Genotype and phenotype of severe mitochondrial cardiomyopathy: a recipient of heart transplantation and the genetic control

Comprehensive analyses of mitochondrial (mt)DNA of a recipient of heart transplantation at age 7 because of severe cardiomyopathy revealed three germ line point mutations, each one in the 12S rRNA gene, in the CO1 gene and in the cytochrome b gene, respectively. As the somatic mutation, extensive fragmentation of mtDNA associated with 212 kinds of deletions was detected in contrast to 5 kinds in an age-matched negative control. A recipient's positive control having almost the same base-substitutions and mutations with the recipient except one in the CO1 gene also developed severe cardiomyopathy died at age 20. The close relation between phenotype and mtDNA genotype provides the basis of our understanding of cell death and premature ageing.     

Metastatic Voyage of Ovarian Cancer Cells in Ascites with the Assistance of Various Cellular Components

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy and has a unique metastatic route using ascites, known as the transcoelomic root. However, studies on ascites and contained cellular components have not yet been sufficiently clarified. In this review, we focus on the significance of accumulating ascites, contained EOC cells in the form of spheroids, and interaction with non-malignant host cells. To become resistant against anoikis, EOC cells form spheroids in ascites, where epithelial-to-mesenchymal transition stimulated by transforming growth factor-β can be a key pathway. As spheroids form, EOC cells are also gaining the ability to attach and invade the peritoneum to induce intraperitoneal metastasis, as well as resistance to conventional chemotherapy. Recently, accumulating evidence suggests that EOC spheroids in ascites are composed of not only cancer cells, but also non-malignant cells existing with higher abundance than EOC cells in ascites, including macrophages, mesothelial cells, and lymphocytes. Moreover, hetero-cellular spheroids are demonstrated to form more aggregated spheroids and have higher adhesion ability for the mesothelial layer. To improve the poor prognosis, we need to elucidate the mechanisms of spheroid formation and interactions with non-malignant cells in ascites that are a unique tumor microenvironment for EOC.     

Analysis of a coal-derived liquid using highpressure liquid chromatography and synchronous fluorescence spectrometry

Synchronous fluorescence spectra of model polycondensed aromatic hydrocarbon molecules were recorded and used to identify the number of condensed rings in the aromatic molecules. A coal-derived liquid from Yubarishinko coal was initially separated into fractions having different number of condensed aromatic rings, and each fraction was further divided into narrow fractions having different numbers of carbon atoms. These fractions were studied using synchronous fluorescence spectroscopy. Results indicate the potential usefulness of synchronous fluorescence spectroscopy as a method of analysis of complex mixtures as coal-derived liquids despite the limitation of the method that some molecules give only weak peaks. Several components in some fractions were identified by a combination of synchronous fluorescence spectra and conventional excitation and emission fluorescence spectra.     

The structure of the core polyol of the ether lipids fromSulfolobus acidocaldarius

The major ether-type lipid structures ofSulfolobus acidocaldarius (ATCC33909) were composed of caldarchaeol and calditoglycerocaldarchaeol. However, the characterization by nuclear magnetic resonance spectroscopy and mass spectrometry showed that the structure of calditol in calditoglycerocaldarchaeol is not nonitol, 2-(1′,2′,3′-trihydroxypropyl)1,2,3,4,5,6-hexahydroxyhexane, but 2-hydroxymethyl-1-(2,3-dihydroxypropoxy),2,3,4,5-cyclopentanetetraol with an ether linkage in the molecule. Such an intermolecular ether linkage was resistant, to BCl₃ treatment, but nonresistant to 57% HI degradation treatment conducted at 100°C for 60 h, producting 2-hydroxymethyl-1,2,3,4,5-cyclopentanepentaol from calditol as reaction product. Further, it was confirmed that the structure of calditol is essentially a derivative of glycerol, and hydrocarbon chains were conjugated to the glycerol-like site in the structure. The calditol with an ether linkage in the molecule suggested an important role regarding the properties of heat-resistance and acid-resistance observed inSulfolobales. Presented at the international workshop on “Molecular Biology and Biotechnology of Extremophiles and Archaebacteria,” Wako, Japan, August 1993.     

Inorganic Design of Protein Assemblies as Supramolecular Platforms

In the last decade, there has been great deal of progress in the study of self-assembly processes of protein assemblies as biotemplates to create and construct one-dimensional arrays of nanocrystalline metals and semiconductors. Successful attempts in fabricating the protein-based bioelectronics could serve as a promising alternative to synthetic template based nanomaterials. Another perspective of protein assemblies is its use in the field of tissue engineering either as scaffold for cell adhesion and proliferation or as a foreign (bio)nanofunctionality to communicate with the macromolecules present in the extracellular or intracellular milieu and participate in the precise control of vital cell functions. Three-dimensionally arranged protein monomers to form bionanotubes are promising in terms of innate biocompatibility, easy bio-conjugation to incorporate multiple functionalities and well-defined nano-scale lengths. Such unique chemical properties of protein assemblies are described in this review.     

A Thermo-Elastic Analysis of the Parallel Surface Thrust Washer

An optical interference method was used to display the distorted film shape in nominally parallel surface thrust washers. The bearings were made of aluminium to accentuate thermal expansion and were carefully lapped flat before use. Both the experimental results and an analysis of the coupled elasticity, Reynolds and energy equations confirm that these bearings operate by the formation of a slightly converging film over the leading 80 percent (or less) of the pad. Fair agreement was obtained between the analysis and previously developed multiple regression equations. Thrust washers for industrial use with random waviness are likely lo perform better than lapped bearings.     

A Study on the Effect of Air on the Dynamic Motion of a MEMS Device and Its Shape Optimization

The authors propose a new design concept for controlling the deflection of a micro-membrane with the aid of its thickness distribution for realizing a prescribed design in the MEMS. As an example, the authors treat a micro air pump that comprises a micro-membrane. The membrane is actuated by an electrostatic force. The membrane deflects and thus the deflection is influenced by the air pressure and the electrostatic field. This is a highly complicated system. To find out a proper thickness distribution, the authors use the genetic algorithm that is appropriate to reduce the searching space of solution.     

Probabilistic enhancement of approximate indexing in metric spaces

Some approximate indexing schemes have been recently proposed in metric spaces which sort the objects in the database according to pseudo-scores. It is known that (1) some of them provide a very good trade-off between response time and accuracy, and (2) probability-based pseudo-scores can provide an optimal trade-off in range queries if the probabilities are correctly estimated. Based on these facts, we propose a probabilistic enhancement scheme which can be applied to any pseudo-score based scheme. Our scheme computes probability-based pseudo-scores using pseudo-scores obtained from a pseudo-score based scheme. In order to estimate the probability-based pseudo-scores, we use the object-specific parameters in logistic regression and learn the parameters using MAP (Maximum a Posteriori) estimation and the empirical Bayes method. We also propose a technique which speeds up learning the parameters using pseudo-scores. We applied our scheme to the two state-of-the-art schemes: the standard pivot-based scheme and the permutation-based scheme, and evaluated them using various kinds of datasets from the Metric Space Library. The results showed that our scheme outperformed the conventional schemes, with regard to both the number of distance computations and the CPU time, in all the datasets.