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Biomedical subjects

Y Hosobuchi

Publications and source records attributed to Y Hosobuchi.

88 records · Page 5Linked to original sources

Chronic thalamic and internal capsule stimulation for the control of central pain.

Thalamic electrical stimulation by means of chemically implanted electrodes and an externally placed transmitter was effected in patients with central pain. Good response was obtained in four patients with anesthesia dolorosa, four with thalamic syndrome, and one with paraplegic pain. Two patients with medullary syndrome experienced no relief. The mechanism of thalamic stimulation in the relief of pain is discussed and further clinical trials are anticipated.

Corpus Striatum↗

Treatment of intercostal neuralgia with 10 per cent ammonium sulfate.

Intercostal nerves were injected with 10 per cent annomium sulfate in 41 patients (52 total sets of injections) for management of intercostal neuralgia from radical mastectomy (six blocks), thoracotomy (20 blocks), or unknown etiology (26 blocks). Five patients failed to return for follow-up evaluation and could not be located. Sixty per cent (28/47) of the treatments produced complete or nearly complete (excellent) relief of pain. Excellent pain relief persisted for more than 20 days after 22 treatments and for more than 90 days after seven treatments. Postblock neuritis never occurred. We conclude that intercostal nerve block with 10 per cent ammonium sulfate effectively relieves intercostal neuralgia and is not associated with postblock neuritis. We therefore believe that ammonium sulfate nerve blocks should be administered for treatment of intercostal neuralgia before phenol or alcohol nerve blocks or a surgical procedure.

Ammonium Sulfate↗

Surgical experience with a microscopic transsphenoidal approach to pituitary tumors and non-neoplastic parasellar conditions.

Improved surgical microscopes and intraoperative radiofluoroscopic television have revived the transsphenoidal approach to pituitary tumors. The transsphenoidal approach offers an alternative to craniotomy, and in certain situations it has distinct advantages. The reported experience includes the common pituitary tumors, hypersecreting microadenomas, cerebrospinal rhinorrhea and parasellar aneurysms. The surgical technique, indications and contraindications, and results in 44 transsphenoidal operations are described.

Adenoma, Chromophobe↗

Effect of naloxone on neurologic deficit and cortical blood flow during focal cerebral ischemia in cats.

Using middle cerebral artery occlusion in the cat as a model of focal cerebral ischemia, we investigated the effect of naloxone on both neurologic deficit and regional cortical blood flow during cerebral ischemia. In all animals with major strokes, 2 mg/ml naloxone administered intravenously produced a dramatic reversal of neurologic symptoms four hours after the ischemic lesion. Animals were then anesthetized and cortical blood flow was measured by the hydrogen clearance method. Blood flow in the ischemic cortex was noted to be approximately 55% that of the control side. Naloxone produced a significant decrease of approximately 20% in cortical blood flow in the ischemic hemisphere while no effect on blood flow on the control side was noted. Thus, naloxone appears to reverse the neurologic deficits following middle cerebral artery occlusion in the cat. This effect appears to be accompanied by a decrease in local blood flow to the ischemic cortex.

Animals↗

Dynorphin(1-13) improves survival in cats with focal cerebral ischaemia.

Since the discovery of opiate receptors in the central nervous system (CNS), it has become apparent that endogenous opiate ligands are involved in CNS function. Most attention has focused on their role in modulating pain, but they have also been implicated in various physiological functions and in disease states. We are concerned with evidence that endogenous opioid peptides may also contribute to the neurological deficits arising from cerebral ischaemia. Dynorphin, which is widely distributed in the brain and pituitary, has been reported to produce unusual motor and behavioural effects and may act as a regulatory neuropeptide, not as a classical opiate agonist or antagonist. We have therefore administered to cats in which the right middle cerebral artery had been occluded both dynorphin (1-13) and analogue and control materials. We find that dynorphin (1-13) prolongs survival.

Animals↗

Proton nuclear magnetic resonance imaging of acute experimental cerebral ischemia.

To determine the efficacy of proton nuclear magnetic resonance (NMR) imaging in documenting acute ischemic infarction and to characterize the changes in these images during the first 24 hours following the ischemic insult, serial NMR imaging was performed in gerbils that had undergone unilateral carotid artery ligation. No significant changes in the signal intensity, T1 or T2 relaxation times were noted for either asymptomatic animals or the control hemisphere of symptomatic gerbils. There was a significant increase in T1 and especially T2 relaxation times and in both the relative signal intensity and Hf(v) for the ischemic hemisphere of symptomatic gerbils. These parameters appeared to increase linearly over 24 hours. The ischemic lesion first could be detected by NMR as early as 3 hours after carotid artery ligation, our earliest time point. The physiologic significance of these changes is discussed. These data suggest that NMR imaging may have significant diagnostic importance for acute cerebral ischemia and infarction in man.

Acute Disease↗

NMR imaging of acute experimental cerebral ischemia: time course and pharmacologic manipulations.

Nuclear magnetic resonance (NMR) imaging was used to evaluate the intracerebral changes over time in gerbils after unilateral carotid artery ligation. Each animal was imaged during one of three stated periods 3-28 hr after surgery and again after administration of dexamethasone, morphine, or naloxone, agents reported to affect the clinical outcome of ischemic cerebral lesions. Asymptomatic animals exhibited no differences between the occluded and control hemispheres in relative signal intensity or in T1 or T2 relaxation times, but symptomatic animals demonstrated significant differences in these parameters between hemispheres. The ischemic lesion was detected at the earliest imaging time, 3 hr after surgery. A linear increase was observed in the relative interhemispheric signal intensity in three of four intensity images and in T1 and T2 relaxation times over the 24 hr experiment. No effect was noted on any image parameter as a result of pharmacologic manipulations. The results suggest that NMR may be of significant diagnostic importance for acute cerebral ischemia and infarction in man.

Animals↗