Catálogo de publicaciones - revistas

<jats:title>Gut Reaction</jats:title> <jats:p> The gut needs to keep its trillions of microbial inhabitants contained. The immune system has evolved a multifaceted approach to this problem, which includes the production of large quantities of immunoglobulin A (IgA) in the intestinal mucosa. In a process that is not well understood, plasma cells that produce IgA specific for the gut microflora are selected in Peyer's patches in the gut. <jats:bold> Kawamoto <jats:italic>et al.</jats:italic> </jats:bold> (p. 485) used genetically manipulated mice to show that the inhibitory co-receptor, programmed cell death-1 (PD-1), is required for the proper selection IgA-secreting cells in the gut. The effect of PD-1 deletion, however, was not intrinsic to the B cells that produce IgA. Instead, the absence of PD-1 affected the differentiation of T follicular helper cells, which provide important signals to B cells that help guide them as they develop the capacity to produce microflora-specific IgA. Mice deficient in PD-1 exhibited alterations in the composition in their microflora, which suggests that defective selection of IgA can perturb the careful balance that exists between the immune system and resident bacteria. </jats:p>

<jats:title>Microbes: Early and Often</jats:title> <jats:p> Epidemiological studies have suggested that the increase in the incidence of asthma and other inflammatory diseases seen in many parts of the world may be due to a reduced exposure to microbes during early childhood. <jats:bold> Olszak <jats:italic>et al.</jats:italic> </jats:bold> (p. 489, published online 22 March) now show that commensal microflora help to regulate the numbers and functions of natural killer T (NKT) cells in the colon and lung in mice. Germ-free mice had elevated numbers of NKT cells in these tissues and were more susceptible to chemically induced colitis and allergic asthma. Neonatal recolonization of germ-free mice with microflora prevented enhanced colitis and asthma sensitivity; however, exposure of adult mice to these conditions was not effective. Thus, early exposure to microbes has important, lasting effects on the immune system's sensitivity to inflammation. </jats:p>

<jats:title>Overthinking Religion?</jats:title> <jats:p> Many theories of human cognition make a distinction between System I, which tends to be rapid and to rely on heuristics or rules of thumb, and System II, which tends to be more deliberative and analytic. This dual-process framework, within which both processes may operate simultaneously and competitively, has been used to explain a variety of situational influences upon decision-making. <jats:bold>Gervais and Norenzayan</jats:bold> (p. 493) studied the application of a dual-process framework to religious disbelief and found that triggering analytic thinking processes through a variety of experimental manipulations resulted in a tendency for subjects to report lower levels of religious belief. </jats:p>

<jats:p>The show includes synchronizing optical clocks, the spread of Neolithic farming in Europe, a measles resurgence, and more.</jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>

<jats:p>The field of regenerative medicine has been gaining increasing momentum in the past two decades. As our understanding of the inner workings of stem cells has grown, and as new stem cell types are discovered or created in the laboratory, the ability to regenerate many different tissues—potentially even complex organs—has moved from the realm of science fiction into a solid reality.</jats:p> <jats:p> This booklet, a special sponsored supplement to <jats:italic>Science</jats:italic> , describes recent advances achieved in regenerative medicine and stem cell research in China, where scientists are pushing the boundaries of what is possible and achieving impressive results in a clinical setting using pluripotent and multipotent stem cells. The focus is not just on understanding what is possible, but on moving potential therapies rapidly from the laboratory into the clinic in order to treat an array of debilitating ailments, with the singular aim of improving the health and standard of living for patients throughout China. </jats:p> <jats:p>In the words of Dr. Xiaobing Fu, Academician of the Chinese Academy of Engineering and director of the Institute of Basic Medical Sciences at the Chinese PLA General Hospital, "Within the next decade, substantial progress in regenerative medicine in China is expected in the following areas: the use of induced stem cells in the synchronized repair and regeneration of multiple tissue types following injury, reconstitution of large organs through tissue engineering, and the large-scale clinical application of tissue engineering products. These advances will provide hope for the improvement of health care and the creation of a healthier society."</jats:p>