Application of large format tissue processing in the histology laboratory

In clinical, research and veterinary laboratories of North America, large format histology has more recently been improved with newer equipment and better methodology. Large tissue specimens are frequently sliced in the grossing room and processed in multiple smaller, standard size tissue cassettes. Justifiably, submitting more blocks inherently lends itself to a greater confidence in the accuracy of the diagnosis, yet guidelines for tissue sampling often suggest taking fewer samples. For example, large tumor specimen protocols recommend taking one standard-sized tissue block for each cm diameter of tumor. However, cancers are the culmination of many complex changes in cell metabolism and often appear dissimilar at different tissue locations. As these changes have an uncertain behavior, many other tissue samples are often taken from areas that appear to have either a variable texture or color. Consequently, at microscopy, the complete tissue sample may need to be reassembled like a jigsaw puzzle as the stained sections are frequently presented over many slides. This problem has easily been overcome by using large format cassettes since the entire cross-section of the tissue sample can often be viewed on a single slide. Because these cassettes can effectively hold up to 10 times the volume of conventional standard size cassettes, they are a more efficient way of assessing large areas of tissue samples. This system is easily adapted for all tissue types and has become the established method for assessing large tissue samples in many laboratory settings

Evaluation of molecular methods for the field study of the natural history of Dicrocoelium dendriticum

There is a need for improved methods for the study of the impacts of climatic and livestock management change on the epidemiology of production-limiting helminth parasitic diseases. In this study we report the application of molecular methods to describe the natural history of the small lancet fluke, Dicrocoelium dendriticum on Machair pastures on the Inner Hebridean Isle of Coll. Our results build upon those of the only previous historic field study of D. dendriticum in the British Isles that had been undertaken on the same study site. We demonstrate the value of combining conventional parasitological methods with PCR amplification of a mitochondrial DNA fragment for the detection of D. dendriticum in ants and snails, and PCR amplification of ITS2 and 28S ribosomal DNA fragments to support the species identity of the intermediate hosts, to improving understanding of the epidemiology of D. dendriticum. We report the presence of D. dendriticum infection in cattle, sheep and rabbits grazing on Machair pastures. D. dendriticum infection was identified in a high percentage of the snails, identified as Cochlicella acuta and Cernuella virgata, and in a high percentage of Formica fusca and Myrmica ruginoides ants that were collected from, or clinging to, the tops of flowers. We have identified the involvement of different intermediate host species and higher prevalences of snail and ant infection than previously reported, in part reflecting differences between the sensitivity and specificity of morphological and molecular speciation methods. Overall, our results highlight the complex life history of dicrocoeliosis and illustrate the parasite’s generalist host strategy that confers potential to exploit new niches created by climatic change or grazing management for habitat conservation

SEMAT - The next generation of inexpensive marine environmental monitoring and measurement systems

There is an increasing need for environmental measurement systems to further science and thereby lead to improved policies for sustainable management. Marine environments are particularly hostile and extremely difficult for deploying sensitive measurement systems. As a consequence the need for data is greatest in marine environments, particularly in the developing economies/regions. Expense is typically the most significant limiting factor in the number of measurement systems that can be deployed, although technical complexity and the consequent high level of technical skill required for deployment and servicing runs a close second. This paper describes the SmartEnvironmental Monitoring and Analysis Technologies (SEMAT) project and the present development of the SEMAT technology. SEMAT is a "smart" wireless sensor network that uses a commodity-based approach for selecting technologies most appropriate to the scientifically driven marine research and monitoring domain/field. This approach allows for significantly cheaper environmental observation systems that cover a larger geographical area and can therefore collect more representative data. We describe SEMAT's goals, which include: (1) The ability to adapt and evolve; (2) Underwater wireless communications; (3) Short-range wireless power transmission; (4) Plug and play components; (5) Minimal deployment expertise; (6) Near real-time analysis tools; and (7) Intelligent sensors. This paper illustrates how the capacity of the system has been improved over three iterations towards realising these goals. The result is an inexpensive and flexible system that is ideal for short-term deployments in shallow coastal and other aquatic environments