Toxicogenomic analysis of immune system-related genes in Japanese flounder (Paralichthys olivaceus) exposed to heavy oil

Heavy oil contamination is one of the most important environmental issues. Toxicities of polycyclic aromatic hydrocarbons (PAHs), including immune toxicities, are well characterized, however, the immune toxic effects of heavy oil, as a complex mixture of PAHs, have not been investigated. In the present study, we selected Japanese flounder (Paralichthys olivaceus) as a model organism, and observed alteration of immune function by the exposure to heavy oil. To analyze the expression profiles of immune system-related genes, we selected 309 cDNAs from our flounder EST library, and spotted them on a glass slide. Using this cDNA array, alteration of gene expression profiles was analyzed in the kidneys of flounders exposed to heavy oil. Six Japanese flounders (mean body weight: 197 g) were acclimated to laboratory conditions at 19-20 degrees C. Three fish were exposed to heavy oil C (bunker C) at a concentration of 3.8 g/L for 3 days, and the others were kept in seawater without heavy oil and used as the control. After the exposure period, the fish were transferred into control seawater and maintained for 4 days, and then they were dissected and their kidneys were removed. Total RNA was extracted from the kidney samples to use in gene expression analyses. The microarray detected alteration of immune system-related genes in the kidneys of heavy oil-exposed flounders, including down-regulation of immunoglobulin light chain, CD45, major histocompatibility complex class II antigens and macrophage colony-stimulating factor precursor, and up-regulation of interleukin-8 and lysozyme. These results suggest that pathogen resistance may be weakened in heavy oil-exposed fish, causing a subsequent bacterial infection, and then proinflammatory genes may be induced as a defensive response against the infection. Additionally, we found candidate genes for use as biomarkers of heavy oil exposure, such as N-myc downstream regulated gene 1 and heat shock cognate 71 kDa proteins.     

Adsorption of tributyltin by tributyltin resistant marine Pseudoalteromonas sp. cells

The isolate, Pesudoalteromonas sp. TBT1, could grow to overcome the toxicity of tributyltin chloride (TBTCl) up to 30 μM in the absence of Cl⁻ in the medium until the cells reached an exponential phase of growth. The viability, however, was reduced after the cells reached a stationary phase. The degradation products, such as dibutyltin (DBT) and monobutyltin (MBT), were not detected in the growth medium, indicating that the isolate has no ability to degrade TBT into less toxic DBT and MBT. Up to about 10^7.5 TBT molecules were adsorbed by a single cell. The observation of morphological changes with an electron microscope showed that the cell surface became wrinkled after exposure to the lethal concentration of 10 mM TBTCl. These results indicate that the resistance of the isolate toward the toxicity of TBTCl is not related to the unique cell surface, which seems to play an important role in preventing the diffusion of TBTCl into the cytoplasm.     

Effects of heavy oil in the developing spotted halibut, Verasper variegatus

It is well known that heavy oil (HO) on the sea surface causes serious problems in the aquatic environment. In particular, some species of teleosts which develop on the sea surface are thought to be affected by the HO which flows out from tankers or coastal industry. However, the toxicological effects of HO are not fully understood. We performed exposure experiments using the Pleuronectiformean fish, spotted halibut (Verasper variegatus), which is an important fishery resource in Japan. In course of the development, HO-exposed embryos showed remarkable delay in developmental processes including somite formation. We further observed abnormal development of the head morphology. Notably, treated embryos had relatively small eyes and craniofacial structures. These findings strongly suggest that HO seriously affects the cell proliferation and differentiation of the embryo. In addition, HO-exposed embryos showed abnormal neuronal development. We also performed the exposure in the larval stage. Treatment of post-hatching larvae with HO resulted in significantly greater mortality compared with controls. Through these observations, we finally conclude that HO is strongly toxic to halibut in their early life stages.     

Molecular dynamics simulation of the effect of the Al-O-Al linkage on the P&1macr;-I&1macr; phase transition of anorthite

Molecular dynamics (MD) simulations of the influence of the Al-O-Al linkage on the P&1macr;-I&1macr; phase transition of pure anorthite (An) were carried out using two different types of structures with fully ordered (FO) and partially disordered (PD) arrangements of Al/Si in tetrahedral sites. Discontinuous changes in unit cell volumes and structure factors at the transition temperature were observed in FO-An but not in PD-An. These results show that the orders of the transitions of FO-An and PD-An are first and non-first, respectively. In both structures, the motions of the Ca atoms and the framework are strongly correlated with each other during the transition and Ca atoms dominate the system. Since high-temperature X-ray studies have shown that the transition of natural anorthite is non-first order, it is suggested that the natural anorthite has a partially disordered arrangement of Al and Si atoms. Received: 22 October 1998 / Revised, accepted: 12 March 1999     

Synthetic analysis of light curves of the close binary system UZ Puppis

BV light curves obtained by Bookmyer (1985) have been analysed with Yamasaki's synthetic technique. As some small difference exists between the light maxima, analysis has been made for the first and the second half of light curve, separately. The result indicates that system parameters deduced from the second half give a better fitting with smaller O-C residuals. These parameters reveal that UZ Pup is contact to the Roche lobe.     

The geometry of the Roche coordinates

The exact geometry of the Roche curvilinear coordinates (, , ) in which corresponds to the zero-velocity surfaces is investigated numerically in the plane, as well as in the spatial, case for various values of the mass-ratio between the two point-masses (m ₁,m ₂) constituting a binary system.The geometry of zero-velocity surfaces specified by -values at the Lagrangian points are first discussed by taking their intersections with various planes parallel to thexy-, xz- andyz-planes. The intersection of the zero-velocity surface specified by the -value at the Lagrangian equilateral-triangle pointsL _4,5 with the planex=1/2 discloses two invariable curves passing through the pointsL _4,5 and situated symmetrically with respect to thexy-plane whose form is independent of the mass-ratio.The geometry of the remaining two coordinates (, ) orthogonal to the zero-velocity surfaces is investigated in thexy- andxz-planes from extensive numerical integrations of differential equations generated from the orthogonality relations among the coordinates. The curves (x, y)=constant in thexy-plane are found to be separated into three families by definite envelopes acting as boundaries whose forms depend upon the mass-ratio only: the inner -constant curves associated with the masspointm ₁, the inner -constant curves associated with the mass-pointm ₂ and the outer -constant curves. All the -constant curves in thexy-plane coalesce at either of the Lagrangian equilateraltriangle pointsL _4,5, except for a limiting case coincident with thex-axis. The curves (x, z)=constant in thexz-plane are also separated by definite envelopes depending upon the mass-ratio into different families: the inner -constant curves associated with the mass-pointm ₁, the inner -constant curves associated with the mass-pointm ₂ and the outer -constant curves on both sides out of the envelopes. For larger values ofz, the curves =constant tend asymptotically to the line perpendicular to thex-axis and passing through the centre of mass of the system, except for a limiting case coincident with thex-axis. The geometrical aspects of the envelopes for the curves (x, y)=constant in thexy-plane and the curves (x, z)=constant in thexz-plane are also discussed independently.In the three-dimensional space, the Roche coordinates can be conveniently defined in such a way as to correspond to the polar coordinates in the immediate neighbourhood of the origin, and to the cylindrical coordinates at great distances. From numerical integrations of simultaneous differential equations generating spatial curves orthogonal to the zero-velocity surfaces, the surfaces (x, y, z)=constant and the surfaces (x, y, z)=constant are constructed as groups of such spatial curves with common values of some parameters specifying the respective surfaces.On leave of absence from the University of Tokyo as an Honorary Fellow of the Victoria University of Manchester.     

福建省印支期磨拉石建造的探讨

通过对福建省三叠纪地层基本特征的野外观察及室内分析,认为中三叠世的安仁组属于印支造山运动同造山期的磨拉石建造;而晚三叠纪的大坑村组、文宾山组、焦坑组则是代表新构造旋回底部层序沉积的磨拉石建造。     

Statistical study of Am stars in spectroscopic binary systems

Using the Am components in spectroscopic binaries, the region of metallicism in the (logm, logR) diagram is statistically discussed. The metallic-line characteristics appear in a slightly evolved stage near the Main Sequence within a belt characterized by logg=3.8–4.2, for which the radiiR/R =1.5–2.7. The distribution in the diagram indicates that appreciable differences should exist in the abundances as well as in the mixing lengths of the atmospheres of the Am components.Synchronism between rotation and revolution for the Am components is discussed, and it is clearly found that the synchronism holds accurately for the Am binaries with periods less than about six days, but for those with periods between six and ten days some Am components corotate and some do not, perhaps depending upon their ages.Using the Am spectroscopic binaries with periods less than twelve days, we find that the excess of metallicity is statistically correlated with the rotational velocity; and it is confirmed that the metallicity grossly decreases with increasing rotational velocity. If the effect of a non-Am secondary component is eliminated from a [m ₁]-value for the combined light, the correlation between metallicity excess and rotational velocity for the Am components only should approach [m ₁]/V (km s^–1)=–0.00077.     

Observations of some oxygen-containing and sulfur-containing organic molecules in cold dark clouds

Observations of nine oxygen- and sulfur-containing organic molecules have been made toward the cold dark clouds TMC-1 and L134N. We have confirmed the presence of para-ketene (H2C2O) in TMC-1, have for the first time observed ortho-ketene, and find a total ketene column density approximately 1 x 10(13) cm-2. Thioformaldehyde (H2CS) is easily detectable in both TMC-1 and L134N, with a column density about 5 times larger in the former source (approximately 3 x 10(13) cm-2). The fractional abundance of ketene is comparable to the predictions of ion-molecule chemistry, while that of thioformaldehyde in TMC-1 is one to two orders of magnitude greater than that expected from such models at steady state. Interstellar sulfur chemistry thus continues to be poorly understood. We set upper limits for the column densities of formic acid (HCOOH), vinyl alcohol (CH2CHOH), methyl formate (HCO2CH3), formamide (NH2CHO), methyl mercaptan (CH3SH), isothiocyanic acid (HNCS), and thioketene (H2C2S) in both sources.     

Microstructural records of multiple retrograde local H2O supplement in the pelitic gneiss,Lützow-Holm Complex at Akarui Point,East Antarctica

The alkali-feldspar and biotite in the sillimanite-biotite-garnet gneiss from East Antarctica preserves characteristic microstructural evidence of multi-stage H₂O supplement during the retrograde metamorphism. The first microstructural evidence is the “zoned feldspar,” in which the mesoperthitic zone, the anti-perthitic zone, and lamella-free plagioclase zone coexist within a single crystal. They are occasionally found next to biotite, and are always depleted in orthoclase (Or) component toward the biotite. The formation process of this microstructure could be explained by the diffusion that oversteps the solvus. The second microstructural evidence is the serrate boundary between alkali-feldspar and biotite. The projections of biotite are selectively developed next to Or lamellae of alkali-feldspar every 3–5 μm. These two microstructures would have formed as the biotite grew by consuming potash in alkali-feldspar when H₂O-bearing fluid locally passed through the grain boundaries. The former microstructure was formed at 825–900 °C before lamella formation, and the latter microstructure was formed after the lamella formation. These microstructures are the indicators of fluid pathways formed under two different temperature conditions. The common coexistence of these microstructures implies that the fluid used similar pathways during the retrograde metamorphism.