Structures of homoleptic eight- and nine-coordinate uranium(IV) perchlorate complexes with sulfoxide molecules as ligands

Homoleptic eight- and nine-coordinate U(IV) perchlorate complexes with sulfoxide ligands have been characterized crystallographically. Crystals of [U(dmso)₈](ClO₄)₄ · 0.75CH₃NO₂, [U(dmso)₉](ClO₄)₄ · 4dmso (dmso = dimethyl sulfoxide), and [U(tmso)₈](ClO₄)₄ · 2tmso (tmso = tetramethylene sulfoxide) were found to have dodecahedral, tricapped trigonal prismatic, and square antiprismatic geometries, respectively. Average U-O bond distances in [U(dmso)₈](ClO₄)₄ · 0.75CH₃NO₂, [U(dmso)₉](ClO₄)₄ · 4dmso, and [U(tmso)₈](ClO₄)₄ · 2tmso are 2.35(3), 2.41 (4), and 2.35(3) Å, respectively. Furthermore, it was found that [U(dmso)₈]⁴⁺ is in equilibrium with [U(dmso)₉]⁴⁺ in CH₃NO₂ solution containing dmso. Thermodynamic parameters for such an equilibrium are as follows: K (25 °C) = 3.4 ± 0.2 dm³ mol⁻¹, ΔH = −54.9 ± 4.5 kJ mol⁻¹, and ΔS = −174 ± 15 J K⁻¹ mol⁻¹.     

Alterations of Glial Cells in the Mouse Hippocampus During Postnatal Development

We investigated the postnatal alterations of neurons, astrocyte, oligodendrocyte, and microglia in the mouse hippocampal CA1 sector and dentate gyrus under the same conditions using immunohistochemistry. Neuronal nuclei (NeuN), Glial fibrillary acidic protein (GFAP), 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNPase), and ionized calcium binding adaptor molecule 1 (Iba 1) immunoreactivity were measured in 1-, 2-, 4-, and 8-week-old mice. Total number of NeuN-positive neurons was unchanged in the mouse hippocampal CA1 sector and dentate gyrus from 1 to 8 weeks of birth. In contrast, a significant increase in the number of GFAP-positive astrocytes was observed only in the hippocampal CA1 sector of 1-week-old mice when compared with 8-week-old animals. Thereafter, total number of GFAP-positive astrocytes was unchanged in the hippocampal CA1 sector and dentate gyrus from 2 to 8 weeks of birth. For microglia, a significant increase in the number of Iba 1-positive microglia was observed in the hippocampal CA1 sector and dentate gyrus of 1-, 2-, and 4-week-old mice as compared with 8-week-old animals. On the other hand, a significant decrease in the area of expression of CNPase-positive fibers was observed in the hippocampal CA1 sector of 1- and 2-week-old mice as compared with 8-week-old animals. In dentate gyrus, a significant decrease in the area of expression of CNPase-positive fibers was found in 1-, 2-, and 4-week-old mice. Furthermore, our double-labeled immunostaining showed that brain-derived neurotrophic factor (BDNF) immunoreactivity was observed in GFAP-positive astrocytes and Iba 1-positive microglia in the hippocampal CA1 sector and dentate gyrus of 1- and 2-week-old mice. These results show that glial cells may play some role in the maintenance and neuronal functions of hippocampal CA1 pyramidal neurons and granule cells of dentate gyrus during postnatal development. Furthermore, our results demonstrate that glial BDNF may play an important role in the maturation of oligodendrocyte in the hippocampal CA1 sector and dentate gyrus during postnatal development. Thus, our findings provide valuable information on the developmental processes.     

Development of urine glucose meter based on micro-planer amperometric biosensor and its clinical application for self-monitoring of urine glucose

The highly sensitive urine glucose meter based on amperometric glucose sensor was developed and commercialized. It shows remarkable performances of wide measurement range in 0-2000 mgdl(-1), rapid response time as 6s and robustness against influence by interferents like ascorbic acid or acetaminophen. Correlation between the developed urine glucose meter and commercialized clinical-use urine glucose analyzer showed excellent linear relationship. The monitoring of postmeal blood glucose levels by assess of urine glucose of actual subjects was performed with the developed urine glucose meter. The experimental results suggest the urine glucose level 120 min following the meal should be the appropriate index for diabetes or impaired glucose tolerance to control blood glucose level. The new portable meter was developed, and is expected for flexible use at places other than home or office.     

Antioxidant activity and antitumor activity (in vitro) of xyloglucan selenious ester and surfated xyloglucan

Two kinds of xyloglucan derivatives (xyloglucan selenious ester and sulfated xyloglucan) were prepared and evaluated on antioxidant activity and antitumor activity. Compared with xyloglucan, xyloglucan derivatives have new bioactivity against oxidative damage and tumor. Furthermore, xyloglucan selenious ester is more potent than sulfated xyloglucan at antioxidant activity and antitumor activity in vitro. The current data suggest for the first time that selenition of xyloglucan significantly increases its bioactivity and the chemical modification of polysaccharide may allow the preparation of derivatives with new properties and a variety of applications.     

Phospholipase C-β4 Is Essential for the Progression of the Normal Sleep Sequence and Ultradian Body Temperature Rhythms in Mice

Background

The sleep sequence: i) non-REM sleep, ii) REM sleep, and iii) wakefulness, is stable and widely preserved in mammals, but the underlying mechanisms are unknown. It has been shown that this sequence is disrupted by sudden REM sleep onset during active wakefulness (i.e., narcolepsy) in orexin-deficient mutant animals. Phospholipase C (PLC) mediates the signaling of numerous metabotropic receptors, including orexin receptors. Among the several PLC subtypes, the β4 subtype is uniquely localized in the geniculate nucleus of thalamus which is hypothesized to have a critical role in the transition and maintenance of sleep stages. In fact, we have reported irregular theta wave frequency during REM sleep in PLC-β4-deficient mutant (PLC-β4−/−) mice. Daily behavioral phenotypes and metabotropic receptors involved have not been analyzed in detail in PLC-β4−/− mice, however.

Methodology/Principal Findings

Therefore, we analyzed 24-h sleep electroencephalogram in PLC-β4−/− mice. PLC-β4−/− mice exhibited normal non-REM sleep both during the day and nighttime. PLC-β4−/− mice, however, exhibited increased REM sleep during the night, their active period. Also, their sleep was fragmented with unusual wake-to-REM sleep transitions, both during the day and nighttime. In addition, PLC-β4−/− mice reduced ultradian body temperature rhythms and elevated body temperatures during the daytime, but had normal homeothermal response to acute shifts in ambient temperatures (22°C–4°C). Within the most likely brain areas to produce these behavioral phenotypes, we found that, not orexin, but group-1 metabotropic glutamate receptor (mGluR)-mediated Ca²⁺ mobilization was significantly reduced in the dorsal lateral geniculate nucleus (LGNd) of PLC-β4−/− mice. Voltage clamp recordings revealed that group-1 mGluR-mediated currents in LGNd relay neurons (inward in wild-type mice) were outward in PLC-β4−/− mice.

Conclusions/Significance

These lines of evidence indicate that impaired LGNd relay, possibly mediated via group-1 mGluR, may underlie irregular sleep sequences and ultradian body temperature rhythms in PLC-β4−/− mice.     

Presence of Thrombin-Activatable Fibrinolysis Inhibitor in Helicobacter pylori-Associated Gastroduodenal Disease

Thrombin-activatable fibrinolysis inhibitor (TAFI) plays a role in the regulation of coagulation and inflammation. In addition to inhibiting the fibrinolytic system, TAFI may also regulate the bradykinin and complement systems. We hypothesized that TAFI also plays a role in defense mechanisms of the gastric mucosa during Helicobacter pylori infection. This study comprised 65 patients with gastroduodenal disorders: 41 patients with H. pylori infection, 13 without, and 11 patients with cured H. pylori infection. The gastric intramucosal concentrations of TAFI were measured by enzyme immunoassay. The gastric levels of TAFI and plasminogen activator inhibitor-1 were significantly increased in patients with H. pylori compared to those without infection or cured H. pylori . The presence of TAFI was detected in gastric mucosal epithelial cells. The concentration of TAFI was correlated with the degree of gastric mucosal atrophy, inflammation, and disease activity. These results show that TAFI is present in the gastric mucosa and that it may play a role in the pathogenesis of H. pylori infection-associated gastroduodenal disorders.     

In vitro characterization of the site-specific recombination system based on actinophage TG1 integrase

We have previously shown that, in vivo, the integration system based on the gene encoding the TG1 integrase and the corresponding attB _TG1 and attP _TG1 sites works well not only in Streptomyces strains, but also in Escherichia coli. Furthermore, the attachment sites for TG1 integrase are distinct from those of ϕC31 integrase. In this report, we expressed TG1 integrase as a GST-TG1 integrase fusion protein and then used affinity separation and specific cleavage to release purified integrase. Conditions for in vitro recombination were established using the purified TG1 integrase and its cognate attP _TG1 and attB _TG1 sites. TG1 integrase efficiently catalyzed a site-specific recombination between attB _TG1 and attP _TG1 sites irrespective of their substrate topology. The minimal sequences of attP _TG1 and attB _TG1 sites required for the substrates of TG1 integrase were demonstrated to be 43 and 39-bp, respectively. These results provide the basic features of the TG1 integrase system to be used as biotechnological tools, as well as to unravel the mechanism of the serine integrase.     

Alpha-1-C-octyl-1-deoxynojirimycin as a pharmacological chaperone for Gaucher disease

The most common lysosomal storage disorder, Gaucher disease, is caused by inefficient folding and trafficking of certain variants of lysosomal beta-glucosidase (beta-Glu, also known as beta-glucocerebrosidase). Recently, Sawker et al. reported that the addition of subinhibitory concentrations (10 microM) of the pharmacological chaperone N-nonyl-1-deoxynojirimycin (NN-DNJ) (10) to Gaucher patient-derived cells leads to a 2-fold increase in activity of mutant (N370S) enzyme [Proc. Natl. Acad. Sci. U.S.A.2002, 99, 15428]. However, we found that the addition of NN-DNJ at 10 microM lowered the lysosomal alpha-glucosidase (alpha-Glu) activity by 50% throughout the assay period in spite of the excellent chaperoning activity in N370S fibroblasts. Hence, we prepared a series of DNJ derivatives with an alkyl chain at the C-1alpha position and evaluated their in vitro inhibitory activity and potential as pharmacological chaperones for Gaucher cell lines. Among them, alpha-1-C-octyl-DNJ (CO-DNJ) (15) showed 460-fold stronger in vitro inhibitory activity than DNJ toward beta-Glu, while NN-DNJ enhanced in vitro inhibitory activity by 360-fold. Treatment with CO-DNJ (20 microM) for 4 days maximally increased intracellular beta-Glu activity by 1.7-fold in Gaucher N370 cell line (GM0037) and by 2.0-fold in another N370 cell line (GM00852). The addition of 20 microM CO-DNJ to the N370S (GM00372) culture medium for 10 days led to 1.9-fold increase in the beta-Glu activity without affecting the intracellular alpha-Glu activity for 10 days. Only CO-DNJ showed a weak beta-Glu chaperoning activity in the L444P type 2 variant, with 1.2-fold increase at 5-20 microM, and furthermore maximally increased the alpha-Glu activity by 1.3-fold at 20 microM. These experimental results suggest that CO-DNJ is a significant pharmacological chaperone for N370S Gaucher variants, minimizing the potential for undesirable side effects such as alpha-Glu inhibition.