Clearing Specimens for the Demonstration of Bone

A brief review is given of some of the older technics of clearing and staining various types of animals, in such a way that the bones are clearly visible in the surrounding tissues. The authors have modified some of these earlier practices. Particularly good results were obtained by combining the Schultze technic with that of Lundvall. Embryos are fixed in 95% alcohol, treated with 1% KOH, stained in 1:10,000 alizarin Red S, cleared in gylcerin, dehydrated with alcohol and further cleared in toluol, toluol saturated with naphthalene, and anise oil saturated with naphthalene. Details of the technic are presented in the text     

Managing the Ethical Issues of Genomic Research using Pathology Specimens

Biobanks of human biospecimens involving tissue taken from surgery require close relationships with diagnostic pathology practices. As most of the tissue will be analysed using genetic or genomic technologies there is the possibility that new information is created that could be of relevance to the donors. Although attention has been recently focused on the responsibilities that may arise from researchers and biobanks in terms of giving back individual genetic research results (IGRRs) to research participants, little has been said in relation to the role of pathology services. In this Commentary, we summarise the issues with respect to pathology services and what guidelines and professional practice documents say about their responsibilities. We also provide points to consider in the development of an ethically defensible plan for giving back individual research results.     

A Method for the Gross and Microscopic Investigation of Vascular Reperfusion in Ischemic Myocardium

Fluorescein-isothiocyanate dextran (FITC-dextran; MW ∼ 70,000) was used in isolated rat hearts to compare normal vascular perfusion of ventricular myocardium with the pattern and extent of reperfusion following 60 minutes of global ischemia. Its gross distribution in frozen transverse sections through the ventricles was similar to that of sodium fluorescein. However, unlike 0.1% sodium fluorescein, 6.7% FITC-dextran has a viscosity similar to that of blood, and its much higher molecular weight prevents its diffusion beyond the ischemically injured vessels. Furthermore, staining by the alcoholic periodic acid-Schiff technique enabled tracer distribution to be confirmed microscopically and distinguished competent from incompetent vessels in paraffin embedded material.