Microdissection of routinely stained or unstained frozen sections has been used successfully to obtain purified cell populations for the analysis of cell-specific gene expression patterns in primary tissues with a complex mixture of cell types. However, the precision and usefulness of microdissection is frequently limited by the difficulty to identify different cell types and structures by morphology alone. We therefore developed a rapid immunostaining procedure for frozen sections followed by laser capture microdissection (LCM) and RNA extraction, which allows targeted mRNA analysis of immunophenotypically defined cell populations. After fixation, frozen sections are immunostained under RNAse-free conditions using a rapid three-step streptavidin-biotin technique, dehydrated and immediately subjected to LCM. RNA is extracted from captured tissue, DNAse I treated, and reverse transcribed. Acetone-, methanol-, or ethanol/acetone-fixed sections give excellent immunostaining after 12 to 25 minutes total processing time. Specificity, precision, and speed of microdissection is markedly increased due to improved identification of desired (or undesired) cell types. The mRNA recovered from immunostained tissue is of high quality. Single-step PCR is able to amplify fragments of more than 600 bp from both housekeeping genes such as beta-actin as well as cell-specific messages such as CD4 or CD19, using cDNA derived from less than 500 immunostained, microdissected cells. Immuno-LCM allows specific mRNA analysis of cell populations isolated according to their immunophenotype or expression of function-related antigens and significantly expands our ability to investigate gene expression in heterogeneous tissues.
The MSQ is a reliable and valid questionnaire in the CM population that can differentiate the functional impact between CM and EM. The MSQ can assist researchers in evaluating treatment effectiveness by obtaining input directly from the patients on multidimensional aspects other than frequency of headache days.
[1] Geodetic strain and late Quaternary faulting in the Basin and Range province is distributed over a region much wider than historic seismicity, which is localized near the margins of the province. In the relatively aseismic interior, both the magnitude and direction of geodetic strain may be inconsistent with the Holocene faulting record. We document the best example of such a disagreement across the NE striking, $55°NW dipping Crescent normal fault, where a NW oriented, 70 km geodetic baseline records contemporary shortening of $2 mm/yr orthogonal to the fault trace. In contrast, our geomorphic, paleoseismic, and geochronologic analyses of the Crescent fault suggest that a large extensional rupture occurred during the late Holocene epoch. An excavation across the fault at Fourmile Canyon reveals that the most recent event occurred at 2.8 ± 0.1 ka, with net vertical tectonic displacement of 4.6 ± 0.4 m at this location, corresponding to the release of $3 m of accumulated NW-SE extension. Measured alluvial scarp profiles suggest a minimum rupture length of 30 km along the range front for the event, implying a moment magnitude M w of at least 6.6. No prior event occurred between $2.8 ka and $6.4 ± 0.1 ka, the 14 C calender age of strata near the base of the exposed section. Assuming typical slip rates for Basin and Range faults ($0.3 mm/yr), these results imply that up to one third, or $1 m, of the extensional strain released in the previous earthquake could have reaccumulated across the fault since $2.8 ka. However, the contemporary shortening implies that the fault is unloading due to a transient process, whose duration is limited to between 6 years (geodetic recording time) and 2.8 ka (the age of the most recent event). These results emphasize the importance of providing accurate geologic data on the timescale of the earthquake cycle in order to evaluate geodetic measurements.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.