Antennae: the strongest magnetic part of the migratory ant

Pachycondyla marginata (P.m.), a migratory and termitophageous ant, hunting only the termite species Neocapritermes opacus, migrates significantly oriented 13 degrees with respect to the magnetic North-South axis. Results of hysteresis curves at room temperature of four Pachycondyla marginata heads, thorax, pairs of antennae and abdomens, oriented parallel to the magnetic field, indicate that the antennae give the strongest saturation magnetization, suggesting this sensory organ as being also a magnetic sensory organ. The total saturation magnetization in a whole P.m. is composed by 42 +/- 3%, 24 +/- 3%, 19 +/- 3% and 15 +/- 3% of antennae, head, thorax and abdomen contributions, respectively. The abdomen hysteresis curve presents a wasp-waisted loop with Hcr/Hc of 4.75, characteristic of mixed magnetic systems.     

Assessment of microsatellite instability in colorectal cancer patients from Brazil

The replication error status analysis of DNA, through microsatellite instability detection, has become an indispensable tool for hereditary non-polyposis colorectal cancer screening. This study investigated the microsatellite instability in Brazilian individuals presenting colorectal cancer. In this study, 66 patients were clinically analyzed according to Amsterdam II and Bethesda guidelines. Normal and tumour tissues were collected and analyzed for MSI degree according to molecular markers BAT25, BAT26, BAT40, APC–D5S346, D2S123, and D17S250. Eight patients (12.1%) fulfilled the Amsterdam II guidelines, and 15 (22.7%) met the Bethesda guidelines. BAT25 was the most sensitive marker (86.7%), while BAT26 was the least sensitive (66.7%). The specificity of both markers was 100%, but all of the markers must be used since the contribution of each marker to the sensitivity and specificity of the test is complementary. Proximal tumours were significantly predominant among RER⁺ patients. Conclusions: Patients with a family history of colorectal cancer with the tumour in the proximal colon must be screened to replication error status as early as possible in order to avoid the progression of the disease.     

Integrated approaches to studying Medicago truncatula genome structure and function and their applications in biotechnology

Plant genetic engineering has become an invaluable tool in plant research. Although plant transformation is a well-established technique, transgene expression is still unpredictable. Silencing may involve epigenetic modifications or nuclear and chromosomal localization of transgenes. In this way, understanding nuclear structure and organization is important not only for increasing our knowledge of fundamental aspects of the genome but also for taking the greatest advantage of inserting foreign genes and controlling their expression in biotechnological applications. Integrated approaches are clearly required in order to elucidate such complex processes. By combining the analysis of the physical position of transgenes with markers for epigenetic modifications in the plant genome we can better understand the factors affecting transgene expression levels and analyze the genomic environments of differentially expressed transgenes. Medicago truncatula Gaertn. has become a well-known model for the legume family and is used in studies ranging from nodulation to environmental stresses. More recently its use in biotechnology has been explored. In this report we describe the application of fluorescence in situ hybridization (FISH) to detect foreign DNA sequences and to determine the organization of the nucleolar organizer regions (NORs) genes in both metaphase chromosomes and interphase nuclei. We also studied chromatin distribution by immunodetection of epigenetic marks in M. truncatula interphase nuclei from tissue sections. We present evidence that M. truncatula is amenable to this kind of studies, which will in turn contribute to a better exploitation of biotechnology applications for this important plant family.     

Predicting the impact of increasing carbon dioxide concentration and temperature on seed germination and seedling establishment of African grasses in Brazilian Cerrado

Global climate changes and biological invasions are environmental disturbances that may interact synergistically, causing loss of biodiversity. As the early stages of development are the most sensitive and easily affected by these constraints, this study investigated the effects of increased carbon dioxide (CO₂) and temperature, as forecasted for 2100, on seed germination and early development of three species of invasive African grasses that have gradually replaced landscapes of the Brazilian Cerrado biome. It was observed that these parameters affected percentage and rate of germination in Urochloa brizantha, rate of germination and mean germination time in Urochloa decumbens and accelerated autotrophy acquisition in U. brizantha, U. decumbens and Megathyrsus maximus. Regarding root elongation, all species showed changes in total length, absolute and relative growth rate, but at different stages of development or time intervals, with increased temperature being more significant than increased CO₂, probably due to seed reserves still being the main carbon sources at this stage. Taken together, the results indicate that the effects of CO₂ and increased temperature are species specific and highlight the greatest potential of U. brizantha to germinate, and of U. decumbens for seedling establishment under these environmental changes.     

Anti-inflammatory and wound healing potential of cashew apple juice (Anacardium occidentale L.) in mice

Cashew apple is a tropical pseudofruit consumed as juice due to its excellent nutritional and sensory properties. In spite of being well known for its important antioxidant properties, the cashew apple has not been thoroughly investigated for its therapeutic potential. Thereby, this study evaluated the antioxidant capacity, anti-inflammatory, and wound-healing activities of cashew apple juice. Juices from ripe and immature cashew apples were analyzed for antioxidant, anti-inflammatory, and wound-healing properties. Those were evaluated in murine models of xylene-induced ear edema and wound excision. Swiss mice were treated with cashew juice by gavage. Edema thickness was measured and skin lesions were analyzed by planimetry and histology. Both antioxidant content and total antioxidant activity were higher in ripe cashew apple juice (RCAJ) than in unripe cashew apple juice (UNCAJ). The UNCAJ presented the main anti-inflammatory activity by a significant inhibition of ear edema (66.5%) when compared to RCAJ (10%). Moreover, UNCAJ also showed the best result for wound contraction (86.31%) compared to RCAJ (67.54%). Despite of higher antioxidant capacity, RCAJ did not promote better anti-inflammatory, and healing responses, which may be explained by the fact that treatment increased antioxidants level leading to a redox “imbalance” turning down the inflammatory response modulation exerted by reactive oxygen species (ROS). The results suggest that UNCAJ presents a greater therapeutic activity due to a synergistic effect of its phytochemical components, which improve the immunological mechanisms as well as an optimal balance between ROS and antioxidants leading to a better wound healing process.