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Biomedical subjects

T Matsuno

Publications and source records attributed to T Matsuno.

At least 19 recordsLinked to original sources
PubMed2005

Three-dimensional computer-aided design based design sensitivity analysis and shape optimization of the stem using adaptive p-method.

The number of stem designs for total hip arthroplasty is increasing, and occasionally design changes have yielded unexpected clinical results. At present, we are not able to clearly identify which parameter of the stem is most important, and the optimum value of many parameters. The goals of this study were to identify which parameter is most important, to understand the effect of design change, and to find the optimum stem shape. For this purpose, we used adaptive p-method together with three-dimensional computer-aided design software program for the design sensitivity analysis (DSA) and shape optimization of the stem. The results suggested that increasing the lateral and medial width of the distal cross-section together with decreasing the medial-lateral width and the medial radius of the distal cross-section from the default value would lead to a decrease in the largest maximum principal stress of the distal cement. The medial width of middle cross-section, however, was not so simple. The result of DSA suggested that decreasing this parameter from the default value decreased the stress in the distal cement, but the optimum shape was obtained by increasing this parameter. The method used in this study will assist our engineers and surgeons in the process of modifying and optimizing the stem design.

Arthroplasty, Replacement, Hip↗
PubMed2005

Coverage dependent desorption dynamics of deuterium on Si(100) surfaces: interpretation with a diffusion-promoted desorption model.

We studied coverage dependence of time-of-flight (TOF) spectra of D2 molecules thermally desorbed from the D/Si(100) surface. The mean translational energies Et of desorbed D2 molecules were found to increase from 0.20+/-0.05 eV to 0.40+/-0.04 eV as the desorption coverage window was decreased from 1.0 ML> or =thetaD> or =0.9 ML to 0.2 ML> or =thetaD> or =0 ML, being consistent with the kinetics switch predicted in the interdimer mechanism. The measured TOF spectra were deconvoluted into 2H, 3H, and 4H components by a curve fitting method along the principle of detailed balance. As a result, it turned out that the desorption kinetics changes from the 4H to the 3H situation at high coverage above thetaD=0.9 ML, while the 2H desorption is dominant for a quite wide coverage region up to thetaD=0.8 ML. A dynamic desorption mechanism by which the desorption is promoted by D-atom diffusion to dangling bonds was proposed.

Journal Article↗
PubMed2005

Pre-coated femoral components in hybrid total hip arthroplasty. Results at 11 years.

We present the medium-term results of hybrid total hip arthroplasties using pre-coated stems with a second-generation cementing technique. The 128 hips in 111 patients (18 men and 93 women) were followed up at a mean of 11 years after surgery. The mean age at the time of surgery was 61 years. Both components of one hip were removed at ten months after surgery for infection. None of the other 127 femoral components showed possible, probable, or definite loosening at the most recent follow-up. Five acetabular components were revised for aseptic loosening, recurrent dislocation, or displacement of the polyethylene liner from the metal shell. The mean Harris hip score at follow-up was 84 points. A pre-coated femoral component with a second-generation cementing technique provides good clinical function and survival in the medium term.

Adolescent↗
PubMed2003

Strength of bond to bone and cytotoxicity of sintered bodies of hydroxyapatite/zirconia composite particles.

Regarding sintered bodies of hydroxyapatite (HAP)/zirconia (PSZ) composite particles prepared by covering the surface of HAP particles with PSZ particles, their strength of the bond to bone after implanting them into an organism and their cytotoxicity were evaluated. Cytotoxicity tests were conducted by the colony formation method. Cytotoxicity was not observed in the sintered bodies of HAP/PSZ composite particles, or in sintered monolithic HAP body and sintered monolithic PSZ body. The strength of bond between a sintered body and a bone was evaluated by measuring the shear strength at the interface between them after a fixed period following implantation of a sintered body into a rabbit femur. In all cases of the sintered monolithic HAP body, and the sintered bodies of HAP/PSZ composite particles and monolithic PSZ body, when the implantation period increased, the shear strength of the sintered body/bone interface tended to increase. In particular, this tendency was very high in the case of sintered bodies of HAP/PSZ with weight ratios of 1/1.0 and 1/1.5, the shear strength for each reaching 20 MPa 12 months after implantation.

Journal Article↗
PubMed2003

Comparison of the surgical approaches for a Chiari pelvic osteotomy.

We present the mid- to long-term results of the Chiari pelvic osteotomy for dysplastic hips. We followed 135 hips in 129 patients, with a mean age at the time of surgery of 24 years, for a mean of 16.2 years We used the anterior iliofemoral approach without trochanteric osteotomy in the initial 31 hips. Thereafter, we used transtrochanteric approaches in an attempt to ensure that the osteotomy was at the most appropriate level, and to advance the high-riding greater trochanter distally. The next 79 hips therefore underwent a posterolateral approach and the most recent 25 hips an Ollier lateral U approach. The clinical result was excellent or good in 103 hips (77%). The outcome in 104 hips in which we used a transtrochanteric approach was superior, the osteotomy level was more appropriate and a Trendelenburg gait less common than in 31 hips in which we used an anterior approach. We therefore recommend the use of a transtrochanteric approach in order to ensure that the osteotomy is at an appropriate level and in order to achieve effective distal advancement of the high-riding greater trochanter.

Adolescent↗
PubMed2003

Mid-term prognosis of non-traumatic osteonecrosis of the femoral head.

We followed, prospectively, 77 patients (90 hips) with early-stage, non-traumatic osteonecrosis of the femoral head for a mean period of nine years. At the time of final review, 56 (62%) were symptomatic. Using the Cox model, the initial radiological stage, the progression of staging, the reduction in size of the lesions and the percentage of necrotic volume on MRI were identified as risk factors. Using the Harris score of < 70 or surgery as the endpoint, the cumulative rates of survival were 60.0% at one year, 43.3% at two years, 38.9% at five years and 37.2% at ten years. Survival curves demonstrated that clinical deterioration could occur 90 months after the initial diagnosis, suggesting that asymptomatic patients should be followed carefully for several years. Radiological time-dependent reduction in size without progressive collapse may represent repair even when the collapse is minimal.

Adult↗
PubMed2002

Comparative biochemical studies of carotenoids in catfishes.

The carotenoids of 12 species of Siluriformes fishes (eight families) were investigated from a comparative biochemical point of view. The patterns of carotenoids in catfishes belonging to the family Siluridae were quite different from those of the other seven families of catfishes (Bagridae, Amblycipitidae, Clariidae, Plotosidae, Ictaluridae, Callichthyidae and Malapteruridae). 7, 8-Dihydro-beta-carotene; 7, 8, 7', 8'- and 7, 8, 9, 10-tetrahydro-beta-carotene; (3R)-7', 8'-dihydro-beta-cryptoxanthin; 7, 8-dihydrolutein A; 7, 8-dihydrolutein B; parasiloxanthin; 7', 8'-dihydroparasiloxanthin; and 4 or 4'-hydroxyparasiloxanthin were characteristic carotenoids found in only one family, Siluridae, and these carotenoids accounted for 24-60% of total carotenoids. In catfishes belonging to the other seven families except Siluridae, the carotenoid patterns were very similar and the most predominant carotenoid was zeaxanthins (23-56%).

Animals↗
PubMed2001

Selective intercalation of charge neutral intercalators into GG and CG steps: implication of HOMO-LUMO interaction for sequence-selective drug intercalation into DNA.

We have synthesized naphthopyranone epoxide 4 from D-isoascorbic acid together with its three diastereoisomers. DNA alkylation of ODNs containing 5'XGT3' and 5'TGY3' by 4 (11R, 13R), where X and Y are any nucleotide bases, occurred at all G residues except at G of the 5'TGC3' sequence. In contrast, the three other diastereoisomers of 4 showed only weak G alkylation activity. Differential (1)H NMR NOE of the 4-G adduct confirmed the G-N7 alkylation at the epoxide carbon of 4 with concomitant S(N)2 ring opening of the epoxide. Quantitative HPLC analysis of G alkylation efficiency for 4 showed the order of G alkylation susceptibility as TGGT approximately CGT >> TGA > AGT > TGT >> TGC. The order was fully consistent with those reported for aflatoxin B(1) oxide and kapurimycin A(3), suggesting that the sequence selectivity observed for these DNA alkylating agents is not structure dependent but most likely due to the intrinsic property of DNA sequences. We found that the order of G alkylation susceptibility obtained for 4 completely matched the calculated HOMO energy level of G-containing sequences. These results underscore that 4 is a unique molecular probe for ranking the HOMO level of G-containing sequences by well-known G alkylation chemistry and suggests that the intercalation of charge neutral intercalators is a HOMO-controlled process.

Base Sequence↗
PubMed2001

Cell proliferation and death of growth plate chondrocyte caused by ischemia and reperfusion.

The aim of this study was to assess the short-term response of cell kinetics of growth plate chondrocytes under conditions of warm ischemia and reperfusion. To understand the time-course changes that occur after reperfusion, 0 and 6 h of warm ischemia was produced in the right hindlimb of 35-day-old Wistar rats by isolating the vascular pedicle occlusion. The animals were killed at 12, 24, 48, or 96 h postoperatively after reperfusion, and proximal tibia growth plates were investigated. To investigate the effect of the ischemia period on the kinetics of growth plate chondrocytes, 0, 2, 4, 6, and 8 h of ischemia was induced, and the animals were killed for evaluation 24 h after reperfusion. For evaluation of cell kinetics, BrdU was used to observe the changes in cell proliferation of growth plate chondrocytes, and TUNEL was used to estimate the changes in rate of cell death. In the time-course study, both 0 and 6 h of ischemia increased cell proliferation at 12 and 24 h after reperfusion; however, at 48 and 96 h, the proliferation rate was not further increased. At 12 and 24 h postoperatively, 6 h of ischemia increased chondrocyte proliferation more than 0 h of ischemia with significant differences; 6 h of ischemia led to an increased cell death rate at 12, 24, and 48 h postoperatively, whereas 0 h of ischemia did not affect the cell death rate. In the ischemia time-dependent study, the cell proliferation rate induced by 4 h of ischemia was highest in all controlled periods of ischemia. Cell death rate increased gradually with increases in ischemia time 24 h after reperfusion. This experiment showed that ischemic damage causes short-term postoperative changes in the kinetics of growth plate chondrocytes.

Analysis of Variance↗
PubMed2001

Paravertebral neurinoma associated with aggressive intravertebral extension.

Neurinomas are relatively common benign tumors thought to arise from nerve sheath cells. Although intraosseous neurinomas may destroy the bone, extraosseous neurinomas with extensive destruction and invasion of bone are considered rare. We present two unusual cases of a benign extraosseous neurinoma that extensively invaded the vertebral body through the nutrient canal.

Adult↗
PubMed2001

Comparison of cytokine-inducing activity in a lipoteichoic acid-related molecule isolated from a penicillin-killed group A Streptococcus and from untreated bacteria.

We previously generated a monoclonal antibody, TS-2, that neutralizes the interferon (IFN)-gamma-inducing activity of OK-432, a penicillin-killed streptococcal preparation [J. Immunother. 13 (1993) 232]. Expression of the TS-2-binding antigen was markedly higher in the cell wall of the penicillin-treated Streptococcus pyogenes (OK-432) than in the untreated bacteria (Su-BBM). We here isolated the antigens from OK-432 and Su-BBM, designated OK-PSA and Su-PSA, respectively. OK-432 markedly induced IFN-gamma and interleukin (IL)-18 as compared with Su-BBM in human peripheral blood mononuclear cells (PBMC). Furthermore, all of the Thl-type and Th1-inducing cytokines tested [IFN-gamma, tumor necrosis factor (TNF)-alpha, IL-12 and IL-18] were secreted by OK-PSA-stimulated PBMC far better than by Su-PSA-treated PBMC. In addition, the cytolytic activities of the PBMC were accelerated by the stimulation with OK-432 or OK-PSA far better than by the stimulation with Su-BBM or Su-PSA. These findings strongly suggested that OK-PSA is a highly important molecule of OK-432 and may be a useful immunotherapeutic agent for the patients with malignant diseases as a potent Th inducer. It was also shown that penicillin treatment effectively enhances OK-PSA-induced anti-cancer immunity.

Caspase 1↗
PubMed2001

Salmoxanthin, deepoxysalmoxanthin, and 7,8-didehydrodeepoxysalmoxanthin from the Salmon Oncorhynchus keta.

The absolute configuration of salmoxanthin (5,6-epoxy-5,6-dihydro-beta,epsilon-carotene-3,3',6'-triol) (1) first isolated from the salmon Oncorhynchus keta was determined to be 3S, 5R, 6S, 3'S, 6'R. Furthermore, two minor carotenoids, deepoxysalmoxanthin (2) and 7,8-didehydrodeepoxysalmoxanthin (3), were isolated, and their structures were determined to be (3R,3'S,6'R)-beta,epsilon-carotene-3,3',6'-triol and (3R,3'S,6'R)-7,8-didehydro-beta,epsilon-carotene-3,3',6'-triol by (1)H NMR and CD spectroscopy.

Animals↗
PubMed2001

Structures of carotenoids with 5,6-dihydro-beta-end groups from the spindle shell Fusinus perplexus.

A series of pirardixanthin derivatives, 1, 2, 3, 4, and 5, possessing the 5,6-dihydro-beta-end group were isolated from the spindle shell Fusinus perplexus.(1,2) Their structures and absolute configurations were determined by modern spectroscopic analysis to be (4S,5S,6S,4'S,5'S,6'S)-5,6,5',6'-tetrahydro-beta,beta-carotene-4,4'-diol (1), (3S,4R,5S,6S,4'S,5'S,6'S)-5,6,5',6'-tetrahydro-beta,beta-carotene-3,4,4'-triol (2), (3S,4R,5S,6S,3'S,4'R,5'S,6'S)-5,6,5',6'-tetrahydro-beta,beta-carotene-3,4,3',4'-tetrol (3), (5S,6S,4'S,5'S,6'S)-4'-hydroxy-5,6,5',6'-tetrahydro-beta,beta-caroten-4-one (4), and (4'S,5'S,6'S)-4'-hydroxy-5',6'-dihydro-beta,beta-caroten-4-one (5).

Animals↗
PubMed2001

Advanced gastric cancer with multiple lymph node metastasis successfully treated with etoposide, adriamycin and cisplatin.

Gastric cancer usually shows poor sensitivity to chemotherapy, and the presence of lymph node metastases is associated with extremely poor prognosis, especially when the number of such nodes is more than 10. We report here a case of advanced gastric cancer with histopathologically confirmed metastases in 15 regional lymph nodes, in which the recurrent tumor was sensitive to combination chemotherapy. Distal gastrectomy with lymphadenectomy was performed for the primary tumor. A hard (recurrent) tumor was detected in the upper abdomen 5 months postoperatively. Abdominal CT revealed two tumors measuring 3.5 x 1.8 and 3.3 x 2 cm in diameter at the front of the pancreatic head, which suggested recurrence. Etoposide, adriamycin and cisplatin (EAP) chemotherapy (20 mg/kg adriamycin, 100 mg/kg etoposide and 50 mg/kg cisplatin (CDDP)) was administered every 6 weeks. The tumors regressed and became undetectable on CT after four cycles. At that stage, CDDP was replaced with 400 mg/kg carboplatin, which was administered every 1 or 2 months. The patient had no recurrence 8 years after surgery. For treatment of advanced gastric cancer with multiple lymph node metastases, a wide resection of the tumor should be performed followed by treatment of the residual tumor cells with a suitable combination chemotherapy taking into consideration the characteristics of the tumor and the condition of the host. We present a patient with gastric cancer and histopathologically confirmed metastases in 15 regional lymph nodes, who was successfully treated by surgery followed by EAP adjuvant chemotherapy. The patient remains alive and well at 8 years after surgery.

Adult↗
PubMed2001

Cytomegalovirus DNA among children attending two day-care centers in Tokyo.

BACKGROUND: In the USA, a high prevalence rate of cytomegalovirus (CMV) excretion among children in day-care centres was reported. However, there is no research about the prevalence rate of CMV among children in day-care centres in Japan. METHODS: The CMV excretion was studied in 54 children's saliva samples, collected from two different day-care centres in Tokyo. As a control, the prevalence of CMV was studied among 61 healthy children who did not attend any day-care centers. The CMV DNA in saliva were examined by polymerase chain reaction (PCR) analysis with one pair of primers for the immediate early region. The sequence of CMV genomes were examined in CMV PCR positive samples. RESULTS: Of the 54 saliva samples, 20.6% (6/29) and 24% (6/25) were CMV PCR positive in children at A and B day-care centres, respectively. The overall positivity of CMV PCR in saliva was 22.2% (12/54). Of the 61 saliva samples as the control study, 6.5% (4/61) were CMV PCR positive. There was a difference in the positivity in each age group of day-care centres and normal control. Each sample of the same day-care center gave conclusive and identical sequence results. CONCLUSION: We suspected that in each day-care center that there was one prevailing viral strain. We suppose that CMV infections were acquired inside the day-care centres. This is a first report which described viral transmission in day-care centres in Japan.

Child Day Care Centers↗
PubMed2001

Destruction of acetabular bone caused by early failure of a constrained acetabular component.

Use of a constrained acetabular component is 1 option for the treatment of dislocation after total hip arthroplasty. We report a case of a constrained acetabular component that resulted in postoperative early fixation loss and required revision 12 days after primary surgery. The superoposterior wall of the acetabulum was destroyed by the migrated acetabular component. Sharp ends of screws with a metal shell may have plowed up acetabular bone gradually after fixation loss of the component. This failure illustrates the potential risk of using a constrained acetabular component for total hip arthroplasty.

Acetabulum↗
PubMed2001

The sphericity of the bearing surface in total hip arthroplasty.

This study evaluated the sphericity of bearing surfaces in total hip arthroplasty. The out-of-roundness of metal femoral heads, the inner surface of polyethylene liners, and commercially available ball bearings was measured. The hip prostheses were obtained directly from the manufacturers. The sphericity of the bearing surfaces was significantly inferior to that of the ball bearings. The sphericity of the femoral head on the sagittal plane was inferior to that on the transverse plane. Several significant differences were found among different manufacturers. The sphericity of the femoral head on the sagittal plane and that of polyethylene significantly improved in 1999 and 2000 compared with those in 1995. Further improvement is desirable, however, because good sphericity is expected to prolong the functional performance of the prosthesis after total hip arthroplasty.

Analysis of Variance↗