A feature selection approach for identification of signature genes from SAGE data

Background  

One goal of gene expression profiling is to identify signature genes that robustly distinguish different types or grades of tumors. Several tumor classifiers based on expression profiling have been proposed using microarray technique. Due to important differences in the probabilistic models of microarray and SAGE technologies, it is important to develop suitable techniques to select specific genes from SAGE measurements.     

Guided bone regeneration produced by new mineralized and reticulated collagen membranes in critical-sized rat calvarial defects

The aim of this study was to evaluate the bone regenerative effect of glutaraldehyde (GA) cross-linking on mineralized polyanionic collagen membranes in critical-sized defects on rat calvarias. Bone calvarial defects were induced in Wistar rats, which were then divided into five groups: a sham group; a control group, which received a commercial membrane; and GA, 25GA, and 75GA groups, which received one of three different polyanionic collagen membranes mineralized by 0, 25, or 75 hydroxyapatite cycles and then cross-linked by GA. Bone formation was evaluated based on digital radiography and computerized tomography. Histological analyses were performed 4 and 12 weeks after the surgical procedure to observe bone formation, membrane resorption, and fibrous tissue surrounding the membranes. Measurement of myeloperoxidase activity, tumor necrosis factor alpha, and interleukin 1beta production was performed 24 h after surgery. The percentage of new bone formation in the GA, 25GA, and 75GA groups was higher compared with the control and sham groups. In the GA and 25 GA groups, the membranes were still in place and were contained in a thick fibrous capsule after 12 weeks. No significant difference was found among the groups regarding myeloperoxidase activity and interleukin 1beta levels, although the GA, 25GA, and 75GA groups presented decreased levels of tumor necrosis factor alpha compared with the control group. These new GA cross-linked membranes accelerated bone healing of the calvarium defects and did not induce inflammation. In addition, unlike the control membrane, the experimental membranes were not absorbed during the analyzed period, so they may offer advantages in large bone defects where prolonged membrane barrier functions are desirable.     

Discovery of a Lipid Synthesising Organ in the Auditory System of an Insect

Weta possess typical Ensifera ears. Each ear comprises three functional parts: two equally sized tympanal membranes, an underlying system of modified tracheal chambers, and the auditory sensory organ, the crista acustica. This organ sits within an enclosed fluid-filled channel–previously presumed to be hemolymph. The role this channel plays in insect hearing is unknown. We discovered that the fluid within the channel is not actually hemolymph, but a medium composed principally of lipid from a new class. Three-dimensional imaging of this lipid channel revealed a previously undescribed tissue structure within the channel, which we refer to as the olivarius organ. Investigations into the function of the olivarius reveal de novo lipid synthesis indicating that it is producing these lipids in situ from acetate. The auditory role of this lipid channel was investigated using Laser Doppler vibrometry of the tympanal membrane, which shows that the displacement of the membrane is significantly increased when the lipid is removed from the auditory system. Neural sensitivity of the system, however, decreased upon removal of the lipid–a surprising result considering that in a typical auditory system both the mechanical and auditory sensitivity are positively correlated. These two results coupled with 3D modelling of the auditory system lead us to hypothesize a model for weta audition, relying strongly on the presence of the lipid channel. This is the first instance of lipids being associated with an auditory system outside of the Odentocete cetaceans, demonstrating convergence for the use of lipids in hearing.     

The extracellular Leucine-Rich Repeat superfamily; a comparative survey and analysis of evolutionary relationships and expression patterns

Correction to Dolan J, Walshe K, Alsbury S, Hokamp K, O'Keeffe S, Okafuji T, Miller SF, Tear G, Mitchell KJ: The extracellular leucine-rich repeat superfamily; a comparative survey and analysis of evolutionary relationships and expression patterns. BMC Genomics 2007, 8:320.     

Polymorphisms in the glucocorticoid receptor gene that modulate glucocorticoid sensitivity are associated with rheumatoid arthritis

Introduction  

The glucocorticoid receptor (GR) plays an important regulatory role in the immune system. Four polymorphisms in the GR gene are associated with differences in glucocorticoid (GC) sensitivity; the minor alleles of the polymorphisms N363 S and BclI are associated with relative hypersensitivity to GCs, while those of the polymorphisms ER22/23EK and 9β are associated with relative GC resistance. Because differences in GC sensitivity may influence immune effector functions, we examined whether these polymorphisms are associated with the susceptibility to develop Rheumatoid Arthritis (RA) and RA disease severity.     

A comparison of menotropin, highly-purified menotropin and follitropin alfa in cycles of intracytoplasmic sperm injection

Background  

Over the last several decades, as a result of an evolution in manufacturing processes, a marked development has been made in the field of gonadotropins for ovarian stimulation. Initially, therapeutic gonadotropins were produced from a simple process of urine extraction and purification; now they are produced via a complex system involving recombinant technology, which yields gonadotropins with high levels of purity, quality, and consistency.     

Relationships of water temperature and aquatic macroinvertebrate community structure with non-native riparian plant densities in the southern Cape,South Africa

Non-native vegetation in the riparian zone impacts on water temperatures, flow patterns, degree of shading, channel modification, and changes to natural sediment loads. Freshwater ecosystems in the Garden Route Initiative planning domain are of particular conservation value, because of the rich Gondwanaland relict aquatic macroinvertebrate fauna found in the rivers there, which are vulnerable to thermal changes. Data were collected during 2013 and 2014 at 19 sites on seven river systems between George and Knysna in the southern Cape, South Africa. These included 12 months of hourly water temperatures at all sites, and quantitative sampling of aquatic macroinvertebrates at ten sites. Each site was characterised in terms of water quality (pH, conductivity and turbidity) and general characteristics, including impacts such as density of non-native riparian trees. At the family level, aquatic macroinvertebrate communities showed variation between sites and seasons. Differences were more pronounced on the basis of natural land cover type (fynbos versus indigenous forest) than densities of non-native invasive riparian vegetation. Conservation of these river systems will depend on maintaining a mosaic of natural vegetation types.