A fluvial population of Cottus pollux (middle-egg type) from the Honmyo River, Kyushu Island, Japan

 Specimens of the Cottus pollux species' group collected from the upper part of the Honmyo River, Nagasaki Prefecture, Japan, were subjected to morphological and allozyme analyses to place them into one of the recognized valid taxa, viz. small-egg type (SE type), middle-egg type (ME type), or large-egg type (LE type). They were identified as ME type on the basis of specific morphological characteristics, such as laterally depressed cross-sectional shape at posterior half of the body and deep caudal peduncle, and by having a diagnostic allozyme allele (MEP ^* 54). This ME-type population is the first recorded from Kyushu Island, Japan. An ecological survey of the population revealed that females spawned larger eggs (2.8–3.2 mm in diameter) than those of other amphidromous populations, from which well-developed yolk-sac larvae of about 8.0 mm TL were hatched out. In addition, ME-type specimens collected on 25 and 26 May 2001 included 15 sex-unknown juveniles ranging from 18.8 to 30.2 mm SL, suggesting that they represented larvae hatched out on a nearby spawning ground, with no experience of downstream migration into Isahaya Bay. This observation strongly suggests that the ME-type population in the Honmyo River has a fluvial lifestyle, being different from other amphidromous populations. The former population may have arisen from an amphidromous ancestor through changes in egg size and early ontogenetic development. Received: February 25, 2002 / Revised: May 21, 2002 / Accepted: June 17, 2002 Acknowledgments We thank Professor M. Azuma, Nagasaki University, for his kind guidance of our field survey in the Honmyo River and Dr. G.S. Hardy, Thames, New Zealand, for correcting the English. Thanks are also offered to Mrs. Y. Miyajima and Y. Masaoka, Kyushu Branch of Construction and Technology Institute Co., for their helpful cooperation in the field survey. Drs. H. Sakai, National Fisheries University and Y. Yamazaki, Toyama University, and Mrs. N. Okabe and Y. Suzuki of Yamagata Prefecture are thanked for their help in sample collection. This work was partly supported by a Grant-in-Aid (No. 13660171) from the Japan Ministry of Education, Culture, Sports, Science and Technology to A. Goto. Correspondence to:Akira Goto     

SOCS2 Balances Metabolic and Restorative Requirements during Liver Regeneration

After significant injury, the liver must maintain homeostasis during the regenerative process. We hypothesized the existence of mechanisms to limit hepatocyte proliferation after injury to maintain metabolic and synthetic function. A screen for candidates revealed suppressor of cytokine signaling 2 (SOCS2), an inhibitor of growth hormone (GH) signaling, was strongly induced after partial hepatectomy. Using genetic deletion and administration of various factors we investigated the role of SOCS2 during liver regeneration. SOCS2 preserves liver function by restraining the first round of hepatocyte proliferation after partial hepatectomy by preventing increases in growth hormone receptor (GHR) via ubiquitination, suppressing GH pathway activity. At later times, SOCS2 enhances hepatocyte proliferation by modulating a decrease in serum insulin-like growth factor 1 (IGF-1) that allows GH release from the pituitary. SOCS2, therefore, plays a dual role in modulating the rate of hepatocyte proliferation. In particular, this is the first demonstration of an endogenous mechanism to limit hepatocyte proliferation after injury.     

Determination of triazolam in serum by deactivated metal capillary gas chromatography with electron-capture detection

A method for the determination of trace amounts of triazolam in serum by deactivated metal capillary gas chromatography with electron-capture detection was established. The column used exhibits excellent thermostability in high-temperature analysis and easy handling and a long lifetime of the column and well shaped peaks on the chromatograms are obtained. With the metal capillary column, it was found to be easier to maintain suitable analytical conditions for the routine assay of triazolam than with a fused-silica column. With this method, 0.5 ng/ml of triazolam in serum can be determined. The method is useful for pharmacokinetic and therapeutic purposes.     

Settlement of Planulae of the Moon Jellyfish Aurelia aurita onto Hydrophilic Polycarbonate Plates Modified by Atmospheric Plasma Treatment

It has been reported that planula larvae of some jellyfish prefer artificial substrates for settlement. This research focused on the relationship between the settlement of planulae and the wettability of artificial substrate surfaces. We used atmospheric plasmas to change the wettability of the surfaces of polycarbonate (PC) plates because plasma treatment has no chemical side effects. The treatment made the surfaces hydrophilic, as evidenced by the decrease of contact angle from 85° to 35°. X-ray photoelectron spectroscopy revealed that the change of wettability of the PC plates could be attributed to N₂, which was probably ionized in the air above the plates. Scanning electron microscopy revealed no difference in the surface morphology of the plates before and after plasma treatment. Results of bioassays using treated PC plates showed that planulae tended to preferentially settle on hydrophobic surfaces.     

Herpes Simplex Virus 1 VP22 Inhibits AIM2-Dependent Inflammasome Activation to Enable Efficient Viral Replication

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Enzyme immunoassay for serum 18-hydroxycorticosterone and its clinical application

An enzyme immunoassay for serum 18-hydroxycorticosterone was established using alkaline phosphatase as a label. The antiserum for 18-hydroxycorticosterone was produced by immunization of rabbits with 18-hydroxycorticosterone 3-(O-carboxymethyl)oxime conjugated to bovine serum albumin. Sephadex LH-20 column chromatography was used to separate 18-hydroxycorticosterone from other steroids in serum samples. The minimal detectable amount of 18-hydroxycorticosterone was 50 pg/tube and the measurable range was from 5 to 1000 ng/dl when a 1.0 ml serum sample was used. Intra- and inter-assay coefficients of variance were 5.0% (n=6) and 5.8% (n=6), respectively. Four of 5 patients with aldosterone-producing adenoma had above-normal serum 18-hydroxycorticosterone levels.     

Separation of novel phosphoproteins of Porphyromonas gingivalis using phosphate‐affinity chromatography

Phosphorylation of serine, threonine and tyrosine is a central mechanism for regulating the structure and function of proteins in both eukaryotes and prokaryotes. However, the action of phosphorylated proteins present in Porphyromonas gingivalis, a major periodontopathogen, is not fully understood. Here, six novel phosphoproteins that possess metabolic activities were identified, namely PGN_0004, PGN_0375, PGN_0500, PGN_0724, PGN_0733 and PGN_0880, having been separated by phosphate‐affinity chromatography. The identified proteins were detectable by immunoblotting specific to phosphorylated Ser (P‐Ser), P‐Thr, and/or P‐Tyr. These results imply that novel phosphorylated proteins might play an important role for regulation of metabolism in P. gingivalis.     

Insecticidal activities of methyleugenol and β-asarone,from the herbal medicines Saishin and Sekishōkon,and other alkoxy-propenyl-benzene derivatives against the cigarette beetle <Emphasis Type="Italic">Lasioderma serricorne</Emphasis> (Coleoptera: Anobiidae)

The principal insecticidal compounds from the herbal medicines Saishin, the root of Asarum sieboldii Miquel, and Sekishōkon, the rhizome of Acorus gramineus Soland, were isolated by successive silica gel column chromatography and high performance liquid chromatography. The active components, which work against larvae of the cigarette beetle, Lasioderma serricorne (F.), were identified as methyleugenol (4-allyl-1,2-dimethoxybenzene) and β-asarone {1,2,4-trimethoxy-5-[(Z)-prop-1-enyl]benzene} by gas chromatography and gas chromatography/mass spectrometry analyses. These two compounds share some structural features, such as a benzene ring with o-dimethoxy groups and a propenyl group in the opposite position. Consequently, the insecticidal activities of 20 structurally related compounds were tested to evaluate their structure–activity relationship. We found myristicin (5-allyl-1-methoxy-2,3-methylenedioxybenzene) exhibited comparable insecticidal activity to methyleugenol and β-asarone, but the other tested compounds were less active. The lack of insecticidal activity of compounds with a hydrogen, hydroxy, or acetoxy substituent in place of one methoxy group indicates that o-dimethoxy groups are essential for insecticidal activity. The position and configuration of a double bond in the propenyl side chain affected the toxicity, but there was a lack of consistency in the structure–activity relationship for this.     

Establishing a new index of muscle cross-sectional area and its relationship with isometric muscle strength

The present study aimed i) to establish an index of muscle cross-sectional area (CSA) based on muscle thickness and circumference through a comparison with muscle CSA determined by magnetic resonance imaging (MRI), and ii) to examine the relationships between muscle strength and the index determined at rest and during the maximal isometric contraction. The muscle CSA of elbow flexors at 60% of the upper arm length (CSA60) and the maximal CSA of elbow flexors (CSAmax) were measured using MRI in 26 men and 8 women. The muscle thickness (MT) of elbow flexors and the circumference (C) of upper arm at 60% of the upper arm length were measured using ultrasonography and anthropometry, respectively, in 29 men and 9 women. The measurements of MT and C were performed in the resting (MT(r) and C(r)) and contracted condition (MT(m) and C(m)), where the subjects performed maximal voluntary contraction (MVC) of isometric elbow joint flexion. The torque developed during MVC was converted into the muscle force (F) of elbow flexors. The MT(r) x C(r) was significantly correlated both with CSA60 and CSAmax (P < 0.001). The F was significantly correlated with MT(m) x C(m) (r = 0.847, P < 0.001) and MT(r) x C(r) (r = 0.839, P < 0.001). However, stepwise multiple regression analysis selected only MT(m) x C(m) as a significant contributor for estimating F. The present study indicates that MT x C reflects muscle CSA, and can be an index for assessing muscle CSA. In addition, the findings obtained here showed a possibility that MT x C during MVC is more closely related to F than that at rest.