Biomedical subjects

Yuichi Wada

Publications and source records attributed to Yuichi Wada.

At least 19 recordsLinked to original sources

PubMed2006

Changes in vertebral wedging rate between supine and standing position and its association with back pain: a prospective study in patients with osteoporotic vertebral compression fractures.

STUDY DESIGN: Prospective consecutive series. OBJECTIVE: To analyze supine and standing radiographs and the association of back pain using subjective pain criteria. SUMMARY OF BACKGROUND DATA: It has been considered that there is little correlation between the degree of collapse of the vertebral body and the level of pain. In previous studies, however, measurements have only been based on supine radiographs. Although there were 2 authors who reported the results of supine lateral and standing lateral radiographs in patients with thoracolumbar vertebral fractures, as far as we know, there has not been any detailed report concerning the correlation between radiologic findings using supine and standing lateral radiographs and back pain. METHODS: We examined 100 consecutively treated patients, prospectively. Back pain and the supine and standing radiographs were assessed 1 month after injury. Changes in vertebral wedging rate (WR) from supine to standing position (Delta WR) was reported by the following equation: Delta WR = WR(standing)-WR(supine). RESULTS: The median age of the cohort was 75 years (range, 60-89 years). The median VAS of back pain at supine position, at standing position, and when standing erect was 13, 33, and 41, respectively. The median wedging rate on the supine and standing radiographs were 28% and 37%, respectively (P < 0.001). There was a significant correlation between Delta WR and back pain when standing erect (r = 0.79, P < 0.001). CONCLUSION: Changes in vertebral wedging rate between supine and standing position and its association with back pain may give a clue to the pathogenesis of pain from osteoporotic thoracolumbar vertebral compression fractures.

Aged↗

PubMed2006

Long term results of anterior cruciate ligament reconstruction with iliotibial tract: 6-, 13-, and 24-year longitudinal follow-up.

Many studies have reported successful outcomes less than 10 years after anterior cruciate ligament (ACL) reconstruction. However, longer-term outcomes have not been analyzed. We assessd outcomes 24 years after anterior cruciate ligament reconstruction with iliotibial tract and compared them with shorter-term results in the same patients. Between 1979 and 1981, 45 patients underwent combined intra- and extra-articular ACL reconstruction with iliotibial tract. Follow-up evaluations of these patients were performed at 6, 13, and 24 years after surgery, which included manual and instrumental laxity testing, functional assessments, and radiography. Twenty-six (60%) patients of the original ACL reconstruction cohort participated in all three follow-up assessments. Three patients had undergone meniscectomy prior to ACL reconstruction and 18 underwent meniscectomy together with ACL reconstruction. Eleven patients underwent subsequent meniscectomy. The mean Lysholm score was 96.2, 93.8, and 87.8 at 6-, 13-, and 24-year follow-up, respectively. A significant decrease in mean Lysholm score was found between 13- and 24-year follow-up. The mean KT-1000 side-to-side difference was 3.5 mm at 24-year follow-up. Overall knee laxity did not change significantly during the follow-up period. At 24-year follow-up, 17 (71%) patients had moderate or severe degenerative changes on radiographs although about 50% of the patients participated in regular sports activities and no patient required regular clinical intervention.

Adolescent↗

PubMed2006

Extracorporeal shockwaves induce the expression of ATF3 and GAP-43 in rat dorsal root ganglion neurons.

Although extracorporeal shockwave has been applied in the treatment of various diseases, the biological basis for its analgesic effect remains unclear. Therefore, we investigated the dorsal root ganglion neurons of rats following shockwave exposure to the footpad to elucidate its effect on the peripheral nervous system. We used activating transcription factor 3 (ATF3) and growth-associated phosphoprotein (GAP-43) as markers for nerve injury and axonal regeneration, respectively. The average number of neurons immunoreactive for ATF3 increased significantly in the treated rats at all experimental time points, with 78.3% of those neurons also exhibiting immunoreactivity for GAP-43. Shockwave exposure induced injury of the sensory nerve fibers within the exposed area. This phenomenon may be linked to the desensitization of the exposure area, not the cause of pain, considering clinical research with a particular absence of painful adverse effect. Subsequent active axonal regeneration may account for the reinnervation of exposed area and the amelioration of the desensitization.

Activating Transcription Factor 3↗

PubMed2006

Delayed gadolinium-enhanced MR to determine glycosaminoglycan concentration in reparative cartilage after autologous chondrocyte implantation: preliminary results.

PURPOSE: To prospectively evaluate delayed gadolinium-enhanced magnetic resonance (MR) imaging of cartilage for assessment of glycosaminoglycan (GAG) concentration in reparative cartilage after autologous chondrocyte implantation (ACI). MATERIALS AND METHODS: The study was approved by the ethics review committee of the National Institute of Radiological Sciences, and informed consent was obtained from all patients. The study group comprised nine knees of nine patients (six male, three female; mean age at ACI, 21.2 years +/- 7.5 [standard deviation]; age range, 13-35 years) who had undergone ACI and second-look arthroscopy with biopsy. MR imaging was performed at 1.5 T before and after intravenous injection of anionic gadopentetate dimeglumine. The precontrast R1 (R1(pre)), postcontrast R1 (R1(post)), and difference between R1(pre) and R1(post) (DeltaR1) were measured in reparative cartilage and normal cartilage. GAG concentrations in cartilage biopsy specimens were measured by using high-performance liquid chromatography. To evaluate delayed gadolinium-enhanced MR imaging of cartilage for assessment of GAG concentration, the authors defined the relative R1(pre), relative R1(post), and relative DeltaR1 (ie, R1(pre), R1(post), or DeltaR1, respectively, in reparative cartilage divided by that in normal cartilage) and the relative GAG concentration (ie, GAG concentration in reparative cartilage divided by that in normal cartilage). They then examined the relationships between relative R1(pre), relative R1(post), relative DeltaR1, and relative GAG by using correlation analysis. RESULTS: A significant correlation between relative DeltaR1 and relative GAG concentration (r = 0.818, P < .05) was observed. However, no significant correlation between relative R1(pre) and relative GAG concentration (r = 0.010, P = .983) or between relative R1(post) and relative GAG concentration (r = 0.660, P = .106) was observed. CONCLUSION: Study results indicate that pre- and postcontrast imaging is necessary for delayed gadolinium-enhanced MR imaging evaluation of reparative cartilage after ACI.

Adolescent↗

PubMed2006

Second application of low-energy shock waves has a cumulative effect on free nerve endings.

Some physicians recommend treating tendinopathies with multiple sessions of shock waves. Some evidence, however, suggests shock wave application can induce nerve fiber degeneration. We questioned whether repeated shock wave application provides a cumulative effect on nerve fibers compared with the effect of one application. One thousand shock wave impulses of an energy flux density of 0.08 mJ/mm were applied to the foot pad of 32 rats. After 14 days, 16 rats received a second application. The foot pads were resected on Days 7, 14, 28, and 42. Sections were processed immunohistochemically using antibodies for sensory nerve. We compared the number of epidermal nerve fibers in rats that received one application of shock waves with the fibers in rats that received two applications. During the first 4 weeks, there was nearly complete degeneration of epidermal nerve fibers in both groups. By the end of 6 weeks, reinnervation of the epidermis began in the single-treatment group. Reinnervation occurred slower in the repeated-treatment group. These data show that a second application has a cumulative effect on nerve fibers. Our data suggest multiple applications of low-energy shock waves might a provide longer-lasting antinociceptive effect.

Animals↗

PubMed2006

[Magnetic resonance imaging of repair cartilage].

In recent years, several MR imaging techniques that enable detailed morphological and qualitative evaluations of repair cartilage have been developed. We perform fat-suppressed three-dimensional spoiled gradient-recalled (3D-SPGR) magnetic resonance (MR) imaging and delayed gadolinium-enhanced MR imaging of cartilage (dGEMRIC) for the evaluation of repair cartilage. Evaluation of the time course changes in signal intensity of repair cartilage by use of 3D-SPGR MR imaging was thought to be useful for the assessment of histological change in repair cartilage. Moreover, evaluation of the glycosaminoglycan concentration in repair cartilage by use of dGEMRIC was thought to be useful to assess the quality and function of repair cartilage. These new MR imaging techniques may be useful for evaluating repair cartilage and for assessing the treatment effect and the long-term durability of repair cartilage.

Cartilage, Articular↗

PubMed2005

Identification of Pip4k2beta as a mechanical stimulus responsive gene and its expression during musculoskeletal tissue healing.

To investigate the mechano-transduction system of cells, we identified genes responsive to a cyclic mechanical stimulus. MC3T3.E1 cells were cultured on a computer-controlled vacuum-pump-operated device designed to provide a cyclic mechanical stimulus. A maximum elongation of 15% of membrane at 10 cycles/min (3 s extension followed by 3 s relax per cycle) was repeated for 48 h. By means of a differential display, the gene expression pattern of cells exposed to the stimulus was compared with that of unexposed cells. As a result, a gene fragment that was exclusively expressed in mechanically stressed cells was identified. By using expressed sequence tag walking together with the oligo-capping method, this gene was identified as phosphatidylinositol 4-phosphate 5-kinase type II beta (initially known as Pip5k2beta but now reclassified as Pip4k2beta). The specific up-regulation of Pip4k2beta upon mechanical stimulus was also confirmed by using another apparatus, viz. a computer-controlled linearized-stepping motor system. To examine the involvement of the cyclic mechanical stimulus in the regulation of Pip4k2beta expression in musculoskeletal tissue, we created an Achilles tendon transection model in rabbits. The temporal expression of Pip4k2beta was assessed by means of a quantitative reverse-transcribed polymerase chain reaction. In the gastrocnemius muscle, expression of Pip4k2beta rapidly decreased 1 week after transection but was restored to normal levels at 4 weeks. In the Achilles tendon, however, expression remained decreased until 4 weeks after transection. We suggest that the expression of Pip4k2beta can be used as a marker for cells receiving a suitable mechanical stimulus.

3T3 Cells↗

PubMed2005

Acetabular augmentation induced by extracorporeal shock waves in rabbits.

We conducted this animal study to demonstrate whether exposing the acetabulum in immature rabbits to extracorporeal shock waves induces bone formation in the acetabulum. Five thousand shock waves of 100 MPa each were directed, from outside, at the acetabular roof of eight immature rabbits. At each of two time points (4 and 8 weeks) after treatment, the pelvises of four rabbits were removed and evaluated morphologically. Woven bone formation was observed on the lateral margin of the acetabular roof at 4 weeks after treatment, and the breadth of the acetabular roof in the coronal plane was significantly increased. Eight weeks after treatment, the woven bone disappeared; the breadth of the acetabular roof, however, was significantly increased. These findings demonstrated that extracorporeal shock waves induced acetabular augmentation in rabbits. We conclude that extracorporeal shock waves, perhaps, could be applied clinically for the treatment of acetabular dysplasia.

Acetabulum↗

PubMed2005

Time course evaluation of reparative cartilage with MR imaging after autologous chondrocyte implantation.

The aim of this study was to evaluate the qualitative change in reparative cartilage after autologous chondrocyte implantation (ACI). Ten knees of 10 patients were studied. The signal intensities of reparative and normal cartilage were evaluated by fat-suppressed three-dimensional spoiled-gradient recalled (FS 3D-SPGR) MR imaging. The signal intensity (SI) index (signal intensity of reparative cartilage divided by that of normal cartilage) was defined and the change in SI index was investigated. Histological and biochemical evaluation was done at the second look arthroscopy. The SI index was at its lowest level immediately after ACI and increased with time to 9 months thereafter. After 9-12 months, the SI index settled to almost level and was maintained at that value for at least 2-3 years postoperatively. The average of the SI indexes after 12 months to the last examination was 74.2 +/- 4.6 (range 64.2-82.8), which means signal intensity of reparative cartilage was maintained at a value lower than that of normal cartilage. The total ICRS score was 11.6 +/- 2.3 points (mean +/- SD). The GAG concentration was 107.9 +/- 17.0 microg/mg (mean +/- SD) in normal cartilage and 65.9 +/- 9.4 microg/mg in reparative cartilage. The quality of reparative cartilage as hyaline cartilage was inferior to that of normal cartilage. In the present study, the time course change in the SI index indicates that the major maturation process of implanted chondrocytes neared completion in 9-12 months. Minor changes, such as matrix remodeling with reorganization of the collagen fibers in reparative cartilage, may continue, but an almost identical condition seemed to be maintained during the first 2-3 years of follow-up. SI index does not always reflect all properties of reparative cartilage but may be a useful parameter for noninvasive evaluation.

Adolescent↗

PubMed2004

Arthroscopic posteromedial release for osteoarthritic knees with flexion contracture.

PURPOSE: To evaluate the clinical outcomes of a new arthroscopic procedure, arthroscopic posteromedial release (PMR), and its potential use as a treatment option for medial-type osteoarthritic (OA) knees. TYPE OF STUDY: Retrospective analysis of clinical outcomes of a case series. METHODS: Knees with medial-type OA and flexion contracture were treated with PMR. They were classified using the Kellgren and Lawrence (K/L) radiographic grading system and classified using magnetic resonance imaging (MRI) into smooth (S) or irregular (IR) groups, based on the subchondral contour of the medial femoral condyle. Clinical outcome was evaluated using the Japanese Orthopaedic Association knee score (JOA score), verbal rating scale (VRS), and patient satisfaction. RESULTS: Fifty-two patients with 58 OA knees were included in the study. The mean age of the patients at the time of surgery was 71.6 years, the average ROM was from 13 degrees to 129 degrees , and the average follow-up period was 3.3 years. Most of the knees were classified as K/L grade III or IV. Overall, the average JOA score improved to 71.6 points from 56.3 points preoperatively. VRS scores decreased in most patients, and 76% of patients were satisfied at their last follow-up. The JOA score of the K/L grade III knees improved to 76.9 from 60.4 points preoperatively and that of the K/L grade IV knees improved to 69.5 from 55.3 points. The improvement in JOA score was less for the IR group, from 54.5 to 66.2 points, than for the S group, from 62.3 to 79.6 points. Five knees from the IR group and 1 from the S group were converted to total knee arthroplasty. CONCLUSIONS: Knees with relatively advanced OA, for which arthroscopic debridement has conventionally been contraindicated, can be treated with PMR if they are selected properly based on MRI findings. LEVEL OF EVIDENCE: Level IV, case series.

Aged↗

PubMed2004

The effects of intraarticularly injected sodium hyaluronate on levels of intact aggrecan and nitric oxide in the joint fluid of patients with knee osteoarthritis.

OBJECTIVE: Intraarticular injections of sodium hyaluronate (Na-HA) appear effective in reducing subjective symptoms of osteoarthritis (OA) and may also have protective effects on the cartilage matrix. The present study analyzed the suppressive effects of Na-HA on the release and degradation of aggrecan and on levels of nitric oxide (NO) in the joint fluid of patients with knee OA. DESIGN: Sixteen OA patients with knee joint effusion were treated by 5 weekly intraarticular injections of Na-HA. Prior to each Na-HA injection, joint fluid was collected to determine the levels of chondroitin 4-sulfate (C4S) and chondroitin 6-sulfate (C6S), intact aggrecan and NO. RESULTS: One week after the final injection, the joint fluid levels of C4S, C6S, and NO were significantly decreased. In contrast, the joint fluid level of intact aggrecan was stable during the series of Na-HA injections. A trend was seen for a positive correlation (P < 0.1) between the clinical score and C4S or C6S joint fluid levels, and for a negative correlation between the joint fluid levels of intact aggrecan and C4S or C6S. No significant correlations were observed between joint fluid levels of NO, the clinical score, and levels of C4S, C6S, and intact aggrecan. CONCLUSION: The results of this study suggest that intraarticularly injected Na-HA is able to improve the clinical symptoms of OA partially based on its ability to reduce the release and degradation of aggrecan and/or to enhance the synthesis of aggrecan in the joint tissues of the patients with knee OA. While Na-HA also reduces the NO level in the joint fluid of patients with knee OA, this effect may be independent from the other effects of Na-HA.

Adjuvants, Immunologic↗

PubMed2004

Effects of extracorporeal shock waves on immature rabbit femurs.

We hypothesized that extracorporeal shock waves induce overgrowth and local increases in bone mineral content (BMC) in immature long bones. Immature male rabbits (n=14; 9 weeks old) were randomized equally between group I, which received 1000 100 MPa shock waves on the femoral shaft and group II, which received 5000. Unexposed femurs were used as controls. No fractures occurred in group I; three occurred in group II. Six weeks after exposure, the length and width were significantly larger (1.0 and 14.9%, respectively), and the BMC was significantly higher (22.8%) than those of control femurs in group I. These results of differences in width and BMC might be clinically useful.

Animals↗

PubMed2004

Cervical cytologic examination during physical checkup of pregnant women: cervical cancer screening in women under the age of thirty.

Recently, the Ministry of Health, Labor and Welfare proposed that cervical cancer screening should be conducted for women aged 20 to 29 years old in Japan. However, there are insufficient data available in Japan concerning the screening conducted for women under the age of 30. Therefore, we made a survey of the results of cervical cytologic examination for pregnant women. 28,616 pregnant women were examined as subjects of a study group. A group of 108,289 women, subjected to group screening for cervical cancer in Miyagi Prefecture, were studied as a control group. The rate of subjects who required close examination in the pregnant women's group was significantly higher than that in the mass screening group (1.12% vs. 0.84%). The rate of close examination was significantly higher in the women 19 years old or younger compared to those in the age group of 25 to 39 years old. The rate was also significantly higher in women aged 20 to 24 years old than those who are 25 to 34 years old. Of the 321 subjects who required close examination, 34 cases underwent treatment, and 17 cases were under age 30. Moreover, all three cases of microinvasive and/or invasive carcinoma were under the age of 30 years (23, 23, 27 years old, respectively). Our results suggest that screening for cervical cancer in pregnancy is a useful means to find cervical neoplasia in young women and is effective in reducing the cervical cancer morbidity rate.

Adult↗

PubMed2003

Application of shock waves to rat skin decreases calcitonin gene-related peptide immunoreactivity in dorsal root ganglion neurons.

There have been several reports on the use of extracorporeal shock waves in the treatment of pseudarthrosis, calcifying tendinitis, and tendinopathies of the elbow. However, the pathomechanism of pain relief has not been clarified. To investigate the analgesic properties of shock wave application, we analyzed changes in calcitonin gene-related peptide (CGRP)-immunoreactive (ir) dorsal root ganglion (DRG) neurons. In the nontreated group, fluorogold-labeled dorsal root ganglion neurons innervating the most middle foot pad of hind paw were distributed in the L4 and L5 dorsal root ganglia. Of these neurons, 61% were CGRP-ir. However, in the shock wave-treated group, the percentage of FG-labeled CGRP-ir DRG neurons decreased to 18%. These data show that relief of clinical pain after shock wave application may result from reduced CGRP expression in DRG neurons.

Animals↗

PubMed2003

Evaluation of articular cartilage with 3D-SPGR MRI after autologous chondrocyte implantation.

To assess the maturation process of the cartilage after autologous chondrocyte implantation (ACI), we performed a longitudinal study with three-dimensional spoiled gradient-recalled (3D-SPGR) magnetic resonance imaging (MRI). Five knees of five patients on which ACI of the femoral condyle was performed were studied. The signal intensity of reparative tissue approached that of normal articular cartilage with time. The volume of reparative tissue remained at an almost constant level after implantation. During second-look arthroscopy, the areas on which ACI was performed were covered with hyaline-like cartilage, and the reparative tissue removed by biopsy consisted of normal chondrocytes and extracellular matrix. The increased signal intensity of the reparative tissue represents maturation of implanted autologous chondrocytes. 3D-SPGR MRI is thought to be useful for evaluating reparative tissue after autologous chondrocyte implantation.

Adolescent↗

PubMed2003

A simple controlled-rate freezing method without a rate-controlled programmed freezer provides optimal conditions for both large-scale and small-scale cryopreservation of umbilical cord blood cells.

BACKGROUND: Umbilical cord blood (CB) is being used as a source of alternative HPCs for transplantation with increasing frequency. The goal of CB banks for unrelated transplantation is to provide good quality-controlled CB units that can be transplanted for HPCs into the largest possible number of patients. STUDY DESIGN AND METHODS: Large CB samples in freezing bags wrapped with insulators and small samples in cryotubes placed into double styrene-foam boxes were cryopreserved at -85 degrees C without a rate-controlled freezing machine, followed by storage in the liquid phase of nitrogen. After thawing these cells, the viability and recovery of cells, as well as the recovery rate of HPCs such as CD34+ cells, CFU-GM, and total CFU were evaluated. RESULTS: Measurement of the freezing rate in CB bags and cryotubes demonstrated that this simple method for cryopreservation of CB cells provided optimal conditions for both large-scale and small-scale cryopreservation. Recovery of CB progenitor cells after cryopreservation was also shown to be potentially acceptable when evaluated with CD34+ cells, CFU-GM, and total CFU. These results were comparable to the method using a rate-controlled programmed freezer. CONCLUSIONS: A simple method for cryopreservation of CB cells without a rate-controlled programmed freezer could provide a sufficient-enough potential for the transplantability of HPCs after thawing.

Blood Banks↗

PubMed2003

[Validity of attentional-style subscales for the Japanese version of the Test of Attentional and Interpersonal Style (TAIS)].

The six attentional-style subscales of the Test of Attentional and Interpersonal Style (TAIS, Nideffer, 1976) have been used mainly in the sport psychology area to investigate the relationship between attentional abilities and performance. This study assessed the validity of the Japanese version of the TAIS attentional-style subscales with 157 male and 163 female students. A confirmatory factor analysis failed to validate Nideffer's attentional dimension of bandwidth (narrow to broad attention) and direction (internal to external). The findings replicate previous studies which showed that the structure of the TAIS attention-related subscales is not reasonable and its factorial validity does not meet the needs of psychometrics.

Adolescent↗

PubMed2003

[Crossmodal attention between vision and touch in temporal order judgment task].

Four experiments investigated the effects of cross-modal attention between vision and touch in temporal order judgment tasks combined with spatial cueing paradigm. In Experiment 1, two vibrotactile stimuli with simultaneous or successive onsets were presented bimanually to the left and right index fingers and participants were asked to judge the temporal order of the two stimuli. The tactile stimuli were preceded by a spatially uninformative visual cue. Results indicated that shift of spatial attention yielded by visual cueing resulted in the modulation of accuracy of the subsequent tactile temporal order judgment. However, this cueing effect disappeared when participants judged simultaneity of the two stimuli, instead of their temporal order (Experiment 2) or when the cue lead time between the visual cue and the stimuli was relatively long (Experiment 3). Experiment 4 replicated an effect of crossmodal attention on the direction of visual illusory line motion induced by a somatosensory cue (Shimojo, Miyauchi, & Hikosaka, 1997). These results demonstrate that substantial crossmodal links exist between vision and touch for covert exogenous orienting of attention.

Adult↗