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Biomedical subjects

Y Ide

Publications and source records attributed to Y Ide.

At least 55 records · Page 3Linked to original sources
PubMed1998

Histological study of the healing process of the attachment site of rat masseter muscle following injury.

The masseter muscle functions by attaching itself to the mandible. Thus, it is important to study the relationship between the masseter muscle and mandible to clarify the complex movement of the jaw. In this study, the chronological changes in the attachment site of the masseter muscle to the mandible following injury were observed in rats. These findings suggest that, in order for the masseter muscle to recover after injury, the tendinous fibers must be repaired, so that the entire muscle can be protected and recover functionality to some degree.

Animals↗
PubMed1997

Hepatitis C virus NS5A protein is phosphorylated in vitro by a stably bound protein kinase from HeLa cells and by cAMP-dependent protein kinase A-alpha catalytic subunit.

Hepatitis C virus (HCV) has a positive-strand RNA genome that codes for a polyprotein precursor, which is processed co- and post-translationally by cellular and viral proteinases into three structural and at least six non-structural (NS) proteins. The NS5A protein, expressed in mammalian cells, exists in two phosphorylated forms of 56-kDa and 58-kDa. In this study, we provide evidence for a stable association between NS5A and a protein kinase from HeLa cells and hepatocellular carcinoma (HepG2) cells by co-immunoprecipitation and by affinity to immobilized glutathione-S-transferase (GST)-NS5A fusion protein produced in E. coli. This protein kinase could phosphorylate in vitro the native NS5A on serine residues, (GST)-NS5A, histone H1, and casein as substrates. In addition, the GST-NS5A was also phosphorylated in vitro by the cAMP-dependent protein kinase A-alpha catalytic subunit.

Binding Sites↗
PubMed1997

Reduced auditory P300 amplitude, medial temporal volume reduction and psychopathology in schizophrenia.

Twenty-five schizophrenic patients diagnosed by DSM-III-R underwent event-related potentials and magnetic resonance imaging scans. Latency and amplitude of P300 waveform were measured using an auditory odd-ball paradigm. Anterior and posterior volumes of the superior temporal gyrus and medial temporal structure were measured from contiguous coronal images using the level of the mammillary body as an anatomical landmark. Principal component analysis of P300 latency and amplitude disclosed two orthogonal independent factors each: overall latency and residual, and amplitudes from posterior and anterior recordings, respectively. Structural volumes consisted of four orthogonally independent factors: left superior temporal volume, anterior medial temporal volume, right superior temporal volume, and posterior medial temporal volume. The factor score of the P300 amplitude from posterior recordings correlated with the factor score of volumetric changes in the anterior medial temporal structures. The present study failed to replicate a previously reported association between auditory P300 amplitude and superior temporal volume. Furthermore, the factor score of the P300 amplitude was correlated with the severity of clinical ratings of attentional impairments and positive thought disorder. These findings demonstrate that the information processing dysfunction of schizophrenia indicated by reduced P300 amplitude is associated with structural abnormality in the medial temporal lobe.

Adult↗
PubMed1997

The amino terminal deletion mutants of hepatitis C virus nonstructural protein NS5A function as transcriptional activators in yeast.

To investigate the biological function of hepatitis C virus (HCV)-NS5A, the NS5A was fused at its N-terminus with the DNA binding domain (DBD) of yeast transcriptional activator GAL4 (GAL4-DBD). The GAL4-DBD alone had no transcriptional activation function. However, a mutant of the GAL4-DBD/NS5A fusion protein, in which 129 amino acid residues were deleted from the N-terminus of NS5A, exhibited strong transcriptional activation in yeast cells, bearing the Escherichia coli lacZ reporter gene encoding the beta-galactosidase under the transcriptional control of GAL4 promoter and TATA box. Further mutational analysis of NS5A revealed that the region between the amino acid residues 130 to 352 were critical for optimal level of transactivation. This region includes two acidic domains and one proline-rich region which have been shown to be involved in the function of several transcriptional activators.

Gene Expression Regulation, Viral↗
PubMed1997

Immuno-scanning electron microscope characterization of large tubules in human deciduous dentin.

BACKGROUND: This study was undertaken to elucidate the type and origin of collagen fibrils which construct the large tubules in deciduous coronal dentin by scanning electron microscope and anti-types I and III collagen antibody procedures. METHODS: The studies were performed on human deciduous teeth. The teeth were fixed in 4% paraformaldehyde solution and then fractured either mesio-distally parallel to the long axis of the tooth or transversely perpendicular to the long axis of the tooth crown. The specimens were three-dimensionally observed employing the scanning electron microscope to distinguish the content of large tubules. Polyclonal antibodies of anti-type I and anti-type III collagen with 20 nm colloidal gold, and secondary electron imaging and backscatter electron imaging of high-resolution field emission scanning electron microscopy were used to examine the types of collagen fibrils. RESULTS: The large tubules extended from the vicinity of the incisal edge of the dentino-enamel junction to the pulp cavity. Inside the large tubules, fibers in compact bundles run parallel to the longitudinal axis of the tubules. The fiber bundles consisted of collagen fibrils which were 50-150 nm in diameter with typical cross striation. Immuno-scanning electron microscopy showed type I collagen-labelling gold particles and type III collagen-labelling gold particles to be abundant on the fibrils. Types I and III collagen-labelling gold particles were present on the banded collagen fibrils regardless of their diameter. CONCLUSIONS: It was found that type III collagen is present together with type I collagen on the fibrils constructing the large tubules of the human deciduous dentin. This immunohistochemical study suggested that the fibrils constructing the large tubules were derived from the von Korff fibers, and types I and III collagens formed copolymers.

Child↗
PubMed1997

Pure akinesia manifested neuroleptic malignant syndrome: a clinical variant of progressive supranuclear palsy.

An autopsy case of pure akinesia (PA) is reported. The patient manifested L-dopa-unresponsive akinesia without accompanying rigidity, tremor, eye movement disorder or dementia from the age of 58 years. Brain magnetic resonance T2-weighted imaging at the age of 63 showed high intensity areas in the subthalamic regions, but brain atrophy was not observed. She received amantadine-HCl and L-threo-3,4-dihydroxyphenylserine (L-DOPS) for 5 years. At the age of 66, she died of the severe illness accompanied by consciousness disturbances, hyperthermia, muscle rigidity, abnormal blood pressure and elevated serum enzymes which were derived from the muscle. We considered her condition to be neuroleptic malignant syndrome (NMS). Pathologically the brain revealed degeneration in the subthalamic nucleus, globus pallidus and substantia nigra. Neurofibrillary tangles were detected in the temporal cortex, hippocampus, amygdaloid body and spinal cord, as well as in the basal ganglia, thalamus and brain stem. These findings were consistent with that of progressive supranuclear palsy (PSP); the change in the ventral pons was insignificant, suggesting that PA may have minimum involvement in the ventral pons. The skeletal muscle showed scattered necrosis that was compatible with NMS. As far as we know, this is the first report of NMS accompanied with PA.

Brain↗
PubMed1997

The effects of an intrathecal NMDA antagonist (AP5) on the behavioral changes induced by colorectal inflammation with turpentine in rats.

Visceral pain, especially that associated with inflammation of visceral organs, is poorly understood and difficult to treat clinically. The purpose of this study was to investigate the effects of intrathecal 2-amino-5-phosphonovaleric acid (AP5, a competitive NMDA antagonist) upon a visceromotor response to distension of colonic tissue inflamed by exposure to turpentine. All experiments were conducted under pentobarbital anesthesia. Animals were prepared with a laminectomy from T12 to L1 to facilitate intrathecal drug administration. Colonic distension thresholds for a visceromotor response were determined in the presence and absence of AP5. Animals were divided into two groups. The NS group received 50 microl of saline intrathecally and the AP5 group 10 mM of AP5 in 50 microl saline. After baseline measurements, intrathecal drugs were administered. Five minutes later, the effects of intrathecal drugs were measured, then 1 ml of 25% turpentine was administered anorectally. Subsequent measurements were made every 5 minutes for the next 90 minutes. Visceromotor thresholds to colorectal distension (CRD) were significantly decreased 50 min after turpentine administration in the NS group. There was no threshold change in the AP5 group. This study suggests that the administration of the competitive NMDA receptor antagonist AP5 in this model blocks the effect of turpentine sensitization on visceromotor response to CRD. The absence of AP5 effects in animals not sensitized by turpentine suggests that NMDA systems may be involved in the sensitization.

2-Amino-5-phosphonovalerate↗
PubMed1997

The role of transforming growth factor-beta in PEG-rHuMGDF-induced reversible myelofibrosis in rats.

Pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) injected at a suprapharmacologic dose (100 microg/kg) daily for 5 d in normal rats caused marked increases in marrow megakaryocytes and platelet counts at 6-8 d followed by gradual decreases to control levels at 10-20 d. Interestingly, in addition to the expected thrombopoiesis, PEG-rHuMGDF was associated with myelofibrosis with a predominance of reticulin fibres at day 10 followed by complete normalization by day 20. At 6-8 d, the levels of transforming growth factor-beta1 (TGF-beta1) in the extracellular fluid of the marrow, the platelet poor plasma, and the platelet extract were increased 23-, 7- and 2-fold, respectively. The elevated levels of TGF-beta1 were gradually reduced to baseline levels at 13-20 d in accordance with the normalization of myelofibrosis and thrombopoiesis. An ultrastructural analysis showed that large fragments of megakaryocytes were deposited in the marrow parenchyma of PEG-rHuMGDF-treated rats at day 6. PEG-rHuMGDF administration at pharmacologic doses (1 and 10 microg/kg) did not induce the deposition of reticulin fibres in the marrow. These findings suggest that TGF-beta1 leaked from megakaryocytes is involved in the development of the PEG-rHuMGDF-induced myelofibrosis and that this is a reversible process related to the regulation of the excess production of platelets.

Animals↗
PubMed1997

Perspectives on the role of the lateral pterygoid muscle and the sphenomandibular ligament in temporomandibular joint function.

The lateral pterygoid muscle plays an important role in the movement of the mandible and has been studied from several points of view, including structural and functional anatomy. What matters clinically is the relative position of the muscle fibers attached medially to the mandibular condyle. In the following study, we observed not only the attachment of the lateral pterygoid muscle fibers to the articular disk, but also the relative position of the mandibular condyle to a base line set up on the mandibular condyle. According to our observations, the lateral pterygoid muscle fibers attach to the articular disk at the inner point of the medial pole. Based on this finding, we can say that the muscle fibers can both draw the articular disk anteriorly and balance it by supporting it posteriorly. That is to say, the lateral pterygoid muscle has two actions: to elevate the articular disk anteriorly and to support the articular disk. Furthermore, the sphenomandibular ligament has continuity with the articular disk tissue medially. This relationship suggests that the ligament fibers attached to the articular disk draw the disk posteriorly in its course of mandibular closing, thus enabling the articular disk to move smoothly.

Adult↗
PubMed1997

An anatomical study of a muscle bundle separated from the medial pterygoid muscle.

When mandibular dentures are fabricated, marginal sealing should be taken into consideration for the stability of the denture. We selected specimens of the medial pterygoid muscle showing insertion of an independent small muscle bundle at its insertion site, and evaluated the anatomical relationship between the morphology of the insertion site and the denture. The insertion of the pterygoid muscle was classified according to the insertion morphology of the independent small muscle bundle into three types using the retromolar pad as a reference: Type I, insertion of the independent muscle bundle posterior to the retromolar pad; Type II, insertion immediately below the retromolar pad; and Type III, insertion into the fascia of the mylohyoid muscle. Types II and III muscles seem to affect the denture because of their closeness to the mandibular denture. In the oral cavity, the independent small muscle bundle studied appeared as a streak-like structure. When such a structure is detected during examination for denture fabrication, the following consideration is necessary. Since the medial pterygoid muscle is a mouth-closing muscle, this independent small muscle bundle may contract during mouth closing, appearing more markedly in the oral cavity. Therefore, examination should be performed not only with the mouth closed but also with assumed centric occlusion.

Aged↗
PubMed1997

Internal structure of the temporomandibular joint and the circumferential bone: comparison between dentulous and edentulous specimens.

To clarify changes in the trabecular structure due to loss of the teeth, the author compared soft X-ray images and morphological measurement values of the mandibular condyle and articular eminence between dentulous and edentulous specimens. The center of the skull base containing the temporomandibular joint was removed along the Frankfort horizontal and median sagittal planes. A block in the center of the cranial base was rejected using the Frankfort horizontal plane and median sagittal plane as references. The specimens were embedded in polyester resin by the routine method. The hardened specimens were horizontally cut into 500 microns sections and photographed using soft X-ray films. Soft X-ray of each section was taken for observation by naked eye and morphometry by computer. Observation of the compact bone in the articular eminence showed thinner compact bone on the posterior slope of the articular eminence, which is a functional plane, than on the anterior slope of the articular eminence. There was a trabecular bone group on the lateral area running from the compact bone on the posterior surface of the articular eminence into the zygomatic arch and a thick trabecular bone group in a network pattern on the medial area. In the central area of the mandibular condyle, spongy bone was surrounded by oval compact bone, and the internal trabecular bone ran anteromedially in nearly the same pattern as the arrangement of the lateral pterygoid muscle. At all sites, the density, width, extent, and index indicating the complexity of the trabecular bone had higher values in dentulous specimens than in edentulous specimens.

Aged↗
PubMed1997

Anatomical study of the pectoral branch of thoracoacromial artery.

Reconstructive surgery uses various musculocutaneous flaps following resection of head and neck malignant tumor. Numerous anatomical studies have reported that the thoracoacromial artery arises from the axillary artery, but those findings have not been completely confirmed. The aim of this study was to investigate the path from the origin of the thoracoacromial artery until its pectoral branches enter the pectoralis major muscle. The following results were obtained. 1. There were no cases in which the thoracoacromial artery arose from the third part of the axillary artery. 2. There were differences between the left and right sides in the vertical and horizontal origins of the thoracoacromial artery in relation to the clavicle and median line. 3. Pectoral branches showed a single origin from the thoracoacromial artery most frequently. 4. Pectoral branches descend in parallel to the median line most frequently on the right side and descended medially to the median line most frequently on the left side. 5. The largest number of branches approached the venter vertically at the height of the third rib. There findings suggest that, during operations involving a musculocutaneous flap, the surgeon must pay attention to the differences in vascular morphology of the right and left sides.

Aged↗
PubMed1997

Anatomical study of arrangement and attachment of the medial pterygoid muscle in Japanese men.

We precisely examined the origin, attachment, manner and insertion of the medial pterygoid muscle to clarify the relationship between muscle morphology and mastication movement. The muscular bundle attachment of the medial pterygoid muscle at the origin could be divided into three types; 1) the muscle was attached to the inner surface of the medial pterygoid plate with a strong tendon, 2) to the posterior maxilla wall with a strong tendon, and 3) directly to the periosteum of the inner surface of the lateral plate without a tendon. Provided that the muscular bundles had a firmly tendinous attachment under strong and significant force during their functioning, significant force would be applied to the medial pterygoid muscle in two directions. Observations of the intersection with the medial pterygoid muscle in the posterior wall of the maxillary bone at the origin revealed intersecting fibers or tendon fusion in all 55 specimens. Since there are different muscular bundle groups within the medial pterygoid muscle, we expect to elucidate more of masticatory function by observing other masticatory muscles as well as the medial pterygoid muscle.

Adult↗
PubMed1997

Vascular consideration in raising the pectoralis major flap.

Several types of musculocutaneous flaps, including that the pectoralis major, have been used for reconstruction following resection of malignant tumors in the head and neck region. Although several clinical studies have investigated the vascularity of such musculocutaneous flaps, the findings have been inconsistent. The present study examined the distribution of arteries in the pectoralis major muscle and surrounding subcutaneous tissue by macroscopic dissection and angiography. Based on the results of this examination, muscle layer and surrounding subcutaneous tissue appear to be supplied by different arteries and show different distribution patterns. However, evidence of penetrating branches from the muscle layer to the subcutaneous tissue layer suggests the existence of blood flow from the muscle layer to the subcutaneous tissue layer. Such arterial branches should be considered when raising the pectoralis major flap in order to prevent necrosis and improve the viability of the flap.

Angiography↗
PubMed1996

Characterization of the nuclear localization signal and subcellular distribution of hepatitis C virus nonstructural protein NS5A.

Hepatitis C virus (HCV) has a positive strand RNA genome that codes for a polyprotein that is processed co-translationally and post-translationally into three structural and at least seven nonstructural (NS) proteins. To investigate the function of NS5A, a recombinant vaccinia virus was constructed in which the NS5A gene was cloned under the control of T7 promoter and encephalomyocarditis virus 5'-untranslated region (EMCV-UTR) for cap-independent translation in mammalian cells. In addition, the NS5A gene was also cloned under the control of cytomegalovirus (CMV) early promoter. The NS5A expressed in monkey kidney (CV-1) cells was located predominantly in the cytoplasm. Using immunohistochemical analysis, the subcellular distribution of NS5A in liver biopsy samples from chronic HCV-infected patients was also found to be in the cytoplasm. However, the NS5A protein has a stretch of positively charged domain in the vicinity of proline and valine residues, (PPRKKRTVV), characteristic of a nuclear localization signal (NLS), in the COOH-terminal half of the protein. To investigate whether the putative NLS of NS5A is functional, chimeric expression plasmids were constructed in which regions containing the NLS were fused to the N-terminus of the E. coli beta-galactosidase (E. coli beta-Gal). The expression of the fusion proteins in CV-1 cells resulted in their nuclear localization, indicating that the putative NLS is functional in targeting the heterologous protein, E. coli beta-Gal, to the nucleus, although the native NS5A is retained in the cytoplasm.

Animals↗
PubMed1996

Specific removal of anti-acetylcholine receptor antibodies in patients with myasthenia gravis.

In short-term therapy for myasthenia gravis caused by an antibody-mediated attack on the acetylcholine receptor (AChR) in skeletal muscle, a specific system for antibody removal, the use of tryptophan-bound immunoadsorbent and synthetic AChR peptide-bound immunoadsorbent, offers advantages over plasma exchange. These two types of immunoadsorption provided selective or semi-selective removal of pathogenic substances from the circulation without the use of plasma products, and minimized side-effects. A difficulty is that the former removed about 65% of the total IgG, and the latter removed only a fraction of the pathogenic antibodies. In neither case can a radical method of treatment for myasthenia gravis be expected. Hopefully, an adsorbent which has a well-balanced bioimmunological specific binding reaction and physicochemical adsorptive affinity will be developed in the future.

Antibodies↗
PubMed1996

Chymotrypsin inhibition induced by side chain-side chain intramolecular CH/pi interaction in D-Thr-L-Phe benzylamide.

The dipeptide benzyl amide H-D-Thr-Phe-NH-CH2-C6H5 was found to inhibit chymotrypsin strongly (K1 = 4.5 x 10(-6) M) in a competitive manner. When a series of phenyl amides H-D-Thr-Phe-NH-(CH2)n-C6H5 (n = 0-4) were tested, inhibitory potency peaked at n = 1 (benzyl amide). Incorporation of a methyl group into the benzyl methylene resulted in formation of stereoisomers, H-D-Thr-Phe-NH-(R or S)-CH(CH3)-C6H5, with considerably different inhibitory potencies. The R-isomer was as active as the benzyl amide, while the S-isomer was about 30-fold less active than the benzyl amide. Furthermore, when a fluorine atom was introduced into the para-position of the amide-benzyl group, the resulting H-D-Thr-Phe-NH-CH2-C6H4(p-F) showed considerably enhanced inhibitory activity (about 5-fold, K1 = 9.1 x 10(-7) M). In conformational analysis by 400 mHz 1H-NMR, all dipeptides having D-Thr-Phe backbone structure showed large upfield shifts of D-Thr-beta OH (shifts in ppm, 0.09-0.17), D-Thr-beta CH (0.23-0.32), and D-Thr-gamma CH3 (0.38-0.53), indicating the presence of shielding effects from the benzene ring. In addition, NOE enhancements between the D-Thr-gamma CH3 and Phe-phenyl groups were evidenced by measurements of two-dimensional NOESY spectra and NOE difference spectra. These observations demonstrated the spatial proximity of these side chains, which is due to side chain-side chain CH/pi interaction. All these results support the idea that the amide-benzyl group binds at the chymotrypsin S1 site, while the hydrophobic core with CH/pi interaction binds at the S2 or S1' site.

Chymotrypsin↗