The influence of visual display terminal use on the physical and mental conditions of administrative staff in Japan

Visual display terminals (VDT) are standard equipment for many office workers. Their use, however, may increase the risk of developing adverse conditions related to vision, the musculoskeletal system, and mental health. We carried out a survey among 3070 workers aged 18 to 67 years (mean, 39.9 years) at a prefectural administrative office, in which 76% of subjects were visual display terminal (VDT) users. We examined the relationship between duration of daily VDT use and eyestrain, neck or upper extremity pain, back pain, and mental health, and estimated the effect of breaks and rest during VDT work on these symptoms. The 12-item General Health Questionnaire (GHQ-12: total scores ranged from 0 to 12) was used to identify potential poor mental health status, and subjects with 4 or more were considered to have symptoms of psychological distress. Seventeen percent of subjects reported eyestrain, 19.1% reported upper extremity pain, 11.6% reported back pain, and 17% of subjects had GHQ-12 scores of 4 or higher. Logistic regression analysis showed that duration of daily VDT use and lack of breaks and rest during VDT work were significantly associated with eyestrain, neck or upper extremity pain, back pain, and psychological distress. In order to protect users from the adverse effects associated with VDT work, reducing daily VDT exposure, taking breaks, and rest during VDT work are important.     

O-Seco-RA-XXIV,a possible precursor of an antitumor peptide RA-XXIV,from Rubia cordifolia L.

O-Seco-RA-XXIV, a new cyclic peptide, cyclo-(d-alanyl-l-glutaminyl-N,O-dimethyl-l-tyrosyl-l-alanyl-N-methyl-l-tyrosyl-N-methyl-l-tyrosyl), was isolated from the roots of Rubia cordifolia L. along with RA-XXIV. Its structure and relative stereochemistry were determined by interpretation of the spectroscopic data and X-ray crystallography, and its absolute stereochemistry by the Marfey's amino acid analysis of its acid hydrolysate. Isolation of the two peptides from the same plant source may indicate that O-seco-RA-XXIV is a possible precursor of RA-XXIV and that the formation of the diphenyl ether linkage in the cycloisodityrosine moiety is to be formed after the formation of the cyclohexapeptide chain in this series of peptides.     

Closing the (Ran)GAP on segregation distortion in Drosophila

Segregation Distorter (SD) is a meiotic drive system in Drosophila that causes preferential transmission of the SD chromosome from SD/SD(+) males owing to induced dysfunction of SD(+) spermatids. Since its discovery in 1956, SD and its mode of action have baffled biologists. Recently, substantial progress has been made in elucidating this puzzle. Sd, the primary gene responsible for distortion encodes a mutant RanGAP, a key protein in the Ran signaling pathway required for nuclear transport and other nuclear functions. The mutant protein is enzymatically active but mislocalized to nuclei, which apparently disrupts Ran signaling by reducing intranuclear Ran-GTP levels. Some evidence suggests that a defect in nuclear transport may be the main cause of sperm dysfunction. Although important questions remain, the basic mechanism of distortion is now understood sufficiently well that specific hypotheses can be formulated and tested. This previously mysterious genetic system may now offer unique insights into novel aspects of regulation by Ran.     

Betagamma-dehydrocurvularin and related compounds as nematicides of Pratylenchus penetrans from the fungus Aspergillus sp

The new nematicidal compound, betagamma-dehydrocurvularin (1), together with three known compounds, alphabeta-dehydrocurvularin (2), 8-beta-hydroxy-7-oxocurvularin (3) and 7-oxocurvularin (4), were isolated from the culture filtrate and mycelial mats of Aspergillus sp. The structures of 1-4 were established by spectroscopic methods including 2D NMR. The biological activities of 1-4 were examined by bioassays with root-lesion nematodes, and lettuce and rice seedlings.     

Participation of Syndecan 2 in the Induction of Stress Fiber Formation in Cooperation with Integrin α5β1: Structural Characteristics of Heparan Sulfate Chains with Avidity to COOH-Terminal Heparin-Binding Domain of Fibronectin

The present study provides direct evidence that syndecan 2 participates selectively in the induction of stress fiber formation in cooperation with integrin α5β1 through specific binding of its heparan sulfate side chains to the fibronectin substrate. Our previous study with Lewis lung carcinoma-derived P29 cells demonstrated that the cell surface heparan sulfate proteoglycan, which binds to fibronectin, is syndecan 2 (N. Itano et al., 1996, Biochem. J. 315, 925–930). We here report that in vitro treatment of the cells by antisense oligonucleotide for syndecan 2 resulted in a failure to form stress fibers on fibronectin substrate in association with specific suppression of its cell surface expression. Instead, localization of actin filaments in the cytoplasmic cortex occurred. A similar response of the cells was observed when the cells were treated to eliminate functions of cell surface heparan sulfates, including exogenous addition of heparin and pretreatment with anti-heparan sulfate antibody, F58-10E4, and with proteinase-free heparitinase I. Size- and structure-defined oligosaccharides prepared from heparin and chemically modified heparins were utilized as competitive inhibitors to examine the structural characteristics of the cell surface heparan sulfates involved in organization of the actin cytoskeleton. Their affinity chromatography on a column linked with a recombinant H-271 peptide containing a C-terminal heparin-binding domain of fibronectin demonstrated that 2-O-sulfated iduronates were essential for the binding. Inhibition studies revealed that a heparin-derived dodecasaccharide sample enriched with an IdoA(2OS)–GlcNS(6OS) disaccharide completely blocked binding of the syndecan 2 ectodomain to immobilized H-271 peptide. Finally, the dodecasaccharide sample was shown to inhibit stress fiber formation, triggered by adhesion of P29 cells to a CH-271 polypeptide consisting of both the RGD cell-binding and the C-terminal heparin-binding domains of fibronectin in a fused form. All these results consistently suggest that syndecan 2 proteoglycan interacts with the C-terminal heparin-binding domain of fibronectin at the highly sulfated cluster(s), such as [IdoA(2OS)–GlcNS(6OS)]₆ present in its heparan sulfate chains, to result in the induction of stress fiber formation in cooperation with integrin α5β1.     

Effect of guanidine on the squid giant synapse

Effects of guanidine on pre- and postsynaptic activities in the untreated or tetrodotoxin-treated squid giant synapses were examined by externally perfusing with various concentrations (423 mM, 42 mM, 21 mM, and 4.2 mM), or by iontophoretic injection of guanidine into the presynaptic terminal. In 423 mM guanidine (Na-free), the pre- and postsynaptic spikes together with PSP were completely abolished. In concentrations of 42 mM or lower of guanidine media the following changes related to the concentration used were observed: reduction of delayed rectification of both axon membranes without significant alteration of resting membrane resistances; a few millivolts decrease in the resting membrane potentials; small decrease in amplitude of pre- and post-synaptic spikes without marked increase of spike duration; enhancement of synaptic activity as manifested by increases in the amplitude and duration of the PSP. Iontophoretically injected guanidine also reduced delayed rectification of the presynaptic membrane. Input-output relation was modified in a way similar to externally applied guanidine and an “Off-PSP” was demonstrated shortly after application of an inside positive presynaptic polarization. Thus, a comparison of the augmentation of synaptic transmission by the extracellular and intracellularly applied guanidine demonstrates that the primary effect is at the presynaptic terminal.     

Circulating Omega-6, But Not Omega-3 Polyunsaturated Fatty Acids,Are Associated with Clinical Outcomes in Patients with Acute Decompensated Heart Failure

BackgroundCirculating polyunsaturated fatty acid (PUFA) levels are associated with clinical outcomes in cardiovascular diseases including coronary artery disease and chronic heart failure (HF). However, their clinical implications in acute decompensated HF (ADHF) remain unclear. The aim of this study was to investigate the clinical roles of circulating PUFAs in patients with ADHF.MethodsCirculating levels of PUFAs, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA) and dihomo-gamma linoleic acid (DGLA), were measured on admission in 685 consecutive ADHF patients. Adverse events were defined as all-cause death and worsening HF.ResultsDuring a median follow-up period of 560 days, 262 (38.2%) patients had adverse events. Although patients with adverse events had lower n-6 PUFA (AA + DGLA) level than those without, n-3 PUFA (EPA + DHA) level was comparable between the groups. Kaplan-Meier analyses showed that lower n-6 PUFA level on admission was significantly associated with the composite of all-cause death and worsening HF, all-cause death, cardiovascular death and worsening HF (p < 0.001, p = 0.005, p = 0.021, p = 0.019, respectively). In a multivariate Cox model, lower n-6 PUFA level was independently associated with increased risk of adverse events (HR 0.996, 95% CI: 0.993–0.999, p = 0.027).ConclusionsLower n-6 but not n-3 PUFA level on admission was significantly related to worse clinical outcomes in ADHF patients. Measurement of circulating n-6 PUFA levels on admission might provide information for identifying high risk ADHF patients.     

Treatment of pituitary dwarfism with methionyl human growth hormone in Japan

Sixty-two patients with pituitary dwarfism were treated with three different preparations of methionyl hGH (m-hGH) for 3 to 14 months. They were given 0.5 IU/kg/week intramuscularly. The growth rate during treatment with the three different preparations was the same for each and increased from 3.5 +/- 0.9 to 8.2 +/- 1.7 cm/year. A high incidence of hGH antibody formation was observed following the treatment, but the titer of antibody was decreased according to the purity of m-hGH preparations. At the end of 12 month treatment with a highly purified preparation (Somatonorm III), 76.2% of the patients had hGH antibody. However, the presence of antibodies did not affect the growth rate except in one patient. No clinical or laboratory side-effects were observed following the treatment with m-hGH. Thus, m-hGH was considered to be useful for the treatment of GH deficient children.