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Biomedical subjects

M Kamimura

Publications and source records attributed to M Kamimura.

At least 19 recordsLinked to original sources
PubMed2001

Molecular cloning of silkworm paralytic peptide and its developmental regulation.

The silkworm paralytic peptide (PP) is a member of the ENF peptide family that exerts multiple biological activities involved in defense reaction and growth regulation. We isolated its cDNA and examined mRNA expression profiles. cDNA encoded 131 amino acids from which the 23-residue PP sequence was found at the C-terminal portion. Immunoblot analysis and paralytic activity assay indicated that inactive pro-protein in larval hemolymph was processed into active peptide immediately after bleeding. In the last larval instar, 0.6-kb PP mRNA was expressed in various tissues, of which the fat body was predominant. Its expression in the fat body decreased during the feeding period and then increased during metamorphic process. Juvenile hormone and 20-hydroxyecdysone upregulated its expression. At the embryonic stage, 1.5-kb mRNA, in addition to 0.6-kb mRNA, was expressed from 1 day after oviposition to hatching. PP was thus expressed stage-specifically under hormonal control.

Amino Acid Sequence↗
PubMed2001

Early-phase enhanced inflammatory reaction after spinal instrumentation surgery.

STUDY DESIGN: The erythrocyte sedimentation rate, C-reactive protein, white blood cell count, and body temperature were measured prospectively in patients after two types of spinal surgery without complications and three cases of infection after spinal instrumentation surgery. OBJECTIVES: To investigate the effects of instrumentation on postoperative inflammatory reaction, and to describe early detection of postoperative wound infection. SUMMARY OF BACKGROUND DATA: In thoracic and abdominal surgery as well as hip arthroplasty, C-reactive protein has proved more valuable than erythrocyte sedimentation rate for early detection of postoperative infectious complications. It has not yet been established, however, how inflammatory parameters change after surgery when spinal instruments have been inserted into the body. METHODS: For this study, two groups of patients were examined: a control group that underwent spinal decompression surgery without instrumentation (n = 36) and another group that underwent spinal decompression and fusion surgery with spinal instrumentation (n = 37). The erythrocyte sedimentation rate, C-reactive protein, white blood cell count, and body temperature were recorded 1 day before surgery and on days 0 to 4, 7, 11, 14, 21, 28, and 42 after surgery. RESULTS: Inflammatory indexes (i.e., C-reactive protein, erythrocyte sedimentation rate, white blood cell count, and body temperature) were significantly higher for the surgery with instrumentation than for the spinal decompression surgery without instrumentation. Multiple regression analysis showed that C-reactive protein and erythrocyte sedimentation rate peaks significantly correlated with the use of instrumentation (C-reactive protein: P = 0.000257, erythrocyte sedimentation rate: P = 0.000132). In the patients with infection after spinal instrumentation surgery, C-reactive protein, white blood cell count, and body temperature started to increase again 4 to 11 days after surgery. The elevation of erythrocyte sedimentation rate levels was prolonged. CONCLUSIONS: Erythrocyte sedimentation rate and C-reactive protein display a significantly higher reaction after spinal surgery with instrumentation. Renewed elevation of C-reactive protein, white blood cell count, and body temperature after postoperative days 4 to 7 may be a critical sign of postoperative infection.

Adult↗
PubMed2001

The juvenile hormone binding protein of silkworm haemolymph: gene and functional analysis.

A cDNA fragment of haemolymph juvenile hormone binding protein (hJHBP) from larvae of Bombyx mori was amplified by RT-PCR using degenerate primers based on the N-terminal amino acid sequence of purified hJHBP and a conserved region near the C-terminus of other lepidopteran hJHBPs. 5'- and 3'-ends were amplified by RACE to yield cDNAs, hJHBP1 and hJHBP2, encoding 225 amino acids with three substitutions. hJHBP-mRNA levels in the fat body were constant in the 4th instar, but decreased in the 5th. JHBP protein was constant until wandering, then declined. Recombinant hJHBP1 expressed in E. coli migrated on SDS-PAGE with a Mr of 32 kDa and showed a Kd of 4.5 x 10-7 M with JH III, both similar to those of native hJHBP.

Amino Acid Sequence↗
PubMed2001

Evaluation of thoracic myelopathy by transcranial magnetic stimulation.

It is sometimes difficult to determine the appropriate surgical site in patients with thoracic myelopathy with diffuse or multisegmental lesions. To solve this problem, a magnetic stimulation study was carried out. Seven patients with myelopathy and 10 healthy control subjects were examined. Transcranial magnetic stimulation was applied and the motor evoked potentials (MEPs) of the intercostal muscles were recorded. The MEP latencies for the two groups were then compared. In patients with thoracic myelopathy, the MEP latencies caudal to the lesion were more extended than those of the control subjects. This method could identify the levels at which myelopathy originates in patients with a radiologically visible lesion. This method has the potential to be used for deciding the surgical site at the level responsible for myelopathy in cases with multiple or diffused compression.

Adult↗
PubMed2001

Mucosa-associated lymphoid tissue in middle ear and eustachian tube.

The presence of mucosa-associated lymphoid tissue (MALT) was investigated histopathologically in every 20th section from 99 vertically cut, celloidin-embedded temporal bone-eustachian tube (ET) specimens. Among specimens from infants and children between 1 month and 7 years of age, MALT was found in 22 of 44 (50%). However, in 26 adults over 18 years of age, MALT was found in only 2 specimens (7.7%), a significantly lower incidence than that in infants and children. Moreover, MALT did not appear in any of the 21 neonates under the age of 1 month. All 99 specimens were classified into 2 groups: 41 specimens with otitis media (OM) and 58 specimens without OM. The presence of MALT was significantly higher in specimens with OM (43.9%) than in specimens without OM (13.8%). Mucosa-associated lymphoid tissue was found in the ET, middle ear, and mastoid process in 18 specimens (43.9%). 5 specimens (12.2%), and 1 specimen (2.4%) with OM, respectively, and in 8 (13.8%), 0, and 0 specimens without OM. In regard to the distribution of MALT, it occurred more frequently in the pharyngeal half of the cartilaginous portion of the ET than in the rest of the ET, middle ear, and mastoid; the presence was significantly greater in the inferior half of the cartilaginous portion of the ET than in the superior half. Inflammatory cell infiltration in the cartilaginous and bony portions of the ET was significantly greater in specimens with OM than in specimens without OM with no MALT. However, even in some specimens without OM, inflammatory cells were found in the ET, particularly in the pharyngeal half of the cartilaginous portion of the ET. These findings suggest that MALT has a close relationship to OM and that it may be a local response to repeated infection.

Adolescent↗
PubMed2001

Ecdysone-inducible foreign gene expression in stably-transformed lepidopteran insect cells.

Cultured cell lines that can be stably transformed with inducible gene constructs could prove extremely valuable for the continuous and economical production of recombinant proteins. Toward this goal, we have established 11 clones (designated NISES-BoMo-DK1 to 11) from a previously reported silkworm cell line, NISES-BoMo-DZ. Nine of these clonal lines showed a distinct morphological change. i.e., cell aggregation, in response to treatment with 1 microM 20-hydroxyecdysone (20E). DK10 cells transfected with various reporter assay plasmids under optimal conditions (i.e., 20-30% transfection efficiency) showed inducibility of gene expression by 20E. The 20E treatment of the prototypical DK10 cells resulted in a simultaneous, transient increase of the nuclear ecdysone (E) receptor levels. Further, this inducibility was also observed in a DK10 cell line stably transformed with the reporter plasmid that carries the hygromycin-resistance gene. This offers an opportunity to achieve efficient, continuous production of recombinant proteins. It could also allow high throughput screening for potential E agonists.

Animals↗
PubMed2000

LambdaN spin-orbit splittings in (9)(Lambda)Be and (13)(Lambda)C studied with one-boson-exchange LambdaN interactions

Movitated by the on-going gamma-ray experiments at the Alternating Gradient Synchrotron at Brookhaven National Laboratory, we discuss the energy splittings of the 5/2(+)(1)-3/2(+)(1) doublet in (9)(Lambda)Be and the 3/2(-)(1)-1/2(-)(1) doublet in (13)(Lambda)C for which the LambdaN spin-orbit ( LS) and antisymmetric spin-orbit ( ALS) forces are relevant. In the microscopic 2alpha+Lambda ( 3alpha+Lambda) model for (9)(Lambda)Be ( (13)(Lambda)C), all the available Nijmegen one-boson-exchange (OBE) model LambdaN interactions lead to a wide range of splittings of 0.08-0.20 MeV in (9)(Lambda)Be and 0.39-0.96 MeV in (13)(Lambda)C. On the other hand, if we use information from quark-model LambdaN interactions which have generally large ALS force, the splittings become about half of the smallest OBE model prediction.

Journal Article↗
PubMed2000

A new system for the anterior restoration and fixation of thoracic spinal deformities using an endoscopic approach.

STUDY DESIGN: A report on the results of animal experiments in which the authors' new system that enables the anterior correction and fixation of thoracic spinal deformity by use of a thoracic endoscope and small incisions was used. The results suggest that the new approach involving thoracoscopic anterior correction and fusion for thoracic spinal deformity could be adapted successfully for the clinic. OBJECTIVE: To develop a new system that enables the anterior correction and fixation of thoracic spinal deformity by use of a thoracic endoscope and small incisions. SUMMARY OF BACKGROUND DATA: Anterior correction and fusion through open thoracotomy have been applied mainly for thoracic scoliosis because this approach provides effective correction with short fusion. However, excellent visualization of the spine during thoracic surgical procedures led to the development of thoracoscopic spine surgery. Therefore, the authors postulated that a thoracoscopic approach could allow not only discectomy but also correction and fusion of the deformed thoracic spine in a single surgical event. METHODS: The vertebral columns and attached thoracic walls were dissected from fresh porcine cadavers and used in the experimental surgery to evaluate the new system. As a next step, thoracoscopic surgery using this new system was performed on four or five vertebrae of five live pigs with an average weight of 50 kg. Initially, the discs and rib heads were removed through the thoracic wall. For each vertebra, a screw connected to a shaft used as a screw holder was inserted through the thoracic wall in a posterior to anterior direction. Each shaft then was linked outside the body to an outrigger. This outrigger was used to both create and restore scoliosis. A rod then was introduced through the thoracic wall and fixed to the screw heads. RESULTS: The animal experiments clearly showed that it was possible to change the Cobb angles of the spine through the use of the outrigger apparatus. In cadaver experiments, it was possible to create scoliosis and re-store it by 25 degrees to 35 degrees. Also, surgery on live pigs resulted in scoliosis of approximately 30 degrees, which means approximately 5 degrees to 10 degrees for each disc space. The procedures used also demonstrated that it was possible to fix a rod, introduced into the pleural cavity through a port, with screw heads. CONCLUSIONS: The use of this system successfully changed the Cobb angle of the spine, which suggests that its use should make it possible to correct spinal deformities. This apparatus also succeeded in fixing the rods in the screw heads, which raises the possibility of its use in spinal fixation. The authors believe that this apparatus could be adapted successfully for clinical use. Studies currently are under way in clinics using the new system.

Animals↗
PubMed2000

Bioactive bone cement: effect of surface curing properties on bone-bonding strength.

The fact that bisphenol-a-glycidyl methacrylate (bis-GMA)-based cements contain an uncured surface is believed to play an important role when determining the surface curing properties of the cements. Therefore, in the present study, the bone-bonding strength of cement plates having an uncured surface on one side and a cured surface on the other side has been evaluated. These cement plates were composites of a bis-GMA-based resin with either an apatite- and wollastonite-containing glass-ceramic (AW-GC) powder or a hydroxyapatite (HA) powder, respectively designated AWC and HAC. The amount of each of these powders in a composite cement was 70 wt %. We formulate the hypothesis that the uncured surface of a cement plate is bioactive having bone-bonding properties. The goal of the present study was to indicate the bone-bonding strength of the uncured surfaces of AWC and HAC and compare the strength with the respective cured surfaces by a detaching in vivo test, as well as to histologically examine the bone-cement interface. Each plate has been implanted into the tibiae of male Japanese white rabbits, taking care to retain the surface properties, and the so-called "failure load has been measured using a detaching test followed 8 weeks after implantation. The failure load for AWC-plates at the uncured surface (2.05 +/- 1.11 kgf, n = 8) was significantly higher than AWC at its cured surface side (0.28 +/- 0.64 kgf, n = 8). The failure load for HAC-plates at the uncured surfaces (1.40 +/- 0.68 kgf, n = 8) was significantly higher than HAC at its cured surface (0.00 +/- 0.00 kgf, n = 8). Failure loads for AWC at its uncured and cured surfaces were both higher than for HAC, although not significantly. Direct bone formation has been observed histologically for both AWC and HAC on the uncured surfaces, and a Ca-P-rich layer was observed only at the uncured surface of AWC. These findings strongly suggest that uncured surfaces are useful for exposing a bioactive filler on a surface of composites, being very effective in inducing bone bonding.

Animals↗
PubMed2000

Bioactive polymethyl methacrylate-based bone cement: comparison of glass beads, apatite- and wollastonite-containing glass-ceramic, and hydroxyapatite fillers on mechanical and biological properties.

A new bioactive bone cement (designated GBC) consisting of polymethyl methacrylate (PMMA) as an organic matrix and bioactive glass beads as an inorganic filler has been developed. The bioactive beads, consisting of MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) glass, have been newly designed, and a novel PMMA powder was selected. The purpose of the present study was to compare this new bone cement GBC's mechanical properties in vitro and its osteoconductivity in vivo with cements consisting of the same matrix as GBC and either apatite- and wollastonite-containing glass-ceramic (AW-GC) powder (designated AWC) or sintered hydroxyapatite (HA) powder (HAC). Each filler added to the cements amounted to 70 wt %. The bending strength of GBC was significantly higher than that of AWC and HAC (p < 0.0001). Cements were packed into intramedullar canals of rat tibiae in order to evaluate osteoconductivity as determined by an affinity index. Rats were sacrificed at 2, 4, and 8 weeks after operation. An affinity index, which equaled the length of bone in direct contact with the cement expressed as a percentage of the total length of the cement surface, was calculated for each cement. At each time interval studied, GBC showed a significantly higher affinity index than AWC or HAC up to 8 weeks after implantation (p < 0.03). The value for GBC increased significantly with time up to 8 weeks (p < 0.006). The handling property of GBC was comparable with that of PMMA bone cement. Our study revealed that the higher osteoconductivity of GBC was due to the higher bioactivity of the bioactive glass beads at the cement surface and the lower solubility of the new PMMA powder to MMA monomer. In addition, it was found that the smaller spherical shape and glassy phase of the glass beads gave GBC strong enough mechanical properties to be useful under weight-bearing conditions. GBC shows promise as an alternative with improved properties to the conventionally used PMMA bone cement.

Animals↗
PubMed2000

Biological and mechanical properties of PMMA-based bioactive bone cements.

We reported previously that a bioactive PMMA-based cement was obtained by using a dry method of silanation of apatite-wollastonite glass ceramic (AW-GC) particles, and using high molecular weight PMMA particles. But handling and mechanical properties of the cement were poor (Mousa et al., J Biomed Mater Res 1999;47:336-44). In the present study, we investigated the effect of the characteristics of PMMA powder on the cement. Different cements containing different PMMA powders (CMW1, Surgical Simplex, Palacos-R and other two types of PMMA powders with Mw 270,000 and 1,200,000) and AW-GC filler in 70 wt% ratio except Palacos-R (abbreviated as B-CMW1 and B-Surg Simp, B-Palacos 50 [50 wt% AW-GC filler] and B-Palacos 70 [70 wt% AW-GC filler], B-270 and B-1200) were made. Dough and setting times of B-CMW1, B-Surg Simp B-270 and B-1200 were similar to the commercial CMW1 cement which did not contain bioactive powder (C-CMW1), but B-palacos which contained large PMMA beads with high Mw had delayed setting time. B-270 had the highest bending strength among the tested cements. After 4 and 8 weeks of implantation in the medullary canals of rat tibiae, the bone-cement interface was examined using SEM. The affinity index of B-1200 was significantly higher than the other types of cements. B-270 showed good combination of handling properties, high mechanical properties and showed higher bioactivity with minimal soft tissue interposition between bone and cement compared with commercial PMMA bone cement. This may increase the strength of the bone-cement interface and increase the longevity of cemented arthroplasties.

Animals↗
PubMed2000

Peroral infection of nuclear polyhedrosis virus budded particles in the host, Bombyx mori l., enabled by an optical brightener, Tinopal UNPA-GX.

Perorally inoculated budded particles of a nuclear polyhedrosis virus was used to infect Bombyx mori (BmNPV) (Lepidoptera; Bombycidae), aided by an optical brightener, Tinopal UNPA-GX (Tinopal). BmNPV budded particles not occluded in the occlusion body do not infect successfully the host, B. mori, when administered perorally. It was found that feeding the host Tinopal enabled perorally delivered BmNPV budded particles to infect the host. B. mori larvae ingesting BmNPV budded particles (1.3 x 10(6) TCID(50) units per larva) after they consumed an artificial diet containing 0. 3% Tinopal died of the viral infection. Peroral administration of these particles to host larvae with 1% Tinopal also resulted in virus infection. Tinopal is a candidate for viral activity enhancing agent promoting viral insecticide infection in hosts. The results suggest that B. mori-BmNPV budded particles are convenient for detecting viral infection enhancement activity of a chemical of interest. Since recombinant baculovirus vectors are constructed by replacing the polyhedrin gene with the foreign gene of interest, they do not produce occlusion bodies, i.e. polyhedra. Budded particles of a baculovirus vector not occluded in polyhedra cannot infect their hosts when administered perorally. The peroral inoculation of BmNPV budded particles by Tinopal leads to industrial pharmaceutics production using a baculovirus vector for a huge number of insect hosts, i.e. an 'insect factory'.

Administration, Oral↗
PubMed2000

Functional retinoid receptors in budding ascidians.

A homolog of retinoid X receptors (RXR), named PmRXR, was cloned from the budding ascidian, Polyandrocarpa misakiensis. Gel-shift assays revealed that PmRXR and a previously identified P. misakiensis retinoic acid receptor (PmRAR) formed a complex to bind vertebrate-type retinoic acid response element (RARE). Transfection assays were carried out using a reporter gene containing a RARE upstream of lacZ. Two chimeric effector genes were constructed by placing PmRXR and PmRAR cDNA fragments (containing the DNA-binding, ligand-binding and ligand-dependent transactivation domains) downstream of the human RXR alpha and RAR alpha cDNA (covering the N-terminal coding region), respectively. Each chimeric cDNA was ligated to a notochord-specific enhancer. In case the embryos were transfected with all three transgenes and treated with retinoic acid (RA), the reporter gene was activated in the notochord cells. The result suggests that the PmRXR/PmRAR complex functions as an RA-dependent transcriptional activator. The PmRXR mRNA was detected in a mesenchymal cell type, called glomerulocyte, in the developing Polyandrocarpa bud. As this cell type has been shown to express PmRAR mRNA, it seems possible that the PmRXR/PmRAR complex mediates RA signaling in this cell type to induce the expression of genes involved in the morphogenesis of the developing bud.

Amino Acid Sequence↗
PubMed2000

Cervical pedicle screw insertion: assessment of safety and accuracy with computer-assisted image guidance.

We used a commercially available computer-assisted image-guidance system for cervical pedicle screw insertion in both the laboratory and in a preliminary clinical setting. Nine plastic cervical spine models (C2-C7) were used in the laboratory test. The StealthStation was used to create the preoperative plan for each screw such that it would be inserted down the center of the pedicle, parallel to the long axis. Using a light-emitting diode-equipped drill guide, 2-mm holes were drilled in 108 pedicles. A total of 108 pedicle holes were drilled. The mean trajectory deviation from the surgical plan in the axial plane was 1.7+/-1.7 degrees (range, 0 to 8 degrees), and the mean deviation of the position of the hole was 1.7+/-0.6 mm (range, 0.1 to 2.9 mm). Eighty-three drill holes (76.9%) were contained within the pedicles, whereas partial cortical perforation was noted in 25 pedicles (23.1%). In the clinical setting, 36 cervical pedicle screws were inserted in nine patients using the image-guided system. Within the limits of imaging artifact, all 36 pedicle screws appear to have been inserted accurately by postoperative computed tomographic examination. No neurologic or vascular complications were encountered.

Aged↗
PubMed2000

Thoracic epidural desmoplastic fibroma.

Desmoplastic fibroma is a relatively uncommon tumor and rarely involves the spine. The authors describe a 20-year-old woman with a thoracic epidural desmoplastic fibroma treated by complete resection and posterior spinal fusion. Four years after surgery, neither the tumor nor clinical symptoms have recurred. Thus, complete resection is considered necessary to treat this tumor.

Adult↗
PubMed2000

Cellular distribution of mucosa-associated lymphoid tissue with otitis media in children.

This study examined mucosa-associated lymphoid tissue (MALT) in the eustachian tube (ET), middle ear (ME), and mastoid antrum (MA) in 163 celloidin-embedded temporal bones from children with or without otitis media. Otitis media was defined by the presence of histopathologically identified inflammatory cell infiltration in the mucosa or cavity of the ME. We found MALT in the ET in 30 cases (46.2%), in the ME in 19 cases (29.2%), and in the MA in 4 cases (6.2%) out of 65 cases of otitis media, and in the ET in 7 (7.1%), in the ME in 0, and in the MA in 0 out of 98 specimens without otitis media. No MALT appeared in any children under the age of 1 month. Immunohistochemical methods were used to investigate MALT in 12 horizontally cut temporal bones with OM. The follicular area contained OPD4-positive (helper-inducer T) cells and a few CD8-positive (cytotoxic and suppressor T) cells, whereas the parafollicular area contained OPD4-positive and CD8-positive T cells. CD57-positive (natural killer) cells were confined to the germinal center. CD30-positive (activated T and B) cells were observed throughout the follicles. A few CD15-positive (granulocyte, monocyte) cells were found in the follicles. Histopathologic and immunohistochemical findings were indistinguishable for MALT in the ET, ME, and MA. Our results suggest that MALT may be a mechanism for producing a rapid and massive local immune reaction to repeated bacterial infections via the ET.

Antigens, CD↗
PubMed2000

Eosinophilic granuloma of the spine: early spontaneous disappearance of tumor detected on magnetic resonance imaging. Case report.

Two cases of eosinophilic granuloma (EG) of the spine associated with neurological deficits are presented. The patients were treated conservatively by using external fixation with a brace as well as bed rest. Neurological deficits and pain diminished and finally disappeared as the tumor mass decreased in size, as seen on magnetic resonance (MR) imaging. During the 5-year follow-up period no recurrence of the tumors was detected on MR images. Surgical treatment for spinal EG in children presenting with typical vertebra plana is not recommended except for those with severe or progressive palsy and for those in whom the disease requires differential diagnosis.

Cervical Vertebrae↗