The influence of posture change on measurements of relative body fat in the bioimpedance analysis method

The purpose of this study was to clarify the influence of posture change on relative body fat in the bioelectrical impedance analysis (BIA) method. The subjects were 30 Japanese healthy young adult males (age: 19.8 +/- 1.4 years, height: 172.3 +/- 5.8 cm, weight: 67.1 +/- 8.2 kg). We used devices with different body segment inductions, between the hand and foot (H-F BIA) and between hands (H-H BIA), and set four measurement conditions differing in posture (supine or sitting), during rest and measurement. The reliabilities of %BF in the H-H and H-F BIA methods were very high (r = 0.995, 0.966), and the relationship in %BF between the UW method and each BIA method was mid-range (r = 0.767, 0.709). Although there were no differences in %BF among different measurement postures in the H-F BIA method, %BF in the H-H BIA method increased significantly when the posture was changed just before measurement. This indicated that it is necessary to pay attention to the posture change just before measurement in the H-H BIA method.     

A recombinant molt-inhibiting hormone of the kuruma prawn has a similar secondary structure to a native hormone: determination of disulfide bond arrangement and measurements of circular dichroism spectra

In crustaceans, molt-inhibiting hormone (MIH) is presumed to regulate molting through suppressing synthesis and/or secretion of ecdysteroids by the Y-organ. Recently, a recombinant MIH of the kuruma prawn Penaeus japonicus was produced in E. coli. To approximate the secondary structure of native and recombinant MIH of P. japonicus containing six cysteine residues, the arrangements of disulfide bridges in both MIHs were determined by characterizing their enzymatic digests, and their circular dichroism spectra were measured. The arrangements of disulfide bonds in both MIHs were determined to be identical, and they were linked between Cys7 and Cys44, Cys24 and Cys40, and Cys27 and Cys53. The circular dichroism spectra of both MIHs were very close, and demonstrated that they were rich in a-helix. a-Helix contents in native and recombinant MIHs were calculated to be 49.3% and 46.0%, respectively. All these results strongly suggested that the recombinant MIH was folded in the same manner as the native MIH.     

A comparative study on the hydroperoxide and thiol specificity of the glutathione peroxidase family and selenoprotein P

Glutathione peroxidase catalyzes the reduction of hydrogen peroxide and organic hydroperoxide by glutathione and functions in the protection of cells against oxidative damage. Glutathione peroxidase exists in several forms that differ in their primary structure and localization. We have also shown that selenoprotein P exhibits a glutathione peroxidase-like activity (Saito, Y., Hayashi, T., Tanaka, A., Watanabe, Y., Suzuki, M., Saito, E., and Takahashi, K. (1999) J. Biol. Chem. 274, 2866-2871). To understand the physiological significance of the diversity among these enzymes, a comparative study on the peroxide substrate specificity of three types of ubiquitous glutathione peroxidase (cellular glutathione peroxidase, phospholipid hydroperoxide glutathione peroxidase, and extracellular glutathione peroxidase) and of selenoprotein P purified from human origins was done. The specific activities and kinetic parameters against two hydroperoxides (hydrogen peroxide and phosphatidylcholine hydroperoxide) were determined. We next examined the thiol specificity and found that thioredoxin is the preferred electron donor for selenoprotein P. These four enzymes exhibit different peroxide and thiol specificities and collaborate to protect biological molecules from oxidative stress both inside and outside the cells.     

Bystander effect for chromosomal aberrations induced in wild-type and repair deficient CHO cells by low fluences of alpha particles

Ultraviolet (UV) irradiation produces DNA photoproducts that are blocks to DNA replication by normal replicative polymerases. A specialized, damage-specific, distributive polymerase, Pol H or Pol h, that is the product of the hRad30A gene, is required for replication past these photoproducts. This polymerase is absent from XP variant (XP-V) cells that must employ other mechanisms to negotiate blocks to DNA replication. These mechanisms include the use of alternative polymerases or recombination between sister chromatids. Replication forks arrested by UV damage in virus transformed XP-V cells degrade into DNA double strand breaks that are sites for recombination, but in normal cells arrested forks may be protected from degradation by p53 protein. These breaks are sites for binding a protein complex, hMre11/hRad50/Nbs1, that colocalizes with H2AX and PCNA, and can be visualized as immunofluorescent foci. The protein complexes need phosphorylation to activate their DNA binding capacity. Incubation of UV irradiated XP-V cells with the irreversible kinase inhibitor wortmannin, however, increased the yield of Mre11 focus-positive cells. One interpretation of this observation is that two classes of kinases are involved after UV irradiation. One would be a wortmannin-resistant kinase that phosphorylates the Mre11 complex. The other would be a wortmannin-sensitive kinase that phosphorylates and activates the p53/large T in SV40 transformed XP-V cells. The sensitive class corresponds to the PI3-kinases of ATM, ATR, and DNA-PK, but the resistant class remains to be identified. Alternatively, the elevated yield of Mre11 foci positive cells following wortmannin treatment may reflect an overall perturbation to the signaling cascades regulated by wortmannin-sensitive PI3 related kinases. In this scenario, wortmannin could compromise damage inducible-signaling pathways that maintain the stability of stalled forks, resulting in a further destabilization of stalled forks that then degrade, with the formation of DNA double strand breaks.     

Aminoacylation of the N-terminal cysteine is essential for Lol-dependent release of lipoproteins from membranes but does not depend on lipoprotein sorting signals

Lipoproteins are present in a wide variety of bacteria and are anchored to membranes through lipids attached to the N-terminal cysteine. The Lol system of Escherichia coli mediates the membrane-specific localization of lipoproteins. Aspartate at position 2 functions as a Lol avoidance signal and causes the retention of lipoproteins in the inner membrane, whereas lipoproteins having residues other than aspartate at position 2 are released from the inner membrane and localized to the outer membrane by the Lol system. Phospholipid:apolipoprotein transacylase, Lnt, catalyzes the last step of lipoprotein modification, converting apolipoprotein into mature lipoprotein. To reveal the importance of this aminoacylation for the Lol-dependent membrane localization, apolipoproteins were prepared by inhibiting lipoprotein maturation. Lnt was also purified and used to convert apolipoprotein into mature lipoprotein in vitro. The release of these lipoproteins was examined in proteoliposomes. We show here that the aminoacylation is essential for the Lol-dependent release of lipoproteins from membranes. Furthermore, lipoproteins with aspartate at position 2 were found to be aminoacylated both in vivo and in vitro, indicating that the lipoprotein-sorting signal does not affect lipid modification.     

Origin of two isoprenoid units in a lavandulyl moiety of sophoraflavanone G from Sophora flavescens cultured cells

Cell suspension cultures of Sophora flavescens produced large amounts of sophoraflavanone G, an 8-lavandulylated flavanone and lupalbigenin, a 6,3'-di-dimethylallylated isoflavone, by the simultaneous addition of cork tissues and methyl jasmonate. The labeling pattern of the isoprene units resulting after administration of [1-13C] glucose into the cell cultures in the presence of the above additives revealed that two isoprene units in the lavandulyl group of sophoraflavanone G and two dimethylallyl groups of lupalbigenin were biosynthesized via the 1-deoxy-D-xylulose-5-phosphate pathway.     

The first synthesis and antifungal activities of 9-methoxystrobilurin-type beta-substituted beta-methoxyacrylate

The first synthesis of 9-methoxystrobilurin-type beta-substituted MOAs was successfully achieved. A chiral oudemansin-type beta-substituted MOA was also synthesized utilizing Mukaiyama's asymmetric aldol reaction. Antifungal activities of the synthesized compounds against several representative fungi were examined by disk-diffusion assay. As a result, unique and superior antifungal properties of 9-methoxystrobilurin-type beta-substituted MOAs compared with those of oudemansin-type analogue were clearly revealed.     

The relationship and its change with aging between ADL and daily life satisfaction characteristics in independent Japanese elderly living at home

The purposes of this study were to examine the characteristics of the relationship between ADL ability and daily life satisfaction and the pattern change with aging in independent Japanese elderly, and to compare these tendencies between males and females. The characteristics of ADL ability and daily life satisfaction of 482 subjects (213 males, 269 females) were investigated in a self-response survey. Seventy-four ADL items, considered from previous studies, were selected from nine ADL domains of 1) movement, 2) going up and down stairs, 3) changing and holding posture, 4) bathing, 5) toileting, 6) dressing, 7) grooming, 8) eating, and 9) manual activities, and nine items of daily life satisfaction were selected from physical, psychological and sociological factors. Both ADL ability and life satisfaction of independent elderly tended to decline with aging. From correlation analysis, since life satisfaction of the elderly was higher with high ADL ability level, it was considered that ADL ability level is one of the important factors in providing for life satisfaction of independent elderly. The subjective symptoms of inconvenience in the lower extremity and lumbar region increased from the 70s in both genders, and the use of assisting devices for movement remarkably increased in the 80s in both genders. The use of assisting devices closely related to the activity area in daily life and influenced the characteristics of life satisfaction and its age-related change in the relationship between ADL ability and life satisfaction. The relationship between ADL ability and satisfaction with physical function was similar in both genders, while the relationship between ADL ability and satisfaction with sociological and psychological factors was different between males and females. Since the relationship between ADL ability and life satisfaction of independent elderly is influenced by a combination of personal, cultural, and environmental factors, additional study must investigate in detail the influence of these factors.     

TX-1123: an antitumor 2-hydroxyarylidene-4-cyclopentene-1,3-dione as a protein tyrosine kinase inhibitor having low mitochondrial toxicity

A series of 2-hydroxyarylidene-4-cyclopentene-1,3-diones were designed, synthesized, and evaluated with respect to protein tyrosine kinase (PTK) inhibition, mitochondrial toxicity, and antitumor activity. Our results show that the cyclopentenedione-derived TX-1123 is a more potent antitumor tyrphostin and also shows lower mitochondrial toxicity than the malononitrile-derived AG17, a potent antitumor tyrphostin. The O-methylation product of TX-1123 (TX-1925) retained its tyrphostin-like properties, including mitochondrial toxicity and antitumor activities. However, the methylation product of AG17 (TX-1927) retained its tyrphostin-like antitumor activities, but lost its mitochondrial toxicity. Our comprehensive evaluation of these agents with respect to protein tyrosine kinase inhibition, mitochondrial inhibition, antitumor activity, and hepatotoxicity demonstrates that PTK inhibitors TX-1123 and TX-1925 are more promising candidates for antitumor agents than tyrphostin AG17.     

Isolation and Characterization of 2-Nitroimidazole Produced by Streptomyces Species as an Inhibitor of Both Carbonic Anhydrase and Shell Formation in the Barnacle Balanus amphitrite

Carbonic anhydrase is thought to be involved in the process of calcium carbonate deposition in calcified tissues of many organisms. Barnacles form hard calcified shells for protection against predation, and represent a class of marine-fouling animals. In order to inhibit barnacle growth by inhibiting shell formation, we searched for carbonic anhydrase inhibitors from microbial secondary metabolites. A simple assay for assessing carbonic-anhydrase-inhibiting activity was developed. Screening of many microorganisms isolated from soil with this assay resulted in a microbial strain that produced a carbonic anhydrase inhibitor. This strain was identified as Streptomyces eurocidicus mf294. The inhibitor was isolated through 4 purification steps and identified as 2-nitroimidazole on the basis of spectroscopic data. 2-Nitroimidazole inhibited barnacle carbonic anhydrase dose-dependently and complete inhibition was reached at the concentration of 1 x 10(-5) M. 2-Nitroimidazole did not affect settlement or metamorphosis of barnacle larvae, but inhibited shell formation at concentrations higher than 1 x 10(-4) M. These findings strongly support the idea that carbonic anhydrase is involved in calcification.