Takuya Arakawa

Electrical stimulation prevents apoptosis in denervated skeletal muscle

The purpose of this study was to investigate the hypothesis that electrical stimulation regulates the levels of gene expression related to apoptosis in denervated muscle and prevents muscle atrophy after denervation.Nineteen rats were used in this study. To denervate soleus muscle, sciatic nerve was resected under aseptic condition. Electrical stimulation with 4 mA rectangular pulses of 0.5 ms duration at 2 Hz lasting for 1 hour was delivered to lower limb including the soleus muscle using two surface electrodes. After the stimulation periods of 4 weeks, the levels of gene expression related to apoptosis were evaluated. Electrical stimulation increased valosin-containing protein (VCP) expression and decreased cleaved caspase-12 expression in denervated muscles. These results indicated that electrical stimulation to denervated muscle suppresses ER-specific apoptosis by enhancing VCP expression. We proposed that electrical stimulation would be a potential treatment for preventing atrophy of denervated skeletal muscles.

Functional electrical stimulation of laryngeal adductor muscle restores mobility of vocal fold and improves voice sounds in cats with unilateral laryngeal paralysis.

Functional electrical stimulation (FES) has been proposed as a potential treatment for restoring motor functions of denervated motor systems. We investigated whether FES of paralyzed laryngeal adductor muscles could restore adduction to the vocal folds. In addition, we studied the effect of stimulated vocal fold adduction on the intensity and overall quality of voice production. We recorded movement of the vocal fold, electromyographic activity of muscles recruited for vocalization, and sound production in unanesthetized decerebrate cats during FES of the paralyzed thyroarytenoid (TA) muscle. FES of the paralyzed TA muscle induced adduction of the vocal fold. Appropriate stimulus parameters for induction was 1.5-3.0 mA intensity pulses delivered at a frequency of 30-50 pulses per second (pps). FES of the paralyzed TA muscle prolonged phonation time and increased intensity of voice sounds during vocalization induced by electrical stimulation (0.2 ms, 20-50 microA, 50 pps) of the periaqueductal gray (PAG). The quality of voice sounds evaluated by sound spectrography was shown to improve during vocalization with FES. We conclude that FES of the paralyzed laryngeal adductor muscle was effective in restoring adduction of the vocal fold and improving voice sounds impaired by unilateral laryngeal paralysis.

Carbachol injection into the pontine reticular formation depresses laryngeal muscle activities and airway reflexes in decerebrate cats.

To understand the role of cholinoceptive, medial pontine reticular formation (mPRF) neurons in the control of upper airway, pharyngolaryngeal reflexes, we measured activities of intrinsic laryngeal muscles (posterior cricoarytenoid, PCA; thyroarytenoid, TA), diaphragm (DIA), genioglossus (GG) and a neck muscle (trapezius) in unanesthetized, decerebrated, spontaneously breathing cats with and without mPRF carbachol injections. The ethimoidal nerve was electrically stimulated to evoke sneezing, and the superior laryngeal nerve to evoke the laryngeal reflex, swallowing, and coughing. Carbachol reduced the amplitudes of the spontaneous electromyographic activities in the neck, TA, PCA, GG, and DIA to 7%, 30%, 54%, 45% and 71% of control, respectively, reduced the respiratory rate to 53% without changes in expiratory CO(2) concentration; the magnitude of the laryngeal reflex in the TA muscle to 56%; increased its latency by 13%; and reduced the probability of stimulus-induced sneezing, swallowing, and coughing to less than 40%. These changes lasted more than 1h. These data demonstrate that important upper airway reflexes are suppressed by increasing cholinergic neurotransmission in the mPRF. Because acetylcholine release in the mPRF changes in accordance with sleep-wake cycles, the present findings are relevant to the control of upper airway reflexes during various vigilance states.

Fos expression in the brainstem nuclei evoked by nasal air-jet stimulation in rats

Background Noxious stimulation of the nasal mucosa may induce protective reflexes in the upper airway in rats. Previously, we have reported that nasal air-jet stimulation increases the activities of the laryngeal muscles in decerebrate cats; however, the neuronal mechanism of this phenomenon still is not clarified. Methods After the application of nasal air-jet stimulation for 2 hours, we investigated the distribution of Fos-positive cells (FPCs) throughout the medulla compared with sham-operated rats using Fos immunoreactivity. Results FPCs in the spinal trigeminal nucleus, the parvocellular reticular nucleus, and the nucleus of the solitary tract were more frequent than the sham-operated rats. Conclusion These results suggest that the afferents induced by air-jet stimulation were conveyed to these FPCs and that some of these cells might participate in the augmentation of laryngeal muscle activities during nasal air-jet stimulation.

Removal of Polyvinyl Alcohol from the External Auditory Canal

We report the case of a 6-year-old girl with a small, round-shaped foreign body, composed of polyvinyl alcohol, in her right external auditory canal. This foreign body was originally a component of toy beads with which children are able to make variously shaped objects by sticking them together using water. Polyvinyl alcohol is a water-soluble polymer and is employed as an adhesive agent. In our case, it was not easy to remove it because it had fully adhered to her external auditory canal.It is important to note that this kind of foreign body should not be attempted to be removed by water irrigation, as this would cause it to dissolve and stick to the tissue.

A Case of Castleman's Disease Followed by Peripheral T-cell Lymphoma.

A 57-year-old male was admitted with severe fatigue and systemic lymphadenopathy. Surgical biopsy specimens revealed Castlemans disease of hyaline vascular type. After admission, Guillain-Bane syndrome developed and the ptient was treated with predonisolone and plasma pheresis was given. The patients symptoms and lymphadenopathy responded and disappeared rapidly. Five months later, systemic lymphadenopathy recurred. Surgical biopsy was performed and the histological features were consistent with a diagnosis of peripheral T-cell lymphoma of diffuse mixed type, probably resulting from the progression of the Castlemans disease.

A Neonatal Case of Neuroblastoma in the Neck.

A neonatal boy presented with a painless, smooth, round mass in the left side of his neck at birth. CT, MRI, and echo examinations revealed a solid tumor with calcification occupying the left upper neck. The levels of serum neuron specific enolase (NSE), urine homovanillic acid (HVA), and vanillylmandelic acid (VMA) were elevated, indicating a diagnosis of neuroblastoma. Surgical resection was performed 23 days later because of airway obstruction due to tumor progression. The resected tumor was 43×35×32mm and was diagnosed as a rosette-fibrillary type of neuroblastoma by histopathological analysis. The tumor was of a favorable histological grade and was classified as stage 2A according to the International Neuroblastoma Staging System. After surgery, the patient received systemic chemotherapy of a regimen including cyclophosphamide and vincristine. He is alive and disease free 4 years after diagnosis.

Long-Term Clinical Outcome of Treatment for Epistaxis with Nd-YAG Laser in Osler's Disease.

The Nd-YAG laser was used to treat 3 patients with hereditary hemorrhagic telangiectasia (Oslers disease). Long-term clinical outcome (2-6 years period) after endonasal laser photocoagulation (ELP) for epistaxis was estimated. Repeated ELP (7-17 times over 6 years) was effective in decreasing the frequency and severity of nasal hemorrhage in 2 patients, though septal cartilage perforation resulted from the laser treatments. The other patient did not benefit from ELP performed 3 times over 2 months. Because of the formation of new lesions, repeated treatment was necessary at 2- to 14-month intervals, and the interval was prolonged after several treatments. Repeated ELP is necessary for successful treatment of epistaxis associated with Oslers disease.

Our Operation for severehyper thyroidism

We performed 11 total thyroidectomy and 13 sub-total thyroidectomy for 24 cases of hyperthyroidism patients from January, 1993 to March, 1996. There were several reasons of operative indication for our cases that (1) uncontrol of anti-thyroid drugs, (2) side effects of anti-thyroid drugs as allergic reaction or agranulocytopenia, (3) prevention of thyroid crisis and (4) to have babies. We selected those two types of operations not to re-use anti-thyroid drugs after our treatment. In operation, we left not only recurrent nerves but also two or three parathyroid glands with active blood supply. After operation there were two cases of transient recurrent nerve palsy and two cases of hypo function of parathyroid glands. But we had no cases of recurrent hyperthyroidism after surgical treatment.

Clinical Anatomy of the Parapharyngeal Space. Study by Imaging of CT and MRI.

The parapharyngeal region of one cadaver was dissected, and enhanced CT scans and T1 weighted MRI of three normal persons from the skull base to the hyoid bone were performed. Three-dimensional reconstruction of the parapharyngeal space was carried out on the basis of CT images. We examined the relationship between the parapharyngeal space which consisted mainly of fatty tissue and the surrounding structures. Our findings seem to be useful for the understanding of the shape and location of the parapharyngeal space and the clinical understanding of parapharyngeal space tumors. We discussed the differences between the parapharyngeal space and the carotid space with the 9th-12th cranial nerves, sympathetic chain, carotid artery and jugular vein.