Relation of preference for location with scores on anxiety and on visibility in golf practice

Previous research has indicated that seating preference in classrooms is related to some personal characteristics. Similar relations are assumed to be found in sports settings. In this study, the associations of rated preference for playing location in group practice of golf with trait anxiety and preference for visibility were investigated. Subjects were 165 Japanese university students who participated in a series of golf lessons. One-factor analyses of variance showed that subjects' rated preference for playing location was significantly related to their scores on trait anxiety and their preference for visibility of location. These results suggest that, in sports practice as in classrooms, preference for location may be associated with measures of personality and visibility.

[Dual energy X-ray absorptiometry]

Dual energy X-ray absorptiometry (DXA) has been widely used in Japan. In this article, we described our lateral measurement of lumbar vertebral body, and reviewed the fracture threshold and the diagnosis of osteoporosis. The bone mineral density was measured in the anteroposterior projection (L2-4BMD) and in the lateral projection (L3 latBMD) by XR-26. The precisions (coefficient of variation) of lateral measurement in lateral decubitus position were 1.73% in BMC, 1.86% in BMD, and 0.82% in Area. The L31atBMD decreased at earlier age than L2-4BMD and showed a significant decrease between the 40s and the early 50s in healthy women as L2-4BMD. The lateral measurement of vertebral body was a very useful method to evaluate the early trabecular bone loss.

Protein ubiquitination in the posterior silk glands of Bombyx mori

Ubiquitin gene expression and the ubiquitination of proteins in the posterior silk glands (PSG) of B. mori were analyzed developmentally with respect to fibroin synthesis and degeneration. Two ubiquitin transcripts are expressed throughout larval stages, and the level of each transcript is regulated differently. The larger transcript, a polyubiquitin mRNA, was abundant during the molt stage, while levels of the smaller ubiquitin transcript increased immediately after molting. Only a single 65 kDa ubiquitinated protein was detected late in the 5th instar, and the amount increased up to spinning stage. This ubiquitinated protein may participate in the PSG degeneration.

Highly repetitive structure and its organization of the silk fibroin gene

We have sequenced a number of cDNAs representing the Bombyx mori silk fibroin heavy chain transcript. These reveal that the central region of the fibroin gene is composed of alternate arrays of the crystalline element a and the noncrystalline element b. The core region is partitioned by a homogeneous nonrepetitive amorphous domain of around 100 bp in length. The element a is characterized by repeats of a highly conserved 18-bp sequence coding for perfect repeats of the unit peptide Gly-Ala-Gly-Ala-Gly-Ser. The element b is composed of repeats of a less-conserved 30-bp sequence which codes for a peptide similar to that in element a except in that (1) Ser is replaced by Tyr and (2) there are irregular substitutions of Ala to Val or Tyr. Therefore, the structure of the fibroin gene core consists of three-step higher-order periodicities. Heterogeneities in numbers of repeats are observed in each step of periodicity. Boundary sequence appeared in each periodicity to be quite homogeneous. Sequence analysis indicates that the unit sequences of elements a and b have homology to those of recombination hotspots reported in other genes and a recombination event may frequently occur between the misaligned sister chromatids, resulting in heterogeneities in repeat numbers and duplication or deletion of repetitive sequences. The repetitive superstructure of the fibroin gene may have been a result of continuous unequal crossovers in a primordial gene during evolution. A couple of important features of the fibroin protein were proved by the present nucleotide sequencing.(ABSTRACT TRUNCATED AT 250 WORDS)

Novel structure of a Chinese hamster polyubiquitin gene

We isolated a polyubiquitin gene, CHUB2, from the V79 Chinese hamster genomic library, and determined its complete structure. Based on sequence homology to the human polyubiquitin gene UbC in the 5' and 3' untranslated region, the CHUB2 gene was characterized as the V79 Chinese hamster equivalent to the human UbC gene. However, the overall coding region structure of the CHUB2 gene was altered from the consensus structure of polyubiquitin genes, with the last ubiquitin coding unit being followed by 161 bp of partially deleted and mutated ubiquitin-like sequence. Although a similarly deleted and mutated polyubiquitin gene was recently reported in a partially sequenced cDNA of mouse (Finch et al. (1992) Cell Growth Differ. 3, 269-278), the present study describes the complete sequence of a polyubiquitin gene containing this unusual structure for the first time, and suggests that this structure is conserved in rodents. By employing both Southern and Northern analysis with a probe specific to the CHUB2 gene, it was found that a second, closely related gene is present in the Chinese hamster genome, and that both loci are transcriptionally active in V79 cells. The two genes, and their respective transcripts, differ in size because of variation in the relative number of repeating ubiquitin coding units.

[DNA fingerprint method of the cultured cells]

DNA fingerprint method is very available not only to examine the cross-contamination of cultured cell lines and their origins and but to know the somatic mutation frequency in the cultured cells by exposure of radiation and chemicals. The method for DNA fingerprint was grouped in the following four types in term of probe; multilocus minisatellite probe, simple sequence repeat probe, locus specific minisatellite probe and repeat unit sequence variation in minisatellites.

[Cell mediated calcification in three-dimensional collagen gel culture of the osteoblast-like cells derived from rat calvaria]

Osteoblast-like cells were obtained by sequential enzymatic digestion of 19-day fetal rat calvaria and cultured within native type 1 collagen gels in alpha-MEM supplemented with 10% fetal bovine serum and 10 mM beta-glycerophosphate for 3 weeks. Cells were also cultured as monolayers in the usual manner and used as controls. The collagen gel discs contracted by one tenth in diameter after 4 days. The cells in the collagen gels seemed to proliferate at a low rate and to differentiate immediately into round cells, spindle-like cells, and adipocytes. In the monolayer cultures, calcifications were recognized after 2 weeks only in the high-density confluent areas where cells were disposed in multiple layers and alkaline phosphatase activity was high. In the collagen gels, some cells showed high alkaline phosphatase activity after 1 day of culture and calcifications were observed after 1 week around the cells with intense alkaline phosphatase activity. In collagen gel cultures, the degree of alkaline phosphatase activity and of calcification correlated with the density of the cell suspension at the time of seeding. The round cells were thought to be osteoblasts since they showed high alkaline phosphatase activity and were closely related to initial calcifications. Some of the spindle-like cells also showed high alkaline phosphatase activity and were apparently involved in the calcification process in the latter phase of culture, so that some of them seemed to be resting osteoblasts or lining cells. In electron-microscopical studies, initial calcification was related to the so-called matrix vesicles, and hydroxyapatite crystals were detected in mitochondria. Gap junctions which are specific to osteocytes were observed mainly between the round cells, but also between the round cells and the other cells. This culture system in which cells form a three-dimensional network is suitable to investigate osteoblastic functions and cell mediated calcification in vitro.

The prognosis of idiopathic portal hypertension in Japan

To clarify the factors relating to the prognosis of patients with idiopathic portal hypertension (IPH), we followed 171 patients with IPH until the end of 1990, who were registered in the database among those with abnormal portal circulation as of 1985 in hospitals of Japan. During the follow-up period, twenty patients died; 6 from gastro-intestinal tract bleeding, 5 from hepatic insufficiency and 9 from other causes. Cox's proportional hazard model suggested that male patients (hazard ratio 4.85, 95% confidence interval 1.82-12.94), with a disease onset at less than 40 years of age (H.R.3.94, 95% C.I. 1.31-11.57), and/or with varices (H.R.2.86, 95% C.I. 1.05-7.77) generally had poorer prognoses.

Essential role of duplications of short motif sequences in the genomic evolution of Bombyx mori

The Bombyx fibroin gene has a discrete mosaic structure of various repetitive sequences, which may have evolved through various repeating arrangements. Detailed sequence analysis of the fibroin gene containing coding and noncoding regions revealed that the whole sequence could be arranged as an array of short repetitive sequences. A portion of the intron of the fibroin gene is one of interspersed repetitive elements. We cloned a 1.5-kb DNA fragment of the Bombyx genome that contains interspersed elements homologous to the intron sequence. Sequence comparison between the intron and the 1.5-kb fragment shows that partial duplication has frequently occurred in evolutionary progress, and the resultant repetitive blocks of short motif sequences are abundant in the genome. These facts suggest that tandem duplication of the short motif sequence is an important rearrangement in genomic evolution of the fibroin gene.

Evolutionarily conserved structure of the 3' non-translated region of a Chinese hamster polyubiquitin gene

From a V79 Chinese hamster genomic library, we isolated a clone containing a polyubiquitin gene (designated as CHUB1), and determined its nucleotide sequence. The coding region of the CHUB1 gene consisted of five direct repeats of the ubiquitin unit with no spacer, followed by a single tyrosine residue. Northern hybridization analysis with a synthesized probe specific to the 3' non-translated region of the CHUB1 gene revealed that it codes for a 1.8 kb mRNA. An evident homology to the human polyubiquitin gene UbB and the chicken UbI gene was observed in the region corresponding to the full extent of the mature mRNA sequence, suggesting that these three genes belong to a common polyubiquitin gene subfamily, and that the sequence in the 3' non-translated region of the CHUB1 gene is unique to this subfamily.

Essential factors determining codon usage in ubiquitin genes

Ubiquitin is ubiquitous in all eukaryotes and its amino acid sequence shows extreme conservation. Ubiquitin genes comprise direct repeats of the ubiquitin coding unit with no spacers. The nucleotide sequences coding for 13 ubiquitin genes from 11 species reported so far have been compiled and analyzed. The G + C content of codon third base reveals a positive linear correlation with the genome G + C content of the corresponding species. The slope strongly suggests that the overall G + C content of codons of polyubiquitin genes clearly reflects the genome G + C content by AT/GC substitutions at the codon third position. The G + C content of ubiquitin codon third base also shows a positive linear correlation with the overall G + C content of coding regions of compiled genes, indicating the codon choices among synonymous codons reflect the average codon usage pattern of corresponding species. On the other hand, the monoubiquitin gene, which is different from the polyubiquitin gene in gene organization, gene expression, and function of the encoding protein, shows a different codon usage pattern compared with that of the polyubiquitin gene. From comparisons of the levels of synonymous substitutions among ubiquitin repeats and the homology of the amino acid sequence of the tail of monomeric ubiquitin genes, we propose that the molecular evolution of ubiquitin genes occurred as follows: Plural primitive ubiquitin sequences were dispersed on genome in ancestral eukaryotes. Some of them situated in a particular environment fused with the tail sequence to produce monomeric ubiquitin genes that were maintained across species. After divergence of species, polyubiquitin genes were formed by duplication of the other primitive ubiquitin sequences on different chromosomes. Differences in the environments in which ubiquitin genes are embedded reflect the differences in codon choice and in gene expression pattern between poly- and monomeric ubiquitin genes.

Specific codon usage pattern and its implications on the secondary structure of silk fibroin mRNA

We have identified two distinctive regions of the repetitive unit nucleotide sequence of fibroin mRNA of Bombyx mori. The codon usage for the major amino acids, glycine, alanine and serine is distinctly different in these two regions, indicating that it is determined by the fibroin mRNA or gene structure but not by the tRNA population. Comparative computer analyses of nucleotide substitutions in the unit sequence suggest that selection has operated on the codon usage to optimize the secondary structure characteristic of the fibroin mRNA.

Interparticle interactions and structural changes of nucleosome core particles in low-salt solution

The structural behavior of the nucleosome core particles in the range of solvent Na+ concentration from 10.45 to 0.45 mM has been studied by small-angle neutron and synchroton radiation X-ray scattering, sedimentation, atomic absorption spectroscopy, density measurements, and circular dichroism. With decreasing salt concentration, the appearance of a scattering peak that is assignable to interparticle interactions, an intraparticle structural transition, a decrease in the sedimentation velocity of the particle, and a release of bound Na+ ions from the particle are all observed concurrently when the ratio of solvent Na+ ions per particle is below approximately 1000. These observations are interpreted to indicate that a release of bound Na+ ions from the particle brings about structural rearrangements and weakens the electrostatic shielding of the particle, and this introduces long-range repulsive ordering of the particle in low-salt solution. Analyses of the scattering data indicate that the rearrangement within the core particle in low-salt solution is slight, changing the particle's shape slightly from cylindrical to a more spherical form by moving the center of the mass of the DNA somewhat inward with accompanying small decreases in the radii of gyration of both the DNA and the histones.

Conformation of the HMG17-nucleosome complex

The nucleosome core binds more than two molecules of HMG17 at low ionic strength (8.9 mM Tris-HCl/8.9 mM boric acid/0.25 mM Na2EDTA, pH 8.3). Circular dichroism of the complexes showed only minor conformational changes of the nucleosome core DNA on binding of HMG17, with no detectable change in the histone secondary structure. The fluorescence of N-(3-pyrene) maleimide bound to -SH groups at Cys-110 of H3 histones in the core particle suggested that the structure of the histone octamer assembly changed little upon binding of HMG17 to the nucleosome. These observations support the idea that even a high level of HMG17 binding, e.g., four HMGs per nucleosome, alone, does not open up the core particle.