Questionnaire of cryopreserved allograft valves in Kyushu and Yamaguchi area

Japanese Society of Cryopreserved Thoracic Tissue Implantation was recently set up. Cryopreserved allograft valves are about to pervade in Japan. To clarify the interest, demands and supply of cryopreserved allograft valve in the area of Kyushu and Yamaguchi, we performed questionnaire investigation regarding this issue. Collection rate of this questionnaire was 87.5% (35/40 hospitals). Ninety-seven percent of the hospitals answered that they were interested in cryopreserved allograft. Ninety-four percent of the hospitals answered that they did not ethically hesitate to use cryopreserved allograft. Ninety-one percent of the hospitals hoped to perform cardiac surgery using allograft aortic valve if allograft is available. With respect to securing donors of allograft, two-third of the hospitals did not decide whether they could be involved in obtaining donors of allograft. As the number of the cadaver kidney donors is about 20 per year in the area of Kyushu and Yamaguchi, shortage of donors of allograft valve is anticipated.     

Structure and expression of the human SM22alpha gene, assignment of the gene to chromosome 11, and repression of the promoter activity by cytosine DNA methylation

The pore-forming alpha 1 subunit of L-type calcium (Ca2+) channels is the molecular target of Ca2+ channel blockers such as phenylalkylamines (PAAs). Association and dissociation rates of (-)devapamil were compared for a highly PAA-sensitive L-type Ca2+ channel chimera (Lh) and various class A Ca2+ channel mutants. These mutants carry the high-affinity determinants of the PAA receptor site in a class A sequence environment. Apparent drug association and dissociation rate constants were significantly affected by the sequence environment (class A or L-type) of the PAA receptor site. Single point mutations affecting the high-affinity determinants in segments IVS6 of the PAA receptor site, introduced into a class A environment, reduced the apparent drug association rates. Mutation I1811M in transmembrane segment IVS6 (mutant AL25/-I) had the highest impact and decreased the apparent association rate for (-)devapamil by approximately 30-fold, suggesting that this pore-lining isoleucine in transmembrane segment IVS6 plays a key role in the formation of the PAA receptor site. In contrast, apparent drug dissociation rates of Ca2+ channels in the resting state were almost unaffected by point mutations of the PAA receptor site.     

Performance of a-WO3/LiClO4-PC electrochromic displays

This paper deals with the improvements in response time and reliability of the aWO₃/LiClO₄-PC (propylene carbonate) electrochromic display. Response time was improved by adopting the highly porous a-WO₃ film, the porous reflector and the high surface area non-polarizable counter-electrode. Results from the reliability tests indicated that the ECD had a sufficient lifetime for practical applications such as in watches, clocks and calculators. The mechanism of performance drift upon cycling the display is investigated using ESCA, AES and atomic absorption methods.     

Prognostic predictor with multiple fuzzy neural models using expression profiles from DNA microarray for metastases of breast cancer

Gene expression profiling data from DNA microarray were analyzed using the fuzzy neural network (FNN) modeling method for predicting the distant metastases of breast cancer. The best model consisting of five genes was able to predict metastases of breast cancer with 94% accuracy. Furthermore, 100% accuracy was achieved by majoritarian decision using only 25 genes from five noninferior models which were constructed independently. From the constructed model, gene expression rules, which may cause distant metastases, were explicitly extracted and 60% of the metastases cases could be explained by this rule. The FNN modeling method described in this paper enables precise extraction of significant biological markers affecting prognosis without prior knowledge.     

Fluorogenic derivatization reagents suitable for isolation and identification of cysteine-containing proteins utilizing high-performance liquid chromatography-tandem mass spectrometry

The fluorogenic derivatization reagents with a positive charge, 4-(dimethylaminoethylaminosulfonyl)-7-chloro-2,1,3-benzoxadiazole (DAABD-Cl) and 7-chloro-2,1,3-benzoxadiazole-4-sulfonylaminoethyltrimethylammonium chloride (TAABD-Cl), are proposed for use in proteomics studies. Following derivatization of protein mixtures with these reagents, a series of standard processes of isolation, digestion, and identification of the proteins were performed utilizing high-performance liquid chromatography-fluorescence detection and tandem mass spectrometry with the probability-based protein identification algorithm. Both DAABD and TAABD derivatives were detected fluorometrically at the femtomole level and showed more than 100-fold improvement in sensitivity compared to the underivatized original compounds with an electrospray ionization ion trap mass spectrometer analysis. The modification of the MASCOT database search system memorized with the fragment information of a DAABD-attached Cys residue allowed the identification of the proteolytic peptide fragments of the derivatized bovine serum albumin (BSA) with an estimated 38% sequence coverage of BSA. Utilizing DAABD-Cl as a derivatization reagent, identification of several proteins was also possible in a soluble extract of Caenorhabditis elegans (10 microg of protein). Consequently, for identification of proteins in the complex matrixes of proteins, DAABD-Cl could be a more appropriate reagent than ammonium 7-fluoro-2,1,3-benzoxadiazole-4-sulfonate as reported previously.     

A new artificial life body: biologically inspired dynamic bipedal humanoid robots

Recently, a biologically inspired, bipedal, dynamic, humanoid robot was developed at the Artificial Life and Robotics Laboratory of Oita University. This bipedal humanoid robot is able to walk dynamically and to go up and down stairs. The central pattern generator developed produces various types of walking pattern. This robot has a pair of small CMOS color CCD cameras, a speaker, and a microphone in the head part, and will have a GPS, a portable telephone, and other sensors in the body part, so that the integration of locomotion and behavior to achieve specific demonstrations will be realized. This project develops dynamic mobility and the ability for autonomous recognition and navigation using the biological central nervous system, the brain system, and the real-time control system. Also, the design principles that demonstrate the dynamic interaction between neural and mechanical controls will be clarified. In Phase I, the platform of a small, bipedal, humanoid robot is used to develop autonomous locomotion and autonomous sensing and navigation. In Phase II of the project, an iteration on the platform design for human-size, bipedal, humanoid robots will be performed for operational testing. The development of bipedal humanoid robots that capture biological systems with unique principles and practices could dramatically increase their performance in tasks for national security needs.This work was presented in part at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January 24–26, 2003     

MgATP-induced conformational changes in a single myosin molecule observed by atomic force microscopy: periodicity of substructures in myosin rods

This paper discusses the conformational changes in a single myosin molecule directly observed using atomic force microscopy (AFM). The myosin molecules were pretreated in rigor solutions without MgATP or in relaxed solutions with various concentrations of MgATP. The images of these molecules were obtained using a tapping mode AFM. The results indicate that the orientation of the myosin's heads and tail strongly depend on the MgATP concentration. Without using MgATP, almost all of the myosin molecules are in the extended form; however, when MgATP is used, the molecules bend according to the level of MgATP concentration. The mean-square end-to-end distance of the myosin molecules is significantly shorter with p[MgATP] = 4 than with p[MgATP] = 6. The rod region did not show the same level of intensity along their length in the extended form. The rods exhibited clusters of discontinuity, which were identified as substructures. The size of these substructures change at intervals that are multiples of 14.3-14.5 nm, which reflects the periodicity of the alpha-helical coiled coils. The substructure clusters also correspond to the myosin crossbridge spacing in muscles (14.3 or 43 nm). These results suggest that the myosin's head bends in conjunction with the bending or tilting in the helical substructures. Conformational changes of the myosin molecule induced by MgATP seem to mimic the molecular motions in a muscle's force generation process.     

Structural change of water with solutes and temperature up to 100 degrees C in aqueous solutions as revealed by attenuated total reflectance infrared spectroscopy

The attenuated total reflectance infrared (ATR-IR) spectra of several aqueous solutions have been measured by using a newly developed heatable rod-type ATR cell. The OH stretching bands showed systematic change with increasing solute concentrations and these changes can be explained by four different OH components based on curve-fitting results. NaCl solutions show longer H-bond distance character, while carbonate solutions present shorter ones. The Na2CO3 1 M solution conserves this shorter H-bond nature up to 100 degrees C. On the other hand, the loose nature of NaCl solutions becomes less pronounced at higher temperatures because of the dissociation of pure water clusters. These in situ observations of water structures are generally in agreement with the expected nature of fluids within the earth.