Biomedical subjects

I Yuh

Publications and source records attributed to I Yuh.

6 recordsLinked to original sources

PubMed2000

Comparison of various biochemical measurements with bone mineral densitometry and quantitative ultrasound for the assessment of vertebral fracture.

We have retrospectively studied postmenopausal elderly Japanese women (n = 288; age range, 60-75 years, 65.8 +/- 4.5 [mean +/- SD]) for the evaluation of biochemical measurements in assessment of bone mass and vertebral fracture, comparing with several bone mineral measurements and quantitative ultrasound (QUS) measurement. Several biochemical parameters [red cell count (RBC), hemoglobin (HB), albumin (ALB), and cholesterol (CHO)] positively correlated with bone mass parameters, but only serum cholesterol showed association with the presence of vertebral fracture. Urinary deoxypyridinoline (DPYD) and n-telopeptide (NTx) showed moderate negative correlation with bone mass parameters, and DPYD showed association with vertebral fracture. All bone mineral measurements (lumbar spine, total body, femoral neck by DXA, calcaneal bone by SXA, distal radius by pQCT) and QUS measurement (os calcaneus by two different QUS machines) showed a higher odds ratio and high chi2 value in logistic regression analysis for association with vertebral fracture. Thus, bone mass measurement is the principal method for assessment of fracture risk, and biochemical measurement should be used for motivation of further bone mass measurement. In biochemical measurements, measurement of serum cholesterol is cheap and easy, and thus might have an advantage, although further study is necessary.

Absorptiometry, Photon↗

PubMed1999

Up-regulated uridine kinase gene identified by RLCS in the ventral horn after crush injury to rat sciatic nerves.

Rat sciatic nerve crush injury is one of the models commonly employed for studying the mechanisms of nerve regeneration. In this study, we analyzed the temporal change of gene expression after injury in this model, to elucidate the molecular mechanisms involved in nerve regeneration. First, a cDNA analysis method, Restriction Landmark cDNA Scanning (RLCS), was applied to cells in the ventral horn of the spinal cord during a 7-day period after the crush injury. A total of 1991 cDNA species were detected as spots on gels, and 37 of these were shown to change after the injury. Temporally changed patterns were classified into three categories: the continuously up-regulated type (10 species), the transiently up-regulated type (22 species), and the down-regulated type (5 species). These complex patterns of gene expression demonstrated after the injury suggest that precise regulation in molecular pathways is required for accomplishing nerve regeneration. Secondly, the rat homologue of uridine kinase gene was identified as one of the up-regulated genes. Northern blot analysis on rat ventral horn tissue and brain revealed that the UK gene had three transcripts with different sizes (4.3, 1. 4, and 1.35 kb, respectively). All of the transcripts, especially the 4.3 kb one, were up-regulated mainly in a bimodal fashion during the 28-day period after the injury. The RLCS method that we employed in the present study shows promise as a means to fully analyze molecular changes in nerve regeneration in detail.

Animals↗

PubMed1999

Comparison of bone mineral density at various skeletal sites with quantitative ultrasound parameters of the calcaneus for assessment of vertebral fractures.

This study investigated the role of quantitative ultrasound (QUS) for evaluation of fracture risk in comparison with bone mineral density (BMD) measurement. Our subjects were postmenopausal Japanese women (n = 260; age, 67 +/- 6.1 years) who were examined for bone densitometry, QUS, and spinal X-ray examination at our department between 1992 and 1996. The subjects were categorized into three groups by the number of atraumatic fractured vertebrae: NF, no vertebral fractures: F1, one vertebral fracture; F2, two or more vertebral fractures. We compared the measured parameters to determine their association with the number of fractured vertebrae. Differences among groups were compared and analyzed by Student's t-test. Odds ratios were also calculated after age adjustment, as well as age and lumbar or calcaneal parameters. Between NF and F1, lumbar BMD and BMD of the Ward's triangle showed more significant differences than other values, while between F1 and F2, whole-body BMD and QUS parameters showed more significant differences. Lumbar BMD also showed the highest age-adjusted odds ratio in differentiating F1 from NF. Although QUS parameters showed no power to differentiate between NF and F1, these values showed higher odds ratios than other measurements for discriminating between F1 and F2. Adjustment for bone density did not totally abolish the association between QUS parameters and vertebral fracture. Additionally, the combination of lumbar BMD and QUS ("stiffness") clearly showed a high power to discriminate NF from F1 + F2. In conclusion, we showed that QUS measurement is effective in evaluating fracture risk in advanced osteoporosis, while lumbar dual X-ray absorptiometry is effective in evaluating risk in early osteoporosis.

Aged↗

PubMed1996

Three-dimensional bone scintigraphy using volume-rendering technique and SPECT.

UNLABELLED: Three-dimensional bone scintigraphic images were made and their usefulness and limitations discussed. METHODS: After usual bone scan procedures, single-photon emission computed tomography (SPECT) data were taken and reconstructed into three-dimensional images. Volume rendering methods were used. RESULTS: Three cases of three-dimensional bone scintigraphy were obtained; one of a normal patient, one of a case of transplanted kidney and incomplete fracture of the left femoral head, and one of a case of degenerative joint disease (DJD) on the left temporomandibular joint (TMJ). The three-dimensional structure of the skeletal system was depicted more clearly by the three-dimensional images than by a conventional bone scan. CONCLUSION: Three-dimensional bone scintigraphs were thought to provide additional information for better understanding of the nature of bone lesions. Some technical improvements including automated threshold level determination and feature extraction for detecting abnormal high uptake are required before routine use can be envisaged.

Adult↗

PubMed1993

[Clinical evaluation of ultrasonic measurement of the calcaneal bone].

We measured the speed of sound (SOS) and broadband ultrasound attenuation (BUA) in the calcaneal bone and compared those values with bone mineral density (BMD) as assessed by single X-ray absorptiometry and dual energy X-ray absorptiometry. Calcaneal speed of sound and broad band ultrasound attenuation showed an earlier decrease with age than lumbar BMD, Calcaneal SOS and BUA correlated well with calcaneal BMD. Calcaneal SOS correlated more closely with neck BMD than lumbar BMD measured by DXA. Furthermore, measurement of calcaneal SOS is more useful than measurement of lumbar BMD to evaluate femoral neck BMD, which might be very important for clinical purposes. Both body weight and height correlated well with calcaneal BMD but not so well with calcaneal SOS or BUA. As ultrasound emits no radiation, we can use it without the restriction of radiation protection.

Absorptiometry, Photon↗

PubMed1992

[Determination of vertebral fracture threshold by measuring bone mineral content in the lumbar vertebrae].

Bone mineral density (BMD) in the lumbar vertebrae (L2-L4) was assessed by dual energy X-ray absorptiometry (DEXA: QDR-1000), and the values obtained were compared with the frequency of vertebral fracture as assessed by spinal X-ray photographs. Patients with spondylosis or scoliosis, which affect BMD values, were excluded from the study. An essentially linear correlation was observed between the frequency of vertebral fracture and lumbar BMD values: no vertebral fractures were observed in those whose BMD more than 0.8 g/cm2, whereas the frequency of fracture was 100% in patients whose BMD was less than 0.45 g/cm2. Thus, measurement of lumbar vertebrae by DEXA would be very useful in predicting vertebral fractures.

Absorptiometry, Photon↗