Mesoangioblast stem cells ameliorate muscle function in dystrophic dogs

Duchenne muscular dystrophy remains an untreatable genetic disease that severely limits motility and life expectancy in affected children. The only animal model specifically reproducing the alterations in the dystrophin gene and the full spectrum of human pathology is the golden retriever dog model. Affected animals present a single mutation in intron 6, resulting in complete absence of the dystrophin protein, and early and severe muscle degeneration with nearly complete loss of motility and walking ability. Death usually occurs at about 1 year of age as a result of failure of respiratory muscles. Here we report that intra-arterial delivery of wild-type canine mesoangioblasts (vessel-associated stem cells) results in an extensive recovery of dystrophin expression, normal muscle morphology and function (confirmed by measurement of contraction force on single fibres). The outcome is a remarkable clinical amelioration and preservation of active motility. These data qualify mesoangioblasts as candidates for future stem cell therapy for Duchenne patients.     

Discovery of five irregular moons of Neptune

Each giant planet of the Solar System has two main types of moons. 'Regular' moons are typically larger satellites with prograde, nearly circular orbits in the equatorial plane of their host planets at distances of several to tens of planetary radii. The 'irregular' satellites (which are typically smaller) have larger orbits with significant eccentricities and inclinations. Despite these common features, Neptune's irregular satellite system, hitherto thought to consist of Triton and Nereid, has appeared unusual. Triton is as large as Pluto and is postulated to have been captured from heliocentric orbit; it traces a circular but retrograde orbit at 14 planetary radii from Neptune. Nereid, which exhibits one of the largest satellite eccentricities, is believed to have been scattered from a regular satellite orbit to its present orbit during Triton's capture. Here we report the discovery of five irregular moons of Neptune, two with prograde and three with retrograde orbits. These exceedingly faint (apparent red magnitude m(R) = 24.2-25.4) moons, with diameters of 30 to 50 km, were presumably captured by Neptune.     

宇宙起源的量子理论

量子宇宙学理论是自大爆炸理论建立以来我们了解宇宙的最重要阶段。这一理论体现了如下观念:宇宙的边界条件就是宇宙没有边界,整个宇宙只由物理定律决定,不需任何初始条件。这一理论也为解决宇宙奇点疑难,宇宙的起源提供了一种可行的方案。     

量子力学有非线性项吗？

人们常常听说检验量子电动力学或相对论理论,但量子力学的基础理论却很少被怀疑.然而,最近温伯格(S.Weinberg)呼吁应高精度地检验量子力学,     

Pyridoxamine as a multifunctional pharmaceutical: targeting pathogenic glycation and oxidative damage

The discovery that pyridoxamine (PM) can inhibit glycation reactions and the formation of advanced glycation end products (AGEs) stimulated new interest in this B₆ vitamer as a prospective pharmacological agent for treatment of complications of diabetes. The mechanism of action of PM includes: (i) inhibition of AGE formation by blocking oxidative degradation of the Amadori intermediate of the Maillard reaction; (ii) scavenging of toxic carbonyl products of glucose and lipid degradation; and (iii) trapping of reactive oxygen species. The combination of these multiple activities along with PM safety posture it as a promising drug candidate for treatment of diabetic complications as well as other multifactorial chronic conditions in which oxidative reactions and carbonyl compounds confer pathogenicity.Received 1 March 2005; received after revision 25 March 2005; accepted 31 March 2005