Biomedical subjects

Yuki Yajima

Publications and source records attributed to Yuki Yajima.

6 recordsLinked to original sources

PubMed2006

Construct validity of the Frenchay Activities Index for community-dwelling elderly in Japan.

Many researchers have developed various measures to evaluate the functional status of community-dwelling elderly. The Frenchay Activities Index (FAI) was developed to measure instrumental activities of daily living in stroke populations. The FAI has undergone the most intensive evaluation, but its factor structure has not been examined in Japan. The primary purpose of this study was to investigate the construct validity of the FAI for non-stroke community-dwelling elderly in Japan. The study subjects were 1,323 randomly selected community older residents in Hojo city, Ehime prefecture, the southern part of Japan. In order to investigate the construct validation, we performed factor analyses, i.e., exploratory factor analysis and confirmatory factor analysis. Furthermore, we examined the influences of age and gender on the FAI constructs. In the results, the FAI had a two-factor structure consisting of domestic chores, including washing clothes and preparing meals, and work and leisure, including gardening, driving and outings. Younger age was significantly related to increased performance on both factors. In addition, relative to females, males had a lower performance on the domestic chores and a greater performance on the work and leisure. These results suggest that the FAI satisfies the construct validity in the Japanese community-dwelling elderly. The FAI and its two factors provide important and clinically valuable information for understanding the patterns of functional status in the Japanese community-dwelling elderly.

Activities of Daily Living↗

PubMed2005

Validity and utility of the Craig Hospital Inventory of Environmental Factors for Korean community-dwelling elderly with or without stroke.

The social environmental barriers are considered to be important because the "social participation" of people with impairments would be facilitated by the prevention and reduction of environmental barriers. The Craig Hospital Inventory of Environmental Factors (CHIEF) is one of the few scales to assess the environmental barriers. In this study, we developed the Korean version of CHIEF and evaluated its construct validity and utility in a sample of Korean community-dwelling elderly with or without stroke. We evaluated the construct validity of the CHIEF by testing the original five-factor structure using a confirmatory factor analysis in 400 elderly in Seoul, Korea. The utility of the CHIEF was then assessed by examining the relationships between individual characteristics, Barthel Index and perceived environmental barriers, measured by the CHIEF, using a structural equation modeling approach. The confirmatory factor analysis result demonstrated the validity of a second-order factor model of the CHIEF comprising the five factors as first-order factors. The perceived environmental barrier was a second-order factor when provided acceptable fit indices after two modifications. The structural equation modeling indicates that perceived environmental barriers are significantly related to activities of daily life but not age, gender, and the episode of stroke. The CHIEF is useful in measuring environmental factors for Korean older adults with or without stroke.

Aged↗

PubMed2005

[Factor structure of the SOC scale 13-item version in Japanese university students].

The purpose of the present study was to examine the construct validity of Antonovsky's (1987) sense of coherence scale (SOC) 13-item version, with a sample of Japanese university students. Subjects were 1,110 university students who completed a self-administered questionnaire including items on individual characteristics (age, sex), the Zung self-rating depression scale (SDS) and the SOC scale. Exploratory factor analysis of the SOC scale yielded an interpretable two-factor solution with "comprehensibility-manageability" and "meaningfulness". Confirmatory factor analysis demonstrated an a priori defined SOC second-order factor model composed of comprehensibility-manageability and meaningfulness factor to have an acceptable fit (chi-square=327.065, df=64, GFI=0.957, CFI=0.872, RMSEA= 0.061). Moreover, structural equation modeling showed that there are theoretically consistent relationships among individual SOC factors and depression. In particular, the meaningfulness factor proved better predictor of depression than the comprehensibility-manageability factor. These findings support the construct validity of the SOC scale and suggest that two SOC sub scores may provide clinically applicable information, rather than the total score.

Adult↗

PubMed2004

Structural characterization of the epitopes of the monoclonal antibodies 473HD, CS-56, and MO-225 specific for chondroitin sulfate D-type using the oligosaccharide library.

The variation in the sulfation profile of chondroitin sulfate (CS)/dermatan sulfate (DS) chains regulates central nervous system development in vertebrates. Notably, the disulfated disaccharide D-unit, GlcUA(2-O-sulfate)-GalNAc(6-O-sulfate), correlates with the promotion of neurite outgrowth through the DSD-1 epitope that is embedded in the CS moiety of the proteoglycan DSD-1-PG/phosphacan. Monoclonal antibody (mAb) 473HD inhibits the DSD-1-dependent neuritogenesis and also recognizes shark cartilage CS-D, which is characterized by the prominent D-unit and is also recognized by two other mAbs, CS-56 and MO-225. We investigate the oligosaccharide epitope structures of these CS-D-reactive mAbs by ELISA and oligosaccharide microarrays using lipid-derivatized CS oligosaccharides. CS-56 and MO-225 recognized the octa- and larger oligosaccharides, though the latter also bound one unique hexasaccharide D-A-D, where A denotes the disaccharide A-unit GlcUA-GalNAc(4-O-sulfate). The octasaccharides reactive with CS-56 and MO-225 shared a core A-D tetrasaccharide, whereas the neighboring structural elements located on the reducing and/or nonreducing sides of the A-D gave a differential preference additionally to the recognition sequence for each antibody. In contrast, 473HD reacted with multiple hexa- and larger oligosaccharides, which also contained A-D or D-A tetrasaccharide sequences. Consistent with the distinct specificity of 473HD as compared with CS-56 and MO-225, the 473HD epitope displayed a different expression pattern in peripheral mouse organs as revealed by immunohistology, extending the previously reported CNS-restricted expression. The epitope of 473HD, but not of CS-56 or MO-225, was eliminated from DSD-1-PG by digestion with chondroitinase B, suggesting the close association of L-iduronic acid with the 473HD epitope. Despite such supplemental information, the integral epitope remains to be isolated for identification and comprehensive analytical characterisation. Thus novel information on the sugar sequences containing the A-D tetrasaccharide core was obtained for the epitopes of these three useful mAbs.

Animals↗

PubMed2004

Development and construct validation of the Korean competence scale (KCS).

A comprehensive Korean competence scale (KCS) designed for Korean older adults, was developed and its construct validity evaluated. KCS assesses their higher levels of functional competence than activities of daily livings (ADL), necessary for independence in the home and community. The internal structure of the scale was tested using an exploratory and confirmatory factor analysis with two elderly Korean sample groups. As expected, the exploratory factor analysis result demonstrated a three-factor solution comprised of the following three domains: instrumental self-maintenance, intellectual activity, and social role. The confirmatory factor analysis results showed that an acceptable solution could be estimated for a second-order factor model comprised of these factors. These findings provide evidence for the construct validity of the instrument and have implications for future research on factorial invariance.

Activities of Daily Living↗

PubMed2003

Heterogeneity of the chondroitin sulfate portion of phosphacan/6B4 proteoglycan regulates its binding affinity for pleiotrophin/heparin binding growth-associated molecule.

PTP zeta is a receptor-type protein-tyrosine phosphatase that is synthesized as a chondroitin sulfate proteoglycan and uses pleiotrophin as a ligand. The chondroitin sulfate portion of this receptor is essential for high affinity binding to pleiotrophin. Here, we purified phosphacan, which corresponds to the extracellular domain of PTP zeta, from postnatal day 7 (P7) and P12 rat cerebral cortex (PG-P7 and PG-P12, respectively) and from P20 rat whole brain (PG-P20). The chondroitin sulfate of these preparations displayed immunologically and compositionally different structures. In particular, only PG-P20 reacted with the monoclonal antibody MO-225, which recognizes chondroitin sulfate containing the GlcA(2S)beta 1-3GalNAc(6S) disaccharide unit (D unit). Analysis of the chondroitinase digestion products revealed that GlcA beta 1-3GalNAc(4S) disaccharide unit (A unit) was the major component in these preparations and that PG-P20 contained 1.3% D unit, which was not detected in PG-P7 and PG-P12. Interaction analysis using a surface plasmon resonance biosensor indicated that PG-P20 had approximately 5-fold stronger affinity for pleiotrophin (dissociation constant (KD) = 0.14 nM) than PG-P7 and PG-P12, although all these preparations showed similar low affinity binding to pleiotrophin after chondroitinase ABC digestion (KD = 1.4 approximately 1.6 nM). We also found that shark cartilage chondroitin sulfate D containing approximately 20% D unit bound to pleiotrophin with moderate affinity (KD = 2.7 nM), whereas whale cartilage chondroitin sulfate A showed no binding to this growth factor. These results suggest that variation of chondroitin sulfate plays important roles in the regulation of signal transduction in the brain.

Aging↗