Mutation of MYH9, encoding non-muscle myosin heavy chain A, in May-Hegglin anomaly

May-Hegglin anomaly (MHA) is an autosomal dominant macrothrombocytopenia of unclear pathogenesis characterized by thrombocytopenia, giant platelets and leukocyte inclusions. Studies have indicated that platelet structure and function are normal, suggesting a defect in megakaryocyte fragmentation. The disorder has been linked to chromosome 22q12-13. Here we screen a candidate gene in this region, encoding non-muscle myosin heavy chain A (MYH9), for mutations in ten families. In each family, we identified one of three sequence variants within either the -helical coiled coil or the tailpiece domain that co-segregated with disease status. The E1841K mutation was found in 5 families and occurs at a conserved site in the rod domain. This mutation was not found in 40 normal individuals. Four families had a nonsense mutation that resulted in truncation of most of the tailpiece. One family had a T1155I mutation present in an affected mother and daughter, but not in the mother's parents, thus representing a new mutation. Among the 30 affected individuals, 21 unaffected individuals and 13 spouses in the 10 families, there was correlation of a variant of MYH9 with the presence of MHA. The identification of MYH9 as the disease gene for MHA establishes the pathogenesis of the disorder, should provide further insight into the processes of normal platelet formation and may facilitate identification of the genetic basis of related disorders.     

Pyrrolizidine alkaloids in overwintering monarch butterflies (Danaus plexippus) from mexico

Summary North American populations of the monarch butterfly,Danaus plexippus, have been found to contain pyrrolizidine alkaloids and their N-oxides. Analytical methods (TLC, GC, and GC/MS) have been developed to isolate, quantitate, and structurally elucidate the alkaloids. Examples of at least two classes of pyrrolizidine alkaloids have been identified, the macrocyclic diesters, senecionine, integerrimine, and seneciphylline, and the monoesters, echinatine, intermedine, and lycopsamine.21 November 1986This work was supported by NSF (Grants BSR-81-19391 and BSR-81-19382), and a Stauffer Chemical Company fellowship. We thank David Hodapp, Mark Stelljes, and Cordula Bruenner for technical help, Dr T.P. Krick, University of Minnesota, St. Paul, Minn., USA, for assistance in GC/MS analysis of PAs, and Dr J.A. Edgar, CSIRO, Parkville, Victoria, Australia, for samples of authentic reference compounds.     

Biodiversity and biogeography of phages in modern stromatolites and thrombolites

Viruses, and more particularly phages (viruses that infect bacteria), represent one of the most abundant living entities in aquatic and terrestrial environments. The biogeography of phages has only recently been investigated and so far reveals a cosmopolitan distribution of phage genetic material (or genotypes). Here we address this cosmopolitan distribution through the analysis of phage communities in modern microbialites, the living representatives of one of the most ancient life forms on Earth. On the basis of a comparative metagenomic analysis of viral communities associated with marine (Highborne Cay, Bahamas) and freshwater (Pozas Azules II and Rio Mesquites, Mexico) microbialites, we show that some phage genotypes are geographically restricted. The high percentage of unknown sequences recovered from the three metagenomes (>97%), the low percentage similarities with sequences from other environmental viral (n = 42) and microbial (n = 36) metagenomes, and the absence of viral genotypes shared among microbialites indicate that viruses are genetically unique in these environments. Identifiable sequences in the Highborne Cay metagenome were dominated by single-stranded DNA microphages that were not detected in any other samples examined, including sea water, fresh water, sediment, terrestrial, extreme, metazoan-associated and marine microbial mats. Finally, a marine signature was present in the phage community of the Pozas Azules II microbialites, even though this environment has not been in contact with the ocean for tens of millions of years. Taken together, these results prove that viruses in modern microbialites display biogeographical variability and suggest that they may be derived from an ancient community.     

和谐就是力量--兼评培根的"知识就是力量"

和谐--无论是结构状态的分布有序还是功能状态的进化有道,都蕴涵着无与伦比的力量与神奇.自我和谐是个人身心微观和谐发展的调适力,人我和谐是社会中观和谐发展的协和力,物我和谐是人与自然宏观和谐发展的自然力,以至在某种意义上我们不得不说,和谐是发展之源,和谐就是力量;反之,自我失衡是身心微观灾变之端,人我失衡是社会中观模糊或畸形运作之始,物我失衡是一场没有胜利的逆变,以至在某种意义上我们不得不说,失衡是畸变之兆,失衡就是耗散."知识就是力量"是一个工具理性张扬的命题,而"和谐就是力量"则是"知识就是力量"的合理升华,是东方智慧的集大成.通过物理学与伦理学的二维证明我们发现,"和谐就是力量"不仅是一个长期被忽视的物理学定律,而且是一个重要的和谐伦理命题.     

An off-axis hydrothermal vent field near the Mid-Atlantic Ridge at 30 degrees N.

Evidence is growing that hydrothermal venting occurs not only along mid-ocean ridges but also on old regions of the oceanic crust away from spreading centres. Here we report the discovery of an extensive hydrothermal field at 30 degrees N near the eastern intersection of the Mid-Atlantic Ridge and the Atlantis fracture zone. The vent field--named 'Lost City'--is distinctly different from all other known sea-floor hydrothermal fields in that it is located on 1.5-Myr-old crust, nearly 15 km from the spreading axis, and may be driven by the heat of exothermic serpentinization reactions between sea water and mantle rocks. It is located on a dome-like massif and is dominated by steep-sided carbonate chimneys, rather than the sulphide structures typical of 'black smoker' hydrothermal fields. We found that vent fluids are relatively cool (40-75 degrees C) and alkaline (pH 9.0-9.8), supporting dense microbial communities that include anaerobic thermophiles. Because the geological characteristics of the Atlantis massif are similar to numerous areas of old crust along the Mid-Atlantic, Indian and Arctic ridges, these results indicate that a much larger portion of the oceanic crust may support hydrothermal activity and microbial life than previously thought.     

Hyperkyphosis in longnose gar ( Lepisosteus osseus ) of north central Texas

Two mature female longnose gar ( Lepisosteus osseus ) exhibiting severe hyperkyphotic spinal deformities were captured during the 2010 spring spawn at Lake Arrowhead, Clay County, Texas. Yet, despite their deformities and impaired motility, both longnose gar were in overall good condition. Hyperkyphosis in both longnose gar resulted from fused trunk vertebrae in the affected areas. Results of morphological examinations and computerized tomography (CT) scans showed no evidence of injury-induced responses and suggested a congenital or possibly environmentally induced aetiology for disruption of the normal vertebral segmentation process. Dos hembras adultas del pejelagarto narigudo ( Lepisosteus osseus ) con severas deformidades espinales hipercifóticas fueron capturadas durante la desovación primaveral del 2010 en Lake Arrowhead, condado de Clay, Texas. No obstante, a pesar de sus deformidades y limitada motilidad, ambos pejelagartos estaban en buenas condiciones generales. La hipercifosis en ambos pejelagartos narigudos resultó de la fusión de vértebras del tronco en las áreas afectadas. Las evaluaciones morfológicas y de tomografía computarizada (TC) no mostraron evidencia de respuestas inducidas por lesiones, y sugirieron una etiología congénita o posiblemente inducida por el ambiente para la interferencia del proceso normal de segmentación vertebral.     

Distribution of inulin-carboxy-C14 in heart and skeletal muscle with respect to in vivo and in vitro extracellular space determinations

Zusammenfassung Gleichmässige Indikatorverteilung im Gewebe ist Ausdruck für Konzentrationsausgleich zwischen Blutstrom bzw. Inkubationsmedium und Extrazellulärraum. Es wurde ein zentraler Block aus einem Gewebsstück herausgeschnitten und die Konzentration von Inulin-carboxyl-C¹⁴ darin mit der im peripheren oberflächlichen Gewebe verglichen. Im Myokard des linken Ventrikels und im Soleusmuskel fand sich in vivo eine gleichmässige Verteilung, in vitro hingegen nicht; selbst bei einer Inkubationsdauer von 5 h in einem als optimal anzusehenden Milieu. Damit ist die Methode, wahre Extrazellulärräume in vitro zu messen, fragwürdig. Hingegen hat sich die Echtheit von in-vivo-Bestimmungen bestätigt.

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This investigation was supported in part by U.S. Public Health Service Research Grant No. HE-09791 from the National Heart Institute and General Research Support Grant No. SO1-FR-05525 from the Division of Research Facilities and Resources, and in part by a grant from the John A. Hartford Foundation.     

The 'zero charge' partitioning behaviour of noble gases during mantle melting

Noble-gas geochemistry is an important tool for understanding planetary processes from accretion to mantle dynamics and atmospheric formation. Central to much of the modelling of such processes is the crystal-melt partitioning of noble gases during mantle melting, magma ascent and near-surface degassing. Geochemists have traditionally considered the 'inert' noble gases to be extremely incompatible elements, with almost 100 per cent extraction efficiency from the solid phase during melting processes. Previously published experimental data on partitioning between crystalline silicates and melts has, however, suggested that noble gases approach compatible behaviour, and a significant proportion should therefore remain in the mantle during melt extraction. Here we present experimental data to show that noble gases are more incompatible than previously demonstrated, but not necessarily to the extent assumed or required by geochemical models. Independent atomistic computer simulations indicate that noble gases can be considered as species of 'zero charge' incorporated at crystal lattice sites. Together with the lattice strain model, this provides a theoretical framework with which to model noble-gas geochemistry as a function of residual mantle mineralogy.