五福花科花部维管结构的比较研究

首次报道了华福花属华福花Ｓｉｎａｄｏｘａｃｏｒｙｄａｌｉｆｏｌｉａ和东方五福花Ａｄｏｘａｏｒｉｅｎｔａｌｉｓ花部维管结构,并对五福花科３属４种植物的花部维管系统进行了比较研究。３属４种的花部维管系统表现出不同的对称性和不同的复化、减化以及不同的融合程度。基于花部维管系统的证据,本工作支持四福花属四福花Ｔｅｔｒａｄｏｘａｏｍｅｉｅｎｓｉｓ为科内原始类群代表的看法。     

Dietary characterization of terrestrial mammals

Understanding the feeding behaviour of the species that make up any ecosystem is essential for designing further research. Mammals have been studied intensively, but the criteria used for classifying their diets are far from being standardized. We built a database summarizing the dietary preferences of terrestrial mammals using published data regarding their stomach contents. We performed multivariate analyses in order to set up a standardized classification scheme. Ideally, food consumption percentages should be used instead of qualitative classifications. However, when highly detailed information is not available we propose classifying animals based on their main feeding resources. They should be classified as generalists when none of the feeding resources constitute over 50% of the diet. The term ‘omnivore’ should be avoided because it does not communicate all the complexity inherent to food choice. Moreover, the so-called omnivore diets actually involve several distinctive adaptations. Our dataset shows that terrestrial mammals are generally highly specialized and that some degree of food mixing may even be required for most species.     

The unilacunar two-trace nodal structure of the caudex of Rhodiola rosea L. (Grassulaceae)

The subterranean, monopodial caudex of Rhodiola rosea has unilacunar, two-trace nodes, whereas its annual leafy flowering shoots have the more common unilacunar, one-trace nodes. The double-traced unilacunar nodal structure of the highly specialized caudex is considered to be the advanced condition in this species as well as in the Crassulaceae in general. The character may be significant in evolutionary and systematics studies of the genus Rhodiola.     

A preliminary survey for changes in urban Fox (Vulpes vulpes) densities in England and Wales, and implications for rabies control

A questionnaire was sent to 139 councils and 44 local mammal groups in England and Wales, requesting data on changes in urban Red Fox (Vulpes vulpes) densities between 1987 and 1997. Of 152 responses, 41% believed Fox numbers had increased, 42% believed Fox numbers were unchanged and 7% believed Fox numbers had decreased. Most of the increases were perceived to be due to increased food availability, and decreases due to sarcoptic mange (Sarcoptes scabiei). In the event of a rabies outbreak in Britain, the models used to determine control strategies are dependent on having sufficiently up‐to‐date urban Fox density data. This survey suggests that urban Fox density data for Britain should be updated in the near future.     

BMPER-induced BMP signaling promotes coronary artery remodeling

The connection of the coronary vasculature to the aorta is one of the last essential steps of cardiac development. However, little is known about the signaling events that promote normal coronary artery formation. The bone morphogenetic protein (BMP) signaling pathway regulates multiple aspects of endothelial cell biology but has not been specifically implicated in coronary vascular development. BMP signaling is tightly regulated by numerous factors, including BMP-binding endothelial cell precursor-derived regulator (BMPER), which can both promote and repress BMP signaling activity. In the embryonic heart, BMPER expression is limited to the endothelial cells and the endothelial-derived cushions, suggesting that BMPER may play a role in coronary vascular development. Histological analysis of BMPER^−/− embryos at early embryonic stages demonstrates that commencement of coronary plexus differentiation is normal and that endothelial apoptosis and cell proliferation are unaffected in BMPER^−/− embryos compared with wild-type embryos. However, analysis between embryonic days 15.5–17.5 reveals that, in BMPER^−/− embryos, coronary arteries are either atretic or connected distal to the semilunar valves. In vitro tubulogenesis assays indicate that isolated BMPER^−/− endothelial cells have impaired tube formation and migratory ability compared with wild-type endothelial cells, suggesting that these defects may lead to the observed coronary artery anomalies seen in BMPER^−/− embryos. Additionally, recombinant BMPER promotes wild-type ventricular endothelial migration in a dose-dependent manner, with a low concentration promoting and high concentrations inhibiting migration. Together, these results indicate that BMPER-regulated BMP signaling is critical for coronary plexus remodeling and normal coronary artery development.     

Discovery of Some of the Biological Effects of Nitric Oxide and its Role in Cell Signaling

The role of nitric oxide in cellular signaling in the past 22 years has become one of the most rapidly growing areas in biology with more than 20,000 publications to date. Nitric oxide is a gas and free radical with an unshared electron that can regulate an ever-growing list of biological processes. In many instances nitric oxide mediates its biological effects by activating guanylyl cyclase and increasing cyclic GMP synthesis from GTP. However, the list of effects of nitric oxide that are independent of cyclic GMP is also growing at a rapid rate. For example, nitric oxide can interact with transition metals such as iron, thiol groups, other free radicals, oxygen, superoxide anion, unsaturated fatty acids and other molecules. Some of these reactions result in the oxidation of nitric oxide to nitrite and nitrate to terminate its effect, while other reactions can lead to altered protein structure, function, and/or catalytic capacity. These diverse effects of nitric oxide that are either cyclic GMP dependent or independent can alter and regulate important physiological and biochemical events in cell regulation and function. Nitric oxide can function as an intracellular messenger, an autacoid, a paracrine substance, a neurotransmitter, or as a hormone that can be carried to distant sites for effects. Thus, it is a unique simple molecule with an array of signaling functions. However, as with any messenger molecule, there can be too little or too much of the substance and pathological events result. Some of the methods to regulate either nitric oxide formation, metabolism, or function have been in clinical use for more than a century as with the use of organic nitrates and nitroglycerin in angina pectoris that was initiated in the 1870’s. Current and future research with nitric oxide and cyclic GMP will undoubtedly expand the clinicians’ therapeutic armamentarium to manage a number of important diseases by perturbing nitric oxide and cyclic GMP formation and metabolism. Such promise and expectations have obviously fueled the interests in these signaling molecules for a growing list of potential therapeutic applications.     

Discovery of Some of the Biological Effects of Nitric Oxide and its Role in Cell Signaling

The role of nitric oxide in cellular signaling in the past 22 years has become one of the most rapidly growing areas in biology with more than 20,000 publications to date. Nitric oxide is a gas and free radical with an unshared electron that can regulate an ever-growing list of biological processes. In many instances nitric oxide mediates its biological effects by activating guanylyl cyclase and increasing cyclic GMP synthesis from GTP. However, the list of effects of nitric oxide that are independent of cyclic GMP is also growing at a rapid rate. For example, nitric oxide can interact with transition metals such as iron, thiol groups, other free radicals, oxygen, superoxide anion, unsaturated fatty acids and other molecules. Some of these reactions result in the oxidation of nitric oxide to nitrite and nitrate to terminate its effect, while other reactions can lead to altered protein structure, function, and/or catalytic capacity. These diverse effects of nitric oxide that are either cyclic GMP dependent or independent can alter and regulate important physiological and biochemical events in cell regulation and function. Nitric oxide can function as an intracellular messenger, an autacoid, a paracrine substance, a neurotransmitter, or as a hormone that can be carried to distant sites for effects. Thus, it is a unique simple molecule with an array of signaling functions. However, as with any messenger molecule, there can be too little or too much of the substance and pathological events result. Some of the methods to regulate either nitric oxide formation, metabolism, or function have been in clinical use for more than a century as with the use of organic nitrates and nitroglycerin in angina pectoris that was initiated in the 1870's. Current and future research with nitric oxide and cyclic GMP will undoubtedly expand the clinicians' therapeutic armamentarium to manage a number of important diseases by perturbing nitric oxide and cyclic GMP formation and metabolism. Such promise and expectations have obviously fueled the interests in these signaling molecules for a growing list of potential therapeutic applications.John S. Dunn Distinguished Chair in Medicine and Physiology, Regental Professor and Chair of Department of Integrative Biology, Pharmacology, and Physiology and Director of the Institute of Molecular Medicine