Biomedical subjects

T Shin

Publications and source records attributed to T Shin.

242 records · Page 14Linked to original sources

PubMedDate not supplied

Misdirected regeneration of injured recurrent laryngeal nerve in the cat.

INTRODUCTION: Misdirected regeneration (MR) frequently occurs following injury to the recurrent laryngeal nerve (RLN) resulting in neurotmesis or axonotmesis. Physiological and anatomic parameters involved in the functional recovery of the larynx following freezing injury or neurorrhaphy of the RLN were studied. A multi-facilitated approach is undertaken to clarify the functional abnormalities caused by the MR after recurrent laryngeal nerve injury. MATERIALS AND METHODS: Three groups of adult cats were studied. These included controls, cats with recurrent laryngeal neurorrhaphy, and cats with recurrent laryngeal nerve freeze injuries. From 2 weeks to 9 months after the nerve injury, the animals were studied endoscopically and with electromyography (EMG). Using the same animal, the number and location of motoneurons supplying the ipsilateral posterior cricoarytenoid (PCA) muscle were examined with horseradish peroxidase (HRP). Animals were subsequently sacrificed to study the pattern of reinnervation. RESULTS: Following neurorrhaphy all cats had vocal cord paralysis. After neurorrhaphy, effective motion function did not return in the affected vocal cord and it remained fixed in the paramedian position. Although EMG of the laryngeal muscles of the affected side showed interference voltage, the pattern of activities was markedly different from that of the unaffected side, and reciprocity among the laryngeal muscles was not restored. The number of PCA motoneurons recovered to the normal range, but a considerable number of neuronal bodies were dispersed outside the normal PCA area. This indicates misdirected reinnervation to the PCA muscle by motoneurons that originally served other laryngeal muscles. In the freezing injury, effective vocal cord movement finally recovered after 6 months. At this time, EMG showed a normal pattern, although a relatively small amount of misdirected neurons was observed. DISCUSSION: Functional recovery of vocal cord motion does not occur following neurorrhaphy. Prominently disorganized arrangement of laryngeal motor neurons was observed in the horseradish peroxidase study. This suggests that inappropriate reinnervation develops in spite of reapproximation and suturing. Altered central organization of the motor nucleus is a significant pathogenic factor in the loss of laryngeal muscular coordination following recurrent laryngeal nerve lesions. The degree of recovery is related to the mechanism of injury.

Animals↗

PubMedDate not supplied

Effect of Rehmannia glutinosa on immediate type allergic reaction.

We investigated the effect of aqueous extract of Rehmannia glutinosa steamed root (RGAE) on the allergic reactions in vivo and in vitro. RGAE dose-dependently inhibited systemic allergic reaction induced by compound 48/80. When RGAE was pre-treated at the same concentrations with systemic allergic reaction test, the plasma histamine levels were reduced in a dose-dependent manner. RGAE dose-dependently inhibited skin allergic reaction activated by anti-dinitrophenyl (DNP) IgE. RGAE also dose-dependently inhibited the histamine release from the rat peritoneal mast cells (RPMC) by compound 48/80 or anti-DNP IgE. Moreover, RGAE had significant inhibitory effect on anti-DNP IgE-induced tumor necrosis factor-alpha production of RPMC. These results indicate that RGAE may be beneficial in the regulation of immediate type allergic reaction.

2,4-Dinitrophenol↗

PubMedDate not supplied

Increased expression of phospholipase D1 in the sciatic nerve of rats with experimental autoimmune neuritis.

Phospholipase D1 (PLD1) expression in the sciatic nerve was studied in induced experimental autoimmune neuritis (EAN) in Lewis rats. PLD1 immunoreactivity was seen in some Schwann cells in the sciatic nerves of normal rats. In parallel with the progression of EAN, PLD1-positive Schwann cells significantly increased in number and showed intense immunoreactivity. PLD1 was also detected in some ED1+ macrophages in EAN lesions. These results suggest that PLD1 in macrophages and Schwann cells plays an important role in the activation of these cells in the pathogenesis of EAN, an animal model of human peripheral demyelinating disease.

Amino Acid Sequence↗

PubMedDate not supplied

Surgical treatment for dysphagia of neuromuscular origin.

There are a number of surgical procedures which can be used to improve swallowing in selected dysphagic patients. These include: vocal fold augmentation or medialization, cricopharyngeal myotomy, laryngeal suspension, intrahyoid myotomy, lateral thyrolaminectomy and tracheoesophageal separation procedures. This article describes these various procedures and their appropriate application to selected dysphagic patients. Results of a study of the location of the recurrent laryngeal nerve in relation to the cricopharyngeal muscle are also presented.

Deglutition Disorders↗

PubMedDate not supplied

Topographic arrangement of motoneurons innervating the suprahyoid and infrahyoid muscles. A horseradish peroxidase study in cats.

The topographic arrangement of motoneurons innervating the muscles which participate in the rostrocaudal movement of the larynx was studied in cats by means of the horseradish peroxidase (HRP) method. After HRP injection into these muscles, all labeled neurons were found in the nuclei of the brainstem and cervical nerves (C1, C2) ipsilaterally. The mylohyoid and anterior digastric motoneurons were seen in a cluster in the medial part of the rostrocaudal area of the motor trigeminal nucleus. Within the medial part of the nucleus, the mylohyoid motoneurons were located ventrally and the anterior digastric motoneurons dorsally. The posterior digastric neurons were situated in the accessory facial nucleus, the stylohyoid neurons in the ventral aspect of the facial nucleus, the geniohyoid motoneurons in the ventral aspect of the hypoglossal nucleus, and the thyrohyoid motoneurons in the lateral aspect of the hypoglossal nucleus and the dorsomedial part of the ventral horn cells of C1. The HRP-labeled neurons of the sternohyoid and sternothyroid muscles were observed in the central portion of the ventral horn cells of C1 and C2.

Animals↗

PubMedDate not supplied

Arrangement of motoneurons innervating the intrinsic laryngeal muscles of cats as demonstrated by horseradish peroxidase.

After HRp injection into the posterior cricoarytenoid (PCA), the thyroarytenoid (TA), the lateral cricoarytenoid (LCA) and the interarytenoid (IA) muscles, labeled neurons were identified in the nucleus ambiguus ipsilaterally. The motoneurons for the cricothyroid muscle (CT) were found ipsilaterally in the retrofacial and ambiguus nuclei. The labeled cell columns of PCA, TA, LCA and IA were situated more caudal than that of CT in the order of PCA, TA, LCA and IA. In the nuc. ambiguus, the motoneurons of CT showed compact form and were located in the ventral part, those of PCA were aggregated and occupied the middle part, those of TA were scattered and were seen in the dorsal part, and those of LCA and IA were sparse and were recognized widely in the nucleus.

Animals↗

PubMedDate not supplied

Enhanced expression of constitutive endothelial nitric oxide synthase by astrocytes in the spinal cords of rats with experimental autoimmune encephalomyelitis.

To investigate the expression of eNOS in a disease affecting the CNS, we induced EAE and analyzed the expression of eNOS by Western blot analysis and immunohistochemistry. Western blot analysis indicated that eNOS increased substantially in the spinal cords of rats with EAE compared with the spinal cords of normal and adjuvant sensitized rats. Immunohistochemistry revealed that eNOS was positive for some macrophages and astrocytes in EAE lesions. The vascular endothelial cells in EAE lesions also showed a light increase of eNOS immunoreactivity. This trial demonstrated that eNOS is increased in the diseased EAE spinal cord and that the source of eNOS is from the exogenous inflammatory cells and from the endogenous spinal cord cells including astrocytes.

Animals↗

PubMedDate not supplied

Perfusion MR imaging in gliomas: comparison with histologic tumor grade.

OBJECTIVE: To determine the usefulness of perfusion MR imaging in assessing the histologic grade of cerebral gliomas. MATERIALS AND METHODS: In order to determine relative cerebral blood volume (rCBV), 22 patients with pathologically proven gliomas (9 glioblastomas, 9 anaplastic gliomas and 4 low-grade gliomas) underwent dynamic contrast-enhanced T2*-weighted and conventional T1- and T2-weighted imaging. rCBV maps were obtained by fitting a gamma-variate function to the contrast material concentration versus time curve. rCBV ratios between tumor and normal white matter (maximum rCBV of tumor / rCBV of contralateral white matter) were calculated and compared between glioblastomas, anaplastic gliomas and low-grade gliomas. RESULTS: Mean rCBV ratios were 4.90 degrees +/- 1.01 for glioblastomas, 3.97 degrees +/- 0.56 for anaplastic gliomas and 1.75 degrees +/-1.51 for low-grade gliomas, and were thus significantly different; p <.05 between glioblastomas and anaplastic gliomas, p <.05 between anaplastic gliomas and low-grade gliomas, p <.01 between glioblastomas and low-grade gliomas. The rCBV ratio cutoff value which permitted discrimination between high-grade (glioblastomas and anaplastic gliomas) and low-grade gliomas was 2.60, and the sensitivity and specificity of this value were 100% and 75%, respectively. CONCLUSION: Perfusion MR imaging is a useful and reliable technique for estimating the histologic grade of gliomas.

Adult↗