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Biomedical subjects

H Moriya

Publications and source records attributed to H Moriya.

At least 37 records · Page 2Linked to original sources
PubMed2001

Shock wave application to rat skin induces degeneration and reinnervation of sensory nerve fibres.

There have been several reports on the use of extracorporeal shock waves in the treatment of pseudarthrosis, calcifying tendinitis, and tendinopathies of the elbow. However, the pathomechanism of pain relief has not been clarified. To investigate the analgesic properties of shock wave application, we analyzed whether it produces morphologic changes in cutaneous nerve fibres. In normal rat skin, the epidermis is heavily innervated by nerve fibres immunoreactive for protein gene product (PGP) 9.5 and by some fibres immunoreactive for calcitonin gene-related peptide (CGRP). There was nearly complete degeneration of epidermal nerve fibres in the shock wave-treated skin, as indicated by the loss of immunoreactivity for PGP 9.5 or CGRP. Reinnervation of the epidermis occurred 2 weeks after treatment. These data show that relief of pain after shock wave application to the skin results from rapid degeneration of the intracutaneous nerve fibres.

Animals↗
PubMed2001

Using cineradiography for continuous dynamic-motion analysis of the lumbar spine.

STUDY DESIGN: Cineradiography was used to analyze continuous dynamic motion in the lumbar spine. OBJECTIVES: To identify motion patterns of the lumbar spine in asymptomatic volunteers and symptomatic patients with L4 degenerative spondylolisthesis, and to use the findings to discuss segmental instability in this disorder. SUMMARY OF BACKGROUND DATA: The use of radiographic findings to assess lumbar spine instability remains controversial. Although some studies have reported on lumbar kinematics during actual movement, the motion patterns in asymptomatic volunteers and symptomatic patients with L4 degenerative spondylolisthesis have not been fully clarified. METHODS: While asymptomatic volunteers (n=20; mean age, 27; control group) and symptomatic patients with L4 degenerative spondylolisthesis (n=41; mean age, 63; degenerative spondylolisthesis [DS] group) flexed from a sitting neutral position and back to the neutral position (flexion course), cineradiography was used to record lateral segmental lumbar motions. Twelve frames were selected during the flexion course, and flexion-extension angle (f-e angle) and translation in the sagittal plane were measured at each motion segment (L2-L3, L3-L4, L4-L5, and L5-S1). The DS group was classified into 2 subgroups according to percentage of slip: DS group I, with a slip equal to or less than 15%; and DS group II, with a slip of more than 15%. The motion pattern was compared between the groups. RESULTS: In the control group, f-e angle and translation at the L2-L3, L3-L4, and L4-L5 segments moved simultaneously, although the L5-S1 segment showed an initial delay. The amount of f-e angle and translation changed almost symmetrically. In both f-e angle and translation, the L4-L5 segment showed a large motion pattern. In DS group I (n=21), the L4-L5 segment showed a large motion pattern in f-e angle and an intermediate motion pattern in translation. In DS group II (n=20), the L4-L5 segment showed an intermediate motion pattern in f-e angle, and a small motion pattern in translation. The relative range of f-e angle at the L4-L5 segment had the largest range in DS group I, and the relative translation showed a serial decrease from the control group through DS group II. A significant correlation between f-e angle and translation (harmonious motion pattern) was noted at the L2-L3, L3-L4, and L4-L5 segments in the control group. The harmonious motion pattern at the L4-L5 segment was significantly less in the DS group than in the control group. The loss of harmonious motion pattern (disordered motion pattern) at L4-L5 was well-revealed in the DS group II. CONCLUSIONS: Motion analyses using cineradiography helped to explain the phenomena of lumbar spine kinematics. Based on continuous dynamic-motion analysis with cineradiography, large f-e angle and disordered motion pattern during the flexion-backward course in the DS group I was considered to be caused by segmental instability. The decreased translation and disordered motion pattern throughout the flexion course in the DS group II was considered to be caused by restabilization.

Adult↗
PubMed2001

Extrathymic development of V alpha 11 T cells in placenta during pregnancy and their possible physiological role.

The molecular and cellular mechanisms of the feto-maternal immune responses in the placenta in connection with natural abortion remain unclear. In this report we provide evidence that V(alpha11) T cells developed in the placenta may be responsible for the induction of natural abortion. The majority of V(alpha11) TCRs detected during pregnancy showed a consensus motif in the CDR3 region, similar to that of anti-GM3 TCR clones, and were of maternal origin. V(alpha11) TCRs were found in the middle to late stages of gestation due to de novo generation in the placenta, not to migration from the maternal side, as evidenced by the significant increases in the out-of-frame V(alpha11) TCR mRNA and the copy number of circular DNA generated by V(alpha11) gene rearrangements. Furthermore, administration of anti-V(alpha11) Ab to pregnant mice resulted in a significant decrease in the incidence of fetal demise, suggesting that V(alpha11) T cells detected in the placenta develop extrathymically and are involved in natural abortion.

Animals↗
PubMed2001

Primary sensory neurons with dichotomizing axons projecting to the facet joint and the sciatic nerve in rats.

STUDY DESIGN: Dorsal root ganglion (DRG) neurons that have dichotomizing axons to the lumbar facet joint and to the sciatic nerve were investigated in rats using a double fluorescent labeling technique. OBJECTIVES: To clarify the existence of DRG neurons with dichotomizing axons projecting to the lumbar facet joint and to the sciatic nerve in rats. SUMMARY OF BACKGROUND DATA: DRG neurons having dichotomizing axons have been reported in several species and are considered to be related to referred pain. However, such DRG neurons have not been investigated in the lumbar spine. Clinically, pain from the lumbar facet joint is sometimes referred to the lower extremities innervated by the sciatic nerve. METHODS: Two kinds of neurotracers (DiI and FG) were used in the present double-labeling study. DiI crystals were placed in the left L5-L6 facet joint, and FG was applied to the ipsilateral sciatic nerve or along the midline of the L5 dermatome. Bilateral DRGs T13-S1 were observed by fluorescence microscope. RESULTS: DRG neurons double labeled with DiI and FG were recognized only in the ipsilateral DRGs from L3 to L6 levels. Approximately 3% of DRG neurons innervating the L5-L6 facet joint had other axons to the sciatic nerve. By contrast, no double-labeled neurons were observed after FG was applied to the L5 dermatome. CONCLUSIONS: In rats approximately 3% of DRG neurons innervating the lumbar facet joints have dichotomized axons projecting to the sciatic nerve.

Animals↗
PubMed2001

Yak1p, a DYRK family kinase, translocates to the nucleus and phosphorylates yeast Pop2p in response to a glucose signal.

POP2 protein of Saccharomyces cerevisiae is a component of a protein complex that regulates the transcription of many genes. We found that the 97th threonine residue (Thr 97) of Pop2p was phosphorylated upon glucose limitation. The Thr 97 phosphorylation occurred within 2 min after removing glucose and was reversed within 1 min after the readdition of glucose. The effects of hexokinase mutations and glucose analogs indicate that this phosphorylation is dependent on glucose phosphorylating activity. We purified a protein kinase that phosphorylates a peptide containing Thr 97 of Pop2p and identified it as Yak1p, a DYRK family kinase. Phosphorylation of Pop2p was barely detectable in a yak1Delta strain. We found that Yak1p interacted with Bmh1p and Bmh2p only in the presence of glucose. A GFP-Yak1p fusion protein shuttled rapidly between the nucleus and the cytoplasm in response to glucose. A strain with alanine substituted for Thr 97 in Pop2p showed overgrowth in the postdiauxic transition and failed to stop the cell cycle at G(1) phase in response to glucose deprivation. Thus, Yak1p and Pop2p are part of a novel glucose-sensing system in yeast that is involved in growth control in response to glucose availability.

Carrier Proteins↗
PubMed2001

Phenotypic inflammation switch in rats shown by calcitonin gene-related peptide immunoreactive dorsal root ganglion neurons innervating the lumbar facet joints.

STUDY DESIGN: The changes in dorsal root ganglion neurons innervating the L5-L6 facet joint were studied using the retrograde neurotransport method and the immunohistochemistry of calcitonin gene-related peptide in an inflammatory model of rats. OBJECTIVES: To determine by inflammatory stimulation the changes in calcitonin gene-related peptide-immunoreactive dorsal root ganglion neurons innervating the L5-L6 facet. SUMMARY OF BACKGROUND DATA: The rat L5-L6 facet joint is innervated from L1-L5 dorsal root ganglia. The presence of calcitonin gene-related peptide-immunoreactive dorsal root ganglion neurons innervating the L5-L6 facet joint has been confirmed, but the changes in the number and distribution of these neurons caused by inflammation have not been studied. METHODS: Retrograde transport of fluorogold was used in 20 rats: 10 in the control group and 10 in the inflammatory group. Using the dorsal approach, fluorogold crystals were injected into the left L5-L6 facet joint. Then 5 days after application, complete Freund's adjuvant (50 microg Mycobacterium butyricum in oil saline emulsion) was injected into the same L5-L6 facet joint (inflammatory group). Of the total fluorogold-labeled dorsal root ganglion neurons from T13-L6, the number and cross-sectional area of the cell profiles of fluorogold-labeled, calcitonin gene-related peptide-immunoreactive neurons in the bilateral dorsal root ganglia of both groups were evaluated. RESULTS: Fluorogold-labeled neurons were distributed throughout the ipsilateral dorsal root ganglia from L1-L5 in both groups. Of the fluorogold-labeled neurons, the ratios of the calcitonin gene-related peptide-immunoreactive L1, L2, L3, L4, and L5 dorsal root ganglion neurons, respectively, were 17%, 24%, 44%, 56%, and 50% in the control group and 50%, 39%, 51%, 61%, and 56% in the inflammatory group. The ratios of the calcitonin gene-related peptide-immunoreactive L1 and L2 dorsal root ganglion neurons labeled by fluorogold were significantly higher in the inflammatory group than in the control group (P < 0.05). The mean cross-sectional area of fluorogold-labeled, calcitonin gene-related peptide-immunoreactive cells from L1-L5 dorsal root ganglia increased from 621 +/- 64 microm2 to 893 +/- 63 microm2 in the inflammatory group (P < 0.01). CONCLUSIONS: The ratio of fluorogold-labeled, calcitonin gene-related peptide-immunoreactive neurons was significantly higher in the L1 and L2 dorsal root ganglia of the inflammatory group than in those of the control group, and the average cross-sectional area of the cells from L1-L5 dorsal root ganglion increased. Associated with the inflammation in the facet joints, the change in calcitonin gene-related peptide-immunoreactive neuron distribution and the phenotypic switch to large neurons may complicate the mechanism of facet joint inflammatory pain.

Animals↗
PubMed2001

Inductive signals from the somatopleure mediated by bone morphogenetic proteins are essential for the formation of the sternal component of avian ribs.

The posterior five pairs of avian ribs are composed of vertebral and sternal components, both derived from the somitic mesoderm. For the patterning of the rib cartilage, inductive signals from neighboring tissues on the somitic mesoderm have been suggested to play critical roles. The notochord and surface ectoderm overlying the somitic mesoderm are essentially required for the development of proximal and distal regions of the ribs, respectively. Involvement of the somatopleure in rib development has already been suggested but is less understood than those of the notochord and surface ectoderm. In this study, we reinvestigated the role of the somatopleure during rib development. We first identified the chicken homologue of the mouse Mesenchymal forkhead-1 (cMfh-1) gene based on sequence similarities. cMfh-1 was observed to be expressed in the nonaxial mesoderm, including the somitic mesoderm, and, subsequently, in cartilage forming the ribs, vertebrae, and appendicular skeletal system. In the interlimb region, corresponding to somites 21-25 (or 26), cMfh-1-positive somitic mesoderm was seen penetrating the somatopleure of E4 embryos, and cMfh-1 was used as a molecular marker demarcating prospective rib cartilage. A series of experiments affecting the penetration of the somitic mesoderm into the somatopleure was performed in the present study, resulting in defects in sternal rib formation. The inductive signals emanating from the somatopleure mediated by BMP family proteins were observed to be essentially involved in the ingrowth of the somitic mesoderm. BMP4 alone, however, could not completely replace inductive signals from the somatopleure, suggesting the involvement of additional signals for rib formation.

Amino Acid Sequence↗
PubMed2001

Sensory innervation of the dorsal portion of the lumbar intervertebral discs in rats.

STUDY DESIGN: The levels of dorsal root ganglions (DRGs) innervating the dorsal portion of the lumbar intervertebral discs from L1-L2 to L4-L5 were investigated in rats by the retrograde transport method. The pathways and functions of nerve fibers supplying the dorsal portion of the discs were investigated by denervation and immuno-histochemistry. OBJECTIVES: To investigate the sensory innervation of the dorsal portion of the lumbar intervertebral discs in rats. SUMMARY OF BACKGROUND DATA: The dorsal portion of the L5-L6 disc has been reported to be innervated multisegmentally, and anesthetic blockade of the paravertebral sympathetic trunks and the L2 spinal nerve can relieve discogenic low back pain. However, sensory innervation of the dorsal portion of the lumbar discs at other levels has not been clarified. METHODS: A retrograde transport of Fluoro-Gold was used. We studied a nonsympathectomy group (n = 44) and a sympathectomy group (n = 50) in which paravertebral sympathetic trunks were resected from L1 to L5 levels. Using a ventral approach, Fluoro-Gold crystals were inserted into the dorsal portion of the L1-L2, L2-L3, L3-L4, and L4-L5 discs. Seven days after surgery, Fluoro-Gold-labeled neurons were counted in the bilateral dorsal root ganglions from T10 to L6. RESULTS: Fluoro-Gold-labeled neurons were distributed in dorsal root ganglions from T11 to L5 levels in the nonsympathectomy group. However, in the sympathectomy group the number of labeled neurons was less than that of the nonsympathectomy group in T11, T12, and T13 dorsal root ganglions of the L1-L2 disc group, in T12, T13, and L1 dorsal root ganglions of the L2-L3 disc group, in T12, T13, L1, and L2 dorsal root ganglions of the L3-L4 disc group, and in T12, T13, L1, and L2 dorsal root ganglions of the L4-L5 disc group. CONCLUSION: The dorsal portion of the lumbar discs from L1-L2 to L4-L5 is multisegmentally innervated by the T11 through L5 dorsal root ganglions. Sensory fibers from the upper dorsal root ganglions innervate the dorsal portion of the discs via the paravertebral sympathetic trunks, although those from the lower dorsal root ganglions innervate via the sinuvertebral nerves. Furthermore, sensory nerve fibers enter the paravertebral sympathetic trunks through the corresponding ramus communicans and reach the dorsal root ganglions via each ramus communicans at the L2 and/or more cranial levels.

Animals↗
PubMed2001

Effects of electrical stimulation of the sciatic nerve on background electromyography and static stretch reflex activity of the trunk muscles in rats: possible implications of neuronal mechanisms in the development of sciatic scoliosis.

STUDY DESIGN: The effects of electrical stimulation of the sciatic nerve on background electromyographic and static stretch reflex activity of the trunk muscles were studied. OBJECTIVES: To verify the hypotheses that sciatic scoliosis is induced reflexively by radiculopathic pain, and that scoliosis might be maintained by prolonged asymmetric alteration of the trunk muscle tonus caused by central sensitization of the spinal neurons that constitute the postural reflex pathways. SUMMARY OF BACKGROUND DATA: Sciatic scoliosis usually occurs with convexity to the side of the herniated disc. The neuronal mechanism of sciatic scoliosis has not been well clarified. Recently, prolonged alteration of motor function in the hindlimbs of animals caused by central sensitization has been reported. METHODS: In spinalized rats (transection of the spinal cord), the sciatic nerve was stimulated electrically as a conditioning stimulus. Muscle stretch elicited by bending of the lumbar spine was applied as a test stimulus. Background and stretch reflex activities of the bilateral oblique abdominal, psoas, and quadratus lumborum muscles were recorded. Rats in which MK-801, an N-methyl-d-aspartate antagonist, was preadministered also were used. RESULTS: The conditioning stimulus enhanced background electromyographic activity in bilateral oblique abdominal, contralateral psoas, and quadratus lumborum muscles. Furthermore, the conditioning stimulus induced prolonged facilitation and depression of stretch reflex activity of the contralateral psoas and quadratus lumborum, and ipsilateral psoas and quadratus lumborum muscles, respectively. Preadministration of MK-801 reduced these excitatory and inhibitory effects. CONCLUSION: It was found that the pattern of electromyographic activity of the trunk muscles evoked by sciatic nerve stimulation coincided with the typical direction of sciatic scoliosis in patients with lumbar disc herniation. It was supposed that the prolonged asymmetric alteration of the trunk muscle tonus was caused by central sensitization, and that central sensitization of spinal neurons may underlie the neuronal mechanism of sciatic scoliosis.

Animals↗
PubMed2001

Sensory innervation of the cervical facet joints in rats.

STUDY DESIGN: With a retrograde neurotracing method with Fluoro-Gold (FG; Fluorochrome, Denver, CO), the level of dorsal root ganglions (DRGs) innervating the C1-C2, C3-C4, and C5-C6 facet joints and their pathways were investigated in rats. OBJECTIVES: To clarify the levels of DRGs and parasympathetic nodose ganglions innervating the cervical facet joints and to determine the pathways from the facet joint to DRGs. SUMMARY OF BACKGROUND DATA: Patients with cervical facet lesions and whiplash sometimes experience diffuse neck pain, headache, arm, and shoulder pain, but the pattern of sensory innervation of the facet joint is still unclear. METHODS: Sixty male Sprague-Dawley rats were used. Fluoro-gold crystals (FG) were applied into the C1-C2 (C1-C2 group), C3-C4 (C3-C4 group) and C5-C6 (C5-C6 group) facet joints, and numbers of the labeled neurons in DRGs from C1 to T5 and nodose ganglions were determined. To determine the sensory pathway, bilateral sympathectomy was performed. RESULTS: Neurons labeled with FG were present in the DRGs from C1 through C8 in the C1-C2 group, from C1 to T2 in the C3-C4 group, and from C3 to T3 in the C5-C6 group without sympathectomy. In the nodose ganglions, 17 FG-labeled neurons were present. The number of the labeled neurons after sympathectomy was not significantly different in the C1, C2, and C3 DRGs in the C1-C2 group, in the C3 and C4 DRGs in the C3-C4 group, and in the C5 and C6 DRGs in the C5-C6 group from that in the groups without sympathectomy. In contrast, the number of labeled neurons in the DRGs was significantly less at the other levels than that in the groups without sympathectomy (P < 0.01). CONCLUSION: Sensory nerve fibers of the cervical facet joint were derived from the C1-T3 DRGs. Some sensory nerves from the cervical facet joint entered the paravertebral sympathetic trunks and reached the DRGs at multisegmental levels. The present findings regarding the multisegmental innervation to the facet joint may be of importance in the treatment of facet joint syndrome.

Animals↗
PubMed2001

Beneficial effects of nitric oxide synthase inhibition on the recovery of neurological function after spinal cord injury in rats.

We have demonstrated recently that treatment with N(G)-monomethyl-L-arginine (L-NMMA) accelerates electrophysiological recovery after transient spinal cord ischaemia in anaesthetized cats. To determine whether nitric oxide synthase (NOS) inhibition in the acute phase of spinal cord injury results in better functional recovery in the chronic phase, we evaluated the influence of L-NMMA on the time course of changes of neurological function and the histopathological changes after spinal cord compression in rats. Experimental spinal cord injury was produced in anaesthetized rats by short-term (5 min) compression with a thread placed around the spinal cord at T13. The recovery of motor function was assessed by a treadmill test 10, 20 and 30 days after spinal cord compression. The latency of potentials evoked by hindlimb stimulation was measured at the funiculus posterior at C1 10 days after the spinal cord injury in anaesthetized rats. Histological examinations were also performed at the same time. The compression-induced spinal cord injury resulted in motor dysfunction of hindlimbs, an increase in the latency of the evoked potentials and neuronal degeneration in funiculus posterior at T13. Repeated administration of L-NMMA for 1 day significantly accelerated the recovery of the motor function, shortened the latency of the evoked potentials and attenuated the myelin vacuolization in the spinal cord. These beneficial effects of L-NMMA on neurological function and histopathological changes were abolished by coadministration of L- but not D-arginine. These results suggest that NOS inhibition during the early stage of spinal cord injury has beneficial effects on the recovery of neurological function and the histopathological changes in the chronic stage.

Animals↗
PubMed2001

Acute up-regulation of brain-derived neurotrophic factor expression resulting from experimentally induced injury in the rat spinal cord.

Brain-derived neurotrophic factor (BDNF), a member of the nerve growth factor family of trophic factors, has multiple functions including a role in the promotion of neuronal survival and nerve fiber elongation in both the central and the peripheral nervous systems. We assessed the expression of endogenous BDNF following an experimentally induced compression injury to the spinal cord. Expression of BDNF mRNA was increased following the spinal cord injury; reaching maximum levels 24 h after the injury. Expression of BDNF mRNA returned to the levels observed in sham-operated control animals within 3 days of the injury. Using the in situ hybridization technique, we observed a wide distribution of BDNF expression among the different cell types in the spinal cord, including motor and sensory neurons, and in glia cells, including astrocytes. We also observed expression of BDNF in putative macrophages and/or microglia; however, this effect was not observed until day 7 following spinal cord injury. These results suggest that BDNF is synthesized in both neurons and astrocytes during the acute response to injury to the spinal cord, functioning in a mainly neuroprotective role. This is followed by a later phase of expression in which BDNF is produced by macrophages and/or microglia, apparently functioning in a restorative capacity.

Animals↗
PubMed2001

Establishment and characterization of tartrate-resistant acid phosphatase and alkaline phosphatase double positive cell lines.

Morphologically macrophage-like cells were cloned from hamster bone marrow cells by coculturing bone marrow cells with hamster chondrocytes. One of the clones (CCP-2) was characterized in the present study. CCP-2 cells were positive in an osteoclast marker enzyme, tartrate-resistant acid phosphatase (TRAP), alkaline phosphatase (ALP) and non-specific esterase (NSE). We showed CCP-2 cells degraded cartilage matrix and hydroxyapatite coated on Osteologic disks. A gelatinase secreted from CCP-2 cells was observed and purified from serum-free conditioned medium of the cells. N-terminal amino acid sequencing of the purified enzyme revealed it was matrix metalloproteinase-9. However, CCP-2 cells failed to express calcitonin receptors, a mature osteoclast marker, even after coculture with osteoblast ST2 cells in the presence of 1alpha, 25-dihydroxyvitamin D3 [1alpha, 25-(OH)2D3]. The cells showed high affinity to types X and I but not to type II collagen. In addition, histochemical studies have shown the presence of tartrate-resistant acid phosphatase and alkaline phosphatase double positive cells at the secondary ossification site of the hamster humerus. From these observations, we concluded that CCP-2 cells are similar to osteoclast but not the same. CCP-2 cells are therefore important tools for investigating chondroclastogenesis/osteoclastogenesis and endochondral ossification.

Acid Phosphatase↗
PubMed2001

A longitudinal study for femoral neck bone mineral density increases in premenopausal caddies using dual-energy X-ray absorptiometry.

This longitudinal study examined whether bone mineral density (BMD) of the lumbar spine and proximal femur is maintained in premenopausal caddies (n = 6; mean age 37.8 years) in comparison with desk workers (n = 6; mean age 40.8 years) at the same golf club. BMD was followed for 12 months using dual-energy X-ray absorptiometry (DXA) and bone metabolic markers and athletic ability were also examined. Longitudinally, for caddies, the change per year in BMD of the lumbar spine was +0.009 g/cm2, while that of the proximal femur was +0.022 g/cm2, showing significant differences (P < 0.05 by signed-rank test). Their athletic ability, in terms of leg-press power, also significantly increased, whereas bone metabolic markers, such as serum alkaline phosphatase, 1,25-(OH), vitamin D3, parathyroid hormone and the deoxypyridiniline/creatinine ratio, did not show significant changes. For desk workers, the change per year in BMD of the lumbar spine was +0.011 g/cm2, while that of the proximal femur was -0.006 g/cm2. Their BMD, athletic ability and bone metabolic markers did not show significant changes. These findings support the results of our previous study, that premenopausal women can achieve continuous gain in femoral neck BMD by regular intense athletic activity, and suggest that this is also true by the continuous extensive walking of golf caddies.

Absorptiometry, Photon↗
PubMed2001

Pressure distribution in the humeroradial joint and force transmission to the capitellum during rotation of the forearm: effects of the Sauvé-Kapandji procedure and incision of the interosseous membrane.

A biomechanical study was undertaken, using four fresh cadaveric arms, to evaluate the changes in pressure distribution in the humeroradial joint (H-R joint) during rotation of the forearm before and after the Sauvé-Kapandji procedure (S-K procedure) and also after incision of the interosseous membrane (IOM) following the S-K procedure. The pressure distribution was measured with a pressure-sensitive conductive rubber sensor while the forearm was rotated. Force transmitted to the capitellum was calculated from the measured pressure. In the intact specimens, pressure was concentrated on the medial side of the capitellum in pronation and on the posterolateral side in supination. The pattern of change after the S-K procedure and that after incision of the IOM following the S-K procedure were almost the same as that in the intact forearm. Although the force transmitted to the capitellum increased after the S-K procedure, there were no significant differences between the forces before and after the S-K procedure. However, the force increased significantly after incision of the IOM following the S-K procedure when the forearm was supinated more than 35 degrees, and it was concentrated on the posterior side of the capitellum. The IOM seemed to have an important axial load-bearing function in the forearm position supinated more than 35 degrees. The S-K procedure in patients suffering from distal radioulnar joint disorders with IOM injury is likely to induce H-R joint osteoarthritis, so it should be avoided in these patients.

Analysis of Variance↗
PubMed2001

Origin and pathway of sensory nerve fibers to the ventral and dorsal sides of the sacroiliac joint in rats.

The purpose of this study is to clarify sensory innervation in the ventral and dorsal sides of the sacroiliac joint. Fluoro-gold, a neural tracer, was injected into the left sacroiliac joint of adult rats from the dorsal side after denervation of the dorsal side, and the bilateral dorsal root ganglia (DRGs) from T13 to S4 were examined by fluorescence microscopy five days after injection. In another rat group, the DRGs were examined using the same methods after injection of fluoro-gold from the ventral side. In the case of dorsal denervation (ventral nerve supply), labeled neurons were mainly located in the ipsilateral DRGs from L1 to S2. On the other hand, in the case of ventral denervation (dorsal nerve supply), labeled neurons were noted in the ipsilateral DRGs from L4 to S2. The sacroiliac joint in rats is innervated differently on the ventral and dorsal sides: the sensory nerve fibers to the dorsal side of the sacroiliac joint were derived from the DRGs of lower lumbar and sacral levels (from L4 to S2); and those to the ventral side from the DRGs of upper lumbar, lower lumbar, and sacral levels (from L1 to S2).

Afferent Pathways↗
PubMed2001

Chondrocyte apoptosis and regional differential expression of nitric oxide in the medial meniscus following partial meniscectomy.

Partial medial meniscectomy leads to tibial articular cartilage degeneration. Nitric oxide (NO) production increases with the development of osteoarthritis (OA) and has been shown to have a catabolic effect on chondrocytes. Since distribution of chondrocytic and fibroblastic cell types within the total cell population comprising meniscus is region-specific, we compared NO production in the peripheral and central regions of the medial meniscus 12 weeks after partial medial meniscectomy and assessed chondrocyte apoptosis and NO production in the tibial articular cartilage. Additionally, transcriptional gene expression of inducible nitric oxide synthetase (iNOS) and immunohistochemical staining of nitrotyrosine were examined. The results showed that following partial medial meniscectomy, NO production in the central region of the medial meniscus and in the tibial articular cartilage were significantly higher than respective NO levels in normal and sham-operated controls. Reverse transcription polymerase chain reaction (RT-PCR) revealed a high transcriptional expression of the iNOS gene in the central region of the meniscus and in tibial articular cartilage following partial medial meniscectomy. Nitrotyrosine immunoreactivity was prominent in the central region of the medial meniscus and in the deep layer of the tibial articular cartilage and apoptotic cells were also detected in situ in the superficial zone of the tibial articular cartilage and central regions of the medial meniscus following partial medial meniscectomy. These observations suggest that the central region of the meniscus is responsible for NO synthesis associated with apoptosis in both meniscal and articular cartilage cells following partial meniscectomy.

Animals↗