Proliferation, apoptosis and their regulatory protein expression in colorectal adenomas and serrated lesions

Background Adenomas and serrated lesions represent heterogeneous sets of early precursors in the colorectum with varying malignant potential. They are often distinguished by their histopathologic differences, but little is known about potential differences in regulation of epithelial proliferation and apoptosis. Methods We conducted a protein expression analysis using tissue microarrays of 625 colorectal adenomas and 142 serrated lesions to determine potential differences in regulation of epithelial proliferation and apoptosis. We quantitated proliferation with Ki-67; apoptosis with activated caspase-3 (CASP3); up- and down-regulators of proliferation with cyclin D1, p16INK2, and p21Cip1; and apoptosis regulators with BAX, BCL2, and survivin. Linear mixed effects models and circos diagrams were used to determine relationships among expression and lesion characteristics. Results Adenomas had a significantly higher CASP-3 labeling index (LI) than serrated lesions, resulting in a lower net growth ratio (Ki-67 LI/activated CASP-3 LI, p-value<0.0001). Cyclin D1 LI, p16 LI and p21 LI were lower in adenomas compared to serrated lesions, while expression of both BCL2 and BAX were higher (p <0.001). Among adenomas, cyclin D1 LI and p16 LI levels increased with greater villous component, and the highest BAX expression was detected in adenomas larger than 2 cm (both p<0.0001). Right-sided adenomas had higher CASP3 LI than left colorectal adenomas (p = 0.008). Significant differences in cyclin D1 LI, p21 LI and survivin LI were also observed across histopathologic subtypes of serrated lesions. Conclusions Our findings demonstrate different patterns of regulatory protein expression in adenomas than serrated lesions, especially involving apoptosis

A comparative ToF-SIMS and GC–MS analysis of phototrophic communities collected from an alkaline silica-depositing hot spring

One of few techniques that is able to spatially resolve chemical data, including organic molecules, to morphologicalfeatures in modern and ancient geological samples, is time-of-flight secondary ion mass spectrometry(ToF-SIMS). The ability to connect chemical data to morphology is key for interpreting thebiogenicity of preserved remains in ancient samples. However, due to the lack of reference data for geologicallyrelevant samples and the ease with which samples can be contaminated, ToF-SIMS data may bedifficult to interpret. In this project, we aimed to build a ToF-SIMS spectral database by performing parallelToF-SIMS and gas chromatography–mass spectrometry (GC–MS) analyses of extant photosyntheticmicrobial communities collected from an alkaline silica-depositing hot spring in Yellowstone NationalPark, USA. We built the library by analyzing samples of increasing complexity: pure lipid standards commonlyfound in thermophilic phototrophs, solvent extracts of specific lipid fractions, total lipid extracts,pure cultures of dominant phototrophic community members, and unsilicified phototrophic streamercommunities.The results showed that important lipids and pigments originating from phototrophs were detected byToF-SIMS (e.g., wax esters, monogalactosyldiacylglycerol, digalactosyldiacylglycerol, sufloquinovosyldiaglycerol,alkanes, etc.) in the streamer lipid extracts. Many of the lipids were also detected in situin the unsilicified streamer, and could even be spatially resolved to individual cells within the streamercommunity. Together with the ToF-SIMS database, this mapping ability will be used to further exploreother microbial mats and their fossilized counterparts in the geological record. This is likely to expandthe geochemical understanding of these types of samples

A systematic survey of floral nectaries

The construction of classifications, as well as the understanding of biological diversity, depends upon a careful comparison of attributes of the organisms studied (Stuessy, 1990). It is widely known that data from diverse sources showing differences from taxon to taxon are of systematic significance. Dur-ing the 20th century, systematists have emphasized that their discipline involves a synthesis of all knowledge (Stevens, 1994) or, in other words, the variation of as many relevant characters as possible should be incorporated into the natural system to be constructed. The extent to which particular characters are constant or labile will determine their usefulness to syste-matics. In general, more conservative characters will be valuable in defining families and orders, whereas more labile characters may be useful at the ge-neric and specific levels (Webb, 1984). There is no doubt that floral characters are among the most used in the classification of flowering plants. At the same time, they constitute essential features in diagnostic keys to taxa in both taxonomic treatments and Floras (Cronquist, 1981, 1988).Fil: Bernardello, Gabriel Luis Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin