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T Futami

Publications and source records attributed to T Futami.

At least 19 recordsLinked to original sources
PubMed1992

Morphology of single medial vestibulospinal tract axons in the upper cervical spinal cord of the cat.

The morphology of single medial vestibulospinal tract (MVST) axons was investigated by iontophoretic injection of horseradish peroxidase into single axons at the upper cervical cord in pentobarbital-anesthetized cats. MVST axons were identified by their monosynaptic responses to stimulation of the vestibular nerve and their direct responses to stimulation of the medial longitudinal fusciculus (MLF). Reconstructions of the axonal trajectory were made from 22 uncrossed and 19 crossed MVST axons at C1-C4. MVST axons ran in the ventral funiculus and gave rise to multiple axon collaterals to the upper cervical gray matter at different segments. These axons could be traced over the distance of 2.5-15.3 mm. Within these lengths, up to 9 axon collaterals were identified per axon (mean +/- s.d., 3.3 +/- 2.0, n = 41). Axon collaterals ramified in the gray matter several times and spread in a delta-like manner in both the transverse and horizontal planes. There were usually gaps free from terminal arborizations between adjacent axon collaterals, since the rostrocaudal extension of individual axon collaterals (mean = 820 microns) was very much limited in contrast to wide intercollateral intervals (mean = 1,510 microns). Axon terminals were distributed mainly in laminae IX, VIII, and VII, and sometimes in laminae VI-IV. Most abundant terminals were observed in lamina IX, including the ventromedial (VM), the spinal accessory (SA) nuclei and the nucleus dorsomedial to the VM nucleus (DM nucleus). A majority of individual axon collaterals provided some terminal branches to at least one of the above three motor nuclei. Axon collaterals projecting to laminae VIII-VI without terminals in the motor nuclei were rarely observed. Individual MVST axons had a preferential terminal distribution in each motor nucleus, but all three motor nuclei were covered by axon terminals of an ensemble of all MVST axons, indicating that all neck muscles innervated by these three motor nuclei are influenced by vestibular inputs through MVST axons. Most collaterals from a single axon produced circumscribed terminal arborizations in one or two common areas in the transverse plane (mainly in lamina IX) that were in line with one another in the longitudinal axis of the cord. This longitudinal arrangement of discontinuous terminal arborizations in lamina IX from a single axon may correspond to a continuous sagittal column of motoneurons for a particular muscle.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

Motion of the bipolar hip prosthesis components. Friction studied in cadavers.

It has been postulated that most hip motion occurs at the inner bearing in bipolar hip prosthesis. However, radiography and cineradiography analyses have shown that the inner bearing is not always the primary articulation. We studied the frictional behavior of bipolar prosthesis and Austin-Moore prostheses and the motion of the bipolar prosthesis using a pendulum apparatus. The primary articulation was altered according to the amount of loading. When a load of 10 kg was applied to the joint, motion occurred at both bearings with friction coefficients 0.061 at the inner bearing and 0.026 at the outer bearing. With loads of over 20 kg, the outer bearing was the primary articulation. The inner bearing was the dominant articulation only when the acetabular cartilage had been removed. Our results suggest that the motion of bipolar prostheses occurs mainly at the outer bearing during normal walking, and that this prosthesis cannot be expected to reduce wear of articular cartilage.

Biomechanical Phenomena↗
PubMed1992

Axon collaterals of mossy fibers from the pontine nucleus in the cerebellar dentate nucleus.

1. Single axons of pontine nucleus neurons (PN axons) receiving cerebral input were stained intra-axonally with horseradish peroxidase (HRP) in the cerebellum of cats. The axonal trajectory of single PN axons was reconstructed from serial sections of the cerebellum and the brain stem. 2. Axons were penetrated in the white matter near the dentate nucleus, and, after electrophysiological identification, PN axons were injected iontophoretically with HRP. The identification criteria for the PN axons were 1) their direct responses to stimulation of the contralateral pontine nucleus (PN), 2) their synaptic activation from the contralateral cerebral cortex, and 3) the decrease in threshold for evoking direct spikes in stimulation of the PN by conditioning stimuli applied in the cerebral cortex. 3. Two hundred thirty-three axons were electrophysiologically identified as PN axons receiving the input from the cerebral cortex. Ninety-six of them were stained successfully with HRP, and reconstructions were made from 40 well-stained PN axons. All of them gave rise to mossy fibers and terminated in the granular layer of the cerebellar cortex as typical mossy fiber rosettes. Out of these, 22 gave axon collaterals to the dentate nucleus. Virtually all of the axon branches observed in the dentate nucleus were axon collaterals of mossy fibers from the PN to the cerebellar cortex. In 7 of these 22 PN axons, cell bodies were retrogradely labeled with HRP, and all of them were found in the contralateral PN. 4. The stained-stem axons arising from the PN ran medially in the pons, crossed the midline, and then ascended dorsocaudally in the branchium pontis. After passing in the white matter anterior to or lateral to the dentate nucleus, they entered into the cerebellar cortex. On their way, one to three axon collaterals were given off from parent axons to the dentate nucleus. The diameter of these collaterals was very thin (mean, 0.6 microns), compared with the large diameter of the parent axons (mean, 2.1 microns). 5. Some axon collaterals were very simple and had only one terminal branch with or without short branchlets, whereas others were more complex, and single axon collaterals ramified before forming a terminal arborization. Axon collaterals of single PN axons mainly spread mediolaterally or dorsoventrally in the frontal plane but had a very narrow rostrocaudal extension. 6. Terminal branches usually bore swellings en passant along their length and one terminal swelling at their end. The number of swellings per axon collateral ranged 23-180 (116 +/- 52, mean +/- SD).(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1992

Rotation osteotomy for dislocation of the radial head. 6 cases followed for 7 (3-10) years.

We performed rotation osteotomy of the radius in 5 patients with congenital and 1 with post-traumatic anterior dislocation of the radial head. At a mean of 7 (3-10) years follow-up, the chief complaints had disappeared and an anatomical radiographic reduction had been obtained in all the cases. Except for 1 case with limited supination of the forearm, no postoperative complication was noted.

Adolescent↗
PubMed1991

Ultrasound diagnosis of pathology of the anterior and posterior cruciate ligaments of the knee joint.

We established a method of diagnosing pathologic conditions of both the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL) by using ultrasound. Normal ACL and PCL were delineated as hyperechoic images on the screen in sagittal and transverse sections. On the other hand, no image of the ligament could be seen when the ligament was ruptured. We examined nine ACL and five PCL injuries by our method. This is a safe and an effective method of determining the rupture of ACL and PCL.

Anterior Cruciate Ligament↗
PubMed1991

Ultrasonography in transient synovitis and early Perthes' disease.

We used ultrasonography to examine 36 children suffering from transient synovitis and 12 children with early Perthes' disease. Widening of the joint space was revealed by ultrasonography in all affected hips with either disease. In the patients with transient synovitis, capsular distension was attributed to synovial effusion, while in the patients with Perthes' disease it was produced by thickening of the synovial membrane. Neither capsular distension nor thickening of the joint cartilage was seen in the contralateral normal hip in the patients with transient synovitis, but they were common in early Perthes' disease. Ultrasonography may provide significant diagnostic clues to differentiate early Perthes' from transient synovitis.

Child↗
PubMed1991

Ultrasonography in congenital dislocation of the hip. Simultaneous imaging of both hips from in front.

We describe a new technique for examining the infant hip using ultrasound. Both hips are imaged simultaneously via an anterior approach. The examination can be done with the hip either extended or flexed and abducted. The method has three advantages: 1) since both hips are imaged simultaneously, lines can be drawn to assist in determining the relationship between the femoral head and the pelvis; 2) proximal, anteroposterior and lateral displacement of the femoral head can all be demonstrated; 3) the method is applicable to the infant in a harness or a plaster cast to demonstrate maintenance of reduction of a dislocated hip. The usual direction of dislocation of the femoral head was anterior and lateral. Proximal migration was also observed in cases with more severe dislocation. In flexion, the dislocated head of the femur often moved posterior to the acetabulum. Of 1276 hips, in 638 infants aged from three weeks to one year, 49 showed congenital dislocation. The accuracy of our anterior method of sonography in diagnosing congenital dislocation of the hip compared well with the method of Graf and with radiography.

Female↗
PubMed1989

Comparison of the branching patterns of lateral and medial vestibulospinal tract axons in the cervical spinal cord.

The morphology of single physiologically-identified lateral and medial vestibulospinal tract (LVST and MVST) axons was analysed, using intracellular staining with horseradish peroxidase (HRP) and three-dimensional reconstruction of axonal trajectories in the cat. Axons were penetrated in the cervical cord at C1-C8 with a microelectrode filled with 7% HRP. These axons were identified as vestibulospinal axons by their monosynaptic responses to stimulation of the vestibular nerve and further classified as either LVST or MVST axons by their responses to stimulation of the LVST and MVST. The stained axons could be traced over distances of 3-16 mm rostrocaudally. Within these lengths, both LVST and MVST axons were found to have multiple axon collaterals at different segments in the cervical cord. Up to seven collaterals were given off from the stems of MVST axons and LVST axons. The LVST axons included both neurones terminating at the cervical cord and those projecting further caudally to the thoracic or lumbar cord. Each collateral of these LVST axons, after entering into the gray matter, ramified successively in a delta-like fashion and terminated mainly in lamina VIII and in the medial part of lamina VII. Many boutons of both terminal and en passant types seemed to make contact with the cell bodies and proximal dendrites of neurones in the ventromedial nucleus (VM). Each collateral had a narrow rostrocaudal extension (0.2-1.6 mm, average 0.8 mm) in the gray matter in contrast to a much wider intercollateral interval (average 1.5 mm), so that there were gaps free from terminal boutons between adjacent collateral arborizations. The morphology of axon collaterals of MVST axons was very similar to that of LVST axons. The rostrocaudal extent of single axon collaterals was very restricted (0.3-2.1 mm) in contrast to the wide spread in a mediolateral or a dorsoventral direction. MVST axons had intensive projections to the upper cervical cord with multiple axon collaterals. One to seven collaterals of single MVST axons were found at C1-C3. Terminals of MVST axons were distributed in laminae VII, VIII and IX, including the VM, the nucleus spinalis n. accessorii (SA), and the commissural nucleus. Many terminals seemed to make contact with retrogradely-labelled motoneurones of neck muscles. Both axosomatic and axodendritic contacts were observed on motoneurones in various sizes. Some collaterals gave rise to terminal arborizations in both the VM and the SA. These results suggest that single LVST and MVST axons may control excitability of multiple dorsal axial muscles concurrently with their multiple axon collaterals at multisegmental levels.

Animals↗
PubMed1989

Chinese external fixation treatment for fractures of the distal end of the radius.

One hundred forty-five patients with fractures of the distal end of the radius (age range, 13 to 76 years; means, 61 years) were treated conservatively with a Chinese system of external fixation. Most of the fractures were of the extension and extraarticular type. The fixation system consists of four splints used in conjunction with three pressure pads and three or four slings. The system was used after successful manipulative reduction, and the patients were instructed to move their joints as soon as possible. The results, especially in elderly patients, were highly encouraging. We believe that this Chinese system of external fixation serves as a kind of functional brace.

Adolescent↗
PubMed1989

[Inputs to cerebellar dentate nucleus from the pontine nucleus in the cat].

We have reported before that there are excitatory inputs to the cerebellar dentate nucleus (DN) from the cerebral cortex. This study was performed to examine whether the pontine nucleus (PN) and the nucleus reticularis tegmenti pontis (NRTP), which are among the precerebellar nuclei that relay inputs to the cerebellar cortex, also play a role as the relay nucleus of the excitatory input to the DN. In anesthetized cats, we stimulated the PN and the NRTP, and recorded intracellular potentials from DN neurons. Short-latency EPSPs were evoked from these nuclei and their latencies ranged from 1.1 to 3.6 msec, which are compatible with monosynaptic latencies. Systematic stimulation of the PN and the NRTP with weak stimulus intensities revealed that low-threshold foci for monosynaptic EPSPs in each cell were localized in the PN or the NRTP or both. We could not find monosynaptic inputs from the red nucleus and by recurrent collaterals of the dentate output neurons. Accordingly, the possibility was excluded that the monosynaptic EPSPs evoked from the PN and the NRTP were evoked by inadvertent current spread to the descending axons of DN neurons in the brain stem. The conditioning-testing stimuli of the cerebral peduncle and the PN or the NRTP yielded spatial facilitation. This result showed that the input from the cerebral cortex to the DN was relayed by way of the PN or the NRTP.

Animals↗
PubMed1989

[Bilateral ectopic ureteroceles: report of a case].

A case of bilateral ectopic ureteroceles with complete duplicated pelves and ureters occurring in a 9-year-old girl is reported. She complained of cloudy urine and urinary incontinence. IVU revealed bilateral complete duplicated collecting systems and hydronephrosis of upper poles of the kidney. Bilateral ureterovesiconeostomy by modified Politano-Leadbetter method was carried out. Her postoperative course was uneventful and hydronephrosis of upper poles on IVU at 1 year after discharge and urinary incontinence improved. The 11 reported cases with bilateral ectopic ureteroceles including our case are reviewed and some characteristics of this entry are discussed.

Child↗
PubMed1989

Congenital soft-part chondroma. A case report.

A soft-part chondroma was found in the back of a new-born infant. The tumor was located in the soft tissue between the spinous processes of T12 and L1 and grew larger. It was successfully removed operatively at the age of two years. It was a completely encapsulated hyaline cartilagelike tumor, and the skeleton. Histologically, it consisted of a cartilaginous tissue with a lobular pattern, and nuclear atypia was found in some areas.

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