Involvement of protease inhibitors in staphylokinase-induced fibrin-specific fibrinolysis

We compared the fibrinolytic properties of recombinant staphylokinase (SAK), a fibrin-specific plasminogen activator, with those of streptokinase and tissue-type plasminogen activator (t-PA) by means of the amidolytic method. We also investigated the involvement of alpha 2-macroglobulin, C1-inactivator and alpha 1-antitrypsin in SAK-induced fibrin-specific fibrinolysis. Both SAK and t-PA activated plasminogen efficiently in the presence of fibrin in human plasma. Although t-PA activated plasminogen dependently on fibrin in the reconstituted plasma system, SAK activated plasminogen independently of fibrin without alpha 2-plasmin inhibitor (alpha 2-antiplasmin, alpha 2-PI). These findings suggest that fibrin and alpha 2-PI play important roles in plasminogen activation by SAK but not by t-PA. Furthermore, protease inhibitors such as alpha 2-PI, alpha 2-macroglobulin, C1-inactivator and alpha 1-antitrypsin inhibited plasminogen activation by SAK and the inhibitory actions of these protease inhibitors disappeared in the presence of fibrin. This shows that alpha 2-macroglobulin, C1-inactivator and alpha 1-antitrypsin, other than alpha 2-PI, contribute to the fibrin-specificity of SAK.     

(+)-Juniperol and (+)-pimaral: Attractants for the cerambycid beetle,Monochamus alternatus Hope

A sesquiterpene and a diterpene were isolated from sound pines and identified as (+)-juniperol and (+)-pimaral, respectively. The combination of these compounds in a certain ratio induced a significant laboratory flight response by the female cerambycid beetle,Monochamus alternatus Hope. Individual compounds elicited a limited response only.     

Oxidation resistance of silicon nitride ceramics with various additives

Five silicon nitride ceramics with various additives were evaluated for their oxidation resistance at 1300 ° C in flowing dry and wet air. In a dry atmosphere, the oxidation of all types of Si₃N₄ except one proceeded in two stages with different reaction rates nearly following the parabolic law. In a wet atmosphere, all types showed a linear relationship between weight gain by oxidation and water varpour content. The water vapour in the atmosphere slightly accelerated the oxidation. The influence of oxidation on room-temperature strength was complex, but there was no observed distinguishable difference of the effect on the flexural strength between dry and wet oxidation.     

8-channel×2.5 Gbit/s hybrid integrated multiwavelengthphotoreceiver module with arrayed-waveguide grating demultiplexer

A compact 8-channel hybrid integrated multiwavelength photoreceiver module has been fabricated. The module, which consists of an arrayed-waveguide grating demultiplexer with a 100 GHz spacing, a photodiode array using a planar lightwave circuit platform, and preamplifier integrated circuits, successfully operated at 2.5 Gbit/s with good receiver sensitivity better than -17.5 dBm at a bit error rate of 10^-9 for all channels     

Frequency stabilization of laser diode using a frequency-locked ring resonator to acetylene gas absorption lines

The frequency stabilization of a 1.5 mu m distributed-feedback (DFB) laser diode using a planar lightwave circuit (PLC) ring resonator whose resonant frequency is locked to /sup 12/C/sub 2/H/sub 2/ and /sup 13/C/sub 2/H/sub 2/ gas absorption lines is described. The resonant frequency of PLC ring resonator was stabilized within a 5 MHz peak-to-peak fluctuation. With this ring resonator the outer frequency fluctuation of the DFB laser diode was stabilized within 10 MHz at every resonant frequency at 5 GHz intervals. The stability demonstrated is as good as the method using molecular absorption lines as a reference. The stabilized frequency can be selected at any point on the optical resonant peaks of the optical resonator.<>     

Detection of platelets activated during acetylcholine-induced coronary vasospasm

Although platelet activation may play a role in coronary artery spasm, platelets activated following coronary vasospasm have not been clinically detected. We performed flow cytometric analysis of activation-dependent granular proteins, CD62P (P-selectin), CD63, PAC-1 (activated glycoprotein [GP] IIb/IIIa) and thrombospondin on the platelet plasma membrane in patients who exhibited acetylcholine-induced coronary vasospasm and compared findings with those in control patients without vasospasm. We simultaneously investigated the plasma levels of thrombin anti-thrombin III complex (TAT), plasmin alpha2-plasmin inhibitor complex (PIC), and thrombomodulin. In patients with vasospasm, the expression of CD62P, CD63 and PAC-1 on the platelet membrane surface increased in coronary sinus blood samples following coronary vasospasm, although the expression in aortic samples did not change. The TAT level also increased in the coronary sinus after vasospasm. Platelets might be activated by coronary vasospasm within the coronary circulation. The platelet activation process may be modulated by thrombin generation.     

Evidence for furin-type activity-mediated C-terminal processing of profibrillin-1 and interference in the processing by certain mutations

Fibrillin-1 is a major component of the 10 nm microfibrils of the extracellular matrix (ECM). It is synthesized as an approximately 350 kDa precursor molecule, profibrillin-1, which is proteolytically processed into its biologically active approximately 320 kDa form. Furin, a calcium-dependent endoprotease of the subtilisin family, which is known to be the processing enzyme for a variety of proproteins, is believed to be responsible for the N-terminal proteolytic cleavage of profibrillin-1. In this article we provide several lines of evidence that the C-terminal trimming of profibrillin-1 also occurs via a furin-type activity. Edman degradation of a small recombinant C-terminal subdomain of fibrillin-1 revealed complete processing of the peptide immediately after the tribasic recognition sequence (R-X-K/R-R) for furin. In vitro expression experiments using another recombinant construct consisting of the C-terminal half of fibrillin-1 indicated that disruption of the putative recognition sequence for furin by site-directed mutagenesis drastically impairs proteolytic processing of the propeptide. In addition, our results suggest that the N-terminal half of fibrillin-1 is necessary for its incorporation into the ECM.     

Small-frequency-difference stabilization of laser diodes using12C2H2 and 13C2H2 absorption lines for transmitter and local oscillator ofoptical heterodyne systems

Small-frequency-difference stabilization of distributed Bragg reflector (DBR) laser diodes has been demonstrated for the first time by using vibrational-rotational absorption of ¹²C₂H ₂ and ¹³C₂H₂ molecules. Frequency stabilization of two DBR laser diodes has been carried out at a wavelength of about 1.536 μm. The frequency difference between the two stabilized lasers was evaluated to be 9 GHz by the beat spectrum measurement. The experimental results suggest that such a pair of frequency-stabilized laser diodes with a small frequency difference could be used as the transmitter and local oscillator of optical heterodyne systems     

Application of the micro-PIXE technique for analyzing arsenic in biomat and lower plants of lichen and mosses around an arsenic mine site, at Gunma, Japan

Microhabitats of bacteria (biomat) and lower plants, such as lichen and mosses, are known to accumulate hazardous elements. Since the concentration of hazardous elements in the environment is quite low, we have applied the in-air μ-PIXE (particle induced X-ray emission) system developed in the TIARA facility of JAERI, which has low concentration detection limit of ppm, to measure As, one of the hazardous elements, distributions in biomat, lichen and mosses observed around an abandoned As mine site in Gunma, Japan to elucidate the applicability of these biomat and lower plants as bio-indicators of As. Spatial distributions of As, Fe, Si and S in all biomat, lichen and moss collected within 3 m from the mine entrance indicate that As is localized, and is associated with silicate and Fe-containing compounds. In addition, the intensity ratio of peak area for As to Fe in μ-PIXE spectrum of the moss collected from the concrete wall at 3 m downstream of the mine water discharge position is different from those of the lower plants on the rock near the closed entrance, but is the same as that of biomat formed at the mine water discharge position. This indicates that As trapped by the moss on the concrete wall probably has the same origin as the biomat. It is concluded that application of μ-PIXE analysis to the measurement of As in the lower plants and biomat gives not only the distribution of the hazardous element of As, but also the information of the origin.