarray disks and the whole tissue sections from which they were derived and determined that analysis of two disks is comparable to analysis of a whole tissue section in more than 95% of cases. To evaluate the potential for using archival tissue in such arrays, we created a breast cancer microarray of 8 to 11 cases from each decade beginning in 1932 to the present day and evaluated the antigenicity of these markers and others. This array demonstrates that many proteins retain their antigenicity for more than 60 years, thus validating their study on archival tissues. We conclude that the tissue microarray technique, with 2-fold redundancy, is a valuable and accurate method for analysis of protein expression in large archival cohorts. (Lab Invest 2000, 80:1943-1949.

Tissue microarrays have facilitated the evaluation of large cohort studies; however, there is little data on the best method for preserving sections once they are cut. We assessed three methods of storing precut breast cancer microarray slides: paraffin coating and storage in a nitrogen desiccator, either alone or in combination. We tested the durability of three antigens, cytokeratin, estrogen receptor, and Ki-67 on microarrays stored under these conditions for 3 months at room temperature. Staining was assessed with both manual scoring using traditional brown stain (0-3 þ ) as well as automated scoring using fluorescently stained sections. Staining intensity was compared to that obtained from freshly cut slides. Slides stored under ambient conditions (room temperature and air) for 3 months exhibited marked degradation of all target antigens, in some cases resulting in slides that were virtually unreadable. We found that combined paraffin coating and nitrogen storage resulted in the best preservation of antigenicity, with retention of 72-99% of the antigenicity of a freshly cut slide, depending upon the marker and detection system used. The use of either paraffin coating or nitrogen storage alone protected slides to a lesser degree.

No abstract

Diagnostic criteria for non‐overt disseminated intravascular coagulation (DIC) have been proposed by the International Society of Thrombosis and Hemostasis, but are not useful for the diagnosis of early phase of overt‐DIC (pre‐DIC). Therefore, in the current study the non‐overt DIC diagnostic criteria were modified using the global coagulation tests, the change rate in the global coagulation tests and molecular hemostatic markers to detect the pre‐DIC state and were prospectively evaluated in 613 patients with underlying DIC disease. The frequencies of patients with DIC (DIC positive), late onset DIC, and without DIC (DIC absent) were 29.5%, 7.2%, and 63.3%, respectively. The modified non‐overt‐DIC criteria can correctly predict 43/44 patients (97.7%) who were DIC absent at admission and became DIC positive, within a week (late onset DIC state). The mortality rate was higher in DIC positive compared with pre‐DIC (37.6% vs. 22.7%, P < 0.05) or DIC negative (37.6 vs. 13.7%, P < 0.01). It was also significantly higher in pre‐DIC compared with DIC negative (P < 0.05). Thus, these modified non‐overt DIC diagnostic criteria might therefore be useful for the diagnosis of early‐phase DIC. © 2010 Wiley‐Liss, Inc. Am. J. Hematol.