Sulfated Hyaluronan Binds to Heparanase and Blocks Its Enzymatic and Cellular Actions in Carcinoma Cells

We examined whether sulfated hyaluronan exerts inhibitory effects on enzymatic and biological actions of heparanase, a sole endo-beta-glucuronidase implicated in cancer malignancy and inflammation. Degradation of heparan sulfate by human and mouse heparanase was inhibited by sulfated hyaluronan. In particular, high-sulfated hyaluronan modified with approximately 2.5 sulfate groups per disaccharide unit effectively inhibited the enzymatic activity at a lower concentration than heparin. Human and mouse heparanase bound to immobilized sulfated hyaluronan. Invasion of heparanase-positive colon-26 cells and 4T1 cells under 3D culture conditions was significantly suppressed in the presence of high-sulfated hyaluronan. Heparanase-induced release of CCL2 from colon-26 cells was suppressed in the presence of sulfated hyaluronan via blocking of cell surface binding and subsequent intracellular NF-κB-dependent signaling. The inhibitory effect of sulfated hyaluronan is likely due to competitive binding to the heparanase molecule, which antagonizes the heparanase-substrate interaction. Fragment molecular orbital calculation revealed a strong binding of sulfated hyaluronan tetrasaccharide to the heparanase molecule based on electrostatic interactions, particularly characterized by interactions of (−1)- and (−2)-positioned sulfated sugar residues with basic amino acid residues composing the heparin-binding domain-1 of heparanase. These results propose a relevance for sulfated hyaluronan in the blocking of heparanase-mediated enzymatic and cellular actions.     

Dynamical coherence patterns in neural field model at criticality

Phase synchronization is a mechanism that plays a crucial role in information processing in the brain, and coherence is one of the factors used to evaluate the pairwise degree of phase synchronization. Coherence is also an important measure for examining brain functions because it implies communication and cooperation among neurons. In this work, we study the coherence patterns of spontaneous activity in a neural field model at criticality where a second-order phase transition occurs with special properties that differentiate it from other regions. The results are summarized as follows. First, in high-frequency bands, the system outside the critical region is unable to communicate efficiently via phase synchronization. Second, the dynamical coherence patterns at the criticality show switching between high and low coherence states. Finally, we found that in a very brief period, there is high broadband coherence between some pairs of spatial points. This phenomenon can be observed only in the critical region.     

Iodine-123-iomazenil and iodine-123-iodoamphetamine SPECT in major cerebral artery occlusive disease

Iodine-123-iomazenil (IMZ) is a SPECT ligand for central-type benzodiazepine receptors, which are located only on neurons. We evaluated the feasibility of using IMZ SPECT for identifying neuronal damage in patients with the chronic phase of thrombotic cerebral ischemia. METHODS: We studied 15 patients with angiographically-confirmed unilateral severe occlusive lesions (occlusion or > 70% stenosis) in the carotid system. IMZ SPECT images obtained 180 min after injection of 167-222 MBq IMZ were analyzed. The regional cerebral blood flow and perfusion reserve were evaluated for comparison with IMZ SPECT findings, using the split-dose 123I-iodoamphetamine (IMP) SPECT method, coupled with intravenous injection of 1 g acetazolamide. On both SPECT images, the count ratio of the affected to the nonaffected whole MCA territory (A/NA ratio) and of the contralateral to the ipsilateral cerebellar cortex (C/I ratio) were determined. RESULTS: The A/NA ratio with IMZ was significantly higher than that with IMP (94.5% +/- 6.2% versus 91.4% +/- 6.6%, p < 0.005), although a significantly positive correlation was found between these two ratios (r = 0.854, p < 0.0001). The C/I ratio with IMP was decreased significantly in 5 patients compared with that in normal subjects, whereas the C/I ratio with IMZ was decreased in only 1 patient. There was no significant correlation between the A/NA ratio with IMZ and the perfusion reserve in the affected MCA territory. In 2 of 5 patients with a decreased A/NA ratio (<90%) with IMZ, decreased blood flow with preserved perfusion reserve and cerebral hemispheric atrophy were observed, which suggested the influence of neuronal loss due to chronic ischemia. CONCLUSION: These findings indicate that IMZ SPECT, which provides new information regarding neuronal damage after ischemic insult to the brain, is useful for evaluating thrombotic cerebral ischemia.     

Suppression effects of active power filter on harmonics of distribution system including capacitors

Voltage distortion of 6.6-kV distribution systems has been increasing recently especially in commercial areas. Harmonic currents of certain orders are amplified and voltage distortions are generated by the resonance between system impedance and static capacitor under the leading power factor condition. This paper describes the results of a test on suppression effects on model systems and an actual system. The effect of the use of an active power filter on the resonant harmonics of the system including capacitor was verified.     

Optical tristability in two-section laser diode

Optical tristability in the current/light output characteristics of a two-section laser diode is observed. Three stable optical outputs are obtained at the same current. Two different types of tristability are observed by controlling injection conditions. The tristability is caused by a cavity structure having a saturable absorber and a complex resonance cavity.<>     

Single lead atrial synchronous ventricular pacing in Japanese patients with complete atrioventricular block

The purpose of this study was to review our experience with atrial synchronous ventricular pacing devices (THERA VDD pacing systems, Medtronic, Inc., U.S.A.) using single atrioventricular leads in Japanese patients with complete atrioventricular block and normal sinus function. Twenty patients with a mean age of 55 +/- 13 years underwent implantation of VDD pacemakers. At implantation the amplitude of atrial signals in the supine position during normal breathing, which was measured directly using an external pacing system analyzer, ranged from 1.8 to 5.8 mV with a mean amplitude of 3.4 +/- 1.4 mV. Atrial amplitudes did not change during deep breathing (3.3 +/- 1.1 mV) or in the semi-Fowler position (3.4 +/- 1.6 mV). Atrial oversensing or undersensing was not observed in any of the patients. During a follow-up period, the percentage of atrial synchronization was >95% in 19 patients, and none of the patients had pacemaker related tachycardia or pacemaker related complications. These results were promising enough to warrant the extension of the clinical use of the VDD pacemaker.     

Viable utilization of polycarbonate as a phosgene equivalent illustrated by reactions with alkanedithiols,mercaptoethanol, aminoethanethiol,and aminoethanol: A solution for the issue of carbon resource conservation

Methods for the chemical recycling of polycarbonate (PC) wastes in the forms of bisphenol A (BPA) and cyclic heterocarbonates, such as 1,3‐dithiolan‐2‐one (DTO), 1,3‐dithiane‐2‐one (DTA), and cyclic unsymmetric heterocarbonates, were investigated to prove that PC can be utilized as a phosgene equivalent for industrial purposes. Treatment of PC pellets or waste PC compact discs with 1,2‐ethanedithiol and a catalytic amount of base (e.g., 1.5 mol % NaOH) in dioxane for a short period at 40°C produced DTO and BPA, both in nearly quantitative yields. The reaction could also be carried out in DTO, which saved the use of conventional solvents. Other cyclic heterocarbonates, that is, DTA, 1,3‐oxathiolan‐2‐one, 1,3‐thiazolidine‐2‐one, and N‐methyl‐1,3‐oxazolidine‐2‐one, were prepared in high yields under analogous conditions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2959–2968, 2003     

Spatial distributions of atmospheric concentrations of radionuclides on 15 March 2011 discharged by the Fukushima Dai-Ichi Nuclear Power Plant Accident estimated from NaI(Tl) pulse height distributions measured in Ibaraki Prefecture

ABSTRACT

A hybrid method for estimation of atmospheric concentrations of multiple radionuclides was developed and applied to NaI(Tl) pulse height records measured in Ibaraki Prefecture in the morning of 15 March 2011 when three radioactive plumes from the Fukushima Dai-Ichi Nuclear Power Plant Accident passed. The method is based on the simple principle for separation from deposited radionuclides’ contribution and the concentration estimation for multiple radionuclides. Difficulty in the concentration estimation due to complexity of surrounding terrains and geometry was overcome to obtain spatiotemporal variations in atmospheric concentrations of Xe-133, Te-132, I-131, I-132 and I-133 in the three plumes at 21 monitoring stations. The plume axis with higher I-131 concentration of 5.40 kBq m-3 than the previous estimations during the second plume was found in the northwestern inland area. A substantially lower Xe-133/I-131 concentration ratio of the first plume than those of the others was again recognized. The details of non-uniform spatial distribution of the radionuclide composition were found for each of the three plumes.     

Electrical resistivity, oxidation resistivity and hardness of single crystal compounds in the Er–Rh–B system

Single crystals of ternary borides ErRh₃B (cubic,Pm3m), ErRh₃B₂ (monoclinic, C2/m) and ErRh₄B₄ (tetragonal, P4₂/nmc) have been grown from copper solution by slow cooling method. The electrical resistivity, oxidation resistivity and Vickers microhardness were studied. The electrical resistivities at room temperature of the (100) face of ErRh₃B, (001) face of ErRh₃B₂ and (100) face of ErRh₄B₄ are 25.6 μΩ·cm, 50.0 μΩ·cm and 106.8 μΩ·cm, respectively. According to thermogravimetric and differential thermal analyses, the oxidation of ErRh₃B, ErRh₃B₂ and ErRh₄B₄ start at 1030°C, 373°C and 690°C, respectively. The weight gain of the same compounds after heating in air up to 1200°C is 0.7%, 15.44% and 5.4%, respectively. The values of the Vickers microhardness for the (100) face of ErRh₃B, the (100) face of ErRh₃B₂ and the (110) face of ErRh₄B₄ are 4.8–5.0 GPa, 10.4–10.9 GPa and 10.9–11.3 GPa, respectively. The effect of boron content and crystal structure of each compound on the electrical resistivity, oxidation resistivity and Vickers microhardness are discussed.