To elucidate the neurotoxic mechanism of methylmercury on cultured bovine oligodendrocytes, neurotoxic effect was estimated by MTT assay after cultures were exposed to various concentrations of methylmercuric chloride (MMC). In addition, neuroprotective effect of antioxidant, allopurinol agonist MMC-induced neurotoxicity was examined on these cultures. Exposure of cultured bovine oligodendrocytes to MMC showed less than 50% of the cell viability 24 hours after treatment with 35µM of MMC. And also, allopurinol blocked the neurotoxicity induced by MMC on these cultures. These results suggest that oxygen radicals involve in MMC-mediated neurotoxicity, and also seletive antioxidants such as allopurinol are effective in blocking the neurotoxicity induced by MMC on cultured bovine oligodendrocytes.
Allopurinol* ; Antioxidants ; Cell Survival ; Neuroprotective Agents ; Oligodendroglia ; Reactive Oxygen Species

Cerebral venous infarction is associated with a wide variety of clinical symptoms and signs, which may often delay appropriate diagnosis. Unilateral vestibular deficit as a presenting sign of cerebral venous infarction has rarely been reported. We report a patient with cerebral venous infarction who had severe prolonged vertigo, vomiting, occipital headache, positive head thrust testing, and unilateral caloric weakness as main clinical features. Although the patient had occipital headache, overall symptoms and signs closely mimicked those of acute peripheral vestibulopathy.
Diagnosis ; Head Impulse Test ; Headache ; Humans ; Infarction* ; Vertigo ; Vestibular Neuronitis ; Vomiting

Vestibular neuritis (VN) is an idiopathic peripheral vestibular syndrome characterized by acute isolated prolonged vertigo. In most cases, it results from inflammation of the vestibular nerve presumably of viral origin. There has been no previous report of VN associated with a vascular cause. We here report a patient with VN of vascular origin who presented with acute onset of prolonged isolated vertigo, a unilateral decreased caloric response, and simultaneously with acute infarcts on brain MRI that were unrelated to patient's vertigo.
Brain ; Humans ; Inflammation ; Magnetic Resonance Imaging ; Vertigo ; Vestibular Nerve ; Vestibular Neuronitis*

BACKGROUND AND OBJECTIVES: Body lateropulsion with falling to one side is a well-known clinical feature of stroke in the posterior circulation. Body lateropulsion as an isolated or predominant manifestation of a pontine stroke has not previously been reported. To elucidate the possible mechanisms of patients presenting with body lateropulsion as an isolated or predominant symptom of isolated pontine infarction. MATERIALS AND METHOD: Between May 2004 and February 2006, out of 134 admitted patients with an isolated pontine stroke we identified 8 consecutive patients (6.0%) in the Keimyung University Stroke Registry who had body lateropulsion as the main presenting symptom. RESULTS: All lesions were localized to the paramedian tegmentum just ventral to the 4th ventricle. All except 1showed a uniform pattern of body lateropulsion, in which the direction of falling was away from the side of infarct. In 2 patients, body lateropulsion was the sole clinical manifestation, whereas the other patients had other neurological signs. All but 1 had contraversive tilting of the subjective visual vertical (SVV). In all cases, the direction of SVV tilt corresponded to the direction of body lateropulsion. The mean net tilt angle was 6.1 CONCLUSION: Based on the known anatomy of ascending vestibular pathways, the SVV tilting, and MRI findings, body lateropulsion probably results from damage to the graviceptive pathway ascending through paramedian pontine tegmentum.
Humans ; Infarction* ; Magnetic Resonance Imaging ; Pons ; Stroke

No abstract available.
Animals ; Atrophy* ; Electric Stimulation* ; Muscle, Skeletal* ; Rats* ; Sciatic Nerve*

Nevus lipomatosus cutaneous superficialis is a very rare skin disease, which usually is present at birth. The lesion shows groups of asymptomatic soft papules or nodules, which have a smooth or folded surface and are skin colored or yellowish. The area of predilection is the pelvic girdle (especially the buttock and sacrococcygeal areas). Microscopically, nevus lipomatosus cutaneous superficialis reveals groups of etopic fat cell nests within the dermis. Only one case was reported in Korea(1969). The authors observed a case of typical nevus lipomatosus cutaneous superficialis. The patient was 19 year-old male, who ha,ve had asymptomatic soft papules and nodules on the buttock, lower back and scalp since 14 years of his age. Routine laboratory findings were within normal limit. Histopathological findings showed etopic fat cell nests within mid and lower dermis (Fig. 3) Diagnosis was confirmed by clinical and histopathological findings. Litercature was briefly reviewed for the discussion.
Adipocytes ; Buttocks ; Dermis ; Diagnosis ; Humans ; Male ; Nevus* ; Parturition ; Scalp ; Skin ; Skin Diseases ; Young Adult

The autonomic nervous system (ANS) integrates the function of the internal organs for the homeostasis against various external environmental changes. The efferent components of the ANS are regulated by sensory signals arising from the viscera as well as non-visceral organs. The central neural networks that integrate these sensory signals and modify visceral motor output are complex, and synaptic reflexes formed in the brainstem and spinal cord integrate behavioral responses and visceral responses through the central neural networks. A detailed understanding of the neural network presented above may explain the role of the vestibular system on the homeostasis more extensively.
Autonomic Nervous System ; Brain Stem ; Homeostasis ; Physiology ; Reflex ; Solitary Nucleus ; Spinal Cord ; Spinal Cord Lateral Horn ; Viscera

Diastasis of the ankle joint was associated with extensive ligamentous rupture and resulted from external rotation or abduction injuries at the ankle. It might occur without associated fracture but was more frequently seen in cases of bimalleolar fracture in which there was fracture of the medial malleolus or rupture of the deltoid ligament with fracture of the lower third of the fibula. Thirty patients of diastasis of the ankle joint were admitted and treated by internal fixation with screw and bolt from January 1978 to December 1981. The following results were obtained: 1. The main cause of the injuries was falling from a height and the other causes were slipping down and sports injury in order. 2. The most common type by Lauge-Hansen classification was supination-external rotation type (20 cases, 67%). 3. Partial diastasis of the ankle joint or anterior type was 14 cases (47%) and complete diastasis or total type was 16 cases (53%). 4. In all cases, mixed oblique fibular fracture and medial instability were seen. 5. The good results were achieved in 24 patients (80%).
Accidental Falls ; Ankle Fractures ; Ankle Joint ; Ankle ; Athletic Injuries ; Classification ; Clinical Study ; Fibula ; Humans ; Ligaments ; Rupture

BACKGROUND: There is a substantial evidence that anatomical connections and functional interactions exist between vestibular and autonomic systems. The nature of these interactions, however, is complex and has not been fully defined. Heart rate variability (HRV) was used to investigate the physiological role of the vestibular system on control of heart rate. METHODS: HRV including mean, standard deviation, coefficient of variation (CV), power spectrum was analyzed from R-R intervals of ECG during vestibular stimulation in rabbits. RESULTS: Urethane anesthesia increased heart rate and maintained regular R-R intervals, however, low frequency region/high frequency region (LF/HF) was not changed. In anesthetized rabbits, electrical stimulation of the vagus nerve decreased heart rate and decreased LF/HF by increasing HF. On the contrary, electrical stimulation of the cervical sympathetic nerve increased heart rate and increased LF/HF by increasing LF. Atropine, cholinergic blocker, increased heart rate and increased LF/HF by reducing HF, and propranolol, beta-adrenergic blocker, decreased heart rate and decreased LF/HF by reducing LF. In unanesthetized rabbits, stimulation of the vestibular system induced by rotation or caloric increased heart rate and increased LF/HF by increasing LF. Also electrical stimulation of the vestibular nerve produced the same effects as rotation or caloric in anesthetized rabbits. CONCLUSION: These results suggest that stimulation of the vestibular system increased heart rate not by inhibiting the parasympathetic nerve but by activating the sympathetic nerve.
Anesthesia ; Atropine ; Autonomic Nervous System ; Electric Stimulation ; Electrocardiography ; Heart Rate* ; Heart* ; Propranolol ; Rabbits* ; Urethane ; Vagus Nerve ; Vestibular Nerve

BACKGROUND: The orthostatic hypotension in response to the assumption of an upright posture is regulated by activation of sympathetic nerves. Role of the vestibular system and neural pathway on orthostatic hypotension were investigated. METHODS: Changes of arterial blood pressure produced by head-up tilting, rotatory stimulation of the vestibular system, or electrical stimulation to the vestibular nerve, vestibular nuclei, and rostral ventrolateral medulla (RVLM) were measured in Sprague-Dawley rats. Also, field potentials were recorded in the vestibular nuclei and RVLM and c-Fos expression was evaluated in the brain stem in order to investigate the vestibulosympathetic pathways. RESULTS: The three phasic blood pressure responses were elicited by head-up tilting: initial fall, early recovery, and late sustained pressure at near control levels, the magnitude of the pressure fall was parallel with the degree of head-up tilting in normal rats. Return position from head-up tilting recovered control level of blood pressure after a brief rapid elevation. However, bilateral labyrinthectomy resulted in exaggerated initial falling and devoid of early recovery phase during postural change. Sinusoidal rotation about off-vertical axis of the vestibular system elicited more elevation of blood pressure than rotation about earth vertical axis. Electrical stimulation of the vestibular nerve, vestibular nucleus, and RVLM produced elevation of blood pressure, which was the most prominent by stimulation of RVLM. Field potentials composed of P, N1, N2 waves in the vestibular nuclei were recorded by stimulation of the vestibular nerve, while weak potentials in RVLM were recorded by stimulation of the vestibular nuclei. An electrical stimulation of the vestibular nuclei expressed c-Fos immunoreactive cells in RVLM. CONCLUSION: These results suggest that the otolith organ of the vestibular system plays a major role in control of orthostatic hypotension, and the pathway of vestibulosympathetic reflex in control of blood pressure involves the vestibular nuclei, RVLM, intermed-iolateral nuclei of the thoracic spinal cord.
Animals ; Arterial Pressure ; Axis, Cervical Vertebra ; Blood Pressure ; Brain Stem ; Electric Stimulation ; Hypotension, Orthostatic* ; Neural Pathways ; Otolithic Membrane ; Posture ; Rats* ; Rats, Sprague-Dawley ; Reflex* ; Spinal Cord ; Vestibular Nerve ; Vestibular Nuclei