Biomedical subjects

A Harada

Publications and source records attributed to A Harada.

At least 19 recordsLinked to original sources

PubMed2006

Can you diagnose for vertebral fracture correctly by plain X-ray?

INTRODUCTION: A wrong diagnosis of latent vertebral fracture is often made when it is based on plain X-ray imaging. Magnetic resonance imaging (MRI) has a high degree of accuracy for the definite diagnosis. This study was designed to identify ways to support improvements in the diagnostic accuracy of plain X-ray (X-P). METHODS: We studied X-P and MRI images of 120 women and men (age range: 50-96 years). Five orthopedists and two radiologists interpreted front and lateral thoracolumbar X-Ps and MRI images. The correct diagnosis rate for the presence and location of incident vertebral fractures and the correct diagnosis rate according to morphological classifications were analyzed. RESULTS: A correct diagnosis of incident fractures was made in 51.5% of cases overall. Diagnoses of non-incident fracture based on X-P in those cases with incident fracture based on MRI (false positive) occurred in 24.8% of the patients, while diagnoses of incident fracture based on X-P in those cases without incident fracture based on MRI (false negative) occurred in 6.5% of the patients. The application of morphological classifications (the primary osteoporosis diagnostic criteria and Yoshida's classification) resulted in the correct diagnosis rate being significantly higher in the group without prevalent fracture even when there were morphological changes (wedge, indented, protruding type) in the anterior bone cortex. Odds ratios were investigated for factors that would affect the correct diagnosis rate, including age, body weight, lumbar vertebrae bone mineral density, and examiner ability. In an overall investigation, age (OR=0.660), body weight (OR=2.082), and examiner ability (p=0.0205) affected the correct diagnosis rate. CONCLUSION: The correct diagnosis rate for incident vertebral fractures with X-Ps was low (24.8%) and in cases with prevalent fractures, the rate was even lower (16.8%), but the number of prevalent fractures and BMD did not exert an effect. One key improving the correct diagnosis rate may be to pay attention to morphological changes in the anterior bone cortex.

Aged↗

PubMed2006

Prevention of radiation-induced pneumonitis by recombinant adenovirus-mediated transferring of soluble TGF-beta type II receptor gene.

To investigate whether radiation-induced pneumonitis in the mouse-irradiated lung could be prevented by recombinant adenovirus-mediated soluble transforming growth factor-beta (TGF-beta) type II receptor gene therapy. Radiation fibrosis-prone mice (C57BL/6J) were randomly divided into four groups consisting of a (1) control group (sham-irradiated); (2) radiation (RT)-alone group; (3) RT+AdCMVsTbetaR group and (4) RT+AdCMVluc group. The RT-alone and sham-irradiated mice were killed at several time points after thoracic irradiation with a single dose of 9 Gy, and then the TGF-beta1 concentrations in serum and broncho-alveolar lavage fluid (BALF) were quantified by enzyme-linked immunosorbent assay (ELISA). We used an adenoviral vector expressing a soluble TGF-beta type II receptor (AdCMVsTbetaR), which can bind to TGF-beta and then block the TGF-beta receptor-mediated signal transduction. The C57BL/6J mice were intraperitoneally (i.p.) injected with either 5 x 10(8) plaque-forming units of AdCMVsTbetaR or AdCMVluc, a control adenovirus-expressing luciferase, a week preceding and a week following the X-ray thoracic irradiation. Four weeks after irradiation, the mice were killed and the concentration of TGF-beta1 in the serum and BALF were then measured using ELISA and the lung tissue specimens were examined histopathologically. Following thoracic irradiation with a single dose of 9 Gy, radiation-induced TGF-beta1 release in the serum reached the first peak concentration at 12 h and then declined. It reached a maximal value at 2 weeks after irradiation. In the BALF, the TGF-beta1 concentration was appreciable within the first hour and thereafter declined. It reached a maximal value at 3 days after irradiation. A one-time i.p. injection of AdCMVsTbetaR 1 week before irradiation could not completely suppress the two peaks of the radiation-induced TGF-beta1 increase, whereas an injection a week preceding and a week following thoracic irradiation was able to suppress those two peaks thoroughly. The TGF-beta1 was completely suppressed in the AdCMVsTbetaR-treated mouse serum and BALF; however, no statistical difference was observed in the serum and BALF between the AdCMVluc-infected mice and the control mice at 4 weeks after irradiation (P < 0.05). A histopathological examination showed only mild radiation pneumonitis in the irradiated lungs of AdCMVsTbetaR-treated mice in comparison to the AdCMVluc-infected and RT-alone mice. Our results demonstrated that TGF-beta1 plays an important role in radiation pneumonitis, thus suggesting that the adenovirus-mediated overexpression in soluble TGF-beta type II receptor gene therapy may be a potentially feasible and effective strategy for the prevention of radiation pneumonitis.

Adenoviridae↗

PubMed2006

Minodronate suppresses prostaglandin F2alpha-induced vascular endothelial growth factor synthesis in osteoblasts.

In our previous study, we showed that prostaglandin F2alpha (PGF2alpha) stimulates vascular endothelial growth factor (VEGF) synthesis via activation of p44/p42 mitogen-activated protein (MAP) kinase via protein kinase C (PKC) in osteoblast-like MC3T3-E1 cells. In addition, we demonstrated that incadronate amplified, and tiludronate suppressed PGF2alpha-induced VEGF synthesis among bisphosphonates, while alendronate or etidronate had no effect. In the present study, we investigated the effects of minodronate, a newly developed bisphosphonate, on PGF (2alpha)-induced VEGF synthesis in MC3T3-E1 cells. Minodronate significantly reduced VEGF synthesis induced by PGF2alpha dose-dependently at levels between 3 and 100 microM. PGF2alpha-stimulated phosphorylation of Raf-1, MEK1/2 and p44/p42 MAP kinase were suppressed by minodronate. 12-O-tetradecanoylphorbol-13-acetate (TPA), a direct activator VEGF synthesis induced by PKC, was inhibited by minodronate. Minodronate inhibited Raf-1, MEK1/2 and p44/p42 MAP kinase phosphorylation induced by TPA. Mevalonate failed to affect the suppressive effect of minodronate on PGF2alpha-induced VEGF synthesis. Taken together, these results indicate that minodronate suppresses PGF2alpha-stimulated VEGF synthesis at the point between PKC and Raf-1 in osteoblasts.

Animals↗

PubMed2005

A new method for measurement of bone deformation by echo tracking.

No method has been available to noninvasively detect bone deformation or strain under loading in vivo. We focused on ultrasonic measurement of the displacement at a certain point on a bone using the echo-tracking method (ET). To develop a method that can noninvasively detect bone deformation in vivo, a preliminary investigation was performed. We investigated the accuracy of measuring displacement with our echo tracking system by using a flat metal panel and found that the method could measure displacement with a precision of a few microns. A three-point bending test of a porcine tibia with both ends fully constrained was performed to measure bone surface displacement, and simultaneous measurement of the surface strain was done using two strain gauges. The correlation between the displacement measured by ET and the strain gauge readings was completely linear (r=0.999), showing that the method could precisely detect bone deformation. The loads versus displacement curves obtained with cyclic loading were typical hysteresis loops that showed viscoelastic properties of the measured bone. We also improved a multi-ET system capable of simultaneously tracking multiple points to detect deformation of the bone surface. Measurement by this echo tracking system was also compared with strain gauge readings during a three point bending test with both ends of the tibia supported. The linearity of both methods was very high (r=0.998). Our ET method might have considerable potential for noninvasive measurement of bone viscoelasticity and plasticity.

Aluminum↗

PubMed2005

[Intrapulmonary aberrant needle; report of a case].

Intrapulmonary aberrant needles are rarely encountered in clinical practice. An intrathoracic aberrant needle should be always surgically removed as soon as possible. We report a case of an intrapulmonary aberrant needle removed with video-assisted thorascopic surgery (VATS) and briefly review the literature. A 47-year-old man referred to us for chest discomfort was found to have an intrapulmonary aberrant needle at the right middle lobe by chest X-ray and computed tomography (CT). We tried simple extraction under thoracoscopy, but a residual fragment was recognized by intraoperative X-ray after the removal of the needle from the surface of the lung. We searched for the residual fragment by real-time fluoroscopic examination. Partial resection was performed to remove the residual needle fragment at the right lower lobe. The postoperative course was uneventful and the man was discharged on the postoperative day 10. Intraoperative chest X-ray is always necessary before closing the chest to avoid leaving the residual fragments in the lung. The real-time fluoroscopy is useful to search for the residual fragment.

Foreign Bodies↗

PubMed2002

Polyion complex micelles as vectors in gene therapy--pharmacokinetics and in vivo gene transfer.

To establish non-viral gene delivery systems for intravenous administration, complexes of DNA and block copolymer consisting of poly-L-lysine and poly(ethylene glycol) were tested in in vivo turnover studies. The polyion complex micelles have self-assembling core-shell structures, yielding spherical nano-particles with small absolute values of zeta-potential. Southern blot analysis showed that supercoiled DNA was observed for 30 min and open circular or linear DNA was seen for 3 h after intravenous administration of PIC micelles having the charge ratios of 1:4 and PLL length of 48 mer. The PIC micelles with shorter PLL length showed lower stability in the blood stream suggesting that DNA is able to persist as an intact molecule in the blood stream using this system. Though having no ligands, PIC micelles with charge ratios of 1:2 and 1:4 transfected efficiently into HepG2 cells. Preincubation with free copolymer inhibited expression of the reporter gene, suggesting that adsorption of block copolymer to the cell surface blocked the interaction site of the PIC micelles. When the PIC micelles were injected via supramesenteric vein, expression of the gene was observed only in the liver and was sustained for 3 days. It was suggested that this gene delivery system is intrinsically efficient.

Carcinoma, Hepatocellular↗

PubMed2001

Synergistic effects of MAP2 and MAP1B knockout in neuronal migration, dendritic outgrowth, and microtubule organization.

MAP1B and MAP2 are major members of neuronal microtubule-associated proteins (MAPs). To gain insights into the function of MAP2 in vivo, we generated MAP2-deficient (map2(-/-)) mice. They developed without any apparent abnormalities, which indicates that MAP2 is dispensable in mouse survival. Because previous reports suggest a functional redundancy among MAPs, we next generated mice lacking both MAP2 and MAP1B to test their possible synergistic functions in vivo. Map2(-/-)map1b(-/-) mice died in their perinatal period. They showed not only fiber tract malformations but also disrupted cortical patterning caused by retarded neuronal migration. In spite of this, their cortical layer maintained an "inside-out" pattern. Detailed observation of primary cultures of hippocampal neurons from map2(-/-)map1b(-/-) mice revealed inhibited microtubule bundling and neurite elongation. In these neurons, synergistic effects caused by the loss of MAP2 and MAP1B were more apparent in dendrites than in axons. The spacing of microtubules was reduced significantly in map2(-/-)map1b(-/-) mice in vitro and in vivo. These results suggest that MAP2 and MAP1B have overlapping functions in neuronal migration and neurite outgrowth by organizing microtubules in developing neurons both for axonal and dendritic morphogenesis but more dominantly for dendritic morphogenesis.

Animals↗

PubMed2001

Association between a polymorphism of the transforming growth factor-beta1 gene and genetic susceptibility to ossification of the posterior longitudinal ligament in Japanese patients.

STUDY DESIGN: A study was conducted to determine the association between polymorphism of the transforming growth factor-beta1 (TGF-beta1) gene and ossification of the posterior longitudinal ligament (OPLL) prevalence. OBJECTIVE: To examine whether the T869-->C polymorphism of the TGF-beta1 gene is associated with genetic susceptibility to OPLL in Japanese subjects. SUMMARY OF BACKGROUND DATA: In the posterior longitudinal ligament, OPLL is associated with abnormal calcium metabolism. Several candidate genes are associated with the prevalence of OPLL. In the ossified matrix and chondrocytes of adjacent cartilaginous areas of OPLL, TGF-beta1 is overexpressed. METHODS: The TGF-beta1 genotype was identified with an allele-specific polymerase chain reaction method in 319 Japanese subjects (46 subjects with OPLL and 273 control subjects). RESULTS: There was a significant association between the T869-->C genotype and the prevalence of OPLL in the cervical spine. Multivariable logistic regression analysis, adjusted for gender, age, height, and body weight, showed that the frequency of the C allele was significantly higher in subjects with OPLL than in control subjects. CONCLUSIONS: The T869-->C polymorphism of the TGF-beta1 gene is a genetic determinant of a predisposition to OPLL, with the C allele representing a risk factor for genetic susceptibility to OPLL in Japanese subjects. Therefore, TGF-beta1 genotyping may be useful in the prevention of OPLL.

Aged↗

PubMed2001

Pronounced activity of enzymes through the incorporation into the core of polyion complex micelles made from charged block copolymers.

Compartmentalization of enzymes in the nanometric-scaled container, to improve their stability and availability, has recently attracted a strong interest in the field of pharmaceutics. In this study, the enzymatic activity of lysozyme in the core of polyion complex (PIC) micelles, which were formed from egg white lysozyme and poly(ethylene glycol)-poly(alpha,beta-aspartic acid) block copolymer (PEG-P(Asp)), was evaluated using a colorimetric method. Apparent enzymatic activity of lysozyme entrapped in the core of PIC micelles remarkably increased compared to that of free lysozyme, which is mainly attributed to a decrease in the observed Michaelis constant (K(m,obs)). The reciprocal of the K(m,obs) values nicely correlated to the corona thickness of PIC micelles, suggesting that the corona layer of PIC micelle may act as the reservoir of the substrate, p-nitrophenyl penta-N-acetyl-beta-chitopentaoside. This result indicates that the enzymatic activity can be controlled by changing the corona thickness of PIC micelles through a variation in the mixing ratio of PEG-P(Asp) to lysozyme. This type of PIC micelle system entrapping enzyme in the core might be useful for the design of diagnostic as well as targetable therapeutic systems of enzyme including antibody-directed enzyme prodrug therapy (ADEPT).

Algorithms↗

PubMed2001

Block copolymer micelles for drug delivery: design, characterization and biological significance.

Recently, colloidal carrier systems have been receiving much attention in the field of drug targeting because of their high loading capacity for drugs as well as their unique disposition characteristics in the body. This paper highlights the utility of polymeric micelles formed through the multimolecular assembly of block copolymers as novel core-shell typed colloidal carriers for drug and gene targeting. The process of micellization in aqueous milieu is described in detail based on differences in the driving force of core segregation, including hydrophobic interaction, electrostatic interaction, metal complexation, and hydrogen bonding of constituent block copolymers. The segregated core embedded in the hydrophilic palisade is shown to function as a reservoir for genes, enzymes, and a variety of drugs with diverse characteristics. Functionalization of the outer surface of the polymeric micelle to modify its physicochemical and biological properties is reviewed from the standpoint of designing micellar carrier systems for receptor-mediated drug delivery. Further, the distribution of polymeric micelles is described to demonstrate their long-circulating characteristics and significant tumor accumulation, emphasizing their promising utility in tumor-targeting therapy. As an important perspective on carrier systems based on polymeric micelles, their feasibility as non-viral gene vectors is also summarized in this review article.

Animals↗

PubMed2001

Association of the C-509-->T polymorphism, alone of in combination with the T869-->C polymorphism, of the transforming growth factor-beta1 gene with bone mineral density and genetic susceptibility to osteoporosis in Japanese women.

Transforming growth factor-beta1 is an important local regulator of bone metabolism, acting downstream of estrogen and cooperatively with vitamin D. The possible association of a C 509-->T polymorphism in the promoter region of the transforming growth factor-beta1 gene, alone or in combination with a T869-->C (Leu10-->Pro) polymorphism, with bone mineral density and genetic susceptibility to osteoporosis was investigated in 625 postmenopausal Japanese women. The frequencies of the CC, CT, and TT genotypes of the C-509-->T polymorphism in the study population were 24%, 49%, and 27%, respectively. A significant association of C-509-->T genotype with bone mineral density was detected: lumbar spine (L2-L4) and total body bone mineral density values were 7% and 5% lower, respectively, in individuals with the TT genotype than in those with the CT or CC genotype. The serum concentration of transforming growth factor-beta1 did not vary with C-509-->T genotype. Multivariable logistic regression analysis, with adjustment for age, height, body weight, time since menopause, smoking status, body fat mass, and lean mass, revealed a significantly higher frequency of the TT genotype of the C-509-->T polymorphism in 286 individuals with osteoporosis than in 170 normal controls. Analysis of combined C-509-->T and T869-->C genotypes showed that L2-L4 bone mineral density decreases and the prevalence of osteoporosis increases with the number of T alleles. These results suggest that the C-509-->T polymorphism, alone or in combination with the T869-->C polymorphism, of the transforming growth factor-beta1 gene is a genetic determinant of bone mass, and that the number of T alleles in the combined genotype is a risk factor for the genetic susceptibility to osteoporosis in postmenopausal Japanese women.

Aged↗

PubMed2001

Hip fracture prevention trial using hip protectors in Japanese nursing homes.

A method to protect the hips during falls could effectively reduce the incidence of hip fractures. We report the results of the first hip protector trial in Japan, performed between July 1996, and September 1999. One hundred and sixty-four elderly female residents of nursing homes, with Activities of Daily Living above the wheelchair level, agreed to participate in this study. Among them, 88 were randomly selected to wear a hip protector and 76 controls did not. All falls and resulting injuries were recorded daily. In anthropometric measurements and ultrasonic bone evaluation, no significant differences were found between the two groups, except in height. During an average of 377 days, the wearers and the non-wearers fell a total of 131 and 90 times, respectively. Among the wearers, there were two non-hip fractures and one hip fracture, so the annual hip fracture rate was calculated at 1.2%, against 8 hip fractures among the non-wearers, or 9.7% per year. The hip fracture rate was significantly lower among the wearers than non-wearers, while the annual number of falls per subject and the distribution of fallers remained the same. According to Cox's proportional hazard regression analysis, the effect of the hip protector on hip fracture prevention was independent of anthropometric data, ultrasonic bone assessment values or number of falls. Moreover, even after limiting the subjects to fallers only, the annual hip fracture rate in non-wearers was higher than in wearers (19.8% vs 2.0%) and the annual hip fracture rate per fall in wearers was lower than that in non-wearers (0.8% vs 8.2%). It was thus concluded that the hip protector is a beneficial device for the prevention of hip fractures.

Accidental Falls↗

PubMed2001

A gene encoding a hydrophobin, fvh1, is specifically expressed after the induction of fruiting in the edible mushroom Flammulina velutipes.

A cDNA clone of the gene fvh1 was previously isolated from a preprimordial cDNA library made from the basidiomycete Flammulina velutipes. Sequence analysis showed that fvh1 encoded for a hydrophobin, a small fungal protein usually secreted by filamentous fungi. FVH1 had a highly conserved arrangement of eight cysteine residues, a putative N-terminal signal sequence and a hydropathy pattern characteristics of class I hydrophobin. A genomic fvh1 clone was isolated from a F. velutipes genomic DNA library and sequenced. Several putative promoter elements and three small introns of fvh1 were identified in this clone. Southern blot analysis of genomic DNA showed that fvh1 was a single copy gene. Northern analysis indicated that fvh1 was specifically and abundantly expressed in mycelia after the induction of fruiting and during fruit body initiation. It was not expressed in mycelia before the induction of fruiting or in mature fruit bodies.

Agaricales↗

PubMed2001

Physicochemical properties and nuclease resistance of antisense-oligodeoxynucleotides entrapped in the core of polyion complex micelles composed of poly(ethylene glycol)-poly(L-lysine) block copolymers.

In this study, the physicochemical properties of polyion complex (PIC) micelles formed from antisense-oligodeoxynucleotides (antisense-ODN) and poly(ethylene glycol)-poly(L-lysine) block copolymers (PEG-PLL) were investigated to utilize them as a novel formulation for antisense-ODN delivery. Angular and concentration dependences of the diffusion coefficient of PIC micelles were evaluated by dynamic light scattering. Results suggested that the formed PIC micelles may have spherical shape with core-shell structure, in which the PIC core formed from antisense-ODN and PLL segment was surrounded by a PEG shell. The average radius of PIC micelles was dependent on the chain length of the PLL segment and was not influenced by the change in the length of ODN molecules at least in the range between 15 and 20 base pairs. Critical association concentration (cac) of PIC micelles was then determined from a profile of light scattering intensity versus concentration (Debye plots). Cac is ca. 0.20 mg/ml, which is low enough to ensure the micelle stability in very diluted condition as is the case with systemic injection into the blood compartment for antisense-ODN therapy. Furthermore, the stability of antisense-ODN against deoxyribonuclease I (DNase I) attack was evaluated using capillary gel electrophoresis, revealing that the complexation of antisense-ODN with PEG-PLL effectively prohibited DNase I attack. These characteristics of the PIC micelle system highlight its promising feature as ODN carrier used in the field of targeting therapy.

Deoxyribonuclease I↗

PubMed2001

Cyclodextrin-based molecular machines.

Cyclodextrins have been used as a cyclic component in the construction of supramolecular architectures. Recently they have been studied as a component in the construction of rotaxanes and catenanes. A cyclodextrin ring can translocate in some rotaxane and catenane structures. Therefore, much attention has been given to cyclodextrins as a component of molecular shuttles, motors, and machines. Attempts to design and synthesize molecular-level machines using cyclodextrins as a cyclic component are described.

Cyclodextrins↗

PubMed2001

Glutathione-sensitive stabilization of block copolymer micelles composed of antisense DNA and thiolated poly(ethylene glycol)-block-poly(L-lysine): a potential carrier for systemic delivery of antisense DNA.

Glutathione (GSH)-sensitive stabilization of polyion complex (PIC) micelles entrapping antisense oligonucleotide (ODN) was achieved by the reversible cross-linking of the core through disulfide bonds, aiming at the development of a novel DNA carrier system for antisense therapy following systemic administration. Thiolated poly(ethylene glycol)-block-poly(L-lysine) (PEG-thioPLL) and ODN spontaneously associated to form the PIC micelles with the core cross-linked through disulfide bonds. The diameters of the cross-linked micelles were similar to those of the non-cross-linked micelles and were determined to be about 40 nm by light scattering measurements. The micelles have sufficient colloidal stability due to the PEG shell surrounding the core of the polyion complex composed of PLL and ODN. The polyanion exchange studies suggested that the dissociation of the micelles was suppressed through the core cross-linking. The stability of the ODN in the core cross-linked micelles against nuclease was appreciably increased compared to that of free ODN and that in the micelles without cross-linking. On the other hand, the micelles dissociated to release ODN in the presence of GSH at a concentration comparable to the intracellular environment, featuring the potential ability of this system for intracellular ODN delivery.

Cross-Linking Reagents↗

PubMed2001

Sugar-installed block copolymer micelles: their preparation and specific interaction with lectin molecules.

Several types of sugar-installed poly(ethylene glycol)/poly(DL-lactide) (sugar-PEG/PLA) block copolymers were synthesized. The synthesized block copolymer forms a core-shell type polymeric micelle in aqueous media possessing sugar molecules on its surface. Specific recognition of lectin proteins with the sugar molecules on the micelle surface was observed. Both the galactose- and lactose-installed micelles specifically interacted with RCA-1; on the other hand the mannose-installed micelle interacted specifically with Con A. With a lectin-immobilized affinity column, the cluster effect of the sugar molecule on the micelle surface was clearly observed.

Biocompatible Materials↗

PubMed2001

Glomerular crescents in renal amyloidosis: an epiphenomenon or distinct pathology?

There have been several reports of cases of renal amyloidosis with glomerular crescents. However, it is not clear whether the association is fortuitous or pathogenic related. The present study analyzed 105 cases of renal amyloidosis (61 autopsy cases and 44 biopsy cases) and found glomerular crescents in 14 (13.3%) cases. Among the 14 cases with crescents, a female predominance was noted (male: female, 3: 11) and rheumatoid arthritis was the most common primary disease of amyloidosis. Immunohistochemical analysis demonstrated amyloid protein of AA type in 12 cases. According to the histologic classification, there were 11 cases of mesangial nodular type, which was almost exclusively accompanied by AA amyloid deposition. Of note, the incidence of crescents neither correlated with the extent of amyloid deposition nor the presence of nephrotic syndrome. By contrast, localization of amyloid deposition was closely related to crescent formation. Moreover, electron microscopic observation displayed rupture of the glomerular basement membrane at the site of amyloid deposition. Our results indicated that glomerular crescents were more frequently associated with renal amyloidosis than previously appreciated. Rupture of the fragile glomerular basement membrane by amyloid deposition, as revealed by immunostaining and electron microscopy, may be the mechanism of crescent formation. We suggest that glomerular crescents are a distinct pathology associated with renal amyloidosis, not fortuitous conditions.

Adult↗