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Biomedical subjects

A Inoue

Publications and source records attributed to A Inoue.

At least 91 records · Page 5Linked to original sources
PubMed2000

Biomechanical study of the resurfacing hip arthroplasty: finite element analysis of the femoral component.

Finite element analysis was performed using 3-dimensional models to examine the biomechanical characteristics of the femoral component in resurfacing hip arthroplasty. Stress concentration was observed in the cortical bone adjacent to the rim of the prosthesis. Stress shielding was observed in the anterosuperior regions on the cancellous bone cross-sections near the cup rim. These biomechanical characteristics may lead to complications such as femoral neck fractures in patients with osteopenic bone and long-term loosening.

Arthroplasty, Replacement, Hip↗
PubMed2000

Concentration of mRNA for the natriuretic peptide receptor-C in hypertrophic chondrocytes of the fetal mouse tibia.

The roles of natriuretic peptides in cardiovascular homeostasis have been well characterized. A recent study revealed that mice lacking natriuretic peptide receptor-C (NPR-C) exhibit skeletal-overgrowth. We therefore, performed in situ hybridization with riboprobes to determine the localization of mRNAs for receptors for natriuretic peptides in the growth plate of the fetal mouse tibia The amount of mRNA for NPR-A was below the detectable level in the growth plate. The mRNA for NPR-B was detected predominantly in proliferating chondrocytes. By contrast, high levels of mRNA for NPR-C were found in hypertrophic chondrocytes. In other regions of the growth plate, the levels of mRNA for NPR-C were very low. The patterns of expression of mRNAs for NPR-B and NPR-C, namely, subtype switching during differentiation from proliferating chondrocytes to hypertrophic chondrocytes, suggest that these receptors might be involved in the growth and differentiation of the growth plate during fetal development in the mouse.

Animals↗
PubMed2000

Functional role of Ca(2+)-binding site IV of scallop troponin C.

Scallop troponin C (TnC) binds only one Ca(2+)/mol and the single Ca(2+)-binding site has been suggested to be site IV on the basis of the primary structure [K. Nishita, H. Tanaka, and T. Ojima (1994) J. Biol. Chem. 269, 3464-3468; T. Ojima, H. Tanaka, and K. Nishita (1994) Arch. Biochem. Biophys. 311, 272-276]. In the present study, the functional role of Ca(2+)-binding site IV of akazara scallop (Chlamys nipponensis akazara) TnC in Ca(2+)-regulation was investigated using a site-directed mutant with an inactivated site IV (TnC-ZEQ), N- and C-terminal half molecule mutants (TnC(N) and TnC(C)), and wild-type TnC (TnC(W)). Equilibrium dialysis using (45)Ca(2+) demonstrated that TnC(W) and TnC(C) bind 0.6-0.8 mol of Ca(2+)/mol, but that TnC-ZEQ and TnC(N) bind virtually no Ca(2+). The UV difference spectra of TnC(W) and TnC(C) showed bands at around 280-290 nm due to the perturbation of Tyr and Trp upon Ca(2+)-binding, while TnC-ZEQ and TnC(N) did not show these bands. In addition, TnC(W) and TnC(C) showed retardation of elution from Sephacryl S-200 upon the addition of 1 mM CaCl(2), unlike TnC-ZEQ and TnC(N). These results indicate that Ca(2+) binds only to site IV and that Ca(2+)-binding causes structural changes in both the whole TnC molecule and the C-terminal half molecule. In addition, TnC(W), TnC-ZEQ, and TnC(C), but not TnC(N), were shown to form soluble complexes with scallop TnI at physiological ionic strength. On the other hand, the Mg-ATPase activity of reconstituted rabbit actomyosin in the presence of scallop tropomyosin was inhibited by scallop TnI and recovered by the addition of an equimolar amount of TnC(W), TnC-ZEQ, or TnC(C), but not TnC(N). These results imply that the site responsible for the association with TnI is located in the C-terminal half domain of TnC. Ternary complex constructed from scallop TnT, TnI, and TnC(W) conferred Ca(2+)-sensitivity to the Mg-ATPase of rabbit actomyosin to the same extent as native troponin, but the TnC(N)-TnT-TnI and TnC-ZEQ-TnT-TnI complexes conferred no Ca(2+)-sensitivity, while the TnC(C)-TnT-TnI complex conferred weak Ca(2+)-sensitivity. Thus, the major functions of scallop TnC, such as Ca(2+)-binding and interaction with TnI, are located in the C-terminal domain, however, the full Ca(2+)-regulatory function requires the presence of the N-terminal domain.

Animals↗
PubMed2000

Vasoactive peptide-regulated gene expression during osteoblastic differentiation.

The formation of bone occurs via a series of events that are regulated by various hormones and cytokines. We previously reported that endothelin (ET) inhibits the mineralization by osteoblastic cells and natriuretic peptide (NP) promotes osteoblastic differentiation. Therefore, we attempted to identify the genes induced by ET or NP in mouse preosteoblastic MC3T3-E1 cells using the method known as differential display-polymerase chain reaction (DD-PCR) to understand the bone metabolism further. Consequently, we found that expression levels of mRNAs for fibronectin, type XII collagen, p160 Rho-associated kinase (ROCK), caldesmon, calpain, nucleolin and a novel gene with a zinc finger motif are downregulated in osteoblasts by ET stimuli. We also found that expression levels of mRNAs for eIF-4A and a novel gene are increased by C-type natriuretic peptide (CNP) stimuli.

Animals↗
PubMed2000

Hemostatic abnormalities in patients with thrombotic complications on maintenance hemodialysis.

Before hemodialysis (HD), plasma levels of tissue factor (TF), free-TF pathway inhibitor (TFPI) and thrombomodulin (TM) were significantly higher in patients with HD than in healthy volunteers. Plasma levels of (T-F) TFPI and plasmin plasmin inhibitor complex (PPIC) were significantly higher in patients with HD than in healthy volunteers. During HD, plasma levels of TF and (T-F) TFPI were not significantly increased, but plasma levels of total TFPI and free TFPI at 1 hour after and at the end of HD were significantly increased, compared with levels before start of HD. Plasma level of PPIC 1 hour after start of HD was significantly higher than before start of HD, and plasma levels of thrombin antithrombin complex (TAT), PPIC, D-dimer, TM, and protein C (PC) at the end of HD were significantly higher than before start of HD. In patients with thrombosis complications, plasma TF levels were significantly higher than in patients without thrombotic complications during HD. Plasma levels of PC were significantly lower in patients with thrombotic complications than in patients without thrombotic complications. There was no significant difference between both groups during HD in hemostatic parameters, with the exception of TF and PC. Hemostatic abnormalities existed in patients with HD; especially, increased TF and decreased PC might cause thrombotic complications.

Antifibrinolytic Agents↗
PubMed2000

[Neural-immune interactions in dorsal root ganglia].

Interleukin-1 (IL-1) beta is a proinflammatory cytokine that is produced by a large variety of cells, including macrophages, fibroblasts, mesangial cells and endothelial cells, and is believed to play important roles in the inflammatory responses, including hyperalgesia. Hyperalgesia is characterized by intensified pain with a reduced threshold to somatic stimulation, and it is involved in chronic inflammatory disease. Substance P (SP), an undecapeptide, has been shown to relay noxious signals as a neurotransmitter in primary afferent neurons. Thus it is expected that the change of neuropeptide activities in primary afferent neurons is attributed to inflammatory hyperalgesia by IL-1 beta. In our recent studies, IL-1 beta was found to stimulate SP release from cultured dorsal root ganglion cells via the cyclooxygenase system. These studies provide a new insight in the neural-immune intercommunication involved in the pain-regulation system observed in inflammation-induced hyperalgesia.

Animals↗
PubMed2000

Synthesis of regioselectively protected forms of cytidine based on enzyme-catalyzed deacetylation as the key step.

N4-Acetylcytidine (77%) and 2',3'-O, N4-triacetylcytidine (95%) were obtained from the hydrolysis of a common precursor, the peracetylated form of cytidine with Aspergillus niger lipase (Amano A) and Burkholderia cepacia esterase (SC esterase S), respectively, under very mild conditions. The experimental procedure for the conversion of triacetylcytidine to a corresponding phosphoramidite (82%), an intermediate for sugar nucleotide synthesis, is also elaborated.

Acetylation↗
PubMed2000

Effects of hydrostatic pressure and temperature on growth and lipid composition of the inner membrane of barotolerant Pseudomonas sp. BT1 isolated from the deep-sea.

A barotolerant member of the genus Pseudomonas was isolated from deep-sea sediment obtained from the Japan Trench, at a depth of 4418 m. The growth temperature was found to affect the hydrostatic pressure range in which the bacterium could grow; the optimum hydrostatic pressure for growth shifted to a higher pressure with increasing temperature. We examined the lipid composition of the inner membrane of cells grown at various hydrostatic pressures and temperatures. The fatty acid components of the inner membrane lipids were C16:0, C16:1, C18:0, and C18:1. The phospholipid components of the inner membrane were phosphatidylethanolamine, cardiolipin, phosphatidylglycerol, and phosphatidylserine. It is evident that the effects of elevated hydrostatic pressure are comparable to the effects of low temperature on both the fatty acid composition of the inner membrane lipids and the phospholipid composition of the inner membrane of this bacterium.

DNA, Ribosomal↗
PubMed2000

The effect of the patellar tendon-bearing cast on loading.

We assessed the unloading effect of the patellar tendon-bearing (PTB) cast in five healthy volunteers using a new system for analysis of dynamic plantar pressure. We devised a method to improve the unloading effect of the PTB cast, and tested this using the same system. Our findings showed that the conventional PTB cast only achieved unloading of 30% of the body-weight and that the part of the cast on the leg had a more important role in the unloading than that which was in contact with the patellar tendon. When the depth of the free space under the foot inside the PTB cast was 1, 2 and 3 cm, the unloading effect was 60%, 80% and 98%, respectively. The unloading effect of the conventional PTB cast was disappointing at only 30% of body-weight. It was improved by producing a space between the sole of the foot and the cast, and was adjustable by altering the depth of this space.

Adult↗
PubMed2000

Successful manual reduction of locked metacarpophalangeal joints in fingers.

BACKGROUND: Many studies on the etiology and operative treatment of locked metacarpophalangeal joints in fingers have been reported, but there have been few investigations on manual reduction. The rate of success of manual reduction in previous reports has been low, and no consensus has been reached with regard to the best method of manual reduction. On the basis of our experience with operative treatment, we devised a safe method of manual reduction. METHODS: Between January 1987 and December 1995, we reduced a locked metacarpophalangeal joint in twelve female patients; every locked finger was successfully reduced, and complications such as fracture did not occur during manual reduction. The average duration of follow-up was five years and nine months (range, three years and two months to nine years and three months). RESULTS: Six patients had no recurrence of the locking. Four of the six remaining patients had one or two incidents of locking, had no alteration in the activities of daily living, and did not want operative treatment. The two remaining patients reported that they had incidents of locking several times a day, and they requested operative treatment as they were afraid of additional recurrences. One patient had an open reduction fifteen months after the initial episode of locking, and the other patient elected not to have an operation for personal reasons. CONCLUSIONS: We believe that our method of manual reduction should be used to treat a locked metacarpophalangeal joint in a finger and that operative treatment should be limited to patients in whom manual reduction is unsuccessful or the reduction is unstable.

Adult↗
PubMed2000

Effectiveness of interferon therapy for reducing the incidence of hepatocellular carcinoma among patients with type C chronic hepatitis.

STUDY PURPOSE: To evaluate the effect of interferon treatment for reducing the incidence of hepatocellular carcinoma among patients with type C chronic hepatitis. METHODS: Retrospective cohort study was conducted on 923 patients with type C chronic hepatitis, who were identified through databases of Osaka Medical Center for Cancer and Cardiovascular Diseases. Two hundred and twenty-four of those had undergone interferon treatment, while the other 699 patients had not. Kaplan-Meier method and the proportional hazards model were used for statistical analysis. RESULTS: Five-years' cumulative incidence of hepatocellular carcinoma was 2.2% among the interferon treated patients, while 9.5% among the interferon untreated. Difference between the 2 curves of the cumulative incidence was statistically significant (p=0.0015). After adjustment for possible confounders, hazard rate ratio of hepatocellular carcinoma was 0.31 in the interferon treated group, significantly lower than that in the untreated (p=0.015). Hazard rate ratio for death from causes other than hepatocellular carcinoma and liver diseases was also lower among the interferon treated group than that among the untreated, although not significant. CONCLUSIONS: Interferon treatment is suggested to reduce the risk of hepatocellular carcinoma among patients with type C chronic hepatitis, and not to increase the risk for death from causes other than hepatocellular carcinoma and liver diseases.

Antiviral Agents↗
PubMed2000

Expression of the SART1 tumor-rejection antigen in human osteosarcomas.

We recently reported a tumor-rejection antigen, SART1259, possessing tumor epitopes capable of inducing cytotoxic T lymphocytes (CTLs). This study investigated the expression of SART1259 antigen in osteosarcoma and other skeletal malignant tumors to explore for a potential molecule for use in specific immunotherapy. The SART1259 antigen was detected in the cytosol fraction of 13 of 21 (62%) osteosarcoma cell lines and 3 of 8 (38%) osteosarcoma tissues, and 3 of 10 (30%) malignant fibrous histiocytoma (MFH) tissues. The HLA-A24+ and SART1259+ osteosarcoma cells were recognized by the HLA-A24 restricted and SART1 specific CTLs. These results raise a possibility that the SART1259 would be an appropriate molecule for use in specific immunotherapy of approximately one-third of HLA-A24+ patients with osteosarcoma and MFH.

Antigens, Neoplasm↗
PubMed2000

[A study of free radical defense and oxidative stress in the sera of patients with neuroimmunological disorders].

Free radicals are molecules that contain at least one unpaired electron and by nature are highly reactive and potentially destructive. Free radical damage can play an important role of demyelination. Glutathione peroxidase, which plays a role in free radical defenses, and myeloperoxidase and lactoferrin, which are considered to reflect the strength of oxidative stress, were examined by monoclonal antibody-based enzyme immunoassay on serum samples taken from patients with neuroimmunological disorders, namely, 35 multiple sclerosis(MS), and 2 Baló disease, 10 Guillain-Barré syndrome(GBS), and 25 human T-lymphotropic virus type-1 associated myelopathy (HAM). The levels of glutathione peroxidase in active phase of MS (8.37 +/- 5.59 micrograms/ml: p < 0.05) were increased rather than in inactive phase (5.05 +/- 2.44 micrograms/ml) and control (5.41 +/- 1.40 micrograms/ml), the levels of myeloperoxidase in HAM (95.5 +/- 89.1 ng/ml: p < 0.05) were increased rather than in controls (21.5 +/- 4.1 ng/ml), and the levels of lactoferrin were not significantly increased than in other disease and control. Moreover the levels of myeloperoxidase and lactoferrin are increased in Baló disease (myeloperoxidase 487, 762 ng/ml; not significant, lactoferrin 2.58, 2.77 ng/ml; not significant) than in control (myeloperoxidase 21.5 +/- 4.1 ng/ml, lactoferrin 0.69 +/- 0.32 ng/ml). In conclusion, we have here first demonstrated that the levels of these enzyme were not paralleled in MS and Baló diseases. In GBS the levels of all these enzyme were not increased. Thus, these findings suggest that these enzyme may play an important role of the disease activity of Baló, and may reflect the activity of the defense of MS.

Adult↗
PubMed2000

[Identification of a free non-tryptophan fluorophore in water-soluble fraction of human brunescent cataractous lens nucleus].

PURPOSE: We previously reported that a unique free fluorophore (Fl-Glc), presumably a beta-glucoside, is particularly abundant in human brunescent cataractous lens nuclei. Our preliminary experiments indicated that incubation of low-molecular weight (MW) fraction of non-brunescent lens nuclei causes an increase in a particular fluorophore (Fl-X). This study was undertaken to compare the Fl-Glc with the Fl-X and subsequently to identify the Fl-X. METHODS: Experiment 1. The purified Fl-X and its beta-glucosidase digest (aglycon) were compared with the Fl-Glc and its aglycon, respectively, by high-performance liquid chromatography (HPLC). Experiment 2. i) The Fl-X and its aglycon were analysed by liquid chromatography/mass spectrometry (LC/MS). ii) Authentic xanthurenic acid was analysed by HPLC and LC/MS. RESULTS: Experiment 1. The retention times of the Fl-X and the Fl-Glc exactly coincided. The fluorescence peaks of both disappeared after beta-glucosidase treatment. Experiment 2. i) LC/MS results suggested that the MWs of the Fl-X and its aglycon were 367 and 205, respectively. ii) HPLC and LC/MS results for xanthurenic acid (MW = 205) were exactly the same as those for the aglycon of the Fl-X. CONCLUSIONS: The Fl-Glc and the Fl-X are identical, and the Fl-X (= Fl-Glc) is a glucoside of xanthurenic acid.

Aged↗
PubMed2000

[Prophylaxis with FK-506 for graft-versus-host disease after transplantation of bone marrow from unrelated donors].

Forty-eight patients who underwent bone marrow transplantation (BMT) from serologically HLA-matched unrelated donors received tacrolimus (FK506) alone or with methotrexate (MTX) and/or methylprednisolone (mPSL) to prevent graft-versus-host disease (GVHD). We analyzed retrospectively the efficacy of FK506 for GVHD prophylaxis, and its toxicity, by comparing three groups of patients: those given FK506 alone, those given FK506 + mPSL, and those given FK506 + MTX + mPSL. Grade III and IV acute GVHD occurred in five of 10 patients given FK506 alone and in 11 of 30 patients given FK506 + mPSL. In these groups, severe acute GVHD was commonly seen in the patients who discontinued FK506 administration early after BMT and in those who received bone marrow from genotypically HLA-mismatched donors. Early withdrawal of FK506 was due mainly to severe nephrotoxicity. The incidence of nephrotoxicity was very high in patients who received high-dose FK506 as well as melphalan-containing preconditioning (80% and 50%). None of eight patients who received FK506 + mPSL + MTX developed grade III-IV acute GVHD even though five of them received bone marrow from genotypically HLA-mismatched donors. In patients receiving bone marrow from unrelated donors, adjustment of the initial dose of FK506 seems essential in order to avoid severe nephrotoxicity, and combination of MTX and FK506 is useful for preventing severe acute GVHD.

Adolescent↗
PubMed2000

Right ventricular aneurysm caused by acute myocarditis.

The first case of right ventricular aneurysm caused by acute myocarditis is reported. Positive gallium-67 uptake and contrast enhancement in the gadolinium diethylenetriaminepentaacetic acid-enhanced magnetic resonance images were detected in the apical region surrounding the aneurysm, suggesting transmural myocardial inflammations in the apical portion of the heart. The aneurysm was repaired surgically, and biopsy of the right ventricular myocardium showed replacement fibrosis and inflammatory infiltrate.

Acute Disease↗