Yukihiro Kai

Tumor necrosis factor and interleukin-1β: suppression of food intake by direct action in the central nervous system

Abstract Intracerebroventricular microinfusion of recombinant human tumor necrosis factor (rhTNF) and recombinant human interleukin-1β (rhIL-1β) suppressed food intake in rats. Central infusion of heat-inactivated rhTNF and rhIL-1β, bovine serum albumin, heparin or transforming growth factor-β had no such effect. Central infusion of rhIL-1β did not affect the dipsogenic response to central administration of angiotensin II. Peripheral administration of rhTNF and rhIL-1β in doses equivalent to or higher than those administered centrally had no effect. Electrophoretically applied rhTNF and rhIL-1β specifically suppressed the activity of glucose-sensitive neurons in the lateral hypothalamic area. Glucose-insensitive neurons were little affected. The results suggest that TNF and IL-1β act directly in the central nervous system to suppress feeding, and this effect may be operative during acute and chronic disease.

Stress-induced anorexia in rats mediated by serotonergic mechanisms in the hypothalamus

The effects of stress on food intake and on neural activity in the lateral hypothalamic area (LHA) were investigated. Significant reduction of daily food intake was observed after 2 hr immobilization. The reduction of body weight was also significant during experimental days. Duplicate injections of methysergide (5 mg/kg, IP) antagonized the immobilization-induced anorexia for 3 hr and injection of naloxone had no effect. Single neuron activity was recorded from a chronically implanted electrode. Activity of 80% of LHA neurons was significantly decreased by immobilization stress. Methysergide significantly attenuated the suppressive effect of immobilization. Further, direct effects of 5-HT on LHA neurons were examined in anesthetized rats. Of 43 LHA neurons tested, the activity of 35 was inhibited by electrophoretic application of 5-HT. These results suggest that immobilization-induced anorexia is mediated at least in part through serotonergic mechanisms in the LHA.

Neurogenic thoracic outlet syndrome in whiplash injury

A prospective study of 110 patients was carried out to determine the pathogenic significance of trauma to the upper body in the development of neural compressive irritation at the thoracic outlet. Twenty-nine patients were reviewed as cervical strain injuries (N group), 25 patients as probable neurogenic thoracic outlet syndrome (NTOS) (PT group), 39 patients as definite NTOS (T group), and 17 patients as NTOS associated with cervical disc disease (CD-T group). The time lapse between accident and diagnosis and the duration of treatment were significantly longer in T patients or CD-T patients than those in the N group. Radiography of NTOS patients also showed a higher percentage of cervical spine-length/height ratio. Traumatic NTOS would suggest two types related to direct damage of scalene muscles that included some physical aspects of cervical disc disease. Pathogenesis provided a key to the resolution of more complex posttraumatic problems of whiplash injury.

Posterior lumbar interbody fusion using local facet joint autograft and pedicle screw fixation

Study Design. This is a retrospective study of 42 patients having lumbar degenerative disease or spondylolytic spondylolisthesis treated by posterior lumbar interbody fusion (PLIF) using local autogenous facet joint graft and pedicle screw fixation with an average follow-up time of 8.5 years. Objectives. To evaluate the radiographic and clinical results of patients treated with PLIF using adjacent facet joint autograft and pedicle screw internal fixation. Summary of Background Data. Some goals of spinal surgery have been achieved by interbody arthrodesis using a posterior approach popularized by Cloward. However, significant problems including bone graft collapse, resorption, nonunion, persistent neurologic compression, and iliac crest donor complication using the classic PLIF remain. There are few reports describing the results of a PLIF by total facet joint excision. Methods. Forty-two patients (average, 53.2 years) treated at our institution with PLIF by total facetectomy were followed for an average period of 8.5 years. The changes in the Japanese Orthopedic Association score, the recovery rate, complications, and radiographic findings were evaluated. Results. Good radiographic fusion (92.9%) and clinical results (postoperative recovery rate of 76% in the Japanese Orthopedic Association score) were achieved by PLIF using local facet joint autograft and pedicle screw fixation in treating patients with debilitating lumbar degenerative disease. The complications related to the operative procedure occurred in three patients of delayed union. Conclusions. For lumbar degenerative diseases with osteophytic changes of facet joints, PLIF using pedicle screw fixation and local autogenous bones obtained from facet excision may be justified as a treatment opinion. The procedure as described offers advantages for spinal surgery when PLIF is warranted.

Relationship Between Evoked Potentials and Clinical Status in Spinal Cord Ischemia

Study Design and Methods Sciatic neurogenic motor-evoked potentials, spinal evoked potentials, and somatosensory-evoked potentials were recorded in 12 anesthetiazed dogs that had arterial ischemia of the lumbar cord produced by ligation of segmental arteries. The presence or absence of the above-mentioneds potentials was compared with the clinical status of repeated wake-up tests. Results Although these results were complicated, sciatic neurogenic motor-evoked potential was more sensitive to the spinal cord ischemia and was a better predictor of clinical outcome than spinal evoked potential and somatosensory-evoked potential. However, the presence was not a guarantee of normal function. The initial morphologic change of these potentials secondary to ischemia consisted of a decrease in amplitude and in the number of peaks without a shift of latency. Conclusions The present study suggests that the peripheral neurogenic motor-evoked potential is better warning system for spinal cord ischemia and that its adoption may contribute to the prevention of cord ischemia during spinal surgery, whereas somatosensoryevoked potential and spinal evoked potential cannot be indices.

Use of sciatic neurogenic motor evoked potentials versus spinal potentials to predict early-onset neurologic deficits when intervention is still possible during overdistraction

Spinal evoked potentials, sciatic neurogenic motor evoked potentials, and somatosensory evoked potentials were recorded before and after overdistraction of the spinal cord, and compared with the clinical status of 14 pigs. The sciatic neurogenic motor evoked potential consisted of two components: fast and slow. The fast component was more sensitive and associated to a greater degree with motor function in wake-up tests than the slow component somatosensory evoked potential and spinal evoked potential. Furthermore, the loss of only the fast component in the initial status allowed the possibility of improvement of motor activity in the final wake-up test. The peripheral neurogenic motor evoked potentials recording yielded more information about spinal cord function: motor and sensory. The current study suggests that a peripheral response is a better index to the onset of overdistraction and to the efficiency of intervention, when the neurologic deficit after overdistraction of the spine is reversible.

Responses of rat lateral hypothalamic neurons to periaqueductal gray stimulation and nociceptive stimuli

The effects of dorsal periaqueductal gray (D-PAG) stimulation and noxious stimuli on neural activity in the lateral hypothalamic area (LHA) were investigated in 56 adult male anesthetized rats. Strong tail pinch was used as noxious stimulation. We examined 234 extracellular and 75 intracellular recordings of LHA responses to electrical stimulation of D-PAG. To determine neurotransmitter candidates, the effects of the opioid agonist, morphine, and its antagonist, naloxone were investigated by systemic administration and microelectrophoresis. Of 234 spontaneously firing LHA neurons, 70 (30%) were inhibited by D-PAG stimulation. Of these 70 neurons, 26/40 tested (65%) were glucose-sensitive, 16/19 (84%) were inhibited by morphine and 12/18 (67%) were inhibited by tail pinch. Glucose-sensitive neurons were selectively inhibited by morphine and tail pinch. Naloxone attenuated inhibitory responses to D-PAG stimulation, tail pinch and electrophoretic morphine. From intracellular recordings these polysynaptic inhibitory responses to D-PAG stimulation were considered to be inhibitory postsynaptic potentials (IPSPs) with 6.1 +/- 3.2 ms (mean +/- S.D.) latency and reversal membrane potential of about -78 mV. Since LHA glucose-sensitive neurons receive, selectively, both inhibitory opioid inputs from the D-PAG and inhibitory inputs through noxious stimulation, we suggest that D-PAG might be an intermediate site for transmission of noxious stimuli to the LHA.

Pseudomalignant myositis ossificans occurring in the hand

This is a case report of a patient with pseudomalignant myositis ossificans of the hand. This entity is usually related to trauma, but there was no history of injury in this patient. Radiographic follow-up, histologic zone phenomena and computerized tomography are helpful in obtaining the correct diagnosis.

Efficacy of Hyperbaric Oxygenation (HBO) Therapy for Spinal Cord or Cauda Equina Lesion

We performed hyperbaric oxgenation (HBO) therapy on 30 cases with spinal cord or cauda equina lesion. All these cases were siven postoperative therapy. HBO therapy was performed under the condition of 2.5 ATA for 90 minntes. The effects of the HBO therapy were evaluated to find whether improved the neurogical symptoms of the upper and lower limbs.The results showed improvement in 20 cases, mainly in the cervical of thoracic myelopathy cases. It was however difficult to evaluate the effects of HBO therapy directly, due to natural healing of the diseases and influence of surgery etc. Most of the 10 cases which showed no effects were cauda equina lesion. They suffered severe symptoms, old age, or long durations of morbidity.From these points, we concluded that HBO therapy produces better results for the postoperative therapy of spinal surgery if the patient does not suffer from severe symptoms, old age, or long duration of morbidity.

Results of Intervertebral Spacer for Posterior Lumbar Interbody Fusion by Total Facetectomy

Seventy-two patients were treated with posterior lumbar interbody fusion (PLIF) by total facetectomy (TF), using intervertebral spacer (i. e. AW glassceramic, hydroxyapatite), for lumbar degenerative disorders. Patients were followed clinically and radiographically from four months to over two years. Fusion was achieved in 95.8% of the cases, and good clinical improvement was shown in the JOA score for most patients. Especially, spinal fusion by PLIF was useful in relieving low back pain. PLIF by TF provides wide decompression, prevents iliac pain caused by picked bone and offers spinal surgeons numerous advanteges for the treatment of lumbar diseases. Use of the intervertebral spacer also provides good support and good filling-up for bone graft.