Human Surfactant Protein B Expression in Humanized Transgenic Mice

Surfactant protein B (SP-B, gene name: sftpb) is essential for normal lung function. It reduces alveoli surface tension, thereby preventing the lung from collapse. A single nucleotide polymorphism (SP-B 1580 C/T) is associated with several lung diseases and altered N-linked glycosylation site at Asn129 of SP-B. This change, present in the human population, has been associated with negative effects on SP-B precursor (proSP-B) processing and function. In this study, hSP-B humanized transgenic mice were generated without mouse SP-B background. Four founding lines, showing only the hSP-B gene, were selected via PCR-based DNA analysis. Genomic sequencing of these mice revealed which allele variant (hSP-B-C/T) they carried. Western blot analysis of BALF samples revealed these hTG mice expressed hSP-B protein in levels significant for survival and comparable to that of a healthy human lung. Characterization of the two hSP-B allele variant hTG strains revealed significant differences in their relative alveolar size and total lipid concentration

Relationship between psychological and biological factors and physical activity and exercise behaviour in Filipino students

The aim of the present study was threefold. Firstly, it investigated whether a general measure or specific measure of motivational orientation was better in describing the relationship between motivation and exercise behaviour. Secondly, it examined the relationship between the four most popular indirect methods of body composition assessment and physical activity and exercise patterns. Thirdly, the interaction between motivation and body composition on physical activity and exercise behaviour was explored in a sample of 275 Filipino male and female students. Males were found to have higher levels of exercise whereas females had higher levels of physical activity. Furthermore, general self-motivation together with body weight and percentage body fat were found to be the best predictor of exercise behaviour whereas the tension/pressure subscale of the ‘Intrinsic Motivation Inventory’ (IMI) was the best predictor of levels of physical activity. However, significant gender differences were observed. That is, for the males only self-motivation and for the females only body weight and BMI predicted exercise behaviour. Also, tension/pressure predicted physical activity levels for the females but not the males. No inverse relationship was found between the four body composition measures and exercise and physical activity behaviour. The results support the notion that the psychobiological approach might be particularly relevant for high intensity exercise situations but also highlights some important gender differences. Finally, the results of this study emphasise the need for more cross-cultural research

The Saffman-Taylor problem on a sphere

The Saffman-Taylor problem addresses the morphological instability of an interface separating two immiscible, viscous fluids when they move in a narrow gap between two flat parallel plates (Hele-Shaw cell). In this work, we extend the classic Saffman-Taylor situation, by considering the flow between two curved, closely spaced, concentric spheres (spherical Hele-Shaw cell). We derive the mode-coupling differential equation for the interface perturbation amplitudes and study both linear and nonlinear flow regimes. The effect of the spherical cell (positive) spatial curvature on the shape of the interfacial patterns is investigated. We show that stability properties of the fluid-fluid interface are sensitive to the curvature of the surface. In particular, it is found that positive spatial curvature inhibits finger tip-splitting. Hele-Shaw flow on weakly negative, curved surfaces is briefly discussed.Comment: 26 pages, 4 figures, RevTex, accepted for publication in Phys. Rev.

Sex-Specific Association of the Putative Fructose Transporter SLC2A9 Variants With Uric Acid Levels Is Modified by BMI

OBJECTIVE—High serum uric acid levels lead to gout and have been reported to be associated with an increased risk of hypertension, obesity, metabolic syndrome, type 2 diabetes, and cardiovascular disease. Recently, the putative fructose transporter SLC2A9 was reported to influence uric acid levels. The aim of the present study was to examine the association of four single nucleotide polymorphisms within this gene with uric acid levels and to determine whether this association is modified by obesity