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Biomedical subjects

K Fujihara

Publications and source records attributed to K Fujihara.

At least 19 recordsLinked to original sources
PubMed2006

Clinical and MRI features of Japanese patients with multiple sclerosis positive for NMO-IgG.

This study investigates the relation between the serological status of NMO (neuromyelitis optica)-IgG and the clinical and MRI features in Japanese patients with multiple sclerosis. Serum NMO-IgG was tested in 35 Japanese patients diagnosed with multiple sclerosis, including 19 with the optic-spinal form of multiple sclerosis (OSMS), three with the spinal form of multiple sclerosis (SMS), and 13 with the conventional form of multiple sclerosis (CMS), which affects the brain. NMO-IgG was detected in 14 patients, 12 with OSMS and 2 with CMS. In these patients, longitudinally extensive (> 3 vertebral segments) spinal cord lesions (93% v 57%) and permanent, complete blindness (no perception of light) in at least one eye (50% v 0%) were the noticeable features as compared with NMO-IgG-negative OSMS. The two patients having CMS with NMO-IgG had unusual brain lesions, but in other respects had features suggesting OSMS. NMO-IgG was detected in more than half the number of patients with OSMS and in some patients with CMS. This newly discovered serum autoantibody was markedly associated with longitudinally extensive spinal cord lesions and with complete blindness, suggesting severe optic-spinal disease.

Adult↗
PubMed2006

Relevance of callosal and periventricular MRI lesions to oligoclonal bands in multiple sclerosis.

OBJECTIVES: To evaluate the association between callosal or periventricular lesions, and the presence of oligoclonal IgG bands (OB) or the IgG index in Japanese patients with multiple sclerosis (MS). MATERIALS AND METHODS: Brain magnetic resonance imaging (MRI) was studied in 34 Japanese clinically definite MS cases. Sagittal 2-mm fast fluid-attenuated inversion-recovery (FLAIR) imaging was added to the routine MRI studies. RESULTS: Among the 34 patients, 20 (59%) were OB positive. Among the 20 patients with OB-positive MS, 17 (85%) had callosal lesions, although only two (14%) of 14 OB-negative MS patients had callosal lesions. The periventricular lesion area was significantly larger in the OB-positive patients compared with the OB-negative patients. CONCLUSIONS: The present study clearly demonstrated a strong association between the periventricular lesions and OB in Japanese MS. Certain OB-related immune mechanisms may contribute to the development of callosal and periventricular lesions in MS. OB may be an important factor to understand the pathomechanisms of MS lesions.

Adult↗
PubMed2005

Intractable hiccup and nausea with periaqueductal lesions in neuromyelitis optica.

Intractable hiccup and nausea (IHN) was found in eight of 47 cases of relapsing neuromyelitis optica (NMO) (17%) but in none of 130 cases of multiple sclerosis (MS). IHN resolved with methylprednisolone. In six cases, MRI detected linear medullary lesions involving the pericanal region, the area postrema, and the nucleus tractus solitarius. Like long and centrally located myelitis, a linear medullary lesion causing IHN may distinguish NMO from MS.

Adult↗
PubMed2005

Guided bone regeneration membrane made of polycaprolactone/calcium carbonate composite nano-fibers.

In this study, new type of guided bone regeneration (GBR) membranes were fabricated by polycaprolactone (PCL)/CaCO3 composite nano-fibers with two different PCL to calcium carbonate (CaCO3) ratios (PCL:CaCO3=75:25 wt% and 25:75 wt%). The composite nano-fibers were successfully fabricated by electrospinning method and CaCO3 nano-particles on the surface of nano-fibers were confirmed by energy disperse X-ray (EDX) analysis. In order to achieve mechanical stability of GBR membranes, composite nano-fibers were spun on PCL nano-fibrous membranes which has high tensile strength, i.e., the membranes consist of two layers of functional layer (PCL/CaCO3) and mechanical support layer (PCL). Two different GBR membranes were prepared, i.e., GBR membrane (A)=PCL:CaCO3=75:25 wt%+PCL, GBR membrane (B)=PCL:CaCO3=25:75 wt%+PCL. Osteoblast attachment and proliferation of GBR membrane (A) and (B) were discussed by MTS assay and scanning electron microscope (SEM) observation. As a result, absorbance intensity of GBR membrane (A) and tissue culture polystyrene (TCPS) increased during 5 days seeding time. In contrast, although absorbance intensity of GBR membrane (B) also increased, its value was lower than membrane (A). SEM observation showed that no significant difference in osteoblast attachment manner was seen on GBR membrane (A) and (B). Because of good cell attachment manner, there is a potential to utilize PCL/CaCO3 composite nano-fibers to GBR membranes.

Biocompatible Materials↗
PubMed2005

An autopsied case of neuromyelitis optica with a large cavitary cerebral lesion.

We report a case of neuromyelitis optica (NMO) with a large cerebral lesion. The patient had an episode of fever and consciousness disturbance with a tumefactive frontal white matter lesion at age 43, and then repeated bilateral optic neuritis and transverse myelitis until she died at age 63. Histopathological examinations revealed that marked tissue destruction, cavities and inflammatory changes typical of NMO were seen in the cerebrum as well as the optic nerves and spinal cord. This is the first autopsied case of NMO with a tumefactive cerebral lesion that later became cavitary.

Fatal Outcome↗
PubMed2004

Absence of IgG1 response in the cerebrospinal fluid of relapsing neuromyelitis optica.

The authors studied immunoglobulin (Ig) G subclasses in the CSF and sera of patients with relapsing neuromyelitis optica (RNMO) and typical multiple sclerosis (MS). Although the total IgG concentrations were elevated in the CSF of patients with RNMO and MS, IgG1% and IgG1 index were significantly elevated only in patients with MS. The absence of the CSF IgG1 responses in the patients with RNMO may suggest less Th1 immunity and may also explain the rarity of oligoclonal IgG bands in patients with this disease.

Adult↗
PubMed2004

Feasibility of knitted carbon/PEEK composites for orthopedic bone plates.

This paper focuses on fabrication and characterization of knitted carbon/PEEK fabric composites for orthopedic bone plate application. Bending performance of the knitted carbon/PEEK composite bone plates was investigated with respect to two principal knitting directions (wale- and course-directions). As a result, the wale-direction knitted composite bone plates had much scattering in bending stiffness and maximum bending moment although they exhibited the same bending behavior as that of the course-direction specimens. In comparison with our previously developed braided composite bone plates, the knitted composite bone plates had 55-59% bending stiffness, 40-63% yield bending moment, and 54-77% maximum bending moment. However, the knitted composite bone plates showed higher deformability. Based on the results of the braided composite bone plates, it is considered that the knitted composite plate with 3.2mm thickness can be suitable for forearm or humerus treatment especially when damaged bones need higher deformation to encourage bone ossification.

Benzophenones↗
PubMed2004

Epitope analysis of the cerebrospinal fluid IgG in HTLV-I associated myelopathy patients using phage display method.

We, for the first time, analyzed the binding motifs of immunoglobulin G (IgG) in the cerebrospinal fluid (CSF) of human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients with a phage library displaying 12-mer random peptides. As a result, the sequences highly homologous to HTLV-I gp46 192-199, 237-243 and 255-261 were the common linear epitopes of high affinity- IgG exclusively detected in both CSF and sera of the patients. These IgG responses were confirmed with corresponding HTLV-I peptides and serum antibody titers significantly correlated with disease severity or duration. Gp46 237-243 has not been detected in previous enzyme-linked immunosorbent assay (ELISA) studies using bound longer peptides, suggesting the usefulness of the phage display method.

Adult↗
PubMed2003

Performance study of braided carbon/PEEK composite compression bone plates.

In addition to unidirectional laminates and short fiber reinforcements for compression bone plate developments in the literature, we have proposed using a textile structure, i.e. braid preform, for this purpose. In the present paper, the influence of braiding angles and plate thicknesses on the bending performance of the braided composite bone plates is investigated. As a result, the influence of the braiding angle, varied in a certain range, on the plate bending properties is not significant when the plate thickness is thin. This influence becomes higher with an increase in the plate thickness. A 10 degrees braiding angle has been seen to be appropriate for all the cases under consideration. The present study indicates that the braided composite plate with 2.6mm thickness can be suitable for forearm treatment whereas the braided composite plate of 3.2mm thickness is applicable to femur or tibia fixation.

Animals↗
PubMed2003

Fabrication of a new composite orthodontic archwire and validation by a bridging micromechanics model.

A new technique based on tube shrinkage is proposed for the fabrication of composite archwires. Compared with a traditional pultrusion method, this new technique can avoid any fiber damage during the fabrication and can provide the archwire with a required curvature in its final clinical usage. The present paper focuses on the technique development and mechanical design and validation in terms of constituent materials by using a micromechanics bridging model. Prototype archwire has been fabricated using fiberglass and an epoxy matrix, with a wire diameter of 0.5mm and a 45% fiber volume fraction. Tensile and three-point bending tests have shown that the mechanical performance of the prototype composite archwire is comparable to that of a clinical Ni-Ti archwire. Another purpose of the present paper is to provide an efficient procedure for a critical design of composite archwires. For this to be possible, the ultimate load especially flexural load carrying ability of the composite archwire must be assessed from the knowledge of its constituent properties. However, difficulty exists in doing this, which comes from the fact that the failure of the utmost filament of the composite archwire subjected to initially the maximum bending stress does not imply its ultimate failure. Additional higher loads can still be applied and a progressive failure process is generated. In this paper, the circular archwire was discretized into a number of parallel laminae along its axis direction, and the bridging micromechanics model combined with the classical lamination theory has been applied to understand the progressive failure process with reasonable accuracy. Only the constituent fiber and matrix properties are required for this understanding. Nevertheless, the ultimate bending strength cannot be obtained only based on a stress failure criterion. This is because neither the first-ply nor the last-ply failure corresponds to the ultimate failure. An additional critical deflection (curvature) condition must be employed also. By using both the stress failure and the critical deflection conditions, the predicted load-deflection up to the ultimate failure agrees well with the measured data. Thereafter, different mechanical performances of composite archwires can be tailored before fabrication by choosing suitable constituent materials, their contents, and the archwire diameters. Several design examples have been shown in the paper.

Computer Simulation↗
PubMed2002

Gamma-aminobutyric acidA and benzodiazepine receptor alterations in the rat brain after unilateral 6-hydroxydopamine lesions of the medial forebrain bundle.

Gamma-aminobutyric acidA (GABA(A)) and benzodiazepine (BZ) receptors and dopamine uptake sites in 6-hydroxydopamine-treated rat brains were studied by receptor autoradiography using [3H]muscimol, [3H]flunitrazepam and [3H]mazindol binding, respectively. The rats were unilaterally lesioned in the medial forebrain bundle and the brains were analyzed at 1, 2, 4 and 8 weeks post-lesion. Degeneration of the nigrostriatal pathway after 6-hydroxydopamine treatment caused a significant loss of dopamine uptake sites in the ipsilateral striatum and substantia nigra (SN) in the lesioned animals. In the contralateral side, however, dopamine uptake sites showed no significant changes in the brain throughout the experiments. On the other hand, no significant changes in GABA(A) receptors were observed in the brain of both the ipsilateral and contralateral sides during post-lesion. In contrast, BZ receptors were observed significantly increased in the ventromedial part of striatum of the ipsilateral side from 2 to 4 weeks post-lesion. Furthermore, a transient increase in BZ receptors was found in the ipsilateral SN only at 2 weeks post-lesion. In contralateral side, most regions examined showed no significant changes in BZ receptors throughout the experiments except for a transient increase in the SN at 1 week post-lesion. These results demonstrate that 6-hydroxydopamine can cause severe functional damage in dopamine uptake sites in the nigrostriatal pathway. Our results also suggest that the change in BZ receptors is more pronounced than that in GABA(A) receptors in the brain after 6-hydroxydopamine treatment. Furthermore, our findings suggest that the increase in BZ receptors in the brain of 6-hydroxydopamine-treated model may be due to the additional disruption of the nigrostriatal dopamine system. Thus, investigations into possible changes in neurotransmitter receptors other than dopaminergic receptors appear to be important for the elucidation of pathogenesis of Parkinsons disease.

Animals↗
PubMed2002

A comparative study of Japanese multiple sclerosis patients with and without oligoclonal IgG bands.

The cerebrospinal fluid oligodonal IgG bands (OB) are less frequently observed in Japanese multiple sclerosis (MS) patients compared with Caucasian patients. We studied 40 consecutive Japanese MS patients to investigate the differences in the clinical and magnetic resonance imaging (MRI) features of MS between OB-positive patients and OB-negative ones. Among the 40 patients, 22 (55%) patients were OB-positive by either agarose gel electrophoresis (AGE) or isoelectric focusing (IEF), and 18 (45%) patients were OB-negative by both AGE and IEF. There were differences between the two groups only in the clincal forms of MS, but not in terms of gender, onset age, disease duration, or disease severity. In the OB-negative group, nine (50%) of the patients had the optic-spinal form of MS (OS-MS), but only one patient (4.5%) in the OB-positive group had OS-MS. Although most OB-positive patients showed brain MRI lesions typical of MS, 13 (72%) of the OB-negative patients showed no or few brain MRI lesions and the rest of the OB-negative patients showed atypical MS lesions, such as diffuse white matter lesions or large ring-enhanced lesions. Our results suggest that the majority of OB-negative Japanese MS patents show either no or few brain MRI lesions or atypical brain MRI lesions.

Adult↗
PubMed2001

Decreased expression of c-myc family genes in thymuses from myasthenia gravis patients.

The thymus is a critical organ for the elimination of autoreactive T cells by apoptosis. We studied the expression of apoptosis-associated genes, bcl-xL, bad, caspase-3, and c-myc family genes in myasthenia gravis (MG) thymuses. We observed that the mRNA levels of myc family genes, c-myc and max, were markedly reduced in MG thymuses. These results indicate that c-myc-mediated signaling is abnormal in MG thymuses. The levels of molecules whose expressions are associated with myc, such as STAM, prothymosin-alpha, and NFkappaB, were also analyzed.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Clinical and physiological significance of abnormally prolonged central motor conduction time in HAM/TSP.

We measured the central motor conduction time (CMCT), central sensory conduction time (CSCT), F wave and mean F wave/M wave amplitude ratio in patients with HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) and controls. CMCTs in upper (U) and lower (L) limbs were significantly prolonged in HAM/TSP. L-CSCT was significantly prolonged in HAM/TSP, but U-CSCT in HAM/TSP and controls were not significantly different. CMCT and CSCT were significantly correlated in HAM/TSP. U-CMCT, but not L-CMCT, correlated with the clinical severity of HAM/TSP. Although F wave conduction velocity and its occurrence were normal in HAM/TSP, U- and L-mean F wave/M wave amplitude ratio tended to be higher in HAM/TSP, and the L-mean F wave/M wave amplitude ratio was significantly correlated with the L- and thoracic CMCT. These findings demonstrate that the prolongation of CMCT sensitively reflects the extension of the lesions and the disinhibition to the anterior horn cells in HAM/TSP.

Aged↗
PubMed2001

Chemokine receptor expression on T cells in blood and cerebrospinal fluid at relapse and remission of multiple sclerosis: imbalance of Th1/Th2-associated chemokine signaling.

The expression of chemokine receptors on lymphocytes in the blood and CSF of multiple sclerosis (MS) patients was analyzed at relapse and remission. Both CD4+ and CD8+ cells in CSF at relapse were enriched for Th1-type receptors CXCR3 and CCR5 expression, and were reduced for Th2-type receptors CCR3 and CCR4 expression compared with those of the blood. CCR1 and CCR2 expressions on T cells were increased in CSF and blood, respectively. At remission, CCR5 expression, but not CXCR3 expression, was reduced in CSF CD4+ cells. A biased Th1/Th2 balance may play a critical role in active inflammation and CCR5 on CSF CD4+ cells is a good marker of the disease activity.

Adult↗
PubMed2001

Linear pontine trigeminal root lesions in multiple sclerosis: clinical and magnetic resonance imaging studies in 5 cases.

BACKGROUND: Magnetic resonance imaging (MRI) is useful for demonstrating demyelinating lesions in patients with multiple sclerosis (MS). Magnetic resonance imaging studies show that MS lesions are generally not uniform in shape, size, or distribution. Linearly shaped lesions at the trigeminal root entry zone have been occasionally reported in single cases of MS, but, to our knowlege, the frequency and the clinical features of such patients have not been comprehensively characterized. OBJECTIVE: To describe the frequency and the clinical and laboratory features of patients with MS who had linearly shaped lesions at the trigeminal root as seen on MRI. DESIGN AND SETTING: A retrospective review of medical records and MRI films of Japanese patients with MS admitted to a university hospital and its affiliated hospital in Sendai, Japan. PATIENTS AND METHODS: Brain MRI films of 74 consecutive Japanese patients with MS (51 females and 23 males) were studied retrospectively and the clinical and laboratory features of the patients with linearly shaped lesions at the trigeminal root were also investigated retrospectively. RESULTS: Five patients (6.8%) were shown to have T1-weighted-hypointense, T2-weighted-hyperintense, nonenhanced linear lesions in the pons on MRI, and these were uniformly localized in the intramedullary portion of the trigeminal root. All of these patients had clinically definite MS and had various types of facial sensory disturbances, such as neuralgia (1 patient), hypesthesia (2 patients), or paresthesia (3 patients). No other clinical or laboratory feature was characteristic in these 5 patients. CONCLUSIONS: Linear pontine trigeminal root lesions were common in our patients with MS. They were associated with various facial sensory symptoms. Since similar lesions are formed in animal models of herpes simplex virus infection, further study is needed to clarify whether these MS lesions are virally induced.

Adolescent↗